JP5890154B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle equipped with a transmission having a synchro mechanism.

  As a control device for a hybrid vehicle equipped with a transmission having a synchro mechanism, the motor is controlled so that the rotational speed of the input shaft becomes the target rotational speed while operating the transmission neutrally in response to a shift request, When the difference between the rotational speed of the input shaft and the target rotational speed falls within a predetermined range by the control of the electric motor, there is known one that causes the transmission to perform a shift operation for switching from neutral to a desired gear ratio (patent) Reference 1). In addition, Patent Documents 2 and 3 exist as prior art documents related to the present invention.

JP 2003-274510 A JP 2010-12927 A JP 2003-335152 A

  In the control device of Patent Document 1, a speed change operation is started before the rotational speed of the input shaft reaches the target rotational speed on condition that the difference between the rotational speed of the input shaft and the target rotational speed is within a predetermined range. The Therefore, the time required for the shift operation of the transmission is shortened. However, since the torque transmission between the input shaft and the electric motor is maintained when the speed change operation is performed, there is a possibility that the load on the synchro mechanism increases.

  Therefore, an object of the present invention is to provide a control device for a hybrid vehicle that can reduce a load on the synchro mechanism while shortening a shift time of the transmission.

The control device according to the present invention relates to an engine and an electric motor provided as a driving source for traveling , a coupling device that receives a shift operation as gearing to enable any one of a plurality of shift stages, and the coupling device A synchronization mechanism capable of eliminating a rotational speed difference in the course of the speed change operation is provided, and a torque between the motor and the input shaft, and a transmission in which torque of the engine and the motor is input via the input shaft. is applied to a hybrid vehicle having a switching mechanism capable of connecting and disconnecting the transmission, the rotational speed of the input shaft before the start of the transmission operation with respect to the coupling device of the transmission so as to approach the target rotational speed, the electric motor Electric motor control means for controlling the electric motor in a state in which torque can be transmitted to the input shaft via the switching mechanism; and the rotational speed of the input shaft is the target rotational speed. When the electric motor is controlled by the electric motor control means so that the difference between the rotational speed of the input shaft and the target rotational speed is within a predetermined range, the electric motor and the input shaft a switching mechanism control means for torque transmission between controls the switching mechanism so as to be cut off, since the shut off torque transmission between the input shaft and the electric motor by the switching mechanism control means of the transmission Shift control means for controlling the transmission so that the shift operation for the coupling device is started, and when the rotation speed synchronization mode is set when a predetermined condition is satisfied, the switching mechanism control means The rotation speed of the input shaft and the target rotation speed are controlled by the motor control means so that the rotation speed of the input shaft approaches the target rotation speed. Even when the difference is within a predetermined range, the switching mechanism is controlled so that torque transmission between the electric motor and the input shaft is maintained, and the shift control means rotates the input shaft. When the speed reaches the target rotational speed, the transmission is controlled so that the shift operation for the coupling device of the transmission is started (Claim 1).

According to this control device, on the condition that the difference between the rotational speed of the input shaft and the target rotational speed is within a predetermined range, the speed change operation is started before the rotational speed of the input shaft reaches the target rotational speed. Therefore, the shift time is shortened. Moreover, since the speed change operation is started in a state where torque transmission between the electric motor and the input shaft is interrupted, the inertia corresponding to the electric motor is reduced by disconnecting the electric motor from the input shaft. Thereby, the load with respect to the synchro mechanism can be suppressed. Further, when the rotation speed synchronization mode is set when the predetermined condition is satisfied, torque transmission between the electric motor and the input shaft is maintained, and the rotation speed of the input shaft reaches the target rotation speed. Shift operation is started. As a result, the speed change operation is started without operating the synchro mechanism, so that responsiveness can be ensured, the load on the synchro mechanism can be reduced, and the operation frequency of the switching mechanism can be reduced.

In one aspect of the control device of the present invention, as the predetermined condition, a case where a response to the vehicle is required may be set (claim 2). According to this aspect, in a situation where responsiveness is required, the speed change operation is started without operating the synchro mechanism, so that the responsiveness can be ensured and the load on the synchro mechanism can be reduced.

In one aspect of the control apparatus of the present invention, as the predetermined condition, a case in which wear of the switching mechanism should be avoided may be set (Claim 3). According to this aspect, in a situation where wear of the switching mechanism should be avoided, the frequency of operation of the switching mechanism is reduced, so that the progress of wear can be suppressed.

As described above, according to the hybrid vehicle control device of the present invention, the input shaft rotation speed is set to the target rotation on condition that the difference between the input shaft rotation speed and the target rotation speed is within a predetermined range. Since the speed change operation is started before the speed is reached, and the electric motor is disconnected from the input shaft when the speed change operation is started, the speed change time can be shortened and the load on the synchronization mechanism can be suppressed. Further, when the rotation speed synchronization mode is set when the predetermined condition is satisfied, the speed change operation is started without operating the synchro mechanism, so that responsiveness can be ensured and the load on the synchro mechanism can be reduced.

1 is an overall configuration diagram schematically showing a vehicle to which a control device according to an embodiment of the present invention is applied. The flowchart which showed an example of the routine of the transmission mode setting process. The flowchart which showed an example of the control routine of gear shift control. The timing chart which showed an example of the execution result of MG isolation | separation mode. The timing chart which showed an example of the execution result of rotation speed synchronous mode.

  As shown in FIG. 1, the vehicle 1 is configured as a so-called hybrid vehicle in which an internal combustion engine 2 and a motor / generator 3 as an electric motor are provided as a driving power source. An internal combustion engine (hereinafter referred to as an engine) 2 is configured as a spark ignition type internal combustion engine. An output shaft 2 a of the engine 2 is connected to an automated transmission (AMT) 8 as a transmission via a friction clutch 7. The friction clutch 7 is engaged and disengaged in accordance with the speed change operation of the AMT 8.

  The AMT 8 can select one shift speed from a plurality of forward shift speeds. The selection of the gear position by the AMT 8 is automatically performed based on the vehicle speed of the vehicle 1 and the accelerator opening. Further, when the AMT 8 is switched to the manual mode, the gear position is selected by the driver operating a shift knob (not shown).

  The AMT 8 includes an input shaft 10, an output shaft 11 extending parallel to the input shaft 10, and first to fourth gear pairs G 1 to G 4 provided between the input shaft 10 and the output shaft 11. . The first to fourth gear pairs G1 to G4 correspond to the first speed to the fourth speed. The backward running of the vehicle 1 is performed when the motor / generator 3 reversely rotates with the first speed selected. The first gear pair G1 includes a first drive gear 13 and a first driven gear 14 that mesh with each other. The second gear pair G2 includes a second drive gear 15 and a second driven gear 16 that mesh with each other. The third gear pair G3 includes a third drive gear 17 and a third driven gear 18 that mesh with each other. The fourth gear pair G4 includes a fourth drive gear 19 and a fourth driven gear 20 that mesh with each other. The gear ratio of each gear pair G1 to G4 is set so as to decrease in the order of the first gear pair G1, the second gear pair G2, the third gear pair G3, and the fourth gear pair G4.

  The first drive gear 13 and the second drive gear 15 are provided on the input shaft 10 so as to rotate integrally with the input shaft 10. On the other hand, the third drive gear 17 and the fourth drive gear 19 are provided on the input shaft 10 so as to be rotatable relative to the input shaft 10. The first driven gear 14 and the second driven gear 16 are provided on the output shaft 11 so as to be rotatable relative to the output shaft 11. On the other hand, the third driven gear 18 and the fourth driven gear 20 are provided on the output shaft 11 so as to rotate integrally with the output shaft 11.

  The AMT 8 is provided with coupling devices C1 to C4 in order to validate any one of the plurality of shift speeds. Each coupling device C1 to C4 is configured as a well-known meshing clutch and is operated by an operation mechanism (not shown). A synchronizing mechanism Sy that operates to eliminate the difference in rotational speed between the coupling devices C1 to C4 and the input shaft 10 or the output shaft 11 between the coupling devices C1 to C4 and the input shaft 10 or the output shaft 11. Intervenes. Since the synchro mechanism Sy is similar to a well-known one, a detailed description of its structure is omitted.

