JP2006300274A - Mode switching controlling device and method for hybrid car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mode switching controlling device and a mode switching controlling method for a hybrid car capable of minimizing switching of modes in a medium vehicle speed zone of high frequency in use, and reducing shock in accompany with transition of mode. <P>SOLUTION: The switching to a LB mode is permitted when a vehicle speed VSP is in the medium vehicle speed zone and required driving force Fdrv is in a maximum required driving force zone near a maximum value in E-iVT mode, and the switching to an EV mode is permitted when the vehicle speed VSP is in a very low vehicle speed zone and the required driving force Fdrv is in a very low driving force zone. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mode switching control device and a mode switching control method for a hybrid vehicle using an engine and a motor as driving force generation sources.

In a conventional hybrid vehicle mode switching control device, chattering when switching between modes is avoided by setting hysteresis in the mode switching condition (see, for example, Patent Document 1).
JP-A-6-48190

  Usually, in a medium vehicle speed range such as when traveling in an urban area, the driving force synthesizing transmission has a continuously variable transmission function and is traveling in a hybrid vehicle continuously variable transmission mode in which the engine and motor are driven as driving forces. When the required driving force increases during traveling in the hybrid vehicle continuously variable transmission mode, the hybrid vehicle fixed transmission mode in which the driving force combining transmission is a fixed transmission function is switched.

  At this time, in the conventional method of setting the hysteresis in the mode switching condition, there is a limit to the mode chattering suppression. There is a problem that the shock generated in the case cannot be reduced.

  The present invention has been made paying attention to the above problems, and its purpose is a hybrid capable of minimizing mode switching in a frequently used medium vehicle speed acceleration range and reducing shocks associated with mode transitions. An object of the present invention is to provide a vehicle mode switching control device and a mode switching control method.

In order to achieve the above object, in the hybrid vehicle mode switching control method of the present invention,
In a hybrid vehicle that switches between an electric vehicle continuously variable transmission mode, an electric vehicle fixed transmission mode, a hybrid vehicle continuously variable transmission mode and a hybrid vehicle fixed transmission mode according to the vehicle speed and the required driving force,
When the vehicle speed is in the middle vehicle speed range, switching from the hybrid vehicle continuously variable transmission mode to the hybrid vehicle fixed transmission mode is limited.
Here, the electric vehicle continuously variable transmission mode refers to a traveling mode in which the driving force combining transmission is switched to the continuously variable transmission function and the vehicle is driven by the driving force of the motor. The electric vehicle fixed transmission mode refers to a traveling mode in which the driving force combining transmission is switched to the fixed transmission function and the vehicle is driven by the driving force of the motor. The hybrid vehicle continuously variable transmission mode refers to a traveling mode in which the driving force synthesizing transmission is switched to a continuously variable transmission function and the vehicle is driven by the driving force of the engine and the motor. The hybrid vehicle fixed transmission mode refers to a traveling mode in which the driving force combining transmission is switched to the fixed transmission function and the vehicle is driven by the driving force of the engine and the motor.

  Therefore, in the present invention, since the switching from the hybrid vehicle continuously variable transmission mode to the hybrid vehicle fixed transmission mode is restricted in the middle vehicle speed range, mode transition in the middle vehicle speed acceleration region that is frequently used is minimized. Thus, the shock accompanying the mode transition can be reduced.

  Hereinafter, the best mode for realizing a mode switching control device for a hybrid vehicle of the present invention will be described based on Examples 1 and 2 shown in the drawings.

First, the configuration will be described.
[Drive system configuration of hybrid vehicle]
FIG. 1 is an overall system diagram illustrating a drive system of a hybrid vehicle according to a first embodiment. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a first motor generator MG1 (motor), a second motor generator MG2 (motor), and an output gear OG (output member). And a driving force synthesis transmission TM.

  The engine E is a gasoline engine or a diesel engine, and the opening degree of a throttle valve and the like are controlled based on a target engine torque command from an engine controller 1 described later.

  The first motor generator MG1 and the second motor generator MG2 are synchronous motor generators in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. This synchronous motor generator includes a first motor generator MG1 composed of an outer rotor OR and a stator S in a multi-layer motor CM in which an inner rotor IR, a stator S, and an outer rotor OR are overlapped in the radial direction. The OR and stator S constitute a second motor generator MG2. The inner rotor IR and the outer rotor OR are independently controlled by applying a three-phase alternating current generated by the inverter 3 to the stator S based on a control command from a motor controller 2 described later.

