JP2000274478A - Vibration damper for precision mechanical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly efficiently and accurately damp vibration of precision mechanical equipment used in an automobile by constituting a vibration damper with a mount part for sealing a magnetic viscous fluid inside, a coil part for applying a magnetic field to this mount part and a control part for controlling this coil part. SOLUTION: A mount part 1 is composed of a base board side end part 3 on the coil part 2 side, an equipment side end part 4 having a cylindrical recessed part capable of supporting a shaft body projecting from the equipment side and an elastic part 5 between the end parts 3, 4, and a magnetic viscous fluid 6 is sealed inside the mount part 1. While, an unarranged side end surface of the mount part 1 of a coil part 2 is installed on a base board. When vibration is transmitted from the base board, this is analyzed by a control part, an electric current is carried to the coil part 2 from the control part so that the mount part 1 has the best vibration damping characteristic, and fluid viscosity is changed to viscosity capable of the best vibration damping by a magnetic field generated from this coil part to damp vibration of equipment to thereby accurately damp vibration to precision mechanical equipment according to an external situation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for precision equipment in which a magneto-rheological fluid is sealed and an effective vibration damping action is exhibited by changing the viscosity of the magneto-rheological fluid. It is.

[0002]

2. Description of the Related Art In recent years, the entry into other fields of the electronics field has necessitated the use of precision instruments which are subject to vibration in various situations. For example, cars are safe,
Due to demands for comfort and the like, it has become indispensable to process a large amount of information accurately and promptly. In the near future, a computer with high processing power will be installed in a car to realize an intelligent transport system being implemented as a national project. In such an automobile, a computer or the like that accurately determines the situation around the vehicle, a car audio or a car navigation that uses an optical pickup or an optical pickup as a recording medium to extract information using an optical pickup, and further controls an engine. In order to accurately operate precision equipment such as an engine control unit, it is necessary to control various vibrations from low-frequency vibrations due to unevenness of the road surface to high-frequency vibrations by the engine.

[0003] In order to control such vibrations, various elastic small vibration damping devices have been proposed. For example, JP-A-61-189336 and JP-A-61-2019
No. 46 discloses an elastic small vibration damping device having a structure in which a viscous fluid such as silicone oil is sealed in an elastic container such as a rubber bag or a rubber / elastomer cylinder to support equipment.

However, these small vibration damping devices are passive type vibration damping methods that generate a damping force in accordance with an external motion, and it is difficult to perform vibration damping according to various surrounding conditions. is there. For example, a mount that consists of two fluid chambers and an orifice that connects the two chambers, and obtains a damping force by using the inertial force of the viscous fluid enclosed inside the mount through the orifice, has a certain frequency. Due to the combined vibration damping setting, it is necessary to sufficiently suppress vibration with relatively low frequency when overcoming unevenness on the road surface and vibration with a certain range of frequency band such as vibration from the engine. Can not.

As an alternative to such a passive vibration damping method, a quasi-active vibration damping device that changes the damping characteristic and rigidity of an actuator in response to the movement of an external vibrating body, An active-type damping device, in which the actuator itself generates a force, can be cited. However, a quasi-active-type damping device is expected to have a certain level of damping effect even when the control system does not function. high. Such a vibration damping device requires a control part in addition to the vibration damping device. However, since the calculation processing has been enriched and the speed has been increased due to the recent spread of computers, these semi-active vibration damping methods have been used. A wide range of researches have been conducted on the control unit used in the system, and it has become sufficiently possible to send a signal to the vibration damping device and control it according to the situation.

One of the fluids that can be used inside such a vibration damping device is a magnetic viscous fluid (hereinafter referred to as an MR fluid). This MR fluid is characterized in that the flow characteristics change when a magnetic field is applied. This MR fluid is usually made by uniformly dispersing particles having a high magnetic permeability having a particle size of 0.1 to several tens of μm in a solvent. And the size of the particles and the difference in the operating mechanism.

