JP2009041737A - Hydraulic torque transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic torque transmission device capable of improving fuel economy and operability of a vehicle. <P>SOLUTION: A torque converter 1 has a front cover 2, an impeller 9, a turbine 10 and a lock-up device 5. The lock-up device 5 has a piston 51, a damper mechanism 7 and a friction generating mechanism 40. The friction generating mechanism 40 generates, by abrasion resistance, hysteresis torque applied in parallel with the damper mechanism 7 between the piston 51 and the turbine 10, and has a first clearance T1 and a second clearance T2. The first clearance T1 suppresses generation of abrasion resistance with respect to twisting vibration within a range of a first angle θ1. The second clearance T2 suppresses generation of part of abrasion resistance with respect to twisting vibration within a range of a second angle θ2 larger than the first angle θ1 and is set larger than the first clearance T1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid torque transmission device, and more particularly to a fluid torque transmission device provided with a lock-up device.

  A torque converter and a fluid coupling are known as fluid type torque transmission devices. For example, a torque converter is a device that transmits torque via hydraulic oil, and mainly includes a front cover, an impeller, a turbine, a stator, and a lockup device. The impeller is fixed to the front cover. The turbine is disposed opposite the impeller in the fluid chamber. When the impeller rotates, hydraulic oil flows from the impeller to the turbine. In this way, torque is transmitted from the impeller to the turbine via the hydraulic oil.

  A lockup device is provided between the turbine and the front cover. The lock-up device is a device that mechanically connects the front cover and the turbine, and directly transmits torque from the front cover to the turbine.

  The lock-up device includes a disc-like piston that can slide with the front cover, and a damper mechanism that elastically connects the piston and the turbine in the rotational direction.

  When the lockup device connects the front cover and the turbine, torque is transmitted from the front cover to the piston, and further to the turbine via the spring. Torsional vibration is absorbed and damped by the damper mechanism of the lockup device.

  In general, the torsional vibration includes a minute torsional vibration that causes abnormal noise during driving (acceleration / deceleration rattle, booming noise). Small torsional vibrations are generated by combustion fluctuations in the engine. For minute torsional vibration, it is preferable that the torsional rigidity of the damper mechanism is low. On the other hand, since it is also necessary to ensure a sufficient stopper torque of the damper mechanism, a simple characteristic that simply lowers the torsional rigidity is not preferable.

  In view of this, a damper mechanism is provided in which a two-stage characteristic is realized by using two types of springs in the lockup device. This damper mechanism has an effect of absorbing minute torsional vibrations because the torsional rigidity in the main region of torsional characteristics is lowered. Further, since the torsional rigidity is increased in a region where the torsion angle is large, a sufficient stopper torque can be realized.

This type of lock-up device is provided with a friction generating mechanism that acts in parallel with the damper mechanism in order to improve torsional vibration damping performance (see, for example, Patent Document 1). In addition, in order to effectively absorb and dampen the minute torsional vibration, a mechanism that suppresses the generation of frictional resistance when the minute torsional vibration is input may be installed in the friction generating mechanism.
JP-A-5-231495

  However, if the frictional resistance is set to be large in order to improve fuel efficiency by expanding the lockup area, the frictional resistance will be reduced when the torsion angle changes from the range where the generation of frictional resistance is suppressed to the range where the frictional resistance is generated. The resulting impact in the rotational direction is increased. Thereby, tip-in and tip-out increase, and the operability of the vehicle decreases.

  As described above, in the conventional fluid torque transmission device, it is difficult to improve the operability while improving the fuel efficiency of the vehicle.

  An object of the present invention is to provide a fluid torque transmission device capable of improving operability while improving fuel efficiency of a vehicle.

  The fluid type torque transmission device according to the first invention includes a front cover, an impeller, a piston, a damper mechanism, and a friction generating mechanism. The impeller forms a fluid chamber together with the front cover. The turbine is disposed opposite the impeller in the fluid chamber. The piston is provided so as to be rotatable and axially movable with respect to the turbine, and is pressed against the front cover by a change in hydraulic pressure. The damper mechanism elastically connects the piston and the turbine in the rotational direction. The friction generating mechanism is a mechanism that generates a hysteresis torque that acts in parallel with the damper mechanism between the piston and the turbine by a frictional resistance, and includes a first gap and a second gap. The first gap suppresses generation of frictional resistance against torsional vibration within the range of the first angle. The second gap suppresses generation of a part of frictional resistance against torsional vibration within a range of the second angle larger than the first angle, and is larger than the first gap.

  In this fluid torque transmission device, when the piston is frictionally connected to the front cover, torque is transmitted to the turbine via the piston and the damper mechanism. When the piston rotates with respect to the turbine, the elastic member is compressed between the input member and the output member in the damper mechanism, and a frictional resistance is generated between the first and second friction plates in the friction generating mechanism. Thus, the torsional vibration input to the piston can be absorbed and damped by the damper mechanism and the friction generating mechanism.

  Here, the generation of the frictional resistance is suppressed within the range of the first angle, and the generation of a part of the frictional resistance is suppressed within the range of the first angle to the second angle. Since the frictional resistance changes stepwise, even if the frictional resistance is relatively large, the impact in the rotational direction when torsional vibration is input to the piston is reduced. As a result, the loud noise can be reduced by a large hysteresis torque, and the lock-up region can be expanded in the low speed region. Further, tip-in and tip-out are reduced, and the accelerator response is improved.

