Hybrid vehicle

Abstract

A vehicle Ve comprises driving wheels, a main drive motor MOT1 that can drive the driving wheels, a battery BAT that supplies electric power to the main drive motor MOT1, an engine ENG that can rotate at an arbitrarily defined rotational speed relative to the rotational speed of the driving wheels, and a control device ECU, wherein: the vehicle Ve can travel on the basis of a plurality of pseudo gear shift positions at which the ratio of an engine rotational speed Ne to the vehicle speed is fixed, and at the plurality of pseudo gear shift positions, it is possible to set a first gear ratio that defines the relationship between the vehicle speed and the engine rotational speed Ne and a second gear ratio having a lower gear ratio tendency than the first gear ratio; and the control device ECU includes a gear ratio setting unit 100 that, on the basis of a prescribed switching condition, switches the setting of the gear ratio at the pseudo gear shift positions between the first gear ratio and the second gear ratio, and a travel control unit 110 that causes the vehicle Ve to travel on the basis of the gear ratio set by the gear ratio setting unit 100.

Description

Hybrid vehicle 【0001】 The present invention relates to a hybrid vehicle. 【0002】 In recent years, efforts to achieve a low-carbon society or a decarbonized society have been activated, and research and development on electrification technologies have been carried out in vehicles as well to reduce CO2 emissions and improve energy efficiency. 【0003】 Conventionally, there is known a vehicle that can perform so-called series running and shifts based on a pseudo gear stage (simulated gear stage) that simulates a stepped transmission to run. In such a vehicle, since the engine speed is fixed according to the gear stage of the pseudo gear stage, sufficient power generation cannot be achieved for the required driving force. In particular, when the power storage amount of the battery is low, the required driving force may not be output. Therefore, for example, in the configuration of Patent Document 1, power generation power is ensured by shifting the shift line to the high-speed side. 【0004】 Japanese Patent Application Laid-Open No. 2021-31034 【0005】 Shifting the shift line may give the user a sense of discomfort caused by the shift of the shift line. Therefore, there was room for improvement in order to ensure power generation power while suppressing the user's sense of discomfort. 【0006】 The present invention provides a hybrid vehicle capable of suppressing the user's sense of discomfort, ensuring power generation power, and thus ensuring driving power. 【0007】One aspect of the present invention relates to a hybrid vehicle comprising: drive wheels; an electric motor capable of driving the drive wheels; a power storage device for supplying power to the electric motor; an engine capable of rotating at an arbitrary rotational speed relative to the rotational speed of the drive wheels; and a control device, wherein the hybrid vehicle is capable of running based on a plurality of pseudo-gear stages in which the ratio of engine rotational speed to vehicle speed is fixed, and in the plurality of pseudo-gear stages, it is possible to set a first gear ratio that defines the relationship between the vehicle speed and the engine rotational speed, and a second gear ratio that tends to have a lower gear ratio than the first gear ratio, and the control device comprises a gear ratio setting unit that switches the setting of the gear ratio in the pseudo-gear stage between the first gear ratio and the second gear ratio based on predetermined switching conditions, and a driving control unit that runs the hybrid vehicle based on the gear ratio set by the gear ratio setting unit. 【0008】 According to the present invention, it is possible to secure power generation while suppressing user discomfort, and consequently, to secure power for driving. 【0009】 Figure 1 is a schematic diagram showing an example of the configuration of vehicle Ve. Figure 2 is a diagram for explaining the setting of simulated gear shifts. Figure 3 is a diagram showing an example of a shift map in simulated gear shifts, specifically an example when normal mode is set. Figure 4 is a diagram showing an example of a shift map in simulated gear shifts, specifically an example when sport mode is set. Figure 5 is a diagram showing an example of a shift map in simulated gear shifts, specifically an example when comfort mode is set. Figure 6 is a block diagram showing an example of a control unit ECU. Figure 7 is a time chart showing an example of a control example in the embodiment. 【0010】 Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The following embodiments are not limiting to the present invention, and not all of the elements described in the following embodiments are essential to the present invention. Furthermore, two or more elements described in the following embodiments may be arbitrarily combined without departing from the spirit of the present invention. In the following, identical or similar elements will be denoted by the same or similar reference numerals, and their descriptions may be omitted or simplified. 【0011】 [Vehicle] The vehicle targeted in this embodiment is a hybrid vehicle capable of so-called series driving (hereinafter simply referred to as "vehicle"). As shown in Figure 1, the vehicle Ve in this embodiment comprises a mechanically independent main drive unit DU1 and a secondary drive unit DU2. Here, "mechanically independent" means that the power of one is not mechanically transmitted to the other by a propeller shaft or the like. In this embodiment, the main drive unit DU1 outputs a main driving force to drive the front wheels FWR, and the secondary drive unit DU2 outputs a secondary driving force to drive the rear wheels RWR. 【0012】 As an example, in this embodiment, the main drive unit DU1 is positioned as the primary drive source in the vehicle Ve, and the secondary drive unit DU2 is positioned as an auxiliary drive source. A relatively large motor is used as the main drive motor MOT1 for the main drive unit DU1, and a smaller motor is used as the secondary drive motor MOT2 for the secondary drive unit DU2 compared to the main drive motor MOT1. 【0013】 Vehicle Ve further includes a battery BAT, which is an energy storage device, a voltage control unit VCU, and a control unit ECU. 【0014】 A battery (BAT) is a rechargeable secondary battery having multiple energy storage cells connected in series or in series-parallel. A battery (BAT) is configured to output high voltages, such as 100 to 400 [V]. Lithium-ion batteries and nickel-metal hydride batteries can be used as the energy storage cells in a battery (BAT). 【0015】 The voltage control unit (VCU) boosts the output voltage from the battery (BAT) while keeping it as DC, and outputs the boosted voltage to the main drive unit (DU1) and the secondary drive unit (DU2). In other words, in vehicle Ve, the boosted voltage generated by a single voltage control unit (VCU) can be supplied to both the main drive unit (DU1) and the secondary drive unit (DU2) in common. The voltage control unit (VCU) may also step down the input voltage input to the battery (BAT). The voltage control unit (VCU) is, for example, a DC-DC converter. 【0016】 [Main drive unit] The main drive unit DU1 comprises an engine ENG, a generator motor GEN which is an example of a generator, a main drive motor MOT1 which is an example of an electric motor, a first inverter INV1, a second inverter INV2, and a first transmission mechanism T1. 【0017】 An engine is an internal combustion engine such as a gasoline engine or a diesel engine, in which engine power is generated by the combustion of air introduced through an intake passage and engine fuel injected from a fuel injection valve. 【0018】 The main drive motor MOT1 and the generator motor GEN are connected to the battery BAT via the voltage control unit VCU, the first inverter INV1, and the second inverter INV2, enabling power supply from the battery BAT and energy regeneration to the battery BAT. In Figure 1, dotted lines indicate power wiring, and dashed lines indicate control signal lines. 【0019】 The first inverter INV1 converts DC voltage to AC voltage and supplies three-phase current to the generator motor GEN. The first inverter INV1 also converts the AC voltage generated by the generator motor GEN to DC voltage. 【0020】 The second inverter INV2 converts DC voltage to AC voltage and supplies three-phase current to the main drive motor MOT1. Furthermore, the second inverter INV2 converts the AC voltage generated by the main drive motor MOT1 to DC voltage when the vehicle Ve is braking. 【0021】 The first transmission mechanism T1 comprises an input shaft 21, a generator motor shaft 23, a counter shaft 25, and a first differential mechanism D1, all of which are arranged parallel to each other. 【0022】 The input shaft 21 is arranged coaxially with the crankshaft 12 of the engine ENG. Power from the crankshaft 12 is transmitted to the input shaft 21 via a damper 13. The input shaft 21 is provided with an output gear 32, which constitutes a gear train for driving the generator motor, as will be described later. 【0023】On the input shaft 21, opposite to the engine ENG side, is an output gear 53 which constitutes an engine power transmission gear train that transmits power from the engine ENG. Between the output gear 32 and the output gear 53 on the input shaft 21 is a hydraulic clutch CL which connects the input shaft 21 and the output gear 53 in a detachable manner. 