  The first coupling device C1 operates between an engaged state in which the first driven gear 14 is coupled to the output shaft 11 and the first driven gear 14 and the output shaft 11 are integrally rotated, and a released state in which the coupling is released. it can. Similarly, the second coupling device C2 includes an engagement state in which the second driven gear 16 is coupled to the output shaft 11 and the second driven gear 16 and the output shaft 11 are integrally rotated, and a released state in which the coupling is released. Can work between. Further, the third coupling device C3 is connected between an engagement state in which the third drive gear 17 is coupled to the input shaft 10 and the third drive gear 17 and the input shaft 10 are integrally rotated and a released state in which the coupling is released. It can work with. Similarly, the fourth coupling device C4 includes an engagement state in which the fourth drive gear 19 is coupled to the input shaft 11 to rotate the fourth drive gear 19 and the input shaft 11 together, and a release state in which the coupling is released. Can work between. The AMT 8 can validate any one of the plurality of shift speeds when any one of the coupling devices C1 to C4 is engaged.

  A switching mechanism 21 is provided between the motor / generator 3 and the input shaft 10 of the AMT 8 so that torque transmission between them can be interrupted. The switching mechanism 21 is configured as, for example, a friction clutch, and an engagement state in which torque transmission between the motor / generator 3 and the input shaft 10 is maintained using an actuator (not shown) as a drive source, and torque transmission therebetween is performed. It is possible to switch the release state to be blocked.

  An output gear 22 is provided on the output shaft 11 so as to rotate integrally. The output gear 22 meshes with a ring gear 26 provided in a case of a differential mechanism 25 connected to a drive wheel (not shown). Torque output from the AMT 8 is transmitted to the left and right drive wheels via the ring gear 26 and the differential mechanism 25.

  Control of the engine 2, the motor / generator 3, the friction clutch 7, the AMT 8, and the switching mechanism 21 is performed by an electronic control unit (ECU) 40 configured as a computer unit. The ECU 40 holds various control programs for obtaining an appropriate traveling state of the vehicle 1. The ECU 40 executes control of the control object such as the engine 2 described above by executing these programs. Various sensors that output information related to the running state of the vehicle 1 are connected to the ECU 40. For example, an input side resolver 41 that outputs a signal according to the rotational speed of the input shaft 10, an output side resolver 42 that outputs a signal according to the rotational speed of the output shaft 11, and a signal according to the crank angle of the engine 2 are output. A crank angle sensor 43 and an accelerator opening sensor 44 that outputs a signal corresponding to the accelerator opening are electrically connected to the ECU 40.

  The ECU 40 performs various controls such as a hybrid travel mode in which the engine 2 and the motor / generator 3 are travel power sources, and an electric travel mode in which only the motor / generator 3 is traveled while the engine 2 is stopped. There is a travel mode switching control for switching the travel mode. Along with the travel mode switching control, stop control and start control of the engine 2 are performed. Further, regenerative control is performed in which the motor / generator 3 generates power using the power input from the drive wheels when the vehicle 1 is decelerated. Hereinafter, control related to the present invention among the control executed by the ECU 40 will be described, and description of other control will be omitted or simplified.

  The present embodiment is characterized in the shift control for the AMT 8 that switches the shift mode according to the traveling state of the vehicle 1. The routine of FIG. 2 sets the transmission mode to either the rotation speed synchronization mode in which the synchro mechanism Sy is not operated or the MG disconnection mode in which the motor / generator 3 is disconnected while operating the synchro mechanism Sy. A program of this routine is stored in the ECU 40, and is read out in a timely manner while the vehicle 1 is traveling, and is repeatedly executed at predetermined calculation intervals.

  In step S1, it is determined whether or not wear of the switching mechanism 21 should be avoided. If the situation should avoid the wear, the process proceeds to step S5, and if not, the process proceeds to step S2. The situation where wear should be avoided corresponds to the case where the switching mechanism 21 approaches the limit of wear. The ECU 40 holds a program for performing an estimation process for estimating the wear state by integrating the operation time of the switching mechanism 21 and its load, and the switching mechanism 21 approaches the limit of wear based on the execution result of the program. It is determined whether or not.

  In step S2, it is determined whether a sports mode switch or a manual mode switch (not shown) is turned on. These switches are operated by the driver of the vehicle 1. When the sport mode switch is turned on, the shift mode of the AMT 8 is switched from the normal mode to the sport mode of the shift schedule in which responsiveness is more important than the normal mode. When the manual mode switch is turned ON, the automatic transmission mode including the normal mode and the sport mode is switched to the manual mode described above. If at least one of the sport mode switch and the manual mode switch is ON, the process proceeds to step S5, and if not, the process proceeds to step S3.

  In step S3, the accelerator opening is obtained with reference to the signal of the accelerator opening sensor 44, and it is determined whether or not the accelerator opening exceeds a predetermined threshold. This threshold value is set to the lower limit value of the accelerator opening range that can be regarded as requiring a high degree of responsiveness. Therefore, when the accelerator opening exceeds this threshold, it can be said that the degree of demand for responsiveness to the vehicle 1 is high. If the accelerator opening exceeds the threshold value, the process proceeds to step S5, and if not, the process proceeds to step S4.

  In step S4, the above-described MG separation mode is set, and the current routine is terminated. Specifically, a variable for managing the shift mode is set to a value corresponding to the MG separation mode. In step S5, the rotation speed synchronization mode described above is set, and the current routine is terminated. Specifically, the variable is set to a value corresponding to the rotation speed synchronization mode. Details of each control content in the MG separation mode and the rotation speed synchronization mode will be described later.

  According to the routine of FIG. 2, the rotation speed synchronization mode is set when wear of the switching mechanism 21 should be avoided (step S1) or when responsiveness is required for the vehicle 1 (step S2 and step S3). In other cases, the MG separation mode is set. Accordingly, in the present embodiment, two types of shift modes can be switched according to the situation required for the vehicle 1.

  The routine of FIG. 3 is executed when a shift request for the AMT 8 is established. A program for this routine is stored in the ECU 40, and is repeatedly executed at predetermined calculation intervals while the shift request is established. The shift request is established according to conditions given for each travel mode. For example, in the automatic shift mode, the shift request is established when the operating point of the vehicle 1 crosses a shift diagram defined by the vehicle speed and the accelerator opening and set for each shift stage. In the manual mode, the vehicle speed and the accelerator opening are within predetermined conditions, and a shift request is established when a shift lever (not shown) is operated by the driver.

  In step S11, the friction clutch 7 is switched to the released state in response to the shift request. In step S12, among the coupling devices C1 to C4 of the AMT 8, the coupling device corresponding to the gear stage before the shift request is switched from the engaged state to the released state. That is, so-called gear removal is performed by the ECU 40. In step S13, the current rotational speed of the output shaft 11 is acquired with reference to the signal of the output-side resolver 42, and the target rotational speed of the input shaft 10 is calculated based on the rotational speed and the gear position after the shift. The calculation is realized, for example, by referring to a map in which the rotation speed of the output shaft 11 is associated with the target rotation speed.

  In step S14, it is determined whether or not the above-described rotation speed synchronization mode is set with reference to the value of the variable that manages the shift mode. When step S14 is a negative determination, that is, when the MG separation mode is set, the processes of steps S15 to S19 are performed to execute the MG separation mode. On the other hand, when step S14 is affirmative determination, the process of step S20-step S22 is performed in order to perform rotation speed synchronous mode.

  In step S15, the motor is controlled so that the rotational speed of the input shaft 10 approaches the target rotational speed calculated in step S13 while controlling the switching mechanism 21 so that torque transmission between the motor / generator 3 and the input shaft 10 is maintained. Control the generator 3 In step S16, the current rotational speed of the input shaft 10 is acquired by referring to the signal of the input side resolver 41, and the rotational speed difference between the rotational speed and the target rotational speed is calculated. If the rotational speed difference falls below a predetermined threshold value, the process proceeds to step S17. If the rotational speed difference does not fall below the threshold value, the process returns to step S15. That is, the process of step S15 for bringing the rotational speed of the input shaft 10 closer to the target rotational speed is continued until the rotational speed difference falls below the threshold value. The range below this threshold corresponds to the predetermined range of the present invention. This threshold value is set so as not to exceed the range of the rotational speed difference that can be eliminated by the synchronization mechanism Sy.

