JP3291983B2 - Vehicle drive system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drive device.

[0002]

2. Description of the Related Art Conventionally, in a vehicle equipped with an internal combustion engine as a torque generating means, it is possible to travel by transmitting engine torque generated by driving the engine to driving wheels via a transmission. I can do it. As shown by an equal fuel consumption curve, it is known that driving an internal combustion engine at a high load has better fuel efficiency than driving an internal combustion engine at a low load.

FIG. 2 is a diagram showing an equal fuel consumption curve of an internal combustion engine. In the figure, the horizontal axis represents the number of revolutions and the vertical axis represents the engine torque. In the figure, when the internal combustion engine is driven at a high load by increasing the generated engine torque as indicated by an arrow A, the fuel efficiency is improved, and as indicated by an arrow B, the engine torque to be generated is reduced and the load is reduced at a low load. When the internal combustion engine is driven, fuel efficiency is deteriorated. Then, a good fuel consumption area as indicated by AR1 is formed.

However, during steady running, the internal combustion engine cannot be driven in the good fuel consumption area AR1.
FIG. 3 is a driving force diagram for a conventional vehicle. In the drawings, the horizontal axis represents vehicle speed, and the vertical axis represents driving force.
In the figure, AR2 is a good fuel consumption area AR of the above constant fuel consumption curve.
A good fuel consumption area corresponding to No. 1 and AR3 is a drive area when the vehicle is steadily driven.

[0005] As shown in the figure, during steady running, a driving force as shown by a driving area AR3 is generated. However, since the internal combustion engine is driven with a low load, a good fuel consumption area AR2 is generated.
Can not be driven. Therefore, it is conceivable to set the gear ratio of the transmission to the high speed side to make the vehicle travel. In this case, the internal combustion engine is constantly driven with a high load, and fuel efficiency can be improved. However, if the gear ratio of the transmission is set to the higher gear, sufficient torque cannot be transmitted to the drive wheels when the vehicle is accelerating, and the acceleration performance is reduced. Therefore, actually, the vehicle is driven with the gear ratio set to the low speed side so as not to affect the acceleration performance.

Further, a hybrid vehicle having an internal combustion engine and an electric motor as torque generating means has been provided. In this case, the electric motor is driven when the hybrid vehicle starts and accelerates, and the electric motor is driven even when the load is low.

[0007]

However, in the above-mentioned conventional vehicle, the internal combustion engine is driven with a low load during steady running, so that it cannot be driven in the good fuel consumption area AR2. Therefore, fuel efficiency cannot be improved. In addition, in the case of the conventional hybrid vehicle, the electric motor is driven when the load is low, so that the electric motor is driven more than necessary at the time of steady driving, and the consumption of electric energy increases. Would.

The present invention solves the above-mentioned problems of the conventional hybrid vehicle, and can always drive the internal combustion engine in a good fuel economy region, improve fuel economy and improve acceleration performance. It is another object of the present invention to provide a vehicle drive device that can not only consume a large amount of electric energy but also reduce the amount of electric energy consumed.

[0009]

For this purpose, in a vehicle drive system according to the present invention, an internal combustion engine, a transmission capable of achieving at least two shift speeds, and a transmission connected to the transmission are provided. And an electric motor. The gear ratio of each speed stage of the transmission is determined by the torque ratio between the maximum value of the engine torque of the engine-driven vehicle having only the internal combustion engine and the engine torque and the maximum value of the motor torque of the hybrid vehicle. It is set based on the gear ratio of the lowest speed stage of the model vehicle and the gear ratio of the highest speed stage of the engine driven type vehicle.

The gear ratio of the lowest gear of the hybrid vehicle is set by multiplying the gear ratio of the lowest gear of the engine-driven vehicle by the torque ratio. The gear ratio of the highest gear of the hybrid vehicle is Is set by multiplying the gear ratio of the highest gear of the engine-driven vehicle by the torque ratio.

[0011]

[0012]

[0013]

According to the present invention, as described above, in a vehicle drive device, an internal combustion engine, a transmission device capable of achieving at least two shift speeds, and an electric device connected to the transmission device are provided. And a motor. The gear ratio of each speed stage of the transmission is determined by the torque ratio between the maximum value of the engine torque of the engine-driven vehicle having only the internal combustion engine and the engine torque and the maximum value of the motor torque of the hybrid vehicle. It is set based on the gear ratio of the lowest speed stage of the model vehicle and the gear ratio of the highest speed stage of the engine driven type vehicle.

The gear ratio of the lowest gear of the hybrid vehicle is set by multiplying the gear ratio of the lowest gear of the engine driven vehicle by the torque ratio, and the gear ratio of the highest gear of the hybrid vehicle is set. Is set by multiplying the gear ratio of the highest gear of the engine-driven vehicle by the torque ratio.
In this case, since the torque ratio is smaller than 1, the gear ratio of the lowest gear and the highest gear of the hybrid vehicle is smaller than the gear ratio of the lowest gear and the highest gear of the engine-driven vehicle, respectively.

Therefore, it is possible to set the gear ratio of the transmission to a higher gear and drive the internal combustion engine with a high load.

[0016]

[0017]

[0018]

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a conceptual diagram of a vehicle drive device according to an embodiment of the present invention, FIG. 4 is a first sectional view of the vehicle drive device according to the embodiment of the present invention, and FIG. 5 is a vehicle drive device according to an embodiment of the present invention. 2 is a second sectional view of FIG.

In FIG. 1, reference numeral 11 denotes an internal combustion engine, and 12 denotes a manual transmission. The transmission 12 achieves a gear selected by a gear selector (not shown), for example, a shift lever. Reference numeral 14 denotes a clutch device for selectively transmitting engine torque to the transmission 12. The clutch device 14 is disposed between an output shaft (crankshaft) 16 of the internal combustion engine 11 and an input shaft of a first shaft 21 of the transmission 12.
The rotation of the internal combustion engine 11 is transmitted to a transmission 12 via a clutch device 14, and the transmission 12 is shifted.

In the clutch device 14, a starting clutch member 26 is connected to the output shaft 16 through a disc-shaped flywheel 24. A torque transmitting member 27 is rotatably supported relative to the flywheel 24, and the flywheel 24 and the torque transmitting member 2
7, a magnetic coupling 28 is formed. Also,
A transmission clutch member 32 is disposed at an end of the input shaft of the first shaft 21 of the transmission 12 via a damper 31.
The damper 31 smoothes fluctuations in engine torque transmitted to the input shaft of the first shaft 21 via the starting clutch member 26 and the transmission clutch member 32.

The pressure plate 100 is connected to the clutch cover 33, and the clutch cover 33 and the release bearing 34 are sandwiched and held by the diaphragm spring 35. And the release bearing 3
By moving the shaft 4 in the axial direction, the transmission clutch member 32 and the torque transmission member 27 can be engaged and disengaged, and the start clutch member 26 and the transmission clutch member 32 and the torque transmission member 27 can be engaged and disengaged.

A release fork 40 is provided to move the release bearing 34 in the axial direction, and the outer end of the release fork 40 faces the rod of the release cylinder 41. The release cylinder 41 is connected to an actuator (not shown) via an oil passage. Therefore, by operating the actuator and supplying the hydraulic pressure generated by the actuator to the release cylinder 41, the release bearing 34 can be moved in the axial direction.

And operating the actuator,
When hydraulic pressure is supplied to the release cylinder 41, the clutch is released, and the starting clutch member 26, the transmission clutch member 32, and the torque transmitting member 27 are released. Next, when the actuator is operated to lower the hydraulic pressure supplied to the release cylinder 41, the engagement between the transmission clutch member 32 and the torque transmission member 27 is started, and a half-clutch state is established. At this time, the engine torque transmitted via the magnetic coupling 28 is transmitted to the transmission 12 via the transmission clutch member 32.

