Vehicle transmission control system

Abstract

To achieve both the improvement of the fuel efficiency and the comfortable traveling performance.SOLUTION: A gear shift control device 20 of an automobile 1 including an engine 4, a driving motor 5, an automatic transmission 8, and the like. The gear shift control device includes: a gear shift map 50 that defines, for each of gear shift points, thresholds of the number of revolutions to determine a switching start timing of each of the gear positions; a transmission control unit 22b that performs switching between the gear positions on the basis of the gear shift map 50; and a regeneration control unit 21d that controls regeneration. The gear shift map 50 includes a non-cooperative regeneration map that defines thresholds on a lower revolution side than thresholds in a cooperative request map 51 used in cooperative regeneration, and the non-cooperative regeneration map includes a combustion request map 52 that defines thresholds on the lower revolution side and is used when an accelerator is not used, and a travel request map 53 that defines thresholds on a relatively higher revolution side and is used when the accelerator is used.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The disclosed technology relates to a transmission control device for a vehicle equipped with an engine and a motor as drive sources.

Background Art

[0002] Regarding the disclosed technology, a control device for a hybrid vehicle is disclosed in Patent Document 1.

[0003] Since the transmission is controlled by hydraulic pressure, its responsiveness is low. Therefore, in the control device of Patent Document 1, at the time of shifting, regenerable torque is calculated in consideration of the response delay. By doing so, the control accuracy of the regenerative torque is improved and the fuel consumption is improved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Improving fuel consumption is an important issue for vehicles, as in the technology disclosed in Patent Document 1. For this purpose, in a vehicle equipped with an engine and a motor as drive sources, it is necessary to suppress fuel consumption in the engine, promote regeneration by the motor, and improve the energy recovery efficiency of the energy consumed during deceleration.

[0006] In this regard, when the vehicle travels by driving the drive source, if the gear position of the transmission is made higher (that is, the gear ratio is made smaller) and the rotational speed on the input side of the transmission is made lower with respect to the vehicle speed, fuel and power consumption can be suppressed. The cabin noise can also be reduced. Therefore, from the viewpoints of improving fuel consumption and suppressing noise, it is preferable to keep the gear position high in the shift pattern of the transmission during driving.

[0007] However, during regeneration, lowering the transmission's gear ratio (i.e., increasing the gear ratio) and raising the input rotation speed of the transmission relative to the vehicle speed increases the amount of electricity generated and improves the energy recovery efficiency. Therefore, a shift pattern that maintains a high gear ratio reduces the efficiency of regenerative energy recovery. In other words, a shift pattern that maintains a high gear ratio may improve fuel efficiency during driving, but worsen fuel efficiency during regeneration.

[0008] Furthermore, with that shift pattern, the high gear ratio prevents the vehicle from accelerating rapidly when the accelerator pedal is pressed and acceleration is required. Consequently, there may be a discrepancy between the acceleration the driver expects and the actual acceleration, potentially resulting in a less exhilarating driving experience.

[0009] The technology we are disclosing aims to achieve both improved fuel efficiency and comfortable driving performance. [Means for solving the problem]

[0010] The disclosed technology relates to a vehicle gear control device comprising an engine and a motor mounted as a drive source, and an automatic transmission interposed between the drive source and the drive wheels, which changes gears by switching between multiple gears between high and low using hydraulic control.

[0011] The gear shift control device includes a gear shift map in which threshold values ​​for both downshift and upshift rotational speeds are defined for each gear shift point in order to determine the timing of the gear shift start; a gear shift control unit that switches the gear shift based on the gear shift map; and a regenerative control unit that controls regeneration by the motor.

[0012] The gear shift map includes a coordinated regeneration map used during coordinated regeneration in conjunction with the brakes, and a non-coordinated regeneration map used at times other than coordinated regeneration, in which the threshold value is defined at a lower rotational speed than that of the coordinated regeneration map. The non-coordinated regeneration map includes a first map in which the threshold value is defined at a relatively lower rotational speed and is used when the accelerator is not used, and a second map in which the threshold value is defined at a relatively higher rotational speed and is used when the accelerator is used.

[0013] In other words, this transmission control device is intended for vehicles equipped with both an engine and a motor as power sources (so-called hybrid vehicles). Therefore, as mentioned above, in order to improve fuel efficiency, it is necessary to suppress fuel consumption by the engine, promote regeneration by the motor, and increase the efficiency of recovering energy consumed during deceleration.

[0014] To achieve this, it is preferable for the transmission's shift pattern during driving to maintain a higher gear ratio, but this may worsen fuel efficiency during regenerative braking and may result in a less exhilarating driving experience during acceleration. In contrast, this transmission control system features a cleverly designed shift map for the automatic transmission, equipped with three different shift patterns corresponding to the vehicle's main driving conditions.

[0015] Specifically, the gear shift map includes a coordinated regeneration map used during coordinated regeneration and a non-coordinated regeneration map used during non-coordinated regeneration when coordinated regeneration does not occur. The threshold for the coordinated regeneration map is set to a higher rotational speed than the threshold for the non-coordinated regeneration map.

[0016] Therefore, when using the coordinated regenerative braking map, the rotational speed (specifically, the rotational speed of the automatic transmission's input) is maintained at a higher level than when using the non-coordinated regenerative braking map. This allows the motor to rotate at a relatively higher speed, resulting in increased power generation from the motor and improved regenerative efficiency. Consequently, fuel efficiency during regeneration can be improved.

[0017] On the other hand, the non-coordinated regenerative braking map includes a first map used when the accelerator is not used and a second map used when the accelerator is used. The threshold for the first map is set to a lower RPM range than the threshold for the second map. The first map is designed to improve fuel efficiency, while the second map is designed to improve driving performance.

[0018] The non-coordinated regenerative braking map is used, for example, during vehicle acceleration or constant-speed driving (powering), or when regenerating during deceleration without coordinating with the brakes. When using the first map, the rotation is relatively low, resulting in lower engine and motor output and reduced fuel and electricity consumption. The booming noise that occurs with increasing rotational speed can also be reduced.

[0019] However, when using the first map, the engine speed is low, so if the accelerator is used for rapid acceleration, there is a risk of insufficient torque, resulting in an exhilarating driving experience. In contrast, this transmission control system allows the engine speed to be increased appropriately by using the second map. As a result, the torque that can be output increases, and acceleration can be achieved in a shorter time. The driver can then experience the acceleration they envisioned and enjoy an exhilarating driving experience.

[0020] Therefore, this transmission control system makes it possible to achieve both an overall improvement in fuel efficiency and comfortable driving performance.

[0021] In the coordinated regeneration map and the second map, the threshold values ​​for each gear shift point higher than a predetermined low gear shift point may be defined to the same value on the downshift side.

[0022] This ensures that the engine downshifts at the same RPM across a wide range of the vehicle's operating speed, regardless of the vehicle's speed. Therefore, it minimizes any discomfort for the driver and avoids compromising the exhilarating driving experience. It allows for a high level of balance between improved fuel efficiency and comfortable driving performance.

[0023] The vehicle further includes a relay clutch interposed between the engine and the automatic transmission and enabling disconnection between the engine and the automatic transmission, and further has a relay clutch control unit that controls the relay clutch. The relay clutch control unit executes a deceleration regeneration start process for disengaging the relay clutch in a predetermined high gear during deceleration, and executes a deceleration regeneration end process for connecting the disengaged relay clutch. The deceleration regeneration end process includes a process of connecting the relay clutch before switching at a predetermined low shift point using the non-cooperative regeneration map. A difference in the threshold value between the predetermined low shift point and a shift point one higher than the low shift point in the non-cooperative regeneration map is defined to be larger than a difference in the threshold value between other shift points.

