JP2007002920A - Power transmission controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in a conventional power transmission wherein abrupt variation of torque and impact noise according to the operation of a stopper mechanically limiting the relative rotation of the turbine shell side to the turbine hub side of the output side rotating element of a fluid transmission device installed between the output shaft of a drive source and the input shaft of a transmission. <P>SOLUTION: In this power transmission controller, a torque converter 11 is installed between the output of an engine 10 and the input shaft 28 of a CVT 13. The torque converter comprises a damper 11E installed between the turbine shell 32 side and the turbine hub 34 side of the output side rotating element and allowing the relative rotation thereof and having a coiled spring 48 elastically deforming along the relative rotation thereof and a stopper 11F mechanically limiting the relative rotation exceeding a predetermined amount of the turbine shell 32 side to the turbine hub 34 side. The power transmission controller further comprises an impact relieving means for relieving impact caused by the operation of the stopper 11F. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission control device in which a damper with a stopper that allows relative rotation of a predetermined amount or less between a driving side and a driven side is incorporated in the middle of a power transmission path between a driving source and an output element.

  While a fluid transmission device such as a torque converter incorporated between the engine and the transmission can reduce the torque fluctuation of the engine and transmit it to the transmission side, a loss due to intervening fluid occurs, It has the disadvantage of causing a reduction in fuel consumption. For this reason, in a high speed region of an engine with little torque fluctuation, it is common to incorporate a lockup clutch capable of integrally connecting the input side rotating element and the output side rotating element into the fluid transmission device. However, in a fluid transmission device incorporating such a lock-up clutch mechanism, when the input-side rotation element and the output-side rotation element are directly connected by the lock-up clutch mechanism, torque fluctuations of an input member such as an internal combustion engine Is transmitted to the output side rotation element as it is. As a result, there is a concern that riding comfort may deteriorate in vehicles and the like.

  For this reason, for example, Patent Document 1 proposes a torque converter in which a damper is incorporated in the middle of the output-side rotating element so that torque fluctuations generated in the input-side rotating element are not directly transmitted to the output-side rotating element. Has been. In the torque converter disclosed in Patent Document 1, relative rotation between the turbine shell side and the turbine hub side of the output side rotating element is allowed by the damper even in a state where the lockup clutch is not connected.

  Usually, in a fluid transmission device incorporating such a damper, a stopper is provided to restrict the relative rotation amount between the turbine shell side and the turbine hub side within a certain range in order to protect the damper spring. Incidentally, the relative rotation allowance between the turbine shell side and the turbine hub side is set to about 1.3 to 1.5 times the maximum driving torque that can be generated in the internal combustion engine, for example.

JP 9-53700 A

  Normally, a lock-up clutch incorporated in a fluid transmission device is in a connected state in an operating region with a high vehicle speed and a low throttle opening, but the lock-up clutch is in a disconnected state in an operating region with a low vehicle speed and a high throttle opening. Become. Therefore, when this fluid transmission device is a torque converter, there is an advantage that torque can be increased in an operation region where the vehicle speed is low and the throttle opening is high. On the other hand, if the throttle opening is greatly changed, for example, when the vehicle is suddenly started, a large driving torque is generated in combination with a torque amplification of about twice in the fluid transmission section. In the fluid transmission device disclosed in Patent Document 1 in which a damper is incorporated between the turbine shell side and the turbine hub side of the output side rotating element, such a large change in driving torque cannot be completely absorbed. As a result, there is a possibility that an impact sound is generated in accordance with the collision of the stopper that restricts the relative rotation between the turbine shell side and the turbine hub side, or a sudden torque fluctuation occurs, which may cause discomfort to the passenger. In particular, in a vehicle incorporating a belt type continuously variable transmission, sudden torque fluctuations cause belt slipping, resulting in a decrease in durability due to wear.

  Similar problems may occur when the above-described damper with a stopper is incorporated in the middle of a power transmission path between a drive source such as an engine and an output element such as a drive wheel.

  An object of the present invention is to provide an elastic deformation element that is incorporated in the middle of a power transmission path for transmitting power from a drive source to an output element and elastically deforms in accordance with relative rotation between the drive side and the driven side, A damper having a stopper that mechanically restricts relative rotation exceeding a predetermined amount between the side and the driven side is provided, and impact noise and unpleasant torque fluctuation generated by the operation of the stopper of the damper can be reduced. The object is to provide a power transmission control device.

  A first aspect of the present invention includes a damper that is incorporated in the middle of a power transmission path for transmitting power from a drive source to an output element and allows relative rotation between the drive side and the driven side. Power transmission comprising: an elastic deformation element that elastically deforms in accordance with relative rotation between the driving side and the driven side; and a stopper that mechanically limits relative rotation exceeding a predetermined amount between the driving side and the driven side. The control device further includes impact mitigation means for mitigating an impact caused by the operation of the stopper.

  In the present invention, the power from the drive source is transmitted to the output element via the power transmission path and the damper incorporated in the middle thereof. In this case, the relative rotation between the driving side and the driven side that occurs with the fluctuation of the driving torque is absorbed by the elastic deformation of the elastic deformation element of the damper. In addition, excessive relative rotation between the driving side and the driven side is mechanically limited by the stopper, but the impact sound and sudden torque fluctuation generated by the operation of the stopper are alleviated by the impact reducing means. .

  It should be noted that the drive source according to the present invention is intended not only for an internal combustion engine but also for an electric motor or a combination thereof. Further, the output element according to the present invention is not only a drive wheel, but also any element incorporated in the middle of a power transmission path between the drive wheel and the drive source, for example, a fluid transmission represented by a manual clutch, a torque converter, etc. It should be understood that devices, transmissions such as automatic transmissions and belt-type continuously variable transmissions, and differential gears are also contemplated. Therefore, if the damper is in the middle of the power transmission path between the drive source and the drive wheel, the installation position can be arbitrarily selected.

  In the power transmission control device according to the first aspect of the present invention, the impact mitigation means may have means for reducing the drive torque of the output shaft of the drive source.

  Further, a fluid transmission device having an input side rotating element and an output side rotating element can be further provided. In this case, the driving side is the turbine shell side of the output side rotating element and the driven side is the turbine hub of the output rotating element. Become the side. In particular, a torque converter having a large torque fluctuation in the low rotation region is particularly suitable as a fluid transmission device in the present invention, and has a lock-up clutch that can mechanically connect the input side rotation element and the output side rotation element. It may be.

  An automatic transmission having a friction engagement element that is connected to the output-side rotation element of the above-described fluid transmission device and contributes to power transmission can be further provided. In this case, the impact reducing means may have means for increasing the slip amount of the friction engagement element of the automatic transmission.

  Alternatively, it may further include a belt type continuously variable transmission connected to the output side rotating element of the fluid transmission. In this case, the belt-type continuously variable transmission may have means for increasing the belt clamping pressure when the impact mitigating means is actuated or when the stopper is actuated.

  An output shaft rotation speed sensor that detects the rotation speed of the output side rotation element of the fluid transmission device described above can be further provided. In this case, the impact mitigation means operates based on the rate of change of the rotational speed of the output side rotational element of the fluid transmission device detected by the output shaft rotational speed sensor, and the rate of change is a predetermined value. If it is less than that, the operation may be stopped.

  The impact mitigating means preferably operates immediately before the stopper mechanically limits the relative rotation between the turbine shell side and the turbine hub side.

  According to a second aspect of the present invention, there is provided a damper that is incorporated in the middle of a power transmission path for transmitting power from a driving source to an output element and allows relative rotation between the driving side and the driven side, and the power transmission. A belt-type continuously variable transmission incorporated in the middle of the path, wherein the damper is elastically deformed with relative rotation between the driving side and the driven side, and the driving side and the driven side A power transmission control device comprising: a stopper that mechanically limits relative rotation exceeding a predetermined amount; and the belt-type continuously variable transmission includes a clamping pressure increasing unit that increases the belt clamping pressure. And a control means for controlling the operation of the clamping pressure increasing means based on the determination result by the determination means. It is characterized by

  In the present invention, the power from the drive source is transmitted to the output element through the power transmission path, the damper and the belt type continuously variable transmission incorporated in the middle of the power transmission path. In this case, the relative rotation between the driving side and the driven side that occurs with the fluctuation of the driving torque is absorbed by the elastic deformation of the elastic deformation element of the damper. Further, excessive relative rotation between the driving side and the driven side is mechanically limited by the stopper. The determining means determines whether or not the relative rotation between the driving side and the driven side exceeds a predetermined amount, and the control means controls the operation of the clamping pressure increasing means based on the determination result.

  The power transmission control device according to the second aspect of the present invention can further include a fluid transmission device having an input side rotation element and an output side rotation element. In this case, in this case, the driving side is the turbine shell side of the output side rotating element, and the driven side is the turbine hub side of the output rotating element. In particular, a torque converter having a large torque fluctuation in the low rotation region is particularly suitable as a fluid transmission device in the present invention, and has a lock-up clutch that can mechanically connect the input side rotation element and the output side rotation element. It may be.

  The determining means has an output shaft rotational speed sensor for detecting the rotational speed of the output side rotational element of the fluid transmission device, and the control means is the rotation of the output side rotational element of the fluid transmission device detected by the output shaft rotational speed sensor. Based on the rate of change of speed, the clamping pressure increasing means may be operated when this is above a predetermined value, and the operation of the clamping pressure increasing means may be stopped when the rate of change is less than a predetermined value. The output side rotation element whose rotation speed is detected may be on the turbine shell side or the turbine hub side.

  Further, the increase of the belt clamping pressure of the belt type continuously variable transmission by the clamping pressure increasing means is preferably performed immediately before the stopper mechanically limits the relative rotation between the turbine shell side and the turbine hub side.

  According to the power transmission control device of the first aspect of the present invention, it is incorporated in the middle of the power transmission path for transmitting power from the drive source to the output element, and allows relative rotation between the drive side and the driven side. An elastic deformation element that includes a damper and elastically deforms as the damper rotates relative to the driving side and the driven side; and a stopper that mechanically limits relative rotation exceeding a predetermined amount between the driving side and the driven side. And further equipped with impact mitigation means for mitigating the impact caused by the operation of this stopper, so that it is possible to alleviate the impact noise and sudden torque fluctuations that occur during the operation of the stopper. Can also be improved.

  When the impact mitigation means has means for reducing the drive torque of the output shaft of the drive source, the impact sound and sudden torque fluctuation generated when the stopper is operated are mitigated by reducing the drive torque of the output shaft of the drive source. Is possible.

  When the fluid transmission device further includes an input side rotation element and an output side rotation element, the drive side is the turbine shell side of the output side rotation element and the driven side is the turbine hub side of the output rotation element, the fluid transmission device The present invention can also be applied to a power transmission control device including the above.

  When the fluid transmission device is a torque converter and the torque converter is attached to the output side rotating element and has a lock-up clutch that can be integrally engaged with the input side rotating element, the larger impact generated when the stopper is operated Sound and sudden torque fluctuations can be effectively reduced.

  An automatic transmission having a frictional engagement element connected to the output side rotation element of the fluid transmission device and contributing to power transmission is further provided, and the means for shock mitigation increases the slip amount of the frictional engagement element of the automatic transmission. In this case, it is possible to mitigate impact noise and sudden torque fluctuations that occur during operation of the stopper by increasing the slip amount of the friction engagement element of the automatic transmission.

  When the transmission is a belt-type continuously variable transmission and the belt-type continuously variable transmission has a means for increasing the belt clamping pressure when the impact mitigating means is operated, a belt generated due to a sudden torque fluctuation It is possible to suppress the slippage of the resin and to prevent the durability from decreasing.

  An output shaft rotational speed sensor for detecting the rotational speed of the output side rotational element of the fluid transmission device is further provided, and the impact mitigation means is configured to detect the rotational speed of the output side rotational element of the fluid transmission device detected by the output shaft rotational speed sensor. Based on the rate of change, if it is activated when it is greater than or equal to a predetermined value and stopped when the rate of change is less than the predetermined value, the possibility of unnecessarily activating the impact mitigation means can be reduced. It is possible to perform smoother power transmission.

  If the impact mitigation means is activated immediately before the stopper mechanically restricts the relative rotation between the turbine shell side and the turbine hub side, the impact noise and unpleasant torque fluctuations that occur during the operation of the stopper are more reliably suppressed. can do.

  According to the power transmission control device of the second aspect of the present invention, the determination means for determining whether or not the relative rotation between the drive side and the driven side exceeds a predetermined amount, and the determination result by the determination means. Since the control means for controlling the operation of the pressure increasing means is provided, it is possible to prevent the belt-type continuously variable transmission from being deteriorated by suppressing the slippage of the belt caused by a sudden torque fluctuation.

  When the fluid transmission device further includes an input side rotation element and an output side rotation element, the drive side is the turbine shell side of the output side rotation element and the driven side is the turbine hub side of the output rotation element, the fluid transmission device The present invention can also be applied to a power transmission control device including the above.

  When the fluid transmission device is a torque converter, and the torque converter has a lock-up clutch that is attached to the output-side rotating element and can be integrally engaged with the input-side rotating element, it is larger than that generated when the stopper is operated. It is possible to efficiently suppress the slippage of the belt that occurs due to an impact sound or sudden torque fluctuation.

  The determining means has an output shaft rotational speed sensor for detecting the rotational speed of the output side rotational element of the fluid transmission device, and the control means is the rotation of the output side rotational element of the fluid transmission device detected by the output shaft rotational speed sensor. Based on the rate of change of speed, if the clamping pressure increasing means is activated when it is above a predetermined value, and if the clamping pressure increasing means is stopped when the rate of change is less than the predetermined value, the clamping pressure increasing means is wastefully activated. Therefore, it is possible to reduce the possibility that the power is transmitted and to perform smoother power transmission.

  Immediately before the stopper mechanically restricts the relative rotation between the turbine shell side and the turbine hub side in the output side rotating element, the belt clamping pressure of the belt type continuously variable transmission is increased by the clamping pressure increasing means. It is possible to further reliably prevent the belt-type continuously variable transmission from being lowered in durability by more reliably suppressing belt slippage that occurs with sudden torque fluctuations.

  An embodiment in which the power transmission control device according to the present invention is applied to a vehicle incorporating a torque converter and a belt type automatic transmission will be described in detail with reference to FIGS. 1 to 13. The present invention is not limited to this embodiment, and all changes and modifications included in the concept of the present invention described in the claims can be made. Therefore, the present invention naturally applies to any other technology belonging to the spirit of the present invention. be able to.

  The concept of the power transmission device in this embodiment is shown in FIG. An output from a spark ignition internal combustion engine (hereinafter referred to as an engine) 10 as a drive source in the present invention is a belt type continuously variable via a torque converter 11 and a forward / reverse switching device 12 as a fluid transmission device in the present invention. It is transmitted to a transmission (hereinafter referred to as CVT) 13. The power from the engine 10 is distributed from the output gear 15 provided on the output shaft 14 of the CVT 13 to the left and right drive wheels via a differential gear device (not shown). The lockup clutch 11A of the torque converter 11, which will be described later, the direct coupling clutch 16 and the reaction force brake 17, which are a pair of friction engagement elements of the forward / reverse switching device 12, and the input pulley 18 and the output pulley 19 of the CVT 13 are all hydraulically controlled. These operations are controlled by a hydraulic fluid supply / discharge operation via the circuit 20. A number of solenoid valves (not shown) incorporated in the hydraulic pressure control circuit 20 are based on detection signals from various sensors (to be described later) together with an engine 10 in which a spark ignition device and a fuel injection device (not shown) are incorporated. Their operation is controlled via 21. The controller 21 detects a vehicle speed sensor 22 that detects the traveling speed of the vehicle, a crank angle sensor 24 that detects the rotational phase of the crankshaft 23 of the engine 10, and the rotational speed of the turbine hub that is the output shaft of the torque converter 11. A turbine rotation speed sensor 25, a shift position sensor 26 for detecting the position of a shift lever (not shown) operated by the driver, an accelerator opening sensor 27 for detecting the depression amount of an accelerator pedal (not shown) operated by the driver, CVT 13 A transmission input shaft rotational speed sensor 29a and a transmission output shaft rotational speed sensor 29b for detecting rotational speeds of the input shaft 28 and the output shaft 14 are connected. The crank angle sensor 24 described above is also used as an engine speed sensor for detecting the rotational speed of the engine 10.

When the lock-up clutch 11A of the torque converter 11 is in a non-engaged state, power transmission from the input side rotating element 11C to the first output side rotating element 11D is via CVT oil (hereinafter referred to as hydraulic fluid). Done. Here, the rotational speed of the input side rotary element 11C, i.e. the rotational speed of the second output rotary element 11B with respect to the rotational speed N _E of the engine 10 (hereinafter, referred to as the turbine rotational speed) ratio of the N _T, and therefore the speed the ratio _{e (= N T / N E} ) is lower than, for example, 0.8 area, the rotational torque of the input side rotary element 11C, i.e. the rotational torque of the second output rotary element 11B for driving torque _{T E} of the engine 10 ( Hereinafter, the ratio of T _T ), that is, the torque ratio t (= T _T / T _E ) becomes larger than 1 and the torque amplification action is activated. Accordingly, in a region where the speed ratio e is, for example, 0.8 or more, the lockup clutch 11A is shifted to the engaged state, and in the power transmission via the hydraulic fluid from the input side rotating element 11C to the first output side rotating element 11D. It can be said that it is desirable to eliminate the loss and thereby improve the fuel consumption.

  FIG. 2 shows a cross-sectional structure (upper half) of the torque converter 11 in this embodiment that is interposed between the engine 10 and the CVT 13, and is a partially broken front view of the damper 11 </ b> E and the stopper 11 </ b> F. 3 and a part of its appearance is shown in an exploded state in FIG. That is, the torque converter 11 according to the present embodiment includes a first rotating element 11 </ b> C including the pump impeller 30, and a turbine runner 33 that is opposed to the pump impeller 30 and includes the blade 31 and the turbine shell 32 that holds the blade 31. The output side rotating element 11D, the second output side rotating element 11B including the turbine hub 34, and the turbine hub 34 of the second output side rotating element 11B and the turbine shell 32 of the first output side rotating element 11D are straddled. A lockup that is integrally connected to the turbine shell 32 via a rivet 35, a damper 11E that is disposed, a stopper 11F that restricts relative rotation between the first output-side rotating element 11D and the second output-side rotating element 11B. The lock-up clutch 11A including the piston 36 and the lock-up clutch 11A Engagement-side fluid chamber 11G to which pressurized hydraulic fluid for engaging with element 11C is supplied, and pressurized hydraulic fluid for releasing engagement of lockup clutch 11A with input-side rotating element 11C are provided. And a disengagement-side liquid chamber 11H to be supplied. The torque converter 11 transmits power from the input side rotating element 11C to the first output side rotating element 11D via the fluid, that is, CVT oil, which is the working fluid, in a state where the lockup clutch 11A is not operated. Power is transmitted from the output side rotating element 11D to the second output side rotating element 11B via the damper 11E.

  The hydraulic pressure control circuit 20 engages and disengages the lockup clutch 11A by selectively supplying and discharging pressure oil to and from the engagement side liquid chamber 11G and the engagement release side liquid chamber 11H.

  In the present embodiment, the rivet 35 is used to connect the turbine shell 32 and the lockup piston 36, and the inner peripheral side and the outer peripheral side of the engagement side liquid chamber 11 </ b> G are separated from each other with the rivet 35 as a boundary. It becomes. For this reason, the pressure distribution of the hydraulic fluid becomes uneven on the outer peripheral side and the inner peripheral side of the engagement side liquid chamber 11G due to the centrifugal force generated especially when the engine 10 rotates at high speed, and the lockup piston 36 is smoothly engaged. It may be difficult to migrate to Therefore, in the present embodiment, radial communication grooves 37 facing the opposed surfaces of the turbine shell 32 and the lockup piston 36 located between the rivets 35 adjacent in the circumferential direction are formed in the lockup piston 36 by press working or the like. ing. By forming such a communication groove 37, the working fluid flows smoothly between the inner peripheral side and the outer peripheral side of the engagement side liquid chamber 11G, and the pressure distribution of the working fluid is made more uniform. The lock-up piston 36 can be smoothly shifted to the engaged state. These communication grooves 37 can also be formed on the turbine shell 32 side.

  In the present embodiment, the head 38 of the rivet 35 protrudes from the surface of the turbine shell 32 that faces the pump impeller 30, and therefore the chamfer 38 a is provided on the head 38 of the rivet 35. As a result, even if the hydraulic fluid flowing along the turbine shell 32 collides with the head 38 of the rivet 35, the flow of the hydraulic fluid is not significantly disturbed, and as a result, a decrease in the torque transmission efficiency of the torque converter 11 is minimized. be able to. From this point of view, it is also effective to form a recess in the portion of the turbine shell 32 to which the rivet 35 is attached so that the tip surface of the rivet head is substantially flush with the inner peripheral surface of the turbine shell 32. An example is shown in FIG. The turbine shell 32 in the embodiment shown in FIG. 5 is formed with a recess 32a that accommodates the head 38 of the rivet 35. Accordingly, the lockup piston 36 also corresponds to the recess 32a of the turbine shell 32. A hollow 36a is formed. That is, in this embodiment, as compared with the embodiment shown in FIG. 2, the attachment portion of the rivet 35 as a whole is shifted to the right side, that is, toward the disengagement side liquid chamber 11H.

  The pump impeller 30 described above has a blade 39 and an annular pump shell 40 with the blade 39 attached to the inside. In addition to the pump impeller 30, the input side rotating element 11 </ b> C is a disc-shaped front cover to which a pump shell 40 is joined at an outer peripheral edge and a drive plate 41 connected to the crankshaft 23 of the engine 10 is screwed. 42 and an end hub 43 whose outer peripheral edge is joined to the inner peripheral edge of the pump shell 40.

  The end hub 43 of the input side rotating element 11C of the torque converter 11 is supplied with high pressure oil to the hydraulic pressure control circuit 20, and oil for lubricating the torque converter 11, the forward / reverse switching device 12, the CVT 13, and the like. A pump (see FIG. 1) 44 is attached.

  The input shaft 45 of the forward / reverse switching device 12 is connected to the second output side rotation element 11B. In this embodiment, a female spline 34a is formed on the inner peripheral surface of the turbine hub 34, and a male spline 45a formed on the outer peripheral surface of the input shaft 45 of the forward / reverse switching device 12 is fitted therein. An oil seal 46 is press-fitted into the inner peripheral surface of the boss portion 34b of the turbine hub 34 of the second output-side rotating element 11B, and the shaft peripheral portion of the input shaft 45 of the forward / reverse switching device 12 and the inner peripheral surface of the boss portion 34b. The gap between the outer peripheral surface of the seal is sealed. A thrust receiver that restricts displacement of the turbine hub 34 along a direction parallel to a rotation axis (not shown) of the torque converter 11 (left and right direction in FIG. 2) is provided at the end of the boss 34b on the front cover 42 side. A member 47 is fitted. A communication passage 47 a that allows the hydraulic fluid to pass therethrough is defined on the end surface of the thrust receiving member 47 that faces the front cover 42.

  The damper 11E includes a plurality (five in the illustrated example) of coil springs 48 that are elastically deformed in accordance with the relative rotation of the turbine hub 34 and the turbine shell 32, and is formed on the turbine shell 32 at the circumferential end surface of the coil spring 48. A drive projection 32b that abuts via a disc-shaped washer 49, and is formed so as to protrude from the outer peripheral edge of the turbine hub 34 and extends across the center of the circumferential end face of the coil spring 48. And the driven projection 34c that comes into contact with the washer 49 through the washer 49 described above, and the drive projection 32b of the turbine shell 32 moves the driven projection 34c of the turbine hub 34 from the radially inner side and the radially outer side. It is bent so as to be sandwiched, and is bent 180 degrees on the lockup piston 36 side. That is, the coil spring 48 is disposed between the driving projection 32b of the turbine shell 32 and the driven projection 34c of the turbine hub 34 in a state where the radially inner side of the torque converter 11 is held on the outer peripheral portion of the turbine hub 34. Are intervened in each.

  The turbine shell 32 and the lock-up piston formed by the rivet 35 are formed at the radially inner end of the turbine shell 32 constituting a part of the first output-side rotating element 11D and radially inward of the blade 31. A plurality of (five in the illustrated example) damper holding portions 32 c that are located radially inward of the connecting portion with the 36 and hold the coil spring 48 described above in a direction parallel to the rotational axis of the torque converter 11. Is formed. The damper holding portions 32c that are curved so as to surround the outer circumference of the coil spring 48 are formed at regular intervals along the circumferential direction at the radially inner end of the turbine shell 32 alternately with the drive protrusion 32b described above. Thus, the rigidity of the turbine shell 32 is improved.

  A similar damper holding portion 36 b facing the damper holding portion 32 c of the turbine shell 32 is also formed on the lockup piston 36, and each coil spring 48 is opposed to each direction parallel to the rotational axis of the torque converter 11. The state is sandwiched between the pair of damper holding portions 32c and 36b. Thus, the deformation direction of the coil spring 48 is regulated so that the compression deformation of the coil spring 48 caused by the relative rotation between the turbine shell 32 and the turbine hub 34 occurs along a plane perpendicular to the rotation axis of the torque converter 11. can do. Further, since the coil spring 48 is held by the highly rigid turbine shell 32 and the damper holding portions 32c and 36b of the lock-up piston 36, the strength and operational stability of the damper 11E are further improved, and its performance and durability. Can be further improved. In addition, the number of dedicated parts for holding the coil spring 48 can be further reduced, and the mounting portion therefor can be omitted. As a result, the axial length of the torque converter 11 can be made shorter than the conventional one.

  As described above, the turbine shell 32 is integrally fixed to the lock-up piston 36 via the rivet 35, and the radially inner end of the lock-up piston 36 is axial with respect to the boss portion 34b of the turbine hub 34 (FIG. 2). Since it is slidably fitted and supported in the middle and right and left directions), a mechanism for supporting the radially inner end side of the turbine shell 32 can be omitted, and a damper 11E is incorporated therein to provide torque. A reduction in the size of the converter 11 can be contemplated.

  The stopper 11F is compressed to a state where the coil spring 48 cannot be elastically deformed, and in order to prevent any adverse effects from occurring, the relative rotation amount between the turbine shell 32 and the turbine hub 34 is restricted within a predetermined range. Is. The stopper 11F in the present embodiment is formed integrally with the damper holding portion 32c of the turbine shell 32 and protrudes further radially inward from the inner peripheral end of the stopper 11F, and the driven projection 34c of the turbine hub 34. And a pair of locking end surfaces 34d formed at both ends in the circumferential direction. The locking piece 32d and the pair of locking end surfaces 34d are located in the same rotation plane. Therefore, when the turbine shell 32 and the turbine hub 34 rotate relative to the spring force of the coil spring 48 by a predetermined angle or more, the locking piece 32d comes into contact with one of the pair of locking end surfaces 34d, and the turbine shell 32 Further relative rotation between the turbine hub 34 and the turbine hub 34 is prevented.

  In the present invention, the operation of the stopper means that, as described above, the locking piece 32d of the stopper 11F comes into contact with either one of the pair of locking end surfaces 34d, the driving side turbine shell 32, and the driven side This means that further relative rotation with the turbine hub 34 is prevented.

As described above, when a large torque fluctuation that cannot be absorbed by only the elastic deformation of the coil spring 48 occurs between the turbine shell 32 and the turbine hub 34, the locking piece 32d and the locking end surface 34d of the stopper 11F May come into contact with each other and an impact sound may be generated, or the turbine shell 32 and the turbine hub 34 may suddenly rotate together to cause uncomfortable torque fluctuations. In this embodiment, if only the elastic deformation of the coil spring 48, such as a large torque variations as not be absorbed occurs, such as by reducing the driving torque T _E of the engine 10 as described later, the problem described above It is an improvement.

  A lock-up clutch 11A capable of integrally connecting a lock-up piston 36 whose radially inner end is slidably fitted in the axial direction with respect to a boss 34b of the turbine hub 34 to the input-side rotating element 11C. The radially outer portion is engaged with the radially outer edge portion of the lockup piston 36, and the radially inner portion is opposed to the front cover 42 in the close state, and the radially inner end portion is the inner side of the front cover 42. A fixed clutch plate 51 that is integrally joined to the outer periphery of the outer periphery and is disposed between the movable clutch plate 50 and the lockup piston 36 so that the radially outer end thereof is opposed to the movable clutch plate 50. Friction plates 52 are joined to both surfaces of 50 and the surface of the fixed clutch plate 51 facing the lockup piston 36, respectively.

  The lock-up piston 36 is interposed in the torque converter 11, and the turbine runner 33 is caused by the differential pressure of the working fluid loaded on both surfaces of the lock-up piston 36, that is, the engagement-side liquid chamber 11 </ b> G and the engagement-side liquid chamber 11 </ b> H. At the same time, it can be displaced in a direction facing the front cover 42, that is, in a direction parallel to the rotational axis of the torque converter 11. Specifically, in a torque converter operation region where rotation of the stator 53 described later does not occur, the lockup piston 36 is displaced toward the turbine hub 34 and the movable clutch plate 50 interposed between the lockup piston 36 and the front cover 42. In addition, the friction plates 52 of the fixed clutch plate 51 are brought into a non-contact state. As a result, the first output-side rotating element 11D is disconnected from the input-side rotating element 11C, and the first and second output-side rotating elements 11D from the input-side rotating element 11C in a state where the torque is increased via the hydraulic fluid. , 11B. Conversely, in the torque converter non-functional region where the rotational speeds of the input side rotating element 11C and the first output side rotating element 11D are substantially equal and the idling of the stator 53 starts, both surfaces of the lockup piston 36, that is, the engagement side liquid chamber. The lockup piston 36 is displaced toward the front cover 42 by operating the differential pressure of the hydraulic fluid loaded on the 11G and the disengagement side liquid chamber 11H, and the lockup piston 36 and the front cover 42 are moved to the movable clutch plate. 50 and the friction plate 52 of the fixed clutch plate 51 are brought into a close contact state. As a result, the input side rotating element 11C and the first output side rotating element 11D are integrally coupled via the lockup clutch 11A, and the driving force of the input side rotating element 11C is transferred from the first output side rotating element 11D to the damper 11E. Is transmitted to the second output-side rotation element 11B.

  In the present embodiment, a plurality of clutch plates 50 and 51 are incorporated between the lock-up piston 36 and the front cover 42 to reduce the load on the individual friction plates 52. In some cases, these may be omitted, and it is of course possible to adopt a configuration in which the radially outer end of the lock-up piston 36 facing the front cover 42 is brought close to the front cover 42 side and a friction plate is joined to the surface. It is.

  Further, the torque converter 11 according to the present embodiment includes a stator 53 interposed between the turbine runner 33 and the pump impeller 30, and a one-way clutch 54 that allows the stator 53 to rotate only in the same direction as the rotation direction of the turbine runner 33. Etc.

  The stator 53 held on the transmission case side (not shown) via the one-way clutch 54 again pumps the hydraulic fluid that flows into the turbine runner 33 of the first output side rotating element 11D by the pump impeller 30 of the input side rotating element 11C. This is for guiding to the 30 side, and a known torque increase is thereby achieved. An extracted enlarged cross-sectional structure of a portion of the one-way clutch 54 shown in FIG. 2 that allows the stator 53 to rotate in the same direction as the rotation direction of the turbine runner 33 is shown in FIG. FIG. 7 shows the appearance of the portions of the second holding plates 55 and 56. That is, the one-way clutch 54 in the present embodiment has a female spline 58a that fits on a male spline 57a formed at the tip of a support cylinder 57 that constitutes a part of a transmission case (not shown) on the inner peripheral surface. The inner ring 58, the outer ring 59 having a male spline 59 a formed on the inner peripheral surface of the stator 53, and a male spline 59 a fitted on the outer peripheral surface, and a pair of end bearings 60. And a sprag 61 held therebetween. The one-way clutch 54 is sandwiched between a first holding plate 55 in which the one-way clutch 54 is accommodated and a second holding plate 56 facing the end hub 43, and is attached to the outer peripheral surface of the second holding plate 56. Is formed with an engaging projection 56a having a gear shape with the same pitch as the male spline 59a of the outer ring 59. The first holding plate 55 having the same thickness as the second holding plate 56 is penetrated by the teeth of the male spline 59a of the outer ring 59 and the engaging protrusions 56a adjacent to the second holding plate 56 are adjacent to each other. A notch 55b is formed to define a gear-like engagement protrusion 55a located between each other. The engaging protrusions 56 a of the second holding plates 56 that are alternately arranged on the same surface and the engaging protrusions 55 a of the flange-shaped first holding plate 55 are in the counterbore holes 53 b formed on the radially inner side of the stator 53. And is integrally fitted to the stator 53 by a retaining ring 62 that is fitted into a retaining ring housing groove 53c formed in the counterbore 53b.

  Thrust bearings 63 and 64 are interposed between the turbine hub 34 and the first holding plate 55 and between the end hub 43 and the second holding plate 56, respectively, and a one-way clutch for the end hub 43 and the turbine hub 34. The relative rotation of the 54 outer rings 59 and the stator 53 is possible. As the one-way clutch 54, other well-known one-way clutches can be appropriately employed besides the one using the sprag 61.

  In the first holding plate 55 in the present embodiment, a plurality of lubricating oil holes 55 c communicating with the sprags 61 are formed. Similarly, the second holding plate 56 is also formed with a plurality of lubricating oil holes 56b communicating with the sprag 61 and a thrust bearing 64 interposed between the second holding plate 56 and the end hub 43, respectively. In consideration of the lubricating oil hole 34e formed in the above, the thrust bearings 63 and 64 and the sprag 61 are carefully lubricated and cooled.

  When such a one-way clutch 54 is assembled to the stator 53, the one-way clutch 54 is attached to the first holding plate 55 such that the teeth of the male spline 59 a of the outer ring 59 fit into the notch 55 b of the first holding plate 55. The second holding plate 56 is one-way so that the engaging projection 56a of the second holding plate 56 is positioned between the adjacent engaging projections 55a of the first holding plate 55, that is, in the notch 55b. After superposing on the clutch 54 and unitizing them, the engagement of the first and second holding plates 55 and 56 is such that the male spline 59a of the outer ring 59 of the one-way clutch 54 meshes with the female spline 53a of the stator 53. The mating protrusions 55a and 56a are fitted into the counterbore 53b of the stator 53, and the retaining ring 62 is fitted into the retaining ring receiving groove 53c in this state. Accordingly, it is possible to assemble the one-way clutch 54 with respect to the stator 53.

  The configuration of the torque converter 11 itself described above is not limited to that of the present embodiment, but is an input side rotating element 11C to which the crankshaft 23 of the engine 10 as an input member is coupled, and an output member. A second output-side rotating element 11B to which the transmission input shaft 28 is coupled, and a lock-up clutch 11A that is attached to the second output-side rotating element 11B and can be integrally engaged with the input-side rotating element 11C; The engagement-side liquid chamber 11G to which pressure oil for engaging the lock-up clutch 11A with the input-side rotation element 11C is supplied and the lock-up clutch 11A are disengaged from the input-side rotation element 11C. The engagement releasing side liquid chamber 11H to which pressure oil is supplied, the first output side rotating element 11D, and the second output side rotating element 11B perform relative rotation exceeding a predetermined amount. As long as it has a stopper 11F of limiting.

  The forward / reverse switching device 12 in the present embodiment is composed of a double pinion type planetary gear device and a pair of hydraulic friction engagement elements, and has a clutch function capable of interrupting power transmission between the engine 10 and the CVT 13. The planetary gear device includes a sun gear 65 integral with an input shaft 45 that is spline-fitted to the turbine hub 34 of the torque converter 11, a rotatable internal gear 66 that surrounds the sun gear 65, and the internal gear 66. A pair of planetary gears 67 a and 67 b incorporated between the sun gear 65 and the sun gear 65 is provided. The pair of planetary gears 67a and 67b mesh with each other, and one located on the inner circumferential side meshes with the sun gear 65 and the other located on the outer circumferential side meshes with the internal gear 66. The pair of planetary gears 67a and 67b are rotatably supported by a carrier 69 integral with the output shaft 68 of the forward / reverse switching device 12, and the carrier 69 has a direct coupling clutch 16 as a hydraulic friction engagement element. Via the input shaft 45. The internal gear 66 can be connected to a transmission case (not shown) via a reaction force brake 17, which is a hydraulic friction engagement element, and hydraulic fluid for the direct coupling clutch 16 and the reaction force brake 17 can be connected. Supply / discharge is performed via the hydraulic pressure control circuit 20.

  Therefore, when the direct clutch 16 is engaged and the reaction force brake 17 is disengaged, the input shaft 45 and the output shaft 68 of the forward / reverse switching device 12 are integrally connected via the direct clutch 16. Are integrally rotated in the same direction, and, for example, a driving force in the forward direction is transmitted to the transmission input shaft 28. In contrast, when the direct coupling clutch 16 is disengaged and the reaction force brake 17 is engaged, the sun gear 65 of the input shaft 45 and the planetary gear 67b located on the outer peripheral side rotate in the same direction. Since the planetary gear 67 b meshes with the fixed internal gear 66, the carrier 69 rotates in the opposite direction to the input shaft 45, and for example, a driving force in the reverse direction is transmitted to the transmission input shaft 28. Further, when both the direct coupling clutch 16 and the reaction force brake 17 are disengaged, the planetary gears 67a and 67b are idling, and the driving force from the input shaft 45 is not transmitted to the output shaft 68 side, and the power transmission path is It is in a blocked state.

  The CVT 13 is wound between an input pulley 18 provided on the input shaft 28 with a variable V groove width, an output pulley 19 provided on the output shaft 14 with a variable V groove width, and the pair of pulleys 18, 19. An endless transmission belt 70 is provided. Power transmission is performed via a frictional force between the pair of pulleys 18 and 19 and the transmission belt 70. The input pulley 18 includes a hydraulic cylinder 18a for changing the groove width to control the transmission ratio, and the output pulley 19 has a hydraulic cylinder 19a for defining a clamping pressure against the transmission belt 70, that is, a transmission torque. Is incorporated. The hydraulic fluid is supplied to and discharged from the hydraulic cylinders 18a and 19a by the control device 21 via the hydraulic pressure control circuit 20. That is, a predetermined hydraulic pressure corresponding to the output of the engine 10 is supplied to the hydraulic cylinder 19a to set a clamping pressure with respect to the transmission belt 70. In this state, hydraulic fluid is supplied to the hydraulic cylinder 18a to The groove width is changed, and as a result, the groove width of the output pulley 19 is also changed at the same time. As a result, the engagement diameter of the transmission belt 70, that is, the effective diameter can be changed to continuously change the speed ratio, that is, the rotational speed of the input shaft 45 / the rotational speed of the output shaft 14.

  Regarding the adjustment of the gear ratio and the clamping pressure for the CVT 13, conventionally known techniques can be used as they are, and are described in, for example, Japanese Patent Application Laid-Open Nos. 2001-340115 and 2003-343707.

The control block of the present invention is shown in FIG. That is, the control device 21 of the present embodiment, the output of the lock-up clutch 11A is an operating region determining unit 71 determines whether it is in the operating area such that disengaged, to derive the turbine driving torque T _T a torque derivation section 72, a turbine drive torque T _T derived at the output torque deriving unit 72 and the stopper operating region determining unit 73 determines whether it is within a predetermined range, the second output side of the torque converter 11 increase rate of the rotational speeds of the rotating elements (hereinafter, referred to as turbine acceleration) and the turbine acceleration calculation unit 74 for calculating a .DELTA.N _T, on the basis of the turbine acceleration .DELTA.N _T calculated by the turbine acceleration calculating section 74 engine a torque down control unit 75 that temporarily reduces the drive torque T _E of 10, turbine acceleration ΔN calculated in turbine acceleration calculation section 74 The belt clamping pressure control unit 76 to increase the belt clamping pressure of CVT13 temporarily the locking piece 32d and the engagement end surface 34d of the stopper 11F against the spring force of the coil spring 48 of the damper 11E abuts based on such torque (hereinafter, referred to as the stopper torque) and a stopper torque learning correction unit 77 for learning correction of T _S.

  The driving region determination unit 71 sets the lock-up clutch 11A in the disengaged state from a map as shown in FIG. 9 set in advance based on detection signals from the vehicle speed sensor 22 and the accelerator opening sensor 27. It is determined whether or not the vehicle is in the driving range.

Output torque deriving unit 72, the following equation and the capacity coefficient C and the torque ratio t of the torque converter 11, from the engine speed N _E which is calculated based on the detection signal from the crank angle sensor 24, a turbine driving torque T _T Calculated by
T _T = C × N _E ² × t

Here, the capacity coefficient C and the torque ratio t is the ratio N _T / N _E of the turbine speed N _T detected by the turbine speed sensor 25 for the engine speed N _E which is derived by the crank angle sensor _24, that is the speed Based on the ratio e, it is read from preset maps as shown in FIGS. It is also effective to further correct the capacity coefficient C and the torque ratio t of the torque converter 11 according to the temperature of the hydraulic fluid, etc., and it is naturally possible to derive the turbine drive torque T _T by other known methods. .

The stopper operation region determination unit 73 determines whether or not the turbine drive torque T _T is within a predetermined torque range, specifically, within a range of T _S ± ΔT with reference to a preset stopper torque T _S. . This range T _S ± ΔT is a range in which it is possible to avoid the possibility that the stopper 11F is operated by controlling the torque of the engine 10 here, but ΔT may be as small as possible. Needless to say, it is preferable.

Turbine acceleration calculating unit 74, the change rate of the value detected by the turbine speed sensor 25, i.e. to calculate the turbine acceleration .DELTA.N _T, if this becomes a predetermined reference acceleration .DELTA.N _R1 above, a possibility that the stopper 11F is operated Judging that there is.

Torque-down control unit 75 in the present embodiment, by controlling the ignition timing of the engine 10, for example retarded by 1 degree, temporarily reduce the driving torque T _E of the engine 10, whereby engagement of the stopper 11F Collision between the stop piece 32d and the locking end face 34d is avoided or the collision energy is reduced. In order to obtain the same effect, the amount of intake air flowing in an intake passage (not shown) of the engine 10 is temporarily reduced, or in the case of a compression ignition internal combustion engine such as a diesel engine, the fuel injection amount is temporarily reduced. Is also effective. In order to reduce the intake amount, it is necessary to use a throttle valve whose opening and closing is controlled by an actuator or the like.

  The belt clamping pressure control unit 76 temporarily increases the supply hydraulic pressure to the hydraulic cylinder 19a of the output pulley 19 of the CVT 13 in parallel with the torque reduction of the engine 10, and slippage occurs in the transmission belt 70 when the stopper 11F is operated. This is to avoid wear. More specifically, a solenoid valve (not shown) for duty-controlling the hydraulic pressure of the hydraulic fluid supplied to the hydraulic cylinder 19a of the output pulley 19 based on detection signals from the transmission input shaft and output shaft rotational speed sensors 29a and 29b. For example, the control duty ratio is changed by 10%.

Stopper torque learning correction unit 77, by learning correction stopper torque T _S used in stopper operating area determination section 73, which is convergent to a more appropriate estimate and the reliability of control in the present invention I try to improve. More specifically, when the turbine rotational speed _NT changes rapidly within a predetermined time, it is determined that the locking piece 32d of the stopper 11F and the locking end surface 34d are in contact with each other, and the turbine of the torque converter 11 at this time The drive torque T _T is updated as the stopper torque T _S.

  Such a control procedure according to the present embodiment will be described with reference to the flowchart of FIG. 12. In step S11, it is determined whether or not the vehicle is in an operation region in which the lockup clutch 11A is disengaged. To do. If it is determined in S11 that the vehicle is not in the driving region where the lockup clutch 11A is not engaged, that is, if the vehicle is in the driving region where the lockup clutch 11A is engaged, the control of the present invention is performed. Since it is in a non-target state, it ends without doing anything.

If it is determined in step S11 that the vehicle is in an operating region in which the lockup clutch 11A is not engaged, the process proceeds to step S12 and the torque converter derived by the output torque deriving unit 72 11 is determined whether the turbine drive torque T _T is within a predetermined range, that is, a range of T _S ± ΔT. Here, when it is determined that the turbine drive torque T _T is out of a predetermined range with reference to the stop torque T _S , that is, there is no possibility that the stopper 11F operates, the state outside the control target of the present invention is determined. Because it becomes, it ends without doing anything.

However, when it is determined that the turbine drive torque T _T is in the vicinity of the stop torque T _S , the process proceeds to step S13 and the rotation speed of the second output side rotation element calculated by the turbine acceleration calculation unit 74 is obtained. increase rate, i.e. whether the turbine acceleration .DELTA.N _T is the reference acceleration .DELTA.N _R1 above was set in advance. Here, less than the reference acceleration .DELTA.N _R1 turbine acceleration .DELTA.N _T, that is, if the impact sound and torque change with the stopper 11F is operated is determined almost felt no control exempt status of the present invention Therefore, it ends without doing anything. Thus, less than the reference acceleration .DELTA.N _R1 turbine acceleration .DELTA.N _T, when the stopper 11F impact is expected to be small even when operated, without torque down of the engine 10, to focus and power performance .

In contrast, it is a turbine acceleration .DELTA.N _T reference acceleration .DELTA.N _R1 above, i.e. determines that the stopper 11F locking piece 32d and the engagement end surface 34d is likely to impact sound or uncomfortable torque variation is felt in contact If this is the case, the process proceeds to step S14, where the torque-down control unit 75 performs the retard control of the ignition advance, whereby the locking piece 32d of the stopper 11F and the locking end surface 34d abut on each other in an impact manner. To mitigate impact noise and unpleasant torque fluctuations.
In parallel with this, in step S15, the belt clamping pressure control unit 76 increases the hydraulic pressure supplied to the hydraulic cylinder 19a of the output pulley 19, increases the clamping pressure on the transmission belt 70, and the stopper 11F is activated. Even so, it is possible to prevent a problem that the transmission belt 70 slips.

On the other hand, it performs fluctuation detection turbine driving torque _{T T} in S16 in step determines whether or not the locking piece 32d and the engagement end surface 34d of the stopper 11F is in contact with at step S17. If in step S17 the locking piece 32d and the engagement end surface 34d of the stopper 11F determines that abuts makes the turbine driving torque T _T calculated in step S12 the stop torque T _S, the next adopting the value of this stop torque T _S at the control cycle.

Here, FIG. 13 shows a procedure for detecting fluctuations in the turbine rotational speed _NT in S <b> 16 performed by the stopper torque learning correction unit 77. First, in step S21, whether or not the turbine rotational speed _NT has changed suddenly within a predetermined time, that is, the latest turbine rotational speed _{NT (C)} detected by the turbine rotational speed sensor 25 and the control cycle one time before that. The difference _{NT (C)} -NT _{(C-1) from} the turbine rotational speed _{NT (C-1)} detected in step ₁ is the average rate of change of the turbine rotational speed _NT in one control cycle unit. Determine if they are significantly different. More specifically, when the predetermined time is expressed as n control cycles, the difference between the latest turbine rotational speed _{NT (C)} and the turbine rotational speed _{NT (C−n)} detected before the predetermined time. n _{T (C)} the rate of change of -N _{T (C-n)} to _{(n T (C) -N T} (C-n)) / n, the _{n T (C) -N T (} C-1) the amount of shift is equal to or within a predetermined value .DELTA.N _R2 is determined. Here, the absolute value of [( _{NT (C)} −NT ₍ CN ₎ ) / n] − ( _{NT (C)} −NT _(C−1) ) is equal to or larger than a predetermined value ΔN _R2 . In other words, if it is determined that the turbine rotational speed _NT has changed suddenly during one control cycle, the process proceeds to step S22 and the count value C of the counter is incremented by one. Then, whether the count value C of the counter from n times the previous control cycle shifts is the value C _R greater than or equal to the preset is determined in S23 in step. The count value C of this counter is the number of sudden changes in the turbine rotational speed _NT determined in step S22.

The count value C of the counter is determined in step S23 is a value less than C _R which is set in advance, that is still when the turbine driving torque T _T of the torque converter 11 can not be judged to have variations, and ends the current control cycle shifts to the next control cycle, but is counter count value C is a value C _R greater than or equal to the preset at S23 in step, i.e. when the turbine driving torque T _T of the torque converter 11 can be judged to have variations Then, the process proceeds to step S24, and it is determined that there is a change in the turbine rotational speed _NT .

In step S21, the absolute value of [( _{NT (C)} −NT ₍ CN ₎ ) / n] − ( _{NT (C)} −NT _(C−1) ) is less than a predetermined value ΔN _R2 . If it is determined that the turbine rotational speed _NT has not changed suddenly during one control cycle, the process proceeds to step S23 without passing through step S22, and the counter from the control cycle n times before is counted. determines the count value C is whether a preset value C _R more than again.

In this way, the sudden change number of turbine speed N _T of each control cycle, counting from n times the previous control cycle, this variation of the turbine driving torque T _T of the torque converter 11 in the case of more than the predetermined value C _R That is, it is determined that the locking piece 32d of the stopper 11F has come into contact with the locking end surface 34d. This makes it possible to grasp the stopper torque T _S more accurately.

  If the transmission of the impact torque associated with the operation of the stopper 11F is alleviated, it can be dealt with by temporarily reducing the engagement force of the friction engagement element during the engagement of the forward / reverse switching device 12. From a similar viewpoint, when a planetary gear type automatic transmission is used as a transmission, at least one engaging hydraulic friction engagement that contributes to power transmission from the engine 10 instead of the torque reduction of the engine 10 described above. It is also possible to reduce the transmission of impact torque accompanying the operation of the stopper 11F by weakening the engaging force with respect to the element.

  The present invention can also be used for a torque converter as disclosed in JP-A-8-312749 in which a lock-up piston rotates integrally with a turbine hub. Further, the present invention can be applied even to a torque converter that does not include the lock-up clutch 11A, and the present invention is also applied to a case where a fluid coupling having no torque amplification function is incorporated in the middle of the power transmission path. Is possible. Furthermore, the present invention can be applied to a type in which power is transmitted from a drive source to a drive wheel via a differential gear device without using a transmission or the like.

1 is a conceptual diagram of an embodiment in which a power transmission control device according to the present invention is incorporated in a vehicle equipped with a belt type continuously variable transmission. It is sectional drawing showing the schematic structure of the part of the torque converter shown in FIG. FIG. 3 is a cutaway front view of portions of a turbine shell, a turbine hub, and a damper in the torque converter shown in FIG. 2. FIG. 4 is a three-dimensional projection view showing a part of the turbine shell, the turbine hub, and the damper shown in FIG. 3 in an exploded state. FIG. 6 is an extracted cross-sectional view showing another embodiment of a connecting portion between a turbine shell and a lockup piston in the torque converter shown in FIG. 2. FIG. 3 is an extracted enlarged cross-sectional view of a portion of a one-way clutch incorporated in the torque converter shown in FIG. 2. It is a three-dimensional projection figure showing the external appearance of the part of the 1st and 2nd holding | maintenance board holding the one-way clutch shown in FIG. FIG. 2 is a control block diagram in the embodiment shown in FIG. 1. It is a map of the operation area | region regarding the engagement area | region and non-engagement area | region of a lockup clutch. It is a graph showing the relationship between the speed ratio of a torque converter and a capacity coefficient. It is a graph showing the relationship between the speed ratio and torque ratio of a torque converter. It is a flowchart showing the control procedure of the power transmission device shown in FIG. FIG. 13 is a flowchart showing a subroutine regarding NT fluctuation detection shown in FIG. 12. FIG.

