JPH028528A - Vibration damper device - Google Patents

Abstract

PURPOSE:To permit the damping characteristic to be changed, even after a device is mounted to an equipment, by constituting a magnet member of electromagnetic coil and connecting a spring pat, formed by possessing expandable elasticity, to an outer cylinder part. CONSTITUTION:An outer cylinder part 21 containing magnetic fluid 24 and an inner cylinder part 22 consisting of magnet member are provided. The magnet member is constituted of an electromagnetic coil 26, and the damping characteristic can be changed by controlling a flow of current in this electromagnetic coil. A spring part 28, formed by possessing expandable elasticity, is connected to the outer cylinder part 21. A device itself is connected through this spring part 28 to a mounting bed 7 mounting an equipment serving as the vibro- isolating object. Thus, the damping characteristic can be changed even after the vibration damper device is mounted to the equipment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes a magnetic fluid that is attached to a device or the like and is housed in an outer cylinder, and an inner cylinder that is made of a magnetic body, and that has a magnetic The present invention relates to a vibration damping device that uses fluid to damp vibrations applied from the outside.

[Conventional technology]

FIG. 2 is a sectional view showing a conventional vibration isolator disclosed in, for example, Japanese Patent Application Laid-Open No. 55-94044.
2 is an outer cylindrical part made of a non-magnetic material, and 2 is an inner cylindrical part made of a magnetic material, and a passage part 3 with an appropriate gap is formed between the outer circumferential surface of the inner cylindrical part 2 and the inner circumferential surface of the outer cylindrical part 1. , and a magnetic fluid 4 is accommodated within the outer cylinder portion 1.

The inner cylinder part 2 is fixed to an inner cylinder support shaft part 5 made of a non-magnetic material on its upper surface, and above the inner cylinder part support shaft part 5 is a flat plate part 6.
An upper rack 7 for equipment, etc. is arranged through the outer cylinder part 1.
A lower pedestal 8 will be placed below. Further, as shown in the figure, the structure of the magnet body constituting the inner cylindrical portion 2 is such that a plurality of permanent magnets 9 are stacked with spacers 10 made of a non-magnetic material interposed therebetween, and a magnetic field is formed around the outer periphery of the inner cylindrical portion 2. This device is disposed between an upper pedestal 7 and a lower pedestal 8 on which equipment (not shown) is mounted, and is used to reduce vibrations and shocks applied from the lower pedestal 8 to the equipment.

Next, the operation will be explained. In the above configuration.

As the inner cylindrical portion 2 moves up and down, the magnetic fluid 4 flows through the narrow passage 3 while creating a velocity gradient, resulting in a pressure difference between the upper and lower surfaces of the inner cylindrical portion 2. This generates braking force. This braking force is used to speed up the transmission of vibrations generated on the lower pedestal 8 to the upper pedestal 7. It can be attenuated to a certain extent.

By configuring the inner cylinder g) 2 with a magnetic body, a magnetic field is applied to the magnetic fluid 4 flowing through the passage section 3.

The apparent viscosity of the magnetic fluid 4 can be further increased. Therefore, the braking force itself, which depends on the viscosity of the magnetic fluid 4 and the gap in the passage section 3, is affected by the magnetic field.
The apparent increase in viscosity provides an even greater damping effect, damping the induced vibrations instantly and with high efficiency.

[The invention attempts to solve the problem. 1! ! [) Since the conventional vibration damping device li is configured as described above, once the concentration of the magnetic fluid is determined, the damping characteristics are determined, and after the device is installed in equipment, etc., the characteristics of other areas cannot be changed. There have been problems in that the damping effect cannot be obtained, and it is not possible to stop or reduce the damping effect at any time when the damping effect is unnecessary.

This invention is a second invention to solve the above-mentioned problems, and its object is to provide a vibration damping device that can control damping characteristics in various ways.

[Charging? Means to solve]

In the vibration damping device according to the present invention, the magnet body is composed of an electromagnetic filter, and the damping characteristics can be changed by controlling the current flowing through the 11E magnetic coil. The device itself is attached to the equipment to be subjected to vibration isolation via a hollow part P having elasticity that can be expanded and contracted.

