JPH028540A - Automatic transmission - Google Patents

Abstract

PURPOSE:To enable the torque capacity to be easily adjusted of an automatic transmission by performing a shift N(R) to D actuating the second piston and also the first clutch with the second clutch thereafter the first piston. CONSTITUTION:In the time of a shift N(R) to D, the second piston 35a, fitted into the first piston 30a, is actuated, and the first clutch C1 is actuated with the second clutch C2, thereafter the first piston 30a of the first hydraulic actuator 30 is actuated. In this case, by selecting area ratio of both the pistons 30a, 35a, an automatic transmission 1 enables its torque capacity to be easily adjusted, decreasing a shift shock. While because the second clutch C2 is connected through a hub member 31 engaged with an input member 25, the second clutch C2 prevents its pressure plate from large sliding in the axial direction, being given no unreasonable force. Thus, the shift shock can be reduced.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an automatic transmission, particularly an automatic transmission having a planetary gear and a large number of clutches and brakes. and an automatic transmission having a first transmission path that transmits rotation of the input member to a predetermined gear element via a one-way clutch, and a second transmission path that directly transmits rotation of the input member to the predetermined gear element via a second clutch. .

(B) Prior Art Conventionally, as shown in Japanese Patent Application Laid-open No. 60-95236, a first clutch is connected between a clutch drum connected to the tip of an input shaft and a sun gear on the small diameter side of a Ravigneau planetary gear unit. An automatic transmission has also been devised in which a first transmission path with a one-way clutch and a second transmission path with a second clutch are arranged in parallel.

In the automatic transmission, an engagement spline for the first clutch is formed on the clutch drum, and the drum also constitutes a cylinder of a hydraulic actuator for the first clutch, and a spline is provided in the cylinder to form an engagement spline for the first clutch. A first piston for operating the first clutch is slidably guided. Further, an engagement spline for a second clutch is formed on the first piston, and the first piston constitutes a cylinder of a hydraulic actuator for the second clutch, and a second clutch is formed in the first piston. A second piston for operating the second clutch is fitted therein.

That is, the first clutch is operated only by the first piston, the second clutch is operated only by the second piston, and both clutches are operated independently by their respective pistons.

As a result, the automatic transmission engages both the first clutch and the second clutch from the first forward speed to the third forward speed.
The rotation of the input shaft is transmitted to the small diameter sun gear through the transmission path and the second transmission path.
At the same time, the first brake is activated to stop the large diameter sun gear, and the rotation from the input shaft is transmitted to the carrier to overrun the small diameter sun gear. On this occasion,
This will cause the second clutch and first brake to be switched, but the presence of the one-way clutch in the first transmission path allows the second clutch to be released early, making the shift timing easier when shifting from 3 to 4. It becomes.

Furthermore, during coasting, the first power transmission path becomes incapable of transmitting power due to the intervention of the one-way clutch, so power is exclusively transmitted through the second power transmission path that does not involve the one-way clutch.

(c) Problems to be Solved by the Invention By the way, the torque capacity T of the clutch is determined by P, the hydraulic pressure acting on the piston, A, the area of the piston, r, the average diameter of the clutch friction material, N, the number of friction materials, and The friction coefficient μ of the material
Then, it is expressed as T=μΦPIA·r6N.

In the above-mentioned automatic transmission in which the first piston is the cylinder of the second piston (the same applies to the one according to the present invention), due to its structure, the first clutch and the second clutch are connected to the piston. It is impossible to make the area and the average diameter of the friction material the same, and the different ratios are respectively denoted by m, and the one for the first clutch is given a subscript, and the one for the second clutch is given a subscript 2. When added, AI=A A,= -A r1=r r,=m ・ rT1=
μ・P−A−r−N1 T2=kIImμmPφA・r・N2.

Since the first clutch C1 always acts when moving forward, it is necessary to transmit the maximum engine torque, and the second clutch C2 is required to transmit the engine brake torque, but normally the engine brake torque is (1/4) of the engine's maximum torque is sufficient, and from the standpoint of space and cost, T8=μ・P−A−r−Nl=To... ■T2=−m・μ・P−A− r-N2 = (1/4)TE...■ However,
It is preferable that T E =maximum engine torque.

Further, both the first clutch and the second clutch are engaged during forward movement, that is, during a N→D shift, and the following three engagement orders can be considered.

bawl.

B. Simultaneous image irregularity of the first and second clutches Cr and Ct, second clutch engagement irregularity after engagement of the first clutch C1, engagement of the first clutch after engagement of the second clutch C2, and In the above-mentioned conventional automatic transmission in which the clutch C0 and the second clutch C3 are independently operated by pistons, the torque capacity of the first clutch C1 is T (engine maximum torque), and the torque capacity of the second clutch C2 is (1/4
) TE, therefore, in the case of order i, at the same time TE+
(1/4)TE= (5/4)T, and in the case of sequential entry, first T, then T2, T, → (5/4)
4) TE, and in the case of order C, first T2, then T, and so on (1/4)T → (5/4)TE.

This relationship is illustrated in Figure 4. In order A, a large torque ((5/4) TE) acts at -, so a shift shock occurs when shifting from N to D or R to D. Also, in order C, when starting forward, the small torque capacity of (1/4) TE is insufficient for the clutch to fully engage, resulting in poor starting performance due to poor clutch engagement. In addition to this, there is a risk that clutch slippage may cause problems in clutch durability. Furthermore, the torque capacity T at the start of forward movement is fixed in the forwarding port, resulting in a lack of freedom in design when adapting to the engine and vehicle.

Further, when the second clutch C2 is in the engaged state and the first clutch C1 is engaged (that is, in the case of the above order C),
The second clutch that is spline-engaged with the first piston needs to move in the axial direction together with the first piston, but since transmission torque is acting on the second clutch C2, A large frictional resistance is generated between the crimp plate and the hub spline, and in order to move the first piston against this frictional resistance, the crimp plate must be moved while being forced to move, which has a negative impact on durability. cause problems.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to configure the second piston to actuate the second clutch and also actuate the first clutch, thereby achieving a compact configuration while achieving torque at the start of forward engagement. To provide an automatic transmission in which the capacity can be easily changed and set to suit various vehicles and engines, and the shift shock from N (R) to D can be reduced.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, when shown with reference to FIG. 1, input members (7), (25)
A first transmission path (25) that transmits the rotation of
→C1→32a-4F2→32b→33), and the rotation of the input members (7) and (25) is controlled by the second clutch (C2).
A second gear which is directly transmitted to the predetermined gear element (R1) via
Transmission path (25 → 31 → C2 → 34 → 32b → 33)
In an automatic transmission (1) comprising: an engaging portion (25a) formed on the input member (25), the first
The clutch (C1) of the first clutch (C1) is engaged, and the hub member (31) of the second clutch (C2) adjacent to the first clutch (C+) is slidably engaged; The piston of the hydraulic actuator (30) for clutch operation (
30a) is arranged with the hub member (31) separated from the first clutch (CI), and the piston (30a) of the second clutch operating hydraulic actuator (35)
5a) is disposed facing the second clutch (C2), and based on the movement of the piston (30a) of the first clutch operating hydraulic actuator (30), a to engage and disengage the first clutch (C+), and engage and disengage the second clutch (C2) based on movement of the piston (35a) of the second clutch operating hydraulic actuator (35). At the same time, the first clutch (C1) is engaged and disengaged via the hub member (31) of the clutch.

- For example, as shown in FIGS. 1 and 2, the planetary gear unit (10) consists of a single planetary gear (2) and a dual planetary gear (3),
The sun gears (S) and the carriers (CR) of both of these planetary gears are integrally connected, and the carrier (CR) is connected to the output member (9), and the predetermined gear element is a ring gear of a single planetary gear. (
RI), the input member is a clutch drum (25) fixed to the input shaft (7), and the clutch drum (25) and the ring gear (RI) of the single planetary gear (2) are connected to the first clutch. (C1) and the first one-way clutch (F2)
transmission path and the second transmission path with the second clutch (C2) interposed therebetween, and the sun gear (S)
and the input shaft (7) via the third clutch (C1), and the sun gear (S) is connected to the first brake (B1).
), and furthermore, the ring gear (R2) of the dual planetary gear (3) and the input shaft (7) are connected via a fourth clutch (CO), and the ring gear (R2) is connected to the input shaft (7) through a fourth clutch (CO). The piston (30) of the first clutch operating hydraulic actuator (30) is configured to be locked by the second brake (B2) and the first one-way clutch (F+), and the piston (30
a), and the piston (35a) of the second clutch operation hydraulic actuator (35) is fitted into the first piston (30a).

(E) Function Based on the above configuration, the first hydraulic actuator (30)
Extend only the piston (30a) of the first clutch (
When engaging C1), the torque capacity T1 of the first clutch (cl) according to the present invention is as follows, as in the conventional example: μIIP@A@r@N1=TE...■ Become.

However, the piston (35a) of the second hydraulic actuator (35) is extended to engage the second clutch (C1) and the first clutch (C1) is engaged via the hub member (31).
C2), the total torque capacity Tr of the first clutch (C1) and second clutch (C2) is T r = km μP A r N z + k
μP A r N I...■, and as mentioned earlier, the first clutch (C1) and the second clutch (C2
) in the most compact way, it is necessary to set its torque capacity as in the above formulas ① and ②. Therefore, the above formula ⋯ is as follows: T r = (1/4) T t + k T E
= ((4k + 1) / 4) / T E
... becomes ■. In addition, TI,...Engine maximum torque, k...Ratio of the second piston area to the first piston surface fJIA+ (=A 2 /A I ).

Therefore, at the start of forward movement, that is, when shifting from N (R) to D, the order in which the first and second pistons (30a) and (35a) operate simultaneously, and the cylinder 2 after the first piston (30a) operates. The order ports through which the pistons (35a) operate are (5/4)T.

(A) , Tr:= (5/4) Tr, (B) is the same as the conventional one, but after the second piston (35a) operates, the order in which the piston (30a) of cylinder 1 operates is ''. , ((4+1)/4)T, → (5/4)Ta.

That is, for example, as shown by the solid line ' in Figure 4, (5/4
) Between Tゎ and T, both pistons (30a) and (35
By changing the area ratio (A * / A t ) in a), the torque capacity Tr can be freely selected, and the optimum torque capacity Tr can be set corresponding to various vehicles and engines, and N (R) → Shift shock during D shift can be reduced.

Specifically, the automatic transmission 1 shown in FIG. 2 operates according to the operation table shown in FIG. 3.

That is, in the first speed state (IST), the first clutch (C1) and the second clutch (C8) are in the connected state, and the first one-way clutch (F) and the second one-way clutch (F R) is in the locked state. In this state, the rotation of the input shaft (7) is controlled by the clutch (C2).
), clutch (CI) and one-way clutch (F
, ) to the single planetary gear ring gear (R
1), and the ring gear (R2) of the dual planetary gear is fixed by the one-way clutch (F), so the rotation of the ring gear (R1) is taken out from the carrier (CR) to the output member (9) as a decelerated rotation. be done.

Then, from the neutral state (or reverse state)
When shifting to range (or 2 range, forward range such as Lunge), firstly, based on the N-+D shift signal, hydraulic pressure is supplied to the second hydraulic actuator (35) and the piston (
35a) and engage the second clutch (C2);
Furthermore, hydraulic pressure is supplied to the first hydraulic actuator (30) via the hub member (3) to extend the piston (30a) and apply an engaging force to the first clutch (C8). As a result, torque is first transmitted to the ring gear (R2) with a torque capacity of ((4+1)/4)TE, and then with a torque capacity of (5/4)T, and the vehicle starts smoothly. In addition, the initial torque capacity ((4 + 1)/4)
TE is arbitrarily set by the area ratio k (A2/AI) of both pistons depending on various engines and vehicles. Also, at this time, with the second clutch (C2) engaged,
The first piston (
30a) is extended, but this state has already been reached by the hub member (31).
) is in contact with the first clutch (C1), and the movement of the piston (30a) causes the second clutch (C2
) will not slide in the axial direction.

Furthermore, when shifting from 1st to 2nd speed, the first brake (B,) operates and the sun gear (S) is fixed, but at this time, the first one-way clutch (F,) overruns and the ring gear (R8 ) allows for idling and shifts smoothly. 2
In the high speed state, the second clutch (C2) is released (it is possible to maintain the connected state until the third speed state is completed).
, the rotation of the input shaft (7) is transmitted to the ring gear (
R1), and 2nd speed rotation is output from the carrier (CR) while idling the other ring gear (R2).

