JPH0272250A - Automatic transmission - Google Patents

Abstract

PURPOSE:To improve the compactness and shift feeling by constituting a hydraulic actuator for operating a clutch by using the space formed from the bottom part of a cup-shaped member and the bottom part of a clutch drum as oil chamber. CONSTITUTION:The oil chamber 7c of a hydraulic actuator 7 is constituted of the bottom part 6b of a clutch drum 6 and the bottom part 10b of a cup- shaped member 10. Therefore, a large piston area can be secured, and the sufficient clutch capacity can be secured even with a relatively small number of clutch plates. Therefore, the compact constitution, in particular, the reduction of length in the axial direction can be schemed, and a lightweight device can be obtained at a low cost. Further, the oil chamber 7c of the hydraulic actuator 7 is arranged inside in the radial direction. Therefore, the influence of the centrifugal force which acts onto the oil can be reduced, and the engagement/ disengagement control of a clutch 3C can be carried out correctly and surely, and the shift feeling can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an automatic transmission, particularly an automatic transmission with a 4-speed automatic transmission mechanism (i* Regarding the hydraulic actuator for use!

(Old Conventional Techniques) Recently, as shown in JP-A-62-93545 and JP-A-62-441344,
We proposed an automatic transmission with a modified 4-speed automatic transmission mechanism consisting of a single planetary gear and a dual planetary gear.

As shown in FIG. 5, the automatic transmission 1' includes a sun gear S of a single planetary gear and a dual planetary gear.
The pinion meshing with the sun gear is a long pinion P1, and the gear unit 2 is provided with a gear unit 2 in which both carriers CR are integrally connected to form an output element, and the input shaft 5 is rotated. is transmitted to the single planetary gear ring gear R1 via the first (forward) clutch C1, the dual planetary gear ring gear R2 is stopped to obtain 1st speed, the sun gear S is stopped to obtain 2nd speed, and this gear is The unit 2 is rotated integrally to obtain the third speed, and the rotation of the input shaft 5 is controlled by the third (overdrive)
The signal is transmitted to the dual planetary gear ring gear R2 via the clutch C3, the sun gear S is stopped, and 4th speed is obtained while overrunning the single planetary gear ring gear R1.

The above-mentioned third (overdrive) clutch C3 is interposed between the clutch drum 6 extending so as to cover the outside of the other clutches C1 and C4 at the outer diameter side portion of the ring gear R1 of the single planetary gear. Furthermore, a hydraulic actuator 7 for operating the clutch C3 is attached to an outer portion of the clutch drum 6.

(c) Problems to be Solved by the Invention In the hydraulic actuator of the above-mentioned automatic transmission 1', the piston member 7a is disposed so as to fit into the outer diameter side portion 6a of the clutch drum 6. The area A becomes narrower, and the latch cannot be pressed with sufficient force. Therefore, in order to obtain the required torque capacity, it is necessary to use a large number of discs in the clutch C3, and it is necessary to form an oil passage 8 communicating with the oil chamber 7c of the hydraulic actuator 97 in the bottom portion 6b of the clutch drum 6. Combined with this, the configuration is disadvantageous in terms of compactness, and is also a cause of increased weight and cost.

In addition, since the oil chamber 7c of the hydraulic actuator 7 is located on the outside in the radial direction, the centrifugal force acting on the oil chamber 7c is large, so that the clutch C
3 is rotating at high speed, a large centrifugal oil pressure is generated in the oil chamber 7c, which may impede proper engagement/disengagement control of the clutch C3 and worsen the shift feel link.

Further, the third clutch C3 is arranged on the inner diameter side of the clutch drum 6 along with the other clutch C1, and has a piston member 7a and a pressing flange member 7d that extend and fit around the clutch drum 6. Therefore, it is necessary to configure the pressing flange portion 7d to wrap around the distal end side of the clutch C3, which increases the axial dimension.

Therefore, the present invention provides a cup-shaped member to cover from the bottom of the clutch drum, and mounts the clutch directly on the cup-shaped member.This improves compactness and meets the requirements for mounting on a vehicle, and improves shift feel. The object of the present invention is to provide an automatic transmission with improved performance.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, as shown in FIG. 1, a planetary gear unit (
2), the input shaft (5) and the predetermined element (R1) of the gear unit
), and a predetermined clutch (C1) that connects the input shaft (5
) and another predetermined element (R2) of the gear unit (2). The hydraulic actuator (9) for operating the predetermined clutch is mounted on the inner diameter side of a clutch drum (6) fixed to the clutch drum (6), and is arranged on the inner diameter side of the clutch drum (6) as a cylinder. A cup-shaped member (1) is provided so as to cover the clutch drum (6) including its bottom (6b) and to be movable only in the axial direction.
0), and the other clutch (C3) is attached to the tip (10a) of the cup-shaped member, and at least the bottom (10b) of the cup-shaped member and the bottom (6b) of the clutch drum
) is used as an oil chamber (7c) to constitute another hydraulic actuator (7) for operating the clutch.

As an example, referring to FIG. 3, the planetary gear unit (2) consists of a single planetary gear (21) and a dual planetary gear (22), and the sun gear (S) of these two planetary gears and the carrier (CR) ) are integrally connected to each other, and the carrier (CR) is further connected to the output member (23).

The predetermined clutch is a second one-way clutch (F2)
The input shaft (5) and the single planetary gear (
21) is a first (forward) clutch (C1) that connects to the ring gear (R1) of the input shaft (5).
and the link gear (R1) to the second (IST&2ND・
3RD coast) clutch, and the sun gear (S) and input shaft (5) are connected via a second (reverse) clutch (C4), and the sun gear is connected to the first (ZND & 4TH) brake. Lock at (B1),
Further, the ring gear of the dual planetary gear is locked by the second (reverse & IST coast) brake (B2) and the first one-way clutch (Fl), and the other clutch is connected to the input shaft (5) and the dual planetary gear (
22) is the third (overdrive) clutch (C3) that connects the ring gear (R2).

(E) Effect Based on the above configuration, when hydraulic pressure is supplied to the hydraulic actuator (9) located on the inner diameter side of the clutch drum (6), the piston member (9a) of the actuator (9) expands to a predetermined ( The first) clutch (C1) is connected. Furthermore, when hydraulic pressure is supplied to the oil chamber (7C) of the hydraulic actuator (7) located outside the clutch drum (6),
The cup-shaped member (10) moves axially to connect the other (third) clutch (C3). Then, the input shaft (5)
The rotation of the other clutch (
C3) and then to another predetermined element (R2) of the planetary gear unit (2). In addition, at this time, the hydraulic actuator (7) has at least its bottom (10b)
is the piston area and exerts a sufficient latch pressing force, and the oil chamber (7C) is on the inner diameter side so that no large centrifugal force acts, and the clutch (C3) is a cup-shaped member that becomes the piston member. (10) is attached to the
It is operated directly by the member (10) itself.

(F) Embodiments Below, embodiments of the present invention will be described.First, an outline of an automatic transmission according to the present invention will be explained with reference to FIG.

The automatic transmission 1 includes a torque converter 31. A 4-speed automatic transmission mechanism 32, a reduction gear 33, and a front differential device 35. An automatic transmission mechanism 32 is disposed, a reduction gear 33 is disposed on a counter shaft 39, and a front differential device 35 is further disposed on front axle shafts 40a, 40b.

The 4-speed automatic transmission mechanism 32 has a planetary gear unit 2 formed by combining a single planetary gear 21 and a dual planetary gear 22, and the gear unit 2 has sun gears S integrally connected to each other and a carrier CR also integrally connected to each other. connected. Further, the carrier CR supports a long pinion P1 that meshes with the sun gear S and a short pinion P2 that meshes with the ring gear R2 (hereinafter referred to as the large ring gear) of the dual planetary gear. Counter drive gear 23 serving as an output element of transmission lll32
or connected. Furthermore, the ring gear R1 (hereinafter referred to as the rate link gear) of the single planetary gear is directly connected via the first (forward) clutch C1 and the second one-way clutch F2, and also via the second (IST & 2ND/3RD coast) clutch C2. , connected to the input shaft 5. In addition, the large link gear R2 is connected to the input shaft 5 via a third overdrive clutch C3, and is connected to the input shaft 5 via a second (reverse & l ST coast) brake B2 and a first one-way clutch F1. It is locked. Furthermore, the sun gear S is connected to the input shaft 5 via a fourth (reverse) clutch C4, and
(2ND & 4TH) is locked by brake B1.

Further, the reduction gear 33 consists of a large gear 41 and a small gear 42 fixed to the counter shaft 39. The large gear 41 meshes with the counter drive gear 23 to become a counter driven gear, and the small gear 42 is connected to the front differential device 35. It meshes with the ring gear 43. Further, the front differential device 35 has a gear mount case 45 that fixes the ring gear 43, and the case 45 serves as a differential carrier that supports a pinion gear 46, and the pinion gear 46 has left and right front axle shafts 40a, 40b, respectively. Side gears 47a and 47b fixed to are in mesh with each other.

Based on the above configuration, the present automatic transmission 1 is configured so that the rotation of the engine crankshaft 36 is directly transmitted to the input shaft 5 via the oil flow of the torque converter 31 or by the lock-up clutch 37, and furthermore, the 4-speed automatic transmission mechanism 32 Then, the speed change rotation is transmitted from the counter drive gear 23 to the reduction gear 33, and from the ring gear 43 via the front differential device 35 to the left and right front axle shafts 40a, 40b.

The four-speed automatic transmission mechanism 32 operates as shown in the operation table of FIG. 4.

That is, in the first speed state (IST), the first clutch C1 and the second clutch C2 are in the connected state, and the first one-way clutch F1 and the second one-way clutch F2 are in the locked state. In this state, the rotation of input shaft 5 is transmitted to small ring gear R1 via clutch C2, clutch C1, and one-way clutch F2, and since large ring gear R2 is fixed by one-way clutch F1, small ring gear The rotation of R1 is taken out from the carrier CR to the counter drive gear 23 as a reduced rotation.

Furthermore, when shifting from 1st to 2nd speed, the first brake B1 is activated and the sun gear S is fixed, but at this time, the first one-way clutch F1 overruns and allows the large ring gear R2 to idle, resulting in a smooth shift. shift. In the second speed state, the second clutch C2 is released, and the rotation of the input shaft 5 is controlled by the first clutch C1 and the second one-way clutch F.
2 to the small ring gear R1, and further, the second speed rotation is output from the carrier CR while causing the large ring gear R2 to idle.

Then, when shifting from 2nd to 3rd speed, the first brake B1 is released and the third clutch C3 is engaged. At this time, if the overlap amount and overlap time between the brake B1 and the clutch C3 are too small, they will return to the 1 state and the tire driving force will increase, causing engine revving, etc. Even if the overlap time is too long and torque is transmitted from the third clutch C3 to the large ring gear R2, the small ring gear R1 will only idle due to the overrun of the second one-way clutch F2, resulting in a mechanical lock. Therefore, when shifting from 2nd to 3rd speed, the speed change is controlled so that care is taken to ensure that the amount of overlap is not too small. And 3
In the high speed state, input is input from the input shaft 5 to both ring gears R1 and R2 via the first clutch C1, second one-way clutch F2, and third clutch C3, and the planetary gear unit 2 rotates integrally. Rotation is carrier C
It is extracted from R.

Furthermore, when shifting from 3rd to 4th speed, in addition to the engagement of the first clutch C1 and the third clutch C3, the first brake B1 is engaged.
is activated. At this time, as the second one-way clutch F2 overruns, the small ring gear R1 begins to idle and is smoothly shifted. In the fourth speed state, the rotation of the input shaft 5 is transmitted to the large ring gear R2 via the third clutch C3, and the overdrive rotation is extracted from the carrier CR while the small ring gear R1 is idling at high speed. Ru.

Note that -E's explanation is for upshifting, but when downshifting, the operation is completely opposite to the above and is similarly smoothly operated.

In addition, in the reverse (REV) range, the fourth clutch C4 and the second brake B2 are activated, and in this state, the rotation of the input shaft 5 is input to the sun gear S.
Reverse rotation is taken out from the carrier CR based on the fixation of the large ring gear R2.

In addition, when engine braking is required, in order to prevent power transmission from being cut off due to overrun of the one-way clutches Fl and F2, the second brake B2 is used in 1st gear, 2nd gear and 3rd gear.
In the case of high speed, the second clutch C2 is operated.

Next, the automatic transmission according to the present invention will be specifically explained with reference to FIGS. 1 and 2.

As shown in FIG. 2, the automatic transmission 1 has an integral case in which a transaxle case 51, a transaxle housing 52, and a rear cover 53 are fixed together, and a torque converter 31.4 is installed in the integral case. An automatic transmission mechanism 32, a reduction gear 1fi33, and a front differential device F35 are housed. The input shaft 5, which is aligned with the engine crankshaft, is divided in the middle and is engaged with each other by splines. A transmission mechanism 32 is provided.

A sleeve shaft 56 is rotatably supported by being fitted onto the input shaft 5. A sun gear S is formed at the rear end of the sleeve shaft 56, and a drum 57 is formed at the front end. Spline connected. The drum 57 has a first brake (2N
A spline for a fourth clutch (reverse clutch) C4, which is a multi-disc clutch, is formed on the inner periphery of the spline. The first brake B1 is interposed between splines formed on the outer circumference of the drum 57 and the inner circumference of the case 51, and the first brake operation hydraulic actuator 59 is connected to an oil pump 55 adjacent to the brake B1.
located on the pump cover. Further, the fourth clutch C4 is interposed between the inner peripheral part of the tram 57 and the hepro 0 fixed to the front input shaft 5a, and the fourth clutch C4 is located between the inner peripheral part of the tram 57 and A member 61a serving as a cylinder of the actuator 6 for clutch C4 of No. 4 is fixedly installed, and a piston is fitted into the cylinder member 60a while being biased by a sublink.

Further, a boss 62 is rotatably supported by being fitted onto the sleeve shaft 56, and the boss 62 has one end connected to a common carrier CR supporting the long pinion P1 and short pinion P2, and the other end It is connected to the counter drive gear 23 by a spline. The drive gear 23
The boss part is rotatably supported by a support wall 51a formed in the case 51 via a tapered roller bearing 63, and one side of the support wall 51a is used for the second brake (reverse & IST coast brake) B2. It serves as a cylinder for the actuator 65. A second brake B2 made of a multi-disc brake is interposed between the outer circumferential surface of the large ring gear R2 of the dual planetary gear 22 disposed on the front side of the planetary gear unit 2 and the inner circumferential surface of the case 51. The brake B2 is controlled by a piston 65a of the actuator 65. Note that the rough portion of the piston 23a extending toward the brake B2 has a comb-teeth shape, and a return spring is interposed between the comb-teeth.

Further, a first one-way clutch F1 is interposed between the large ring gear R2 and the outer race of the bearing 63 fixed to the support wall 51a.

On the other hand, as shown in detail in FIG.
The sleeve member 5b is rotatably fitted onto the hub portion 53a of the cover 53, and the clutch drum 6 is fixed to the rear end portion of the sleeve member 5a. A cup-shaped member 1 is provided on the outside of the clutch drum 6 so as to cover the entire drum including the bottom 6b.
0 is disposed, and the cup-shaped member 10 has its base end 10c fitted into the sleeve member 5b in an oil-tight manner with an O-ring, and its outer diameter side is connected to the clutch drum 6. They are engaged for free movement only in the axial direction. That is, in the embodiment shown in FIG. 2, splines S are formed on a portion of the inner peripheral surface of the cup-shaped member 10 and a portion of the outer peripheral surface of the clutch drum 6, and the splines Sp engage with each other. In the embodiment shown in FIG. 1, a groove 60 is formed on the outer peripheral surface of the tip of the clutch drum 6, and the groove 6C and the spline 1 at the tip of the cup-shaped member are connected to each other.
Relative rotation is prevented by interposing a claw member 67 between it and Oa. Furthermore, a third (overdrive) clutch C3 consisting of a multi-plate clutch is disposed on the spline 10a formed at the tip of the cup-shaped member 10, and the third (overdrive) clutch C3 is connected to the large ring gear R of the dual planetary gear 22.
It is interposed between the collar member 69 extending from 2. Further, the hydraulic actuator 7 for operating the third clutch 03 configures a space between the bottom portion 6b of the clutch drum 6 and the bottom portion tab of the cup-shaped member 10 as an oil chamber 7C.
Hydraulic pressure is supplied to the oil chamber 7c of the actuator 7 through the oil passage a in the hub 53a and the hole in the sleeve member 5a, and the oil pressure causes the cup-shaped member 10 to slide and close the clutch C.
3 can be directly controlled. Note that a wave spring 70 is interposed between the clutch drum 6 and the cup-shaped member 10 via a snap link, and the spring 70 is used to return the cup-shaped member 10, which becomes the piston member for the third clutch C3. Configure the spring. Further, a check ball 78a is installed in the cup-shaped member 10 for discharging the centrifugal hydraulic pressure acting on the oil chamber 7c. Further, a first piston member 9a is fitted inside the clutch drum 6, and a crimp plate of a first latch (forward clutch) C1 is splined on the inner peripheral surface of the front end side of the clutch drum 6. A connecting ring 72 is splined alongside the crimp plate. Further, the clutch plate of the first clutch C1 is a second one-way sandwiched between a thrust washer 74 held by a snap ring for preventing removal of the first clutch C1 and a thrust washer 73 at the tip of the large ring gear R1. clutch F2
A hub member 75a fixed to an outer race 75 of
The inner race of the one-way clutch F2 is spline-engaged with the outer circumferential surface of the small ring gear R1.

