JP2007182934A - Rotation transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation transmission device which prevents the engagement error of an engagement element. <P>SOLUTION: An engagement element 8 is incorporated in between a cam face 7 formed on the outer periphery of a cam ring 1 and a cylinder face 6 formed on the inner periphery of an outer wheel 4. Spring force of a switch spring 11 is imparted to a retainer 9 to hold the retainer 9 in a neutral position where the engagement element 8 is disengaged. An armature 15 is adsorbed by a rotor 19 with an electromagnet 21 so that the engagement element 8 is displaced to an engagement position by the relative rotation of the cam ring 1 and the retainer 9. When the energization of the electromagnet 21 is shut off, the armature 15 is estranged from the rotor 19 by an elastic member 20 incorporated in a space with the rotor 19. A cylinder part 24 provided to the armature 15 is fitted to the inside of the switch spring 11 so as to prevent the diameter of the switch spring 11 from being contracted. The engagement error of the engagement element 8 is thereby prevented. The switch spring 11 is made up of a wire material with an angular section to facilitate the entry of the cylinder part 24. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotation transmission device used for switching between transmission and cutoff of power in a power transmission path.

  As this type of rotation transmission device, one described in Patent Document 1 has been conventionally known. In this rotation transmission device, a cam surface is provided on the outer periphery of a cam ring that is prevented from rotating by an input shaft, and an engaging member made of a roller is incorporated between the cam surface and a cylindrical surface formed on the inner periphery of the outer ring. The combination is held by a cage incorporated between the cam ring and the outer ring, and the spring force of the switch spring is applied to the cage to hold the engagement element in a neutral position where it is disengaged from the cam surface and the cylindrical surface. The container is held elastically.

  Further, the armature that is prevented from rotating with respect to the cage and is supported so as to be movable in the axial direction is opposed to the rotor that is prevented from rotating around the outer ring, and the armature is energized by energizing the electromagnetic coil of the electromagnet facing the rotor. The cam ring and the cage are rotated relative to the elasticity of the switch spring by the friction force acting on the contact portion by suction, and the engagement element is engaged with the cam surface and the cylindrical surface. The rotation of the cam ring is transmitted to the outer ring.

  Here, when the cam ring and the cage rotate relative to each other, the switch spring is deformed to reduce the diameter. For this reason, when energization to the electromagnet is interrupted, the cage is rotated by the restoring elasticity of the switch spring, the engagement element is returned to the neutral position where the engagement is released, and the rotation transmission from the cam ring to the outer ring is interrupted.

  As described above, the rotation transmission is such that the armature is brought into contact with the rotor by energization of the electromagnet, and the rotation of the armature is controlled by the frictional resistance acting on the contact portion so that the engagement element is engaged with the cam surface and the cylindrical surface. In the device, if the support structure is configured to contact and guide the outer diameter surface of the armature with the inner diameter surface of the rotor guide fitted to the inner diameter surface of the outer ring, it acts on the contact portion between the armature and the rotor guide when the rotation transmission device is idling. When drag torque is generated at the outer diameter of the armature due to frictional resistance, and the drag torque becomes greater than the spring force of the switch spring, the cage rotates relative to the cam ring, and the engagement element moves to the cam surface and cylinder. The problem of misengaging with the surface occurs.

In order to solve such a problem, in the rotation transmission device described in Patent Document 2, the armature is separated from the rotor by an elastic member incorporated between the rotor and the armature when the energization to the electromagnet is cut off. A cylindrical portion provided in the inner diameter portion of the switch spring is fitted inside the switch spring to prevent the switch spring from being reduced in diameter and to prevent misengagement of the engagement element.
JP-A-11-105576 Japanese Patent Laying-Open No. 2005-083560

  By the way, in the conventional rotation transmission device described in Patent Document 2, since the switch spring is formed from a wire having a round cross section, the armature is separated from the rotor by the pressing of the elastic member when the electromagnet is cut off. The radial gap between the switch spring and the armature cylindrical part is not constant even if it is moved in the direction of movement, so there is a problem that the cylindrical part is difficult to fit inside the switch spring and is easy to come off. The reliability for reliably preventing this problem was low, and there were still points to be improved.

  An object of the present invention is to provide a highly reliable rotation transmission device capable of reliably preventing misengagement.