Subsequently, the actuator is operated,
When the hydraulic pressure supplied to the release cylinder 41 is further reduced, the torque transmitting member 27 and the starting clutch member 26 are engaged, and a clutch engaged state is established. At this time, the starting clutch member 26 and the transmission clutch member 32 are engaged with the torque transmitting member 27, and the rotation of the flywheel 24 is transmitted through the starting clutch member 26 to the torque transmitting member 2.
7 is transmitted directly to the transmission 12 via the transmission clutch member 32.

The transmission 12 has a plurality of gear sets G1 to G4 having different gear ratios disposed on a first shaft 21 and a second shaft 22 which are parallel to each other.
A specific gear ratio can be set by selecting and meshing one of G4 to G4. An output gear 55 is disposed on the second shaft 22, and the rotation at the speed selected in the transmission 12 is output from the output gear 55 and transmitted to the differential device 18.

The differential device 18 includes a differential case 6 having a ring gear 57 on its outer periphery.
1, a pinion shaft 62 fixed to the differential case 61, a pinion 63 rotatably supported by the pinion shaft 62, and left and right side gears 64 and 65 meshing with the pinion 63. Therefore, the rotation transmitted to the ring gear 57 can be transmitted to the left and right drive shafts 67 and 68 by the differential device 18 and the drive shafts 67 and 68 can be made differential to absorb a difference in the number of rotations.

The drive wheels 19 and 20 are fixed to the drive shafts 67 and 68, and the rotation transmitted to the drive shafts 67 and 68 is transmitted to the drive wheels 19 and 20. Incidentally, three gears 45 to 47 are disposed at the rearmost end of the transmission 12, and the transmission 12 and the electric motor 51 are connected via the gears 45 to 47. Then, a motor torque is generated by the electric motor 51, and the motor torque is transmitted to the first shaft 21 via the gears 45 and 46 to start the internal combustion engine 11 or to use a hybrid type motor only with the motor torque. The vehicle can be driven, or the hybrid vehicle can be driven by assisting the engine torque.

The electric motor 51 is disposed on an axis parallel to the first shaft 21 and has an output shaft 5 for outputting rotation.
2. A rotor 53 fixed to the output shaft 52 and rotatably disposed, and a stator 5 disposed around the rotor 53
4 and a coil 56 wound around the stator 54. The electric motor 51 generates a motor torque by a current supplied to the coil 56. For this purpose, the coil 56 is connected to an electric motor controller (not shown), and a current controlled by the electric motor controller is supplied to the coil 56.

When a current is supplied to the coil 56 of the electric motor 51 and the electric motor 51 is driven, the rotor 53 is rotated. The rotation of the rotor 53 is controlled by the first shaft via gears 45 to 47. 21. Further, the electric motor 51 can be used as a generator. Therefore, there is no need to externally charge a battery (not shown). In addition, since the hybrid vehicle can be driven by operating only the electric motor 51 as necessary, low noise and no pollution can be achieved depending on the area.

By the way, in the vehicle drive device having the above-described structure, the hybrid type vehicle can be driven by driving the internal combustion engine 11 and the electric motor 51 and using the engine / motor torque obtained by combining the engine torque and the motor torque. Has become. The gear ratio of the transmission 12 is set to a value such that the internal combustion engine 11 is driven with a high load during steady running.

FIG. 6 is a torque diagram of the engine torque in the embodiment of the present invention. In the figure, the horizontal axis represents the number of revolutions and the vertical axis represents the engine torque. In FIG, L1 is a torque curve of the engine torque, L2 torque curve of the engine motor torque, T ₁ is the maximum value of the engine torque, T ₂ is the maximum value of the engine motor torque.