[Effect]

In the vibration damping device of this invention, since the magnet body is made of an electromagnetic coil, by controlling the T current flowing through the electromagnetic coil, the strength of the magnetic field is adjusted and the apparent viscosity of the magnetic fluid is changed. By changing the viscous resistance at the viscosity, it is possible to obtain the desired damping effect from a wide range of areas, and even when the viscosity changes significantly, the optimum characteristics can always be maintained instantaneously.

Furthermore, by attaching the device itself via an extensible spring section, the magnet body can also be moved in the horizontal direction, making it possible to attenuate imaging in all directions.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

8 in FIG. 1, 4 is an outer WI portion made of a non-magnetic material, and n is an inner cylindrical portion made of an electromagnet. forming a passageway in the gap;
The outer cylinder part n houses a magnetic fluid 60. The inner cylinder part 22 includes a shaft part 3, a coil part wound around the shaft part δ, and a magnetic material. From the yoke n (11) excited by The lower end of the periphery is fixed to the upper end surface of the outer cylinder part 21, and the center part is interposed between the upper end of the shaft part δ and the passage member,
In addition, it is fastened to the frame 7 via the M section 4, and not only obtains elastic properties due to the spring, but also seals the soil surface of the outer cylindrical section 4 to prevent magnetic fluids from leaking to the outside. is prevented.

The operation of this device will be explained next. As mentioned above, this device is used by fixing the equipment to be vibration-isolated on the upper mount 7.
First, calculate the damping characteristics for the expected vibration and impact load. In other words, a magnetic field is generated under the current P flowing through the coil and in the vicinity of the inner cylindrical portion 1, and the apparent viscosity of the magnetic fluid 24 in this portion changes due to the magnetic force. This change in apparent viscosity changes the damping characteristics, so
The current value of the coil I is adjusted to obtain the desired damping characteristic.If a vertical force is applied from the outside through the lower mount 8 to this installation, the outer cylinder part 21 will move up and down. Accordingly, the magnetic fluid 24 flows through the passage n due to the viscosity set by the magnetic force.

A damping effect occurs due to the resistance, and a desired damping effect is obtained. In this case, if you use an electromagnetic coil to generate the magnetic field as described above, you can instantly change the damping characteristics, so even if the load fluctuates significantly, you can always maintain the optimal characteristics! ! An answer? Even if an impact load is suddenly applied in a state where the damping effect is adjusted to be small in order to increase the speed, this can be alleviated by rapidly increasing the current.

Also, since it is connected to the frame 7 via the expandable spring Miyakoda, there is a phantom gap in the passageway. If the resistance is increased, the damping effect due to the resistance becomes smaller, but it is possible to generate a damping effect not only against vibrations in the vertical direction but also in the horizontal direction.

〔Effect of the invention〕

As described above, according to this invention, 1! Since a desired damping effect can be obtained by controlling the flow current in the magnetic coil, the damping characteristics can be changed even after the device is attached to a device such as an Ia device, which facilitates manufacturing.

! ! Furthermore, by attaching the device itself via a spring portion, there is an effect that the force can be damped in all directions.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing an image pickup attenuation device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional image pickup attenuation device. In the figure, ``Sa'' is an outer cylinder part, 22 is an inner cylinder part, ``magnetic fluid'' is a magnetic fluid, ``coils'' are shown, and 28 is a spring part.

Claims (1)

[Claims] An outer cylinder part containing a magnetic fluid and an inner cylinder part made of a magnet body are provided, and the apparent viscosity of the magnetic fluid passing between the outer cylinder part and the inner cylinder part is controlled by a magnetic field generated from the magnet body. In a vibration damping device that damps vibrations and shocks applied from the outside with the resulting large damping effect, the magnet body is composed of an electromagnetic coil, and the damping is achieved by controlling the current flowing through the electromagnetic coil. The device is configured such that its characteristics can be changed, and a spring portion having expandable and contractible elasticity is connected to the outer cylindrical portion, and the device itself is attached to equipment to be subjected to vibration isolation via this spring portion. A vibration damping device characterized by: