KR102487191B1 - Clutch device for automatic transmission - Google Patents

Abstract

A power transmission device for an automatic transmission according to an embodiment of the present invention is composed of a clutch drum connected to one rotational element, and connected to another rotational element through a clutch hub configured inside the clutch drum to transmit rotational power. A power transmission device for an automatic transmission comprising a clutch configured and a piston unit operating the clutch by hydraulic pressure in a state in which the front end is disposed toward the clutch, the piston unit comprising the one rotation element and the one a first piston disposed in a sealed state between a connecting plate connected to a rotating element and receiving hydraulic pressure through a first flow path formed in the one rotating element and operating toward the clutch; It is arranged in a sealed state between the one rotating element and the first piston, and is supplied with hydraulic pressure through a second flow path formed in the one rotating element, so that the tip is a second piston acting directly on the clutch; a spring retainer installed between the one rotating element and the second piston; a return spring installed between the spring retainer and the second piston to provide restoring force to the first and second pistons; and a synchronizing unit configured between the connecting plate and the clutch drum to selectively and synchronously connect the rotational power of the one rotating element to the clutch drum in conjunction with the operation of the first piston.

Description

Power transmission device for automatic transmission {CLUTCH DEVICE FOR AUTOMATIC TRANSMISSION}

The present invention relates to a power transmission device for an automatic transmission, and more particularly, to a power transmission device for an automatic transmission that provides optimized clearance control and coupling force between friction members for each operating section by applying a double piston to drive a clutch that transmits rotational force. It's about transmission.

Eco-friendly technology in vehicles is a key technology on which the survival of the future automobile industry depends. Recently, as exhaust gas regulations have been intensified, car makers are concentrating their efforts on developing eco-friendly vehicles through environmental regulations and fuel efficiency improvement.

In order to achieve this goal of improving fuel efficiency, various studies such as high-efficiency engines, high-efficiency transmissions, and lightweight car bodies are being actively conducted. Development of manual transmissions and the like is actively being carried out.

These transmissions transmit engine rotational force and torque through a dry or wet clutch. The clutch applied to a double clutch transmission and an automated manual transmission does not go through a torque converter like the clutch of an automatic transmission, but engine torque that is directly transmitted from the engine. Since it transmits, large coupling force and control precision are required.

That is, these double clutch transmissions and clutches for automated manual transmissions require a high operating speed of the piston for rapid power transmission until the initial period of engagement between the clutch disk and the clutch plate, which are friction materials, and after the clutch disk and clutch plate are coupled, the power At the beginning of transmission, a large binding force for power transmission is required rather than a fast operating speed of the piston.

From this point of view, recent clutches that transmit rotational force satisfy both the conditions of fast operating speed and large coupling force of the piston, but do not precisely control them for each operating section even though they do not require both fast operating speed and large coupling force of the piston at the same time. There is a disadvantage in that the overall operating efficiency of the clutch is reduced.

In addition, as the large coupling force and high operating speed of the piston repeatedly act on the clutch plate, there is a disadvantage in that the clutch is damaged due to cumulative fatigue.

An embodiment of the present invention is to provide a power transmission device for an automatic transmission that secures shift responsiveness and coupling force by rapidly controlling a gap between friction members by applying a double piston that operates sequentially to drive a clutch that transmits rotational force.

In addition, a synchronizing unit that interlocks with the operation of the double piston is formed between one rotating element and the clutch drum to fundamentally block the rotational power transmitted to the clutch when the clutch is released, preventing drag loss. Power transmission for automatic transmission We want to provide you with a device.

In addition, an embodiment of the present invention is a power for an automatic transmission that secures control reliability by canceling the centrifugal hydraulic pressure of the remaining fluid while preventing drag loss when the clutch is released by a return spring and compensating hydraulic pressure that directly act on the double piston. We want to provide a delivery device.

