JP2019011868A - Adsorption structure of armature by electromagnet - Google Patents

Abstract

To provide a rotation transmission device which hardly generates a collision sound between an armature and a rotor, and is stabilized in a motion in which the armature is adsorbed to the rotor.SOLUTION: A cushioning member 50 is arranged between an armature 30 and a rotor 31. The cushioning member 50 is composed of a metal ring 51 which is movably supported to the armature 30 in an axial direction, and a rubber ring 52 which is compressed in the axial direction between the armature 30 and the metal ring 51 as the armature 30 approximates the rotor 31. The rubber ring 52 has a shape in which a thickness in the axial direction is changed along a peripheral direction so as to be compressed in a region which is long in the peripheral direction in the case that a compression amount in the axial direction is large compared with the case that the compression amount in the axial direction is small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an armature and rotor adsorption structure suitable for a rotation transmission device used for switching between rotation transmission and cutoff.

  As a rotation transmission device used for switching between a state in which rotation is transmitted from an input shaft to an output shaft and a state in which transmission of the rotation is interrupted, those disclosed in Patent Documents 1 and 2, for example, are known.

  The rotation transmission device described in Patent Document 1 is circumferentially opposed between an outer ring, an inner member disposed inside the outer ring, a cylindrical surface on the inner periphery of the outer ring, and a cam surface on the outer periphery of the inner member. A pair of rollers incorporated in such a manner, a spring member that presses each roller in a direction that widens the distance between the pair of rollers, and a roller holder that holds the pair of rollers.

  The roller holder is composed of two divided holders supported so as to be relatively rotatable. The two split cages individually support the pair of rollers so that the interval between the pair of rollers changes according to the relative rotation thereof, and by increasing the interval between the pair of rollers, An engagement position for engaging each roller between the inner circumferential cylindrical surface and the outer circumferential cam surface of the inner member, and the inner circumferential cylindrical surface and inner member of the outer ring by narrowing the distance between the pair of rollers. It is possible to move between an engagement release position for releasing the engagement of each roller with the cam surface on the outer periphery.

  The rotation transmission device also includes an armature that is supported so as to be movable in the axial direction as a means for moving the two split cages from the engagement position to the disengagement position, and is opposed to the armature in the axial direction. The rotor arranged in this way, the electromagnet that attracts the armature to the rotor by energization, and the operation that the armature is attracted to the rotor are converted into the operation that the two split cages move from the engagement position to the disengagement position. A ball ramp mechanism.

  Here, the armature is urged in a direction away from the rotor by the force of the spring member pressing each roller. That is, the force by which the spring member presses each roller in the direction of increasing the distance between the pair of rollers is transmitted to the two split cages, and the circumferential force received by the split cage is axially applied by the ball ramp mechanism. The armature is in a state in which a spring load is applied in a direction away from the rotor.

  The rotation transmission device of Patent Document 1 is in an engaged state in which rotation is transmitted between the outer ring and the inner member when energization to the electromagnet is stopped. That is, when energization of the electromagnet is stopped, the pair of rollers are pressed by the spring member in a direction in which the distance between the rollers is increased, so that each roller is inwardly connected to the inner circumferential cylindrical surface of the outer ring. It will be in the state engaged between the cam surfaces of the outer periphery of a member. When rotation is input to the outer ring or the inner member in this state, the rotation is transmitted between the outer ring and the inner member via a roller.

  On the other hand, when the electromagnet is energized, it is in the disengaged state (idling state) in which the rotation transmission between the outer ring and the inner member is interrupted. That is, when the electromagnet is energized, the armature is attracted to the rotor, and the two split cages rotate relative to each other in the direction of narrowing the distance between the pair of rollers in conjunction with the operation of the armature. In this state, the engagement of each roller with is released. Even if rotation is input to the outer ring or the inner member in this state, the rotation is not transmitted between the outer ring and the inner member.

  A rotation transmission device described in Patent Document 2 includes an outer ring, an inner member disposed inside the outer ring, a roller incorporated between an inner peripheral cylindrical surface of the outer ring and an outer peripheral cam surface of the inner member. And a roller holder for holding the roller. This roller retainer has an engagement position for engaging the roller between the inner cylindrical surface of the outer ring and the outer peripheral cam surface of the inner member, and an engagement release position for releasing the engagement of the roller. It is supported so that it can move in the circumferential direction. Further, the roller holder is held at the disengagement position by the force of the switch spring.

  In addition, the rotation transmission device is disposed as a means for moving the roller holder from the disengagement position to the engagement position, and is supported so as to be movable in the axial direction, and opposed to the armature in the axial direction. The rotor, the spring member that presses the armature away from the rotor, the electromagnet that attracts the armature to the rotor by energization, and the operation that the armature is attracted to the rotor. And a friction clutch mechanism for converting the movement to the movement.

  In the rotation transmission device of Patent Document 2, when energization to the electromagnet is stopped, the rotation transmission device between the outer ring and the inner member is disengaged (idling state) in which rotation transmission is interrupted. That is, when energization to the electromagnet is stopped, the roller cage is held at the disengagement position by the switch spring, so that the engagement of the roller between the outer ring and the inner member is released. Become. Even if rotation is input to the outer ring or the inner member in this state, the rotation is not transmitted between the outer ring and the inner member.

  On the other hand, when the electromagnet is energized, an engagement state is established in which rotation is transmitted between the outer ring and the inner member. That is, when the electromagnet is energized, the armature is attracted to the rotor, and the roller retainer moves from the disengagement position to the engagement position in conjunction with the operation of the armature, so that the roller is a cylindrical surface on the inner periphery of the outer ring. And the cam surface on the outer periphery of the inner member. When rotation is input to the outer ring or the inner member in this state, the rotation is transmitted between the outer ring and the inner member via a roller.

JP 2009-293654 A JP 2009-008172 A

  By the way, in the rotation transmission device as described above, when the armature is attracted to the rotor by energizing the electromagnet, a collision sound is generated between the armature and the rotor. In recent years, this collision noise is particularly problematic in the field of automobiles that require high noise reduction (for example, the field of backup clutches used in steer-by-wire steering systems).

