JP7284317B2 - rotary damper - Google Patents

Description

The present invention relates to a rotary damper, particularly a mechanical rotary damper using a gear mechanism.

For example, a rice cooker is provided with a lid that can be swiveled between a closed position covering the top surface of the rice cooker and an open position exposing the top surface of the rice cooker by hinge means. The lid is locked at the closed position by a locking mechanism while being biased by an appropriate biasing member such as a spring. be forced. The swivel speed (kinetic energy) of the urged swivel lid is damped by the action of a rotary damper connected to the rotating shaft of the lid, and the lid stops at the open position without causing impact. Such a rotary damper may also be provided on the toilet seat of a toilet, the winding mechanism of a blind, etc., in addition to the lid of a rice cooker.

As a rotary damper, a so-called oil damper having a housing in which a relatively highly viscous fluid such as silicone oil is enclosed and a rotating member rotatably mounted in the housing is widely used. . In the oil damper, the rotational speed of the input rotary member or the output rotary member is reduced by applying torque to the rotary member in the opposite direction to the rotation of the rotary member due to the viscous resistance of the fluid. Patent Literature 1 listed below discloses an example of an oil damper.

JP-A-7-12166

Therefore, in the oil damper disclosed in Patent Document 1, there is a possibility that the fluid sealed in the housing may leak to the outside. In addition, since the viscous resistance of the fluid generally changes with temperature, the reverse torque applied by the oil damper changes between the high temperature summer and the low temperature winter. The rotational speed of the member or output member will also be different.

The present invention has been made in view of the above facts, and its main technical problem is to provide a novel rotary damper that can mechanically reduce the rotational speed of a rotating body without using the viscous resistance of fluid. to provide.

According to the present invention, a damper that achieves the above main technical problem comprises a fixed housing having an inner space, and a rotatable external gear housed in the inner space and capable of rotating around a central axis. ,
The inner space is divided into a gear forming space portion in which a fixed internal gear is formed on the inner peripheral surface of the housing and a non-gear forming space portion having a circular cross section in which the fixed internal gear is not formed. Both the formed space and the non-gear-formed space have a central axis common to the central axis of the rotating external gear,
An operating member is further accommodated in the inner space, and the operating member is an operating internal gear and an operating external gear that are commonly arranged on an eccentric shaft that is eccentric with respect to the central axis of the rotating external gear. wherein the working internal gear meshes with the rotating external gear, the working external gear meshes with the fixed internal gear, the rotating external gear, the fixed internal gear, the working internal gear, and All of the operating external gears have a trochoidal tooth profile,
The actuating member also includes an axially projecting actuating pin, the actuating pin being inserted through a hole formed in a circular brake plate to which braking torque is applied by the friction applying means,
The brake plate is fitted to the housing in a state in which the brake plate is restricted from revolving around the central axis of the externally toothed external gear but allowed to rotate in the non-gear-formed space. A rotary damper characterized by:

Preferably, the actuating pin has a circular cross section and the hole has a radially elongated oval shape. Both the cross-section of the actuation pin and the hole may be circular. An annular shoulder surface perpendicular to the central axis of the rotary external gear is provided on the inner surface of the housing in the non-gear-formed space, and the shoulder surface allows the braking plate to move in the axial direction. It is good that movement to is regulated. Preferably, the friction imparting means is a wave spring arranged between the housing and the brake plate to axially press the brake plate. A shaft portion having a circular cross section extending axially along the central axis is connected to the rotating external gear, and the shaft portion is preferably inserted through the inner side of the brake plate. Preferably, the number of teeth of the working internal gear is one larger than that of the rotating external gear, and the number of teeth of the fixed internal gear is one larger than the number of teeth of the working external gear.

In the rotary damper configured according to the present invention, the rotating external gear rotates because the rotating external gear, the fixed internal gear, the operating internal gear, and the operating external gear all have a trochoidal tooth profile. , the working member revolves in the same direction as the rotating external gear by meshing the working internal gear and the rotating external gear, and rotates the rotating external gear by meshing the working external gear and the fixed internal gear. rotates in the direction opposite to the direction of rotation of At this time, the addendum of the rotating external gear and the addendum of the working external gear simultaneously ride on the addendum of the working internal gear and the addendum of the fixed internal gear, or the addendum of the working internal gear and the fixed internal gear. get off the tip of the tooth. Also, the rotating external gear rotates while receiving braking torque due to meshing with the operating internal gear and meshing between the operating external gear and the fixed internal gear. Such braking torque gradually increases as the addendum of the rotating external gear and the addendum of the operating external gear rise from the addendum of the operating internal gear and the addendum of the fixed internal gear toward the respective addendums. It becomes maximum when it increases and rides on the addendum of the working internal gear and the addendum of the fixed internal gear, and gradually decreases after passing the addendum of the working internal gear and the addendum of the fixed internal gear. That is, the rotating external gear rotates while receiving fluctuating braking torque. Therefore, the amount of variation in such braking torque is small.

