JP5764915B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention provides torque input / output between the drive shaft and a differential mechanism capable of transmitting torque of the internal combustion engine to the drive shaft by applying reaction force torque from the first rotating electric machine via the reaction force element. TECHNICAL FIELD The present invention relates to a technical field of a hybrid vehicle control device that controls a hybrid vehicle including a second rotating electrical machine capable of locking, a lock mechanism that locks the first rotating electrical machine, and a clutch mechanism that connects and disconnects the second rotating electrical machine and a drive shaft. .

  As a device of this type, when the hybrid vehicle is driven by directly connecting the internal combustion engine to the drive shaft by locking the first rotating electrical machine, the second rotation is performed for the purpose of avoiding power loss due to friction or inertia of the second rotating electrical machine. There is one that separates the electric machine from the drive shaft. In particular, the above locking mechanism and clutch mechanism are intended for those that require rotational synchronization between the engagement elements when the engagement elements are engaged, and need to reduce the torque that acts between the engagement elements when released. (For example, refer to Patent Document 1). According to the device disclosed in Patent Document 1, when the first rotating electrical machine is at zero rotation, the brake mechanism as the lock mechanism is engaged, and then the torque of the second rotating electrical machine is reduced to zero torque.

  The technical idea of separating the second rotating electrical machine from the drive shaft when the first rotating electrical machine is locked in the same mechanism is also disclosed in Patent Document 2.

  Patent Document 3 discloses a technique for setting an upper limit for the rate of change in the rotational speed of the first rotating electrical machine in a configuration in which the first rotating electrical machine can be locked.

JP 2005-192284 A JP 2003-104072 A JP 2001-001773 A

  For example, an engagement mechanism that requires a rotation synchronization measure between engagement elements when engaged, such as a meshing clutch, and a measure that reduces a transmission torque between engagement elements when released from engagement, Since the torque transmission efficiency is good, it is remarkably effective in suppressing reduction in fuel consumption (fuel consumption rate) and power consumption (power consumption rate) due to power loss. Therefore, it is preferably used as the lock mechanism and the clutch mechanism.

  By the way, when the second rotating electrical machine is disconnected from the drive shaft along with the locking of the first rotating electrical machine and the second rotating electrical machine is connected to the drive shaft along with the unlocking of the first rotating electrical machine, the lock mechanism and the clutch mechanism are For example, it is possible to obtain a high profit in terms of vehicle cost and vehicle mountability by operating the actuator simultaneously by sharing the actuator.

  Here, when the lock mechanism and the clutch mechanism in such a configuration are the engagement mechanisms that require the above-described rotation synchronization measure at the time of engagement and the transmission torque reduction measure at the time of disengagement, the engagement and engagement Since the release cannot be performed independently of each other, when the operation state of the engagement mechanism is actually switched, the rotation synchronization measure is completed in one of the engagement mechanisms to be engaged, and the other of the engagement mechanisms is released. It is necessary to complete the transmission torque reduction measure in the engagement mechanism.

  On the other hand, the device disclosed in Patent Document 1 does not keep in mind the configuration in which the lock mechanism and the clutch mechanism are simultaneously operated as described above, and the transmission torque of the clutch mechanism is reduced to zero torque after the lock mechanism is engaged. ing. Therefore, when the device disclosed in Patent Document 1 is applied to such a configuration, the adjustment of the transmission torque of the clutch mechanism is started after the rotation synchronization measure of the lock mechanism is completed, and the lock mechanism is rotated until the transmission torque converges to zero torque. It is necessary to maintain synchronization. This lengthens the switching period of the operating state of the engagement mechanism, which is not desirable for travel control of the hybrid vehicle.

  As described above, the apparatus disclosed in Patent Document 1 assumes a configuration in which a lock mechanism and a clutch mechanism that require a rotation synchronization measure at the time of engagement and a transmission torque reduction measure at the time of disengagement are simultaneously operated. As a result, there is a technical problem that the temporal correlation between the rotation synchronization measure and the transmission torque reduction measure is difficult to improve. Such a problem also applies to the devices disclosed in Patent Documents 2 and 3.

  The present invention has been made in view of the above technical problems, and simultaneously operates a lock mechanism and a clutch mechanism that require a rotation synchronization measure at the time of engagement and a transmission torque reduction measure at the time of disengagement. It is an object of the present invention to provide a control device for a hybrid vehicle that can suitably switch the operation state of these engagement mechanisms.

  In order to solve the above-described problems, a control apparatus for a hybrid vehicle according to the present invention includes an internal combustion engine, a first rotating electrical machine, a second rotating electrical machine, a first rotating element coupled to the first rotating electrical machine, A power transmission mechanism comprising a plurality of rotating elements that make a differential action with each other, including a second rotating element connected to an internal combustion engine and a third rotating element connected to a drive shaft connected to the axle; A plurality of engagements configured to be able to engage with each other in a rotationally synchronized state that is less than a reference value, and to be able to disengage each other in a torque non-transmission state in which the absolute value of the transmission torque between them is less than a reference value A first engagement mechanism that locks the first rotating electrical machine at a predetermined rotational speed in an engagement state in which the plurality of engagement elements are engaged with each other; Engageable and non-torque transmission A plurality of engagement elements configured to be disengaged from each other in a state, enabling torque transmission between the second rotating electrical machine and the drive shaft in the engagement state; A second engagement mechanism for separating the second rotating electrical machine from the drive shaft in an engagement release state in which engagement between engagement elements is released; and the first engagement mechanism is in the engagement state; A first operation state in which the second engagement mechanism is in the disengagement state, and a second operation in which the first engagement mechanism is in the disengagement state and the second engagement mechanism is in the engagement state. A control device for a hybrid vehicle, comprising: an engagement device capable of selectively switching an operation state between states; and the operation from the second operation state to the first operation state. When a state switching request occurs, Rotation synchronization control execution means for executing rotation synchronization control for bringing the plurality of engagement elements in the first engagement mechanism into the rotation synchronization state with respect to one rotating electric machine, and after the rotation synchronization control is started And torque adjustment control execution means for executing torque adjustment control for setting the plurality of engagement elements in the second engagement mechanism to the torque non-transmitting state with respect to the second rotating electrical machine. (Claim 1).

  The hybrid vehicle according to the present invention has physical and mechanical characteristics such as fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, and cylinder arrangement as power elements capable of supplying torque to the drive shaft. Alternatively, 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), which can take various modes regardless of electrical configuration, etc. First and second rotating electrical machines.

  In addition, the hybrid vehicle according to the present invention is provided between the internal combustion engine as the power element and the first and second rotating electric machines and the drive shaft directly connected to the axle or indirectly connected through various gear mechanisms. The power transmission mechanism which enables torque transmission is provided.

  The power transmission mechanism includes at least a first rotating element connected to the first rotating electrical machine, a second rotating element connected to the internal combustion engine, and a third rotating element connected to the drive shaft. It is preferably configured as a differential mechanism with two degrees of freedom of rotation, which includes a plurality of rotating elements that act. The number of rotating elements or differential mechanisms provided in the power transmission mechanism may be ambiguous. For example, 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 may be appropriately shared between the plurality of planetary gear mechanisms.

  In view of the differential action between the rotating elements in the power transmission mechanism, the first rotating element coupled to the first rotating electrical machine functions as a reaction force element that applies reaction torque to the internal combustion engine. As for the torque of the internal combustion engine inputted through the second rotating element, a part of direct torque corresponding to this reaction force torque is transmitted to the drive shaft through the third rotating element. In such a configuration, the operating point of the internal combustion engine can be continuously variable at least within a predetermined range by the first rotating electric machine. Therefore, the power transmission mechanism and the first rotating electrical machine preferably function as a kind of electric CVT (Continuously Variable Transmission).

  On the other hand, the second rotating electrical machine is connected directly to the drive shaft or indirectly through various gear mechanisms when a second engagement mechanism, which will be described later, is in an engaged state. I / O is possible. The second rotating electrical machine uses the input torque in the positive rotation region, for example, when torque is input through a power transmission path that sequentially passes through the driving wheel, the axle, and the driving shaft (that is, negative torque). Power regeneration is possible, and for example, by supplying a positive torque (ie, powering) to the drive shaft in the positive rotation region, at least a part of the drive shaft torque as the torque supplied to the drive shaft is borne. Is possible.

  The traveling mode in the hybrid vehicle according to the present invention is a so-called hybrid mode in which at least the direct torque of the internal combustion engine and the torque of the second rotating electrical machine are used in a coordinated manner as appropriate (the mode of cooperation is ambiguous. Including the case where there is no torque assist from the rotating electrical machine), and at least using only the torque of the second rotating electrical machine as the vehicle driving power (that is, simply idling or operating the internal combustion engine to obtain auxiliary drive power, etc.) Can be appropriately selected) so-called EV (electric vehicle) mode can be selected as appropriate.

  The hybrid vehicle according to the present invention includes an engagement device including a first engagement mechanism and a second engagement mechanism. Each of the first and second engagement mechanisms includes a plurality of engagement elements that can be engaged in a rotationally synchronized state and can be disengaged in a torque non-transmission state. Note that the rotation synchronization state means that the relative rotational speed of the engagement elements is inconvenient in practically engaging the engagement elements, for example, experimentally, empirically, theoretically or based on simulation. Means a state that is less than a fixed or variable reference value that prescribes the upper limit of a predetermined speed range (including cases where there is no clear reference value setting and the relative rotational speed is zero). To do. Similarly, in the torque non-transmission state, the absolute value of the transmission torque between the engagement elements is determined based on the relationship between the engagement elements, for example, experimentally, empirically, theoretically, or based on simulation. A condition that is less than a fixed or variable reference value that prescribes a predetermined torque range and that is determined to have no practical inconvenience in canceling the connection (there is no clear reference value setting and the absolute value is zero) In some cases, etc.).