As shown in the figure, the engine / motor torque increases in a low rotational speed range, so that the acceleration performance can be improved. Then, the gear ratio of the transmission 12 is set to a high load side so that the internal combustion engine 11 (FIG. 1) can be driven in the high fuel consumption region. FIG. 7 is a driving force diagram of the hybrid vehicle according to the embodiment of the present invention. In the drawings, the horizontal axis represents vehicle speed, and the vertical axis represents driving force.

In the figure, L3 is a driving force curve when the internal combustion engine 11 (FIG. 1) is driven, L4 is a driving force curve when the internal combustion engine 11 and the electric motor 51 are driven,
AR3 is a driving area during steady running, and AR4 is a good fuel consumption area. As shown in the figure, when the hybrid vehicle is driven by driving only the internal combustion engine 11, in a low-load running state such as a steady running state, a driving force as indicated by a driving area AR3 is generated. The internal combustion engine 11 is driven with a high load. Therefore, the frequency of driving the internal combustion engine 11 in the good fuel consumption area AR4 increases, so that the fuel consumption can be improved.

Further, since the frequency at which the electric motor 51 is driven is also reduced, the consumed electric energy is reduced, and a small battery can be used.
The hybrid vehicle can be reduced in size and weight. Further, a certain amount of driving force can be generated even when the second hold travel is performed, and the number of revolutions can be suppressed even when the vehicle speed increases.

Next, a method of setting the gear ratio of the transmission 12 to a higher load will be described. For this purpose, in the present embodiment, an engine-driven vehicle of the same vehicle type and having only the internal combustion engine 11 is assumed, and the transmission 12 is referred to based on the gear ratio of the transmission 12 of the engine-driven vehicle. Calculate the gear ratio of For this purpose, first, the torque ratio α between the maximum value T ₁ of the engine torque of the engine-driven vehicle (FIG. 6) and the maximum value T ₂ of the engine-motor torque of the hybrid vehicle is set. Is calculated.

Next, when the gear ratio of the lowest gear of the engine-driven vehicle was r _EL, the gear ratio r _HL of the lowest gear of the hybrid vehicle is set to r _HL = α · r _EL. On the other hand, when the gear ratio of the highest gear of the engine-driven vehicle is r _EH , the gear ratio r _HH of the highest gear of the hybrid vehicle is set to r _HH = α · r _EH .

In this manner, the gear ratio r _{HL at} the lowest speed and the gear ratio r _HH at the highest speed of the hybrid vehicle can be set to the higher load side. The gear ratios of the intermediate gears between the lowest gear and the highest gear are freely adjusted so as to have predetermined characteristics required for the hybrid vehicle between the gear ratios r _HL and r _HH. Can be set to

It is not necessary that the internal combustion engine 11 of the hybrid vehicle be the same as the internal combustion engine 11 of the engine driven vehicle. Next, a description will be given of a case where the gear ratio of the transmission 12 is calculated without using the gear ratio of the transmission 12 of the engine-driven vehicle as a reference. In this case, first, an additional torque T _A of the maximum value of the engine torque of the hybrid vehicle and the maximum value of the motor torque is obtained.
Is calculated.

Assuming that the gross vehicle weight of the hybrid vehicle is W and the effective radius of the tire (not shown) is R,
The gear ratio r _HL at the lowest gear of the hybrid vehicle is given by r _HL = (k ₁ · W / T _A ) · R, and the gear ratio r _HH at the highest gear is given by r _HH = (k ₂ · W / T _A ) ・ Set to R. Incidentally, k ₁ is a constant for the lowest gear stage, k ₂ is a constant for the highest gear position, a _{k 1 = 1/2 k 2} = 1/10.