Then, when shifting from 2nd to 3rd speed, the first brake (Bl) is released and the fourth clutch (C0) is engaged. In the third speed state, the input shaft (7) passes through the fourth clutch (Co), the first clutch (C,'), and the second one-way clutch (F2) to both ring gears (R
) (R2), and the planetary gear unit (10
) is rotated integrally, and the integral rotation is taken out from the carrier (CR).

Further, when shifting from 3rd to 4th speed, in addition to the engagement of the fourth clutch (CO) and the first clutch (cl), the first brake (B, ) is also operated. At this time, the second one-way clutch (F2) overruns, so that the ring gear (R1) starts to idle but is smoothly shifted.

In the 4th speed state, the rotation of the input shaft (7) is
The overdrive rotation is transmitted to the ring gear (Rl) of the dual planetary gear (3) via the fourth clutch (Co), and the overdrive rotation is extracted from the carrier (CR) while the ring gear (R2) of the single planetary gear (2) idles at high speed. be done.

Note that the above description is about 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 third clutch (C3) and the second brake (B,) are activated,
In this state, the rotation of the input shaft (7) is caused by the sun gear (
S), and reverse rotation is taken out from the carrier (CR) based on the fixation of the ring gear (R2).

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

Note that the above-mentioned symbols in parentheses do not limit equivalent configurations. Furthermore, it goes without saying that the present invention is not limited to the above-mentioned specific example, but can be similarly applied to, for example, the automatic transmission shown in the conventional example.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the 4-speed automatic transmission 1 has a planetary gear unit 10 consisting of a single planetary gear 2 and a dual planetary gear 3.
In addition to connecting the three sun gears S to form an integral structure,
The pinion that meshes with the sun gear S is the long pinion P1.
In addition, both carriers CR are connected to form an integral structure. Then, a first clutch (forward clutch) C1 is connected to an input shaft 7 that transmits power from the engine crankshaft 4 via a lock-up clutch 5 or a torque converter 6.
and the ring gear R of the single planetary gear 2 are connected via the second one-way clutch F2, and the second
It is directly connected to the ring gear R1 via the clutch (forward clutch) C2, and the third
The sun gear S is connected via the clutch (reverse clutch) C3, and the fourth clutch (high clutch) Co
The ring gear R2 of the dual planetary gear 3 is connected via the. In addition, the sun gear S is connected to the first brake (forceful second coast brake) B+, and the ring gear R2 of the dual planetary gear is connected to the second brake (reverse stage first coast brake) B2, and the fixed member It is connected to a first one-way clutch F interposed between the two.

Furthermore, the 4-speed automatic transmission 11 has a transaxle case 12 and a transaxle cover 13, as shown in FIG.
2, C3T, each brake B, , B2 and each one-way clutch Fl, F2 are housed.

Then, attach the tip to the hub part 1 of the transaxle cover 13.
3a, an input shaft 7 is disposed, and the input shaft 7 has a lubricating oil hole 15 formed in its axial center, and horizontal holes 15a, 15b, and 1
5c and 15d are formed. A sleeve shaft 16 is rotatably supported by being fitted onto the input shaft 7, and a sun gear S is formed at the rear end of the sleeve shaft 16, and a drum 17 is formed at the front end. Spline connected. The outer periphery of the drum 17 is a drum for the first brake (second & force brake) Bl, which is a band brake, and the inner periphery is a drum for the third clutch (reverse clutch), which is a multi-disc clutch. The third clutch C3 is a spline for C3, and the third clutch C3 is interposed between a collar 19 connected to the input shaft 7 by a spline. Further, a member 20a that serves as a cylinder of the actuator 20 for the third clutch C3 is fixed to the inner circumference of the drum 17, and a piston 20b is biased by a spring 20c within the cylinder member 2Oa. They are mated.