  Therefore, the inventors of the present application have tried a configuration in which a rubber member is added between the armature and the rotor in the same rotation transmission device as that of Patent Document 1 in order to reduce the collision noise when the armature is attracted to the rotor. The work was produced in-house and evaluated. As a result of this test, it has been found that when a rubber member is added between the armature and the rotor, the operation of the armature may become unstable.

  That is, when the electromagnet is energized, not only the force attracted to the rotor by the energization of the electromagnet but also the force in the direction away from the rotor by the rubber member and the spring member acts. The armature is attracted to the rotor when the force with which the armature is attracted to the rotor exceeds the force in the direction away from the rotor.

  Here, the force with which the armature is attracted to the rotor by energizing the electromagnet changes according to the distance between the armature and the rotor, and increases as the armature approaches the rotor. This increase is gradual when the armature is relatively far from the rotor and abrupt when the armature is relatively close to the rotor. That is, the armature tends to accelerate greatly as it approaches the rotor.

  For this reason, if a rubber member having a small rubber compression load (ie, a force required to compress the rubber member) is used, acceleration of the armature just before the armature is attracted to the rotor cannot be suppressed. The impact noise of the rotor cannot be reduced effectively. On the other hand, when a rubber member with a large rubber compression load is used, the force in the direction away from the rotor that the armature receives from the rubber member and the spring member in the middle of the time when the armature starts moving toward the rotor and is attracted to the rotor, It has been found that energization of the electromagnet may temporarily exceed the force with which the armature is attracted to the rotor, and the armature may not be attracted to the rotor.

  Similarly, in the rotation transmission device of Patent Document 2, when a rubber member is added between the armature and the rotor in order to reduce the collision sound between the armature and the rotor, the operation of the armature may become unstable.

  The problem to be solved by the present invention is to provide a rotation transmission device in which the collision sound between the armature and the rotor is less likely to be generated, and the operation in which the armature is attracted to the rotor is stable.

In order to solve the above problems, in the present invention, the following configuration is employed in the rotation transmission device.
Outer ring,
An inner member disposed inside the outer ring and supported to be rotatable relative to the outer ring;
An engagement member incorporated between the inner periphery of the outer ring and the outer periphery of the inner member;
An engagement position for engaging the engagement element between the outer ring and the inner member so that rotation is transmitted between the outer ring and the inner member via the engagement element, and between the outer ring and the inner member. An engagement holder supported so as to be movable between an engagement release position for releasing the engagement of the engagement element so that rotation transmission of the engagement element is interrupted;
An armature supported so as to be movable in the axial direction;
A rotor supported so as not to move in the axial direction and disposed opposite to the armature in the axial direction;
A spring member for urging the armature in a direction away from the rotor;
An electromagnet for attracting the armature to the rotor by energization;
In the rotation transmission device having an operation conversion mechanism that converts an operation in which the armature is attracted to the rotor into an operation in which the engagement holder moves from one of the engagement position and the engagement release position to the other.
Provided between the armature and the rotor is a buffer member that absorbs an impact when the armature is attracted to the rotor;
The buffer member includes a metal ring supported by one of the armature and the rotor so as to be movable in the axial direction, and the metal ring of the armature and the rotor as the armature approaches the rotor. A rubber ring provided between both members so as to be compressed in the axial direction between the member that supports the metal ring and the metal ring,
The rubber ring has a shape in which the axial thickness changes along the circumferential direction so that when the axial compression amount is large, the rubber ring is compressed in a region longer in the circumferential direction than when the axial compression amount is small. A rotation transmission device comprising:

  In this way, the rubber ring has an axial thickness in the circumferential direction so that it is compressed in a region that is longer in the circumferential direction when the axial compression amount is larger than when the axial compression amount is small. Therefore, the method of increasing the force required to compress the rubber ring in the axial direction becomes gentle when the amount of axial compression of the rubber ring is small, and the amount of compression in the axial direction of the rubber ring is large. It becomes steep at the stage. Therefore, when the armature is attracted to the rotor by energizing the electromagnet, the force in the direction away from the rotor that the armature receives from the rubber ring and the spring member exceeds the force that the armature is attracted to the rotor by energizing the electromagnet As a result, the operation in which the armature is attracted to the rotor is stabilized. Further, the acceleration of the armature immediately before the armature is attracted to the rotor is effectively suppressed, and the collision noise between the armature and the rotor can be effectively reduced.

  In addition, when the armature is attracted to the rotor, the armature or rotor does not directly contact the rubber ring, but indirectly contacts the rubber ring via the metal ring. It is possible to ensure the durability of the rubber ring while using a rubber ring excellent in absorption performance.

  The rubber ring includes a ring-shaped base portion having a constant axial thickness, a first protrusion formed to protrude in the axial direction from the base portion at a plurality of positions spaced in the circumferential direction, and a circumferential direction. It is possible to employ one having a plurality of second protrusions that are formed to protrude in the axial direction from the base portion at a plurality of positions spaced apart from each other and at a height lower than that of the first protrusion.

  In this case, when the rubber ring is compressed in the axial direction, the compression amount of the rubber ring in the axial direction is relatively small (that is, the first protrusion is compressed in the axial direction. In the stage where the portion is not compressed in the axial direction, the method of increasing the force required to compress the rubber ring in the axial direction becomes gentle, and the amount of compression in the axial direction of the rubber ring is relatively large (that is, the first protrusion). In the stage where both the portion and the second protrusion are compressed in the axial direction), the method of increasing the force required to compress the rubber ring in the axial direction becomes abrupt. Then, by changing the dimensions of the first protrusion and the second protrusion, it is possible to easily adjust how the force required to compress the rubber ring in the axial direction is increased.

  In addition, the first protrusion and the second protrusion may be formed so as to be continuous without a gap in the circumferential direction, but the second protrusion is between the first protrusion and the second protrusion. Preferably, it is formed at a position away from the first protrusion in the circumferential direction so that a portion having a lower height than the second protrusion is formed.

  If it does in this way, since the 1st projection part is separated from the 2nd projection part via the part whose height is lower than the 2nd projection part, when the 1st projection part is compressed and deformed in the axial direction The space between the first protrusion and the second protrusion acts as a refuge for the first protrusion. Therefore, the first protrusion can be compressed with a small force.

