JP4585087B2 - Automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission for a vehicle having a friction engagement element such as a clutch or a brake.
[0002]
[Prior art]
An automatic transmission, that is, an automatic transmission, has a plurality of planetary gear mechanisms and a plurality of clutches and brakes for turning them on and off, and controls the hydraulic circuit according to the throttle opening and the vehicle speed, so that it can respond to the driving state. The gear shifting operation is automatically performed.
[0003]
The clutch has a clutch hub fixed to the inner rotating member and a clutch drum fixed to the outer rotating member, and includes a plurality of clutch disks attached to the clutch hub and a plurality of pieces attached to the clutch drum. When the clutch disk is frictionally engaged, both rotating members are connected, and when each clutch disk is slid, the connecting of the rotating members is released.
[0004]
In order to frictionally engage and release both clutch disks, a piston is incorporated in the clutch drum, and the piston presses the clutch disk by the hydraulic pressure supplied to the piston oil chamber. Yes. When the rotary shaft is driven to rotate, the piston oil chamber also rotates, so that centrifugal force also acts on the hydraulic oil in the piston oil chamber. In order to cancel this centrifugal force, for example, a cancel oil chamber may be provided on the opposite side of the piston as disclosed in Japanese Patent Laid-Open No. 9-32919.
[0005]
[Problems to be solved by the invention]
However, when a piston oil chamber is provided on one side of the piston and a cancel oil chamber is provided on the other side, the axial dimension of the power train becomes long, and an increase in the size of the automatic transmission cannot be avoided. There is a problem. Further, as disclosed in the above publication, when a clutch having a double structure is provided on the inner side and the outer side and the outer diameter of the outer piston is larger than that of the inner clutch disc, the inner clutch drum Since the shape of the outer piston is complicated and the pressing force of the piston that operates the inner clutch cannot be increased, the clutch capacity can be increased only by increasing the number of multi-plate clutch discs. The extension of the powertrain will lead to an increase in size and weight.
[0006]
An object of the present invention is to achieve a reduction in size and weight of an automatic transmission for a vehicle having a friction engagement element such as a clutch or a brake.
[0007]
[Means for Solving the Problems]
The automatic transmission according to the present invention includes a clutch hub having a plurality of clutch disks mounted on the outside, and a clutch drum having a plurality of clutch disks frictionally engaged with the clutch disks mounted on the inside. And a clutch drum, which is fixed between a hollow shaft having a smaller diameter than the clutch hub and the clutch drum, and a piston drum having a larger diameter than the clutch disc. A piston having an outer peripheral surface smaller in diameter than the inner diameter of the piston drum and provided in the piston drum so as to be movable in the axial direction, and forming a piston oil chamber with an end wall of the piston drum; A retainer disposed between an outer peripheral surface and an inner peripheral surface of the piston drum, and forming a cancel oil chamber radially outward of the piston oil chamber The has provided the cancel oil chamber radially outward relative to the piston oil chamber, said clutch drum and a flange portion projecting outwardly of the cylindrical portion and the cylindrical portion, the flange portion The sealing member is baked and sealed and joined to the piston drum . In the present invention, since the cancel oil chamber is provided concentrically outside the piston oil chamber, it is possible to reduce the size and weight of the clutch mechanism including each oil chamber.
[0008]
Further, in the present invention, a cancel mechanism for canceling the centrifugal oil chamber can be provided without extending the axial dimension, and the overall length of the transmission is shortened, and the weight reduction and size reduction thereof are achieved. can do.
[0009]
The automatic transmission according to the present invention is characterized in that a communication hole communicating with the cancel oil chamber is provided in the piston. In the present invention, the hydraulic pressure of the cancel oil chamber can be set arbitrarily.
[0010]
The automatic transmission according to the present invention is characterized in that a lubricating oil supply hole for supplying lubricating oil to the clutch disk is formed in the piston. In the present invention, the clutch disk can be lubricated and the durability of the clutch can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
FIG. 1 is a skeleton diagram showing an automatic transmission according to an embodiment of the present invention. The automatic transmission includes a torque converter 11, a main transmission unit 12, and a sub-transmission unit 13, which are transmissions. It is incorporated in the case 14.
[0013]
The torque converter 11 has a drive plate 16 connected to a crankshaft 15 of the engine and rotating, and a pump side case 17 connected to the drive plate 16, and is opposed to a pump impeller 18 provided in the pump side case 17. The turbine runner 19 arranged in this manner is directly connected to the turbine shaft 21. A stator 22 is disposed between the pump impeller 18 and the turbine runner 19, and the stator 22 is supported by a one-way clutch 23.
