JP2006112524A - Reverse input intercepting clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a reverse input intercept clutch by which without using a roller for the purpose of not generating phenomena such as pop-out and rollover of the roller, motive energy can be transmitted and intercepted, a reverse input can be intercepted, and a torque limiter mechanism is internally incorporated to allow excessive torque transmission to be intercepted with a compact size. <P>SOLUTION: The reverse input intercept clutch C is equipped with a torque cam mechanism T<SB>C</SB>including a cam means between an input shaft 1 and an output shaft 2 that are provided coaxially and separately and between one rotary plate 5 and the other one 4, a friction clutch portion including friction surfaces 3<SB>S</SB>, 4<SB>S</SB>of flange portions 3<SB>F</SB>, 4<SB>F</SB>that are provided, at a slant and in contiguity with each other, at a clutch plate 3 and at the other rotary plate 4, a torque limiting means T<SB>L</SB>for transmitting no revolution torque value not less than a predetermined value. According to this structure, the flange portions 3<SB>F</SB>, 4<SB>F</SB>are made to separate from an elastic member 11, so that the reverse input from the output shaft 2 can be intercepted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reverse input blocking clutch that transmits rotational torque input to an input shaft to an output shaft, but blocks reverse input from the output shaft to the input shaft.

  In a shaft system that transmits power by controlling the input torque from a rotary drive source such as an electric sliding door of an automobile, an electric curtain, etc. by means of a clutch, the forward / reverse rotational force from the input shaft is transmitted to the output shaft. In some cases, a reverse input cutoff clutch in which the rotational force from the output shaft side is not reversely input to the input shaft is suitable. As an example of such a device, a “reverse input cut-off clutch and rotation drive device” of Patent Document 1 is known. This reverse input shut-off clutch has a concentric output inner ring inside an input outer ring having a cam surface on the inner periphery, a roller as a torque transmission member between the outer ring and the inner ring, a cage for holding the roller, A centering spring as an elastic member for positioning, a housing as a stationary member, and a sliding spring that engages with the cage while sliding with respect to the housing.

  The sliding spring gives a frictional resistance to the cage that rotates with the sliding spring due to the rotation resistance of the stationary member due to the rotation of the input outer ring, so that a phase delay with respect to the input outer ring occurs in the cage. Since the cage holds the roller, the clutch is engaged when the roller is pushed into a wedge space formed by the cam surface of the input outer ring and the output inner ring. The power of the input outer ring is transmitted in both forward and reverse rotation directions. On the other hand, when the input is input from the output inner ring, the cage does not cause a phase delay with respect to the input outer ring, and the roller is not pushed into the wedge space, that is, the input from the output inner ring is transmitted to the input outer ring. There is no.

  A similar clutch is used in the “rotary drive device” of Patent Document 2. However, in this example, a viscous resistance (rotational resistance) due to viscous fluid is given to the cage to cause a relative rotation (rotation delay of the cage) between the cage and the input outer ring. The rotation is transmitted by engaging with.

However, in the above-described conventional reverse input cutoff clutch, when the transmission torque increases from the initial stage of clutch engagement, the roller continues to be pushed into the wedge space formed by the cylindrical surface of the inner ring and the cam surface of the outer ring, and the roller and its contact Excessive deformation may occur near the surface. If the deformation is too large, the deformation energy may cause a pop-out phenomenon in which the roller pops out of the wedge space, or a roll-over phenomenon in which the deformation reaches an excessive amount and the roller reaches the adjacent cam surface. is there. As a method for preventing such abnormal deformation from occurring, it is conceivable to add a so-called torque limiter that interrupts transmission of excessive torque to the power transmission system. However, if such a member is added, the unit The whole becomes large and increases the cost.
JP 2003-120715 A JP 2002-213486 A

  In consideration of the above problems, the present invention does not cause a phenomenon such as pop-out or roll-over of a roller, so that power transmission, interruption and reverse input interruption can be performed without using a roller, and a torque limiter is provided inside. It is an object of the present invention to provide a reverse input cutoff clutch that has a built-in mechanism and is compact and capable of blocking transmission of excessive torque.

  As a means for solving the above problems, the present invention provides a pair of rotations in a clutch mechanism that transmits and shuts off rotational torque between an input shaft and an output shaft that are provided coaxially and separated from each other on a power transmission path. A torque cam mechanism for transmitting the rotational torque of the input shaft from one to the other rotating plate via a cam means provided on the plate and generating axial thrust on the other rotating plate; and the other by the above axial thrust The friction clutch portion that transmits and shuts off the rotational torque to the output shaft by frictional contact between the friction surface of the rotating plate and the clutch plate provided on the output shaft, and the torque cam mechanism when the rotational torque to the output shaft exceeds a predetermined value Torque limiting means for limiting the transmission of the rotational torque to the output shaft, and the reverse input from the output shaft is prevented from transmitting the reverse input by shutting off the clutch plate and the other rotary plate. It was an inverted input cutoff clutch to.

  In the reverse input cutoff clutch of the present invention configured as described above, the input shaft and the output shaft are shut off when the rotational torque is not transmitted to the input shaft, and when the rotational torque is input to the input shaft, the torque cam mechanism, the friction The clutch is turned on via the clutch portion, and the rotational torque is transmitted to the output shaft. When the rotational torque transmitted to the output shaft exceeds a predetermined limit value, the torque value transmitted by the action of the torque limiter mechanism included in the clutch is limited, and torque is transmitted within a range not exceeding the predetermined value. Is done.

  When rotational torque is input to the input shaft, torque is transmitted from one to the other rotating plate via the cam mechanism, and the other rotating plate is moved by the thrust in the axial direction of the other rotating plate by the cam mechanism. Displacement in the axial direction causes the other rotating plate to move slightly toward the clutch plate, and this displacement causes frictional engagement between the other rotating plate of the friction clutch portion and the friction surface of the clutch plate, and rotational torque is applied to the clutch plate. The torque is transmitted to the output shaft by connecting the clutch plate to the output shaft in a non-rotatable manner. At the time of so-called reverse input when rotational torque is input to the clutch from the output shaft side, the friction clutch is disconnected (off) by separating the other rotational plate from the clutch plate, and the rotational torque is transmitted to the input shaft. There is no. Therefore, reverse input is blocked.

  In the above torque limiter mechanism, for example, an elastic member is provided between one rotary plate and the output shaft end, and the rotational phase shift between one rotary plate and the other rotary plate is converted into an axial displacement by the torque cam mechanism. When the other rotating plate comes into contact with the clutch plate, the one rotating plate is displaced in a direction away from the other rotating plate. This displacement is configured to be absorbed by an elastic member, for example, but functions as a torque limiter when the displacement exceeds a range in which the rotational phase shift of the torque cam mechanism can be converted into an axial displacement. Further, at the time of reverse input from the output shaft, as long as there is no input to the input shaft, reverse input is interrupted if the other rotating plate is separated from the clutch plate by an elastic member, for example.

  The reverse input cutoff clutch of the present invention comprises a torque cam mechanism having cam means on a pair of rotating plates, a friction clutch portion having a clutch plate, and torque limiting means, and smoothly transmits and shuts off torque from the input shaft. Since the rotational torque exceeding the predetermined value is regulated by the internal torque limiting means and the reverse input is cut off, it is a clutch that can cut off the reverse input and limit the rotational torque, and it is compact. There is an extremely remarkable effect that it can be provided as an inexpensive clutch unit housed in the housing.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main longitudinal sectional view of a reverse input cutoff clutch according to an embodiment. As shown in the figure, the input shaft 1 and the output shaft 2 on the power transmission path are coaxial, are separated from each other, and are provided close to each other. A reverse input shut-off clutch C is used as a clutch mechanism for transmitting and shutting off rotational torque from the input shaft 1 to the output shaft 2. The reverse input cutoff clutch C includes a clutch plate 3 and a pair of rotating plates 4 and 5 on the output shaft 2. One rotating plate (thrust cam flange) 5 is axially connected to the input shaft 1 by a connecting cup 6. It is movably connected to only. Flange portions 3 _F and 4 _F that are inclined in sectional view are integrally formed on the outer periphery of the clutch plate 3 and the other rotating plate (driven thrust cam flange) 4. As the friction surfaces 3 _S and 4 _{S of} 3 _F and 4 _F approach and separate, the clutch C is turned on (engaged) and turned off (disconnected).

Connected to the connecting cup 6, the engaging piece 5 _T provided on the (four positions in the illustrated example) a plurality of locations on the outer circumference of one rotating plate 5, the same number of switching provided in connection cup 6 Correspondingly It is engaged with the loosely fitted to the lack 6 _T are seen connected in the axial direction. Further, the rotating plates 4 and 5 are mutually sandwiched by holding the balls 10 inserted in holes provided at a plurality of locations (four locations in the illustrated example) at equal intervals in the circumferential direction on the holding plate 16 disposed therebetween. It is provided opposite to. On the opposing surfaces of the rotating plates 4 and 5 corresponding to the balls 10, concave grooves (cam grooves) 4a and 5a that serve as torque cams, which will be described later, are provided.

The concave grooves (cam grooves) 4a and 5a have a substantially elliptical outer shape that is long in the circumferential direction as shown in FIG. 2A, and the center depth of both grooves is the deepest and shallow in the circumferential direction. As shown in FIG. 6B, the rotating plates 4 and 5 are placed in a slidable contact with each other with the ball 10 and the holding plate 16 in a stationary state in which the ball 10 is located at the center. Therefore, in the stationary state, the ball 10 is located at the deepest portion of the concave grooves 4a and 5a or in the very vicinity thereof. Further, the concave grooves 4a and 5a function as a cam mechanism because when one rotary plate 5 is out of phase with the other rotary plate 4 due to the rotational torque from the input shaft 1, the ball 10 has a concave groove 4a. This is because an axial force is generated to move to the shallow groove portion of 5a. Thus, the recessed groove (cam groove) 4a in this example, 5a, ball 10, the torque cam mechanism T _C by the holding plate 16 is formed.

On the outer periphery of the rotating plate 4 and the clutch plate 3, flange portions 4 _F and 3 _{F that} are inclined by a predetermined angle with respect to the center lines of the input / output shafts 1 and 2 are integrally formed with the rotating plate 4 and the clutch plate 3, respectively. The formed surfaces facing each other are provided as friction surfaces 4 _S and 3 _S. The clutch plate 3 is connected to the output shaft 2 by a spline 15 provided on the output shaft 2, and its axial position is restricted by a stop ring 17. Further, an elastic member (spring) 11 is provided between the rotating plate 4 and the clutch plate 3, and when the rotational torque from the input shaft 1 is not acting, the elastic force of the elastic member 11 causes the FIG. As shown, the friction surfaces 4 _S and 3 _S are set to be in a non-contact state slightly apart.

Further, an elastic member (spring) 12 having an elastic force in a direction for separating both of them is provided between the end face of the flange portion 4 _F of the rotating plate 4 and the housing (radius portion) 9. It is set to such a size that the gap between the rotating plate 4 and the clutch plate 3 is maintained in a state where the axial force is smaller than 11 and there is no rotational torque of the input shaft 1. Further, an elastic member (spring) 7 is also provided between the rotating plate 5 and an end plate 2b provided at an end portion of the output shaft 2 facing the input shaft 1 and a flange portion formed by the sleeve 2a. The torque limiter mechanism T _L is configured by the rotating plate 5, the elastic member 7, and the flange portion.

The torque limiter mechanism T _L is activated when the rotational torque to the input shaft exceeds a set value determined by the elastic coefficient K ₇ of the elastic member 7, and the clutch is turned on (engaged) in the range of the rotational torque below. The clutch is set to be off (disengaged) when the rotational torque is not applied. Also, for the housing (radius portion) 9 and the housing (outer peripheral portion) 8 surrounding the flange portion 3 _F of the clutch plate 3, the input shaft 1 and the output shaft 2 are rotated by bearings 13 and 14, respectively. It is held freely.

The operation of the reverse input cutoff clutch C of this embodiment configured as described above will be described. First, in the state shown in FIGS. 1 and 2, no rotational torque is transmitted to the input shaft 1, and the state of the clutch C is OFF (disengaged). In the torque cam mechanism T _C, the ball 10 is recessed grooves 4a, the deepest portion or location on the close proximity of 5a (in this position the distance d between the groove bottom) and are, axial force in this condition still occur _Therefore , the friction surfaces 3 _S and 4 _S between the flange portions 3 _F and 4 _{F of the} clutch plate 3 and the rotating plate 4 are slightly separated from each other by the elastic member 11 and are in a non-contact state. That is, the input / output shafts 1 and 2 are shut off.

  As shown in FIG. 3, when rotational torque is transmitted to the input shaft 1, one rotary plate 5 rotates in the direction of the rotational torque, while the other rotary plate 4 is an elastic member provided between the housing 9. A phase lag is caused by twelve sliding resistances. That is, the concave grooves 4a and 5a are shifted from each other in the rotational direction at the center of the deepest portion as shown in FIG. For this reason, the ball 10 moves to the shallower side of the concave grooves 4a and 5a, and both ends of the symmetrical (diagonal) positions around the ball 10 of the concave grooves 4a and 5a are separated according to the magnitude of the rotational torque. Shift to position. Since the diameter of the ball 10 does not change, the distance d ′ between the groove positions that come into contact with the ball 10 when the ball 10 moves between the shallow positions of the groove is slightly larger than the distance d in the stationary state (d '> D).

At this time, an axial force is generated, and one of the rotating plates 4 and 5 moves in the axial direction. At this time, since the elastic coefficient K ₇ of the elastic member 7 is set larger than the elastic coefficient K ₁₁ of the elastic member 11, the rotating plate 4 is pressed in a direction away from 5. Since the elastic member 12 is provided between the end of the flange portion 4 _F of the rotating plate 4 and the housing 9, sliding resistance by the elastic member 12 is applied to the flange portion 4 _F of the rotating plate 4, and the input shaft even when the torque from the 1 is relatively small, certainly in the torque cam mechanism T _C and generates a phase shift. As a result of the above operation, the friction surfaces 4 _S and 3 _S of the flange portions 4 _F and 3 _F are brought into close contact with each other, whereby the rotational torque from the input shaft 1 is transmitted to the output shaft 2.

Next, as shown in FIG. 4, when an excessive torque of a predetermined value or more is transmitted as the rotational torque to the input shaft 1, the ball 10 moves to a shallower portion of the concave grooves 4a and 5a, and further the holding plate 16 (See FIG. 5B). In the process, after the friction surfaces 3 _S and 4 _S are brought into close contact with each other, the axial separation distance between the rotating plates 4 and 5 increases while the ball 10 moves to a shallower portion of the concave grooves 4a and 5a. When the movement of the other rotating plate 4 in the axial direction is stopped by the close contact of the friction surfaces 3 _S and 4 _S , the one rotating plate 5 is separated and the elastic member 7 is pressed. Then, the transmission torque increases until the ball 10 rides on the parallel surfaces of the rotating plates 4 and 5 from the concave grooves 4a and 5a as shown in FIG.

  Accordingly, when the elastic member 7 absorbs the amount of axial movement of the rotating plate 5 during this time and the ball 10 rides on the parallel plane, this state is the operating state of the torque limiter, and the input torque at that time becomes the torque limit value. . The above is the operation of the torque limiter mechanism. The spring force (elastic coefficient) of the elastic members 7, 11, and 12 can be smoothly switched between the stationary state, torque transmission, and torque limit state according to the magnitude of the rotational torque. Set to In the above operation, the rotation torque from the input shaft 1 is the same whether the rotation is forward or reverse, and may be either forward or reverse.

On the other hand, rotation is not transmitted from the output shaft 2 in the direction of the input shaft 1. As shown in FIG. 1, as long as the input shaft 1 is stationary, the friction surfaces 3 _S and 4 _S of the clutch plate 3 and the rotating plate 4 are slightly separated from each other and are not in frictional contact. This is because rotational torque is not transmitted to the input shaft 1. In the middle of transmitting the rotational torque from the input shaft 1 to the output shaft 2, the output shaft 2 rotates with other power, and when the rotational torque is not transmitted to the input shaft 1, the output shaft 2 is input. Although rotate relative to the axis 1, this friction surface 3 _S, 4 _S since the torque cam mechanism T _C is not operated even become non-contact, rotational torque from the clutch plate 3 to the rotary plate 4 is not transmitted, so that the output No rotational torque is transmitted from the shaft 2 to the input shaft 1.

FIG. 5 is a diagram showing various modified examples of combinations of the shapes of the friction surfaces 3 _S and 4 _S of the flange portions 3 _F and 4 _F of the clutch plate 3 and the rotating plate 4. (A) The figure shows a case where the entire friction surface 4 _S of the flange portion 4 _F has a curved surface with a radius of curvature R, and (b) shows the case where both ends of the friction surface 4 _S are partially curved with a radius of curvature R. shows a case where the radius of curvature R of the curved surface of the entire (c) drawing the friction surface 3 _S of the flange portion 3 _F of the clutch plate 3. By adopting the above modification, it is possible to prevent the frictional surfaces 3 _S and 4 _S from contacting each other and uneven wear resulting therefrom.

In the above configuration, the torque cam mechanism T _C has been described as a combination of concave grooves and the ball facing. However, the torque cam mechanism T _C is not intended to be limited to, for example, a combination of irregularities, it may be a so-called face cam, or the like.

  The reverse input cut-off clutch of the present invention is a clutch that incorporates a torque limiter and does not use a roller that cuts off the reverse input.

Main longitudinal cross-sectional view of reverse input cutoff clutch of embodiment (A) Sectional view taken along the line II-II in FIG. 1, (b) Partial sectional view taken along the line BB in the figure (a). Explanatory drawing of the effect | action of the reverse input interruption | blocking clutch of embodiment (torque transmission state) Explanatory drawing of the effect | action of the reverse input interruption | blocking clutch of embodiment (at the time of a torque limiter action | operation) The figure which shows the three modifications of the friction surface of a clutch plate and a rotating plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Output shaft 3 Clutch plate 3 _F , 4 _F flange part 3 _S , 4 _S friction surface 4, 5 Rotating plate 6 Connection cup 7, 11, 12 Elastic member 8, 9 Housing 10 Ball 16 Holding plate

Claims (8)

  In a clutch mechanism that transmits and shuts off rotational torque between an input shaft and an output shaft that are coaxially provided on the power transmission path and separated from each other, rotation of the input shaft via cam means provided on a pair of rotating plates A torque cam mechanism that transmits torque from one to the other rotating plate and generates axial thrust on the other rotating plate, and provided on the friction surface of the other rotating plate and the output shaft by the axial thrust. A friction clutch that transmits and shuts off rotational torque to the output shaft by frictional contact with the clutch plate; and torque limiting means that restricts transmission of rotational torque to the torque cam mechanism when the rotational torque to the output shaft exceeds a predetermined value; The reverse input cutoff clutch is characterized in that the reverse input from the output shaft is not transmitted by blocking the clutch plate and the other rotating plate.   A ball is inserted between a pair of concave grooves provided on the opposing surfaces of the pair of rotating plates so as to gradually become shallower in the circumferential direction, and the rotational torque of the input shaft is transmitted through the balls. The reverse input cutoff clutch according to claim 1, wherein the reverse input cutoff clutch is configured as described above.   The cam means is configured to provide an uneven portion having an inclined surface in the circumferential direction on each facing surface of the pair of rotating plates, and to transmit the rotational torque of the input shaft by contact of the inclined surfaces. The reverse input cutoff clutch according to claim 1, wherein   The friction clutch portion is characterized in that flange portions are provided on the outer peripheral portions of the clutch plate and the other rotary plate, and each flange portion is formed as a friction surface inclined at a predetermined angle with respect to the center line of the input / output shaft. Item 4. The reverse input cutoff clutch according to any one of Items 1 to 3.   5. The reverse input according to claim 1, wherein movement of the friction clutch portion in the axial direction of the clutch plate is restricted by a stop ring, and the output shaft is connected to the output shaft so as not to rotate but to be movable in the axial direction. Breaking clutch.   A first elastic member is provided between the clutch plate of the friction clutch portion and the other rotary plate, and a first elastic member is provided between the flange provided at the output shaft end and the one rotary plate. 6. The reverse input cutoff clutch according to claim 1, wherein two elastic members are provided, and an elastic coefficient of the second elastic member is set larger than an elastic coefficient of the first elastic member.   When rotational torque is input to the input shaft, the other rotating plate is displaced in the axial direction by axial thrust by the torque cam mechanism against the elastic force of the first elastic member, and the friction surface of the friction clutch portion is fastened. When the rotational torque is input from the output shaft, the other rotational plate is separated from the clutch plate by the elastic force of the first elastic member to release the engagement of the friction clutch portion, and the reverse input is cut off. The reverse input cutoff clutch according to claim 6.   5. The reverse input cutoff clutch according to claim 4, wherein either one of the friction plate of the friction clutch portion and the friction surface of the other rotary plate is partially or entirely formed as a curved surface having a predetermined radius of curvature.

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