JP2000145899A - Automatic transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the easiness in the on-board mounting property of a common automatic transmission for vehicles by enabling compact formation owing to replacement of only the backmost part of transmission in compliance with smaller construction of the vehicle mountable. SOLUTION: A transmission case is divided into a main case to accommodate the major portion of the shifting mechanism and a rear case 10B to block the tail opening of the main case, and friction members 63 and 73 of a clutch are arranged overlapping on the peripheries of rotary members G1 and G in a position behind the major portion of the shifting mechanism accommodated in the main case, and hydraulic servo elements 6 and 7 of the clutch are arranged inside the rear case 10B covering the servo elements along the contour of their tail parts, and it is made practicable to replace with a compact one together with the rear case in compliance with a decrease in the requisite torque transmitting capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission mounted on a vehicle, and more particularly, to a technology capable of changing an outer shape according to a partial change according to a torque transmission capacity of a transmission mechanism.

[0002]

2. Description of the Related Art As one form of an automatic transmission for a vehicle, there is a horizontal automatic transmission for a front engine / front drive (FF) vehicle or a rear engine / rear drive (RR) vehicle. In such a type of automatic transmission, the engine and the automatic transmission are arranged side by side in series between the left and right wheels of the vehicle, so that the axial length of the automatic transmission is significantly limited. Therefore, the gear train of such an automatic transmission must have a configuration that minimizes the number of planetary gear sets, which have a large number of shifting elements that mainly extend the shaft length, and the number of clutches and brakes that operate the shifting elements, as much as possible. No.

On the other hand, there is a demand for an automatic transmission having multiple stages in order to not only ensure drivability but also to improve fuel efficiency which is indispensable for energy saving. It is necessary to further reduce the number of transmission elements and the number of clutches and brakes. Therefore,
Japanese Patent Application Laid-Open No. 4-219553 proposes a gear train that uses a planetary gear set having a minimum number of shift elements and achieves six forward speeds and one reverse speed by using three clutches and two brakes for operating the planetary gear set. I have. The gear train according to this proposal employs three clutches to convert the engine output rotation and its reduced rotation to a planetary gear set consisting of four transmission elements of a transmission as appropriate.
The two speeds are input as different speeds, and the two shift elements are locked and controlled by the two brakes to achieve the multi-stage six speeds.

[0004]

The gear train configuration according to the above proposal is very reasonable in the number of shift elements per shift speed and the number of clutches and brakes required, but is reduced to a planetary gear set. As the amplified torque is input, the size of the planetary gear set becomes large and the handling of the members transmitting the two different speeds becomes complicated. Inevitable. By the way, in the case of the horizontal type automatic transmission, in order to improve the mountability to the vehicle, the rear end (the power is input through the present specification) outside the center in the width direction of the vehicle, that is, on the main shaft. It is important to avoid interference between the side and the members on the vehicle side in order to avoid the interference between the side and the member on the vehicle side. Is important.

Further, regarding the method of mounting the transmission on the vehicle, since the diameter of a small vehicle is generally small, the positions of the engine and the transmission are relatively set with respect to the vehicle in order to secure the minimum ground clearance. Is often set high.
With this arrangement, even if the transmission can be mounted in a small space due to a slight increase in the size of the transmission, there is no clearance between the rear end of the transmission main shaft and the vehicle members. May disappear. Therefore,
The downsizing of the rear end of the transmission becomes an even more important issue in improving the mountability in a small vehicle.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enables the rear end of a main shaft to be made more compact in accordance with the miniaturization of a vehicle to be mounted. It is an object of the present invention to provide an automatic transmission with improved performance.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a transmission mechanism provided on a main shaft, which is accommodated in a case, the case comprising a main case accommodating a main part of the transmission mechanism. In a vehicle automatic transmission divided into a rear case and a rear case that closes a rear end opening of a main case, an appropriate rotating member of the transmission mechanism is provided at a rear side of a main portion of the transmission mechanism housed in the main case. The friction member of the clutch is arranged on the outer peripheral side, and the hydraulic servo of the clutch is substantially
It is arranged in a rear case that covers the hydraulic servo along the outer shape of the rear end.

[0008] The transmission mechanism includes a planetary gear set having four transmission elements around an input shaft;
A first speed change element of the planetary gear set is connected to the input shaft via the speed reduction planetary gear by the first clutch, and a second speed change element is connected to the third speed change element; The clutch is connected to the input shaft via a deceleration planetary gear and can be locked to the case by the first brake. The third transmission element is connected to the input shaft by the second clutch, and In the case of a transmission mechanism in which the torque can be locked to the case and the fourth transmission element is an output element, the torque amplified by the multi-stage is input to the planetary gear set. And a friction member of the first and third clutches to which the torque amplified by the reduction planetary gear is input. Is, the hydraulic servo, it is effective to a configuration in which the hydraulic servo for engaging the friction members.