Explanation of symbols

C capacity factor e speed ratio t torque ratio N _E engine speed N _T turbine speed .DELTA.N _R1 reference change rate .DELTA.N _R2 predetermined value .DELTA.N _T turbine acceleration T _E engine drive torque T _S stopper torque T _T turbine drive torque 10 engine 11 torque Converter 11A Lock-up clutch 11B Second output side rotating element 11C Input side rotating element 11D First output side rotating element 11E Damper 11F Stopper 11G Engagement side liquid chamber 11H Disengagement side liquid chamber 12 Forward / reverse switching device 13 CVT
14 Output shaft (CVT)
DESCRIPTION OF SYMBOLS 15 Output gear 16 Direct coupling clutch 17 Reaction force brake 18 Input pulley 18a Hydraulic cylinder 19 Output pulley 19a Hydraulic cylinder 20 Hydraulic control circuit 21 Controller 22 Vehicle speed sensor 23 Crankshaft 24 Crank angle sensor 25 Turbine speed sensor 26 Shift position Sensor 27 Accelerator opening sensor 28 Input shaft (CVT)
29a Transmission input shaft rotational speed sensor 29b Transmission output shaft rotational speed sensor 30 Pump impeller 31 Blade 32 Turbine shell 32a Depression 32b Drive protrusion 32c Damper holding part 32d Locking piece 33 Turbine runner 34 Turbine hub 34a Female spline 34b Boss part 34c Driven protrusion 34d Locking end surface 34e Lubricating oil hole 35 Rivet 36 Lock-up piston 36a Depression 36b Damper holding portion 37 Communication groove 38 Head 38a Chamfering 39 Blade 40 Pump shell 41 Drive plate 42 Front cover 43 End hub 44 Oil pump 45 Input shaft (forward / reverse switching device)
45a Male spline 46 Oil seal 47 Thrust receiving member 47a Communication path 48 Coil spring 49 Washer 50 Movable clutch plate 51 Fixed clutch plate 52 Friction plate 53 Stator 53a Female spline 53b Counterbore 53c Retaining ring receiving groove 54 One-way clutch 55 First way Holding plate 55a Engaging projection 55b Notch 55c Lubricating oil hole 56 Second holding plate 56a Engaging projection 56b Lubricating oil hole 57 Support cylinder 57a Male spline 58 Inner ring 58a Female spline 59 Outer ring 59a Male spline 60 End bearing 61 Sprag 62 Stop Ring 63, 64 Thrust bearing 65 Sun gear 66 Internal gear 67a, 67b Planetary gear 68 Output shaft (forward / reverse switching device)
69 Carrier 70 Transmission belt 71 Operation region determination unit 72 Output torque deriving unit 73 Stopper operation region determination unit 74 Turbine acceleration calculation unit 75 Torque down control unit 76 Belt clamping pressure control unit 77 Stopper torque learning correction unit

Claims (13)

Provided with a damper that is incorporated in the middle of a power transmission path for transmitting power from the drive source to the output element and allows relative rotation between the drive side and the driven side, and this damper is connected to the drive side and the driven side. A power transmission control device having an elastic deformation element that is elastically deformed in accordance with relative rotation, and a stopper that mechanically limits relative rotation exceeding a predetermined amount between the driving side and the driven side,
A power transmission control device, further comprising impact mitigation means for mitigating an impact caused by the operation of the stopper.   The power transmission control device according to claim 1, wherein the impact mitigating means includes means for reducing drive torque of an output shaft of the drive source.   A fluid transmission device having an input-side rotating element and an output-side rotating element; wherein the driving side is a turbine shell side of the output-side rotating element, and the driven side is a turbine hub side of the output rotating element. The power transmission control device according to claim 1, wherein the power transmission control device is a power transmission control device.   The fluid transmission device is a torque converter, and the torque converter includes a lock-up clutch that is attached to the output-side rotating element and can be integrally engaged with the input-side rotating element. The power transmission control device described in 1.   The automatic transmission further includes an automatic transmission having a friction engagement element that is connected to an output-side rotation element of the fluid transmission device and contributes to power transmission, and the impact reducing means increases a slip amount of the friction engagement element of the automatic transmission. 5. The power transmission control device according to claim 3, further comprising means for causing the power transmission to occur.   The belt-type continuously variable transmission further includes a belt-type continuously variable transmission connected to the output-side rotating element of the fluid transmission device, and the belt-type continuously variable transmission has means for increasing the belt clamping pressure when the impact mitigating means is operated. 5. The power transmission control device according to claim 3 or 4, wherein:   An output shaft rotational speed sensor for detecting the rotational speed of the output side rotational element of the fluid transmission device is further provided, and the impact mitigating means is a sensor for detecting the output side rotational element of the fluid transmission device detected by the output shaft rotational speed sensor. 7. The operation according to any one of claims 3 to 6, wherein when the change rate is less than a predetermined value, the operation is stopped based on the change rate of the rotation speed, and when the change rate is less than the predetermined value, the operation is stopped. Power transmission control device.   The power according to any one of claims 3 to 7, wherein the impact relaxation means operates immediately before the stopper mechanically restricts relative rotation between the turbine shell side and the turbine hub side. Transmission control device. A damper incorporated in the middle of the power transmission path for transmitting power from the drive source to the output element and allowing relative rotation between the drive side and the driven side; and a belt type A step transmission, and an elastic deformation element in which the damper is elastically deformed in association with the relative rotation between the driving side and the driven side, and a relative rotation exceeding a predetermined amount between the driving side and the driven side mechanically And a belt-type continuously variable transmission having a clamping pressure increasing means for increasing the clamping pressure of the belt.
Determining means for determining whether or not the relative rotation between the turbine shell side and the turbine hub side exceeds a predetermined amount;
A power transmission control device further comprising control means for controlling the operation of the clamping pressure increasing means based on a determination result by the determination means.   A fluid transmission device having an input-side rotating element and an output-side rotating element; wherein the driving side is a turbine shell side of the output-side rotating element, and the driven side is a turbine hub side of the output rotating element. The power transmission control device according to claim 9, wherein the power transmission control device is a power transmission control device.   11. The fluid transmission device is a torque converter, and the torque converter includes a lock-up clutch that is attached to the output-side rotating element and can be integrally engaged with the input-side rotating element. The power transmission control device described in 1.   The determination means includes an output shaft rotational speed sensor that detects a rotational speed of the output side rotational element of the fluid transmission device, and the control means outputs the output of the fluid transmission device detected by the output shaft rotational speed sensor. Based on the rate of change of the rotational speed of the side rotation element, the clamping pressure increasing means is operated when this is greater than or equal to a predetermined value, and the operation of the clamping pressure increasing means is stopped when the rate of change is less than the predetermined value. The power transmission control device according to claim 10 or 11, characterized in that the power transmission control device is a power transmission control device. The increase of the belt clamping pressure of the belt-type continuously variable transmission by the clamping pressure increasing means is performed immediately before the stopper mechanically limits the relative rotation between the turbine shell side and the turbine hub side. The power transmission control device according to any one of claims 10 to 12.

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