In one or more embodiments of the present invention, a clutch drum connected to one rotational element, and a clutch configured inside the clutch drum and connected to another rotational element through a clutch hub to transmit rotational power; In the power transmission device for an automatic transmission including a piston unit operating the clutch by hydraulic pressure in a state in which the front end is disposed toward the clutch, the piston unit is connected to the one rotation element and the one rotation element. a first piston disposed in a sealed state between plates and operated toward the clutch by receiving hydraulic pressure through a first passage formed in the one rotating element; It is arranged in a sealed state between the one rotating element and the first piston, and is supplied with hydraulic pressure through a second flow path formed in the one rotating element, so that the tip is a second piston acting directly on the clutch; a spring retainer installed between the one rotating element and the second piston; a return spring installed between the spring retainer and the second piston to provide restoring force to the first and second pistons; and a synchronous unit configured between the connecting plate and the clutch drum to selectively and synchronously connect the rotational power of the one rotating element to the clutch drum in conjunction with the operation of the first piston. may be provided.

delete

delete

In addition, the inner circumferential end of the spring retainer is supported in the clutch direction by a stopper installed at the center of the one rotating element, and the outer circumferential end is in contact with the inner surface of the outer diameter of the second piston via a seal, It may be configured to receive hydraulic pressure through a third flow path formed in the one rotating element between the second piston and form a compensating hydraulic pressure.

The stopper may be made of a snap ring.

In addition, the synchronizing unit may include a synchronizer configured such that a front end of an outer diameter portion of the first piston is connected to a sleeve to interlock with the operation of the first piston.

In addition, each outer diameter of the first and second pistons is disposed parallel to the axial direction, and the outer diameter of the first piston has an outer surface and an inner surface between the inner surface of the connection plate and the outer surface of the outer diameter of the second piston, respectively. can be contacted through a sealing, respectively.

In addition, each inner diameter of the first and second pistons may be configured to slide in contact with each seal installed on the one rotation element and disposed in parallel to the one rotation element.

In addition, the one rotation element may be formed of an input shaft that is power-connected to the output side of the engine, and the other rotation element may be formed of one rotation element among three rotation elements of the planetary gear set.

In the embodiment of the present invention, by applying a double piston to drive a clutch that transmits rotational force, shift response is improved by controlling the gap between friction materials at a rapid operating speed, and power transmission efficiency can be increased by securing coupling force.

In this way, the fast gap control and coupling force between the friction materials of the double piston are sequentially performed for each operating section to minimize accumulated fatigue that repeatedly acts on the clutch plate, thereby eliminating the cause of clutch damage.

In addition, a synchronizing unit that interlocks with the operation of the double piston is formed between one rotational element and the clutch drum, so that when the clutch is released, the rotational power transmitted to the clutch is cut off by the synchronizing unit, resulting in relative rotation between the friction materials inside the clutch. Drag loss can be fundamentally prevented.

In addition, in an embodiment of the present invention, when the clutch is released through a return spring directly acting on the double piston and compensation hydraulic pressure supplied between the double piston and the spring retainer, the centrifugal hydraulic pressure of the remaining fluid is reduced while preventing drag loss when the clutch is released. By offsetting, control reliability can be secured.

In addition, since the control starts at more than the spring force of the return spring applied to the double piston, control of the unstable hydraulic solenoid valve in the low pressure section is excluded, thereby increasing control reliability.

1 is a configuration cross-sectional view of a power transmission device for an automatic transmission according to an embodiment of the present invention.
2 is a cross-sectional view of a first-stage operating state of a power transmission device for an automatic transmission according to an embodiment of the present invention.
3 is a cross-sectional view of a two-stage operating state of a power transmission device for an automatic transmission according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail through the accompanying drawings.

However, in order to clearly describe the embodiments of the present invention, parts irrelevant to the description are omitted, and the same reference numerals are applied to the same or similar components throughout the specification to be described.

In the following description, the names of the components are divided into first, second, etc. to distinguish them because the names of the components are the same, and are not necessarily limited to the order.

1 is a configuration cross-sectional view of a power transmission device for an automatic transmission according to an embodiment of the present invention.

Referring to FIG. 1 , a power transmission device for an automatic transmission according to an embodiment of the present invention will be described as an example of a clutch device applied between rotating elements to enable power transmission.

That is, the clutch device is basically configured to transmit the rotational power of the engine between the rotational elements, and in the embodiment of the present invention, the input shaft (IS) as a rotational element and the planetary carrier (one rotational element of the planetary gear set) PC) will be described through an example configured between.

