JP6232369B2 - Method for producing magnetic viscoelastic elastomer - Google Patents

Description

  The present invention relates to a method for producing a magneto-viscoelastic elastomer in which magnetic particles are encapsulated in an elastic material and the elastic modulus is variable depending on the magnitude of applied magnetic force.

  Patent Document 1 discloses a method for producing a conductive elastic body from a magnetic conductor and a rubber-like elastic body. In this manufacturing method, a mixture of a magnetic conductor and a rubber-like elastic body is injected into a mold made of a magnetic material. Thereafter, a mold in which the mixture is injected is disposed between the pair of magnetic field generators, and a constant parallel magnetic field is applied to the mixture. Thereafter, the mixture in the mold is solidified.

JP 2005-322492 A

  In the case of the manufacturing method described in Patent Document 1, it is necessary to orient the magnetic conductor inside the rubber-like elastic body by parallel magnetic lines of force from one magnetic field generator to the other magnetic field generator. In this case, the magnetic field applied to the mixture becomes weaker as the distance between the pair of magnetic field generators increases. Therefore, in order to produce a conductive elastic body having a thickness in the orientation direction of the magnetic conductor (direction parallel to the lines of magnetic force), it is necessary to increase the magnetic field generated by the magnetic field generator, which is necessary for the generation of the magnetic field. Power consumption is enormous, and the manufacturing apparatus needs to be enlarged.

  The present invention reduces power consumption and manufacturing apparatus when manufacturing a magnetic viscoelastic elastomer having a thickness in the orientation direction of magnetic particles oriented in an elastic material (direction parallel to the magnetic field lines when a magnetic field is applied). An object of the present invention is to provide a method for producing a magneto-viscoelastic elastomer that can be miniaturized.

[1] A method for producing a magnetic viscoelastic elastomer according to the present invention is a method for producing a magnetic viscoelastic elastomer in which magnetic particles are encapsulated in an elastic material and the elastic modulus is variable depending on the magnitude of a magnetic field to be applied. Injecting a mixture of the magnetic particles and the elastic material into a mold made of a non-magnetic material, applying a magnetic field to the mixture in the mold by a magnetic field applying means for applying a magnetic field to the mold, and Solidifying the mixture in the mold, and two magnetic field applying means are provided so as to apply magnetic fields in opposite directions, and when applying a magnetic field to the mixture in the mold The mold is arranged at a position where the magnetic fields of the two magnetic field applying means overlap in the same direction.

  With the above configuration, the magnetic particles can be oriented in the direction in which the magnetic field directions of the two magnetic field applying units overlap, and therefore, rather than being oriented along the magnetic field lines generated between the two magnetic field generators as in Patent Document 1. A magnetic viscoelastic elastomer having a thickness in the orientation direction can be easily produced. In addition, since the magnetic particles are aligned at positions where the magnetic fields overlap in the same direction, the alignment can be performed with more power saving.

[2] In the present invention, the mold is provided so that the mixture is formed in an annular shape, and the two magnetic field applying means are wound in opposite directions to be supplied with power in the same direction. Or an excitation coil that is wound in the same direction and supplied with power in the opposite direction, and the mixture in the mold is positioned between the excitation coils in the axial direction of the excitation coil. In addition, the magnetic field may be arranged at a position that receives the magnetic field radially in the annular radial direction.

  With the above configuration, it is possible to easily manufacture a magnetic viscoelastic elastomer that is formed in an annular shape and in which magnetic particles are radially oriented in the radial direction.

[3] In the present invention, the mold is provided so that the mixture is formed in a rectangular parallelepiped shape, and the two magnetic field applying units are wound in opposite directions so that power is supplied in the same direction. A coil or an exciting coil wound in the same direction and supplied with power in the opposite direction, and the mixture in the mold is positioned between the exciting coils in the axial direction of the exciting coil And it may be arrange | positioned in the position which receives the said magnetic field in parallel in one direction.

