Vibration control unit

Abstract

[Problem] To address the technical problem of developing a vibration control unit capable of exhibiting vibration control action even with respect to a sudden vibration load and a vibration load from a direction other than a main vibration control direction while demonstrating vibration control performance in the main vibration load direction. [Solution] A vibration control unit 1 according to the present invention is provided with: a basal part base 2 located in a vibration environment; a second basal part base 3 independently provided in non-contact with the basal part base 2; a load vibration control body 4 provided between the basal part bases; a support base 5 independently provided in non-contact with the second basal part base 3; a magnetic field-responsive variable viscoelastic body 6 provided between the second basal part base 3 and the support base 5; and a magnetic field generating means 7 for exciting the variable viscoelastic body 6. The magnetic field generating means 7 is arranged along an arrangement form of the variable viscoelastic body 6 in a plan view, and when sudden vibration is generated, the variable viscoelastic body 6 is excited by the magnetic field generating means 7 so as to change a complex elastic modulus of the variable viscoelastic body 6 in an increasing direction.

Description

Anti-vibration unit

[0001] The present invention relates to vibration-damping units that support various types of equipment (supported bodies), and in particular to vibration-damping units that have vibration-damping properties in the main vibration load direction, while also exhibiting vibration-damping properties against sudden vibration loads and vibration loads from directions other than the main vibration-damping direction, thereby being able to adequately protect the supported body that is supported or mounted on it.

[0002] Various precision instruments, such as precision measuring instruments, are placed in highly vibration-damping and vibration-isolated environments to ensure accurate data output. Therefore, the supported body of this type of equipment is often installed in an appropriate location via a vibration isolation unit that provides vibration isolation. The functions and performance required of the vibration isolation unit are determined based on the vibration load expected in the installation environment. However, in actual installation environments, while most of the vibration loads are within the range set by the vibration isolation design, a steady vibration input (hereinafter referred to as a "steady rest state") can sometimes result in excessive sudden vibration loads, or vibration loads can occur in directions other than the expected direction due to changes in the center of gravity of the supported body.

[0003] Such excessive loads or vibration loads from unexpected vibration load directions cannot be handled by vibration isolation units that have vibration control and vibration absorption capabilities that are designed for vibration loads in specific directions. Of course, it is possible to determine and select the performance and specifications of the vibration isolation unit so that it can also handle such unexpected vibration loads, but the range of vibration isolation capabilities is limited, and naturally the responsiveness of the vibration isolation capabilities to the vibration loads in the specific directions that are primarily used will be extremely slow, so in reality this type of response is not appropriate.

[0004] Japanese Patent Application Publication No. 2020-133699 Japanese Patent No. 6941524 Japanese Patent No. 6166975

[0005] The present invention was made taking this background into consideration, and its technical objective was to develop an anti-vibration unit that has vibration-damping properties in the main vibration load direction, while also being able to provide vibration-damping effects in response to sudden vibration loads and vibration loads from directions other than the main vibration-damping direction.

[0006] In other words, the vibration-damping unit described in claim 1 is a vibration-damping unit that exhibits an overload buffering effect to reduce and avoid the effects of sudden vibration loads input from outside the vibration-damping unit that attenuates specified vibrations, and also exhibits a steady buffering effect when the vibration environment reaches a steady, resting state.This vibration-damping unit comprises: a base base in a vibration environment; a second base base that is provided independently and non-contacting the base base; a load vibration-damping body that is provided between the base base and the second base base; a support base that is provided independently and non-contacting the second base base; a magnetic field-responsive variable viscoelastic body that is provided between the second base base and the support base; and a magnetic field generating means that magnetizes the variable viscoelastic body, wherein the magnetic field generating means is arranged to follow the arrangement of the variable viscoelastic body in a planar view; and when sudden vibration occurs, the variable viscoelastic body is excited by the magnetic field generating means, thereby changing the complex elastic modulus of the variable viscoelastic body in an increasing direction.

[0007] In addition to the requirements of claim 1, the vibration isolation unit described in claim 2 is characterized in that the second base is a mounting base that supports a supported body.

[0008] Furthermore, the vibration-damping unit described in claim 3 is characterized in that, in addition to the requirements described in claim 1 or 2, the support base is configured to form a circumferential area that is double-cylindrical on the peripheral side of the second base base.

[0009] Furthermore, the vibration-damping unit described in claim 4 is characterized in that, in addition to the requirements described in claim 3, the load vibration-damping body mainly supports the load of the supported body when the supported body is placed on the vibration-damping unit, and the compression amount of the load vibration-damping body when unloaded is set so that the apparent load acting on the variable viscoelastic body is zero.

[0010] Furthermore, the vibration-damping unit described in claim 5 is characterized in that, in addition to the requirements described in claim 4, the vibration-damping unit is provided with an elastic force adjustment means for adjusting the compression amount of the load vibration-damping body so that the apparent load acting on the variable viscoelastic body becomes zero.

[0011] Furthermore, the vibration isolation unit described in claim 6 is characterized in that, in addition to the requirements of any one of claims 1 to 5, one end of the second base is embedded and fixed in a load vibration isolation body.

[0012] Furthermore, the vibration-damping unit described in claim 7 is characterized in that, in addition to the requirements described in any one of claims 1 to 6, one end of the second base is embedded and fixed in a variable viscoelastic body.

[0013] Furthermore, the vibration-damping unit described in claim 8 is characterized in that, in addition to the requirements described in any one of claims 3 to 7, a portion of the base also serves as a support base, and is configured to have a peripheral area and be combined with a second base in a double-tube shape.

[0014] Furthermore, the vibration-damping unit described in claim 9 is characterized in that, in addition to the requirements described in claim 8, the second base is formed in an inverted bowl shape, and a load-absorbing vibration-damping body is provided between the inner lower surface of this inverted bowl shape and the base.

[0015] Furthermore, the vibration-damping unit described in claim 10 is characterized in that, in addition to the requirements of claim 8, the variable viscoelastic body is provided inside a support base in the base base, and the magnetic field generating means for magnetizing the variable viscoelastic body is arranged between the variable viscoelastic body and the support base.

[0016] Furthermore, the vibration-isolating unit according to claim 11 is characterized in that, in addition to the requirements of any one of claims 1 to 10, the load vibration-isolating body is made of a molded body of rubber or a viscoelastic material.

[0017] Furthermore, a vibration isolation unit according to claim 12 is characterized in that, in addition to the requirements of any one of claims 1 to 10, the load vibration isolator is formed of a spring element.

[0018] Furthermore, the vibration-isolating unit described in claim 13 is characterized in that, in addition to the requirements of any one of claims 1 to 10, the load vibration-isolating body has a composite structure that combines a molded body made of rubber or a viscoelastic material with a spring element.The above-mentioned problems are solved by the means described in each claim.

