JP2017020612A - Reverse input cutoff clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of noise and vibration caused by a tooth jump phenomenon, and to surely control the cutoff and transmission of rotation torque.SOLUTION: A reverse input cutoff clutch comprises: an input shaft 11 to which rotation torque is inputted; a fixed outer ring 12 which is constrained in rotation; an output shaft 13 from which the rotation torque is outputted; an engagement piece 14 which is arranged between the fixed outer ring 12 and the output shaft 13, engaged between the fixed outer ring 12 and the output shaft 13 at the cutoff of the rotation torque from the output shaft 13, and released in the engagement between the fixed outer ring 12 and the output shaft 13 at the transmission of the rotation torque from the input shaft 11; and a pin 15 which is arranged between the input shaft 11 and the output shaft 13, and transmits the rotation torque from the input shaft 11 to the output shaft 13 at the release of the engagement of the engagement piece 14. The fixed outer ring 12 and the engagement piece 14 have opposing faces which can be engaged with each other and released from each other, the opposing face of the fixed outer ring 12 is formed of a recessively-curved face 29, and the opposing face of the engagement piece 14 is formed of a protrusively-curved face 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reverse input cutoff clutch having a function of transmitting rotational torque input from an input member to an output member while blocking rotational torque input reversely from the output member.

  For example, a device that performs a required operation by transmitting rotational torque input from a drive source to an output side mechanism is required to have a function of holding the output side mechanism so that the position of the output side mechanism does not fluctuate when the drive source is stopped. There is a case. For example, the electric shutter device performs the opening / closing operation of the shutter by inputting the rotational torque in the forward / reverse direction from the drive motor to the opening / closing mechanism on the output side.

  In this electric shutter device, when the driving source stops due to some reason (power failure etc.) during the opening / closing operation of the shutter, when the rotational torque reversely input due to the lowering of the weight of the shutter returns to the input side, May cause damage. Therefore, in the electric shutter device, a mechanism having a function of holding the position of the shutter and preventing the rotational torque reversely input from the shutter from returning to the input side is required.

  The present applicant has previously proposed a reverse input cutoff clutch as a mechanism having a function of transmitting rotational torque input from the input member to the output member while blocking reverse rotational torque input from the output member. (For example, refer to Patent Document 1).

  The reverse input cutoff clutch disclosed in Patent Document 1 includes an input member to which rotational torque is input, a stationary member to which rotation is constrained, an output member to which rotational torque is output, and a stationary member and an output member. The engaging element is disposed between the control element and the control means for controlling the interruption and transmission of the rotational torque by engaging and releasing the concave and convex portions.

  In the reverse input cutoff clutch having the above-described configuration, when the rotational torque input from the input member is transmitted, the control member releases the engaging member between the stationary member and the output member, thereby outputting the stationary member and the output member. Release the engagement of the concavo-convex portion with the member. By releasing the engagement of the concave and convex portions, the rotational torque from the input member is transmitted to the output member.

  On the other hand, when the rotational torque reversely input from the output member is interrupted, the engaging portion is engaged between the stationary member and the output member by the control means so that the uneven portion is engaged between the stationary member and the output member. . Due to the engagement of the uneven portions, the output member is locked with respect to the stationary member, and the rotational torque from the output member is cut off so as not to return to the input member.

JP 2013-224692 A

  By the way, in the conventional reverse input cutoff clutch disclosed in Patent Document 1, when the rotational torque reversely input from the output member is cut off, the engagement member is engaged between the stationary member and the output member to The concave and convex portions are meshed between the member and the output member. Further, when the rotational torque input from the input member is transmitted, the engagement between the stationary member and the output member is released by releasing the engagement member between the stationary member and the output member. ing.

  As described above, the interruption and transmission of the rotational torque are controlled by the engagement and release of the concavo-convex portion between the stationary member and the output member. For this reason, if the output member is unloaded or close to it, there is a possibility that a tooth skipping phenomenon that repeats the engagement and release of the concavo-convex portion may occur. Such tooth skipping phenomenon causes generation of abnormal noise and vibration. In addition, there is a concern that the unevenness of the uneven portion may occur due to wear of the uneven portion.

  Therefore, the present invention has been proposed in view of the above-described improvements, and the object of the present invention is to prevent the generation of abnormal noise and vibration due to the tooth skip phenomenon, and to reliably control the interruption and transmission of rotational torque. The object is to provide a reverse input shut-off clutch.