  Thus, in this fluid type torque transmission device, it is possible to improve the operability while improving the fuel efficiency of the vehicle.

  A fluid type torque transmission device according to a second invention is the device according to the first invention, wherein the friction generating mechanism includes a first friction plate, a second friction plate, and a third friction plate. . The first friction plate is provided so as to be rotatable within the first angle range with respect to the piston and movable in the axial direction. The second friction plate is slidably disposed on the first friction plate, and is provided so as to be integrally rotatable with respect to the turbine and movable in the axial direction. The third friction plate is slidably disposed on the second friction plate, and is provided so as to be rotatable within the second angle range with respect to the piston and to be movable in the axial direction.

  The fluid type torque transmitting device according to a third aspect of the invention is the device according to the second aspect of the invention, wherein the effective radius of the friction surface of the third friction plate is different from the effective radius of the friction surface of the first friction plate.

  A fluid type torque transmission device according to a fourth invention is the device according to the third invention, wherein the piston has an annular piston body and an inner cylindrical portion extending from the inner periphery of the piston body to the transmission side. is doing. The inner cylindrical portion has a plurality of first protrusions extending outward in the radial direction. The first friction plate includes an annular first main body portion and a plurality of first internal teeth disposed between adjacent first protrusions extending radially inward from the first main body portion. The third friction plate has an annular third main body portion and a plurality of second internal teeth disposed between adjacent first protrusions extending radially inward from the third main body portion. The first gap is secured between the rotation direction of the first protrusion and the first internal tooth. The second gap is secured between the rotation direction of the first protrusion and the second internal tooth.

  A fluid type torque transmission device according to a fifth invention is the device according to the fourth invention, wherein the turbine is a turbine shell, a plurality of turbine blades fixed to the turbine shell, and a turbine hub fixed to the turbine shell. ,have. The second friction plate is supported by at least one of the turbine shell and the turbine hub so as to be integrally rotatable and movable in the axial direction.

  A fluid type torque transmission device according to a sixth aspect of the present invention is the device according to the fifth aspect of the present invention, wherein the turbine hub includes a cylindrical hub body, an annular first flange portion, and an annular second flange portion. Have. The hub body supports the inner cylindrical portion in the radial direction so as to be movable in the axial direction. The first flange portion extends radially outward from the hub body. The second flange portion projects from the first flange portion radially outward and to the engine side. The second flange portion has an annular second flange portion main body and a plurality of second protrusions extending radially inward from the inner peripheral portion of the second flange portion main body. The second friction plate has an annular second main body portion and a plurality of external teeth disposed between adjacent second protrusions extending radially inward from the second main body portion.

  A fluid type torque transmission device according to a seventh invention is the device according to the fifth invention, wherein the turbine shell has an annular shell body and a plurality of third protrusions extending radially inward from the shell body. ing. The second friction plate includes an annular second main body portion and a plurality of external teeth disposed between adjacent third protrusions that extend radially outward from the second main body portion.

  A fluid type torque transmission device according to an eighth invention is the device according to the seventh invention, wherein the damper mechanism includes an input member that rotates integrally with the piston, an output member fixed to the turbine, an input member, and an output member. And an elastic member for elastically connecting the two in the rotation direction. The friction generating mechanism is disposed between the output member and the turbine in the axial direction, and includes a pressing member that presses the first, second, and third friction plates toward the output member or the turbine.

  According to a ninth aspect of the present invention, there is provided the fluid torque transmission device according to the second aspect, wherein the turbine includes a turbine shell, a plurality of turbine blades fixed to the turbine shell, and a turbine hub fixed to the turbine shell. ,have. The friction generating mechanism is disposed between the turbine shell and the turbine hub in the axial direction. The third friction plate is a member that is elastically deformable in the axial direction, and presses the first and second friction plates toward the turbine shell side or the turbine hub side.

  Since the fluid type torque transmission device according to the present invention has the above-described configuration, it is possible to improve the operability while improving the fuel efficiency of the vehicle.

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

[First Embodiment]
<Overall structure of torque converter>
A fluid type torque transmission device according to the present invention will be described. Here, the torque converter 1 will be described as an example of the fluid torque transmission device. FIG. 1 is a schematic cross-sectional view of the torque converter 1. FIG. 2 is a partial cross-sectional view of the torque converter 1. An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of the figure. A line OO shown in FIG. 1 is a rotating shaft of the torque converter 1.

  The torque converter 1 is a device for transmitting torque from an engine crankshaft (not shown) to an input shaft (not shown) of a transmission. As shown in FIG. 1, the torque converter 1 mainly includes a front cover 2, an impeller 9, a turbine 10, a stator 11, and a lockup device 5.

  The front cover 2 is fixed to the crankshaft via a flexible plate, and receives torque generated by the engine. An impeller 9 is fixed to the front cover 2. The front cover 2 forms a fluid chamber together with the impeller 9.

  The turbine 10 is disposed to face the impeller 9 in the fluid chamber. The turbine 10 includes a turbine shell 14, a plurality of turbine blades 15 fixed to the turbine shell 14, and a turbine hub 16 fixed to the inner peripheral portion of the turbine shell 14. The turbine shell 14 includes an annular shell body 14a and a plurality of third protrusions 14b extending radially inward from the shell body 14a.

  The turbine hub 16 includes a cylindrical hub body 16b connected to an input shaft (not shown), an annular first flange portion 16a, an annular second flange portion 16c, and a plurality of second protrusions 16d. have. The first flange portion 16a extends radially outward from the hub body 16b. The second flange portion 16c extends radially outward from the outer periphery of the first flange portion 16a, and protrudes from the first flange portion 16a to the engine side. A friction generating mechanism 40 (to be described later) is housed inside the first flange portion 16a in the radial direction and on the engine side of the first flange portion 16a.

  The second protrusion 16d extends radially inward from the inner peripheral portion of the second flange portion 16c. When viewed from the axial direction, the second protrusion 16d has substantially the same shape as the third protrusion 14b. The first and second flange portions 16a and 16c have an output plate 53 (output member), which will be described later, and the second projection 16d has an inner portion of the turbine shell 14 so that the position in the rotational direction substantially coincides with the third projection 14b. The peripheral portion is fixed by a plurality of rivets 17.

<Lock-up device>
As shown in FIG. 2, the lockup device 5 mainly includes a piston 51, a damper mechanism 7, and a friction generating mechanism 40.

(1) Piston The piston 51 is supported by the hub body 16b so as to be rotatable with respect to the turbine 10 and movable in the axial direction. The piston 51 mainly has a disc-shaped piston main body 61 and an inner cylindrical portion 62 as a first cylindrical portion extending from the inner peripheral portion of the piston main body 61 to the transmission side. As shown in FIG. 1, an oil chamber S <b> 1 is formed on the engine side of the piston 51, and an oil chamber S <b> 2 is formed on the transmission side of the piston 51.

  The piston body 61 is provided with an annular friction facing 63. The friction facing 63 can slide on the front cover 2. The piston 51 moves in the axial direction in accordance with a change in hydraulic pressure in the fluid chamber. The friction facing 63 is pressed against the front cover 2 by operating the piston 51 with hydraulic pressure. Thereby, the clutch function of the lock-up device 5 can be realized.

  The inner cylindrical portion 62 is supported by the hub body 16b so as to be rotatable and movable in the axial direction. A friction generating mechanism 40 to be described later is disposed on the radially outer side of the inner cylindrical portion 62. A plurality of first protrusions 62a are formed on the inner cylindrical portion 62 so as to protrude outward in the radial direction. The first protrusion 62a extends in the axial direction over the entire length of the inner cylindrical portion 62, and in the rotational direction with the first inner teeth 41b of the first friction plate 41 and the second inner teeth 43b of the third friction plate 43, which will be described later. Abutment is possible.

(2) Damper mechanism The damper mechanism 7 mainly includes a retaining plate 52 as an input member, an output plate 53 as an output member, a plurality of first springs 58, and a plurality of second springs 59. ing. The first spring 58 and the second spring 59 are examples of elastic members.

  The retaining plate 52 is provided so as to be rotatable integrally with the piston 51 and movable in the axial direction, and holds the first and second springs 58 and 59 so as to be elastically deformable in the rotational direction. The retaining plate 52 has a pair of plate members 56 and 57 fixed to each other by a plurality of rivets 55. The plate member 56 is formed with a first support portion 56a and a second support portion 56b. The plate member 57 is formed with a second support portion 57a and a second support portion 57b. The first support portions 56a and 57a hold the first spring 58 and can abut on both ends of the first spring 58 in the rotation direction. The second support portions 56b and 57b hold the second spring 59, and can abut against both ends of the second spring 59 in the rotation direction.

  The output plate 53 is a disk-shaped member disposed between the plate members 56 and 57 in the axial direction. The output plate 53 is fixed to the second flange portion 16 c of the turbine hub 16 by a plurality of rivets 17 together with the turbine shell 14. The output plate 53 is formed with a first opening 53a and a second opening 53b. The first spring 58 is disposed in the first opening 53a. The second spring 59 is disposed in the second opening 53b. A gap is secured in the rotational direction between the end of the second spring 59 and the edge of the second opening 53b. Thereby, the damper mechanism 7 can realize two-stage torsional characteristics.

  The inner peripheral portion 53 c of the output plate 53 extends radially inward to the vicinity of the inner cylindrical portion 62. A friction generating mechanism 40 is disposed between the inner circumferential portion 53c and the first flange portion 16a in the axial direction.

<Friction generating mechanism>
The friction generation mechanism will be described with reference to FIGS. 3 is a cross-sectional view taken along the line VV in FIG. 4 is a cross-sectional view taken along line XX in FIG. FIG. 5 is a torsional characteristic diagram of the lockup device 5.

(1) Outline of Friction Generation Mechanism In order to improve torsional vibration damping performance, the lockup device 5 is provided with a friction generation mechanism 40. The friction generating mechanism 40 is a mechanism for generating a hysteresis torque acting in parallel with the damper mechanism 7 by friction resistance.

  In the torsional characteristics shown in FIG. 5, the first hysteresis torque H1, the second hysteresis torque H2 that is larger than the first hysteresis torque H1, the first angle θ1 that suppresses the generation of the first hysteresis torque H1, and the second hysteresis torque. The friction generating mechanism 40 realizes the second angle θ2 that suppresses the generation of H2.

