JPH0134748Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a clutch device for an automatic transmission.

(Prior Art) Automatic transmissions used in automobiles and the like are equipped with a hydraulically operated clutch device for shifting gears. One of the clutch devices includes a cylindrical clutch drum and a cylindrical shoulder that extends in the axial direction of the clutch drum and comes into sliding contact with the outer peripheral surface of the clutch inner, in a cylindrical space formed inside the clutch drum. It is widely known that an annular piston is fitted into the piston. A hydraulic oil chamber is formed between the clutch drum and the piston in the clutch device, and when hydraulic oil is pressurized into the hydraulic oil chamber, the piston moves to apply braking. Hydraulic oil is supplied to the hydraulic oil chamber through an oil passage provided in the drum inner, but in the clutch device as described above, when the brake is not applied, that is, when the piston is retracted, the cylindrical shape of the piston is Because the shoulder and the outer peripheral surface of the drum inner are in close contact with each other, hydraulic oil cannot be supplied by the hydraulic oil passage that penetrates the drum inner in the radial direction. Conventionally, a separate oil passage that extends in the axial direction inside the drum inner is used. was established. Hydraulic oil is supplied from the inner peripheral surface of the drum inner, and it is necessary to connect this axially extending oil passage to the inner peripheral surface of the drum inner. It was difficult to form the oil passage. Furthermore, the provision of this oil passage increases the radial size of the drum inner, which is a factor that hinders miniaturization of clutch devices and automatic transmissions.

(Purpose of the invention) The object of the invention is to provide a cylindrical clutch drum and a cylindrical space formed inside the clutch drum with a cylindrical member extending in the axial direction of the clutch drum and slidingly contacting the outer peripheral surface of the clutch inner. A clutch device for an automatic transmission, in which an annular piston having a shoulder portion is fitted and arranged, can easily form an oil passage in a drum inner, and can achieve miniaturization of the clutch device. It is about providing.

(Structure of the invention) The clutch device of the automatic transmission of the invention includes a cylindrical clutch drum, a large diameter portion arranged in the axial direction at a distance from the clutch drum, and arranged radially inwardly of the clutch drum. and a generally cylindrical drum inner formed with a small diameter portion, and an annular piston slidably fitted and disposed between the clutch drum and the drum inner, the piston having a radially inner portion thereof. It extends in the axial direction along the outer circumferential surface of the large diameter portion of the drum inner so as to act as a guide member during sliding, and the inner circumferential surface slides on the outer circumferential surface of the large diameter portion of the drum inner. A cylindrical shoulder part is formed in contact with the shoulder part, and a disc-shaped part that extends radially inward continuously and has an inner peripheral end in sliding contact with the outer peripheral surface of the small diameter part of the drum inner. An oil passage extending in the radial direction is formed in the large diameter portion, and a portion of the outer peripheral surface of the large diameter portion is machined in the axial direction so that an oil passage extending in the axial direction is formed between it and the cylindrical shoulder of the piston. It is characterized by being formed. In this invention, a gap is formed between a part of the outer surface of the drum inner and the shoulder of the piston, and the oil passage is opened in this gap, so there is no need to provide an oil passage extending in the axial direction inside the drum inner. In both cases, hydraulic oil is supplied smoothly. Furthermore, the outer surface of the drum inner where no oil passage is formed still serves as a guide for the shoulder of the piston, so that the piston can operate smoothly.

(Embodiment) An automatic transmission according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating an automatic transmission for an automobile using the clutch device of the present invention.

In FIG. 1, reference numeral 1 indicates a crankshaft of an engine (not shown) which is an input shaft, and a torque converter 2 and a multi-speed gearing device 10 are arranged coaxially with this crankshaft 1 in order from the engine side. . The torque converter 2 includes a pump 3, a turbine 4, and a stator 5,
The pump 3 is fixed to the crankshaft 1. The stator 5 is connected to a fixed shaft 7 integrally connected to the case 11 of the multi-speed gearing device 10 via a one-way clutch 6.
rotate on top. The one-way clutch 6 allows the stator 5 to rotate in the same direction as the pump 3, but does not allow it to rotate in the opposite direction.

