JP2003014074A - Gear ratio infinitely continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transmission efficiency while enlarging the range of a gear ratio of a gear ratio infinitely continuously variable transmission. SOLUTION: A first variable speed mechanism comprises a continuously variable transmission, and a second variable speed mechanism comprises a transmission capable of connecting and disconnecting rotation between input and output and realizing two large and small gear ratios. The output part of the first variable speed mechanism is connected to a sun gear of a planetary gear mechanism and to a ring gear through a clutch. The output part of the second variable speed mechanism is connected to a carrier of the planetary gear mechanism. The ring gear is connected to the output shaft side for driving a driving wheel. It is constituted to have the relation of Ig2/Id<λ1(1+α)/(λ1/λ2+α) among the maximum gear ratio λ1 and minimum gear ratio 12 of the continuously variable transmission, the smaller gear ratio Ig2 of the second variable speed mechanism, the number-of-teeth ratio αbetween the number-of-teeth of the sun gear of the planetary gear mechanism and the number-of-teeth of the ring gear, and a rotation ratio Id between the sun gear input rotation of the planetary gear mechanism and the output rotation of the continuously variable transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission adopted in a vehicle or the like, and more particularly to an improvement of an infinitely variable transmission continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, a belt type or toroidal type continuously variable transmission has been known as a transmission for a vehicle. In order to further expand the transmission range of such a continuously variable transmission, for example, the present application is proposed. Japanese Patent Laid-Open No. 11-303969 previously proposed by a person
There is known an infinitely variable transmission continuously variable transmission (IVT) which is capable of controlling a gear ratio up to infinity by combining a planetary gear mechanism with a continuously variable transmission as shown in No.

This is because the gear ratio of the unit (infinitely variable transmission continuously variable transmission) is continuously changed from a negative value to a positive value by including the infinite transmission ratio (= geared neutral point GNP) depending on the selection of the clutch. Select a power circulation mode that performs gear shift control, a continuously variable transmission direct connection mode that performs gear shift control according to the gear ratio of a continuously variable transmission (CVT), and a speed increase mode that expands the range of the gear ratio on the Hi side. It can be used for various purposes.

[0004]

However, in such an infinitely variable transmission continuously variable transmission, in the speed increasing mode, the CVT transmission ratio becomes Lo (= the unit transmission ratio becomes Hi), It was confirmed that the CVT input power was relatively large.

In the above-mentioned conventional example, the flow of power transmission in the speed-up mode is simply shown in FIG.

That is, in the planetary gear for the speed increasing mode, the torque T _IN from the drive source is input to the ring gear and the circulating torque Ts via the CVT is input to the sun gear, and is output from the carrier. .

The power transmission efficiency η of the entire transmission at this time is calculated as follows.

The input torque of the unit is T _IN , the output torque of the unit is T _OUT , the input rotation speed of the unit is ω _IN ,
The output rotation speed of the unit is ω _OUT , the gear ratio of the unit is Ii ₀ , the gear ratio of the CVT is Ic, the gear ratio of the output gear train of the CVT is Id, the gear ratio Ig of the constant speed change mechanism, and the transmission efficiency of the CVT is ηc, The transmission efficiency of the output gear train of the CVT is ηd, the transmission efficiency of the constant speed change mechanism is ηg, the gear ratio between the number of sun gears and the number of ring gears of the planetary gear mechanism (planetary gear mechanism gear ratio) is α, and the planetary gear mechanism's gear ratio is α. The torque of the sun gear is T _S , the torque of the carrier is T _C , the torque of the ring gear is T _R , the rotation speed of the sun gear of the planetary gear mechanism is ω _S , the rotation speed of the carrier is ω _C , the rotation speed of the ring gear is ω _R , and the planet When the transmission efficiency of the gear mechanism and _{η 0, T S = T C} · 1 / (1 + η 0 · i 0) ... (30) T R = T C · i 0 / (η 0 + i 0) ... (31) However , I ₀ = 1 / α and T _SO = T _S · (Id · Ic) / (ηd · η from c) ... (32) _{above, T OUT = T C · ηg} · Ig-T S · (Id · Ic) / (ηd · ηc) = T R · ηg · Ig · (η 0 + i 0) / i 0 -T _R · [(Id · Ic) / (ηd · ηc)] · [(1 + η ₀ / i ₀ ) / (1 + η ₀ · i ₀ )] (33) ∴ Torque ratio t = T _OUT / T _IN = ηg · Ig · (1 + η ₀ / i ₀ ) − [(Id · Ic) / (ηd · ηc)] · [(1 + η ₀ / i ₀ ) / (1 + η ₀ · i ₀ )] = (1 + η ₀ / i ₀₎ ) ・ [Ηg ・ Ig-[(Id ・ Ic) / (ηd ・ ηc)] ・ [1 / (1 + η ₀・ i ₀ )]] (34) Also, ω _R + α ・ ω _S = (1 + α) ・ω _C (35) ω _C / Ig = ω _S / (Id · Ic) (36) From ω _R + α · ω _C · Id · Ic / Ig = (1 + α) · ω _C ω _R = [(1 + α ) -α · Id · Ic / Ig ] · ω C ... (37) ∴ speed ratio _{e = 1 / Ii 0 = ω} OUT / ω IN = (ω C / I _{) / Ω R = (1 /} Ig) · [1 / [(1 + α) -α · Id · Ic / Ig]] = 1 / [(1 + α) · Ig-α · Id · Ic] ... (38) Therefore, The transfer efficiency η of the unit is as follows: η = t · e = (1 + α · η ₀ ) · [ηg · Ig − [(Id · Ic) / (ηd · ηc)] · [1 / (1 + η ₀ / α)]]・ [1 / [(1 + α) ・ Ig−α ・ Id ・ Ic]] (40), and the calculation result is shown below the specifications in FIG.
2 and the gear ratio I of the CVT in the speed increasing mode
It can be seen that the transmission efficiency decreases as c increases.

This is because as the gear ratio Ic of the CVT increases in the speed increasing mode, the ratio of the circulation torque Ts via the frictional engagement of the CVT, which has lower transmission efficiency than the gear mesh, increases. Indicated by.

The ratio h of the CVT input power T _i · ω _{I to} the input power T _IN · ω _IN of the unit is h = (T _i · ω _I ) / (T _IN · ω _IN ) = [[1 / (1 + η ₀ · i ₀ )] / [i ₀ / (η ₀ + i ₀ )]] · [[(Id · Ic / Ig) · ω _C ] / [(1 + α) −α · Id · Ic / Ig] · ω _C ] = [(1 + α · η ₀ ) / (1 + η ₀ / α)] ・ [1 / [Ig · (1 + α) / (Id · Ic) −α]] = [(η ₀ + 1 / α) / (1 + η ₀ / Α)] · [1 / [(1 + 1 / α) · Ig / (Id · Ic) −1]] (41), and as is clear from the calculation result shown in FIG. It can be seen that as the Ic increases, the CVT input power ratio h increases, the ratio of the circulation torque Ts via the CVT increases, and the power transmission efficiency of the entire transmission decreases.

As described above, the conventional IVT realizes a gear ratio smaller than that of the direct connection mode, but C
There has been a problem that the power transmission efficiency of the entire transmission decreases as the VT speed ratio increases.

Further, because of the speed increasing mode, a plurality of clutches are added, which causes a problem that the transmission becomes large.

It is an object of the present invention to expand the range of the gear ratio of an infinitely variable gear continuously variable transmission and solve these problems.

[0014]

SUMMARY OF THE INVENTION A first aspect of the present invention is to drive a first transmission mechanism and a second transmission mechanism for inputting a driving force from a drive source, and an output of these first and second transmission mechanisms for input. A planetary gear mechanism for outputting to the wheel side, the first speed change mechanism is a continuously variable transmission capable of continuously changing the speed change ratio, and the second speed change mechanism is provided between the input and output of the second speed change mechanism. The transmission comprises a transmission capable of connecting / disconnecting rotation and realizing two gear ratios, large and small. The output portion of the first transmission mechanism is connected to a ring gear via a sun gear and a clutch of the planetary gear mechanism. The output part of the two-speed mechanism is connected to the carrier of the planetary gear mechanism, the ring gear is connected to the output shaft side for driving the drive wheels, and the maximum speed ratio λ1 and the minimum speed ratio λ2 of the continuously variable transmission are The smaller gear ratio Ig2 of the second transmission mechanism Between the sun gear tooth number ratio α of the planetary gear mechanism and the ring gear tooth number α, and the rotation ratio Id of the sun gear input rotation of the planetary gear mechanism and the output rotation of the continuously variable transmission, Ig2 / It has a relationship of Id <λ1 (1 + α) / (λ1 / λ2 + α).

According to a second aspect of the present invention, in the first aspect of the present invention, the second speed change mechanism includes two large and small gears arranged on an input shaft from a drive source, and gear trains having different gear ratios are formed. , The output side of each gear train is connected to the carrier of the planetary gear mechanism via a clutch.

