JPH0610496B2 - Vehicle automatic transmission clutch structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a clutch structure in an automatic transmission for a vehicle, and particularly when the two clutches are arranged in the radial direction in an overlapping manner, the weight of the clutch portion can be reduced. At the same time, the present invention relates to a clutch structure in which parts can be easily shared when, for example, a 4-speed gear is diverted to a 3-speed gear.

[Conventional technology]

Generally, an automatic transmission for a vehicle includes a speed change gear device including a planetary gear and an input path switching device having a plurality of clutches and brakes for selecting and inputting an output from a torque converter to the device. In such an automatic transmission for a vehicle, since the mounting space is generally narrow, it is required to make the size and weight as small as possible. Especially, in a vehicle employing a horizontal engine, the axial length is shortened as much as possible. An automatic transmission is required.

Therefore, the present inventors have developed a clutch structure in which two clutches are arranged in a radial direction so as to overlap each other, as an automatic transmission capable of reducing the axial length. In this clutch structure, a friction plate is arranged between the outer drum and the hub on the outer side, and an outer piston for pressing the friction plate is provided, thereby forming an outer clutch, which is arranged inside the outer hub. A friction plate is arranged between the outer drum and the hub, and a driving inner piston is provided, thereby forming an inner clutch.

In the clutch structure according to the above development, since the two clutches are superposed in the radial direction, the axial length is shortened accordingly, and the above-mentioned demand for miniaturization can be met.

[Problems to be solved by the invention]

By the way, in the structure in which the above-mentioned clutch is arranged double, as described above, the outer drum for the outer clutch, the outer drum for the inner clutch and the hub are arranged inside the hub, and the pistons for press-contacting the respective friction plates are arranged. Therefore, depending on the design, the structure becomes complicated and the weight may increase.

Therefore, to prevent such problems from occurring, for example,
The outer clutch piston and the inner clutch outer drum are integrally formed, and a torque transmitting pawl is formed on the piston, and the pawl is engaged with the outer clutch outer drum as an input member so as to be movable in the axial direction. Conceivable.

With such a structure, the structure can be simplified. However, since the integrally formed outer piston and inner outer drum require high strength to withstand the transmission torque, they must be made of heavy steel, and as a result, the demand for weight reduction cannot be met.

Generally, in the above automatic transmission, for example, the one for the fourth speed may be diverted to the one for the third speed by removing one of the overlapped clutches. In this case, it is possible to share parts as much as possible. desired. However, when the outer piston and the inner outer drum are integrated, it may be difficult to share the integrated parts.

Therefore, an object of the present invention is to solve the above-mentioned problems.
The structure can be simplified and the weight can be reduced, and 4
An object of the present invention is to provide a clutch structure for an automatic transmission for a vehicle, in which parts can be easily shared when the speed is converted to the third speed.

[Means for Solving Problems] The present invention relates to a transmission gear device including a planetary gear and an input path switching device having a plurality of clutches for selectively inputting an output from a torque converter to the transmission gear device. In a clutch structure for an automatic transmission for a vehicle including: a plurality of outer friction plates are arranged between an outer outer drum formed at a tip portion of an input member and an outer hub, and in a cylinder portion of the input member. An outer clutch is formed by disposing an outer piston in the inner outer drum, which is disposed inside the outer hub and whose flange portion is axially movably engaged with the outer outer drum, and the inner hub. A large number of inner friction plates are arranged between them, the flange is fixed to the outer piston, and the inner piston is arranged in the outer piston. The feature is that the inner clutch is configured.

[Action]

In the clutch structure of the present invention, the outer drum for the inner clutch and the outer piston are formed by separate members to connect them, and the outer drum for the outer clutch is engaged with the flange portion of the outer drum for the inner clutch so as to be movable in the axial direction. As a result, the inner outer drum, which requires high strength to withstand the transmitted torque, is made of steel to ensure strength, while the outer piston, which does not require much strength, can be made of lightweight aluminum, aiming to reduce the overall weight. be able to.

In addition, as described above, since the inner outer drum is connected to the outer piston, the outer piston is for the fourth speed,
When the speed is approximately the same, and the 4-speed gear is converted to the 3-speed gear, it is only necessary to remove the inner outer drum and slightly change the outer piston machining shape. It can be easily converted.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show a Ravigneaux type four-speed automatic transmission according to one embodiment of the present invention.

In the figure, an automatic transmission 30 of the present embodiment includes a torque converter 1 with a lockup mechanism, a first sun gear and a second sun gear.
Speed change gear device 2 including a Ravigneaux gear train including S1, S2, first and second pinion gears P1 and P2, and a ring gear 9.
And an input path switching device 3 mainly including first to third clutches C1 to C3.

The torque converter 1 includes a converter housing 1c.
A pump impeller 1f is connected to a converter case 1e connected to a crankshaft 1d of an engine, a turbine runner 1a is arranged opposite to the pump impeller 1f, and a stator 1g is interposed between the pump impeller 1f and a one-way clutch 1h. It is arranged so as to be rotatable via. The clutch 1h
And an input shaft 1b connected to the turbine runner 1a
Are rotatably supported by a support member 18 fixed to the transmission case 13. Further, 1i is a lockup clutch.

The transmission gear device 2 and the input path switching device 3 are arranged in the transmission case 13. The second sun gear S2 of the speed change gear device 2 is rotatably arranged around the output side shaft 14 coaxially arranged with the input shaft 1b.
The first sun gear S1 is rotatably disposed on the boss portion 5a of the second sun gear S2. The boss portion 8a of the carrier 8 is spline-fitted to the output side shaft 14.
By the carrier 8, the first and second pinion gears P
1, 2 are rotatably supported, and the second pinion gear P2 meshes with the second sun gear S2, and the first pinion gear P1 meshes with the first sun gear S1 and the second pinion gear P2. A one-way clutch C4 and a second brake B2 are arranged on the outer peripheral portion 8b of the carrier 8. 16a is a piston for operating the brake B2. Furthermore, the boss portion 8a of the carrier 8 is rotatably mounted with the boss portion 9b of the output take-out ring gear 9 meshing with the first pinion gear P1, and the boss portion 9b is provided with the bearing 13a through the bearing 13a. The transmission case 13 is pivotally supported. A reduction gear 9a is spline-fitted to the axial end of the boss 9b.

The reduction gear 9a meshes with the input gear 21a of the counter shaft 21, and the output gear 21b of the reduction gear 9a meshes with the ring gear 22a of the actuating gear device 22.
A wheel is attached to the tip of the output shaft 22b of the operating gear device 22.

The first clutch C1 of the input path switching device 3 is rotatable with respect to the support member 18 and the first hub 10a fixedly formed on the dish-shaped input member 17 having the bottom wall 17b fixed to the input shaft 1b. The first outer drum 10b supported by the
A large number of friction plates 10c are arranged between the first and second friction plates 10c, and a first clutch operating piston 10d is axially slidably arranged in the outer drum 10b functioning as a cylinder. Further, a cylindrical transmission member 10e is connected to the outer drum 10b, and a tip end portion of the cylindrical transmission member 10e is spline-fitted to the first sun gear S1. In addition,
B1 is a first brake that stops the rotation of the transmission member 10e.

The second clutch (outer clutch) C2 is the input member 17
Outer drum 17a formed at the tip of the side wall of the
And a large number of outer friction plates 11b are arranged between the outer hub 11e and the outer hub 11e arranged inside of the outer hub 11e, and an outer piston 11c made of aluminum is arranged in the cylinder portion 17e of the input member 17. ing. The outer hub 11e is spline-fitted to the boss portion 5a of the second sun gear S2.

The third clutch (inner clutch) C3 is a steel inner outer drum 12 disposed inside the outer hub 11e.
A large number of inner friction plates 12b are arranged between d and an inner hub 12a fixed to the output side shaft 14, and an inner piston 12c made of aluminum is arranged in the outer piston 11c. . In addition, the inner outer drum 12
An outwardly extending flange portion 12e is integrally formed at a rear end portion of d, and a dog claw 12f formed on the outer periphery of the flange portion 12e is axially formed in a dog groove 17c formed on a side wall of the input member 17. It is movably engaged.

The outer piston 11c is riveted to the flange portion 12e of the outer drum 12d of the third clutch C3, and the flange portion 12e is connected to the second clutch C2.
Of the friction plate 11b.

Next, the function and effect of this embodiment will be described.

In the automatic transmission 30 of this embodiment, the output from the torque converter 1 is selected and input to any of the sun gears or carriers by operating the clutches, brakes, etc. in the combinations shown in Table 1. Each gear is realized by.

For example, at low speeds such as the first speed and the second speed, only the second clutch C2 is operated and the one-way clutch C4 is operated.
Alternatively, the first brake B1 is operated, and in the case of the third speed, the first brake B1 is released from the state of the second speed, and
The third clutch C3 is also activated, and in the case of the 4th speed,
Only the third clutch C3 is activated and the first brake B1 is activated. As a result, the rotation of the torque converter 1 causes the input member plate 17, the first to third clutches C1 to
It is selectively input to the first and second sun gears S1 and S2 or the carrier 8 via C3. As a result, a reduction gear ratio corresponding to each gear is obtained.

In this case, when the second clutch C2 is operated, the outer drum 11c moves the third clutch C3 outer drum 12d forward by being guided by the dog groove 17c.
e presses the outer friction plates 11b together. The input to the third clutch C3 is input from the input member 17 via the steel dog claw 12f and the inner outer drum 12d that can withstand the transmission torque.

