JPH0445701B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a vibration damping device.

Normally, in the upper structure of a ship, vibrations are generated by external excitation forces such as propeller excitation force or engine excitation force, which often impairs livability. Conventionally, in order to prevent these problems, the structure itself was reinforced to separate its natural frequency from the excitation frequency.

Problems to be Solved by the Invention According to the above-mentioned conventional structure, there is a problem that the structure must be strongly reinforced, which makes the reinforcing work troublesome and increases the cost.

Therefore, an object of the present invention is to provide a vibration damping device that can solve the above problems.

Means for Solving the Problem In order to solve the above-mentioned problem, the vibration damping device of the present invention has a leaf spring erected in the center of a closed container, the front and rear ends of which are supported on the wall of the container, and a load is placed on the leaf spring. In addition to attaching the weight, a communication hole is formed in the leaf spring to communicate with each other the left and right spatial chambers in the container separated by the leaf spring, and an adjustment tool is provided for adjusting the opening area of the communication hole, and the above-mentioned A container filled with liquid.

Function In the above configuration, when the container body is attached to a vibrating object, the weight and leaf spring reciprocate from side to side.
At this time, when the liquid in the space chambers on both sides of the leaf spring moves through the communication holes, the flow rate of the liquid is throttled to produce a damping function.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Reference numeral 1 denotes a closed container which is detachably attached to a vibrating object by means of bolts, for example, and is composed of a container body 2 filled with liquid and a lid 3 bolted to the container body 2. The container body 2 is elongated as a whole, and has a wide part 2a at the center.
In addition, the front and rear portions thereof are formed into narrow width portions 2b. Reference numeral 4 denotes a leaf spring that is disposed in the center of the container body 2 in the front-rear direction and in an upright state, and only its front and rear ends are supported by the end walls of the narrow portion 2b. As shown by A and B, it can vibrate in the left and right directions. 5 is the center notch 4a of the leaf spring 4
A weight engaged with the leaf spring 4 through the bolt 6
is fixed. Note that a weight adjustment hole 5a is formed in the weight 5 to prevent torsional deformation due to non-uniform rigidity of the leaf spring 4. Reference numeral 7 denotes communication holes formed in two upper portions of the leaf spring 4, which connect the left and right spatial chambers 8A, 8 partitioned by the leaf spring 4.
This is to allow comrades B to communicate. 9 is an adjustment tool for adjusting the opening area of the communication hole 7;
It is composed of a threaded rod 10 that is screwed and inserted into the. Reference numeral 11 denotes a changing device provided on both narrow width portions 2b of the container body 2 to change the range in which the leaf spring 4 vibrates. That is, this changing tool 11 includes a pair of wedge bodies 12A disposed on the left and right sides of the leaf spring 4,
12B, a plurality of threaded rods 13 that move these wedge bodies 12A, 12B in the front-back direction, and a fixing member that contacts the wedge surfaces of the wedge bodies 12A, 12B to press the wedge bodies 12A, 12B toward the leaf spring 4 side. It is composed of bodies 14A and 14B. In addition,
The threaded rod 13 and the wedge bodies 12A, 12B are each connected via a universal joint 15. Reference numeral 16 denotes a cushioning material provided on the central side wall of the container body 2 to prevent excessive vibration of the weight 5. In addition, a gasket (not shown) is installed between the container body 2 and the lid 3 to prevent the liquid filled in the container body 2 from leaking to the outside, and as shown in FIG. A spacer 18 with a packing 17 attached thereto is attached to the protruding portion of each threaded rod 10, 13, and a cap nut 19 is attached to the end face thereof. Note that the gap formed between the leaf spring 4 and the container body 2 and lid 3 is extremely small.

Next, the effect will be explained.