  The driving force synthesis transmission TM has a Ravigneaux type planetary gear train PGR and a low brake LB. The Ravigneaux planetary gear train PGR has a first sun gear S1, a first pinion P1, and a first ring gear R1. And the second sun gear S2, the second pinion P2, the second ring gear R2, and the common carrier PC that supports the first pinion P1 and the second pinion P2 that mesh with each other. That is, the Ravigneaux type planetary gear PGR has five rotating elements: the first sun gear S1, the first ring gear R1, the second sun gear S2, the second ring gear R2, and the common carrier PC. The connection relationship of the input / output members with respect to these five rotating elements will be described.

  A first motor generator MG1 is connected to the first sun gear S1. The first ring gear R1 is provided so as to be fixed to the case via a low brake LB. A second motor generator MG2 is connected to the second sun gear S2. An engine E is connected to the second ring gear R2 via an engine clutch EC. An output gear OG is directly connected to the common carrier PC. A driving force is transmitted from the output gear OG to the left and right driving wheels via a differential and a drive shaft (not shown).

  2, the first motor generator MG1 (first sun gear S1), engine E (second ring gear R2), output gear OG (common carrier PC), low brake LB (first It is possible to introduce a rigid lever model that is arranged in the order of 1 ring gear R1) and second motor generator MG2 (second sun gear S2) and can simply express the dynamic operation of the Ravigneaux planetary gear train PGR.

  Here, the “collinear diagram” is a velocity diagram used in a simple and easy-to-understand method of drawing instead of the method of obtaining by equation when considering the gear ratio of the differential gear, The rotation number (rotation speed) of the rotation element is taken, each rotation element is taken on the horizontal axis, and the interval between each rotation element is arranged so as to be a collinear lever ratio based on the gear ratio of the sun gear and the ring gear. .

  The engine clutch EC and the low brake LB are a multi-plate friction clutch and a multi-plate friction brake that are fastened by hydraulic pressure from a hydraulic control device 5 to be described later. The engine clutch EC is the engine E in the collinear diagram of FIG. The low brake LB is arranged at a position that coincides with the rotational speed axis of the second ring gear R2, and the low brake LB has a rotational speed axis of the first ring gear R1 (second rotational speed axis of the output gear OG (Position between the rotational speed axis of the sun gear S2).

[Hybrid vehicle control system configuration]
As shown in FIG. 1, the hybrid vehicle control system in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a hydraulic control device 5, an integrated controller 6, and an accelerator opening. A sensor 7, a vehicle speed sensor 8, an engine speed sensor 9, a first motor generator speed sensor 10, a second motor generator speed sensor 11, and a second ring gear speed sensor 12 are configured. Has been.

  The engine controller 1 responds to a target engine torque command from the integrated controller 6 that inputs the accelerator opening AP from the accelerator opening sensor 7 and the engine speed Ne from the engine speed sensor 9, in accordance with the engine operating point (Ne, A command for controlling Te) is output to, for example, a throttle valve actuator (not shown).

  The motor controller 2 operates the motor of the first motor generator MG1 in response to a target motor generator torque command from the integrated controller 6 that inputs motor generator rotation speeds N1 and N2 from both motor generator rotation speed sensors 10 and 11 by a resolver. A command (device control signal) for independently controlling the point (N1, T1) and the motor operating point (N2, T2) of the second motor generator MG2 is output to the inverter 3. The motor controller 2 outputs information on the battery S.O.C representing the state of charge of the battery 4 to the integrated controller 6.

  The inverter 3 is connected to the respective stator coils of the first motor generator MG1 and the second motor generator MG2, and generates an independent three-phase alternating current according to a command from the motor controller 2. The inverter 3 is connected to a battery 4 that is discharged during power running and charged during regeneration.

  The hydraulic control device 5 receives a hydraulic pressure command from the integrated controller 6 and performs engagement hydraulic pressure control and release hydraulic pressure control of the engine clutch EC and the low brake LB. The engagement hydraulic pressure control and the release hydraulic pressure control include a half-clutch control based on the slip engagement control and the slip release control.

  The integrated controller 6 includes an accelerator opening AP from the accelerator opening sensor 7, a vehicle speed VSP from the vehicle speed sensor 8, an engine speed Ne from the engine speed sensor 9, and a first motor generator speed sensor 10. Information such as the first motor generator rotational speed N1, the second motor generator rotational speed N2 from the second motor generator rotational speed sensor 11, the engine input rotational speed ωi from the second ring gear rotational speed sensor 12, and the like. Predetermined arithmetic processing is performed. Then, a control command is output to the engine controller 1, the motor controller 2, and the hydraulic control device 5 according to the calculation processing result.

  The integrated controller 6 and the engine controller 1 and the integrated controller 6 and the motor controller 2 are connected by bidirectional communication lines 14 and 15 for information exchange, respectively.

[Driving mode of hybrid vehicle]
The travel modes in the hybrid vehicle of the first embodiment include an electric vehicle continuously variable transmission mode (hereinafter referred to as “EV mode”), an electric vehicle fixed transmission mode (hereinafter referred to as “EV-LB mode”), and a hybrid. It has a vehicle fixed speed change mode (hereinafter referred to as “LB mode”) and a hybrid vehicle continuously variable speed change mode (hereinafter referred to as “E-iVT mode”). The “EV mode” and the “EV-LB mode” are “electric vehicle travel mode”, and the “LB mode” and the “E-iVT mode” are “hybrid vehicle travel mode”.

  The “EV mode” is a continuously variable transmission mode in which only two motor generators MG1 and MG2 run as shown in the collinear diagram of FIG. 2 (a), and the engine E is driven (minimum speed control). The engine clutch EC is released.

  The “EV-LB mode” is a fixed speed change mode in which only the two motor generators MG1 and MG2 run with the low brake LB engaged, as shown in the collinear diagram of FIG. E is drive (minimum speed control) and the engine clutch EC is released. Since the reduction ratio from the first motor generator MG1 to the output Output and the reduction ratio from the second motor generator MG2 to the output Output are large, this is a mode in which a large driving force is generated.

  As shown in the collinear diagram of FIG. 2 (c), the “LB mode” is a fixed speed change mode in which the engine E and the motor generators MG1 and MG2 travel with the low brake LB engaged. The engine clutch EC is engaged during operation. This is a mode in which the driving force is large because the reduction ratio from the engine E and the motor generators MG1, MG2 to the output Output is large.

  The “E-iVT mode” is a continuously variable transmission mode in which the engine E and the motor generators MG1 and MG2 run as shown in the nomogram of FIG. 2 (d). The engine E is operated and the engine clutch EC is It is conclusion.

  Then, the mode switching control of the four travel modes is performed by the integrated controller 6. That is, the integrated controller 6 is preset with a driving mode map in which four driving modes are allocated to a three-dimensional space by the required driving force Fdrv (determined by the accelerator opening AP), the vehicle speed VSP, and the battery SOC. (FIGS. 3 and 4), when the vehicle is stopped or traveling, a travel mode map is searched based on the detected values of the required driving force Fdrv, the vehicle speed VSP, and the battery SOC, and the vehicle operating point determined by the required driving force Fdrv and the vehicle speed VSP The optimum travel mode is selected according to the battery charge amount. 3 and 4 are examples of travel mode maps that are represented in two dimensions by the required driving force Fdrv and the vehicle speed VSP by cutting out the three-dimensional travel mode map at a value with a sufficient capacity range of the battery S.O.C.

  In the first embodiment, the traveling mode map is switched between when traveling in a traveling mode other than the E-iVT mode (FIG. 3) and when traveling in the E-iVT mode (FIG. 4).

  As shown in Fig. 3, when driving in a driving mode other than E-iVT mode, both modes are driven so that unnecessary engagement and release of low brake LB does not occur between EV-LB mode and LB mode. Force lower limit value is set to the same value. Hereinafter, the travel mode map of FIG.

  As shown in FIG. 4, when the vehicle is traveling in the E-iVT mode, the area of the other mode is deleted or greatly reduced in order to avoid mode chattering. Specifically, when the vehicle speed VSP is in the middle vehicle speed range, which is the vehicle speed range during urban driving, and the required drive force Fdrv is the maximum required drive force region near the maximum value, switching to the LB mode is permitted, and the vehicle speed VSP is When the vehicle speed is extremely low and the required driving force Fdrv is in the extremely low driving force region, switching to the EV mode is permitted. Switching from E-iVT mode to EV-LB mode is prohibited.

