JP2011105024A - Shift control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shift control device for a hybrid vehicle, which enables the driving timing of an electric motor to be quickened and enables failure on rotation matching control to be avoided in shift during traveling using the electric motor. <P>SOLUTION: When a shift request is detected, a main clutch 4 and a sub-clutch 22 are disconnected, then shift to a desired shift position is performed by a shift control means 40d, and the rotational speed of an internal combustion engine is synchronized with the rotational speed of the input shaft of a transmission, and the rotational speed of the electric motor is synchronized with the rotational speed of the driven shaft of the transmission by a synchronization control means 40f, then control is performed so that the simultaneous connection of the main clutch and the sub-clutch is commanded. Also, when the connection of the main clutch 4 is established in a shift completion period, the output torque of the internal combustion engine 2 is restored to torque which is based on request torque, and at this time, when the connection of the sub-clutch 22 is not established, correction control corresponding to torque change or vehicle speed change is added to control to synchronize the rotational speed of the electric motor 30 with the rotational speed of the driven shaft of the transmission 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shift control device for a hybrid vehicle, and more particularly to a shift control device for a hybrid vehicle including a PTO device capable of transmitting power extracted from a transmission to a work device.

  For hybrid vehicles that have an internal combustion engine and a traveling motor mounted on the vehicle, the engine drives the generator, the series hybrid vehicle that drives the motor (electric motor) with the generated power, and the motor drives the wheels at the same time as the engine. A parallel hybrid vehicle that can drive wheels, and a dual that can drive wheels with an engine at the same time that the engine drives a generator and the motor can be driven by the generated power. There are hybrid vehicles.

  In such a series hybrid vehicle and parallel hybrid vehicle, the drive pattern according to the driving mode of the vehicle can be selected to improve the energy use efficiency, but the mechanism to be mounted on the vehicle becomes complicated and dedicated. The parts are used. As a result, the vehicle becomes expensive and it becomes very difficult to install dedicated equipment and parts on the existing vehicle. Dissemination is not promoted.

  On the other hand, some vehicle transmissions are provided with a power take-off shaft (PTO shaft, PTO; Power Take Off) via a clutch (PTO clutch). In such a vehicle, a technique for providing a hybrid vehicle that can be easily modified by attaching electrical equipment such as a generator motor (motor generator) from an existing vehicle using this power take-out shaft is proposed. (See Patent Document 1).

  In this technology, a power take-out shaft is connected to the transmission counter shaft so that power can be transmitted. In parallel with this power take-out shaft, a power transmission shaft other than the power take-out shaft is connected to the counter shaft so that power can be transmitted. A generator motor is connected to the power transmission shaft. As a result, the power of the internal combustion engine or the power received from the drive wheels during braking is transmitted from the transmission to the generator motor via the power transmission shaft, the generator motor is driven as a generator, and this generated power is mounted on the vehicle. Can be charged. Conversely, the generator motor can be operated as an electric motor, and the power generated thereby can be transmitted from the transmission to the drive wheel via the power transmission shaft, and the drive wheel can be driven in cooperation with the power of the internal combustion engine.

JP 2000-289476 A

However, as in Patent Document 1, in a hybrid vehicle (a hybrid vehicle using PTO) in which a power transmission shaft is connected in parallel with a power take-off shaft installed in a transmission and connected to an electric motor (PTO-use hybrid vehicle), when traveling using the electric motor If there is a transmission shift request, the drive timing of the motor may be delayed.
In other words, in a hybrid vehicle using PTO, if there is a shift request during traveling using an electric motor, for example, as shown in FIG. The transmission of power to the shaft is cut off (step A20), and then normal shift control, that is, disengagement of the main clutch, disengagement of the gear pair used (gear release), and shift of the shift destination Engagement (gearing) after the synchronization operation for adjusting the rotation of the stepped gear pair and the engagement of the main clutch are sequentially performed (step A30). Then, the PTO clutch is engaged while adjusting the rotation speed of the electric motor (step A40), and torque sharing control between the engine (internal combustion engine) and the electric motor is performed (step A50).

  In this way, before and after the normal speed change operation, the PTO clutch is disengaged and engaged, and after these are completed, the motor is driven to return the torque of the motor. It takes a long time to restart, and while the motor torque is lost during this period, the engine's torque is covered only by the engine, which increases the burden on the engine and is disadvantageous in terms of fuel consumption and exhaust gas. Become.

However, when a clutch for connecting an electric motor such as a PTO clutch to the transmission is added to the clutch between the engine and the transmission, the rotation adjustment control for the clutch connection control and the torque control after the connection are performed simultaneously. Therefore, there is a possibility that the rotation adjustment control may cause a problem. Therefore, it is required to prevent such a problem when performing the shift control.
For example, it is determined that the clutch connection between the engine and the transmission is achieved before the PTO clutch, and the engine torque return control is started first, while the rotational speed adjustment for the PTO clutch is performed. During the rotation speed adjustment, a change in the vehicle speed occurs due to the return of the engine torque. Therefore, the rotation speed adjustment cannot be achieved easily, and the torque control of the electric motor cannot be started easily.

  The present invention was devised in view of such a problem, and in a hybrid vehicle in which a power take-off shaft equipped with a transmission and an electric motor are connected, the transmission of the electric motor is performed at the time of shifting the transmission when traveling using the electric motor. It is an object of the present invention to provide a shift control device for a hybrid vehicle that can advance the drive timing and avoid problems associated with rotational alignment control.

