JPH02296073A - Hydraulic device in automatic transmission - Google Patents

Abstract

PURPOSE:To perform the specified shift operation correctly and smoothly by forming a drain orifice at the oil pressure chamber of a second hydraulic actuator as well as a cancel oil chamber for centrifugal oil pressure at the back face of a second piston member. CONSTITUTION:The outer diameter part 3a of a first piston member 3 is formed into stepped shape, oil chambers 5a, 7a for a first and a second hydraulic actuators are formed, and a cancel oil chamber 11 for centrifugal oil pressure is disposed. Oil pressure can be thereby fed rapidly even in the first hydraulic actuator 5 as well as drained in the appropriately tuned state. Moreover, a drain orifice is formed at a first piston member 3. The oil that leaks into the oil pressure chamber 7a of the second hydraulic actuator 7 is thereby prevented from being accumulated when the actuator 7 is in the draining state. The centrifugal oil pressure cancelling function of the cancel oil chamber 11 can be therefore positively demonstrated so as to perform the specified upshift and downshift correctly and smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to automatic transmissions installed in automobiles, especially forward
It relates to a hydraulic system suitable for use in an automatic transmission having an automatic speed change mechanism, and more specifically, a centrifugal hydraulic system in a hydraulic actuator in which a second piston member is fitted onto the inner periphery of a first piston member and arranged in an overlapping manner. This invention relates to the structure of a hydraulic canceling device.

(0) Prior Art Recently, the present applicant has developed a forward drive system consisting of a planetary gear unit that combines a single planetary gear and a dual planetary gear, as shown in, for example, Japanese Patent Application Laid-open No. 62-93545 and Japanese Patent Application Laid-Open No. 62-141343. This automatic transmission is equipped with a 3-speed or 4-speed automatic transmission mechanism, and uses common parts and production lines for the 3-speed forward and 4-speed transmission mechanisms, making it compatible with a wide variety of vehicle models without significantly increasing costs. devised.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 63-259253, the present applicant has interposed a fourth clutch (C3) in the one-way clutch (FO) that operates during 3rd and 4th speed shifting,
We devised an automatic transmission mechanism that prevents mechanical locking in the reverse direction.

The automatic transmission mechanism includes a first (forward) clutch that connects and separates the input shaft and the ring gear of the single planetary gear, and a second (reverse) clutch that connects and separates the sun gear and gear common to the input shaft and the planetary gear unit. It has a clutch, and in addition, for the 4-speed automatic transmission mechanism, it has a third (overdrive) clutch that connects and separates the input shaft and the ring gear of the dual planetary gear.

The hydraulic actuator for operating the first clutch has a first piston member that fits into a clutch drum fixed to the input shaft, and the hydraulic actuator for operating the second clutch has a first piston member that fits into a clutch drum fixed to the input shaft. The first piston member has a second piston member that fits into the first piston member.
and the second piston member have an overlapping structure. Further, a hydraulic actuator for operating a third clutch is disposed on the rear side of the clutch drum in the axial direction.

During the first to third forward speeds, hydraulic pressure is supplied to the first hydraulic actuator and the first clutch is engaged, and in this state, the brake and one-way clutch are activated as appropriate to shift to the first speed. , 2nd speed is obtained, and the third clutch (or second clutch) is activated to obtain 3rd speed,
In the fourth forward speed, the hydraulic pressure of the first hydraulic actuator is drained and the first clutch is released, and in this state, hydraulic pressure is supplied to the third hydraulic actuator and the third clutch is released. or engaged. Note that in the forward movement state, the second hydraulic actuator is in the drain state and the second clutch is held in the released state.

(C) Problems to be Solved by the Invention By the way, since the above-mentioned first clutch is engaged in the first to third forward speeds and released in the fourth speed, the first hydraulic actuator connected to the input shaft is 3 → in high speed rotation state
It drains when changing to 4th speed, and is supplied when changing from 4th to 3rd speed, which is also a high speed rotation state. Under such high-speed rotation conditions, centrifugal force acts on the oil in the hydraulic chamber of the hydraulic actuator, and it is difficult to drain the oil from the oil passage located on the inner diameter side with the return force of the return spring. Therefore, a check ball is generally used that can be switched to be seated on or separated from the valve seat by centrifugal force and oil pressure in a hydraulic chamber.

However, even if the check ball is used, the release time of the check ball varies depending on the rotation speed because it is affected by the centrifugal force acting on the check ball and the centrifugal oil pressure in the hydraulic chamber.
Drainage may not occur quickly, and smooth 3rd to 4th gear shift up may be hindered. In addition, if the check hole attempts to remove centrifugal hydraulic pressure quickly, when hydraulic pressure is supplied during high-speed rotation, it will take time for the hydraulic pressure to rise and the clutch slip time will become longer, which will impede a quick 4 to 3 town shift and also cause the clutch to slip. There is a risk that the durability of the board will be reduced.

It is also possible to provide a canceling oil chamber for centrifugal hydraulic pressure on the back surface of the piston member, but in this case, the problem arises because the first screw member and the second piston member are arranged in an overlapping manner. Therefore, it is difficult to install a canceling oil chamber for the first hydraulic actuator, and in particular, in order to completely cancel the centrifugal hydraulic pressure acting on the first piston member, it is difficult to install a canceling oil chamber for the first hydraulic actuator. It is difficult to provide a cancel oil chamber with a similar outer diameter.

On the other hand, the second hydraulic actuator is in a drain state when moving forward, but the first piston member that constitutes the cylinder of the actuator is always in a rotating state! 5, oil leaking from the valve body etc. accumulates in the hydraulic chamber of the hydraulic actuator due to centrifugal force and presses the second piston member. As shown in Fig. 6, the pressing force X due to the centrifugal hydraulic pressure increases according to a quadratic function according to the rotation speed N of the input shaft, but since the return force is constant S due to the return spring, when the rotation speed is above the predetermined rotation speed N. In this case, the second piston member cannot return completely. This may generate drag torque in the second clutch, affect the movement of the first piston member, and impede a quick shift from 3rd to 4th speed.