  Furthermore, the switching from the E-iVT mode to the LB mode is permitted only when staying in the LB mode area of FIG. 4 for a set time or when it is estimated that the set time will be exceeded. The set time is set based on the time required for mode transition from E-iVT mode to EV mode. Hereinafter, the travel mode map of FIG.

  When switching the mode between “EV mode” and “EV-LB mode” in Map 1 or Map 2, the low brake LB is engaged / released as shown in FIG. When the mode is switched between the “E-iVT mode” and the “LB mode”, the low brake LB is engaged / released as shown in FIG. When the mode is switched between the “EV mode” and the “E-iVT mode”, the engine clutch EC is engaged / released as shown in FIG. When the mode is switched between the “EV-LB mode” and the “LB mode”, the engine clutch EC is engaged / released as shown in FIG.

Next, the operation will be described.
[Mode switching control processing]
FIG. 6 is a flowchart illustrating the flow of the mode switching control process executed by the integrated controller 6 according to the first embodiment. Each step will be described below. This control process is executed every predetermined control cycle.

  In step S1, it is determined whether or not the current travel mode is the E-iVT mode. If YES, the process proceeds to step S2, and if NO, the process proceeds to step S8.

  In step S2, the travel mode map is set to map 2 (FIG. 4), and the process proceeds to step S3.

  In step S3, the target mode is set using the map 2 from the vehicle speed VSP and the required driving force Fdrv. If the target mode is the EV mode, the process proceeds to step S4. If the target mode is the LB mode, the process proceeds to step S5. If the target mode is the E-iVT mode, the process proceeds to step S7.

  In step S4, the EV mode is set, the engine clutch EC is released, and the process proceeds to return.

  In step S5, it is determined whether or not a set time has elapsed since the target mode was changed to the LB mode in step S3. If YES, the process proceeds to step S6, and if NO, the process proceeds to step S7.

  In step S6, the LB mode is set, the low brake LB is engaged, and the process proceeds to return.

  In step S7, the E-iVT mode is set, the engaged state of the engine clutch EC and the released state of the low brake LB are maintained, and the process proceeds to return. Step switching restriction means is constituted by steps S2 to S7.

  In step S8, the travel mode map is set to map 1 (FIG. 3), and the process proceeds to step S9.

  In step S9, the target mode is set using the map 1 from the vehicle speed VSP and the required driving force Fdrv. When the target mode is EV mode, the process proceeds to step S10.When the target mode is EV-LB mode, the process proceeds to step S11. When the target mode is the LB mode, the process proceeds to step S12. When the target mode is the E-iVT mode, the process proceeds to step S13.

  In step S10, the EV mode is set, the engine clutch EC is released, and the process proceeds to return.

  In step S11, the EV-LB mode is set, the engine clutch EC is released and the low brake LB is engaged, and the process proceeds to return.

  In step S12, the LB mode is set, the low brake LB is engaged, and the process proceeds to return.

  In step S13, the E-iVT mode is set, the engaged state of the engine clutch EC and the released state of the low brake LB are maintained, and the process proceeds to return.

[Mode switching control action]
When traveling in an urban area in the E-iVT mode, in the flowchart of FIG. 6, the flow proceeds from step S1 to step S2 to step S3 to step S7. In step S7, the E-iVT mode is set. Therefore, in urban driving where acceleration / deceleration is repeated at medium vehicle speed, the transition to the LB mode is restricted, so that the shock due to the release of the low brake LB due to frequent mode transition can be reduced.

  In step S3, the EV mode is set by proceeding to step S4 only when the vehicle speed VSP is in the extremely low vehicle speed region and the required driving force Fdrv is in the extremely low driving force region. That is, since the transition to the EV mode is restricted, the frequency of engine start / stop accompanying the mode transition can be minimized, and the shock can be reduced.

  When traveling on an uphill road in the E-iVT mode, the process proceeds from step S1, step S2, step S3, step S5, and step S6. In step S6, the LB mode is set. Therefore, when the high driving force is required continuously, the E-iVT mode can be shifted to the LB mode, so that it is possible to achieve both reduction of the shift shock accompanying the mode transition and realization of the high driving force.