[0007]

SUMMARY OF THE INVENTION The present invention has been accomplished in view of the above circumstances, and a quasi-active vibration damping method capable of controlling a damping characteristic in response to an external movement is provided.
It is a main object of the present invention to provide a vibration damping device for a precision instrument which can accurately and precisely control a precision instrument used inside an automobile or the like.

[0008]

According to the present invention, in order to achieve the above object, according to the first aspect, there is provided a mounting part in which an MR fluid is sealed, and a coil part for applying a magnetic field to the mounting part. And a control unit for controlling the coil unit.

Since the vibration damping device for precision equipment of the present invention has such a configuration, the viscosity of the MR fluid sealed in the mount portion can be controlled according to external circumstances. Therefore, the vibration damping characteristics of the mount portion can be changed according to the external situation, whereby highly efficient vibration damping with high efficiency and precision for precision equipment according to various external situations can be performed.

In this case, it is preferable that the mount portion and the coil portion are formed separately from each other. By forming the mount part and the coil part separately, the conventionally used vibration-proof liquid ring mount can be used as the mount part as it is, and the coil part and the control part for controlling it are attached to this. It is possible to easily obtain the vibration damping device for precision equipment according to the present invention, which is capable of damping precision equipment according to various external situations.

Further, in the present invention, as described in claim 3, it is preferable that the inside of the mount portion is formed by one fluid chamber. Two fluid chambers are formed,
In a vibration damping device of the type that communicates with an orifice during this time, MR
The orifice is clogged due to the property that the fluid is liable to precipitate, and the fluid with low particle concentration passes through, and the originally designed effect cannot be obtained, making it impossible to perform good vibration suppression for precision equipment Because.

Further, in the vibration damping device for precision equipment according to the present invention, the mounting portion supports the precision equipment side end disposed on the precision equipment side and the precision equipment. It consists of a board side end arranged on the board side and an elastic part provided between this precision instrument side end and the board side end, and a coil part is provided between the board side end and the board. Preferably, they are arranged. By arranging the coil portion between the substrate and the end of the mount portion on the substrate side in this manner, the coil portion can be arranged without affecting the vibration damping action of the mount portion. This is because a magnetic field can be applied.

The vibration damping device for precision equipment of the present invention has high social demands because it is used in a large amount, and receives vibrations of different types such as vibration from an engine and vibration from a road surface. It is preferable that the present invention is applied to an in-vehicle precision device in which it is difficult to control the vibration with a single vibration control characteristic.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vibration damping device for precision equipment according to the present invention will be specifically described with reference to FIG. A vibration damping device for precision equipment, which is an example of the present invention shown in FIG. 1, includes a mount unit 1, a coil unit 2 disposed at a lower end thereof, and a control unit (not shown) for controlling the coil unit 2. It is composed.

The mount portion 1 is disposed on the side of the coil portion 2 and is mounted on the substrate side end portion 3 to which the upper end surface of the coil portion 2 is attached.
A cylindrical concave portion is provided at a substantially center so as to be able to support a shaft body provided on the precision device side and protruding from the precision device side, and the concave portion supports the precision device via the shaft body. It comprises a precision device side end 4 and an elastic portion 5 disposed between the substrate side end 3 and the precision device side end 4. An MR fluid 6 is provided in the sealed interior of the mount 1.
Is sealed, and the viscosity is controlled by the coil unit 2 and a control unit that controls the coil unit 2. On the other hand, coil part 2
Is formed by winding a conducting wire 8 around a bobbin 7 formed in a bobbin shape, and a columnar iron core 9 is inserted in the center.

The end face of the coil section 2 on the side where the mount section 1 is not provided is mounted on a substrate (not shown) to which vibration is transmitted. On the other hand, an unillustrated shaft protruding from the precision device is inserted into a concave portion on the cylinder at the center of the precision device side end 4 of the mount portion 2, thereby supporting the precision device via the shaft. ing. As described above, when the precision device is supported on the substrate via the vibration damping device of the present invention, when vibration is transmitted to the substrate, the vibration can be attenuated by the vibration damping device for a precision device of the present invention. Therefore, vibration applied to precision equipment can be suppressed.

