JPH0545819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power train for an automatic transmission that provides five forward gears.

(Prior Art) Conventionally, 3-speed automatic transmissions have been replaced by 4-speed automatic transmissions with overdrive (O/D) due to the need to save energy at high speeds.

This usually consists of three planetary gear sets, and some have two planetary gear sets.

Recently, there has been a desire for further performance improvements (particularly improved acceleration in low gear positions, etc.), and the appearance of 5-speed automatic transmissions is expected.

An example of this 5-speed automatic transmission is the one shown in Fig. 7 of Japanese Patent Application Laid-Open No. 62-93546, which is a Lavigneau type planetary gear set (two sets of planetary gears). It has a configuration in which an auxiliary transmission consisting of a single pinion type planetary gear set is added to the main transmission.

(Problems to be Solved by the Invention) However, in such a conventional device, although the output structure is from a planetary carrier, there is only one Lavigneau type planetary gear set which is the main transmission. Because it is a type with a sun gear of
Although it can be applied to FF cars, it cannot be applied to FR cars. Furthermore, since the main transmission and the sub-transmission shift simultaneously during gear shifting, there are problems in that the shift shock becomes large and difficult control must be used to reduce the shift shock.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and to achieve this purpose, the present invention uses a sun gear which is divided into two parts. Rotates an inner pinion that meshes with the first sun gear, the second sun gear, the first ring gear, the second ring gear, and both the first and second sun gears, an outer pinion that meshes with both the inner pinion, the second ring gear, and both the inner and outer pinions. A single pinion having a Lavigneau type planetary gear set having a first pinion carrier that freely supports it, a third sun gear, a third ring gear, a third pinion that meshes with both of these, and a third pinion carrier that rotatably supports the pinion. Two planetary gear sets including a type planetary gear set are disposed between the input shaft and the output shaft, and the first ring gear is connected to the input gear via the first clutch which is engaged in the first to fourth speeds. The third ring gear can be connected to the shaft, and the third ring gear can be stopped by a one-way clutch that operates in the first speed and a first brake that is engaged in the 1st and R ranges. One of the sun gears can be connected to the input shaft via a second clutch that is engaged in fourth and fifth gears, and the first sun gear is coupled to the input shaft via a third clutch that is engaged in R range. The second ring gear is always connected to a third pinion carrier and can be stopped by a second brake that is applied in second gear, and the second sun gear is always connected to a third sun gear. Along with being
It is possible to stand still with the third brake applied in the third and fifth gears, and the first pinion carrier is taken out from the divided portion of the first sun gear and the second sun gear and is always connected to the output shaft. This is a means to do so.

(Function) At 1st speed, if only the first clutch is actuated to connect the input shaft and the first ring gear, the first one-way clutch will prevent the third ring gear from rotating in the reverse direction, and the input shaft will move from the input shaft to the first ring gear. →
Power is transmitted from the inner pinion to the first pinion carrier to the output shaft, and a first gear with a large reduction gear ratio is obtained from the output shaft.

In 2nd gear, the first clutch and second brake are operated to couple the input shaft and first ring gear, and when the second ring gear is stationary, the input shaft → first
Power is transmitted from the ring gear to the inner pinion to the first pinion carrier to the output shaft, and from the output shaft, a second speed with a smaller reduction gear ratio than the first speed is obtained.

In 3rd gear, the first clutch and third brake are operated to connect the input shaft and first ring gear, and the second sun gear and third sun gear are stationary, so that the input shaft → first ring gear → inner pinion →
Power is transmitted from the first pinion carrier to the output shaft, and from the output shaft a third speed gear position having a smaller reduction gear ratio than second speed is obtained.

In 4th gear, the first clutch and the second clutch are operated to connect the input shaft and the first ring gear, and also connect the input shaft and the third ring gear, so that the input shaft → first ring gear → inner pinion → first pinion carrier → The power is transmitted to the output shaft, and the power is transmitted from the input shaft to the third ring gear to the third pinion to the third pinion carrier to the second ring gear to the outer pinion to the inner pinion to the first pinion carrier to the output shaft. There are two transmission paths for power transmission, and a four-speed gear with a gear ratio of 1 can be obtained from the output shaft.

In 5th gear, when the second clutch and third brake are operated to connect the input shaft and the second or third ring gear and the second sun gear and third sun gear are stationary, the input shaft → (third ring gear → third
Pinion → 3rd pinion carrier →) 2nd ring gear → outer pinion → inner pinion → 1st pinion carrier → output shaft, and the power is transmitted from the output shaft to 5th speed by increasing speed with gear ratio 1 or less transmission gears can be obtained.

Therefore, 4 speed←→5 speed compatibility, easy speed change control, high degree of freedom in setting the speed ratio, small tooth stress, FR
While simultaneously satisfying the adaptability to car and FF car specifications,
It is possible to obtain five forward speeds including overdrive.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

First, the configuration will be explained.

The power train ₁ of the automatic transmission according to the embodiment is as follows:
As shown in Figure 1, which is an FR vehicle specification and is a skeleton with the axially symmetrical lower half omitted, a Ravigneau type planetary gear set R/G is installed between the input shaft I and the output shaft O as a gear train. and a single pinion type planetary gear set S/G.

In addition, the transmission elements include a first clutch C ₁ , a second clutch C ₂ , a third clutch C ₃ , and a first brake.
B ₁ , a second brake B ₂ , a third brake B ₃ , and a first one-way clutch OWC ₁ , and five forward speeds and one reverse speed are obtained by operating combinations of the aforementioned speed change elements.

Said Lavigneaux type planetary gear set R/
G has a unique configuration in that the sun gear is divided into two and there is only one pinion carrier.
Inner pinion Pi that meshes with sun gear S ₁ and second sun gear S ₂ , first ring gear R ₁ and second ring gear R ₂ , and both first and second sun gears S 1 _{and S 2 .}
, an outer pinion Po that meshes with both the inner pinion Pi and the second ring gear _R2 , an inner pinion,
It has a first pinion carrier P _C1 that rotatably supports both outer pinions Pi and Po.

The single pinion type planetary gear set S/G includes a third sun gear _S3 and a third ring gear.
R ₃ , a third pinion P ₃ that meshes with both S ₃ and R ₃ , and a third pinion carrier P _C3 that rotatably supports the pinion P ₃ .

Next, the combinations of each rotational element (sun gear, ring gear, pinion carrier) of the gear train and each transmission element will be described.

The first ring gear _R1 can be connected to an input shaft I that is connected to a torque converter output section (not shown) via a first clutch _C1 that is engaged in the first to fourth speeds.

The third ring gear R ₃ can be made stationary with respect to the case K by a one-way clutch OWC ₁ operating in the first gear and the first brake B ₁ engaged in the first range and the R range, and can be stopped in the fourth gear, It can be connected to the input shaft I via the second clutch _C2 , which is engaged in the fifth gear.

The first sun gear _S1 can be connected to the input shaft I via a third clutch _C3 that is engaged in the R range.

The second ring gear _R2 is constantly connected to the third pinion carrier _PC3 , and can be stopped by the second brake _B2 , which is applied at the second speed.

The second sun gear S ₂ is always connected to the third sun gear S ₃ and can be stopped by a third brake B ₃ that is engaged at the third and fifth speeds.

The first pinion carrier P _C1 is always connected to the output shaft O.

Next, the effect will be explained.

First, the operational state of each of the transmission elements in each range is as shown in FIG. 2, where the ◯ mark indicates engagement or operation, and the cross mark indicates non-operation.

(a) In D (drive) range At D1 speed, if only the first clutch _C1 is operated to connect the input shaft I and the first ring gear _R1 ,
While preventing the third ring gear R ₃ from rotating in the reverse direction by the first one-way clutch OWC ₁ , input shaft I → first ring gear R ₁ → inner pinion Pi →
Power is transmitted from the first pinion carrier P _C1 to the output shaft O.

At this time, as a constraint condition, the third ring gear R ₃ is prevented from rotating in the reverse direction by the first one-way clutch OWC ₁ , so both the outer and inner pinions Po and Pi rotate in the normal direction along with the second ring gear R ₂ . The first pinion carrier P _C1 , which supports both pinions Po and Pi, is rotated at a reduced speed by the second ring gear _R2 .

Therefore, the first gear with a large reduction gear ratio is obtained from the output shaft O connected to the first pinion carrier P _C1 .

At D2 speed, the first clutch _C1 and the second brake
When B ₂ is activated and the input shaft I and the first ring gear R ₁ are connected, and the second ring gear R ₂ is made stationary on the case K, the input shaft I → the first ring gear R ₁ →
Inner pinion Pi → 1st pinion carrier P _C1 →
Power is then transmitted to the output shaft O.

