JP4145062B2 - Rotating damper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary damper that exhibits a constant damping force in the process of rotating a rotating body relative to a casing, and that allows the damping force to be finely adjusted.
[0002]
[Prior art]
As a rotary damper in which the damping force can be finely adjusted, an invention described in Japanese Patent Laid-Open No. 5-263848 has been conventionally known, and FIGS. 11 and 12 show this. As is clear from these drawings, the conventional rotary damper incorporates the rotary body 3 in the casing 2 whose one end is covered with the cap 1, and the rotary shaft 4 provided integrally with the rotary body 3 is attached to the outside of the casing 2. It protrudes in the direction.
[0003]
The casing 2 is formed with a pair of partition walls 5 and 6 projecting in the diameter direction. The rotating body 3 rotates while being in contact with the partition walls 5 and 6 and has sufficient contact with the contact portion. Has a good sealing function. On the other hand, the rotating body 3 is formed with a pair of control pieces 7, 8 in the diameter direction, and provided with damping force generating means 9, 10 that contacts the inner periphery of the casing 2 at the tips of the control pieces 7, 8. Yes. Thus, by bringing the damping force generating means 9 and 10 into contact with the inner periphery of the casing 2, the first fluid chamber 11 and the second fluid chamber 12 are formed in one semicircular portion of the casing 2, and the other half is formed. The first fluid chamber 13 and the second fluid chamber 14 are also formed in the circular portion.
[0004]
The damping force generating means 9 and 10 configured as described above function as follows. That is, when the rotating body 3 rotates in the direction of the arrow 15, the volumes of the first fluid chambers 11 and 13 are reduced and the volumes of the second fluid chambers 12 and 14 are increased. At this time, the notched grooves 7a and 8a of the control pieces 7 and 8 are in contact with the side walls of the damping force generating means 9 and 10 to be blocked. Therefore, the fluid in the first fluid chambers 11, 13 whose volume is reduced passes through the contact surface between the damping force generation means 9, 10 and the inner peripheral surface of the casing 2, and the second fluid chamber 12 whose volume is increased, Although it flows out to the 14 side, the flow resistance at this time becomes a damping force.
[0005]
On the other hand, when the rotating body 3 rotates in the direction opposite to the arrow 15, the volume of the second fluid chambers 12 and 14 is reduced and the volume of the first fluid chambers 11 and 13 is increased. At this time, the notched grooves 7a and 8a of the control pieces 7 and 8 coincide with the notched portions 9a and 10a formed in the damping force generating means 9 and 10, respectively. Therefore, the fluid in the second fluid chambers 12 and 14 whose volume is reduced flows out to the first fluid chambers 11 and 13 whose volume is increased through the notches 9a and 10a and the notch grooves 7a and 8a. However, the flow resistance hardly occurs at this time. As is clear from the above, when the rotating body 3 rotates in the direction of the arrow 15, a large damping force is generated, so that a certain damper effect is exhibited. However, when the rotating body 3 rotates in the direction opposite to the arrow 15, the damper effect is hardly exhibited.
[0006]
The rotating body 3 as described above is formed with a pair of through holes 16 and 17 that are crossed with each other. One through hole 16 has openings 16a and 16b on the first fluid chamber 11 and 13 side. The other through-hole 17 has its openings 17a and 17b opened to the second fluid chambers 12 and 14 side. Under such a configuration, when the rotating body 3 rotates in the direction of the arrow 15, the first fluid chambers 11 and 13 become high pressure, so that the high-pressure fluid in the first fluid chambers 11 and 13 has openings 16 a and 16 b. To the second fluid chambers 12 and 14 through the openings 17a and 17b.
[0007]
A circular cross hole 18 is formed in the cross portion of the through holes 16 and 17 as described above, and the tip of the adjusting screw 19 provided in the cap 1 can enter and leave the cross hole 18. Yes. The effective diameters of the through holes 16 and 17 are made different depending on the size of the gap between the tip of the adjustment screw 19 and the bottom 18a of the cross hole 18 facing the tip. In other words, the larger the interval, the larger the effective flow diameter, and the smaller the channel resistance.