Further, in the rotary damper constructed according to the present invention, the braking plate to which the braking torque is applied by the friction applying means is fitted in the housing so as to be capable of only rotating around the central axis of the rotating external gear. Since the actuating pin formed in the member and protruding in the axial direction is inserted through the hole formed in the brake plate, when the actuating pin moves as the actuating member revolves and rotates as described above, The braking torque imparted from the friction imparting means is applied to the braking plate only to the circumferential movement component of the operating pin. That is, braking torque is applied from the friction applying means only to the orbital motion component of the operating member via the braking plate, thereby sufficiently increasing the fluctuation amount of the braking torque received by the rotary external gear. Since the kinetic energy of the rotary external gear is effectively attenuated by increasing the amount of fluctuation of the braking torque, the rotational speed of the rotary external gear can be reduced without using the viscous resistance of the fluid.

1 shows the overall structure of a preferred embodiment of a rotary damper constructed in accordance with the present invention; FIG. The figure which shows the housing of the rotary damper shown in FIG. 1 alone. The figure which shows the rotation external gear of the rotary damper shown in FIG. 1 alone. FIG. 2 is a view showing a single operating member of the rotary damper shown in FIG. 1; FIG. 2 is a view showing a single braking plate of the rotary damper shown in FIG. 1; FIG. 2 is a diagram for explaining the operation of the rotary damper shown in FIG. 1; FIG. 4 shows another embodiment of a rotary damper constructed in accordance with the present invention;

A more detailed description will now be given with reference to the accompanying drawings showing a preferred embodiment of a rotary damper constructed in accordance with the present invention.

Referring to FIG. 1, a rotary damper generally indicated by numeral 2 includes a fixed housing 4 and a rotatable external gear 6 capable of rotating around a central axis o1 within the housing 4. As shown in FIG.

2 together with FIG. 1, the housing 4 comprises a housing body 10 shown in FIG. 2(a) and a shield plate 12 shown in FIG. 2(b). The housing body 10 has a substantially square end plate 14 arranged perpendicular to the central axis o1, and an outer peripheral wall 16 extending axially from the outer peripheral edge of the end plate 14. A space 18 is provided. The inner space 18 includes a gear forming space 24 in which a fixed internal gear 22 (with 36 teeth) having a trochoidal tooth profile is formed on the inner peripheral surface of the outer peripheral wall 16, and a cross section in which the fixed internal gear 22 is not formed. The gear forming space 24 and the gear non-forming space 26 both have a central axis common to the central axis o1. Furthermore, the non-gear-formed space 26 is located closer to the open edge side of the outer peripheral wall 16 than the gear-formed space 24, and both spaces are adjacent to each other in the axial direction. The inner diameter of the open end portion of the outer peripheral wall 16 is increased, and as a result, in the space 26 where the gear is not formed, the inner surface of the housing 4 has an annular shoulder surface 28 perpendicular to the central axis o1. is provided. A bolt hole 30 extending linearly in the axial direction from the end face on the open end side toward the end plate 14 is formed in the corner of the outer peripheral wall 16 . A circular through hole 31 is formed in the center of the end plate 14 . The shield plate 12 has substantially the same shape as the end plate 14 of the housing body 10, and has a circular through hole 32 in the center and circular rectangular holes 34 in the corners. The shield plate 12 is aligned with the end surface of the outer peripheral wall 16 of the housing body 10 on the open end side, and a proper bolt (not shown) is inserted through the square hole 34 and fastened to the bolt hole 30 of the housing body 10 . Then, the shield plate 12 closes the inner space 18 of the housing body 10 and is integrated with the housing body 10 .

As shown in FIG. 1 , the rotary external gear 6 has a trochoidal tooth profile and is arranged in a gear forming space 24 of the housing 4 . The rotating external gear 6 has 29 teeth. Referring to FIG. 3 together with FIG. 1, the rotary external gear 6 is formed with a connecting hole 36 having a regular hexagonal cross-section and penetrating in the axial direction along the central axis o1. A rotation shaft of the lid of the rice cooker (not shown) is connected, and the rotary external gear 6 rotates integrally with the lid of the rice cooker. A shaft portion 40 having a circular cross section is formed on one axial side surface of the rotary external gear 6 so as to surround the outer peripheral edge of the connection hole 36 and extend axially along the central axis o1. The tip of the shaft portion 40 is rotatably supported by the through hole 32 of the shield plate 12 . Circular protrusions 42 are formed on the other side surface of the rotary external gear 6 in the axial direction so as to surround the outer peripheral edge of the connection hole 36 and protrude in the axial direction along the central axis o1. The protrusion 42 is rotatably supported by the through hole 31 of the housing body 10 .

As shown in FIG. 1, the interior space 18 of the housing 4 also accommodates an actuating member generally designated 43 . Referring to FIG. 4 together with FIG. 1, the operating member 43 includes an operating internal gear 44 and an operating external gear 46 commonly disposed on an eccentric axis o2 eccentric to the central axis o1. Both the operating internal gear 44 and the operating external gear 46 have trochoidal tooth profiles and are formed on the inner and outer peripheral surfaces of a common cylindrical wall 48, respectively. The operating internal gear 44 meshes with the rotating external gear 6, and the operating external gear 46 meshes with the fixed internal gear 22, respectively. Therefore, both the operating internal gear 44 and the operating external gear 46 are arranged in the gear forming space 24 . The number of teeth of the operating internal gear 44 is preferably one larger than that of the rotating external gear 6, and the number of teeth of the fixed internal gear 22 is preferably one larger than that of the operating external gear 46. In terms of configuration, the active internal gear 44 has 30 teeth and the active external gear 46 has 35 teeth. An operating end plate 50 is formed on one side of the cylindrical wall 48 in the axial direction, and the operating end plate 50 is arranged in the gear-free space 26 of the housing 4 . More specifically, the working end plate 50 is arranged axially in the non-gear-forming space 26 closer to the end plate 14 than the shoulder surface 28 . A circular through hole 52 is formed in the center of the operating end plate 50 , and the shaft portion 40 connected to the rotary external gear 6 is inserted through the through hole 52 . An operating pin 54 having a circular cross section and protruding in the axial direction is formed on the outer peripheral edge of the surface of the operating end plate 50 opposite to the side where the cylindrical wall 48 is formed.

As shown in FIG. 1, a circular braking plate 56 is also arranged in the non-gear-formed space 26 of the housing 4 . For easy understanding, the braking plate 56 is shown with light ink in cross-sectional views such as FIG. The brake plate 56 is fitted to the housing 4 (more specifically, the housing main body 10) in a state in which it is restricted from revolving around the central axis o1 but is capable of rotating. Axial movement is restricted by the plate 12 . 5 together with FIG. 1, a circular through hole 58 is formed in the center of the brake plate 56, and the shaft portion 40 connected to the rotary external gear 6 is inserted through the through hole 58. ing. An axially penetrating hole 60 is formed in the outer peripheral edge of the brake plate 56. As shown in the AA and CC sectional views of FIG. 54 is inserted. In the illustrated embodiment, the hole 60 has a radially elongated oval shape, and one hole 60 and one actuation pin 54 are provided.

A predetermined braking torque is applied to the braking plate 56 by the friction applying means. In the illustrated embodiment, the friction imparting means is arranged between the shield plate 12 of the housing 4 and the brake plate 56 to press the brake plate 56 in the axial direction, as shown in the AA section of FIG. wave spring 62; Although the brake plate 56 is pressed in the axial direction by the wave spring 62 , the outer peripheral edge contacts the shoulder surface 28 of the housing 4 and is restricted from moving in the axial direction. Do not push in any direction. If desired, the friction imparting means may be a leaf spring or well known tolerance rig positioned between the outer peripheral surface of the brake plate 56 and the inner peripheral surface of the outer peripheral wall 16 of the housing 4 .

Next, operation of the rotary damper 2 will be described with reference to FIG. As shown in the AA cross-sectional view of FIG. 6, when the rotating external gear 6 is rotated counterclockwise when viewed from the right side of the figure, the rotating external gear 6, the fixed internal gear 22, and the operating internal gear Due to the fact that both the gear 44 and the operating external gear 46 have a trochoidal tooth profile, the operating member 43 consists of the operating internal gear 44 and the rotating external gear 6 as indicated by arrows in the BB cross-sectional view. By meshing with, it revolves in the counterclockwise direction which is the same direction as the rotation direction of the rotating external gear 6 (large arrow shown on the operating member 43 in the figure), and the operating external gear 46 and the fixed internal gear 22 , rotates in the clockwise direction opposite to the direction of rotation of the rotating external gear 6 (small arrow shown above the operating member 43 in the figure). At this time, the addendum of the rotating external gear 6 and the addendum of the operating external gear 46 ride on the addendum of the operating internal gear 44 and the addendum of the fixed internal gear 22 at the same time. and descends from the tip of the fixed internal gear 22 . Further, the rotating external gear 6 rotates while receiving braking torque due to meshing with the operating internal gear 44 and meshing between the operating external gear 46 and the fixed internal gear 22 . Such braking torque is applied from the addendum of the rotating external gear 6 and the addendum of the operating external gear 46 toward the addendum of the operating internal gear 44 and the fixed internal gear 22 from the addendum of each tooth. As it rises, it gradually increases and reaches a maximum when it rides on the addendum of the operating internal gear 44 and the addendum of the fixed internal gear 22, and reaches the addendum of the operating internal gear 44 and the addendum of the fixed internal gear 22. After passing, it gradually decreases. That is, the rotating external gear 6 rotates while receiving fluctuating braking torque. Therefore, the amount of variation in such braking torque is small.

Further, in the rotary damper 2, a circular braking plate 56 to which braking torque is applied by a wave spring 62 (friction applying means) rotates in a circular non-gear-formed space 26 partitioned inside the housing 4. 6 is fitted so that it can only rotate about the central axis o1, and the operating pin 54 formed in the operating member 43 and protruding in the axial direction is inserted through the hole 60 formed in the braking plate 56. When the operating member 43 revolves and rotates as described above, the operating pin 54 rotates around the central axis o1 while radially reciprocating within the hole 60 formed in the brake plate 56 as shown in the CC sectional view. The brake plate 56 is rotated around the central axis o1 by the operating pin 54. As shown in FIG. The braking plate 56 is rotated counterclockwise as a whole while alternately repeating counterclockwise rotation and clockwise rotation in small increments. At that time, the braking torque applied from the wave spring 62 (friction applying means) to the braking plate 56 is added only to the circumferential movement component in which the operating pin 54 moves around the central axis o1. It is not added to the radial motion component that moves radially with respect to o1. That is, the braking torque applied to the braking plate 56 from the wave spring 62 (friction applying means) is applied only to the orbital motion component of the operating member 43, and the fluctuation amount of the braking torque received by the rotary external gear 6 is sufficiently increased. Since the kinetic energy of the rotary external gear 6 is effectively attenuated by increasing the amount of fluctuation of the braking torque, the rotational speed of the rotary external gear 6 can be reduced without using the viscous resistance of the fluid. It becomes possible.

Another embodiment of a rotary damper constructed in accordance with the present invention is shown in FIG. In the rotary damper shown in FIG. 7 and indicated as a whole by numeral 2', both the cross section of the operating pin formed in the operating member 43' and the hole formed in the braking plate 56' are circular. Instead of one actuating pin and one hole, a plurality (six in the illustrated embodiment) are provided at equal angular intervals in the circumferential direction. Each actuation pin and hole is designated 54a'-54f' and 60a'-60f', respectively. As shown in the CC sectional view of FIG. 7, the diameters of the operating pins 54a' to 54f' are all the same, but the diameters of the holes 60b' and 60f' 60e'), the actuating pins 54b' and 54f' do not abut the inner peripheral surface of the brake plate 56' in the holes 60b' and 60f', but the actuating pins 54a' and 54c'-54e ' contacts the inner peripheral surface of the brake plate 56' at holes 60a' and 60c' to 60e'.

