JP2013119920A - Rotary damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary damper whose resisting force during revolving can be easily adjusted.SOLUTION: The rotary damper is composed of a brake drum 10 whose end portion is integrally fixed to a first member 100, a cylindrical case 20 which is covered to the brake drum 10 in a relatively revolvable condition and is connected and linked to a second member 200 in a revolvable condition and a brake spring 30 which comprises a coil spring which is fit onto the brake drum 10 in a fastening condition and whose one end and other end are fixed to one end and other end of the cylindrical case 20, respectively. On an outer peripheral surface of a section onto which the brake spring 30 in the brake drum 10 is fit, a concave portion 10c for relief is provided. On both of the end portions of the brake drum 10, winding fixing portions 20a, 20b revolving independent of the brake drum 10 are provided, and one end and other end of the brake spring 30 of predefined number of turns are fit onto outer peripheral surfaces of the winding fixing portions 20a, 20b, respectively.

Description

  The present invention relates to a rotary damper that is interposed between two members and applies resistance to the rotation when the other member is rotated relative to the other member.

  When adjusting the angle of the reclining seat, folding the folding seat, putting in and out the retractable ottoman, opening and closing the hinged door, opening and closing the lids of various devices, etc. A rotary damper is interposed between the moving members, and resistance is given to the rotation to perform a heavy motion. Rotary dampers are classified into various types according to their operating principles. For example, there is known one in which a resistance force is applied to the rotation by using a viscous resistance of a viscous fluid such as silicon oil (hereinafter, sometimes referred to as “viscous fluid type rotary damper”). ing. As a viscous fluid type rotary damper, a highly functional one has been proposed (for example, Patent Document 1). However, the viscous fluid type rotary damper is required to have high liquid tightness, and each member constituting it is required to have high dimensional accuracy. For this reason, each member in the viscous fluid type rotary damper is generally manufactured by die casting. Therefore, in the viscous fluid type rotary damper, when setting the resistance force, it is necessary to make it from a die-casting mold, and there is a disadvantage that a design development period becomes long and a manufacturing cost becomes high. In addition, the viscous fluid type rotary damper has a drawback that it is difficult to reduce the weight and size.

  In addition, the conventional rotary damper is provided with a resistance force to the rotation by a frictional force received from an outer peripheral surface of the brake drum by a brake spring comprising a coil spring that is externally fitted to the brake drum in a tightened state. (Hereinafter, it may be referred to as “coil spring type rotary damper”) (for example, Patent Document 2). The coil spring type rotary damper can change its resistance force only by adjusting the number of turns of the brake spring and the position where the end of the brake spring is fixed. In addition, it is easy to reduce weight and size. However, the coil spring type rotary damper has a risk of deformation of the brake spring (particularly near its end) when an excessive load is applied. In addition, there was no coil spring type rotary damper whose resistance was changed depending on the direction of rotation. In this respect, Patent Document 3 uses a coil spring in which a small diameter portion is provided at one end and a large diameter portion is provided at the other end so that different resistance force is generated depending on the direction of rotation. An angle-adjustable headrest is described. However, this coil spring is for locking the headrest at a predetermined angle, and is not used as a rotary damper.

JP 2011-190917 A JP-A-11-002278 JP 2010-142439 A

  The present invention solves the above-described problems, and provides a coil spring type rotary damper that can easily set the resistance force when rotating by easy adjustment, and can be easily reduced in weight, size, and cost. To do. It is another object of the present invention to provide a coil spring type rotary damper in which the brake spring is not deformed for a long period of use. Furthermore, it is another object of the present invention to provide a coil spring type damper that can easily realize a complicated operation such as changing a resistance force depending on a rotating direction.

The above issues
It is interposed between the first member and the second member that rotates relative to the first member, and the rotation is performed when the second member is rotated relative to the first member. A rotary damper for imparting resistance,
A brake drum whose end is fixed integrally to the first member;
A cylindrical case which is covered in a rotatable state relative to the brake drum and connected in a rotatable state in conjunction with the second member;
A brake spring comprising a coil spring that is externally fitted to the brake drum in a tightened state and whose one end and the other end are respectively fixed to one end and the other end of the cylindrical case;
Consists of
In the outer peripheral surface of the section of the brake drum where the brake spring is fitted, a relief recess is provided along the outer peripheral direction of the brake drum,
A winding fixing portion that rotates independently of the brake drum is provided at both ends of the section of the brake drum. This is solved by providing a rotary damper characterized in that each is fitted on the outside.