Further, when the diameter of the rear end of the transmission can be reduced, the hydraulic servos of the first and third clutches include a first piston inserted inside a common cylinder and an externally inserted piston. A second piston inserted therein, a common cylinder constituting a drum of one of the first and third clutches, a second piston constituting a drum of the other clutch, The friction members of the first and third clutches are arranged side by side in the axial direction, and a hydraulic servo of the first clutch is provided on one side of a power transmission member for transmitting the deceleration torque output from the deceleration planetary gear. It is effective to adopt a configuration in which a hydraulic servo of the third clutch is provided on the other side of the member.

In order to further reduce the size of the drum, the one drum and the other drum are axially movably connected to each other by spline engagement by being superposed in the radial direction. It is effective that any one of the friction members of the third clutch is disposed, and the friction member is sandwiched between the radially inner drum and the radially outer drum to transmit the deceleration torque.

[0011]

According to the structure of the first aspect,
By arranging the friction member of the clutch inside the main case on the outer peripheral side of the other rotating member at the rear of the transmission mechanism, the diameter of the friction member is increased so as to be compatible with large vehicles, and a large torque capacity is provided on the friction member side By replacing the hydraulic servo, which has been able to secure a small capacity and small diameter by increasing the diameter of the friction member, it can be handled by replacing it with a small capacity together with the rear case according to the size of the vehicle to be mounted. Accordingly, the size of the rear portion of the transmission can be reduced in accordance with the size reduction of the vehicle so as not to interfere with the members on the vehicle side. Therefore,
According to this configuration, it is possible to change the rear outer shape of the common transmission in accordance with the vehicle to be mounted, thereby improving vehicle mountability.

Further, according to the second aspect of the present invention, the hydraulic servos of the first and third clutches, which require a large capacity when the deceleration torque amplified by the deceleration planetary gear is input, are disposed in the rear case. Therefore, compared to the case where the hydraulic servo of the second clutch, which originally has a small capacity due to the direct input of the input torque, is disposed in the rear case, the ratio of the smaller diameter to the smaller required capacity is increased. Therefore, the size of the rear case can be effectively reduced.

According to the third aspect of the present invention, since the power transmission member for transmitting the deceleration torque to the first and third clutches is shared, the hydraulic servos of both clutches can be made compact. Further, in accordance with the operation of disengaging the friction members of both clutches by the push / pull operation by both hydraulic servos, the friction members of these clutches and the hydraulic servo can be offset and arranged, so that the first and the second are provided in the rear case. Since the arrangement in which only the two hydraulic servos of the third clutch are accommodated can be adopted, the rear end of the transmission can be made compact by reducing the diameter of the rear case.

According to the fourth aspect of the invention, the power transmission to one friction member of the first and third clutches can be performed by the drum of the other clutch. The rear case can be made more compact by making the rear case more compact accordingly.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a gear train according to a first embodiment of a vehicular automatic transmission embodying the present invention, which is developed by a skeleton with a shaft-to-shaft developed in a common plane. FIG. 2 shows an actual axial positional relationship of the automatic transmission as viewed from an end face. This automatic transmission has a main axis X, a counter axis Y,
It has a three-axis configuration in which each element is disposed on each axis of the differential axis Z. And around the input shaft 11 on the main axis X, 4
Transmission elements S2, S3, C2 (C3), R2 (R3)
, A speed change mechanism including a reduction planetary gear G1, two brakes B-1, B-2, and three clutches C-1, C-2, C-3.

In this automatic transmission, the first transmission element S3 of the planetary gear set G is connected to the input shaft 11 via the reduction planetary gear G1 by the first clutch C-1, and the second transmission element S2 is connected to the third transmission element S3. Is connected to the input shaft 11 via the deceleration planetary gear G1 by the clutch C-3 and can be locked to the case 10 by the first brake B-1, and the third speed change element C2 (C3) is It is connected to the input shaft 11 by the clutch C-2 and can be locked to the case 10 by the second brake B-2, and the fourth transmission element R2 (R3) is connected to the counter drive gear 19 as an output element. ing. In the gear train shown in the figure, a one-way clutch F-1 is arranged in parallel with the brake B-2. This is because a one-way clutch F-2 and a brake B- 1
Avoid complicated hydraulic control for gripping
-2 clutch F which releases the engaging force naturally with the engagement of the brake B-1 in order to simplify the release control of the clutch B-2.
-1 and is equivalent to the brake B-2.

