JP2013189024A - Vehicle driving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly efficient and compact vehicle driving mechanism for a hybrid vehicle.SOLUTION: A vehicle driving mechanism 100 includes: an engine 10; a first motor 20 configured by mechanically joining the input side of a rotating shaft 21 to an output shaft 11 of the engine 10, and mechanically joining the output side of the rotating shaft 21 to an axle 17, to be used as a generator; a second motor 30 configured by mechanically joining the output side of a rotating shaft 31 to the axle 17; and a battery 50 which supplies electric power to the first motor 20 and the second motor 30 and accumulates electric power generated by the first motor 20. A first step-up gear 40 is provided between the first motor 20 and the second motor 30. Optimum rotation speed N2 of the second motor 30 is designed to be higher than optimum rotation speed N1 of the first motor 20.

Description

  The present invention relates to a vehicle drive mechanism, and more particularly to a vehicle drive mechanism of a hybrid vehicle including an engine and a motor as power sources.

  The spread of hybrid vehicles equipped with engines and motors as power sources has begun. Patent Document 1 discloses a vehicle drive mechanism for a hybrid vehicle including an engine and two motors. In this vehicle drive mechanism, the input side of the rotary shaft of the first motor is connected to the output shaft of the engine, the output side of the rotary shaft of the first motor and the input side of the rotary shaft of the second motor are connected, and the second motor The output side of the rotary shaft is connected to the axle via a planetary gear and a differential. When the first and second motors are driven by the power from the engine, the driving force is transmitted to the axle through the planetary gear and the differential, and the vehicle travels. At that time, if the first and second motors are operated as electric motors, the vehicle can be assisted, and if the first and second motors are operated as generators, the engine power is generated. Can do.

JP 2005-88746 A

  The motor of the vehicle drive mechanism preferably operates efficiently and is small. First, considering the operation efficiency, the operation efficiency of a general motor is related to the rotation speed and torque, which is shown in FIG. In the operating efficiency characteristics shown in FIG. 6, the operating efficiency of the motor is highest in the region surrounded by the innermost contour line α. In the present specification, the rotational speed N of the motor at the center of the region having the highest operating efficiency is referred to as “optimal rotational speed”. In the configuration of Patent Document 1, since the first and second motors are driven at the same rotational speed as the engine, in order to operate the first and second motors efficiently, their optimum rotational speeds are set to It is preferable that the first and second motors are designed to be nearly equal to the standard rotation speed and operate near the optimum rotation speed.

  Next, considering miniaturization, the motor becomes easier to miniaturize as the optimum rotational speed is designed higher. However, in the configuration of Patent Document 1, since the first and second motors are driven at the same rotational speed as the engine, if the optimum rotational speed is designed high for miniaturization, the first and second motors are It becomes impossible to operate near the optimum rotational speed. That is, with the configuration of Patent Document 1, it is impossible to achieve both the efficient operation and the miniaturization of the first and second motors.

  The present invention has been made to solve such problems, and an object thereof is to provide a highly efficient and small vehicle drive mechanism for a hybrid vehicle.

  In order to solve the above problems, a vehicle drive mechanism according to the present invention includes an internal combustion engine (engine), an input side of a rotary shaft mechanically connected to an output shaft of the internal combustion engine, and an output side of the rotary shaft that is an axle. A first electric motor (first motor) that is mechanically connected to the motor and operable as a generator, a second electric motor (second motor) mechanically connected to the axle and the output side of the rotary shaft, And a power storage means for supplying power to the second motor and storing the power generated by the first motor. A first speed increaser is provided between the first motor and the second motor. The optimum rotation speed is higher than the optimum rotation speed of the first electric motor.

  A second speed increaser may be provided between the first motor and the internal combustion engine, and the optimum rotational speed of the first motor may be higher than the rotational speed of the internal combustion engine.

  A first clutch may be provided between the first electric motor and the internal combustion engine, and the first clutch may be in a disconnected state when the first electric motor is operated by electric power supplied from the power storage means.

  A second clutch is provided between the first motor and the axle, and when the first motor is driven by the power of the internal combustion engine and operates as a generator, the second clutch may be in a disconnected state. Good.

  According to the present invention, a highly efficient and small vehicle drive mechanism for a hybrid vehicle can be obtained.

It is a figure which shows the structure of the vehicle drive mechanism which concerns on Embodiment 1 of this invention. It is a figure which shows the operating efficiency characteristic of the 1st, 2nd motor of the vehicle drive mechanism which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the vehicle drive mechanism which concerns on Embodiment 2 of this invention. It is a figure which shows the operating efficiency characteristic of the 1st, 2nd motor of the vehicle drive mechanism which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the modification of the vehicle drive mechanism which concerns on Embodiment 1 of this invention. It is a figure which shows the operating efficiency characteristic of a general motor.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows the configuration of a vehicle drive mechanism 100 for a hybrid vehicle according to Embodiment 1 of the present invention.

