JPH03101822A - Pendulum structure using elastic contracted body - Google Patents

Abstract

PURPOSE:To maintain oscillation without impeding the movement of a system by providing an elastic contracted body, a body to be oscillated and a supply and discharge device. CONSTITUTION:A frame 12 is provided with a leg 12a and a top 12b, and one end of the elastic contracted body 16 is connected to a tube arranged at the center of the top through a bearing 14. The body 16 is sheathed with a braided reinforcing structure 22, and the openings on both ends are sealed by a closing member 24. The initial braiding angle theta of the structure 22 is controlled to about 15-25 deg. when the tube 20 is expanded to its maximum diameter, and the structure 22 is stuck integrally to the member 24 with a caulking cap 28. A pressurized fluid is supplied to the body 16 through the supply and discharge pipe 38 connected to an air compressor. Consequently, oscillation can be sufficiently imparted, and the amplitude is increased.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention vibrates a vibrated body by supplying and discharging pressurized fluid to and from an elastic contractile body in accordance with the natural frequency of the vibrated body. It concerns a pendulum structure.

(Prior art) An elastic system that is not subjected to external forces, such as a cylinder floating on water, a suspended weight, or a cantilever beam with one end fixed, is in an equilibrium state when some external force is applied to it. When subjected to turbulence, each system freely oscillates at its own unique frequency.

For example, when a system as shown in FIG. 4 vibrates freely, assuming that the mass of the weight is m and the length of the thread is 1, the equation of motion is given by the following equation.

Here, when the amplitude is small, it is sufficient to consider sinθξθ, so the above equation can be rewritten as d2θ/d"t + (g/1)θ=0. Therefore, the period T of this system is , T=2π・F77T.

(Problems to be Solved by the Invention) Incidentally, in such an elastic system, the given potential energy is lost due to the movement of the mass point, so its amplitude gradually decreases as time passes. In other words, it is impossible to sustain the motion of a system unless some external force is applied to it.

The present invention was made in view of such problems,
The purpose is to provide a pendulum structure that can maintain its vibration without inhibiting the movement of the system.

(Means for achieving the object) In order to achieve this object, the device of the present invention has one end attached directly or indirectly to a fixed part, and expands in diameter and contracts in the axial direction by supplying pressurized fluid. an elastic contractile body that generates force;
It includes a vibrated body connected directly or indirectly to the other end of the elastic contraction body, and a supply/discharge device that supplies and discharges pressurized fluid to and from the elastic contraction body at predetermined intervals.

(Function) Since the elastic contractile body contracts and restores expansion in its axial direction by alternately supplying and discharging pressurized fluid, the supply and discharge interval is set to the characteristic circumference of the system including the vibrated body (3tJ) (or the characteristic Frequency)
By changing it accordingly, it is possible to maintain the free vibration of the system and adjust its amplitude.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a pendulum device 10 to which the present invention is applied, in which a frame 12 formed by joining pipe materials has a leg portion 12a and a top portion 12b, and is arranged at the center of the top portion. One end of an elastic contracting body 16 is connected to the pipe material 16 via a known bearing 14.

In this embodiment, the bearing 14 and the elastic contraction body 16 are connected via a connecting screw 18. This connecting screw 18
has a right-handed threaded portion and a left-handed threaded portion with the intermediate portion as a boundary, and these threaded portions are screwed into the bearing and the elastic contraction body to integrally connect these members. By changing the length and the length of the threaded part,
The length of those connections can be adjusted.

The elastic contractile body 16 is of an air bathog type,
As shown in FIG. 2, a tubular body 20 made of rubber or rubber-like elastic material is covered with a braided reinforcing structure 22, preferably of high tensile strength fibers, such as aromatic polyamide fibers (Kevlar), and A member 24 closes the openings at both ends.
At least one of the closing members is provided with a connecting hole that communicates with the internal space 26 of the tubular body.

The dovetail reinforcing structure 22 has an inner space 2 of the tubular body.
It has a pigeon-braided structure that reaches a so-called resting angle (54°44') when the tubular body 20 expands at its maximum diameter due to the application of pressurized fluid to 6, and the initial braiding angle θ is preferably shall be selected from within the range of 10° to 25°. In order to prevent the tubular body 20 and the braided reinforcing structure 22 from falling off the closure member 24, they are integrally fixed to the closure member 24 from the outside using a caulking cap 28.

Furthermore, a connecting tool 30 is screwed into the connecting hole formed in one of the closing members of the elastic contracting body, and a female threaded portion 32 is formed in the axial direction of the other closing member. The supply/discharge hole 30a and the through hole 30b, each shaped like this, supply and discharge pressurized fluid to the internal space 22 of the elastic contractile body, and are used for connection with another elastic contractile body or other member. The female threaded portion 32 formed on the other closing member is similarly provided for connection with another elastic contraction body or other member.

Since this elastic contractile body 16 has an extremely simple structure, it is extremely lightweight compared to other actuators such as electric motors and fluid cylinders, and since it is an air bag type, it can absorb the energy of pressurized fluid. It has the advantage of being able to efficiently convert motion into motion.

In the embodiment shown in FIG. 1, a pair of connecting bodies in which a plurality of elastic contracting bodies 16 are connected in series is used, and a seat 34 is attached to the lower end of the connecting bodies. The length of the connecting body can be adjusted by changing the number of . Of course, it is also possible to use one long elastic contraction body instead of a plurality of elastic contraction bodies.