  Preferably, the first protrusions are arranged at equal intervals in the circumferential direction, and the second protrusions are also arranged at equal intervals in the circumferential direction.

  If it does in this way, since a 1st projection part and a 2nd projection part are located in the circumferential direction at equal intervals, when a rubber ring is compressed to an axial direction, it is compressed uniformly, without bias. Therefore, the operation in which the armature is attracted to the rotor is extremely stable.

  The metal ring preferably has an annular plate portion to which the rubber ring is bonded and fixed, and an outer cylindrical portion that extends in the axial direction from the outer edge of the annular plate portion so as to cover the outer diameter side of the rubber ring. .

  In this case, in the unlikely event that a part of the rubber ring breaks into pieces, the outer cylindrical part of the metal ring receives the pieces of rubber ring. Can be prevented from being discharged.

  The metal ring may further include an annular inner protrusion extending from the inner edge of the annular plate portion to the side where the rubber ring is disposed.

  In this way, if a part of the rubber ring breaks into pieces, the inner protrusions can prevent the broken pieces from being discharged radially inward of the metal ring. It becomes possible to further improve the property.

  The rotation transmission device according to the present invention has an axial thickness so that the rubber ring is compressed in a region longer in the circumferential direction when the axial compression amount is larger than when the axial compression amount is small. Since it has a shape that changes along the circumferential direction, the method of increasing the force required to compress the rubber ring in the axial direction becomes gentle when the amount of compression in the axial direction of the rubber ring is small. It becomes steep when the amount of compression in the direction is large. Therefore, it is possible to effectively reduce the collision sound between the armature and the rotor, and at the same time stabilize the operation of the armature being attracted to the rotor.

Sectional drawing which shows the rotation transmission apparatus concerning embodiment of this invention Sectional view along the line II-II in FIG. Sectional drawing which expands and shows the vicinity of a pair of roller which opposes the circumferential direction on both sides of the spring member of FIG. Sectional view along line IV-IV in FIG. Sectional view along line VV in FIG. Sectional view along line VI-VI in FIG. 6A is a cross-sectional view taken along line VII-VII in FIG. 6, and FIG. 6B is a diagram illustrating that the ball shown in FIG. 6A rolls toward the deepest portion of each inclined groove, whereby the first split cage and the second Sectional view showing the state where the split cage of the relative rotation Sectional drawing which expands and shows the vicinity of the 1st projection part of the buffer member shown in FIG. Sectional drawing which expands and shows the vicinity of the 2nd projection part of the buffer member shown in FIG. FIG. 1 is a view of the buffer member shown in FIG. 1 taken out from the rubber ring side in the axial direction. Sectional view along line XI-XI in FIG. Sectional view along line XII-XII in FIG. Sectional view along line XIII-XIII in FIG. In the rotation transmission device according to the embodiment of the present invention, the force by which the armature is attracted to the rotor, the resultant force of the spring load and the rubber compression load, the spring load, and the rubber compression load depend on the distance between the armature and the rotor. Shows how each changes. In place of the rubber ring shown in FIGS. 10 to 13, when a rubber ring is used in which the circumferential length of the region compressed in the axial direction does not change regardless of the amount of compression in the axial direction, the armature is attracted to the rotor. The figure which showed how force, the resultant force of a spring load and a rubber compression load, a spring load, and a rubber compression load each change according to the distance between an armature and a rotor.

  FIG. 1 shows a rotation transmission device according to an embodiment of the present invention. The rotation transmission device includes an outer ring 1, an inner member 2 disposed inside the outer ring 1, and a plurality of rollers 3 a and 3 b incorporated between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2. The roller holder 4 holds the rollers 3a and 3b. An input shaft 5 is connected to the inner member 2, and an output shaft 6 is connected to the outer ring 1. The input shaft 5 and the output shaft 6 are arranged coaxially.

  The input shaft 5 has a serration shaft portion 7 having serrations formed on the outer periphery. The serration shaft portion 7 is fitted in a serration hole 8 formed at the center of the inner member 2. By fitting the serration shaft portion 7 and the serration hole 8, the input shaft 5 is connected to the inner member 2 so as to rotate integrally with the inner member 2. In this embodiment, the input shaft 5 and the inner member 2 are separate members. However, the input shaft 5 and the inner member 2 may be formed as a seamless integral member.

  The output shaft 6 is formed integrally with the outer ring 1. In this embodiment, the output shaft 6 and the outer ring 1 are integrally formed as a seamless member. However, the output shaft 6 and the outer ring 1 are separate members, and the output shaft 6 is attached to the outer ring 1 so as to rotate integrally with the outer ring 1. You may connect. A rolling bearing 9 is incorporated between the outer ring 1 and the inner member 2 to support the inner member 2 so as to be rotatable relative to the outer ring 1. A rolling bearing 11 that rotatably supports the output shaft 6 is incorporated in an end portion on the output shaft 6 side of the cylindrical housing 10 that houses the constituent members of the rotation transmission device.

  As shown in FIGS. 2 and 3, a plurality of cam surfaces 12 are provided on the outer periphery of the inner member 2 at equal intervals in the circumferential direction. The cam surface 12 includes a front cam surface 12a and a rear cam surface 12b disposed behind the inner member 2 in the forward rotation direction with respect to the front cam surface 12a. A cylindrical surface 13 that is opposed to the cam surface 12 in the radial direction is provided on the inner periphery of the outer ring 1.

  Between the cam surface 12 and the cylindrical surface 13, a pair of rollers 3 a and 3 b that are opposed to each other in the circumferential direction with a spring member 14 interposed therebetween is incorporated. Of the pair of rollers 3a and 3b, the forward roller 3a in the forward rotation direction is incorporated between the front cam surface 12a and the cylindrical surface 13, and the rear roller 3b in the forward rotation direction is the rear cam surface 12b and the cylindrical surface 13. Is built in between. Between this pair of rollers 3a, 3b, a spring member 14 is incorporated that presses each of the rollers 3a, 3b in the direction of increasing the distance between the pair of rollers 3a, 3b.

