JP2004150450A - Gear shifting control device for hybrid electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear shifting control device for a hybrid electric vehicle performing the gear shifting capable of reducing the load of a synchronizing mechanism, while shortening a gear shifting time. <P>SOLUTION: This gear shifting control device reduces the transmission torque input to an automatic transmission 4 while keeping the connection of an automatic clutch device 2, when the necessity of gear shifting is determined, to switch the automatic transmission 4 to a neutral state, and then to switch the automatic transmission 4 to a target gear shifting stage after a rotating speed of an engine 1 is changed to a rotating speed zone corresponding to a gear change ratio of the target gear shifting stage. Whereby the gear shifting to the target gear shifting stage is performed while keeping the connection of the automatic clutch device 2, which reduces the load of the synchronizing mechanism while shortening the gear shifting time of the automatic transmission 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shift control device for a hybrid electric vehicle that controls a shift of a power unit configured by connecting an automatic clutch device, a motor device, and an automatic transmission to an engine.
[0002]
[Prior art]
The automatic transmission used for trucks has been changed to a manual transmission (a transmission structure having a constantly meshing gear mechanism that synchronizes with a synchro mechanism) in order to withstand high loads and to reduce costs. There is an example in which an automatic transmission in which an electric or hydraulic actuator for performing the above operation is combined, that is, an automatic manual transmission is used.
[0003]
By the way, in general, a transmission is assembled in a parallel type hybrid electric vehicle, but in order to reduce costs, in order to use existing equipment as much as possible, an engine is combined with an automatic clutch, a motor device, and the above automatic manual transmission. There is an example in which a power unit is adopted and a structure is adopted in which a shift is appropriately performed according to the driving state of the truck.
[0004]
In order to reduce the burden on the synchronization mechanism, such hybrid electric vehicles for trucks use a motor device that assists in traveling during gear shifting performed by an automatic manual transmission, and appropriately adjusts the rotation speed on the input side. That is being done. This is, for example, using an automatic clutch device immediately after the engine, using a power unit configured by providing a motor device and an automatic manual transmission after this automatic clutch device, and using both the clutch device and the motor device at the time of shifting I do. That is, from the state where the engine and the automatic manual transmission are separated by the automatic clutch device, the input side is forcibly changed to the rotation speed corresponding to the gear ratio of the target gear by the output of the motor device, and then the target gear is changed. Is performed, and thereafter, the connection between the engine and the automatic manual transmission is restored by the automatic clutch device. More specifically, for example, when the truck is running only with the power of the engine (the power of the engine is transmitted to the automatic manual transmission through the automatic clutch device), for example, shifting up from 2nd to 3rd speed or downshifting from 3rd to 2nd speed When the instruction is input, the automatic clutch device is initially disconnected by the instruction of the control unit, the torque input to the automatic manual transmission is cut off, the current gear is switched to the neutral position, and then the motor device is automatically operated. After changing the input side of the manual transmission to a rotational speed corresponding to the gear ratio of the target gear, switch to the gear of the upshift or downshift to the target gear, and then switch the automatic clutch device again. Connection (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2002-120602
[Problems to be solved by the invention]
By the way, it is desirable that the shift by the automatic manual transmission be performed in a shortest possible time without a shift shock so as not to cause discomfort.
[0007]
However, according to the above-described shift control, although the load on the synchronization mechanism can be suppressed by the input-side rotation speed control by the motor device, the automatic clutch device can be operated (first disconnection operation, last contact operation). Therefore, the time from the start of the shift to the end of the shift, that is, the shift time tends to be long.
[0008]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a shift control device for a hybrid electric vehicle capable of shifting while reducing the shift time while reducing the load on a synchronization mechanism.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that, when the shift control means determines that a shift is necessary, the transmission torque input to the automatic transmission while maintaining the automatic clutch device in the connected state. , The automatic transmission is switched to neutral, and then the rotation speed of the engine is changed to a rotation speed range according to the gear ratio of the target gear by the motor device, and then the automatic transmission is switched to the target gear. That is, control is performed.
[0010]
As a result, gear shifting performed by the automatic transmission is performed with the automatic clutch device connected. In other words, there is no need to disconnect or connect the automatic clutch device from the start to the end of the shift. Therefore, the time spent for shifting is reduced. Of course, at the time of shifting, the rotational speed on the input side of the automatic transmission is adjusted to a rotational speed range according to the gear ratio of the target shift speed by the motor device, so that the load on the synchronization mechanism is reduced. In addition, since the automatic clutch device is maintained in the connected state until the shift is completed, the synchronization between the engine and the automatic transmission is also improved.