[0024] Although details will be described later, at the time of the deceleration regeneration end process of connecting the relay clutch before switching at a predetermined low shift point using the non-cooperative regeneration map, a torque shock occurs at the time of switching at that low shift point. If the torque shock is large, there is a risk of giving the driver a sense of discomfort. Therefore, it is necessary to connect the relay clutch and start the engine before that, and apply engine torque to suppress the torque shock.

[0025] However, it takes time to execute these series of processes. On the other hand, according to this shift control device, the difference in the threshold value between a predetermined low shift point and a shift point one higher than it is defined to be larger than the difference in the threshold value between other shift points. Therefore, sufficient time for the process for suppressing the torque shock can be ensured, and the torque shock can be stably and effectively suppressed.

[0026] The threshold value of the lowest shift point in each of the non-cooperative regeneration map and the cooperative regeneration map may be defined to be the same value.

[0027] If so, when shifting at the lowest vehicle speed, it can be switched at the same speed and rotational speed. Therefore, it can be difficult to give the driver a sense of discomfort and can achieve a smooth driving feeling without sacrificing it. It is possible to achieve both fuel efficiency improvement and comfortable driving performance in a high dimension.

[0028] When comparing the shift points of the same gear position on both the downshift side and the upshift side of the shift map, the threshold value is defined to be larger on the upshift side than on the downshift side, and when first shifting between the downshift side and the upshift side, the same shift map may be used.

[0029] If so, when first shifting from acceleration to deceleration or from deceleration to acceleration, it does not shift to a different map and the same map is used. Further, when comparing the shift points of the same gear position on both the downshift side and the upshift side, the threshold value is defined to be larger on the upshift side than on the downshift side. Thereby, the same gear position is used until decelerating or accelerating by a predetermined speed, and no shift change is made.

[0030] Therefore, it is possible to suppress complicated shifting and it can be difficult to give the driver a sense of discomfort. It is possible to achieve both fuel efficiency improvement and comfortable driving performance in a high dimension.

Effect of the Invention

[0031] According to the shift control device of a vehicle to which the disclosed technology is applied, it is possible to achieve both fuel efficiency improvement and comfortable driving performance.

Brief Description of the Drawings

[0032] [Figure 1] It is a schematic diagram showing the main configuration of an automobile to which the disclosed technology is applied. [Figure 2] It is a clutch table of an automatic transmission. [Figure 3] It is a block diagram showing a PCM and the main input / output devices related thereto. [Figure 4] It is a block diagram showing a TCM and the main input / output devices related thereto. [Figure 5] This is a diagram illustrating basic examples of automobile driving. [Figure 6] This is a schematic diagram showing an example of a gear shift map. [Figure 7] This graph shows the threshold values ​​for each gear shift point on the gear shift map. [Figure 8] This is a flowchart of the gear shift control performed by the gear shift control device during regenerative braking. [Figure 9] This is a flowchart following Figure 8. [Figure 10] This is a time chart of the main elements corresponding to the completion of the second regenerative braking process. [Modes for carrying out the invention]

[0033] The following describes the technologies being disclosed. However, the following description is essentially illustrative.

[0034] <Vehicle> Figure 1 shows an automobile 1 (an example of a vehicle) to which the disclosed technology is applied. This automobile 1 is a hybrid vehicle capable of running on electricity. The automobile 1 has four wheels 2 (2F, 2F, 2R, 2R). Each wheel 2 is fitted with a brake 3 to slow its rotation.

[0035] The vehicle 1 is equipped with an engine 4 and a drive motor 5 as its power source. These work together to drive two of the four wheels 2F, 2F, 2R, 2R, which are positioned symmetrically on the left and right sides (drive wheels 2R). As a result, the vehicle 1 moves. The drive motor 5 is used not only as a power source but also as a generator during regenerative braking.

[0036] As described later, this vehicle 1 is equipped with a high-voltage battery 9 with a rated voltage of 50V or less. Power supplied from this high-voltage battery 9, the drive motor 5 primarily assists the engine 4 in propulsion (a so-called mild hybrid vehicle). Vehicle 1 may also be a so-called plug-in hybrid vehicle that can receive power from an external power source.

[0037] In this automobile 1, the engine 4 is located at the front of the vehicle, and the drive wheels 2R are located at the rear of the vehicle. In other words, this automobile 1 is a so-called FR (front-engine, rear-wheel drive) vehicle. Automobile 1 is not limited to FR vehicles; it may also be a four-wheel drive vehicle.

[0038] Automobile 1 is equipped with an engine 4, a drive motor 5, and other drivetrain components such as a relay clutch 6, an inverter 7, and an automatic transmission 8. Automobile 1 is also equipped with control system components such as a power control module (PCM) 21 and a transmission control module (TCM) 22.

[0039] Vehicle speed sensor 31, engine sensor 32, motor sensor 33, transmission sensor 34, brake sensor 35, accelerator sensor 36, etc., are also installed in the vehicle 1 in conjunction with the control system devices.

[0040] (Drive system components) Engine 4 is an internal combustion engine that uses gasoline as fuel for combustion. Engine 4 is also a so-called four-stroke engine that generates rotational power by repeating the intake, compression, expansion, and exhaust cycles. Engine 4 can be of various types and forms, such as diesel engines, but the disclosed technology does not particularly limit the type or form of engine 4.

[0041] In this automobile 1, the engine 4 is positioned approximately in the center of the vehicle width direction, with the crankshaft 4a, which outputs rotational power, facing in the longitudinal direction of the vehicle body. The automobile 1 is equipped with various devices and mechanisms associated with the engine 4, such as an intake system, exhaust system, and fuel supply system, but their illustrations and descriptions are omitted.

[0042] The drive motor 5 is a permanent magnet type synchronous motor driven by three-phase alternating current. The drive motor 5 is located in series behind the engine 4 via a relay clutch 6. The drive motor 5 is also located in series in front of the automatic transmission 8.

[0043] The intermediate clutch 6 is installed between the front end of the shaft 5a of the drive motor 5 and the crankshaft 4a of the engine 4. The intermediate clutch 6 is configured to switch between a state in which the crankshaft 4a and shaft 5a are connected (connected state) and a state in which the crankshaft 4a and shaft 5a are separated (separated state) depending on whether or not its frictional fastening element is engaged.

[0044] The rear end of the shaft 5a of the drive motor 5 is connected to the input shaft 8a of the automatic transmission 8. Therefore, the engine 4 is connected to the automatic transmission 8 via the intermediate clutch 6 and the shaft 5a. By disengaging the intermediate clutch 6, the engine 4 is disconnected from the automatic transmission 8.

[0045] As will be explained in more detail later, while the vehicle 1 is in motion, the relay clutch 6 is switched between a engaged state and a disengaged state. For example, when the vehicle 1 is decelerating, the relay clutch 6 is disengaged, and regeneration is performed with the engine 4 disconnected.

[0046] When regenerative braking is performed in coordination with brake 3 (coordinated regeneration), the relay clutch 6 is engaged until the vehicle comes to a stop (until the rotational speed of shaft 5a becomes zero). When regenerative braking is performed without coordination with brake 3 (non-coordinated regeneration), the relay clutch 6 is engaged at the timing when shaft 5a reaches a predetermined rotational speed.