  The first engagement mechanism is an engagement mechanism that locks the first rotating electrical machine at a predetermined rotation speed in the engaged state. In practical operation, the engagement element in the first engagement mechanism includes a lock-side engagement element having a predetermined rotational speed, and a first rotating electrical machine side connected directly or indirectly to the first rotating electrical machine. Engaging elements. If the predetermined rotational speed is zero, the lock-side engagement element means a fixed element (brake element).

  The first rotating electrical machine is a power element that applies a reaction torque to the torque of the internal combustion engine as described above, but in such a state that is always locked at a predetermined rotational speed, the first engagement is performed. Since reaction force torque can be applied from the mechanism, the operation of the first rotating electrical machine can be stopped. For example, as in the case where the hybrid vehicle is in a high-speed and light-load traveling state, power circulation (first rotation) caused by the first rotating electrical machine enters a power running state in which a negative torque (reaction torque) is supplied in the negative rotation region. It is possible to avoid an inefficient electric path in which the electric power required for powering the electric machine is covered by the generated electric power obtained by the electric power generating action of the second rotating electric machine.

  The second engagement mechanism is an engagement mechanism that directly or indirectly connects the drive shaft and the second rotating electrical machine in the engaged state and disconnects the second rotating electrical machine from the drive shaft in the disengaged state. In practical operation, the engagement element in the second engagement mechanism includes a drive shaft side engagement element coupled to the drive shaft, and a second rotary electrical machine side engagement element coupled to the second rotary electrical machine. Comprising.

  The second rotating electrical machine is effective as an auxiliary power source that appropriately assists the drive shaft with torque when the required value of the drive shaft torque is not satisfied with only the direct torque of the internal combustion engine, for example, in the hybrid mode described above. However, on the other hand, a situation in which the required value of the drive shaft torque can be provided only by the direct torque of the internal combustion engine as in the engine direct connection mode in which the first rotating electrical machine is locked by the action of the first engagement mechanism (such a situation In this case, the lock condition may be determined so that the first rotating electrical machine is locked in step S1), the friction and inertial resistance may cause power loss. According to the second engagement mechanism, for example, in such a case, the second rotating electrical machine can be separated from the drive shaft, which is beneficial for improving fuel consumption and power consumption.

  Thus, it is desirable that the second engagement mechanism is in the disengaged state when the first engagement mechanism is in the engaged state, and the first engagement mechanism is in the disengaged state when the first engagement mechanism is in the disengaged state. The two-engagement mechanism is preferably in the engaged state. Therefore, the engagement device according to the present invention includes, as its operation state, a first operation state in which the first engagement mechanism is in the engagement state and the second engagement mechanism is in the disengagement state, and the first engagement mechanism is in the engagement state. The operation state is selectively switched between the second operation state in which the engagement is released and the second engagement mechanism is in the engagement state. In addition, such a structure may be implement | achieved in control and may be implement | achieved structurally.

  Here, in order to realize simultaneous switching of the operation state, the engagement elements in the engagement mechanism on the side (hereinafter, appropriately referred to as “engagement side”) that transitions to the engagement state at the time of switching of the operation state. It is desirable that the engagement elements in the engagement mechanism on the side that shifts to the engagement disengagement state (hereinafter referred to as “the disengagement side” as appropriate) are converged to the torque non-transmission state. . Therefore, in the hybrid vehicle control device according to the present invention, the rotation synchronization control execution means executes rotation synchronization control for bringing the engagement element in the engagement mechanism on the engagement side into the rotation synchronization state, and torque The adjustment control execution means executes torque adjustment control for bringing the engagement element on the engagement release side into a torque non-transmission state.

  More specifically, the rotation synchronization control refers to engagement-side engagement in order to reduce or converge the relative rotational speed of the engagement element in the engagement-side engagement mechanism to a target value less than the reference value described above. It is the control of the rotational speed performed with respect to the rotary electric machine which can give torque to the engaging element in a mechanism. The rotation synchronization control may include, for example, feedforward control corresponding to a preset control amount, feedback control for feeding back the relative rotation speed, and the like. More specifically, the torque adjustment control is to reduce or converge the absolute value of the transmission torque between the engagement elements in the engagement mechanism on the engagement release side to the target value less than the reference value described above. This is torque control performed on the rotating electrical machine capable of providing torque to the engagement element in the engagement mechanism on the engagement release side. With these controls, it is possible to converge the engagement element in the engagement mechanism on the engagement side to the rotationally synchronized state and the engagement element in the engagement mechanism on the engagement release side to the torque non-transmission state.

  By the way, in the structure which switches the state of the 1st and 2nd engagement mechanism simultaneously like the engagement apparatus which concerns on this invention, the increase of the operation sound (for example, rattling sound) of each engagement mechanism, and the shock accompanying it, for example The positional relationship on the time axis between the rotation synchronization control on one side and the torque adjustment control on the other side is important because it is necessary to prevent, suppress or alleviate the increase in torque, torque fluctuation of the drive shaft, and the lengthening of the switching period. .

  In particular, during the rotation synchronization control in the first engagement mechanism, that is, the rotation speed control of the first rotating electric machine, an inertia torque corresponding to the time differential value of the rotation speed of the first rotating electric machine, that is, the rate of change of the rotation speed is generated. . The inertia torque in the second operation state in which the first rotating electrical machine has not yet been locked promotes a relative decrease in the reaction torque that antagonizes the torque of the internal combustion engine, and as a result, the drive shaft torque fluctuates aside from its magnitude. It becomes easy to do. Accordingly, when a request for switching the operation state of the engagement device from the second operation state in which the second rotating electrical machine is connected to the drive shaft to the first operation state in which the first rotating electrical machine is locked occurs, both controls are performed. It is necessary to pay attention to the temporal relationship between each other.

  In view of this point, in the control device for a hybrid vehicle according to the present invention, when a request for switching the operation state from the second operation state to the first operation state is generated, the torque adjustment control execution means is the rotation synchronization control execution means. Torque adjustment control is executed after the start of rotation synchronous control. That is, the rotation synchronization control is started prior to the execution of the torque adjustment control.

  If the rotation synchronization control is started prior to the torque adjustment control in this way, the torque between the drive shaft and the second rotating electrical machine during the period from the start of the rotation synchronization control until the torque adjustment control is started. Input / output is not hindered. Therefore, for example, the second rotating electrical machine appropriately absorbs the generation of contact noise and physical shock between the engaging elements due to the change in the transmission torque of the second engagement mechanism due to the decrease in the drive shaft torque due to the inertia torque. It is also possible to compensate or absorb the torque fluctuation of the drive shaft due to the inertia torque by supplying the torque from the second rotating electrical machine, and the traveling performance of the hybrid vehicle during the operation state switching period of the engagement device Further, it is possible to suitably prevent, suppress or alleviate a decrease in comfort performance.

  Supplementally, in the situation where the torque fluctuation of the drive shaft due to the inertia torque becomes obvious in this way, when the torque adjustment control of the second engagement mechanism is executed without any guideline, it is connected to the drive shaft. There is a possibility that the period during which the torque of the second rotating electrical machine in the state cannot be used for adjusting the drive shaft torque or the transmission torque in the second engagement mechanism will become so long that it cannot be ignored in practice. is there. In particular, when the rotation synchronization control of the first engagement mechanism is executed after the torque adjustment control of the second engagement mechanism is completed, or when both controls are started simultaneously or substantially simultaneously, the torque fluctuation of the drive shaft is Power performance and comfort performance can be significantly reduced.

  In view of the effect expected by the operation of the rotation synchronization control execution means, the start timing of the torque adjustment control after the start of the rotation synchronization control is naturally determined experimentally, empirically, and theoretically in advance. It is desirable that the inertia torque is determined in correspondence with the magnitude of the influence of the inertia torque on the drive shaft torque obtained based on simulation or the like. It is desirable that the torque adjustment control be executed at least after a delay period that can be significant from a practical standpoint.

  The hybrid vehicle control device according to the present invention may be, for example, one or more CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors or various controllers, or ROM (Read Various processing units such as single or multiple ECUs (Electronic Controlled Units), various controllers, or microcomputer devices, which may appropriately include various storage means such as only memory (RAM), RAM (Random Access Memory), buffer memory or flash memory It can take the form of various computer systems.

  In one aspect of the hybrid vehicle control device according to the present invention, when a request for switching the operation state from the first or second operation state to the second or first operation state occurs, the first and second The plurality of engagement elements in one of the second engagement mechanisms that should transition to the engagement state transition to the rotation synchronization state and transition to the engagement release state of the first and second engagement mechanisms. An engagement control means is further provided for controlling the engagement device so that the operation state is switched on the condition that the plurality of engagement elements on the other to be shifted to the torque non-transmission state are permitted. ).

  According to this aspect, since switching of the operation state is not permitted unless the engagement mechanism on the engagement side is in the rotation synchronization state and the engagement mechanism on the engagement release side shifts to the torque non-transmission state, It is possible to suppress as much as possible the occurrence of contact noise and physical impact between the engaging elements at the time of release, and it is possible to suitably switch the operating state of the engaging device.

  In another aspect of the hybrid vehicle control device according to the present invention, the drive caused by the inertia torque of the first rotating electrical machine during a period from when the rotation synchronization control is started to when the torque adjustment control is started. A drive shaft torque control means for controlling the second rotating electrical machine so as to reduce the torque fluctuation of the shaft, and a relative relationship between the plurality of engagement elements in the first engagement mechanism corresponding to the size of the inertia torque. First specifying means for specifying a change rate of the rotation speed, and the torque adjustment control executing means starts the torque adjustment control when the specified change rate becomes less than a reference value (claim). Item 3).

  According to this aspect, since the drive shaft torque control means alleviates the torque fluctuation of the drive shaft caused by the inertia torque, the hybrid vehicle travels during the operation state switching period of the engagement device, which is a kind of transient period. A decrease in performance and comfort performance can be suppressed as much as possible.