[0011]
In addition to the above object, the invention according to claim 2 is a traveling mode in which the automatic clutch device is disengaged and the motor device is powered when it is determined that the vehicle is in a state of starting from a stop so that smoother starting can be performed. The start is performed by the power of the motor device.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on one embodiment shown in FIGS.
[0013]
FIG. 1 shows a schematic configuration of a shift control device in a hybrid electric vehicle, for example, a parallel hybrid electric vehicle for trucks. In the figure, reference numeral 1 denotes an engine used for running a truck (for driving a vehicle), for example, a diesel engine (hereinafter, simply referred to as an engine), and 2 denotes an automatic clutch device (for example, a dry single-plate clutch 2a is connected and disconnected by an actuator 2b. Configuration) 3 is a motor device, for example, a motor / generator configured by combining a rotor 3a and a stator 3b (having both a motor function for generating driving force and a power generation function for generating electric power), 4 The figure shows an automatic transmission, for example, an automatic manual transmission having a constant mesh gear transmission mechanism 4a.
[0014]
Here, the gear transmission mechanism 4a is an element of a manual transmission mechanism, for example, an input shaft 6, a counter shaft 7, a pair of relay gears 8 for guiding rotation from the input shaft 6 to the counter shaft 7, and an output parallel to the counter shaft 7. A plurality of variable speed gears 10a to 10d that are always meshed at a gear ratio for each speed stage disposed between the output shaft 9 and the counter shaft 7 and the output shaft 9 (note that one side gear, for example, the gear on the output shaft side is free. ), A synchronous mechanism for synchronizing the peripheral speed between the output shaft 9 and the transmission gears 10a to 10d (free gear), for example, synchronous meshing mechanisms 11a and 11b having a synchronous sleeve (not shown). I have. Each of the synchromesh mechanisms 11a and 11b is combined with an actuator 12 for operating each synchro sleeve of the synchromesh mechanisms 11a and 11b, which is an element of automation. That is, the automatic manual transmission has a structure in which the structure of the manual transmission mechanism can be used as it is, and the speed can be shifted by an external signal.
[0015]
The automatic clutch device 2, the motor / generator 3, and the automatic manual transmission 4 are sequentially connected to the output unit 1 a of the engine 1. Thus, the power unit 14 is configured. By the power unit 14, the driving force output from the output unit 1a of the engine 1 is output from the motor unit 3 through the power transmission path via the automatic clutch device 2, the rotor 3a, the input shaft 6, and the gear transmission mechanism 4a. The generated driving force is output from the output shaft 9 of the automatic manual transmission 4 through a power transmission path via the input shaft 6 and the gear transmission mechanism 4a. An output section of the power section 14, that is, the output shaft 9 is connected to a driving wheel (not shown) of the truck via a power transmission member, for example, a propeller shaft or a differential (neither is shown). That is, the vehicle travels with power from the engine 1 and the motor / generator 3 functioning as a motor.
[0016]
A control device is connected to the power unit 14. For example, an engine control unit 16 that controls the operation of the engine 1 is connected to the engine 1, a clutch control unit 17 that controls disconnection and connection is connected to the automatic clutch device 2, and a motor / generator 3 is A motor control unit 18 for controlling the motor operation is connected, and a shift control unit 19 for controlling gear switching is connected to the automatic manual transmission 4. Each of the control units 16 to 19 is connected to a vehicle control and control unit 20 having a communication function (each of which is configured by, for example, a microcomputer and its peripheral devices; hereinafter, simply referred to as a control unit 20). 16 to 19 are integratedly controlled.
[0017]
A speed change operation device 21 for automatic speed change that enables manual operation is connected to the overall unit 20. In the device 21, for example, by operating the change lever 21a, an automatic shift position such as R (reverse), N (neutral), D (drive) is selected, or the change lever 21a is shifted up (+) or down (-). ), A structure in which a shift-up operation or a shift-down operation can be performed manually by a shift operation is used. Further, the supervising unit 20 includes a rotation speed sensor 22 for detecting a rotation speed of the output shaft 9 of the automatic manual transmission 4 (an output rotation speed of the transmission), an accelerator opening sensor 24 for detecting an opening of an accelerator pedal 23, A brake sensor 26 for detecting the presence or absence of a brake operation by the brake pedal 25, a vehicle speed sensor (not shown) for detecting a vehicle speed, and the like are connected.