[0019] According to the first or second aspect of the present invention, the vibration-isolating unit provides a combined vibration-isolating effect through the cooperation of the load vibration isolator and the variable viscoelastic body when a steady-state vibration load is applied between the base base and the second base base. When a sudden vibration load exceeding the steady-state vibration load occurs, the magnetic field generating means is energized to excite the variable viscoelastic body, increasing the complex modulus of elasticity to withstand the excessive vibration load. When the excessive vibration load is eliminated, the magnetic field is adjusted to decrease the complex modulus of the variable viscoelastic body, restoring the combined action of the load vibration isolator and the variable viscoelastic body to their original state. This restores the vibration-isolating effect to the steady-state vibration-isolating state, thereby providing stable vibration-isolating performance. Furthermore, when a vibration load from a direction different from the expected vibration load direction occurs due to a change in the center of gravity of the supported body, the variable viscoelastic body is similarly excited, changing the complex modulus within an increasing range in response to the vibration load from the different direction, thereby adjusting the cooperative action with the load vibration isolator, thereby providing vibration-isolating effect in the steady-state vibration-isolating state. Furthermore, when the vibration load from the expected vibration load direction changes, the variable viscoelastic body is excited to change the complex elastic modulus within the increasing region, and by working in cooperation with the load vibration isolator, it is possible to achieve vibration damping action according to the changing vibration load.

[0020] Furthermore, according to the invention described in claim 3, the support base is arranged so as to form a circumferential area that is double-cylindrical on the circumferential side of the second base base, thereby enabling the effect of the above-mentioned variable viscoelastic body to be exerted against circumferential vibration modes.

[0021] According to the fourth aspect of the present invention, when the supported object is placed on the vibration isolation unit, the load vibration isolator mainly supports the load of the supported object, and the apparent load acting on the variable viscoelastic object is set to 0, so that the control of the variable viscoelastic object can be designed starting from an unloaded state. In other words, the control of the variable viscoelastic object can be designed without taking the load of the supported object into consideration.

[0022] Furthermore, according to the invention described in claim 5, the compression amount of the load vibration-isolating body can be adjusted even after the supported body has been placed on the vibration-isolating unit, and the apparent load acting on the variable viscoelastic body can be more accurately set to zero.

[0023] According to the sixth aspect of the present invention, one end of the second base is embedded in a load vibration isolator including a viscoelastic body. This allows vibration damping to be achieved by combining the shear and torsional deformation of the load vibration isolator with the deformation of the second base in the vibration direction, i.e., the compression or other deformation of the variable viscoelastic body. When the magnitude or direction of vibration applied to the second base changes, the variable viscoelastic body can be excited as needed to change the complex modulus within an increasing range, thereby adjusting the vibration damping effect due to the compression or other deformation of the variable viscoelastic body, thereby achieving vibration damping in accordance with the changing vibration load. Furthermore, when sudden excessive vibration occurs in the base, the vibration load on the supported object can be reduced by exciting the variable viscoelastic body in accordance with the vibration load and increasing the complex modulus before the load vibration isolator exceeds its vibration-damping limit.

[0024] According to the seventh aspect of the present invention, one end of the second base is embedded and fixed in the variable viscoelastic body. This allows vibration damping to be achieved by combining the damping action of vibrations applied to the second base through shear and torsional deformation of the variable viscoelastic body with the damping action of deformation in the vibration direction applied to the second base, i.e., compression and other deformation of the load vibration isolator. When the magnitude or direction of vibrations applied to the second base changes, the variable viscoelastic body can be excited as needed to change the complex modulus within an increasing range, thereby adjusting the vibration damping action caused by the shear and torsional deformation of the variable viscoelastic body and achieving vibration damping according to the changing vibration load. Furthermore, when sudden excessive vibrations occur in the base, the vibration load on the supported object can be reduced by magnetizing the variable viscoelastic body to increase the complex modulus according to the vibration load before the load vibration isolator exceeds its vibration-damping limit.

[0025] Furthermore, according to the invention described in claim 8, the support base is arranged to form a circumferential area that is double-cylindrical on the peripheral side of the second base base, and a part of the base base is also used as the support base, and is combined with the second base base in a double-cylindrical shape having a circumferential area, so that the vibration-damping unit can be made compact while still achieving the above-mentioned vibration-damping effect.

[0026] Furthermore, according to the invention described in claim 9, the second base is formed in an inverted bowl shape, and a load-bearing vibration-damping body is provided between the inner lower surface of this inverted bowl shape and the base base. This allows the vibration-damping function to be achieved while also making the vibration-damping unit more compact in the thickness direction, thereby enabling the vibration-damping unit to be made thinner.

[0027] Furthermore, according to the invention described in claim 10, the variable viscoelastic body is provided inside the support base of the base base, and a magnetic field generating means for magnetizing the variable viscoelastic body is arranged between the variable viscoelastic body and the support base, thereby making it possible to easily control the magnetic field of the variable viscoelastic body in the above-mentioned vibration-damping action while also making the vibration-damping unit more compact.

[0028] According to the invention of claim 11, the load vibration isolator is made of a molded body of rubber or viscoelastic material, so that the vibration damping effect is excellent in the vibration damping action, and the vibration damping performance of the vibration damping unit can be improved.

[0029] According to the invention as set forth in claim 12, since the load vibration isolator is composed of a spring element, it is possible to improve the bearing capacity for a high load while achieving the vibration isolating effect described above.

[0030] Furthermore, according to the invention described in claim 13, the load vibration damper is a composite structure that combines a molded body made of rubber or a viscoelastic material with a spring element, thereby improving the design freedom in balancing the vibration damping effect and the ability to support high loads, and making it possible to realize a vibration damping unit with excellent load support and vibration damping properties.

[0031] FIG. 1 is a longitudinal cross-sectional view showing Examples 1 to 3 of the image stabilization unit according to the present invention. FIG. 2 is a longitudinal cross-sectional view showing Example 4 of the same. FIG. 3 is a longitudinal cross-sectional view showing Examples 5 and 6 of the same. FIG. 4 is a longitudinal cross-sectional view showing Examples 7 to 13 of the same. FIG. 5 is a longitudinal cross-sectional view showing Examples 14 to 17 of the same. FIG. 6 is a longitudinal cross-sectional view showing Examples 18 and 19 of the same. FIG. 7 is a longitudinal cross-sectional view showing Examples 20 and 21 of the same. FIG. 8 is a longitudinal cross-sectional view showing Examples 22 and 23 of the same.

[0032] The present invention is as shown in the following examples, but it is possible to make appropriate modifications to these examples within the scope of the technical concept of the present invention.

