JPH0570743B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to an automatic transmission installed in an automobile, and more specifically, the invention relates to an automatic transmission installed in an automobile, and more specifically, to an automatic transmission equipped with two frictional engagement elements, such as an overdrive gear unit. The present invention relates to a structure of a piston for an inner frictional engagement element arranged in an overlapping manner in a radial direction.

(B) Prior Art Generally, an automatic transmission includes a torque converter and a planetary speed change gear mechanism, and the speed change gear mechanism consists of an overdrive (O/D) planetary gear unit, a front planetary gear unit, and a rear planetary gear unit. In the overdrive gear unit, an O/D direct clutch _C0 is arranged on the inner diameter side of the flange part that is integrally connected to the sun gear, and an O/D brake _B0 is arranged on the outer diameter side of the flange part. Based on the connection of the direct clutch _C0 , the sun gear and the carrier are integrally connected to directly connect the gear unit, and the sun gear is stopped based on the locking of the O/D brake _B0 . The input rotation from the carrier is accelerated and transmitted to the ring gear. In addition, the flange portion is O/D
It also serves as the cylinder of the direct clutch actuator, and a piston for clutch operation is fitted into the cylinder.

The piston, like other pistons for frictional engagement elements (see, for example, the piston for direct clutch C ₂ and the piston for forward clutch C ₁ in FIG. 4), has an annular flange on the outer diameter side. The wall is thick, and a large number of blind holes are formed in the thick wall to reduce weight.

(c) Problems that the invention aims to solve By the way, in recent years, with the increase in engine capacity and the high running speed of automobiles, the frequency of use of the O/D brake B ₀ used at maximum speed has increased. ,
The torque acting on the brake B ₀ also tends to increase. Conventionally, the brake _B0 is supplied with oil in the transaxle case by splashing or oil bath lubrication, but the structure is such that the oil supplied from the shaft by the oil pump is difficult to reach. In contrast to the above-mentioned recent trends, the durability of the brake B ₀ is not sufficient, and there is a risk that the amount of lubricating oil at the start of engagement of the brake B ₀ , which requires particularly sufficient lubricating oil, may be insufficient. .

Therefore, the present invention provides a piston for an O/D direct clutch on an inner diameter side, for example, an O/D direct clutch, and a piston on an outer diameter side, for example, an O/D direct clutch.
An object of the present invention is to provide an automatic transmission configured as a lubrication control means for discharging lubricating oil toward the friction elements of a brake, thereby improving the durability of the friction elements on the outer diameter side and reducing the weight of the piston. This is the purpose.

(d) Means for solving the problem The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIGS. 1 to 3, a first A friction engagement element (for example, an O/D direct clutch) C ₀ is disposed, and a piston 52 for operating the friction engagement element C ₀ is disposed, and a second friction engagement element is disposed on the outer diameter side of the flange portion 41. In an automatic transmission 1 comprising a gear unit 17 in which an element (for example, an O/D brake) _B0 is arranged, the piston 52
An annular collar portion 52a on the outer diameter side includes an outer circumferential wall 57 whose inner circumferential surface is made of a surface that expands outward, for example, a tapered surface 56, and a number of protrusions that hang down from the outer circumferential wall 57 in the inner diameter direction. 59 is provided. Then, the outer diameter side annular collar portion 52a is connected to the first frictional engagement element C ₀
When the outer circumferential wall 57, the protrusion 59, and the frictional engagement element _C0 in contact form an oil reservoir C whose inner diameter side is released, the annular flange 52a forms an oil reservoir C that is free from the first frictional engagement element C0. When separated from element C ₀ , the lubricating oil stored in the oil reservoir C flows into the tapered surface 56
It is characterized in that it is configured to be emitted toward the second frictional engagement element B ₀ along the hole 44 provided in the flange portion 41 .

Note that a predetermined proportion of the outer circumferential wall 57 divided by the protrusion 59 is in a state in which the outer diameter side annular collar 52a is in contact with the first frictional engagement element _C0. However, it may be configured to include a communication portion 60 through which lubricating oil leaks to the second frictional engagement element B ₀ .

Further, the present invention is used in the overplanetary gear unit 17, wherein the first frictional engagement element is an overdrive direct clutch _C0 consisting of multiple plates, and the second frictional engagement element is an overdrive brake consisting of multiple plates. It is preferable to set B to ₀ , but
However, the present invention is not limited to this, and the first frictional engagement element may be a direct clutch C ₂ (see Fig. 4), and the second frictional engagement element may be a 2nd course brake B ₁ consisting of a band brake. Of course, the present invention may also be applied to an engagement element.

(E) Effect Based on the above configuration, when pressure oil is supplied to the hydraulic actuator 42, the piston 52 expands and its outer diameter side collar 52a presses the first frictional engagement element _C0 to bring it into the connected state. . In this state, the outer diameter side collar portion 52a is in contact with the frictional engagement element _C0 , and the outer peripheral wall 57 and the protruding portion 59 form an oil reservoir C whose inner diameter side is open, and therefore the hydraulic pump The lubricating oil that is supplied through the shaft and blown outward by centrifugal force after lubricating other parts is led to the oil reservoir C from the released inner diameter side and collected therein. In addition, the predetermined proportion of the parts divided by the protruding parts 52
Even when the flange 52a is in contact with the friction engagement element _C0 , the lubricating oil in the oil reservoir C' passes through the communication part 60 to the inner and outer peripheries of the flange 41. An appropriate amount of lubricating oil may be supplied to the second frictional engagement element through a hole 44 that communicates with the second frictional engagement element, and the frictional engagement element _B0 in the released state may be lubricated with an appropriate amount of lubricating oil. Then, when the hydraulic pressure of the hydraulic actuator 42 is drained to release the first frictional engagement element C ₀ , the piston 52 separates from the frictional engagement element C ₀ . Then, the lubricating oil that has been stored in the oil reservoir C flows along the tapered surface 56 to the flange 5.
2a and the flange part 4 from the gap between the frictional engagement element _C0
1 through the hole 44 of the second frictional engagement element at one time.
A sufficient amount of lubricating oil is supplied to the friction engagement element B ₀ that is being slid into engagement with the frictional engagement element B ₀ .

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

As shown in FIGS. 4 and 5, the multi-stage automatic transmission 1 includes a torque converter 2, a planetary transmission gear mechanism 3, and a hydraulic control mechanism 5, each of which includes a converter housing 6, a transmission case 7, and an extension case. housing 9,
It is housed in a valve body 10 and an oil pan 11. The torque converter 2 is equipped with a lock-up clutch 12, and the rotation of the input member 13 is transmitted through the oil flow of the torque converter 2 or directly by the lock-up clutch 12 to the transmission gear mechanism 3.
is transmitted to the input shaft 15 of. The speed change gear mechanism 3 is an overdrive (O/D) planetary gear unit 1
7, and a main transmission unit 21 consisting of a front planetary gear unit 19 and a rear planetary gear unit 20. The O/D planetary gear unit 17 includes a carrier 24 that is directly connected to the input shaft 15 and supports a planetary pinion 22;
It has a sun gear 23 fitted on the input shaft 15 and a ring gear 25 connected to the input shaft 26 of the main transmission unit 21. Also, as will be described in detail later, the planetary carrier 24 and the sun gear 23 are connected to each other. An O/D direct clutch C ₀ and a one-way clutch F ₀ are interposed therebetween, and an O/D brake B ₀ is disposed between the sun gear 23 and the case 7. The front planetary gear unit 19 also includes a carrier 29 that is directly connected to the output shaft 27 and supports a planetary pinion 28, a sun gear 30a that is fitted onto the output shaft 27 and is integrally formed with the sun gear 30b of the rear planetary gear unit 20, and a ring gear 31 connected to the input shaft ₂₆ via a forward clutch C1, and a direct clutch _C2 interposed between the input shaft 26 and the sun gear 30,
A 2nd coast brake _B1 consisting of a band brake is interposed between the sun gear 30 and case 7, and a 2nd coast brake B1 consisting of multiple discs is further interposed between the sun gear 30 and case 7 via a one-way clutch _F1 . ₂ are installed. The rear planetary gear unit 20 includes a carrier 33 supporting a planetary pinion 32, a sun gear 30b, and a ring gear 35 directly connected to the output shaft 27.
1st & Rev brake B ₃ and one-way clutch F ₂
are arranged in parallel. In addition, 36 in Figure 4
is an oil pump.

