JP2007232095A - Anti-reverse input clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-reverse input clutch, hardly varying a delay angle in rotation when the rotation of an input side member is transmitted to an output side member. <P>SOLUTION: An input side cylindrical engagement part 12 is inserted in an engagement hole 13 of an output side inner ring 3 with a clearance in the rotating direction, two engagement surfaces 12a parallel to the axis and parallel to each other are formed on the outer periphery of the cylindrical engagement part 12, and an engagement surface 13a coming into surface contact with the engagement surface 12a of the cylindrical engagement part 12 when the input is applied to the input side, whereby the contact load at the contact part is dispersed so that the plastic deformation of the contact part is hardly caused and an increase in delay angle of rotation is hardly caused. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reverse input prevention clutch that transmits rotation of an input side member to an output side member and prevents rotation of the output side member from being transmitted to the input side member.

  The reverse input preventing clutch transmits the rotation of the input side member to which the torque is input in both the forward and reverse directions to the output side member, while preventing the rotation of the output side member due to the reverse input torque from being transmitted to the input side member. (For example, refer to Patent Document 1). FIG. 5 shows an example of a clutch provided with such a reverse input prevention mechanism. This clutch connects the input side member 51 and the output side member 52 rotating around the same axis so as to be able to transmit torque, and circulates cam surfaces 52 a and 52 b inclined in opposite directions to the outer periphery of the output side member 52. A plurality of wedge-shaped spaces 54 gradually narrowing on both sides in the circumferential direction are formed between the inner peripheral cylindrical surface of the fixed outer ring 53 and the outer peripheral surface of the output side member 52, and are integrated with the input side member 51. Is inserted into the respective wedge-shaped spaces 54 so as to be positioned on both sides in the circumferential direction, and the pair of cylindrical rollers 56 and the respective rollers 56 are pushed into the narrow portions of the wedge-shaped spaces 54. A coil spring 57 is incorporated.

  In this clutch, since each roller 56 is pushed into the narrow portion of the wedge-shaped space 54 by the elasticity of the spring 57, the roller 56 on the rear side in the rotational direction is moved to the outer ring 53 even when reverse input torque is applied to the output side member 52. By engaging with the output side member 52, the output side member 52 is locked, and the input side member 51 does not rotate.

  On the other hand, when input torque is applied to the input side member 51, the retainer column portion 55 rotates integrally with the input side member 51 and pushes the roller 56 on the rear side in the rotational direction against the elasticity of the spring 57. Thus, the engagement between the roller 56 and the outer ring 53 and the output side member 52 is released, the output side member 52 is released from the locked state, and the rotation of the input side member 51 is transmitted to the output side member 52. .

  Here, as a means for connecting the input side member 51 and the output side member 52 so as to be able to transmit torque, as shown in FIG. 5, a cylindrical engaging portion 58 provided on the input side member 51 is connected to the output side. A planar portion 58a, which is inserted into the engagement hole 59 provided in the member 52 with a clearance in the rotational direction, and is opposed to each other in parallel with the axis on the outer periphery of the engagement portion 58 and the inner periphery of the engagement hole 59, 59a is formed. According to this torque transmission means, when an input torque is applied to the input side member 51, the engaging portion 58 engages with the engagement hole 59 of the output side member 52, thereby rotating the input side member 51. It is transmitted to the output side member 52 with a slight angular delay.

However, in the torque transmission means, as shown in FIG. 6, the boundary portion between the flat portion 58 a on the outer periphery of the engaging portion 58 of the input side member 51 and the cylindrical surface portion 58 b is the flat portion of the engaging hole 59 of the output side member 52. Since the rotation of the input side member 51 is transmitted to the output side member 52 in line contact with 59a, if the input torque is large and the number of repetitions of torque input is large, the contact portion is plastically deformed (sagging). May occur. When such plastic deformation occurs in the contact portion between the input side member 51 and the output side member 52, the rotation delay angle from when the input side member 51 rotates to when the output side member 52 rotates at the start of torque transmission is large. Therefore, there may be a problem of an operation delay of a device or the like (not shown) connected to the output side member 52. Further, since the distance that the retainer column 55 pushes the roller 56 becomes longer and the amount of compression of the spring 57 becomes larger, the spring 57 is subjected to compressive stress in a state where there is no elastic compression allowance during torque transmission. May break.
JP-A-2-271116

  An object of the present invention is to provide a reverse input prevention clutch in which the rotation delay angle is difficult to change when the rotation of the input side member is transmitted to the output side member.