Here, the planetary gear set consists of a sun gear, a planet carrier, and a ring gear with three rotating elements. That is, a planetary carrier that supports the sun gear and a plurality of pinion gears externally meshed radially at regular intervals on the outer circumference of the sun gear to enable rotation and revolution, and is internally meshed with the plurality of pinion gears to power the sun gear. It includes a ring gear that becomes

The clutch device applied to the embodiment of the power transmission device of the present invention includes a clutch (CL) including a friction material between a clutch drum (11) and a clutch hub (13), and a piston unit (20) for driving and controlling the clutch (CL). ).

That is, the clutch drum 11 is selectively power-connected to the input shaft IS connected to the engine output side by power through a connection plate 9, and a plurality of clutch plates 15 are spline-coupled to the inner circumferential surface.

The clutch hub 13 has an inner circumferential side connected to the planetary carrier PC of the planetary gear set and a plurality of clutches on the outer circumferential surface so as to transmit the rotational power of the input shaft IS to the planetary carrier PC of the planetary gear set when the clutch is operated. The disk 17 is splined.

At this time, the plurality of clutch disks 17 are disposed between the plurality of clutch plates 15, and the plurality of clutch plates ( 15) is supported.

And the piston unit 20 is composed of a double piston composed of first and second pistons 21 and 23 in a ring plate shape, a spring retainer 25 providing restoring force, a return spring 27, and a synchronous unit. It consists of

In the piston unit 20, the front end of the second piston 23 opposite to the clutch CL operates the clutch CL by hydraulic pressure to transmit rotational power.

First, the first piston 21 is disposed in a sealed state between the input shaft IS and the connection plate 9 connected to the input shaft IS, and the first flow path L1 formed on the input shaft IS. ) receives hydraulic pressure and achieves a certain period of stroke operation toward the clutch CL. At this time, the first piston 21 operates in stroke with the second piston 23 to control a gap so that the plurality of clutch plates 15 and the clutch disk 17 of the clutch CL are brought into close contact with each other. .

The second piston 23 is disposed in a sealed state between the input shaft IS and the first piston 21 and between the input shaft IS and the first piston 21, and the input shaft IS ) is supplied with hydraulic pressure through the second flow path L2 formed in the clutch CL, and the front end directly acts on the plurality of clutch plates 15 and the clutch disk 17 of the clutch CL to provide coupling force to each other.

delete

delete

In addition, the outer diameters of the first and second pistons 21 and 23 are disposed parallel to each other in the axial direction, and the outer and inner surfaces of the outer diameter of the first piston 21 are of the connection plate 9, respectively. Between the inner surface and the outer surface of the outer diameter of the second piston 23, a contact state is maintained so that the stroke operation is possible while maintaining airtightness through a seal ring SR.

In addition, the first and second pistons 21 and 23 are slide-moving by contacting respective seal rings SR installed on the input shaft IS with inner diameters arranged parallel to the input shaft IS. is configured to

In addition, the spring retainer 25 is installed between the input shaft IS and the second piston 23 on one side of the second piston 23 in the direction of the clutch CL.

That is, the spring retainer 25 is formed in a disk shape, the inner circumferential end is supported in the clutch direction by the stopper 31 installed at the center of the input shaft IS, and the outer circumferential end extends beyond the second piston 23. It is brought into contact with the inner surface of the neck via the seal SR.

The spring retainer 25 receives hydraulic pressure through a third flow path formed in the input shaft IS between the spring retainer 25 and the second piston 23 to form compensating hydraulic pressure.

Here, the stopper 31 may be formed of a snap ring fitted and installed on the input shaft IS.

In addition, the return spring 27 is installed between the spring retainer 25 and the second piston 23 in a state in which both ends are supported to provide restoring force to the first and second pistons 21 and 23, , It may be formed of a plurality of coil springs.

The synchronization unit is composed of a synchronizer (SL), and the synchronizer (SL) is configured between the connecting plate (9) and the clutch drum (11) and interlocks with the operation of the first piston (21). A sleeve (SLE) is configured to be connected to the front end of the outer diameter of the first piston (21).

That is, the synchronizer SL selectively and synchronously connects the rotational power of the input shaft IS to the clutch drum 11 according to the operation of the first piston 21 .

2 is a cross-sectional view of a power transmission device for an automatic transmission according to an embodiment of the present invention in a first-stage operating state, and FIG. 3 is a cross-sectional view of a power transmission device for an automatic transmission in a second-stage operating state according to an embodiment of the present invention.