[0014]
The turbine runner 19 is provided with a lock-up clutch 25 that engages with the front cover 24. One side of the lock-up clutch 25 is an apply chamber 26a, and the other side is a release chamber 26b. By circulating the hydraulic pressure supplied into the release chamber 26b through the apply chamber 26a, the torque converter 11 becomes in an operating state. On the other hand, the lockup clutch 25 is engaged with the front cover 24 and is brought into a lockup state by supplying hydraulic pressure to the apply chamber 26a and lowering the hydraulic pressure in the release chamber 26b.
[0015]
The main transmission unit 12 has a structure in which the rotation of the turbine shaft 21 is automatically shifted from the first speed to the fourth speed and is reversely rotated and transmitted to the intermediate shaft 27. A clutch drum 31 is fixed to the turbine shaft 21. A clutch drum 32 having a larger diameter than that of the clutch drum 31 is disposed outside the clutch drum 31, and a reverse clutch ReC is provided between the clutch drums 31 and 32. The clutch drum 32 is provided inside the clutch drum 32. A high clutch HC is provided between the clutch hub 33 and the clutch drum 31.
[0016]
The clutch drum 32 front sun gear S _F is fixed with the brake hub 34 is fixed, this is outside of the sun gear S _F and front ring gear R _F is disposed on the carrier 35 fixed to the clutch hub 33 is , planetary gears P _F meshed with the sun gear S _F and the ring gear R _F is rotatably mounted. A rear sun gear S _R is fixed to the turbine shaft 21, and a rear ring gear R _R is disposed outside the sun gear S _R. The carrier 36 fixed to the ring gear R _F includes the sun gear S _R and the ring gear R. _A planetary gear PR meshing with _R is rotatably mounted.
[0017]
Between the brake hub 34 and the case 14, there are provided brakes 2 and 4B that are engaged at the second speed, the fourth speed, and the fifth speed. A clutch drum 37 is fixed to the carrier 35, and a low clutch LC is provided between the clutch hub 38 fixed to the ring gear R _R and the clutch drum 37.
[0018]
A brake hub 39 is fixed to the clutch drum 37, and a low and reverse brake LRB is provided between the brake hub 39 and the case 14, and the clutch drum 37 is rotatably supported on the case 14 via a one-way clutch FL. Has been.
[0019]
Auxiliary transmission section 13 has a structure for transmitting the rotation of the intermediate shaft 27 to the output shaft 28 as a directly connected state or decelerated, the intermediate shaft 27 is fixed to the output side ring gear R _O, the center of the ring gear R _O An output side sun gear S _O is disposed, and a planetary gear P _O meshing with the ring gear R _O and the sun gear S _O is rotatably provided on an output side carrier 41 fixed to the output shaft 28.
[0020]
A direct clutch DC is provided between the clutch hub 42 fixed to the carrier 41 and the clutch drum 43 fixed to the sun gear S _O , and a reduction brake RB is provided between the clutch drum 43 and the case 14. Is provided.
[0021]
Each of the above-described clutches and brakes has a plurality of annular inner disks that are mounted on an inner member such as a clutch hub so as to be slightly movable in the axial direction, and an outer member such as a clutch drum or a case that is slightly axially moved. A plurality of annular outer disks mounted movably on the inner disk, and when the inner disk and the outer disk are frictionally engaged by tightening and intimately contacting, the inner member and the outer member are connected to each other. It becomes. On the other hand, when the tightening force is released, the engaged state is released and the connection between both members is broken. The setting of the state in which the tightening force is applied to the disk which is the frictional engagement element and the state in which the tightening force is released is performed by the hydraulic piston. The operation of each hydraulic piston is performed by the hydraulic pressure generated by the hydraulic pump 29 that is directly driven by the crankshaft 15.
[0022]
2 is a skeleton diagram showing the power transmission path of the speed change element shown in FIG. 1, and FIG. 3 is an operation table showing the relationship between the intermittent state of each friction engagement element shown in FIGS. 1 and 2 and the gear ratio. In FIG. 3, the ◯ marks indicate the fastening state in which each friction engagement element is on, that is, frictionally engaged.
[0023]
As shown in FIGS. 2 and 3, when the reduction brake RB is on, the rotation of the intermediate shaft 27 that is the output shaft of the main transmission unit 12 is decelerated by the sub-transmission unit 13 and output to the output shaft 28. It will be. On the other hand, when the reduction brake RB is off and the direct clutch DC is on, the intermediate shaft 27 is directly connected to the output shaft 28 and output.
[0024]
For example, when the shift to the first speed, as shown in FIG. 3, the low clutch LC, the low and reverse brake LRB and the reduction brake RB is set to ON, the rotation of the turbine shaft 21 of each planetary gear P _R, P _O is transmitted to the output shaft 28 by the revolution of the sun gears S _R and S _O.
[0025]
As shown in FIG. 3, by operating the respective clutches and brakes, shift control of the fifth forward speed is automatically performed according to the running state.