In a third aspect based on the first aspect, the second speed change mechanism includes a second planetary gear mechanism different from the planetary gear mechanism and a ring gear of the second planetary gear mechanism with respect to the transmission case. Has a brake that can be fixed in place and a clutch,
One of the sun gear of the second planetary gear mechanism and the carrier is connected to the carrier of the planetary gear mechanism, and the other is connected to the drive source side, and the sun gear of the second planetary gear mechanism and the carrier can be integrally rotated through a clutch. I chose

In a fourth aspect based on the first aspect, the minimum speed ratio λ2 of the continuously variable transmission, the smaller speed ratio Ig2 of the second speed change mechanism, and the sun gear input rotation of the planetary gear mechanism. The output ratio of the continuously variable transmission and the rotation ratio Id have a relationship of Ig2 / Id ≧ λ2.

[0018]

According to the first aspect of the invention, in the speed increasing mode, the planetary gear mechanism receives the carrier and outputs the sun gear and the ring gear. Infinite ratio continuously variable transmission) The ratio to the input power becomes smaller as the gear ratio of the continuously variable transmission becomes closer to Lo (large) (the torque flowing to the continuously variable transmission becomes smaller), and the transmission efficiency of the unit increases. improves.

In this case, Ig2 / Id <λ1 (1+
By satisfying the relationship of α) / (λ1 / λ2 + α), the gear ratio of the unit can be set to be equal to or higher than the continuously variable transmission direct connection mode in which the output portion of the first transmission mechanism is connected to the ring gear of the planetary gear mechanism, and The gear ratio can be expanded.

Further, the number of clutches can be reduced,
It can contribute to the miniaturization of the unit.

According to the second aspect of the invention, the speed increasing mode can be realized by one set of planetary gear mechanisms by the plurality of gear trains of the second speed change mechanism, and the cost can be reduced.

According to the third invention, by using the planetary gear mechanism for the second transmission mechanism, the diameter of the gear arranged on the unit input side can be reduced.

According to the fourth aspect of the invention, by satisfying the relation of Ig2 / Id ≧ λ2, the maximum Lo gear ratio of the unit in the speed increasing mode becomes equal to or less than the maximum Hi gear ratio of the unit in the continuously variable transmission direct connection mode. Therefore, it is possible to ensure continuity of the gear ratio when switching between the continuously variable transmission direct connection mode and the speed increasing mode.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an infinitely variable transmission continuously variable transmission according to a first embodiment. An infinitely variable transmission continuously variable transmission (IV) is connected to a crankshaft of an engine (not shown).
The first transmission mechanism 2 and the second transmission mechanism 3 are connected in parallel to the unit input shaft 1 of T).

The first transmission mechanism 2 is provided with a toroidal type continuously variable transmission (CVT) 4 capable of continuously changing the gear ratio, and an output gear train 5 of the continuously variable transmission 4, and its output shaft 2a. Is connected to the sun gear 6a of the planetary gear mechanism 6 and the unit output shaft 8 which is the output shaft of the continuously variable transmission having an infinite transmission ratio via the continuously variable transmission direct coupling mode clutch 7.

The second transmission mechanism 3 includes two gears (small gear 9 and large gear 10) having different numbers of teeth on the unit input shaft 1 and gear trains 11 and 1 having different gear ratios.
2, the output side of each gear train 11, 12 is a power circulation mode clutch (first power circulation mode clutch 13, second power circulation mode clutch 14), output shaft 3a.
Is connected to the carrier 6b of the planetary gear mechanism 6 via.

The ring gear 6c of the planetary gear mechanism 6 is connected to the unit output shaft 8 and is connected to the output shaft 2 of the first speed change mechanism 2.
a, the output shaft 3a of the second speed change mechanism 3 is the unit output shaft 8
Is rotatably supported relative to.

The unit output is transmitted to the drive shaft 18 via the transmission output gear 15, the final gear 16, and the differential gear 17.

The first speed change mechanism 2, the second speed change mechanism 3 and the planetary gear mechanism 6 are the continuously variable transmission 4 of the first speed change mechanism 2.
Maximum gear ratio (maximum Lo gear ratio) λ1, minimum gear ratio (maximum H gear ratio)
i gear ratio) λ2, the smaller gear ratio of the second gear mechanism 3 (gear ratio on the large gear 10 side) Ig2, and the gear ratio of the number of sun gear teeth and the number of ring gear teeth of the planetary gear mechanism 6 (planetary gear). Mechanical gear ratio) α and the rotation ratio between the sun gear input rotation of the planetary gear mechanism 6 and the output rotation of the continuously variable transmission 4 of the first transmission mechanism 2 (the gear ratio of the output gear train 5 of the continuously variable transmission 4) Id The gear trains 5 and 12, the planetary gear mechanism gear ratio, etc. are set so that the following relationship is established: Ig2 / Id <λ1 (1 + α) / (λ1 / λ2 + α) (1).

