JPH0438059Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a rotary damper suitable as a shock absorber for absorbing a falling impact caused by free rotation of a rotating object.

<Conventional Examples and Problems> Generally, pianos, record players, portable computers, cobby machines and other office equipment,
Opening/closing lids, toilet seats, toilet lids, etc. of Western-style toilets, etc.,
The general base is axially supported, and the other end is a free end, which is rotatable within a rotation angle range of about a quarter circle to about 120 degrees.

When closing such a rotating object, such as the keyboard lid of a piano, the keyboard lid becomes a free-falling rotating object, and if you do not close it with your hands all the way, it will make a loud impact sound at its final horizontal stopping point. At the same time, the collision vibration may damage other components or cause an imbalance in tuning.

Therefore, as a means of alleviating the impact of free falling of a rotating object, it is conceivable to provide a damping spring or a rotary damper that utilizes liquid resistance or frictional resistance on the support shaft of the rotating base. However, according to the former method, it is necessary to set the spring force to be suitable for damping at the final stop, but smooth movement cannot be obtained simply by using the spring alone. It also has the disadvantage of being large in shape.

On the other hand, since the latter rotary damper generally has the same damping force at any position, if an appropriate damping force is applied at the final stop, the damping effect at the start of rotation will be too strong and the closing operation will be poor. On the other hand, if it is set appropriately at the start, there will be almost no damping effect at the final stop. In other words, the torque of a rotating object that is in free fall motion is not constant from the beginning to the end, and the torque fluctuates as the horizontal distance from the rotation axis to the gravity direction from the rotation axis to the center of gravity changes.
This means that a simple rotary damper with a constant damping rate cannot be used.

<Means for Solving the Problems> The present invention was provided to eliminate the above-mentioned drawbacks, and its purpose is to reduce the rotational speed of a free-falling rotating object to an appropriate rotational speed in response to torque changes. To provide a small-sized rotary damper combined with a spring that can rotate smoothly while maintaining the same.

Another object of the present invention is to provide a spring-combined rotary damper that can be applied to various existing products involving rotating objects without major design changes.

Still another object of the present invention is to provide a spring-combined rotary damper that has a simple structure, low manufacturing cost, and is easy to install. Therefore, the above purpose is to provide a case body having a hollow part with a circular cross section, a case body which is loaded into the hollow part formed to have a diameter slightly smaller than the inner diameter of the hollow part, and which is extended and fixed to one end of the case body. A rotating body formed such that a connecting rod protrudes from the case body, a viscous liquid liquid-tightly filled in a gap between the hollow part and the rotating body, and an insertion hole formed in the axial direction of the rotating body. One end is hooked to the case body and the other end is hooked to the rotating body so that it can be loaded into the hole and freely move within a predetermined rotational angle range without any elastic force acting on it. This is achieved by a spring-combined rotary damper characterized by having a spring and a spring.

<Example> Next, the present invention will be explained in more detail according to an example shown in the drawings.

FIG. 1 shows an embodiment applied to a piano keyboard lid 1, in which reference numeral 11 denotes a rotation support shaft of the keyboard lid, and 2
9 is a rotary damper according to the present invention, and 9 is a joint for connecting and fixing the rotary damper 2 to a rotating support shaft 11.

An example of the structure of the rotary damper 2 is shown in FIGS. 2 to 4, and 21 is a hollow portion 22 having a circular cross section.
The case body 23 is a hollow bottom portion formed at one end of the hollow portion 22, and is integrally formed with the case body 21. Reference numeral 24 denotes an engagement hole formed at a suitable position in the hollow bottom portion 23. 3 is a rotating body formed to have a diameter slightly smaller than the inner diameter of the hollow portion 22;
is a connecting rod extending in the axial direction at one end of the rotating body 3 and rotating integrally with the rotating body 3. The rotating body 3 is loaded into the hollow part 22 so that the connecting rod 31 protrudes from the open end of the hollow part 22. Reference numerals 32 and 33 indicate a groove-shaped recess for fitting an O-ring formed near the end of the rotating body; 4 indicates a spring insertion hole formed through the axis of the rotating body 3 and the connecting rod 31; 34;
35a and 35b are notched stepped portions. Reference numeral 5 designates a torsion bar spring that is stretched between the case body 21 and the rotating body 3, and is loosely inserted into the insertion hole 4, and has bent portions formed at both ends as shown in FIG. Bent part 51
is inserted into and engaged with the case body 21, and the other bent portion 52 is inserted into and engaged with the engagement hole 36 formed near the tip of the connecting rod 31. In addition, the engagement hole 2
As shown in FIG. 4, reference numeral 4 is formed into an arcuate elongated hole concentrically with the hollow portion 22, and a bent portion 51 of the torsion bar spring 5 is fitted into the central portion of the elongated arc hole.
can be moved left and right by angles θ ₁ and θ ₂ . 6 is from the bottle hole 37 to the spring insertion hole 4
A retaining pin is inserted into the interior and fixed in contact with the bent portion 52. 71 and 72 are sealing O-rings fitted into the O-ring recesses 32 and 33;
8 is liquid-tightly sealed by O-rings 71 and 72 between the circumferential surface of the rotating body 3 and the inner surface of the hollow portion 22.
It is a viscous liquid filled with grease.