Further, a hub member 77 is fixed to the support root 76 that supports the small ring gear R1, and a second (IST&2N
D・3RD Coast) Clutch C2 is involved. Further, a second piston member 79a is fitted inside the first piston member 9a, and the piston member 79a
A spring 80 is compressed between the back surface of the sleeve member 5a and a collar provided on the sleeve member 5a, and thus the spring 80 serves as a common return spring for the first and second piston members 9a, 79a. And the bottom 6 of the clutch drum 6
b The first piston member 19a has an inner surface as a cylinder,
The hydraulic actuator 9 for operating the first clutch 01 is constituted, and the inner surface of the first piston member 9a is used as a cylinder, and the second piston member 79a is used to operate the second clutch C.
A hydraulic actuator 79 for two operations is configured.

Incidentally, the first piston member 9a and the second piston member 79a are provided with tinic balls 78b and 78c for centrifugal hydraulic pressure relief, respectively.

Further, as shown in FIG. 2, the speed reducer 33 is arranged on a counter shaft 39 which is arranged parallel to the input shaft 5, and the counter shaft 39 is provided with roller bearings 81, 82 in the cases 51 and 52. It is rotatably supported via. Further, a small gear 42 is formed on the counter shaft 39, and a large gear 41 is spline-engaged on the Lj shaft 39. The large gear 41 meshes with the counter drive gear 23 of the automatic transmission mechanism 32 to constitute a counter driven gear.

Further, the front differential device 35 has a gear mount case 45 that constitutes a differential carrier.
The case 45 is rotatably supported by the cases 51 and 52 via roller bearings 83 and 85, and
A large ring gear 43 is fixed, and this gear 43 meshes with the small gear 42 to constitute a final reduction mechanism. Further, a pinion gear 46 is rotatably supported within the mount case 45 by a shaft 46a, and left and right side gears 47a and 47b are meshed with the pinion gear 46. These side gears 47a, 47b
are engaged with left and right front axle shafts 40a and 40b, respectively.

Next, the operation of the above embodiment will be explained.

In the first speed state, in the oil chamber of the hydraulic actuator 9,
Hydraulic pressure is supplied through the oil passage C formed in the collar portion 53a of the rear cover 53 and the hole in the sleeve member 5b, and the piston member 9a of the actuator 9 is extended, and the connecting ring 7
2, the first clutch C1 is engaged, and hydraulic pressure is supplied to the hydraulic actuator 79 via the oil path d,
The piston member 79a is extended to engage the second clutch C2. In this state, the rotation of the input shaft 5 is transmitted to the first clutch C1 via the sleeve member 5b and the clutch drum 6, and is also connected to the second clutch C2 via the connecting link 72, and is further transmitted to the second clutch C2 via the coupling link 72. The signal is transmitted from C1 to small ring gear R1 via one-way clutch F2, and directly to small ring gear R1 via clutch C2. Then, the large ring gear R2 of the dual planetary gear 22 or the first one-way clutch F1 is in a fixed state, and the rotation of the small ring gear R1 is transmitted to the carrier CR at a reduced speed while the sun gear S is idling.
Furthermore, it is transmitted to the counter drive gear 23 via the boss 62. The rotation of the drive gear 23 is transmitted to the counter driven gear 41, further decelerated by the small gear 42 and the large ring gear 43, and transmitted to the front differential device 35, where the rotation is transmitted to the left and right front axle shafts 41.
It is transmitted to 0a and 40b.