  In the rotary damper of the present invention, when the second member is rotated relative to the first member, the cylindrical case is also rotated in conjunction with the second member. One end portion and the other end portion of the brake spring that are externally fitted to the brake drum in a tightened state are fixed. For this reason, when rotating the second member relative to the first member, the inner peripheral surface of the brake spring tightens the outer peripheral surface of the brake drum. The resistance force accompanying this tightening becomes the resistance force (torque) at the time of rotation. This tightening force is generated at a portion where the brake spring is in contact with the outer peripheral surface of the brake drum, and is not generated at a portion where the escape recess is provided on the outer peripheral surface of the brake spring. For this reason, in the rotary damper of the present invention, the rotational resistance force can be easily adjusted by changing the size, shape, or arrangement of the relief recess. Specific examples thereof will be described later. Further, the rotary damper of the present invention does not require liquid tightness, and each member constituting the rotary damper can be processed by press working or resin injection molding. Furthermore, weight reduction, size reduction, and cost reduction are easy. Furthermore, in the rotary damper of the present invention, the one end portion and the other end portion of the brake spring are externally fitted by a predetermined number of turns to the winding fixing portion that rotates independently from the brake drum. When a load is applied between the second members, the winding fixing portion is tightened, and a large local load is not applied to one end and the other end of the brake spring. For this reason, the brake spring is not easily deformed.

  In the rotary damper of the present invention, the specific aspect of the cylindrical case is not particularly limited, but the cylindrical case includes a first case to which the one end portion of the brake spring is fixed, and the other end portion of the brake spring. The structure is separable from the second case to be fixed, and a plurality of inward engagement teeth are predetermined along the inner peripheral direction of the first case on the inner peripheral surface of the first case on the second case side. On the other hand, a plurality of outward engagement teeth that engage with the inward engagement teeth are formed on the outer peripheral surface of the first case side of the second case at predetermined intervals along the outer peripheral direction of the second case. It is preferable to form with. When this configuration is adopted for a brake drum provided with a relief recess, the inward engagement tooth and the outward engagement tooth to be engaged with each other can be changed, and the assembly angle of the second case with respect to the first case Can be adjusted. Therefore, it is possible to adjust the tightening force of the brake spring against the brake drum by adjusting the relative positional relationship between the one end and the other end of the brake spring. A plurality of outward engagement teeth are formed at predetermined intervals along the outer peripheral direction of the first case on the outer peripheral surface of the second case side in the first case, while in the end portion on the first case side in the second case Even if a plurality of inward engagement teeth that engage with the outward engagement teeth are formed on the peripheral surface at predetermined intervals along the inner peripheral direction of the second case, the same effect as that of the configuration can be obtained. Can do.

  By the way, in the rotary damper of the present invention, since a relief recess is provided in the brake drum, when the brake drum is an injection-molded product of resin, in consideration of die cutting, it is relatively aligned along the longitudinal direction of the brake drum. In addition to two molds (two-way punching molds) that move in general, a mold (three-way punching mold) that moves along the radial direction of the brake drum is required. However, a mold removal recess extending from the end of the section of the brake drum where the brake spring is fitted to the relief recess is provided intermittently in the outer peripheral direction of the brake drum, and the mold is provided on one end side of the brake drum. By alternately arranging the punching recesses and the punching recesses provided on the other end side, the brake drum can be injection-molded with only the above two-way punching die. The mold release recess can be used as a grease storage recess for storing grease.

  The present invention solves the above-described problems, and provides a coil spring type rotary damper that can easily set the resistance force when rotating by easy adjustment, and can be easily reduced in weight, size, and cost. It becomes possible to do. It is also possible to provide a coil spring type rotary damper in which the brake spring is not deformed with respect to long-term use. Furthermore, it is also possible to provide a coil spring type damper that can easily realize a complicated operation such as changing the resistance force depending on the direction of rotation.

It is the perspective view which showed the state which decomposed | disassembled the rotary damper of the 1st embodiment into each component. It is sectional drawing which showed the state which cut | disconnected the rotary damper of 1st embodiment by the plane containing the centerline of a brake drum. It is a graph explaining the anisotropy of the resistance force (torque) of the rotary damper of a 1st embodiment. It is sectional drawing which showed the state which cut | disconnected the rotary damper of 2nd embodiment with the plane containing the centerline of a brake drum. It is sectional drawing which showed the state which cut | disconnected the rotary damper of 3rd embodiment by the plane containing the centerline of a brake drum. It is the perspective view which showed the brake drum in the rotary damper of a 4th embodiment.

[Outline of Rotary Damper of the Present Invention]
A preferred embodiment of the rotary damper of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a perspective view showing a state in which the rotary damper according to the first embodiment is disassembled into respective components. FIG. 2 is a cross-sectional view showing a state in which the rotary damper of the first embodiment is cut along a plane including the center line L of the brake drum 10. FIG. 3 is a graph illustrating the anisotropy of resistance (torque) of the rotary damper according to the first embodiment.