Therefore, in the present invention, the first piston member has a stepped shape, a drain orifice is formed in the hydraulic chamber of the second hydraulic actuator, and a centrifugal hydraulic pressure corresponding to the first hydraulic actuator is provided on the back surface of the second piston member. It is an object of the present invention to provide a hydraulic system for an automatic transmission that solves the above-mentioned problems by forming a cancel oil chamber for use in the automatic transmission.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIG. A first hydraulic actuator (5) with a first piston member (3) fitted on the inner periphery of the first hydraulic actuator (2), and a second piston member (3) fitted on the inner periphery of the first piston member (2);
6), and a second hydraulic actuator (7) fitted with the first hydraulic actuator (5), the first clutch being engaged and released during high-speed rotation during forward movement. (C1), and the second actuator (7) operates the second clutch (C2) which is released at least when the first clutch (C1) is in the engagement 0 release operating state. In the automatic transmission (A) that is operated, the outer diameter part (3a) of the first piston member (3) has a stepped shape, and the outer circumferential surface (3a+) of the small diameter part thereof is attached to the clutch drum (2). They fit together to form the first hydraulic actuator hydraulic chamber (5a), and the second piston member (6
) to form the second hydraulic actuator hydraulic chamber (
7a), and further includes an outer diameter portion (1) of the cancel plate (9) on the inner peripheral surface (6a) of the second piston member (6).
0) in an oil-tight manner, and the inner diameter part of the plate (
9b) is disposed on the input shaft (1) so as not to be able to move in the axial direction, and a cancel oil chamber (11) for centrifugal hydraulic pressure is formed by the back surface of the second piston member (6) and the cancel plate (9); And the inner diameter side (16) of the cancel oil chamber (11)
A lubricating oil supply hole (13) is provided in the cancel plate (9), and a drain passage (9) is provided in the inner diameter end portion of the cancel plate (9).
a...), and furthermore, the first piston member (3) is formed.
) is characterized in that a drain orifice (15) communicating with the outside from the outer diameter portion of the second hydraulic actuator hydraulic chamber (7a) is formed in the stepped portion (3a3).

As an example, the outer diameter portion (
10), the second piston member inner circumferential surface (6a
) has approximately the same diameter as the outer circumferential surface (3aI) of the small diameter portion of the first piston member (3) that fits into the clutch drum (2).

Further, the diameter of the drain orifice (15) is within a range of 0.2 to 0.5 of the diameter of the supply oil passage (16) that supplies hydraulic pressure to the second hydraulic actuator hydraulic chamber (7a).

Furthermore, the pressure receiving area of the second piston member (6) is larger than the pressure receiving area of the first piston member (3).

Further, a return spring (17) is provided between the back surface of the second piston member (6) and the cancel plate (9).
) is abbreviated.

Further, the drain passage formed in the cancel plate (9) has notches (9a...
).

Further, the cancel plate (9) has a cylindrical portion (9C) extending in the axial direction at its intermediate portion, and a flange portion (20) that hangs down in the inner diameter direction is provided on the cylindrical portion.

Specifically, the first clutch is a forward clutch (C1) that is engaged when moving forward except at the highest speed, and the second clutch is disengaged when moving forward and engaged when moving backward. It is a reverse clutch (C2).

(E) Effect Based on the above configuration, the predetermined gear stage in the forward high speed state,
For example, when upshifting from 3rd to 4th speed, the first hydraulic actuator (5) rotates at high speed together with the input shaft (1).
), the hydraulic pressure is drained from the hydraulic chamber (5a), and the first clutch (C1) is released. At this time, the cancel oil chamber (11) for centrifugal hydraulic pressure is filled with lubricating oil supplied from the inner diameter side oil passage (12), and the cancel oil chamber (11) rotates together with the input shaft. Therefore, the centrifugal hydraulic pressure equivalent to the centrifugal hydraulic pressure acting on the first piston member (3) from the hydraulic chamber (5a) of the first hydraulic actuator is applied to the second hydraulic actuator.
is acting on the back surface of the piston member (6). As a result, the centrifugal oil pressure in the first hydraulic actuator oil pressure chamber (5a) is canceled by the centrifugal oil pressure in the cancellation oil chamber (11), and the oil pressure in the oil pressure chamber (5a) is maintained even though it is in a high-speed rotation state. It is quickly discharged.

In addition, in a forward high speed state, a predetermined gear stage, for example 4→3
When downshifting to high speed, the first hydraulic actuator (
Hydraulic pressure is supplied to the hydraulic chamber (5a) of 5), and the first clutch (C1) is engaged, but at this time as well, the centrifugal hydraulic pressure acting on the hydraulic pressure supplied to the hydraulic chamber (5a) is canceled by the centrifugal oil pressure in the cancel oil chamber (11), and the input shaft (1
Hydraulic pressure is supplied to the hydraulic chamber (5a) in a properly tuned state that is not affected by the rotation speed of the hydraulic chamber (5a). Furthermore,
Based on the hydraulic pressure supplied to the hydraulic chamber (5a), the first piston member (3) and the second screw 1-2 member (6) move in the axial direction to increase the volume of the cancel oil chamber (11). However, at this time, the oil in the cancel oil chamber is drained from the drain passage (9a) on the inner diameter side of the cancel plate (9).
...) is quickly discharged without becoming constricted.

On the other hand, while the second hydraulic actuator (7) is in the drain state during the upshift or downshift to the above-mentioned predetermined gear, oil may leak into the hydraulic chamber (7a) due to leakage in the valve body. be guided. However, the oil is always discharged from the drain orifice (15) and does not accumulate in the hydraulic chamber (7a), and even under the action of centrifugal force, centrifugal hydraulic pressure does not act on the hydraulic chamber (7a). This does not affect the operation of the first hydraulic actuator (5).

In addition, in a predetermined speed change state, for example, in a reverse state,
Hydraulic pressure is supplied to the hydraulic chamber (7a) of the second hydraulic actuator (7), the second clutch (C2) is engaged, and when shifting from the predetermined speed change state to another state, the hydraulic pressure chamber ( 7a) is drained and the second clutch (C2
) releases. In this case as well, the hydraulic chamber (7a)
The centrifugal hydraulic pressure acting on the canceling oil chamber (11) is canceled out by the centrifugal hydraulic pressure in the canceling oil chamber (11), and the second piston member (6) is quickly moved. Also, when hydraulic pressure is supplied to the hydraulic chamber (7a), oil is discharged from the drain orifice (15), but the amount is small compared to the amount supplied, and the second piston member (6) The engagement of the second clutch (C2) is performed without any problem. Furthermore, when draining from the hydraulic chamber (7a), the centrifugal hydraulic pressure acting on the hydraulic chamber (7a) formed from the outer circumference of the second piston member (6) is applied to the inner circumferential surface (6).
Although it cannot be completely canceled by the centrifugal oil pressure in the cancellation oil chamber (11) consisting of (a), it is quickly and reliably drained by discharging the remaining oil from the drain orifice (15).

(f) As described in detail, according to the present invention, the outer diameter portion (3a) of the first piston member (3) has a stepped shape, and the outer peripheral surface (3a 1) of the small diameter portion has a stepped shape. It constitutes the hydraulic chamber (5a) for the hydraulic actuator of No. 1, and the inner circumferential surface of the large diameter part (
3a2) and the second hydraulic actuator hydraulic chamber (7a
), the second hydraulic actuator (7)
A centrifugal hydraulic canceling oil chamber (11) having an outer diameter corresponding to the first hydraulic actuator hydraulic chamber (3a) can be disposed on the back surface of the piston member (6), which allows high-speed rotation state. Even in the first hydraulic actuator (3) to which oil is supplied or discharged in the first hydraulic actuator (3), it is possible to eliminate the influence of centrifugal hydraulic pressure and supply hydraulic pressure reliably and quickly. The oil pressure can always be drained in an appropriate tuning state without any trouble, and during high-speed rotation, for example, upshifting from 3rd to 4th speed and downshifting from 4th to 3rd speed can be performed accurately and smoothly.