Then, from the first speed state, when hydraulic pressure is supplied to the hydraulic actuator 59 to operate the first brake B1, the sun gear S is fixed and the first one-way clutch F is activated.
1 overruns and the large ring gear R2 of the dual planetary gear spins idly. Then, the rotation of the small link gear R1 from the input shaft 5 is taken out to the carrier CR as second speed rotation, and further transmitted to the counter drive gear 23. At this time, the hydraulic pressure of the hydraulic actuator 79 is released, the second clutch C2 is released, and the rotation of the input shaft 5 is exclusively transmitted to the link gear R2 via the first clutch C1 and the second one-way clutch F2. be done.

Further, from the second speed state, when the first brake B1 is released and hydraulic pressure is supplied to the oil chamber 7C of the hydraulic actuator 7 through the oil passage a of the collar portion 53a of the rear cover 53 and the hole of the sleeve member 5b. , the cup-shaped member 10 moves to the left in the figure, and the third clutch C3 is brought into contact with the tip of the clutch drum 6 (FIG. 2) or the pawl member 67 (FIG. 1), thereby engaging the third clutch C3. In this state, the rotation of the input shaft 5 is transmitted to the small ring gear R1 via the first clutch C1 and the second one-way clutch F2, and also to the clutch drum 6, the cup-shaped member 10, and the third clutch. The rotation is transmitted to the large ring gear R2 via C3, causing the planetary gear unit 2 to rotate together, and the direct rotation is transmitted to the counter drive gear 23 via the carrier CR.

At this time, the hydraulic actuator 7 is given a large pressing force by the relatively wide piston area formed at the bottom 10b of the cup-shaped member 10, and directly operates the third clutch C3, applying a large operating force to the third clutch C3. It works reliably. Further, during upshifting from 2nd speed to 3rd speed and downshifting from 3rd speed to 2nd speed, the hydraulic actuator 7 is rotating, but the oil chamber 7c of the actuator 7 is located on the relatively small diameter side, To accurately and reliably control a clutch C3 without applying a large centrifugal force and without having the oil pressure significantly affected by the centrifugal force.

Then, when the first brake B1 is operated again from the third speed state, the sun gear S is fixed, the small ring gear R1 is idled at high speed by the second one-way clutch F2, and the rotation of the large link gear R2 is transferred to the carrier CR. It is taken out as an overdrive and further transmitted to the counter drive gear 23.

In the reverse range, hydraulic pressure is supplied to the hydraulic actuator 61 to extend the piston and engage the fourth clutch C4, and at the same time, hydraulic pressure is supplied to the hydraulic actuator 65 to extend the piston 65a and engage the fourth clutch C4. 2 brake B2 is activated. In this state, the rotation of the input shaft 5 is transmitted to the sun gear S via the hub 60, the fourth clutch C4, the drum 57, and the sleeve shaft 56, and because the link gear R2 is fixed, the carrier CR
The reverse rotation is taken out from and transmitted to the counter drive gear 23.

Furthermore, when the engine brake is activated, in 1st gear, the 2nd
Activate brake B2 to fix large ring gear R2,
In addition, in 2nd and 3rd speeds, the second clutch C2 is engaged and the input shaft 5 and small ring gear R are connected regardless of reverse drive.
Connect 1.

In the above embodiment, a simple speed reduction device is disposed on the counter shaft 39, but it is also possible to dispose an underdrive transmission mechanism for switching between direct coupling and underdrive on the shaft, resulting in a 5-speed automatic transmission. It goes without saying that the present invention can be applied, and furthermore, although the above-mentioned embodiments have been described as being applied to a planetary gear unit consisting of a single planetary gear and a dual planetary gear, it is also of course applicable to other planetary gear units.