  In order to solve the above-described problems, the present invention provides an input side member and an output side member that rotate around the same axis, and an engaging portion that is opposed to each other with a gap in the rotation direction. When the input torque is applied, the engaging portion of the input side member and the engaging portion of the output side member are engaged, whereby the rotation of the input side member is transmitted to the output side member with a slight angular delay. In the reverse input prevention clutch configured as described above, the engaging portion of the input side member and the engaging portion of the output side member are formed in a shape that engages with each other in surface contact with each other.

  That is, by making the engaging portion of the input side member and the engaging portion of the output side member in surface contact with each other, the contact load at the contact portion is dispersed, and plastic deformation of the contact portion is performed. It was made difficult to occur and the rotation delay angle was difficult to increase.

  Specifically, the engaging portion of the input side member is formed in a cylindrical shape and has an engaging surface parallel to the axis on the outer periphery thereof, and the engaging portion of the output side member is the input portion. An engagement hole into which the cylindrical engagement portion of the side member is inserted, and the engagement surface and the surface of the cylindrical engagement portion when an input torque is applied to the input side member on the inner periphery of the engagement hole The structure in which the engaging surface which contacts is formed is employable.

  As described above, the reverse input prevention clutch of the present invention has a shape in which the engaging portion of the input side member and the engaging portion of the output side member are engaged with each other in surface contact with each other. And the output side member are not easily plastically deformed and the rotation delay angle is difficult to increase. Accordingly, it is possible to stabilize the operation timing of the device or the like connected to the output side member. In addition, when a compression coil spring is used as a mechanism for locking the output side member, there is less possibility that the member that releases the lock will compress the spring more than necessary as the input side member rotates, and the spring breaks. Etc. can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the reverse input prevention clutch includes an input shaft (input side member) 1, an output side member 4 including an output shaft 2 and an inner ring 3, and an outer ring 6 integrally formed with a housing 5. A fixing member 8 having a presser lid 7 attached to one end thereof, a cage 9 having a plurality of column portions 9a inserted between the inner ring 3 and the outer ring 6, and a cylinder incorporated between the column portions 9a of the cage 9. The roller 10 and the compression coil spring 11 are basically configured.

  In the input shaft 1, an engagement portion 12 formed in a cylindrical shape is inserted into an engagement hole 13 provided in the center of the inner ring 3 with a clearance in the rotation direction, and a small-diameter cylindrical portion at the tip is the output shaft 2. It is fitted into a hole in the center of the end face and rotates around the same axis as the output shaft 2. The retainer 9 is configured such that a cylindrical portion 9b provided on the side opposite to the column portion 9a is fitted into the outer diameter of the input shaft 1, and rotates together with the input shaft 1. In the output side member 4, the output shaft 2 and the inner ring 3 formed separately are connected so as to be integrally rotatable, but the output shaft and the inner ring may be integrally formed.

  As shown in FIGS. 2 and 3A, two engaging surfaces 12a that are parallel to the shaft center and parallel to each other are formed on the outer periphery of the engaging portion 12 of the input shaft 1, and the inner ring 3 is engaged. On the inner periphery of the hole 13, two convex engagement surfaces 13 a that are opposed to the respective engagement surfaces 12 a of the input shaft 1 are formed. When the input shaft 1 rotates, as shown in FIG. 3B, the engaging portion 12 of the input shaft 1 and the engaging hole 13 of the inner ring 3 face each other at the engaging surfaces 12a and 13a. By engaging in contact, the rotation of the input shaft 1 is transmitted to the inner ring 3 and the output shaft 2 connected thereto with a slight angular delay. 3B shows a state in which the input shaft 1 rotates counterclockwise, but when the input shaft 1 rotates in the clockwise direction, the engaging portion of the input shaft 1 is similar to the state in FIG. 3B. The 12 engaging surfaces 12 a and the engaging surface 13 a of the engaging hole 13 of the inner ring 3 are in surface contact.

  As shown in FIG. 2, cam surfaces 3 a and 3 b that are inclined in opposite directions are alternately provided on the outer periphery of the inner ring 3, and the inner peripheral surface of the outer ring 6 and the outer peripheral surface of the inner ring 3 are A plurality of wedge-shaped spaces 14 that are gradually narrowed on both sides in the circumferential direction are formed therebetween. Then, the pillar portions 9a of the cage 9 are inserted on both sides in the circumferential direction of each wedge-shaped space 14, and a pair of rollers 10 sandwiches springs 11 for pushing each roller 10 into a narrow portion of the wedge-shaped space 14 in each wedge-shaped space 14. It is arranged in a state.

  Therefore, even when reverse input torque is applied to the output shaft 2, the roller 10 on the rear side in the rotational direction is pushed into the narrow portion of the wedge-shaped space 14 by the spring 11 and engages with the inner peripheral surface of the outer ring 6 and the outer peripheral surface of the inner ring 3. Therefore, the inner ring 3 is locked, and the rotation of the output shaft 2 is not transmitted to the input shaft 1.

  On the other hand, when an input torque is applied to the input shaft 1, the column portion 9 a of the cage 9 that rotates integrally with the input shaft 1 causes the rollers 10 on the rear side in the rotation direction to resist the elasticity of the spring 11 and to form a wedge-shaped space 14. Therefore, the engagement between the roller 10 and the inner peripheral surface of the outer ring 6 and the outer peripheral surface of the inner ring 3 is released, and the inner ring 3 is released from the locked state. When the input shaft 1 further rotates and the engaging portion 12 engages with the engagement hole 13 of the inner ring 3, the rotation of the input shaft 1 is transmitted to the output shaft 2 through the inner ring 3.

  This clutch is configured as described above, and when input torque is applied to the input shaft 1, the engagement portion 12 of the input shaft 1 and the engagement hole 13 of the inner ring 3 engage with each other in surface contact with each other. Therefore, the contact portion is less likely to be plastically deformed than in the case of conventional line contact, and the rotation delay angle is difficult to increase. Therefore, the operation timing of a device or the like (not shown) connected to the output shaft 2 can be stabilized, and the column portion 9a of the retainer 9 compresses the spring 11 more than necessary via the roller 10 during torque transmission. There is little fear and problems such as breakage of the spring 11 are unlikely to occur.

  FIG. 4 shows a modification of the shape of the contact portion between the input shaft 1 and the inner ring 3. In this modification, two engagement surfaces 13 b that are parallel to the shaft center and parallel to each other are formed on the inner periphery of the engagement hole 13 of the inner ring 3, and the input shaft 1 is formed on the outer periphery of the engagement portion 12 of the input shaft 1. Two convex engagement surfaces 12b are formed which come into surface contact with the respective engagement surfaces 13b of the engagement holes 13 when 1 rotates.

  Note that the shape of the contact portion between the input shaft 1 and the inner ring 3 can be the same as the modification shown in FIG. 4, but the outer periphery of the input shaft 1 is finished by machining such as milling, and the inner ring 3 is forged. In many cases, the shape shown in FIGS. 2 and 3 is easier to manufacture and practical.

Longitudinal front view of the reverse input prevention clutch of the embodiment Sectional view along line II-II in FIG. 2 is an enlarged cross-sectional view showing a main part of FIG. 2, and b is an enlarged cross-sectional view showing a torque transmission state of the clutch of FIG. 1 corresponding to a. The principal part expanded sectional view which shows the modification of the shape of the contact part of an input shaft and an inner ring | wheel Sectional drawing explaining the structure of the conventional reverse input prevention clutch (cross section corresponding to FIG. 2) The principal part expanded sectional view which shows the torque transmission state of the clutch of FIG.

Explanation of symbols

1 Input shaft (input side member)
2 Output shaft 3 Inner ring 3a, 3b Cam surface 4 Output side member 5 Housing 6 Outer ring 7 Presser lid 8 Fixing member 9 Cage 9a Column 9b Tube 10 Roller 11 Spring 12 Engagement 12a, 12b Engagement surface 13 Engagement Hole 13a, 13b Engagement surface 14 Wedge-shaped space

Claims (2)

  The input side member and the output side member that rotate around the same axis are provided with engaging portions that face each other with a gap in the rotation direction, and when input torque is applied to the input side member, the input side member In the reverse input prevention clutch, the rotation of the input side member is transmitted to the output side member with a slight angular delay by engaging the engaging portion of the output side member with the engaging portion of the output side member. A reverse input preventing clutch, wherein the engaging portion of the member and the engaging portion of the output side member are formed in a shape that engages with each other in surface contact with each other.   The engaging part of the input side member is formed in a cylindrical shape and has an engaging surface parallel to the axis on the outer periphery thereof, and the engaging part of the output side member is a cylindrical shape of the input side member An engagement hole into which the engagement portion is inserted, and an engagement surface that is in surface contact with the engagement surface of the tubular engagement portion when an input torque is applied to the input side member on the inner periphery of the engagement hole The reverse input preventing clutch according to claim 1, wherein the reverse input preventing clutch is formed.

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