JP2002310214A - Method of preventing vertical vibration caused by industrial machine, etc., by using float - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the vertical vibration caused by an industrial machine etc., by utilizing the spring effect of the compressibility of air while securing the restoring function and the stability of a float as well as a floating structure without an air room. SOLUTION: An industrial machine 15 is set in the float 12 inside a liquid tub 11, and a sealed air room 14 communicating with the lower part of the liquid tub is formed on the side of the liquid tub 11 for preventing the vertical vibration generated by the industrial machine 5. The vertical vibration in the float 12 is reduced by the spring effect produced by the compressibility of air in the air room 14, and the propagation of the vibration to the outside is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating type vertical vibration isolating method for preventing vibration generated by an industrial machine or the like, particularly vertical vibration when the industrial machine or the like is installed on a floating body in a liquid tank.

[0002] In general, vibration isolators and vibration isolators are mainly used for industrial machines such as forging machines, press machines, compressors and the like, which are sources of vibrations in factories and the like. Those using are widely known.

[0005] As an anti-vibration means for a forging machine, as shown in FIG. 5, a hollow floating body 2 is floated on a liquid 3 in a liquid tank 1, and the forging machine 5 is installed thereon. A floating type vibration isolating method is known. This floating type vibration isolation method
The vibration damping effect is remarkably higher than that using a metal spring or an air spring against horizontal vibration, and the lower surface of the floating body 2 is opened to make the air chamber 4 inside the bottom part against vertical vibration. It has been confirmed that a reduction effect is exhibited. However, at the same time, the following issues have been pointed out.

A large dead space is generated inside the floating body. In order to exhibit a sufficient vibration damping effect, a certain volume of air chamber is required. Therefore, a space (dead space) that cannot be used is generated inside the floating body 2.

[0005] The safety of the floating body is reduced. By providing the air chamber 4 at the bottom, the center of gravity of the floating body 2 becomes very high. In addition, a liquid surface exists inside the floating body.
It is widely known that these factors significantly reduce the stability of a roll movement. In other words, there is a serious problem in stability, such as the floating body 2 being greatly inclined with respect to the eccentric load and the moving load.

[0006] As shown in FIG.
Although the air chamber 4 can be slightly reduced by dividing the air chamber 4 into several parts by the partition wall 6, a considerably large number of the air chambers 4a are required in order to obtain a restoration performance comparable to a floating structure having no air chamber 4. , 4b, 4n.

There is a high danger when the airtightness of the air chamber is lost. If the airtightness of the air chamber 4 is lost for some reason, the floating body 2
Will be in a very dangerous situation. For example, FIG.
In the case of the floating body 2 shown in FIG.
If the air of b and 4n leaks, the function of the air chamber in that part is lost, and it tends to sink in general. In the peripheral part, the part sinks due to sinking, and in the worst case, the capsizing etc. There is also a danger of accidents.

[0008] Maintenance becomes complicated. Since the air chamber 4 is provided at the bottom of the floating body 2 in an airtight manner,
Maintenance work is not easy, and in some cases, it may be necessary to lift the floating body 2 from the liquid tank 1.

The present invention has been conceived in order to solve the problem of vibration isolation by a floating body of an industrial machine or the like.
The purpose is to reduce the vibration by using the spring effect of the compressibility of air, but to ensure the stability and stability of the floating body equivalent to a floating body structure without air chamber. An object of the present invention is to provide a vertical vibration isolating method.

According to the present invention having the above object, in order to prevent vertical vibration of an industrial machine or the like by installing an industrial machine or the like on a floating body in a liquid tank, a closed air chamber is provided in communication with a lower portion of the liquid tank. The vertical vibration of the floating body is reduced by a spring effect due to the compressibility of the air in the air chamber, and the propagation of the vibration to the outside is prevented.

In the above configuration, since there is no air chamber at the bottom of the floating body, the stability of the floating body is relatively high, and the air in the air chamber on the side of the liquid tank may leak to the outside. However, since the liquid level supporting the floating body falls while keeping the level, the floating body does not tilt. That is, the stability when the airtightness is lost is much higher than when the air chamber is provided in the floating body.

Further, maintenance work such as adjustment of air pressure is much easier than when an air chamber is provided in the floating body, and the air chamber may be communicated not with the lower part of the floating body but with the liquid tank part. It is possible to design flexibly with respect to the position and arrangement.