As shown in detail in FIG. 1, in the O/D planetary gear unit 17, the boss portion of the sun gear 23 expands in diameter and extends in the axial direction, and the O/D one-way clutch F ₀ is mounted on the expanded diameter portion 23a. is supported,
The outer race of the one-way clutch F ₀ is a ring member 40 fixed to the carrier 24.
It is locked in. Further, an annular flange portion 41 is fixed to the expanded diameter portion 23a, and the flange portion 41 has flanges 41a and 41b extending in the axial direction on the outer diameter side and the inner diameter side, respectively, and the O/D Hydraulic actuator 42 for direct clutch C ₀
It consists of a cylinder. In addition, the outer diameter side flange 4
1a further extends in the axial direction, has splines formed on its outer peripheral surface and inner peripheral surface, respectively, and has a large number of holes 44.... A large number of outer and inner friction plates 43a, 43b constituting the clutch _C0 are alternately engaged with the inner circumferential spline of the collar portion 1a and the outer circumferential spline of the ring-shaped member 40, and are also engaged with the snap ring 45. A large number of outer and inner friction plates 46a and 46b constituting the brake _B0 are alternately engaged with the outer circumferential spline of the flange portion 41a and the inner circumferential spline formed on the case 7, respectively. At the same time, it is prevented from coming off by a snap spring 47. Further, a partition wall-like bracket member 49 extending in the inner diameter direction is fixed to a position adjacent to the brake B ₀ of the case 7, and a cylinder of a hydraulic actuator 50 for the brake B ₀ is formed in the bracket member. A piston 51 is fitted in an oil-tight manner, and the piston 51 has a corner portion 51a extending toward the brake _B0 in a comb-tooth shape, and a spring is inserted between the piston 51 and the plate 48 fixed to the bracket member 49. 54 has been reduced. On the other hand, a piston 52 is installed in the cylinder for the hydraulic actuator 42, which is constituted by the outer diameter side and inner diameter side flanges 41a and 41b of the flange portion 41.
They are fitted in an oil-tight manner by rings 53, 53,
In addition, a return spring 92 is fixed to the expanded diameter portion 23a and compressed between the plate 91 and the expanded diameter portion 23a.

And, as detailed in FIGS. 2 and 3,
The piston 52 is made of an annular member, and the outer diameter side annular collar 52a has a concave groove 55 for the O-ring 53 formed on its outer circumferential surface, and a tapered surface that expands outward on its inner circumferential surface. 56, and a large number of protrusions 5 hanging down from the outer circumferential wall 57 at predetermined intervals in the inner radial direction.
It has 9. Furthermore, the tip of the outer peripheral wall 57 is cut out for every other chamber C divided by the protrusion 59, and a groove 6 is formed which communicates the chamber C' to the outside in the radial direction.
0 is formed, and thick parts 61a and 61b are formed at positions 180 degrees apart, and one of them 6
1a, a check ball 62 (first
A hole 62a (see figure) is formed. on the other hand,
A recess 63 for the O-ring 53 is formed on the inner peripheral surface of the inner annular collar 52b, and a large number of shallow round holes 65 are formed adjacent to the collar 52b.

On the other hand, the input shaft 26 of the main transmission unit 21 has
As shown in FIG. 1, an oil hole 70 through which lubricating oil is supplied from a hydraulic pump is drilled in the shaft core, and an oil chamber 71 is formed at the tip of the hole formed in the input shaft 15. are doing. In addition, the input shaft 15
Lateral holes 72 and 73 are formed in the sun gear 23, and oil holes 75, 76, and 77 are also formed in the sun gear 23. The lubricating oil from the oil chamber 71 passes through the horizontal hole 73 to lubricate the needle bearings 78, 79 and the thrust bearing 80, and further passes through the oil hole 77 to lubricate the meshing surfaces of the sun gear 23 and the planetary pinion 22. It also lubricates the O/D one-way clutch _F0 through the oil passage 76. In addition, the horizontal hole 72
The lubricating oil passing through lubricates the needle bearings 78, 81 and the thrust bearing 83, and further lubricates the oil hole 7.
5 and is discharged in the one-way clutch _F0 direction.