  The front cam surface 12a is formed such that the radial distance from the cylindrical surface 13 gradually decreases from the position of the roller 3a toward the front in the forward rotation direction. The rear cam surface 12b is formed such that the radial distance from the cylindrical surface 13 gradually decreases from the position of the roller 3b toward the rear in the forward rotation direction. In the figure, the front cam surface 12a and the rear cam surface 12b are formed so as to be separate planes inclined in opposite directions, but the front cam surface 12a and the rear cam surface 12b are forwardly rotated in a single plane. It is also possible to form on the same plane so that the front portion in the direction becomes the front cam surface 12a and the rear portion becomes the rear cam surface 12b. Further, the front cam surface 12a and the rear cam surface 12b can be curved surfaces. However, if the front cam surface 12a and the rear cam surface 12b are flat as shown in the figure, the processing cost can be reduced.

  As shown in FIGS. 1 to 3, the roller holder 4 is a first divided holder 4 </ b> A that supports one roller 3 a of a pair of rollers 3 a and 3 b that face each other in the circumferential direction with a spring member 14 therebetween. And a second divided holder 4B that supports the other roller 3b. The first divided holder 4A and the second divided holder 4B are supported so as to be rotatable relative to each other, and the pair of rollers 3a, 3b is changed so that the distance between the pair of rollers 3a, 3b changes according to the relative rotation. Are supported individually.

  4 A of 1st division | segmentation holder | retainers have the some pillar part 15a arrange | positioned at intervals in the circumferential direction, and the cyclic | annular flange part 16a which connects the edge parts of these pillar parts 15a. Similarly, the 2nd division | segmentation holder | retainer 4B also has the some pillar part 15b arrange | positioned at intervals in the circumferential direction, and the cyclic | annular flange part 16b which connects the edge parts of these pillar parts 15b.

  The column portion 15a of the first divided holder 4A and the column portion 15b of the second divided holder 4B sandwich the pair of rollers 3a and 3b opposed in the circumferential direction with the spring member 14 therebetween from both sides in the circumferential direction. Thus, it is inserted between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2.

  As shown in FIG. 1, the flange portion 16a of the first split cage 4A and the flange portion 16b of the second split cage 4B are the same as the flange portion 16b of the second split cage 4B. The 4A flange portion 16a is opposed to the inner member 2 in the direction closer to the axial direction and is opposed to the axial direction. The flange portion 16b of the second split cage 4B is provided with a plurality of notches 17 at intervals in the circumferential direction to avoid interference with the column portion 15a of the first split cage 4A. .

  The inner circumference of the flange portion 16a of the first split cage 4A and the inner circumference of the flange portion 16b of the second split cage 4B are respectively rotatably supported by a cylindrical surface 18 provided on the outer circumference of the input shaft 5. ing. As a result, the first divided holder 4A and the second divided holder 4B engage each roller 3a, 3b between the cylindrical surface 13 and the cam surface 12 by widening the distance between the pair of rollers 3a, 3b. Between the engagement position to be combined and the engagement release position for releasing the engagement of each roller 3a, 3b between the cylindrical surface 13 and the cam surface 12 by narrowing the distance between the pair of rollers 3a, 3b. It is movable. The flange portion 16a of the first split retainer 4A is supported in the axial direction by an annular protrusion 20 provided on the outer periphery of the input shaft 5 via a thrust bearing 19, thereby restricting movement in the axial direction. .

  As shown in FIG. 4, a side plate 21 is fixed to the side surface of the inner member 2. The side plate 21 has a stopper piece 22 positioned between both pillar portions 15a and 15b that are opposed to each other in the circumferential direction with the pair of rollers 3a and 3b interposed therebetween. In the stopper piece 22, when both the pillar portions 15a and 15b are moved in the direction of narrowing the distance between the pair of rollers 3a and 3b, the edges on both sides of the stopper piece 22 receive the pillar portions 15a and 15b. This prevents the spring member 14 between the pair of rollers 3a and 3b from being excessively compressed and broken, and each roller with respect to the inner member 2 when the distance between the pair of rollers 3a and 3b is narrowed. The positions of 3a and 3b can be made constant.

  As shown in FIG. 5, the side plate 21 has a spring holding piece 23 that holds the spring member 14. The spring holding piece 23 is formed integrally with the stopper piece 22 so as to extend in the axial direction between the inner circumference of the outer ring 1 and the outer circumference of the inner member 2. The spring holding piece 23 is disposed so as to face the spring support surface 24 (see FIG. 2) formed between the front cam surface 12a and the rear cam surface 12b on the outer periphery of the inner member 2 in the radial direction. Yes. A concave portion 25 for accommodating the spring member 14 is formed on the surface of the spring holding piece 23 facing the spring support surface 24. The spring member 14 is a coil spring. This spring holding piece 23 prevents the spring member 14 from dropping in the axial direction from between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2 by restricting the movement of the spring member 14 by the recess 25. ing.

  As shown in FIG. 1, this rotation transmission device is movable in the axial direction as means for moving the first divided holder 4A and the second divided holder 4B from the engaged position to the disengaged position. The armature 30 supported by the armature 30, the rotor 31 disposed so as to face the armature 30 in the axial direction, the electromagnet 32 for attracting the armature 30 to the rotor 31 by energization, and the operation for attracting the armature 30 to the rotor 31. The first split holder 4A and the second split holder 4B have a ball ramp mechanism 33 that converts the movement from the engagement position to the disengagement position.

  The armature 30 includes an annular disk portion 34 and a cylindrical portion 35 that is integrally formed so as to extend in the axial direction from the outer periphery of the disk portion 34. The cylindrical portion 35 of the armature 30 is press-fitted with a cylindrical portion 36 that is integrally formed so as to extend in the axial direction from the outer periphery of the flange portion 16b of the second split retainer 4B. The second divided holder 4B is connected to the second divided holder 4B so as to move integrally with the second divided holder 4B in the axial direction. The armature 30 is supported by a cylindrical surface 37 provided on the outer periphery of the input shaft 5 so as to be rotatable and movable in the axial direction. Here, the armature 30 is supported by the armature 30 so as to be movable in the axial direction at two locations separated in the axial direction (that is, the inner circumference of the armature 30 and the inner circumference of the second split cage 4B). Is prevented from tilting with respect to the direction perpendicular to the axis.