  On the other hand, in the configuration in which the rotation synchronization control is simply executed prior to the torque adjustment control, the effect may vary. More specifically, when the torque adjustment control is started after the completion of the rotation synchronization control, the execution period of both controls is a so-called series control in which the time periods do not overlap with each other, and the period required for switching the operation state of the engagement device is reduced. It may become unnecessarily long. On the other hand, if the torque adjustment control is started immediately after the start of the rotation synchronization control, both controls are executed almost in parallel on the time axis, and the operation state switching period is shortened. Although obtained, there is a possibility that the effect of suppressing the torque fluctuation of the drive shaft can hardly be expected.

  Here, the inertia torque of the first rotating electrical machine that causes the torque fluctuation of the drive shaft is the change rate of the relative rotational speed of the plurality of engagement elements in the first engagement mechanism, in other words, the change of the rotational speed of the first rotating electrical machine. Proportional to rate. Therefore, the change rate of the relative rotational speed specified by the first specifying means (where “specific” is a concept that can be accompanied by various practical aspects such as detection, calculation, estimation, identification, selection, or acquisition). By starting the torque adjustment control when is less than the reference value, it is possible to shorten the switching period of the operating state of the engagement device as much as possible while suppressing a relatively large fluctuation of the drive shaft torque. It is extremely useful in practice.

  The reference value set for the rate of change of the relative rotational speed is, for example, in advance such that the drive shaft torque does not fluctuate more than a predetermined value based on experiments, experience, theory or simulation. It may be set as a fixed value or a variable value corresponding to the inertia torque.

  In this aspect, the target value of the absolute value of the transmission torque in the torque adjustment control may be zero (claim 4).

  If the absolute value of the transmission torque is zero, the engagement of the engagement elements of the second engagement mechanism can be released very smoothly.

  In another aspect of the hybrid vehicle control device according to the present invention, the rotation synchronization control includes feedback control according to a relative rotation speed of the plurality of engagement elements in the first engagement mechanism, and the rotation synchronization control. The execution means limits the torque required for the feedback control after the start of the torque adjustment control, with the value corresponding to the start time of the torque adjustment control as an upper limit (Claim 5).

  According to this aspect, in the period after the start of the torque adjustment control in which the adjustment of the drive shaft torque by the second rotary electric machine is difficult, the feedback torque of the first rotary electric machine in the rotation synchronous control is a value equivalent to the torque adjustment control start time ( For example, it may be a torque value at the start of torque adjustment control, or may be a correction value obtained by appropriately performing a correction operation on the torque value). An increase in inertia torque is prevented, and torque fluctuations of the drive shaft during the execution period of torque adjustment control can be suppressed as much as possible.

  In another aspect of the hybrid vehicle control device according to the present invention, the rotation synchronization control execution means is configured to switch the first operation state when a request for switching the operation state from the first operation state to the second operation state occurs. Rotation synchronization control is performed for the two-rotary electric machine to bring the plurality of engagement elements in the second engagement mechanism into the rotation-synchronized state, and the torque adjustment control execution unit rotates the second rotation electric machine. After the synchronous control is started, torque adjustment control is performed for the first rotating electrical machine to place the plurality of engagement elements in the first engagement mechanism in the torque non-transmission state (Claim 6). .

  According to this aspect, even when switching from the first operation state to the second operation state, the rotation synchronization control in the second engagement mechanism on the engagement side is executed prior to the torque adjustment control in the first engagement mechanism. Is done.

  Here, in particular, in the first operating state, the second rotating electrical machine is in a state of being disconnected from the drive shaft. Therefore, unlike the second operating state in which the first rotating electrical machine is indirectly connected to the drive shaft. The torque fluctuation of the drive shaft does not occur due to the rotation speed control of the second rotating electrical machine. On the other hand, the engagement elements of the first engagement mechanism in the torque non-transmission state may come into contact or collide with each other due to, for example, a minute torque change of the internal combustion engine. Even in the first operation state, the torque adjustment It is difficult to find a rational reason for executing the control prior to the rotation synchronization control or simultaneously with the rotation synchronization control. That is, the period during which the engagement element on the disengagement side is maintained in the torque non-transmitting state is preferably shorter in any operating state.

  In particular, when the fixed rotational speed in the first engagement mechanism (that is, the rotational speed of the first rotating electrical machine in the first operation state is not unique) is not zero, torque adjustment for the first rotating electrical machine in the locked state is performed. There is a possibility that torque fluctuations of the drive shaft due to inertia torque occur in the control execution process. In view of this point, it is clear that the prevention or suppression of the lengthening of the execution period of the torque adjustment control is effective in suppressing the decrease in power performance or comfort performance of the hybrid vehicle, and the rotational speed relative to the second rotating electrical machine. The technical significance of making the control precede the torque adjustment control for the first rotating electrical machine is clear.

  In another aspect of the hybrid vehicle control device according to the present invention, the first engagement mechanism is a brake mechanism that fixes the first rotating electrical machine to zero rotation in the engagement state, and the second engagement mechanism. And further comprising a second specifying means for specifying relative rotational speeds of the plurality of rotating elements, wherein the torque adjustment control executing means is configured such that the specified relative rotational speed is higher than a reference value defining the rotational synchronization state. The torque adjustment control is started when it becomes less than a large predetermined value (Claim 7).

  According to this aspect, since the first engagement mechanism is a brake mechanism that fixes the first rotating electrical machine to zero rotation, the torque fluctuation of the drive shaft due to the inertia torque of the first rotating electrical machine is hardly caused in the execution process of the torque adjustment control. Can be ignored. Therefore, even if the torque adjustment control is started on the condition that the relative rotation speed of the engagement elements in the second engagement mechanism is less than a predetermined value, no problem occurs in practice. In addition, since it is relatively easy to specify the relative rotational speed in practice, it is possible to satisfactorily switch the operating state from the first operating state to the second operating state by using the relative rotational speed as a criterion. It becomes possible relatively easily.

  The predetermined value related to the relative rotational speed is a value larger than a reference value that defines the rotational synchronization state. Therefore, when the torque adjustment is started when the relative rotational speed reaches the predetermined value, the absolute value control of the transmission torque of the engagement element of the first engagement mechanism toward the torque region less than the reference value, and the reference Control of the relative rotational speed of the engagement element of the second engagement mechanism toward the rotation region less than the value is executed in parallel on the time axis, and the operation state switching period can be shortened.

  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 shift control executed by an ECU in the hybrid vehicle of FIG. 5 is a flowchart of first engagement control executed in the shift control of FIG. FIG. 6 is a timing chart illustrating one operating characteristic of the hybrid drive device when the first engagement control of FIG. 5 is executed. 6 is a flowchart of second engagement control executed in the shift control of FIG. FIG. 8 is a timing chart illustrating one operating characteristic of the hybrid drive device when the second engagement control of FIG. 7 is executed. 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.

<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 shift control described later according to a control program stored in the ROM.

  Note that the ECU 100 includes “rotation synchronization control execution means”, “torque adjustment control execution means”, “engagement control means”, “drive shaft torque control means”, “first specifying means” and “second specification” according to the present invention. It is an integrated electronic control unit configured to function as an example of each of the “specifying means”, and all the operations related to these means 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. Including an 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 (ie, in this case, This is a control unit configured to be able to control power transfer between the motor generators without passing through 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 (for example, several hundreds) of unit battery cells such as lithium ion battery cells are connected in series, and a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. Is an example of the “power storage means” according to the present invention.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Ta as 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 apparatus 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 MG2 deceleration. A mechanism 400, a drive shaft 500, a speed reduction mechanism 600, an MG2 output shaft 700, and an engagement device 800 are provided.

  The engine 200 is a gasoline engine that is an example of an “internal combustion engine” according to the present invention that is configured to function as a main power source of the hybrid vehicle 1. The engine 200 is a known gasoline engine, and a detailed configuration thereof is omitted here, but the engine torque Te that is the output power of the engine 200 is input to the power split mechanism 300 via a crankshaft (not shown). It is configured to be transmitted to the shaft 310. 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, and is an example of the “first rotating electrical machine” according to the present invention. is there.

  Motor generator MG2 is a motor generator that is an example of a “second rotating electrical machine” according to the present invention and that is larger than motor generator MG1, and, like motor generator MG1, has a power running function that converts electrical energy into kinetic energy. And a regenerative function for converting 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 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 the “first rotating element” according to the present invention provided in the center, and a “third rotation” according to the present invention provided concentrically around the outer periphery of the sun gear S1. The ring gear R1, which is another example of the “element”, a plurality of pinion gears (not shown) which are arranged between the sun gear S1 and the ring gear R1 and revolve around the outer periphery of the sun gear S1, and each of the pinion gears And a carrier C1 as another example of the “second rotating element” according to the present invention, which supports the rotating shaft.

  Sun gear S1 is a reaction force element that bears a reaction force torque that antagonizes engine torque Te, and is fixed to MG1 output shaft 320 that is an output rotation shaft of motor generator MG1. Therefore, the rotational speed of sun gear S1 is equivalent to MG1 rotational speed Nmg1 (which means the rotational speed of MG1 output shaft 320), which is the rotational speed of motor generator MG1. The ring gear R1 is an output element of the power split mechanism 300, and is connected to the power output shaft 330 so as to share the rotation shaft. As described above, the carrier C1 is coupled to the power input shaft 310 coupled to the crankshaft of the engine 200 so as to share the rotation axis thereof, and the rotation speed thereof is determined by the engine rotation speed Ne of the engine 200. Is equivalent to

  The MG2 speed reduction mechanism 400 is connected to the first gear 410 connected to the power output shaft 330 of the power split mechanism 300 and the drive shaft 500 serving as the power output shaft of the hybrid drive device 10, and includes the first gear 410 and the third gear 430. The speed reduction device includes a third gear 430 that is engaged with a second gear 420 and a drive shaft side engaging element 822, which will be described later, and meshes with the second gear 420. The rotation speed of the second gear 420 is equivalent to the rotation speed of the drive shaft 500, that is, the output rotation speed Nout of the hybrid drive device 10.