  In order to achieve the above object, a shift control device for a hybrid vehicle is provided with an internal combustion engine, and a shift for a hybrid vehicle provided in parallel with the internal combustion engine and capable of assisting the driving force of the internal combustion engine. A control device comprising: a transmission that outputs driving force from the internal combustion engine or driving force from the internal combustion engine and the electric motor to driving wheels; and an output shaft of the internal combustion engine and an input shaft of the transmission. A main clutch provided between the internal combustion engine and the transmission, and provided between a driven shaft of the transmission and an input shaft of the electric motor; A sub-clutch capable of connecting / disconnecting driving force to / from the machine, clutch control means for controlling connection / disconnection of the main clutch and the sub-clutch, and when the main clutch and the sub-clutch are disengaged, Times Based on the running condition of the vehicle, and synchronous control means for synchronizing the speed with the rotational speed of the input shaft of the transmission and for synchronizing the rotational speed of the electric motor with the rotational speed of the driven shaft of the transmission When the shift request detecting means for detecting the shift request of the transmission and the shift request to the desired shift stage are detected by the shift request detecting means, the clutch control means disconnects the main clutch and the sub-clutch. The shift control means shifts to the desired shift stage, and the synchronization control means synchronizes the rotation speed of the internal combustion engine with the rotation speed of the input shaft of the transmission and the rotation speed of the electric motor. Is synchronized with the rotational speed of the driven shaft of the transmission, and the clutch control means causes the main clutch and the sub-clutch to be synchronized with each other. Shift control means to be connected when the condition is established, demand torque calculation means for calculating demand torque based on the accelerator opening of the vehicle, and when the main clutch and the sub clutch are in a disconnected state, the internal combustion engine and the electric motor Output torque control means for controlling the output torque of the internal combustion engine and the electric motor based on the required torque calculated by the required torque calculating means when the synchronous control by the synchronous control means is completed while controlling each output torque to zero And when the connection of the sub-clutch is not achieved, the synchronization control means changes the rotation speed of the motor to the target rotation speed according to a correction amount according to a change in the torque of the vehicle or a change in the vehicle speed. It is characterized in that control is performed so that the correction target rotational speed is added with the correction amount.

  The sub-clutch is preferably a PTO clutch that connects and disconnects the driving force transmission between the PTO device that extracts the driving force of the internal combustion engine from the driven shaft of the transmission and the transmission.

  According to the shift control device for a hybrid vehicle of the present invention, when there is a shift request, the clutch control means disconnects the main clutch and the sub-clutch, and then shifts to a desired gear stage and the synchronization control means performs internal combustion. When synchronous control is performed to synchronize the rotational speed of the engine with the rotational speed of the input shaft of the transmission and the rotational speed of the electric motor to the rotational speed of the driven shaft of the transmission, and when the synchronization conditions are established for the main clutch and the sub-clutch, respectively. Since it is connected, the shift operation time can be shortened.

Therefore, in shifting when traveling using the torque of the motor, the motor torque once removed at the time of shifting operation can be quickly restored by the quick connection of the sub clutch, and the torque of the internal combustion engine at the time of shifting The burden can be reduced, which is advantageous in terms of fuel consumption and exhaust gas.
Further, when the vehicle is decelerating, it is possible to immediately return to the regenerative braking by the electric motor by the quick connection of the sub-clutch, which contributes to the improvement of the fuel consumption due to the increase in the regeneration amount.

In addition, the PTO clutch is connected to the PTO device, and the PTO clutch capable of connecting and disconnecting the driving force between the PTO device and the transmission is used as the sub-clutch. The hybrid vehicle can be configured at a low cost by adding.
In addition, the main clutch is connected before the sub-clutch, and engine torque recovery control is started, and the rotation speed of the motor is synchronized with the rotation speed of the driven shaft of the transmission in order to synchronize the sub-clutch. When control is performed, correction control according to torque change or vehicle speed change is added to the synchronous control of the rotational speed of the electric motor. Therefore, this correction becomes so-called predictive control, and even if the vehicle speed changes, the sub-clutch Can be quickly achieved, and the motor torque control can be started immediately.

1 is a schematic plan view showing an overall configuration of a drive system of a hybrid vehicle according to an embodiment of the present invention. 1 is a schematic diagram showing a main configuration of a drive system of a hybrid vehicle according to an embodiment of the present invention. It is a flowchart explaining the shift control of the hybrid vehicle which concerns on one Embodiment of this invention. It is a flowchart explaining the shift control of the hybrid vehicle which concerns on one Embodiment of this invention. It is a time chart explaining the shift control of the hybrid vehicle which concerns on one Embodiment of this invention. It is a graph explaining the prediction control used for the shift control of the hybrid vehicle which concerns on one Embodiment of this invention. It is a flowchart explaining the shift control of the hybrid vehicle which concerns on the subject of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of Drive System of this Embodiment>
First, a drive system for a hybrid vehicle common to the present embodiment will be described.
FIG. 1 is a schematic plan view showing an overall configuration of a drive system of a hybrid vehicle 1 according to the present embodiment. As shown in FIG. 1, an input shaft of a clutch (main clutch) 4 is connected to a crankshaft that is an output shaft of a diesel engine (an internal combustion engine, hereinafter referred to as an engine) 2, and an automatic output shaft of the clutch 4 is connected to the crankshaft. An input shaft of a transmission (hereinafter referred to as a transmission) 6 is connected. The output shaft of the transmission 6 is connected to the left and right drive wheels 14 via a propeller shaft 8, a differential 10 and a drive shaft 12. Although not shown, the main clutch 4 has a synchronization mechanism, and even if there is a rotational speed difference between the clutch engagement elements, the main clutch 4 is engaged when the rotational speed difference falls within a predetermined allowable value. Is possible.