[0033] The vibration isolation unit 1 of the present invention has an overload buffering effect that reduces and avoids the effects of sudden vibration loads input from outside the vibration isolation unit 1, which attenuates specified vibrations, and also has a steady buffering effect when the vibration environment reaches a steady, resting state, and also has a vibration isolation effect that responds to vibration loads from directions other than the main vibration isolation direction.As an example, various embodiments are disclosed, as shown in Figures 1 to 5. The basic configuration of the vibration isolation unit 1 comprises a base base 2 in a vibration environment, a second base base 3 that is provided independently and without contact with the base base 2, a load vibration isolation body 4 that is provided between the base base 2 and the second base base 3, a support base 5 that is provided independently and without contact with the second base base 3, a magnetic field responsive variable viscoelastic body 6 that uses a magnetic elastic gel and is provided between the second base base 3 and the support base 5, and a magnetic field generating means 7 that magnetizes the variable viscoelastic body 6.When sudden vibration occurs or when a vibration load is applied from a direction other than the main vibration isolation direction, the magnetic field generating means 7 excites the variable viscoelastic body 6, thereby changing the complex elastic modulus of the variable viscoelastic body 6 in an increasing direction.

[0034] The magnetic field generating means 7 is arranged to follow the arrangement of the variable viscoelastic body 6 in a planar view. For example, if the variable viscoelastic body 6 is arranged in a ring shape, the magnetic field generating means 7 is arranged along the outer or inner circumference of the ring. The complex modulus, also known as the dynamic modulus, is the sum of the storage modulus and the loss modulus. The storage modulus corresponds to the dynamic modulus derived from elasticity, and the loss modulus corresponds to the dynamic modulus derived from viscosity. By exciting the variable viscoelastic body 6, both the storage modulus and the loss modulus change, resulting in a change in the complex modulus. In the present invention, the ratio between the storage modulus and the loss modulus varies depending on the excitation strength and the strain rate when the variable viscoelastic body 6 is excited, and this effect of changing the complex modulus is utilized.

[0035] The base base 2, second base base 3, and load vibration isolator 4 will be described below. First, the base base 2 is a base member attached to an installation environment member B, such as a building floor, a specified deck member, or a frame of movable equipment, and multiple vibration isolation units 1 are installed on this base base 2. On the other hand, the second base base 3 is a member that often serves as a mounting base (indicated by the symbol 3M) for a supported body W, such as precision equipment, to be protected. However, the vibration isolation unit 1 can also be used upside down, and it is possible to select which of the base base 2 and the second base base 3 should essentially be the mounting base 3M. Therefore, the term "mounting base 3M" is not defined, but rather referred to as the second base base 3.

[0036] Furthermore, the load vibration isolator 4 supports the load of the mounted supported body W with a substantial cushioning effect, and is composed of a spring element such as a rubber / viscoelastic material, a metal spring, or a composite of these, as will be described later. A member responsible for vibration control and vibration absorption is combined with the second base 3. That is, a support base 5 is provided in a non-contact manner with the second base 3, and a variable viscoelastic body 6 is provided between the second base 3 and the support base 5. Furthermore, as described above, a magnetic field generating means 7 is provided to magnetize the variable viscoelastic body 6.

[0037] Next, the variable viscoelastic body 6 will be described. The variable viscoelastic body 6 is made of a magnetic field-responsive composition that, in a non-magnetized state, can deform and restore in response to a vibration load, changes its complex modulus when magnetized, and returns to its original complex modulus when the magnetic field is removed. The magnetic field-responsive composition is not particularly limited as long as it can achieve the effects of the present invention, but from the perspective of durability such as strength, a resin composition in which a magnetic filler is dispersed in a soft resin is preferred. Furthermore, from the perspective of ease of incorporation into the vibration-damping unit 1 and vibration-damping properties, it is preferable that the magnetic field-responsive composition be in a state that retains its shape in the operating environment of the vibration-damping unit 1.

[0038] As the soft resin, a viscoelastic material such as rubber or gel is preferred from the viewpoint of vibration load damping. Viscoelastic materials that can disperse magnetic fillers and have a predetermined hardness and viscoelasticity can be used, such as various known rubbers, elastomers, and organic gels. Examples of organic gels include silicone gels, acrylic gels, polyolefin gels, polyurethane gels, butadiene gels, isoprene gels, butyl gels, styrene-butadiene gels, ethylene-vinyl acetate copolymer gels, ethylene-propylene-diene terpolymer gels, and fluorine gels. In particular, when long-term stability, such as low compression set, is required from the viewpoint of heat resistance and the ability to restore shape and complex modulus after repeated magnetization and demagnetization, silicone-based viscoelastic resin materials are suitable, and silicone rubber, silicone-based elastomers, and silicone-based gels can be used. Silicone-based viscoelastic resin materials can be any of addition reaction type, condensation type, energy ray curing type, and millable type (thermal vulcanization type), but addition reaction type silicone-based viscoelastic resin materials are preferred.

[0039] As the magnetic filler, known soft magnetic fillers and / or hard magnetic fillers can be used depending on the purpose. However, from the viewpoints of magnetic field response (magnitude and speed) and control stability, it is preferable to use soft magnetic fillers. Known soft magnetic metal powders or oxide magnetic powders (ferrite powders) are used as the soft magnetic filler. Examples of such soft magnetic metal powders include iron-based alloy powders such as Fe—Si alloys, Fe—Al alloys, Fe—Si—Al alloys (Sendust), Fe—Si—Cr alloys, Fe—Ni alloys (Permalloy), Fe—Ni—Co alloys (Mumetal), Fe—Ni—Mo alloys (Supermalloy), Fe—Co alloys, Fe—Si—Al—Cr alloys, Fe—Si—B alloys, and Fe—Si—Co—B alloys, as well as iron powders (carbonyl iron powders). Examples of such ferrite powder include spinel ferrites such as Mn-Zn ferrite, Mn-Mg-Zn ferrite, Mg-Cu-Zn ferrite, Ni-Zn ferrite, Ni-Cu-Zn ferrite, and Cu-Zn ferrite, and hexagonal ferrites such as W-type, Y-type, Z-type, and M-type. The blending ratio of the magnetic filler to the soft resin can be set appropriately depending on the design of the complex elastic modulus before excitation and the rate of change in the complex elastic modulus upon excitation.

[0040] In the vibration-isolating unit 1 configured as described above, the load isolator 4 exerts a vibration-isolating effect against vibration loads from the direction in which the supported body W is supported, and in a steady state of rest, the load isolator 4 and the variable viscoelastic body 6 work together to provide a combined vibration-isolating effect that absorbs micro-vibrations and supports the supported body W in a stationary state. On the other hand, if a sudden vibration load exceeding the steady state of rest occurs, an input signal from a vibration sensor (not described separately) supplies power to the magnetic field generating means 7 to excite the variable viscoelastic body 6, increasing the complex elastic modulus so as to withstand the excessive vibration load. When the excessive vibration load is eliminated, the magnetic field is adjusted to reduce the complex elastic modulus of the variable viscoelastic body 6, restoring the combined action of the load isolator 4 and the variable viscoelastic body 6 to their original state, thereby restoring the vibration-isolating effect to the steady state of rest and enabling stable vibration-isolating performance. Furthermore, when a vibration load occurs from a direction different from the expected vibration load direction due to a change in the center of gravity of the supported body W, the variable viscoelastic body 6 is similarly excited, and the complex elastic modulus is changed within the increasing region in response to the vibration load from the different direction, thereby adjusting the cooperative action with the load vibration isolator 4, thereby restoring the vibration isolation action to a steady resting state and providing stable vibration isolation. Furthermore, when the vibration load from the expected vibration load direction changes, the variable viscoelastic body 6 is excited, and the complex elastic modulus is changed within the increasing region, thereby providing a vibration isolation action according to the changing vibration load through cooperative action with the load vibration isolator 4.

[0041] The basic common configuration and operation of the vibration isolation unit 1 have been outlined above. Specific examples will now be described. Of course, each of these examples is encompassed by the technical matters set forth in claim 1 in the claims. The components of the examples described below are symbolically illustrated to facilitate understanding of the operating and structural principles. Examples 1-3: Separate Support Base: Examples 1-3 are characterized in that the support base 5 and the base base 2 are not integrated but are separate entities. In other words, the basic technical concept of the present invention is that the second base base 3 is coupled to the base base 2 via the load-absorbing vibration isolator 4, while the variable viscoelastic body 6 does not necessarily have to be directly connected to the base base 2. Note that in both Example 1 ( FIG. 1( a) ) and Example 2 ( FIG. 1( b) ), the magnetic field-responsive variable viscoelastic body 6 is provided on the outer periphery of the second base base 3. That is, the support base 5 is provided in a double-cylindrical shape on the circumferential side of the second base 3, and the area of ​​this double-cylindrical shape is referred to as the circumferential area AR. In this circumferential area AR, the variable viscoelastic body 6 is provided continuously or discontinuously between the second base 3 and the support base 5. The support base 5 provided in a double-cylindrical shape on the circumferential side of the second base 3 includes not only a cylindrical shape but also a configuration in which a plurality of discontinuous support base pieces are arranged on the circumferential side of the second base 3, resulting in an apparent double-cylindrical support base 5. In this case, the variable viscoelastic body 6 is provided at least between the support base piece and the second base 3. Furthermore, a magnetic field generating means 7 for magnetizing the variable viscoelastic body 6 is provided in a position facing the variable viscoelastic body 6. The position facing the variable viscoelastic body 6 is specifically, for example, the outer peripheral surface of the circumferential area AR on the support base 5, but the point is that as long as a magnetic field can be applied so that the variable viscoelastic body 6 can be excited in a predetermined direction, it can also be a location located above or below the outer peripheral surface.

[0042] Example 1 In Example 1, as shown in FIG. 1( a), for example, the base 2 is a flat plate-shaped member, and a load vibration isolator 4 having a general shape such as a truncated cone is provided at the center of the upper surface of the base 2. A second base 3 having a block shape like a short cylinder is supported above the base 2. A support base 5 is provided to surround the outer periphery of the second base 3, and the support base 5 itself is attached to an appropriate fixing member. Specifically, for example, the base 2 may be mounted on an installation environment member B, such as a table or stand, placed on the floor, while the support base 5 may be fixed to a member extending from a wall or ceiling surface away from the floor. Furthermore, the support base 5 and the second base 3 are arranged in a double cylindrical shape as described above, constituting the circumferential area AR. A variable viscoelastic body 6 is provided between the two in the circumferential area AR. Furthermore, on the outer periphery of the support base 5, a magnetic field generating means 7 for magnetizing the variable viscoelastic body 6 is provided.

[0043] In the first embodiment, the load-type vibration isolator 4 and the variable viscoelastic body 6 are configured to exert vibration-damping effects in different vibration directions. Specifically, for vibrations in the vertical direction, the deformation behavior due to compression and extension (restoration) of the load-type vibration isolator 4 (hereinafter referred to as compression mode deformation) is the main force, and works in cooperation with the shear deformation behavior of the variable viscoelastic body 6 (hereinafter referred to as shear mode deformation) to exert vibration-damping effects. For vibrations in the horizontal direction, the compression mode deformation of the variable viscoelastic body 6 is the main force, and with this configuration, the load-type vibration isolator 4 and the variable viscoelastic body 6 work together to exert a combined vibration-damping effect for a steady-state vibration load input between the base 2 and the second base base 3. In addition, when a sudden vibration load exceeding the steady-state vibration load occurs, the variable viscoelastic body 6 is excited by supplying power to the magnetic field generating means 7, thereby increasing the complex elastic modulus so as to withstand the excessive vibration load. When the excessive load is eliminated, the magnetic field is adjusted to reduce the complex modulus of the variable viscoelastic body 6, restoring the combined action of the load-type vibration isolator 4 and the variable viscoelastic body 6 to their original state, thereby restoring the vibration-damping action to a steady state of rest and providing stable vibration-damping performance. Furthermore, even when a vibration load from a direction different from the expected vibration load direction occurs due to a change in the center of gravity of the supported body W, the variable viscoelastic body 6 is similarly excited, changing the complex modulus within the increasing region in response to the vibration load from the different direction, and adjusting the cooperative action with the load-type vibration isolator 4, thereby restoring the vibration-damping action to a steady state of rest and providing stable vibration-damping performance. Furthermore, when the vibration load from the expected vibration load direction changes, the variable viscoelastic body 6 is excited, changing the complex modulus within the increasing region, and through the cooperative action with the load-type vibration isolator 4, vibration-damping action according to the changing vibration load can be provided.

[0044] Example 2 Example 2 shown in FIG. 1( b) differs significantly from Example 1 in the second base 3. Specifically, the second base 3 is configured as a support member that is bent into an L-shape in vertical cross section, for example. The base 2 is formed as a cylindrical, bowl-shaped structure with a bottom, and a load vibration isolator 4 is housed inside. The tip of a columnar portion 31 of the second base 3 is embedded and fixed in the load vibration isolator 4. A horizontal portion 32 is provided above the columnar portion 31, and the upper surface or tip of the horizontal portion 32 serves as a mounting base 3M for the supported body W. A support base 5 is provided on the outer periphery of the upper part of the columnar portion 31 via a variable viscoelastic body 6. A magnetic field generating means 7 for magnetizing the variable viscoelastic body 6 is further provided on the outer periphery of the support base 5. Specifically, the second base 3 of this type is expected to be applied to an anti-vibration mechanism of an image stabilization device for an imaging device such as that exemplified in JP 2008-292900 A, and in this example, the damping means corresponds to the load vibration isolator 4 of the present application, and the rod-shaped portion corresponds to the columnar portion 31 of the present application. In Example 2 of the present invention, when excessive sudden vibration occurs in the columnar portion 31, for example, the variable viscoelastic body 6 is magnetized in accordance with the vibration load to increase the complex elastic modulus before the vibration isolation limit of the load vibration isolator 4 is exceeded, thereby ensuring appropriate anti-vibration performance and preventing damage to the anti-vibration mechanism.