In addition,     Ig2 / Id ≧ λ2 (2) Are set to have the relationship of.

Next, the operation of the infinitely variable transmission ratio continuously variable transmission thus configured will be described.

In this continuously variable transmission with an infinite transmission ratio, the first power circulation mode, the continuously variable transmission direct connection mode, and the second power circulation mode (acceleration mode) are selectively selected by engaging and releasing the clutch shown in FIG. Can be used for

It should be noted that the gear ratio (unit gear ratio = unit input shaft rotation speed / unit output shaft rotation speed) Ii of the continuously variable transmission with infinite gear ratio is Ii ₁ in the first power circulation mode, and is directly connected to the continuously variable transmission. Ii ₀ in the mode, Ii ₂ in the second power circulation mode, and the gear ratio (C
VT gear ratio) is Ic, and the larger gear ratio of the second transmission mechanism 3 (gear ratio on the small gear 9 side) is Ig1. However, the minimum speed ratio λ2 ≦ Ic ≦ the maximum speed ratio λ1 of the continuously variable transmission 4 is satisfied.

In the first power circulation mode, the first power circulation mode clutch 13 is engaged, while the continuously variable transmission direct-coupling mode clutch 7 and the second power circulation mode clutch 14 are released, whereby the continuously variable transmission 4 operates. The relationship between the gear ratio Ic and the unit gear ratio Ii ₁ is expressed by 1 / Ii ₁ = (1 + α) / Ig 1-α / (Ic · Id) (3), and it depends on the gear ratio Ic of the continuously variable transmission 4. Thus, the unit speed ratio Ii can be changed almost continuously from a negative value to a positive value including infinity.

In the continuously variable transmission direct coupling mode, the continuously variable transmission direct coupling mode clutch 7 is engaged, while the first power circulation mode clutch 13 and the second power circulation mode clutch 14 are released, whereby the continuously variable transmission 4 is released. The relationship between the gear ratio Ic and the unit gear ratio Ii ₀ is expressed by 1 / Ii ₀ = 1 / (Ic · Id) (4), and according to the gear ratio Ic of the continuously variable transmission 4, the unit gear ratio Ii can be continuously changed.

In the second power circulation mode, the second power circulation mode clutch 14 is engaged, while the continuously variable transmission direct connection mode clutch 7 and the first power circulation mode clutch 13 are released. That is, the rotation higher than that in the first power circulation mode is input to the carrier 6b of the planetary gear mechanism 6, and the relationship between the gear ratio Ic of the continuously variable transmission 4 and the unit gear ratio Ii ₂ is 1 / Ii ₂ = ( 1 + α) / Ig2-α / (Ic · Id) (5)

In this case, comparing the unit maximum Hi gear ratio Ii _2Hi in the second power circulation mode with the unit maximum Hi gear ratio Ii _0Hi in the continuously variable transmission direct connection mode, the unit maximum Hi gear ratio Ii _0Hi in the second power circulation mode is compared. The Hi gear ratio Ii _2Hi is the maximum gear ratio λ1 of the continuously variable transmission 4, and the unit maximum Hi gear ratio Ii _0Hi in the continuously variable transmission direct connection mode is the minimum gear ratio λ2 of the continuously variable transmission 4. _Therefore , 1 / Ii _2Hi = 1 / Ii ₂ (Ic = λ1) = (1 + α) / Ig2-α / (λ1 · Id) (6) 1 / Ii _0Hi = 1 / Ii ₀ (Ic = λ2) = 1 / (λ2 · Id) (7) Therefore, 1 / Ii _2Hi −1 / Ii _0Hi = (1 + α) / _Ig2 -α / (λ1 · Id) −1 / (λ2 · Id) = (1 + α) / Ig2 -(Α / λ1 + 1 / λ2) / Id = [(1 + α) / (α / λ1 + 1 / λ2) -Ig2 Id] × (α / λ1 + 1 / λ2) / Ig2 = [λ1 (1 + α) / (λ1 / λ2 + α) −Ig2 / Id] × (α / λ1 + 1 / λ2) / Ig2 (8) Since Ig2 / Id <λ1 (1 + α) / (λ1 / λ2 + α) is set, the equation (8) becomes> 0 and Ii _2Hi <Ii _0Hi (9).