FIG. 2 is a schematic configuration diagram of such a PTO device 20 and the transmission 6. As shown in FIG. 2, the transmission 6 includes an input shaft 62 coupled to the output side rotation shaft of the clutch 4, a counter shaft ( (Driven shaft) 64 and an output shaft 66 connected to the propeller shaft 8.
A pair of input gears 68 for transmitting rotation from the input shaft 62 to the counter shaft 64 are provided between the input shaft 62 and the counter shaft 64, and a gear position is provided between the counter shaft 64 and the output shaft 66. A plurality of pairs of transmission gears 70a, 70b, 70c, and 70d that are always meshed at each gear ratio are provided. Regarding the transmission gears 70 a and 70 b, the gears on the output shaft 66 side can rotate relative to the output shaft 66, and the gears on the counter shaft 64 side are fixed to the counter shaft 64, respectively.

On the other hand, for the transmission gears 70c and 70d, the gear on the counter shaft 64 side can rotate relative to the counter shaft 64, and the gear on the output shaft 66 side is fixed to the output shaft 66, respectively. The transmission gear 70a corresponds to the first speed, the transmission gear 70b corresponds to the second speed, the transmission gear 70c corresponds to the third speed, and the transmission gear 70d corresponds to the fourth speed.
On the output shaft 66 side, there is provided a synchro mechanism 72a for synchronizing the rotational speed between the output shaft 66 and the speed change gear 70a or the speed change gear 70b, and switching the gear position. Is provided with a synchro mechanism 72b between the transmission gear 70c and the transmission gear 70d for synchronizing the rotational speed between the counter shaft 64 and the transmission gear 70c or the transmission gear 70d to switch the gear position. Yes.

  Since the synchro mechanisms 72a and 72b themselves are well-known configurations, a detailed description thereof is omitted here, but the transmission 6 operates the synchro mechanisms 72a or 72b in response to a control signal from a vehicle ECU 40 described later. And a gear shift actuator 74 for switching the gear position. Further, the transmission 6 is provided with a shift position sensor 76 that detects which gear stage is currently used in the transmission 6 and outputs it to the vehicle ECU 40, including that the transmission 6 is in a neutral state. Yes.

  The PTO device 20 includes an electromagnetic PTO clutch 22 whose connection / disconnection state is controlled by a control signal from the vehicle ECU 40, a PTO input shaft 24 connected to the input side of the PTO clutch 22, and an output side of the PTO clutch 22. And a PTO output shaft 26 that transmits power to the connection target device. Note that the PTO clutch 22 is a dog clutch that does not have a synchro mechanism, and the rotational speed difference between the engagement elements of the clutch is eliminated, that is, the predetermined allowable rotational speed is relatively small (very close to 0). Only when the difference is within the range, the engagement operation can be performed.

A PTO gear 28 is provided between the counter shaft 64 of the transmission 6 and the PTO input shaft 24 so as to be always meshed and take out the power of the transmission 6. The gear of the PTO gear 28 on the counter shaft 64 side is a counter. The gear of the PTO gear 28 fixed to the shaft 64 and fixed to the PTO input shaft 24 is fixed to the PTO input shaft 24.
Further, the PTO device 20 is provided with a PTO rotation sensor 78 that detects the rotation speed of the PTO output shaft 26 that is the output rotation speed of the PTO clutch 22, and the detection signal of the PTO rotation sensor 78 is sent to the vehicle ECU 40. It has become.

  The electric motor (motor generator) 30 of the hybrid vehicle 1 is attached using the PTO device 20. That is, the PTO output shaft 26 of the PTO device 20 is configured as a motor rotation shaft of an electric motor 30 as a connection target device, and is an input shaft that inputs the power of the electric motor 30 to the transmission 6 when viewed from the transmission 6 side. ing. Therefore, by connecting the PTO clutch 22, during power running, the electric motor 30 and the transmission 6 are input, and the power output from the electric motor 30 is transmitted to the drive wheels 14 via the transmission 6 and the driving force of the vehicle. Is done. Further, at the time of braking, the electric motor 30 is switched to a generator, and the electric motor 30 can be driven by the braking energy of the drive wheels 14 to be regenerated into electric power energy.

  Further, when the clutch 4 is connected, the output shaft of the engine 2 can be mechanically connected to the drive wheels 14 via the transmission 6, and when the clutch 4 is disconnected, the output shaft and the engine 2 can be shifted. The connection with the input shaft of the machine 6 is released. The clutch 4 can be controlled in its clutch stroke by a clutch actuator (not shown) mounted inside.

  Therefore, when the clutch 4 is connected and the PTO clutch 22 is connected, both the output shaft of the engine 2 and the rotating shaft of the electric motor 30 can be mechanically connected to the drive wheels 14 via the transmission 6. Further, when the clutch 4 is connected but the PTO clutch 22 is disconnected, only the output shaft of the engine 2 can be mechanically connected to the drive wheels 14 via the transmission 6. When the clutch 4 is disconnected but the PTO clutch 22 is connected, only the rotating shaft of the electric motor 30 can be mechanically connected to the drive wheels 14 via the transmission 6.

  The electric motor 30 is connected to a battery 32 through an inverter 36 and a contactor 38, and operates by converting a direct current and high voltage current stored in the battery 32 into an alternating current by the inverter 36 and supplying it. . Thus, when the PTO clutch 22 is connected, the drive torque of the electric motor 30 is transmitted to the drive wheels 14 after being shifted to an appropriate speed by the transmission 6.

  Moreover, the electric motor 30 is a motor generator, and when the charging rate (hereinafter referred to as SOC) of the battery 30 decreases and the battery 30 needs to be charged, the electric motor 30 operates as a generator. At this time, the electric motor 30 is driven by the power from the engine 2 or the power of the driving wheels during braking. The electric power generated by the electric motor 30 is converted from AC power to DC power by the inverter 36 and stored in the battery 32.

