JP2019199925A - Rotary damper - Google Patents

Abstract

To provide a rotary damper capable of increasing braking torque per unit weight and decreasing current consumption while being able to control the braking torque.SOLUTION: A rotary damper includes: a torque generation unit 7 positioned between a relatively rotatable case 3 and a rotor 5 and generating brake torque for relative rotation between the case 3 and the rotor 5 by fastening; a driving source 9 for generating driving force to fasten the torque generation unit 7 in accordance with power feeding; an irreversible speed reduction mechanism 11 for decelerating the driving force from the driving source 9 and outputting the driving force; and a ball cam mechanism 13 positioned between the speed reduction mechanism 11 and the torque generation unit 7 for generating fastening force to the torque generation unit 7 in accordance with an output of the speed reduction mechanism 11. The ball cam mechanism 13 is formed in a spiral shape with a cam groove 73 gradually deflected inward in a radial direction with respect to rotation directions of first and second cam plates 71a, 71b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary damper capable of controlling a damping force.

  As a conventional rotary damper, as disclosed in Patent Document 1, a rotating body having a blade is provided in a housing filled with viscous oil, and braking torque (damping force) is generated by a resistance that the blade receives from the oil when the rotating body rotates. There are things that give rise to.

  However, such a rotary damper has a problem that the braking torque is small and cannot be controlled.

  On the other hand, there is a rotary damper using a magnetorheological fluid as in Patent Document 2. The rotary damper accommodates a rotatable shaft in a case and is filled with a magnetorheological fluid, and generates a controllable braking torque by applying a magnetic field to the magnetorheological fluid by an electromagnetic coil.

  However, the rotary damper disclosed in Patent Document 2 has a problem that the braking torque per unit weight is small, and that the weight increases remarkably when the braking torque is increased. In addition, when braking torque is generated, it is necessary to always supply current to the electromagnetic coil, which causes a problem that current consumption is large.

Japanese Utility Model Publication No. 6-35693 JP 2008-202744 A

  The problem to be solved is that if the braking torque can be controlled, the braking torque per unit weight is small and the current consumption is large.

  According to a first aspect of the present invention, in order to increase the braking torque per unit weight and reduce the current consumption while controlling the braking torque, the inner rotating member and the outer rotating member that are relatively rotatable are provided. A torque generating unit that is disposed between the inner rotating member and the outer rotating member and generates a braking torque for the relative rotation by fastening, and a driving source that generates a driving force for fastening the torque generating unit according to power supply And a ball cam mechanism for generating a fastening force for the torque generating portion by the output of the drive source, the ball cam mechanism being respectively provided on the first and second cam plates and the first and second cam plates. A cam groove that is provided and gradually deviates inward in the radial direction with respect to the rotation direction of the first and second cam plates, and is disposed between the first and second cam plates. And a cam ball that engages the intersection of the cam groove of the first and second cam plates, characterized in that.

  Further, the second aspect of the present invention includes an inner rotating member and an outer rotating member that are relatively rotatable, and a torque generator that is disposed between the inner rotating member and the outer rotating member and generates a braking torque for the relative rotation by fastening. A driving source that generates a driving force for fastening the torque generator in response to power supply, an irreversible reduction mechanism that decelerates and outputs the driving force from the driving source, the reduction mechanism, A ball cam mechanism arranged between the torque generating unit and generating a fastening force to the torque generating unit in accordance with an output of the speed reducing mechanism, wherein the ball cam mechanism is provided on the speed reducing mechanism side and the torque generating unit side, respectively. First and second cam plates provided, and provided on the first and second cam plates, respectively, gradually inward in the radial direction with respect to the rotation direction of the first and second cam plates. The rotary damper is provided with a cam groove that folds and a cam ball that is disposed between the first and second cam plates and engages with an intersection of the cam grooves of the first and second cam plates. Main features.

  The rotary damper according to the first aspect of the present invention can increase the braking torque per unit weight by the torque generator that generates the braking torque by fastening, while the braking torque can be controlled by the power supply control of the drive source.

  In addition, by holding the cam ball at the intersection of the cam groove of the ball cam mechanism, it is not necessary to provide a separate member for holding the cam ball, and the braking torque per unit weight can be increased accordingly.

  Further, since the cam ball is naturally positioned at the intersection of the cam grooves, the operation can be made smooth.

  Moreover, the cam groove can be lengthened by gradually deviating inward in the radial direction, thereby making it possible to generate a large fastening force while reducing the cam groove inclination and reducing the drive torque of the drive source.

  Therefore, the braking torque per unit weight can be reduced more reliably and the power consumption can be reduced.