That is, in the vibration damping device for precision equipment of the present invention, when the vibration is transmitted from the substrate, the vibration is analyzed by the control unit or the like so that the mounting unit has the best vibration damping characteristics. An electric current is sent from the control unit to the coil unit 2, and the magnetic field generated by the coil unit 2 changes the viscosity of the MR fluid inside the mount unit 1 to a viscosity at which the best vibration can be controlled with respect to the current vibration. Damping can be done.

Next, the relationship between the mount and the coil used in the present invention will be described. The features of the vibration damping device for precision equipment of the present invention include a mount section in which the MR fluid is sealed, a coil section for applying a magnetic field to the mount section, and a control section (not shown) for controlling the coil section. In that it consists of Here, in the example shown in FIG. 1, the mount unit 1 and the coil unit 2 are formed separately from each other, but the present invention is not limited to this. A coil part may be formed. For example, a coil may be wound around the end 3 on the substrate side to integrally provide a coil portion. However, if the mount part and the coil part are formed separately, as in the example of FIG. 1, the conventional liquid ring type mount is used as it is as the mount part, and the coil part and the control part for controlling it are attached to this. Accordingly, it is possible to provide the vibration damping device for precision equipment according to the present invention, which can easily perform vibration suppression for precision equipment according to various external situations. Also, if the coil part and the mount part are formed separately,
The coil unit can be arranged at any position as long as a magnetic field can be applied to the mount unit. Further, if a magnetic field can be applied to the mount section, the coil section and the mount section can be arranged apart from each other.
Therefore, the degree of freedom in design can be greatly expanded. In the present invention, for various reasons as described above, it is preferable that the mount portion and the coil portion are formed separately.

As described above, when the coil portion and the mount portion are formed separately, the positional relationship between the coil portion and the mount portion is, as shown in FIG.
It is not limited to the positional relationship in which the coil part 2 and the coil part 2 are in contact with each other, that is, the structure in which the mount part 1 is supported by the substrate via the coil part 2. Any position is possible as long as it is possible. For example, as in the case where a coil portion is provided around a shaft protruding from the precision device side, a coil portion may be formed on the precision device side end side of the mount portion, and further, for example, around the elastic portion 5. An arrangement such as providing a coil unit may be used.

In the present invention, it is preferable to arrange the coil section so that a magnetic field can be applied to the mount section most efficiently. For this purpose, it is preferable to dispose the coil portion in the portion having the largest cross-sectional area of the mount portion,
Specifically, as an example shown in FIG. 1, an example in which the coil portion 2 is disposed on the lower surface of the substrate-side end portion 3 of the mount portion 1 can be mentioned as a preferable example.

Next, the mount used in the present invention will be described. The mount portion used in the present invention can be generally the same as the liquid ring mount used as a vibration isolating mount for precision equipment, and is connected to the substrate side to which vibration is transmitted as described above. This is usually constituted by a substrate side end to be connected, a precision device side end to be connected to a precision device which needs to suppress the vibration, and an elastic portion therebetween. In the present invention, the MR fluid is sealed inside the mount.

The shape of the mount is not particularly limited as long as it can seal the MR fluid inside. However, as described above, the two-fluid chamber is formed, and the orifice is clogged because the MR fluid has a characteristic that sedimentation is liable to occur if the damping device is of a type in which the orifice communicates with the orifice. Since the originally designed effect cannot be obtained due to the passage of a fluid with a low particle concentration, and good vibration control cannot be performed on precision equipment, the inside of the mount section must be formed by one fluid chamber. preferable.

In the present invention, the end of the mounting portion on the substrate side is a substrate supporting a precision instrument, for example, when the precision instrument is a vehicle-mounted precision instrument (such as a car audio), with or without a coil portion on the vehicle body. This is the part for attaching the mount part to In the example shown in FIG. 1, the shape of the substrate side end 3 is formed in a substantially disc shape, but a cylindrical concave portion is formed at the center as in the example of the precision instrument side end 4 described above. Any shape may be used as long as the mount portion can be supported by the coil portion or the substrate, such as a structure that supports the shaft protruding from the substrate side in the concave portion.