Furthermore, a lubricating oil supply hole (13) is provided on the inner diameter side (1b) of the cancel oil chamber (11), and a drain passage (9a...) is formed on the inner diameter portion of the cancel plate (9). The cancellation oil chamber (11) can always be filled with oil, and the centrifugal hydraulic pressure acting on the first hydraulic actuator (5) and the second hydraulic actuator (7) can be reliably canceled, and the cancellation The oil in the oil chamber (11) can be quickly drained from the drain passage (, 9a...) without being squeezed, and the movement of the piston members (3), (6) is not inhibited. Stepped portion of piston member (3) (3C3
), the drain orifice (15) was formed in the second
When the hydraulic actuator (7) is in the drain state,
For example, when moving forward, leaked oil will not accumulate in the actuator hydraulic chamber (7a), and the cancel oil chamber (1
The centrifugal hydraulic pressure canceling effect according to 1) acts directly on the first hydraulic actuator piston member (3) through mechanical connection, so that the centrifugal hydraulic pressure canceling function by the above-mentioned canceling oil chamber (11) can always be reliably exerted. Yes, the second
Even when the hydraulic actuator (7) is drained,
Even if the outer diameter of the hydraulic chamber (7a) is larger than the outer diameter of the canceling oil chamber (11) and the structure is such that centrifugal hydraulic pressure cannot be completely canceled, the drain orifice can be removed from the outer diameter of the hydraulic chamber (7a). The hydraulic pressure can be discharged to the outside through (15) to perform a reliable and quick drain, and a predetermined shift operation, such as a shift from reverse to forward, can be performed reliably and quickly.

In addition, a second
When the inner circumferential surface (6a) of the piston member is made approximately the same diameter as the outer circumferential surface (3al) of the small diameter portion of the first piston member that constitutes the outer diameter portion of the first hydraulic chamber (5a) for the first hydraulic actuator, The centrifugal hydraulic pressure acting on the hydraulic chamber (5a) can be completely canceled out, and the influence of the rotation speed can be completely eliminated. Furthermore, the diameter of the drain orifice (15) is
When set to 0.2 to 0.5 of the diameter of the supply oil path (16),
Hydraulic pressure can be supplied to the second hydraulic actuator (7) without any problems, and the oil that leaks and accumulates during draining can be reliably drained, and the influence of centrifugal hydraulic pressure caused by the accumulated oil can be reliably eliminated. .

Furthermore, by making the first piston member outer diameter portion (3a) have a stepped structure, the pressure receiving area of the second piston member (6) can be made larger than that of the first piston member (3). As a result, for example, when the second piston member operates the reverse clutch (C2) that is engaged when moving backward, even though a large torque acts on the clutch (C2) due to the gear ratio, the second piston member By applying a large pressing force from the piston member (6), the number of friction plates of the clutch can be reduced, and the automatic transmission can be made more compact, particularly in its axial dimension.

In addition, when the return spring (17) is compressed between the back surface of the second piston member (6) and the cancel plate (9), the return spring (17) is prevented from coming out by the cancel plate (9) and its fixation. It can also be used with the snap ring (19), and the cancel plate (
9) has a double-supported structure in which its inner diameter side and outer diameter side are held, and the spring (17) can be held securely. In particular, when the gold (18) is brought into contact with the vertical part (9d) and stepped part (9e) formed on the cancel plate (9) and the gold (18) is held, the axis of the return spring (17) Vertical accuracy in the direction and positioning accuracy in the radial direction can be maintained reliably and well.

Furthermore, if the drain passage is a notch (9a...) formed at multiple locations on the circumference between the cancel plate fixing snap rings (19), the cancel oil chamber (1
By making the inner diameter side of 1) approximately coincide with the inner diameter side of the hydraulic chambers (5a) and (7a), it is possible to maintain a sufficient inner diameter side oil level in the cancel oil chamber (11) corresponding to the hydraulic chambers. , When discharging oil from the cancel oil chamber (11),
A large flow rate can be discharged reliably and quickly from multiple locations around the circumference.

Furthermore, if the cylindrical portion (9C) of the cancel plate (9) is provided with a flange (20) that hangs down in the radial direction, foreign matter such as iron powder that has entered the cancel oil chamber (11) can be removed from the cylindrical portion by centrifugal force. (9C) and is blocked by the flange (20) to prevent it from flowing to the O-ring (10), thereby preventing damage to the O-ring and poor sliding of the piston member (6) due to foreign objects. I can do it.

Note that the numerals in parentheses are for reference and for comparison with the drawings, but do not limit equivalent configurations, and even if the same numerals are used, they do not represent generic concepts in accordance with the scope of the claims. Due to the relationship mentioned above, some names may be different from those of the embodiments shown below.

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

First, an outline of the automatic transmission A to which the present invention is applied will be explained with reference to FIG.
and front axle shafts 42a and 42b, and a torque converter 45 having a lock-up clutch 43 on the input shaft 1 and a four-speed forward automatic transmission mechanism 46.
An underdrive mechanism 47 is supported on the counter shaft 41, and a front axle shaft 42a is supported on the counter shaft 41.
, 42b, a front differential device 49 is supported.

The 4-speed automatic transmission mechanism 46 has a planetary gear unit 52 formed by combining a single planetary gear 50 and a dual planetary gear 51, and the planetary gear unit 52 is constructed by integrally connecting the sun gears S1 and the carriers CR1 of the two planetary gears. The pinion that meshes with the sun gear S1 is the long pinion P.
1. Then, the input shaft 1 and the ring gear R1 (small ring gear) of the single planetary gear 50
are connected via a first (forward) clutch C1, and input shaft 1 and sun gear S1 are connected via a second (reverse) clutch C2. Also,
The sun gear S1 is directly connected and locked by a first brake B1, and its one-way rotation is locked by a second brake B2 via a first one-way clutch F1. Furthermore, the ring gear R2 (large ring gear) of the dual planetary gear 51 is directly locked by the third brake B3, and is locked from rotating in one direction by the second one-way clutch F2. And carrier C
R1 is connected to a counter drive gear 55 supported by a case bulkhead, and this gear 55 becomes an output member of the four-speed automatic transmission mechanism 46. Furthermore, in addition to the above configuration,
A third clutch CO5 that connects the input shaft 1 and the large ring gear R2; the output side member of the clutch CO and the small ring gear R
1, a fourth clutch C3 and a third one-way clutch FO are provided.

Further, the underdrive mechanism 47 has one single planetary gear 57, and a carrier CR3 of the planetary gear and a sun gear S3 are connected via a fifth (direct) clutch C4. Also, Sun Gear S
3 is directly locked by a fourth (underdrive) brake B4, and one-way rotation is locked by a fourth one-way clutch F3. A ring gear R3 is connected to a counter driven gear 56 that meshes with the counter drive gear 55 and becomes an input member of the underdrive mechanism 47, and a carrier CR3 is connected to the counter shaft 41. Further, a reduction gear 59 serving as an output member of the underdrive mechanism 47 is fixed to the counter shaft 41.