When the rotary external gear 6' is rotated counterclockwise as seen from the right direction of the cross section A--A in FIG. rotate in the direction At this time, in the rotary damper 2' of the present embodiment, the holes 60a' to 60f' formed in the braking plate 56' are circular rather than elliptical. It revolves counterclockwise while rotating clockwise along the inner peripheral surface of each of the holes 60a' to 60f' into which they are inserted. As the operating pins 54a' to 54f' revolve, the braking plate 56' is pushed in the circumferential direction and rotated counterclockwise. At this time, since the operating pins 54b' and 54f' do not contact the inner peripheral surface of the brake plate 56' in the holes 60b' and 60f', the operating pins 54b' and 54f' act on the brake plate 56'. no. Therefore, the brake plate 56' is pushed in the circumferential direction by the operating pins 54a' and 54c' to 54e' and rotated counterclockwise. The brake plate 56' intermittently rotates counterclockwise. Braking torque is applied to the brake plate 56' by a wave spring 62', and the braking torque is applied to the operating member 43' only when the operating pins 54a', 54c' to 54e' push the brake plate 56 in the circumferential direction. Therefore, this embodiment also has the same effects as the rotary damper 2 described above. At this time, although the operating pins 54a', 54c' and 54e' are in contact with the inner peripheral surface of the braking plate 56' at the holes 60a', 60c' and 60e', the operating pins 54a', 54c' and 54e ' are equally angularly spaced in the circumferential direction, the sum of the moments acting on the brake plate 56' at the respective holes 60a', 60c' and 60e' of the operating pins 54a', 54c' and 54e' is becomes constant, and the above-described variations in the braking torque due to the operating pins 54a', 54c' and 54e' cancel each other out. That is, in the present embodiment, the above-described variation in braking torque is caused only by the operating pin 54d' and the hole 60d' that are out of phase with the other operating pins and holes. It corresponds to the actuation pin 54 and hole 60 of the damper 2 . In this embodiment, (1) the operating pins 54a' to 54f' and the holes 60a' to 60f' are arranged at equal angular intervals in the circumferential direction, and (2) the operating pins 54b' and 54f' does not contact the inner peripheral surface of the brake plate 56' in the holes 60b' and 60f'. And if the holes through which these are inserted are arranged at unequal angular intervals in the circumferential direction, it is possible to generate fluctuations in the braking torque by means of a plurality of operating pins. In this embodiment, since a plurality of operating pins 54a' to 54f' and holes 60a' to 60f' are provided, the operating pins do not fall down, that is, the operating member 43' does not incline with respect to the central axis o1'. This prevents the rotating external gear 6' from rotating stably.

2: Rotary damper 4: Housing 6: Rotating external gear 18: Inner space 22: Fixed internal gear 24: Gear forming space 26: Gear non-forming space 28: Shoulder surface 43: Operating member 44: Operating internal gear 46: Operating external gear 54: Operating pin 56: Braking plate 62: Wave spring (friction imparting means)

Claims (7)

A fixed housing having an inner space, and a rotating external gear housed in the inner space and capable of rotating around a central axis,
The inner space is divided into a gear forming space portion in which a fixed internal gear is formed on the inner peripheral surface of the housing and a non-gear forming space portion having a circular cross section in which the fixed internal gear is not formed. Both the formed space and the non-gear-formed space have a central axis common to the central axis of the rotating external gear,
An operating member is further accommodated in the inner space, and the operating member is an operating internal gear and an operating external gear that are commonly arranged on an eccentric shaft that is eccentric with respect to the central axis of the rotating external gear. wherein the working internal gear meshes with the rotating external gear, the working external gear meshes with the fixed internal gear, the rotating external gear, the fixed internal gear, the working internal gear, and All of the operating external gears have a trochoidal tooth profile,
The actuating member also includes an axially projecting actuating pin, the actuating pin being inserted through a hole formed in a circular brake plate to which braking torque is applied by the friction applying means,
The brake plate is fitted to the housing in a state in which the brake plate is restricted from revolving around the central axis of the externally toothed external gear but allowed to rotate in the non-gear-formed space. A rotary damper that features 2. The rotary damper according to claim 1, wherein the actuating pin has a circular cross section and the hole has a radially elongated oval shape. 2. The rotary damper of claim 1, wherein both the cross section of the actuation pin and the hole are circular. An annular shoulder surface perpendicular to the central axis of the rotary external gear is provided on the inner surface of the housing in the non-gear-formed space, and the shoulder surface allows the braking plate to move in the axial direction. 2. The rotary damper of claim 1, wherein movement to is restricted. 2. The rotary damper according to claim 1, wherein said friction imparting means is a wave spring arranged between said housing and said brake plate to axially press said brake plate. 2. The rotary according to claim 1, wherein a shaft portion having a circular cross-section extending axially along the central axis is connected to the rotating external gear, and the shaft portion is inserted inside the brake plate. damper. 2. The number of teeth of said working internal gear is one more than the number of teeth of said rotating external gear, and the number of teeth of said fixed internal gear is one more than that of said working external gear. rotary damper.

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