【0024】 The generator motor shaft 23 is a double-structured rotating shaft comprising an inner shaft 27 and an outer shaft 29 arranged concentrically with respect to the inner shaft 27 on the outer circumference. On the engine ENG side of the inner shaft 27, there is an input gear 34 that meshes with the output gear 32 on the input shaft 21. The output gear 32 on the input shaft 21 and the input gear 34 on the inner shaft 27 constitute a gear train for driving the generator motor, which transmits power from the input shaft 21 to the inner shaft 27. 【0025】 Furthermore, an outer circumferential shaft 29 is installed on the outer diameter side of the inner circumferential shaft 27, approximately in the center, so as to be rotatable relative to it. A generator motor GEN is attached to the inner circumferential shaft 27 on the side opposite to the engine ENG side. The generator motor GEN comprises a rotor R fixed to the inner circumferential shaft 27 and a stator S fixed to a case (not shown) and positioned opposite the outer diameter side of the rotor R. 【0026】 The driving force from the input shaft 21 is transmitted to the inner circumferential shaft 27 of the generator motor shaft 23 via a gear train for driving the generator motor. As a result, the rotation of the inner circumferential shaft 27 causes the rotor R of the generator motor GEN to rotate. This allows the driving force from the input shaft 21 to be converted into electricity by the generator motor GEN. 【0027】 On the outer circumferential shaft 29, an output gear 52 is provided that meshes with an input gear 54 on the counter shaft 25, which will be described later. On the side opposite to the engine EN side, a main drive motor MOT1 is attached. The main drive motor MOT1 comprises a rotor R fixed to the outer circumferential shaft 29 and a stator S fixed to a case (not shown) and positioned opposite the outer diameter side of the rotor R. 【0028】The output gear 52 on the outer shaft 29 and the input gear 54 on the counter shaft 25 form a motor power transmission gear train for transmitting power from the outer shaft 29 to the counter shaft 25. Therefore, when the outer shaft 29 rotates due to the driving force of the main drive motor MOT1, that rotation is transmitted to the counter shaft 25 via the motor power transmission gear train. 【0029】 The counter shaft 25 is provided with, in order from the engine ENG side, an output gear 56 that meshes with the ring gear 58 of the first differential mechanism D1, and an input gear 54 that meshes with the output gear 53 on the input shaft 21 and the output gear 52 on the outer circumferential shaft 29. The output gear 53 on the input shaft 21 and the input gear 54 on the counter shaft 25 constitute an engine power transmission gear train for transmitting power from the input shaft 21 to the counter shaft 25. In addition, the output gear 56 on the counter shaft 25 and the ring gear 58 of the first differential mechanism D1 constitute a final gear train for transmitting the driving force of the counter shaft 25 to the first differential mechanism D1. 【0030】 The driving force of the main drive motor MOT1, which is input to the counter shaft 25 via the motor power transmission gear train, and the driving force of the engine ENG, which is input to the counter shaft 25 via the engine power transmission gear train, are output as the main driving force of the main drive unit DU1, transmitted to the first differential mechanism D1 via the final gear train, and then transmitted from the first differential mechanism D1 to the front wheel FWR. 【0031】 In this embodiment, the first transmission mechanism T1 of the main drive unit DU1 includes a first transmission mechanism 41 that mechanically connects the generator motor GEN and the engine ENG in a power-transmitting manner, and a second transmission mechanism 42 that mechanically connects the main drive motor MOT1 and the front wheel FWR in a power-transmitting manner. Specifically, the first transmission mechanism 41 consists of an input shaft 21, an output gear 32, an input gear 34, and an inner circumferential shaft 27, and the second transmission mechanism 42 consists of an outer circumferential shaft 29, an output gear 52, an input gear 54, a counter shaft 25, an output gear 56, and a first differential mechanism D1. 【0032】Furthermore, the hydraulic clutch CL is configured to selectively switch between a state in which the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is connected and a state in which the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is disconnected. That is, by engaging the hydraulic clutch CL, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is mechanically connected, and by releasing the hydraulic clutch CL, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is mechanically disconnected. In the first transmission mechanism T1, the input gear 54 meshes with the output gear 53 on the input shaft 21 and the output gear 52 on the outer shaft 29. Therefore, when the hydraulic clutch CL is engaged, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is mechanically connected, enabling power transmission between the first transmission mechanism 41 and the second transmission mechanism 42. On the other hand, when the hydraulic clutch CL is released, the output gear 53 disengages from the input shaft 21, mechanically interrupting the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42, making power transmission between the first transmission mechanism 41 and the second transmission mechanism 42 impossible. 【0033】 [Subordinate Drive Unit] The subordinate drive unit DU2 comprises a subordinate drive motor MOT2, a third inverter INV3, and a second transmission mechanism T2. The subordinate drive motor MOT2 is connected to the battery BAT via a voltage control unit VCU and a third inverter INV3, enabling power supply from the battery BAT and energy regeneration to the battery BAT. In Figure 1, dotted lines indicate power wiring, and dashed lines indicate control signal lines. 【0034】 The second transmission mechanism T2 comprises motor output shafts 26 and 28 arranged parallel to each other, and a second differential mechanism D2. 【0035】The subordinate drive unit DU2 has a third drive gear 62 mounted on one end of the motor output shaft 26 of the subordinate drive motor MOT2 so as to rotate integrally with it. A third driven gear 64 that meshes with the third drive gear 62 and an output gear 66 are mounted on an output shaft 28 that extends parallel to the motor output shaft 26 of the subordinate drive motor MOT2 so as to rotate integrally with the output shaft 28. Therefore, the driving force of the subordinate drive motor MOT2 is transmitted to the output shaft 28 via the third drive gear 62 and the third driven gear 64. The driving force transmitted to the output shaft 28 is then transmitted from the output gear 66 to the rear wheel RWR via the second differential mechanism D2. Conversely, the driving force from the rear wheel RWR is transmitted to the subordinate drive motor MOT2 via the second differential mechanism D2, the output gear 66, the output shaft 28, the third driven gear 64, the third drive gear 62, and the motor output shaft 26. 【0036】 Vehicle Ve also includes an accelerator pedal that acquires acceleration and deceleration requests, where the acceleration request to Vehicle Ve increases as the amount of operation increases and decreases as the amount of operation decreases; paddle shifters that shift up or down in the simulated gear shift described later; and a brake pedal (none of which are shown) that acquires deceleration requests to Vehicle Ve. 【0037】 [Drive Mode of Main Drive Unit] Next, the drive mode of the main drive unit DU1 will be explained. 【0038】 The drive modes of the main drive unit DU1 include an electric drive mode in which the driving force of the main drive motor MOT1 is output as the main driving force, and an engine drive mode in which the driving force of the engine ENG is output as the main driving force. In electric drive mode, the hydraulic clutch CL is released and the driving force of the main drive motor MOT1 is output as the main driving force. Electric drive mode includes EV driving and series driving, which will be described later. In engine drive mode, the hydraulic clutch CL is engaged and the driving force of the engine ENG is output as the main driving force. Engine drive mode includes engine driving, which will be described later. 【0039】<EV Driving (Electric Drive Mode)> In EV driving mode, the engine ENG is deactivated, and the main drive motor MOT1 is driven by electricity supplied from the battery BAT. Specifically, by driving the main drive motor MOT1 with electricity supplied from the battery BAT, the driving force of the main drive motor MOT1 rotates the outer circumferential shaft 29 of the generator motor shaft 23, and this rotation is transmitted to the counter shaft 25 via the motor power transmission gear train. The driving force of the main drive motor MOT1 transmitted in this way is output as the main driving force via the final gear train and the first differential mechanism D1, and transmitted to the front wheels FWR. This enables EV driving. 【0040】 <Series Operation (Power Drive Mode)> In series operation, the engine ENG is running, and the power generated by the generator motor GEN drives the main drive motor MOT1. Specifically, the driving force of the engine ENG is input from the input shaft 21 to the inner shaft 27 via the generator motor drive gear train, causing the inner shaft 27 to rotate. This causes the rotor R of the generator motor GEN, which is fixed to the inner shaft 27, to rotate, and the generator motor GEN generates electricity. The power generated by the generator motor GEN is supplied to the main drive motor MOT1, and this power drives the main drive motor MOT1. The driving force of the main drive motor MOT1 rotates the outer shaft 29 of the generator motor shaft 23, and this rotation is transmitted to the counter shaft 25 via the motor power transmission gear train. The driving force transmitted by the main drive motor MOT1 in this manner is output as the main driving force via the final gear train and the first differential mechanism D1, and transmitted to the front wheel FWR. This makes it possible to operate in so-called series driving mode, where the driving force of the engine ENG is entirely converted into electricity by the generator motor GEN. 【0041】Furthermore, when the vehicle Ve is decelerating, it performs regenerative driving, recovering energy through the regenerative operation of the main drive motor MOT1. Normally, the regenerated power is stored in the battery BAT, but in cases such as when continuously driving downhill, the battery BAT may reach full charge and charging of the battery BAT may not be possible. In such cases, the regenerated power is consumed by waste power, which is used to consume excess power that cannot be stored in the battery BAT. 【0042】 <Engine Driving (Engine Drive Mode)> In engine driving mode, with the hydraulic clutch CL engaged, the driving force of the engine ENG is output as the main driving force and transmitted to the front wheel FWR. That is, by engaging the hydraulic clutch CL, the driving force of the input shaft 21 is transmitted to the counter shaft 25 via the engine power transmission gear train, and then to the front wheel FWR via the final gear train and the first differential mechanism D1. This enables engine driving. Here, since the input shaft 21 and the inner shaft 27 are always connected via the gear train for driving the generator motor, the rotor R of the generator motor GEN rotates in conjunction with the rotation of the inner shaft 27. Therefore, since the generator motor GEN can generate electricity, the generated electricity can rotate the main drive motor MOT1, and so-called parallel driving is also possible, where the driving force of the engine ENG and the driving force of the main drive motor MOT1 are output as the main driving force. 【0043】 In addition, the Vehicle Ve offers several driving modes that allow for changes in driving force characteristics: a Sport mode that enhances acceleration / deceleration responsiveness and steering responsiveness; a Normal mode that prioritizes a balance between steering operability and acceleration; and a Comfort mode (or Eco mode) that suppresses fluctuations in fuel injection amount and motor torque to promote fuel-efficient driving. These Sport, Normal, and Comfort modes can be set and switched using, for example, a user-operated switch (not shown). 【0044】Further, in the pseudo gear stage, the vehicle Ve can be set to a pseudo shift mode in which the user can select an arbitrary gear stage. Here, the pseudo gear stage is a gear stage that simulates a gear stage determined based on, for example, the vehicle speed and the accelerator opening degree in a state where the engine ENG and the drive wheels are disengaged. The pseudo shift mode can run at an engine speed based on a plurality of pseudo gear stages and the vehicle speed. Thereby, it becomes possible to produce a pseudo gear shift simulating a stepped transmission. In the following description, when simply referred to as a gear stage, it is assumed to be a pseudo gear stage unless otherwise specified. 【0045】 The pseudo shift mode is set, for example, when the user performs a predetermined shift operation, a switch operation, or the like. And the switching of the gear stage in the pseudo gear stage is switched, for example, based on the operation of the accelerator pedal or by the operation of paddle shift by the user. Note that the pseudo shift mode is not accepted for setting in consideration of the durability of the device, etc., even when the user sets the pseudo shift mode, for example, when the temperature of the catalyst is higher than a predetermined temperature (high temperature) or the temperature of the battery BAT is higher than a predetermined temperature (high temperature). The setting of the pseudo gear stage and the shift map in the pseudo gear stage will be described later. 【0046】 [Control Device] The control device ECU is a computer that comprehensively controls the entire vehicle Ve and has, for example, a processor that performs various operations, a storage unit that stores various information such as a predetermined map and program in a non-transitory storage medium, and an input / output unit (both not shown) that controls the input / output of data inside and outside the control device ECU. For example, the control device ECU is realized by one ECU (Electronic Control Unit) or by a plurality of ECUs cooperating with each other. 【0047】For example, the control device ECU is communicably provided with each inverter INV, voltage control unit VCU, engine ENG, hydraulic clutch CL, etc. For example, the control device ECU controls the output of the engine ENG by controlling the engine ENG, controls the output of the power generation motor GEN by controlling the first inverter INV1, and controls the output of the main drive motor MOT1 by controlling the second inverter INV2, respectively. 【0048】 The control device ECU executes various programs stored in, for example, the storage unit. As described above, in the vehicle Ve in the embodiment, it is possible to set a pseudo-shifting mode in which pseudo-shifting simulating stepped shifting is performed for traveling. On the other hand, in the pseudo-shifting mode, since the engine speed Ne is uniquely determined for each shift stage of the pseudo-shift stage, for example, when the required driving force increases, the power generation amount may be insufficient and the electric power for traveling (hereinafter referred to as "traveling electric power") may not be secured. As such a countermeasure, it is conceivable to change the shift stage or shift line to be used, but in that case, the user may feel uncomfortable due to the change in the shift stage or shift line. Therefore, in the embodiment, it is configured to secure the generated electric power and thus the traveling electric power while suppressing giving the user a sense of discomfort. 【0049】Here, we will explain how to set the pseudo-gear stages when the pseudo-gear mode is set. Figure 2 is a diagram for explaining the setting of pseudo-gear stages, with the vertical axis showing engine speed Ne and the horizontal axis showing vehicle speed. As shown in Figure 2, the pseudo-gear stages can be set from 1st to 8th gear. The slope of each gear stage indicates the gear ratio. That is, similar to a stepped transmission, the gear ratio decreases as the gear stage becomes higher. In this embodiment, two gear ratios, including different gear ratios, are set for each gear stage. Here, one of the two gear ratios will be called the "first gear ratio" and the other the "second gear ratio". In the example shown in Figure 2, as an example, two different gear ratios are set for gear stages 4 to 8. Note that for gears 1 to 3, the first gear ratio and the second gear ratio are the same and are common. In Figure 2, the thin solid line shows the first gear ratio that can be set during normal operation (not high power output), and the thick solid line shows the second gear ratio that can be set during high power output. The first gear ratio is determined based on the relationship between vehicle speed and engine speed Ne, as shown in Figure 2. The second gear ratio, here, is a gear ratio that tends to be lower than the first gear ratio, and is set to a gear ratio that can suppress the feeling of discomfort given to the user when switching between the first and second gear ratios. The setting of the first and second gear ratios is switched according to, for example, the accelerator opening or the amount of charge stored in the battery BAT. Details will be described later. 【0050】The reason why two gear ratios, a first gear ratio and a second gear ratio, are provided is, as mentioned above, because if the required driving force increases, for example, the amount of power generated may be insufficient, making it impossible to secure driving power. Specifically, for example, when high output is required on a highway, the amount of power generated may be insufficient, making it impossible to secure driving power to meet the required driving force. When the pseudo-gear mode is set, the ratio of engine speed Ne to vehicle speed is fixed for each gear in the pseudo-gear stage, so the amount of power generated is limited depending on the engine speed Ne. Therefore, in this embodiment, a first gear ratio and a second gear ratio are set, and when high output is required, the gear ratio is switched from the first gear ratio to the second gear ratio for driving. Here, we assume a situation where the engine ENG is running and the main drive motor MOT1 is driven by the power generated by the generator motor GEN, so we assume that it is in a series driving state. Furthermore, the dashed line in the example shown in Figure 2 indicates the change in engine speed Ne when the transmission is shifted in steps based on pseudo-gear stages, in cases where high output is required. 【0051】 Furthermore, as shown in Figure 2, the maximum engine speed for each gear corresponding to the same vehicle speed is the same whether the first gear ratio is set or the second gear ratio is set. In other words, the vehicle speed corresponding to the maximum engine speed when the first gear ratio is set is the same as the vehicle speed corresponding to the maximum engine speed when the second gear ratio is set. For example, in the example shown in Figure 2, the maximum engine speed corresponding to the same vehicle speed is the same for both the first gear ratio setting and the second gear ratio setting from 4th to 6th gear. By making the maximum engine speed the same for both the first and second gear ratio settings in this way, it is possible to suppress the sense of discomfort that may be caused to the user when the gear ratio setting is switched, compared to when the maximum engine speed changes depending on the gear ratio setting. 【0052】Furthermore, in setting the second gear ratio, as described above, a smaller gear ratio than the first gear ratio is set, resulting in a positive engine speed Ne when the vehicle speed is 0 [km / h]. In other words, using the same upper limit for engine speed for both the first and second gear ratios as a reference, the intercept, which is the point of intersection with the engine speed shown on the vertical axis, is made different, and the setting of the second gear ratio results in a larger positive value than the setting of the first gear ratio. For example, in the example shown in Figure 2, in setting the second gear ratio, among the 4th to 8th gears, which have a smaller gear ratio than the first gear ratio, the 4th to 6th gears take the same positive value, while the 7th and 8th gears take a larger positive value than the 4th to 6th gears. The reason why the 7th and 8th gears take a larger positive value than the 4th to 6th gears is that the amount of power generation required is greater in the higher gears. Thus, in the second gear ratio, since the engine speed Ne is a positive value when the vehicle speed is 0 [km / h], the engine speed Ne when the second gear ratio is set can be increased, and the amount of power generated can be secured by the increase in engine speed Ne. 【0053】 In the second gear ratio set in this manner, the engine speed Ne is configured to maintain its upper limit in a predetermined vehicle speed range at a predetermined gear in the pseudo-gear stage. In the example shown in Figure 2, the engine speed Ne extends horizontally from 4th to 6th gear to maintain its upper limit. The reason why the range of the predetermined vehicle speed range in which the upper limit is maintained increases with increasing speed in gears 4 through 6 is that higher output is required in higher gears, and therefore it is necessary to ensure sufficient power generation. 【0054】 The gear selection configured in this way is determined according to changes in throttle opening and vehicle speed. Figures 3 to 5 are shift maps illustrating this simulated gear selection. Figure 3 shows an example of a shift map when driving in normal mode, Figure 4 shows an example of a shift map when driving in sport mode, and Figure 5 shows an example of a shift map when driving in comfort mode. 【0055】For example, in the shift map shown in Figure 3, the solid line shows the shift line when shifting based on the first gear ratio, and the dashed line shows the shift line when shifting using the second gear ratio. In the shift line for the second gear ratio, parts not shown in the figure are considered to overlap with the shift line for the first gear ratio, and other figures are omitted. In other words, in the shift map shown in Figure 3, the second gear ratio is set only in the region where the accelerator opening is α or greater when shifting between 4th and 5th gear, and between 5th and 6th gear. This specification may be set as appropriate by the manufacturer of the vehicle Ve. Furthermore, the accelerator pedal position "β" and the accelerator pedal position "α" represent the hysteresis that occurs when setting the second gear ratio or releasing the setting of the second gear ratio (in other words, switching from the second gear ratio to the first gear ratio). For example, when the accelerator pedal is pressed further and the accelerator pedal position becomes β or greater, the second gear ratio is set. When the accelerator pedal is released from a state where the accelerator pedal position is β or greater and the accelerator pedal position becomes less than α, the setting of the second gear ratio is released, i.e., the first gear ratio is set. In other words, the threshold for switching from the first gear ratio to the second gear ratio based on the accelerator pedal position is set higher than the threshold for switching from the second gear ratio to the first gear ratio. 【0056】 As is well known, gear changes based on a shift map configured in this way are performed, for example, by increasing or decreasing the accelerator opening based on the operation of the accelerator pedal, or by increasing or decreasing the vehicle speed. 【0057】 In this shift map, downshifts and upshifts are configured to shift based on the same shift line. However, to prevent shifts from occurring multiple times across the same shift line in a short period of time, separate upshift and downshift lines may be provided, and a predetermined hysteresis may be introduced between the upshift and downshift lines. 【0058】The shift map for Sport mode in Figure 4 and the shift map for Comfort mode in Figure 5 are shown using a similar configuration. Note that the configuration of the shift maps for Sport mode and Comfort mode is the same as that of the shift map for Normal mode, which was explained using Figure 3, so its explanation is omitted here. 【0059】 The control unit (ECU) uses the thus set gear ratio to execute a predetermined program to ensure sufficient power for driving while minimizing any discomfort to the user. As functional units realized by the execution of such a program, the control unit (ECU) includes a gear ratio setting unit 100 and a driving control unit 110, as shown in Figure 6. The processes described below as being performed by the gear ratio setting unit 100 and the driving control unit 110 are processes realized by the control unit (ECU). 【0060】 The control unit (ECU) receives input from various sensors. For example, it receives input from an accelerator position sensor 120 that detects the amount of operation on the accelerator pedal of the vehicle Ve, a vehicle speed sensor 130 that detects the vehicle speed of the vehicle Ve, a catalyst temperature sensor 140 that detects the temperature of the catalyst, a battery temperature sensor 150 that detects the temperature of the battery BAT, a battery SOC sensor 160 that detects the amount of charge stored in the battery BAT, and a shift position sensor 170 that detects the shift position of a shift device such as a paddle shift. The values ​​from the various sensors are not limited to those detected; they may also be obtained by estimation or other means. 【0061】 The gear ratio setting unit 100 switches the gear ratio setting in the simulated gear stage between the first gear ratio and the second gear ratio based on predetermined switching conditions. That is, it switches the settings of the first gear ratio and the second gear ratio, as explained using Figure 2 above, based on predetermined switching conditions. 【0062】Here, the predetermined switching conditions are conditions based on at least one of the following parameters: the amount of accelerator pedal operation (i.e., accelerator opening), vehicle speed, and battery output. Parameters related to battery output include, for example, the allowable output power that the battery BAT can handle, the amount of charge stored in the battery BAT, and the temperature of the battery BAT. The allowable output power of the battery BAT is determined based on the current amount of charge stored in the battery BAT. In this embodiment, thresholds for the predetermined switching conditions are set for each of the parameters related to accelerator opening, vehicle speed, and battery output. 【0063】 Specifically, the gear ratio setting unit 100 determines that predetermined switching conditions are met, for example, when the accelerator opening is greater than or equal to a predetermined value, when the vehicle speed is greater than or equal to a predetermined vehicle speed, when the allowable output power of the battery BAT is less than a predetermined power, when the amount of charge stored in the battery BAT is less than a predetermined amount of energy, or when the temperature of the battery BAT is below a first temperature or above a second temperature higher than the first temperature. 【0064】 In one embodiment, the gear ratio switching conditions are determined based on the accelerator opening and the allowable output power of the battery BAT. Specifically, the gear ratio setting is switched from the first gear ratio to the second gear ratio when the accelerator opening is greater than or equal to a predetermined value and the allowable output power of the battery BAT is less than a predetermined power. By switching the gear ratio setting from the first gear ratio to the second gear ratio when the conditions of two parameters are met in this way, the switching conditions become stricter compared to, for example, determining the gear ratio switching based on one parameter, thus reducing the discomfort to the user caused by the change in gear ratio. The switch from the second gear ratio to the first gear ratio is performed when the accelerator opening is less than a predetermined value or the allowable output power of the battery BAT is greater than or equal to a predetermined power, while the second gear ratio is set. 【0065】Furthermore, a predetermined hysteresis may be set for the accelerator opening and the allowable output power. Regarding the accelerator opening, as explained using Figure 3 above, for example, the threshold for switching from the first gear ratio to the second gear ratio is set higher than the threshold for switching from the second gear ratio to the first gear ratio. Also, regarding the allowable output power, for example, the threshold for switching from the first gear ratio to the second gear ratio is set lower than the threshold for switching from the second gear ratio to the first gear ratio. 【0066】 Here, we have described an example of switching the gear ratio based on the accelerator opening and the allowable power output, but the conditions for determining the gear ratio change are not limited to these. Other parameters or similar parameters mentioned above may also be used to determine the gear ratio change. The selection of such parameters may be set by the manufacturer as appropriate, depending on, for example, the required driving force and the driving situation. 【0067】 Furthermore, the gear shifting based on the first and second gear ratios is configured to occur based on the gear shifting conditions for each gear ratio. Specifically, when shifting with the first gear ratio setting, the gear shifting is performed along the gear shift line for the first gear ratio based on the shift map shown in Figure 3, etc. Similarly, when shifting with the second gear ratio setting, the gear shifting is performed along the gear shift line for the second gear ratio based on the shift map shown in Figure 3, etc. When the vehicle is running with the first gear ratio setting, the gear ratio setting unit 100 refers to the shift map and switches the gear ratio setting from the first gear ratio to the second gear ratio based on the gear shift line for the first gear ratio when the predetermined switching conditions described above are met. In other words, even when the predetermined switching conditions for switching the gear ratio setting from the first gear ratio to the second gear ratio are met, the gear ratio setting is not switched immediately, but rather the system waits for the gear shift timing based on the shift map before switching the gear ratio. In this way, by switching the gear ratio settings based on the shift timing, the user's discomfort caused by the change in gear ratio settings can be reduced compared to when the gear ratio settings are switched immediately after a predetermined switching condition is met. In other words, by coordinating with the shift timing, it becomes less likely for the user to notice that the gear ratio settings have been changed simply by shifting gears. 【0068】Similarly, when the vehicle is running with the second gear ratio setting, the gear ratio setting unit 100, when the predetermined switching conditions described above are met, refers to the shift map and switches the gear ratio setting from the second gear ratio to the first gear ratio based on the shift line of the second gear ratio. This is to reduce the user's discomfort caused by the change in the gear ratio setting, similar to the switching from the first gear ratio to the second gear ratio. Note that the shifting along the shift line of the first gear ratio described above is an example of the "first shift condition" in the embodiment, and the shifting along the shift line of the second gear ratio is an example of the "second shift condition" in the embodiment. 【0069】 The driving control unit 110 controls the main drive motor MOT1 to drive the front wheel FWR with a driving force based on the simulated gear ratio, thereby driving the vehicle Ve. The driving control unit 110 also drives the vehicle Ve based on the gear ratio set by the gear ratio setting unit 100. That is, during normal driving, the vehicle drives based on the setting of the first gear ratio, and when high output is required and the above-mentioned switching conditions are met, the vehicle drives based on the setting of the second gear ratio set by the gear ratio setting unit 100. 【0070】 Furthermore, as explained using Figure 2, in setting the second gear ratio, the system is configured to maintain the engine speed Ne at its upper limit when it reaches that limit. Therefore, when the engine speed Ne reaches its upper limit, the driving control unit 110 drives the vehicle in a manner that maintains the engine speed Ne at that upper limit for a predetermined time. In a normal stepped transmission, for example, when the engine speed approaches the upper limit, the gear is changed by upshifting. However, in this embodiment, the purpose is to secure power generation by setting the second gear ratio. Therefore, in order to secure that power generation, or in other words, to suppress the drop in engine speed Ne that would occur if upshifting were performed, the system is configured to maintain the upper limit of the currently set gear for a predetermined time. By suppressing the drop in engine speed Ne, power generation can be secured accordingly. 【0071】Furthermore, the predetermined time for maintaining the upper limit of rotational speed may be set to increase as the simulated gear ratio increases. This is because higher gear ratios require higher output and thus more power generation. In other words, by increasing the predetermined time for maintaining the upper limit of rotational speed for higher gear ratios, it becomes possible to secure the amount of power generation corresponding to the required driving force. 【0072】 [Time Chart] Next, an example of control in the embodiment will be explained using a time chart. Figure 7 shows the time chart, and here, as an example, it shows the case when the accelerator pedal is pressed down significantly while cruising using a cruise control system, etc., and high output is required, and the gear ratio is switched from the first gear ratio to the second gear ratio. Note that in the example shown in Figure 7, it is assumed that the operation to select the pseudo-gear mode has been performed. 【0073】 In the example shown in Figure 7, the vertical axis represents the gear position display in the simulated gear shift, vehicle speed, accelerator opening, battery charge level, battery power allowable, high power request flag, time to maintain upper limit rotational speed, engine speed, and current gear position, while the horizontal axis represents time. In this embodiment, as an example, accelerator opening and battery power allowable are used as parameters to switch the gear ratio setting. Therefore, thresholds for switching the gear ratio setting, indicated by dashed lines, are set for the accelerator opening and battery power allowable. Although a predetermined hysteresis may be provided for the threshold as described above, an example without hysteresis is shown here for the sake of explanation. 【0074】 Furthermore, in the change of engine speed Ne, the thin solid line shows the change in engine speed Ne when the first gear ratio is set, and the thick solid line shows the change in engine speed Ne when the second gear ratio is set. The thin dashed line shows the change in engine speed Ne when the engine is operated with the first gear ratio set, and the thick dashed line shows the change in engine speed Ne when the engine is operated with the second gear ratio set. A detailed explanation follows below. 【0075】 Up to time t1, the vehicle is cruising with the accelerator pressed down, for example, in the "8th gear" of the simulated gear shift. In other words, it is cruising at a high speed on a highway or similar road. Therefore, the vehicle speed, accelerator opening, battery charge level, battery power rating, and engine speed Ne are all approximately constant up to time t1. Also, since the accelerator opening and battery power rating do not exceed their respective thresholds, the high power request flag is off. Furthermore, the timer does not measure the time required to maintain the upper limit of engine speed because the engine speed Ne has not reached the upper limit. And since the current gear is 8th gear, the gear status is displayed as "8th gear" on a designated display unit (not shown), such as the instrument panel or navigation system. 【0076】 From this state, for example, the user may perform a so-called kickdown operation, causing the accelerator opening to increase rapidly (at time t1). For example, this could occur when changing lanes on a highway. 【0077】 As a result, the engine speed Ne increases significantly with increasing throttle opening. Also, as the throttle opening increases, the gear in the simulated gear shift is downshifted from "8th gear" to "4th gear" (at time t2) by crossing the gear shift line in the shift map mentioned above. In the example shown in Figure 7, at time t2, the throttle opening exceeds a predetermined value, surpassing the threshold for switching the gear ratio setting. In this embodiment, as described above, two parameters are set for switching the gear ratio setting: throttle opening and the allowable output power of the battery BAT. At time t2, the allowable output power of the battery BAT is not below the predetermined value and has not exceeded the threshold, so the condition for switching the gear ratio setting is not met. Therefore, the high output request flag remains off. As the throttle opening increases, the vehicle speed also begins to increase. Also, since the gear in the simulated gear shift has become "4th gear", the gear display changes to "4th gear". 【0078】On the other hand, as the accelerator opening increases, the supply of driving power from the battery BAT to the main drive motor MOT1 increases, and the battery BAT's charge gradually begins to decrease. As the battery BAT's charge decreases, the battery BAT's allowable output power also begins to decrease (at time t3). During this time, the engine speed Ne and vehicle speed continue to increase. 【0079】 When the battery BAT's allowable output power falls below a predetermined level, the battery BAT's allowable output power exceeds the threshold for switching the gear ratio setting, meaning both the accelerator opening and the battery BAT exceed the threshold. Therefore, the high-power request flag is turned on (at time t4). In this embodiment, to minimize user discomfort caused by the gear ratio change, the gear ratio setting is not changed when this high-power request flag is turned on. In other words, the gear ratio setting remains at the first gear ratio. During this time, the engine speed Ne continues to rise, and the battery BAT's charge and allowable output power continue to decrease. 