Next, the operation of this embodiment will be explained.

Each clutch C ₀ , C ₁ , C ₂ , brake B ₀ , B ₁ , B ₃ , and each one-way clutch of the automatic transmission 1
F ₀ , F ₁ , F ₂ are each position P, R, R (V≧
7), N, D, 2, and L gears are controlled as shown in the operation table shown in FIG. 6, respectively.

That is, at the first speed in the D range or the 2nd range, the O/D direct clutch C ₀ , the one-way clutches F ₀ and F ₂ and the forward clutch C ₁ are engaged, and the others are in the released state. Therefore,
The O/D planetary gear unit 17 is a clutch
They are directly coupled together via C ₀ and one-way clutch F ₀ , and the rotation of the input shaft 15 is directly transmitted to the input shaft 26 of the main transmission unit 21 . Further, in the main transmission unit 21, the rotation of the input shaft 26 is transmitted to the ring gear ₃₁ of the front planetary gear unit 19 via the forward clutch C1, and further transmitted to the carrier 29 and the output shaft 27 integrated with the carrier 29. With,
A leftward rotational force is applied to the carrier 33 of the rear planetary gear unit 20 via the sun gear 30, but this rotation is prevented by the one-way clutch _F2 , and the planetary pinion 32 rotates to the ring gear 35 integrated with the output shaft 27. power is transmitted to.

Further, in the second gear in the D range, the O/D direct clutch C ₀ , one-way clutch F ₀ , forward clutch C ₁ , one-way clutch F ₁ and 2nd brake B ₂ are engaged, and the others are in a released state. Therefore, the O/D planetary gear unit 17
are in the directly connected state mentioned above, and the rotation of the input shaft 15 is directly transmitted to the input shaft 26 of the main transmission unit 21. Furthermore, in the main transmission unit 21, the rotation of the input shaft 26 is transmitted to the ring gear 31 of the front gear unit ₁₉ via the forward clutch C1, and applies a leftward rotational force to the sun gear 30 via the pinion 28. The sun gear 30 is prevented from rotating in this direction by the one-way clutch F ₁ when the 2nd brake B ₂ is engaged, and therefore, the carrier 29 rotates while the planetary pinion 28 rotates, and the rotation is carried out only through the front gear unit 19. te2
The high speed rotation is transmitted to the output shaft 27.

In addition, at 3rd speed in D range and 2 range, O/D direct clutch C ₀ , one-way clutch F ₀ , forward clutch C ₁ , direct clutch C ₂ and 2nd brake B ₂ are engaged, and the others are in the released state. It is in. Therefore, the O/D planetary gear unit 17 is in the above-mentioned directly connected state, and the main transmission unit 21 is connected to the input shaft 26 by integrating the front planetary gear unit 19 with the engagement of both clutches C ₁ and C ₂ . The rotation is directly transmitted to the output shaft 27.

In the fourth gear, that is, the highest gear in the D range, the forward clutch C ₁ , the direct clutch C ₂ and the 2nd brake B ₂ are in an engaged state, and the main transmission unit 21 is in a directly coupled state as in the third gear. However, in the O/D planetary gear unit 17, the direct clutch _C0 releases and the brake _B0
is switched to engage. Therefore, the sun gear 23 is locked by the brake _B0 , and the carrier 24 rotates while the planetary pinion 22 rotates and transmits power to the ring gear 25, and the increased rotation (O/D) is directly connected to the main transmission. unit 21
is transmitted to the input shaft 26 of.