  When power is generated by the electric motor 30 using power from the engine 2, the clutch 4 and the PTO clutch 22 are connected. Thus, a part of the driving torque of the engine 2 is transmitted to the driving wheel 14 after being shifted to an appropriate speed via the transmission 6, and the remaining driving torque of the engine 2 is transmitted via the transmission 6. The electric motor 30 that is transmitted to the electric motor 30 and operates as a generator is driven.

  When power is generated by the kinetic energy generated by the rotation of the driving wheel 14 during braking, the kinetic energy generated by the rotation of the driving wheel 14 is transmitted via the transmission 6 by connecting the PTO clutch 22 and disconnecting the clutch 4 during braking. Regenerative braking torque is generated by transmitting to the electric motor 30 and converting (generating) AC power. Thereby, the kinetic energy by rotation of the drive wheel 14 is collect | recovered efficiently as electrical energy.

  And in order to control the drive system of this vehicle, in addition to the vehicle ECU (control means) 40 for controlling the entire drive system of the vehicle, the engine ECU 42 for controlling the engine 2 and the battery 32 are controlled. A battery ECU 44 for controlling the inverter 36 and an inverter ECU 46 for controlling the inverter 36 are provided. Any ECU 40 to 46, an input / output device (not shown), a storage device (ROM, RAM, etc.) used for storing a control program, a control map, etc., a central processing unit (CPU), a timer counter, etc. .

  Further, in addition to the shift position sensor 76 and the PTO rotation sensor 78, a vehicle speed sensor 80 and an accelerator opening sensor 84 for detecting the depression amount of the accelerator pedal 82 are provided, and any of the sensors 76, 78, 80, 84 is a vehicle. It is connected to ECU40. Further, since the rotation shaft 30a of the electric motor 30 rotates at a speed ratio corresponding to the gear ratio between the PTO output shaft 24 and the gear pair 28, the PTO rotation sensor 78 also functions as an electric motor rotation speed sensor (motor rotation speed detection means). .

  The vehicle ECU 40 includes information on the driving state of the vehicle such as the traveling speed of the vehicle detected by the vehicle speed sensor 80, the driving state of the engine 2, the rotational speed of the electric motor 30 detected by the electric motor speed sensor 78, and the battery ECU 44. In accordance with the information from the inverter ECU 46, etc., the connection / disconnection control of the clutch 4 and the shift stage switching control of the transmission 6 are performed, and these control states and vehicle driving, acceleration, deceleration, etc. Thus, integrated control for appropriately operating the engine 2 and the electric motor 30 is performed.

  The engine ECU 42 performs control for starting / stopping the engine 2 based on information from the vehicle ECU 40, and also operates the engine 2 itself such as idle operation control of the engine 2 and regeneration control of an exhaust gas purification device (not shown). The engine 2 controls the fuel injection amount and the injection timing so that the engine 2 generates the torque required for the engine 2 set by the vehicle ECU 40.

On the other hand, the inverter ECU 46 monitors the state of the electric motor 30 and the inverter 36 and sends the information to the vehicle ECU 40, and controls the inverter 36 based on the torque generated by the electric motor 30 set by the vehicle ECU 40. Thus, the operation of the electric motor 30 is controlled by operating the motor or the generator.
Further, the battery ECU 44 detects the temperature of the battery 32, the voltage of the battery 32, the current flowing between the inverter 36 and the battery 32, and the SOC of the battery 32 is obtained from these detection results, and the obtained SOC is detected. The result is sent to the vehicle ECU 40.

The vehicle ECU 40 instructs the engine ECU 42 and the inverter ECU 46 to appropriately control the engine 2 and the electric motor 30 while exchanging information with the engine ECU 42, the inverter ECU 46, and the battery ECU 44. The PTO clutch 22 and the transmission 30 are appropriately controlled.
That is, for such control, the vehicle ECU 40 calculates the required torque required for traveling of the vehicle based on the detection results of the accelerator opening sensor 84, the vehicle speed sensor 80, and the motor rotation speed sensor 78. Based on information from the calculation unit (required torque calculation means) 40a and each of the ECUs 42, 44, and 46, this required torque is determined according to the operation state of the vehicle and the operation state of the engine 2 and the motor 30 at that time. Based on the torque distribution unit (torque distribution means) 40b that sets the torque to be distributed to the electric motor 30 and instructs the engine ECU 42 and the inverter ECU 46, the running state (driving state) of the vehicle, and the gear position information from the shift position sensor 76. A shift request detecting unit (shift request detecting means) 40c for detecting a shift request of the transmission 6 and a change of the shift request detecting unit 40c. A transmission control unit (transmission control unit) 40d that controls the transmission 6 as required, a clutch control unit (clutch control unit) 40e that controls connection / disconnection of the main clutch 4 and the PTO clutch 22, and the main clutch 4 or PTO When the clutch 22 is switched from the disconnected state to the connected state, a synchronous control unit (synchronous control means) 40f that controls rotation speed matching (that is, synchronization) on the input / output sides of the clutches 4, 22 and torque of the torque distribution unit 40b An output torque control unit (output torque control means) 40g for controlling the output torque of the engine 2 and the electric motor 30 according to the distribution is provided as a functional element.

The shift control device for a hybrid vehicle according to each embodiment includes a transmission 6, a main clutch 4, a PTO clutch (sub clutch) 22, a clutch control unit 40e, a synchronization control unit 40f, and a shift request detection unit 40c. The shift control means 40d and the output torque control unit 40g are provided.
The functional elements 40a to 40f of the vehicle ECU 40 including the elements of such a shift control device operate in cooperation with each other.