The material forming the substrate side end is not particularly limited, and any material can be used as long as it can be bonded to the elastic portion. For example, various resins such as polypropylene, metals, ceramics and the like can be mentioned. Since this portion is a portion for fixing the mount portion on the substrate or the coil portion, it is preferable that a member having a certain degree of rigidity be used, but if necessary, it has rubber elasticity used for an elastic portion described later. It is also possible to use a material.

On the other hand, the precision device side end disposed on the precision device side of the mount portion may have any shape as long as it can support the precision device, similarly to the substrate side end. For example, a disk-like shape or a shape in which a cylindrical concave portion is formed inside as in the example shown in FIG. 1 described above, and a shaft protruding from the precision equipment side is housed and fixed here may be used. . In addition, the same material as that of the above-described end portion on the substrate side can be used. In the example shown in FIG. 1, since the shaft protruding from the precision instrument side needs to be movable in a three-dimensional direction, the precision instrument side end 4 needs to be flexible. It is formed integrally with the elastic portion 5 using a material exhibiting the same rubber elasticity as the elastic portion 5 described later.

An elastic portion is provided between the substrate side end of the mount portion used in the present invention and the precision device side end. Since the elastic portion needs to have a function of suppressing vibration from the substrate side together with the MR fluid sealed inside the mount portion, the elastic portion is usually formed in a cylindrical shape made of a thin elastic body.

As the material that can be used for such an elastic portion, various elastic materials can be used, and are appropriately selected and used depending on the environment in which the elastic portion is used, the required elasticity, and the like. Specifically, natural rubber, isoprene rubber,
Styrene butadiene rubber, butadiene rubber, ethylene propylene rubber, acrylonitrile butadiene rubber, chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, acrylic rubber, thermoplastic elastomer (styrene, olefin, urethane, polyester, polyamide, polybutadiene , Vinyl chloride and fluorine).

The mount used in the present invention may be one in which the end on the precision instrument side, the end on the substrate side, and the elastic portion are integrally formed of the same material, or may be formed of different materials. May be used.

The present invention has a great feature in that an MR fluid is sealed inside such a mount portion. As the MR fluid used in the present invention, any fluid can be used as long as it has a function as an MR fluid.

A commonly used MR fluid is a fluid in which magnetizable solid powder (MR particles) is dispersed in a liquid vehicle. As the liquid vehicle used here,
Any material can be used as long as it does not react with the MR particles, but specific examples include water, hydrocarbon oil,
Mineral oils, fatty acid esters, other liquid organic substances, polydimethylsiloxane and the like can be mentioned. Preferred materials are those which are liquid at the operating temperature of the vibration damping device for precision equipment and which have a desirable viscosity for dispersion of MR particles.

As the MR particles, a substance which can be magnetized and has low coercivity (that is, little or no residual magnetism when the magnetic field is removed) is preferable.
Examples include powders of iron, nickel, cobalt, iron-nickel alloy, iron-cobalt alloy, iron-silicon alloy and the like. These MR particles are preferably spherical or nearly spherical, and preferably have a particle size in the range of 0.1 to several tens of μm.

In the MR fluid used in the present invention, other additives such as an antiwear agent and a surfactant can be added as required.

Next, the coil unit and the control unit used in the present invention will be described. The coil unit used in the vibration damping device for precision equipment of the present invention may be a coil unit that can apply a magnetic field to the MR fluid sealed in the mount unit and can control the strength of the magnetic field. The present invention is not limited to this. For example, by using one or a plurality of permanent magnets and controlling the positional relationship with the mount unit,
A device that applies a magnetic field to the R fluid and controls the strength of the magnetic field may be used. However, from the viewpoint of ease of control and the like, in the present invention, it is preferable to use a coil as the coil unit. Such coils include commonly used solenoid type, toroidal type, spiral type,
Pot-shaped coils and the like can be mentioned. In the present invention, a type having a magnetic core is preferably used from the viewpoint of increasing the magnetic flux density.