[0008]
In the above configuration, the damper effect of the rotary damper is determined by the damping force generated by the gap between the inner periphery of the cylinder 2 and the damping force generating means 9 and 10. However, the adjustment screw 19 is turned to adjust the distance between the adjustment screw 19 and the bottom portion 18a of the cross hole 18 so that the damping force can be finely adjusted. Therefore, in this conventional rotary damper, the damper effect can be finely adjusted according to the purpose of use of the damper.
[0009]
[Problems to be solved by the invention]
In the conventional rotary damper as described above, the through hole formed in the rotating body is used as a flow path for fine adjustment of the damping force. However, in order to form a through hole in the rotating body, it is very difficult to form the hole. There was a problem of becoming. For example, an attempt to mold a rotating member including a through-hole, because it must be considered that to pull the mold, inevitably has many number of split mold. The more split molds, the higher the manufacturing cost. It is also conceivable to cut the through hole with a drill or the like. However, this cutting process is never easy. In any case, as described above, the conventional rotary damper has a problem that it is very difficult to manufacture.
An object of the present invention is to provide a rotary damper that is easy to manufacture.
[0010]
[Means for Solving the Problems]
According to the present invention, a rotating body is incorporated in a casing so as to be relatively rotatable, and a first fluid chamber and a second fluid chamber are partitioned by a control piece provided in the rotating body and a partition wall provided in the casing, thereby generating a damping force. The fluid chambers are communicated with each other via On the other hand, in addition to the flow path through the damping force generating means, a short-circuit passage that communicates both fluid chambers is provided, and the short-circuit passage is provided with a throttle portion and a variable throttle mechanism that makes the opening of the throttle portion variable. Is provided. The rotating body is formed with one of a bearing recess and a bearing protrusion, and the casing is formed with either the bearing recess or the bearing protrusion, and the bearing recess formed on the rotating body or The bearing convex portion and the bearing convex portion or the bearing concave portion formed on the casing are fitted so as to be relatively rotatable so as to exert a bearing function, and a communication groove is formed on a contact surface between the bearing concave portion and the bearing convex portion. The short-circuit passage is constituted by the communication groove.
[0011]
In the above configuration, by rotating the rotating body relative to the casing, the fluid in one fluid chamber flows into the other fluid chamber via the damping force generating means. In this way, when the fluid flows through the damping force generating means, a predetermined damping force is generated and the initial damper effect is exhibited. The damping force generation means may generate a damping force with respect to the rotation of the rotating body in both directions, or may generate a damping force only in any one direction of rotation. Further, any number of the fluid chambers may be provided by combining the first fluid chamber and the second fluid chamber.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the first embodiment shown in FIGS. 1 to 4, a cylindrical casing c is configured such that one side is closed by a side wall 20 and the other side is closed by a cap 21. I try to stop it with screws.
Further, as shown in FIG. 1 , the rotating body 22 incorporated in the casing c is provided with a rotating shaft 23 on one side surface, and a bearing recess 24 is formed on the surface opposite to the rotating shaft 23. And this bearing recessed part 24 is made to fit the bearing convex part 25 formed in the side wall 20 of the casing c, and the fitting part is rotatably supported. Further, the rotating shaft 23 is rotatably supported by a bearing bush 26 provided on the cap 21. Therefore, the rotating body 22 and the rotating shaft 23 are supported rotatably about their axes.
[0013]
A pair of partition walls 27 and 28 facing each other in the diametrical direction are provided on the inner periphery of the casing c as described above. The rotating body 22 incorporated in the casing c contacts the partition walls 27 and 28. In addition, the sealing property of the contact portion is sufficiently maintained.
Further, the rotating body 22 is provided with a pair of control pieces 29 and 30 in the diameter direction, and is provided with valve mechanisms 31 and 32 at the tips of the control pieces 29 and 30. Then, by bringing the valve mechanisms 31 and 32 into contact with the inner periphery of the casing c, the first fluid chamber 33 and the second fluid chamber 34 are formed on one semicircular side with the partition walls 27 and 28 as a boundary. In addition, the first fluid chamber 35 and the second fluid chamber 36 are also partitioned on the other semicircular side.