Next, the effect will be described.
In the hybrid vehicle mode switching control apparatus and mode switching control method of the first embodiment, the effects listed below can be obtained.

  (1) When the vehicle speed VSP is in the middle vehicle speed range, it is equipped with mode switching restriction means (steps S2 to S7) that restricts switching from the E-iVT mode to the LB mode. The mode transition can be minimized and the shock accompanying the mode transition can be reduced.

  (2) The mode switching limiting means allows mode switching in the middle vehicle speed acceleration range to permit switching to the LB mode when the vehicle speed VSP is in the middle vehicle speed range and the required driving force Fdrv is in the maximum required driving force region near the maximum value. When the required driving force Fdrv reaches the maximum required driving force range while reducing the shock associated with the above, it is possible to achieve a high driving force corresponding to the required driving force Fdrv by shifting to the LB mode.

  (3) The mode switching restriction means permits switching to the LB mode when the vehicle speed VSP is in the middle vehicle speed range and the required driving force Fdrv is in the maximum required driving force region near the maximum value for a set time or more. When a high driving force is continuously required on an uphill road or the like, it is possible to achieve both a reduction in shock associated with mode transition and a high driving force by shifting to the LB mode.

  (4) When the vehicle speed VSP is in the middle vehicle speed range and the required driving force Fdrv is in the maximum required driving force region near the maximum value, it is estimated that the mode switching restriction means will switch to the LB mode. When it is estimated that a high driving force is required continuously on an uphill road to allow switching, it is possible to reduce the shock associated with mode transition and realize a high driving force by shifting to the LB mode. Can be compatible.

  (5) The mode switching restriction means sets the set time based on the time required for mode transition from the E-iVT mode to the LB mode. That is, since it is determined whether or not to perform mode transition in consideration of the time required for mode transition, mode chattering can be further reduced.

  (6) The mode switching limiting means allows switching to the EV mode when the vehicle speed VSP is in the extremely low vehicle speed range and the required driving force Fdrv is in the extremely low driving force region. Therefore, it is possible to reduce the occurrence of shock accompanying engine start / stop.

  (7) The mode switching control means sets the lower limit value of the required driving force for switching from another driving mode to the EV-LB mode and the lower limit value of the required driving force for switching from the other driving mode to the LB mode to the same value. Therefore, when the vehicle speed fluctuates across EV-LB mode and LB mode without a sudden change in the driving force command value, unnecessary mode transitions can be avoided. Shock can be reduced.

  The second embodiment is different from the first embodiment in the travel mode map when traveling in the E-iVT mode. That is, in the second embodiment, as shown in FIG. 7, when the vehicle is traveling in the E-iVT mode, the vehicle speed VSP is a medium vehicle speed region that is a vehicle speed region traveling in an urban area, and the required driving force Fdrv is near the maximum value. When the maximum required driving force range is selected, switching to LB mode is prohibited, and switching to EV mode and EV-LB mode is prohibited. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

Next, the operation will be described.
[Mode switching control processing]
FIG. 8 is a flowchart showing the flow of the mode switching control process executed by the integrated controller 6 according to the second embodiment. The difference is that step S21 is provided instead of step S4 in FIG. Therefore, the same step number is assigned and the description is omitted.

  In step S21, the E-iVT mode is set, the engaged state of the engine clutch EC and the released state of the low brake LB are maintained, and the process proceeds to return.

  That is, in the second embodiment, since the transition from the E-iVT mode to the EV mode is prohibited, the frequency of engine start / stop can be further suppressed compared to the first embodiment, and the engine start / stop can be performed. The accompanying shock can be reduced.

(Other examples)
The hybrid vehicle mode switching control device of the present invention has been described based on the first and second embodiments. However, the specific configuration is not limited to each embodiment, and each claim of the claims Design changes and additions are permitted without departing from the spirit of the invention.

  The present invention can be applied to a hybrid vehicle having an engine and one or more motors as a driving force generation source, and having a driving force combining transmission capable of switching between a continuously variable transmission function and a fixed transmission function. Moreover, although the example which has a Ravigneaux type planetary gear train as a driving force synthetic | combination transmission was shown, for example, it can apply also to the driving force synthetic | combination transmission which has a differential apparatus etc. provided with several simple planetary gear trains. .

1 is an overall system diagram showing a hybrid vehicle of Example 1. FIG. FIG. 3 is a collinear diagram showing each traveling mode by a Ravigneaux planetary gear train employed in the hybrid vehicle of the first embodiment. 6 is a travel mode map when traveling in a travel mode other than the E-iVT mode according to the first embodiment. 3 is a travel mode map when traveling in an E-iVT mode according to the first embodiment. It is a figure which shows the mode switching path | route between the four driving modes in the hybrid vehicle of Example 1. FIG. 6 is a flowchart illustrating a flow of mode switching control processing executed by the integrated controller 6 according to the first embodiment. 6 is a travel mode map when traveling in the E-iVT mode according to the second embodiment. 10 is a flowchart illustrating a flow of mode switching control processing executed by the integrated controller 6 of the second embodiment.

Explanation of symbols

E engine
MG1 1st motor generator (motor)
MG2 Second motor generator (motor)
OG output gear (output member)
TM Driving force transmission
PGR Ravigneaux type planetary gear train
EC engine clutch
LB Low brake 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 Hydraulic control device 6 Integrated controller 6a Target rotational speed calculation section 6b Torque command value setting section 7 Accelerator opening sensor 8 Vehicle speed sensor 9 Engine rotational speed sensor 10 First motor generator Speed sensor 11 Second motor generator speed sensor 12 Second ring gear speed sensor

Claims (8)

A driving force source by an engine and at least one motor;
A driving force combining transmission that connects the engine, a motor, and an output member, and is capable of switching between a continuously variable transmission function and a fixed transmission function;
Mode switching control means for switching between the electric vehicle continuously variable transmission mode, the electric vehicle fixed transmission mode, the hybrid vehicle continuously variable transmission mode and the hybrid vehicle fixed transmission mode according to the vehicle speed and the required driving force;
In a hybrid car with
A mode switching control device for a hybrid vehicle, comprising mode switching limiting means for limiting switching from the hybrid vehicle continuously variable transmission mode to the hybrid vehicle fixed transmission mode when the vehicle speed is in a middle vehicle speed range. In the hybrid vehicle mode switching control device according to claim 1,
The mode switching limiting means permits switching to a hybrid vehicle fixed shift mode when the vehicle speed is in a medium vehicle speed range and the required driving force is in a maximum required driving force region in the vicinity of the maximum value. Control device. In the hybrid vehicle mode switching control device according to claim 1 or 2,
The mode switching limiting means permits the switching to the hybrid vehicle fixed shift mode when the vehicle speed is in the middle vehicle speed range and the required driving force is in the maximum required driving force region near the maximum value for a set time or more. A hybrid vehicle mode switching control device. In the hybrid vehicle mode switching control device according to any one of claims 1 to 3,
The mode switching limiting means switches to the hybrid vehicle fixed shift mode when it is estimated that the vehicle speed is in the middle vehicle speed range and the required driving force is in the maximum required driving force region near the maximum value after a set time. A mode change control device for a hybrid vehicle characterized in that In the hybrid vehicle mode switching control device according to claim 4,
The mode switching control device for a hybrid vehicle, wherein the mode switching limiting means sets the set time based on a time required for mode transition from a hybrid vehicle continuously variable transmission mode to a hybrid vehicle fixed transmission mode. In the hybrid vehicle mode switching control device according to any one of claims 1 to 5,
The mode switching limiting means permits switching to an electric vehicle continuously variable transmission mode when the vehicle speed is in an extremely low vehicle speed range and the required driving force is in an extremely low driving force range. apparatus. In the hybrid vehicle mode switching control device according to any one of claims 1 to 6,
The mode switching control means has the same value as the lower limit value of the requested driving force for switching from the other travel mode to the electric vehicle fixed shift mode and the lower limit value of the requested drive force for switching from the other travel mode to the hybrid vehicle fixed shift mode. A mode switching control device for a hybrid vehicle, characterized in that In a hybrid vehicle that switches between an electric vehicle continuously variable transmission mode, an electric vehicle fixed transmission mode, a hybrid vehicle continuously variable transmission mode and a hybrid vehicle fixed transmission mode according to the vehicle speed and the required driving force,
A hybrid vehicle mode switching control method that restricts switching from a hybrid vehicle continuously variable transmission mode to a hybrid vehicle fixed transmission mode when the vehicle speed is in a middle vehicle speed range.

Images