[0047] In other words, when the relay clutch 6 is engaged during non-coordinated regeneration, a certain rotational speed is required to prevent stalling when acceleration begins. The rotational speed at which the relay clutch 6 is engaged is set to be higher than the lower limit rotational speed at which stalling is possible, plus the rotational speed reduction due to the time required for gear shift control and engine 4 starting.

[0048] The drive motor 5 is connected to a high-voltage battery 9 mounted on the vehicle as a power source via an inverter 7 and a high-voltage cable 40. In the case of this automobile 1, the high-voltage battery 9 is a DC battery with a rated voltage of 50V or less, specifically a 48V battery.

[0049] The high-voltage battery 9 supplies high-voltage DC power to the inverter 7. The inverter 7 converts this DC power into three-phase AC power and energizes the drive motor 5. This causes the drive motor 5 to rotate.

[0050] The high-voltage battery 9 is also connected to the DC-DC converter 10 via a high-voltage cable 40. The DC-DC converter 10 converts 48V high-voltage DC power to 12V low-voltage DC power and outputs it. The DC-DC converter 10 (its output side) is connected to the low-voltage battery 11 (a so-called lead-acid battery) via a low-voltage cable 41.

[0051] The low-voltage battery 11, although not shown in the diagram, is connected to various electrical components via low-voltage cables 41. The DC-DC converter 10 is also connected to the CAN (Controller Area Network) 12 via low-voltage cables 41. As a result, the DC-DC converter 10 supplies low-voltage DC power to the CAN 12.

[0052] The automatic transmission 8 is a multi-stage automatic transmission (so-called AT). The automatic transmission 8 has an input shaft 8a at its front end, and this input shaft 8a is connected to the shaft 5a of the drive motor 5 as described above. The automatic transmission 8 has an output shaft 8b at its rear end, which rotates independently of the input shaft 8a.

[0053] Between the input shaft 8a and the output shaft 8b, a transmission mechanism consisting of a torque converter 8c, multiple planetary gear mechanisms 8d, and multiple transmission clutches 8e is incorporated. Each of the transmission clutches 8e has multiple friction engagement elements that can be switched between an engaged and disengaged state by hydraulic pressure.

[0054] The transmission mechanism's clutch 8e is switched by hydraulic control, which allows for switching between forward and reverse gears, and also enables changing the rotational speed between the input shaft 8a and output shaft 8b of the automatic transmission 8, i.e., switching between gears.

[0055] For example, the input side of each transmission clutch 8e is configured to be connectable to the input shaft 8a via a torque converter 8c. The output side of each transmission clutch 8e is connected to the output shaft 8b via a corresponding planetary gear mechanism 8d.

[0056] Then, when a specific transmission clutch 8e is selected and a predetermined hydraulic pressure is supplied to that transmission clutch 8e, the friction engagement elements of that transmission clutch 8e are engaged. As a result, the input shaft 8a and the output shaft 8b are connected via the transmission clutch 8e and its corresponding planetary gear mechanism 8d.

[0057] On the other hand, when the hydraulic pressure supplied to the transmission clutch 8e is recovered, the friction engagement elements of the transmission clutch 8e separate. This disconnects the input shaft 8a and the output shaft 8b, which were connected via the transmission clutch 8e and its corresponding planetary gear mechanism 8d.

[0058] To supply hydraulic pressure to the automatic transmission 8, a mechanical pump (MOP) 13 driven by a drive source (engine 4 and / or drive motor 5) and an electric pump (EOP) 14 driven by electricity are attached to the automatic transmission 8. The EOP 14 is connected to a low-voltage battery 11 and operates on power supplied from the low-voltage battery 11.

[0059] Figure 2 shows the engagement table for this automatic transmission 8. Circles in the table indicate engagement. This automatic transmission 8 incorporates five transmission clutches 8e, which consist of three clutch elements: a first clutch CL1, a second clutch CL2, and a third clutch CL3, and two brake elements: a first brake BR1 and a second brake BR2.

[0060] The automatic transmission 8 uses hydraulic control to select and engage three of the five transmission clutches 8e. This switches the transmission to either the forward gears from 1st to 8th gear, or the reverse gear (reverse speed).

[0061] For example, in 1st gear, the first clutch CL1, the first brake BR1, and the second brake BR2 are engaged. When shifting up from 1st gear, the transmission switches from 1st to 2nd gear by engaging the second clutch CL2 instead of the first clutch CL1. The transmission switches from 2nd to 3rd gear by engaging the first clutch CL1 instead of the first brake BR1. The transmission switches from 3rd to 4th gear by engaging the third clutch CL3 instead of the first clutch CL1.

[0062] Shifting up to 5th gear and beyond is done in the same way. Shifting down follows the reverse procedure of shifting up.

[0063] The higher the gear, the smaller the gear ratio. For example, the gear ratio of 2nd gear is smaller than that of 1st gear. Typically, lower gears are used for low-speed driving, and higher gears are used for high-speed driving. While the automobile 1 is in motion, the automatic transmission 8 switches between these gears from 1st to 8th gear, changing the rotational speed input from the drive source and outputting it.

[0064] Furthermore, if the transmission clutch 8e is not engaged, the input shaft 8a and the output shaft 8b are disconnected (so-called neutral). Even if rotational power is input to the automatic transmission 8 from the drive source, that rotational power is not output from the automatic transmission 8.

[0065] As shown in Figure 1, the output shaft 8b of the automatic transmission 8 is connected to the differential gear 16 via a propeller shaft 15 that extends in the longitudinal direction of the vehicle body. The differential gear 16 is connected to a pair of drive shafts 17, 17 that extend in the vehicle width direction and are connected to the left and right drive wheels 2R, 2R. The rotational power output through the propeller shaft 15 is distributed by the differential gear 16 and then transmitted to each drive wheel 2R through this pair of drive shafts 17, 17.

[0066] (Speed ​​control device) Automobile 1 is equipped with the aforementioned PCM21 and TCM22 to control its movement by controlling the engine 4, drive motor 5, relay clutch 6, automatic transmission 8, etc., in response to the driver's input. Each of these PCM21 and TCM22 consists of hardware such as a processor, memory, and interface, and software such as a database and control programs.

[0067] The PCM21 is a unit that primarily controls the operation of the drive source (engine 4 and drive motor 5). The PCM21 also controls the operation of the brake 3. The TCM22 is a unit that primarily controls the operation of the intermediate clutch 6 and the automatic transmission 8. Each of the PCM21 and TCM22 is connected by CAN12 as described above and is configured to communicate with each other electrically. The transmission control device 20 is composed of these PCM21 and TCM22.

[0068] Figure 3 shows the PCM21 and its main related input / output devices. In addition to the CAN12, the PCM21 is connected to a vehicle speed sensor 31, engine sensor 32, motor sensor 33, brake sensor 35, accelerator sensor 36, inverter 7, engine 4, brake 3, MOP13, EOP14, etc. The PCM21 also has a functional configuration, consisting of a motor control unit 21a, engine control unit 21b, oil pump control unit 21c, and regenerative control unit 21d, which are provided by its hardware and software.

[0069] The motor control unit 21a has the function of controlling the drive of the drive motor 5, and by controlling the inverter 7, it outputs the rotational power required for the drive motor 5. The engine control unit 21b has the function of controlling the drive of the engine 4, and outputs the rotational power required for the engine 4.