[0045] In this embodiment, the load vibration isolator 4 and the variable viscoelastic body 6 exert vibration-damping effects in the same vibration direction (here, the horizontal direction). This configuration allows one end of the second base 3 to be embedded and fixed in the load vibration isolator 4, which includes a viscoelastic body. Therefore, vibration damping can be achieved by the cooperation of the damping action of the load vibration isolator 4 due to shear and torsional deformation and the damping action of the deformation in the vibration direction applied to the second base 3, i.e., the deformation such as compression of the variable viscoelastic body 6. When a change occurs in the magnitude or direction of the vibration applied to the second base 3, the variable viscoelastic body 6 is excited as necessary to change the complex elastic modulus within the increasing region, thereby adjusting the vibration damping action through the deformation such as compression of the variable viscoelastic body 6, thereby achieving vibration damping effects according to the changing vibration load. Furthermore, if excessive vibrations suddenly occur in the base 2, the vibration load received by the supported body W can be reduced by exciting the variable viscoelastic body 6 in accordance with the vibration load to increase the complex elastic modulus before the load vibration isolator 4 exceeds its vibration isolation limit.

[0046] Example 3 Example 3 employs a configuration in which the positions of the load vibration isolator 4 and the variable viscoelastic body 6 in Example 2 are interchanged. However, instead of merely exchanging the composition that exhibits vibration-damping properties, the positions of the base base 2 and the support base 5, which are provided on the outer periphery of the composition, are also interchanged. With this configuration, one end of the second base base 3 is fixed in an inserted state to the variable viscoelastic body 6, and vibration-damping properties can be achieved by the cooperation of the action of attenuating vibrations applied to the second base base 3 through shear and torsional deformation of the variable viscoelastic body 6 and the action of attenuating vibrations applied to the second base base 3 through deformation in the vibration direction, i.e., compression and other deformation of the load vibration isolator 4. When a change occurs in the magnitude or direction of vibration applied to the second base base 3, the variable viscoelastic body 6 is excited as necessary to change the complex elastic modulus within the increasing region, thereby adjusting the vibration-damping action due to the shear and torsional deformation of the variable viscoelastic body 6, and thereby achieving vibration-damping action according to the changing vibration load. Furthermore, if excessive vibrations suddenly occur in the base 2, the variable viscoelastic body 6 can be magnetized to increase the complex elastic modulus in accordance with the vibration load before the load vibration isolator 4 exceeds its vibration-isolating limit, thereby reducing the vibration load on the supported body W. Even in Example 3 having such a configuration, it is the load vibration isolator 4 that primarily bears the load of the supported body W. If excessive vibrations suddenly occur in the columnar portion 31, the variable viscoelastic body 6 can be magnetized in accordance with the vibration load to increase the complex elastic modulus, thereby ensuring appropriate vibration isolation and preventing damage to the vibration-isolating mechanism. Incidentally, as shown in Examples 2 and 3, when the variable viscoelastic body 6 is disposed on the outer periphery of the columnar portion 31 of the second base 3, the magnetic field generating means 7 can also be incorporated into the columnar portion 31.

[0047] Example 4 In Example 4 shown in FIG. 2, the load vibration isolator 4 and the variable viscoelastic body 6 also exert vibration-damping effects in the same vibration direction (here, the vertical direction). Here, the magnetic field generating means 7 is configured by winding a coil around the outer periphery of an iron core. The second base 3 is formed in a case shape using a non-magnetic material such as synthetic resin. The load vibration isolator 4 is a vibration isolator obtained by molding a viscoelastic material and is formed in a ring shape (annular shape). However, this load vibration isolator 4 can also be formed by arranging multiple short arc-shaped members concentrically. In this case, each arc-shaped member (load vibration isolator 4) has a truncated cone shape, and multiple such members are arranged at regular intervals. Furthermore, the vibration isolator indicated by 6A in the figure does not necessarily have to be made of a variable viscoelastic body because it does not directly receive the load of the supported body W relative to the magnetic field-responsive variable viscoelastic body 6 and only needs to follow the vibration of the second base 3 (here, the vertical vibration). The base 2 and the support base 5 are made of a highly magnetically permeable material in order to efficiently magnetize the variable viscoelastic body 6. The spacer 8 provided between the variable viscoelastic body 6 and the vibration-isolating body 6A is also made of a highly magnetically permeable material.

[0048] With this configuration, the load vibration isolator 4 and the variable viscoelastic body 6 cooperate to provide a combined vibration-damping effect in the main direction (the load direction in FIG. 2 ) in which load and vibration are applied. When the vibration load changes, the variable viscoelastic body 6 is excited to change the complex modulus within an increasing range, thereby providing a vibration-damping effect in response to the changing vibration load through cooperation with the load vibration isolator 4. Furthermore, when a sudden vibration load exceeding the steady-state rest state occurs from the main direction or when a sudden vibration load occurs from a direction different from the main direction, power is supplied to the magnetic field generating means 7 to excite the variable viscoelastic body 6, increasing the complex modulus to withstand the excessive vibration load. When the excessive load is eliminated, the magnetic field is adjusted to reduce the complex modulus of the variable viscoelastic body 6, restoring the combined action of the load vibration isolator 4 and the variable viscoelastic body 6 to their original state. This restores the vibration-damping effect to the steady-state rest state, thereby providing stable vibration-damping performance.

[0049] Examples 5 to 8: Integrated Holding Frame and Base Next, we will explain Examples 5 to 8. In these examples, the base 2 is formed as a cylindrical, bowl-shaped structure with a bottom, and the upper portion of the cylindrical tip of this base constitutes the support base 5 (part of the base 2 also serves as the support base 5), which is arranged relative to the second base 3 to form a double cylindrical shape, thereby forming the peripheral area AR.

[0050] Example 5 In Example 5 shown in FIG. 3( a), a low-profile, truncated cone-shaped elastic block made of, for example, rubber or a viscoelastic material is used as the load vibration isolator 4. The variable viscoelastic body 6 is configured, for example, as a parallelogram with a raised inner side in a longitudinal cross section in an unloaded state. This is intended to ensure that the cross-sectional shape of the variable viscoelastic body 6 becomes rectangular when subjected to the load of the supported body W (steady state of rest). The portion (cylindrical portion) of the base 2 that becomes the support base 5 is provided with a magnetic field generating means 7 on its outer side. In Example 5, the second base 3 is configured as a short, cylindrical block. This configuration eliminates the need to fix the support base 5 to the supported body W or the like, and allows the variable viscoelastic body 6 to be positioned and fixed in the peripheral area AR formed by the support base 5 and the second base 3. This allows for the vibration isolator 1 to be individually configured while still providing the characteristic vibration isolation function of the vibration isolator unit 1.