  As technical means for achieving the aforementioned object, the present invention provides an input member to which rotational torque is input, a stationary member to which rotation is constrained, an output member to which rotational torque is output, a stationary member and an output. An engagement element disposed between the member and engaged between the two members when the rotational torque from the output member is interrupted, and disengaged between the two members upon transmission of the rotational torque from the input member; and the input member and the output member And a torque transmission member that transmits rotational torque from the input member to the output member when the engagement member is disengaged, wherein the stationary member and the engagement member are engaged with each other. Each of the opposite surfaces of the stationary member and the engaging element is formed of a curved surface.

  In the present invention, the stationary member and the engaging element each have opposing surfaces that can be engaged and disengaged from each other, and the opposing surfaces of the stationary member and the engaging element are configured by curved surfaces, so The engagement element is smoothly disengaged. Therefore, even when the output member is unloaded or in a state close to it, the conventional tooth skipping phenomenon that repeats the engagement and release of the uneven portion does not occur.

  As a result, the locked state of the output member can be reliably maintained, and abnormal noise and vibration can be prevented. Further, since the stationary member and the engaging element come into contact with each other at the curved surfaces, it is possible to avoid the occurrence of the meshing failure of the concavo-convex part due to the wear of the concavo-convex part as in the conventional case.

  In the present invention, the stationary member has a cylindrical shape and the engaging element has a convex shape, and the opposing surface of the stationary member is configured by a concave curved surface, and the opposing surface of the engaging element has a smaller radius of curvature than the concave curved surface of the stationary member. It is desirable to use a convex curved surface. If such a structure is employ | adopted, it can implement | achieve much more easily to disengage an engagement element smoothly between a stationary member and an output member.

  In the present invention, it is desirable that at least one facing surface of the stationary member and the engaging member is made of a material having high friction characteristics. When such a configuration is adopted, when the engaging element is engaged between the stationary member and the output member, slippage is unlikely to occur between the stationary member and the engaging element. By preventing the slip, the rotational torque from the output member can be reliably cut off, and it becomes easy to maintain the locked state of the output member even when the output member is unloaded or close to it.

  In the present invention, a configuration in which a friction material is attached to at least one of the stationary member and the engaging member is desirable. By adopting such a configuration, it is possible to prevent slippage between the stationary member and the engaging member by a simple means of attaching a friction material without being restricted by the material of the stationary member and the engaging member. As a result, the rotational torque from the output member is reliably cut off, and it becomes easy to maintain the locked state of the output member even when the output member is unloaded or close to it.

  In this invention, the structure which formed the ditch | groove along a rotation direction in at least one opposing surface among a stationary member and an engaging element is desirable. If such a structure is employ | adopted, it will become easy to cut | disconnect the oil film of the lubricating oil interposed between a stationary member and an engagement element. This oil film breakage can surely prevent slippage between the stationary member and the engagement element. As a result, the rotational torque from the output member is reliably cut off, and it becomes easy to maintain the locked state of the output member even when the output member is unloaded or close to it.

  According to the present invention, the stationary member and the engaging element each have opposing surfaces that can be engaged with and disengaged from each other, and both the opposing surfaces of the stationary member and the engaging element are configured by curved surfaces. Since the engagement element smoothly disengages between them, even if the output member is unloaded or close to it, there is no occurrence of a tooth skipping phenomenon that repeatedly engages and releases the uneven portion as in the conventional case. .

  In this way, the locked state of the output member can be reliably maintained, and abnormal noise and vibration can be prevented. Further, since the stationary member and the engaging element come into contact with each other at the curved surfaces, it is possible to avoid the occurrence of the meshing failure of the concavo-convex part due to the wear of the concavo-convex part as in the conventional case. As a result, it is possible to realize a high-quality reverse input cutoff clutch that can prevent abnormal noise and vibration, and can reliably control the cutoff and transmission of rotational torque.

In an embodiment of the present invention, it is a sectional view showing a reverse input interception clutch. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which shows the state which the input member contacted the engagement element by rotation of the input member from the state of FIG. It is sectional drawing which shows the state which the input member contacted the pin member by rotation of the input member from the state of FIG. It is sectional drawing which shows the state which an output member rotates by rotation of an input member from the state of FIG. It is an expanded sectional view showing an engagement child in other embodiments of the present invention. In other embodiment of this invention, it is an enlarged side view which shows an engaging element.

  An embodiment of a reverse input cutoff clutch according to the present invention will be described in detail below with reference to the drawings.

  In the following embodiments, a reverse input cut-off clutch incorporated in an electric shutter device that opens / closes a shutter by inputting forward / reverse rotational torque input from a drive source to an output-side opening / closing mechanism will be exemplified. In addition, this reverse input interruption | blocking clutch is applicable to various apparatuses, such as a steering device with a reverse input interruption | blocking function other than an electric shutter apparatus.

  The electric shutter device may be required to have a function of holding the shutter so that the position of the shutter does not fluctuate when the drive source is stopped. The reverse input shut-off clutch of this embodiment is a type called a lock type, and transmits the rotational torque input from the input member to the output member, while locking the rotational torque input reversely from the output member to the input member. It has a reverse input blocking function that prevents it from refluxing.

  As shown in FIGS. 1 and 2, the reverse input cutoff clutch includes an input shaft 11 that is an input member to which rotational torque is input, a fixed outer ring 12 that is a stationary member to which rotation is constrained, and rotational torque that is output. The output shaft 13, which is an output member, is disposed between the fixed outer ring 12 and the output shaft 13, and is engaged between the fixed outer ring 12 and the output shaft 13 when the rotational torque from the output shaft 13 is interrupted. The engaging member 14 is disengaged between the fixed outer ring 12 and the output shaft 13 when the rotational torque is transmitted from the input shaft 11, and is disposed between the input shaft 11 and the output shaft 13, and when the engaging member 14 is disengaged. The main part is composed of a pin 15 which is a torque transmission member for transmitting rotational torque from the input shaft 11 to the output shaft 13.

  The fixed outer ring 12 has a cylindrical shape and is attached to a housing 17 that supports a motor 16 that is a drive source. The fixed outer ring 12 is arranged coaxially with the output shaft 21 of the motor 16.

  The input shaft 11 is disposed inside the fixed outer ring 12 and is rotatably attached to the fixed outer ring 12 by a rolling bearing 18. The input shaft 11 includes a cylindrical portion 19 and a column portion 20 formed integrally with the cylindrical portion 19. The cylindrical portion 19 is coaxially connected to the output shaft 21 of the motor 16 so that torque can be transmitted. The column part 20 is expanded in diameter from the cylindrical part 19 and extends in the axial direction, and a notch 22 is formed between adjacent column parts 20 at a position opposite to the circumferential direction by 180 °. The engagement element 14 is accommodated in the notch 22. One pillar 20 is provided with a hole 23, and a pin 15 is accommodated in the hole 23.

  The output shaft 13 is rotatably attached to the fixed outer ring 12 by a rolling bearing 24. The output shaft 13 is arranged coaxially with the input shaft 11. The input side end portion 25 of the output shaft 13 is disposed inside the column portion 20 of the input shaft 11, and the output side end portion 26 of the output shaft 13 protrudes from the fixed outer ring 12 in the axial direction. An engagement element 14 and a pin 15 are provided at the input side end 25 of the output shaft 13. The output side end portion 26 of the output shaft 13 is connected to a shutter opening / closing mechanism (not shown) by appropriate means such as a gear so as to transmit torque.

  The engagement element 14 is a member having a cross-sectional mushroom shape and integrally formed with a head part 27 located on the radially outer side and a leg part 28 located on the radially inner side. The head portion 27 of the engagement element 14 is accommodated and disposed in the notch 22 positioned between the column portions 20 of the input shaft 11 with a clearance in the circumferential direction.

  The inner peripheral portion of the fixed outer ring 12 and the head portion 27 of the engaging element 14 have opposing surfaces 29 and 30 that can be engaged and disengaged with each other. The facing surface 29 of the inner peripheral portion of the fixed outer ring 12 is configured by an arcuate concave curved surface (hereinafter, the concave curved surface is denoted by reference numeral 29), and the facing surface 30 of the head portion 27 of the engaging element 14 is an arcuate convex curved surface ( Hereinafter, the convex curved surface is denoted by reference numeral 30). The convex curved surface 30 of the head 27 of the engagement element 14 is set to have a smaller radius of curvature than the concave curved surface 29 of the fixed outer ring 12. Thus, since the opposing surface of the head 27 of the engaging element 14 and the fixed outer ring 12 has a simple shape, the processing is easy and the cost can be reduced.

  The leg portion 28 of the engagement element 14 is inserted along a radial direction through a coil spring 32 that is an elastic member into a recessed hole 31 formed in the outer peripheral surface of the output shaft 13. The coil spring 32 urges the elastic force toward a direction in which the convex curved surface 30 of the head 27 of the engaging element 14 is brought into contact with the concave curved surface 29 of the fixed outer ring 12, that is, radially outward. In this embodiment, the case where the coil spring 32 is used as the elastic member is illustrated, but an elastomer may be employed in addition to the coil spring 32.