  The rotor 31 is disposed between the armature 30 and the electromagnet 32. Further, the rotor 31 is supported on the outer periphery of the input shaft 5 so as not to move in either the axial direction or the circumferential direction by fitting to the outer periphery of the input shaft 5 with a tightening margin. The rotor 31 and the armature 30 are made of a ferromagnetic metal. On the surface of the rotor 31 facing the armature 30, a plurality of long holes 38 that penetrate the rotor 31 in the axial direction and extend in the circumferential direction are formed at intervals in the circumferential direction.

  The electromagnet 32 includes a solenoid coil 39 and a field core 40 around which the solenoid coil 39 is wound. The field core 40 is inserted into the end portion of the housing 10 on the input shaft 5 side and is prevented from being detached by a retaining ring 41. A rolling bearing 42 that rotatably supports the input shaft 5 is incorporated in the inner periphery of the field core 40. The electromagnet 32 energizes the solenoid coil 39 to form a magnetic path that passes through the field core 40, the rotor 31, and the armature 30, and causes the armature 30 to be attracted to the rotor 31. At this time, the surface of the armature 30 facing the rotor 31 is in surface contact with the surface of the rotor 31 facing the armature 30.

  As shown in FIG. 6 and FIGS. 7A and 7B, the ball ramp mechanism 33 is formed on the surface of the flange portion 16a of the first divided holder 4A facing the flange portion 16b of the second divided holder 4B. The provided inclined groove 43a, the inclined groove 43b provided on the surface of the flange portion 16b of the second divided holder 4B facing the flange portion 16a of the first divided holder 4A, the inclined groove 43a and the inclined groove 43b. And a ball 44 incorporated between the two. The inclined groove 43a and the inclined groove 43b are formed so as to extend in the circumferential direction, respectively. In addition, the inclined groove 43a has a shape having a groove bottom 46a that is inclined so as to gradually become shallower in the circumferential direction from the deepest portion 45a having the deepest axial depth, and the inclined groove 43b is also axially The groove bottom 46b is inclined so as to gradually become shallower from the deepest portion 45b having the deepest depth toward the other direction in the circumferential direction. The ball 44 is disposed so as to be sandwiched between the groove bottom 46a and the groove bottom 46b.

  In the ball ramp mechanism 33, when the flange portion 16b of the second divided holder 4B is moved in the axial direction toward the flange portion 16a of the first divided holder 4A, the ball 44 is moved to the inclined grooves 43a, By rolling toward the deepest portions 45a and 45b of 43b, the first divided holder 4A and the second divided holder 4B rotate relative to each other. As a result, the first divided holder 4A and the column portion 15a of the first divided holder 4A It operates so that the column part 15b of the 2 division | segmentation holder | retainer 4B may move to the direction which narrows the space | interval of a pair of roller 3a, 3b.

  The armature 30 is biased in a direction away from the rotor 31 by the force of the spring member 14. That is, the force by which the spring member 14 shown in FIG. 2 presses the rollers 3a and 3b in the direction of increasing the distance between the pair of rollers 3a and 3b is transmitted to the first divided holder 4A and the second divided holder 4B. To do. The circumferential force received by the first divided holder 4A and the second divided holder 4B is the direction away from the rotor 31 by the ball ramp mechanism 33 shown in FIGS. 6 and 7A and 7B. Is converted to an axial force and transmitted to the second divided holder 4B. Here, as shown in FIG. 1, the armature 30 is fixed to the second divided holder 4 </ b> B, so that the armature 30 is eventually transmitted by the force transmitted from the spring member 14 via the ball ramp mechanism 33. It is in a state of being biased in a direction away from the rotor 31.

  As shown in FIG. 1, a buffer member 50 is provided between the armature 30 and the rotor 31 to absorb an impact when the armature 30 is attracted to the rotor 31.

  As shown in FIGS. 8 and 9, the buffer member 50 includes a metal ring 51 that is supported by the armature 30 so as to be movable in the axial direction, and between the armature 30 and the metal ring 51 as the armature 30 approaches the rotor 31. And a rubber ring 52 fixed to the metal ring 51 so as to be compressed in the axial direction. The metal ring 51 is made of stainless steel (for example, SUS304). The rubber ring 52 is formed of rubber (for example, ethylene propylene diene rubber (EPDM)).

  The metal ring 51 includes an annular plate portion 53 to which a rubber ring 52 is bonded and fixed, an outer cylindrical portion 54 that extends in the axial direction from the outer edge of the annular plate portion 53 so as to cover the outer diameter side of the rubber ring 52, and an annular plate portion. And an annular inner protrusion 55 extending from the inner edge of 53 to the side where the rubber ring 52 is disposed.

  On the other hand, the opposing surface of the armature 30 to the rotor 31 is provided with an annular recess 56 formed open to the outer periphery of the armature 30 and an annular groove 57 formed adjacent to the inner diameter side of the annular recess 56. Yes. In the metal ring 51, the annular plate portion 53 faces the axial direction with the annular recess 56 of the armature 30 and the rubber ring 52 interposed therebetween, and the outer cylindrical portion 54 faces the outer periphery of the armature 30 in the radial direction. As shown, the armature 30 is attached. Here, when the energization to the electromagnet 32 is stopped and the armature 30 is separated from the rotor 31, the annular plate portion 53 is more elastic than the opposing surface of the armature 30 to the rotor 31 by the elastic restoring force of the rubber ring 52. It is in a state of protruding to the side.

  As shown in FIG. 8, a retaining projection 59 that engages with a circumferential groove 58 formed on the outer periphery of the armature 30 is formed on the outer cylindrical portion 54 of the metal ring 51. The retaining protrusion 59 is in contact with the inner surface 60 of the circumferential groove 58 on the side close to the rotor 31, thereby restricting the movement range of the metal ring 51 in the direction approaching the rotor 31, and the buffer member 50 from the armature 30. Prevents falling off. The retaining protrusion 59 is formed by pressing the outer cylindrical portion 54 so that an opening penetrating the outer cylindrical portion 54 in the radial direction does not occur.