On the other hand, in the first to third speeds, pressure oil is supplied to the C ₀ hydraulic actuator 42, the piston 52 extends against the spring 92, and the outer diameter side flange 52a is connected to the O/D direct Clutch C ₀
Press to connect. In this state,
The lubricating oil from the oil hole 70 is applied to the thrust bearing 8.
3. After lubricating the meshing surfaces of the one-way clutch _F0 , the sun gear 23, and the planetary pinion 22, they are blown in the outer radial direction by centrifugal force and guided by the ring member 40, and then the outer circumferential wall 5 of the piston 52
7 and a protrusion 59. At this time, since the outer diameter side flange 52a of the piston 52 is in contact with the clutch _C0 , the chamber C constitutes an oil reservoir, and the above-mentioned scattered lubricating oil is collected in the oil reservoir. Further, a portion of the oil stored in the oil reservoir C leaks from the inner diameter side of the outer friction plate 43a to the outer peripheral spline portion of the flange portion 41. In addition, one of the two chambers C' is provided with a brake that is released by centrifugal force in the outer diameter direction from the groove 60 formed in the outer peripheral wall 57 and passes through the hole 44 formed in the flange portion 41. B ₀ is supplied between each friction plate 46a, 46b. Therefore, approximately 1/2 of the total amount of lubricating oil supplied to the piston 52 is constantly supplied even when the brake B ₀ is released, ensuring that the brake B ₀ is maintained in the released state and dissipating heat. There is.

When switching to the fourth speed state, the pressure oil in the C ₀ hydraulic actuator 42 is drained, and the pressure oil is supplied to the B ₀ hydraulic actuator 50. Then, first, the piston 52 for the clutch C ₀ is separated from the clutch C ₀ by the spring 56, and the clutch C ₀ is released.
The lubricating oil stored in the oil reservoir C is simultaneously released from the gap between the tip of the outer peripheral wall 57 and the clutch C ₀ by the taper surface 56 and the centrifugal force, and is supplied to the brake B ₀ through the hole 44 . At this time, the brake B ₀ is in a state of whether or not to start contact with the piston 51, and the aforementioned large amount of lubricant released is applied to the friction plate 46.
a and 46b, the brake B ₀ is engaged after an appropriate slipping condition, but the heat generated due to the slipping is reliably released. Also, some of the lubricating oil leaking to the outer circumferential spring of the ring member 40 and the lubricating oil released when the piston 52 is released is supplied between the friction plates 43a and 43b as the clutch _C0 is released. be done.

Furthermore, when in 2nd speed in the 2nd range and 1st range, the 2nd coast brake B ₁ is engaged compared to when in 2nd speed in the D range, and the main transmission unit 21
Lock sun gear 30 and apply engine braking.

Furthermore, when in the 1st speed in the 1st range, the 1st & Rev brake _B3 is engaged compared to when in the 1st speed in the D range, locking the carrier 33 of the rear planetary gear unit 20 and applying engine braking.

Further, when in the R range, the O/D direct clutch C ₀ , one-way clutch F ₀ , direct clutch C ₂ and brake B ₃ are engaged, and the others are in the released state. Therefore, the O/D planetary gear unit 17 is in a direct connection state, and the main transmission unit 21
Since the rotation of the input shaft 26 is directly transmitted to the sun gear 30 by the clutch C ₂ and the rotation of the rear carrier 33 is locked by the brake B ₃ , the rotation of the sun gear 30 is directly transmitted to the sun gear 30 by the planetary pinion 3.
2 is transmitted as a reverse rotation to the ring gear 35, and the output shaft 27 is rotated in the reverse direction.

Further, when the shift lever is shifted to the R range while the vehicle is traveling in the forward direction at a predetermined speed, for example, 7 km/h or higher, the direct clutch C ₀ is released and the 1st & Rev brake B ₃ is released. This state is similar to that in parking P and neutral N, and the main transmission unit 21 is in a free state to prevent damage to the gears.