[0051] 3(b), the second base 3 is configured as an inverted bowl-shaped installation form, in other words, an inverted cylindrical bowl-shaped installation form with a bottom, and due to such a configuration, the vibration-damping effect of Example 5 is achieved, and the height dimension of the load vibration isolator 4 can be sufficiently ensured, making it possible to adopt an appropriate form according to the load of the supported body W. Of course, if the height of the load vibration isolator 4 can be the same dimension as in Example 4, the overall height dimension of the vibration-damping unit 1 can be reduced, and the vibration-damping unit 1 can be made more compact.

[0052] 4(a) and 4(b) show an embodiment 7 and an embodiment 8 in which a magnetic field generating means 7 is provided inside (on the inner peripheral surface) of a support base 5, and a variable viscoelastic body 6 is provided between the magnetic field generating means 7 and the side peripheral surface of a second base 3 (corresponding to claim 7). With this configuration, it is possible to obtain an anti-vibration unit 1 that provides the effects of embodiments 5 and 6 while facilitating magnetic field control of the variable viscoelastic body 6. 4(a) and 4(b), the opening formed between the support base 5 and the base base 2 is an air vent hole H for discharging air to prevent an air spring action from occurring when the air inside the vibration isolation unit is compressed due to deformation of the load vibration isolator 4 and the variable viscoelastic body 6 caused by the vibration load from the second base base 3, causing an air spring action, and this air vent hole H is provided when the cup-shaped, bottomed, cylindrical opening formed by the base base 2 and the support base 5 is configured to be sealed by the second base base 3, the variable viscoelastic body 6, and the magnetic field generating means 7. Incidentally, in the configurations of Examples 5 and 6 above, it is preferable to similarly provide an air vent hole H when air is blocked inside the vibration isolation unit 1.

[0053] Examples 9 to 15: Load Vibration Isolator Variations Examples 9 to 15 illustrate other variations in the load vibration isolator 4. First, Examples 9 and 10 shown in FIGS. 4(c) and 4(d) are examples in which a compression-type coil spring is used as the load vibration isolator 4. Because the load vibration isolator 4 is configured as a spring element, it is possible to achieve the vibration-damping effect of Examples 5 to 8 while also improving the bearing capacity for heavy loads. Furthermore, Example 9 employs a so-called block-shaped second base 3, while Example 10 illustrates an inverted bowl-shaped configuration. The support base 5 may be configured as part of the base base 2 (a configuration in which a portion of the base base 2 doubles as the support base 5), or the support base 5 may be configured as a separate body from the base base 2. Furthermore, in Examples 11 to 13 shown in FIGS. 4(e) to 4(g), the load vibration isolator 4 is configured by combining a spring element with a molded body made of rubber or a viscoelastic material. Furthermore, among the above-mentioned Examples 11 and 12, they are arranged independently. On the other hand, Example 13 is an Example that uses a composite member called an Eligospring, in which a coil spring is cast as a spring element into rubber or a viscoelastic material and molded as an integral part. Because the load vibration isolator 4 has a composite structure that combines a molded body made of rubber or a viscoelastic material with a spring element, the design freedom for balancing the vibration-damping effect and the ability to support high loads is improved, and therefore a vibration-damping unit 1 with excellent load support and vibration-damping properties can be realized.

[0054] 5(a) is an example in which a spring element is used as the load vibration isolator 4, but a tension coil spring 41 is used instead of a compression coil spring. Specifically, a suspender 21 is formed above the base 2, and the upper end of the tension coil spring 41, which is the load vibration isolator 4, is suspended from this suspender 21, and the lower end is connected to a receiving portion 34 that protrudes outward in a flange-like manner on the second base 3, thereby supporting the load applied to the second base 3. The lower part of the tension coil spring 41 forms a double-cylindrical circumferential area AR made up of the base base 2 and the second base base 3, and a variable viscoelastic body 6 is provided here, and a magnetic field generating means 7 is provided on the inner circumferential side of the second base base 3.

[0055] Example 15 shown in Figure 5(b) is an example in which a diaphragm spring 42 is used as the load vibration isolator 4. In this example 15, the second base 3 is supported above the diaphragm spring 42. Because the shape of this diaphragm spring 42 creates a sufficiently large gap in the center, it is possible to combine a block-shaped molded body made of rubber or a viscoelastic material with this gap as one component of the load vibration isolator 4 (see the imaginary lines in Figure 5(b)). The variable viscoelastic body 6 is provided in the circumferential area AR, i.e., between the support base 5 of the base base 2 and the side periphery of the second base 3, and the magnetic field generating means 7 is provided on the inner periphery of the second base 3.

[0056] <Examples 16 and 17: Inner Arrangement of Support Base> In the above-described examples, many of the embodiments have been described in which the support base 5 is arranged on the outer periphery of the second base 3. However, the support base 5 is not necessarily limited to this arrangement. That is, for example, as in Example 16 shown in Figure 5(c), the support base 5 rising from the base 2 can be arranged inside the second base 3. That is, in this example, the outer periphery of the second base 3 is provided outside the support base 5, the space between them is defined as a circumferential area AR, and the variable viscoelastic body 6 is provided in this circumferential area AR.

[0057] 5(d) is also formed based on the same technical concept, but in constructing a flat vibration isolation unit 1, for example, the mounting portion 23 of the base base 2 is positioned somewhat higher than the main body of the base base 2. The configuration in which the outer periphery of the second base base 3 is provided outside the support base 5 is also the same as in Example 4. As described above, the vibration isolation unit 1 of the present invention can take on various embodiments, which can fully exert vibration control and vibration absorption effects not only in absorbing minute vibrations in a steady state of rest, but also when a sudden vibration load that exceeds the steady state of rest occurs.

[0058] Examples 18 to 21 are configuration examples in which, when a supported body W is placed on the vibration isolation unit 1, the load vibration isolator 4 mainly supports the load of the supported body W, thereby reducing the support burden on the variable viscoelastic body 6 as much as possible. In other words, this configuration is intended to support the supported body W with the vibration isolation unit 1 while minimizing the load of the supported body W acting on the variable viscoelastic body 6 as much as possible, and is referred to in this specification as "(configuration) that reduces the apparent load acting on the variable viscoelastic body 6 to 0 (zero)." This state, that is, the state in which the apparent load acting on the variable viscoelastic body 6 is 0 (zero), can also be said to be a statically balanced state in which the load of the supported body W is supported mainly by the load vibration isolator 4 alone.