  In addition to the effects of the first aspect, the rotary damper according to the second aspect of the present invention can reduce the current consumption because the fastening force does not change even if power is stopped by the irreversible deceleration mechanism. it can.

(Example 1) which is sectional drawing of a rotation damper. (Example 1) which is a top view which shows the cam plate used for the rotary damper of FIG. (Example 1) which is a top view which shows the cam plate used for the rotary damper which concerns on a modification. (Example 1) which is a conceptual diagram which shows the relative positional relationship of the cam groove which the 1st and 2nd cam plates oppose. (Example 2) which is sectional drawing of a rotation damper. (Example 2) which is a top view which shows the cam plate used for the rotary damper of FIG.

  The objectives of increasing the braking torque per unit weight and reducing the current consumption while controlling the braking torque are realized by a rotary damper using a torque generator that generates the braking torque by fastening.

  Specifically, an inner rotating member and an outer rotating member capable of relative rotation, a torque generating unit that is disposed between the inner rotating member and the outer rotating member and generates a braking torque for relative rotation by fastening, and torque generation according to power supply A driving source for generating a driving force for fastening the portion and a ball cam mechanism for generating a fastening force for the torque generating portion by the output of the driving source.

  The ball cam mechanism is provided on the first and second cam plates and the cam grooves provided on the first and second cam plates, respectively, and gradually deviating inward in the radial direction with respect to the rotation directions of the first and second cam plates. And a cam ball that is disposed between the first and second cam plates and engages with the intersection of the cam grooves of the first and second cam plates.

  The rotating damper includes an inner rotating member and an outer rotating member that are relatively rotatable, a torque generating unit that is disposed between the inner rotating member and the outer rotating member, and generates a braking torque with respect to the relative rotation between the rotating member and the torque generating unit. A drive source for fastening the motor, an irreversible speed reduction mechanism that decelerates and outputs the driving force from the drive source, and a torque that is arranged between the speed reduction mechanism and the torque generation unit according to the output of the speed reduction mechanism A ball cam mechanism for fastening the parts.

  The ball cam mechanism includes first and second cam plates provided on the speed reduction mechanism side and the torque generating unit side, and rotation directions of the first and second cam plates provided on the first and second cam plates, respectively. The cam groove is gradually biased inward in the radial direction, and the cam ball is disposed between the first and second cam plates and engages with the cam groove.

  The shape of the cam groove can be a linear shape, a curved shape, or the like as long as it is a shape that gradually deviates inward in the radial direction with respect to the rotation direction of the first and second cam plates.

  The cam grooves provided in the first and second cam plates are preferably curved in a reverse spiral shape.

  The cam groove may be formed so as to be gradually shallow toward either the inner side or the outer side in the radial direction, but it is preferable to gradually reduce the cam groove toward the inner side in the radial direction.

  A plurality of cam grooves may be formed in each of the first and second cam plates, and two or more cam grooves may overlap in the radial direction in each of the first and second cam plates.

  The speed reduction mechanism only needs to be irreversible, and a worm gear, a differential gear, or the like can be used.

  In the case of a differential gear, the speed reduction mechanism includes an input gear that is rotationally driven by a drive source, and a pair of output gears that are provided integrally with the first and second cam plates of the ball cam mechanism and that have different numbers of teeth that mesh with the input gear. It is good also as a structure provided with.

  Further, the outer rotating member includes a rotating shaft that supports the shaft center portion of the inner rotating member so as to be relatively rotatable in the shaft center portion, and the first and second cam plates include an opening portion in the shaft center portion. It is good also as a structure which penetrated the rotating shaft and was supported by the opening part.

  In the case of a worm gear, the speed reduction mechanism may include a worm that is rotationally driven by a drive source, and a worm wheel that meshes with the worm gear and rotates the first cam plate of the ball cam mechanism.

  Further, the first cam plate includes a support shaft portion that supports the shaft center portion of the inner rotation member so as to be relatively rotatable in the shaft center portion, and the second cam plate has a shaft center direction on the inner periphery of the outer rotation member. It is good also as a structure engaged with slidably.

[Structure of rotating damper]
1 is a cross-sectional view of a rotary damper according to a first embodiment of the present invention.

  The rotary damper 1 of the present embodiment includes a case 3 that is an outer rotating member, a rotating body 5 that is an inner rotating member, a torque generator 7, a drive source 9, a speed reduction mechanism 11, and a ball cam mechanism 13. ing.

  The case 3 has a configuration in which a cylindrical case body 15 is provided with an integral one end wall portion 17 on one side in the axial direction, and the other side is closed by a separate other end wall portion 19. Lubricating oil is enclosed in the case 3. The axial direction means a direction along the axial center of the case 3. The radial direction means a direction along the diameter of the case 3 that intersects the axial direction.

  The other end wall portion 19 is fixed with a flange 20 fastened to a flange 22 of the case body 15 by a bolt 21. The other end wall portion 19 is integrally provided with a rotating shaft 23 protruding into the case 3 at the shaft center portion. The rotating body 5 is supported on the rotating shaft 23 so as to be rotatable about the axis. Therefore, the case 3 has a configuration in which the rotation shaft 23 that supports the shaft portion of the rotating body 5 so as to be relatively rotatable is provided on the shaft portion.

  The rotating body 5 is formed in a cylindrical shape, and is inserted through the inside and outside of the case 3. The space between the rotating body 5 and the case 3 is sealed by a seal member 25 held by one end wall portion 17 of the case 3.

  In the rotating body 5, the inner end portion 27 located in the case 3 has a concave portion 29 in the axial center portion. The recess 29 engages with the rotating shaft 23 of the case 3 so that the rotating body 5 is rotatably supported.

  The rotating shaft 23 is supported on the inner periphery of the one end wall portion 17 of the case 3 via a bearing 31. Accordingly, the rotating body 5 is rotatable relative to the case 3. The bearing 31 is disposed inside the case 3 adjacent to the seal member 25.

  The rotating body 5 has a step portion 35 between the bearing 31 and the seal member 25, and the step portion 35 to the outer end portion 37 outside the case 3 are formed with a slightly smaller diameter than the inner end portion 27 side. Has been. The outer end 37 of the rotating body 5 is coupled to the object and receives input from the object.

  In response to the relative rotation between the rotating body 5 and the case 3 due to this input, the torque generator 7 disposed between the rotating body 5 and the case 3 generates a braking torque by fastening.

  The torque generating unit 7 of this embodiment includes a friction unit 39 and a pressing plate 41.

  The friction part 39 includes a plurality of outer plates 43, a plurality of inner plates 45, and a plurality of friction members 47.

  The plurality of outer plates 43 are formed in a ring shape, and an outer peripheral recessed portion 49 is engaged with a pin 51 fixed to the inner periphery of the case 3 so as to be slidable in the axial direction.

  The plurality of inner plates 45 have ring shapes that are slidable in the axial direction with the female splines 55 engaged with the male splines 53 on the outer periphery of the rotating body 5, and are disposed between the adjacent outer plates 43.

  The plurality of friction members 47 are ring-shaped attached to one of the outer plate 43 and the inner plate 45, and generate a braking torque due to the friction force between the outer plate 43 and the inner plate 45 according to the fastening force. Let

  The pressing plate 41 is disposed at the end of the friction part 39. The pressing plate 41 is formed in a ring shape, and, like the outer plate 43, is engaged with a pin 51 on the inner periphery of the case 3 so as to be slidable in the axial direction by a recess 57 provided on the outer periphery. The pressing plate 41 fastens the friction portion 39 to the one end wall portion 17 of the case 3 by sliding to one side in the axial direction.

  The pressing plate 41 is slid by the driving torque (driving force) of the driving source 9 via the speed reduction mechanism 11 and the ball cam mechanism 13.

  The drive source 9 is composed of an electric motor and operates with power supplied from a power source (not shown). Thereby, the drive source 9 produces | generates the drive torque for fastening the torque generation part 7 by electric power feeding.

  The drive source 9 is fixed to the other end wall portion 19 of the case 3. With respect to the other end wall portion 19 of the case 3, the drive source 9 is disposed along the axial center direction of the case 3 and biased radially outward with respect to the axial center of the case 3.

  The output shaft 59 of the drive source 9 passes through the other end wall portion 19 of the case 3 and is positioned in the case 3. The speed reduction mechanism 11 is connected to the output shaft 59 of the drive source 9 in the case 3.

  The deceleration mechanism 11 is irreversible with zero reverse efficiency, and decelerates and outputs the drive torque from the drive source 9. The speed reduction mechanism 11 of this embodiment is a differential gear mechanism, and includes an input gear 61 and a pair of output gears 63a and 63b.

  The input gear 61 is coupled to the output shaft 59 of the drive source 9 so as to rotate integrally. Therefore, the input gear 61 is rotationally driven by the drive source. The input gear 61 is arranged biased on the outer peripheral side of the case 3 according to the position of the drive source 9. In response to this, the case 3 has a bulging portion 65 bulging outward in the radial direction so as to avoid the input gear 61. The bulging portion 65 bulges within the range of the fastening flange 20 of the other end wall portion 19 with respect to the case main body 15, and suppresses the expansion of the outer diameter. The input gear 61 is engaged with a pair of output gears 63a and 63b.