Hereinafter, the gear train of this embodiment will be described in more detail. A torque converter 4 with a lock-up clutch for transmitting the rotation of an engine (not shown) to the input shaft 11 is arranged on the main shaft X. A counter gear 2 is arranged on the counter shaft Y. The counter gear 2 is fixed to a counter shaft 20 and has a large-diameter counter driven gear 21 meshing with the counter drive gear 19;
Similarly, it is fixed to the counter shaft 20 at a different axial position,
A small-diameter differential drive pinion gear 22 that meshes with the differential ring gear 31 is provided.
The function of reducing the output from the side and inverting the output and transmitting it to the differential device 3 is achieved. A differential device 3 is provided on the differential shaft Z. The differential device 3 is provided with a differential case 32 fixed to the differential ring gear 31, and the differential rotation of the differential gear disposed therein is output to the left and right shafts 30, and is used as the final wheel driving force.

The planetary gear set G is meshed with a pair of large and small sun gears S2 and S3, one of which meshes with the large diameter sun gear S2 and the ring gear R2.
(R3) and a carrier C supporting a pair of pinion gears P2 and P3, the other of which meshes with the small-diameter sun gear S3.
2 (C3). In this embodiment, the small-diameter sun gear S3 is a first transmission element, the large-diameter sun gear S2 is a second transmission element, the carrier C2 (C3) is a third transmission element, and the ring gear R2 (R3) is a third transmission element. 4 speed change element.

The reduction planetary gear G1 has its sun gear S1 fixed to the transmission case 10, is connected to the input shaft 11 with the ring gear R1 as an input element, and has the first clutch C-1 and the third clutch C3 with the carrier C1 as an output element. It is connected to the planetary gear set G via the clutch C-3. The first transmission element of the planetary gear set G, that is, the small-diameter sun gear S3, is connected to the first clutch C-1, and the second transmission element, that is, the large-diameter sun gear S2,
It is connected to the third clutch C-3 and can be locked to the automatic transmission case 10 by a first brake B-1 constituted by a band brake. The carrier C2 (C3), which is the third transmission element, is connected to the input shaft 11 via the second clutch C-2, and is locked to the transmission case 10 by the second brake B-2. In addition, the one-way clutch F-1 enables the transmission case 10 to be locked in one-way rotation. The fourth speed change element, that is, the ring gear R2 (R3) is connected to the counter drive gear 19.

The automatic transmission having such a configuration shifts gears based on the vehicle load and the vehicle speed in a speed range corresponding to the range selected by the driver under the control of an electronic control unit and a hydraulic control unit (not shown). Do. FIG. 3 graphically illustrates the shift speeds achieved by engaging and disengaging the clutches and brakes (showing engagement with a circle and disengagement without a mark). Also,
FIG. 4 is a speed diagram showing the relationship between the shift speed achieved by the engagement of each clutch and brake (the engagement is indicated by a mark) and the rotational speed ratio of each shift element at that time.

As can be seen by referring to both figures, the first speed (1ST) corresponds to the engagement of the clutch C-1 and the brake B-2 (in this embodiment, as shown in the operation table, One-way clutch F instead of engagement of brake B-2
The automatic engagement of -1 is used. The reason for using this engagement and the reason why this engagement corresponds to the engagement of the brake B-2 will be described later in detail. ).
In this case, the rotation reduced from the input shaft 11 via the reduction planetary gear G1 is input to the small-diameter sun gear S3 via the clutch C-1, and a reaction force is applied to the carrier C3 locked by the engagement of the one-way clutch F-1. The reduction rotation of the ring gear R3 at the maximum reduction ratio is the counter drive gear 1
9 is output.

Next, in the second speed (2ND), the clutch C-
This is achieved by the engagement of 1 with the brake B-1. In this case, the rotation reduced from the input shaft 11 via the reduction planetary gear G1 is input to the small-diameter sun gear S3 via the clutch C-1, and the reaction force is applied to the large-diameter sun gear S2 locked by the engagement of the brake B-1. Take ring gear R2 (R3)
Is output to the counter drive gear 19.
As shown in FIG. 4, the reduction ratio at this time is the first speed (1S
T).

In the third speed (3RD), the clutch C-
1 and the clutch C-3 at the same time. In this case, the rotation reduced from the input shaft 11 via the reduction planetary gear G1 is simultaneously input to the large-diameter sun gear S2 and the small-diameter sun gear S3 via the clutch C-1 and the clutch C-3, so that the planetary gear set G is directly connected. The rotation of the ring gear R2 (R3), which is the same as the input rotation of both sun gears, is output to the counter drive gear 19 as a rotation that is reduced with respect to the rotation of the input shaft 11.

Further, in the fourth speed (4TH), the clutch C-
1 and the clutch C-2 at the same time. In this case, on the other hand, the rotation reduced from the input shaft 11 via the reduction planetary gear G1 is transmitted to the sun gear S via the clutch C-1.
3, the non-decelerated rotation input from the input shaft 11 via the clutch C-2 is input to the carrier C3, and a rotation intermediate between the two input rotations is The rotation is output to the counter drive gear 19 as the slightly reduced rotation of the ring gear R3.