That is, in the second power circulation mode, Hi
The gear ratio Ii on the side can be increased.

Further, since the unit maximum Lo gear ratio Ii _2Lo in the second power circulation mode is the minimum gear ratio λ2 of the continuously variable transmission 4, 1 / Ii _2Lo = 1 / Ii ₂ (Ic = λ2) = (1 + α) / Ig2-α / (λ2 · Id) (10) Therefore, 1 / Ii _2Lo −1 / Ii _0Hi = (1 + α) / _Ig2 -α / (λ2 · Id) −1 / (λ2 · Id) ) = (1 + α) / Ig2- (1 + α) / (λ2 · Id) = (λ2-Ig2 / Id) × (1 + α) / (λ2 · Ig2) ... (11), whereas Ig2 // Since Id ≧ λ2 is set, the equation (11) becomes ≦ 0, and Ii _2Lo ≧ Ii _0Hi (12).

That is, it is possible to ensure continuity of the gear ratio when switching between the continuously variable transmission direct connection mode and the second power circulation mode.

On the other hand, the flow of power transmission in the second power circulation mode is shown in FIG. That is, the planetary gear mechanism 6 has a configuration in which the torque T _IN from the drive source and the circulating torque T _i transmitted to the sun gear 6a and passed through the continuously variable transmission 4 are input to the carrier 6b and output from the ring gear 6c. There is.

Transmission efficiency of the unit in the second power circulation mode
The ratio η is the input torque of the unit T _IN, Unit output
Torque to T_OUT, The input rotation speed of the unit is ω_IN, Uni
Output rotation speed of_OUT, Transmission torque of continuously variable transmission 4
Ku to T_i, The transmission efficiency of the continuously variable transmission 4 is ηc, and the continuously variable transmission 4 is
The transmission efficiency of the output gear train 5 of
The transmission efficiency of the gear train 12 with the smaller speed ratio is ηg,
The torque of the sun gear 6a of the car mechanism 6 is T_S, Carrier 6b
Torque of T_C, Torque of ring gear 6c to T_R, Planetary teeth
The transmission efficiency of the vehicle mechanism 6 is η₀As a simple formula,
For carrier input, sun gear, ring gear output (forward
Status),     T_S= T_C・ Η₀/ (Η₀+ Ii₀)… (13)     T_R= T_C・ (Η₀・ Ii₀) / (1 + η₀・ Ii₀)… (14)   Also,     T_i= T_S・ (Ηd / Id) ・ (ηc ・ Ic) (15)     T_C= (T_i1 + T_IN) ・ Ig2 ・ ηg (16)   From the above,     T_C/(Ig2.eta.g)=[(.eta.d.eta.c)/(Id.Ic)]                         ・ [Η₀/ (Η₀+ Ii₀)] ・ T_C+ T_IN  … (17)     T_C・ [[1 / (Ig2 ・ ηg)]-[(ηd ・ ηc) / (Id ・ Ic)]         ・ [Η₀/ (Η₀+ Ii₀)]] = T_IN                      … (18)   Therefore, the transmission efficiency η of the unit is     η = (T_OUT・ Ω_OUT) / (T_IN・ Ω_IN)       = (T_R/ T_IN) ・ (1 / Ii₀)       = [(Η₀・ Ii₀) / (1 + η₀・ Ii₀)]         ・ (T_C/ T_IN) ・ (1 / Ii₀)       = [(Η₀・ Ii₀) / (1 + η₀・ Ii₀)] ・ [1 / [1 / (Ig2 ・ ηg)         −ηd ・ ηc ・ η₀/ (Id ・ Ic ・ (η₀+ Ii₀))]] ・ (1 / Ii₀)       = [1 / [1 + 1 / (1 + η₀・ Ii₀)] ・ [1 / (Ig2 ・ ηg)         −ηd ・ ηc / (Id ・ Ic ・ (1 + Ii₀/ Η₀))]] ・ (1 / Ii₀)                                                             … (19) However, 1 / Ii₀= (1 + α) / Ig2-α / (Ic
・ It is obtained from Id).

The ratio h of the continuously variable transmission input power to the unit input power in the second power circulation mode is h = (T _i · ω _I ) / (T _IN · ω _IN ) = [(ηd · ηc) / (Id · Ic)] ・ (T _S / T _IN ) ・ (ω _IN / ω _IN ) = [(ηd ・ ηc) / (Id ・ Ic)] ・ [η ₀ / (η ₀ + Ii ₀ )] ・(T _C / T _IN ) = [(ηd · ηc) / (Id · Ic)] · [[η ₀ / (η ₀ + Ii ₀ )] · T _C ] / [[1 / (Ig 2 · ηg)]- [(Ηd ・ ηc) / (Id ・ Ic)] ・ [η ₀ / (η ₀ + Ii ₀ )] ・ T _C ] = 1 / [[1 / (Ig2 ・ ηg)] ・ [Id ・ Ic ・ (η ₀ + Ii ₀ ) / (ηd · ηc · η ₀ )] − 1] = 1 / [[(Id · Ic) / (Ig2 · ηg · ηd · ηc)] ・ (1 + Ii ₀ / η ₀ ) -1] = 1 / [[(Id · Ic) / (Ig2 · ηg · ηd · ηc)] · [1 + 1 / (α · η ₀ )] − 1] (20).

That is, the ratio h of the continuously variable transmission input power and the unit input power in the second power circulation mode becomes smaller as the gear ratio Ic of the continuously variable transmission 4 becomes Lo (large), unlike the conventional case. (The torque flowing to the continuously variable transmission 4 side is reduced). Therefore, the transmission efficiency η of the unit in the second power circulation mode is improved.

Next, the results calculated under the gear ratio setting and efficiency conditions shown in FIG. 4 are shown in FIGS. 5, 6 and 7. Since the transmission efficiency ηc of the continuously variable transmission (variator) 4 is lower than the transmission efficiency of a constant transmission composed of one set of gear trains,
Calculated by setting a low value.

FIG. 5 shows the unit speed ratio (= reciprocal of gear ratio)
1 / Ii is shown, and in the second power circulation mode,
The gear ratio Ii on the Hi side is expanding. That is, in the second power circulation mode, the rotation higher than that in the first power circulation mode is input to the carrier 6b of the planetary gear mechanism 6 by the gear train 12 of the second transmission mechanism 3 having a smaller gear ratio. By so doing, the second power circulation mode has a characteristic of being offset to a higher gear ratio side than the first power circulation mode, and a wide gear ratio Ii can be obtained on the Hi side (speed increasing side).

FIG. 6 shows the unit efficiency η, and FIG. 7 shows the ratio h between the variator input power and the unit input power. In the present invention, the variator input power and the unit input power in the second power circulation mode are shown. The ratio h is
It is sufficiently smaller than the speed increasing mode of the conventional example, and is smaller than 1. Therefore, it can be confirmed that the IVT of the present invention can achieve higher transmission efficiency η than the speed increasing mode of the conventional example and higher than the direct coupling mode as shown in FIG.

As shown in FIG. 1, the continuously variable transmission 4 is of a toroidal type in which the power roller 20 is sandwiched and pressed by the input disk 21 and the output disk 22. But good. A chain transmission mechanism may be used instead of the output gear train 5 of the continuously variable transmission 4.

FIG. 8 shows a second embodiment of the present invention. This uses a second planetary gear mechanism 31 other than the planetary gear mechanism (first planetary gear mechanism) 6 for the second speed change mechanism 30, and uses a second planetary gear mechanism 31 in a first power circulation mode and a second power circulation mode. The rotation input to the carrier 6b of the planetary gear mechanism 6 is changed.

Carrier 31b of second planetary gear mechanism 31
Is connected to the unit input shaft 1 via a predetermined gear train 32, and is configured to be integrally rotatable with the sun gear 31a via a power circulation mode clutch 33 (first power circulation mode clutch). The sun gear 31a is the first planetary gear mechanism 6
To the carrier 6b. The ring gear 31c is configured to be fixed to the transmission case via a brake 34 (corresponding to a second power circulation mode clutch).

The output shaft of the continuously variable transmission 4 of the first transmission mechanism 2 is connected to the output shaft 2a via the sprocket 35a, the chain 35b and the sprocket 35c, and the output shaft 2a is the sun gear 6a of the first planetary gear mechanism 6. And a unit output shaft 8 via a continuously variable transmission direct coupling mode clutch 7.

The other structure is the same as that of the first embodiment.

In the first power circulation mode, the first power circulation mode clutch 33 is engaged, while the continuously variable transmission direct connection mode clutch 7 and the brake 34 are released. In this case, the input rotation of the unit is the gear train 32 of the second speed change mechanism 30,
It is transmitted to the carrier 6b of the first planetary gear mechanism 6 via the first power circulation mode clutch 33.

In the continuously variable transmission direct connection mode, the continuously variable transmission direct connection mode clutch 7 is engaged, while the first power circulation mode clutch 13 and the brake 34 are released.

In the second power circulation mode, the brake 34 is engaged while the continuously variable transmission direct coupling mode clutch 7 and the first
The power circulation mode clutch 13 is released. In this case, the input rotation of the unit passes through the gear train 32 of the second transmission mechanism 30, is accelerated by the second planetary gear mechanism 31, and is transmitted from the sun gear 31a to the carrier 6b of the first planetary gear mechanism 6.

The gear ratio of the second speed change mechanism 30 in the first power circulation mode is Ig1 (the input rotation speed of the unit / the rotation speed output to the carrier 6b of the first planetary gear mechanism 6) and the second power circulation mode. The gear ratio is Ig2 (the input rotation speed of the unit / the rotation speed output to the carrier 6b of the first planetary gear mechanism 6), and the tooth ratio of the sun gear teeth number and the ring gear teeth number of the second planetary gear mechanism 31 is β (< 1), the gear ratio of the second planetary gear mechanism 31 in the second power circulation mode is: carrier rotation speed / sun gear rotation speed = 1 / (1 + 1 / β) (21) Therefore, Ig2 = Ig1 / (1 + 1 / β) <Ig1 (22), and Ig2 is set to a speed ratio higher than Ig1.

By doing so, the diameter of the gear arranged on the unit input shaft 1 can be reduced.

FIG. 9 shows a third embodiment of the present invention. This is the second planetary gear mechanism 31 of the second transmission mechanism 30.
The sun gear 31a of the
2 via a carrier 31 of the second planetary gear mechanism 31
b is connected to the carrier 6b of the first planetary gear mechanism 6, and the power circulation mode clutch 33 for integrally rotating the carrier 31b of the second planetary gear mechanism 31 and the sun gear 31a is used as the second power circulation mode clutch. The brake 34 for fixing the ring gear 31c of the two-planetary gear mechanism 31 to the transmission case is a first power circulation mode clutch.

The other structure is the same as that of the second embodiment.

In the first power circulation mode, the brake 34
While engaging the (first power circulation mode clutch), the continuously variable transmission direct coupling mode clutch 7 and the power circulation mode clutch 33 (second power circulation mode clutch) are released. In this case, the input rotation of the unit passes through the gear train 32 of the second transmission mechanism 30, is decelerated by the second planetary gear mechanism 31, and is transmitted from the carrier 31b to the carrier 6b of the first planetary gear mechanism 6.

In the continuously variable transmission direct connection mode, the continuously variable transmission direct connection mode clutch 7 is engaged while the brake 34 and the power circulation mode clutch 33 are released.

In the second power circulation mode, the power circulation mode clutch 33 (second power circulation mode clutch) is engaged, while the continuously variable transmission direct connection mode clutch 7 and the brake 3 are engaged.
4 (first power circulation mode clutch) is released. In this case, the input rotation of the unit passes through the gear train 32 of the second speed change mechanism 30 and the power circulation mode clutch 33 (second power circulation mode clutch) and then the carrier 6 of the first planetary gear mechanism 6.
b.

That is, the gear ratio of the second planetary gear mechanism 31 in the second power circulation mode is Sun gear rotation speed / carrier rotation speed = (1 + 1 / β) (23), so that Ig1 = Ig2 × (1 + 1) / Β)> Ig2 (24).

Further, in each of the embodiments, the total number of clutches can be reduced and the IVT can be downsized as compared with the conventional one.

In the second and third embodiments, the gear train 32 of the second transmission mechanism 30 is used, and the output gear train 5 of the continuously variable transmission 4 in the first embodiment or the second and third gear trains. The transmission mechanism of the continuously variable transmission 4 according to the embodiment may be configured as shown in FIG. Further, the output of the unit output shaft 8 may be transmitted to the final gear 16 side via the counter shaft 40 as shown in FIG.
By doing so, the gear ratio is set at two places, that is, the counter gear train 41 and the final gear train (15, 16), so that it is possible to increase the reduction ratio of the through gear, and the gear shift increased in the second power circulation mode. There is an effect that the specific width can be designed so as to improve both the performance of the driving force and the performance of the constant fuel consumption in a well-balanced manner.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an infinitely variable transmission continuously variable transmission according to a first embodiment.

FIG. 2 is a table showing engagement and disengagement patterns of a clutch.