  The output gears 63a and 63b are provided on the outer periphery of the disk-shaped main body portions 67a and 67b. The body portions 67a and 67b of the output gears 63a and 63b are provided with openings 69a and 69b at the shaft center portions, and the rotation shaft 23 of the case 3 is inserted into the openings 69a and 69b and is rotatably supported. ing. The details of the body portions 67a and 67b of the output gears 63a and 63b will be described later as cam plates 71a and 71b.

  These output gears 63a and 63b have different numbers of teeth. In the present embodiment, the number of teeth of the output gears 63a and 63b is 50 and 51, and one more output gear 63b is set. Due to the number of teeth, the output gears 63a and 63b are configured to rotate relative to each other while rotating in the same direction according to the input gear 61.

  The ball cam mechanism 13 is disposed between the speed reduction mechanism 11 and the torque generation unit 7, and generates a fastening force for the torque generation unit 7 according to the output of the speed reduction mechanism 11. The ball cam mechanism 13 of this embodiment includes first and second cam plates 71a and 71b, cam grooves 73 provided in the cam plates 71a and 71b, and cam balls 75 engaged with the cam grooves 73. .

  The cam plates 71a and 71b are constituted by main body portions 67a and 67b of output gears 63a and 63b. Therefore, the cam plates 71a and 71b are disk-like as a whole, and the output gears 63a and 63b are integrally provided. Accordingly, the cam plates 71a and 71b are supported through the rotation shaft 23 through the openings 69a and 69b in the inner peripheral portion so as to be separated from each other and to be rotatable.

  The outer peripheral portions of the cam plates 71a and 71b are formed thinner in the axial direction than the inner peripheral portion. The outer peripheral portions of the cam plates 71a and 71b have flat cam surfaces 77a and 77b, and are opposed to each other with a cam ball 75 interposed between the cam surfaces 77a and 77b.

  Stepped portions 79a and 79b are provided on the outer peripheral portions of the cam plates 71a and 71b on the surface opposite to the cam surfaces 77a and 77b in the axial direction. Bearings 81a and 81b such as thrust bearings are held on the step portions 79a and 79b, respectively. The first cam plate 71a is axially received by the other end wall portion 19 of the case 3 via the bearing 81a, and the second cam plate 71b is pivoted to the pressing plate 41 of the torque generating portion 7 via the bearing 81b. Abut in direction.

  FIG. 2 is a plan view showing the cam plate.

  The cam grooves 73 are provided on the cam surfaces 77a and 77b of the cam plates 71a and 71b, respectively. Since the cam surfaces 77a and 77b of the cam plates 71a and 71b are configured symmetrically, only the first cam plate 71a is shown in FIG. 2, and the second cam plate 71b is indicated by parentheses. Only shown.

  A plurality of cam grooves 73 of the present embodiment are formed for each of the cam plates 71a and 71b. Although the number of cam grooves 73 is three in the embodiment, it can be changed to two, four, or one.

  Each cam groove 73 is formed so as to be gradually displaced inward in the radial direction with respect to the rotation direction of the cam plates 71a and 71b. In this embodiment, the cam grooves 73 facing the cam plates 71a and 71b have a reverse spiral shape. However, the cam groove 73 can have a curved shape other than the spiral shape, such as a linear shape that gradually deviates inward in the radial direction with respect to the rotation direction or a spiral shape.

  Moreover, the spiral shape of each cam groove 73 is provided in the range of about 180 degrees, for example. However, the range of the spiral shape can be appropriately changed according to the size of the cam surfaces 77a and 77b.

  Two or more spiral cam grooves 73 partially overlap in the radial direction. In the present embodiment, two cam grooves 73 adjacent in the circumferential direction partially overlap in the radial direction. The cam groove does not have to overlap in the radial direction.

  The cross-sectional shape of the cam groove 73 is a concave curved surface, and is inclined so as to become gradually shallower from the outer peripheral side to the inner peripheral side. This inclination can be extended by making the cam groove 73 spiral, so that the inclination is set accordingly. Note that the tilt direction can be reversed. That is, the cam groove 73 may be inclined so as to become gradually shallower from the inner peripheral side to the outer peripheral side as shown in FIG. FIG. 3 is a plan view showing a cam plate 71a according to a modification.

  The cam ball 75 is a steel ball and is disposed between the first and second cam plates 71a and 71b. As will be described later, the cam ball 75 engages with an intersecting portion 73a of the cam groove 73 of the first and second cam plates 71a and 71b. The cam ball 75 is engaged with a relatively deep portion on the outer peripheral side of the cam groove 73 in a normal state, and the inner peripheral side of the cam groove 73 by the relative rotation of the first and second cam plates 71a and 71b. Engagement transitions to a shallow portion.

  As a result, the cam ball 75 widens the space between the cam plates 71a and 71b, and the second cam plate 71b causes the pressing plate 41 of the torque generating unit 7 to slide to one side in the axial direction to be fastened to the torque generating unit 7. Generate power. The cam balls 75 are provided in the same number as the cam grooves 73 in order to engage with the cam grooves 73.

  FIG. 4 is a conceptual diagram showing the relative positional relationship between the cam grooves 73 facing each other of the first and second cam plates 71a and 71b.

  When the engagement of the cam ball 75 is changed as described above, the opposing cam groove 73 has an intersecting portion corresponding to the relative rotation of the first and second cam plates 71a and 71b as shown in FIG. Become. Since the cam ball 75 is automatically positioned at the intersecting portion 73a of the cam groove 73, in this embodiment, the cam ball 75 holding member is not required.

  At this time, the engagement of the cam ball 75 with respect to the cam groove 73 is changed at half the relative angular velocity of the first and second cam plates 71a and 71b, but the intersecting portion 73a where the cam ball 75 is located is also the first and second. The cam plates 71a and 71b move at a half of the relative angular velocity. Therefore, the cam ball 75 can be reliably positioned and held at the intersecting portion 73 a of the cam groove 73.

[Rotation damper operation]
The rotary damper 1 is used, for example, by fixing the case 3 and connecting the outer end of the rotating body 5 to an object.

  When torque is input from the object to the rotating body 5, the rotating body 5 rotates relative to the case 3. A braking torque (damping force) is applied to the relative rotation by the torque generator 7. In this embodiment, the braking torque is controlled according to the power supply to the drive source 9.

  That is, when power is supplied to the drive source 9, drive torque is output from the output shaft 59 of the drive source 9 according to the power supply. With this driving torque, the input gear 61 of the speed reduction mechanism 11 rotates, and the pair of output gears 63 a and 63 b are driven to rotate by the input gear 61.

  At this time, since the output gears 63a and 63b have different numbers of teeth, they rotate relative to each other while rotating in the same direction. By this relative rotation, the cam plates 71a and 71b of the ball cam mechanism 13 are relatively rotated. Thus, the drive torque of the drive source 9 is output to the ball cam mechanism 13. This output torque can be greatly reduced by increasing the drive torque of the drive source 9 by the relative rotation of the output gears 63a and 63b and the gear ratio between the input gear 61 and the output gears 63a and 63b.

  When the cam plates 71 a and 71 b rotate relative to each other, in the ball cam mechanism 13, the cam ball 75 rolls and the engagement transitions to a shallow portion on the inner peripheral side of the cam groove 73. At this time, in this embodiment, since the cam groove 73 is gently inclined, the engagement of the cam ball 75 to the shallow portion on the inner peripheral side of the cam groove 73 can be reliably performed with a small driving torque. .

  When the engagement of the cam ball 75 is shifted to a shallow portion of the cam groove 73, the interval between the cam plates 71a and 71b is widened.

  At this time, since the first cam plate 71a is received by the other end wall portion 19 of the case 3 via the bearing 81a, the second cam plate 71b is moved to the torque generating portion 7 side. Therefore, the second cam plate 71b presses the pressing plate 41 of the torque generating unit 7 via the bearing 81b and slides it to one side in the axial direction.

  As a result, in the torque generating part 7, the pressing plate 41 fastens the friction part 39 to the one end wall part 17 of the case 3 and generates a braking torque according to the fastening force.

  After the target braking torque is generated in this way, the speed reduction mechanism 11 is irreversible, so that even if power supply to the drive source 9 is stopped, the fastening force does not change, so that the braking torque can be maintained. . For this reason, power consumption can be suppressed.

[Effect of Example 1]
The rotary damper 1 according to the present embodiment includes a case 3 and a rotating body 5 that are relatively rotatable, and a torque that is disposed between the case 3 and the rotating body 5 and generates a braking torque for the relative rotation between the case 3 and the rotating body 5 by fastening. A generator 7; a drive source 9 that generates a drive torque for fastening the torque generator 7 in response to power supply; an irreversible reduction mechanism 11 that decelerates and outputs the drive torque from the drive source 9; A ball cam mechanism 13 is provided between the speed reduction mechanism 11 and the torque generation unit 7 and generates a fastening force for the torque generation unit 7 according to the output of the speed reduction mechanism 11.

  The ball cam mechanism 13 is provided on each of the first and second cam plates 71a and 71b and the first and second cam plates 71a and 71b provided on the speed reduction mechanism 11 side and the torque generating unit 7 side, respectively. And a cam groove 73 formed in a spiral shape and gradually displaced inward in the radial direction with respect to the rotation direction of the second cam plates 71a and 71b, and the cams disposed between the first and second cam plates 71a and 71b. And a cam ball 75 engaged with the groove 73.

  Therefore, the rotary damper 1 according to the present embodiment can control the braking torque according to the driving torque by the power supply to the driving source 9.

  In addition, the rotary damper 1 of the present embodiment is smaller and lighter and has a higher braking torque than the rotary damper using a magnetorheological fluid or a magnetic fluid because the torque generator 7 generates a braking torque by fastening. . As a result, the braking torque per unit weight can be increased.

  Further, in this embodiment, the cam ball 75 is held at the intersecting portion 73a of the cam groove 73 of the ball cam mechanism 13, so that it is not necessary to provide a separate member for holding the cam ball 75, and braking per unit weight accordingly. Torque can be increased.

  Further, since the cam ball 75 is naturally positioned at the intersecting portion 73a of the cam groove 75, the operation can be made smooth.

  Furthermore, since the speed reduction mechanism 11 of the rotary damper 1 of this embodiment is irreversible, it is sufficient to supply power to the drive source 9 until the target braking torque is obtained, and the current consumption can be reduced.

  Moreover, in the rotary damper 1 of this embodiment, since the cam groove 73 can be formed longer in a spiral shape, the cam groove 73 is gently inclined without reducing the difference in depth between the shallow portion and the deep portion. can do.

  For this reason, it is possible to generate a large fastening force while reducing the driving torque of the driving source 9, and from this point of view, it is possible to increase the braking torque per unit weight and reduce the current consumption.

  Further, the rotary damper 1 of the present embodiment can reduce the residual torque seen in the rotary damper using a magnetorheological fluid or a magnetic fluid as much as possible.

  Since the opposing cam grooves 73 provided in the first and second cam plates 71a and 71b are spirally wound in the reverse direction, the position of the cam ball 75 automatically becomes the intersection of the opposing cam grooves 73. A holding member for the cam ball 75 becomes unnecessary. For this reason, in this embodiment, the interval between the cam plates 71a and 71b can be narrowed, and the size can be further reduced.

  Further, in this embodiment, the cam groove 73 has a spiral shape whose diameter decreases toward the inner side in the radial direction and becomes gradually shallower toward the inner side in the radial direction, so that the groove gradient of the cam groove 73 is made constant. However, when the cam ball 75 moves to a shallow portion of the cam groove 73 on the inner diameter side, the fastening force increases even at the same driving torque.

  Therefore, the braking torque per unit weight can be reduced more reliably, and the power consumption can be reduced more reliably.

  A plurality of cam grooves 73 are formed in each of the first and second cam plates 71a and 71b, and two or more cam grooves 73 overlap in the radial direction in each of the first and second cam plates 71a and 71b. .

  Therefore, in this embodiment, even if a plurality of cam grooves 73 are provided, each cam groove 73 can be reliably extended to make the inclination gentle.

  Further, the cam surfaces 77a and 77b of the cam plates 71a and 71b can be effectively used to provide a plurality of cam grooves 73 and cam balls 75, thereby improving the stability of the fastening force generation.

  In addition, since the cam groove 73 is gradually shallower or gradually deeper toward the inner peripheral side, even when the plurality of cam grooves 73 are overlapped as described above, mutual interference can be easily suppressed. it can.

  The speed reduction mechanism 11 is a pair of outputs with different numbers of teeth that are provided integrally with the input gear 61 rotated by the drive source 9 and the first and second cam plates 71a and 71b of the ball cam mechanism 13 and mesh with the input gear 61. Gears 63a and 63b are provided.

  Therefore, the irreversible speed reduction mechanism 11 can be realized easily and reliably, and current consumption is reduced.

  In addition, the case 3 includes a rotation shaft 23 that supports the shaft center portion of the rotating body 5 so as to be relatively rotatable in the shaft center portion, and the cam plates 71a and 71b include opening portions 69a and 69b in the shaft center portion. The rotating shaft 23 is inserted into and supported by the portions 69a and 69b. As a result, the rotary damper 1 of this embodiment can reliably support the rotating body 5 and can align the axes of the case 3, the rotating body 5, and the cam plates 71a and 71b with a simple structure. Therefore, smooth operation can be achieved.

  FIG. 5 is a cross-sectional view of the rotary damper according to the second embodiment, and FIG. 6 is a plan view showing a cam plate (pressing plate). In the second embodiment, components corresponding to those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The rotary damper 1 of the second embodiment is obtained by changing the speed reduction mechanism 11 and the ball cam mechanism 13 from the first embodiment.

  The speed reduction mechanism 11 of the present embodiment is configured by a worm gear mechanism. Specifically, the speed reduction mechanism 11 includes a worm 83 and a worm wheel 85 and is accommodated in a gear case 87.

  The gear case 87 is disposed adjacent to the outside of the other end wall portion 19 of the case 3. The gear case 87 is fixed by fastening a flange 89 to the flange 20 of the other end wall portion 19 of the case 3 with a bolt (not shown).

  The drive source 9 is biased and fixed to one side in the radial direction in the gear case 87, and is arranged along the direction intersecting the axial direction. The output shaft 59 of the drive source 9 is located in the gear case 87.

  The worm 83 is attached to the output shaft 59 of the drive source 9 so as to rotate integrally. Therefore, the worm 83 is configured to be rotationally driven by the drive source 9. The worm 83 is located on the outer peripheral side according to the position of the drive source 9. Accordingly, the gear case 87 has a bulging portion 65 bulging outward in the radial direction so as to avoid the worm 83. A worm wheel 85 is engaged with the worm 83.

  The worm wheel 85 is formed in a disc shape and is rotatably supported in the gear case 87. In the worm wheel 85 of this embodiment, a cylindrical support boss portion 91 is formed in the axial center on the back surface opposite to the axial direction with respect to the case 3. A rotating shaft 23 provided at the axial center of the gear case 87 is rotatably engaged with the inner periphery of the support boss portion 91 via a bush 93.

  A coupling shaft 95 projects from the surface of the worm wheel 85 on the case 3 side. The coupling shaft 95 passes through the gear case 87 and reaches the case 3. A first cam plate 71 a of the ball cam mechanism 13 is coupled to the tip of the coupling shaft 95 by a spline or the like in the case 3. Thus, the worm wheel 85 is configured to rotate the first cam plate 71a of the ball cam mechanism 13 in an interlocking manner.

  In the ball cam mechanism 13 of the present embodiment, a first cam plate 71 a is separately provided, and the second cam plate 71 b is configured by the pressing plate 41 of the torque generating unit 7.

  The first cam plate 71 a is formed in a disc shape and is disposed adjacent to the other end wall portion 19 of the case 3. A stepped portion 79a is formed on the back side of the first cam plate 71a, and a bearing 81a such as a thrust bearing is held on the stepped portion 79a. The first cam plate 71a is received by the other end wall portion 19 of the case 3 by the bearing 81a.

  A cylindrical coupling boss portion 97 is provided at the axial center portion on the back side of the first cam plate 71a. The coupling boss portion 97 is disposed on the inner periphery of the other end wall portion 19 of the case 3, and the coupling shaft 95 of the worm wheel 85 of the speed reduction mechanism 11 is coupled to the inner periphery of the coupling boss portion 97.

  On the surface side of the first cam plate 71a, a support shaft portion 101 projects from the shaft center portion. The tip of the support shaft 101 is rotatably engaged with the recess 29 of the rotating body 5 via the bush 103. As a result, the first cam plate 71a includes a support shaft portion 101 that supports the rotating body 5 so as to be relatively rotatable at the shaft center portion.

  The outer peripheral portion on the surface side of the first cam plate 71a is a flat cam surface 77a, and faces the flat cam surface 77b of the second cam plate 71b via the cam ball 75. Since the second cam plate 71b is constituted by the pressing plate 41, the second cam plate 71b is engaged with the inner periphery of the case 3 so as to be slidable in the axial direction.

  Cam grooves 73 are formed in the cam surfaces 77a and 77b of the first and second cam plates 71a and 71b, respectively.

  As in the first embodiment, a plurality of cam grooves 73 (three in the embodiment) are formed for each of the cam plates 71a and 71b. Each cam groove 73 is formed in a spiral shape that gradually deviates inward in the radial direction with respect to the rotation direction of the cam plates 71a and 71b. The spiral shape is provided in the range of about 360 degrees in this embodiment. In the present embodiment, the three cam grooves 73 overlap in the radial direction.

  The cam groove 73 is inclined so as to gradually become shallower from the outer peripheral side to the inner peripheral side, and this inclination is set so as to be loose by the extension of the cam groove 73 in a spiral shape.

  Similar to the first embodiment, the cam ball 75 is disposed between the first and second cam plates 71a and 71b and engages with a relatively deep portion on the outer peripheral side of the cam groove 73 in the normal state. The engagement is shifted to a shallow portion on the inner peripheral side of the cam groove 73 by the relative rotation of the second cam plates 71a and 71b. These cam balls 75 are held by a holding plate 105 as a holding member, and the engagement is shifted in synchronization. The holding plate 105 can be omitted in the same manner as in the first embodiment because the opposing cam groove 73 has a reverse spiral shape.

  In the rotary damper 1 of the second embodiment, the same operational effects as the first embodiment can be obtained.

  Further, in the second embodiment, the shaft portion of the first cam plate 71a is provided with the support shaft portion 101, the support shaft portion 101 supports the shaft portion of the rotating body 5 so as to be relatively rotatable, and the second cam. The plate 71b is engaged with the inner periphery of the case 3 so as to be slidable in the axial direction.

  Therefore, the rotating body 5 can be reliably supported using the first cam plate 71a. Further, with this configuration, the axes of the case 3, the rotating body 5, and the cam plates 71a and 71b can be made to coincide with each other, and the operation can be smoothly performed as in the first embodiment.

DESCRIPTION OF SYMBOLS 1 Rotation damper 3 Case 5 Rotating body 7 Torque generation part 9 Drive source 11 Deceleration mechanism 13 Ball cam mechanism 39 Friction part 41 Press plate 43 Outer plate 45 Inner plate 47 Friction member 61 Input gear 63a, 63b Output gear 71a, 71b Cam plate 73 Cam groove 73a Intersection 75 Cam ball

Claims (9)

An inner rotating member and an outer rotating member capable of relative rotation;
A torque generating unit that is disposed between the inner rotating member and the outer rotating member and generates a braking torque for the relative rotation by fastening;
A driving source for generating a driving force for fastening the torque generating unit according to power supply;
A ball cam mechanism that generates a fastening force with respect to the torque generator by the output of the drive source,
The ball cam mechanism is
First and second cam plates, cam grooves provided on the first and second cam plates, respectively, and gradually deviating inward in the radial direction with respect to the rotation directions of the first and second cam plates; A cam ball disposed between the first and second cam plates and engaged with an intersecting portion of the cam grooves of the first and second cam plates;
This is a rotating damper. An inner rotating member and an outer rotating member capable of relative rotation;
A torque generating unit that is disposed between the inner rotating member and the outer rotating member and generates a braking torque for the relative rotation by fastening;
A driving source for generating a driving force for fastening the torque generating unit according to power supply;
An irreversible deceleration mechanism that decelerates and outputs the driving force from the drive source;
A ball cam mechanism that is disposed between the speed reduction mechanism and the torque generation unit and generates a fastening force for the torque generation unit according to an output of the speed reduction mechanism;
The ball cam mechanism is
First and second cam plates provided on the speed reduction mechanism side and the torque generating unit side, respectively, and rotation directions of the first and second cam plates provided on the first and second cam plates, respectively. A cam groove that gradually deviates inward in the radial direction, and a cam ball that is disposed between the first and second cam plates and engages with an intersection of the cam grooves of the first and second cam plates; With
This is a rotating damper. The rotary damper according to claim 2,
The cam grooves provided in the first and second cam plates have a reverse spiral shape,
Rotating damper characterized by that. The rotary damper according to claim 2 or 3,
The cam groove gradually becomes shallower inward in the radial direction.
This is a rotating damper. The rotary damper according to any one of claims 2 to 4,
A plurality of the cam grooves are respectively formed in the first and second cam plates, and in each of the first and second cam plates, two or more cam grooves overlap in the radial direction.
Rotating damper characterized by that. The rotary damper according to any one of claims 1 to 5,
The speed reduction mechanism includes an input gear that is rotationally driven by the drive source, and a pair of output gears that are provided integrally with the first and second cam plates of the ball cam mechanism and have different numbers of teeth that mesh with the input gear. Prepared,
This is a rotating damper. The rotary damper according to claim 6, wherein
The outer rotating member includes a rotating shaft that rotatably supports the shaft center portion of the inner rotating member on the shaft center portion,
The first and second cam plates each have an opening at an axial center, and are supported by inserting the rotating shaft into the opening.
This is a rotating damper. The rotary damper according to any one of claims 1 to 5,
The speed reduction mechanism includes a worm that is rotationally driven by the drive source, and a worm wheel that meshes with the worm gear and rotates the first cam plate of the ball cam mechanism in an interlocking manner.
This is a rotating damper. The rotary damper according to claim 8, wherein
The first cam plate includes a support shaft portion that rotatably supports the shaft center portion of the inner rotation member on the shaft center portion,
The second cam plate is slidably engaged with the inner periphery of the outer rotation member in the axial direction.
This is a rotating damper.

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