[0013] As for vibration isolation, in addition to the horizontal vibration isolation effect of the conventional floating type vibration isolation means, it also exerts an effect on vertical vibration, and the vibration isolation effect against vertical vibration is remarkable. It can be widely applied as a vibration preventing means for industrial machines such as presses, compressors and the like.

[0014]

FIG. 1 shows an embodiment of the present invention, in which reference numeral 11 denotes a liquid tank of a required scale, and 12 denotes a floating body, in which various industrial machines 15 serving as vibration sources are accommodated. It is constituted by a box so that it can be installed in a position, and is floated on a liquid (for example, water) 13 injected into a liquid tank 11 with an opening thereof facing upward.

Numerals 14 and 14 denote sealed air chambers of a required height provided on both sides of the liquid tank 11 so that a part of the liquid 13 in the liquid tank 11 flows out and in through openings provided in the lower part. And the air chambers 14, 14.
Is constantly pressurized by the pressure of the air in the air chamber, and when stationary, the liquid 13a is balanced at a position where the liquid level is lower than that of the floating body installation portion.

FIG. 2 shows a case where a forging machine 16 is installed above the floating body. Although air chambers 14 and 14 are provided on both sides of the liquid tank 11 in the drawing, this is not limited to the side of the liquid tank, and the illustration is omitted, but at an arbitrary position away from the liquid tank 11. Even if it is provided so as to communicate with the lower part of the liquid tank, it is possible to exhibit the vibration isolating effect.

In the above configuration, the air inside the air chamber 14 acts as a spring against the vertical movement of the liquid 13 caused by the vibration acting on the floating body 12, thereby exhibiting a vibration reducing effect. At this time, the volume of the air chamber 14 corresponds to the softness of the spring. The larger the volume of the air chamber 14 is, the lower the response peak frequency to the vertical vibration becomes.

The pressure applied to the air chamber 14 (head difference)
Is a factor that determines the magnitude of the inertial force of the fluid motion caused by vibration, and changes the amplitude of the vertical motion of the liquid surface. Specifically, as the applied pressure is increased (= the head difference is increased), the vibration damping effect against the vertical vibration is improved.

FIG. 3 shows the dimensions of each part in the unit of m in the vibration isolator according to the present invention used in the numerical simulation when a sine wave external force (vertical direction) acts on the floating body 12. Figure 4 is one in which an example of a result of the action of sinusoidal external force to 6H _Z to float 12 within the device, shown as ground reaction forces respond magnification at the bottom.

[0020] According to this, the frequency of the external force acting on the float 12 indicates a peak value at 1.0H _Z, 1.2H
_A minimum was seen at _Z. Ground reaction force ratio to 1.2H _Z or more high-frequency external force from the trend seen for asymptotic to about approximately 0.6 can be expected vibration reduction effect of approximately about 60% for an external force vibrations of higher frequency It is supposed to be.

Therefore, the floating vertical vibration isolating method according to the present invention can be applied to many machines that can be a source of vibration, for example, a forging machine, a press machine, a feeder, a compressor, a vibrating conveyor, and a washing machine for business use. It can be applied in various fields, such as mechanical looms, mold making machines, crushers, cogeneration, and power generators.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment showing an outline of a floating vertical vibration isolating method for an industrial machine or the like according to the present invention.

FIG. 2 is an explanatory diagram of another embodiment.

FIG. 3 is a longitudinal sectional view showing each part of the vibration isolator according to the present invention used in a numerical simulation together with real numbers.

FIG. 4 is a diagram showing a frequency characteristic of a ground reaction force response magnification by a numerical simulation.

FIG. 5 is an explanatory view of a floating vibration isolator employed in a conventional forging machine.

FIG. 6 is an explanatory view of a floating vibration isolator formed by dividing an air chamber at the bottom of the floating body into a plurality of chambers.

[Explanation of symbols]

 Reference Signs List 11 liquid tank 12 floating body 13 liquid in liquid tank 13a liquid in air chamber 14 air chamber 15 various industrial machines 16 forging machine

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuyoshi Nozu 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 3J048 AA02 AC04 BE02 BE03 DA01 EA07 3J069 AA04 CC40

Claims (1)

[Claims] 1. An industrial machine or the like is installed on a floating body in a liquid tank,
In order to prevent vertical vibration of industrial machines, etc., a closed air chamber is provided in communication with the lower part of the liquid tank, and vertical vibration in the floating body is reduced by a spring effect due to the compressibility of the air in the air chamber. A floating vertical vibration isolation method for industrial machines and the like, characterized by preventing vibration propagation.