Next, in the fifth speed (5TH), the clutch C-
2 and the clutch C-3 at the same time. In this case, on the other hand, the rotation reduced from the input shaft 11 via the reduction planetary gear G1 is transmitted to the sun gear S via the clutch C-3.
2, the non-decelerated rotation input from the input shaft 11 via the clutch C-2 is input to the carrier C2, and the rotation slightly higher than the rotation of the input shaft 11 of the ring gear R3 is counter-driven. Output to the gear 19.

In the sixth speed (6TH), the clutch C
-2 and brake B-1. In this case, the non-decelerated rotation is input only from the input shaft 11 to the carrier C2 via the clutch C-2, and the brake B-1
The rotation of the ring gear R3, which takes a reaction force to the sun gear S2 locked by the engagement of the ring gear R3, is output to the counter drive gear 19.

The reverse (REV) is controlled by the clutch C-3.
And the brake B-2. in this case,
The rotation reduced from the input shaft 11 via the reduction planetary gear G1 is input to the sun gear S2 via the clutch C-3, and the carrier C locked by the engagement of the brake B-2.
The reverse rotation of the ring gear R <b> 3 that takes a reaction force at 2 is output to the counter drive gear 19.

Here, the one-way clutch F mentioned earlier
The relationship between -1 and the brake B-2 will be described. As can be seen from the engagement / disengagement relationship between the two brakes B-1 and B-2 at the first speed and the second speed, these two brakes release one of them during the up-down shift between the two shift speeds. At the same time, the other engagement is performed, that is, a so-called gripped friction element. Such gripping of frictional elements requires precise simultaneous control of the engagement pressure and release pressure of the hydraulic servos that operate them, and such control requires the addition of control valves and complicated hydraulic circuits. Will be invited. Therefore, in the present embodiment, the engagement direction of the one-way clutch F-1 is changed to the first speed by utilizing the fact that the reaction torque applied to the carrier C2 (C3) is reversed between the first speed and the second speed. By setting according to the reaction torque supporting direction,
By causing the one-way clutch F-1 to exhibit substantially the same function as the engagement of the brake B-2, the brake B-
2 (in the vehicle coast state of the wheel drive, the direction of the reaction torque applied to the carrier C2 (C3) is reversed with respect to the state of the engine drive. Therefore, in order to obtain the engine braking effect, ○ in parentheses in Figure 3
Requires the engagement of brake B-2, as indicated by the mark),
That is, the carrier C2 (C3) is locked.
Therefore, in order to achieve the shift speed, a configuration in which the first speed is achieved by engaging the brake B-2 without providing a one-way clutch may be adopted.

Each of the speed stages achieved in this manner can be qualitatively understood on the speed diagram of FIG. 4 by referring to the vertical interval between the circles indicating the speed ratio of the ring gears R2 and R3. Thus, good speed steps with relatively equal intervals for each shift speed are obtained. When this relationship is specifically set to numerical values and quantitatively expressed, the gear ratio shown in FIG. 3 is obtained. The gear ratio in this case is such that the gear ratio λ1 = 44/78 between the sun gear S1 of the reduction planetary gear G1 and the ring gear R1, the sun gear S2 and the ring gear R2 on the large diameter sun gear side of the planetary gear set G.
(R3) tooth ratio λ2 = 36/78, tooth ratio λ3 = 30/7 between sun gear S3 and ring gear R3 on the small diameter sun gear side
When the gear ratio is set to 8, the first gear (1ST): (1 + λ1) /λ3=4.067 The second gear (2ND): (1 + λ1) (λ2 + λ3) / λ3
(1 + λ2) = 2.354 Third speed (3RD): 1 + λ1 = 1.564 Fourth speed (4TH): (1 + λ1) / (1 + λ1-λ1 ·
λ3) = 1.161 Fifth speed (5TH): (1 + λ1) / (1 + λ1 + λ1 ·
λ2) = 0.857 Sixth speed (6TH): 1 / (1 + λ2) = 0.684 Reverse (REV): − (1 + λ1) /λ2=3.389. The steps between these gear ratios are as follows: 1st and 2nd speed: 1.73 2nd and 3rd speed: 1.51 3rd and 4th speed: 1.35 4th and 5th speed: 1.35 Between the 5th and 6th speeds: 1.25.

Next, FIG. 5 is a schematic cross-sectional view showing the structure of the automatic transmission more specifically. The components described above with reference to the skeleton will be denoted by the same reference numerals and will not be described, but details that cannot be referenced from the skeleton will be described here. Note that throughout this specification, the terms clutch and brake generally refer to a friction member and a hydraulic servo. Therefore, the first clutch C
-1 is the friction member 63 and the hydraulic servo 6, the second clutch C-2 is composed of the friction member 53 and the hydraulic servo 5, and the third clutch C-3 is composed of the friction member 73 and the hydraulic servo 7. I have. Also, regarding the brakes B-1 and B-2,
In the case of a band brake configuration, each of them is composed of a band and a hydraulic servo (not shown), and in the case of a multiple disc brake, it is composed of a friction member and a hydraulic servo.

The case 10 accommodating the transmission mechanism includes a main case 10A for accommodating a main part of the transmission mechanism by rotatably supporting the front end side of the input shaft 11 by a front boss 10a via a bearing, and an input shaft 11 Rear case 10B that closes the rear end opening of the main case 10A by rotatably supporting the rear end of the main case 10A via the bearing on the inner periphery of the rear boss 10b.
And is divided into: A support 10C for supporting the counter drive gear 19 is provided substantially at the center of the main case 10A. The front boss 10
The servo pressure oil passage 10y of the second clutch C-2 is formed in a, and the servo pressure oil passages 10x and 10z of the first and third clutches are formed in the rear boss 10b.

The input shaft 11 has a flange 11a formed adjacent to the tip of a front boss 10a as a front support, and a flange 11b formed adjacent to a rear boss 10b as a rear support. , Is configured as a hollow shaft having a lubricating oil passage inside. These two flange portions 11
a and 11b transmit the input rotation to the second clutch C-2 and the reduction planetary gear G1 at both ends of the input shaft 11, and both boss portions 10a and 10b and both flange portions 11
The input shaft is provided in the axial direction by inserting a bearing between a and 11b.

Next, the planetary gear set G is disposed around the rear shaft of the input shaft 11, supports the sun gear S3 on the input shaft 11 via bearings, and supports the sun gear S2 on the sun gear S3 via bearings. It is positioned and supported. The sun gear S3 as a first transmission element of the planetary gear set G is connected to the hub 64 of the first clutch C-1. Further, the sun gear S2 as the second speed change element is connected to the hub 74 of the third clutch C-3. The carrier C2 (C3) as the third speed change element is connected to the hub 54 of the second clutch C-2 by spline engagement. Further, the ring gear R2 (R3) as a fourth speed change element is connected to the counter drive gear 19 supported on the immediately preceding support 10C via the bearing 12 by spline engagement.

The reduction planetary gear G1 is connected to the rear boss 1
A sun gear S1 as a reaction element is fixed to the outer periphery of the leading end of the shaft 0b, and a ring gear R1 as an input element is connected to the flange 11b of the input shaft 11, so that the planetary gear set G and the first and third clutches C-1 and C are connected. -3. The carrier C1 as an output element is connected to the drum 62 of the first clutch using the cylinder 60 common to the hydraulic servos 6 and 7 of the first and third clutches C-1 and C-3 as a power transmission member. .

Next, the first and third clutches C-1, C
-3 hydraulic servos 6 and 7 constitute their pressure receiving parts,
Cylinder portions 6a, 7a whose outer diameters are substantially determined according to their pressure receiving areas are arranged on the rear side of the reduction planetary gear G1, and the cylinder portions 6a, 7a are rotatable around the rear boss portion 10b of the rear case 10B. The configuration includes a supported common cylinder 60, a first piston 61 inserted inside the cylinder 60, and a second piston 71 inserted outside. And the common cylinder 60
Is expanded and extended in accordance with the outer diameter of the friction member 63 so that the first
Of the clutch 62, and the second piston 71
Similarly, the diameter of the friction member 73 is expanded and extended in accordance with the outer diameter of the friction member 73 to constitute the drum 72 of the other third clutch. Therefore, the hydraulic servos 6, 7 of these two clutches
The outer shape of the rear case 10B that covers the hydraulic servo along the outer end of the cylinder portion 6a, 7a along the outer end of the
And the outer shape of the drum 72 connected thereto. In the figure, reference numerals 65 and 75 indicate the piston 6
Numerals 1 and 71 denote a cancel plate for canceling the centrifugal oil pressure applied to the back surface, and numerals 66 and 76 denote return springs.

The friction member 63 of the first clutch C-1
A backing plate fixed to the end of the drum 62, comprising a multi-plate friction material and a separator plate, the inner periphery of which is spline-engaged with the hub 64 and the outer periphery of which is spline-engaged with the drum 62; A torque is transmitted from the drum 62 to the hub 64 by a clutch engagement operation sandwiched between the piston 61 and the piston 61 pushed out of the cylinder 60 by the supply of hydraulic pressure to the inside.

The friction member 73 of the third clutch C-3 is
A backing plate fixed to the end of the drum 72, comprising a multi-plate friction material and a separator plate, the inner periphery of which is spline-engaged with the hub 74 and the outer periphery of which is spline-engaged with the drum 72; A torque is transmitted from the drum 72 to the hub 74 by a clutch engagement operation sandwiched between the piston 71 pushed out of the cylinder 60 by the supply of hydraulic pressure to the inside.

