JPH0555742B2 - - 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 four forward gears.

(Prior Art) Conventionally, as a power train for an automatic transmission with four forward speeds, the one shown in FIG. 7, which is cited as a conventional example in Japanese Patent Laid-Open No. 62-93545, is known.

Further, as an improved version of this, the ones shown in FIGS. 1 to 6 of the same publication are known.

(Problems to be Solved by the Invention) However, in the device shown in FIG. 7 of the conventional publication, the shaft size can be shortened by using the Lavigneau type gear train, and it can be used in both FF and FR vehicles. As stated in the publication, it is a sun gear input, which is disadvantageous in terms of strength.

On the other hand, in the devices shown in Figures 1 to 6 of the conventional publication, although the above problem could be solved by using a ring gear input, the output is from a pinion carrier, and the sun gear is integrally shared by two ring gears. It has been transformed into

For this reason, as described in the conventional gazette, a cylindrical gear shaft with which a sun gear is engaged is arranged extending in the axial direction on the outer periphery of the input shaft, and a cylindrical gear shaft with which a pinion carrier is engaged with the outer periphery of this gear shaft is arranged. The structure is such that the output shaft is extended in the axial direction and a counter drive gear is provided on the output shaft, that is, the output is taken out in a direction orthogonal to the input/output shaft.

Therefore, although it can be applied to FF cars, it is not applicable to FR cars that require an axial extraction structure, and furthermore, the input/output shaft and gear shaft result in a coaxial triple shaft structure, which increases costs. . Incidentally, the apparatus described in Japanese Patent Application Laid-Open No. 62-93546 also has the same drawbacks as above.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this purpose, the present invention includes a first sun gear and a first ring gear. A first pinion that meshes with these, a single pinion type first planetary gear set that has a first pinion carrier that rotatably supports the first pinion, a second sun gear, a second inner pinion that meshes with the sun gear, and a second ring gear. A double pinion type second planetary gear set having a second outer pinion that meshes with both the second inner pinion and the second ring gear, and a second pinion carrier that rotatably supports both the second inner and outer pinions. In the power train of an automatic transmission, two planetary gear sets are disposed between the input shaft and the output shaft, and the clutch obtains multiple gears by operating combinations of shift elements such as brakes. and a second inner pinion, and have sun gears that mesh with the integrated pinion as a first sun gear and a second sun gear separated from each other, and the first and second pinion carriers of both planetary gear sets. are coupled to each other and integrated, and a second ring gear, a first ring gear, and a first sun gear are coupled to the input shaft via a first clutch, a second clutch, and a third clutch, respectively;
The second sun gear is installed in the case so as to be stationary and releasable via a brake, and the second ring gear is prevented from rotating in one direction but is rotatable in the other direction via a one-way clutch. The invention is characterized in that the output shaft is connected to a common pinion carrier via a split extraction portion between the first sun gear and the second sun gear.

(Function) At 1st speed, if only the second clutch is operated to connect the input shaft and the first ring gear, the operation of the one-way clutch will prevent the second 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 ring gear to the first pinion to the pinion carrier to the output shaft, and a first gear with a large reduction gear ratio is obtained from the output shaft.

When in second gear, the second clutch and brake are operated to connect the input shaft and the first ring gear, and the second sun gear is rested on the case, so that the input shaft →
Power is transmitted from the first ring gear to the first pinion to the pinion carrier to the output shaft, and from the output shaft, a second speed gear position having a smaller reduction gear ratio than the first speed is obtained.

In 3rd gear, when the first clutch and the second clutch are operated and the input shaft is connected to the first ring gear and the second ring gear, the input shaft → first ring gear (second ring gear) → first pinion (second ring gear) is activated. Power is integrally transmitted from the output shaft to the output shaft (outer pinion) → pinion carrier → output shaft, and a 3-speed gear position with a gear ratio of 1 is obtained from the output shaft.