[0018]
The general control unit 20 controls the speed of the automatic manual transmission 4 in accordance with the operating state of the vehicle, in addition to the function of controlling the engine 1 in accordance with the operating state of the vehicle (detected by the accelerator opening and the vehicle speed). And a function of controlling the shift of the automatic manual transmission 4 by the shift operation of the shift operation device 21. For the shift control of the automatic manual transmission 4, a control for shifting while the automatic clutch device 2 is connected is used. This control is constituted by the following functions.
[0019]
From the shift map (for example, a map using the accelerator opening and the vehicle speed as a parameter) set in the general control unit 20 or the position of the change lever 21a indicating the driving state of the vehicle, the vehicle is running (only the engine 1 is running). ), Or a combination of the engine 1 and a motor / generator, and the like, and determines whether a shift is necessary.
[0020]
A function of maintaining the automatic clutch device 2 in a connected state when shifting is required.
[0021]
A function of reducing the transmission torque input to the automatic manual transmission 4 while maintaining the connection state, specifically, when the vehicle is running only with the power of the engine 1, for example, the instantaneous current fuel injection When the vehicle is running with the power of the engine 1 and the motor / generator 3, the current fuel injection amount is momentarily reduced, and the motor energization is reduced, for example.
[0022]
Subsequently, the function of guiding the synchro sleeve of the synchronous meshing mechanism to the neutral position where power is not transmitted by the actuator 12 to release gear meshing at the current gear position (means for switching to neutral).
[0023]
Subsequently, the motor / generator 3 forcibly changes the input side of the automatic manual transmission 4 to a rotational speed corresponding to the gear ratio of the target gear while being connected to the engine 1 (according to the gear ratio). Means for changing the rotation speed).
[0024]
Subsequently, a function of engaging the gear of the target shift speed by the actuator 12 and switching to the gear of the target shift speed (means for switching to the target shift speed).
[0025]
Subsequently, the engine 1 (in the case of engine running), which is a power source of the running, and the engine 1 and the motor / generator 3 (in the case of running using both the engine 1 and the motor) are restored, that is, the operating state of the vehicle again. Function to return to the control according to.
[0026]
In addition, the control unit 20 is set with a mode in which the vehicle is started by motor running. In this mode, when the vehicle changes from a stopped state (brake: on, vehicle speed is zero) to a start state (brake: off, accelerator: on), for example, the automatic manual transmission 4 changes from a state in which the gear is set to a gear suitable for starting. A function of operating the automatic clutch device 2 in a disengaged state and operating the motor / generator 3 (function as a motor) according to the accelerator opening, and then adjusting the number of rotations of the engine 1 and the number of rotations of the motor / generator 3 And a function of connecting the automatic clutch device 2. When the engine 1 has not been started, the engine 1 is started before the automatic clutch device 3 is connected.
[0027]
In addition, a regenerative mode in which the motor / generator 3 functions as a generator when the vehicle is decelerated to recover the deceleration energy is also set in the general unit 20.
[0028]
Next, the operation of the thus-configured shift control device for a hybrid electric vehicle will be described.
[0029]
Now, it is assumed that the vehicle changes from a stop state to a start state. This state is a state in which the vehicle speed at which the vehicle stops is zero and the brake pedal 25 is depressed, and the brake pedal 25 is released and the accelerator pedal 23 is depressed.
[0030]
Then, the clutch device 2 is controlled to be “disengaged” through the clutch control unit 17 according to a command from the supervising unit 20. The automatic manual transmission 4 is set to a gear suitable for starting via the gear change control unit 19. From this state, the motor / generator 3 operates as a motor according to an instruction from the motor control unit 18. Thereby, the power generated from the motor / generator 3 passes through the input shaft 6, the gear transmission mechanism 4a of the automatic manual transmission 4, the propeller shaft (not shown), the differential (not shown), and the driving wheel (not shown). To start the truck. During this time, the engine 1 has been started. Then, during the independent traveling by the motor output, the clutch device 2 is brought into the “contact” state while adjusting the rotation speed of the engine 1 and the rotation speed of the motor / generator 3 according to a command of the general control unit 20. Then, the motive power from the engine 1 is also transmitted, and traveling using the engine 1 and the motor / generator 3 together is performed. Subsequently, the operation of the motor / generator 3 is stopped (output: zero), and only the power output from the engine 1 is transmitted to the input shaft 6 of the automatic manual transmission 4 through the clutch device 2 and traveling by the engine output. Switch to and continue running. Then, at any time, the motor / generator 3 operates in accordance with the driving state of the vehicle to assist the engine 1 and perform traveling using both the engine 1 and the motor / generator 3.