  Within the range of the first angle θ1, a third hysteresis torque H3 that is generated outside the friction generating mechanism 40 is generated. Within the range from the first angle θ1 to the second angle θ2, the first hysteresis torque H1 is generated. The first hysteresis torque H1 is generated by the third hysteresis torque H3 and the fourth hysteresis torque H4 acting in parallel. The fourth hysteresis torque H4 is a hysteresis torque generated by a first friction plate 41 described later.

  Within the range equal to or greater than the second angle θ2, the second hysteresis torque H2 is generated. The second hysteresis torque H2 is generated by the third hysteresis torque H3, the fourth hysteresis torque H4, and the fifth hysteresis torque H5 acting in parallel. The fifth hysteresis torque H5 is a hysteresis torque generated by the third friction plate 43.

  As a specific configuration for realizing these characteristics, as shown in FIG. 3, the friction generation mechanism 40 includes a first friction plate 41, a second friction plate 42, a third friction plate 43, and a fourth friction plate. A plate 44 and a cone spring 45 are provided.

(2) First Friction Plate The first friction plate 41 is a member for generating the fourth hysteresis torque H4, and is disposed between the inner peripheral portion 53c of the output plate 53 and the second friction plate 42 in the axial direction. ing. In order to suppress the generation of the fourth hysteresis torque H4 within the range of the first angle θ1, the first friction plate 41 is rotatable and axially movable with respect to the piston 51 within the range of the first angle θ1. Is provided.

  Specifically, as shown in FIGS. 2 and 3, the first friction plate 41 includes an annular first main body portion 41 a including a pair of friction facings 41 c and a plurality of first internal teeth 41 b. ing. The friction facing 41 c of the first main body 41 a slides with the inner peripheral portion 53 c of the output plate 53 and the second friction plate 42. The first internal teeth 41 b extend radially inward from the inner peripheral portion of the first main body portion 41 a and are disposed between the rotation directions of the plurality of first protrusions 62 a provided on the piston 51. As shown in FIG. 3, a first gap T1 is secured between the rotation directions of the first internal teeth 41b and the first protrusions 62a. Thus, the first friction plate 41 can rotate with respect to the piston 51 within the range of the first angle θ1.

(3) Second Friction Plate The second friction plate 42 is disposed between the first friction plate 41 and the third friction plate 43 in the axial direction, and can rotate integrally with the turbine 10 and move in the axial direction. It is provided as possible.

  Specifically, as shown in FIG. 2, the second friction plate 42 has an annular second main body 42 a and a plurality of first external teeth 42 b (external teeth). The second main body portion 42 a includes a portion that slides with the first friction plate 41 and the third friction plate 43. The first external teeth 42b extend radially outward from the outer peripheral portion of the second main body portion 42a, and are arranged between the rotation directions of the plurality of third protrusions 14b provided on the turbine shell 14. A slight gap is formed between the rotation directions of the first external teeth 42 b and the third protrusions 14 b so that the second friction plate 42 can move in the axial direction with respect to the turbine 10. This gap is significantly smaller than the first gap T1. For this reason, the second friction plate 42 hardly rotates with respect to the turbine 10 and rotates integrally with the turbine 10.

(4) Third Friction Plate The third friction plate 43 is a member for generating the fifth hysteresis torque H5, and is disposed between the second friction plate 42 and the fourth friction plate 44 in the axial direction. In order to suppress the generation of the second hysteresis torque H2 within the range of the second angle θ2, the first friction plate 41 is rotatable and axially movable within the range of the second angle θ2 with respect to the piston 51. Is provided.

  Specifically, as shown in FIGS. 2 and 4, the third friction plate 43 has an annular third main body portion 43a including a pair of friction facings 43c, and a plurality of second internal teeth 43b. ing. The friction facing 43 c of the third main body 43 a slides with the second friction plate 42 and the fourth friction plate 44. The second internal teeth 43b extend radially inward from the inner peripheral portion of the third main body portion 43a, and are disposed between the rotation directions of the plurality of first protrusions 62a provided on the piston 51. As shown in FIG. 4, a second gap T2 is secured between the rotation directions of the second internal teeth 43b and the first protrusions 62a. As a result, the third friction plate 43 can rotate with respect to the piston 51 within the range of the second angle θ2.

  As shown in FIGS. 2 to 4, the effective radius L3 of the friction surface of the third friction plate 43 is different from the effective radius L1 of the friction surface of the first friction plate 41. Specifically, the effective radius L3 is smaller than the effective radius L1. Therefore, as shown in FIG. 5, the fifth hysteresis torque H5 related to the effective radius L3 is smaller than the fourth hysteresis torque H4 related to the effective radius L1.

  Here, the effective radius of the friction surface means a representative radial dimension of the friction surface. When the friction surface is annular, the effective radius is the center radius of the friction surface in the radial direction.

(5) Fourth Friction Plate The fourth friction plate 44 is disposed between the third friction plate 43 and the cone spring 45 in the axial direction, and can rotate integrally with the turbine 10 and can move in the axial direction. Is provided. The fourth friction plate 44 has substantially the same shape as the second friction plate 42.