[0059] Example 18 Example 18 is an example (modification) based on Example 9, in which a compression coil spring is used as the load vibration isolator 4, as shown in Figures 6(a) and 6(b). Specifically, as shown in Figure 6(a), the base base 2 and the support base 5 are first formed separately. Before joining (assembling) these, the uncompressed load vibration isolator 4 is placed between the base base 2 and the second base base 3. Then, as shown in Figure 6(b), the base base 2 and the support base 5 are joined (fixed) to each other. This joining brings the load vibration isolator 4 into a compressed state, as shown in Figure 6(b), before supporting the supported body W. When the supported body W is placed on the vibration isolation unit 1 configured in this manner, the load vibration isolator 4 mainly supports the load of the supported body W, thereby reducing the apparent load acting on the variable viscoelastic body 6 to zero. 6(b) above, that is, when the load vibration isolator 4 is in the unloaded state with no supported body W placed on it and the load vibration isolator 4 assembled in a compressed state, the force that maintains the compressed state of the load vibration isolator 4 acts mainly on the variable viscoelastic body 6 (for example, shear force acting on the variable viscoelastic body 6), but when the supported body W is placed on the vibration-isolating unit 1, the load of the supported body W is mainly supported by the load vibration isolator 4, and the force (shear force) acting on the variable viscoelastic body 6 apparently does not act. In other words, the amount of compression of the load vibration isolator 4 in the unloaded state with the support base 5 fixed to the base 2 is adjusted in advance so that the apparent load acting on the variable viscoelastic body 6 becomes zero when the supported body W is placed on it.

[0060] Example 19 Example 19 is a configuration example in which a truncated cone-shaped elastic block made of, for example, rubber or a viscoelastic material is used as the load vibration isolator 4, in contrast to Example 18. That is, Example 19 shows that in a configuration example in which the apparent load acting on the variable viscoelastic material 6 is made to be zero, the load vibration isolator 4 is not necessarily composed of a spring element, and a load vibration isolator 4 made of rubber or a viscoelastic material may also be used. Note that Example 19 is also intended to make the apparent load acting on the variable viscoelastic material 6 zero by having the load of the supported material W, when the supported material W is placed on the vibration isolation unit 1, as shown in FIG. 6( d ).

[0061] 7( a) and 7(b), Example 20 is a configuration example in which the second base 3 is mainly modified from Example 18. Specifically, the second base 3 is configured with an inner male thread portion 35 that exerts a compressive effect on the load vibration isolator 4 and an outer female thread portion 36 that is provided on the outside of the inner male thread portion 35 and is joined to the variable viscoelastic body 6. By screwing (screwing) the inner male thread portion 35 into the outer female thread portion 36, the load vibration isolator 4 is installed in an appropriately compressed state between the second base 3 (inner male thread portion 35) and the base base 2. Note that in Example 20 as well, when the supported body W is placed on the vibration isolation unit 1, the load of the supported body W is mainly supported by the load vibration isolator 4 made of a spring element, so that the apparent load acting on the variable viscoelastic body 6 becomes zero.

[0062] 7(c) and 7(d), Example 21 is a configuration example in which a truncated cone-shaped elastic block made of, for example, rubber or a viscoelastic material is used as the load vibration isolator 4 in comparison with Example 20. That is, Example 21 shows that even in a configuration example like Example 20, the load vibration isolator 4 does not necessarily have to be made of a spring element, and a load vibration isolator 4 made of rubber or a viscoelastic material may be used. Note that, in Example 21 as well, when the supported body W is placed on the vibration isolation unit 1, the load of the supported body W is mainly supported by the load vibration isolator 4 made of rubber or a viscoelastic material, so that the apparent load acting on the variable viscoelastic body 6 becomes zero. Incidentally, in this Example 21, a plate member (torsion prevention plate 43) is provided between the load vibration isolator 4 and the inner male thread portion 35, more specifically on the top of the load vibration isolator 4, but without this plate member, the inner male thread portion 35 and the load vibration isolator 4 would come into direct contact, which would cause the load vibration isolator 4, which is made of a viscoelastic material or the like, to twist and deform as the inner male thread portion 35 is twisted in; this plate member is provided to prevent this, and is referred to in this specification as the torsion prevention plate 43. This torsion prevention plate 43 is formed from a material that has low friction against the compressive twisting of the inner male thread portion 35 and has sufficient rigidity to withstand the pushing force caused by the twisting of the inner male thread portion 35 and the reaction force of the compressed load vibration isolator 4, and it also functions as a member for uniformly transmitting the pushing force caused by the twisting of the inner male thread portion 35 to the load vibration isolator 4.

[0063] Examples 22 and 23: Equipped with elastic force adjusting means for adjusting the state in which the apparent load is 0 Examples 22 and 23 are configuration examples in which the amount of compression of the load vibration isolator 4 can be adjusted so that the apparent load acting on the variable viscoelastic body 6 becomes 0 when the supported body W is placed on the vibration isolation unit 1. In other words, this is a configuration example in which an elastic force adjusting means is provided that makes it possible to adjust the amount of compression of the load vibration isolator 4 even after placement so that the load of the supported body W placed on the vibration isolation unit 1 is supported mainly by the load vibration isolator 4 alone.

[0064] Example 22 is a configuration example in which the compression amount of the load vibration isolator 4 can be adjusted by an elastic force adjustment means even after the load is placed on the vibration isolation unit 1 so that the load of the supported object W placed on the vibration isolation unit 1 can be supported almost entirely by the load vibration isolator 4. Here, Example 22 is a configuration example in which a spring element is used as the load vibration isolator 4, as shown in FIG. 8( a), for example, and in Example 22, the portion of the base 2 that supports the load vibration isolator 4 (adjustment portion 24) can be screwed into the main body portion 25 to adjust the distance between the adjustment portion 24 and the second base base 3, i.e., the compression amount of the load vibration isolator 4. This makes it possible to adjust the compression amount of the load vibration isolator 4 even after the supported object W is placed on the vibration isolation unit 1, and more accurately set the apparent load acting on the variable viscoelastic body 6 to zero.

[0065] Example 23 Example 23 is a configuration example in which, as shown in FIG. 8( b), a truncated cone-shaped elastic block formed of, for example, rubber or a viscoelastic material is used as the load vibration isolator 4 in Example 22. That is, Example 23 shows that, even in a configuration example like Example 22, the load vibration isolator 4 does not necessarily have to be formed of a spring element, and a load vibration isolator 4 made of, for example, rubber or a viscoelastic material may be used. In Example 23, the adjustment portion 24 of the base 2 is also twisted into the main body 25 to adjust the distance between the adjustment portion 24 and the second base 3, i.e., the compression amount of the load vibration isolator 4. This allows the apparent load acting on the variable viscoelastic body 6 to be more accurately set to zero. Furthermore, in Example 23, a torsion prevention plate 43 is also provided below the load vibration isolator 4, more specifically, between the load vibration isolator 4 and the adjustment portion 24. In addition, in the above-mentioned Examples 20 and 21, it is possible to adjust the amount of compression of the load vibration isolator 4 by adjusting the amount of screwing of the inner male screw portion 35.