A boss 21 is rotatably supported by being fitted onto the sleeve shaft 16, and one end of the boss 21 is connected to a common carrier supporting a long pinion P and a chute pinion P2 (see FIG. 1). CR, and the other end is connected to the output gear 9 by a spline. The boss portion of the output gear 9 is rotatably supported by a support wall 12a formed in the case 12 via a bearing 22, and one side of the support wall 12a is connected to a second brake (first coast reverse brake). ) It is the cylinder of the actuator 23 for B2. A second brake B2 consisting of a multi-disc brake is disposed between the outer peripheral surface of the ring gear R2 of the dual planetary gear 3 disposed on the front side of the planetary gear unit 10 and the inner peripheral surface of the case 12.
The brake B2 is controlled by the piston 23a of the actuator 23. Note that the lug portion of the piston 23a extending toward the brake B2 has a comb-teeth shape, and a return spring 23b is interposed between the comb-teeth. Furthermore, the ring gear R2 and the support wall 12
A first one-way clutch F1 is interposed between the outer race of the bearing 22 and the outer race of the bearing 22 fixed to a.

On the other hand, the transaxle cover 1 at the tip of the input shaft 7
A sleeve member 7a is fixed to the housing portion 3, and the sleeve member 7a is attached to the hub portion 1°3a of the cover 13.
The clutch drum 25 is rotatably fitted into the sleeve member 7a, and a clutch drum 25 is fixed to the rear end portion of the sleeve member 7a. A cover member 26 is disposed on the outside of the clutch drum 25 so as to fit the drum 25, and the cover member 26 partially engages with the clutch drum 25 in a spline-like manner. A return elastic body 24 is interposed between both members so that they cannot rotate relative to each other and are slidable by a predetermined amount in the axial direction. Furthermore, a fourth clutch (high clutch) C0 consisting of a multi-plate clutch is disposed at the tip of the cover member 26, and the clutch C0 is connected to the member 27 extending from the ring gear R2 of the dual planetary gear 3. intervening in between. Further, an actuator 29 for the fourth clutch C0 is configured between the clutch drum 25 and the cover member 26, and the actuator 29 is operated through an oil passage in the hub portion 3a and a hole in the sleeve member 7a. Clutch C8 can be controlled by sliding cover member 26 using the supplied hydraulic pressure.

On the other hand, a first piston 3 is located inside the clutch drum 25.
0a is fitted, and a crimp plate of a first clutch (forward clutch) C8 is spline-coupled to the spline 25a on the tip side of the piston 25, and a crimp plate of a first clutch (forward clutch) C8 is spline-coupled to the spline 25a on the tip side of the piston 25. The hub member 31 is engaged with the spline. Further, the clutch plate of the first clutch C8 is connected to the outer race 32 of the second one-way clutch F2 arranged in parallel on the rear side of the gear unit 10.
The inner race 32b of the one-way clutch F2 is connected to the ring gear R8 of the single planetary gear 2 via a connecting piece 33. Further, a second clutch (forward coast clutch) C2 is interposed between the brim member 34 extending from the inner race 32b and the hub member 31. Furthermore, a second piston is provided inside the first piston 30a.
A spring 36 is compressed between the back surface of the piston 35a and a collar provided on the sleeve member 7a. It becomes a common return spring. The clutch drum 25 and the first piston 30a constitute a hydraulic actuator 30 for operating the first clutch 00, and the first piston 30a and the second piston 35a constitute a cylinder,
This constitutes a hydraulic actuator 35 for operating the clutch C3.

Next, the operation of the four-speed automatic transmission 1 will be explained.

In the first speed state, the cover 1 is attached to the actuator 30.
The oil passage formed in the hub portion 13a of No. 3 and the sleeve member 7a
Hydraulic pressure is supplied through the hole in the actuator 30 to extend the piston 30a of the actuator 30 and engage the first clutch CI via the hub member 31. Similarly, hydraulic pressure is supplied to the actuator 35 to extend the piston 30a and engage the first clutch CI through the hub member 31. Extend the second
Clutch C2 is engaged. In this state, the rotation of the input shaft 7 is transmitted to the first clutch CI via the sleeve member 7a and the flange member 25, and the rotation of the input shaft 7 is transmitted to the first clutch CI via the sleeve member 7a and the flange member 25.
1 to the second clutch C2, and is further transmitted from the clutch C8 to the ring gear R1 via the one-way clutch F2 and the connecting piece 33, as well as the clutch C2,
It is transmitted to the ring gear R1 via the inner race 32b and the connecting piece 33. Then, the ring gear R3 of the dual planetary gear 3 is in a fixed state by the first one-way clutch F, and the rotation of the ring gear R1 is transmitted to the carrier CR at a reduced speed while idling the sun gear S.
Furthermore, it is transmitted to the output gear 9 via the boss 21. At this time, a large load torque acts on the transmission system due to acceleration, etc., but it is transmitted through the first transmission path via the first clutch C1 and the second transmission path via the second clutch C2. ,
Maximum engine torque Tr, larger torque capacity (5/
4) Sufficient response can be achieved at Tt.