  In this embodiment, for example, when the SOC of the battery 32 is sufficient (SOC is within a preset range) and the required torque of the vehicle can be covered by the output torque of only the electric motor 30, the torque distribution unit 40b The torque is distributed only to the electric motor 30 and is set so as not to distribute the torque to the engine 2. In this case, the clutch control unit 40e disconnects the clutch 4 and connects the PTO clutch 22, and the torque distribution unit 40b instructs the inverter ECU 46 to set the output torque of the electric motor 30 as the required torque. In this case, the engine ECU 42 idles the engine 2, while the inverter ECU 46 controls the inverter 36 according to the torque instructed by the vehicle ECU 40, and the DC power of the battery 32 is converted into AC power by the inverter 36. The electric motor 30 is supplied. When the AC power is supplied to the electric motor 30, the motor operates to output a required torque, and this required torque is transmitted to the drive wheels 14 via the transmission 6.

  The torque distribution unit 40b distributes the torque to both the engine 2 and the electric motor 30 when the SOC of the battery 32 is sufficient but the required torque of the vehicle cannot be covered by the output torque of only the electric motor 30. Set torque distribution to. In this case, the clutch control unit 40e connects the clutch 4 and the PTO clutch 22 together, and the torque distribution unit 40b instructs the output torque distributed to the engine 2 to the engine ECU 42 and to the inverter ECU 46. The output torque distributed to the motor 30 is instructed. In this case, for example, the output torque of the electric motor 30 is maximized and the insufficient output torque is shared with the engine 2, or the engine 2 is set to a constant output state that is good in terms of efficiency and exhaust, and the insufficient output The motor 30 is assigned the torque.

  The engine ECU 42 controls the engine 2 so that the engine 2 outputs the torque instructed by the vehicle ECU 40, and the inverter ECU 46 controls the inverter 36 in accordance with the torque instructed by the vehicle ECU 40, thereby generating the output torque of the engine 2. The sum of the torque of the electric motor 30 is the required torque, and this required torque is transmitted to the drive wheels 14 via the transmission 6.

  On the other hand, when SOC of battery 32 is not sufficient (SOC is less than a preset range), torque distribution unit 40b sets torque distribution only to engine 2 and does not distribute torque to motor 30. . In this case, the vehicle ECU 40 sets the clutch 4 in a connected state, instructs the engine ECU 42 to set the output torque of the engine 2 to the required torque, and sets the output torque of the electric motor 30 to zero to the inverter ECU 46. Instruct.

The engine ECU 42 controls the engine 2 so that the engine 2 outputs the required torque instructed by the vehicle ECU 40, and the inverter ECU 46 controls the inverter 36 so that the electric motor 30 does not operate as either a motor or a generator. The required torque output from the engine 2 is transmitted to the drive wheels 14 via the transmission 6.
On the other hand, when paying attention to this shift control device, the shift request detecting unit 40c requests the shift of the transmission 6, that is, the shift to be used, based on the running state (driving state) of the vehicle and the shift stage information from the shift position sensor 76. When the switching request is detected at the stage, the shift control unit 40d performs shift control as shown in FIGS. 3 and 4, for example, in cooperation with the torque distribution unit 40b, the clutch control unit 40e, and the synchronization control unit 40f.

That is, as shown in FIG. 3, first, it is determined whether or not there is a shift request from the detection information of the shift request detection unit 40c based on the running state (driving state) of the vehicle and the shift stage information from the shift position sensor 76 (step B10) When there is a shift request, the shift control shown in FIG. 4 is performed (step B20).
In this shift control, as shown in FIG. 4, first, the torque distribution unit 40b gradually shifts the required torque to the engine 2 and the electric motor 30 to 0 (step S10, lamp control). When the required torque of the engine 2 and the electric motor 30 becomes less than a preset threshold value as a result of the determination in step S20, the clutch control unit 40e controls to disconnect the main clutch 4 and the PTO clutch 22 (step S30).

  When the disconnection of the main clutch 4 and the PTO clutch 22 is completed by the determination in step S40, the shift control unit 40d performs a control for releasing the engagement of the currently used shift gear (gear release) (step S50). When the gear removal is completed, the process proceeds to step S70 based on the determination in step S60 to engage (gear on) the next shift target gear to be used, and the synchronization control unit 40f Synchronization control (engine rotation matching control) and PTO clutch 22 synchronization control (PTO rotation matching control) are performed.

That is, as the synchronization control of the main clutch 4, the rotation speed (rotation speed) of the engine 2 is adjusted so that the rotation speed of the input / output shaft of the main clutch 4 when the target shift speed is achieved, and the synchronization of the PTO clutch 22 is achieved. Then, the rotational speed (the number of revolutions) of the electric motor 30 is adjusted so that the rotational speeds of the input / output shafts of the PTO clutch 22 when the target gear stage is achieved are matched.
When completion of gear engagement is determined based on the shift speed information from the shift position sensor 76, the determination in step S80 proceeds to step S90, where the clutch control unit 40e controls the connection of the main clutch 4 and the connection of the PTO clutch 22. Control. In this connection control, each of the clutches 4 and 22 by the synchronization control unit 40f waits until the rotation alignment is achieved to each target state by the respective rotation alignment control, and when the rotation alignment is achieved to each target state, the connection is established. Start operation. Each rotation matching control is continued until it is determined that the corresponding clutches 4 and 22 are engaged.

Since the main clutch 4 can be started from the half-clutch engagement in which slippage occurs between the engagement elements, the engagement of the main clutch 4 has a rotational speed difference between the engagement elements with respect to the connection command. However, in order for the main clutch 4 to be fully engaged, the engaging element of the main clutch 4 is gradually stroked, so that it takes a certain time from the start of engagement to the complete engagement.
However, even if the main clutch 4 does not reach full engagement, if the stroke amount of the engagement element reaches a preset level, torque transmission is possible even in the half-clutch state. When the stroke amount of the engagement element reaches a preset level, it can be determined that the engagement of the main clutch 4 has been achieved.