According to the feature of the present invention, one of the first
The drum 62 of the clutch C-1 and the drum 72 of the other third clutch C-3 are superposed in the radial direction, are connected in an axially movable manner by spline engagement, and are capable of transmitting torque. The friction members 63 and 73 of the clutch 3
They are arranged adjacent to each other in the axial direction. A third clutch C-3 is attached to the tip of the drum 62 on the radially inner side.
The friction member 73 is arranged between the backing plates of the radially inner drum 62 and the radially outer drum 73 to transmit the deceleration torque. The friction members 63, 7 thus arranged
3, in this embodiment, an appropriate rotating member of the transmission mechanism is formed as a reduction planetary gear G1 and a planetary gear set G on the rear side of the main part of the transmission mechanism housed in the main case 10A, and is superposed on the outer peripheral side thereof. Are located.

The second clutch C-2 is disposed at the front of the counter drive gear 19, that is, at the forefront of the transmission mechanism. Specifically, the hydraulic servo 5 of the second clutch
The inner peripheral side of the cylinder 50 is fixed to the flange portion 11a of the input shaft 11 and is supported by the input shaft 11, and is disposed on the outer periphery of the front boss portion 10a. The drum 52, and the cylinder 50
A centrifugal oil pressure cancel plate 55 and a return spring 56 are provided.

The friction member 53 of the second clutch C-2 is
A backing plate fixed to the end of the drum 52, comprising a multi-plate friction material and a separator plate, the inner side of which is spline-engaged with the hub 54 and the outer side of which is spline-engaged with the drum 52; The torque is transmitted from the drum 52 to the hub 54 by a clutch engagement operation sandwiched by the piston 51 pushed out of the cylinder 50 by the supply of hydraulic pressure to the inside.

The first brake B-1 is a band brake, and the brake band 81 tightens a brake drum 82 connected to the hub 74 of the third clutch C-3. As a result, the first brake B-1 is arranged without requiring any space in the axial direction and with almost no increase in the radial dimension. It should be noted that the hydraulic servo of this band brake is applied to the brake drum 82 at the same axial position as the brake band 81.
The drawing is omitted because it extends in a tangential direction with respect to.

The second brake B-2 has a multi-plate construction like each clutch, and has a hydraulic servo 9 and a friction member 93.
Is arranged on the outer peripheral side of the planetary gear set G side by side with the one-way clutch F-1, and the brake hub and the inner race of the one-way clutch are connected to the carrier C2 (C3).
It is connected to. The hydraulic servo 9 of the second brake B-2 is configured such that one side of the support 10C is built in the support 10C as a cylinder 90.

The counter drive gear 19 has a boss extending rearward on the inner peripheral side thereof supported on the inner periphery of the support 10C of the case 10 via the bearing 12, and is provided between the planetary gear set G and the second clutch C-2. Are located in Then, the counter drive gear 19 and the ring gear R
3 is formed by spline engagement with a boss of a connecting member extending from the ring gear R3.

In the transmission having the above configuration, the friction members 63 and 73 of the first and third clutches are
0A, by overlapping the reduction gear planetary gear G1 and the planetary gear set G on the outer peripheral side of the speed reduction mechanism rear portion,
Increase the friction member diameter to fit large vehicles,
Hydraulic servos 6, 7 capable of securing a large torque capacity on the friction member side and capable of reducing the capacity by increasing the diameter of the friction member, in particular, the cylinder portion 6 constituting the pressure receiving surface thereof
Since the a and 7a are arranged in the rear case, the hydraulic servos 6 and 7 can be exchanged together with the rear case 10B with a small capacity together with the rear case 10B according to the size of the vehicle to be mounted. The rear outer shape does not interfere with the vehicle-side member B. Therefore, according to this configuration, it is possible to change the rear outer shape of the common transmission in accordance with the vehicle to be mounted, thereby improving vehicle mountability.

Further, by disposing hydraulic servos 6 and 7 of the first and third clutches, which require a large capacity by inputting the deceleration torque, in the rear case 10B, the input torque is directly input. This makes it possible to increase the ratio of the reduction in diameter to the reduction in required capacity, as compared with the case where the hydraulic servo 5 of the second clutch, which is originally small in capacity, is disposed in the rear case 10B. Therefore, the size of the rear case 10B can be reduced.

The first and third clutches C-1, C
By sharing the power transmission member 60 for transmitting the deceleration torque to the clutch -3, the hydraulic servo of both clutches can be made compact, and the friction members 63, Since the friction members 63 and 73 of the clutches and the hydraulic servos 6 and 7 can be offset and arranged in accordance with the operation of engaging and disengaging the 73, the two cases of the first and third clutches are provided in the rear case 10B. Since it is possible to adopt an arrangement in which only the hydraulic servos 6 and 7 are accommodated, the rear end of the transmission can be made compact by reducing the diameter of the rear case 10B in accordance with the arrangement.