[0070] The oil pump control unit 21c has the function of controlling the operation of the MOP 13 and EOP 14 and adjusting the hydraulic pressure supplied to the automatic transmission 8. The regenerative control unit 21d has the function of controlling regeneration and, for example, when the vehicle 1 is decelerating, it performs regeneration by the drive motor 5 in coordination with the brake 3 (coordinated regeneration).

[0071] Figure 4 shows the TCM22 and its main related input / output devices. In addition to the CAN12, the TCM22 is connected to the transmission sensor 34, relay clutch 6, automatic transmission 8, etc. The TCM22 also has a functional configuration in which a relay clutch control unit 22a and a transmission control unit 22b are provided by its hardware and software.

[0072] The relay clutch control unit 22a controls the operation of the relay clutch 6. That is, the relay clutch control unit 22a switches the relay clutch 6 between a connected state and a disconnected state according to the driving state of the automobile 1. The transmission control unit 22b switches the gear of the automatic transmission 8 based on a predetermined gear map 50, which will be described later, according to the driving state of the automobile 1. That is, the transmission control unit 22b changes the output rotational speed in relation to the rotational speed input to the automatic transmission 8.

[0073] As shown in Figure 1, the vehicle speed sensor 31 is attached to each wheel 2, for example, and detects the rotational speed of each wheel 2 and outputs it to the PCM 21. The PCM 21 calculates the vehicle speed from these detected values. The engine sensor 32 is attached to the engine 4 and detects the rotational speed and torque of the engine 4 and outputs them to the PCM 21. The motor sensor 33 is attached to the drive motor 5 and detects the rotational speed and torque of the drive motor 5 and outputs them to the PCM 21.

[0074] The brake sensor 35 is attached to the brake pedal 18 and detects the amount it is pressed and outputs the result to the PCM 21. The accelerator sensor 36 is attached to the accelerator pedal 19 and detects the amount it is pressed and outputs the result to the PCM 21. The transmission sensor 34 is attached to the automatic transmission 8 and detects the rotational speed and engagement torque of each transmission clutch 8e, the rotational speed of the output shaft 8b, etc., and outputs the result to the TCM 22.

[0075] Based on the signals of the detected values ​​input from these sensors, the PCM21 and TCM22 work together to control each device in the drive system, causing the vehicle 1 to move. In the case of this vehicle 1, the engine 4 and the drive motor 5 are used in combination for driving. For example, when starting or accelerating the vehicle 1, the drive motor 5 assists the output of the engine 4. When the vehicle speed reaches the medium or high speed range and the vehicle 1 is running stably, it may run using both the engine 4 and the drive motor 5, or it may run using only the drive motor 5 with the engine 4 disconnected.

[0076] Furthermore, in the case of this vehicle 1, when the vehicle 1 decelerates, the engine 4 is disconnected, and braking is performed by coordinated control with the brake 3 as needed, while the drive motor 5 actively performs regenerative braking. As a result, this vehicle 1 recovers more energy consumed during deceleration, improving fuel efficiency.

[0077] <Examples of vehicle operation> Figure 5 shows a basic example of vehicle 1 in operation. The upper part of the figure shows the driving state of vehicle 1 (change in vehicle speed). The state diagrams C1 to C7 shown at the bottom of the figure indicate whether the intermediate clutch 6 and transmission clutch 8e are engaged or not, the output state of rotational power (torque or load), and the power supply state, corresponding to the driving state of vehicle 1.

[0078] The solid line L1 indicates whether the intermediate clutch 6 is engaged or not, and the solid line L2 indicates whether the transmission clutch 8e is engaged or not (i.e., whether it is in neutral or not). The thick arrow Y1 indicates the output of rotational power from the drive source (engine 4 and / or drive motor 5), and the thin arrow Y2 indicates the input and output of power from the high-voltage battery 9 to the drive motor 5.

[0079] The leftmost part of Figure 5 shows the state in which car 1 is completely stopped. Based on the driver's key operation, the starter motor of car 1 is activated, and the engine 4 starts. At this time, as shown in state diagram C1, the relay clutch 6 is engaged and the automatic transmission 8 is in neutral.

[0080] Next, when the accelerator is pressed and the vehicle 1 starts moving, as shown in state diagram C2, the automatic transmission 8 is coupled in a low gear, and rotational power is output from the engine 4 according to the amount the accelerator is pressed. At this time, the drive motor 5 assists the engine 4 in driving. In detail, the drive motor 5 adjusts the rotational power that the engine 4 outputs to the automatic transmission 8 in order to optimize fuel efficiency, and performs driving, stopping, or power generation (regeneration).

[0081] When vehicle 1 is in motion, depending on the driving state, vehicle 1 may run using both the engine 4 and the drive motor 5 (HEV driving) (state C2 in the state diagram), or it may run using only the drive motor 5 with the engine 4 disconnected (EV driving) (state C3 in the state diagram). At this time, the automatic transmission 8 is set to a high gear, suppressing fuel and electricity consumption. Therefore, fuel efficiency is improved. Because the rotational speed is low, booming noise is also reduced. Therefore, noise is also reduced.

[0082] In particular, in the case of this vehicle 1, EV driving is prioritized in driving ranges where EV driving is possible. In EV driving, the engine 4 is stopped, so no fuel is consumed. There is also no energy loss due to combustion. Therefore, fuel efficiency can be further improved.

[0083] Examples of situations in which the engine 4 is disconnected while the vehicle 1 is in motion include when performing EV driving as described above, and when performing regenerative braking as described later. On the other hand, examples of situations in which the engine 4 is connected include when driving in an operating range where EV driving is not possible, when performing idle stop, when there is a request for increased output due to the use of the air conditioner, and when there is a request for regeneration to charge the high-voltage battery 9.

[0084] When switching from EV driving to HEV driving, as shown in state diagram C4, the engine 4 is connected and restarted by the inertia of the moving vehicle 1 and the rotational power driven by the drive motor 5.

[0085] Then, when car 1 begins to decelerate towards a stop, in the case of car 1, as shown in phase diagram C5, engine 4 is disconnected and regenerative braking is performed. By disconnecting engine 4, more energy can be recovered.

[0086] When the vehicle speed decreases significantly and vehicle 1 approaches a stop, in the case of vehicle 1, the engine 4 is engaged and preparations for idle stop are made, as shown in state diagram C6.

[0087] In other words, the intermediary clutch 6 is engaged when the automatic transmission 8 is in a low gear. By idling stop, even if the vehicle 1 stops, the engine 4 can be immediately restarted by the drive motor 5. When idling stop is activated, the automatic transmission 8 is in neutral, and the vehicle 1 is in the same state as shown in state diagram C1.

[0088] When the idle-stopped vehicle 1 restarts, the drive motor 5 is driven by power supplied from the high-voltage battery 9, as shown in the state diagram C7. The engine 4 starts with this rotational power. Therefore, the engine 4 can be restarted smoothly and with low noise.

[0089] <Gear Shift Map> As mentioned above, while the automobile 1 is in motion, it is preferable to set the automatic transmission 8 to a higher gear from the standpoint of improving fuel efficiency and reducing noise.

[0090] However, when the automatic transmission 8 is in a high gear, the rotational speed of the shaft 5a is low, which suppresses the amount of electricity generated when the drive motor 5 regenerates power. Consequently, the energy recovery efficiency decreases, and fuel efficiency worsens.