  On the other hand, the PTO clutch 22 is a dog clutch, and the connection is achieved almost instantaneously when the connection operation is started. However, in order to start the connection, the rotational speed difference between the engagement elements is zero [here, zero is extremely strict. This is not zero, and a rotational speed difference that does not cause a mechanical collision between the engagement elements even when the engagement of the dog clutch is started is allowed, and within a threshold value d (d≈0) extremely close to 0 It is assumed that the difference in rotational speed is zero when the value of _ is reached], the engagement can be started for the first time. Accordingly, torque transmission is possible only when the PTO clutch 22 is fully engaged, and therefore, when the engagement element of the PTO clutch 22 is completely engaged, it can be determined that the engagement of the PTO clutch 22 has been achieved. it can.

  Then, the process proceeds from step S90 to step S100, whether or not the connection of the main clutch 4 has been achieved, that is, whether or not the stroke amount of the engagement element of the main clutch 4 has reached a preset level as described above. Determine whether or not. This determination is made when the engagement of the main clutch 4 is achieved when the stroke amount of the engaging element of the main clutch 4 reaches a preset level.

  Here, the process waits until it is determined that the main clutch 4 is engaged. If it is determined that the main clutch 4 is connected, it is determined whether the PTO clutch 22 is connected (step S110). The connection of the PTO clutch 22 starts operating only when it is determined that the rotational speed difference between the engagement elements is zero (within a threshold value d (d≈0) very close to 0) by adjusting the rotational speed of the motor. After the operation is started, complete engagement is quickly performed and it is determined that the PTO clutch 22 has been connected.

If the connection of the PTO clutch 22 has been achieved, the output torque control unit 40g controls the engine 2 and the electric motor 30 to return to the required torque state (step S120). Also during this return, each torque is gradually returned from zero toward the required torque.
On the other hand, if the connection of the PTO clutch 22 is not achieved, the output control unit 40g controls the engine 2 to return to the required torque state while continuing the connection control of the PTO clutch 22 by the clutch control unit 40e (step S132). ). Also at the time of this recovery, the torque is gradually recovered from zero toward the required torque.

However, in this apparatus, a device is added to the connection control of the PTO clutch 22 in step S132.
The processing content of step S132 is demonstrated.
If it is determined that the main clutch 4 has been connected prior to the PTO clutch 22 and the engine torque return control is started, the engine torque is applied to the drive wheels 14 and the vehicle speed may change. On the other hand, at the time of this engine torque return control, in parallel with this, connection control of the PTO clutch 22, that is, control for bringing the rotational speed difference between the engagement elements closer to 0 by adjusting the rotation speed of the electric motor 30 is also performed.

  The rotation speed adjustment of the electric motor 30 is performed until the difference in rotation speed between the engagement elements converges within a threshold value d that is very close to 0. If the vehicle speed changes during the rotation speed adjustment, the rotation speed adjustment is performed. Since the control is performed in a follow-up state with respect to a change in the vehicle speed, a situation in which the rotational speed difference between the engaging elements does not converge within the threshold value d is difficult. This makes it difficult to start motor torque control.

Therefore, in this embodiment, the connection control of the PTO clutch 22 in step S132, that is, the target rotational speed (target rotational speed) of the electric motor 30 for adjusting the rotational speed of the electric motor 30, the change in the vehicle speed, and the driving wheel Correction is performed to add a correction amount corresponding to a change in torque (here, engine torque).
That is, with respect to the acceleration of the vehicle (change in vehicle speed), as shown in FIG. 6A, the target rotational speed of the electric motor 30 is increased as the vehicle acceleration increases (according to the increase rate of the vehicle speed). Is added with a positive correction amount, and a negative correction amount is added to the target rotational speed of the electric motor 30 as the vehicle acceleration decreases (in accordance with the reduction rate of the vehicle speed).

Further, as shown in FIG. 6B, the rate of change in the torque of the vehicle increases with respect to the rate of change in the torque of the vehicle (time rate of change in the torque required to drive the vehicle including the engine torque and the motor torque). Accordingly, a positive correction amount is added to the target rotational speed of the electric motor 30, and a negative correction amount is added to the target rotational speed of the electric motor 30 as the vehicle torque change rate decreases.
In the present embodiment, as shown in FIGS. 6A and 6B, the addition correction amount for the vehicle acceleration and the addition correction amount for the vehicle torque change rate are both set to the simplest linear relationship. However, these relationships are not limited to linear.

Further, in the present embodiment, the larger one of the addition correction amount for the vehicle acceleration in FIG. 6A and the addition correction amount for the vehicle torque change rate in FIG. 6B is adopted as the correction amount. I am doing so.
Therefore, in the rotational speed matching control of the electric motor 30 related to the connection control of the PTO clutch 22 in step S132, the additional correction amount with respect to the acceleration of the vehicle and the torque change of the vehicle with respect to the target rotational speed given as the ramp control of the electric motor 30 A larger one of the additional correction amounts with respect to the rate is selected and added to obtain a corrected target rotational speed, and the rotational speed of the electric motor 30 is controlled.

Then, after the connection of the PTO clutch 22 is achieved after step S132, the output torque control unit 40g controls the motor 30 together with the engine 2 to return to the required torque state after the determination of step S140 (step S120).
Thereafter, as shown in FIG. 3, the output torque control unit 40g normally controls the engine 2 and the electric motor 30 in accordance with the required torque (step B30).

  The shift control apparatus for a hybrid vehicle according to an embodiment of the present invention is configured as described above. When there is a shift request, the clutch control unit 40e disconnects the main clutch 4 and the PTO clutch (sub clutch) 22. Then, the gear shift to the desired gear stage is performed, and the rotation speed of the engine 2 is synchronized with the rotation speed of the input shaft of the transmission 6 by the synchronization control unit 40f. Synchronize and synchronize the rotational speed of the electric motor 30 with the rotational speed of the driven shaft of the transmission 6 to synchronize the rotational speed of the engaging elements of the PTO clutch 22, and then connect the main clutch 4 and the PTO clutch 22 simultaneously. Therefore, the shift operation time can be shortened.

  In particular, the main clutch 4 has a synchronization mechanism and can be engaged even when there is a difference in rotational speed between the engagement elements of the clutch, whereas the PTO clutch 22 is a dog clutch that does not have a synchronization mechanism. Since the engagement operation cannot be performed until the difference in rotational speed between the engagement elements of the clutch reaches a slight threshold value d that is very close to 0, normally, as shown in FIG. Is determined, and then the connection of the PTO clutch 22 is determined.

  For example, as shown in FIG. 5, when there is a shift request (change to the target gear stage) at time t1, the ramp control is performed so that each torque of the engine 2 and the electric motor (motor) 30 gradually decreases toward zero. Then, at the time t2 when the torques of the engine 2 and the electric motor (motor) 30 approach zero to a predetermined state, the main clutch 4 and the PTO clutch 22 are requested to be disconnected. Here, the ramp control is performed so that each torque of the engine 2 and the electric motor 30 reaches zero at the same time, and the time when each torque approaches a predetermined state is the remaining time until each torque becomes zero (t ) Is the time when the value falls below a certain threshold.

  When the disengagement request is made to the main clutch 4 and the PTO clutch 22, the PTO clutch 22, which is a simple dog clutch, is disengaged at the time t3 after the response delay time from the time t2, and the main clutch 4 having the synchronization mechanism is disengaged at the time t2. From time t4, the stroke of the main clutch 4 becomes smaller than the threshold value a for releasing the gear, and at this time t4, command to release the gear of the current shift stage is given, and the response delay time from time t4 Only at a later time t5, the current gear is disengaged.

In parallel with this, the torques of the engine 2 and the electric motor 30 that have been subjected to the ramp control eventually reach zero (time t6). In the example shown in the figure, the torque of the electric motor 30 reaches substantially zero after once suddenly overshooting. This is because the motor rotation speed is quickly controlled synchronously with the target motor speed.
The rotational speeds of the engine 2 and the electric motor 30 are changed to target speeds (target engine speed, target motor speed) that match the gear ratio of the gear speed to be shifted at the shift request time t1, but each torque is reduced and controlled. During this time, the rotational speed only changes gently. However, after the gear removal time t5 or after the time t6 when the torque of the engine 2 and the electric motor 30 reaches zero, each rotational speed is higher than before. Get closer to the target speed. In the example shown in the figure, the rotational speed of the electric motor 30 approaches the target speed by repeating a delicate overshoot.

In this example, a connection request is made to the main clutch 4 at time t7 when the rotational speed of the engine 2 reaches within a relatively large tolerance d1 with respect to the target speed and the gear engagement is completed.
The PTO clutch 22 can be connected, but until the rotational speed of the electric motor 30 approaches the target speed and the rotational speed difference between the engaging elements of the PTO clutch 22 converges within a small threshold d, the PTO clutch 22 is reached. Does not initiate a connection.

  When the stroke of the main clutch 4 becomes larger than the threshold value b for returning the engine torque, at this time t8, the return of the engine torque is started. The engine torque is also gradually restored (ramp control). At this time, since only the engine torque is obtained, the return target of the engine torque is set to the required torque of the vehicle so that the required torque is covered only by the engine torque.

  The threshold value b is set smaller than the threshold value a (b <a). That is, the threshold value a is set to the value on the connection side even in the half-clutch state in consideration of the fact that it takes time until the gear is actually released after the gear removal is instructed, and the threshold value b is set so that the clutch is connected by the half-clutch. If the torque has recovered somewhat at the time, the shift shock is less and the torque recovery is slightly faster, so the value is set to the disconnected side even in the half-clutch state.

At the time t9 ′ when the rotational speed of the electric motor 30 approaches the target speed and the rotational speed difference between the engaging elements of the PTO clutch 22 converges within a minute threshold value d, the connection of the PTO clutch 22 is started. The PTO clutch 22 which is a simple dog clutch is connected at a time t9 after a slight response delay time from the time t9 ′.
At this time t9, the motor torque recovery is started. The motor torque is also gradually restored (lamp control). From this time t9, since the motor torque is added to the engine torque, the engine torque is recovered by subtracting the amount corresponding to the return of the motor torque. Then, the engine torque, the motor torque, and the required torque distribution state are controlled so that the total torque of the engine torque and the motor torque approaches the required torque. In this example, since the total torque reaches the target torque at time t10 after time t9, the engine torque decreases to the required distribution torque in accordance with the increase of the motor torque to the required distribution torque after time t10. Thereafter, at the time t11, the engine torque and the motor torque are in a required torque distribution state.

In this way, in the shift when traveling using the torque of the electric motor 30, the quick return of the torque of the electric motor 30 once removed during the shift operation can be quickly performed by the quick connection of the PTO clutch 22. The torque burden on the engine 2 at the time can be reduced, which is advantageous in terms of fuel consumption and exhaust gas.
Further, when the speed change is performed during deceleration, the regenerative braking by the electric motor 30 can be immediately restored by the quick connection of the PTO clutch 22, which contributes to the improvement of fuel consumption due to the increase in the regeneration amount.

Moreover, since the electric motor 30 is connected to the transmission 6 using the existing PTO device, the hybrid vehicle can be configured at a low cost by adding the electric motor 30 and the like to the vehicle having the existing PTO device. .
Further, before the start of shifting, the output torque of the engine 2 and the electric motor 30 is controlled to zero, and after the connection operation of the main clutch 4 and the PTO clutch 22 is started at the same time, the output torque of the engine 2 and the electric motor 30 is changed to the required torque. By returning, rotation alignment (synchronization) of the clutches 4 and 22 can be performed smoothly and quickly, and the vehicle torque can be returned more quickly.