  With the above configuration, a magnetic viscoelastic elastomer formed in a rectangular parallelepiped shape and having magnetic particles oriented in parallel in one direction can be easily manufactured.

[4] In the present invention, the method may include a step of laminating the mixture solidified in the mold in a direction orthogonal to the orientation of the magnetic particles.

  With the above configuration, a magnetic viscoelastic elastomer having a thickness in a direction perpendicular to the orientation of the magnetic particles can be easily manufactured, and it is not necessary to increase the applied magnetic field of the magnetic field applying means. It becomes possible to produce a viscoelastic elastomer.

  According to the present invention, when manufacturing a magnetic viscoelastic elastomer having a thickness in the orientation direction of magnetic particles oriented in the elastic material (direction parallel to the magnetic field lines when a magnetic field is applied), power consumption can be reduced. The manufacturing apparatus can be downsized.

FIG. 1A is a plan view showing a magnetic viscoelastic elastomer manufactured by the manufacturing method according to the present embodiment as viewed from above, and FIG. 1B is a side view of the magnetic viscoelastic elastomer. FIG. 2A is a process diagram showing an example of the manufacturing method according to the present embodiment, and FIG. 2B is a process diagram showing another example of the manufacturing method according to the present embodiment. FIG. 3A is a cross-sectional view showing a state in which a mixture of a liquid elastic material and a large number of magnetic particles is injected into a mold cavity, and FIG. 3B shows a state where a large number of magnetic particles are randomly dispersed in an annular elastic material. It is a top view seen from the upper surface. FIG. 4A is an explanatory view showing a state in which a mold is disposed between two magnetic field applying means, and FIG. 4B is an explanatory view showing a state in which the magnetic fields from the two magnetic field applying means overlap in the same direction. FIG. 5A is a plan view showing a magneto-viscoelastic elastomer produced by another production method according to the present embodiment as viewed from above, and FIG. 5B produces a magneto-viscoelastic elastomer by laminating a mixture of unit thicknesses. It is a side view which shows the state which carried out. FIG. 6A is a longitudinal cross-sectional view showing a configuration of an example of a dynamic damper using a magneto-viscoelastic elastomer, and FIG. 6B is an explanatory diagram showing a part of FIG. FIG. 7A is a plan view showing a magnetic viscoelastic elastomer manufactured by another manufacturing method as viewed from above, and FIG. 7B is a side view of the magnetic viscoelastic elastomer. FIG. 8A is an explanatory view showing a state in which a mold is disposed between two magnetic field applying means, and FIG. 8B is an explanatory view showing a state in which the magnetic fields from the two magnetic field applying means overlap in the same direction. FIG. 9A is a plan view showing a magnetic viscoelastic elastomer manufactured by another manufacturing method as viewed from above, and FIG. 9B is a side view of the magnetic viscoelastic elastomer.

  Hereinafter, an embodiment of a method for producing a magnetic viscoelastic elastomer according to the present invention will be described with reference to FIGS. 1A to 9B.

  Before describing the method of manufacturing the magnetic viscoelastic elastomer according to the present embodiment, the magnetic viscoelastic elastomer 10 manufactured by the manufacturing method will be described.

  As shown in FIGS. 1A and 1B, for example, the magnetic viscoelastic elastomer 10 includes a large number of conductive magnetic particles 14 encapsulated in an annular elastic material 12 (substrate elastomer) having a constant thickness t. It is configured. The elastic material 12 as a matrix has viscoelasticity. A large number of magnetic particles 14 are oriented in the radial direction of the elastic material 12. That is, in the magneto-viscoelastic elastomer 10, a plurality of magnetic particle rows 16 in which magnetic particles 14 are radially oriented are arranged radially inside an annular elastic material 12 having a through hole 15 in the center. It has a configuration.

  Examples of the constituent material of the elastic material 12 include known polymer materials having viscoelasticity at room temperature, such as ethylene-propylene rubber, butadiene rubber, isoprene rubber, and silicone rubber.