  Specifically, as shown in FIG. 2, the fourth friction plate 44 has an annular fourth main body 44a and a plurality of second external teeth 44b. The second main body portion 42 a includes a portion that slides with the first main body portion 41 a and the third friction plate 43. The second external teeth 44b extend radially outward from the outer peripheral portion of the fourth main body 44a, and are arranged between the rotation directions of the plurality of third protrusions 14b provided on the turbine shell 14. A slight gap is formed between the rotation directions of the second external teeth 44b and the third protrusions 14b so that the fourth friction plate 44 can move in the axial direction with respect to the turbine 10. This gap is significantly smaller than the second gap T2. For this reason, the fourth friction plate 44 hardly rotates with respect to the turbine 10 and rotates integrally with the turbine 10.

(6) Cone Spring The cone spring 45 is a member for pressing the first to fourth friction plates 41, 42, 43, and 44 toward the engine side (more specifically, the output plate 53 side). It arrange | positions in the state compressed between 44 and the 1st flange part 16a of the turbine hub 16 between the axial directions. The cone spring 45 rotates integrally with the fourth friction plate 44 and the turbine hub 16 <Operation of the torque converter>
The operation of the torque converter will be described with reference to FIGS.

  The front cover 2 and the impeller 9 are rotated by torque generated by the engine. When the impeller 9 rotates, hydraulic oil flows from the impeller 9 to the turbine 10. The turbine 10 is rotated by the flow of the hydraulic oil, and torque is output to the input shaft (not shown) via the turbine 10.

  When the speed ratio of the torque converter 1 increases and the input shaft reaches a substantially constant rotational speed, the hydraulic oil in the oil chamber S1 is discharged through the oil passage inside the input shaft. As a result, the hydraulic pressure in the oil chamber S2 on the turbine 10 side of the piston 51 becomes higher than the hydraulic pressure in the oil chamber S1 on the front cover 2 side. Due to this differential pressure, the piston 51 moves to the front cover 2 side, and the friction facing 63 is pressed against the front cover 2. As a result, torque is transmitted to the turbine 10 via the front cover 2, the piston 51 and the damper mechanism 7.

  When torsional vibration with a relatively large torsion angle is input to the front cover 2 in a state where the lockup device 5 connects the front cover 2 to the turbine 10, the piston 51 rotates with respect to the output plate 53. At this time, only the first spring 58 is compressed between the rotation directions of the retaining plate 52 and the output plate 53 until a predetermined twist angle. When the twist angle exceeds a predetermined angle, the first spring 58 and the second spring 59 are compressed in parallel between the rotation directions of the retaining plate 52 and the output plate 53. As described above, the first spring 58 and the second spring 59 realize two-stage torsional characteristics.

  In the lockup device 5, for a torsional vibration with a large torsional angle, a second hysteresis torque H <b> 2 that acts in parallel with the damper mechanism 7 is generated in the first and second stage regions of the torsional characteristics. Specifically, as shown in FIG. 5, when the retaining plate 52 (piston 51) and the output plate 53 rotate relative to each other, in the friction generating mechanism 40, the first friction plate 41 and the third friction plate 43 are subjected to the second friction. It rotates with respect to the plate 42 and the fourth friction plate 44. As a result, the first friction plate 41 slides with the inner peripheral portion 53 c of the output plate 53 and the second friction plate 42, and a fourth hysteresis torque H 4 is generated between the piston 51 and the output plate 53.

  In the friction generating mechanism 40, the third friction plate 43 slides with the second friction plate 42 and the fourth friction plate 44, and a fifth hysteresis torque H5 is generated between the piston 51 and the output plate 53.

  Further, when the first spring 58 and the second spring 59 slide with the retaining plate 52 and the output plate 53, a third hysteresis torque H3 is generated at a portion other than the friction generating mechanism 40.

  As described above, the second hysteresis torque H2, which is the sum of the third hysteresis torque H3, the fourth hysteresis torque H4, and the fifth hysteresis torque H5, is generated.

  On the other hand, as shown in FIG. 5, when torsional vibration (microtorsional vibration) having a torsion angle smaller than the first angle θ1 is input to the front cover 2, the first protrusion 62a of the piston 51 and the first internal teeth 41b Since the first gap T1 corresponding to the first angle θ1 is secured between the rotation directions of the first inner teeth 41b, the first protrusions 62a do not contact the first inner teeth 41b. Move in the direction. Moreover, since the 2nd clearance gap T2 larger than 1st clearance gap T1 is ensured between the rotation directions of the 1st protrusion 62a and the 2nd internal tooth 43b, the 1st protrusion 62a contact | abuts with the 2nd internal tooth 43b. Without moving between the second internal teeth 43b in the rotational direction. As a result, within the range of the first angle θ1, the fourth hysteresis torque H4 and the fifth hysteresis torque H5 are not generated, but only the third hysteresis torque H3 is generated.

  Further, when a torsional vibration having an angle larger than the first angle θ1 and smaller than the second angle θ2 is input to the front cover 2, the first protrusion 62a comes into contact with the first internal teeth 41b. Torque H4 is generated. Since the first protrusion 62a moves between the second inner teeth 43b in the rotational direction without contacting the second inner teeth 43b, the fifth hysteresis torque H5 is not generated. That is, in this case, the first hysteresis torque H1, which is the sum of the third hysteresis torque H3 and the fourth hysteresis torque H4, acts in parallel with the damper mechanism 7.

<Features of torque converter>
(1)
As described above, in this torque converter 1, three types of hysteresis torque (third hysteresis torque H3, first hysteresis torque H1, and second hysteresis torque H2) are applied to the damper mechanism 7 in accordance with the magnitude of the torsion angle. Act in parallel.

  Specifically, within the range of the first angle θ1, the generation of the fourth hysteresis torque H4 and the fifth hysteresis torque H5 is suppressed, and only the third hysteresis torque H3 is generated. Within the range from the first angle θ1 to the second angle θ2, the generation of the fifth hysteresis torque H5 (part of the hysteresis torque) is suppressed, and the first hysteresis torque H1 is generated.

  Thus, in this torque converter 1, the hysteresis torque can be changed stepwise by adjusting the first gap T1 and the second gap T2. Thereby, the 2nd hysteresis torque H2 can be enlarged and the increase in tip-in and tip-out can be suppressed.

  When the third hysteresis torque H3 is reduced, it is possible to reduce the muffled noise and to expand the lockup region to the low speed region. That is, the fuel efficiency of the vehicle is improved.

  When the tip-in and tip-out are reduced, the response of the torque converter 1 is improved and the operability of the vehicle is improved.

  Therefore, in this torque converter 1, it is possible to improve operability while improving the fuel efficiency of the vehicle.

(2)
In the torque converter 1, the first friction plate 41 is provided so as to be rotatable with respect to the piston 51 within the range of the first angle θ <b> 1 and movable in the axial direction. The third friction plate 43 is provided so as to be rotatable with respect to the piston 51 within the range of the second angle θ2 and movable in the axial direction. Thereby, the mechanism in which the hysteresis torque changes stepwise can be realized with a simple configuration.

(3)
In the torque converter 1, since the effective radius L3 of the friction surface of the third friction plate 43 is different from the effective radius L1 of the friction surface of the first friction plate 41, the magnitudes of the fourth hysteresis torque H4 and the fifth hysteresis torque H5. Can be changed. Thus, since the magnitude | size of hysteresis torque can be set freely, the freedom degree of design of the friction generation mechanism 40 can be raised.

(4)
In the torque converter 1, the inner cylindrical portion 62 of the piston 51 has a plurality of first protrusions 62 a extending radially outward, and the first protrusions 62 a engage with the first friction plate 41 and the third friction plate 43. is doing. For this reason, it is not necessary to increase the axial dimension of the inner cylindrical portion 62 for the purpose of installing the friction generating mechanism 40. That is, in the torque converter 1, the axial dimension can be shortened.

(5)
In the torque converter 1, the positions where the first gap T <b> 1 and the second gap T <b> 2 are provided are the inner circumferential portions of the friction generating mechanism 40 (more specifically, the inner circumferences of the first friction plate 41 and the third friction plate 43. Part) around. For this reason, compared with the case where the position where the first gap T1 and the second gap T2 are provided is around the outer periphery of the friction generating mechanism 40, the first protrusion 62a of the piston 51 is formed in the manufacturing process of the torque converter 1. The operation | work fitted to the 1st friction plate 41 and the 3rd friction plate 43 becomes easy.

(6)
In the torque converter 1, the friction generating mechanism 40 is disposed radially inside the second flange portion 16c and between the inner peripheral portion 53c of the output plate 53 and the first flange portion 16a in the axial direction. For this reason, the friction generating mechanism 40 can be provided without increasing the size of the torque converter 1.

  Further, the second friction plate 42 and the fourth friction plate 44 are disposed on the radially inner side of the turbine shell 14 and the second flange portion 16c. The second friction plate 42 and the fourth friction plate 44 are supported by the turbine shell 14 and the second flange portion 16c. With these configurations, the second friction plate 42 and the fourth friction plate 44 can be integrally rotated with respect to the turbine hub 16 and can be moved in the axial direction without bending the second friction plate 42 and the fourth friction plate 44. Can be provided. Thereby, the axial direction dimension of the friction generation mechanism 40 can be shortened, and the friction generation mechanism 40 can be reduced in size.

[Second Embodiment]
The following embodiments are also conceivable. In addition, about the structure which has the substantially same function as above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

<Lock-up device>
As shown in FIG. 6, the torque converter 101 according to the second embodiment includes a lockup device 105 and a friction generating mechanism 140.

  The lockup device 105 is different from the lockup device 5 described above in the configurations of the damper mechanism 107 and the friction generation mechanism 140. Specifically, as shown in FIG. 6, the lockup device 105 includes a piston 151, a damper mechanism 107, and a friction generation mechanism 140, and the damper mechanism 107 is held on the outer periphery of the piston 151. ing.

  The piston 151 includes an annular piston main body 161, an inner cylindrical portion 162 extending from the inner peripheral portion of the piston main body 161 toward the transmission side, and an outer cylindrical portion 163 extending from the outer peripheral portion of the piston main body 161 toward the transmission side. is doing. The inner cylindrical portion 162 has a first protrusion 162a that extends outward in the radial direction. The first protrusion 162a corresponds to the first protrusion 62a described above.

  The piston 151 is supported by the turbine 110 so as to be rotatable and movable in the axial direction. Specifically, the turbine 110 includes a turbine shell 114, a plurality of turbine blades 115 fixed to the turbine shell 114, and a turbine hub 116 fixed to the turbine shell 114.

  The turbine hub 116 has a cylindrical portion 116b, a first flange portion 116a, and a second flange portion 116c. The first flange portion 116a and the second flange portion 116c generally correspond to the first flange portion 16a and the second flange portion 16c. The second flange portion 116c has a plurality of second protrusions 116d extending inward in the radial direction.

  The inner peripheral portion of the turbine shell 114 is fixed to the second flange portion 116c. A friction generation mechanism 140 is accommodated between the inner peripheral portion of the turbine shell 114 and the axial direction of the first flange portion 116a on the radially inner side of the second flange portion 116c.

  The damper mechanism 107 is disposed on the radially inner side of the outer cylindrical portion 163, and includes a retaining plate 152, a plurality of springs 158, and an output plate 153 fixed to the turbine 110. The retaining plate 152 is fixed to the piston body 161. The spring 158 is held on the retaining plate 152 so as to be elastically deformable. The output plate 153 can contact the end of the spring 158 in the rotational direction.

<Friction generating mechanism>
As shown in FIG. 7, the friction generation mechanism 140 is accommodated between the turbine hub 116 and the turbine shell 114 in the axial direction, and includes a first friction plate 141, a second friction plate 142, and a third friction plate 143. And have.

(1) First Friction Plate The first friction plate 141 corresponds to the first friction plate 41 described above, and has an annular first main body portion 141a and a first inner portion extending radially outward from the first main body portion 141a. Teeth 141b. A first gap T1 is secured between the rotation directions of the first internal teeth 141b and the first protrusions 162a. Thus, the first friction plate 141 can rotate and move in the axial direction with respect to the piston 151 within the range of the first angle θ1.

(2) Second Friction Plate The second friction plate 142 corresponds to the second friction plate 42 described above, and has an annular second main body 142a and external teeth 142b extending radially outward from the second main body 142a. And have. A slight gap is formed between the rotation directions of the external teeth 142b and the second protrusions 116d so that the second friction plate 142 can move in the axial direction with respect to the turbine 110.

(3) Third Friction Plate Unlike the above-described third friction plate 43, the third friction plate 143 has a function as a friction member and a function as a spring. The third friction plate 143 is, for example, a wave spring or a cone spring, and presses the first friction plate 141 and the second friction plate 142 toward the engine side (the turbine shell 114 side). The third friction plate 143 is disposed in a compressed state between the second friction plate 142 and the first flange portion 116a in the axial direction.

  The third friction plate 143 has an annular third main body 143a and second internal teeth 143b extending radially inward from the third main body 143a. A second gap T2 is secured between the rotation directions of the second internal teeth 143b and the first protrusions 162a. Accordingly, the third friction plate 143 can rotate and move in the axial direction with respect to the piston 151 within the range of the second angle θ2.

  Further, the effective radius L13 of the friction surface of the third friction plate 143 is different from the effective radius L11 of the friction surface of the first friction plate 141, and more specifically, is set smaller than the effective radius L11. For this reason, as in the first embodiment, the fourth hysteresis torque H4 related to the effective radius L13 is smaller than the fifth hysteresis torque H5 related to the effective radius L11.

<Features of torque converter>
The characteristics of the torque converter 101 are as follows. Here, the description will focus on the characteristics of the torque converter 101 different from the torque converter 1 described above.

(1)
In the torque converter 101, the third friction plate 143 has a function as a friction member and a function as a spring. Therefore, the fourth friction plate 44 and the cone spring 45 of the first embodiment described above can be omitted, and the friction generating mechanism 140 can be downsized in the axial direction.

(2)
In the torque converter 101, the friction generating mechanism 140 is accommodated between the turbine shell 114 and the first flange portion 116a of the turbine hub 116, so that the friction is equal to the thickness of the output plate 53 compared to the first embodiment. The axial dimension around the generating mechanism 140 can be reduced.

  Conversely, since the friction generating mechanism 140 is reduced in size in the axial direction by the third friction plate 143, the friction generating mechanism 140 is also applied to the lockup device 105 in which the damper mechanism 107 is held by the piston 151 like the torque converter 101. The generation mechanism 140 is applicable.

[Other Embodiments]
As described above, the specific configuration of the fluid torque transmission device according to the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the invention.

(1)
For example, the first and second embodiments can be combined. Specifically, when the friction generating mechanism is accommodated between the output plate 53 and the turbine hub 16 in the axial direction as in the first embodiment, the friction generating mechanism 140 according to the second embodiment is used as the friction generating mechanism. It may be adopted.

  Further, when the friction generation mechanism is accommodated between the turbine shell 114 and the turbine hub 116 in the axial direction as in the second embodiment, the friction generation mechanism 40 according to the first embodiment is adopted as the friction generation mechanism. Also good.

(2)
The arrangement of the friction plate and the cone spring is not limited to the above-described embodiment. For example, in the first embodiment described above, the first gap T1 and the second gap T2 are provided in the radially inner portion of the friction generation mechanism 40, but the first gap T1 and the second gap T2 are the friction generation mechanism 40. It may be provided in the radially outer part of the. Similarly, in the second embodiment, the first gap T <b> 1 and the second gap T <b> 2 may be provided in the radially outer portion of the friction generating mechanism 140.

(3)
The device on which the friction generating mechanism is mounted is not limited to a torque converter, and any fluid type torque transmission device such as a fluid coupling can be applied.

Schematic cross section of torque converter (first embodiment) Partial sectional view of torque converter (first embodiment) VV sectional view of FIG. 2 (first embodiment) XX sectional view of FIG. 2 (first embodiment) Torsional characteristic diagram of lock-up device Schematic cross section of torque converter (second embodiment) Partial sectional view of torque converter (second embodiment)

Explanation of symbols

1 Torque converter (fluid torque transmission device)
DESCRIPTION OF SYMBOLS 2 Front cover 5 Lockup apparatus 10 Turbine 14 Turbine shell 14a Shell main body 14b 3rd protrusion 15 Turbine blade 16 Turbine hub 16a 1st flange part 16b Cylindrical part 16c 2nd flange part 16d 2nd protrusion 40 Friction generating mechanism 41 1st Friction plate 41a First body part 42a Second body part 42 Second friction plate 42a Second body part 42b First external teeth (external teeth)
43 3rd friction plate 43a 3rd main body part 43b 2nd internal tooth 44 4th friction plate 44a 4th main body part 44b 2nd external tooth 45 Cone spring 51 Piston 61 Piston main body 62 Inner cylindrical part 62a 1st protrusion 143 3rd Friction plate 143a Third body portion 143b Second internal teeth

Claims (9)

A front cover;
An impeller that forms a fluid chamber with the front cover;
A turbine disposed opposite the impeller in the fluid chamber;
A piston that is rotatably and axially movable with respect to the turbine and is pressed against the front cover by a change in hydraulic pressure;
A damper mechanism for elastically connecting the piston and the turbine in a rotational direction;
A mechanism that generates, by frictional resistance, a hysteresis torque that acts in parallel with the damper mechanism between the piston and the turbine, and that suppresses generation of the frictional resistance against torsional vibration within a first angle range. A friction generating mechanism having a gap and a second gap that is larger than the first gap and suppresses generation of a part of the frictional resistance against torsional vibration within a range of a second angle larger than the first angle;
A fluid-type torque transmission device. The friction generating mechanism is disposed so as to be slidable on the first friction plate, and a first friction plate provided so as to be rotatable within the range of the first angle and movable in the axial direction with respect to the piston. A second friction plate provided so as to be integrally rotatable with respect to the turbine and axially movable, and slidably disposed on the second friction plate, and within a range of the second angle with respect to the piston. A third friction plate provided so as to be rotatable and movable in the axial direction.
The fluid type torque transmission device according to claim 1. The effective radius of the friction surface of the third friction plate is different from the effective radius of the friction surface of the first friction plate;
The fluid type torque transmission device according to claim 2. The piston has an annular piston main body, and an inner cylindrical portion extending from the inner peripheral portion of the piston main body to the transmission side,
The inner cylindrical portion has a plurality of first protrusions extending radially outward,
The first friction plate includes an annular first body portion and a plurality of first internal teeth disposed between the adjacent first protrusions extending radially inward from the first body portion. And
The third friction plate includes an annular third body portion and a plurality of second internal teeth disposed between the adjacent first protrusions extending radially inward from the third body portion. And
The first gap is secured between the rotation direction of the first protrusion and the first internal tooth,
The second gap is secured between the rotation direction of the first protrusion and the second internal tooth.
The fluid type torque transmission device according to claim 3. The turbine has a turbine shell, a plurality of turbine blades fixed to the turbine shell, and a turbine hub fixed to the turbine shell,
The second friction plate is supported by at least one of the turbine shell and the turbine hub so as to be integrally rotatable and movable in the axial direction.
The fluid torque transmission device according to claim 4. The turbine hub includes a cylindrical hub body that radially supports the inner cylindrical portion so as to be movable in an axial direction, an annular first flange portion that extends radially outward from the hub body, and the first hub portion. An annular second flange portion that protrudes radially outward and engine side from the one flange portion,
The second flange portion includes an annular second flange portion main body and a plurality of second protrusions extending radially inward from an inner peripheral portion of the second flange portion main body,
The second friction plate has an annular second main body portion and a plurality of external teeth disposed between the adjacent second protrusions extending radially inward from the second main body portion.
The fluid type torque transmission device according to claim 5. The turbine shell includes an annular shell body and a plurality of third protrusions extending radially inward from the shell body,
The second friction plate includes an annular second main body portion and a plurality of external teeth disposed between the adjacent third protrusions extending radially outward from the second main body portion.
The fluid type torque transmission device according to claim 5. The damper mechanism includes an input member that rotates integrally with the piston, an output member that is fixed to the turbine, and an elastic member that elastically connects the input member and the output member in a rotational direction. And
The friction generating mechanism is disposed between the output member and the turbine in the axial direction, and has a pressing member that presses the first, second, and third friction plates toward the output member or the turbine. ing,
The fluid torque transmission device according to claim 7. The turbine has a turbine shell, a plurality of turbine blades fixed to the turbine shell, and a turbine hub fixed to the turbine shell,
The friction generating mechanism is disposed between the turbine shell and the turbine hub in the axial direction,
The third friction plate is a member that is elastically deformable in the axial direction, and presses the first and second friction plates toward the turbine shell side or the turbine hub side.
The fluid type torque transmission device according to claim 2.

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