  On the other hand, the number of teeth of the third gear 430 is greater than the number of teeth of the second gear 420, and the rotational speed of the drive shaft 500 is transmitted to the drive shaft side engagement element 822 in a decelerated state. On the other hand, the rotational speed of third gear 430 is equivalent to MG2 rotational speed Nmg2, which is the rotational speed of motor generator MG2, in a state where drive shaft side engaging element 822 is engaged with MG2 side engaging element 821 described later. Therefore, MG2 rotation speed Nmg2 is decelerated with respect to output rotation speed Nout.

  The configuration of MG2 reduction mechanism 400 is only one form that can be adopted by a mechanism that decelerates motor generator MG2, and this type of reduction mechanism can have various forms. For example, this type of speed reduction mechanism includes a plurality of mutually rotatable components including a rotating element fixed to the drive shaft, a rotating element fixed to the fixed element, and a rotating element fixed to the rotor of the MG2. You may be comprised as a kind of differential gear mechanism containing a rotation element. Further, this type of reduction mechanism is not necessarily provided in the hybrid drive device.

  The speed reduction mechanism 600 is a gear mechanism that transmits torque between the left axle SFL and right axle SFR described above and the drive shaft 500.

  MG2 output shaft 700 is an output rotation shaft of motor generator MG2 fixed to the rotor of motor generator MG2.

  Engagement device 800 indirectly connects MG2 output shaft 700 to drive shaft 500 in first engagement mechanism 810 that locks motor generator MG1 in the engaged state, and MG2 output in the disengaged state. A second engagement mechanism 820 that separates the shaft 700 from the drive shaft 500, and an engagement control mechanism 830 that selectively switches the operation state of the engagement device 800 defined by the states of the first and second engagement mechanisms. 1 is an example of an “engagement device” according to the present invention.

  The first engagement mechanism 810 includes an MG1 side engagement element 811, a brake side engagement element 812, and a first sleeve 813, which is an example of a “first engagement mechanism” according to the present invention. Mechanism.

  The MG1 side engaging element 811 is a disk-like engaging member that is fixed to the MG1 output shaft 320 described above and rotates integrally with the MG1 output shaft 320. On the outer peripheral surface of the MG1 engagement element 811, external teeth (not shown) as meshing tooth-like members are arranged at equal intervals.

  The brake side engaging element 812 is a rotating element having a rotational speed of zero, such as a chassis of the hybrid vehicle 1, that is, a disc-shaped engaging member fixed to the fixed element and disposed opposite to the MG1 side engaging element 811. is there. On the outer peripheral surface of the brake-side engagement element 812, external teeth (not shown) as meshing tooth-like members are arranged at equal intervals. The MG1 side engaging element 811 and the brake side engaging element 812 are examples of “a plurality of engaging elements” according to the present invention.

  The first sleeve 813 is an annular member configured to allow a predetermined amount of stroke in a predetermined stroke direction (left and right direction in the drawing). On the inner peripheral surface of the first sleeve 813, internal teeth (not shown) as meshing tooth-like members are arranged at equal intervals. The internal teeth are configured to be able to mesh with the above-described external teeth respectively formed on the MG1 side engaging element 811 and the brake side engaging element 812 in a rotationally synchronized state. FIG. 2 illustrates a state in which the first sleeve 813 is meshed only with the MG1 side engaging element 811.

  Thus, in the state in which the first sleeve 813 is engaged only with the MG1 side engaging element 811, the MG1 side engaging element 811 and the brake side engaging element 812 are not engaged, and the MG1 side engaging element is engaged. The element 811 can rotate irrespective of the state of the brake side engagement element 812. That is, this state is an example of the “disengaged state” according to the present invention. On the other hand, in a state where the first sleeve 813 has stroked a predetermined amount in the stroke direction (more specifically, the left direction in the drawing), the internal teeth formed on the first sleeve 813 are the external teeth of the MG1 side engagement element 811. At the same time, it meshes with the external teeth of the brake side engaging element 812. In this state, the MG1 side engagement element 811 and the brake side engagement element 812 are indirectly engaged, and the rotation of the motor generator MG1 is blocked by the brake side engagement element 812. MG1 is locked to zero rotation. That is, this state is an example of the “engagement state” according to the present invention.

  The second engagement mechanism 820 includes an MG2 side engagement element 821, a drive shaft side engagement element 822, and a second sleeve 823. The second engagement mechanism 820 is a rotation synchronization mesh type that is an example of the “second engagement mechanism” according to the present invention. It is a dog clutch mechanism.

  The MG2 side engaging element 821 is a disc-shaped engaging member that is fixed to the MG2 output shaft 700 and rotates integrally with the MG2 output shaft 700. On the outer peripheral surface of the MG2 engagement element 821, external teeth (not shown) as meshing tooth-like members are arranged at equal intervals.

  The drive shaft side engagement element 822 is a disk-shaped engagement member that shares the rotation shaft with the third gear 430 of the MG2 reduction mechanism 400. On the outer peripheral surface of the drive shaft side engaging element 822, external teeth (not shown) as meshing tooth-like members are arranged at equal intervals.

  The second sleeve 823 is an annular member configured to allow a predetermined amount of stroke in a predetermined stroke direction (left and right direction on the paper surface). On the inner peripheral surface of the second sleeve 823, internal teeth (not shown) as meshing tooth-like members are arranged at equal intervals. The internal teeth are configured to be able to mesh with the above-described external teeth respectively formed on the MG2 side engaging element 821 and the drive shaft side engaging element 822 in a rotationally synchronized state. FIG. 2 illustrates a state in which the second sleeve 823 is engaged with the MG2 side engagement element 821 and the drive shaft side engagement element 822.

  Thus, in the state where the second sleeve 823 is engaged with both the MG2 side engagement element 821 and the drive shaft side engagement element 822, the MG1 side engagement element 811 and the brake side engagement element 812 are indirect. The motor generator MG2 can transmit torque to and from the drive shaft 500. That is, this state is another example of the “engaged state” according to the present invention. On the other hand, when the second sleeve 823 is stroked by a predetermined amount in the stroke direction (more specifically, the left direction in the drawing), the internal teeth formed on the second sleeve 823 are the external teeth of the MG2-side engagement element 821. And is engaged with only the drive shaft side engagement 822. In this state, MG2 side engagement element 821 and drive shaft side engagement element 822 are not engaged, and transmission of torque between motor generator MG2 and drive shaft 500 is interrupted. That is, this state is another example of the “disengaged state” according to the present invention.

  The engagement control mechanism 830 includes a fork 831, a rod 832, and an actuator 833.

  The fork 831 is a drive member having one end fixed to the first sleeve 813 in the first engagement mechanism 810 and the other end fixed to the second sleeve 823 in the second engagement mechanism 820. The fork 831 and each of these sleeves are configured to be able to reciprocate integrally in the stroke direction described above.

  The rod 832 is a power transmission member that is fixed to the fork 831 and transmits power from the actuator 833 to the fork 831. The rod 832 can be stroked by a predetermined amount in the stroke direction described above, and the stroke motion of the rod 832 is converted into the reciprocating motion of the fork 831 connected to the rod 832.

  The actuator 833 is a known direct acting electromagnetic actuator capable of applying a driving force for causing the rod 832 to move the fork 831 in the stroke direction. The actuator 833 includes a solenoid (electromagnet) as a driving force source, and an electromagnetic force for displacing the rod 832 in the stroke direction is generated by supplying an excitation current as a driving current to the solenoid. It has become. The actuator 833 is electrically connected to the PCU 11 and can supply a drive current by supplying power from the PCU 11. Therefore, the operation state of the actuator 833 is also controlled by the ECU 100. The stroke direction of the rod 832 is reversed by reversing the sign of the drive current.

  Thus, in the engagement device 800, the actuator 833 is shared between the first engagement mechanism 810 and the second engagement mechanism 820, and the first engagement mechanism 810 and the second engagement mechanism 820 are moved by the stroke motion of the rod 832. The state of the second engagement mechanism 820 is switched at the same time.

  In particular, as shown in the drawing, when the first engagement mechanism 810 is in the disengaged state in which the engagement between the engagement element MG1 side engagement element 811 and the brake side engagement element 812 is released. The second engagement mechanism 820 is in an engaged state in which the MG2 side engagement element 821 and the drive shaft side engagement element 822 as the engagement elements are engaged. On the other hand, when the first engagement mechanism 810 is in an engaged state in which the MG1 side engagement element 811 and the brake side engagement element 812 as the engagement elements are engaged, the second engagement mechanism 820 is The MG2 side engagement element 821 as the engagement element and the drive shaft side engagement element 822 are disengaged from each other. That is, the operation state of the engagement device 800 is that the first engagement mechanism 810 is in the engagement state and the second engagement mechanism 820 is in the disengagement state, and the first engagement mechanism 810 is in a disengaged state and is configured to be selectively switched between a second operation state in which the second engagement mechanism 820 is in an engaged state.

  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, A2, and A3 shown in the figure, so that 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 MG1 rotational speed Nmg1, and the rotational speed of the part corresponding to the illustrated broken line frame A2 is MG2 rotational speed Nmg2. Further, the rotational speed of the portion corresponding to the illustrated broken line frame A3 is the output rotational speed Nout.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the power input shaft 310 is transferred to the sun gear S1 and the ring gear R1 by the carrier C1 under the above-described configuration (the gear ratio between the gears). It is possible to divide the engine torque Te into two systems. At this time, in order to make the operation of the power split mechanism 300 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 power output shaft 330 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.

<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 the transmission mode.

  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 rotational speed, and the horizontal axis represents the sun gear S1 (uniquely motor generator MG1), carrier C1 (uniquely engine 200) and ring gear R1 (in order from the left). The motor generator MG2 and the drive shaft 500) are 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. 3 (a), it is assumed that the ring gear R1 that has a unique rotational relationship with the vehicle speed V and the output rotational speed Nout is rotating at a rotational speed corresponding to the illustrated white circle m1. In this case, if the motor generator MG1 is rotating at a rotation speed corresponding to the white circle g1 shown in the figure, the rotation speed of the engine 200 connected to the carrier C1, which is the remaining rotation element (that is, the engine rotation speed Ne) is inevitably. Therefore, the rotation speed corresponds to the illustrated white circle e1. At this time, while maintaining the rotation speed of the ring gear R1 (that is, uniquely maintaining the output rotation speed Nout and the MG2 rotation speed Nmg2), the rotation speed of the motor generator MG1 corresponds to the white circle g2 and the white circle g3 shown in the figure. If the speed is changed, the rotational speed of the engine 200 changes to the rotational speeds corresponding to the white circle e2 and the white circle e3 shown in the drawing, respectively.

  That is, in this case, by making the motor generator MG1 function as a rotational speed control mechanism, it means that the engine 200 has a desired operating point (here, one operating condition defined by a combination of the engine rotational speed Ne and the engine torque Te). ) Can be operated. 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 is basically controlled to the optimum fuel consumption operating point at which the fuel consumption rate of the engine 200 is minimized.

  In the continuously variable transmission mode, of course, the MG1 rotational speed Nmg1 needs to be variable. For this reason, when the continuously variable transmission mode is selected, the engagement device 800 enters the above-described second operation state in which the first engagement mechanism 810 is disengaged and the second engagement mechanism 820 is engaged. Be controlled.

  In power split mechanism 300, in order to supply torque Ter corresponding to engine torque Te described above to drive shaft 500, MG1 output shaft 320, which is the rotation shaft of sun gear S1, according to engine torque Te as MG1 torque Tmg1. It is necessary to supply the reaction torque having the same magnitude and the opposite sign (that is, negative torque) appearing on the above-described torque Tes from the motor generator MG1 to the MG1 output shaft 320. In this case, at the operating point in the positive rotation region such as the white circle g1 or the white circle g2, the MG1 is in a power regeneration state (that is, a power generation state) with a positive rotation 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 500 (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 Tmg2 as the assist torque is appropriately supplied from the motor generator MG2 to the drive shaft.

  On the other hand, when the engine speed Ne is relatively low for a relatively high output rotational speed Nout, such as when traveling at high speed and light load, for example, the motor generator MG1 operates at an operating point in a negative rotational area such as the white circle g3 shown in the figure. It becomes. 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 Tmg1 output from 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 Tmg2 matches the driver request torque. When MG1 falls into a power running state, motor generator MG2 enters a negative torque state in order to absorb excessive torque supplied to drive shaft 500 relative to the required torque. In this case, motor generator MG2 is in a power regeneration state of positive rotation negative torque. 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, for example, in an operation region that is determined in advance such that such power circulation can occur, the operation state of the engagement device 800 is the engagement state of the first engagement mechanism 810 and the second engagement state. The combined mechanism 820 is controlled to the above-described first operation state where the engagement state is released, and the motor generator MG1 is locked. This is shown in FIG. Since one engagement element of the first engagement mechanism 810 is the zero-rotation fixed brake side engagement element 812, when the motor generator MG1 shifts to the locked state by the first engagement mechanism 810, the motor generator MG1 Locked to zero rotation corresponding to the illustrated white circle g4.

  In this case, the remaining engine rotational speed Ne is uniquely determined to be a rotational speed corresponding to the illustrated white circle e4 based on the output rotational speed Nout and the MG1 rotational speed Nmg1 (Nmg1 = 0). That is, when the motor generator MG1 is locked, the engine rotational speed Ne is uniquely determined by the vehicle speed V and the unambiguous output rotational speed Nout (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 first engagement mechanism 810. 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 split to the drive shaft side by the power split mechanism 300 out of the engine torque Te, and the hybrid drive apparatus 10 performs mechanical power transmission. The transmission efficiency is improved.

  Here, when the engagement device 800 shifts to the first operation state, the second engagement mechanism 820 disengages the engagement between the MG2 side engagement element 821 and the drive shaft side engagement element 822. It becomes a state. When the motor generator MG2 is in a non-operating idle state, the motor generator MG2 is merely an inertia body that prevents the rotation of the drive shaft 500 due to its friction and rotational inertia. In this way, the motor generator MG2 is in the first operation state. Therefore, the fuel consumption rate in the hybrid drive device 10 is suppressed as much as possible. In particular, the engagement device 800 can drive the first engagement mechanism 810 and the second engagement mechanism 820 simultaneously by the configuration of the engagement control mechanism 830. Therefore, the engagement device 800 can efficiently switch the operation state from the first operation state to the second operation state and the operation state from the second operation state to the first operation state. Furthermore, since each engagement mechanism can be driven by a single actuator 833, an actuator is provided for each engagement mechanism in terms of power consumption, vehicle mountability, and cost. This is advantageous compared to the configuration provided.

<Outline of shift control>
By the way, the first engagement mechanism 810 and the second engagement mechanism 820 are both rotation-synchronized dog clutch mechanisms, and it is necessary to synchronize the engagement elements when engaging the engagement elements. In a state where the engagement elements are not rotationally synchronized, the internal teeth formed on the sleeve cannot be engaged with the external teeth formed on the engagement element at the engagement destination. This is because the occurrence of physical impact and impact sound due to contact with each other is unavoidable, and in some cases, gear teeth may be lost. Further, in these engagement mechanisms, in order to release the engagement between the engagement elements, it is necessary to reduce the transmission torque between the engagement elements. In the state where torque is transmitted in the rotation direction, the driving force of the actuator 833 is insufficient, and the sleep cannot be stroked. This is because it is unavoidable and, in some cases, gear teeth may be lost.

  Therefore, when the operation state is selectively switched in the engagement device 800, the engagement in one engagement mechanism that shifts from the disengagement state to the engagement state before actually stroking the sleeve of each engagement mechanism. It is necessary to complete the rotation synchronization control between the elements and the transmission torque adjustment control between the engagement elements in the other engagement mechanism that shifts from the engagement state to the engagement release state.

  The rotation synchronization control according to the present embodiment means control for converging the relative rotation speed of the engagement elements in the engagement mechanism to zero rotation (that is, an example of “less than the reference value” according to the present invention). Practically speaking, the adjustment of the relative rotation speed is realized by controlling the rotation speed of the engagement element connected to each motor generator. This is because one engagement element in the first engagement mechanism is a brake-side engagement element 812 whose rotation speed is fixed to zero, and one engagement element in the second engagement mechanism has a rotation speed thereof. This is because the drive shaft side engaging element 822 is linked to the rotational speed of the axle of the hybrid vehicle 1 at the time (uniquely the vehicle speed V).

  The torque adjustment control according to the present embodiment means control for reducing the transmission torque representing the torque transmitted between the engagement elements in the engagement mechanism to zero torque. Practically speaking, the adjustment of the transmission torque is realized by controlling the torque of the engagement element connected to each motor generator. This is because one engagement element in the first engagement mechanism is a zero-rotation fixed brake side engagement element 812 in which active torque adjustment is impossible, and one engagement element in the second engagement mechanism. This is because the drive shaft side engagement element 822 is controlled by the output torque (ie, drive shaft torque) of the drive shaft 500 of the hybrid vehicle 1 at that time.

  By the way, while sharing the actuator 833 among the plurality of engagement mechanisms, the above-described various benefits are brought about. On the other hand, the transmission device 800 has an operation state switching period due to a configuration in which the operation state is switched in a binary manner. There are various practical problems such as the generation of vibration and noise during the operation state switching period. For example, when the rotation synchronization control in one engagement mechanism that shifts to the engagement state and the transmission torque adjustment control in the other engagement mechanism that shifts to the engagement release state are series controls that do not overlap on the time axis. There is a possibility that the operation state switching period as a period required for switching the operation state may be unnecessarily lengthened.

  Further, in the process of changing the rotation speed of the motor generator, an inertia torque corresponding to the time differential value of the rotation speed is generated. A part of the torque output from the motor generator to change the rotation speed cancels out this inertia torque, but the motor generator MG1 is indirectly connected to the drive shaft 500 via the MG1 output shaft 320 in the second operation state. These inertia torques cause torque fluctuations of the drive shaft 500.

  Here, this type of torque fluctuation can be compensated by outputting MG2 torque Tmg2 as assist torque from motor generator MG2 indirectly connected to drive shaft 500 in the second operation state. Once the adjustment control is started, the transmission torque converges toward zero torque, so this assist torque does not contribute to suppression of torque fluctuation of the drive shaft 500. Therefore, when the positional relationship on the time axis between the transmission torque adjustment control and the rotation synchronization control is not taken into consideration, the torque fluctuation of the drive shaft may continue unnecessarily.

  Furthermore, this kind of torque fluctuation of the drive shaft causes a torque fluctuation of the drive shaft side engagement element 822 indirectly connected to the drive shaft 500. Therefore, the drive shaft side engagement element 822 is in the second operation state. The transmission torque between the MG2 engagement element 821 engaged with the MG2 also changes. This change in transmission torque can also be compensated for by the MG2 torque Tmg2 before the start of the torque adjustment control, but if the torque adjustment control is started, the practice is significantly restricted.

  Thus, from a practical standpoint, when switching the operation state of the engagement device 800, particularly when switching from the second operation state to the first operation state (ie, switching from MG1 non-lock to MG1 lock), It is necessary to optimize the positional relationship on the time axis between the rotation synchronization control in the first engagement mechanism 810 and the torque adjustment control in the second engagement mechanism 820. In the present embodiment, this point is conceived, and the speed change control executed by the ECU 100 realizes quick and smooth switching of the operating state of the speed change device 800.

<Details of shift control>
Here, the details of the shift control will be described with reference to FIG. FIG. 4 is a flowchart of the shift control.

  In FIG. 4, the ECU 100 determines whether or not the engagement device 800 is in the second operation state (step S101). As already described, the second operation state is a state in which the first engagement mechanism 810 is in the disengagement state and the second engagement mechanism 820 is in the engagement state, and the motor generator MG1 is not locked. means. The operation state of the engagement device 800 is held as control information by the ECU 100 itself that controls the operation state of the actuator 833.

  When engagement device 800 is in the second operation state (step S101: YES), ECU 100 determines whether or not the operating condition of hybrid vehicle 1 falls within the MG1 lock region that is determined in advance as to lock motor generator MG1. Is determined (step S102). In addition, although the driving conditions used for determination in step S102 are not unambiguous, for example, the vehicle speed V of the hybrid vehicle 1 and the required driving force Ft (driving force to be supplied to the axle) or the like can be preferably used. Further, the definition of the MG1 lock region can be appropriately set experimentally, empirically, or theoretically. For example, it may be set to a region corresponding to high-speed and light-load traveling as described above.

  When the driving condition of the hybrid vehicle 1 corresponds to the MG1 lock region (step S102: YES), the ECU 100 executes the first engagement control (step S200). The first engagement control is a control for switching the first engagement mechanism 810 from the disengaged state to the engaged state while switching the second engagement mechanism 820 from the engaged state to the disengaged state. This is control for switching the operation state of the engagement device 800 from the second operation state to the first operation state. When the first engagement control is executed, the process returns to step S101. The first engagement control will be described later.

  In step S101, if the engagement device 800 is not in the second operation state (step S101: NO), that is, if it is in the first operation state, the ECU 100 determines whether or not there is a request for releasing the MG1 lock (step S101). S103). The MG1 lock release request is basically generated when the operating condition of the hybrid vehicle 1 corresponds to a region other than the previous MG1 lock region. When there is no MG1 lock release request (step S103: NO), the ECU 100 returns the process to step S101. That is, the engagement device 800 is maintained in the previous state.

  On the other hand, when there is no MG1 lock release request (step S103: YES), the ECU 100 executes the second engagement control (step S300). The second engagement control is a control for switching the first engagement mechanism 810 from the engaged state to the disengaged state while switching the second engagement mechanism 820 from the disengaged state to the engaged state. This is control for switching the operation state of the engagement device 800 from the first operation state to the second operation state. When the second engagement control is executed, the process returns to step S101. The second engagement control will be described later.

<Details of first engagement control>
Next, the details of the first engagement control will be described with reference to FIG. FIG. 4 is a flowchart of the first engagement control.

  In FIG. 4, the ECU 100 starts first relative rotational speed feedback (hereinafter, abbreviated as “F / B” as appropriate) control (step S201).

  Here, the first relative rotational speed F / B control is the first relative rotational speed of the engagement elements in the first engagement mechanism 810 (that is, the brake side engagement element 812 and the MG1 side engagement element 811). This means control for converging the relative rotational speed Nr1 to the target value Nr1tg.

  Here, in particular, in the present embodiment, since the brake side engagement element 812 is a fixed element fixed at zero rotation, the first relative rotation speed Nr1 is the rotation speed of the MG1 side engagement element 812, that is, MG1 rotation. Means speed Nmg1. That is, the first relative rotational speed F / B control is control for converging the MG1 rotational speed Nmg1 to the target value Nr1tg. In the present embodiment, the target value Nr1tg is zero (that is, an example of “less than the reference value” according to the present invention).

  In step S201, the ECU 100 sets the first relative rotational speed Nr1 (that is, MG1 rotational speed Nmg1 here) as a deviation, and based on such deviation, for example, a proportional term (P term), an integral term (I term), and The first relative rotational speed F / B control torque Tfb1 including the D term (differential term) is calculated, and the first relative rotational speed F / B control torque Tfb1 is output from the motor generator MG1 through the control of the PCU 11. . Here, the first relative rotational speed Nr1 is converged to the target value Nr1tg only by the first relative rotational speed F / B control, but this is an example. For example, this type of F / B control is used. In addition, F / F control according to a preset feed-forward (hereinafter, abbreviated as “F / F” as appropriate) control term may be appropriately executed.

  When the first relative rotational speed F / B control is started, the ECU 100 calculates a first relative rotational speed change rate dNr1 (step S202). The first relative rotational speed change rate dNr1 is a time differential value of the first relative rotational speed Nr1, and is an example of “a relative rotational speed change rate of a plurality of engagement elements in the first engagement mechanism” according to the present invention. It is.

  The ECU 100 determines whether or not the calculated first relative rotational speed change rate dNr1 is less than a reference value X (an example of the “reference value” according to the present invention) (step S203). If the first relative rotational speed change rate dNr1 is equal to or greater than the reference value X (step S203: NO), the process returns to step S202.

  Here, when changing the rotational speed of motor generator MG1, an inertia torque Tint proportional to the time change rate of MG1 rotational speed Nmg1 is generated. Since a part of the MG1 torque Tmg1 is offset with the inertia torque Tint, the execution period of the first relative rotational speed F / B control, in particular, the control with a relatively large deviation (that is, in this case, the MG1 rotational speed Nmg1). The drive shaft torque, which is the torque of the drive shaft 500, tends to fluctuate remarkably from the start to the initial stage.

  In addition, the torque fluctuation of the drive shaft 500 directly affects the running performance of the hybrid vehicle 1, but in addition, the engagement elements in the second engagement mechanism 820, that is, the drive shaft side engagement, are added. This also causes a variation in the second transmission torque Ttr2, which is a torque transmitted between the joint element 822 and the MG2-side engagement element 821. When the second transmission torque Ttr2 fluctuates, the contact state between the internal teeth formed on the second sleeve 823 and the external teeth formed on one of the engagement elements changes. Impact noise and physical shock called rattling shock occur, which causes a decrease in comfort.

  In order to prevent such a decrease in running performance and comfort, the ECU 100 corrects the MG2 torque Tmg2, which is the output torque of the motor generator MG2, so that a sudden change in the drive shaft torque and the second transmission torque Ttr2 is suppressed. (Hereinafter, such control of the MG2 torque Tmg2 is appropriately referred to as “inertiak compensation control”).

  On the other hand, as described above, when the actuator 833 is finally driven to switch the operation state of the engagement device 800 from the second operation state to the first operation state, the second transmission in the second engagement mechanism 820 is performed. The torque Ttr2 must be reduced to such an extent that at least the engagement between the engagement elements can be smoothly released. In the torque non-transmission state as such a state, the execution of the inertia torque compensation control described above is difficult or at least significantly restricted. Therefore, the reference value X described above is set to such a small value that it is determined experimentally, empirically, or theoretically that a decrease in running performance and comfort is not practically manifested.

  When the first relative rotational speed change rate dNr1 is less than the reference value X (step S203: YES), the ECU 100 determines the above-described first relative rotational speed F / B control torque Tfb1 in the subsequent period. The value of the first relative rotational speed F / B control torque Tfb1 is limited as an upper limit value (step S204). That is, in the subsequent period, an inertia torque larger than the inertia torque generated at that time is not basically generated (note that this is not necessarily the case when the F / F control is executed in parallel). However, basically the F / F control term at this point is sufficiently small so that there is no problem).

  Subsequently, the ECU 100 sets a second transmission torque command value Ttr2cm that is a command value of the second transmission torque Ttr2 (step S205), and sets the MG2 torque Tmg2 so that the second transmission torque Ttr2 becomes the command value Ttr2cm. The second torque adjustment control as an example of the “torque adjustment control” according to the present invention to be adjusted is started. Note that the second transmission torque Ttr2 is a torque that acts between the engagement elements in the second engagement mechanism 820, and is a torque whose sign can change depending on which engagement element is supplied with the torque. However, the positive and negative setting criteria may be set in any way.

  In view of the concept of the inertia torque compensation control described above, torque is transmitted from the MG2 side engagement element 821 to the drive shaft side engagement element 822 at least at the start of step S205 (that is, MG2 torque Tmg2). Is positive torque). Therefore, in the torque adjustment control after step S205, the MG2 torque Tmg2 is controlled to the decreasing side.

  Here, in the second torque adjustment control, the target value Ttr2tg of the second transmission torque Ttr2 is zero (that is, an example of “less than the reference value” according to the present invention), and the command value Ttr2cm set in step S205 is: This is a so-called stepwise target value in the process of reaching the second transmission torque Ttr2 to the target value Ttr2tg. By taking such stepwise reduction measures, it is possible to suppress a rapid fluctuation in the second transmission torque Ttr2 or the drive shaft torque.

  When second transmission torque command value Ttr2cm is set, ECU 100 determines whether or not second transmission torque command value Ttr2cm is set to zero, which is a final target value (step S206). If the command value Ttr2cm is not yet the target value (step S206: NO), the process returns to step S205. Although the determination is based on the torque command value here, the actual second transmission torque Ttr2 may be calculated by calculating the difference between the drive shaft torque and the MG2 torque Tmg2 and used as the determination reference value.

  On the other hand, when the second transmission torque command value Ttr2cm is zero (step S206: YES), the ECU 100 determines whether or not the first relative rotational speed Nr1 is less than the reference value Y (step S207). Instead of providing the reference value Y, it may be determined whether or not the first relative rotational speed Nr1 is the target value Nr1tg (ie, zero), but it is completely zero because of the nature of the F / B control. Since it may be difficult to maintain the rotation state, the reference value Y is set to a zero equivalent value having a fine width that is adapted in advance. If the first relative rotational speed Nr1 is still greater than or equal to the reference value Y (step S207: NO), the process returns to step S205.

  When the first relative rotational speed Nr1 is already less than the reference value Y or falls to less than the reference value Y at the end of the corresponding standby time (step S207: YES), the ECU 100 operates the actuator 833 and the rod 832 In addition, by stroking the fork 831, the first sleeve 813 of the first engagement mechanism 810 is engaged with the brake side engagement element 812, and at the same time, the second sleeve 823 of the second engagement mechanism 820 is engaged with the MG2 side. Detach from element 821. That is, the operation state of the engagement device 800 is switched from the second operation state to the first operation state (step S208). When the operating state is switched, the first engagement control ends.

  Next, the effect of the first engagement control will be described visually with reference to FIG. FIG. 6 is a timing chart illustrating one operating characteristic of the hybrid drive device when the first engagement control is executed.

  In FIG. 6, time transitions of the first relative rotational speed Nr1, the inertia torque Tint, the first relative rotational speed F / B control torque Tfb1, the second transmission torque Ttr2, and the second relative rotational speed Nr2 are illustrated in order from the top. The The second relative rotation speed Nr2 is a relative rotation speed between the engagement elements in the second engagement mechanism 820 (that is, the drive shaft side engagement element 822 and the MG2 side engagement element 821).

  It is assumed that the first relative rotational speed F / B control in the first engagement control according to the MG1 lock request is started at the illustrated time T1. When the first relative rotation speed F / B control is started, the first relative rotation speed Nr1 starts to decrease toward the target value of zero rotation.

  In the process where the first relative rotational speed Nr1 converges toward zero rotation, particularly in the beginning to the initial stage, the inertia torque Tint accompanying the change in the rotation of the motor generator MG1 is significantly increased. Accordingly, the absolute value of the first relative rotational speed F / B control torque Tfb1 also increases.

  On the other hand, the second transmission torque Ttr2 has a transmission direction from the drive shaft side engagement element 822 toward the MG2 side engagement element 821 before the time T1 (for the sake of convenience, a positive direction), but at the time T1. Thereafter, when it is necessary to compensate for torque fluctuations of the drive shaft 500, torque transmission from the MG2 side engagement element 821 to the drive shaft side engagement element 822 is required, and the transmission direction is reversed. Here, while compensating for torque fluctuations of the drive shaft 500, as part of the inertia torque compensation control described above, generation of physical impact and impact sound due to contact between the engagement elements in the second engagement mechanism 820 is suppressed. Is done. Therefore, the second transmission torque Ttr2 is a value obtained by correcting the influence of the inertia torque Tint on the second transmission torque Ttr2, and changes as indicated by the solid line in the figure.

  When the influence of the inertia torque is not taken into account, the time transition of the second transmission torque Ttr2 is as shown by the broken line in the figure, and the absolute value of the second transmission torque Ttr2 is larger than the original value by the amount corresponding to the inertia torque Tint. Become. As a result, a torque shock occurs in the second engagement mechanism 820, and comfort is reduced.

  Here, in the first engagement control according to the present embodiment, the second torque adjustment control is started to set the second transmission torque Ttr2 to the target value (zero) at the time T2 when the inertia torque Tint has sufficiently decreased. The Then, at time T3, when the second transmission torque Ttr2 decreases to the target value of zero torque and the first relative rotational speed Nr1 decreases below the reference value Y, the engagement device 800 is controlled via the drive control of the actuator 833. The operating state is switched. When the switching of the operation state is completed at time T4, the MG1 side engagement element 811 is fixed to the brake side engagement element 812, and thus the first relative rotational speed Nr1 becomes zero. Further, as the operation state of engagement device 800 is switched, rotation synchronization between drive shaft 500 and motor generator MG2 is lost, so that second relative rotational speed Nr2 starts to increase at time T3.

  As described above, according to the first engagement control according to the present embodiment, when the lock request for the motor generator MG1 is generated, the first relative rotational speed F / B control in the first engagement mechanism 810 is the second engagement control. Prior to the second torque adjustment control in the combined mechanism 820, the inertia torque causing the fluctuation of the drive shaft torque and the second transmission torque Ttr2 in the process of changing the first relative rotational speed Nr1 is sufficiently reduced. For the period, the start of the second torque adjustment control is prohibited, and only the first relative rotational speed F / B control is executed.

  For this reason, during this period, torque transmission between the motor generator MG2 and the drive shaft 500 is not limited, torque fluctuation of the drive shaft 500 due to the inertia torque Tint, impact sound in the second engagement mechanism 820, and physical Generation of impact can be suitably suppressed by inertia torque compensation control using MG2 torque Tmg2. For example, when the second torque adjustment control is executed prior to the first relative rotational speed F / B control, or when both are started almost simultaneously, the period during which the second transmission torque Ttr2 is maintained at zero torque becomes longer. Therefore, the period during which it is difficult to adjust the torque of the drive shaft torque and the second transmission torque becomes longer, and the decrease in power performance and comfort performance becomes unnecessarily manifested.

  On the other hand, when it is determined that the influence of the inertia torque Tint is sufficiently small (in this embodiment, it is determined by the first relative rotation speed change rate dNr1), the second engagement mechanism 820 quickly Since the torque adjustment control is started, the torque adjustment control in the second engagement mechanism 820 is prohibited until the engagement elements of the first engagement mechanism 810 are in the rotation synchronization state (a state where Nr1 <Y). The time required for switching the operation state of the engagement device 800 can be shortened.

  That is, according to the first engagement control according to the present embodiment, the time axis between the first relative rotational speed F / B control in the first engagement mechanism 810 and the second torque adjustment control in the second engagement mechanism 820. By optimizing the upper positional relationship, the operation state of the engagement device 800 from the second operation state to the first operation state can be suitably switched.

<Details of second engagement control>
Next, details of the second engagement control will be described with reference to FIG. FIG. 7 is a flowchart of the second engagement control.

  In FIG. 7, the ECU 100 starts second relative rotational speed feedback (hereinafter, abbreviated as “F / B” where appropriate) control (step S301).

  Here, the second relative rotational speed F / B control is the first relative rotational speed of the engaging elements in the second engaging mechanism 820 (that is, the driving shaft side engaging element 822 and the MG2 side engaging element 821). 2 Control that causes the relative rotational speed Nr2 to converge to the target value Nr2tg. In the present embodiment, the target value Nr2tg is zero (that is, an example of “less than the reference value” according to the present invention).

  Here, in particular, the drive shaft side engaging element 822 is indirectly connected to the drive shaft 500, and the control of the rotational speed significantly affects the traveling state of the hybrid vehicle 1. Therefore, practically, the second relative rotational speed F / B is MG2 rotational speed Nmg2, which is the rotational speed of motor generator MG2, and drive shaft side engagement element 822 corresponding to output rotational speed Nout, which is the rotational speed of drive shaft 500. It is the control which converges to the rotational speed of.

  When the second relative rotation speed F / B control is started, the ECU 100 determines whether or not the second relative rotation speed Nr2 is less than the reference value Z (step S302). Here, the reference value Z is an example of the “predetermined value” according to the present invention, which is larger than the above-described reference value Y that defines whether or not the engagement elements are in a rotationally synchronized state.

  When the engagement device 800 is in the first operation state, the motor generator MG2 is disconnected from the drive shaft 500. Therefore, in the second engagement control, the inertia torque in the process of changing the rotation speed of the motor generator MG2 does not affect the drive shaft 500, and the reference considering the inertia torque as in the first engagement control. It is not necessary to set a value. On the other hand, the period during which the engagement elements are in the torque non-transmitting state in the first engagement mechanism 810 is preferably shorter as in the first engagement control. The value of the reference value Z is a first transmission torque that is a torque transmitted between the engagement elements in the first engagement mechanism 810 in advance experimentally, empirically, or theoretically in consideration of these points. It is determined that the first torque adjustment control for adjusting Ttr1 toward zero torque and the second relative rotational speed F / B control are finished almost simultaneously.

  Next, the ECU 100 sets a first transmission torque command value Ttr1cm that is a command value of the first transmission torque Ttr1 (step S303), and sets the MG1 torque Tmg1 so that the first transmission torque Ttr1 becomes this command value Ttr1cm. The first torque adjustment control as an example of the “torque adjustment control” according to the present invention to be adjusted is started. The first transmission torque Ttr1 is a torque that acts between the engagement elements in the first engagement mechanism 810, and is a torque that can change the sign of positive or negative depending on which engagement element is supplied with the torque. However, the positive and negative setting criteria may be set in any way.

  Here, the target value Ttr1tg of the first transmission torque Ttr1 in the first torque adjustment control is zero (that is, an example of “less than the reference value” according to the present invention), and the command value Ttr1cm set in step S303 is This is a so-called stepwise target value in the process of bringing the first transmission torque Ttr1 to the target value Ttr1tg.

  When first transmission torque command value Ttr1cm is set, ECU 100 determines whether or not first transmission torque command value Ttr1cm is set to zero, which is a final target value (step S304). If the command value Ttr2cm is not yet the target value (step S304: NO), the process returns to step S303. Here, although the determination is based on the torque command value, the reaction force torque borne by the brake side engagement element 812 is calculated, the actual first transmission torque Ttr1 is calculated as the difference from the MG1 torque Tmg1, and the determination criterion It may be used as a value.

  On the other hand, when the first transmission torque command value Ttr1cm is zero (step S303: YES), the ECU 100 has the second relative rotational speed Nr2 less than the reference value Y (Y <Z) similar to the first engagement control. Whether or not (step S305). Instead of providing the reference value Y, it may be determined whether or not the second relative rotational speed Nr2 is the target value Nr2tg (that is, zero), but is completely zero due to the nature of the F / B control. Since it may be difficult to maintain the rotation state, the reference value Y is set to a zero equivalent value having a fine width that is adapted in advance. If the second relative rotational speed Nr2 is still greater than or equal to the reference value Y (step S305: NO), the process returns to step S303.

  When the second relative rotational speed Nr2 is already less than the reference value Y or falls to less than the reference value Y at the end of the corresponding standby time (step S305: YES), the ECU 100 operates the actuator 833 and the rod 832 And the fork 831 is stroked to engage the second sleeve 823 of the second engagement mechanism 820 with the MG2 side engagement element 821 and simultaneously engage the first sleeve 813 of the first engagement mechanism 810 with the brake side. Disconnect from element 812. That is, the operation state of the engagement device 800 is switched from the first operation state to the second operation state (step S306). When the operating state is switched, the second engagement control ends.

  Next, the effect of the second engagement control will be described visually with reference to FIG. FIG. 8 is a timing chart illustrating one operating characteristic of the hybrid drive device when the second engagement control is executed. In the figure, the same parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 8, time transitions of the second relative rotational speed Nr2, the second relative rotational speed F / B control torque Tfb2, the first transmission torque Ttr1, and the first relative rotational speed Nr1 are illustrated in order from the top. The second relative rotational speed F / B control torque Ttb2 is a second for converging the rotational speed of the MG2 side engagement element 821 in the second engagement mechanism 820 to the rotational speed of the drive shaft side engagement element 822. It means MG2 torque Tmg2 used for relative rotational speed F / B control.