In 4th gear, when the first clutch and second brake are operated, the input shaft and second ring gear are connected, and the second sun gear is stationary on the case, the input shaft → second ring → second outer pinion → pinion Power is transmitted from the carrier to the output shaft, and from the output shaft, 4
A speed change gear position can be obtained.

When reversing, instead of using the ring gear input when moving forward,
By actuating the third clutch and providing an input to the first sun gear, a reverse gear position for reversing the output shaft is obtained.

Therefore, while obtaining four forward speeds, it is basically compact because it is a Lavigneau type gear train, has an advantage in strength due to the ring gear input, and has a pinion carrier output due to the sun gear being divided into two. However, it is possible to simultaneously achieve adaptation to FR and FF vehicles and a simplified output extraction structure that requires only two coaxial shafts.

(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 Fig. 1, which is an FR vehicle specification and is a skeleton with the axially symmetrical lower half omitted, the gear train is a front planetary gear set ( 1st planetary gear set) FR and rear planetary gear set (2nd planetary gear set) RP
It is equipped with

In addition, as the transmission elements, a first clutch (first clutch) C ₁ , a second clutch C ₂ (second clutch) C ₂ , a third clutch C ₃ (third clutch), a first brake B ₁ , Second brake (brake) B ₂ ,
1st one-way clutch (one-way clutch)
The vehicle is equipped with an OWC ₁ , and is configured to obtain four forward speeds and one reverse speed through the operational combination of the aforementioned transmission elements.

The front planetary gear set FP is
Single pinion type, first sun gear
S ₁ , a first pinion P ₁ , and a first ring gear R ₁ ,
The rear planetary gear set RP is a double pinion type and includes a second sun gear S ₂ , a first pinion (second inner pinion) P ₁ , a second outer pinion P ₂ , a second ring gear R ₂ The first pinion _P1 and the second pinion _P2 mesh with each other,
The sun gear is divided into a first sun gear _S1 and a second sun gear _S2 , and both planetary gear sets FP and RP are connected to an integrated pinion carrier.
Have P _C.

That is, it has an improved Lavigneaux-type planetary gear set structure with a split sun gear.

Then, as shown in FIGS. 3 and 4, the first
The sun gear S ₁ is formed in a shaft-shaped first sun gear member S _M1 , the second sun gear S ₂ is formed in a cylindrical shaft-shaped second sun gear member S _M2 , and the pinion carrier P _C is formed in the second sun gear member S _M2 . It is formed integrally with the inserted output shaft O, and the first sun gear member S _M1 and the output shaft O are coaxially arranged in series via a centering mechanism C _M.

In FIGS. 3 and 4, P _G1 and P _G2 are pins that support both pinions, R _M1 is a first ring gear member, and R _M2 is a second ring gear member.

The coupling relationship between each rotating element (sun gear, ring gear, pinion carrier) of the gear train and each transmission element will be described below.

For the input shaft I, the second ring gear R ₂ is connected to the first clutch C 1 , the first ring gear R ₁ is connected to the second clutch C ₂ , and the first sun gear S ₁ is connected to the third sun gear S 1 _.
It is provided so that it can be connected and released via clutch _C3 .

For case K, the second ring gear R ₂ is connected to the first brake B ₁ and the second sun gear S ₂ is connected to the second
It is provided so as to be stationary and releasable _via a brake _B2 , and a second ring gear _R2 is provided via a first one-way clutch OWC1.

As mentioned above, the pinion carrier P _C is
Connected to output shaft O.

Next, the effect will be explained.

First, the operating state of each transmission element is as shown in FIG. 2, where a circle mark indicates engagement or operation, and an x mark indicates non-operation.

(a) In D (drive) range At D1 speed, if only the second clutch _C2 is operated to connect the input shaft I and the first ring gear _R1 ,
The second one-way clutch OWC ₁ is operated by the first one-way clutch OWC 1.
While preventing rotation of ring gear _R2 in the reverse direction,
Input shaft I → 1st ring gear R ₁ → 1st pinion P ₁
→ Pinion carrier P _C → Power is transmitted to output shaft O.

At this time, as a constraint condition, the second ring gear R ₂ is prevented from rotating in the reverse direction by the first one-way clutch OWC ₁ , so the first pinion gear P ₁
The second outer pinion P ₂ that meshes with the second ring gear R ₂ revolves in the normal rotation direction along the second ring gear R 2 and causes the pinion carrier _PC that supports both the pinions P ₁ and P ₂ to rotate at a reduced speed.

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

At D2 speed, the second clutch _C2 and the second brake
B ₂ is activated to couple the input shaft I and the first ring gear R ₁ and at the same time, the second sun gear S ₂ is made stationary on the case K, the input shaft I → the first ring gear R ₁ → the first
Power is transmitted from pinion P ₁ to pinion carrier P _C to output shaft O. At this time, one constraint condition is that the second sun gear _S2 is stationary due to the second brake _B2 , so the first pinion _P1 revolves in the normal rotation direction along the second sun gear _S2 , and the first pinion
The pinion carrier P _C that supports P ₁ is rotated at a reduced speed.

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

At D3 speed, the first clutch _C1 and the second clutch
When _C2 is activated and the input shaft I is connected to the first ring gear _R1 and the second ring gear _R2 , the input shaft I
→ 1st ring gear R ₁ (2nd ring gear R ₂ ) → 1st ring gear
Power is transmitted from pinion P ₁ (second outer pinion P ₂ ) to pinion carrier _PC to output shaft O.

At this time, the first and second pinions P ₁ and P ₂ are
And because it revolves integrally with both ring gears R ₁ and R ₂ in the forward direction due to the input from the second ring gears R ₁ and R ₂ ,
Rotate the pinion carrier P _C at the same rotation as the input shaft I.

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

At D4 speed, the first clutch _C1 and the second brake
When B ₂ is activated to couple the input shaft I and the second ring gear R _{2 and the second sun gear S 2 is} made stationary on the case K, input shaft I → second ring gear R ₂ → second
Power is transmitted from the outer pinion P ₂ to the pinion carrier P _C to the output shaft O. At this time, the second sun gear S ₂ is the second brake B ₂ as a constraint condition.
Since the pinion carrier P _C rotates with a gear ratio of 1, the first
Pinion P ₁ and second outer pinion P ₂ revolve in the normal rotation direction along second sun gear S ₂ due to rotation input from second ring gear R ₂ , and both pinion gears P ₁ ,
Increase the speed of the pinion carrier P _C that supports P ₂ .

Therefore, from the output shaft O connected to the pinion carrier P _C , a 4-speed gear position is obtained by increasing the speed with a gear ratio of 1 or less.

In addition, in the engine brake region (engine brake region) where torque is input from the wheels via the output shaft O, the first brake B ₁ is used instead of the first one-way clutch OWC ₁ , as shown in the engine brake region in Fig. 2. By activating the engine brake, the engine brake is activated to prevent idling.

(b) When in R (reverse) range When in R range, third clutch _C3 and first brake _B1 are operated, and input shaft I and first sun gear _{S1 are} operated.
and the second ring gear R ₂ to the case K.
When it is stopped, input shaft I → 1st sun gear S ₁ → 1st pinion P ₁ → pinion carrier P _C → output shaft O
power is transmitted. At this time, as the second ring gear _R2 is stationary as a constraint condition,
The first pinion P ₁ and the second outer pinion P ₂ that mesh with each other revolve in a decelerated state along the second ring gear R ₂ in the reverse direction.

Therefore, the output shaft O connected to the pinion carrier P _C provides a reverse gear position based on the reduction gear ratio.

By the way, when α = Z _S / Z _RF , β = Z _S / Z _RR (however, Z _S : number of teeth of sun gear, Z _RF : number of teeth of first ring gear _R1 , Z _RR : second ring gear R ₂ teeth), and the gear ratios for each gear are as follows.

i ₁ = α + β / β = 1 + α / β i ₂ = 1 + α i ₃ = 1.000 i ₄ = 1 - β i _R = 1 - β / β As explained above, the power train of the automatic transmission of the example 1 ₁ In this case, while obtaining four forward speeds, it is basically compact because it is a Lavigneau type gear train, has an advantage in strength due to ring gear input, and has two sun gears.
By dividing the system, it is possible to simultaneously achieve the effects of adapting it to FR vehicles (of course, adapting it to FF vehicles) and simplifying the output extraction structure while using the pinion carrier _PC output.

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, as shown in the power train ₁₂ in Fig. 5, a second clutch _C2 , which is engaged in 1st, 2nd, and 3rd gears, is a well-known method to reduce shift shock while simplifying shift control. A fourth clutch _C4 and a second one-way clutch _OWC2 may be provided in parallel, and as shown in power train ₁₃ in FIG.
A third brake _B3 and a third one-way clutch _OWC3 may be provided in parallel with _B2 .

(Effects of the Invention) As explained above, in the power train of the automatic transmission of the present invention, as described in the claims, in the two planetary gear sets with a single pinion and a double pinion, Integrating the pinion and pinion carrier,
Since the input is a ring gear input and the output is a pinion carrier output via the split extraction part between the first sun gear and the second sun gear, it is basically a Lavigneau type gear train while obtaining four forward speeds. This makes it compact, the ring gear input has an advantage in strength, and by splitting the sun gear into two, it can be adapted to FR and FF cars even though it is a pinion carrier output, and the output can be done with two coaxial axes. This has the effect of simplifying the extraction structure and simultaneously achieving the following.

[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 cross-sectional view taken along the line A-A showing the gear train of the embodiment, FIG. 4 is a cross-sectional view taken along the line B-B of FIG. 3 showing the gear train of the embodiment, and FIG. FIG. 6 is a skeleton diagram showing a power train of another embodiment. 1 ₁ ...Automatic transmission power train, I...
Input shaft, O...Output shaft, K...Case, FP...
Front planetary gear set (1st planetary gear set), RP... Rear planetary gear set (2nd planetary gear set), S ₁ ...
1st sun gear, P ₁ ... 1st pinion, R ₁ ... 1st ring gear, S ₂ ... 2nd sun gear, P ₂ ... 2nd outer pinion, R ₂ ... 2nd ring gear, P _C
... Pinion carrier, C ₁ ... 1st clutch (first clutch), C ₂ ... 2nd clutch (second clutch)
clutch), C ₃ ... 3rd clutch, B ₁ ... 1st clutch
Brake, B ₂ ...Second brake (brake),
OWC ₁ ...1st one-way clutch (one-way clutch).

Claims (1)

[Scope of Claims] 1. A single pinion type first planetary gear set having a first sun gear, a first ring gear, a first pinion that meshes with these, and a first pinion carrier that rotatably supports the first pinion; a second sun gear, a second inner pinion that meshes with the sun gear, a second ring gear and a second inner pinion, a second outer pinion that meshes with both the second ring gear, and a second pinion that rotatably supports both the second inner and outer pinions. Two planetary gear sets, including a double pinion type second planetary gear set with a carrier, are arranged between the input shaft and the output shaft, and multiple gear stages can be created by operating combinations of transmission elements such as clutches and brakes. In the power train of an automatic transmission that is configured to obtain and the first and second pinion carriers of both planetary gear sets are coupled to each other and integrated, and with respect to the input shaft, the second ring gear and the first
The ring gear and the first sun gear are provided so that they can be coupled and released via a first clutch, a second clutch, and a third clutch, respectively, and the second sun gear can be stopped and released via a brake for the case. The second ring gear is provided to be prevented from rotating in one direction and rotatable in the other direction via a one-way clutch. An automatic transmission powertrain characterized by being connected to a common pinion carrier through a section.