The transmission of power to one friction member 73 of the first and third clutches is performed by the drum 6 of the other clutch.
2, the hydraulic servo can be made more compact by using common components, and the rear case 10B can be made more compact in accordance with it, so that the rear end of the transmission can be made more compact.

FIGS. 6 and 7 show the effect of the compactness of the rear part of the transmission according to the present embodiment in comparison with the actual cross-sectional shape. FIG. 7 shows the hydraulic servo shown in FIG. It is a thing. As can be seen from comparison between the two figures, for the boss 10b supporting the rear end of the input shaft 11 having the same outer diameter, the common cylinders 60 are used in accordance with the reduction in the capacity of the hydraulic servos 6 and 7. By reducing the pressure receiving area of the first and second pistons 61 and 71, the outer diameter is reduced, and the outer diameter of the rear case 10B is reduced along the outer diameter of the piston 71 and the subsequent drum 72 accordingly. As a result, the outer shape of the rear portion of the transmission main shaft is significantly reduced in size.

By the way, the compactness of the rear portion of the transmission main shaft by replacing the hydraulic servos 6, 7 and the rear case 10B, which is a basic feature of the present invention, can be realized by other forms. Therefore, such an embodiment will be described next. FIG. 8 shows a second embodiment in which the second clutch C-2 and the deceleration planetary gear G1 which are separately arranged before and after the planetary gear set G and the counter drive gear 19 in the first embodiment are moved to the rear of the planetary gear set G.
The embodiment is shown in a schematic cross section. Hereinafter, differences from the first embodiment will be sequentially described.

First, regarding the case 10 accommodating the transmission mechanism, the boss portion 10b of the rear case 10B is extended by the space for disposing the second clutch C-2 in connection with the transfer of the second clutch C-2. Then, the servo pressure oil passage of the front boss 10a is abolished, and a similar servo pressure oil passage 10y is formed in the rear boss 10b.

Next, since the input shaft 11 transmits the input rotation to the second clutch C-2 through the ring gear R1 of the reduction planetary gear G1, the front flange is eliminated, and the rear boss 10b is extended. The shaft length has been shortened by the same amount.

[0052] The planetary gear set G is moved forward to be located substantially at the center of the input shaft 11, and transmits the non-reduced rotation through the second clutch C-2 to the carrier C2 (C3) on the inner peripheral side. Therefore, the size of the power transmission member 13 is slightly increased. And the sun gear S3
Is further supported via a bearing on a power transmission member 13 supported on the input shaft 11 via a bearing. The sun gear S2 is supported by the sun gear S3 via a bearing and is positioned and supported. The carrier C2 (C3) as a third speed change element is connected to the drum 52 of the second clutch C-2 via the power transmission member 13. Further, the ring gear R2 (R3) as the fourth speed change element is connected to the immediately preceding counter drive gear 19
It is connected to.

As for the reduction planetary gear G1, the point that the ring gear R1 is connected to the hub 54 of the second clutch C-2 is a different point.

The second clutch C-2 is disposed between the reduction planetary gear G1 and the hydraulic servos 6 and 7 of the first and third clutches. Specifically, the hydraulic servo 5 of the second clutch C-2 supports the drum 52 on the power transmission member 13 and connects the cylinder 50 to the cylinders of the first and third clutches C-1, C-3. It is arranged on the outer periphery of the power transmission member 60 also serving as And the hub 54
Is connected to the ring gear R1 as described above. Due to the above related arrangement, the friction member 53 of the second clutch C-2, together with the deceleration planetary gear G1, is provided with the first and third clutches C-1 and C- arranged side by side as described above.
The three friction members 63 and 73 are arranged radially superposed on the inner peripheral side.

The second brake B-2 and the one-way clutch F-1 are arranged to have the same positional relationship with the planetary gear set G. However, due to the arrangement space of the cylinder 90 instead of the support 10C, They are arranged with their front and rear positions reversed with their directions.

Finally, since the counter drive gear 19 is located at the forefront of the transmission mechanism by the transfer of the second clutch C-2, it is supported by the front boss 10a instead of the second clutch C-2. , Without providing an extension boss
The inner peripheral side of the gear is directly supported by the front boss 10 a via the bearing 12.

Even with such an arrangement, the rear portion of the transmission, which is the main feature of the present invention, can be made compact. In particular, in the configuration of the second embodiment, the arrangement of the deceleration planetary gear G1 and the second clutch C-2 complicates the handling of the non-deceleration rotation input. Although the diameter cannot be denied, the axial length is obtained by radially overlapping the second clutch C-2 and the reduction planetary gear G1 with the friction members 63 and 73 of the first and third clutches C-1 and C-3. The effect of shortening is large.
This is apparent from a comparison of the positional relationship between the transmission and the vehicle-side member B in FIGS.