Further, the front differential device 49 includes a differential carrier 60 and left and right side gears 61a, 61b, and a ring gear 62 is fixed to the differential carrier 60, which serves as a gear mount case. The ring gear 62 meshes with the reduction gear 59 to constitute a final reduction mechanism, and left and right side gears 61a and 61b are connected to left and right front axle shafts 42a and 42b, respectively.

Next, the 4-speed automatic transmission mechanism 46 in the automatic transmission A
The operation will be explained with reference to FIG.

The rotation of the engine crankshaft 4o is controlled by the torque converter 45
or via the lock-up clutch 43 to the input shaft 1. In the first speed state in the D range, the first clutch C1 is in a poor connection state. In this state, the rotation of the input shaft 1 is transmitted to the small ring gear R1 via the first clutch C1, and in this state, the rotation of the large ring gear R2 is prevented by the second one-way clutch F2. , the common carrier CRI is rotated at a significantly reduced speed in the forward direction while causing the sun gear S1 to idle in the reverse direction, and the rotation is taken out from the counter drive gear 55.

Further, in the second speed state in the D range, the second brake B2 is operated in addition to the engagement of the first clutch C1. Then, rotation of the sun gear S1 is stopped by the operation of the first one-way clutch F1 based on the brake B2, and therefore, the rotation of the small ring gear R1 from the input shaft 1 is caused to rotate the carrier CRI in the positive direction while causing the large ring gear R2 to idle in the positive direction. The rotation is decelerated in the direction of the counter drive gear 55.
It is taken out as a 2nd speed. Note that during the 1->2 shift, the second one-way clutch F2 is switched from the locked state to the overrun state, and shifts smoothly without causing any shift shock due to clutch switching.

In the third speed state in the D range, the third clutch CO and the fourth clutch C3 are connected from the second speed state. Then, the information is transmitted from the input shaft 1 to the small ring gear R1 via the first clutch C1 and to the large ring gear R2 via the third clutch CO, and the planetary gear unit 52 rotates integrally, so that the direct rotation is transferred to the counter. The signal is transmitted to drive gear 55.

Note that during the 2->3 shift, the first one-way clutch F1 is switched from the locked state to the overrun state, and shifts smoothly without causing any shift shock due to clutch change. In addition, in the third speed state, the fourth clutch C3 is connected together with the third clutch CO, and the rotation of the input shaft 1 is controlled by the third clutch CO1, the fourth clutch C3, and the third one-way clutch FO. The rotation of the input shaft 1 is also transmitted to the small ring gear R1 through the path.

When upshifting from 3rd speed to 4th speed in the D range, first clutch C1 is released. In this state, rotation is exclusively transmitted to the small ring gear R1 through a path via the third clutch CO1, the fourth clutch C3, and the third one-way clutch FO, and in this state, the rotation is transmitted to the small ring gear R1 through the path exclusively via the third clutch CO1, the fourth clutch C3, and the third one-way clutch FO. is activated. Then, the sun gear S1 is also stopped for reverse rotation, and the large ring gear R, which is transmitted from the input shaft 1 via the third clutch CO, is stopped.
During rotation 2, the one-way clutch FO overruns and the small ring gear R1 idles at high speed, while the carrier CRI
is taken out as an overdrive rotation. At this time, the first clutch C1 is in the released state and the gears are shifted under the action of the third one-way clutch FO, so that the shift is performed smoothly without causing a shift shock due to the clutch change.

Furthermore, in the engine brake operating state such as 3rd range, 2nd range, or lunge, the third brake B3 operates in 1st gear to stop the large ring gear R2 against reverse rotation, and also in 2nd gear. At this time, the first brake B1 is operated to stop the sun gear S1 even in reverse rotation.

In the reverse range, the second clutch C
2 is connected, and the third brake B3 is activated.

In this state, the rotation of the input shaft 1 is transmitted to the sun gear S1 via the second clutch C2, and in this state, the large ring gear R2 is fixed by the operation of the third brake B3. While the ring gear R1 is being reversed, the carrier CR1 is also reversed, and the reverse rotation of the carrier is taken out by the counter drive gear 55.

On the other hand, the underdrive mechanism 47
When the sun gear S3 is stopped by the fourth one-way clutch F3 and/or the fourth one-way clutch F3, the rotation from the counter driven gear 55 is transferred from the ring gear R3 to the carrier CR3.
It is extracted as a deceleration (underdrive) rotation. Further, when the fifth brake B4 is released and the fifth clutch C4 is engaged, the carrier CR3 and the sun gear S3
are integrated, and direct rotation is taken out to the counter shaft 41.

And automatic transmission 11A is 4-speed automatic transmission 1fi! t4
The forward four-speed transmission of No. 6 and the deceleration and direct connection of the underdrive mechanism 47 are appropriately combined to obtain a predetermined speed, and the rotation is transmitted to the front differential device 29 via the reduction gear 59 and the ring gear 62. The signal is transmitted to the left and right front axle shafts 42a and 42b. for example,
The 4-speed automatic transmission mechanism 46 and the underdrive mechanism 47
The combination is to set the underdrive mechanism 47 to the deceleration state and operate the 4-speed automatic transmission mechanism 46 to set the power mode,
And the underdrive mechanism 47 is directly connected to operate the 4-speed automatic transmission mechanism 46 to set the economy mode.
The underdrive mechanism 47 may be used as a mode switching means, or the underdrive mechanism 47 may be set to extra low or high to operate in special cases. It is conceivable to insert the speed between the two speeds, resulting in five forward speeds.

Next, an embodiment of the automatic transmission A described above will be described with reference to FIG.

The automatic transmission A has an integrated case consisting of a transaxle case 65, a transaxle housing (not shown), and a rear cover 66, and the case includes an input shaft 1.
, a ring gear mount case 6 that serves as a differential carrier for the counter shaft 41 and the front differential device 49.
0 (see FIG. 4) is rotatably supported. On the input shaft 1 is a torque converter 45 (see Figure 4).
and a four-speed automatic transmission mechanism 46 are disposed, and an underdrive mechanism 47 is disposed on the counter shaft 41. Further, the transaxle case 65 is provided with a part body (not shown) covered with a side cover.

The 4-speed automatic transmission mechanism 46 includes a brake section (not shown), an output section 67, a planetary gear unit 52, and a clutch section 69, which are arranged in this order toward the rear in the axial direction from the engine crankshaft 4o. An oil pump (not shown) is disposed between the input shaft 1 and the torque converter, and six hollow shafts are fitted onto the input shaft 1 and rotatably supported.

The planetary gear unit 52 includes a single planetary gear 50 and a dual planetary gear 51 (see FIG. 4), and the single planetary gear 50 supports a sun gear S1, a ring gear R1, and a binion P1 that meshes with these gears, which are formed on a hollow shaft 69. The dual planetary gear 51 includes a sun gear S1, a ring gear R2, and a ring gear R2 formed on a hollow shaft 69.
qtL consists of a carrier CR1 that supports a first pinion P1 that meshes with a sun gear S1 and a second pinion P2 that meshes with a ring gear R2 so as to mesh with each other. Both of these planetary gears are composed of a sun gear S1 or a single gear having the same number of teeth formed on the hollow shaft 69, and the carrier CRI is integrally constructed, and the pinion P1
consists of an integrated long pinion.

On the other hand, the output section 67 has a counter drive gear 55 located approximately in the center of the 4-speed automatic transmission mechanism 46, and the counter drive gear 55 is connected to the axle case 65.
It is rotatably supported by a partition wall 65a formed in
is connected to. Furthermore, the outer race of the bearing 70 is spline-engaged and fitted to the inner peripheral surface of the case partition 65a, and a second one-way clutch F2 is attached to the outer peripheral surface of the race extension, and a ring gear R2 is attached to the outer race of the bearing 70. A third brake B3 is interposed between the outer periphery and the axle case 65. Further, a third brake hydraulic actuator 71 is installed on one side of the case partition 65a, and a piston member 72 of this actuator extends in the axial direction in a comb-like shape to operate the third brake B3, and also operates the third brake B3. A return spring 75 is compressed in the .

As shown in detail in FIG. 1, the clutch section 69 is
It includes a first (forward) clutch C1 and a second (reverse) clutch C2, and is located at the rear end of the 4-speed automatic transmission mechanism 46 and housed in the transaxle rear cover 66 portion. In addition, the input shaft lf&end has a swollen diameter portion 1a, and a cover 6 is attached to the swollen portion 1a.
The sleeve portion 1b is fitted over the central hub portion 66a of the sleeve 6.
is fixed thereto, and a clutch drum 2 is integrally connected to the sleeve portion 1b. Further, a first piston member 3 is fitted to the clutch drum 2 by a spline so as to be slidable only in the axial direction, and a second piston member 6 is fitted to the first piston member 3. ing.

The first piston member 3 has a stepped outer diameter portion 3a, and an O-ring 76 is held on the outer circumferential surface 3a+ of the small diameter portion, and the first piston member 3 is connected to the clutch drum 2.
The hydraulic chamber 5a of the hydraulic actuator 5 for the clutch C1 is formed. Moreover, the large diameter inner circumferential surface 3a of the first piston member 3.

An O-ring 77 held on the outer circumferential surface of the second piston member 6 is fitted, and between the back surface of the first piston member 3 and the second piston member 6, the first hydraulic actuator The hydraulic actuator 7 for the second clutch C2 has a larger outer diameter and therefore a larger pressure receiving area than the hydraulic chamber 5a.
A hydraulic chamber 7a is formed. Further, the first piston member 3a has a corrugation portion 3b on the further distal end side, and the outer diameter side of the corrugation portion 3b is connected to a spline groove 2 formed on the inner circumferential surface of the outer diameter portion of the clutch drum 2.
a, and two outer friction plates and a backup plate of the second clutch C2 are engaged with the inner diameter side of the corrugation portion 3b in a manner such that they are prevented from slipping out. The two inner friction plates of the second clutch C2 are engaged with splines formed on the outer circumference of a flange member 79 fixed to the tip of the hollow shaft 69. C
2 is operated at the outer peripheral tip portion of the second piston member 6. It should be noted that due to the axial movement of the first piston member 3, the second piston member 6 also moves, or the second clutch C2
Since is fitted into the corrugation portion 3b of the first piston member, the second clutch C2 also moves in the same way, and there is no change in the relative positional relationship between the second piston member 6 and the second clutch C2. do not have. Further, the outer friction plate and the backup plate of the first clutch C1 are engaged with the tip of the spline groove 2a of the clutch drum 2 in a manner that prevents them from coming off.
Further, the inner friction plate of the clutch C1 engages with a spline formed on the outer periphery of a lug 80 extending from the small ring gear R1 (see FIG. 2).

A cancel plate 9 is fixed to the sleeve portion 1b on the back side of the second piston member 6 with a snap ring 19, and an O-ring 10 held on the outer circumferential surface of the cancel plate 9 is fixed. Second
The first hydraulic actuator 3 and the second hydraulic actuator tough are fitted on the inner circumferential surface 6a of the piston member 6 in an oil-tight manner, and on the back surface of the cancel plate 9 and the second piston member 6. It constitutes a cancel oil chamber 11 for the centrifugal hydraulic pressure that acts. The inner circumferential surface 6a of the second piston member 6, which is the outer diameter of the cancel oil chamber, has approximately the same diameter as the small diameter outer circumferential surface 3a+, which is the outer diameter of the first hydraulic actuator hydraulic chamber 5a. Therefore, the cancel oil chamber 11 almost completely cancels out the centrifugal oil pressure acting on the oil pressure chamber 5a.

Further, the inner diameter portion 9b of the cancel plate 9 has a gap 9a between it and the sleeve portion 1b, and notches 9a are formed between the snap ring 19 and the snap ring 19 at four locations on the circumference, and these gaps 9al and , and the notch 9a constitute a drain passage for quickly draining the oil in the cancel oil chamber 11. Further, the cancel plate 9 vertically stands up from the inner diameter portion 9b to form a vertical portion 9d, is further bent to form a stepped portion 9e, and forms a cylindrical portion 9C extending in the axial direction. It further extends in the outer diameter direction and holds the O-ring 10. Further, a flange portion 20 is formed on the inner circumferential surface of the cylindrical portion 9c so as to hang down in the inner radial direction.
0 constitutes a weir that prevents foreign matter such as iron powder stuck to the inner peripheral surface of the cylindrical portion 9c from moving toward the O-ring due to centrifugal force. Further, a return spring 17 is provided between the back surface of the first piston member 6 and the cancel plate 9.
is compressed, and the receiver of the spring 17 is connected to the metal fitting 1.
8 is the vertical part 9d and stepped part 9 of the cancel plate 9
It is supported in contact with e. As a result, the return spring 17 is reliably supported by the double-supported cancel plate 9 and by the common snap ring 19, and the vertical accuracy in the axial direction is maintained by the vertical portion 9d, and further by the stepped portion 9e. Radial positioning accuracy is maintained.

On the other hand, the outer diameter stepped portion 3a of the first piston member 3
3 is formed with a drain orifice 15 that communicates with the outside from the outer diameter portion of the hydraulic chamber 7a for the second hydraulic actuator, and a supply oil passage 16 to the hydraulic chamber 7a is formed in the sleeve portion 1b. has been done. The relationship between the supply oil passage 16 and the drain orifice 15 is such that the flow rate of the drain orifice 15 is smaller than that of the supply oil passage 16 by a predetermined amount, for example, a diameter of 0.2-0.
It is set within the range of 5, preferably 0.4 sheets. Further, a communication hole 81 is formed in the clutch drum 2 corresponding to the drain orifice 15, and the oil from the drain orifice 15 is discharged to the outside. A similar drain orifice 82 is also formed in the clutch tram 2, and the orifice 82 communicates the outer diameter portion of the first hydraulic actuator hydraulic chamber 3a with the outside at a predetermined flow rate.

On the other hand, the present 4-speed automatic transmission mechanism 46 includes the following devices in addition to the parts common to the above-mentioned 3-speed automatic transmission mechanism.

That is, the sleeve support member 27 is fitted into the annular hub portion 66a of the rear cover 66.
The cylinder member 21 is connected to the cylinder member 21 via the needle bearing 31.
The inner diameter portion 21a is rotatably inserted. Further, a piston member 22 is fitted into the cylinder member 21 in an oil-tight manner to constitute a third hydraulic actuator 23.

Further, the engaging portion 2 protrudes in the outer radial direction of the cylinder portion 21.
1b engages with a spline-like slit 85a of an axially extending drum member 85, and the drum member 85 is radially and axially positioned and connected to the cylinder member 21, and slit 8
The outer friction plate and the backup plate of the third clutch CO are engaged with the third clutch 5a, with only the rotational direction being blocked.

Furthermore, as shown in FIG. 2, the front end of the drum member 85 is engaged with the outer friction plate and backup plate of the fourth clutch C3, and is further connected and fixed to the large link gear R2. . The inner friction plate of the third clutch CO is an outer circumferential spline 2 formed on the clutch drum 2.
c (see Figure 1), and the inner friction plate of the fourth clutch C3 is formed on the outer circumferential surface of the outer race 86 of the third one-way clutch FO attached to the outer circumferential surface of the small ring gear R1. (See Figure 2). Further, a tube member 87 is interposed between the front end backup plate of the third clutch CO and the rear end backup plate of the fourth clutch C3. They are integrally operated based on the actuator 23.

The third piston member 22 is a piston portion 22.
a, It has a cylinder part 24 extending to the back side and a clutch pressing part 22b extending in the outer diameter direction, and the cancel plate 25 is prevented from coming out by a snap ring 35 on the cylinder member inner diameter part 21a on the back surface of the piston member 22.・Supported. The cancel plate 25 is 1
It is formed by bending a sheet of steel plate by press working, has a stepped part 25a on its inner diameter part, further has a vertical part 25a rising vertically, and has an X-shaped cross section etc. on its outer diameter part. O-ring holding part 25c that holds the O-ring 28
is formed. By fitting the O-ring 28 into the inner circumferential surface 24a of the cylinder portion of the piston member in an oil-tight manner, cancel oil for centrifugal hydraulic pressure for the third hydraulic actuator 23 is supplied to the back surface of the piston member 22 and the cancel plate 25. It constitutes a chamber 26. Note that the inner circumferential surface 24a of the cylinder portion forming the outer diameter of the cancel oil chamber 26
has approximately the same diameter as the outer peripheral surface of the piston portion 22a that constitutes the outer diameter of the hydraulic chamber 23a of the hydraulic actuator 23, and the cancel oil chamber 26 is set to almost completely cancel out the centrifugal hydraulic pressure acting on the hydraulic chamber 23a. ing. Further, a return spring 32 is compressed between the back surface of the piston member 22 and the cancel plate 25, and a metal fitting 33 of the spring 32 is brought into contact with the vertical portion 25a and stepped portion 25b of the cancel plate.・Supported. As a result, the return spring 32 is reliably supported by the cancel plate 25 having a double-sided structure and by the common snap ring 35, and the vertical portion 2
The vertical accuracy in the axial direction is maintained by the stepped portion 25a, and the positioning accuracy in the radial direction is further maintained by the stepped portion 25b.

Further, an oil passage 89 branched from a lubricating oil passage 87 is formed in the rear case cylindrical hub portion 66a (see Fig. 3).
A small lubricating oil supply hole 29 is formed in the sleeve support member 27 in communication with the oil passage 89 . Further, an oil passage 30 facing the small hole 29 and having a larger cross-sectional area than the small hole 29 is formed in the inner diameter portion 21a of the cylinder member.

In addition, in FIG. 1, the reference numeral 90 is a sensor that detects the rotation speed of the input shaft 1.

On the other hand, the underdrive mechanism 47 has one single planetary gear 57, as shown in FIG.

Further, a counter driven gear 56 is rotatably supported on the counter shaft 41 via a bearing 91, and a reduction gear 59 (see FIG. 4) is fixed on the shaft 41. And ring gear R3 of planetary gear 57
is connected to the counter driven gear 56, and the carrier CR3 supporting the pinion P3 is integrally formed with the counter shaft 41 bulging in the outer radial direction. Further, the sun gear S3 is formed on a hub 92 rotatably supported on the shaft 41, and a drum 9 fixed to the outer diameter of the hub.
3, a fifth brake B4 made of a band brake is engaged on its outer peripheral surface. Further, a fifth clutch C4 is interposed between the inner peripheral surface of the drum 93 and a hub fixed to the carrier CR3, and a piston member is fitted into the hub 92 adjacent to the clutch C4. This constitutes a hydraulic actuator 95 for clutch C4. Furthermore, a fourth one-way clutch F3 is interposed between the extension of the hub 92 and the case 65.

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

In the first forward speed state, hydraulic pressure is supplied to the hydraulic chamber 5a of the first hydraulic actuator 5 through an oil passage formed in the rear cover 66. Then, the first piston member 3 uses the clutch drum 4 as a cylinder and the return spring 17
and engages the first (forward) clutch C1. In this state, the rotation of the input shaft 1 is transmitted to the small ring gear R1 via the clutch drum 2 and the first clutch C1, and the large ring gear R2 is locked by the second one-way clutch F2. Together,
First speed rotation is taken from carrier CRI. In addition, when the engine brake is activated, the third brake B3 is activated,
Directly locks small ring gear R1. And the rotation is
As previously explained with reference to the schematic diagram in FIG. The signal is then transmitted to the left and right front axle shafts 42a, 42b.

In addition, in the second forward speed state, hydraulic pressure is supplied to a hydraulic actuator (not shown) to operate the second brake B2. Then, the sun gear S1 is stopped via the first one-way clutch F1 and the hollow shaft 69, and the first clutch C
The rotation of small ring gear R1 through gear 1 is taken out from carrier CR1 as second speed rotation, as described above. Note that when the engine is in second gear and engine braking is required, the first brake B1 is engaged to directly fix the sun gear S1.

In the third forward speed, in addition to supplying hydraulic pressure to the hydraulic actuator 5 for the first clutch C1, a third
Hydraulic pressure is supplied to the hydraulic actuator 23 to move the piston member 22 against the return spring 32, and the clutch pressing portion 22b engages the third (overdrive) clutch CO. 4th
Clutch C3 is engaged. As a result, the rotation of the input shaft 1 is transmitted to the large ring gear R2, and the rotation of the input shaft 1 is transmitted to the first clutch C.
Small ring gear R1 via the first and fourth clutches C3
Together with the rotation of the gear unit 52, the direct rotation of the gear unit 52 is taken out from the carrier CR1.

At this time, lubricating oil is introduced into the centrifugal hydraulic canceling oil chamber 26 via a lubricating oil passage and a small hole 29 and an oil passage 30, and the oil chamber 26 is filled with oil. The chamber 26 rotates together with the hydraulic actuator 23.

Therefore, even though hydraulic pressure is supplied during rotation of the hydraulic chamber 23a of the hydraulic actuator 23, the centrifugal hydraulic pressure acting on the hydraulic chamber 23a is canceled by the centrifugal hydraulic pressure acting on the canceling oil chamber 26, and the rotational speed is reduced. The oil pressure in the oil pressure chamber 23a increases in a proper tuning state without being affected. Further, the outer diameter 24a of the cancel oil chamber 26 is the same as the outer diameter of the hydraulic chamber 23a, and the oil level on the inner diameter side of the cancel oil chamber 26 is filled up to the inner diameter part 21a of the cylinder member, similar to the hydraulic chamber 23a. Therefore, the cancel oil chamber 26 completely cancels the centrifugal oil pressure in the oil pressure chamber 23a. Furthermore, the large ring gear R2 rotates at a lower rotation speed than the input shaft 1 in 2nd gear, but when the third clutch CO starts to engage, the large ring gear R2 rotates at a rotation speed of about 2 to become integrated with the input shaft 1. Rapidly increases speed to double the rotation speed. Therefore, the hydraulic actuator 23 integrated with the large ring gear R2 also rapidly increases its rotation speed, but as described above, the cancel oil chamber 26
Since the centrifugal hydraulic pressure in the hydraulic chamber 23a is completely canceled by this, the hydraulic pressure in the hydraulic chamber 23 rises smoothly regardless of the above-mentioned rapid change in rotational speed, and the clutch CO is engaged smoothly and reliably. . Furthermore, due to the sudden speed increase of the hydraulic actuator 23, the inner diameter portion 21 of the cylinder member
The load on the needle bearing 31 that supports the needle a increases rapidly, but due to the axial movement of the piston member 22, the oil in the cancel oil chamber 26 is discharged through the oil passage 30, and Since the supply hole 29 has a significantly smaller diameter, the oil discharged from the oil passage 30 is forcibly sent to the bearing 31, sufficiently lubricating the bearing 31, and preventing the bearing 31 from being subjected to sudden loads. The inner diameter portion 21a is reliably supported regardless of the increase in the inner diameter portion 21a. In addition, since the oil discharged from the cancel oil chamber 26 is quickly discharged from the oil passage 30 without being throttled, the piston member 22
does not interfere with smooth movement.

On the other hand, when downshifting from the third forward speed to the second speed, the hydraulic pressure in the hydraulic chamber 23a for the third hydraulic actuator 23 is drained. At this time, as described above, since the centrifugal oil pressure in the hydraulic chamber 23a is completely canceled by the cancel oil chamber 26, the piston member 22 is quickly returned by the return spring 32 and is not affected by changes in the rotation speed. To quickly and surely release a third clutch CO without any problem.

Furthermore, before upshifting to 4th forward gear, first
The first clutch C1 is released by draining the hydraulic actuator 5 for the first clutch C1. At this time, a large centrifugal oil pressure is acting on the oil pressure chamber 5a of the actuator 5 due to the high speed rotation directly connected to the input shaft 1, but the centrifugal oil pressure is applied to the centrifugal oil pressure canceling oil chamber 11 which rotates at high speed together with the actuator 5. Since this is canceled by the centrifugal hydraulic pressure of the oil stored therein, the first piston member 3 and the second piston 6 are quickly moved toward the clutch drum 2 by the return spring 17. Therefore, since the hydraulic actuator 5 for the first clutch C1 contracts quickly, even when the centrifugal hydraulic pressure is acting strongly due to the high speed rotation of the hydraulic actuator 5, which is the time of upshifting to the fourth forward speed, The first clutch C1 is immediately released without being equally affected by the centrifugal oil pressure.

Further, the cancel oil chamber 11 is filled with lubricant introduced from a lubricant supply oil passage 13 formed in the sleeve portion 1b, and its outer diameter matches the outer diameter of the hydraulic chamber 5a. At the same time, the inner diameter side oil level is almost completely filled to the level of the gap 9a, and the centrifugal oil pressure acting on the hydraulic chamber 5a is almost completely canceled. Furthermore, even if the second hydraulic actuator 7 is in the drain state,
Although leakage oil from the valve body etc. is guided to the hydraulic chamber 7a by centrifugal force, the leakage oil is discharged from the drain orifice 15 and does not accumulate in the hydraulic chamber 7a.
The second piston member 6 is kept in direct contact with the back surface of the first piston member 3, and the centrifugal hydraulic pressure canceling function by the canceling oil chamber 11 always acts directly on the first hydraulic actuator 5, and the hydraulic pressure canceling function by the canceling oil chamber 11 always acts directly on the first hydraulic actuator 5. To completely and reliably eliminate the influence of centrifugal hydraulic pressure when draining from the In addition,
When the oil is discharged from the hydraulic chamber 5a, the oil is also discharged from the drain orifice 82 located on the outer diameter of the hydraulic chamber 5a, thereby quickly and reliably draining the oil from the hydraulic chamber 5a.

On the other hand, when downshifting from 4th speed to 3rd speed in the forward state, hydraulic pressure is supplied to the hydraulic chamber 5a of the first hydraulic actuator 5, and the first clutch C1 is engaged. At this time, as in the case described above, the centrifugal oil pressure acting on the oil pressure supplied to the oil pressure chamber 5a is completely canceled by the centrifugal oil pressure acting on the cancel oil chamber 11, without being affected by the rotation speed of the input shaft 1. Hydraulic pressure is supplied to the hydraulic chamber 5a in an appropriate tuning state, and the clutch C1 is smoothly and reliably engaged. At this time, based on the hydraulic pressure supplied to the hydraulic chamber 5a,
The first piston member 3 and the second piston member 6 move together in the axial direction to reduce the volume of the cancel oil chamber 11, but the oil in the oil chamber is absorbed into the gap 9a on the inner diameter side of the cancel plate, and It is quickly discharged from the numerous notches 9a without being squeezed, and the quick movement of the piston member 3.6 is not hindered.

In the reverse range, hydraulic pressure is supplied to the hydraulic chamber 7a of the second hydraulic actuator 7, and the second piston member 6 moves against the return spring 17 using the first piston member 3 as a cylinder. C1 engages the second (Rebus) clutch C2, and hydraulic actuator 7
2 and locks the third brake B3. In this state, the rotation of the input shaft 1 is transmitted to the sun gear S1 via the clutch drum 2, the first piston member 3, the second clutch 02, etc., and is transmitted to the large ring gear R2 based on the third brake B3. Combined with the stoppage of the carrier CR
Reverse rotation is taken out from 1.

At this time, the second piston member 6 has a larger diameter than the first piston member outer diameter portion 3a3 and therefore has a large pressure receiving area, so it transmits a large torque due to the gear ratio. In order to support the second clutch C2 with fewer friction plates, a large pressing force is generated. Also, when supplying hydraulic pressure to the hydraulic chamber 7a, the drain orifice 15
Drain the oil from the drain orifice 15
The amount of leakage from the oil supply line 16 is smaller than the amount of oil supplied from the oil supply path 16, and the oil pressure can be supplied to the oil pressure chamber 7a without any problem.

On the other hand, when switching from the reverse range to another range, the second hydraulic actuator is drained, but at this time,
The hydraulic actuator 7 is in a rotating state and its hydraulic chamber 7
Centrifugal oil pressure is acting on a, but as described above, the centrifugal oil pressure is canceled by the cancellation oil chamber 11 on the back surface of the piston member 6, and the oil in the oil pressure chamber 7a is quickly drained. Further, the hydraulic chamber 7a is constituted by the outer circumferential surface of the piston member 6, and the oil in the cancel oil chamber 11 formed on the inner circumferential surface 6a completely cancels the centrifugal hydraulic pressure acting on the hydraulic chamber 7a. Although it is not possible to do so, the residual oil is reliably drained from the drain orifice 15 located at the outer diameter.

Next, a partially modified embodiment will be described with reference to FIG.

In the above-described embodiment, the piston member, cancel plate, clutch drum, etc. are formed by cutting out by machining, but in this embodiment, they are formed by press working in consideration of productivity.

That is, the clutch drum 2 has a spline flange 102 for engaging the third clutch CO in addition to the press-molded drum member 101, and the flange 102 is connected to the drum member 1.
01 by welding or the like.

Further, the cancel plate 9 for the first and second hydraulic actuators 3.7 has a press-molded main body 103, and a flange 20 made of a separate member is fixed to the main body 103, and an O-ring A holding plate 105 is fixed thereto.

Furthermore, the piston member 2 of the third hydraulic actuator 23
2 has a piston main body 22a, and the main body 22a
A clutch pressing portion 22b is integrally formed so as to protrude in the outer diameter direction, and a separate cylinder portion 24 is provided on the back side of the clutch pressing portion 22b.
to be placed. The cylinder portion 24 has a flange shape formed by press molding, has a cylinder inner circumferential surface 24a into which the cancel plate 25 is fitted on the outer diameter portion thereof, and has an inner circumference surface 24a on the outer diameter portion thereof, and the inner circumferential portion 24b of the cylinder portion 24 has a cylinder inner circumferential surface 24a into which the cancel plate 25 is fitted. , a, and are pressed and positioned by the return spring 32 while being fitted into the inner diameter portions and abutting against the back surfaces.

It goes without saying that the present invention is applicable not only to the automatic transmission described above but also to other automatic transmissions.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a clutch portion of an automatic transmission according to the present invention, and FIG. 2 is a sectional view showing a part of the automatic transmission. Moreover, FIG. 3 is a sectional view showing a clutch portion according to another embodiment. FIG. 4 is a schematic diagram of the entire automatic transmission according to the present invention, and FIG. 5 is a diagram showing the operation of each clutch, brake, and one-way clutch of the 4-speed automatic transmission mechanism. Furthermore, FIG. 6 is a diagram showing the relationship between the rotation speed and the centrifugal oil pressure acting on the second piston. 1...Input shaft 2...Clutch drum 3...
First piston member 3a...outer diameter part, 3a,...
・・Outer peripheral surface of small diameter portion 3a2 ・・Inner peripheral surface of large diameter portion
・3a3...Stepped part, 5...First hydraulic actuator, 5a...Hydraulic chamber 6...Second piston member 6a...Inner peripheral surface, 9...Cancel plate 9a・・Drain passage (notch)
9b...Inner diameter part 9c...Cylindrical part
9d...Vertical part 9e...Stepped part
10... Outer diameter part (0 ring) 11... Canceling oil chamber for centrifugal hydraulic pressure 13... Lubricating oil supply hole, 15
...Drain orifice, 16...Supply oil path
17... Return spring 19... Snap ring 2o... Flange A... Automatic transmission, cl... First (forward) clutch, C
2...Second (reverse) clutch

Claims (1)

[Claims] 1. A first hydraulic actuator in which a first piston member is fitted on the inner periphery of a clutch drum disposed coaxially with the input shaft, and a first hydraulic actuator on the inner periphery of the first piston member. a second hydraulic actuator fitted with a second piston member, the first hydraulic actuator operates a first clutch that is engaged and released during high-speed rotation during forward movement;
and the second actuator is at least the first actuator.
In an automatic transmission that operates a second clutch which is released in the engagement state of the clutch and the disengagement state, the outer diameter portion of the first piston member is formed into a stepped shape, and the small diameter portion of the first piston member is stepped. The outer peripheral surface is fitted to the clutch drum to form a hydraulic chamber for the first hydraulic actuator, and the second piston member is fitted to the inner peripheral surface of the large diameter part to form a hydraulic chamber for the second hydraulic actuator. A hydraulic chamber is configured, and an outer diameter portion of a cancel plate is fitted to the inner peripheral surface of the second piston member in an oil-tight manner, and an inner diameter portion of the plate is disposed on the input shaft so as to be immovable in the axial direction. A cancel oil chamber for centrifugal hydraulic pressure is formed by the back surface of the second piston member and the cancel plate, and a lubricating oil supply hole is provided on the inner diameter side of the cancel oil chamber, and a lubricant supply hole is provided on the inner diameter side of the cancel plate. An automatic transmission comprising: a drain passage formed in an end portion; and a drain orifice communicating with the outside from an outer diameter portion of the hydraulic chamber for the second hydraulic actuator formed in a stepped portion of the first piston member. Hydraulic system in. 2. The inner peripheral surface of the second piston member that fits into the outer diameter portion of the cancel plate has approximately the same diameter as the outer peripheral surface of the small diameter portion of the first piston member that fits into the clutch drum. A hydraulic system for an automatic transmission according to claim 1. 3. The automatic transmission according to claim 1, wherein the diameter of the drain orifice is within a range of 0.2 to 0.5 of the diameter of the supply oil passage that supplies hydraulic pressure to the second hydraulic actuator hydraulic chamber. Hydraulic equipment. 4. The hydraulic system for an automatic transmission according to claim 1, wherein a pressure receiving area of the second piston member is larger than a pressure receiving area of the first piston member. 5. The hydraulic system for an automatic transmission according to claim 1, further comprising a return spring compressed between the back surface of the second piston member and the cancel plate. 6. The hydraulic system for an automatic transmission according to claim 1, wherein the drain passage formed in the cancel plate is a notch formed at multiple locations on the circumference between the plate fixing snap rings. 7. The hydraulic system for an automatic transmission according to claim 4, wherein the cancel plate has a cylindrical portion extending in the axial direction at an intermediate portion thereof, and the cylindrical portion is provided with a flange portion that hangs down in the inner diameter direction. 8. The first clutch is a forward clutch that is engaged during forward movement except at the highest speed, and the second clutch is a reverse clutch that is released during forward movement and engaged during reverse movement. 1. The hydraulic system in the automatic transmission according to 1.