  The vehicle drive mechanism 100 is an engine 10 that generates gasoline by burning gasoline fuel internally, and generates power by operating with AC power, and also operates as a generator when driven by external power. 1 motor 20 and a second motor 30 that operates by AC power and generates power.

  The output shaft 11 of the engine 10 is connected to the input side of the rotating shaft 21 of the first motor 20 via the first clutch 12, and the output side of the rotating shaft 21 of the first motor 20 is connected to the second clutch 13. To the input shaft 41 of the first speed increaser 40. The output shaft 42 of the first speed increaser 40 is connected to the axle 17 via the first gear 14, the second gear 15, and the differential 16. The output side of the rotating shaft 31 of the second motor 30 is connected to the axle 17 via the third gear 18, the second gear 15, and the differential 16.

  In a state where the first clutch 12 is connected, the rotation shaft 21 of the first motor 20 rotates integrally with the output shaft 11 of the engine 10, and the rotation speed of the first motor 20 becomes equal to the rotation speed of the engine 10. Therefore, the optimum rotational speed N1 of the first motor 20 shown in the operation efficiency characteristic of FIG. 2 is designed to be substantially equal to the standard rotational speed Ne of the engine 10.

  Further, since the first speed increaser 40 is interposed between the first motor 20 and the second motor 30, the rotational speed of the second motor 30 is higher than the rotational speed of the first motor 20, A value obtained by multiplying the rotation speed of the first motor 20 by the speed increase ratio of the first speed increaser 40. Therefore, the optimum rotational speed N2 of the second motor 30 shown in the operation efficiency characteristic of FIG. 2 is substantially equal to a value obtained by multiplying the optimum rotational speed N1 of the first motor 20 by the speed increasing ratio of the first speed increaser 40. Designed as such. Since the optimum rotational speed N2 of the second motor 30 can be designed high, the second motor 30 can be reduced in size.

  The vehicle drive mechanism 100 includes a battery 50 that stores DC power, and a first inverter 51 and a second inverter 52 that convert DC power output from the battery 50 into AC power. The AC power output from the first inverter 51 is supplied to the first motor 20, and the AC power output from the second inverter 52 is supplied to the second motor 30. Further, the first inverter 51 converts the AC power output from the first motor 20 into DC power that can charge the battery 50 when the first motor 20 is driven by the power of the engine 10 and operates as a generator. It also has a function to convert.

  Further, the vehicle drive mechanism 100 includes a control unit 60 constituted by a microcomputer, and the control unit 60 controls the first clutch 12, the second clutch 13, the first inverter 51, and the second inverter 52. .

  Next, regarding the operation of the vehicle drive mechanism 100 for the hybrid vehicle according to the first embodiment, the operation during EV travel in which the vehicle only travels by the motor without generating power, and the vehicle travels by power generation and the motor. The description will be divided into the RE power generation + EV operation performed together.

(1. Operation during EV travel)
When the vehicle is traveling on EV, the vehicle drive mechanism 100 uses both the first motor 20 and the second motor 30 for traveling. Specifically, the control unit 60 of the vehicle drive mechanism 100 supplies electric power from the second inverter 52 to the second motor 30 to drive the axle 17 and disconnects the first clutch 12 while the second clutch 13. Are connected to each other, and power is supplied from the first inverter 51 to the first motor 20 to cause the first motor 20 to operate as an electric motor and drive the axle 17. As a result, the axle 17 is driven by the first motor 20 and the second motor 30, and the vehicle travels.

  In the above, by adjusting the frequency of the AC power output from the first inverter 51, the first motor 20 is controlled to operate in the vicinity of the optimum rotational speed N1. Further, by adjusting the frequency of the AC power output from the second inverter 52, the second motor 30 is controlled to operate in the vicinity of the optimum frequency N2. Further, since the first clutch 12 is in a disconnected state, the engine 10 is prevented from being a load when the axle 17 is driven by the first motor 20 and the second motor 30.

(2. Operation during RE power generation + EV travel)
During the RE power generation + EV traveling of the vehicle, the vehicle driving mechanism 100 operates the first motor 20 as a generator to generate power, and the second motor 30 travels the vehicle. Specifically, the control unit 60 of the vehicle drive mechanism 100 supplies electric power from the second inverter 52 to the second motor 30 to drive the axle 17 and connects the first clutch 12 to the second clutch 13. Then, the first motor 20 is driven by the power of the engine 10 to operate as a generator. The AC power generated by the first motor 20 is converted into DC power by the first inverter 51 and stored in the battery 50.

  In the above, since the first motor 20 is driven at the same rotational speed as the engine 10, the first motor 20 is driven in the vicinity of the optimum frequency N1. Further, by adjusting the frequency of the AC power output from the second inverter 52, the second motor 30 is controlled to operate in the vicinity of the optimum frequency N2. Further, since the second clutch 13 is in the disconnected state, the first motor 20 can be separated from the drive of the axle 17 and can be devoted to power generation, and the power generation efficiency of the vehicle is improved.