[0014]
The valve mechanisms 31 and 32 form concave portions 37 and 38 that are always open on the second fluid chambers 34 and 36 side, and when the rotating body 22 rotates in the direction of the arrow 39, the pressure action in the rotational direction of FIG. While slightly turning from the state, the second fluid chambers 34 and 36 are communicated with the first fluid chambers 33 and 35 via the recesses 37 and 38. However, when the rotating body 22 rotates in the direction opposite to the arrow 39, the state of FIG. 2 is maintained by the pressure action in the rotating direction, and the communication between the two chambers through the recesses 37 and 38 is blocked. However, even if the recesses 37 and 38 are closed, the first fluid chambers 33 and 35 and the second fluid chambers 34 and 36 communicate with each other through a slight gap between the valve mechanisms 31 and 32 and the casing c. I am doing so. That is, in the first embodiment, the damping force is increased with respect to one rotation of the rotating body 22, and the damping force is decreased with respect to the other rotation.
[0015]
In the figure, reference numeral 40 denotes a resin bush placed on the bearing convex portion 25, and the rotating body 22 and the bearing convex portion 25 are made of metal, so that these metals are prevented from directly rubbing against each other. Reference numeral 41 denotes a washer interposed between the rotating body 22 and the cap 21 for holding the O- ring .
[0016]
As is apparent from FIG. 4, a pair of communication grooves 42 and 43 that cross each other are formed in the bearing recess 24 of the rotating body 22 as described above. The open ends 42 a and 42 b of one communication groove 42 are opened to the first fluid chambers 33 and 35 side at positions adjacent to the control pieces 29 and 30. Further, the opening ends 43 a and 43 b of the other communication groove 43 are opened toward the second fluid chambers 34 and 36 at positions adjacent to the control pieces 29 and 30. A narrowed portion 44 formed of a circular recess is formed at a portion where the pair of communication grooves 42 and 43 intersect as described above.
[0017]
An adjustment screw 45 is inserted into the bearing projection 25 from the outside of the casing c so that the tip of the adjustment screw 45 can enter and leave the throttle portion 44. Then, they and the tip and the diaphragm portion 44 of the adjusting screw 45 is the while maintaining full dimensional relationships, and the diameter of the throttle portion 44 is larger than the groove width of the communication groove 42, 43.
[0018]
By forming the communication grooves 42 and 43 in the bearing concave portion 24 of the rotating body 22 as described above, when the concave portion 24 and the bearing convex portion 25 are fitted together, the communication grooves 42 and 43 and the bush are combined. It constitutes the short-circuit passage of the invention.
In the present invention, the contact surface between the inner surface of the casing and the rotating body is formed with a communication groove in either the casing or the rotating body, and the communication groove constitutes a short-circuit path when the rotating body is incorporated in the casing. In this case, the bush 40 provided in the casing c is regarded as a part of the casing. In other words, the bush 40 is not necessarily an essential component for the present invention.
[0019]
In any case, in the short-circuit passage having the communication grooves 42 and 43 as main elements, one open ends 42a and 42b open to the first fluid chambers 33 and 35, and the other open ends 43a and 43b are the second fluid. Open into chambers 34 and 36. Therefore, when the first fluid chambers 33 and 35 become high pressure, the high-pressure fluid flows from the one opening end 42a and 42b to the second fluid chamber 34 and 36 via the other opening end 43a and 43b.
[0020]
The opening degree of the throttle portion 44 in this short circuit path is determined by the amount of the adjustment screw 45 that enters and exits the throttle portion 44. For example, when the tip of the adjusting screw 45 is completely retracted from the throttle portion 44, the opening degree of the throttle portion 44 is maximized. On the contrary, when the tip of the adjustment screw 45 is completely in the throttle portion 44, the throttle portion 44 is closed. If the throttle portion 44 is closed in this way, the first fluid chambers 33 and 35 and the second fluid chambers 34 and 36 do not communicate with each other via the short-circuit path.