  This engagement element 14 is provided at the input side end 25 of the output shaft 13 at a position 180 ° opposite to the circumferential direction. As described above, by disposing the two engaging elements 14 in the opposite directions of 180 °, the engagement with the fixed outer ring 12 can be disengaged with good balance. A tapered surface 33 is formed at the circumferential end of the column portion 20 of the input shaft 11 that contacts the convex curved surface 30 of the engagement element 14 in order to make the contact with the engagement element 14 smooth. In addition, although this embodiment illustrates the case where the two engaging elements 14 are provided, the present invention is not limited to this, and the number of engaging elements 14 is arbitrary.

  The pin 15 is a rod-like member and is attached by press-fitting into a concave hole 34 formed on the outer peripheral surface of the output shaft 13. The protruding end portion of the pin 15 is accommodated and disposed in a hole 23 provided in the column portion 20 of the input shaft 11 with a clearance in the circumferential direction. The pin 15 is disposed at an intermediate 90 ° position between the two engaging elements 14 disposed in the opposite directions of 180 °. In this way, by disposing at the intermediate 90 ° position between the two engagement elements 14, the engagement element 14 can be detached from the fixed outer ring 12 in a balanced manner.

  In the reverse input cutoff clutch configured as described above, even when rotational torque is reversely input to the output shaft 13, as shown in FIG. 1, the engagement element 14 protrudes radially outward due to the elastic force of the coil spring 32. Therefore, the convex curved surface 30 of the head 27 of the engagement element 14 is in contact with and engaged with the concave curved surface 29 of the fixed outer ring 12. Thereby, the output shaft 13 is locked to the fixed outer ring 12. In this manner, the rotational torque reversely input from the output shaft 13 is locked by the engagement element 14 and the return to the input shaft 11 is blocked.

  In the reverse input cutoff clutch of this embodiment, the opposing surfaces of the fixed outer ring 12 and the engagement element 14 are constituted by the concave curved surface 29 and the convex curved surface 30, so that the engagement element 14 is interposed between the fixed outer ring 12 and the output shaft 13. Engages and disengages smoothly. Therefore, even when the output shaft 13 is in an unloaded state or close to it, the conventional tooth skipping phenomenon that repeats the engagement and release of the uneven portions does not occur.

  As a result, the locked state of the output shaft 13 can be reliably maintained, and abnormal noise and vibration can be prevented. In addition, since the fixed outer ring 12 and the engagement element 14 are in contact with each other at the curved surfaces, it is possible to avoid the occurrence of the meshing failure of the concavo-convex part due to the wear of the concavo-convex part as in the prior art.

  In this embodiment, the convex curved surface 30 of the head 27 of the engaging element 14 is set to have a smaller radius of curvature than the concave curved surface 29 of the stationary outer ring 12, so that the engaging element is interposed between the stationary outer ring 12 and the output shaft 13. 14 is configured to smoothly engage and disengage, but the convex curved surface 30 of the head 27 of the engaging element 14 may have the same radius of curvature as the concave curved surface 29 of the fixed outer ring 12. In this case, the contact area between the head 27 of the engagement element 14 and the fixed outer ring 12 is increased, so that the engagement element 14 can be reliably engaged with the fixed outer ring 12 and the locked state of the output shaft 13 can be easily secured. It becomes.

  On the other hand, as shown in FIG. 3, when the rotational torque in the counterclockwise direction (see the white arrow in the figure) is input from the motor 16 to the input shaft 11, the column portion 20 of the input shaft 11 becomes the head of the engaging element 14. By pressing 27, the engagement element 14 is pushed down radially inward against the elastic force of the coil spring 32. At this time, in the column portion 20 of the input shaft 11, the portion that contacts the convex curved surface 30 of the head portion 27 of the engagement element 14 is a tapered surface 33, so that the contact of the column portion 20 of the input shaft 11 with the engagement element 14 is achieved. Smoothes out and suppresses wear and vibration.

  In this way, when the engaging element 14 is pushed down and displaced radially inward, the convex curved surface 30 of the head 27 of the engaging element 14 is separated from the concave curved surface 29 of the stationary outer ring 12 (see FIG. 4). ). Thereby, the locked state of the output shaft 13 with respect to the fixed outer ring 12 is released, and the output shaft 13 can rotate counterclockwise.

  As shown in FIG. 4, when the column portion 20 of the input shaft 11 contacts the pin 15 protruding from the output shaft 13 and the input shaft 11 further rotates counterclockwise, the counterclockwise rotation from the input shaft 11 is performed. Torque is transmitted to the output shaft 13 via the pin 15, and the output shaft 13 rotates counterclockwise (see FIG. 5).

