JPS6120331Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a hydraulic servo mechanism used in a multi-disc clutch of an automatic transmission for a vehicle.

BACKGROUND OF THE INVENTION In friction engagement devices of automatic transmissions, hydraulic servomechanisms of multi-disc clutches used, for example, to achieve third forward speed and reverse, are designed to cope with the disparity in transmitted torque in each case. , a first annular piston with a large pressure-receiving area and a second annular piston with a small pressure-receiving area are provided in series in an annular cylinder, and hydraulic pressure is selectively applied to these annular pistons to apply pressure to the clutch plate. They were configured to apply different engagement forces and obtain different transmission torques.

Furthermore, since the hydraulic pressure is supplied to the annular cylinder of the hydraulic servo mechanism of such an annular multi-disc clutch from the inner circumferential wall, the two annular pistons have the same inner diameter and different external dimensions to achieve a predetermined value. As a result, the hydraulic servo mechanism is constructed compactly by making the outer circumferential wall of the annular cylinder in the part where the annular piston with a small pressure receiving area is fitted into a small diameter part, and the small diameter part of the annular cylinder outer circumferential wall. For example, a brake device was arranged on the outer periphery for fixing a gear element connected to the annular cylinder.

Problems to be Solved by the Invention When the second annular piston is fitted into the annular cylinder during assembly of a hydraulic servo mechanism having such a configuration, the inner O-ring of the annular piston is inserted into the first annular piston. It must pass through the oil passage (hole) that supplies hydraulic oil to the oil chamber with a certain clearance. Furthermore, burrs are likely to form on the edges of the oil passage during machining of the oil passage, and as a result, the O-ring attached to the inner circumferential side of the second annular piston may be damaged at the edge of the oil passage. Problems such as loss of sealing performance sometimes occurred.

In order to solve this problem, the inner diameter of the second annular piston is made larger than the outer diameter of the inner peripheral wall of the annular cylinder where the oil passage is arranged, so that when the second annular piston is assembled, the inner diameter of the annular piston is It is possible to prevent the O-ring from contacting the edge of the oil passage, but in order to ensure that the O-ring does not come into contact with the edge of the oil passage, it is necessary to make the inner diameter of the second annular piston considerably large. There has been a problem in that the compactness of the hydraulic servo mechanism is impaired due to the increase in diameter of the small diameter portion of the outer peripheral wall of the annular cylinder as the diameter of the piston increases.

In a hydraulic servo mechanism that has two annular pistons with different pressure-receiving areas in series in such an annular cylinder, the present invention is designed to prevent O-rings on the inner circumferential side of the annular piston during assembly work without impairing the compactness of the hydraulic servo mechanism. An object of the present invention is to provide a hydraulic servo mechanism that can prevent deterioration in sealing performance due to damage to an O-ring by reliably preventing contact with the edge of an oil passage.

Means for Solving the Problems In order to solve the above problems, the hydraulic servo mechanism for a multi-plate clutch of the present invention includes an annular cylinder having a side wall, an outer circumferential wall and an inner circumferential wall connected to the side wall;
The annular cylinder includes a first annular piston and a second annular piston that are fitted between the outer circumferential wall and the inner circumferential wall, and the outer circumferential wall of the annular cylinder has a small diameter portion continuous to the side wall, and a small diameter portion connected to the small diameter portion. The inner circumferential wall of the annular cylinder has a large diameter portion continuous to the side wall and a small diameter portion continuous to the large diameter portion, and the first annular piston has a seal ring on the inner circumference and outer circumference. is installed,
A first oil chamber is fitted between a large diameter portion of the outer circumferential wall and a small diameter portion of the inner circumferential wall to form a first oil chamber between the second annular piston and the second annular piston. A seal is attached to the
A second oil chamber is formed between the small diameter portion of the outer circumferential wall and the large diameter portion of the inner circumferential wall, and a second oil chamber is formed between the small diameter portion of the inner circumferential wall and the large diameter portion of the inner circumferential wall. A first hydraulic oil supply passage is formed, a second hydraulic oil supply passage to the second oil chamber is formed in a large diameter portion of the inner circumferential wall, and the second annular piston is connected to the annular cylinder. When the first
The outer periphery of the second annular piston fits into a small diameter portion of the outer peripheral wall of the annular cylinder on the hydraulic oil supply path.

Effects of the invention In the hydraulic servo mechanism of the invention, the outer circumferential wall of the annular cylinder has a small-diameter portion continuous to the side wall and a large-diameter portion continuous to the small-diameter portion, and the first annular piston is connected to the large-diameter portion of the outer circumferential wall. fitted between the inner circumferential wall and forming a first oil chamber between the second annular piston and the second annular piston;
The inner circumferential wall of the annular cylinder of the hydraulic servo mechanism is configured such that the second annular piston is fitted between the small diameter portion of the outer circumferential wall and the inner circumferential wall to form a second oil chamber between the side wall and the inner circumferential wall of the annular cylinder. a large diameter portion continuous to the large diameter portion and a small diameter portion continuous to the large diameter portion, a first hydraulic oil supply oil passage to the first oil chamber is formed in the small diameter portion of the inner circumferential wall, and the second annular piston When the second annular piston is fitted into the annular cylinder, the outer periphery of the second annular piston fits into the small diameter portion of the outer peripheral wall of the annular cylinder on the first hydraulic oil supply and drain path. When assembling the second annular piston, the annular piston is attached to the first annular piston.
is guided by the small diameter portion of the outer circumferential wall of the annular cylinder on the hydraulic oil supply and drain path of the annular cylinder, and the outer diameter of the large diameter portion of the inner circumferential wall of the annular cylinder and the inner diameter of the second annular piston are different from those of the conventional one. By making it slightly larger, the O-ring at the inner circumference of the annular piston can pass through the small diameter portion of the inner circumferential wall where the hydraulic oil supply/drainage path is formed while reliably maintaining a gap. A compact hydraulic servo that can prevent the O-ring from being damaged at the edge of the hydraulic oil supply and drain path without compromising the compactness of the mechanism, and that does not cause a reduction in sealing performance due to damage to the O-ring. mechanism can be provided.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an automatic transmission equipped with a hydraulic servo mechanism according to the present invention, in which a hydraulic torque converter 1 includes a pump impeller 5, a turbine liner 6, and a stator 7, and the pump impeller 5 is connected to an engine (not shown). The turbine liner 6 is connected to a crankshaft 8, and the turbine liner 6 is connected to a turbine shaft 9a. Torque converter 1 is surrounded in the circumferential direction of turbine shaft 9a by housing 17a.

Rear of torque converter 1 (hereinafter, the side closer to the engine is referred to as "front", and the side farther from the engine is referred to as "rear")
are partitioned by an oil pump body 20. The oil pump cover 21 is arranged adjacent to the oil pump body 20 and defines a pump chamber of the oil pump 71 together with the oil pump body 20. Oil pump gear 5 of oil pump 71
0 is connected to the pump impeller 5. Passage 72 formed within oil pump body 20
is connected to the suction port of the oil pump 71, and is also connected to a passage 73 formed at the bottom of the oil pump cover 21.

Behind the oil pump 71 and adjacent to the oil pump cover 21, an underdrive device 3 with three forward speeds and one reverse speed is installed coaxially with the torque converter 1. The turbine shaft 9a serves as an input shaft of the underdrive device 3. The underdrive device 3 is housed in a transmission case 18, and its front portion is covered with an oil pump cover 21. oil pump body 20,
Oil pump cover 21 and transmission case 18 are coupled to each other by a plurality of bolts 22a.

The turbine shaft 9a is connected to a clutch cylinder 65, and a multi-plate clutch 24 is provided between the clutch cylinder 65 and the intermediate shaft 29. The hub 66 is fitted with a clutch cylinder 65. A multi-plate clutch 25 is provided between the hub 66 and the sun gear shaft 30, and a second annular piston 9 with a small pressure receiving area is attached to the annular clutch cylinder 80.
0 and the first annular piston 95 with a large pressure receiving area.
It is operated by a hydraulic servo mechanism 40 which is fitted in series. This multi-plate clutch 25 is engaged by the operation of only the second annular piston during the third forward speed, and is engaged by the operation of only the second annular piston when the transmission torque is large.
and a second annular piston. A multi-disc brake 26, a one-way clutch 61 and a multi-disc brake 60 connected in series are provided between the sun gear shaft 30 and a support 31 fixed to the transmission case 18. A sun gear 32 is formed on the sun gear shaft 30. Sun gear 32 meshes with planetary pinions 34 and 37, one planetary pinion 34 meshes with ring gear 35, and the other planetary pinion 37 meshes with ring gear 38. In other words, a two-row planetary gear device including the sun gear 32, the planetary pinion 34, and the ring gear 35, and the sun gear 32, the planetary pinion 37, and the ring gear 38 is configured. Ring gear 35 is connected to intermediate shaft 29 via flange 67. Further, the planetary pinion 34 is the pinion shaft 6 of the carrier 33.
The planetary pinion 37 is rotatably supported on a pinion shaft 68 of the carrier 36 . An output shaft 39 of the underdrive device 3 is connected to a ring gear 38 and a carrier 33. A multi-disc brake 27 and a one-way clutch 28 are provided between the carrier 36 and the transmission case 18.

Below the underdrive device 3 is the oil pan 75.
It is covered by a. Inside the oil pan 75a, a hydraulic control device 4a (only a portion of which is shown) is arranged to control the hydraulic pressure supplied to the hydraulic servo mechanism of the underdrive device. A passage 76 formed at the lower front end of the transmission case 18
connects the oil passage 73 of the oil pump cover 21 into the oil pan 75a.

In addition to the oil passage 73, the oil pump cover 21 is provided with an oil passage that connects the hydraulic control device 4a and the clutch cylinder 65, and an oil passage that connects the discharge port of the oil pump 71 and the hydraulic control device 4a. There is. Further, the oil pump body 20 and the oil pump cover 21 are formed with an oil passage for supplying oil from the hydraulic control device 4a to the torque converter 1, and an oil passage for returning oil from the torque converter 1 to the hydraulic control device 4a.

As shown in FIG. 2, the annular clutch cylinder 80
is a side wall 81 and a small diameter portion 83 connected to the side wall 81.
and an outer peripheral wall consisting of a large diameter portion 84 connected thereto;
It has an inner circumferential wall consisting of a large diameter portion 85 continuous to the side wall 81 and a small diameter portion 86 continuous to this. The outer diameter D ₁ of the large diameter portion 85 of the peripheral wall is approximately 1 mm larger than the outer diameter D ₂ of the small diameter portion 86 . The first annular piston 95 has an outer diameter and an inner diameter corresponding to the inner diameter of the large diameter portion 84 of the outer circumferential wall and the outer diameter of the small diameter portion 86 of the inner circumferential wall, and has seal rings 96 and 97 on the inner and outer circumferences. The first oil chamber 100 is fitted between the large diameter portion 84 of the outer circumferential wall and the small diameter portion 86 of the inner circumferential wall, and forms a first oil chamber 100 between the second annular piston 90 and the second annular piston 90 . Second annular piston 90
are formed with an outer diameter and an inner diameter corresponding to the inner diameter of the small diameter portion 83 of the outer circumferential wall and the outer diameter of the large diameter portion 85 of the inner circumferential wall, and seal rings 91 and 92 are attached to the inner and outer circumferences of the outer circumferential wall. A second oil chamber 103 is formed between the small diameter portion 83 and the side wall 81 by being fitted between the small diameter portion 83 and the large diameter portion 85 of the inner circumferential wall.
A first hydraulic oil supply oil passage 101 for supplying hydraulic oil to the first oil chamber 100 is formed in the small diameter portion 86 of the inner peripheral wall, and a second oil chamber 1 is formed in the large diameter portion 85 of the inner peripheral wall.
Second hydraulic oil supply oil passage 1 that supplies hydraulic oil to 03
02 is formed.

In the work of assembling the second annular piston 90 to the annular cylinder 80 of the hydraulic servo mechanism 40, the inner diameter of the piston 90 is larger than the outer diameter of the inner peripheral wall small diameter portion 86 of the annular cylinder 80, and the first hydraulic oil supply/drainage is performed. Since the outer periphery of the second annular piston 90 is fitted and guided in the small diameter portion 83 of the outer peripheral wall of the annular cylinder on the passage 101, the O-ring 91 is guided in the oil passage 101.
The edges of the O-ring 91 do not come into contact with each other, thereby preventing damage to the O-ring 91 and improving assembly work.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the automatic transmission, and FIG. 2 is an enlarged view of its main parts. In the figure, 40... Hydraulic servo mechanism, 80... Annular cylinder, 85, 86... Annular cylinder inner peripheral wall,
90,95...Annular piston.

Claims (1)

[Scope of utility model registration request] an annular cylinder having a side wall and an outer circumferential wall and an inner circumferential wall connected to the side wall; a first annular piston and a second annular piston fitted between the outer circumferential wall and the inner circumferential wall of the annular cylinder; The outer circumferential wall of the annular cylinder has a small diameter portion continuous to the side wall and a large diameter portion continuous to the small diameter portion, and the inner circumferential wall of the annular cylinder has a large diameter portion continuous to the side wall and a small diameter portion continuous to the large diameter portion. The first annular piston has a seal ring attached to its inner and outer circumferences, and is fitted between a large diameter portion of the outer circumferential wall and a small diameter portion of the inner circumferential wall to connect with the second annular piston. A first oil chamber is formed between the
Seal rings are attached to the inner and outer circumferences of the second annular piston, and are fitted between a small diameter portion of the outer circumferential wall and a large diameter portion of the inner circumferential wall to form a second oil chamber between the side wall and the second annular piston. A first hydraulic oil supply passage to the first oil chamber is formed in a small diameter portion of the inner circumferential wall, and a second hydraulic oil supply passage to the second oil chamber is formed in a large diameter portion of the inner circumferential wall. An oil supply oil path is formed,
When the second annular piston is fitted into the annular cylinder, the outer periphery of the second annular piston fits into a small diameter portion of the outer peripheral wall of the annular cylinder on the first hydraulic oil supply path. A multi-disc clutch hydraulic servo mechanism for an automatic transmission, characterized by: