JP5637482B2 - Torque converter - Google Patents

Description

  The present invention relates to a torque converter in which a plurality of stators are arranged.

  In recent years, with the aim of improving fuel efficiency, in order to satisfy both the reduction of engine speed during cruise driving and the improvement of climbing and starting performance, the number of reciprocal oranges has been expanded by increasing the number of automatic transmissions. However, it may not be possible from the viewpoint of cost and weight increase only by expanding the ratio orange of the automatic transmission main body.

  Therefore, it is desired to increase the ratio of the orange by increasing the torque ratio of the torque converter, particularly in the low speed ratio region. Further, in order to reduce slip loss of the torque converter during cruise traveling, it is desired to increase the capacity coefficient particularly in the high speed ratio region. Against this background, torque converters are required to have a performance that achieves both a high torque ratio and a high capacity.

  In order to satisfy such requirements, a torque converter has been proposed in which a plurality of stators are arranged and the direction of the flow of hydraulic oil from the turbine runner can be appropriately changed by the stator according to the speed ratio range. Yes. For example, in Patent Document 1, in order to achieve both a high torque ratio in a low speed ratio range and a high capacity in a high speed ratio range, two stators are connected to a fixed shaft that does not rotate via separate one-way clutches. A torque converter is disclosed.

Japanese Utility Model Publication No. 62-100365

  However, in the torque converter of Patent Document 1, the one-way clutch of each stator is arranged side by side in the axial direction of the torque converter, so that the axial length of the torque converter becomes long. For this reason, the axial length of the entire automatic transmission including the torque converter becomes long, and there is a problem that the weight of the entire automatic transmission increases.

  An object of the present invention is to provide a torque converter in which a plurality of stators are arranged with a reduced axial length.

  The present invention is a torque converter that transmits a rotational force input to a pump impeller to the turbine runner using a fluid circulating between the pump impeller, the turbine runner, and the stator as a transmission medium, and the stator includes: The first stator disposed on the turbine runner side and the second stator disposed on the pump impeller side are arranged in parallel in the rotational axis direction of the pump impeller, and the first stator is the second stator. An annular first projecting portion projecting toward the stator side is provided, and the second stator has an annular second projecting portion projecting toward the first stator side radially inward of the first projecting portion. The torque converter further includes a clutch plate attached to an inner peripheral surface of the first protrusion so as to be movable only in the rotation axis direction, and the second protrusion. Clutch discs attached to the outer peripheral surface of the part so as to be movable only in the rotational axis direction are alternately arranged in the rotational axis direction, and the first stator is arranged in only one direction with respect to the second stator. A first one-way clutch that allows rotation about the rotation axis, and an inner peripheral surface of the second projecting portion and a fixing member that is fixed radially inward from the second stator; The stator includes a second one-way clutch that allows the stator to rotate about the rotation axis in only one direction relative to the fixed member.

  According to the present invention, the clutch plate constituting the first one-way clutch is attached to the first protrusion and the clutch disk is attached to the second protrusion. Thereby, the first one-way clutch and the second one-way clutch are arranged concentrically around the rotation axis, and the first one-way clutch is arranged on the outer peripheral side of the second one-way clutch.

  Therefore, the axial length of the torque converter can be reduced as compared with the torque converter described in Patent Document 1 in which two one-way clutches are arranged in the axial direction.

Further, in the present invention, Ru a pressing member that presses the first stator to the turbine runner side.

As a result , when there is no rotational difference between the first stator and the second stator in the coupling range state where the frequency of use is high, the clutch plate and the clutch disk are pressed by pressing the first stator toward the turbine runner with the pressing member. And non-contact with each other, the drag torque generated in the first one-way clutch becomes very small. As a result, power loss in the first one-way clutch is reduced, and transmission efficiency is improved.

Sectional drawing which shows the upper half of the torque converter which concerns on embodiment of this invention. The expanded sectional view which shows the periphery of the 1st and 2nd one-way clutch of FIG. The graph which shows the relationship between a speed ratio, a torque ratio, and a volume coefficient. It is a figure explaining the relationship between the flow of hydraulic oil and the force which acts on a stator blade, (a) shows a low speed ratio area, (b) shows a medium speed ratio area, (c) shows a high speed ratio area, respectively. .

  Hereinafter, a torque converter 10 according to an embodiment of the present invention will be described.

  As shown in FIG. 1, the torque converter 10 includes three types of impellers, that is, a pump impeller 12, a turbine runner 14, a stator 16, and a front cover 21. An annular path for circulating hydraulic oil is formed by the pump impeller 12, the turbine runner 14, and the stator 16.

  The torque converter 10 further includes two one-way clutches 40 and 50 and a lock-up clutch 22 disposed between the turbine runner 14 and the front cover 21.

  The pump impeller 12 is attached to a flywheel (not shown) connected to a drive shaft (engine crankshaft) (not shown) to which an engine output (not shown) is transmitted.

  The turbine runner 14 is disposed so as to face the pump impeller 12, and has an annular fluid inlet disposed in proximity to the annular fluid discharge port of the pump impeller 12, and is coupled to the speed change mechanism. The stator 16 deflects the flow of hydraulic oil that flows into the pump impeller 12 from the turbine runner 14.

  The pump impeller 12 includes an outer pump shell 12a formed in a bowl shape, an inner pump core ring 12b, and a plurality of pump blades 12c having base ends attached to the pump core ring 12b.

  The outer peripheral end of the pump shell 12a is attached to a front cover 21 connected to the drive shaft that rotates along the rotation axis O. The inner peripheral end of the pump shell 12 a is fixed to the pump hub 13. Accordingly, the pump impeller 12 is formed in an annular shape and is configured to rotate along the rotation axis O. An output shaft 30 is disposed in the pump hub 13 so as to be rotatable about the rotation axis O.

  The turbine runner 14 includes an outer turbine shell 14a formed in a bowl shape, an inner turbine core ring 14b, and a plurality of turbine blades 14c whose base ends are attached to the turbine core ring 14b.

  An inner peripheral end of the turbine shell 14 a is fixed to the turbine hub 15 by a rivet 23. The turbine hub 15 is coupled to the output shaft 30, and the turbine runner 14 rotates integrally with the output shaft 30.

  The stator 16 is disposed so as to be sandwiched between the pump impeller 12 and the turbine runner 14.

  The stator 16 includes a first stator (first stage stator) 17 and a second stator (second stage stator) 18 that are arranged side by side in the axial direction of the torque converter 10. The axial direction of the torque converter 10 is a direction in which the rotation axis O extends, and is also simply referred to as “axial direction” hereinafter.

  The first stator 17 includes an inner first shell side ring 17a, an outer first core side ring 17b, and a plurality of first stator blades 17c whose base ends are attached to the first shell side ring 17a. ing.

  The second stator 18 is configured similarly to the first stator 17. The second stator 18 includes an inner second shell side ring 18a, an outer second core side ring 18b, and a plurality of second stator blades 18c having base ends attached to the second shell side ring 18a. ing.

  The stator blades 17c and 18c are fixed to the outer peripheral surfaces of the shell-side rings 17a and 18a, respectively, and extend outward in the radial direction.

  Referring also to FIG. 4A, the first stator blade 17c has a blade-shaped cross section, the turbine runner 14 side end is a rounded head, and the pump impeller 12 side end is an elongated tail. It has become. The surface (the lower surface in FIG. 4A) of the first stator blade 17c is formed in a curved concave shape, and the back surface (the upper surface in FIG. 4A) is formed in a curved convex shape.

  The second stator blade 18c has an elongated, substantially rectangular cross section, and both the turbine runner 14 side end and the pump impeller 12 side end are rounded. The surface of the second stator blade 18c is formed in a slightly curved concave shape, and the back surface is formed in a slightly curved convex shape.

  The outlet angle α2 of the second stator blade 18c is set larger than the outlet angle α1 of the first stator blade 17c. The exit angle is an angle formed by a tangent at the exit side end of the center line connecting the thickness centers of the stator blades 17c and 18c and a line O1 parallel to the rotation axis O.

  The first stator 17 is supported by the second stator 18 via the first one-way clutch 40. On the other hand, the second stator 18 is supported by a fixed shaft 31 that is supported by a housing (not shown) via a second one-way clutch 50 so as not to rotate.

  The first one-way clutch 40 and the second one-way clutch 50 are arranged concentrically around the rotation axis O. The first one-way clutch 40 is disposed on the outer peripheral side of the second one-way clutch 50.

  As shown in FIG. 2, the first one-way clutch 40 is a friction clutch that operates in the axial direction in response to a reaction force acting on the first stator 17, and the clutch plate 41 and the clutch disk 42 are alternately arranged in the axial direction. It is arranged and configured.

  A first hub 17d, which is a protruding portion that protrudes in the axial direction toward the second stator 18 side, is formed on the first shell side ring 17a. The clutch plate 41 is attached to the first hub 17d so as to be movable only in the axial direction. In the embodiment, the plurality of clutch plates 41 are attached to the first hub 17d by engaging the splines formed on the outer peripheral side of each clutch plate 41 with the splines formed on the inner peripheral side of the first hub 17d. It has been.

  The second shell side ring 18a is formed with a second hub 18d that protrudes in the axial direction toward the first stator 17 on the radially inner side of the first hub 17d. A clutch disk 42 is attached to the second hub 18d so as to be movable only in the axial direction. In the embodiment, the plurality of clutch disks 42 are attached to the second hub 18d by engaging the splines formed on the inner peripheral side of each clutch disk 42 with the splines formed on the outer peripheral side of the second hub 18d. It has been.

  In the embodiment, the clutch plate 41 is attached to the first hub 17d, and the clutch disk 42 is attached to the second hub 18d. However, conversely, the clutch disk 42 may be attached to the first hub 17d, and the clutch plate 41 may be attached to the second hub 18d.

  Further, a pressing member 43 that presses the first shell side ring 17 a toward the turbine runner 14 is disposed between the first stator 17 and the second stator 18. Here, the pressing member 43 is an urging member made of a known spring such as a disc spring. However, you may comprise the press member 43 from the hydraulic device etc. which were connected to the control apparatus.

  The second one-way clutch 50 includes an inner ring 51 that is spline-fitted to the fixed shaft 31, an outer ring 52 that is disposed around the inner ring 51, and an engagement body 53 that is provided between the inner ring 51 and the outer ring 52. Has been. The outer ring 52 is fixed to the second stator 18. In the embodiment, the outer ring 52 is fixed to the second hub 18d by fitting the spline formed on the inner peripheral side of the second hub 18d of the second stator 18 to the spline formed on the outer peripheral side of the outer ring 52. Has been.

  Further, a first thrust bearing 24 is disposed between the axial direction of the pump hub 13 and the second shell side ring 18a. A second thrust bearing 25 is arranged between the turbine hub 15 and the first shell side ring 17a in the axial direction.

(Torque converter operation)
In the torque converter 10 configured as described above, when a condition such as the vehicle speed reaching a predetermined value is satisfied, the pump impeller 12 is turned on by operating a hydraulic device (not shown) to turn on the lock-up clutch 22. The turbine runner 14 is held in a directly connected state, and the power of the drive shaft (not shown) is directly transmitted to the automatic transmission side.

  On the other hand, when the lockup clutch 22 is off (lockup release), torque transmission between the front cover 21 and the turbine runner 14 is performed by fluid transmission between the pump impeller 12 and the turbine runner 14.

  When the drive shaft rotates and the front cover 21 rotates, the pump shell 12a attached thereto also rotates at the same time. Due to the rotation of the pump impeller 12, a flow indicated by an arrow in FIG. 1 is generated in the hydraulic oil, and this flow is transmitted through the stator 16 to rotate the turbine runner 14. The output shaft 30 also rotates integrally with the rotation of the turbine runner 14, and an input shaft of a transmission (not shown) connected to the output shaft 30 is rotationally driven.

  The hydraulic fluid flowing from the pump impeller 12 to the turbine runner 14 rotates the turbine runner 14 and then moves toward the stator 16. When passing through the stator 16, the hydraulic oil abuts on the stator blades 17 c and 18 c to change its direction, and is returned to the pump impeller 12.

  The turbine runner 14 generates torque by the flow of hydraulic oil, and this torque is transmitted to the input shaft of a transmission mechanism (not shown) via the turbine hub 15 and the output shaft 30. During this operation, the stator 16 functions to amplify the torque transmitted from the pump impeller 12 to the turbine runner 14 by changing the flow direction of the hydraulic oil. The hydraulic oil corresponds to a torque transmission medium that circulates between the pump impeller 12 and the turbine runner 14.

  The hydraulic oil flows from the turbine runner 14 to the stator 16 by the swirl flow generated according to the operating state of the torque converter 10. The hydraulic oil abuts on the first and second stator blades 17 c and 18 c, flows along these, and flows into the pump impeller 12.

  The inflow angle of the hydraulic oil flowing from the turbine runner 14 to the stator 16 greatly depends on the speed ratio e, that is, the speed ratio between the turbine runner 14 and the pump impeller 12, and the lower the speed ratio e, the more the hydraulic oil generates in the stator 16. The thrust force to be increased.

  Here, as shown in FIG. 3, the operation of the torque converter 10 in each region will be described in three regions R <b> 1 to R <b> 3 according to the speed ratio e.

(Low speed ratio range)
In the low speed ratio region R1 where the speed ratio e is about 0 to 0.3, for example, as shown in FIG. 4A, the speed V1 of the hydraulic oil flowing from the turbine runner 14 to the stator 16 has a large thrust component. Therefore, a large thrust force S1 is generated in the first stator blade 17c by the flow of the hydraulic oil.

  The thrust force S1 is larger than the pressing force P of the pressing member 43 in the direction opposite to the thrust force S1. The first stator 17 is configured to be movable in the direction of the second stator 18, but the thrust force S 1 that exceeds the pressing force P becomes a thrust, and the first stator 17 has moved to the second stator 18 side. It has become.

  As a result, the clutch plate 41 of the first one-way clutch 40 and the clutch disk 42 are frictionally engaged, and the first stator 17 is locked to the second stator 18 so as not to move. At this time, the second stator 18 is stopped by the second one-way clutch 50, and the first stator 17 is also maintained stopped.

  The hydraulic oil flowing from the turbine runner 14 into the stator 16 generates a force radially outward (upward in FIG. 4A) on the first and second stator blades 17c and 18c. However, since the first and second stators 17 and 18 cannot rotate and are kept stationary, the torque T1 is applied to the first and second stators 17 and 18 in the radially outward direction as a reaction force of the force. Will occur.

  The hydraulic oil whose direction of flow is changed in contact with the stator blades 17c, 18c flows into the pump impeller 12, and boosts the rotation of the pump impeller 12. Thus, in the low speed ratio region R1, the torque increasing action is performed, and the torque ratio K becomes high.

(Medium speed ratio range)
As the speed ratio e increases, the component in the thrust direction of the speed V2 of the hydraulic oil flowing from the turbine runner 14 to the stator 16 decreases, and the thrust force S1 generated in the first stator blade 17c decreases by the flow of the hydraulic oil. When the speed ratio e becomes a medium speed ratio range R2 of about 0.3 to 0.8, for example, the thrust force S2 becomes smaller than the pressing force P of the pressing member 43 as shown in FIG. . At this time, the first stator 17 moves to the front cover 21 side, and the engagement between the first stator 17 and the second stator 18 by the first one-way clutch 40 is released.

  When the pressing member 43 is made of a spring such as a disc spring, the release of the engagement by the first one-way clutch 40 is determined according to the magnitude of the pressing force P that is the urging force of the spring and the thrust force S1. The first stator 17 in the fixed state starts to rotate smoothly. Further, drag torque in the first one-way clutch 40 by the rotating first stator 17 is also small.

  The hydraulic oil that flows into the stator 16 from the turbine runner 14 abuts against the back surface of the first stator blade 17c and acts to rotate the first stator 17. And since the engagement by the 1st one-way clutch 40 is cancelled | released, the 1st stator 17 rotates freely in the outline arrow direction of FIG.4 (b).

  On the other hand, even at this time, the second stator 18 is still stopped. The hydraulic oil flowing from the turbine runner 14 into the stator 16 generates a force in the second stator blade 18c in the radially outward direction. However, since the second stator 18 is non-rotatable and kept stationary due to the engagement of the second one-way clutch 50, the second stator 18 is torqued outward in the radial direction as a reaction force of the force. T2 occurs.

(High speed ratio range)
When the speed ratio e further increases, the component in the thrust direction of the speed V3 of the hydraulic oil flowing from the turbine runner 14 to the stator 16 is further reduced. When the speed ratio e becomes a high speed ratio region R3 of about 0.8 to 1, for example, as shown in FIG. 4C, the hydraulic oil flowing from the turbine runner 14 rotating at high speed into the stator 16 is second stator blades. The second stator 18 is rotated in contact with the back surface of 18c. As a result, the engagement of the second one-way clutch 50 is released, and the second stator 18 also rotates in the direction of the white arrow in FIG.

  In particular, when the speed ratio e is 1, that is, when the torque converter 10 approaches the coupling state, the rotational difference between the first stator 17 and the second stator 18 disappears and the first hub 17d of the first stator 17 is engaged. The rotational difference between the clutch plate 41 and the clutch disc 42 engaged with the second hub 18d of the second stator 18 is reduced. Accordingly, the drag torque is very small, so that the power loss is small and the transmission efficiency is good.

  Further, the inlet angle of the second stator blade 18c is set so as to substantially coincide with the inflow angle of the hydraulic oil flowing from the turbine runner 14 into the stator 16. For this reason, the hydraulic fluid does not substantially collide with the second stator blade 18c and does not flow smoothly and peel off, so that the effective flow path area does not decrease. Therefore, a high capacity coefficient τ can be obtained in the high speed ratio region R3.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, although the case where the stator 16 is composed of two stators 17 and 18 has been described, the stator may be composed of three or more stators. The type of the second one-way clutch 50 is not limited, and may be a one-way clutch such as a ratchet type, a sprag type, or a roller type.