(G) Effects of the Invention As explained above, according to the present invention, the piston ₅ is attached to the first frictional engagement element C0 located on the inner diameter side.
When the two outer diameter side annular collar portions 52a are in contact with each other,
Outer peripheral wall 57, protrusion 59, and first frictional engagement element
Since an oil reservoir C is formed with the inner diameter side open at C ₀ , the lubricating oil scattered from the shaft side by centrifugal force can be collected, and the annular collar portion 52a is connected to the first frictional engagement element C. ₀ , the lubricating oil stored in the oil reservoir C along the inner circumferential surface, which is the expanding surface of the outer circumferential wall of the annular collar portion, flows toward the second frictional engagement element on the outer diameter side. A second
Therefore, a large amount of lubricating oil can be supplied to the second frictional engaging element, which requires sufficient lubricating oil, when the second frictional engaging element starts engaging. In addition to improving the durability of B ₀ , it is possible to improve heat dissipation and increase heat capacity. Further, sufficient lubricating oil can be supplied when necessary without the need for a special hydraulic pump, and it is possible to prevent the structure from becoming complicated and to prevent an increase in power loss. Further, the piston 52 can be made even lighter in weight than the conventional thinning method.

Furthermore, if the inner circumferential surface of the outer circumferential wall 57 of the annular flange 52a is configured with a tapered surface 56 that expands outward, when the annular flange 52a is separated from the frictional engagement element _C0 , the oil will be removed. The lubricating oil can be reliably and quickly released from the reservoir C.

Further, when the communication portion 60 is configured in a predetermined proportion C' of the chamber C partitioned by the outer peripheral wall 57 and the protruding portion 59, the piston outer diameter side collar portion 52a is the first (inner diameter side)
A predetermined amount of lubricating oil can always be supplied to the second (outer diameter side) frictional engagement element even when it is in contact with the frictional engagement element _C0 , improving durability and heat dissipation. I can do it.

Further, when used in the overdrive planetary gear unit 17, it is possible to easily cope with the recent increase in the frequency of use of the O/D brake _B0 and the increase in the applied torque without making any major changes to the brake itself.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of an automatic transmission according to the present invention, FIG. 2 is a sectional view of its piston, and FIG. 3 is a front view thereof. FIG. 4 is an overall sectional view showing an automatic transmission to which the present invention is applied, FIG. 5 is a schematic view thereof, and FIG. 6 is a diagram showing the operating states of each clutch, brake, and one-way clutch in each position. . DESCRIPTION OF SYMBOLS 1... Automatic transmission, 17... Overdrive planetary gear unit, 19... Front planetary gear unit, 20... Rear planetary gear unit, 21... Main transmission unit, 41... Flange portion, 42... Hydraulic actuator, 52...
...Piston, 52a...Outer diameter side flange, 56...Tapered surface, 57...Outer peripheral wall, 59...Protrusion, C...
...Oil reservoir, 60...Communication section (groove), C ₀ ...First frictional engagement element (O/D direct clutch), B ₀
...Second frictional engagement element (O/D brake).

Claims (1)

[Claims] 1. A first friction engagement element is disposed on the inner diameter side of the flange portion, and a piston for operating the friction engagement element is disposed, and a second friction engagement element is disposed on the outer diameter side of the flange portion. In an automatic transmission equipped with a gear unit in which frictional engagement elements are arranged, a hole is formed in the flange portion to communicate between an inner diameter side and an outer diameter side, and an outer peripheral wall and an outer peripheral wall are formed on the outer diameter side of the piston. an annular flange having a large number of protrusions hanging in the inner diameter direction from an outer peripheral wall; an inner peripheral surface of the outer peripheral wall of the annular flange has a surface that expands outward; the annular flange; When contacting the first frictional engagement element, the outer circumferential wall, the protrusion, and the contacted frictional engagement element form an oil reservoir whose inner diameter side is open, and the annular flange part the first The lubricating oil stored in the oil reservoir is discharged along the expanding surface toward the second frictional engagement element when the lubricating oil is separated from the second frictional engagement element. Automatic transmission. 2. The automatic transmission according to claim 1, wherein the surface formed on the inner circumferential surface of the outer circumferential wall of the annular collar portion is formed in a tapered shape. 3 Even if a predetermined proportion of the outer circumferential wall partitioned by the protruding portion is in a state in which the outer annular collar portion is in contact with the first frictional engagement element, lubricating oil remains in the second frictional engagement element. The automatic transmission according to claim 1, further comprising a communication portion that leaks into the frictional engagement element. 4. Claim 1, wherein the gear unit is an overdrive planetary gear unit, the first frictional engagement element is an overdrive direct clutch, and the second frictional engagement element is an overdrive brake. Automatic transmission as described in section.