  Further, it is determined that the connection of the main clutch 4 has been achieved before the PTO clutch 22, and the engine torque return control is started. In parallel with this, the connection control of the PTO clutch 22, that is, the rotational speed of the electric motor 30 is started. When the control is performed to bring the difference in rotational speed between the engagement elements close to 0 by matching, the target rotational speed of the electric motor 30 for adjusting the rotational speed of the electric motor 30 is changed to the change in the vehicle speed and the torque to the drive wheels. Since a correction is added to add a correction amount corresponding to the change, this correction is a predictive control, and even if the vehicle speed changes, the rotational speed difference between the engagement elements of the PTO clutch 22 is within the threshold value d. The PTO clutch 22 can be quickly engaged and the motor torque control can be started immediately.

  In the present embodiment, the larger one of the addition correction amount for the acceleration of the vehicle in FIG. 6A and the addition correction amount for the torque change rate of the vehicle in FIG. 6B is adopted as the correction amount. However, since the change in the vehicle speed follows the change in the torque, while the engine torque is returning to the target torque, the engine torque is returned to the target torque by using the additional correction amount with respect to the vehicle torque change rate. After that, an additional correction amount for the acceleration of the vehicle can be used.

Although the embodiments of the present invention have been described above, the present invention can be implemented by modifying such embodiments or adding further configurations without departing from the spirit of the present invention.
For example, in each of the above embodiments, the hybrid vehicle 1 is configured by attaching the electric motor 30 using the PTO device 20, but via a clutch (sub clutch) corresponding to the PTO clutch 22 of the PTO device 20. The present invention can also be applied to a transmission that is retrofitted so that an electric motor can be connected.

  Further, the main clutch may be of any type as long as it has a synchro mechanism and can be slidably engaged, and the auxiliary clutch is not limited to a dog clutch but may be of any type as long as it is simple.

1 Hybrid vehicle 2 Diesel engine (internal combustion engine)
4 Clutch (main clutch)
6 Automatic transmission (transmission)
8 Propeller shaft 10 Differential device 12 Drive shaft 14 Drive wheel 20 PTO device 22 PTO clutch (sub clutch)
24 PTO input shaft 26 PTO output shaft and motor rotation shaft (input shaft to transmission)
28 PTO gear 30 Electric motor (motor generator)
32 Battery 34 DC / DC converter 36 Inverter 38 Contactor 40 Vehicle ECU
40a Required torque calculation unit (Requested torque calculation means)
40b Torque distribution unit (torque distribution means)
40c Shift request detecting unit (shift request detecting means)
40d Shift control unit (shift control means)
40e Clutch control unit (clutch control means)
40f Synchronization control unit (synchronization control means)
42 Engine ECU
44 Battery ECU
46 Inverter ECU
62 Input shaft of transmission 6 64 Counter shaft (driven shaft) of transmission 6
66 Output shaft 70a, 70b, 70c, 70d of transmission 6 Gears 72a, 72b Synchro mechanism 74 Shifting actuator 76 Shifting position sensor 78 PTO rotation sensor 80 Vehicle speed sensor 82 Accelerator pedal 84 Accelerator opening sensor

Claims (2)

A shift control device for a hybrid vehicle, comprising: an internal combustion engine; and an electric motor provided in parallel with the internal combustion engine and capable of assisting the driving force of the internal combustion engine,
A transmission that outputs driving force from the internal combustion engine or driving force from the internal combustion engine and the electric motor to drive wheels; and
A main clutch provided between an output shaft of the internal combustion engine and an input shaft of the transmission, and capable of connecting and disconnecting a driving force between the internal combustion engine and the transmission;
A sub-clutch provided between the driven shaft of the transmission and the input shaft of the electric motor, and capable of connecting and disconnecting the driving force between the electric motor and the transmission;
Clutch control means for controlling connection / disconnection of the main clutch and the sub-clutch;
When the main clutch and the sub-clutch are disengaged, the rotational speed of the internal combustion engine is synchronized with the rotational speed of the input shaft of the transmission, and the rotational speed of the electric motor is synchronized with the rotational speed of the driven shaft of the transmission. Synchronization control means for controlling to synchronize with,
Shift request detecting means for detecting a shift request of the transmission based on a running state of the vehicle;
When the shift request to the desired shift stage is detected by the shift request detecting means, the clutch control means disconnects the main clutch and the sub-clutch, and then the shift control means shifts to the desired shift stage. Synchronous control for shifting and synchronizing the rotational speed of the internal combustion engine with the rotational speed of the input shaft of the transmission and the rotational speed of the motor with the rotational speed of the driven shaft of the transmission. Shift control means for connecting the main clutch and the sub-clutch when the synchronization condition is established by the clutch control means,
Request torque calculating means for calculating the required torque based on the accelerator opening of the vehicle;
When the main clutch and the sub-clutch are disengaged, the output torques of the internal combustion engine and the electric motor are controlled to zero, and when the synchronization control by the synchronization control unit is completed, the request torque calculated by the request torque calculation unit Output torque control means for controlling output torque of the internal combustion engine and the electric motor based on torque, and
When the connection of the sub-clutch is not achieved, the synchronization control means adds a correction amount corresponding to a change in the torque of the vehicle or a correction amount corresponding to a change in the vehicle speed to the target rotation speed of the motor. A shift control apparatus for a hybrid vehicle, characterized in that control is performed to achieve a corrected target rotational speed. The sub-clutch includes a PTO clutch that connects and disconnects the driving force transmitted between the transmission and a PTO device that extracts the driving force of the internal combustion engine from the driven shaft of the transmission. Item 2. A shift control apparatus for a hybrid vehicle according to Item 1.

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