JP3888834B2 - Automatic transmission for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an automatic transmission for a vehicle.
[0002]
[Prior art]
Conventionally, various automatic transmissions for vehicles have been proposed that include a planetary gear device and a plurality of wet multi-plate frictional engagement elements, and which can be appropriately engaged and released to achieve a plurality of shift stages. Has been put to practical use.
Among this type of automatic transmission, a compact automatic transmission with a particularly short axial dimension has been proposed, for example, in Japanese Patent Laid-Open Nos. 2000-46159 and 2000-55088. The automatic transmission includes a Ravigneaux planetary gear unit, a reverse clutch C1, a forward low speed clutch C2, a forward high speed clutch C3, a forward brake B1, a reverse brake B2, and a one-way clutch F. The forward sun gear of the planetary gear unit is connected to the input shaft via the reverse clutch C1, and is connected to the transmission case via the forward brake B1, and the rear sun gear is connected to the input shaft via the forward low speed clutch C2. The coupled carrier that supports the long pinion and the short pinion is coupled to the input shaft via the forward high speed clutch C3. Further, the carrier is connected to the transmission case via a reverse brake B2 and a one-way clutch F that allows only forward rotation of the carrier (in the engine rotation direction). The forward sun gear meshes with the long pinion, the rear sun gear meshes with the long pinion via the short pinion, and the ring gear meshing with only the long pinion is connected to the output shaft.
[0003]
The forward low speed clutch C2, the reverse clutch C1, and the forward brake B1 are arranged side by side in the axial direction, and the forward high speed clutch C3 is arranged on the inner diameter side thereof. The forward high speed clutch C3 requires a smaller transmission torque than the other engagement elements, and therefore can be configured to have a relatively small diameter and can be disposed on the inner diameter side of the other engagement elements. The reverse brake B2 and the one-way clutch F are disposed on the outer peripheral portion of the planetary gear device.
[0004]
[Problems to be solved by the invention]
In the automatic transmission having such a structure, the friction engagement elements are arranged in a compact manner, and there is a feature that wasteful space can be reduced as much as possible. However, since the friction engagement element is provided with an operating piston in addition to the multi-plate clutch, there is a problem that the axial dimension of the entire automatic transmission is enlarged depending on the arrangement of the operating piston. That is, although the three friction engagement elements, ie, the forward low speed clutch C2, the reverse clutch C1, and the forward brake B1, are arranged in series in the axial direction, the operating piston of the reverse clutch C1 located in the center is provided. It is difficult to arrange compactly without interfering with other engaging elements. Similarly, the pistons for operating the forward high speed clutch C3 disposed on the inner diameter side of the clutches C1, C2 and the forward brake B1 are also devised to be compactly disposed without interfering with other friction engagement elements. Cost.
[0005]
Accordingly, an object of the present invention is to provide a compact automatic transmission for a vehicle having a short axial dimension.
[0006]
[Means for Solving the Problems]
The object is achieved by the invention described in claim 1.
That is, a Ravigneaux type planetary gear unit, a reverse clutch C1, a forward low speed clutch C2, a forward high speed clutch C3 and a forward brake B1 are provided, and the forward sun gear of the planetary gear device is input via the reverse clutch C1. The shaft is connected to the transmission case via the forward brake B1, the rear sun gear is connected to the input shaft via the forward low speed clutch C2, and the carrier supporting the long pinion and the short pinion is advanced. An automatic transmission that is connected to an input shaft via a high speed clutch C3, a forward sun gear meshes with a long pinion, a rear sun gear meshes with a long pinion via a short pinion, and a ring gear that meshes with only the long pinion and an output shaft. Operation of the forward low speed clutch C2 Between the piston and the actuating piston for the forward brake B1, the forward low speed clutch C2, the reverse clutch C1, and the forward brake B1 are arranged side by side in the axial direction without interposing the actuating piston. The forward high speed clutch C3 is disposed across the inner diameter side of the forward brake B1 from the inner diameter side of the forward clutch C1, and the operating piston of the forward high speed clutch C3 is disposed on the inner diameter side of the forward low speed clutch C2. The operating piston of the forward low speed clutch C2 is disposed inside the operating piston of the reverse clutch C1 to have a double piston structure, and the outer diameter portion of the operating piston of the reverse clutch C1 is the forward low speed stage. It extends axially beyond the outer periphery of the low-speed forward gear clutch C2 so as also serving as a clutch drum of use clutch C2, the operation of the backward clutch C1 The piston 14, the actuating piston 15 of the forward low speed clutch C2 and the actuating piston 31 of the forward high speed clutch C3 are arranged side by side in the axial direction, and the inner diameter portions of the actuating piston 14 and actuating piston 15 are actuated. An automatic transmission for a vehicle is provided that extends from the outer diameter portion of the piston 31 to the inner diameter side, and the operating piston of the forward brake B1 is disposed on the outer peripheral portion of the planetary gear device.
[0007]
The forward low speed clutch C2, the reverse clutch C1, the forward brake B1, and the other piston are not interposed between the operating piston of the forward low speed clutch C2 and the operating piston of the forward brake B1. By arranging them in the axial direction, the axial dimension of the three friction engagement elements can be shortened. The forward high speed clutch C3 is disposed on the inner diameter side of the reverse clutch C1 and the forward brake 1, and the operating piston of the forward high speed clutch C3 is disposed on the inner diameter side of the forward low speed clutch C2. The forward high speed clutch C3 and its operating piston can be efficiently arranged in the space formed on the inner diameter side of the three engaging elements (C1, C2, B1), and the axial dimension can be shortened. Thus, by arranging the four engaging elements so as to overlap inside and outside, the axial dimension can be shortened as much as possible.
Of the three engaging elements (C1, C2, B1) arranged in series in the axial direction, the operating piston of the reverse clutch C1 located in the center is arranged without interfering with other engaging elements. Therefore, in the present invention, the operating piston of the forward low speed clutch C2 and the operating piston of the reverse clutch C1 have a double piston structure. That is, the input members of the forward low speed clutch C2 and the reverse clutch C1 are both connected to the input shaft, so that the operating piston of the reverse clutch C1 also serves as the clutch drum of the forward low speed clutch C2. By simply engaging the clutch drum of the clutch C1 and the operating piston so that they can rotate together and move in the axial direction, it can be easily configured. With the double piston structure, the axial dimension of the working piston portion is greatly shortened.
If the double piston structure is used, both pistons cannot be operated simultaneously, but the reverse clutch C1 and the forward low speed clutch C2 are clutches that are not operated simultaneously. There is no problem.
Further, since the operating piston of the forward brake B1 is disposed on the outer peripheral portion of the Ravigneaux type planetary gear device, the operating piston of the forward brake B1 can be absorbed in the empty space on the outer peripheral portion of the planetary gear device. It is possible to prevent the directional dimension from expanding.
The forward brake B1 may be a brake that engages only at the fourth speed in addition to a brake that engages at the second and fourth speeds. In this case, another forward brake and a one-way clutch that connect the forward sun gear and the transmission case may be provided in parallel with the brake B1.
[0008]
According to the second aspect of the present invention, the operating pistons of the forward low speed clutch C2, the reverse clutch C1, and the forward high speed clutch C3 are arranged on the input shaft, and the operating piston of the forward low speed clutch C2 is provided. In the meantime, a hydraulic canceller chamber may be formed on the opposite side of the piston chamber, and an operating piston of the forward high speed clutch C3 may be interposed therebetween to form a hydraulic canceller chamber on the opposite side of the piston chamber.
Lubricating oil is supplied to the hydraulic canceller chamber and has a function of generating centrifugal hydraulic pressure as it rotates and canceling the centrifugal hydraulic pressure generated in the piston chamber. In this case, since the hydraulic canceller chamber always rotates with the rotation of the input shaft, no hydraulic oil remains in the piston chamber. Therefore, the generation of drag torque can be prevented. Further, since the hydraulic canceller chamber of the forward low speed clutch C2 also serves as the hydraulic canceller chamber of the reverse clutch C1, the centrifugal hydraulic pressures of both clutches can be offset by one hydraulic canceller chamber.
[0009]
As in claim 3, the hydraulic pressure of the forward low speed clutch C2 and the reverse clutch C1 is guided from the oil passage of the support member fixed to the transmission case to the piston chamber of each clutch, and the forward high speed clutch C3. Is preferably guided from the oil passage of the support member to the piston chamber of the clutch through the internal oil passage of the input shaft.
That is, many oil passages such as an input to the torque converter, an output oil passage and a lubricating oil passage are formed on the input shaft. The hydraulic oil may be supplied not only to the forward high speed clutch C3 but also to the forward low speed clutch C2 and the reverse clutch C1 via the input shaft. And the input shaft becomes thicker, and the axial dimension becomes longer due to the handling of the oil passage. Therefore, the hydraulic pressure is directly guided from the oil passage of the support member to the piston chambers of the forward low speed stage clutch C2 and the reverse clutch C1 having a double piston structure without passing through the input shaft, thereby the axial direction of the input shaft. And the radial dimension can be shortened.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the overall structure of an automatic transmission for a vehicle according to the present invention, in particular, an FF automatic transmission, and FIG.
This automatic transmission includes a torque converter 1, an input shaft 2 to which engine power is transmitted via the torque converter 1, three multi-plate clutches C1 to C3, two multi-plate brakes B1 and B2, a one-way clutch F, A Ravigneaux type planetary gear device 4, an output gear 5, an output shaft 7, a differential device 8 and the like are provided.
[0011]
The forward sun gear 4a of the planetary gear unit 4 is connected to the input shaft 2 via a C1 clutch, and the forward sun gear 4a is also connected to the transmission case 6 via a B1 brake. The rear sun gear 4b is connected to the input shaft 2 via a C2 clutch. The carrier 4c is connected to the input shaft 2 via the intermediate shaft 3 and the C3 clutch. The carrier 4c is connected to the transmission case 6 via a B2 brake, and is connected to the transmission case 6 via a one-way clutch F that allows only the carrier 4c to rotate forward (engine rotation direction). The carrier 4c supports two types of pinion gears 4d and 4e, the forward sun gear 4a meshes with a long pinion 4d having a long shaft length, and the rear sun gear 4b meshes with the long pinion 4d via a short pinion 4e having a short shaft length. . A ring gear 4f that meshes only with the long pinion 4d is coupled to the output gear 5. The output gear 5 is connected to the differential device 8 via the output shaft 7.
[0012]
The automatic transmission achieves four forward speeds and one reverse speed as shown in FIG. 3 by operating the clutches C1, C2, C3, the brakes B1, B2, and the one-way clutch F. FIG. 3 shows the operation of each engaging element in the D range and the R range, and ◯ shows the engaged state.
That is, the C1 clutch is a reverse clutch that is engaged during reverse, the C2 clutch is a forward low speed clutch that is engaged at 1st to 3rd speeds, and the C3 clutch is an advanced high speed stage that is engaged at 3rd and 4th speeds. The clutch B1, the brake B1 is a forward brake engaged at the second speed and the fourth speed, and the B2 brake is a reverse brake engaged at the reverse. The B2 brake is engaged not only at the time of reverse but also at the 1st speed, but is engaged only at the L range at the 1st speed and is therefore indicated by a broken line ◯.
[0013]
FIG. 4 shows an arrangement structure of the C1 clutch, the C2 clutch, the B1 brake, and the C3 clutch.
The input shaft 2 is inserted into a cylindrical portion 10 a of a support member 10 fixed to the transmission case 6. A sleeve 12 that supports the input shaft 2 via a bush 11 is fixed inside the support member 10. On the outer periphery of the cylindrical portion 10a of the support member 10, a boss portion 13a of a clutch drum 13 for C1, C2 clutch is rotatably supported, and a tip end portion of the boss portion 13a is spline-fitted with the input shaft 2. .
[0014]
Inside the clutch drum 13, operating pistons 14 and 15 having a double piston structure are disposed. A first piston chamber 16 is formed between the clutch drum 13 and the first piston 14, and the first piston 14 and the first piston 14 A second piston chamber 17 is formed between the two pistons 15. The first piston 14 is engaged with the clutch drum 13 by a spline so as to be integrally rotatable and axially movable. The first piston 14 is operated by the hydraulic oil supplied to the first piston chamber 16, and the C1 clutch disposed between the clutch drum 13 and the first clutch hub 18 is engaged. The first clutch hub 18 is fixed to the forward sun gear 4 a of the planetary gear device 4. The second piston 15 is operated by the hydraulic oil supplied to the second piston chamber 17, and the C2 clutch disposed between the first piston 14 and the second clutch hub 19 is engaged. The second clutch hub 19 is connected to the rear sun gear 4b so as to be integrally rotatable. The inner periphery of the canceller plate 21 is locked to the outer periphery of the tip of the boss portion 13 a of the clutch drum 13 by a snap ring 20, and the first piston 14 and the second piston 15 are interposed between the canceller plate 21 and the second piston 15. A return spring 22 is disposed to urge the two pistons 15 in the axial direction. The outer peripheral portion of the canceller plate 21 is in sliding contact with the inner peripheral surface of the second piston 15 in a sealed state, and a hydraulic canceller chamber 23 is formed between the canceller plate 21 and the second piston 15. The canceller chamber 23 has a function of canceling the centrifugal hydraulic pressure generated by the oil in the first piston chamber 16 or the second piston chamber 17.
[0015]
A B1 brake is disposed between the transmission case 6 and the first clutch hub 18. The piston 25 for operating the B1 brake is disposed inside a drum 26 fixed inside the transmission case 6, and supplies hydraulic oil to a piston chamber 27 formed between the drum 26 and the piston 25. The piston 25 is actuated to the right in FIG. 4 to engage the B1 brake. The piston 25 for actuating the B1 brake is arranged on the outer peripheral portion of the planetary gear device 4 so as to overlap in the axial direction.
[0016]
A clutch drum 30 of a C3 clutch is fixed on the input shaft 2, and a third piston 31 is disposed in the clutch drum 30 so as to be movable in the axial direction, and the clutch drum 30 and the third piston 31 are connected to each other. A third piston chamber 32 is formed therebetween. The third piston 31 is actuated by the hydraulic oil supplied to the third piston chamber 32, and the C3 clutch disposed between the clutch drum 30 and the third clutch hub 33 is engaged. The third clutch hub 33 is fixed to the intermediate shaft 3 arranged coaxially with the input shaft 2. The inner periphery of the canceller plate 34 is locked to the outer periphery of the tip of the input shaft 2 by a snap ring 35, and the third piston 31 is returned in the axial direction between the canceller plate 34 and the third piston 31. An energizing return spring 36 is arranged. The outer peripheral portion of the canceller plate 34 is in sliding contact with the inner peripheral surface of the third piston 31 in a sealed state, and a hydraulic canceller chamber 37 is formed between the canceller plate 34 and the third piston 31. The canceller chamber 37 has a function of canceling the centrifugal hydraulic pressure generated by the oil in the third piston chamber 32.
[0017]
The B1 brake, the C1 clutch, and the C2 clutch are arranged side by side in the axial direction between the piston 15 for operating the C2 clutch and the piston 25 for operating the B1 brake. The C3 clutch is disposed on the inner diameter side of the C1 clutch and the B1 brake so as to overlap in the axial direction, and the operation piston 31 of the C3 clutch is disposed on the inner diameter side of the C2 clutch so as to overlap in the axial direction. The C3 clutch is disposed adjacent to the planetary gear unit 4 in the axial direction with the clutch hubs 18 and 19 therebetween. Further, the piston 25 for operating the B1 brake is disposed on the outer peripheral portion of the carrier 4c of the planetary gear device 4 so as to overlap in the axial direction.
[0018]
The support member 10 includes an oil path 40 for operating the C1 clutch, an oil path (not shown) for operating the C2 clutch, an oil path 41 for operating the C3 clutch, an oil path (not shown) for lubrication, and a torque converter. An oil passage (not shown) for supplying and discharging hydraulic pressure to 1 is formed toward the center. Each said oil path is formed in the position from which a phase differs in the circumferential direction. The oil passage 40 for operating the C1 clutch includes an oil passage 42 formed in the outer peripheral surface of the sleeve 12, a tubular portion 10a of the support member 10, and a boss portion 13a of the clutch drum 13 in the radial direction. The first piston chamber 16 is connected via 43. Further, the oil passage for operating the C2 clutch is connected to the oil passage 44 formed in the sleeve 12, the tubular portion 10 a of the support member 10, and the oil passage 45 penetrating the boss portion 13 a of the clutch drum 13 in the radial direction. It is connected to the second piston chamber 17. Further, the oil passage 41 for operating the C3 clutch is connected to the third piston via a groove-like oil passage 46 formed on the outer peripheral surface of the sleeve 12 and an oil passage 47 formed in the axial direction inside the input shaft 2. It is connected to the chamber 32.
The lubricating oil supplied from the lubricating oil passage of the support member 10 is supplied to the hydraulic canceller chamber 23 through an oil passage 48 formed in the axial direction inside the input shaft 2, and the inner diameter of the hydraulic canceller chamber 23 is supplied. The lubricating oil overflowed from the part lubricates the C1 clutch and the C2 clutch. Further, the lubricating oil passing through the oil passage 48 is guided to the shaft center hole 49 of the intermediate shaft 3 and supplied to the hydraulic canceller chamber 37 and other lubricating parts (C3 clutch, B1 brake, planetary gear device 4 and the like). .
Finally, an oil passage for supplying and discharging hydraulic pressure to the torque converter 1 is connected to the torque converter through an oil passage 50 formed in the axial direction from the support member 10 to the inside of the input shaft 2.
[0019]
As described above, the hydraulic oil to the C1 clutch and the C2 clutch is supplied without passing through the input shaft 2, and the number of oil passages formed in the input shaft 2 is reduced, and the length of the oil passage is shortened. ing. Further, the hydraulic oil for the C3 clutch is supplied via the input shaft 2 because the third piston chamber 32 is located away from the support member 10 in the axial direction. Since the lubricating oil needs to be supplied to many places, it is supplied via the internal oil passage 48 of the input shaft 2. By handling the oil passages in this way, five oil passages can be efficiently arranged in a small space, and the axial dimension of the input shaft 2 can be shortened.
[0020]
Next, the planetary gear device 4 will be described with reference to FIG.
The long pinion 4d is rotatably supported by a first shaft 60 via a needle bearing 61, and the short pinion 4e is also rotatably supported by a second shaft 62 via a needle bearing 63. Both ends of the first shaft 10 and both ends of the second shaft 62 are fitted and supported by the carrier 4c. A roller pin 64 is inserted into the fitting hole of the carrier 4c that supports one end of the first shaft 60 in the orthogonal direction, and the first shaft 60 is fixed to the carrier 4c in the axial direction and the rotational direction by the roller pin 64. Yes.
[0021]
An inner diameter portion of the carrier 4 c is splined to the intermediate shaft 3. A carrier cover 65 is attached to one end of the carrier 4c in the axial direction (the right end in FIG. 5). That is, the side wall portion of the carrier cover 65 and the carrier 4 c are integrally fixed by the countersunk screws 66. The carrier cover 65 is formed in a drum shape so as to cover the outer peripheral portion of the carrier 4c, and includes a spline hub 65a with which the clutch plate of the B2 brake is engaged, and an inner ring portion 65b constituting an inner ring of the one-way clutch F. Yes. Therefore, the B2 brake and the one-way clutch F are arranged on the outer periphery of the planetary gear unit 4 so as to overlap in the axial direction. As described above, the B1 brake operating piston 25 is also arranged on the outer peripheral portion of the planetary gear device 4. The piston 67 for operating the B2 brake is disposed on the outer periphery of the support portion 70 of the transmission case 6 that supports the outer ring of the bearing 69, and a piston chamber 68 is formed between the piston 67 and the transmission case 6. .
[0022]
An oil cover 71 is fitted on the outer side surface (left side surface in FIG. 5) of the carrier 4c. The oil cover 71 receives the lubricating oil flowing in the outer diameter direction along the outer surface of the carrier 4 c and supplies the lubricating oil to the axial lubrication hole 60 b of the first shaft 60. The oil that has entered the shaft center lubricating hole 60b lubricates the needle bearing 61 disposed between the first shaft 60 and the long pinion 4d.
A hub portion 72 is connected to one end portion of the ring gear 4f so as to be integrally rotatable. The hub portion 72 is disposed adjacent to the intermediate shaft 3 in the axial direction, and the output gear 5 is spline fitted to the outer periphery thereof. ing.
[0023]
As described above, by arranging the four engagement elements C1 to C3 and B1 so as to overlap inside and outside, the axial dimension can be shortened as much as possible. Further, by disposing the B2 brake, the one-way clutch F, and the B1 brake operating piston 25 on the outer peripheral portion of the planetary gear unit 4, a necessary mechanical portion can be disposed in a compact space. In this way, by arranging the engaging elements C1 to C3, B1, B2, and F and the planetary gear unit 4 together, a very small speed change mechanism can be configured.
[0024]
FIG. 6 shows a second embodiment of the automatic transmission according to the present invention, and FIG. 7 shows the operation of each engagement element.
The configurations of the Ravigneaux type planetary gear unit 4, the reverse clutch C1, the forward low speed clutch C2, the forward high speed clutch C3, the forward brake B1, and the reverse brake B2 are the same as those in the first embodiment (FIG. 2). is there. The one-way clutch F1 has the same function as the one-way clutch F in FIG.
In this embodiment, a one-way clutch F2 and a brake B3 are added between the forward sun gear 4a of the planetary gear device 4 and the transmission case 6. In the first embodiment, the B1 brake is engaged at the second and fourth speeds, but in this embodiment, the B1 brake is engaged only at the fourth speed. On the other hand, the B3 brake is engaged at the 2nd to 4th speeds but is not effective at the 3rd and 4th speeds because the one-way clutch F2 idles.
Note that, as indicated by a broken line ◯ in FIG. 7, the B1 brake is operated for engine braking at the second speed in the second range, and the B2 brake is operated for engine braking at the first speed in the L range.
[0025]
In the above-described embodiment, the automatic transmission having the forward four-speed gear stage has been described. However, by adding an auxiliary transmission, a five-speed or higher gear stage can be configured.
Further, the automatic transmission of the present invention is not limited to the FF vehicle but can be applied to the FR vehicle.
[0026]
【The invention's effect】
As is apparent from the above description, according to the present invention, the forward low speed clutch C2 and the reverse clutch C1 are provided between the operating piston of the forward low speed clutch C2 and the operating piston of the forward brake B1. And the forward brake B1 are arranged side by side in the axial direction, the forward high speed stage clutch C3 is disposed on the inner diameter side of the reverse clutch C1 and the forward brake B1, and the forward speed is increased on the inner diameter side of the forward low speed clutch C2. The actuating piston of the stage clutch C3 is arranged, the actuating pistons of the forward low speed stage clutch C2 and the reverse clutch C1 have a double piston structure, and the actuating piston of the forward brake B1 is arranged on the outer periphery of the planetary gear unit. Since it is arranged, the four engaging elements can be arranged compactly, and an automatic transmission for a vehicle with a short axial dimension can be realized.
[Brief description of the drawings]
FIG. 1 is an overall cross-sectional view of an example of an automatic transmission for a vehicle according to the present invention.
FIG. 2 is a skeleton diagram of the automatic transmission shown in FIG.
FIG. 3 is an operation diagram of each engagement element of the automatic transmission shown in FIG. 1;
4 is a detailed sectional view of an engaging element portion of the automatic transmission shown in FIG. 1. FIG.
FIG. 5 is a detailed cross-sectional view of a planetary gear unit portion of the automatic transmission shown in FIG. 1;
FIG. 6 is a skeleton diagram of a second embodiment of the automatic transmission for a vehicle according to the present invention.
7 is an operation diagram of each engagement element of the automatic transmission shown in FIG. 6. FIG.
[Explanation of symbols]
C1 reverse clutch 14 operating piston C2 forward low speed clutch 15 operating piston C3 forward high speed clutch 31 operating piston B1 forward brake 25 operating piston B2 reverse brake 4 Ravigneaux planetary gear unit

Claims (3)

A Ravigneaux type planetary gear unit, a reverse clutch C1, a forward low speed clutch C2, a forward high speed clutch C3 and a forward brake B1;
The forward sun gear of the planetary gear unit is connected to the input shaft via the reverse clutch C1, and is connected to the transmission case via the forward brake B1, and the rear sun gear is connected to the input shaft via the forward low speed clutch C2. The carrier supporting the long pinion and the short pinion is connected to the input shaft via the forward high speed clutch C3, the forward sun gear meshes with the long pinion, the rear sun gear meshes with the long pinion via the short pinion, In an automatic transmission in which a ring gear meshing only with a long pinion is connected to an output shaft,
Between the operating piston 15 of the forward low speed clutch C2 and the operating piston 25 of the forward brake B1, the forward low speed clutch C2, the reverse clutch C1, and the forward brake B1 interpose the operating piston. Arranged side by side in the axial direction without
A forward high speed clutch C3 is disposed across the inner diameter side of the forward brake B1 from the inner diameter side of the reverse clutch C1,
The piston 31 for operating the forward high speed clutch C3 is disposed on the inner diameter side of the forward low speed clutch C2.
The operating piston 15 of the forward low speed clutch C2 is disposed inside the operating piston 14 of the reverse clutch C1 to form a double piston structure.
The outer diameter portion of the operating piston 14 of the reverse clutch C1 extends in the axial direction beyond the outer peripheral portion of the forward low speed clutch C2 so as to serve also as the clutch drum of the forward low speed clutch C2.
The actuating piston 14 of the reverse clutch C1, the actuating piston 15 of the forward low speed clutch C2, and the actuating piston 31 of the forward high speed clutch C3 are arranged side by side in the axial direction, and the actuating piston 14 and the actuating piston 31 are actuated. The inner diameter portion of the piston 15 extends from the outer diameter portion of the working piston 31 toward the inner diameter side,
An automatic transmission for a vehicle, wherein an operating piston 25 of the forward brake B1 is disposed on an outer peripheral portion of the planetary gear device. On the input shaft, pistons for operating the forward low speed clutch C2, the reverse clutch C1, and the forward high speed clutch C3 are arranged,
A hydraulic canceller chamber is formed on the opposite side of the piston chamber with the piston for operation of the forward low speed clutch C2 in between.
2. The automatic transmission for a vehicle according to claim 1, wherein a hydraulic canceller chamber is formed on the opposite side of the piston chamber with the operating piston of the forward high speed clutch C3 interposed therebetween. The hydraulic pressures of the forward low speed clutch C2 and the reverse clutch C1 are guided to the piston chamber of each clutch from the oil passage of the support member fixed to the transmission case, and the hydraulic pressure of the forward high speed clutch C3 is as described above. The automatic transmission for a vehicle according to claim 1 or 2, wherein the automatic transmission for a vehicle is guided from an oil passage of the support member to an inner oil passage of the input shaft to a piston chamber of the clutch.

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