【0080】 If the engine speed Ne continues to rise, it will reach its upper limit (at time t5). Therefore, at time t5, in order to maintain the upper limit, a timer is turned on to count a predetermined time corresponding to the currently set simulated gear (e.g., 4th gear). The upper limit is then maintained until the predetermined time has elapsed. 【0081】Furthermore, as explained using Figure 2 above, the upper limit of rotational speed is the same for both the first and second gear ratios. Although the setting for maintaining this upper limit of rotational speed is the setting for the second gear ratio, maintaining this upper limit of rotational speed is unlikely to cause discomfort to the user, and can be said to be essentially equivalent to the setting for the first gear ratio. Therefore, the setting for the second gear ratio is performed prior to the shift timing. In other words, the use of the second gear ratio when the intercept at the vehicle speed of "0 km / h" is "positive" is not performed at this point. The use of the second gear ratio when the intercept is "positive" is performed when the shift timing is reached. This is because changing the gear ratio setting at the timing when the gear ratio effectively changes can suppress discomfort to the user. 【0082】 Then, after a predetermined time has elapsed, a gear change is performed in the simulated gear (at time t6). Here, the gear is upshifted from "4th gear" to "5th gear". Therefore, using this gear change timing as a trigger, the engine speed Ne is controlled using the second gear ratio in effect. Note that "in effect" means that, as mentioned above, at time t5, the engine speed Ne reaches its upper limit and the second gear ratio is specified to maintain that upper limit, but at time t6, the second gear ratio with a positive intercept at vehicle speed "0 km / h" is used. At time t6, the gear display becomes "5th gear". 【0083】 In this way, by upshifting from "4th gear" to "5th gear," the engine speed Ne temporarily decreases based on the setting of the second gear ratio. Then, since the accelerator pedal is maintained at the predetermined position where it has been pressed further, the engine speed Ne begins to rise again. During this time, the vehicle speed also continues to increase. 【0084】When the engine speed Ne rises again, it reaches the upper limit of the current simulated gear ratio, "5th gear" (at time t7). Therefore, to maintain the upper limit of the engine speed, the timer is turned on and a predetermined time corresponding to the currently set gear ratio of "5th gear" is counted. The upper limit of the engine speed is then maintained until the predetermined time has elapsed. The specific details are the same as those at time t5, so a detailed explanation is omitted. 【0085】 Then, after a predetermined time has elapsed, the gear shifts up from the current "5th gear" to "6th gear," and the gear indicator changes to "6th gear" (at time t8). 【0086】 In this way, by upshifting from "5th gear" to "6th gear," the engine speed Ne temporarily decreases based on the setting of the second gear ratio. Then, since the accelerator pedal is maintained at the predetermined position where it has been pressed further, the engine speed Ne begins to rise again. During this time, the vehicle speed also continues to increase. 【0087】 Next, in the example shown in Figure 7, the accelerator pedal is released, and the accelerator opening begins to decrease (at time t9). When the accelerator opening falls below a predetermined value, it exceeds the threshold for switching the gear ratio setting, and the predetermined switching condition is met (at time t10). In other words, the condition for returning the gear ratio setting from the second gear ratio to the first gear ratio is met. Therefore, the high power request flag is turned off. The condition for switching the gear ratio setting from the second gear ratio to the first gear ratio is met when one of the parameters, either the accelerator opening or the allowable output power, exceeds a threshold. At time t10, the high power request flag is turned off, and it is also possible to switch the gear ratio setting from the second gear ratio to the first gear ratio. However, in this embodiment, in order to suppress discomfort for the user as described above, the gear ratio setting is switched after waiting for the gear shift timing (i.e., the gear shift timing based on the setting of the second gear). During this time, the vehicle speed and engine speed Ne remain high because the accelerator pedal is still at a high opening. 【0088】As the accelerator opening gradually decreases, for example, the accelerator opening crosses the gear shift line on the shift map, causing the system to shift up from the current "6th gear" to "7th gear" (at t11). At this point t11, the gear ratio setting is switched from the second gear ratio to the first gear ratio. Since the high power request flag is turned off, the power generated by the generator motor GEN is stored in the battery BAT, and the amount of charge in the battery BAT gradually begins to increase. In addition, as the amount of charge in the battery BAT increases, the allowable output power also begins to increase. 【0089】 Then, as the allowable output power increases, the allowable output power recovers to above a predetermined level and exceeds the threshold (at time t12). Also at this time t12, for example, as the accelerator opening decreases, the gear shift in the simulated gear shift step shifts up from "7th gear" to "8th gear" by crossing the gear shift line on the shift map. As a result, the gear shift display changes from "7th gear" to "8th gear". 【0090】 Furthermore, from time t11 onward, the first gear ratio is set, and the engine speed Ne is controlled based on the setting of the first gear ratio. 【0091】 As described above, in this embodiment, when a high power output request is made, the gear ratio is switched from the first gear ratio to a second gear ratio which has a smaller gear ratio than the first gear ratio. As a result, the engine speed Ne is controlled to the higher rotational speed side, which allows for greater power generation than when the first gear ratio is set, and consequently, sufficient power for driving can be secured. For example, in the example shown in Figure 7, the engine speed Ne can be shifted to the higher rotational speed side by the amount enclosed by the thick solid line and the thin dashed line from t5 to t11, and the amount shifted to the higher rotational speed side allows for greater power generation and, consequently, sufficient power for driving. In other words, if the second gear ratio is not set as in this embodiment, even if the high power output request flag is turned on, the engine speed Ne will be controlled based on the setting of the first gear ratio, and there is a risk that the power generation and driving power will be insufficient for the requested driving force. However, in this embodiment, when the high power output request flag is turned on, a second gear ratio that can be shifted to the higher rotational speed side is set, which prevents insufficient power generation and inability to secure power for driving. 【0092】 Furthermore, by securing sufficient power for driving, the required driving force can be met, resulting in high output and high acceleration. 【0093】 Furthermore, in this embodiment, when setting the second gear ratio, the gear ratio is switched within the same gear position. Therefore, compared to a configuration that changes the set gear position or gear line to shift the engine speed Ne to a higher side when high output is required, for example, this reduces the sense of discomfort for the user. 【0094】 Furthermore, in this embodiment, the upper limit of the engine speed at the same vehicle speed is set to be the same for both the first and second gear ratios, thereby suppressing the discomfort caused to the user due to the difference in upper limit of engine speed between the first and second gear ratios. 【0095】 Furthermore, in this embodiment, the timing for switching the gear ratio setting between the first gear ratio and the second gear ratio is set to the shift timing based on the currently set gear ratio, thus suppressing the sense of unfamiliarity to the user caused by the switching of the gear ratio setting. In other words, it is possible to make the user feel that the engine speed Ne has changed due to the gear shift operation. 【0096】 Thus, in this embodiment, it is possible to secure power generation while suppressing discomfort to the user, and as a result, to secure power for driving. 【0097】 Although embodiments of the present invention have been described above with reference to the drawings, it goes without saying that the present invention is not limited to the embodiments described above. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these are also understood to naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined arbitrarily without departing from the spirit of the invention. 【0098】Furthermore, the control described in the above-mentioned embodiments can be realized by executing a pre-prepared control program on a computer. This control program is recorded on a computer-readable storage medium and executed by reading it from the storage medium. This control program may also be provided in the form of a non-transient storage medium such as flash memory, or it may be provided via a network such as the Internet. The computer that executes this control program may be included in the control device, included in an electronic device such as a smartphone, tablet terminal, or personal computer that can communicate with the control device, or included in a server device that can communicate with these control devices and electronic devices. 