As a method of applying a magnetic field to the mount portion using such a coil portion, a method of applying a magnetic field to the MR fluid sealed in the mount portion simply by passing a current through the coil portion may be employed. A method may be used in which a magnetic field is applied in advance by a permanent magnet or the like, and a current is applied to the coil portion to increase or decrease the magnetic field. Further, the number of coil units is not limited to one, and a plurality of coil units may be arranged. In this case, the viscosity of the MR fluid changes depending on the direction of the magnetic field, and the vibration damping characteristics of the mount portion change.Therefore, by arranging the coil portions so that magnetic fields can be applied in different directions, and controlling the plurality of coil portions, More accurate vibration suppression control may be performed.

The control section used in the present invention is a section for controlling the strength of the magnetic field applied to the MR fluid inside the mount section by the above-described coil section. When a coil is used as the control unit in the present invention, any device can be used as long as it is a control device capable of controlling the amount of current or the like flowing through the coil. At this time, the control unit may control a current or the like flowing to the coil unit based on information sent from another unit, or the control unit includes a sensor such as an acceleration sensor for grasping a vibration state. Then, the generated vibration may be analyzed, and the coil unit may be controlled based on the analysis result.

The vibration damping device for precision equipment of the present invention is applicable to precision equipment used in a place where vibrations occur.
It can be used for any precision equipment. Above all, since it is mass-produced and used, there are high social demands, and there are multiple vibrations, such as vibrations from driving parts such as engines, and vibrations from the road surface. It is suitably used as a vibration damping device for in-vehicle precision equipment which is difficult to control. Examples of such in-vehicle precision equipment include computers for automatic driving of vehicles,
Examples include a computer for controlling various components, an engine control unit for controlling an engine, and precision equipment using an optical pickup such as a car audio system and a car navigation system.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

[0038]

EXAMPLE A vibration damping device for precision equipment as shown in FIG. 1 was prepared. The mount part 1 is formed by welding a diaphragm made of butyl rubber (the end part 4 and the elastic part 5 on the precision device side) on a polypropylene case (end part 3 on the substrate side). The small mount case was used as it was.

Approximately 2 cc of MR is
The fluid was sealed. The MR fluid used was MRF-132LD (trade name) of Lord Corporation. An outline of the composition of this MR fluid is PAO
(Synthetic base oil, manufactured by Chevron) 4.0 cSt; 20 wt
%, Dispersed particles (α-iron fine particles);
In addition, a phosphate ester as an antiwear agent and further a surfactant are added. The average particle diameter of the α-iron fine particles was about 1 μm.

The coil portion used was a bobbin made of aluminum with an S10C iron core inserted therein, and a 0.3 mm polyimide-coated conductor wound 300 times. FIG. 2 shows the results of measuring the magnetic flux density of the coil at 0.5 mm above the coil while changing the current flowing by 0.2 A at a time.
From this, it was found that the current and the generated magnetic flux density were almost in a proportional relationship, and a magnetic flux density of 25 mT was obtained with a current of 1.0 A. FIG. 3 shows the results of measuring the self-impedance of the coil, which is an index of the time change of the applied voltage and the flowing current. From this figure, it was found that a current instantaneously flows in response to the application of a voltage.

In order to examine the damping characteristics of such a damping device in which the MR fluid was sealed, a Bode diagram was created by inputting a sweep sine wave. FIG. 4 shows an outline of the experimental apparatus. On the upper side of the shaker 10, the prepared variable attenuation, mass,
A simulating device 11 for simulating a vibrating state of a CD player in a one-degree-of-freedom system having a spring is provided. Referring to the characteristic value of the support system in the actual in-vehicle CD player, the magnitude of the mass to be loaded on the
kg (including the mass of the mass-side acceleration pickup 12), and the spring constant was 196 N / m.