  The magnetic particles 14 have the property of being magnetically polarized by the action of a magnetic field and have conductivity. Examples of the constituent material of the magnetic particles 14 include magnetic soft iron, directional silicon steel, Mn—Zn ferrite, Ni—Zn ferrite, magnetite, cobalt, nickel and other metals, 4-methoxybenzylidene-4-acetoxyaniline, triamino Known materials such as organic substances such as benzene polymers and organic / inorganic composites such as ferrite-dispersed anisotropic plastics can be used.

  The shape of the magnetic particle 14 is not particularly limited, and may be, for example, a spherical shape, a needle shape, a flat plate shape, or the like. The particle size of the magnetic particles 14 is not particularly limited, and may be, for example, about 0.01 μm to 500 μm. The ratio of the magnetic particles 14 to the elastic material 12 can be arbitrarily set, but may be, for example, about 5% to 60% in volume fraction.

  Next, a manufacturing method according to the present embodiment will be described with reference to FIGS. 2A to 5B.

  First, in step S1 of FIG. 2A, as shown in FIG. 3A, a mixture 18 of a liquid elastic material 12 and a large number of magnetic particles 14 is poured into a mold 20 made of a nonmagnetic material. The mold 20 is provided so that the mixture 18 is formed in an annular shape as shown in FIG. 3B by injecting the mixture 18 into the cavity 22 formed by the first mold 20a and the second mold 20b. . In the mixture 18 in the cavity 22, a large number of magnetic particles 14 are randomly dispersed in the liquid elastic material 12.

  After that, in step S2 of FIG. 2, as shown in FIG. 4A, the magnetic field Bi is applied to the mixture 18 in the mold 20 by the magnetic field applying means 24 that applies the magnetic field Bi to the mold 20. Two magnetic field applying means 24 are provided so as to apply magnetic fields Bi in opposite directions. That is, the first magnetic field applying means 24A has an annular shape and is configured by a first exciting coil 28A in which a first conducting wire 26a is wound in one direction. The second magnetic field applying unit 24B has an annular shape, and is configured by a second exciting coil 28B in which a second conductive wire 26b is wound in the other direction (a direction opposite to one direction). Alternatively, the first magnetic field applying unit 24A is configured by the first exciting coil 28A in which the first conducting wire 26a is wound in one direction, and the second magnetic field applying unit 24B is similarly wound in the one direction by the second conducting wire 26b. You may comprise by the 2nd exciting coil 28B wired.

  Further, when the magnetic field Bi is applied to the mixture 18 in the mold 20, the mold 20 is disposed at a position where the magnetic fields Bi from the first magnetic field applying unit 24A and the second magnetic field applying unit 24B overlap in the same direction. Specifically, as shown in FIG. 4A, for example, the mold 20 is disposed between the first excitation coil 28A and the second excitation coil 28B. At this time, the mixture 18 in the mold 20 is positioned between the first excitation coil 28A and the second excitation coil 28B in the axial direction of the first excitation coil 28A and the second excitation coil 28B, and the magnetic field Bi. Are disposed at positions that receive the ring radially in the annular radial direction.

  In this case, as shown in FIG. 4B, the axis 30a of the first excitation coil 28A, the axis 32 of the mold 20 (the axis of the mixture in the mold), and the axis 30b of the second excitation coil 28B may be aligned. Good. Each axis 30a, 30b and 32 may be along the vertical direction (gravity direction) or along the horizontal direction.

  Of course, the angle formed between the axis 30a of the first excitation coil 28A and the axis 32 of the mold 20 need not be 0 °, and may have a certain margin (for example, less than 10 °). Further, when the first excitation coil 28A is projected onto the mold 20, it is preferable that the center of the first excitation coil 28A and the center of the mold 20 coincide with each other, but they may not coincide with each other. There may be some margin (for example, less than ½ of the inner diameter of the mixture 18). The same applies to the relationship between the second exciting coil 28B and the mold 20.

  Further, the first excitation coil 28A and the mold 20 may be brought into contact with each other, and a certain amount of gap (for example, less than ½ of the thickness of the first excitation coil 28A) is provided between the first excitation coil 28A and the mold 20. May be placed. The same applies to the relationship between the second excitation coil 28B and the mold 20.

  The inner diameters Di1 and Di2 and the outer diameters Do1 and Do2 of the first excitation coil 28A and the second excitation coil 28B can be arbitrarily set, but at least the inner diameters Di1 and Di2 of the first excitation coil 28A and the second excitation coil 28B are set. When the outer diameter of the mixture 18 in the mold 20 is Do and the inner diameter is Di, 0 <Di1 ≦ (Do + Di) / 4 and 0 <Di2 ≦ (Do + Di) / 4 may be set. (Do + Di) / 4 indicates the diameter of a circle that passes through a half point of the width W of the mixture 18 (annular).

  By disposing the mold 20 as described above, if the winding directions of the first excitation coil 28A and the second excitation coil 28B are opposite to each other, the first excitation coil 28A and the second excitation coil 28B are, for example, in the positive direction. Current. If the winding directions of the first excitation coil 28A and the second excitation coil 28B are the same, a current is passed through the first excitation coil 28A in the positive direction and a current is passed through the second excitation coil 28B in the negative direction. As a result, as shown in FIG. 4B, magnetic lines of force 34a from the inner peripheral portion of the mixture 18 toward the outer peripheral portion are formed around the first excitation coil 28A, and the inner periphery of the mixture 18 is also formed around the second excitation coil 28B. Magnetic field lines 34b from the portion toward the outer peripheral portion are formed. In this case, in the mixture 18, the magnetic lines of force 34 a by the first excitation coil 28 </ b> A and the magnetic lines of force 34 b by the second excitation coil 28 </ b> B are added, and many magnetic lines 34 a and 34 b pass through the mixture 18. The intensity of the applied magnetic field Bi increases. As a result, the magnetic particles 14 in the mixture 18 are easily oriented in the direction of the magnetic field Bi, and the mixture 18 is oriented in the radial direction inside the annular elastic material 12 as shown in FIG. The plurality of magnetic particle rows 16 thus formed are arranged in a radial pattern.

  Thereafter, in step S3 of FIG. 2A, the mixture 18 in the mold 20 is solidified by heating the mold 20 at, for example, 150 ° C. for 2 minutes. Thereby, the magnetic viscoelastic elastomer 10 shown in FIG. 1 is manufactured.

  Thus, in the method for manufacturing the magneto-viscoelastic elastomer according to the present embodiment, the magnetic particles 14 can be oriented in the direction in which the directions of the magnetic fields Bi of the first excitation coil 28A and the second excitation coil 28B overlap. Therefore, it is possible to easily manufacture a magneto-viscoelastic elastomer having a thickness in the alignment direction, which has been difficult with the conventional manufacturing method as in Patent Document 1. For example, as shown in FIG. 1, a plurality of magnetic particle rows 16 in which magnetic particles 14 are radially oriented are arranged radially in a wide annular elastic material 12 having a thickness in the orientation direction. The magnetic viscoelastic elastomer 10 having the above-described configuration can be easily manufactured. Moreover, since the magnetic particles 14 can be oriented in the direction in which the directions of the magnetic fields Bi overlap, the magnetic particles 14 can be oriented with more power saving. That is, since it is not necessary to increase the applied magnetic field of the magnetic field applying means 24, the magneto-viscoelastic elastomer 10 can be manufactured with power saving.

  In the above-described example, an example in which the magneto-viscoelastic elastomer 10 is manufactured using one solidified mixture 18 is shown, but the following method can also be preferably employed.

  That is, in steps S1 to S3 in FIG. 2B, as shown in FIGS. 5A and 5B, a plurality of thin mixtures 18a having a unit thickness ta (<constant thickness t) are produced. In step S4 in FIG. The thin mixture 18 a may be laminated in a direction y perpendicular to the orientation direction x of the magnetic particles 14 to produce one magneto-viscoelastic elastomer 10. In this case, since the magnetic field applying means 24 only needs to apply a magnetic field to the thin mixture 18a, the magnetic particles 14 are oriented with a magnetic field weaker than the magnetic field applied to the mixture 18 having a constant thickness t. Can do. As a result, it becomes possible to manufacture the magnetic viscoelastic elastomer 10 with power saving.

  Here, an example of the dynamic damper 100 using the magnetic viscoelastic elastomer 10 manufactured by the manufacturing method according to the present embodiment will be described with reference to FIGS. 6A and 6B.

  As shown in FIGS. 6A and 6B, the dynamic damper 100 includes a housing 104 attached to the vibration isolation target member 102, the above-described magnetic viscoelastic elastomer 10 attached to the housing 104, and a magnetic viscoelasticity with respect to the housing 104. And a mass member 106 disposed via the elastomer 10.

  The dynamic damper 100 also includes two coils 110 (a first coil 110 </ b> A and a second coil 110 </ b> B) that apply a magnetic field to the magneto-viscoelastic elastomer 10 by supplying power from the control circuit 108. The first coil 110 </ b> A and the second coil 110 </ b> B are adjacent to the magnetic viscoelastic elastomer 10 and are disposed on the housing 104 so as to be wound apart on the outer side in the circumferential direction of the mass member 106. The first coil 110 </ b> A and the second coil 110 </ b> B form a magnetic field Bo in a direction that intersects the direction (vertical direction) in which the mass member 106 vibrates due to the input from the vibration isolation target member 102 when power is supplied.

  Specifically, the housing 104 includes a base 112 that is installed on the upper surface of the vibration isolation target member 102 and a cylindrical body 114 that is installed on the base 112 and has a closed upper surface, for example.

  In the accommodation space of the cylindrical body 114, at least the mass member 106, the magnetic viscoelastic elastomer 10, the first coil 110A, and the second coil 110B are accommodated.

  That is, the magnetic viscoelastic elastomer 10 having a through hole 15 (see FIG. 1) formed in the center is attached to the inner wall of the housing 104, and the mass member 106 is fixed to the through hole 15 so that the mass member 106 is magnetic. Suspended by a viscoelastic elastomer 10. Thereby, the mass member 106 can swing in the vertical direction, and in this embodiment, the vertical direction is the operation direction (vibration suppression direction).

  A first coil 110 </ b> A is installed on the inner wall of the housing 104 between the magnetic viscoelastic elastomer 10 and the upper portion of the cylindrical body 114 and adjacent to the magnetic viscoelastic elastomer 10. A second coil 110 </ b> B is provided between the elastic elastomer 10 and the base 112 and at a position adjacent to the magnetic viscoelastic elastomer 10. The first coil 110A and the second coil 110B are connected in series, for example, and the winding direction of the first coil 110A and the winding direction of the second coil 110B are opposite to each other. In this case, each winding of the first coil 110 </ b> A and the second coil 110 </ b> B is wound along the circumferential direction of the mass member 106.

  When, for example, a positive drive current is passed through the first coil 110A and the second coil 110B, as shown in FIG. 6B, around the first coil 110A, from the inner peripheral portion of the magneto-viscoelastic elastomer 10 to the outer peripheral portion. A magnetic field line 116 is formed toward the outer peripheral part of the magneto-viscoelastic elastomer 10 even around the second coil 110B. That is, a magnetic field Bo is formed from the inner peripheral portion of the magneto-viscoelastic elastomer 10 toward the outer peripheral portion. The direction of the magnetic field Bo is a direction that intersects the vibration direction (vertical direction) of the mass member 106 and the vibration isolation target member 102. In this case, in the magnetic viscoelastic elastomer 10, the magnetic lines of force 116 by the first coil 110A and the magnetic lines of force 116 by the second coil 110B are added, and many magnetic lines 116 pass through the magnetic viscoelastic elastomer 10. The strength of the magnetic field Bo applied to the elastic elastomer 10 increases. In addition, the strength of the magnetic field Bo changes according to the drive current flowing through the first coil 110A and the second coil 110B, and the strength of the generated magnetic field Bo increases as the drive current increases.

  When a negative direction drive current is passed through the first coil 110A and the second coil 110B, a magnetic field from the outer peripheral portion to the inner peripheral portion of the magneto-viscoelastic elastomer 10 is formed contrary to the above. The direction of this magnetic field is also a direction that intersects the vibration direction (vertical direction) of the mass member 106 and the vibration isolation target member 102.

  When the magnetic field Bo is applied to the magneto-viscoelastic elastomer 10 by energizing the first coil 110A and the second coil 110B, the magnetic particles 14 are polarized according to the strength of the magnetic field Bo to form a magnetic coupling. . For example, when the magnetic particles 14 are linked in a chain to form a network structure, the elastic modulus of the magneto-viscoelastic elastomer 10 is greater than the elastic modulus (rigidity) of the elastic material 12 (substrate elastomer) itself. The stronger the magnetic field Bo applied to the magnetic viscoelastic elastomer 10, the more the magnetic coupling between the magnetic particles 14 increases, and the elastic modulus of the magnetic viscoelastic elastomer 10 increases. Therefore, as the drive current supplied to the first coil 110A and the second coil 110B increases, the elastic modulus of the magnetic viscoelastic elastomer 10 increases, and the magnetic viscoelastic elastomer 10 is less likely to be deformed with respect to the load. In the above-described example, the winding directions of the first coil 110A and the second coil 110B are opposite to each other, and currents are made to flow in the same direction. However, the first coil 110A and the second coil 110B are respectively connected to each other. Independently, the magnetic field Bo similar to that described above can be formed even if the winding directions are the same direction and currents flow in opposite directions.

  The dynamic damper 100 structurally vibrates in an opposite phase to the vibration frequency of the vibration isolation target member 102, and reduces the vibration of the vibration isolation target member 102 by using the inertial force of the movable mass. In particular, as described above, since the elastic modulus of the magneto-viscoelastic elastomer 10 changes due to the formation of the magnetic field Bo, the resonance frequency of the dynamic damper 100 is changed to the vibration frequency even if the vibration frequency of the vibration isolation target member 102 changes. It becomes possible to match.

  Thus, in the dynamic damper 100 to which the magneto-viscoelastic elastomer 10 manufactured by the manufacturing method according to the present embodiment is applied, when the mass member 106 vibrates, the mass member 106, the first coil 110A, and the first coil The two coils 110B can be arranged so as not to interfere with each other. Since the first coil 110 </ b> A and the second coil 110 </ b> B are arranged on the inner wall of the housing 104, the electrical wiring can be easily handled. Usually, the electrical wiring is wired through a vibration isolation target member 102 (frame or the like). If the first coil 110 </ b> A and the second coil 110 </ b> B are mounted on the mass member 106, the mass member 106 vibrates in the opposite phase to the vibration of the vibration isolation target member 102, and thus the electric wiring may be disconnected. For this reason, it is necessary to manage the electric wiring so as not to be disconnected, and there arises a problem that the wiring work takes time. However, in this dynamic damper 100, the first coil 110 </ b> A and the second coil 110 </ b> B are mounted on the housing 104 fixed to the anti-vibration target member 102, so that the disconnection is caused by the antiphase vibration of the mass member 106. This makes it easy to handle the electrical wiring and shortens the wiring work time.

  Further, the windings of the first coil 110A and the second coil 110B are wound along the circumferential direction (outer circumferential direction) of the mass member 106, and the first coil 110A and the second coil 110B are respectively attached to the magnetic viscoelastic elastomer 10. Since they can be arranged adjacent to each other, the magnetic field Bo can be applied to the magneto-viscoelastic elastomer 10 in a direction crossing the swinging direction (vertical direction) of the mass member 106. Therefore, the elastic modulus with respect to the swinging direction of the mass member 106 can be increased, and the vibration of the vibration isolation target member 102 can be reduced.