【0099】 This specification contains at least the following information. The components indicated in parentheses in the embodiments described above are, but are not limited thereto. 【0100】 (1) A hybrid vehicle (vehicle Ve) comprising: drive wheels (front wheels FWR); an electric motor (main drive motor MOT1) capable of driving the drive wheels; a power storage device (battery BAT) that supplies power to the electric motor; an engine (engine ENG) capable of rotating at any rotational speed relative to the rotational speed of the drive wheels; and a control device (control device ECU), wherein the hybrid vehicle is capable of running based on a plurality of pseudo-gear stages in which the ratio of engine rotational speed (engine rotational speed Ne) to vehicle speed is fixed, and in the plurality of pseudo-gear stages, it is possible to set a first gear ratio that defines the relationship between the vehicle speed and the engine rotational speed, and a second gear ratio that tends to have a lower gear ratio than the first gear ratio, and the control device comprises a gear ratio setting unit (gear ratio setting unit 100) that switches the setting of the gear ratio in the pseudo-gear stage between the first gear ratio and the second gear ratio based on predetermined switching conditions, A hybrid vehicle comprising a driving control unit (driving control unit 110) that drives the hybrid vehicle based on the gear ratio set by the gear ratio setting unit. 【0101】According to (1), for example, by switching the gear ratio setting from the first gear ratio to the second gear ratio based on predetermined switching conditions, the engine speed can be shifted to the higher speed side, and as a result, power generation can be secured, and consequently power for driving can be secured. Furthermore, since the second gear ratio is a gear ratio set in the same pseudo-gear stage (in other words, the gear stage or gear line is not changed), power for driving can be secured while suppressing any discomfort that may be given to the user. 【0102】 (2) A hybrid vehicle as described in (1), wherein the predetermined switching condition is a condition based on at least one of the amount of operation of the accelerator pedal, the vehicle speed, and the output of the energy storage device, and the gear ratio setting unit switches the gear ratio setting between the first gear ratio and the second gear ratio when the predetermined switching condition is met. 【0103】 According to (2), for example, the gear ratio setting can be switched between the first gear ratio and the second gear ratio depending on the state of each parameter. 【0104】 (3) A hybrid vehicle as described in (2), wherein the setting of the first gear ratio is configured to be set based on a first shift condition for switching gears in the pseudo-gear stage, the setting of the second gear ratio is configured to be set based on a second shift condition for switching gears in the pseudo-gear stage, and the gear ratio setting unit switches the setting of the gear ratio from the first gear ratio to the second gear ratio based on the first shift condition when the vehicle is running with the setting of the first gear ratio and the predetermined switching condition is met. 【0105】 According to (3), by switching from the first gear ratio to the second gear ratio under the shifting conditions for the currently set first gear ratio (for example, shifting timing based on the shift map), the discomfort that may be caused to the user can be suppressed compared to when the gear ratio is switched at a timing other than such a shifting timing. 【0106】(4) A hybrid vehicle as described in (3), wherein the predetermined switching conditions for switching the gear ratio setting from the first gear ratio to the second gear ratio are that the amount of operation of the accelerator pedal is greater than or equal to a predetermined value, and the allowable output power that allows the output of the energy storage device is less than a predetermined power. 【0107】 According to (4), by using two parameters as the switching condition, it is possible to reduce the sense of discomfort that may be caused to the user compared to, for example, the case where the gear ratio setting is switched from the first gear ratio to the second gear ratio using one parameter as the condition. 【0108】 (5) A hybrid vehicle as described in (4), wherein the gear ratio setting unit switches the gear ratio setting from the second gear ratio to the first gear ratio based on the second gear condition when the vehicle is running with the second gear ratio setting and the predetermined switching condition is met. 【0109】 According to (5), by switching from the second gear ratio to the first gear ratio under the shifting conditions for the currently set second gear ratio (for example, shifting timing based on the shift map), the discomfort that may be caused to the user can be suppressed compared to when the gear ratio is switched at a timing other than such a shifting timing. 【0110】 (6) A hybrid vehicle as described in (5), wherein the predetermined switching condition for switching the gear ratio setting from the second gear ratio to the first gear ratio is that the amount of operation of the accelerator pedal is less than a predetermined value, or the allowable output power that allows the output of the energy storage device is equal to or greater than a predetermined power. 【0111】 According to (6), the condition for switching back from the second gear ratio to the first gear ratio is to make one of the two conditions the switching condition, which allows for a quicker return to the normal gear ratio (first gear ratio), and as a result, the discomfort that may be caused to the user as described above can be suppressed. 【0112】(7) A hybrid vehicle according to (5) or (6), wherein in each gear step of the pseudo-gear step, the vehicle speed corresponding to the upper limit of the engine rotational speed when the first gear ratio is set and the vehicle speed corresponding to the upper limit of the engine rotational speed when the second gear ratio is set are the same. 【0113】 According to (7), having the same upper limit for rotational speed for the first gear ratio and the second gear ratio can reduce the discomfort that may be caused to the user compared to the case where the upper limits for rotational speed are different. 【0114】 (8) A hybrid vehicle as described in (7), wherein the engine speed when the vehicle speed is 0 km / h with the second gear ratio set is a positive value. 【0115】 According to (8), since the engine speed is positive when the vehicle speed is 0 km / h with the second gear ratio, the engine speed can be increased, and thus the amount of power generated can be secured. 【0116】 (9) A hybrid vehicle according to (8), wherein the second gear ratio is set such that the engine speed maintains the upper limit speed in a predetermined vehicle speed range in at least one of the pseudo-gear stages. 【0117】 According to (9), by maintaining the upper limit of engine speed within a predetermined vehicle speed range, it is possible to maintain a high engine speed, and thus the amount of power generated can be secured. In other words, when upshifting, the engine speed that decreases due to the upshift can be kept higher than when the predetermined vehicle speed range is not maintained. This ensures that the amount of power generated can be secured. 【0118】 (10) A hybrid vehicle as described in (9), wherein the driving control unit, when the second gear ratio is set, reaches the upper limit speed, maintains the engine speed at the upper limit speed for a predetermined time and drives the vehicle. 【0119】According to (10), by maintaining the upper limit rotation speed for a predetermined time, more power generation can be secured. 【0120】 (11) A hybrid vehicle as described in (10), wherein the predetermined time is longer as the gear ratio of the simulated gear ratio increases. 【0121】 According to (11), higher speeds require higher output and thus more power generation. Therefore, by increasing the predetermined time for maintaining the upper limit rotational speed in higher speeds, it is possible to secure power generation that corresponds to the required driving force. 【0122】 (12) A hybrid vehicle according to (1) or (2), wherein in at least some of the pseudo-gear stages, the first gear ratio and the second gear ratio are the same gear ratio. 【0123】 According to (12), by making at least some of the gear ratios common between the first gear ratio and the second gear ratio, the sense of discomfort that may be caused to the user can be suppressed. 【0124】 (13) A hybrid vehicle according to (1) or (2), wherein the hybrid vehicle is equipped with a generator (generator motor GEN) that converts the power of the engine into electricity, is capable of series driving by driving the electric motor with the electricity generated by the generator, and the driving control unit controls the electric motor to drive the drive wheels with the driving force based on the pseudo-gear steps. 【0125】 According to (13), by supplying the generated power when the second gear ratio is set to the motor for driving, high output and high acceleration can be achieved. 【0126】 100 Gear ratio setting unit 110 Driving control unit BAT Battery (energy storage device) ENG Engine ECU Control unit FWR Front wheel (drive wheel) GEN Generator motor MOT1 Main drive motor (electric motor) Ne Engine speed Ve Ve Vehicle (hybrid vehicle)