As a method of the experiment, a vibration signal from the digital sine controller 13 is input to the electromagnetic vibration device 10 through the power amplifier 14 to perform sweep vibration.
The signals from the input-side acceleration pickup 15 and the mass-side acceleration pickup 12 were taken into an FFT analyzer 17 via an amplifier 16, and the acceleration and transfer of both pickups 12, 15 were measured and arranged using a Bode diagram.
The input excitation frequency is 5 to 20 Hz and the amplitude is 0.3 m
m, a current of 1.5 A and two kinds of currents without current were used. Further, the change in the characteristics of the vibration damping device is caused by the external DC power supply 1.
8, a voltage was applied to the coil portion 2 to flow a current, and the generated magnetic field changed the characteristics of the MR fluid inside the mount portion 1 to change the vibration damping characteristics of the mount portion itself.
FIG. 5 shows the results.

FIG. 5 shows the results obtained by setting the sweep speed to 1 Hz / sec by the above-described experimental apparatus and experimental method. In the figure, a solid black line indicates a case where a current of 1.5 A flows through the coil, and a gray line indicates a case where no current flows through the coil. It can be seen that the amplitude ratio is reduced by about 70% by flowing the current, and the resonance point frequency is increased from 10 Hz to 15 Hz. In the case of a one-degree-of-freedom system having proportional viscous damping, the resonance frequency should decrease slightly as the damping term increases, but in this experiment, the resonance point increases as the damping term increases. The rigidity of the damping device is 50
%, Indicating that it is possible to change the damping characteristics of the damping device by passing a current.

[0044]

According to the vibration damping device for precision equipment of the present invention, there are provided a mount section in which an MR fluid is sealed, a coil section for applying a magnetic field to the mount section, and a control section for controlling the coil section. Since it is characterized by consisting of
The viscosity of the MR fluid sealed in the mount section can be controlled by the control section depending on external circumstances. Therefore, the vibration damping characteristics of the mount portion can be changed according to the external situation, and thereby, it is possible to accurately control the vibration of the precision equipment according to various external situations, and Can be performed favorably.

[Brief description of the drawings]

FIG. 1 is a schematic front view of an example of a vibration damping device for precision equipment according to the present invention, as viewed in partial cross section.

FIG. 2 is a graph showing a magnetic flux density with respect to a current of a coil portion manufactured in an example.

FIG. 3 is a graph showing self-impedance of a coil unit manufactured in an example.

FIG. 4 is an explanatory diagram for explaining an experimental apparatus in an example.

FIG. 5 is a graph showing characteristics of the vibration damping device of the present invention manufactured in the example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mount part, 2 ... Coil part, 3 ... Board side end part, 4 ... Precision equipment side end part, 5 ... Elastic part, 6 ... MR fluid, 7 ... Bobbin, 8 ...
Lead wire, 9 ... iron core, 10 ... shaker, 11 ...
Simulator, 12 ... Mass-side acceleration pickup, 1
3 Digital sign controller 14 Power amplifier 15 Input acceleration pickup
16… amplifier, 17… FFT analyzer, 1
8 DC power supply.

Claims (5)

[Claims] 1. A precision device, comprising: a mount section in which a magneto-rheological fluid is sealed, a coil section for applying a magnetic field to the mount section, and a control section for controlling the coil section. Damping device. 2. The vibration damping device for precision equipment according to claim 1, wherein said mount portion and said coil portion are formed separately. 3. The vibration damping device for precision equipment according to claim 1, wherein the inside of the mount portion is formed by one fluid chamber. 4. The mounting device according to claim 1, wherein the mounting portion is a precision device side end disposed on the precision device side, a substrate side end portion disposed on a substrate side supporting the precision device, and the precision device side end portion and the substrate. 4. An elastic part provided between the substrate and the side end, wherein the coil part is disposed between the substrate side end and the substrate. A vibration damping device for precision equipment according to any one of the preceding claims. 5. The vibration damping device for precision equipment according to claim 1, wherein the precision equipment is a vehicle-mounted precision equipment.