  Even when the first coil 110A and the second coil 110B are arranged on the housing 104 side so as not to interfere with the mass member 106, the magnetic field Bo generated by the first coil 110A and the second coil 110B is applied to the magneto-viscoelastic elastomer 10. On the other hand, it can be applied in a direction crossing the swinging direction of the mass member 106. Therefore, the rigidity change by the magneto-viscoelastic elastomer 10 can be set large.

  In the above-described example, the embodiment applied to the case of manufacturing the magneto-viscoelastic elastomer 10 having an annular shape and having the magnetic particles 14 radially oriented in the radial direction is shown. As shown, the present invention can also be applied to the production of a magnetic viscoelastic elastomer 10 having a rectangular parallelepiped shape having a constant thickness t and in which magnetic particles 14 are oriented in parallel in one direction.

  That is, as shown in FIGS. 8A and 8B, the mold 20 has, for example, a rectangular parallelepiped shape, and the mixture 18 is injected by injecting the mixture 18 into the cavity 22 formed by the first mold 20a and the second mold 20b. Is formed in a rectangular parallelepiped shape. Track-shaped excitation coils are used as the first excitation coil 28A and the second excitation coil 28B, respectively. Also in this case, when the magnetic field Bi is applied to the mixture 18 in the mold 20, the mold 20 is disposed at a position where the magnetic fields of the first excitation coil 28A and the second excitation coil 28B overlap in the same direction. For example, the mold 20 is disposed between the first excitation coil 28A and the second excitation coil 28B, particularly between the linearly extending portion 36. In the example of FIG. 8A, an example is shown in which two molds 20 (indicated by two-dot chain lines) are arranged between portions 36 that extend linearly.

  If the winding directions of the first excitation coil 28A and the second excitation coil 28B are opposite to each other, for example, a positive current is passed through the first excitation coil 28A and the second excitation coil 28B. If the winding directions of the first excitation coil 28A and the second excitation coil 28B are the same, a current is passed through the first excitation coil 28A in the positive direction and a current is passed through the second excitation coil 28B in the negative direction. As a result, as shown in FIG. 8B, a magnetic line of force 34 a is formed around the first excitation coil 28 </ b> A from one side surface portion of the mixture 18 to the other side surface portion, and even around the second excitation coil 28 </ b> B. Magnetic field lines 34b from one side surface portion to the other side surface portion are formed.

  Even in this case, since the strength of the magnetic field Bi applied to the mixture 18 is increased, the magnetic particles 14 in the mixture 18 are easily oriented in the direction of the magnetic field Bi, and the mixture 18 in the cavity 22 is shown in FIG. 7A. As described above, a plurality of magnetic particle rows 16 in which the magnetic particles 14 are linearly aligned in one direction are arranged in parallel inside the rectangular parallelepiped elastic material 12. Therefore, by solidifying the mixture 18, the magnetic viscoelastic elastomer 10 formed in a rectangular parallelepiped shape and having the magnetic particles 14 oriented in parallel in one direction can be obtained.

  In the above-described example, an example in which the magneto-viscoelastic elastomer 10 is manufactured using one solidified mixture 18 is shown. However, as shown in FIGS. 9A and 9B, a thin film having a unit thickness ta (<constant thickness t). A plurality of mixtures 18a may be produced, and a plurality of thin mixtures 18a may be laminated in a direction y orthogonal to the orientation direction x of the magnetic particles 14 to produce one magnetic viscoelastic elastomer 10. Also in this case, since the magnetic field applying means 24 only needs to apply a magnetic field to the thin mixture 18a, the magnetic particles 14 are oriented with a magnetic field weaker than the magnetic field applied to the mixture 18 having a constant thickness t. be able to. As a result, it becomes possible to manufacture the magnetic viscoelastic elastomer 10 with power saving.