[0091] Furthermore, if the accelerator pedal 19 is pressed and rapid acceleration of the vehicle 1 is required, the automatic transmission 8, being in a high gear, may be unable to respond due to insufficient torque. Consequently, a discrepancy may arise between the acceleration the driver expects and the actual acceleration, potentially resulting in an unexhilarating driving experience.

[0092] In contrast, in this automobile 1, a shift map 50 that defines the shift pattern of the automatic transmission 8 is designed to achieve both improved fuel efficiency and comfortable driving performance. Figure 6 shows an example of this shift map 50. The shift map 50 is set in the memory of the TCM 22. The data format is not limited to tables; it can also be mathematical formulas, numerical data sets, etc., and can be selected as appropriate according to the specifications.

[0093] The gear shift map 50 is broadly composed of three different maps. Specifically, the gear shift map 50 includes a regeneration request map 51, a combustion request map 52, and a driving request map 53. The regeneration request map 51 is used during coordinated regeneration, that is, when decelerating and regenerating in coordination with the brake 3, and corresponds to the "coordinated regeneration map".

[0094] The combustion request map 52 and the driving request map 53 are maps used during non-coordinated regeneration, that is, outside of coordinated regeneration. For example, these maps are used when the vehicle 1 is accelerating and driving at a constant speed (powering), or when decelerating and regenerating without coordinating with the brake 3, and correspond to the "non-coordinated regeneration map". The combustion request map 52 also corresponds to the "first map", and the driving request map 53 also corresponds to the "second map".

[0095] These maps define thresholds for determining the timing of the gear shift change (shift start timing) for each gear shift point, for both the downshift and upshift sides. Specifically, on the upshift side, gear shift points U1 to U7 are defined as multiple switching points for switching between high and low gears, while on the downshift side, gear shift points D1 to D7 are defined.

[0096] Furthermore, for each of these gear shift points, the minimum rotational speed required to switch gears (the rotational speed on the input side of the automatic transmission 8) is defined as a threshold, along with the corresponding vehicle speed. Note that the threshold is not limited to rotational speed itself, but may be any other value correlated with rotational speed.

[0097] On the upshift side of the combustion request map 52, the vehicle speed at which the gear change begins and the corresponding engine speed (Ra:U1~Ra:U7) are specified for each gear change point from U1 to U7. For example, gear change point U3 in the combustion request map 52 switches from 3rd gear to 4th gear. Therefore, when the vehicle speed of car 1, which is traveling in 3rd gear, increases to 30 km / h and the engine speed reaches Ra:U3, the gear change to 4th gear occurs at that moment, and an upshift is performed.

[0098] Furthermore, the regenerative request map 51 specifies, for each shift point from D1 to D7, the vehicle speed at which the gear change begins and the corresponding engine speed (Rc:D1 to Rc:D7). For example, shift point D2 in the regenerative request map 51 switches from 3rd gear to 2nd gear. Therefore, when the vehicle speed of car 1, which is traveling in 3rd gear, decreases to 23 km / h and the engine speed reaches Rc:D2, the gear changes to 2nd gear at that moment, and a downshift occurs.

[0099] Figure 7 shows the threshold values ​​for each gear shift point in each of these maps, plotted graphically. The dashed line represents the graph for the regeneration request map 51, the dashed line represents the graph for the running request map 53, and the solid line represents the graph for the combustion request map 52. Each element in the graph corresponds to a gear shift point (with threshold values ​​corresponding to some elements indicated). The vertical axis represents the threshold value, and R0 and R1 represent predetermined rotational speeds.

[0100] The regeneration request map 51 has a threshold set at a higher rotational speed than both the combustion request map 52 and the driving request map 53. In other words, the regeneration request map 51 is set to maintain a higher rotational speed than both the combustion request map 52 and the driving request map 53.

[0101] For example, when comparing the downshift point D7, with the regeneration request map 51, the gear changes from 8th to 7th when the engine speed reaches Rc:D7, whereas with the driving request map 53, the gear changes from 8th to 7th when the engine speed reaches a lower Rb:D7. With the combustion request map 52, the gear changes at an even lower engine speed, Ra:D7.

[0102] Therefore, according to the regeneration request map 51, the drive motor 5 can be rotated at a relatively higher rotational speed, resulting in increased power generation and improved regeneration efficiency. Consequently, fuel efficiency during regeneration can be improved.

[0103] On the other hand, the combustion request map 52 has thresholds set at lower RPMs than the driving request map 53. In other words, the thresholds for the combustion request map 52 are set at relatively lower RPMs, while the thresholds for the driving request map 53 are set at relatively higher RPMs. The driving request map 53 is set to maintain a higher RPM than the combustion request map 52.

[0104] The combustion request map 52 is set to prioritize fuel efficiency. In contrast, the driving request map 53 is set to prioritize comfortable driving performance. The combustion request map 52 is mainly used when the accelerator is not being used, and the driving request map 53 is mainly used when the accelerator is being used.

[0105] For example, at gear shift point U7, if the combustion request map 52 is selected, the gear will switch from 7th to 8th when the rotational speed reaches Ra:U7, whereas if the driving request map 53 is selected, the gear will switch from 7th to 8th when the rotational speed reaches the higher Rb:U7.

[0106] Therefore, according to the combustion demand map 52, the engine rotates at a relatively low RPM, resulting in lower output from the engine 4 and drive motor 5, thus reducing fuel and electricity consumption. The booming noise that occurs with increasing rotational speed can also be reduced.

[0107] On the other hand, according to the driving request map 53, the engine can rotate at relatively higher RPMs, resulting in greater torque output and faster acceleration. Consequently, the driver can achieve the acceleration they envision and enjoy an exhilarating driving experience.

[0108] In both the regenerative braking request map 51 and the driving request map 53, the threshold values ​​for each gear shift point higher than a predetermined low gear shift point are defined to the same value on the downshift side.

[0109] Specifically, all gear shift points other than gear shift points D1 and D2 in the regeneration request map 51, i.e., gear shift points D3 and above, have the same threshold value defined (Rc:D3 to Rc:D7 have the same value). Similarly, all gear shift points D3 and above in the driving request map 53 also have the same threshold value defined (Rb:D3 to Rb:D7 have the same value).

[0110] As a result, the vehicle 1 downshifts at the same engine speed across a wide range of its driving range, regardless of the vehicle speed. Therefore, it is less likely to cause discomfort to the driver and does not compromise the exhilarating driving experience. It is possible to achieve a high level of balance between improved fuel efficiency and comfortable driving performance.

[0111] The threshold values ​​for each gear shift point below a predetermined low gear shift point (specific gear shift point D2, described later) on the downshift side of both the combustion request map 52 and the driving request map 53 are set to the same value along with the vehicle speed. Furthermore, the threshold values ​​for each gear shift point below a predetermined low gear shift point on the upshift side of both the combustion request map 52 and the driving request map 53 are set to the same value along with the vehicle speed between the corresponding gear shift points in both maps.

[0112] Specifically, the threshold values ​​for shift points D1 and D2 in the combustion request map 52, and the threshold values ​​for shift points D1 and D2 in the driving request map 53, are set to the same value along with the vehicle speed (Ra:D1=Rb:D1, Ra:D2=Rb:D2). Furthermore, the threshold value for shift point U1 in the combustion request map 52 is set to the same value along with the vehicle speed as the threshold value for shift point U1 in the driving request map 53 (Ra:U1=Rb:U1), and the threshold value for shift point U2 in the combustion request map 52 is set to the same value along with the vehicle speed as the threshold value for shift point U2 in the driving request map 53 (Ra:U2=Rb:U2).