  The circumferential groove 58 on the outer periphery of the armature 30 has a shape with an axial play with respect to the retaining protrusion 59 so as to allow the axial movement of the metal ring 51 accompanying the compression of the rubber ring 52 in the axial direction. Has been. That is, the groove width of the circumferential groove 58 on the outer periphery of the armature 30 is larger than the axial width of the retaining protrusion 59 so that the retaining protrusion 59 can move in the direction away from the rotor 31 in the circumferential groove 58. Is set. Accordingly, when the rubber ring 52 is compressed in the axial direction, the retaining protrusion 59 is prevented from interfering with the inner side surface 61 of the circumferential groove 58 far from the rotor 31, and the metal accompanying the compression of the rubber ring 52 is prevented. The ring 51 can be moved in the axial direction.

  The annular groove 57 on the surface facing the rotor 31 of the armature 30 is disposed so as to face the inner protrusion 55 of the metal ring 51 in the axial direction. An axial gap is provided between the inner protrusion 55 and the annular groove 57 so that the inner protrusion 55 does not contact the inner surface of the annular groove 57 when the armature 30 is attracted to the rotor 31. Further, the inner protrusion 55 of the metal ring 51 is arranged such that the tip of the inner protrusion 55 is positioned in the annular recess 56 in a state where the retaining protrusion 59 is in contact with the inner surface 60 of the circumferential groove 58 on the side close to the rotor 31. (That is, the tip of the inner protrusion 55 is located on the inner side of the surface of the armature 30 facing the rotor 31).

  The rubber ring 52 is vulcanized and bonded to the surface of the annular plate portion 53 of the metal ring 51 opposite to the side in contact with the rotor 31. The rubber ring 52 has a shape in which the axial thickness changes along the circumferential direction so that the rubber ring 52 is compressed in a region longer in the circumferential direction when the axial compression amount is larger than when the axial compression amount is small. It is supposed to have.

  As the rubber ring 52 having such a shape, in this embodiment, as shown in FIGS. 10 to 13, an annular base portion 62 having a constant axial thickness and a plurality of positions spaced in the circumferential direction are provided. The first protrusion 63 is formed so as to protrude in the axial direction from the base portion 62, and protrudes in the axial direction from the base portion 62 at a plurality of positions spaced in the circumferential direction at a height lower than that of the first protrusion 63. What has the 2nd projection part 64 formed is employ | adopted. That is, when the rubber ring 52 is compressed in the axial direction, when the amount of compression is relatively small, only the first protrusion 63 of the first protrusion 63 and the second protrusion 64 is compressed in the axial direction. When the amount of compression is relatively large, both the first protrusion 63 and the second protrusion 64 are compressed in the axial direction. The base portion 62 has a trapezoidal cross section in which the radial width increases as the annular plate portion 53 is approached. Thereby, when the rubber ring 52 is compressed in the axial direction, the base portion 62 is prevented from being inclined with respect to the axial direction, and the first protruding portion 63 and the second protruding portion 64 are prevented from falling.

  As shown in FIG. 10, the first protrusion 63 and the second protrusion 64 are disposed on the same circumference. The circumferential length of the first projecting portion 63 is set so that the ratio of the first projecting portion 63 to the entire circumference is in the range of 10 to 20%, and the circumferential length of the second projecting portion 64 is set. The ratio of the second protrusion 64 to the entire circumference is set to be in the range of 50 to 75%. The first protrusions 63 are arranged at equal intervals in the circumferential direction, and the second protrusions 64 are also arranged at equal intervals in the circumferential direction.

  The second protrusion 64 is separated from the first protrusion 63 in the circumferential direction so that a portion 65 having a lower height than the second protrusion 64 is formed between the first protrusion 63 and the second protrusion 64. It is formed in the position. That is, a portion 65 having a height lower than that of the second protrusion 64 between the first protrusion 63 and the second protrusion 64 so that the distance between the first protrusion 63 and the second protrusion 64 is discontinuous. (In the figure, a portion having the same height as the base portion 62) is formed.

  As shown in FIG. 8, the height of the first protrusion 63 is such that the first protrusion 63 is annular even when the retaining protrusion 59 is in contact with the inner surface 60 of the circumferential groove 58 on the side close to the rotor 31. The height is set so as to maintain contact without being separated from the inner surface of the recess 56. Thereby, rattling of the buffer member 50 in a state where the armature 30 is separated from the rotor 31 is prevented.

  An operation example of this rotation transmission device will be described.

  As shown in FIG. 1, when energization of the electromagnet 32 is stopped, the rotation transmission device is in an engaged state in which rotation is transmitted between the outer ring 1 and the inner member 2. That is, the armature 30 is separated from the rotor 31 by the force of the spring member 14 when energization to the electromagnet 32 is stopped. At this time, the roller 3a on the front side in the forward rotation direction causes the cylindrical surface on the inner periphery of the outer ring 1 by the force of the spring member 14 that presses the rollers 3a and 3b in the direction in which the distance between the pair of rollers 3a and 3b increases. 13 and the front cam surface 12a on the outer periphery of the inner member 2, and the roller 3b on the rear side in the forward rotation direction is connected to the cylindrical surface 13 on the inner periphery of the outer ring 1 and the outer periphery of the inner member 2. Between the rear cam surface 12b and the rear cam surface 12b. In this state, when the inner member 2 rotates in the forward rotation direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the roller 3b on the rear side in the forward rotation direction. When the inner member 2 rotates in the reverse direction, the rotation is transmitted from the inner member 2 to the outer ring 1 via the roller 3a on the front side in the forward direction.