The operation of the clutch device, which is a power transmission device having the above configuration, will be described with reference to FIGS. 2 and 3 .

Referring to FIG. 2 , first, when hydraulic pressure is supplied between the connecting plate 9 and the first piston 21 through the first flow path L1 for the clutch CL to operate, the first piston 21 and the second The piston 23 achieves a rapid stroke operation in the direction of the clutch CL.

At this time, the synchronizer (SL) of the synchronization unit also moves the sleeve (SLE) in conjunction with the operation of the first piston (21), and accordingly, the connection plate (9) and the clutch drum (11) are synchronously connected to the input shaft ( IS) is transmitted to the clutch drum (11).

At the same time, the tip of the outer diameter of the second piston 23 moves to the clutch plate 15 of the clutch CL at a high operating speed to bring the plurality of clutch plates 15 and the plurality of clutch discs 17 into close contact. to control the gap.

Then, referring to FIG. 3 , when hydraulic pressure is supplied between the first piston 21 and the second piston 23 through the second flow path L2, the second piston 23 moves from the first piston 21 to the clutch. (CL) direction to achieve stroke operation.

Accordingly, the front end of the outer diameter of the second piston 23 presses the clutch plate 15 of the clutch CL to form a coupling force between the plurality of clutch plates 15 and the plurality of clutch disks 17 .

With the sequential operation of the first and second pistons 21 and 23 over two stages, the clutch CL transfers the rotational power of the input shaft IS to the planetary carrier PC of the planetary gear set with quick response and sufficient engagement force. forward to

In addition, the synchronizer (SL), which is a synchronizing unit constructed between the connecting plate 9 and the clutch drum 11 and interlocked with the operation of the first piston 21, operates the clutch CL when the clutch operation is released. After this is first released, the synchroniser SL blocks the rotational power of the input shaft IS transmitted to the clutch CL, thereby fundamentally preventing drag loss due to relative rotation between the friction materials inside the clutch CL.

In addition, referring to FIG. 1, in the clutch device, which is a power transmission device according to an embodiment of the present invention, in a state in which the clutch operation is released, the return spring ( 27) and the first and second pistons 21 and 23 and the connection plate by the compensating hydraulic pressure supplied between the second piston 23 and the spring retainer 25 through the third flow path L3. The centrifugal hydraulic pressure of the fluid remaining between (9) is offset to prevent drag loss of the friction material and increase control reliability.

As such, the power transmission device according to the embodiment of the present invention uses a double piston composed of first and second pistons 21 and 23 to drive the clutch CL that transmits rotational force while rotating with the rotation element. By applying it, it is possible to improve shift response by controlling the gap between friction materials at a rapid operating speed, and to increase power transmission efficiency by securing sufficient coupling force.

In addition, with the sequential two-stage operation of the double piston consisting of the first and second pistons 21 and 23, the fast gap control and coupling force between the friction materials are made for each operating section, resulting in accumulated fatigue that repeatedly acts on the clutch plate 15. is minimized, thereby minimizing damage to the clutch CL.

delete

delete

In addition, since control starts at or above the spring force of the return spring 27 acting on the second piston 23, control of an unstable hydraulic solenoid valve (not shown) in the low pressure section is excluded, thereby increasing control reliability.

Although preferred embodiments of the present invention are disclosed above, the present invention is not limited to the above embodiments, and from the embodiments of the present invention, those skilled in the art can easily invent and recognize that the invention is equivalent. Includes all changes within the scope of

CL: Clutch
9: connection plate
11: clutch drum
13: clutch hub
15: clutch plate
17: clutch disc
19: snap ring
20: piston unit
21, 23: first and second pistons
25: spring retainer
27: return spring
31: stopper
IS: input axis
L1, L2, L3: 1st, 2nd, 3rd flow path
SR: sealing
PC: Meteor Carrier
SL: synchronizer
SLE: sleeve

Claims (14)