The vibration damping device is fixed to a vibrating object, for example a superstructure of a ship. Then, the leaf spring 4 and the weight 5
vibrates as shown by arrows A and B due to the excitation force acting on the hull, and the liquids in the respective chambers 8A and 8B flow into and out of each other through the communication hole 7, producing a damping effect. Further, in the above configuration, the changing tool 1
1 allows the support position of the leaf spring 4 to be changed (if changed, the fixed body 14A,
14B and rotate the threaded rod 13), the frequency of the vibration system consisting of the plate spring 4 and the weight 5 can be easily matched to the frequency of the vibrating object, and therefore the vibration of the vibrating object can be easily adjusted. As the frequency changes, the amplitude can also be reduced. Furthermore, when the frequency of the vibration damping device approaches the frequency of the vibrating object, a phenomenon of repulsion appears and the frequency of the vibrating object can be changed, and if the two are matched, the amount of repulsion becomes the largest. . Furthermore, the dynamic vibration absorption effect is greatly influenced by the damping value of the vibration system of the leaf spring 4 and the weight 5, and if an appropriate damping value is selected, the vibration absorption effect will be increased. In this device, liquid is placed inside the container body 2 to provide a damping effect, and
The flow of liquid caused by the vibrations of the leaf spring 4 and the weight 5 can be controlled by adjusting the opening area of the communication hole 7 to obtain an optimal damping value.

Next, another embodiment will be described based on FIGS. 5 to 7. In this device, the weight of the device of the previous embodiment is divided and made movable along a leaf spring. That is, the center of the leaf spring 21 is cut out over a certain range, and the connecting member 22 is arranged in this cut out part, and the both side leaf springs 21A, 2
1B via bolts 23. Projections 22a in the front and rear direction are formed on both sides of the leaf spring 21, and a pair of front and rear weights 24A, 24B are fitted and held in each projecting line 22a, and the front and rear weights 24A, A threaded rod 25 is inserted between 24B. Note that the threaded portions on both sides of the threaded rod 25 are threaded in opposite directions. 26 is a fixing nut.

Therefore, by rotating the threaded rod 25, the front and rear weights 24A, 24B can be moved toward and away from each other. In this way, since the weights can be divided and their positions moved relative to each other, the frequency of the vibration system consisting of the plate spring and the weight can be easily changed.

Effects of the Invention According to the configuration of the present invention described above, it is only necessary to attach the vibration damping device itself to the vibrating object, and therefore there is no need to reinforce the structure itself as in the conventional case, which eliminates the need for reinforcement work and reduces costs. can be reduced. In addition, a leaf spring is placed in the center of the container body filled with liquid, a communication hole is provided in the leaf spring, and an adjustment tool is provided to adjust the opening area of the communication hole, so that vibrations of the leaf spring can cause
When the liquid in the two-sided space moves through the communication hole to produce a damping function, the optimum damping effect can be obtained by adjusting the opening area of the communication hole. moreover,
Because the plate spring to which the weight is attached vibrates, a larger amount of liquid flows through the communication hole than if the inside of the container was divided only by the weight, so the damping effect can be exerted over a wide range. , an effective damping effect can be obtained even for minute movements of the weight.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is an overall vertical cross-sectional view, FIG. 2 is a view taken along the - arrow in FIG. 1, and FIG. 3 is a - arrow view in FIG. 4 is a sectional view of the main part, and FIGS. 5 to 7 show other embodiments. FIG. 5 is a plan view of the main part, and FIG. 6 is a sectional view of the main part. 7 is a view taken along the - arrow in FIG. 5. 1... Airtight container, 2... Container body, 3... Lid, 4...
Leaf spring, 5... Weight, 7... Communication hole, 8A, 8B... Space chamber, 9... Adjuster, 10... Threaded rod, 11... Modifier, 12A, 12B... Wedge body, 13... Threaded rod.

Claims (1)

[Claims] 1. With a leaf spring erected in the center of the closed container, its front and rear ends are supported on the wall of the container, a weight is attached to the leaf spring, and the left and right parts of the container divided by the leaf spring are attached to the leaf spring. A vibration damping device characterized in that a communication hole is formed to communicate the space chambers with each other, an adjustment tool is provided to adjust the opening area of the communication hole, and a liquid is filled in the container.