For convenience of understanding of the technical concept of the present invention, a gear train using a Ravigneaux type planetary gear set as a speed change element has been described with only two examples in which the arrangement of components is different. By changing the form of the components of the train itself, the planetary gear set can be used in the same way as a combination of a simple planetary gear and a double planetary gear, or a combination of double planetary gears, by devising the connection relationship of their inputs and outputs. Good gear ratio steps are obtained, and the present invention can of course be applied to such cases. Therefore, the present invention is not limited to these embodiments, and various specific configurations can be changed and implemented within the scope of the items described in the individual claims of the claims. Things.

[Brief description of the drawings]

FIG. 1 is an expanded skeleton diagram showing a gear train of a first embodiment of a vehicle automatic transmission to which the present invention is applied.

FIG. 2 is an axial end view showing an actual three-axis positional relationship of the gear train.

FIG. 3 is a chart showing the operation of the gear train and the gear ratios and gear ratio steps achieved.

FIG. 4 is a velocity diagram of the gear train.

FIG. 5 is a sectional view schematically showing only a main shaft portion of the gear train.

FIG. 6 is a sectional view showing in detail a shape of a rear portion of a main shaft portion of the gear train having a specific torque transmission capacity.

FIG. 7 is a cross-sectional view showing in detail a shape of a rear portion of the main shaft portion with a reduced torque transmission capacity.

FIG. 8 is a schematic sectional view of a main shaft portion of a gear train according to a second embodiment of the present invention.

[Explanation of symbols]

 G Planetary gear set (rotating member) G1 Reduction planetary gear (rotating member) S2, S3 Sun gear (shifting element) C2, C3 Carrier (shifting element) R2, R3 Ring gear (shifting element) B-1 First brake B-2 Second C-1 First clutch C-2 Second clutch C-3 Third clutch 6,7 Hydraulic servo 6a, 7a Cylinder unit 10 Case 10A Main case 10B Rear case 11 Input shaft 60 Cylinder (power transmission member) 61 first piston 62 drum 63 friction member 71 second piston 72 drum 73 friction member

Continued on the front page (72) Inventor Kazumasa Tsukamoto 10 Takane, Fujiimachi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Inventor, Masahiro Hayabuchi 10 Takane, Fujiicho, Anjo, Aichi Aisin A・ Within Wu Co., Ltd. (72) Inventor Satoru Kasuya 10th Takane, Fujii-cho, Anjo-shi, Aichi F-Term (within Aisin AW Co., Ltd.) 3J028 EA24 EA25 EB08 EB13 EB31 EB35 EB37 EB54 EB62 EB66 FB06 FC13 FC17 FC20 FC24 FC63 GA03 HA14 HA15 HA24

Claims (4)

[Claims] 1. A speed change mechanism arranged on a main shaft is housed in a case, and the case is divided into a main case housing a main part of the speed change mechanism and a rear case closing a rear end opening of the main case. In the automatic transmission for a vehicle, a friction member of a clutch is disposed on a rear side of a main part of the transmission mechanism housed in the main case and on an outer peripheral side of an appropriate rotating member of the transmission mechanism. Is disposed in a rear case substantially covering a hydraulic servo along an outer shape of a rear end portion thereof. 2. The transmission mechanism comprises: a planetary gear set having four transmission elements; a reduction planetary gear;
The first transmission element of the planetary gear set is connected to the input shaft via a deceleration planetary gear by the first clutch, and the second transmission element is connected to the deceleration planetary gear by the third clutch. Connected to the input shaft via the first shaft and can be locked to the case by the first brake. The third transmission element can be connected to the input shaft by the second clutch and locked to the case by the second brake. A fourth transmission element as an output element; a second clutch disposed in the main case; and a friction member to which the torque amplified by the reduction planetary gear is input. The vehicle automatic transmission according to claim 1, wherein the friction servo is a friction member, and the hydraulic servo is a hydraulic servo that engages the friction member. 3. The hydraulic servo of the first and third clutches includes a first piston inserted inside a common cylinder and a second piston inserted outside, and a common cylinder. Constitutes one of the drums of the first and third clutches, the second piston constitutes the drum of the other clutch, and the friction member of the first and third clutches comprises a shaft. The hydraulic servo of the first clutch is provided on one side of the power transmission member that transmits the reduction torque output from the reduction planetary gear, and the hydraulic servo of the third clutch is provided on the other side of the power transmission member. The vehicle automatic transmission according to claim 2, wherein the automatic transmission is provided. 4. The one of the first and third clutches, wherein the one drum and the other drum are overlapped in the radial direction and are axially movably connected by spline engagement. 4. The automatic transmission for a vehicle according to claim 3, wherein said friction member is disposed between said radially inner drum and said radially outer drum to transmit a deceleration torque.