JP4265469B2 - Fluid transmission device with lock-up clutch - Google Patents

Description

  The present invention relates to a fluid transmission device with a lockup clutch, and more particularly to a torque converter with a lockup clutch.

Conventionally, a torque converter with a lockup clutch is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-194188 (Patent Document 1).
JP 2003-194188 A

  The fluid torque transmission device described in the above document includes a mechanism for generating a frictional resistance when the lockup device is operated. This friction generating mechanism is disposed between the front cover and the turbine hub, and has a gap in the circumferential direction so as not to operate the friction generating mechanism within a minute twist angle. When a low-frequency and large-amplitude input such as when the accelerator is suddenly depressed in the vehicle, the friction generating mechanism is activated to increase the hysteresis torque, thereby obtaining a damper characteristic that effectively attenuates the shock. Damper characteristics that suppress the hysteresis torque by not operating the friction generation mechanism when inputting high frequency and small amplitude, such as during lockup steady running, and effectively attenuate the engine rotation fluctuations that cause the roaring noise in the vehicle Get. In this friction generating mechanism, the pressing load for generating the frictional force uses the lockup pressure applied to the turbine hub.

  However, since the friction generation mechanism and the turbine hub rotate relative to each other during vibration, it is necessary to install a thrust bearing and a washer with a low friction coefficient in the friction generation mechanism in order to achieve low hysteresis torque at high frequencies and small amplitudes. Space is required.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a fluid transmission device with a lock-up clutch capable of obtaining a reliable vibration damping characteristic.

  In the fluid transmission with a lockup clutch according to the present invention, the lockup clutch is provided with a damper mechanism. A friction generating mechanism is provided between the front cover and the turbine hub, is arranged to function in parallel with the damper mechanism of the lockup clutch, and generates a frictional resistance when the lockup clutch is operated. The friction generating mechanism has a friction surface and a minute clearance in the circumferential direction for preventing the friction surface from being operated within a minute twist angle range. The friction generating mechanism includes a washer that seals the inner periphery of the lockup piston and the outer periphery of the input shaft provided on the inner diameter side of the lockup piston, and a working surface on which the lockup pressure acts is provided at one axial end of the washer. At the other end in the axial direction of the washer, a friction surface is provided which contacts the front cover and acts on the low pressure side of the differential pressure.

  In the fluid transmission device with a lockup clutch configured as described above, a pressing load for generating a frictional force is generated by a differential pressure of the lockup pressure applied to the washer. Since the washer is not in contact with the components that rotate relative to each other, good vibration damping characteristics can be obtained without separately providing a bearing or a low friction coefficient washer.

  According to this invention, it is possible to provide a fluid transmission device with a lock-up clutch that can obtain good vibration damping characteristics without providing a separate member other than a washer.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a cross-sectional view of a torque converter 1 according to the present invention. The torque converter 1 is a device for transmitting torque from an engine crankshaft to an input shaft 6 of a transmission. The engine is arranged on the left side of FIG. 1, and the transmission is arranged on the right side so as to be connected to the input shaft 6. The input shaft 6 is a rotating shaft of the torque converter 1.

  The torque converter 1 includes a fluid working chamber having a turbine runner 2, which is three types of impellers, a pump impeller 8, and a stator 123, and a lockup mechanism 70.

  A disc-shaped front cover 3 is disposed on the front side of the torque converter 1, that is, on the side close to the engine, and the front cover 3 is positioned so as to extend outward from the rotating shaft, that is, to extend in the radial direction. . The front cover 3 acts as a front case of the torque converter 1. An impeller shell 126 is fixed to the front cover 3, and the front cover 3 and the impeller shell 126 constitute a predetermined space, and various elements of the torque converter 1 are arranged in this space. A space surrounded by the front cover 3 and the impeller shell 126 is a substantially sealed space, and automatic fluid (ATF) is sealed in this space.

  The front cover 3 is a member that receives power from the engine. When power is input from the engine to the front cover 3, this power is transmitted to the impeller shell 126.

  The impeller shell 126 constitutes the pump impeller 8, and the pump impeller 8 is configured integrally with the impeller shell 126. The pump impeller 8 is disposed so as to face the turbine runner 2 and can rotate around the rotation shaft of the input shaft 6. The pump impeller 8 is provided with blades shaped to extrude the working fluid toward the turbine runner 2, and the working fluid in the vicinity of the pump impeller 8 moves toward the turbine runner 2 as the pump impeller 8 rotates. Extruded.

  The stator 123 is interposed between the pump impeller 8 and the turbine runner 2 and functions to change the flow direction of the hydraulic oil flowing from the turbine runner 2 to the pump impeller 8. The stator 123 is attached to the fixed shaft 39 via the one-way clutch 37 and can rotate only in one direction. As the one-way clutch 37, a structure using a roller, a sprag or a ratchet can be employed. The stator 123 is a blade for rectifying the flow of hydraulic oil returning from the turbine runner 2 to the pump impeller 8, and is made of resin or aluminum alloy.

  The turbine runner 2 has a turbine shell 130 that constitutes a space for circulating hydraulic oil, and is disposed so as to face the pump impeller 8. The turbine runner 2 receives the hydraulic oil sent out by the pump impeller 8, and a rotational force is applied by the hydraulic oil. The hydraulic oil transmitted to the turbine runner 2 moves to the inner peripheral side and is sent again to the pump impeller 8 side through the stator 123. The turbine runner 2 can rotate independently of the pump impeller 8.

  The pump impeller 8 rotates integrally with the front cover 3, whereas the turbine runner 2 rotates integrally with the lockup piston 4. The power transmission member 204 is disposed so as to contact the turbine shell 130. The power transmission member 204 is integrated with the turbine shell 130 with fasteners such as rivets or bolts, and rotates together with the turbine shell 130.

  The power transmission member 204 and the turbine shell 130 are both fixed to the turbine hub 7 and can rotate together with the turbine hub 7 about the input shaft 6 as a rotation axis. The turbine hub 7 is splined to the input shaft 6 and is positioned on the outer peripheral side of the input shaft 6. The turbine hub 7 connects the input shaft 6 and the turbine shell 130, and functions to transmit the rotational force input to the turbine shell 130 to the input shaft 6.

  Next, the lockup mechanism 70 will be described. The lock-up mechanism 70 is a device for directly transmitting the rotational force of the front cover 3 to the input shaft 6. When the facing 76 as a friction member contacts the inner peripheral surface of the front cover 3, the rotational force of the front cover 3 is reduced. It is transmitted to the input shaft 6. The lockup mechanism 70 has a lockup piston 4 for attaching a facing 76. The lock-up piston 4 can move in the axial direction, that is, in the direction approaching the front cover 3 and in the direction away from the front cover 3, and the facing 76 can abut on the front cover 3. The lock-up piston 4 has a disk shape extending in the radial direction (radial direction) of rotation, and is disposed so as to face the front cover 3.

  A facing 76 is fixed to the outer peripheral side of the lockup piston 4, and the inner peripheral side is in contact with the washer 5. The inner peripheral surface 4 i of the lockup piston 4 is in direct contact with the washer 5. The washer 5 surrounds the end of the input shaft 6 and functions to seal the lockup pressure. The washer 5 has an outer peripheral surface 5 u that faces the lockup piston 4, an inner peripheral surface 5 i that contacts the input shaft 6, a friction surface 51 that contacts the front cover 3, and a working surface 52 that contacts the turbine hub 7.

  A space between the front cover 3 and the lockup piston 4 is the first hydraulic chamber 10a, and a space between the lockup piston 4 and the power transmission member 204 is the second hydraulic chamber 10b. Each of the first and second hydraulic chambers 10a and 10b is filled with hydraulic oil, and by changing the hydraulic pressure, the lockup piston 4 moves in a direction toward the front cover 3 and away from the front cover 3. It is possible to make it.

  The lockup mechanism 70 is provided with a lockup damper 174 and plays a role of buffering the fluctuation input. The lock-up damper 174 is composed of a spring member, and when torque is applied, the lock-up damper 174 functions to reduce fluctuations by the action of the spring. The lockup damper 174 is interposed between the lockup piston 4 and the power transmission member 204.

  The operation of the lock-up mechanism 70 will be described. When the torque amplifying action of the torque converter 1 is not particularly required, the rotational force of the front cover 3 is directly transmitted to the input shaft 6 by bringing the facing 76 into contact with the front cover 3. Specifically, the hydraulic oil in the first hydraulic chamber 10a is discharged through the through hole 6h. As a result, the hydraulic pressure in the first hydraulic chamber 10a is lower than the hydraulic pressure in the second hydraulic chamber 10b. As a result, the lock-up piston 4 moves in a direction approaching the front cover 3, and the facing 76 contacts the front cover 3. As a result, the power of the front cover 3 is transmitted to the input shaft 6 through the facing 76, the lockup piston 4, the power transmission member 204, and the turbine hub 7. In this state, power loss due to the torque converter 1 hardly occurs.

  When the torque amplifying action of the torque converter is required, the hydraulic oil is fed into the first hydraulic chamber 10a through the through hole 6h. As a result, the pressure in the first hydraulic chamber 10a increases, and the lockup piston 4 is pushed back in a direction away from the front cover 3. As a result, a gap is generated between the front cover 3 and the facing 76, and the rotational force of the front cover 3 is not directly transmitted to the facing 76.

  Next, the friction generating mechanism 10 will be described. The friction generating mechanism 10 has a washer 5, and the washer 5 is in contact with the input shaft 6, the front cover 3, the lockup piston 4, and the turbine hub 7.

  FIG. 2 is a cross-sectional view taken along the line II-II in FIG. Referring to FIGS. 1 and 2, an inner peripheral surface 6i of the input shaft 6 defines a through hole 6h. A spline is provided on the outer peripheral surface 6 u of the input shaft 6, and the inner peripheral surface of the turbine hub 7 is engaged with the spline. The turbine hub 7 is fitted on the input shaft 6. A plurality of protrusions 7 t are provided on the outer periphery of the turbine hub 7, and the protrusions 7 t are received in a recess 53 formed on the inner periphery of the washer 5. A gap 7s is provided between the recess 53 and the protruding part 7t, and the gap 7s becomes play. The turbine hub 7 can rotate relative to the washer 5 by a minute angle.

  In the state shown in FIG. 2, since the gap 7s is provided on both sides of the projecting portion 7t, the turbine hub 7 can move by a minute angle with respect to both sides. The outer peripheral surface 5 u of the washer 5 faces and contacts the inner peripheral surface 4 i of the lockup piston 4. Since the inner peripheral surface 4i of the lockup piston 4 is in contact with the outer peripheral surface 5u of the washer 5, but is not fixed, the lockup piston 4 can freely slide and rotate with respect to the washer 5. It is. However, the washer 5 and the lock-up piston 4 are in intimate contact with each other, and no gap is formed between them, thereby preventing hydraulic oil from leaking.

  Referring to FIG. 1 again, the friction surface 51 of the washer 5 is located in the first hydraulic chamber 10a, and the same hydraulic pressure as that in the first hydraulic chamber 10a is applied. On the other hand, the action surface 52 is located in the second hydraulic chamber 10b, and the same hydraulic pressure as that of the second hydraulic chamber 10b is applied. As a result, when a hydraulic pressure difference (differential pressure) is generated between the first hydraulic chamber 10a and the second hydraulic chamber 10b, this hydraulic pressure is also applied to the washer 5. As a result, the washer 5 is pressed toward the front cover 3.

  In order to generate the differential pressure as described above, the washer 5 has a sealing function. Specifically, the outer peripheral surface 6u of the input shaft 6 and the inner peripheral surface 5i of the washer 5 are brought into close contact with each other to have a sealing function for preventing hydraulic fluid from leaking. Further, the outer peripheral surface 5u of the washer 5 and the inner peripheral surface 4i of the lock-up piston 4 are also in close contact with each other, and have a sealing function for preventing leakage of hydraulic oil. The washer 5 is made of metal, for example, and may be quenched so that the friction surface 51 has wear resistance. In FIG. 1, the washer 5 is substantially “L” -shaped, but is not limited thereto, and various shapes of the washer 5 may be employed.

  Since the inner peripheral surface 4 i of the lock-up piston 4 is in contact with the outer peripheral surface 5 u of the washer 5 but is not fixed, the lock-up piston 4 can slide and move in the axial direction with respect to the washer 5. Become.