  In step S17, the switching mechanism 21 is controlled such that torque transmission between the motor / generator 3 and the input shaft 10 is interrupted. That is, the motor / generator 3 is disconnected from the input shaft 10.

  In step S18, a shifting operation is started. That is, among the coupling devices C1 to C4, the coupling device corresponding to the gear position after the shift is switched from the released state to the engaged state. That is, so-called gearing is performed by the ECU 40. Since there is a rotational speed difference less than a threshold value during the gearing process, the rotational speed difference is eliminated by the operation of the synchro mechanism Sy.

  In step S19, the switching mechanism 21 is controlled such that torque transmission between the motor / generator 3 and the input shaft 10 is maintained. That is, the switching mechanism 21 is controlled so that the motor / generator 3 is connected to the input shaft 10.

  On the other hand, in step S20, as in step S15, the switching mechanism 21 is controlled so that torque transmission between the motor / generator 3 and the input shaft 10 is maintained, while the rotational speed of the input shaft 10 is calculated in step S13. The motor / generator 3 is controlled so as to approach the rotation speed.

  In step S21, the current rotational speed of the input shaft 10 is acquired with reference to the signal of the input-side resolver 41, and it is determined whether or not the rotational speed has reached the target rotational speed. Whether or not the target rotational speed has been reached is determined based on whether or not the target rotational speed is completely matched, and whether or not the target rotational speed is within a certain range. It is also possible to use this as a standard. When the rotational speed of the input shaft 10 reaches the target rotational speed, the process proceeds to step S22, and when the rotational speed does not reach the target rotational speed, the process returns to step S20. That is, the process of step S20 for bringing the rotational speed of the input shaft 10 closer to the target rotational speed is continued until the rotational speed of the input shaft 10 reaches the target rotational speed.

  In step S22, a shifting operation is started. That is, among the coupling devices C1 to C4, the coupling device corresponding to the speed after the shift is switched from the released state to the engaged state. That is, so-called gearing is performed by the ECU 40. Since the rotational speed of the input shaft 10 has reached the target rotational speed during the gearing process, the synchro mechanism Sy does not substantially operate. Further, in the rotation speed synchronization mode, the torque transmission between the motor / generator 3 and the input shaft 10 is transmitted by the switching mechanism 21 even when the difference between the rotation speed of the input shaft 10 and the target rotation speed falls below the threshold value. Controlled to a maintained state.

  In step S23, the friction clutch 7 is switched from the disengaged state to the engaged state in the state where the operation of the MG disconnection mode or the rotation speed synchronization mode is completed and the gear position of the AMT 8 is switched. As a result, the shift operation after the shift request is established is completed.

  According to the control shown in FIG. 3, the following effects can be obtained. As shown in FIG. 4, when the MG disconnection mode is set, the friction clutch 7 is switched to the released state at the time t1 when the shift request is established, and the rotational speed Nin of the input shaft 10 is set to the target rotational speed Ntrg. The motor / generator 3 is controlled so as to approach. At time t2, the rotational speed difference between the rotational speed Nin of the input shaft 10 and the target rotational speed Ntrg falls below the threshold value Δth, and the speed change operation is started. At that time, the torque transmission between the motor / generator 3 and the input shaft 10 is interrupted by the switching mechanism 21, and the motor / generator 3 is disconnected from the input shaft 10. During the speed change operation, the synchronizing mechanism Sy is operated to eliminate the rotational speed difference, and the rotational speed Nin matches the target rotational speed at time t3. The shift time T includes a period T1 in which the motor / generator 3 is controlled to bring the rotational speed Nin closer to the target rotational speed Ntrg, and a period T2 in which the motor / generator 3 is disconnected from the input shaft 10 and the synchronization mechanism Sy operates. It is a thing. In the MG separation mode, the shift operation is started before the rotational speed Nin reaches the target rotational speed Ntrg, so that the shift time T can be shortened. Since the speed change operation is started in a state where torque transmission between the motor / generator 3 and the input shaft 10 is interrupted, the inertia corresponding to the motor / generator 3 is reduced by disconnecting the motor / generator 3. . Thereby, the load with respect to the synchronization mechanism Sy can be suppressed.