  As described above, the first one-way clutch 40 and the second one-way clutch 50 are disposed concentrically around the rotation axis O, and the first one-way clutch 40 is disposed on the outer peripheral side of the second one-way clutch 50. ing.

  Specifically, the clutch plate 41 attached to the first hub 17d protruding from the first shell side ring 17a to the second stator 18 side, and the second protruding from the second shell side ring 18a to the first stator 17 side. The clutch disk 42 is attached to the hub 18d. The second one-way clutch 50 includes an inner ring 51 that is spline-fitted to the fixed shaft 31, an outer ring 52 that is fixed to the second hub 18d, and an engagement body 53 that is provided between the inner ring 51 and the outer ring 52. It is composed of

  This makes it possible to reduce the axial length of the torque converter as compared with the torque converter described in Patent Document 1 in which two one-way clutches are arranged in the axial direction.

  The first one-way clutch 40 is a friction clutch that operates in the axial direction in accordance with the reaction force acting on the first stator 17, and the clutch plates 41 and the clutch disks 42 are alternately arranged in the axial direction. It is configured.

  Therefore, when there is no rotational difference between the first stator 17 and the second stator 18 in the high speed ratio region R3, the clutch plate 41 engaged with the first hub 17d of the first stator 17 and the second stator 18 2 The rotational difference from the clutch disk 42 engaged with the hub 18d becomes small, and the drag torque becomes very small. Therefore, the power loss in the first one-way clutch 40 is small and the transmission efficiency is good.

  Further, the first one-way clutch 40 engages or disengages the first stator 17 based on the magnitude of the thrust force S <b> 1 generated in the first stator 17 by the swirling flow according to the operating state of the torque converter 10.

  Therefore, it is not necessary to provide a special oil passage for engaging or releasing the first stator 17, and the number of parts can be reduced as compared with the conventional one-way clutch illustrated in Patent Document 1. . Therefore, the cost of the torque converter 10 can be suppressed.

  DESCRIPTION OF SYMBOLS 10 ... Torque converter, 12 ... Pump impeller, 12a ... Pump shell, 12b ... Pump coring, 12c ... Pump blade, 13 ... Pump hub, 14 ... Turbine runner, 14a ... Turbine shell, 14b ... Turbine coring, 14c ... Turbine blade 15 ... Turbine hub, 16 ... Stator, 17 ... First stator, 17a ... First shell side ring, 17b ... First core side ring, 17c ... First stator blade, 17d ... First hub (first protrusion) 18 ... 2nd stator, 18a ... 2nd shell side ring, 18b ... 2nd core side ring, 18c ... 2nd stator blade, 18d ... 2nd hub (2nd protrusion part), 21 ... Front cover, 22 ... Lock Up clutch, 30 ... Output shaft, 31 ... Fixed shaft (fixed member) 40 ... the first one-way clutch, 41 ... clutch plate, 42 ... clutch disk, 43 ... pressing member 50 ... second one-way clutch, 51 ... inner ring, 52 ... outer ring, 53 ... engaging member.

Claims (1)

A torque converter that transmits a rotational force input to a pump impeller to the turbine runner using a fluid circulating between the pump impeller, the turbine runner, and a stator as a transmission medium;
The stator is configured such that a first stator disposed on the turbine runner side and a second stator disposed on the pump impeller side are arranged side by side in the rotation axis direction of the pump impeller.
The first stator has an annular first protrusion that protrudes toward the second stator.
The second stator has an annular second protrusion that protrudes toward the first stator on the radially inner side of the first protrusion,
The torque converter further includes a clutch plate attached to the inner peripheral surface of the first protrusion so as to be movable only in the rotational axis direction, and is movable only in the rotational axis direction to the outer peripheral surface of the second protrusion. The first one-way clutch which is configured by alternately arranging the clutch disks attached to the rotation axis, and allows the first stator to rotate about the rotation axis in only one direction with respect to the second stator. ,
The second stator is disposed between an inner peripheral surface of the second projecting portion and a fixing member fixed radially inward from the second stator, and the second stator is rotated around the rotation axis in only one direction with respect to the fixing member. second one-way clutch that allows the rotating, and
A torque converter comprising a pressing member that presses the first stator toward the turbine runner .

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