The rotary damper 2 assembled in this way is attached to the rotation support shaft 1 when the keyboard lid 1 of the piano is in the open state 1'.
Connect and fix to 1. When the keyboard lid 1 is rotated in the direction of arrow P for closing and allowed to fall freely, the rotating body 3 rotates within the hollow portion 22 via the joint 9 and the connecting rod 31. At this time, the torsion bar spring 5 also rotates, but no elastic force is generated while its bent portion 51 is moving rightward within the angle θ ₂ in FIG. 4. On the other hand, viscous resistance due to the viscous liquid 8 occurs on the circumferential surface of the rotating body 3, and frictional resistance due to sliding of the O-rings 71 and 72 acts. Therefore, when the rotational torque of the rotary support shaft 11 is small when the keyboard lid 1 starts closing, the braking by the torsion bar spring 5 does not act, and a small braking force due to viscous resistance and frictional resistance acts. The keyboard lid 1 rotates relatively quickly.

Next, the rotating body 3 further rotates to form the bent portion 51.
After it has finished rotating within the angle θ ₂ and is locked at the end of the engagement hole 24, the rotating body 3 has the above-mentioned liquid resistance,
In addition to frictional resistance, a spring force is applied by the torsion bar spring 5. Therefore, the keyboard lid 1
The large rotational torque of the rotating support shaft 11 in the second half of the free fall is mainly absorbed by the elastic force of the torsion bar spring 5, and the keyboard lid 1 falls and closes at a gentle speed. FIG. 5 shows an embodiment in which the torsion bar spring 5 is replaced with a coil spring 5a that utilizes torsion elastic force. The action and effect in this case are the same as described above.

Note that the shape of the rotary damper 2, the viscous liquid 8, etc.
viscosity, frictional force of O-rings 71, 72, torsion bar spring 5 or coil spring 5a
It is an embodiment included in the present invention to appropriately select and change the length, thickness, etc.

<Effects> According to the present invention, it is possible to prevent the occurrence of large impact noises and vibrations at the final stopping point of a freely falling rotating object, and also to allow a smooth fall without feeling that the entire falling motion is too slow or too fast. It is possible to realize the operation.

In addition, since it is a combination type, the spring needed to obtain a predetermined buffering force can be shortened or shortened, and the overall shape can be made compact, thus achieving the above-mentioned objectives well.

[Brief explanation of drawings]

The drawings show an embodiment of the rotary damper according to the present invention. FIG. 1 is a partially omitted perspective view showing an example applied to a piano keyboard lid, FIG. FIG. 4 is a sectional view taken along the - line in FIG. 2, and FIG. 5 is a central vertical sectional view showing another embodiment. 2...Rotary damper, 3...Rotating body, 4...
... Spring insertion hole, 5 ... Torsion bar spring, 6 ... Retaining pin, 8 ... Viscous liquid, 9
...Joint, 11...Rotating shaft, 21...Case body, 22...Hollow part, 31...Connection rod.

Claims (1)

[Claims for Utility Model Registration] 1. A case body having a hollow part with a circular cross section, and a case body which is loaded into the hollow part and whose diameter is slightly smaller than the inner diameter of the hollow part, and which is extended and fixed at one end of the case body. A rotating body formed such that a connecting rod protrudes from the case body, a viscous liquid that is liquid-tightly filled in a gap between the hollow portion and the rotating body, and an insertion hole formed in the axial direction of the rotating body. One end is hooked to the case body and the other end is hooked to the rotating body so that it can be loaded into the body and move freely within a predetermined rotational angle range without any elastic force acting on it. A spring combination type rotary damper characterized by having a spring; 2. The spring combination type rotary damper according to claim 1, wherein the viscous liquid is liquid-tightly filled with a sealing O-ring fitted to the circumferential surface of the rotating body. 3. The spring combination type rotary damper according to claim 1 or 2, wherein the spring is a torsion bar spring. 4. The spring combination type rotary damper according to claim 1 or 2, wherein the spring is a coil spring.