  On the other hand, as shown in FIG. 5, when the rotation speed synchronization mode is set, the friction clutch 7 is switched from the engaged state to the released state at the time t1 when the shift request is established, and the rotational speed of the input shaft 10 The motor / generator 3 is controlled so that Nin approaches the target rotational speed Ntrg. The control is continued until the rotation speed Nin reaches the target rotation speed Ntrg (time t2). Then, since the speed change operation is started in a state where the rotational speed Nin reaches the target speed Ntrg at time t2, the speed change operation is completed without substantially operating the synchro mechanism Sy. Since the synchronization mechanism Sy does not operate in the rotation speed synchronization mode, the load on the synchronization mechanism Sy can be reduced. Since the rotational speed synchronization mode is set in a situation where responsiveness to the vehicle 1 is required or in a situation where wear of the switching mechanism 21 should be avoided, the responsiveness of the vehicle 1 in a situation where responsiveness to the vehicle 1 is required. Can be ensured, and the frequency of operation of the switching mechanism 21 is reduced in a situation where wear of the switching mechanism 21 should be avoided, so that the progress of wear can be suppressed.

  In the said form, ECU40 functions as a control apparatus of this invention by performing the control routine of FIG.2 and FIG.3. Further, the ECU 40 executes step S15 and step S20 in FIG. 3 as motor control means of the present invention, and executes step S17 in FIG. 3 as switching mechanism control means of the present invention to execute step S18 in FIG. And by performing step S22, each functions as a shift control means of the present invention.

  However, this invention is not limited to the said form, It can implement with a various form within the range of the summary of this invention. The vehicle to which the control device of the present invention can be applied is not limited to the form shown in FIG. As long as the electric motor can transmit torque to the input shaft of the transmission, the mounting position is not limited. In addition to a mode in which the electric motor is directly connected to the input shaft of the transmission, various transmission elements such as a speed reducer may be interposed between the electric motor and the input shaft. The transmission mounted on the vehicle is not limited to the AMT, and the present invention can be applied to a vehicle mounted with a manual transmission (MT).

1 Vehicle 2 Engine 3 Motor generator (electric motor)
8 AMT (transmission)
10 input shaft 21 switching mechanism 40 ECU (electric motor control means, switching mechanism control means, shift control means)
Sy synchro mechanism

Claims (3)

An engine and an electric motor provided as a driving source for traveling;
A coupling device that accepts a shift operation as gearing to enable any one of a plurality of shift speeds, and a synchro mechanism that can eliminate a rotational speed difference in the process of the shift operation with respect to the coupling device , A transmission in which torque of the engine and the electric motor is input via an input shaft;
A switching mechanism capable of interrupting torque transmission between the electric motor and the input shaft ;
Applied to a hybrid vehicle having
In a state where the torque of the electric motor can be transmitted to the input shaft via the switching mechanism so that the rotational speed of the input shaft approaches the target rotational speed before the start of the speed change operation for the coupling device of the transmission. Motor control means for controlling the motor;
By controlling the electric motor so that the rotational speed of the input shaft approaches the target rotational speed, the difference between the rotational speed of the input shaft and the target rotational speed falls within a predetermined range. Switching mechanism control means for controlling the switching mechanism so that torque transmission between the electric motor and the input shaft is interrupted,
Shift control means for controlling the transmission so that the shift operation for the coupling device of the transmission is started after the torque transmission between the electric motor and the input shaft is interrupted by the switching mechanism control means. When,
Equipped with a,
When the rotation speed synchronization mode is set when the predetermined condition is satisfied,
The switching mechanism control means is configured to control the motor between the input shaft rotation speed and the target rotation speed by controlling the electric motor so that the rotation speed of the input shaft approaches the target rotation speed. Controlling the switching mechanism so that torque transmission between the electric motor and the input shaft is maintained even when the difference falls within a predetermined range; and
The control apparatus for a hybrid vehicle , wherein the shift control means controls the transmission so that the shift operation for the coupling device of the transmission is started when the rotation speed of the input shaft reaches the target rotation speed. . The control device according to claim 1, wherein the predetermined condition is set to a situation where responsiveness is required for the vehicle. The control device according to claim 1, wherein the predetermined condition is set to a situation where wear of the switching mechanism should be avoided.

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