Then, at the time of N-D shift, the first
and the order in which the second pistons 30a, 35b extend simultaneously;
There is an order in which piston 5a operates, and an order in which first piston 30a operates after second piston 35a operates, but the above-mentioned order may be changed as appropriate to match the engine capacity and vehicle.
For example, if the engine capacity is large for the vehicle, set the order entrance and change T6 → (5/4) T6
With this torque capacity, shift shock during N→D shift can be reduced.

In particular, for the order ′, the torque capacity is ((4 + 1)/4)
T, → (5/4)TE, and the torque capacity Tr when the second piston 35a is activated = ((4+1)/4)T, but the area ratio of both pistons 35a and 30a k (At/At)
It can be set arbitrarily by changing the torque capacity of the automatic transmission, and can be easily adjusted to suit the engine and vehicle.

1. When the first brake B1 is activated from the first speed state, the sun gear S is fixed, the first one-way clutch F is overrun, and the ring gear R2 of the dual planetary gear is idled. Then, the rotation of ring gear R0 from input shaft 7 is taken out to carrier CR as second speed rotation, and further transmitted to output gear 9. At this time, the hydraulic pressure of the actuator 35 is released and the second
Clutch C2 is released and the rotation of the input shaft 7 is exclusively transmitted to the ring gear R8 via the first clutch CI and the second one-way clutch F2 using the torque capacity Tr, or
Alternatively, the second clutch C2 may be maintained in the connected state until the third gear is completed, and the torque may be transmitted to the ring gear R2 at the torque capacity (5/4) TE as in the first gear.

Further, when the first brake B is released from the second speed state and hydraulic pressure is supplied to the actuator 29, the cover member 26 moves to the left in the figure, and the fourth clutch C8
is brought into contact with the tip of the clutch drum 25 to engage the clutch C6. In this state, the rotation of the input shaft 7 is at the first
The transmission is transmitted to the ring gear R1 via the clutch CI and the second one-way clutch F2, and is also transmitted to the ring gear R2 via the clutch drum 25, the cover member 26, and the fourth clutch Co, and the planetary gear unit 10 is integrated. The direct rotation is transmitted to the output gear 9 via the carrier CR. At this time, the amount of overlap between brake B1 and clutch C8 is controlled to be large to prevent both brake B and clutch C8 from being released and the engine revving up, and the second one-way clutch Ring gear Rt due to F2 overrun
By allowing the second one-way clutch F2 to idle and controlling it in the direction of shifting to fourth gear, the second one-way clutch F2
This provides a margin for grip change control and prevents mechanical locking within the transmission.

When the first brake B1 is activated from the third speed state, the sun gear S is fixed, the ring gear R0 is idled at high speed by the second one-way clutch F2, and the rotation of the ring gear R2 is transferred to the carrier CR as an overdrive. and further transmitted to the output gear 9.

In addition, in the reverse range, the actuator 20
Oil pressure is supplied to the actuator 23 to extend the piston 20b and engage the third clutch C3, and at the same time, oil pressure is supplied to the actuator 23 to extend the piston 23a and operate the second brake B2.

In this state, the rotation of the input shaft 7 is caused by the hub 19, the third
The reverse rotation is transmitted to the sun gear S via the clutch C3, the drum 17, and the sleeve shaft 16, and because the ring gear R2 is fixed, the reverse rotation is extracted from the carrier CR and transmitted to the output gear 9.

Furthermore, when the engine brake is activated, in 1st gear, the 2nd
The brake B2 is actuated to fix the ring gear R2, and in the second and third speeds, the second clutch C2 is engaged to connect the input shaft 7 and the ring gear R1 regardless of reverse drive.

Although the above-described 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 of course applicable to other planetary gear units.

(g) As described in detail, according to the present invention, the second piston (
35a) so that the first clutch (C1) is activated together with the second clutch (C8), so when shifting from N (R) to D, the second piston (35a)
After operation, the piston (30a) of cylinder 1 is operated in sequence (8'
), the area ratio of both pistons k(A,
/At) to arbitrarily set the torque capacity (Tr) during operation of the second piston, thereby adjusting the torque capacity of the automatic transmission (11) in accordance with the type of engine and the type of vehicle. It can be easily adjusted, and shift eye trouble during N-D shifting can be reduced.

Further, since the second clutch (C2) is connected to the input member (25) via the hub member (31), the second piston (35a) extends and the second clutch (C2) is connected to the input member (25) through the hub member (31). (C2) is in an engaged state, and even if the first piston (30a) is extended in this state and the first clutch (C4) is engaged, the crimp plate of the second clutch (C2) is There is no significant sliding in the axial direction, and there is no problem with durability due to excessive force being applied to the clutch.

Further, the first clutch (C3) is engaged with the engagement portion (25a) of the clutch drum (25), which is the input member, and the hub member (31) for the second clutch (C2) is engaged. and a first piston (30a) is fitted into the clutch drum (25), and the first piston (30a)
Since the second piston (35a) is fitted inside, the first clutch (C1), the second clutch (C8) and their hydraulic actuators (30) and (35) can be assembled into a compact subassembly. As a result, ease of assembly can be improved, and the entire automatic transmission can be configured compactly, thereby improving mountability on the vehicle W4.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an automatic transmission according to the present invention, FIG. 2 is a schematic view thereof, and FIG. 3 is a diagram showing its operation. , and FIG. 4 is a diagram showing the torque capacity of each order. 1... Automatic transmission 2... Single planetary gear 3 Dual planetary gear 7... Input shaft 9... Output member (gear) 25...
Input member (clutch drum) 25a... Engaging portion (spline) 30... Hydraulic actuator for first clutch operation 30a... (first) piston 31... Hub portion 35... Second Hydraulic actuator for clutch operation 35a... (second) piston CI... first clutch C2...
Second clutch C3...Third clutch
Co...Fourth clutch B1...First brake, B2...Second brake F2...(Second) one-way clutch F,...First one-way clutch S... Sun gear R1...
・Predetermined gear element (ring gear of single planetary gear) R2...Ring gear of dual planetary gear R8...Long pinion P2...Short pinion CR...Carrier

Claims (1)

[Scope of Claims] 1. A first transmission path that transmits the rotation of the input member to a predetermined gear element of the planetary gear unit via a first clutch and a one-way clutch, and a second clutch that transmits the rotation of the input member. and a second transmission path through which transmission is directly transmitted to the predetermined gear element, wherein the first clutch is engaged with an engagement portion formed on the input member, and the first clutch is engaged with the engagement portion formed on the input member. A hub member of a second clutch is slidably engaged adjacent to the clutch of the second clutch, and a piston of the hydraulic actuator for operating the first clutch is engaged with the hub member of the second clutch adjacent to the first clutch. and a piston of the second clutch operating hydraulic actuator is disposed facing the second clutch, and the hub member is moved based on movement of the piston of the first clutch operating hydraulic actuator. The first clutch is engaged and disengaged via the second clutch, and the second clutch is engaged and disengaged through the second clutch operating hydraulic actuator.
An automatic transmission, characterized in that the first clutch is engaged and disengaged via a hub member of the clutch, and the first clutch is engaged and disengaged via a hub member of the clutch. 2. The planetary gear unit includes a single planetary gear and a dual planetary gear, the sun gears and carriers of both planetary gears are integrally connected, and the carrier is connected to the output member, and the predetermined gear element is a single planetary gear. The clutch drum is composed of a ring gear of a planetary gear, and the input member is a clutch drum fixed to an input shaft, and the clutch drum and the ring gear of a single planetary gear are connected to the first clutch and the one-way clutch with the one-way clutch interposed therebetween. The sun gear and the input shaft are connected via the third clutch, and the sun gear is connected by the first brake. Further, the ring gear of the dual planetary gear and the input shaft are connected via a fourth clutch, and the ring gear is configured to be locked by a second brake and a first one-way clutch. , and a piston of the first clutch operating hydraulic actuator is fitted into the clutch drum, and a piston of the second clutch operating hydraulic actuator is fitted into the first piston. Automatic transmission as described.