[0113] As a result, when shifting gears at low vehicle speeds, even if the maps are different, the system will shift down or up at the same vehicle speed and engine RPM. Therefore, even if the vehicle 1 frequently accelerates or decelerates with gear changes, it is less likely to cause discomfort to the driver, and the exhilarating driving experience is not compromised. This allows for a high level of balance between improved fuel efficiency and comfortable driving performance.

[0114] The threshold value for the minimum gear shift point in each of these maps (combustion request map 52, driving request map 53, and regeneration request map 51) is defined to be the same value.

[0115] In other words, the minimum shift point D1 on the downshift side of each map has the same threshold value defined along with the vehicle speed (Ra:D1=Rb:D1=Rc:D1). The minimum shift points U1 on both the upshift side of each map also have the same threshold value defined along with the vehicle speed (Ra:U1=Rb:U1=Rc:U1).

[0116] As a result, regardless of which map is used, when shifting gears at the slowest vehicle speed, the downshift or upshift will occur at the same speed and RPM. Therefore, it is less likely to cause discomfort to the driver and does not compromise the exhilarating driving experience. It is possible to achieve a high level of balance between improved fuel efficiency and comfortable driving performance.

[0117] When comparing the same gear shift point on both the downshift and upshift sides of each of these maps (combustion request map 52, driving request map 53, regeneration request map 51), the threshold value is set higher on the upshift side than on the downshift side.

[0118] Specifically, the shift point on the upshift side has a hysteresis of approximately +5 km / h in vehicle speed compared to the same shift point on the downshift side. Furthermore, the same map is used when initially transitioning between the downshift and upshift sides.

[0119] For example, when car 1 is driving using the regenerative braking request map 51, if the vehicle speed decelerates to 23 km / h (engine speed Rc:D2), it will downshift from 3rd gear to 2nd gear according to the specifications of gear shift point D2. Then, when accelerating for the first time, the same regenerative braking request map 51 is used instead of switching to the driving request map 53.

[0120] In other words, the gear change is performed based on the shift-up specification of the regenerative request map 51, and the gear shifts up from 2nd to 3rd gear according to the specification of gear shift point U2. As a result, when accelerating for the first time, no gear change is performed until the vehicle speed reaches 28 km / h (engine speed Rc:U2). In other words, the same gear is used until the vehicle speed increases by about 5 km / h.

[0121] For example, when car 1 is driving using the combustion request map 52, if the vehicle speed increases to 33 km / h (engine speed Ra: U4), it shifts up from 4th gear to 5th gear according to the specifications of the gear shift point U4. Subsequently, when decelerating for the first time, the same combustion request map 52 is used instead of switching to the regenerative braking request map 51.

[0122] In other words, the gear change is performed based on the downshift specification of the combustion request map 52, and the gear changes from 5th gear to 4th gear according to the specification of gear change point D4. As a result, when decelerating for the first time, no gear change is performed until the vehicle speed reaches 28 km / h (engine speed Ra: D4). In other words, the same gear is used until the vehicle speed decreases by about 5 km / h.

[0123] This reduces the need for cumbersome gear changes and minimizes discomfort for the driver. Consequently, it avoids compromising the exhilarating driving experience. It achieves a high level of balance between improved fuel efficiency and comfortable driving performance.

[0124] The transition to a different gear map 50 is performed at the timing of the subsequent gear change. If the thresholds for the two maps are different, the system is configured to shift at an intermediate value between the two thresholds to allow for a continuous transition.

[0125] For example, when decelerating in 4th gear using the combustion request map 52, when the vehicle speed reaches 23 km / h (engine speed Ra:D3), the system will shift down to 3rd gear according to the specifications of shift point D3. In that case (when decelerating in 4th gear using the combustion request map 52), if the system transitions to the driving request map 53, the shift point D3 of the driving request map 53 specifies a vehicle speed of 24 km / h (engine speed Rb:D3). Therefore, the system is set to shift down to 3rd gear in the driving request map 53 at an intermediate value (for example, a vehicle speed of 23.5 km / h and the corresponding engine speed).

[0126] Thus, the transmission control device 20 is equipped with a transmission map 50 consisting of three different shift patterns corresponding to the main driving conditions of the automobile 1, making it possible to achieve both an overall improvement in fuel efficiency and comfortable driving performance.

[0127] <Gear shifting of the automatic transmission during regenerative braking> As mentioned above, in the case of this automobile 1, when deceleration begins towards a stop, the engine 4 is disconnected and regenerative braking is performed in order to recover more energy.

[0128] However, in such a case, when the automatic transmission 8 shifts down to a lower gear, the inertia of the vehicle 1 is large, so a torque difference is created between the input side of the transmission clutch 8e, which is acted only by the torque associated with the regeneration of the drive motor 5, and the output side of the transmission clutch 8e, which is acted by the torque associated with the inertia of the vehicle 1.

[0129] If this torque difference is not eliminated, a significant torque shock will occur during gear changes, specifically when the transmission clutch 8e engages. This torque shock can cause discomfort to the driver.

[0130] Normally, deceleration is accompanied by brake operation. The drive motor 5 performs regeneration in coordination with the braking by the brake 3 (coordinated regeneration). When the brake pedal 18 is pressed and the braking force from the brake 3 is acting during deceleration, the torque on the output side of the transmission clutch 8e decreases due to that braking force. Since the torque difference decreases, torque shock can be reduced.

[0131] In contrast, it is possible that vehicle 1 may decelerate without braking by brake 3, and come to a stop or reach a very slow speed. In such cases of regenerative braking when brake 3 is not used (non-coordinated regeneration), the braking force of brake 3 does not act, resulting in a large torque shock during gear changes.

[0132] One might consider slipping the transmission clutch 8e to reduce torque shock. However, the slippage of the transmission clutch 8e is insufficient to compensate for the torque associated with the vehicle's inertia. The same is true even when adding torque associated with regeneration from the drive motor 5.

[0133] Therefore, in order to prevent torque shock, it is necessary to engage the intermediate clutch 6 and apply torque from the engine 4 before downshifting to a lower gear. By applying torque from the engine 4, the torque associated with the vehicle's inertia can be offset.

[0134] However, doing so would prevent regenerative braking. The fuel efficiency improvement benefits obtained from regenerative braking with engine 4 disconnected would be lost.

[0135] Therefore, in this gear shift control device 20, threshold values ​​for each map are defined according to the driving conditions of the vehicle 1 so that gear changes can be performed appropriately even during regenerative braking, and both improved fuel efficiency and comfortable driving performance can be achieved.

[0136] Specifically, in the combustion request map 52 and the driving request map 53 (non-cooperative regeneration map), the threshold for a predetermined low gear shift point on the downshift side is set to be smaller than the threshold for each gear shift point higher than that low gear shift point, and is also set to be smaller than the threshold for that predetermined low gear shift point on the downshift side in the regeneration request map 51 (cooperative regeneration map).

[0137] The predetermined low gear shift point referred to here is, in the case of this automobile 1, the gear shift point D2 (hereinafter also referred to as the specific gear shift point D2) at which the gear changes from 3rd gear to 2nd gear. As will be described later, the relay clutch 6 switches from the disengaged state to the engaged state prior to the switching timing at this specific gear shift point D2.

[0138] As shown in Figure 7, the threshold values ​​(Ra:D2, Rb:D2) for specific gear shift points D2 in the combustion request map 52 and the driving request map 53 are set to be smaller than the threshold values ​​(Rc:D2) for gear shift points D3 to D7, which are higher. Furthermore, the threshold values ​​(Ra:D2, Rb:D2) for specific gear shift points D2 in the combustion request map 52 and the driving request map 53 are set to be smaller than the threshold value (Rc:D2) for specific gear shift points D2 in the regeneration request map 51.

[0139] Therefore, when using the brake 3 and coordinating regeneration using the regeneration request map 51, the gear shifts from 3rd gear to 2nd gear at a relatively high rotational speed. Since a high rotational speed is maintained, the decrease in the regenerative efficiency of the drive motor 5 can be suppressed.

[0140] Because braking force is applied by brake 3, the output torque of the transmission clutch 8e decreases due to this braking force. Since the torque difference decreases, torque shock can be reduced.

[0141] On the other hand, when non-coordinated regeneration is performed using either the combustion request map 52 or the driving request map 53, along with the non-use of brake 3, the gear shifts from 3rd to 2nd gear at a relatively lower rotational speed. Consequently, the timing of the downshift can be delayed accordingly.

[0142] As a result, the timing of engaging the intermediate clutch 6 and starting the engine 4 can be delayed in order to suppress torque shock. This allows for longer regenerative braking, thus mitigating the reduction in the fuel efficiency improvement effect.

[0143] Moreover, the threshold for the specific gear shift point D2 is smaller than the thresholds for each gear shift point D3 to D7 that are higher than D2. In other words, the thresholds for each gear shift point D3 to D7 that are higher than D2 are larger than the threshold for D2. As a result, higher rotational speeds can be maintained in gears higher than D2. Consequently, the decrease in the regenerative efficiency of the drive motor 5 can be suppressed during this process.

[0144] (Gear shift control during regenerative braking) Figures 8 to 10 show an example of gear shift control during regenerative braking as vehicle 1 comes to a stop. Figures 8 and 9 are flowcharts of the gear shift control performed by the gear shift control device 20 (PCM21 and TCM22). Figure 10 is a time chart corresponding to the second regenerative braking completion process, which will be described later. Here, vehicle 1 is assumed to be decelerating from a medium speed range (e.g., 40 km / h).

[0145] As shown in Figure 8, the gear shift control device 20 reads signals output from various sensors while the vehicle 1 is in motion and determines the driving state of the vehicle 1 based on these signals (step S1). By doing so, the gear shift control device 20 determines whether or not to perform regenerative braking (step S2).

[0146] As a result, if it is determined that regenerative braking should be performed (Yes in step S2), the transmission control device 20 (relay clutch control unit 22a) determines whether the relay clutch 6 is disengaged or not, that is, whether the engine 4 is disconnected or not (step S3).

[0147] Then, if it is determined that the relay clutch 6 is engaged (No in step S3), the relay clutch 6 is disengaged (step S5), assuming that the gear of the automatic transmission 8 is a predetermined high gear (at least 4th gear or higher) (Yes in step S4).

[0148] In other words, the transmission control device 20 (intermediate clutch control unit 22a) performs a process (recovery start process) to disengage the intermediate clutch 6 at a predetermined high-speed gear prior to regenerative braking. This allows the engine 4 to be stopped and regenerative braking to be performed without being affected by the engine 4, thereby improving fuel efficiency. Therefore, the transmission control device 20 starts regenerative braking after the intermediate clutch 6 has been disengaged.

[0149] Next, the transmission control device 20 performs a process (deceleration regeneration termination process) to engage the disengaged relay clutch 6 while the vehicle 1 is coming to a stop. The deceleration regeneration termination process performs different operations depending on whether the deceleration regeneration is coordinated regeneration using the brake 3 or uncoordinated regeneration without using the brake 3.

[0150] Specifically, the system performs either the following: using the regenerative request map 51 to connect the relay clutch 6 before coming to a stop (first deceleration regeneration completion process), or using the combustion request map 52 or the driving request map 53 to connect the relay clutch 6 before switching at a predetermined low gear shift point (second deceleration regeneration completion process).

[0151] In other words, the gear shift control device 20 determines whether or not the brake 3 is being used (step S6). For example, if the brake pedal 18 is being pressed, the gear shift control device 20 executes the first deceleration regeneration termination process. Then, it selects the regeneration request map 51 from the gear shift maps 50 (step S7).

[0152] As a result, even if the vehicle 1 decelerates further and the automatic transmission 8 shifts to a lower gear, the gear shift occurs at a relatively high rotational speed. Since a high rotational speed is maintained, the decrease in the regenerative efficiency of the drive motor 5 can be suppressed.

[0153] Because braking force is applied by brake 3, the output torque of the transmission clutch 8e decreases due to this braking force. Since the torque difference decreases, torque shock can be reduced.

[0154] Therefore, in this case, the transmission control device 20 engages the relay clutch 6 before the vehicle comes to a stop, connecting the engine 4 and the automatic transmission 8 (step S8).

[0155] On the other hand, if it is determined that brake 3 is not being used (No in step S6), the transmission control device 20 executes the second deceleration regeneration termination process. Then, from the transmission map 50, it selects either the combustion request map 52 or the driving request map 53 according to the driving state of the vehicle 1 (step S9).

[0156] Figure 10 is a time chart corresponding to the end of the second deceleration regeneration process. It shows the state of car 1 from the point when it decelerates to about 25 km / h until it comes to a stop. As mentioned above, the relay clutch 6 has already been disengaged, so the engine 4 is disconnected and stopped (engine speed is zero, and there is no fuel consumption).

[0157] Although the engine 4 is stopped, the drive motor 5 is rotating, so the MOP 13 is activated and supplies hydraulic pressure to the automatic transmission 8. In the case of this automobile 1, the specific gear shift point D2, which switches from 3rd gear to 2nd gear, is used as the predetermined low gear shift point mentioned above. That is, the intermediate clutch 6 is engaged before the gear shift at the specific gear shift point D2.

[0158] At the start of the time chart in Figure 10, the vehicle speed is approximately 25 km / h, so the automatic transmission 8 is in 4th gear. In this example, regenerative braking is initiated during the 4th gear phase (timing t1). With the start of regenerative braking, the motor torque output by the drive motor 5 becomes a negative value, the opposite of the torque output during driving, and the energy consumed during deceleration is recovered through power generation.

[0159] As shown in Figure 9, the gear shift control device 20 determines whether the vehicle 1 has reached a gear shift point during the deceleration process (step S10). If a gear shift point has been reached, it determines whether the gear at that time is the gear before the shift to the specific gear shift point D2 (3rd gear) (step S11).

[0160] Then, if it is determined that the vehicle is not in third gear (No in step S11), the gear shift control device 20 increases the torque output of the drive motor 5 to shift gears while suppressing the occurrence of torque shock (step S12). In Figure 10, this corresponds to the period from t2 to t3.

[0161] In other words, when the gear change control device 20 switches gears at a gear change point higher than the specific gear change point D2 in the second deceleration regeneration termination process, it drives the drive motor 5 according to that gear change point to prevent the occurrence of torque shock. Since the rotational speed of the drive motor 5 is relatively high, the occurrence of torque shock can be prevented by simply increasing the torque of the drive motor 5.

[0162] On the other hand, if it is determined that the vehicle is in 3rd gear (Yes in step S11), the gear shift control device 20 determines whether the rotational speed of the drive motor 5 has reached a predetermined engagement rotational speed Rs (step S13). The engagement rotational speed Rs is a rotational speed slightly higher than the specific gear shift point D2, and is the rotational speed at which the intermediate clutch 6 is engaged. The engagement rotational speed Rs is preset in the gear shift control device 20.