[Summary of embodiment]
As described above, the magnetic viscoelastic elastomer manufacturing method according to the above-described embodiment includes the magnetic particles 14 in the elastic material 12, and the magnetic modulus is made variable according to the magnitude of the applied magnetic field. A method for producing a viscoelastic elastomer 10 comprising the steps of injecting a mixture 18 of magnetic particles 14 and an elastic material 12 into a mold 20 made of a nonmagnetic material, and a magnetic field applying means 24 for applying a magnetic field Bi to the mold 20. The magnetic field Bi is applied to the mixture 18 in the mold 20, and the process of solidifying the mixture 18 in the mold 20 is performed. Two magnetic field applying means 24 are provided so as to apply the magnetic fields Bi in opposite directions. When the magnetic field Bi is applied to the mixture 18 in the mold 20, the mold 20 is disposed at a position where the magnetic fields Bi of the two magnetic field applying units 24A and 24B overlap in the same direction.

  When the magnetic field Bi is applied to the mixture 18 in the mold 20, the mold 20 is disposed at a position where the magnetic fields of the two magnetic field applying units 24 </ b> A and 24 </ b> B overlap in the same direction.

  In the present embodiment, the mold 20 is provided so that the mixture 18 is formed in an annular shape, and the two magnetic field applying means 24A and 24B are wound in opposite directions so that power is supplied in the same direction. Coil 28A and 28B, or exciting coils 28A and 28B wound in the same direction and supplied with power in the opposite direction, the mixture 18 in the mold 20 is in the axial direction of the exciting coils 28A and 28B. It may be disposed at a position sandwiched between the exciting coils 28A and 28B and receiving the magnetic field Bi radially in the annular radial direction.

  In the present embodiment, the mold 20 is provided so that the mixture 18 is formed in a rectangular parallelepiped shape, and the two magnetic field applying means 24A and 24B are wound in opposite directions to be supplied with electric power in the same direction. The excitation coils 28A and 28B, or the excitation coils 28A and 28B wound in the same direction and supplied with power in the opposite direction, are formed by the mixture 18 in the mold 20 in the axial direction of the excitation coils 28A and 28B. Further, it may be disposed at a position between the exciting coils 28A and 28B and receiving the magnetic field Bi in parallel in one direction.

  In the present embodiment, a step of laminating the mixture 18 a solidified in the mold 20 in a direction orthogonal to the orientation of the magnetic particles 14 may be included.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the content described in this specification.

10 ... Magnetic viscoelastic elastomer 12 ... Elastic material (substrate elastomer)
DESCRIPTION OF SYMBOLS 14 ... Magnetic particle 16 ... Magnetic particle row | line | column 18, 18a ... Mixture 20 ... Type | mold 24 ... Magnetic field application means 24A ... 1st magnetic field application means 24B ... 2nd magnetic field application means 28A ... 1st excitation coil 28B ... 2nd excitation coil 100 ... Dynamic damper

Claims (2)

A magnetic viscoelastic elastomer manufacturing method in which magnetic particles are encapsulated in an elastic material, and the elastic modulus is variable depending on the magnitude of a magnetic field to be applied,
Injecting a mixture of the magnetic particles and the elastic material into a mold made of a non-magnetic material;
Applying a magnetic field to the mixture in the mold by magnetic field applying means for applying a magnetic field to the mold;
Solidifying the mixture in the mold,
Two magnetic field applying means are provided so as to apply magnetic fields in opposite directions,
When applying a magnetic field to the mixture in the mold, the mold is arranged at a position where the magnetic fields of the two magnetic field applying means overlap in the same direction ,
The mold is provided so that the mixture is formed in an annular shape,
The two magnetic field applying means are constituted by exciting coils that are wound in opposite directions and supplied with power in the same direction, or excited coils that are wound in the same direction and supplied with power in opposite directions. And
The mixture in the mold is disposed at a position sandwiched between the exciting coils in the axial direction of the exciting coil and receiving the magnetic field radially in the annular radial direction. A method for producing a magnetic viscoelastic elastomer. In the manufacturing method of the magnetic viscoelastic elastomer of Claim 1 ,
A method for producing a magneto-viscoelastic elastomer, comprising: laminating the mixture solidified in the mold in a direction perpendicular to the orientation of the magnetic particles.

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