A clutch drum connected to one rotational element, a clutch configured inside the clutch drum and connected to another rotational element through a clutch hub to transmit rotational power, and a front end disposed toward the clutch In the power transmission device for an automatic transmission including a piston unit that operates the clutch by hydraulic pressure,
The piston unit
A first piston disposed in a sealed state between the one rotation element and a connecting plate connected to the one rotation element and receiving hydraulic pressure through a first flow path formed in the one rotation element and operating toward the clutch;
It is arranged in a sealed state between the one rotating element and the first piston, and is supplied with hydraulic pressure through a second flow path formed in the one rotating element, so that the tip is a second piston acting directly on the clutch;
a spring retainer installed between the one rotating element and the second piston;
a return spring installed between the spring retainer and the second piston to provide restoring force to the first and second pistons; and
a synchronizing unit configured between the connecting plate and the clutch drum to selectively and synchronously connect the rotational power of the one rotating element to the clutch drum in conjunction with the operation of the first piston;
A power transmission device for an automatic transmission comprising a. delete delete According to claim 1,
The spring retainer
The inner circumferential end is supported in the clutch direction by a stopper installed at the center of the one rotating element, the outer circumferential end is in contact with the inner surface of the outer diameter of the second piston through a seal, and the second piston A power transmission device for an automatic transmission configured to receive hydraulic pressure through a third flow path formed in the one rotating element between the two and form compensating hydraulic pressure. According to claim 1,
The synchronization unit
A power transmission device for an automatic transmission comprising a synchronizer configured such that a front end of an outer diameter of the first piston is connected to a sleeve to interlock with the operation of the first piston. According to claim 1,
The first and second pistons have respective outer diameters disposed parallel to the axial direction,
An outer surface and an inner surface of the outer diameter of the first piston are in contact with each other between the inner surface of the connecting plate and the outer surface of the outer diameter of the second piston, respectively, through a seal. According to claim 1,
The first and second pistons
A power transmission device for an automatic transmission, wherein each inner diameter portion is disposed parallel to the one rotating element and slides in contact with each seal installed on the one rotating element. According to claim 1,
The one rotating element is composed of an input shaft connected to the output side of the engine by power,
The other rotational element is a power transmission device for an automatic transmission consisting of one rotational element among three rotational elements of a planetary gear set. A clutch drum connected to the input shaft, a clutch formed inside the clutch drum and connected to the rotating element of the planetary gear set through the clutch hub and including a friction material to transmit rotational power, and a hydraulic pressure with the front end disposed toward the clutch. In the power transmission device for an automatic transmission including a piston unit that operates the clutch by
The piston unit
a first piston disposed in a state of contact between the input shaft and a connection plate connected to the input shaft through a seal, receiving hydraulic pressure through a first flow path formed on the input shaft and operating toward the clutch;
It is placed in contact between the input shaft and the first piston and between the input shaft and the first piston through a seal, receives hydraulic pressure through a second flow path formed on the input shaft, and the front end of the outer diameter directly operates on the clutch. a second piston to;
a spring retainer installed between the input shaft and the second piston in a state supported in a clutch direction through a stopper installed on the input shaft;
a return spring installed between the spring retainer and the second piston to provide restoring force to the first and second pistons; and
a synchronizing unit configured between the connecting plate and the clutch drum to selectively and synchronously connect the rotational power of the input shaft to the clutch drum in conjunction with the operation of the first piston;
A power transmission device for an automatic transmission comprising a. delete According to claim 9,
The spring retainer
The inner circumferential end is supported in the clutch direction by a stopper installed at the center on the input shaft, the outer circumferential end is in contact with the inner surface of the outer diameter of the second piston through a seal, and between the second piston and the A power transmission device for an automatic transmission configured to receive hydraulic pressure through a third flow path formed on an input shaft and form compensating hydraulic pressure. According to claim 9,
The synchronization unit
A power transmission device for an automatic transmission comprising a synchronizer configured such that a front end of an outer diameter of the first piston is connected to a sleeve to interlock with the operation of the first piston. According to claim 9,
The first and second pistons have respective outer diameters disposed parallel to the axial direction,
An outer surface and an inner surface of the outer diameter of the first piston are in contact with each other between the inner surface of the connecting plate and the outer surface of the outer diameter of the second piston, respectively, through a seal. According to claim 9,
The first and second pistons
A power transmission device for an automatic transmission, wherein each inner diameter portion is disposed parallel to the input shaft and slides in contact with each seal installed on the input shaft.

Images