However, the restricting portion 44 may not be completely closed in a state where the adjustment screw 45 is fully inserted. If it does not close completely, a small amount of fluid will flow in the short circuit path.
[0021]
In FIG. 1, reference numeral 46 denotes an accumulator provided in the rotating body 22 and the rotating shaft 23. The accumulator 46 has a piston 48 to which a spring force of a spring 47 is applied as a main element. However, the spring force of the spring 47 can be adjusted by turning the plug 49 to change the position in the axial direction. Then, the pressure of the throttle portion 44 acts on the piston 48. Therefore, even if the pressure in the first fluid chambers 33 and 35 suddenly increases for some reason, the impact can be absorbed by the accumulator 46.
[0022]
Next, the operation of the first embodiment will be described.
Now, when the rotary body 22 rotates in the direction of the arrow 39, the valve mechanisms 31 and 32 rotate slightly, and the second fluid chambers 34 and 36 communicate with each other via the recesses 37 and 38. Therefore, the fluid in the second fluid chambers 34 and 36 flows smoothly into the first fluid chambers 33 and 35. Since the fluid in the second fluid chambers 34 and 36 flows smoothly into the first fluid chambers 33 and 35 in this manner, the rotation in the direction of the arrow 39 is almost equal to free rotation.
[0023]
When the rotating body 22 is rotated in the direction opposite to the arrow 39, the valve mechanisms 31 and 32 maintain the state shown in the figure, so that the communication via the recesses 37 and 38 is blocked. Therefore, the fluid in the first fluid chambers 33 and 35 flows into the second fluid chambers 34 and 36 through a slight gap between the valve mechanisms 31 and 32 and the inner peripheral surface of the casing c. In this way, the flow resistance when the fluid passes through a slight gap becomes a damping force and exhibits a predetermined damper effect.
As is clear from the above, the valve mechanisms 31 and 32 constitute the damping force generating means of the present invention when it exerts a damper effect. Accordingly, the damping force generating means of the present invention is not limited to the valve mechanism, it is conceivable in various configurations. In short, any device that generates a damping force with respect to the rotation of the rotating body may be used. Moreover, it is good also as a damping-force generation means with the clearance gap formed between the control pieces 29 and 30 and the casing c, without providing a valve mechanism.
[0024]
A predetermined damper effect is exhibited when the rotating body 22 rotates in the direction opposite to the arrow 39 as described above, but the damper effect can be finely adjusted by adjusting the opening of the throttle portion 44. . For example, if the opening degree of the throttle unit 44 is increased, fine adjustment is made in the direction in which the damping force is reduced. Conversely, if the opening degree of the throttle unit 44 is reduced, fine adjustment is made in the direction in which the damping force is increased. And since a damper effect changes according to the magnitude of this damping force, an optimal damper effect can be acquired according to the use etc. of the damper concerned.
[0025]
Further, in this first embodiment, the short-circuit passage is constituted by the communication grooves 42 and 43, but it is sufficient if the communication grooves 42 and 43 are formed on the inner surface of the bearing recess 24 of the rotating body 22. . Therefore, it suffices to form a convex portion in the male mold when forming the concave portion 24, and there is no need to form the through holes 16 and 17 as in the prior art. Thus, since it is sufficient to form the convex portion on the male mold, the manufacturing cost can be reduced as compared with the conventional damper.
In the first embodiment, the accumulator 46 that absorbs the impact of the rotating body 22 is provided. However, the accumulator 46 is not an essential component of the present invention.
[0026]
When the accumulator 46 is not provided as described above, the adjusting screw 45 can be provided at the position of the accumulator 46 of the first embodiment as in the second embodiment shown in FIG. In other words, in the present invention, the adjustment screw 45 may be provided on the casing side or on the rotating body 22 side. However, functionally, the second embodiment is exactly the same as the first embodiment.