[0031]
During such traveling, a shift command is output according to the shift map (when the change lever 21a is shifted to the D range and the automatic shift is performed), or a shift command (shift up or down) by operating the change lever 21a by lever operation (shift up or down). Is output, the automatic manual transmission 4 shifts to the target shift speed specified by the shift map or the lever operation while the clutch device 2 is kept in the "on" state.
[0032]
FIG. 2 shows a flowchart of this shift control. FIG. 2 shows a shift state when the vehicle is running using both the engine 1 and the motor / generator 3.
[0033]
The shift control will be described with reference to this flowchart. First, the meshing in the synchronous meshing mechanism 11a (or 11b) of the currently engaged gear is released.
[0034]
At this time, the supervising unit 20 first performs control to reduce the motor torque of the engine 1 and the motor / generator 3 as shown in step S1. Specifically, first, a torque instruction range (instruction value) for setting the torque applied to the input shaft 6 to zero is calculated from, for example, the current engine speed and motor speed. Next, the engine control unit 16 and the motor control unit 18 are instructed to reduce the fuel injection amount of the engine 1 and to energize the motor / generator 3 so that the engine torque and the motor torque are adjusted according to the set instruction range. Decrease. That is, the torque transmitted to the input shaft 6 of the automatic manual transmission 4 is reduced to zero (decrease). Subsequently, as shown in step S2, when it is confirmed that the engine torque and the motor torque fall within the specified range, the supervising unit 20 sets the engaged meshing mechanism 11a (or 11b) to a state in which it is likely to be disengaged. When it is determined that the shift has occurred, the shift control unit 19 is instructed to shift to neutral as shown in step S3. Specifically, the actuation of the actuator 12 causes the synchro sleeve to be displaced to the neutral point. When it is confirmed that the shift stroke value has been shifted from the shift stroke value to the neutral point as shown in step S4, it is determined that the currently engaged synchronous meshing mechanism 11a (or 11b) has been released. Thus, the power transmission path of the automatic manual transmission 4 is separated from the upstream side and the downstream side, for example, between the counter shaft 7 and the output shaft 9.
[0035]
Subsequently, the motor control unit 18 is instructed to perform control to change the rotation speed according to the gear ratio of the target gear in order to shift the input side as shown in step S5. Specifically, first, for example, an input-side rotation speed range (instruction value) suitable for the shift is calculated from the gear ratio of the target shift speed based on the rotation speed of the output shaft 9 of the automatic manual transmission 4. This speed range is lower than the current input side speed by the gear ratio of the target gear in the case of upshifting, and higher than the current input side speed by the target gear in the case of downshifting. Is shown. Next, the motor / generator 3 functions as a motor, and rotates the input shaft 6 to the indicated value within the rotation speed range. Thereby, the rotation speed of the input shaft 6 is forcibly changed to a rotation speed suitable for the shift of the target shift speed while being connected to the engine 1.
[0036]
Next, when the motor / generator 3 operates until the motor rotation speed becomes the same as the specified rotation speed range, as shown in step S6, the central unit 20 causes the input side to reach a rotation speed substantially synchronized with the output side. It is determined that the shift has been performed, and as shown in step S7, the shift control unit 19 is instructed to shift to the target shift speed. Then, by the operation of the actuator 12, the synchro sleeve of the synchronous meshing mechanism 11a (or 11b) corresponding to the target shift speed is displaced to the meshing point of the gear to be shifted. Then, when the synchro sleeve is displaced to a predetermined instruction value as shown in step S8, the gear shift of the target gear is completed.
[0037]
Subsequently, the supervising unit 20 instructs the engine control unit 16 and the motor control unit 18 to restore the engine torque and the motor torque according to the driving state of the vehicle as shown in step S8. Then, first, the fuel injection amount and the motor torque value of the engine 1 required for the return are calculated from the rotation speed of the output shaft 9 of the automatic manual transmission 4 and the accelerator opening, for example. Then, as shown in step S10, according to the fuel injection amount and the motor torque value (instruction value), the engine torque and the motor torque are restored, thereby completing the shift control.
[0038]
It should be noted that the shift during traveling only with the engine 1 is different from the case where the vehicle is traveling using both the engine 1 and the motor in combination with the control for reducing only the torque of the engine 1 when the transmission gear is disengaged. The only difference is that when the gear is returned to the target gear, the control to restore only the torque of the engine 1 is performed. The motor output is used to forcibly synchronize the input-side rotational speed with the output-side rotational speed. The point to try is the same.
[0039]
Thus, the shift performed by the automatic manual transmission 4 is performed from the start to the end of the shift while the automatic clutch device 2 is kept in the “connected” state.
[0040]
Therefore, the gear shifting performed by the automatic manual transmission 4 does not require the operation of disconnecting or connecting the automatic clutch device 2, and the gear shifting time can be shortened accordingly. In addition, at the time of shifting, the rotational speed on the input side of the automatic manual shift 4 is adjusted to the rotational speed according to the gear ratio of the target shift speed by the motor output, so that the synchronizing mechanisms 11a and 11b are constituted. The load on the mechanism can be reduced, and both the reduction of the shift time in the hybrid vehicle and the reduction of the load on the synchronization mechanism can be achieved. Moreover, since the automatic clutch device 2 is maintained in the connected state until the shift is completed, the synchronization between the engine 1 and the automatic manual transmission 4 is also satisfactorily performed, and the shift is smooth until the end.
[0041]
In addition, since the start is performed only by the motor output with the automatic clutch device 2 being "disengaged", a smooth start can be obtained. In particular, if the clutch device 2 is brought into "contact" after the engine speed and the motor speed are matched after the motor starts, favorable acceleration can be obtained. The power unit 14 has a configuration in which the motor torque is not directly transmitted to the drive wheels, but is transmitted to the drive wheels through the automatic manual transmission 4. Small equipment that does not require large torque can be used, and it is excellent in cost.
[0042]
The present invention is not limited to the above-described embodiment, and may be implemented with various modifications without departing from the gist of the present invention. For example, in one embodiment, a control system in which an individual control unit and a supervising unit are connected by a communication function and a control signal is exchanged with each other has been described. However, the present invention is not limited to this. It may be a system.
[0043]
【The invention's effect】
As described above, according to the first aspect of the present invention, while the automatic clutch device is in the connected state, the rotational speed on the input side of the automatic transmission is adjusted to the rotational speed range according to the gear ratio by the motor output. Since the shift at the target shift speed is performed, the shift can be performed while reducing the load on the synchronization mechanism while shortening the shift time of the automatic transmission. In addition, since the automatic clutch device is maintained in the connected state until the shift is completed, good synchronization can be achieved between the engine and the automatic transmission.
[0044]
According to the second aspect of the present invention, in addition to the above-described effects, the starting is performed by the power of the motor device, so that there is an effect that the vehicle can be started smoothly.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a shift control device for a hybrid electric vehicle according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating shift control in the shift control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Automatic clutch device 3 ... Motor / generator (motor device)
4: Automatic manual transmission (automatic transmission)
14. Power units 16 to 20: Engine control unit, clutch control unit, motor control unit, shift control unit, vehicle control overall unit (shift control means).

Claims (2)

An engine for driving a vehicle, an automatic clutch device for connecting / disconnecting power transmission, a motor device, a power unit configured by sequentially connecting an automatic transmission, and the automatic clutch device and the automatic clutch device according to the driving state of the electric vehicle. A shift control device for a hybrid electric vehicle having shift control means for controlling an automatic transmission,
The shift control means,
Driving state determining means for determining a driving state of the vehicle;
When the operating state determining means determines that a shift is necessary, the transmission torque input to the automatic transmission is reduced while maintaining the automatic clutch device in the connected state, and the automatic transmission is neutralized to the automatic transmission. Means for instructing switching,
Means for changing the number of revolutions of the engine to a number of revolutions corresponding to a gear ratio of a target gear by the motor device after the neutral switching;
Means for instructing the automatic transmission to switch to the target gear after the engine speed is changed. The shift control device for a hybrid electric vehicle according to claim 1,
The hybrid electric machine further includes means for executing a running mode in which the automatic clutch device is disengaged and the motor device is used as a power when the operating state determining means determines that the vehicle is in a state of starting from a stop. Shift control device for automobile.

Images