  On the other hand, when the electromagnet 32 is energized, the rotation transmission device is in the disengaged state (idling state) in which the rotation transmission between the outer ring 1 and the inner member 2 is blocked. That is, when the electromagnet 32 is energized, the armature 30 is attracted to the rotor 31, and in conjunction with the operation of the armature 30, the flange portion 16b of the second split holder 4B is connected to the flange portion 16a of the first split holder 4A. Move axially toward At this time, the ball 44 of the ball ramp mechanism 33 rolls toward the deepest portions 45a and 45b of the inclined grooves 43a and 43b, so that the first divided holder 4A and the second divided holder 4B rotate relative to each other. . Then, due to the relative rotation of the first divided holder 4A and the second divided holder 4B, a pair of the column portion 15a of the first divided holder 4A and the column portion 15b of the second divided holder 4B are paired. The rollers 3a and 3b are pressed in the direction in which the distance between the rollers 3a and 3b is reduced, and as a result, the positive contact between the inner circumferential cylindrical surface 13 of the outer ring 1 and the outer front cam surface 12a of the inner member 2 is positive. The engagement of the roller 3a on the front side in the rolling direction is released, and the roller on the rear side in the forward direction between the cylindrical surface 13 on the inner periphery of the outer ring 1 and the rear cam surface 12b on the outer periphery of the inner member 2 The engagement of 3b is also released. In this state, even if rotation is input to the inner member 2, the rotation is not transmitted from the inner member 2 to the outer ring 1, and the inner member 2 idles.

  By the way, when the electromagnet 32 is energized, not only a force attracted to the rotor 31 by the energization of the electromagnet 32 but also a force in a direction away from the rotor 31 by the rubber ring 52 and the spring member 14 acts. The armature 30 is attracted to the rotor 31 when the force that the armature 30 is attracted to the rotor 31 by energizing the electromagnet 32 exceeds the force in the direction away from the rotor 31 by the rubber ring 52 and the spring member 14.

  Here, as shown in FIGS. 14 and 15, the force with which the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32 changes according to the distance between the armature 30 and the rotor 31, and the armature 30 approaches the rotor 31. Increase according to. This increase is gradual when the armature 30 is relatively far from the rotor 31, and is abrupt when the armature 30 is relatively close to the rotor 31. That is, the armature 30 tends to accelerate greatly as it approaches the rotor 31.

  On the other hand, a force that biases the armature 30 away from the rotor 31 by the spring member 14 (hereinafter referred to as “spring load”) and a force required to compress the rubber ring 52 in the axial direction (hereinafter referred to as “rubber compression load”). Also increases as the armature 30 approaches the rotor 31. The manner of increasing the spring load is approximately constant and linear. The method of increasing the rubber compression load is also a rubber ring in which the circumferential length of the region compressed in the axial direction does not change regardless of the amount of compression in the axial direction (for example, a rubber ring whose axial thickness is constant over the entire circumference) Is used, it is approximately constant and linear as shown in FIG.

  Therefore, if a rubber ring in which the circumferential length of the region compressed in the axial direction is not changed regardless of the amount of compression in the axial direction is used instead of the rubber ring 52 in the above embodiment, as shown in FIG. In addition, in a stage where the distance between the armature 30 and the rotor 31 is relatively long (a region indicated by symbol A in the drawing), the force (spring load) in the direction in which the armature 30 is separated from the rotor 31 received from the rubber ring 52 and the spring member 14. There is a possibility that the + rubber compression load) temporarily exceeds the force (attraction force by the electromagnet) that the armature 30 is attracted to the rotor 31 by energizing the electromagnet 32. At this time, the armature 30 is not attracted to the rotor 31 and the operation of the armature 30 may become unstable.

  On the other hand, in the rotation transmission device of the above-described embodiment, the axial thickness is such that when the axial compression amount is large, the compression is performed in a longer region in the circumferential direction than when the axial compression amount is small. Since the rubber ring 52 that changes along the circumferential direction is used, as shown in FIG. 14, the compression amount of the rubber ring 52 in the axial direction is small (that is, the first protrusion 63 is compressed in the axial direction). However, when the second protrusion 64 is not compressed in the axial direction (in FIG. 14, the gap between the armature 30 and the rotor 31 corresponds to about 0.2 mm to 0.5 mm), the rubber compression load increases. 14 is a step where the amount of compression of the rubber ring 52 in the axial direction is large (that is, a step where both the first protrusion 63 and the second protrusion 64 are compressed in the axial direction. In FIG. The gap between the rotors 31 In step) corresponding to 0Mm～0.2Mm, how an increase in the rubber compression load becomes steeper. Therefore, when the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32, a force (spring load + rubber compression load) in a direction away from the rotor 31 that the armature 30 receives from the rubber ring 52 and the spring member 14 is A situation in which the armature 30 is attracted to the rotor 31 by energization of the electromagnet 32 (attraction force by the electromagnet) is prevented, and as a result, the operation of attracting the armature 30 to the rotor 31 is stabilized. Further, the acceleration of the armature 30 immediately before the armature 30 is attracted to the rotor 31 is effectively suppressed, and the collision sound between the armature 30 and the rotor 31 can be effectively reduced.

  Moreover, when the armature 30 is adsorbed to the rotor 31, the armature 30 or the rotor 31 does not directly contact the rubber ring 52 but indirectly contacts the rubber ring 52 via the metal ring 51. It is possible to ensure the durability of the rubber ring 52 while using the rubber ring 52 that is superior in impact absorption performance compared to the elastic member.

  Moreover, in the rotation transmission apparatus of the said embodiment, as shown in FIGS. 10-13, from the base part 62 in the cyclic | annular base part 62 which has fixed axial direction thickness, and the multiple positions spaced in the circumferential direction. A first protrusion 63 that protrudes in the axial direction and a second protrusion that protrudes in the axial direction at a plurality of positions spaced in the circumferential direction from the base 62 at a height lower than that of the first protrusion 63. Since the rubber ring 52 having the protrusion 64 is employed, the rubber ring 52 is moved in the axial direction by changing the dimensions (particularly the circumferential length) of the first protrusion 63 and the second protrusion 64, respectively. It is possible to easily adjust how the force required to compress is increased.

  Although it is possible to form the first protrusion 63 and the second protrusion 64 so as to be continuous with no gap in the circumferential direction, in this embodiment, as shown in FIG. The second protrusion 64 is formed at a position away from the first protrusion 63 in the circumferential direction so that a portion 65 having a height lower than that of the second protrusion 64 is formed between the two protrusions 64. If it does in this way, since the 1st projection part 63 is separated from the 2nd projection part 64 via the part 65 lower in height than the 2nd projection part 64, the 1st projection part 63 is compressed to an axial direction. Thus, the space between the first protrusion 63 and the second protrusion 64 acts as a refuge for the first protrusion 63. Therefore, it is possible to compress the first protrusion 63 with a small force.

  In the rotation transmission device of the above embodiment, as shown in FIG. 10, the first protrusion 63 and the second protrusion 64 are both arranged at equal intervals in the circumferential direction, so that the rubber ring 52 is the shaft. When compressed in the direction, it is uniformly compressed without bias. Therefore, the operation in which the armature 30 is attracted to the rotor 31 becomes extremely stable.

  In the rotation transmission device of the above embodiment, as shown in FIGS. 8 and 9, the metal ring 51 has the outer cylindrical portion 54 extending so as to cover the outer diameter side of the rubber ring 52. When a part of 52 is broken into pieces, the pieces are received by the outer cylindrical portion 54 of the metal ring 51, and the pieces of the rubber ring 52 are prevented from being discharged as foreign matter to the outside of the metal ring 51. can do. As a result, it is possible to prevent poor engagement of the rollers 3a and 3b due to mixing of pieces of the rubber ring 52.

  Further, in the rotation transmission device of the above embodiment, since the metal ring 51 has the annular inner protrusion 55 extending from the inner edge of the annular plate portion 53, a part of the rubber ring 52 is broken and broken. Sometimes, the fragments can be prevented from being discharged radially inward of the metal ring 51. As a result, it is possible to more effectively prevent the engagement failure of the rollers 3a and 3b due to mixing of the pieces of the rubber ring 52.

  In the above embodiment, the buffer member 50 is mounted on the armature 30, but the buffer member 50 may be mounted on the rotor 31 instead of the armature 30.

  In the above embodiment, the ball ramp mechanism 33 is employed as an operation conversion mechanism that converts the operation of the armature 30 being attracted to the rotor 31 into the operation of the roller holder 4 moving from the engagement position to the engagement release position. However, other types of motion conversion mechanisms may be employed. For example, you may employ | adopt a friction clutch mechanism like patent document 2. FIG.

  Moreover, in the said embodiment, although the cylindrical surface 13 is provided in the inner periphery of the outer ring | wheel 1 and the cam surface 12 is provided in the outer periphery of the inner member 2, the cam surface 12 (front cam surface 12a and the inner periphery of the outer ring 1 is provided. A rear cam surface 12b) is provided, a cylindrical surface 13 is provided on the outer periphery of the inner member 2, and a pair of rollers 3a, 3b is provided between the inner peripheral cam surface 12 of the outer ring 1 and the outer peripheral cylindrical surface 13 of the inner member 2. May be incorporated.

  In the above embodiment, the rollers 3a and 3b are employed as the engaging members incorporated between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2, but it is also possible to employ engaging members other than the rollers. . For example, between the cylindrical surface formed on the inner periphery of the outer ring 1 and the cylindrical surface formed on the outer periphery of the inner member 2, it engages between the inner periphery of the outer ring 1 and the outer periphery of the inner member 2 in a standing state. A plurality of sprags (not shown) having a shape whose height dimension changes according to the posture can be incorporated so that the engagement is released in the lying state.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner member 3a, 3b Roller 4 Roller retainer 14 Spring member 30 Armature 31 Rotor 32 Electromagnet 33 Ball ramp mechanism 50 Buffer member 51 Metal ring 52 Rubber ring 53 Annular plate part 54 Outer cylinder part 55 Inner protrusion 62 Base part 63 1st projection part 64 2nd projection part 65 The part whose height is lower than the 2nd projection part 64

The present invention relates to an armature adsorption structure using an electromagnet .

Claims (6)

An axially supported armature (30);
A rotor (31) supported so as not to move in the axial direction and disposed opposite to the armature (30) in the axial direction;
A spring member (14) for biasing the armature (30) away from the rotor (31);
An electromagnet (32) for attracting the armature (30) to the rotor (31) by energization;
In the armature and rotor adsorption structure having
Provided between the armature (30) and the rotor (31) is a buffer member (50) for absorbing an impact when the armature (30) is attracted to the rotor (31),
The buffer member (50) includes a metal ring (51) supported on one of the armature (30) and the rotor (31) so as to be movable in the axial direction, and the armature (30) As the rotor (31) is approached, the armature (30) and the rotor (31) are compressed in the axial direction between the metal ring (51) and a member that supports the metal ring (51). A rubber ring (52) provided between the two members,
The rubber ring (52) has an axial thickness along the circumferential direction so that when the axial compression amount is larger than when the axial compression amount is small, the rubber ring (52) is compressed in a region longer in the circumferential direction. Armature and rotor adsorption structure characterized by having a changing shape.   The rubber ring (52) is formed to protrude in the axial direction from the base portion (62) at a plurality of positions spaced in the circumferential direction, and an annular base portion (62) having a constant axial thickness. A first protrusion (63) and a second protrusion that protrudes in the axial direction from the base portion (62) at a plurality of positions spaced in the circumferential direction with a height lower than that of the first protrusion (63). The armature and rotor adsorption structure according to claim 1, further comprising a protrusion (64).   In the second protrusion (64), a lower portion (65) than the second protrusion (64) is formed between the first protrusion (63) and the second protrusion (64). The armature and rotor adsorbing structure according to claim 2, wherein the armature and rotor adsorbing structure is formed at a position away from the first protrusion (63) in the circumferential direction.   The said 1st projection part (63) is arrange | positioned so that it may become equal intervals in the circumferential direction, and the said 2nd projection part (64) is also arrange | positioned so that it may become equal intervals in the circumferential direction. Adsorption structure of armature and rotor.   The metal ring (51) includes an annular plate portion (53) to which the rubber ring (52) is bonded and fixed, and an outer edge of the annular plate portion (53) so as to cover the outer diameter side of the rubber ring (52). The armature / rotor adsorbing structure according to any one of claims 1 to 4, further comprising an outer cylindrical portion (54) extending in an axial direction from the armature.   The armature and the rotor according to claim 5, wherein the metal ring (51) further includes an annular inner protrusion (55) extending from an inner edge of the annular plate portion (53) to a side where the rubber ring (52) is disposed. Adsorption structure.

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