The multi-speed gear device 10 has a base end fixed to the crankshaft 1 and a distal end extending through the center of the multi-speed gear device to drive an oil pump P disposed on the side wall of the device. It has a central shaft 12 connected to the pump. On the outside of this central shaft 12, a hollow turbine whose base end is connected to the turbine 4 of the torque converter 2, whose distal end extends to the side wall of the multi-speed gear unit 10, and is rotatably supported by the side wall. A shaft 13 is provided. A Ravigneau type planetary gear unit 14 is provided on the turbine shaft 13, and this planetary gear unit 14 is connected to a small diameter sun gear 15, and a large diameter sun gear 1 disposed on the side of the small diameter sun gear 15 far from the engine.
6, a long pinion gear 17, a short pinion gear 18, and a ring gear 19.
First and second clutch devices 20 and 21 are arranged in parallel on the side of the planetary gear unit 14 that is far from the engine. The first clutch device 20 connects and disconnects power transmission between the small diameter sun gear 15 and the turbine shaft 13 via the first one-way clutch 22. On the other hand, the second clutch device 21 is connected in parallel with the first clutch device 20 to connect and disconnect power transmission between the small diameter sun gear 15 and the turbine shaft 13. A first brake device 2 is disposed radially outwardly of the second clutch device 21.
3 is placed. This first brake device 2
3 is a band brake, which includes a brake drum 23a connected to the large-diameter sun gear 16 and a brake band 23b hung on the brake drum.
has. radially outward of the first clutch device 20 and the first brake device 2
A third clutch device 24 is disposed on the side of the clutch device 3, and this third clutch device 24 is connected to the brake drum 23a of the first clutch device 23.
The power transmission between the large-diameter sun gear 16 and the turbine shaft 13 is switched on and off through the .

A carrier 14a of the planetary gear unit 14 and a case 10a of the multi-speed gear device 10 are arranged radially outwardly of the planetary gear unit 14.
A second brake device 25 is arranged to engage and disengage the. The first and second brake devices 23
and 25, a second one-way clutch device 26 is disposed in parallel with the second brake device 25 for engaging and disengaging the carrier 14a and the case 10a. On the side of the planetary gear unit 14 on the engine side, a carrier 14a of the planetary gear unit and the turbine shaft 13 are arranged.
a fourth clutch device 2 for intermittent power transmission between
7 is placed. This fourth clutch device 2
An output gear 28 connected to a ring gear 19 is arranged on the side of the engine 7 on the engine side. Note that the reference numeral 29 in the figure indicates the turbine shaft 1.
3 shows a lock-up clutch for directly connecting the crankshaft 1 to the crankshaft 1 without going through the torque converter 2.

Next, with reference to FIG. 2, the structure of each of the above-mentioned devices constituting the automatic transmission will be explained.

Second Clutch Device 21 The second clutch device 21 is spline-coupled to the turbine shaft 13 and includes a clutch drum 21a having a substantially U-shaped cross section. A clutch hub 21c is disposed inside the clutch drum 21a, and the clutch hub 21c is integrally supported by a support portion 21d splined to the small diameter sun gear 15. The clutch drum 21a and the clutch hub 21c respectively support alternately arranged clutch plates 21e and clutch discs 21b by spline connection. A piston 21f having a substantially U-shaped cross section is fitted into the clutch drum 21a in a shape corresponding to the contour of the inner wall of the drum 21a. This piston 21
A hydraulic oil chamber 2 is located between f and the clutch drum 21a.
1g is formed, and by controlling the supply of hydraulic oil to this hydraulic oil chamber 21g, the clutch plate 21e and the clutch disc 21
The second clutch device 21 is engaged and disengaged by pressing or releasing b.
Furthermore, as is clear from the figure, the clutch hub 21c
The base of the support portion 21d constitutes the inner race of the first one-way clutch 22.

First clutch device 20 Piston 21f of the second clutch device 21
also serves as the clutch drum 20a of this first clutch device 20. A clutch hub 20c is arranged inside the clutch drum 20a,
The base of the clutch hub 20c is integrally supported by a support portion 20d that constitutes the outer race of the one-way clutch 22. The clutch drum 20a and clutch hub 20c support alternately arranged clutch plates 20e and clutch disks 20b by spline connection. A piston 20f is fitted inside the clutch drum 20a, and a hydraulic fluid chamber 20g is formed between the piston 20f and the clutch drum 20a. By controlling the supply of hydraulic oil to the hydraulic oil chamber 20g, the clutch plate 20e and clutch disc 20b are pushed or released, and the first clutch device 20 is engaged or disengaged. It's summery. In addition, 20h in the figure is the piston 20f of the first and second clutch devices 20, 21,
The return spring for 21f is shown.

Third Clutch Device 24 The third clutch device 24 includes a substantially U-shaped clutch drum 24a that is integral with the clutch drum 21a. A clutch hub 24c is disposed inside the clutch drum 24a, facing the clutch drum 24a.
4c is formed by an extension of the clutch drum 23a of the first brake device 23. The clutch drum 24a and clutch hub 24c support alternately arranged brake plates 24d and clutch discs 24b, respectively, by spline connection. A piston 24e is fitted inside the clutch drum 24a, and a hydraulic fluid chamber 24f is formed between the piston 24e and the clutch drum 24a. This hydraulic oil chamber 2
By controlling the supply of hydraulic oil to 4f,
The third clutch device 20 is engaged and disengaged by pressing or releasing the clutch plate 24d and the clutch plate 24b. This third clutch device 24 is equipped with a diaphragm-type return spring 24g for the piston 24e. The reason why a diaphragm type return spring is used in this third clutch device 24 is that this diaphragm type is thin and does not require a large space.

First Brake Device 23 The brake drum 23a of the first brake device 23 is supported by a support portion 23c that is integrally supported by the large diameter sun gear 16. Therefore, when this first brake device 23 is activated,
The large diameter sun gear 16 is fixed.

Second brake device 25 This second brake device 25 is a disc type brake, and its brake drum 25a
is the carrier 14a of the planetary gear unit 14.
It is supported by a support portion 25b that is integrally fixed to the support portion 25b. Therefore, this second brake device 2
3 is activated, the carrier 14a is fixed.

Fourth Clutch Device This fourth clutch device 27 is an embodiment of the clutch device of the automatic transmission of the present invention. As clearly shown in FIG. 3, which is a partially enlarged view of FIG. Cylindrical drum inner 27
i is placed. A clutch drum 27a having a U-shaped cross section is attached to the outer periphery of the end of this drum inner 27i.
The disc-shaped part is fixed. A plurality of clutch plates 27d are attached to the inner peripheral surface of the drum-shaped portion of the clutch drum 27a by spline connection. These clutch plates 27d
A clutch disk 27b is disposed between them and is attached to an inner clutch hub 27c by spline connection. An annular piston 27e that presses the clutch plate 27d and the clutch disc b is fitted into the cylindrical space formed by the clutch drum 27a and the drum inner 27i. A cylindrical shoulder extending in the axial direction and in contact with the drum inner 27i is formed on the inner circumference of the annular piston 27e, and the tip of this shoulder is bent radially inward. . Annular seal members 27h and 27h' are fitted to the outer and inner peripheral ends of the piston, and a hydraulic oil chamber 27 is fitted between the clutch drum 27a and the piston 27e.
f is formed. An annular diaphragm spring 27g is arranged between the piston 27e, the clutch plate 27d, and the clutch disk 27b. As is clear from FIG. 4, which is a plan view, the drum inner 27i has a cylindrical body with a portion cut out, and the piston 27e
When fitted into the cylindrical shoulder portion of the oil passage 27k, a gap is formed and an oil passage 27k extending in the axial direction is provided. An oil passage 27j extends substantially perpendicularly to the axis of the drum inner 27i and opens into the notch. In this invention, the oil passage 2
Since the opening of the piston 7j is not blocked by the shoulder of the piston 27e, there is no need to provide an oil passage extending in the axial direction as in the conventional case. Hydraulic oil is supplied to the central shaft 1 by the oil pump P shown in Figure 2.
2 and the turbine shaft 13, and is press-fitted into the hydraulic oil chamber 27f through the oil passage 27j and the oil passage 27k of the drum inner 27i, the piston 27e moves to the right in the figure against the diaphragm spring 27g. Then, the clutch plate 27d and the clutch disk 27b are pressed, and the fourth clutch device 27 is braked.
When the injection of hydraulic oil is stopped, the piston 27e is moved to the left in the figure by the diaphragm spring 27g, and the braking of the fourth clutch device is released.

In the above embodiment, the oil passage 27k is provided between the shoulder of the piston 27e and the drum inner 27i by providing a flat part along the axial direction in a part of the cylindrical drum inner 27i. , the drum inner 2 as shown in FIG.
An oil passage 27k extending in the axial direction may be formed between the shoulder of the piston 27e and the opening of the oil passage 27j by forming a groove along the axial direction in the piston 7i.

In each of the above embodiments, the drum inner 27i is provided with two opposing oil passages 27j, but more oil passages are provided, and accordingly, the shoulder portion of the piston 27e is formed in the same way as in the above embodiments. An oil passage may be provided that communicates with the opening on the outer peripheral side of the oil passage 27j.

(Effects of the invention) In the present invention, an oil passage extending in the axial direction is formed between the shoulder of the piston and a part of the outer surface of the drum inner that makes sliding contact, and the oil passage extending in the axial direction has one side. The oil passage that opens extends into the drum inner, and the oil passage is not blocked by the shoulder of the piston.
There is no need to form an oil passage extending in the axial direction in the drum inner, making it easy to form the oil passage. Furthermore, the radial size can be reduced by not forming an axial oil passage, and the clutch device and, by extension, the automatic transmission can be made smaller. Furthermore, since the outer surface of the drum inner where no oil passage is formed still serves as a guide for the shoulder of the piston, the piston operates smoothly. Further, it is possible to obtain the advantage that the oil passage extending in the radial direction is formed in the large diameter portion of the drum inner, which is advantageous in terms of strength.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram schematically showing an automatic transmission using the clutch device of the present invention, and FIG.
FIG. 3 is a partially enlarged view of FIG. 2, and FIG. 4 shows a drum inner of an embodiment of the clutch device of the present invention. FIG. FIG. 5 is a sectional view showing a drum inner according to another embodiment. 1...Input shaft, 2...Torque converter, 10
...Multi-speed gear device, 12...Central shaft, 13...
...Turbine shaft, 14...Planetary gear unit, 15...Small diameter sun gear, 16...Large diameter sun gear, 17...Long pinion gear, 18...
Short pinion gear, 19...Ring gear, 2
0...First clutch device, 21...Second clutch device, 22...First one-way clutch device, 23...First brake device, 24...Third clutch device, 25...Third clutch device Second brake device,
26... Second one-way clutch, 27... Fourth clutch device, 27a... Clutch drum,
27b...Clutch inner, 27c...Clutch hub, 27d...Clutch plate, 27e...
Piston, 27f... Hydraulic oil chamber, 27g... Diaphragm spring, 27h, 27h'... Seal member, 27i... Drum inner, 27j... Oil passage, 27k... Oil passage, 28... Output gear.

Claims (1)

[Scope of utility model registration request] a cylindrical clutch drum; a generally cylindrical drum inner having a large diameter portion and a small diameter portion spaced apart from the clutch drum and arranged in axial alignment; An annular piston is slidably fitted between the drum and the drum inner, and a radially inner portion of the piston is provided with a ring of the drum inner so as to act as a guide member during sliding of the piston. It extends in the axial direction along the outer peripheral surface of the large diameter part,
a cylindrical shoulder portion whose inner circumferential surface slides on the outer circumferential surface of the large-diameter portion of the drum inner; and a circle that extends radially inward continuously from the shoulder portion and whose inner circumferential end slides on the outer circumferential surface of the small-diameter portion of the drum inner. A plate-shaped portion is formed, and an oil passage extending in the radial direction is formed in the large diameter portion of the drum inner, and a portion of the outer circumferential surface of the large diameter portion is machined in the axial direction so that the piston A clutch device for an automatic transmission, characterized in that an oil passage extending in the axial direction is formed between the clutch device and the cylindrical shoulder portion of the clutch device.