[0026]
Figure 4 is a sectional view showing the details of the auxiliary transmission unit 13, the carrier 41 is fixed by a spline 44 to the output shaft 28, planetary gear P _O is bearing 46 in the support shaft 45 fixed to the carrier 41 It is mounted rotatably via A plurality of annular clutch disks 47 are mounted on the outside of the clutch hub 42 fixed to the carrier 41 so as to be slightly movable in the axial direction. On the other hand, the inside of the clutch drum 43 fixed to the sun gear S _O and a plurality of clutch disks 48 which becomes circular is slightly movably mounted in the axial direction, each of the clutch discs 47 and 48 alternately Has been placed.
[0027]
The clutch drum 43 has a cylindrical portion 43a and a flange portion 43b projecting radially outward at the end thereof. The clutch drum 43 includes a hollow shaft portion 51 fixed to the sun gear _So by a meshing portion 51a, and the hollow shaft portion 51. It is secured to the sun gear S _O through the cylinder section, that the piston drum 52 fixed to an end portion of the shaft portion 51.
[0028]
The piston drum 52 has a large-diameter portion 52a, a small-diameter portion 52b, and an end wall 52c. The inner diameters of the large-diameter portion 52a and the small-diameter portion 52b are both set larger than the outer diameters of the clutch disks 47 and 48. Yes. A piston 53 is provided in an annular space defined by the piston drum 52 and the hollow shaft portion 51 so as to be movable in the axial direction. The piston 53 has a smaller diameter portion 53a smaller than the clutch hub 42, and A large-diameter portion 53b having an intermediate diameter between the inner diameter of the clutch drum 43 and the outer diameter of the clutch hub 42 is provided. A partition wall portion 53c is provided between them, and an end portion of the piston 53 is radially outward. A protruding flange portion 53d is provided.
[0029]
A piston oil chamber 54 is formed in the piston drum 52 by the rear end surface of the piston 53 and the piston drum 52, and when hydraulic pressure is supplied into the piston oil chamber 54 through an oil passage 55 a formed in the case 14, the piston 53 4 is driven to the left in FIG. 4, and the clutch disks 47 and 48 are pressed by the large-diameter portion 53b and are brought into close contact with each other to be in a friction engagement state. When the pressurization to the piston oil chamber 54 is stopped, the piston 53 is returned to the right side by the spring force of the return coil spring 56, and the clutch disks 47, 48 are changed from the engaged state to the disengaged state.
[0030]
An inner peripheral surface of a flange portion 43 c that protrudes inwardly at the end of the clutch drum 43 is slidably in contact with the outer peripheral surface of the piston 53, and the outer peripheral surface of the piston 53 and the inner peripheral surface of the piston drum 52 A retainer 57 is disposed between the two. The retainer 57 is sealed and fixed to the outer peripheral surface of the piston 53 at its inner peripheral portion, and a seal portion provided on the outer peripheral portion is slidably in contact with the inner peripheral surface of the piston drum 52. A cancel oil chamber 58 is formed between the clutch drum 43 and the end of the clutch drum 43.
[0031]
Therefore, when the clutch drum 43 and the piston drum 52 rotate, centrifugal hydraulic pressure is applied to the hydraulic oil in the piston oil chamber 54 by centrifugal force, and this centrifugal hydraulic pressure acts in the direction of tightening the clutch disk. The hydraulic pressure is canceled out by the centrifugal hydraulic pressure applied to the hydraulic oil in the cancel oil chamber 58 by the centrifugal force. Thereby, the operation precision of direct clutch DC can be raised.
[0032]
Thus, the cancel oil chamber 58 is not provided in the axial direction with respect to the piston oil chamber 54, but is provided concentrically outward in the radial direction, so that the diameter of the piston drum 52 is set outside the clutch disks 47 and 48. Even if it is set larger than the diameter, the centrifugal oil pressure generated in the piston oil chamber 54 can be canceled by the cancel oil chamber 58 without increasing the axial dimension of the transmission, and the clutch mechanism can be made smaller and lighter. And ensuring of hydraulic control accuracy can be achieved.
[0033]
As shown in FIG. 4, the partition wall 53c of the piston 53 is provided with a communication hole 59 that communicates with the cancel oil chamber 58. The communication hole 59 communicates with the oil passage 55b. By changing the diameter, the cancel oil chamber generated in the cancel oil chamber 58 can be arbitrarily set.
[0034]
A lubricating oil supply hole 61 is formed in the small diameter portion of the piston 53, and a lubricating oil supply hole 62 is formed in the clutch hub 42 corresponding to the supply hole 61. The lubricating oil supply holes 61 and 62 are cancel oils. The hydraulic oil leaking from the oil passage communicating with the chamber 58 is guided to the clutch hub 42. As a result, the hydraulic oil leaking from the oil passage is supplied as lubricating oil to the clutch disks 47 and 48 through the lubricating oil supply holes 61 and 62, and the multi-plate clutch portion is stably lubricated, and the direct clutch DC It is possible to improve the durability.
[0035]
A brake disc 63 made of the same member as the clutch disc is mounted on the outside of the clutch drum 43, and a brake disc 64 is mounted on the inside of the case 14 alternately with the brake disc 63. A reduction brake RB is formed. The case 14 is provided with an annular brake piston 65. When hydraulic pressure is supplied to the oil chamber 66, a dog 67 provided at the tip of the brake piston 65 presses the disks 63 and 64, and the reduction brake RB is brought into a friction engagement state. Is set. Since the oil chamber 66 is provided in the case 14, centrifugal hydraulic pressure is not generated in the hydraulic oil in the oil chamber 66, and when the supply of hydraulic pressure to the oil chamber 66 is stopped, the brake piston 65 is returned by the spring member 68. It will be.
[0036]
FIG. 5 is an enlarged perspective view showing a part of the clutch drum 43 and the piston drum 52. The flange portion 43b of the clutch drum 43 is formed with teeth and grooves, and corresponds to the large-diameter portion 52a of the piston drum 52. The teeth and grooves are formed, and the sealing member is fired on one of these meshing portions, and is assembled and joined in a liquid-tight manner. Thereby, the clutch drum 43 and the piston drum 52 are joined in a sealed state, and it is possible to reliably prevent the hydraulic oil in the cancel oil chamber 58 from leaking from the joined portion.
[0037]
It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
[0038]
For example, FIG. 4 shows a case where the present invention is applied to the direct clutch DC portion of the auxiliary transmission unit 13, but the present invention may be applied to other clutches.
[0039]
【The invention's effect】
According to the present invention, since the cancel oil chamber is formed radially outward of the piston oil chamber that applies hydraulic pressure to the piston for operating the friction engagement element, the axial dimension of the transmission can be shortened. Thus, the clutch mechanism can be reduced in size and weight.
[0040]
Since the centrifugal hydraulic pressure can be canceled even in a clutch mechanism having a piston drum having a diameter larger than that of the clutch disk, the hydraulic control accuracy can be improved.
[0041]
Since the flange portion of the clutch drum and the piston drum are sealed and joined by firing, the axial length of the clutch mechanism can be suppressed while maintaining the sealing performance of the hydraulic oil. The axial dimension of can be shortened.
[0042]
By connecting the communication hole to the cancel oil chamber, the centrifugal hydraulic pressure generated in the cancel oil chamber can be set to an arbitrary pressure.
[0043]
Since the lubricating oil is supplied to the clutch disk from the lubricating oil supply hole, the clutch disk can be stably lubricated, and the durability of the clutch can be improved.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing an automatic transmission according to an embodiment of the present invention.
2 is a skeleton diagram showing a power transmission path of the speed change element shown in FIG. 1; FIG.
FIG. 3 is an operation table showing a relationship between an intermittent state of a friction engagement element and a gear ratio.
FIG. 4 is a cross-sectional view showing details of an auxiliary transmission unit.
FIG. 5 is an enlarged perspective view showing a part of a clutch drum and a piston drum.
[Explanation of symbols]
11 Torque converter 12 Main transmission part 13 Sub transmission part 14 Transmission case 41 Carrier 42 Clutch hub 43 Clutch drum 43a Cylindrical part 43b Flange parts 47, 48 Clutch disk 51 Hollow shaft part 52 Piston drum 53 Piston 54 Piston oil chamber 58 Cancellation Oil chamber 59 Communication holes 61, 62 Lubricating oil supply hole

Claims (3)

A clutch hub having a plurality of clutch discs attached to the outside; and a clutch drum having a plurality of clutch discs frictionally engaged with the clutch discs, the power of the clutch hub and the clutch drum being An automatic transmission that performs intermittent operation,
Fixed between the hollow shaft portion having a smaller diameter than the clutch hub and the clutch drum, and a piston drum having a larger diameter than the clutch disc;
A piston having an outer peripheral surface having a smaller diameter than the inner diameter of the piston drum and provided in the piston drum so as to be movable in the axial direction, and forming a piston oil chamber with an end wall of the piston drum;
A retainer disposed between the piston outer peripheral surface and the piston drum inner peripheral surface, and forming a cancel oil chamber radially outward of the piston oil chamber;
The cancellation oil chamber is provided radially outward with respect to the piston oil chamber ,
The clutch drum has a cylindrical portion and a flange portion projecting outward from the cylindrical portion, and a sealing member is fired on the flange portion and sealed and joined to the piston drum. apparatus. 2. The automatic transmission according to claim 1 , wherein a communication hole communicating with the cancellation oil chamber is provided in the piston. 3. The automatic transmission according to claim 1, wherein a lubricating oil supply hole for supplying lubricating oil to the clutch disk is formed in the piston.

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