  In order to solve the above-mentioned problems, in the present invention, the input side member and the output side member provided on the outside thereof are relatively rotatably supported, and the outer periphery of the input side member and the inner side of the output side member are A cylindrical surface is provided on one side of the circumference, and a cam surface is formed on the other side to form a wedge-shaped space between the cylindrical surface, and an engagement element built between the cam surface and the cylindrical surface is connected to the input side member and the output side. A pair of engaging pieces formed outwardly from both ends of a C-shaped switch spring are held by a cage built in between the members, and a member on the side having the notch formed in the cage and the cam surface is provided. The retainer is elastically held in a neutral position where the engaging element is pressed and engaged with the circumferentially opposed end surfaces of the formed notch and the engagement element is disengaged from the cylindrical surface and the cam surface. Armature that is supported so as to be non-rotating and movable in the axial direction In contrast, the rotor is opposed in the axial direction, the rotor is prevented from rotating with respect to the member having the cylindrical surface, an elastic member is provided to press the armature in a direction away from the rotor, and the armature is sucked by energization. Then, an electromagnet that attracts the armature to the rotor is disposed opposite to the rotor, and the armature is fitted inside the switch spring when the armature moves in the axial direction by the pressing of the elastic member to reduce the diameter of the switch spring. In the rotation transmission device provided with the diameter reduction preventing member to prevent, the configuration in which the switch spring is formed of a wire having a square cross section is adopted.

  The diameter-reducing prevention member may be a cylindrical portion that can be fitted inside the switch spring, or may be a protrusion that is fitted between a pair of engagement pieces of the switch spring.

  As described above, when the switch spring is formed of a wire having a square cross section, the diameter reduction prevention member provided on the armature is easily fitted inside the switch spring, and is difficult to come out, and the energization of the electromagnet is cut off. Thus, the diameter reduction preventing member smoothly enters the switch spring and fits securely. As a result, the armature can be prevented from being reduced in diameter, and a rotation transmission device with high reliability for preventing misengagement can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, a cam ring 1 as an input side member is fitted to an input shaft (not shown) that is rotatably supported by a bearing 2 and has a serration for rotation prevention with respect to the input shaft on its inner periphery. 3 is provided.

  An outer ring 4 as an output side member is provided outside the cam ring 1, and the outer ring 4 and the cam ring 1 are supported via a bearing 5 so as to be relatively rotatable.

  On the outer periphery of the cam ring 1, a plurality of cam surfaces 7 forming a wedge-shaped space with the cylindrical surface 6 formed on the inner periphery of the outer ring 4 are provided in the circumferential direction, and between the cam surface 7 and the cylindrical surface 6. An engaging member 8 made of a roller is incorporated in the main body. The engagement element 8 is held by a cage 9 incorporated between the cam ring 1 and the outer ring 4.

  The cam ring 1 has a cylindrical portion 10 at an end portion, and a switch spring 11 is incorporated in the cylindrical portion 10. The switch spring 11 is formed of a wire having a square cross section and has a C shape, and a pair of engagement pieces 12 facing the outer diameter direction are provided at both ends thereof. Each engagement piece 12 is inserted into a notch 14 provided at an end of the retainer 9 from a notch 13 formed in the cylindrical part 10 and faces the notch 13 and the notch 14 in the circumferential direction. By pressing the end surfaces in opposite directions, the retainer 9 is elastically held in a neutral position where the engaging element 8 is disengaged from the cylindrical surface 6 and the cam surface 7 by the pressing.

  An armature 15 that is opposed to the end face of the cage 9 in the axial direction is incorporated inside the outer ring 4. An engagement hole 16 is formed in the armature 15. On the other hand, a protrusion 17 that engages with the engagement hole 16 is provided on the end surface of the cage 9. Thus, the armature 15 is prevented from rotating with respect to the retainer 9 and is movable in the axial direction.

  A cylindrical rotor guide 18 made of a nonmagnetic material is fitted into the end of the outer ring 4. A rotor 19 that is axially opposed to the armature 15 is fitted in the rotor guide 18.

  The rotor 19 is made of a magnetic material. The rotor 19 is prevented from rotating with respect to the outer ring 4 and is supported rotatably relative to a sleeve 32 attached to an input shaft (not shown) by a bearing 31 incorporated on the inner diameter side thereof.

  The rotor 19 has a U-shaped cross section, and an elastic member 20 incorporated between the rotor 19 and the armature 15 presses the armature 15 in a direction away from the rotor 19.

  In the rotor 19, an electromagnet 21 is incorporated between cylindrical portions having different diameters. The electromagnet 21 has an electromagnetic coil 22, and an attractive force is applied to the armature 15 by energization of the electromagnetic coil 22 so as to be attracted and held by the rotor 19.