[0066] It should be noted that Examples 18 to 21 are configuration examples (modified examples) based on Example 9, which introduce a "configuration in which the apparent load acting on the variable viscoelastic body 6 is set to 0 (zero)." However, similar modifications can also be made to the configurations of Examples 5 to 13 and Examples 15 to 17.

[0067] Furthermore, when the support base 5 is configured as a separate body from the base 2, as in each of the vibration-damping units 1 of Examples 1 to 3, when the vibration-damping unit 1 is placed between the supported body W and the installation environment component B, the support base 5 can be left unfixed to support the load of the supported body W and achieve a static equilibrium state, and then the support base 5 can be fixed to use the unit in a state where the apparent load acting on the variable viscoelastic body 6 is 0 (zero).

[0068] Furthermore, in the case of the vibration-damping unit 1 of Example 4, the second base 3 and the spacer 8 are connected by a connecting means that can be switched between a fixed state and an unfixed state (the second base 3 and the spacer 8 are movable independently), so that the connecting means can support the load of the supported body W in the unfixed state to achieve a static equilibrium state, and then the connecting means can be switched to the fixed state, so that the apparent load acting on the variable viscoelastic body 6 can be used in a state of 0 (zero).

[0069] The vibration isolation unit 1 of the present invention is used by being arranged, one or more, between the supported body W and the installation environment member B. When multiple vibration isolation units 1 are arranged at multiple locations, the excitation conditions of the variable viscoelastic body 6 may be controlled differently for each vibration isolation unit 1 at each location, depending on the center of gravity of the supported body W and the load distribution of the constituent parts. This makes it possible to appropriately change the vibration isolation characteristics based on the viscoelasticity of each vibration isolation unit 1, thereby effectively suppressing the moment of inertia around the center of gravity of the supported body W and achieving better vibration isolation. In this case, the vibration isolation units 1 arranged at multiple locations may all have the same structure, or may be arranged by combining units with different structures.

[0070] As a control method for sudden vibrations in the vibration-damping unit 1 of the present invention, under conditions where the location and timing of sudden vibration occurrence can be predicted, a control method may be used in which excitation of the variable viscoelastic body 6 is initiated before the predicted timing of sudden vibration occurrence so that the change in the complex elastic modulus of the variable viscoelastic body 6 is maximized at the timing of sudden vibration occurrence. Specifically, for example, in cases where the table periodically experiences sudden vibrations or where sudden vibrations occur at a specific position on the table, such as in operation control of an XY table, position information at which sudden vibrations will occur is set based on position information of the table, and excitation of the variable viscoelastic body 6 is initiated before the set position is reached so that the change in the complex elastic modulus of the variable viscoelastic body 6 is maximized at the set position. This maximizes the change in the complex elastic modulus of the variable viscoelastic body 6 simultaneously with the occurrence of sudden vibration. This eliminates the time lag between when the variable viscoelastic body 6 is excited and when the change in the complex elastic modulus reaches its maximum, thereby achieving more effective vibration damping.

[0071] REFERENCE SIGNS LIST 1 vibration isolation unit 2 base base 3 second base base 3M mounting base 4 load vibration isolation body 5 support base 6 variable viscoelastic body 6A vibration isolation body 7 magnetic field generating means 8 spacer 21 suspension part 23 assembly part 24 adjustment part 25 main body part 31 columnar part 32 horizontal part 34 receiving part 35 inner male thread part 36 outer female thread part 41 tension coil spring 42 diaphragm spring 43 torsion prevention plate AR surrounding area B installation environment member H air vent hole W supported body

Claims

1. A vibration isolation unit that damps specified vibrations and provides an overload buffering effect to reduce and avoid the effects of sudden vibration loads input from outside the vibration isolation unit, and also provides a steady buffering effect when the vibration environment reaches a steady resting state, the vibration isolation unit comprising: a base base in the vibration environment; a second base base that is provided independently and without contact with the base base; a load vibration isolation body that is provided between the base base and the second base base; a support base that is provided independently and without contact with the second base base; a magnetic field responsive variable viscoelastic body that is provided between the second base base and the support base; and magnetic field generating means that magnetizes the variable viscoelastic body, the magnetic field generating means being arranged to follow the arrangement of the variable viscoelastic body in a planar view; and when sudden vibrations occur, the variable viscoelastic body is excited by the magnetic field generating means, thereby increasing the complex elastic modulus of the variable viscoelastic body.

2. The vibration isolation unit according to claim 1, wherein the second base is a mounting base that supports a supported body.

3. An anti-vibration unit according to claim 1 or 2, characterized in that the support base is arranged so as to form a double cylindrical peripheral area on the peripheral side of the second base.

4. A vibration isolation unit as described in claim 3, characterized in that the load vibration isolation body mainly supports the load of the supported body when the supported body is placed on the vibration isolation unit, and the compression amount of the load vibration isolation body when unloaded is set so that the apparent load acting on the variable viscoelastic body is zero.

5. The vibration isolation unit according to claim 4, further comprising elastic force adjusting means for adjusting the compression amount of the load vibration isolation body so that the apparent load acting on the variable viscoelastic body becomes zero.

6. The vibration isolation unit according to any one of claims 1 to 5, wherein one end of the second base is embedded and fixed in a load vibration isolation body.

7. The vibration isolation unit according to any one of claims 1 to 6, wherein one end of the second base is embedded and fixed in a variable viscoelastic body.

8. An anti-vibration unit according to any one of claims 3 to 7, characterized in that a portion of the base also serves as a support base, and is configured to be combined with a second base in a double-tube shape, with a peripheral area being provided.

9. The vibration isolation unit according to claim 8, wherein the second base is formed in an inverted bowl shape, and a load vibration isolator is provided between the inner lower surface of the inverted bowl shape and the base.

10. The vibration isolation unit according to claim 8, wherein the variable viscoelastic body is provided inside the support base of the base base, and the magnetic field generating means for magnetizing the variable viscoelastic body is disposed between the variable viscoelastic body and the support base.

11. A vibration isolation unit according to any one of claims 1 to 10, characterized in that the load isolator is made of a molded body of rubber or viscoelastic material.

12. A vibration isolation unit according to any one of claims 1 to 10, characterized in that the load isolator is composed of a spring element.

13. A vibration isolation unit according to any one of claims 1 to 10, characterized in that the load vibration isolator has a composite structure combining a molded body made of rubber or a viscoelastic material with a spring element.

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