FIG. 3 is a diagram showing a flow of power transmission.

FIG. 4 is a table showing an example of setting gear ratios and efficiency conditions.

FIG. 5 is a graph showing a relationship between a continuously variable transmission and a unit speed ratio.

FIG. 6 is a graph showing unit efficiency η.

FIG. 7 is a graph showing the relationship between unit speed ratio and variator input power / unit input power.

FIG. 8 is a schematic configuration diagram of an infinitely variable transmission continuously variable transmission according to a second embodiment.

FIG. 9 is a schematic configuration diagram of an infinitely variable transmission continuously variable transmission according to a third embodiment.

FIG. 10 is a schematic configuration diagram of an infinitely variable transmission continuously variable transmission according to a fourth embodiment.

FIG. 11 is a diagram showing a flow of power transmission in a conventional example.

FIG. 12 is a graph showing a unit efficiency η of a conventional example.

FIG. 13 is a graph showing the relationship between unit speed ratio and variator input power / unit input power in a conventional example.

[Explanation of symbols]

1 unit input shaft 2 First speed change mechanism 2a Output shaft 3 Second speed change mechanism 3a Output shaft 4 continuously variable transmission 5 output gear train 6 Planetary gear mechanism 6a sun gear 6b carrier 6c ring gear 7 Continuously variable transmission direct coupling mode clutch 8 unit output shaft 9 small gears 10 gears 11,12 Gear train 11,12 13 First power circulation mode clutch 14 Second power circulation mode clutch 30 Second speed change mechanism 31 Second planetary gear mechanism 31a sun gear 31b carrier 31c ring gear 33 Power circulation mode clutch 34 Brake 35a sprocket 35b chain 35c sprocket

Continued front page    F-term (reference) 3J051 AA03 AA08 BA03 BD02 BE09                       CB07 ED15 FA01                 3J062 AA01 AA18 AB01 AB06 AB33                       AB35 AC02 AC03 BA12 BA31                       BA35 CG02 CG14 CG35 CG38                       CG44 CG52 CG82

Claims (4)

[Claims] 1. A first speed change mechanism and a second speed change mechanism for inputting a driving force from a drive source, and a planetary gear mechanism for inputting outputs of the first and second speed change mechanisms to output to a drive wheel side. The first speed change mechanism is a continuously variable transmission capable of continuously changing the speed change ratio, the second speed change mechanism is capable of connecting and disconnecting rotation between the input and output of the second speed change mechanism, and has a large and small size. A transmission capable of realizing two gear ratios, wherein an output portion of the first transmission mechanism is connected to a ring gear through a sun gear and a clutch of the planetary gear mechanism, and an output portion of the second transmission mechanism is connected to the planetary gear. And a ring gear connected to the output shaft side for driving the drive wheels. The maximum speed ratio λ1, the minimum speed ratio λ2 of the continuously variable transmission, and the smaller speed ratio of the second speed change mechanism. Ig2 and the support of the planetary gear mechanism. Ig2 / Id <λ1 (1 + α) between the gear ratio α between the gear teeth and the ring gear teeth, and the rotation ratio Id between the sun gear input rotation of the planetary gear mechanism and the output rotation of the continuously variable transmission. An infinitely variable transmission continuously variable transmission having a relationship of / (λ1 / λ2 + α). 2. The second speed change mechanism includes two large and small gears arranged on an input shaft from a drive source, forms gear trains having different gear ratios, and clutches an output side of each gear train. The infinitely variable transmission continuously variable transmission according to claim 1, wherein the infinitely variable transmission is connected to the carrier of the planetary gear mechanism via. 3. The second speed change mechanism comprises a second planetary gear mechanism different from the planetary gear mechanism, and a brake capable of fixing the ring gear of the second planetary gear mechanism to the transmission case.
And a clutch, wherein one of a sun gear and a carrier of the second planetary gear mechanism is connected to the carrier of the planetary gear mechanism and the other is connected to a drive source side, and the sun gear and the carrier of the second planetary gear mechanism are clutched. The infinitely variable transmission continuously variable transmission according to claim 1, wherein the continuously variable transmission is made integral with the gear. 4. A minimum speed ratio λ2 of the continuously variable transmission, a smaller speed ratio Ig2 of the second speed change mechanism, a sun gear input rotation of the planetary gear mechanism, and an output rotation of the continuously variable transmission. The infinitely variable transmission continuously variable transmission according to claim 1, having a relationship of Ig2 / Id ≧ λ2 with the rotation ratio Id.