  The armature 15 is provided with a cylindrical portion 24 as a diameter reduction preventing member that is fitted inside the switch spring 11 to prevent the switch spring 11 from being reduced in a state where the electromagnetic coil 22 of the electromagnet 21 is cut off. .

  A tapered surface 25 is provided at the outer peripheral tip of the cylindrical portion 24, and the tapered surface 25 faces the switch spring 11 in the radial direction in a state where the armature 15 is adsorbed to the rotor 19, and the opposed state The switch spring 11 can be reduced in diameter.

  As described above, when the tapered surface 25 is formed on the outer periphery of the distal end portion of the cylindrical portion 24, the cylindrical portion 24 can be smoothly fitted inside the switch spring 11.

  In addition, the taper surface 25 can be omitted by regulating the length of the cylindrical portion 24 so as to come out from the inside of the switch spring 11 while the armature 15 is attracted to the rotor 19.

  The rotation transmission device shown in the embodiment has the above structure, and when the electromagnetic coil 22 of the electromagnet 21 is energized while the cam ring 1 is rotated in the direction indicated by the arrow in FIG. 2, an attractive force is applied to the armature 15. The armature 15 moves to the rotor 19 side against the elasticity of the elastic member 20, and the armature 15 is attracted to the rotor 19 and held in contact as shown in FIG. As a result, a rotational resistance is applied to the armature 15.

  At this time, since the armature 15 is prevented from rotating with respect to the cage 9, a rotational resistance is also applied to the cage 9, and the rotational resistance is preset to a value larger than the spring force of the switch spring 11. The cam ring 1 and the cage 9 rotate relative to the elasticity of the switch spring 11, and the engaging element 8 engages with the cylindrical surface 6 and the cam surface 7 by the relative rotation.

  For this reason, the rotation of the cam ring 1 is transmitted to the outer ring 4 via the engagement element 8, and the outer ring 4 rotates together with the cam ring 1.

  Here, when the cam ring 1 and the cage 9 rotate relative to each other, the pair of engaging pieces 12 formed at both ends of the switch spring 11 are pressed in directions approaching each other. At this time, since the cylindrical surface 24 provided in the armature 15 is in a state in which the tapered surface 25 faces the switch spring 11 in the radial direction, the switch 24 is pressed when the pair of engaging pieces 12 are pressed toward each other. The diameter of the spring 11 is reduced, and the relative rotation between the cam ring 1 and the cage 9 is not hindered by the reduced diameter, and the cam ring 1 and the cage 9 are smoothly rotated relative to each other.

  When the energization of the electromagnet 21 to the electromagnetic coil 22 is interrupted, the armature 15 moves away from the rotor 19 due to the elasticity of the elastic member 20, and the retainer 9 causes the engagement element 8 to move to the cylindrical surface by the spring force of the switch spring 11. 6 and the cam surface 7 are returned to the neutral position to be disengaged, the rotation transmission from the cam ring 1 to the outer ring 4 is cut off, and only the cam ring 1 or the outer ring 4 rotates in the rotation transmission device. It will be in the idling state which the outer ring | wheel 4 rotates with a relative rotation.

  Here, when the armature 15 moves in a direction away from the rotor 19 by the pressing of the elastic member 20, the cylindrical portion 24 provided on the armature 15 enters the inside of the switch spring 11 as shown in FIG.

  At this time, since the switch spring 11 is formed of a wire having a square cross section, the radial gap between the cylindrical portion 24 and the switch spring 11 is constant, and the cylindrical portion 24 smoothly enters the switch spring 11. The switch spring 11 is prevented from coming out, and the diameter of the switch spring 11 is prevented by the penetration.

  For this reason, when the rotation transmission device is idling, the cam ring 1 is rotated at a high speed, and the engaging member 8 that rotates together with the cam ring 1 comes into contact with the cylindrical surface 6 of the outer ring 4 by centrifugal force, and the drag torque acting on the contact portion is applied. Even when a rotational resistance exceeding the spring force of the switch spring 11 is applied to the cage 9, the cage 9 does not rotate relative to the cam ring 1, and misengagement of the engagement element 8 can be prevented.

  Further, due to the inertia of the retainer 9 and the engagement element 8 that are elastically coupled to the cam ring 1, the cam ring 1 cannot follow the rapid acceleration / deceleration rotation, and the cam ring 1, the retainer 9 and the engagement element 8 are relatively rotated. Can also be prevented.

  As shown in the above embodiment, by forming the switch spring 11 with a wire having a square cross section, the cylindrical portion 24 as a diameter reduction preventing member provided in the armature 15 can be easily fitted inside the switch spring 11. In addition, the cylindrical portion 24 smoothly and surely enters the switch spring 11 in a state where the energization to the electromagnet 21 is cut off, and prevents the switch spring 11 from being reduced in diameter. For this reason, a highly reliable rotation transmission device for preventing misengagement can be obtained.

  1 to 3, the cylindrical portion 24 is shown as a diameter reduction preventing member for preventing the diameter reduction of the switch spring 11, but the diameter reduction preventing member is not limited to this. 6 and 7 show another example of the diameter reduction preventing member. In this example, a projection 26 is provided on the surface of the armature 15 that faces the switch spring 11, and when the electromagnet 21 is turned off, the armature 15 is separated from the rotor 19 by the pressing of the elastic member 20 to switch the projection 26. The switch spring 11 is prevented from being reduced in diameter by being fitted between a pair of engagement pieces 12 provided at both ends of the spring 11.

  Also in this example, by forming the switch spring 11 with a wire having a square cross section, the protrusion 26 can smoothly enter between the pair of engaging pieces 12 of the switch spring 11. In this case, by providing tapered surfaces on both sides of the distal end portion of the protruding portion 26, the protruding portion 26 can be more smoothly intruded between the pair of engaging pieces 12.

  1 to 7, the cam surface 7 is provided on the outer periphery of the cam ring 1 and the cylindrical surface 6 is formed on the inner periphery of the outer ring 4. On the contrary, the cylindrical surface is provided on the outer periphery of the cam ring 1 and the outer ring 4. You may make it form a cam surface in the inner periphery.

  In this case, the switch spring 11 is incorporated on the inner diameter side of the cage 9, and a pair of engagement pieces 12 provided on both ends of the switch spring 11 are connected to the inner circumference of the outer ring 4 from the notches formed on the end surface of the cage 9. The notch and the circumferentially opposing end surfaces of the notch are pressed in opposite directions, and the retainer 9 is moved by the switch spring 11 between the engagement element 8 and the cylindrical surface and the cam surface. The neutral position is released from the engagement.

Longitudinal front view showing an embodiment of a rotation transmission device according to the present invention Sectional view along the line II-II in FIG. Sectional drawing which expands and shows the assembly part of the rotor and armature of FIG. Sectional view showing the suction release state of the rotor Sectional view showing the suction state of the rotor Sectional drawing which shows the other example of the diameter reduction prevention member which prevents the diameter reduction of a switch spring. Sectional drawing along the VII-VII line of FIG.

Explanation of symbols

1 Cam ring (input side member)
4 Outer ring (output side member)
6 cylindrical surface 7 cam surface 8 engaging element 9 cage 11 switch spring 12 engaging piece 13 notched portion 14 notched portion 15 armature 19 rotor 20 elastic member 21 electromagnet 24 cylindrical portion (diameter reduction preventing member)
26 Protrusion (diameter prevention member)

Claims (3)

An input side member and an output side member provided outside thereof are relatively rotatably supported, and a cylindrical surface is provided on one of the outer periphery of the input side member and the inner periphery of the output side member, and the cylindrical surface is provided on the other side. A cam surface that forms a wedge-shaped space between the cam surface and the cylindrical surface is held by a cage assembled between the input side member and the output side member, A pair of engaging pieces formed outward from both ends of the switch spring are pressed against the end faces facing in the circumferential direction of the notch formed in the retainer and the notch formed in the member having the cam surface. The retainer is elastically held in a neutral position where the engagement element is disengaged from the cylindrical surface and the cam surface, and the retainer is elastically held with respect to the retainer and supported so as to be movable in the axial direction. The rotor is axially opposed to the armature, and the rotor is An elastic member is provided to prevent rotation against the member having the cylindrical surface and press the armature in a direction away from the rotor, and an electromagnet that attracts the armature by energizing the rotor and opposes the rotor to the rotor In the rotation transmission device, the armature is provided with a diameter reduction preventing member that fits inside the switch spring when the armature moves in the axial direction by pressing the elastic member and prevents the diameter of the switch spring from being reduced.
The rotation transmission device, wherein the switch spring is formed of a wire having a square cross section.   The rotation transmission device according to claim 1, wherein the diameter-reducing prevention member includes a cylindrical portion that can be fitted inside the switch spring.   The rotation transmission device according to claim 1, wherein the diameter-reducing prevention member includes a protrusion that can be fitted between a pair of engagement pieces of a switch spring.

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