Pressurized fluid to each elastic contractile body 16 forming the connection is provided via a supply/discharge pipe 38 connected to a suitable operating pressure source 36, for example an air compressor; A supply/discharge means 40 for supplying and discharging pressurized fluid supplied from the operating pressure source 36 is provided in the section, and the operation of the supply/discharge means 40 is controlled by a control means 42 .

The supply/discharge means 40 includes a pair of electromagnetic flow control valves, and these valves operate in opposite directions, that is, when one flow control valve connected to the operating pressure source is opened, the other valve is opened to the atmosphere. By closing the flow control valves of the wells, the pressure of the pressurized fluid between the flow control wells is adjusted. On the other hand, the control stage 42 generates operation signals according to a predetermined procedure to control the valve opening degrees of the flow control valves, and can freely control the time interval of the procedure, that is, the operation timing of the flow control valves. Can be changed settings.

Next, I will explain the operation of this pendulum structure.

Note that if the length of a connected body consisting of a plurality of elastic contracting bodies 16 when an initial setting pressure is applied is 1, then the natural period T of this elastic system is given by T=2π・F7T .

Therefore, when the seat 34 is released by pulling it forward or backward, for example, the seat 34 has a circumference XJI (
or natural frequency).

At this time, if the pressurized fluid is supplied and discharged to and from the coupling body in accordance with the period or frequency specific to the system, the system will resonate.
The seat 34 will vibrate with a certain degree of amplitude. In addition, under vibration conditions, the vibration applied to the system is shifted from its natural frequency by advancing or delaying the timing of supplying and discharging the pressurized fluid via the control means,
It is also possible to reduce the amplitude of the seat 34.

Furthermore, by increasing the initial setting pressure to contract each elastic contraction and shorten the initial length l of the connecting body in which they are connected, the natural frequency of the elastic system including the seat can be increased, and the natural frequency Vibration motion can be performed with numbers.

On the other hand, when the length of the connecting body is set longer by lowering the initial setting pressure, the natural frequency of the system can be lowered.

FIG. 3 is a schematic diagram showing another embodiment of the present invention. In this embodiment, a support member 46 is attached to each end of the elastic contracting body 16 spaced apart from each other, one end of which is fixed to the fixed part 44. A plurality of lobes, chains, support rods, etc. are connected to each other in the middle of the rod member 46, and one end of the rod member is spaced apart, while weights 48a and 48b are attached to the other end. , preferably two to three types of ropes, etc. are used.

Note that in order to ensure smooth movement of the ropes and other rod members 46, they are connected via appropriate bearings.

In this embodiment as well, the operation is similar to that of the structure shown in FIG. 1, and prior to vibration, each weight 48a,
48b is given an initial motion.

Pressurized fluid from the operating pressure source 36 is alternately supplied and discharged from the operating pressure source 36 to the elastic contractile body 16 via the supply and discharge means 40 in accordance with the natural frequency of the system including each weight.

Then, for example, when the rod member 46 is vibrated by supplying and discharging pressurized fluid to the elastic contractile body in accordance with the natural frequency of the system related to the weight 48a and the long rope, the system resonates. Increase amplitude.

In this case, the vibration of the system related to the weight 48b and the short rope tends to decrease because the vibration of the rod member 46 is different from the natural frequency of the system. By controlling the supply and discharge of pressurized fluid to and from the system by the control stage 42 so as to correspond to the natural frequency of the system including the weights 48b, sufficient vibrational motion is imparted to the system related to each weight. becomes.

Furthermore, in this embodiment, position sensors 50 are arranged along the vibration plane of each weight, and these sensors 5
0 is used to measure the amplitude of each weight, and based on the measurement signal corresponding to each amplitude, the control means 42 controls the feeding/discharging means 40, and the elastic contractile body 16 is
The supply and discharge of pressurized fluid to and from the pump can be changed.

That is, the amplitude of each weight can be set in advance, and the control can be performed to match the amplitude.

Note that the present invention is not limited to these examples,
For example, r-'-- can be applied to a stirring device that uses vibrations, and also to a separation device that uses centrifugal force generated during vibrations, and various modifications can be made within the scope of the claims. It is.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a pendulum structure according to the present invention, FIG. 2 is a partial cross-sectional view of an air bag type elastic contracting body suitable for the present invention, and FIG. 3 is a perspective view showing a pendulum structure according to the present invention. A schematic diagram showing another preferred embodiment, and FIG. 4 is an explanatory diagram showing a vibration system having a pendulum structure. 10 - Pendulum structure 12 - Frame 16 - Elastic contraction body 34 - Seat 36 - Operation pressure source 3
8 - Supply and discharge pipe 4 - Supply and discharge means 42 - Control means 44
- Fixed part 46 - Rod members 48a, 48b - Weight Fig. 1 Fig. 3

Claims (1)

[Claims] 1. An elastic contracting body whose one end is directly or indirectly attached to a fixed part and which expands and deforms in diameter by supplying pressurized fluid to generate a contractile force in the axial direction; 1. A pendulum structure using an elastic contractile body, comprising a connected vibrating body and a supply/discharge device for supplying and discharging pressurized fluid to and from the elastic contracture body at predetermined intervals.