Claims

1. A hybrid vehicle comprising: drive wheels; an electric motor capable of driving the drive wheels; a power storage device for supplying power to the electric motor; an engine capable of rotating at any rotational speed relative to the rotational speed of the drive wheels; and a control device, wherein the hybrid vehicle is capable of running based on a plurality of pseudo-gear stages in which the ratio of engine rotational speed to vehicle speed is fixed, and in the plurality of pseudo-gear stages, it is possible to set a first gear ratio that defines the relationship between the vehicle speed and the engine rotational speed, and a second gear ratio that tends to be lower than the first gear ratio, and the control device comprises: a gear ratio setting unit that switches the setting of the gear ratio in the pseudo-gear stage between the first gear ratio and the second gear ratio based on predetermined switching conditions, and a driving control unit that runs the hybrid vehicle based on the gear ratio set by the gear ratio setting unit.

2. A hybrid vehicle according to claim 1, wherein the predetermined switching condition is a condition based on at least one of the amount of operation of the accelerator pedal, the vehicle speed, and a parameter relating to the output of the energy storage device, and the gear ratio setting unit switches the setting of the gear ratio between the first gear ratio and the second gear ratio when the predetermined switching condition is met.

3. A hybrid vehicle according to claim 2, wherein the setting of the first gear ratio is configured to be set based on a first shift condition for switching gears in the pseudo-gear stage, the setting of the second gear ratio is configured to be set based on a second shift condition for switching gears in the pseudo-gear stage, and the gear ratio setting unit switches the setting of the gear ratio from the first gear ratio to the second gear ratio based on the first shift condition when the vehicle is running with the setting of the first gear ratio and the predetermined switching condition is met.

4. A hybrid vehicle according to claim 3, wherein the predetermined switching condition for switching the gear ratio setting from the first gear ratio to the second gear ratio is that the amount of operation of the accelerator pedal is greater than or equal to a predetermined value, and the allowable output power that allows the output of the energy storage device is less than a predetermined power.

5. A hybrid vehicle according to claim 4, wherein the gear ratio setting unit switches the gear ratio setting from the second gear ratio to the first gear ratio based on the second gear condition when the vehicle is running with the second gear ratio setting and the predetermined switching condition is met.

6. A hybrid vehicle according to claim 5, wherein the predetermined switching condition for switching the gear ratio setting from the second gear ratio to the first gear ratio is that the amount of operation of the accelerator pedal is less than a predetermined value, or the allowable output power that allows the output of the energy storage device is equal to or greater than a predetermined power.

7. A hybrid vehicle according to claim 5 or 6, wherein in each gear step of the pseudo-gear step, the vehicle speed corresponding to the upper limit of the engine rotational speed when the first gear ratio is set and the vehicle speed corresponding to the upper limit of the engine rotational speed when the second gear ratio is set are the same.

8. A hybrid vehicle according to claim 7, wherein the engine speed is a positive value when the vehicle speed is 0 km / h when the second gear ratio is set.

9. A hybrid vehicle according to claim 8, wherein the second gear ratio is set such that the engine speed maintains the upper limit speed in a predetermined vehicle speed range in at least one of the pseudo-gear stages.

10. A hybrid vehicle according to claim 9, wherein the driving control unit, when the second gear ratio is set, reaches the upper limit speed, maintains the engine speed at the upper limit speed for a predetermined time and drives the vehicle.

11. A hybrid vehicle according to claim 10, wherein the predetermined time increases as the gear ratio of the simulated gear ratio increases.

12. A hybrid vehicle according to claim 1 or 2, wherein in at least some of the pseudo-gear stages, the first gear ratio and the second gear ratio are the same gear ratio.

13. A hybrid vehicle according to claim 1 or 2, wherein the hybrid vehicle is equipped with a generator that converts the power of the engine into electricity, is capable of series driving by driving the electric motor with the electricity generated by the generator, and the driving control unit controls the electric motor to drive the drive wheels with a driving force based on the pseudo-gear stage.

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