  As described above, in the vehicle drive mechanism 100 for a hybrid vehicle according to the first embodiment, the first speed increaser 40 is provided between the first motor 20 and the second motor 30, and the second motor. The optimum rotational speed N2 of 30 is designed to be higher than the optimum rotational speed N1 of the first motor. As a result, the second motor 30 can be reduced in size while operating the first motor 20 and the second motor 30 in the vicinity of their optimum rotational speeds N1 and N2. Therefore, a highly efficient and small vehicle drive mechanism can be obtained. can do.

  Further, the first clutch 12 is provided between the first motor 20 and the engine 10, and when the first motor 20 operates as an electric motor by the electric power supplied from the battery 50, the first clutch 12 is in a disconnected state. It becomes. As a result, the engine 10 is prevented from becoming a load when the axle 17 is driven by the first motor 20 and the second motor 30, and the traveling efficiency of the vehicle is improved.

  A second clutch 13 is provided between the first motor 20 and the axle 17, and when the first motor 20 is driven by the power of the engine 10 and operates as a generator, the second clutch 13 is disconnected. It becomes a state. Thereby, the first motor 20 can be dedicated to power generation, and the power generation efficiency of the vehicle is improved.

Embodiment 2. FIG.
FIG. 3 shows the configuration of a vehicle drive mechanism 200 for a hybrid vehicle according to Embodiment 2 of the present invention. In the following description, the same reference numerals as those in FIG. 1 are the same or similar components, and thus detailed description thereof is omitted.

  In the vehicle drive mechanism 200 in the second embodiment, a second speed increaser 270 is provided between the first motor 220 and the engine 10. In a state where the first clutch 12 is connected, the rotation speed of the first motor 220 is a value obtained by multiplying the rotation speed of the engine 10 by the speed increase ratio of the second speed increaser 270. Therefore, the optimum rotational speed N1 ′ of the first motor 220 shown in the operation efficiency characteristic of FIG. 4 is substantially equal to a value obtained by multiplying the standard rotational speed Ne of the engine 10 by the speed increasing ratio of the second speed increaser 270. Designed to be Accordingly, the speed increasing ratio of the first speed increaser 240 is adjusted to be equal to the value obtained by dividing the optimum rotational speed N2 of the second motor 30 by the optimum rotational speed N1 ′ of the first motor 220. . As a result, the optimum rotational speed N1 ′ of the first motor 220 becomes higher than the optimum rotational speed N1 in the first embodiment, so that the first motor 220 and the second motor 30 are in the vicinity of their optimum rotational speeds N1 ′ and N2. The first motor 220 can be reduced in size while operating at.

Other embodiments.
In the first embodiment, as shown in FIG. 5 (a) or (b), the first motor 20 and the second motor 30 may be connected in series, and the same applies to the second embodiment. .

  100, 200, 300, 400 Vehicle drive mechanism, 10 engine (internal combustion engine), 11 engine output shaft (internal combustion engine output shaft), 12 first clutch, 13 second clutch, 17 axle, 20, 220 first motor (First motor), 21, 221 first motor rotation shaft (first motor rotation shaft), 30 second motor (second motor), 31 second motor rotation shaft (second motor rotation shaft), 40,240 First speed increaser, 50 Battery (power storage means), 270 Second speed increaser, N1, N1 ′ Optimal rotation speed of first motor (optimal rotation speed of first motor), N2 Optimal speed of second motor The number of revolutions (the optimum number of revolutions of the second electric motor), the number of revolutions of the Ne engine (the number of revolutions of the internal combustion engine).

Claims (4)

An internal combustion engine;
A first electric motor that is mechanically connected to an output shaft of the internal combustion engine and an output side of the rotary shaft is mechanically connected to an axle and is operable as a generator;
A second electric motor that mechanically connects the output side of the rotating shaft to the axle;
Power storage means for supplying power to the first and second motors and storing the power generated by the first motor;
A vehicle is characterized in that a first speed increaser is provided between the first motor and the second motor, and the optimum rotational speed of the second motor is higher than the optimum rotational speed of the first motor. Drive mechanism.   The second speed increaser is provided between the first electric motor and the internal combustion engine, and the optimum rotational speed of the first electric motor is higher than the rotational speed of the internal combustion engine. The vehicle drive mechanism described. A first clutch is provided between the first electric motor and the internal combustion engine;
The vehicle drive mechanism according to claim 1 or 2, wherein the first clutch is disengaged when the first electric motor is operated by electric power supplied from the power storage means. A second clutch is provided between the first electric motor and the axle;
The said 2nd clutch will be in a cutting | disconnection state, when the said 1st electric motor drives with the motive power of the said internal combustion engine, and operate | moves as a generator, It is any one of Claims 1-3 characterized by the above-mentioned. Vehicle drive mechanism.

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