[0163] Then, if it is determined that the connection speed Rs has been reached (Yes in step S13), the transmission control device 20 engages the relay clutch 6 and connects the engine 4 to the automatic transmission 8 (step S14). This corresponds to the timing t4 in Figure 10.

[0164] After that, the gear shift control device 20 drives the drive motor 5 and restarts the engine 4 by adding starting torque (step S15). As a result, the motor torque increases to a predetermined value. In Figure 10, this corresponds to the period from t4 to t5. With the restart of the engine 4, fuel consumption begins. However, since regenerative braking can be performed until just before the specific gear shift point D2, the reduction in the fuel efficiency improvement effect can be suppressed.

[0165] Then, when the gear shift control device 20 determines that the specific gear shift point D2 has been reached (Yes in step S16), it causes the transmission clutch 8e (specifically its friction engagement element) to slip, switching the gear to 2nd gear (step S17). In Figure 10, this corresponds to the period from t5 to t6.

[0166] In other words, the transmission control device 20 drives both the engine 4 and the drive motor 5 when switching at a specific gear shift point D2 during the second deceleration regeneration termination process, and also causes the friction engagement elements of the automatic transmission 8 to slip. As a result, the torque associated with the vehicle's inertia is offset by the combination of the torque of both the engine 4 and the drive motor 5 and the slip effect of the transmission clutch 8e. Therefore, the occurrence of torque shock can be prevented.

[0167] Performing this series of processes takes time. In contrast, in both the combustion request map 52 and the driving request map 53, the threshold difference between a specific gear shift point D2 and the next higher gear shift point D3 is defined to be larger than the threshold difference between other gear shift points (see Figure 7).

[0168] Therefore, sufficient time can be secured for processing to suppress torque shock, and torque shock can be suppressed stably and effectively.

[0169] Subsequently, the drive motor 5 stops, and the automobile 1 is driven by the engine 4. The transmission control device 20 determines whether or not the gear shift point D1 has been reached (step S18). If it determines that the gear shift point D1 has been reached (Yes in step S18), the transmission control device 20 slips the transmission clutch 8e to switch the gear to 1st gear (step S19). In Figure 10, this corresponds to the period from t7 to t8.

[0170] Since the rotational speed is low and both the engine 4 and the drive motor 5 are connected to the automatic transmission 8, torque shock can be prevented by slippage of the transmission clutch 8e alone. When the automatic transmission 8 shifts to 1st gear, the transmission control device 20 stops the engine 4. Since both the engine 4 and the drive motor 5 are stopped, the transmission control device 20 activates the EOP 14. The EOP 14 supplies hydraulic pressure to the automatic transmission 8 and maintains the gear in 1st gear.

[0171] Thus, this transmission control device 20 is configured to disconnect the engine 4 during deceleration, perform regenerative braking using a transmission map 50 corresponding to the driving state of the vehicle 1, and suppress torque shocks that may occur when the automatic transmission 8 switches gears during deceleration. Therefore, it is possible to achieve both an overall improvement in fuel efficiency and comfortable driving performance.

[0172] The disclosed technology is not limited to the embodiments described above, but also encompasses various other configurations. For example, the configuration of automobile 1 is illustrative. Its configuration can be modified as appropriate depending on the specifications. [Explanation of Symbols]

[0173] 1. Automobile (vehicle) 3. Brake 4 engines 5. Drive motor 6. Intermediate clutch 7 Inverter 8 Automatic transmission 9 High-voltage battery 10 DC-DC converters 11 Low-voltage batteries 12 CAN 13. Mechanical pump (MOP) 14. Electric Pump (EOP) 18 Brake pedal 19. Accelerator pedal 20. Transmission control device 21 Power Control Module (PCM) 21a Motor control unit 21b Engine control unit 21c Oil pump control unit 21d Regenerative Control Unit 22. Transmission Control Module (TCM) 22a Relay clutch control unit 22b Transmission control unit 50 Gear Shift Map 51 Regeneration Request Map (Cooperative Regeneration Map) 52 Combustion Demand Map (Non-Cooperative Regeneration Map, Map 1) 53. Driving Requirement Map (Non-Cooperative Regeneration Map, Second Map)

Claims

1. The engine and motor are installed as the power source, An automatic transmission interposed between the drive source and the drive wheel, which changes gears by switching between multiple gears between high and low using hydraulic control, A vehicle gear control device equipped with, In order to determine the timing of the gear shift start, a gear shift map is used in which threshold values ​​for the rotational speeds of both the downshift and upshift sides are defined for each gear shift point along with the corresponding vehicle speed. A transmission control unit that switches the gear position based on the gear map, A regenerative control unit that controls regeneration by the motor, It has, The aforementioned gear shift map, The coordinated regenerative braking map used during coordinated regeneration, Non-cooperative regeneration maps used outside of cooperative regeneration, This includes, The aforementioned non-coordinated regenerative map is The first map is used when the accelerator is not being used, The second map used when the accelerator is used, Includes, In the aforementioned coordinated regeneration map and the aforementioned non-coordinated regeneration map, the threshold values ​​for the shift point group corresponding to a predetermined intermediate or higher vehicle speed are defined to different values ​​in both maps, wherein the threshold value for the shift point group in the coordinated regeneration map is defined to be on a higher rotational speed side than the threshold value for the shift point group in the non-coordinated regeneration map. A gear shift control device wherein, in the first map and the second map, the threshold values ​​for the gear shift point group corresponding to a predetermined intermediate or higher vehicle speed are defined to different values ​​in both maps, and the threshold value for the gear shift point group in the second map is defined to be on a higher rotational speed side than the threshold value for the gear shift point group in the first map.

2. In the gear shift control device according to claim 1, A gear shift control device in which, on the downshift side in both the coordinated regeneration map and the second map, the threshold values ​​for each shift point that is higher than the lowest shift point corresponding to the slowest vehicle speed and higher than a predetermined low shift point which is a low shift point corresponding to a slower shift at or below the vehicle speed of the shift point group are defined to the same value.

3. In the gear shift control device according to claim 1, The vehicle further comprises an intermediate clutch interposed between the engine and the automatic transmission, enabling the engine and the automatic transmission to be disconnected, and an intermediate clutch control unit that controls the intermediate clutch, The relay clutch control unit executes a deceleration regeneration start process to disengage the relay clutch at a predetermined high-speed stage during deceleration, and also executes a deceleration regeneration end process to reconnect the relay clutch in the disengaged state. The deceleration regeneration termination process includes a process of connecting the relay clutch before switching at a predetermined low gear shift point using the non-coordinated regeneration map, A gear control device wherein the difference in the threshold between a predetermined low gear shift point and a gear shift point one level higher than the low gear shift point in the non-coordinated regenerative braking map is defined to be greater than the difference in the threshold between other gear shift points.

4. In the gear shift control device according to claim 1, A gear shift control device in which the threshold value for the lowest gear shift point corresponding to the slowest vehicle speed in both the non-coordinated regenerative map and the coordinated regenerative map is defined to be the same value.

5. In the gear shift control device according to claim 1, A gear shift control device in which, when comparing the same gear shift point on both the downshift and upshift sides of the gear shift map, the threshold value is defined to be larger on the upshift side than on the downshift side, and the same gear shift map is used when first transitioning between the downshift side and the upshift side between different gear shift maps.

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