JPS6367281B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a vibration-resistant hanging tool used when hanging equipment such as lighting equipment from a member that vibrates frequently.

[Conventional technology]

Continuous vibrations are applied to beams and the vicinity to which equipment such as cranes and conveyors are attached. Therefore, when suspending equipment from such a location, it is necessary to prevent vibrations from being transmitted to the equipment, and in general, it is necessary to maintain a balance between the unique vibration frequency of the equipment and the vibration of the parts on which the equipment is hung. A method is used to avoid resonance by shifting the frequency. FIG. 6 shows an example of this, in which the hanging pipe 1, to which equipment is attached to the lower end, is passed through the bottom plate part 5 of the cylindrical main body 2, which is fixed to a member such as a beam or ceiling. Flange part 6 and bottom plate part 5 provided at the upper end
A coil spring 3 is interposed between the coil spring 3 and the load of the hanging pipe 1 and the equipment attached to the hanging pipe 1.
It is received by the main body 2 via.

[Problem to be solved by the invention]

Conventionally, the natural frequency changes depending on the weight of the equipment to be suspended, and the vibration at each vibration location is a combination of various frequencies and is not constant, so the vibration frequency of the attached member and the hanging The natural frequency must be determined according to the weight of the equipment. However, in the conventional example shown in FIG. 6, there is a problem that it is not possible to set a natural frequency different from the vibration frequency without preparing a plurality of coil springs 3 having different materials, diameters, wire diameters, number of turns, etc. Ta. The present invention has been made in view of the above circumstances, and its purpose is to provide a vibration-resistant hanging tool that can easily adjust the natural frequency, that is, the vibration frequency that can be absorbed.

[Means to solve the problem]