(g) As described in detail of the invention, according to the present invention, the clutch drum (
6) and the bottom (10) of the cup-shaped member (10).
0b) and the oil chamber (7c) of the hydraulic actuator (7).
Because of this structure, a large piston area can be taken, and a sufficient latch capacity can be secured even with a relatively small number of clutch plates.This reduces the number of clutch plates, making it more compact, especially in the axial direction. Not only can the length be shortened, but also the weight and cost can be reduced based on the reduction in the number of parts. In addition, since the oil chamber (7c) of the hydraulic actuator (7) is arranged radially inward, the influence of centrifugal force acting on the oil in the oil chamber (7c) is reduced, and the engagement and disengagement control of the clutch (C3) is controlled. It is possible to improve shift feeling accurately and reliably. Furthermore, since the clutch (C3) is directly attached to the cup-shaped member (10) which becomes the piston member, there is no need for a wrapping member for operating the clutch, and the length in the axial direction can be shortened accordingly. .

In addition, the clutch is connected to the input shaft (5) that operates during overdrive and the ring gear (R) of the dual planetary gear.
2) is the third clutch (C3) that connects 4
An automatic transmission (1) having a 4-speed automatic transmission mechanism, which can shorten the axial direction of the automatic transmission mechanism part (32).
It is possible to solve the problem of mounting on the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the main parts of an automatic transmission according to the present invention, Fig. 2 is a sectional view showing the entire automatic transmission, Fig. 3 is a schematic diagram of the automatic transmission, and Fig. 4 shows its operation. FIG. FIG. 5 is a sectional view showing the main parts of a conventional automatic transmission. DESCRIPTION OF SYMBOLS 1... Automatic transmission 2... Single planetary gear, 5... Input shaft, 6... Clutch drum 6b... Bottom 7... Hydraulic actuator, 7c... Oil chamber, 9... ...Hydraulic actuator, 9a...Piston member 10...
・Cup-shaped member, 10b...Bottom 21...Single planetary gear 22...Dual planetary gear, 23...Output member (counter drive gear) C1...First ()ward) clutch, C2...・Second (IST&2ND・3RD
Coast) clutch, C3...Third (overdrive) clutch, C4...Fourth (reverse) clutch, Bl...First (2ND & 4T)
H) Tsureki B2...Second (Reverse & IS
T coast) Tsureki Fl...First one-way clutch F2...Second one-way clutch
, S... Sun gear R1... Predetermined element (ring gear of single planetary gear) R2... Other predetermined element (link gear of dual planetary gear), Pl
...Long pinion P2...Short pinion,
CR...Carrier Figure 3 Figure 4

Claims (1)

[Claims] 1. A planetary gear unit, a predetermined clutch that connects an input shaft and a predetermined element of the gear unit, and another clutch that connects the input shaft and another predetermined element of the gear unit. In the automatic transmission, the predetermined clutch is mounted on the inner diameter side of a clutch drum fixed to the input shaft, and the hydraulic actuator for operating the predetermined clutch is arranged on the inner diameter side of the clutch drum as a cylinder. Further, a cup-shaped member is disposed on the clutch drum so as to cover the clutch drum, including the bottom thereof, and is movable only in the axial direction, and the other clutch is attached to the tip of the cup-shaped member, and An automatic transmission characterized in that a hydraulic actuator for operating the other clutch is constructed by using a space formed by at least the bottom of the clutch drum and the bottom of the clutch drum as an oil chamber. 2. The planetary gear unit includes a single planetary gear and a dual planetary gear, and the sun gears and carriers of both planetary gears are integrally connected, and the carrier is further connected to an output member, and the predetermined clutch is a second one-way clutch. a first clutch that connects the input shaft and a ring gear of a single planetary gear via a second clutch; and a first clutch that directly connects the input shaft and the ring gear via a second clutch; 4, the sun gear is engaged with the first brake, the ring gear of the dual planetary gear is engaged with the second brake and the first one-way clutch, and the other clutch is engaged with the first one-way clutch. The automatic transmission according to claim 1, wherein the automatic transmission is a third clutch that connects the input shaft and a ring gear of a dual planetary gear.