  When a clockwise rotational torque is input to the input shaft 11, the output shaft 13 rotates in the clockwise direction by the reverse operation to that described above. Accordingly, the rotational torque in the forward and reverse rotational directions from the input shaft 11 is transmitted to the output shaft 13 via the pin 15 and the output shaft 13 rotates in the forward and reverse rotational directions.

  The convex curved surface 30 of the head 27 of the engaging member 14 described above is made of a material having high friction characteristics. For example, a sintered metal or an aluminum alloy is effective as a material having high friction characteristics. In order to configure with such a material, there are a case where the entire engagement element 14 is composed of the aforementioned material, and a case where the convex curved surface 30 of the engagement element 14 is coated with the aforementioned material. The concave curved surface 29 of the fixed outer ring 12 may be made of the above-described material.

  By configuring the fixed outer ring 12 or the engagement element 14 with the above-described material, when the engagement element 14 is engaged between the fixed outer ring 12 and the output shaft 13, slipping occurs between the fixed outer ring 12 and the engagement element 14. It becomes difficult to occur. By preventing this slipping, the rotational torque reversely input from the output shaft 13 can be reliably interrupted, and the locked state of the output shaft 13 can be maintained even when the output shaft 13 is unloaded or close to it. It becomes easy.

  Further, as shown in FIG. 6, it is possible to adopt a configuration in which a friction material 35 is attached to the convex curved surface 30 of the head portion 27 of the engaging element 14. For example, a clutch facing material or a brake pad material is effective as the friction material 35. In this case, the friction material 35 may be attached to the concave curved surface 29 of the fixed outer ring 12.

  By adopting such a configuration, the sliding between the fixed outer ring 12 and the engagement element 14 can be performed by a simple means of applying the friction material 35 without being restricted by the material of the fixed outer ring 12 and the engagement element 14. Can be prevented. As a result, the rotational torque from the output shaft 13 is reliably cut off, and it becomes easy to maintain the locked state of the output shaft 13 even when the output shaft 13 is not loaded or close to it.

  Furthermore, as shown in FIG. 7, it is also possible to have a configuration in which a concave groove 36 along the rotational direction is formed on the convex curved surface 30 of the head 27 of the engaging element 14. The size, number and arrangement of the concave grooves 36 are arbitrary. In this case as well, a configuration in which a concave groove 36 along the rotational direction is formed on the concave curved surface 29 of the fixed outer ring 12 may be adopted.

  By adopting such a configuration, it becomes easy to cut the oil film of the lubricating oil interposed between the fixed outer ring 12 and the engagement element 14. By this oil film breakage, it is possible to reliably prevent slippage between the fixed outer ring 12 and the engagement element 14. As a result, the rotational torque from the output shaft 13 is reliably cut off, and it becomes easy to maintain the locked state of the output shaft 13 even when the output shaft 13 is not loaded or close to it.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

11 Input member (input shaft)
12 Static member (fixed outer ring)
13 Output member (output shaft)
14 Engagement 15 Torque transmission member (pin)
29 Opposite surface (concave surface)
30 Opposing surface (convex curved surface)
35 Friction material 36 Groove

Claims (5)

An input member to which rotational torque is input, a stationary member that is constrained to rotate, an output member that outputs rotational torque, and a rotational torque from the output member that is disposed between the stationary member and the output member. Between the input member and the output member, and an engagement element that engages between the two members when the rotation is interrupted and is disengaged between the two members when the rotational torque is transmitted from the input member. A reverse input cutoff clutch provided with a torque transmission member that transmits rotational torque from the input member to the output member,
The stationary input member and the engagement element each have opposing surfaces that can be engaged and disengaged from each other, and both opposing surfaces of the stationary member and the engagement element are configured by curved surfaces.   The stationary member has a cylindrical shape and the engaging element has a convex shape, and the opposing surface of the stationary member is configured by a concave curved surface, and the opposing surface of the engaging element has a smaller radius of curvature than the concave curved surface of the stationary member. The reverse input cutoff clutch according to claim 1, wherein the reverse input cutoff clutch is configured by a convex curved surface.   3. The reverse input cutoff clutch according to claim 1, wherein at least one opposing surface of the stationary member and the engaging element is made of a material having high friction characteristics.   The reverse input cutoff clutch according to claim 1 or 2, wherein a friction material is attached to at least one opposing surface of the stationary member and the engaging element.   The reverse input cut-off clutch according to claim 1 or 2, wherein a concave groove along a rotation direction is formed on at least one of the stationary member and the engaging element.

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