[0027]
In the third embodiment shown in FIGS. 6 and 7, the communication grooves 50 and 51 are formed on the surface of the bearing projection 25, and the presence or absence of the communication grooves 50 and 51 and the accumulator 46 is the first embodiment. Otherwise, the rest is the same as in the first embodiment. However, in the case of the third embodiment, the open ends 50a, 50b and 51a, 51b of the communication grooves 50, 51 are provided in the vicinity of the partition walls 27, 28, respectively. As described above, the opening ends 50a to 51b are provided in the vicinity of the partition walls 27 and 28, regardless of the position of the control pieces 29 and 30. The opening ends are arranged in the first fluid chamber or the second fluid. This is for always opening the chamber. Also in the case of the third embodiment, the opening of the throttle portion 44 can be adjusted by moving the adjusting screw 45 in and out so that the damping force can be finely adjusted, which is exactly the same as the first embodiment.
[0028]
In the fourth embodiment shown in FIGS. 8 and 9, a bearing convex portion 52 is formed at the tip of the rotating body 22, and communication grooves 53 and 54 are formed on the periphery and the end surface of the bearing convex portion 52. And the bearing recessed part 55 is formed in the wall surface of the casing c, and the said bearing convex part 52 is engage | inserted in this bearing recessed part 55. FIG. Reference numeral 56 in the drawing denotes a resin bush provided in the bearing recess 55.
Each of the open ends 53a, 53b and 54a, 54b of the communication grooves 53, 54 as described above is the surface of the rotating body 22 and is formed at a position adjacent to the control pieces 29, 30. A narrowed portion 57 formed of a circular recess is formed at a portion where the communication grooves 53 and 54 intersect.
The casing c is provided with an adjusting screw 45, and the opening of the restricting portion 57 is adjusted by moving the tip of the adjusting screw 45 into and out of the restricting portion 57 as in the first embodiment. Therefore, the fine adjustment function of the damping force is the same as that of the first embodiment.
[0030]
【The invention's effect】
According to the rotary damper of the present invention, the communication groove is formed in the contact surface between the rotating body and the casing, and when the rotating body is incorporated in the casing, the communication groove constitutes the short-circuit path. In addition, it is not necessary to form a through hole as in the prior art. Since only groove formation is sufficient in this way, the manufacturing cost can be greatly improved both when the die is formed and when it is formed by cutting.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view along an axis showing a first embodiment.
FIG. 2 shows a first embodiment and is a cross-sectional view in a direction perpendicular to the axis.
FIG. 3 is a side view of the first embodiment, which is partially cut away.
FIG. 4 is a front view of a bearing recess according to the first embodiment.
FIG. 5 is a cross-sectional view along an axis showing a second embodiment.
FIG. 6 is a cross-sectional view along an axis showing a third embodiment.
FIG. 7 shows a third embodiment and is a cross-sectional view in a direction perpendicular to the axis.
FIG. 8 shows a fourth embodiment and is a cross-sectional view along the axis.
FIG. 9 is a perspective view of an essential part showing a fourth embodiment.
FIG. 10 is a cross-sectional view along an axis showing a conventional rotary damper.
FIG. 11 is a cross-sectional view showing a conventional rotary damper in a direction perpendicular to the axis.

Claims (1)

With incorporated freely rolling rotating body relative times to the casing, and partition the first fluid chamber and the second fluid chamber by the partition wall provided in the control piece and the casing provided on the rotating body, the damping force generating means While the two fluid chambers are communicated with each other via a damping path, a short-circuit passage that communicates with both fluid chambers is provided separately from the flow path that passes through the damping force generating means. In the rotary damper provided with a variable throttle mechanism that makes the opening degree of the shaft variable , either the bearing concave portion or the bearing convex portion is formed on the rotating body, and either the bearing concave portion or the bearing convex portion is formed on the casing. When the other side is formed and the bearing concave portion or the bearing convex portion formed on the rotating body and the bearing convex portion or the bearing concave portion formed on the casing are fitted so as to be relatively rotatable, the bearing function is exhibited. To, to form the communication groove in the contact surface between the bearing recess and the bearing protrusion, the rotary damper, characterized in that forming the short-circuit passage by the communication groove.

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