At this time, since the second ring gear R ₂ is stationary on the case K as a constraint condition, both the outer and inner pinions Po, Pi revolve in the normal rotation direction along the second ring gear R ₂ , and both pinions Po, The first pinion carrier P _C1 that supports Pi is rotated at a reduced speed.

Therefore, from the output shaft O connected to the first pinion carrier P _C1 , a second speed gear position having a smaller reduction gear ratio than the first speed can be obtained.

At D3 speed, 1st clutch C ₁ and 3rd brake
B ₃ is activated to connect the input shaft I and the first ring gear R ₁ , and also connect the second sun gear S ₂ and the third sun gear
When S ₃ is stationary, input shaft I → 1st ring gear
R ₁ → Inner pinion Pi → 1st pinion carrier
Power is transmitted from P _C1 to output shaft O.

At this time, as a constraint condition, the second sun gear S ₂ and the third sun gear S ₃ are kept stationary by the third brake B ₃ , so the inner pinion Pi rotates on its axis and revolves in the forward rotation direction along the second sun gear S ₂ . .

Therefore, from the output shaft O connected to the first pinion carrier P _C1 , a third speed gear position having a smaller reduction gear ratio than the second speed can be obtained.

At D4 speed, the first clutch _C1 and the second clutch
When C ₂ is activated and the input shaft I and the first ring gear R ₁ are coupled together, and the input shaft I and the third ring gear R ₃ are coupled, the input shaft I → the first ring gear R ₁ → the inner pinion Pi → the first pinion carrier Power transmission from P _C1 → output shaft O, and input shaft I → third
Ring gear R ₃ → 3rd pinion P ₃ → 3rd pinion carrier P _C3 → 2nd ring gear R ₂ → Outer pinion Po → Inner pinion Pi → 1st pinion carrier P _C1 → Power transmission to output shaft O 2
The street becomes a communication channel.

At this time, both pinions Po and Pi are the first and second pinions.
Since it revolves in the normal rotation direction together with input shaft I while its rotation is restricted by the input from ring gears R ₁ and R ₂ , the first pinion carrier rotates at the same time as input shaft I.
Rotate P _C1 .

Therefore, a four-speed gear position with a gear ratio of 1 is obtained from the output shaft O connected to the first pinion carrier P _C1 .

At D5 speed, the second clutch _C3 and the third brake
When B ₃ is activated to couple the input shaft I and the third ring gear R ₃ and the second sun gear S ₂ and the third sun gear S ₃ are brought to rest in the case K, the input shaft I → the third ring gear
Ring gear R ₃ → 3rd pinion P ₃ → 3rd pinion carrier P _C3 → 2nd ring gear R ₂ → Outer pinion Po → Inner pinion Pi → 1st pinion carrier P _C1 → Power is transmitted to output shaft O. Ru.

At this time, as a constraint condition, the second sun gear S ₂ and the third sun gear S ₃ are stationary due to the third brake B ₃ , so the inner pinion Pi revolves along the second sun gear S ₂ at the same rotation as the input shaft I. At the same time, it rotates.

Therefore, from the output shaft O connected to the first pinion carrier P _C1 , 5
A speed change gear position can be obtained.

In addition, in the engine braking region (engine braking region) where torque is input from the wheels via the output shaft O, the first one-way clutch is activated as shown in Fig. 2.
Activate the first brake B ₁ instead of OWC ₁ ,
Engine brake operation is ensured by preventing idling.

(b) When in R (reverse) range and R1 speed, the third clutch _C3 and the first brake
When B ₁ is activated, input shaft I and first sun gear S ₁ are connected, and third ring gear R ₃ is made stationary,
Input shaft I → 1st sun gear S ₁ → Inner pinion Pi →
Power is transmitted from the first pinion carrier P _C1 to the output shaft O.

At this time, since the third ring gear R ₃ is stationary on the case K as a constraint condition, the inner pinion Pi and the outer pinion Po that mesh with each other revolve in a decelerated state along the second ring gear R ₂ in the reverse direction.
Note that the reverse deceleration state can be achieved by restraining the second ring gear _R2 , but the third ring gear
If R ₃ is restrained, the reduction gear ratio will be smaller.

Therefore, the output shaft O connected to the first pinion carrier P _C1 provides a reverse gear position due to reverse deceleration.

Incidentally, α ₁ =Z _S1 /Z _R1 , α ₂ =Z _S2 /Z _R2 , α ₃ =Z _S3 /
In the case of Z _R3 , each gear has the gear ratio described below.

However, Z _S1 , Z _S2 , Z _S3 are the numbers of teeth of the first, second, and third sun gears, and Z _R1 , Z _R2 , and Z _R3 are the numbers of teeth of the first, second, and third ring gears.

i ₁ =1−α ₁ /α ₃ −α ₃・α ₂ −α ₂ i ₂ =1+α ₁ /α ₂ i ₃ =1+α ₁ i ₄ =1.00 i ₅ = (1−α ₂ )(1+α ₃ ) i _R = (1 - α ₂ ) (1 + α ₃ ) / α ₂ - (1 - α ₂ ) α ₃ As explained above, in the power train ₁₁ of the automatic transmission of the embodiment, the 5th speed A gear stage is obtained, and the following effects are simultaneously achieved.

Lavigneaux type planetary gear set R/G
By adding a single pinion type planetary gear set S/G to the 4-speed automatic transmission,
Because it is configured to obtain a 4-speed automatic transmission, a 5-speed automatic transmission can be converted to a 4-speed automatic transmission and vice versa by simply adjusting the single pinion type planetary gear set S/G. ←→5-speed compatibility is high and can easily meet 4-speed or 5-speed requirements.

Lavigneaux type planetary gear set R/G
Since the shift control is not a combination of 4-speed shifting using the S/G single-pinion planetary gear set and 2-speed shifting using the single pinion planetary gear set S/G, there is no need to switch two shifting elements at the same time when changing gears, which requires difficult countermeasures against shifting shocks. , gear change control becomes very easy.

Since the gear ratios of the main and sub transmissions are not combined to obtain the five-speed gear ratio, there is a high degree of freedom in setting the gear ratio.

When moving forward, the ring gear is always input, so tooth stress is small.

Despite having an output structure from a planetary carrier, Lavigneau type planetary gear set R/G has two sun gears S ₁ and S ₂ , so the output is from between the two sun gears S ₁ and S ₂ . can be taken out, as in the example
Of course, it can also be applied to FR vehicle specifications, and although not listed, it can also be applied to FF vehicle specifications.

Next, a modification of the above embodiment will be explained using the power train ₁₂ shown in FIG.

In the embodiment shown in FIG. 3, the third ring gear R ₃ of the above embodiment can be connected to the input shaft I via the second clutch C ₂ which is engaged in the fourth and fifth gears. On the other hand, the difference is that the second ring gear _R2 can be connected to the input shaft I via the second clutch _C2 which is engaged in the fourth and fifth speeds.

The operation of the transmission element is the same as that shown in FIG. 2, and by partially changing the configuration as described above, the transmission ratio at the fifth speed becomes _i5 =1- _α2 .

Although the embodiment has been described above based on the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change within the scope of the gist of the present invention, it is included in the present invention. .

For example, it is a well-known method to reduce the shift shock while simplifying the shift control by selecting at least one of the power train ₁₃ shown in Fig. 4 and the three options shown below to control the clutch and brake. A one-way clutch and a clutch (or brake) may be provided in parallel.

A second one-way clutch OWC 2 _and a fourth clutch C ₄ are provided between the input shaft I and the second ring gear R ₂ in parallel with the second clutch C ₂ .

A third one-way clutch OWC ₃ and a fourth brake B ₄ are provided between the second ring gear R ₂ and the case K in parallel with the second brake B ₂ .

A third one-way clutch OWC 3 and _a fifth brake B ₅ are provided between the second and third sun gears S ₂ , S ₃ and _the case K in parallel with the third brake B 3 .

(Effects of the Invention) As explained above, in the power train of the automatic transmission of the present invention, two planetary gear sets, a Lavigneau type planetary gear set and a single pinion type planetary gear set, are input. The first ring gear is disposed between the shaft and the output shaft, and the first ring gear is connected at the first to fourth speeds.
The third ring gear can be connected to the input shaft via a clutch, and the third ring gear can be stopped by a one-way clutch that operates in the first speed and a first brake that is engaged in the 1st and R ranges, and the third ring gear is connected to the second ring gear. One of the third ring gear is the fourth speed,
The first sun gear is connectable to the input shaft via a second clutch that is engaged in the fifth gear, and the first sun gear is connectable to the input shaft via a third clutch that is engaged in the R range. The ring gear is always connected to the third pinion carrier and can be made stationary by a second brake that is applied in second gear, and the second sun gear is always connected to the third sun gear and The vehicle can be stopped by a third brake that is applied at fifth speed, and the first pinion carrier is taken out from a divided portion between the first sun gear and the second sun gear and is always connected to the output shaft. Therefore, a five-speed gear stage is obtained, and the effects listed below are simultaneously achieved.

A 5-speed automatic transmission is obtained by adding a single-pinion type planetary gear set to a 4-speed automatic transmission with a Lavigneaux-type planetary gear set, so 5-speed automatic transmission can be achieved by simply adding or subtracting the single pinion type planetary gear set. It is possible to convert an automatic transmission into a 4-speed automatic transmission and vice versa, and the 4-speed ← 5-speed compatibility is high, and it can easily meet the 4-speed or 5-speed requirement.

Since the shift control is not a combination of a 4-speed shift using a Lavigneaux-type planetary gear set and a 2-speed shift using a single-pinion type planetary gear set, two shift elements must be switched at the same time when shifting requires difficult shift shock countermeasures. There is no need for this, and gear change control becomes very easy.

Since the gear ratios of the main and sub transmissions are not combined to obtain the five-speed gear ratio, there is a high degree of freedom in setting the gear ratio.

When moving forward, the ring gear is always input, so tooth stress is small.

Despite having an output structure from a planetary carrier, the Lavigneau type planetary gear set has a two-part sun gear that meshes with a common inner pinion, and is structured to be taken out from the split part of the sun gear and connected to the output shaft. , can be applied to both FR and FF vehicle specifications.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing the power train of an automatic transmission according to an embodiment of the present invention, FIG. 2 is an operation diagram showing the operating state of each transmission element in the power train of the automatic transmission according to the embodiment, and FIG. FIG. 4 is a sectional view showing a power train according to another embodiment. FIG. 4 is a skeleton diagram showing a power train according to another embodiment in which a one-way clutch and a clutch (or brake) are added. 1 ₁ ...power train of automatic transmission, I...output shaft, O...output shaft, K...case, R/G...Ravigneau type planetary gear set, S/G...single pinion type planetary gear set, S ₁ ... 1st sun gear, Pi...inner pinion, _R1 ...1st ring gear, _S2 ...2nd sun gear, Po...outer pinion,
R ₂ ... 2nd ring gear, P _C1 ... 1st pinion carrier, S ₃ ... 3rd sun gear, P ₃ ... 3rd pinion, R ₃
...Third ring gear, P _C3 ...Third pinion carrier,
_{C1 ...} first clutch, C2 _... second clutch, C3 _... third clutch, B1...first brake, _B2 ...second brake, _B3 ...third brake, OWC ₁ ...first one-way clutch.

Claims (1)

[Scope of Claims] 1. A first sun gear, a second sun gear, a first ring gear, a second ring gear, an inner pinion that meshes with both the first and second sun gears, the inner pinion, and the second ring gear, which are obtained by dividing one sun gear into two. A Lavigneaux-type planetary gear set includes an outer pinion that meshes with both the inner and outer pinions, and a first pinion carrier that rotatably supports both the inner and outer pinions, a third sun gear, a third ring gear, a third pinion that meshes with both of these, and a third sun gear and a third ring gear. Two planetary gear sets, a single pinion type planetary gear set having a third pinion carrier that rotatably supports a pinion, are disposed between the input shaft and the output shaft, and the first ring gear is arranged between the first ring gear and the first ring gear. - The third ring gear can be connected to the input shaft via the first clutch that is engaged in the fourth gear, and the third ring gear is a one-way clutch that operates in the first gear and a first brake that is engaged in the 1st and R ranges. one of the second ring gear and the third ring gear can be connected to the input shaft via a second clutch that is engaged in the fourth and fifth gears, and the first sun gear is The second ring gear can be connected to the input shaft via the third clutch that is engaged in the R range, and the second ring gear is constantly connected to the third pinion carrier and can be stopped by the second brake that is engaged in the second gear. The second sun gear is always connected to the third sun gear and can be stopped by a third brake that is engaged in the third and fifth gears, and the first pinion carrier is connected to the first sun gear and the third sun gear. A power train for an automatic transmission characterized by being extracted from a split portion of two sun gears and constantly connected to an output shaft.