  Assume that the second relative rotational speed F / B control in the second engagement control in response to the MG1 unlock request is started at the time T5 shown in the figure. When the second relative rotation speed F / B control is started, the second relative rotation speed Nr2 starts to decrease toward the target value of zero rotation. In the process in which the second relative rotational speed Nr2 converges toward zero rotation, particularly in the beginning to the initial stage, the inertia torque Tint associated with the rotational change of the motor generator MG2 becomes significantly large. Accordingly, the absolute value of the second relative rotational speed F / B control torque Tfb2 also increases. The inertia torque does not affect the torque of the drive shaft 500 as described above.

  On the other hand, the brake side engagement element 811 of the first engagement mechanism 810 is a zero rotation fixed brake element, and the second relative rotation speed F / B control described above does not affect the torque of the drive shaft 500. . Therefore, in the process in which the second relative rotational speed F / B control is executed in advance, the first transmission torque Ttr1 is maintained at the reaction force equivalent value in the fixed speed change mode.

  When the second relative rotational speed Nr2 becomes less than the reference value Z at time T6 in the process in which the second relative rotational speed F / B control precedes in this way, the first transmission torque Ttr1 is set to the target value (zero). 1 Torque adjustment control is started. When the first torque adjustment control is started, the absolute value of the first transmission torque Ttr1 starts to decrease toward zero torque.

  Here, at time T7, when the first transmission torque Ttr1 decreases to the target value of zero torque and the first relative rotational speed Nr1 decreases below the reference value Y, the engagement device 800 is controlled via the drive control of the actuator 833. The operation state of is switched. When the switching of the operation state is completed at time T8, the MG2 side engagement element 821 is fixed to the drive shaft side engagement element 822, and therefore the second relative rotational speed Nr2 becomes zero. Further, as the operation state of the engagement device 800 is switched, the rotation-synchronization between the brake-side engagement element 812 and the motor generator MG1 is lost, so the first relative rotational speed Nr1 starts to increase at time T7.

  Thus, according to the second engagement control according to the present embodiment, the second relative rotational speed F / B control in the second engagement mechanism 820 is the first when the unlock request for the motor generator MG1 is generated. Prior to the first torque adjustment control in the engagement mechanism 810, the start of the first torque adjustment control is prohibited during a period until the second relative rotational speed Nr2 decreases to a region below the reference value Z. 2 Relative rotational speed F / B control only is executed.

  Here, in particular, the reference value Z is determined in advance so that the first torque adjustment control and the second relative rotational speed F / B control are finished almost simultaneously.

  Accordingly, on the other hand, in the execution process of the first torque adjustment control, the period during which the first transmission torque Ttr1 in the first engagement mechanism 810 is maintained at zero torque is as short as possible, and is required in the fixed speed change mode. The fluctuation of the torque of the drive shaft 500 or the generation of impact noise and physical shock in the first engagement mechanism 810 due to the fluctuation of the first transmission torque Ttr1 when the reaction force torque changes or the like is suppressed. On the other hand, since the first torque adjustment control is prevented from starting even though the first torque adjustment control and the second relative rotational speed F / B control can be overlapped, the engagement device is prevented. It is also possible to prevent the period required for switching the operation state of 800 from becoming unnecessarily long.

That is, according to the second engagement control according to the present embodiment, the time axis between the second relative rotational speed F / B control in the second engagement mechanism 820 and the first torque adjustment control in the first engagement mechanism 810. By optimizing the upper positional relationship, the operation state of the engagement device 800 from the first operation state to the second operation state can be suitably switched.
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. 9, the structure of the hybrid drive device 20 which concerns on 2nd Embodiment of this invention is demonstrated. FIG. 9 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. 9, hybrid drive apparatus 20 does not include MG2 reduction mechanism 400, and MG2 output shaft 700, which is the output rotation shaft of motor generator MG2, in the second operation state in which second engagement mechanism 820 is engaged. However, the power split mechanism 300 is directly connected to the drive shaft 500 connected to the ring gear R1.

  Even in such a configuration, the target value of the MG2 rotational speed Nmg2 during the execution of the second relative rotational speed F / B control in the second engagement control only changes by an amount corresponding to the gear ratio of the MG2 reduction mechanism 400. Thus, the first engagement control and the second engagement control described above can be applied.

  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.

  According to the present invention, a first engagement mechanism that switches between a continuously variable transmission mode and a fixed transmission mode by selectively locking the first motor generator, and a second motor generator from a drive shaft. The present invention can be applied to a hybrid vehicle including a second engagement mechanism to be separated.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 100 ... ECU, 200 ... Engine, 300 ... Power split mechanism, 400 ... MG2 reduction mechanism, 500 ... Drive shaft, 600 ... Reduction mechanism, 700 ... MG2 output shaft, 800 ... 810 ... first engagement mechanism, 811 ... MG1 side engagement element, 812 ... brake side engagement element, 820 ... second engagement mechanism, 821 ... MG2 side engagement mechanism, 822 ... drive shaft side engagement Mechanism, 830 ... engagement control mechanism, 831 ... actuator.

Claims (6)

An internal combustion engine;
A first rotating electrical machine;
A second rotating electrical machine;
A plurality of mutually differential actions including a first rotating element connected to the first rotating electrical machine, a second rotating element connected to the internal combustion engine, and a third rotating element connected to a drive shaft connected to the axle. A power transmission mechanism with a rotating element;
It is configured to be able to engage with each other in a rotationally synchronized state where the relative rotational speed is less than a reference value and to be able to disengage between each other in a torque non-transmitted state where the absolute value of the transmission torque between them is less than the reference value. A first engagement mechanism that includes a plurality of engagement elements, and that locks the first rotating electrical machine at a predetermined rotation speed in an engagement state in which the plurality of engagement elements are engaged with each other; and the rotation synchronization A plurality of engagement elements configured to be able to engage with each other in a state and to be disengaged from each other in the torque non-transmission state, and in the engagement state, the second rotating electrical machine and the drive shaft A second engagement mechanism for separating the second rotating electrical machine from the drive shaft in a disengaged state in which the torque is transmitted between the engagement elements and the engagement between the plurality of engagement elements is released. First engagement mechanism and second engagement mechanism Are simultaneously operated, the first operating state in which the first engaging mechanism is in the engaged state and the second engaging mechanism is in the disengaged state, and the first engaging mechanism is in the disengaged state And a control device for a hybrid vehicle that controls a hybrid vehicle including an engagement device capable of selectively switching an operation state between a second operation state in which the second engagement mechanism is in the engagement state. There,
When there is a request for switching the operation state from the second operation state to the first operation state, the plurality of engagement elements in the first engagement mechanism are rotated and synchronized with the first rotating electrical machine. Rotation synchronization control execution means for executing rotation synchronization control for setting a state;
Torque adjustment control for executing torque adjustment control for setting the plurality of engagement elements in the second engagement mechanism to the torque non-transmitting state with respect to the second rotating electrical machine after the rotation synchronization control is started. Execution means;
The permission condition is that the plurality of engagement elements in the first engagement mechanism shift to the rotation synchronization state and the plurality of engagement elements in the second engagement mechanism shift to the torque non-transmission state. Engagement control for controlling the engagement device so that the operation state is switched from the second operation state to the first operation state by simultaneously operating the first engagement mechanism and the second engagement mechanism. Means ,
In the period from the start of the rotation synchronization control to the start of the torque adjustment control, the second rotating electrical machine is configured so that the torque fluctuation of the drive shaft due to the inertia torque of the first rotating electrical machine is reduced. Drive shaft torque control means for controlling
First specifying means for specifying a rate of change in relative rotational speed of the plurality of engagement elements in the first engagement mechanism corresponding to the size of the inertia torque ;
The torque adjustment control execution means starts the torque adjustment control when the specified rate of change becomes less than a reference value . The engagement control means includes the first and second engagement mechanisms when the request for switching the operation state from the first or second operation state to the second or first operation state occurs. The plurality of engagement elements on one side to be shifted to the engagement state are shifted to the rotation synchronization state and the other is to be shifted to the engagement release state among the first and second engagement mechanisms. 2. The control device for a hybrid vehicle according to claim 1, wherein the engagement device is controlled so that the operation state is switched based on a permission condition that the combined element shifts to the torque non-transmission state. The hybrid vehicle control device according to claim 1 , wherein a target value of an absolute value of the transmission torque in the torque adjustment control is zero. The rotation synchronization control includes feedback control according to a relative rotation speed of the plurality of engagement elements in the first engagement mechanism,
The rotation synchronization control execution means, after the start of the torque adjustment control, the torque required for the feedback control, of claims 1 to 3, the start time corresponding value of the torque adjustment controls and limits the upper limit The control apparatus of the hybrid vehicle as described in any one. The rotation synchronization control executing means is configured to cause the second engagement mechanism to perform the plurality of operations in the second engagement mechanism when a request for switching the operation state from the first operation state to the second operation state occurs. Rotation synchronization control for bringing the engagement element into the rotation synchronization state,
The torque adjustment control execution means sends the plurality of engagement elements in the first engagement mechanism to the torque non-transmitting state with respect to the first rotating electrical machine after rotation synchronization control for the second rotating electrical machine is started. 5. The hybrid vehicle control device according to any one of claims 1 to 4 , wherein torque adjustment control is performed. The first engagement mechanism is a brake mechanism that fixes the first rotating electrical machine to zero rotation in the engaged state;
Further comprising second specifying means for specifying relative rotational speeds of the plurality of rotating elements in the second engagement mechanism;
The torque adjustment control execution means starts the torque adjustment control when the specified relative rotational speed becomes less than a predetermined value that is larger than a reference value that defines the rotation synchronization state. Item 6. The hybrid vehicle control device according to any one of Items 1 to 5 .

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