The vibration-resistant hanging tool of the present invention connects the upper end of a hanging pipe 1 with a device such as a lighting fixture attached to the lower end to a main body 2 fixed to another member such as a beam or a ceiling surface via a coil spring 3. This is a vibration-proof hanging device which applies torque to the coil spring 3 by locking one end of the coil spring 3 to the main body 2 and locking the other end to an adjustment ring 4 that can be rotated with respect to the main body 2. The spring constant is changed, and this structure solves the above problem. [Function] By rotating the adjustment ring 4, the coil spring 3 is twisted to change the center diameter of the coil, and by changing the elastic modulus, the natural frequency is changed according to the vibration frequency of the vibration place, the weight of the suspended equipment, etc. It is possible to accommodate vibration absorption under a wide range of vibration conditions without replacing other members or parts. [Example] An adjustment ring 4 is screwed onto the cylindrical main body 2, both ends of the coil spring 3 are locked to the bottom plate 5 of the main body 2 and the adjustment ring 4, and a flange is attached to the upper end of the hanging pipe 1. 6 is placed on top of the coil spring 3 through the opening window 7 in the center of the adjustment ring 4. Note that this collar portion 6 is prevented from rotating with respect to the adjustment ring 4, so that when the adjustment ring 4 is rotated, it rotates together with the adjustment ring 4.
The position where the coil spring 3 rests on the coil spring 3 is kept unchanged. In addition, the upper end of the coil spring 3 and the adjustment ring 4 are engaged so that the upper end of the coil spring 3 can freely slide in the axial direction so that the coil spring 3 can be compressed when the load of the equipment is applied, and even when the coil spring 3 is compressed. The engagement depth l is set large to prevent it from coming off. Within the range of this engagement depth l, the coil spring 3 absorbs vibrations as shown in FIGS. 3a and 3b. When it is necessary to change the natural frequency of this product, insert a jig into the hole 8 provided in the adjustment ring 4 and rotate the adjustment ring 4 relative to the main body 2.
This is done mainly by changing the diameter of the coil spring 3. As the adjustment ring 4 rotates, the coil spring 3, whose upper end is secured to the adjustment ring 4 and whose lower end is secured to the bottom plate portion 5 of the main body 2, is unwound or wound up to change its diameter. The spring constant K of the coil spring 3 is the transverse elastic modulus of the material G, the wire diameter d,
When the effective number of turns is n and the diameter is D, it is given by K=Gd ⁴ /8nD ³ (), so depending on the change in diameter D, the spring constant K
changes, and the natural frequency also changes. However, in this case, although the rate of change in the spring constant K decreases because the number of turns n increases as the diameter D becomes smaller, the rate of change due to a change in the diameter D is greater than the rate of change in the opposite direction due to a change in the number of turns n. It's bigger than that, so it doesn't have much of an effect. That is, if the increase Δn in the number of turns n when the coil spring 3 receives torque is 0.5, the diameter D of the coil spring 3 when free is 10, and the number n of turns when free is 5, then the diameter D of the coil spring 3 is The reduction ΔD is ΔD=Δn・D/n=0.5×10/5=1 Therefore, the ratio of the spring constant Kn when free and the spring constant Kt when torque is applied is Gd ⁴ according to the above formula (). /8×5×10 ³ :Gd ⁴ /8×5.5×9 ³ Decrease rate of spring constant K Kt/Kn=5.5×9 ³ /5×
10 ³ =0.8 As described above, if torque is applied to the coil spring 3 to change the diameter D, the spring constant K will change. By the way, the adjustment ring 4 is designed not only to be rotated relative to the main body 2, but also to be screwed into the main body 2, so that when the diameter D is changed by applying torque to the coil spring 3, the coil This is to prevent the vibration absorption range from becoming smaller due to the change in the pitch of the spring 3, especially if it becomes smaller. Now, assuming that the adjustment ring 4 and the main body 2 are screwed together with a right-handed thread, the coil spring 3 is right-handed, and the pitches of both are approximately the same, then the adjustment ring 4
When viewed from above and rotated counterclockwise, the adjustment ring 4 moves upward, increasing the distance between the adjustment ring 4 and the bottom plate 5 of the main body 2, and the coil spring 3 increases its diameter while increasing its number of turns n. Decrease D. If the coil spring 3 in the free state is in the state shown in FIG. 4a, it will be as shown in FIG. 4b. If you turn the adjustment ring 4 clockwise, the coil spring 3
As the diameter D increases and the number of turns n decreases, the distance between the adjustment ring 12 and the bottom plate 4 of the main body 2 decreases, as shown in FIG. In either case, the pitch P of the coil spring 3 hardly changes. The same applies to left-handed and left-handed threads. Of course, the pitch P of the coil spring 3 in the free state is large, and if it is possible to secure a sufficient vibration absorption range even if the pitch P becomes a little small, then the adjustment ring 4 and the main body 2 should be screwed together to the right. The screw and the coil spring 3 may be wound to the left. In this case, the rotation of the adjustment ring 4 results in the rotation as shown in FIGS. 5a and 5b. Furthermore, the adjustment ring 4 can be freely rotated at the same position without being screwed into the main body 2, and can be locked at any rotational position to prevent the adjustment ring 4 from returning due to the torque applied to the coil spring 3. It's good.
In this case, the change in pitch P is not as large as in the case shown in FIG.

【Effect of the invention】

In the present invention, one end of the coil spring is locked to the main body and the other end is locked to an adjustment ring that can be rotated with respect to the main body, thereby applying torque to the coil spring and changing its spring constant. By rotating the adjustment ring, you can twist the coil spring and change the center diameter of the coil.
By changing the elastic modulus, the natural frequency can be changed depending on the vibration frequency of the vibrating place and the weight of the hanging equipment, etc., making it possible to absorb vibrations under a wide range of vibration conditions without replacing other parts or components. It is something that can be made compatible.

[Brief explanation of drawings]

FIG. 1 is a cutaway perspective view of one embodiment of the present invention, and FIG.
The figure is a partial perspective view of the same as above, Figures 3a and b are sectional views showing the vibration absorption effect in the same as above, Figures 4a and b,
c and FIGS. 5a and 5b are cross-sectional views showing the same as above with different diameters of the coil springs, and FIG. 6 is a cross-sectional view of a conventional example, in which 1 is a suspension pipe, 2 is a main body, and 3 is a coil spring. , 4 is an adjustment ring.

Claims (1)

[Claims] 1. An earthquake-resistant hanging device in which the upper end of a hanging pipe with a device such as a lighting fixture attached to the lower end is connected via a coil spring to a main body that is fixed to another member such as a beam or ceiling surface. A vibration-proof type characterized in that one end is locked to the main body and the other end is locked to an adjustment ring that can be rotated relative to the main body, thereby applying torque to the coil spring and changing its spring constant. Hanging equipment.