In this way, in this embodiment, the outer clutch outer drum 17a is engaged with the inner clutch outer drum 12d so as to be movable in the axial direction, and is coupled to the outer piston 11c.
The structure is simplified as compared with the case where d is provided separately from the outer outer drum 12a.

Further, since the outer piston 11c and the inner outer drum 12d are configured as separate parts, the outer piston 11c does not have a portion requiring strength such as a torque transmitting claw portion, and as a result, the outer drum 12d requiring high strength is made of steel. While ensuring strength, the outer piston 11c, which does not require so much strength, can be made of lightweight aluminum, and the overall weight can be reduced.

When the second and third clutch actuating pistons are provided independently of each other, when hydraulic pressure is supplied to both pistons at the same time, for example, when switching from the fourth speed to the third speed, However, there is a problem that the gear shift shock is large due to the excessive pressing force. On the other hand, in this embodiment, since the inner piston 12c is disposed inside the outer piston 11c, when hydraulic pressure is supplied to both pistons, the effective pressure receiving area of the outer piston 11c is the pressure receiving area of the inner piston 12c. As a result, the clutch pressing force is controlled to be excessive, so that an appropriate clutch capacity can be obtained and the shift shock can be reduced accordingly.

By the way, as described above, the 4-speed automatic transmission according to this embodiment may be diverted to the 3-speed by removing the third clutch C3. FIG. 4 shows an essential part of a three-speed automatic transmission designed in this way, and the same reference numerals as those in FIG. 1 show the same or corresponding parts.

In this example, the inner outer drum 12d and the hub 12a constituting the inner clutch C3 described above are removed, and the outer piston 11c 'is the outer piston 11 for the fourth speed.
It is formed using the same material as c. The piston 11c 'is integrally formed with a pressing portion 11f at a portion facing the outer friction plate 11b.

As described above, in the clutch structure of this embodiment, the flange portion 12e of the inner outer drum 12d is connected to the outer piston 11c by rivets. Therefore, in the case of converting to the third speed, the inner clutch outer drum and the hub are eliminated. It is only necessary to slightly change the shape of the outer piston 11c, and in any case, the same piston material can be used, and the material cost of the parts can be reduced as much as this piston material can be shared. Incidentally, when the outer piston 11c and the inner outer drum 12d are integrally formed, it is difficult to share this material.

〔The invention's effect〕

As described above, according to the clutch structure of the vehicle automatic transmission according to the present invention, the outer piston for the inner clutch is coupled to the outer piston, and the inner piston is arranged in the outer piston. The inner outer drum that bears the load can be made of high-strength steel, and the piston can be made of lightweight aluminum, which has the effect of achieving weight reduction while ensuring the required strength. In the case of diverting to 3rd speed, the clutch operating piston can be shared, and the material cost can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing outer and inner clutch portions of a Ravigneaux type four-speed automatic transmission according to one embodiment of the present invention.
FIG. 4 is a cross-sectional plan view showing the overall structure, FIG. 3 is a schematic view thereof, and FIG. In the figure, 1 is a torque converter, 1b is an input shaft, 2
Is a speed change gear device, 3 is an input path switching device, 8 is a carrier, 11b is an outer friction plate, 11c is an outer piston, 1
1e is an outer hub, 12a is an inner hub, 12b is an inner friction plate, 12c is an inner piston, 12d is an inner outer drum, 12e is a flange portion, 14 is an output shaft, 17 is an input member, 17a is an outer outer drum, and 17e is a cylinder. , 30 is an automatic transmission, C2 is a second clutch (outer clutch), C3 is a third clutch (inner clutch), P1 and P2 are first and second pinion gears, and S1 and S2 are first and second sun gears. is there.

Claims (1)

[Claims] 1. A transmission gear device comprising a planetary gear, and an input path switching device having a plurality of clutches for selectively inputting an output from a torque converter to a carrier that axially supports a sun gear or a pinion gear of the transmission gear device. In a clutch structure in an automatic transmission for a vehicle including, an input member having a cylinder portion is fixed to an input shaft
An outer outer drum formed at the tip of the input member,
A large number of outer friction plates are arranged between the inner hub and an outer hub, and an outer piston is arranged in the cylinder portion of the input member, which constitutes an outer clutch. An inner outer drum arranged in the hub,
A large number of inner friction plates are arranged between the inner hub arranged inward of the inner hub and the flange portion formed on the inner outer drum so as to be axially movably engaged with the outer drum. A clutch for an automatic transmission for a vehicle, characterized in that the flange portion is fixed to the outer piston, and the inner piston is arranged inside the outer piston so as to face the inner friction plate, thereby forming an inner clutch. Construction.