Each of the gear ratios of the intermediate gear between the lowest gear and the lowest gear of the hybrid vehicle is a predetermined gear ratio required for the hybrid vehicle between the gear ratios r _HL and r _HH. Can be set freely so as to obtain the characteristics of In this case, the gear ratio of the transmission 12 can be set to the high-speed side without using the gear ratio of the engine-driven vehicle as a reference, and the internal combustion engine 11 can be driven with a high load.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0043]

As described above in detail, according to the present invention, in a vehicle drive system, an internal combustion engine, a transmission capable of achieving at least two shift speeds, and a transmission An electric motor coupled to the device. The gear ratio of each speed stage of the transmission is determined by the torque ratio between the maximum value of the engine torque of the engine-driven vehicle having only the internal combustion engine and the engine torque and the maximum value of the motor torque of the hybrid vehicle. It is set based on the gear ratio of the lowest speed stage of the model vehicle and the gear ratio of the highest speed stage of the engine driven type vehicle.

The gear ratio of the lowest gear of the hybrid vehicle is set by multiplying the gear ratio of the lowest gear of the engine-driven vehicle by the torque ratio. The gear ratio of the highest gear of the hybrid vehicle is Is set by multiplying the gear ratio of the highest gear of the engine-driven vehicle by the torque ratio.
In this case, since the engine torque generated by the internal combustion engine and the motor torque generated by the electric motor can be used, the engine torque and the motor torque increase in a low rotation speed region. Therefore, acceleration performance can be improved.

Further, the gear ratio of the transmission can be set to the higher gear, so that the internal combustion engine can be driven with a high load. Therefore, when the hybrid vehicle is driven by driving only the internal combustion engine, the frequency of driving the internal combustion engine in the good fuel consumption region in a low load driving state such as during steady driving increases, so that it is possible to improve the fuel efficiency. it can. Further, since the frequency at which the electric motor is driven is reduced, the consumed electric energy is reduced, a small battery can be used, and the hybrid vehicle can be reduced in size and weight.

Further, a certain amount of driving force can be generated even when the second hold travel is performed, and the number of revolutions can be suppressed even when the vehicle speed increases.

[0047]

[0048]

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a vehicle drive device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an equal fuel consumption curve of an internal combustion engine.

FIG. 3 is a driving force diagram for a conventional vehicle.

FIG. 4 shows a first example of the vehicle drive device according to the embodiment of the present invention.
FIG.

FIG. 5 shows a second example of the vehicle drive device according to the embodiment of the present invention.
FIG.

FIG. 6 is a torque diagram of engine torque in the embodiment of the present invention.

FIG. 7 is a driving force diagram of the hybrid vehicle according to the embodiment of the present invention.

[Explanation of symbols]

11 internal combustion engine 12 transmission 51 electric motor T _1, T ₂ maximum _{r EL, r EH, r HL} , r HH gear ratio W gross vehicle weight T _A additional torque R effective radius k _1, k ₂ constants

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F16H 61/02 F16H 59:14 // F16H 59:14 B60K 9/00 ZHVE (56) References JP-A-5-229352 (JP) JP-A-5-193382 (JP, A) JP-A-5-229350 (JP, A) JP-A-6-38303 (JP, A) JP-A-7-96759 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) B60K 6/02-6/04 F16H 3/08 B60K 17/04 B60L 11/14 F02D 29/02 F16H 61/02

Claims (1)

(57) [Claims] 1. An internal combustion engine, a transmission capable of achieving at least two shift speeds, and an electric motor coupled to the transmission, and a gear at each shift speed of the transmission. The ratio is the torque ratio between the maximum value of the engine torque of the engine-driven vehicle having only the internal combustion engine and the maximum value of the engine torque and the motor torque of the hybrid vehicle, the gear ratio of the lowest gear of the engine-driven vehicle , and The gear ratio of the lowest gear of the hybrid vehicle is set based on the gear ratio of the highest gear of the engine-driven vehicle, and the gear ratio of the lowest gear of the engine-driven vehicle is set by multiplying the torque ratio. The gear ratio of the highest gear of the hybrid vehicle is set by multiplying the gear ratio of the highest gear of the engine-driven vehicle by the torque ratio. Dual-use drive.