  That is, the washer 5 that seals the inner peripheral surface 4 i of the lockup piston 4 and the outer peripheral surface 6 u of the input shaft 6 is provided between the front cover 3 and the turbine hub 7. The washer 5 and the turbine hub 7 are constrained to each other in the rotational direction, and a gap 7s is set so as to have a predetermined rotational direction backlash. As a result, low hysteresis torque is applied to high-frequency small-amplitude vibrations that cause drive system noise, and high-hysteresis torque is applied to low-frequency large-amplitude vibrations such as chip-in input. Attenuation characteristics are realized at low cost and space saving.

  In the present invention, the pressing load for generating the frictional force uses the lock-up pressure applied to the washer 5 itself, and does not use other components. As a result, the washer 5 does not come into contact with the components that rotate relative to each other when the washer 5 is loaded. Therefore, a low-friction bearing or the like as in the prior art is not required, and low cost and space saving can be realized.

  Further, since the number of parts is small, internal play can be reduced, the thrust clearance adjustment process can be eliminated, and simplification can be realized. Further, the controllability of the lockup clutch can be improved.

  The torque converter 1 according to the present invention is a fluid transmission device with a lockup clutch in which a lockup damper 174 is provided in a lockup mechanism 70 as a lockup clutch. The friction generation mechanism 10 is disposed between the front cover 3 and the turbine hub 7 and is disposed so as to function in parallel with the lockup damper 174 of the lockup mechanism 70. The friction generating mechanism 10 generates a frictional resistance when the lockup mechanism 70 is operated. The friction generating mechanism 10 includes a friction surface 51 and a minute gap 7s in the circumferential direction for preventing the friction surface 51 from operating within a minute twist angle range. The friction generating mechanism 10 includes a washer 5 that is provided on the inner diameter side of the lockup piston 4 and seals the inner peripheral surface 4 i of the lockup piston 4 and the outer peripheral surface 6 u of the input shaft 6. At one end in the axial direction of the washer 5, a working surface 52 on which a lockup pressure (high pressure) acts is provided. The other end of the washer 5 is provided with a friction surface 51 that abuts the front cover 3 and acts on the low pressure side of the differential pressure.

  In such a torque converter 1, since the washer 5 is not in contact with a component that relatively rotates at the time of lock-up, good vibration damping characteristics can be obtained without separately providing a bearing and a washer having a low friction coefficient.

  Although the embodiment of the present invention has been described above, the embodiment shown here can be variously modified. First, the present invention can be applied not only to a torque converter but also to other fluid transmission devices with a lockup device such as a fluid coupling. Furthermore, the present invention can be applied not only to a torque converter mounted on a vehicle but also in the field of fluid coupling.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be used in the field of fluid transmission devices with lock-up clutches, for example, the field of torque converters or fluid couplings.

1 is a cross-sectional view of a torque converter 1 according to the present invention. It is sectional drawing along the II-II line | wire in FIG.

Explanation of symbols

  1 torque converter, 2 turbine runner, 3 front cover, 4 lock-up piston, 5 washer, 5i inner peripheral surface, 5u outer peripheral surface, 6 input shaft, 6i inner peripheral surface, 6u outer peripheral surface, 7 turbine hub, 7t protrusion, 8 pump impeller, 10 friction generating mechanism, 10a first hydraulic chamber, 10b second hydraulic chamber, 37 one-way clutch, 39 fixed shaft, 51 friction surface, 52 working surface, 53 recess, 76 facing, 123 stator, 126 impeller shell, 130 Turbine shell, 174 Lock-up damper.

Claims (1)

A fluid transmission device with a lock-up clutch in which a damper mechanism is provided in the lock-up clutch,
The mechanism is disposed between a front cover and a turbine hub, and is arranged to function in parallel with the damper mechanism of the lockup clutch, and is a mechanism for generating frictional resistance when the lockup clutch is operated. A friction generating mechanism having a minute gap in the circumferential direction to prevent the friction surface from operating within a minute twist angle range,
The friction generating mechanism includes a washer that seals an inner peripheral surface of the lockup piston and an outer peripheral surface of the input shaft provided on the inner diameter side of the lockup piston, and a working surface on which a lockup pressure acts on one axial end of the washer And a friction surface on the other end in the axial direction of the washer that abuts against the front cover and acts on the low pressure side of the differential pressure.

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