  The rotary damper of the first embodiment is interposed between the first member 100 and the second member 200 as shown in FIGS. The rotary damper includes a brake drum 10, a cylindrical case 20, and a brake spring 30. The brake drum 10 is externally fitted to a shaft body (bolt) 101 erected from the first member 100 and is prevented from coming off by a retaining means (nut) 102. The brake drum 10 is in a state of being integrally fixed to the first member 100 by fitting a protrusion 10 d provided on one end 10 a thereof into the fitting hole 103 of the first member 100. Further, the cylindrical case 20 is covered in a state where it can be rotated relative to the brake drum 10. The cylindrical case 20 is inserted in a through hole 20c provided in a flange portion standing from its outer peripheral portion in a state in which a shaft body (bolt) 201 standing from the second member 200 has play. It is designed to rotate in conjunction with. Further, the section excluding both ends of the brake spring 30 is externally fitted to the brake drum 10 in a tightened state. , 20b in a tightened state. A relief recess 10c is provided at a location along the outer peripheral surface of the intermediate portion of the brake drum 10, so that the tightening force of the brake spring 30 is divided so that the tightening force of the brake spring does not act at the location. ing.

  In the rotary damper of the first embodiment, as shown in FIGS. 1 and 2, the cylindrical case 20 includes a first case 21 to which one end 30a of the brake spring 30 is fixed and a first case 21 to which the other end 30b is fixed. The structure is separable into two cases 22. A plurality of inward engagement teeth 21 a are formed at predetermined intervals along the inner peripheral direction of the first case 21 on the inner peripheral surface of the first case 21 on the second case 22 side. On the other hand, a plurality of outward engagement teeth 22 a are formed at predetermined intervals along the outer peripheral direction of the second case 22 on the outer peripheral surface of the end of the second case 22 on the first case 21 side. For this reason, the assembly angle of the second case 22 with respect to the first case 21 can be adjusted by changing the inward engagement teeth 21a and the outward engagement teeth 22a to be engaged with each other. . Inside the first case 21 and the second case 22, there are provided winding fixing portions 20a and 20b for fitting a predetermined number of turns of the one end 30a and the other end 30b of the brake pull 30, respectively. . In the rotary damper according to the first embodiment, the pair of hook-shaped portions integrally provided on the inner side of the cylindrical case 20 is used as the winding fixing portions 20a and 20b, but the winding fixing portions 20a and 20b are cylindrical. It is good also as a case and a separate body.

  The location of the relief recess 10c is appropriately determined according to the function required for the rotary damper. In the rotary damper according to the first embodiment, the relief recess 10c is provided at a position shifted toward the other end 30b of the coil spring 30 when viewed from the midpoint of the section of the brake drum 10 where the brake spring 30 is fitted. Yes. Thus, by selecting and providing the position of the relief recess 10c, the resistance force when the second member 200 is rotated relative to the first member 100 as shown in FIG. Difference in resistance (when anisotropy is given) between when rotating in the direction (direction of arrow A in FIG. 2) and when rotating in the other direction (direction of arrow B in FIG. 2) Is possible. The reason is as follows. That is, by providing the relief recess 10c, the clamping action of the brake spring 30 is divided, and when the second member 200 is rotated relative to the first member 100, either one of the brake springs 30 is provided. The end is pulled in the direction of tightening the brake spring 30, and the other end is pushed in the direction of loosening the brake spring 30. At this time, the brake spring 30 performs a tightening operation in a section closer to the one end than the middle point of the brake spring 30, and the brake spring 30 performs a relaxation operation in a section on the other end. In addition, by providing the relief recess 10c at the above position, the effective number of turns on the one end 30a side of the brake spring 30 and the effective number of turns on the other end 30b side are different. Appears as a difference in resistance.

  FIG. 4 is a cross-sectional view showing a state in which the rotary damper according to the second embodiment is cut along a plane including the center line L of the brake drum 10. The rotary damper of the second embodiment is provided with a third case 23 between the first case 21 and the second case 22 as shown in FIG. A plurality of inward engagement teeth are provided at predetermined intervals along the inner circumferential direction of the inner peripheral surfaces of the one end portion 23a and the other end portion 23b of the third case 23, respectively. The cylindrical case 20 can be integrated by engaging with outward engaging teeth provided on the outer peripheral surface of the end of the two cases 22. The flange portion having the through hole 20 c is provided on the outer peripheral portion of the third case 23. About another structure, since it is substantially the same as that of the rotary damper of a 1st embodiment, description is omitted.

  FIG. 5 is a cross-sectional view showing a state in which the rotary damper according to the third embodiment is cut along a plane including the center line L of the brake drum 10. As shown in FIG. 5, the rotary damper of the third embodiment is provided with relief recesses 10c at two locations. Each relief recess 10c is provided at a position that is equidistant from the midpoint of the section of the brake drum 10 where the brake spring 30 is fitted. In this way, by providing the relief recess 10c at a position that is symmetrical when viewed from the intermediate point, the effective number of turns on the one end 30a side and the effective number of turns on the other end 30b side of the brake spring 30 can be made equal. it can. Accordingly, the resistance force when the second member 200 is rotated relative to the first member 100 is rotated in one direction (the direction of arrow A in FIG. 5) and the other direction (FIG. 5). In the direction of the arrow B).

  FIG. 6 is a perspective view showing the brake drum 10 in the rotary damper of the fourth embodiment. As shown in FIG. 6, the rotary damper according to the fourth embodiment has a die-cutting recesses 10f, 10g extending from both end portions of the enlarged diameter portion (section where the brake spring 30 is fitted) to the relief recess 10c. (Parts indicated by hatching in FIG. 6) are provided intermittently in the outer peripheral direction of the brake drum 10. The brake spring 30 is tightened against the top surface of the convex portion 10 h on the outer peripheral surface of the brake drum 10. The die-cutting recesses 10f provided on one end side of the brake drum 10 and the die-cutting recesses 10g provided on the other end side are alternately arranged, and the brake drum 10 is injection-molded with a two-way punching die. Is possible. The brake drum 10 can be suitably molded by resin injection molding.

  The rotary damper of the present invention described above is not limited in its application and can be used in various applications. Specifically, a folding mechanism of a folding seat, a reclining seat, a headrest, an armrest, an angle adjustment mechanism of an ottoman, a door opening / closing mechanism, and the like are exemplified. Since the rotary damper of the present invention can be easily reduced in size and weight or reduced in cost, it is particularly suitable for use in various mechanisms of automobiles that have strong demands for them.

DESCRIPTION OF SYMBOLS 10 Brake drum 10a One end part 10b Other end part 10c Relief recessed part 10d Protrusion 10e Through-hole 10f Die release recessed part (grease reservoir recessed part)
10g Concavity for die cutting (Concavity for grease storage)
10h convex part 10i convex part 20 cylindrical case 20a winding fixed part 20b winding fixed part 20c through hole 21 first case 21a inward engagement tooth 22 second case 22a outward engagement tooth 23 third case 23a one end part 23b Other end 30 Brake spring 30a One end 30b Other end 100 First member 101 Shaft (bolt)
102 Stopping means (nut)
103 fitting hole 200 second member 201 shaft body (bolt)

Claims (3)

It is interposed between the first member and the second member that rotates relative to the first member, and the rotation is performed when the second member is rotated relative to the first member. A rotary damper for imparting resistance,
A brake drum whose end is fixed integrally to the first member;
A cylindrical case which is covered in a rotatable state relative to the brake drum and connected in a rotatable state in conjunction with the second member;
A brake spring comprising a coil spring that is externally fitted to the brake drum in a tightened state and whose one end and the other end are respectively fixed to one end and the other end of the cylindrical case;
Consists of
In the outer peripheral surface of the section of the brake drum where the brake spring is fitted, a relief recess is provided along the outer peripheral direction of the brake drum,
At both ends of the section of the brake drum, a winding fixing portion that rotates independently from the brake drum is provided, and the outer peripheral surface of the winding fixing portion has a predetermined number of turns at one end and the other end of the brake pulling. Rotary dampers characterized by external fittings. The cylindrical case is structured to be separable into a first case to which the one end of the brake spring is fixed and a second case to which the other end of the brake spring is fixed,
A plurality of inward engagement teeth are formed at predetermined intervals along the inner peripheral direction of the first case on the inner peripheral surface of the second case side in the first case, while the end on the first case side in the second case Forming a plurality of outward engaging teeth that engage with the inward engaging teeth on the outer peripheral surface of the second case at predetermined intervals along the outer peripheral direction of the second case;
Or
A plurality of outward engagement teeth are formed at predetermined intervals along the outer peripheral direction of the first case on the outer peripheral surface of the second case side in the first case, while in the end portion on the first case side in the second case The rotary damper according to claim 1, wherein a plurality of inward engagement teeth that engage with the outward engagement teeth are formed on the peripheral surface at predetermined intervals along the inner peripheral direction of the second case. A die-cutting recess extending from the end of the section of the brake drum where the brake spring is fitted to the relief recess is provided intermittently in the outer peripheral direction of the brake drum, and the die-cutting is provided at one end of the brake drum. The rotary damper according to claim 1 or 2, wherein the concave portions and the concave portions for punching provided on the other end side are arranged alternately.

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