JP6664996B2 - Magneto-rheological fluid device - Google Patents

Description

  The present invention relates to a magnetorheological fluid device in which a magnetorheological fluid is interposed between members provided so as to be relatively displaceable from each other, and a magnetic field by a permanent magnet is applied to the magnetorheological fluid.

  For example, the magnetorheological fluid device disclosed in Patent Document 1 has a magnetorheological fluid interposed between a disk (11) and a casing (20), and applies a magnetic field by a permanent magnet (40) to the magnetorheological fluid. Like that. In this device, the strength of the magnetic field applied to the magnetorheological fluid can be adjusted by adjusting the distance of the permanent magnet (40) to the casing (20) made of a magnetic material.

  For example, Patent Document 2 discloses a magnetorheological fluid device provided in a fishing reel. This device is arranged such that a cylindrical fixing member (36) having a plurality of holes (36b) into which a magnetorheological fluid enters, and a strong magnetic field and a weak magnetic field are alternately formed at axial positions. And three permanent magnets (39a) to (39c). The position of the fixing member (36) in the axial direction can be adjusted to an arbitrary position by a screw mechanism and a spring (S). By adjusting the position, the fixing member (36) is present in the hole (36b) of the fixing member (36). The strength of the magnetic field to be applied to the magnetorheological fluid is variable. This fishing reel is provided with a drag mechanism that rotates the spool, which is rotationally braked, when the fishing line is pulled with a certain tension or more to prevent the line from breaking. According to the strength of the magnetic field applied to the magnetorheological fluid in 36b), the tension of the thread on which the drag mechanism operates is adjusted.

JP 2013-167318 A JP 2014-198017 A

  By the way, in the case of adjusting the strength of the magnetic field of the permanent magnet applied to the magnetorheological fluid as in the magnetorheological fluid device according to the conventional example, the adjustment changes the relative position between the magnetorheological fluid and the permanent magnet. This is done by: Therefore, in order to increase the ON / OFF ratio (the ratio between the maximum magnetic flux density and the minimum magnetic flux density) of the magnetic field applied to the magnetorheological fluid, the relative position between the magnetorheological fluid and the permanent magnet must be largely changed. This necessitates the necessity, and as a result, there has been a problem that the device becomes large.

  The present invention has been made in view of such a problem, and in a magneto-rheological fluid device capable of adjusting the strength of a magnetic field of a permanent magnet applied to a magneto-rheological fluid, a relative position between the magneto-rheological fluid and the permanent magnet is provided. It is an object of the present invention to provide a magnetorheological fluid device that can increase the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid even if the change in the magnetic fluid is small.

A magnetorheological fluid device according to the present invention has a portion extending in the same direction via a space, a magnet portion having a pair of magnetic pole portions formed at a tip end of the portion, and a part of which is the magnet portion. A first magnetic path forming portion made of a magnetic material arranged to face one of the magnetic pole portions, and a second magnetic path forming portion made of a magnetic material having a portion thereof arranged to face the other magnetic pole portion of the magnet portion Relative to these magnetic path forming parts, between the other part of the first magnetic path forming part and the other part of the second magnetic path forming part. And a magnetic member interposed between the relative displacement portion, the other portion of the first magnetic path forming portion, and the other portion of the second magnetic path forming portion. and the viscous fluid, said with some or al plant leaves constant distance of said one magnetic pole portion is the first magnetic path forming portion, the other magnetic pole portion is the second magnetic A first position away said predetermined distance from said part of the formation portion, wherein with pole portion is connected to the portion of the first magnetic path forming portion, the other magnetic pole portion is the second magnetic A magnet section moving means for moving the magnet section with respect to the first and second magnetic path forming sections between a second position connected to the part of the path forming section and the magnet section; When located at a first position with respect to the first and second magnetic path forming portions, the magnetic portion is disposed between the two magnetic pole portions of the magnet portion, and the magnet portion is disposed at the first and second magnetic path forming portions. On the other hand, when in the second position, a shortcut member made of a magnetic material is provided at a position separated from both magnetic pole portions of the magnet portion.

  According to the magnetorheological fluid device having such a configuration, when the position of the magnet portion with respect to the magnetic path forming portion is the first position, a magnetic circuit that bypasses the magnetorheological fluid is formed. The magnetic flux can be prevented from leaking from the formed magnetic circuit to the magnetic path forming portion side by merely securing a small distance from the portion. Therefore, even if the amount of change in the position of the magnet portion with respect to the magnetic path forming portion is small, it is possible to increase the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid.

  The relative displacement portion is, for example, between the other portion of the first magnetic path forming portion and the other portion of the second magnetic path forming portion, with respect to these magnetic path forming portions. The disk unit may be provided so as to be relatively rotatable.

  The magnetorheological fluid device is disposed between both magnetic pole portions of the magnet portion when the magnet portion is at a second position with respect to the first and second magnetic path forming portions, and the magnet portion is A regulating member made of a non-magnetic material disposed at a position separated from between the two magnetic pole portions of the magnet portion when the magnet portion is at a first position with respect to the first and second magnetic path forming portions; It is desirable that

  According to the magneto-rheological fluid device having such a configuration, when in the second position, the regulating member made of a non-magnetic material is disposed between the two magnetic pole portions of the magnet portion, so that the magnetic field applied to the magneto-rheological fluid is Can be increased, whereby the ON / OFF ratio of the intensity of the magnetic field applied to the magnetorheological fluid in this device can also be increased.

The magneto-rheological fluid device may include a portion of the first magnetic path forming portion disposed to face the one magnetic pole portion, and the second magnetic field disposed to face the other magnetic pole portion. It is desirable to provide a regulating member made of a non-magnetic material disposed between the path forming portion and the part.

  According to the magneto-rheological fluid device having such a configuration, the regulating member made of a non-magnetic material is disposed between the part of the first magnetic path forming part and the part of the second magnetic path forming part. Therefore, when in the second position, the strength of the magnetic field applied to the magnetorheological fluid can be increased, whereby the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid in this device also increases. Can be bigger.

  The magnet section moving means is, for example, provided with one of the male and female screw sections provided integrally with the magnet section and the first and second magnetic path forming sections, and provided with a screw on the screw section. And the other male or female screw portion.

  According to the magneto-rheological fluid device having such a configuration, the movement between the first position and the second position can be easily and reliably performed with a simple structure.

  ADVANTAGE OF THE INVENTION According to the magnetorheological fluid apparatus which concerns on this invention, even if the change of the relative position of a magnetorheological fluid and a permanent magnet is small, the ON / OFF ratio of the intensity of the magnetic field provided to a magnetorheological fluid can be enlarged. .

FIG. 3 is a cross-sectional view of the magneto-rheological fluid device according to the embodiment of the present invention cut along a plane including an axis, in which a magnet unit (magnet unit) is referred to as a “first It is also a diagram showing a state at the “position”. FIG. 2 is a diagram corresponding to FIG. 1, in which a cross section of a magnetic member is represented by mesh-shaped hatching. Illustration of bolts, screws, and the like is omitted. It is sectional drawing which cut | disconnected and represented the magneto-rheological fluid apparatus which concerns on embodiment of this invention in the plane containing an axis, and was the figure which represented the cross section of the magnetic body member by mesh-shaped hatching. It is also a figure showing a state where a magnet unit (magnet part) is in a "2nd position" with respect to a main body unit (magnetic path formation part). Illustration of bolts, screws, and the like is omitted.

  Hereinafter, a magneto-rheological fluid device according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the magneto-rheological fluid device 1 according to the present embodiment mainly includes a magnet unit 2 and a main body unit 3 that are combined to be able to approach and separate in the direction of the axis N via screw portions 16 and 18. Have been.

  The magnet unit 2 includes a magnet unit 4, a female screw cylinder 6, and the like.

  The magnet section 4 is composed of a permanent magnet 7 and magnetic bodies 9 and 11, and an N-pole magnetic pole section 8N and an S-pole magnetic pole section 8S are formed in the same direction. The magnet section 4 illustrated in FIG. 1 includes an annular permanent magnet 7 having a rectangular cross section, a first yoke 9 made of an annular magnetic body having a substantially L-shaped cross section, and a second yoke made of an annular magnetic body having a rectangular cross section. 11 and the like. The first yoke 9, the second yoke 11, and the permanent magnet 7 have substantially the same inner diameter, and the outer diameter of the first yoke 9 is larger than the second yoke 11 and the permanent magnet 7. The first yoke 9, the permanent magnet 7, and the second yoke 11 are joined in this order in a state of being overlapped in the direction of the axis N, and an industrial adhesive is used for the joining, for example. The first yoke 9, the permanent magnet 7, and the second yoke 11 are fitted around the outer circumference of the female screw cylinder 6 described later, and are fixed to the female screw cylinder 6 by, for example, an industrial adhesive.

  A cylindrical portion 9 a protruding in one direction in the axis N direction is formed on an outer diameter portion of the first yoke 9. An annular space 12 is formed between the inner peripheral surface of the cylindrical portion 9a and the outer peripheral surfaces of the permanent magnet 7 and the second yoke 11. In this space 12, a short-cut member 13, a regulating member 14, and the like described later intervene.

  The female screw cylinder 6 has a female screw part 16 screwed with a male screw part 18 of a male screw cylinder 17 described later. The female screw portion 16 and the male screw portion 18 move the magnet unit 2 with respect to the main unit 3 between a first position 21 (see FIGS. 1 and 2) and a second position 22 (see FIG. 3). It functions as the means 23. The female screw cylinder 6 and the male screw cylinder 17 are made of a non-magnetic material.

  The main body unit 3 includes a first magnetic path forming section 19, a second magnetic path forming section 20, a disk shaft 24, a regulating member 14, a shortcut member 13, a magnetic viscous fluid 26, and the like.

  The first magnetic path forming portion 19 has a connecting portion 19a arranged to face the magnetic pole portion 8N of the magnet portion 4 at a part, and a disk facing another surface of a disk portion 24a at another part. It has an opposing surface 19b. When the magnet unit 2 is at the first position 21 with respect to the main unit 3 (see FIGS. 1 and 2), the connection unit 19a is separated from the magnetic pole 8N by a predetermined distance, while the magnet unit 2 is When it is in the second position 22 (see FIG. 3), it is connected to the magnetic pole 8N by surface contact. The first magnetic path forming portion 19 illustrated in FIG. 1 is an annular member having an L-shaped cross section, and includes a cylindrical member 27 made of a magnetic material and a disk-shaped member 28 made of a magnetic material. With bolts.

  The second magnetic path forming part 20 has a connecting part 20a arranged in a part facing the magnetic pole part 8S of the magnet part 4, and a disk facing another surface of a disk part 24a in another part. It has an opposing surface 20b. When the magnet unit 2 is at the first position 21 with respect to the main unit 3 (see FIGS. 1 and 2), the connecting unit 20a is separated from the magnetic pole unit 8S by a predetermined distance, while the magnet unit 2 is When in the second position 22 (see FIG. 3), the magnetic pole 8S is connected by surface contact. In addition, the second magnetic path forming unit 20 illustrated in FIG. 1 is formed of an annular member having a convex cross section made of a magnetic material.

  In the second magnetic path forming portion 20, the base 17a of the male screw cylinder 17 is fitted into a portion where the inner peripheral surface and the end surface on the magnet unit 2 side intersect, and is fixed with, for example, an industrial adhesive. The base 17a of the male screw cylinder 6 is formed in a flange shape.

  The disk shaft 24 is made of a magnetic material, and includes a shaft portion 24b and a disk portion 24a provided integrally with each other.

  The shaft portion 24b illustrated in FIG. 1 is formed of a hollow member, and has a small-diameter portion 24ba formed on the distal end side and a large-diameter portion 24bb formed on the proximal end side. The small diameter portion 24ba is relatively rotatably fitted to the inner peripheral surface of the male screw cylinder 17, and the large diameter portion 24bb is relatively rotatably fitted to the inner peripheral surface of the second magnetic path forming portion 20. The large-diameter portion 24bb is relatively rotatably supported by a soft metal (for example, copper) bearing 29 fixed to the inner peripheral surface of the first magnetic path forming portion 19.

  The restricting member 14 is made of a non-magnetic material, and its one side portion 14a has two magnetic pole portions 8N, 8N of the magnet portion 4 when the magnet unit 2 is at the second position 22 with respect to the main body unit 3 (see FIG. 3). 8S, when the magnet unit 2 is at the first position 21 with respect to the main unit 3 (see FIGS. 1 and 2), the magnet unit 2 is separated from the two magnetic pole portions 8N and 8S of the magnet unit 4. Placed in position.

  Further, the other side portion 14b of the regulating member 14 is fitted between the connecting portion 19a of the first magnetic path forming portion 19 and the connecting portion 20a of the second magnetic path forming portion 20, for example, an industrial adhesive. Thus, it is fixed to these magnetic path forming portions 19 and 20.

  The shortcut member 13 is made of a magnetic material. When the magnet unit 2 is at the first position 21 with respect to the main unit 3 (see FIGS. 1 and 2), the shortcut member 13 is disposed between the magnetic pole portions 8N and 8S of the magnet portion 4. When the magnet unit 2 is located at the second position 22 with respect to the main unit 3 (see FIG. 3), the magnet unit 4 is disposed at a position separated from between the magnetic pole portions 8N and 8S of the magnet unit 4. The shortcut member 13 illustrated in FIG. 1 is an annular member having a rectangular cross section, and is bolted to one surface of the regulating member 14.

  As shown in FIG. 1, the magnetic viscous fluid 26 is interposed in a gap between the disk portion 24a, the disk facing surface 19b of the first magnetic path forming portion 19, and the disk facing surface 20b of the second magnetic path forming portion 20. ing. In FIG. 1, the magnetorheological fluid 26 is sealed in a region surrounded by the first magnetic path forming section 19, the second magnetic path forming section 20, the regulating member 14, the disk shaft 24, and the O-rings 31 to 33. ing.

  The magnetic viscous fluid 26 is a liquid in which magnetic particles are dispersed in a dispersion medium, and in particular, a liquid in which the magnetic particles are nano-sized metal particles (metal nanoparticles) can be used. The magnetic particles are made of a magnetizable metal material, and the metal material is not particularly limited, but a soft magnetic material is preferable. Examples of the soft magnetic material include alloys such as iron, cobalt, nickel, and permalloy. The dispersion medium is not particularly limited, but one example is a hydrophobic silicone oil. The blending amount of the magnetic particles in the magnetorheological fluid may be, for example, 3 to 40 vol%. Various additives can also be added to the magnetorheological fluid to obtain various desired properties.

  In the magneto-rheological fluid device 1 having the above configuration, as shown in FIG. 2, when the position of the magnet unit 2 with respect to the main unit 3 is the first position 21, the shortcut member 13 made of a magnetic material is And a magnetic circuit is formed along the direction indicated by the arrow P in FIG. In this state, the magnetic flux does not leak from the formed magnetic circuit to the first and second magnetic path forming sections 19 and 20, and the first and second magnetic path forming sections 19 and 20 and the disk section The magnetic flux density of the magnetic field applied to the magnetorheological fluid 26 interposed in the gap with the gap 24a is almost zero. For this reason, in this state, the disk shaft 24 can rotate with extremely low torque with respect to the magnetic path forming portions 19 and 20 and the like.

  Next, when the magnet unit 2 is rotated with respect to the main unit 3 and the position of the magnet unit 2 with respect to the main unit 3 is set to the second position 22, as shown in FIG. The restricting member 14 is separated from the magnetic pole portions 8N and 8S, and is interposed between the magnetic pole portions 8N and 8S. Therefore, the magnetic circuit formed between the magnetic pole portions 8N and 8S disappears. Then, the magnetic pole portion 8N is connected to the connecting portion 19a of the first magnetic path forming portion 19 and the magnetic pole portion 8S is connected to the connecting portion 20a of the second magnetic path forming portion 20, whereby the magnetic pole portion shown in FIG. A new magnetic circuit is formed along the direction indicated by arrow P. As a result, a magnetic field is applied to the magnetorheological fluid 26 interposed in the gap between the first and second magnetic path forming portions 19 and 20 and the disk portion 24a, and the viscosity (corresponding to the strength of the magnetic field ( Shear stress) appears. As a result, the torque required to rotate the disk shaft 24 relative to the magnetic path forming portions 19 and 20 increases.

  As is clear from the above description, according to the magnetorheological fluid device 1 according to the embodiment of the present invention, if the position of the magnet unit 2 with respect to the main unit 3 is set to the first position 21, the magnetorheological fluid 26 is bypassed. Since the magnetic circuit (shortcut magnetic path) is formed, even if the gap between the magnetic pole portions 8N, 8S and the magnetic path forming sections 19, 20 through the air is small, the magnetic path forming section 19 is removed from the formed shortcut magnetic path. , 20 can be prevented from leaking. That is, according to the magneto-rheological fluid device 1, even if the amount of change in the position of the magnet unit 2 from the first position 21 to the second position 22 is small, the intensity of the magnetic field applied to the magneto-rheological fluid 26 is reduced to almost zero. As a result, the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid 26 can be easily increased.

  Further, according to the magnetorheological fluid device 1 according to the embodiment of the present invention, when the position of the magnet unit 2 with respect to the main unit 3 is at the second position 22, the regulating member 14 made of a non-magnetic material is used for the first magnetic member. Since it is interposed between the connecting portion 19a of the path forming portion 19 and the connecting portion 20a of the second magnetic path forming portion 20 and between the magnetic pole portions 8N and 8S, the strength of the magnetic field applied to the magneto-rheological fluid 26 is increased. Therefore, the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid 26 in this device can be further increased.

<Other embodiments>
In the embodiment described above, the magnet part moving means 23 is constituted by the screw parts 16 and 18, but the magnet part 4 is moved to the first position 21 with respect to the first and second magnetic path forming parts 19 and 20. The magnet part moving means is not limited to the screw part as long as the means can move between the first position and the second position 22.

  In the embodiment described above, the disk shaft 24 is entirely made of a magnetic material. However, only the disk portion 24a of the disk shaft 24 is made of a magnetic material, and the other portions are made of a non-magnetic material. Is desirable. In this case, the magnetic circuit indicated by the arrow P in FIG. 3 can be formed more efficiently, and the ON / OFF ratio of the strength of the magnetic field applied to the magnetorheological fluid 26 can be further increased.

  INDUSTRIAL APPLICABILITY The present invention is applicable to, for example, a magnetorheological fluid device in which a magnetorheological fluid is interposed between members provided so as to be relatively rotatable with each other, and a magnetic field by a permanent magnet is applied to the magnetorheological fluid.

DESCRIPTION OF SYMBOLS 1 Magneto-rheological fluid device 4 Magnet part 8N, 8S Magnetic pole part 13 Shortcut member 14 Restriction member 16 Female screw part 17 Male screw part 19 First magnetic path forming part 19a Connection part (part of the first magnetic path forming part)
19b Disk facing surface (other part of first magnetic path forming portion)
20 Second magnetic path forming part 20a Connection part (part of second magnetic path forming part)
20b Disk facing surface (other part of the second magnetic path forming portion)
21 1st position 22 2nd position 23 Magnet part moving means
24a disk part (relative displacement part)
26 Magneto-rheological fluid

Claims (5)

A magnet portion having a portion extending in the same direction through the space, and a pair of magnetic pole portions formed at the tip of the portion ;
A first magnetic path forming part, a part of which is made of a magnetic material disposed so as to face one magnetic pole part of the magnet part;
A second magnetic path forming part of which a part is made of a magnetic material disposed to face the other magnetic pole part of the magnet part;
Relative displacement provided between the other part of the first magnetic path forming part and the other part of the second magnetic path forming part so as to be relatively displaceable with respect to these magnetic path forming parts. Department and
A magneto-rheological fluid interposed between the relative displacement part and the other part of the first magnetic path forming part and the other part of the second magnetic path forming part;
Together with the one magnetic pole portion leaves the constant distance or part et locations of the first magnetic path forming portion, the said other magnetic pole portions are separated the predetermined distance from said portion of said second magnetic path forming portion 1 position, with the one pole portion is connected to the portion of the first magnetic path forming portion, the other magnetic pole portion is connected to said portion of said second magnetic path forming portion and a second position, the magnet portion moving means for moving the magnet portion relative to said first and second magnetic path forming portion that,
When the magnet portion is located at a first position with respect to the first and second magnetic path forming portions, the magnet portion is disposed between both magnetic pole portions of the magnet portion, and the magnet portion is arranged between the first and second magnetic path forming portions. A short-circuit member made of a magnetic material disposed at a position separated from between the two magnetic pole portions of the magnet portion when the magnetic member is at the second position relative to the magnetic path forming portion;
A magneto-rheological fluid device comprising: The magneto-rheological fluid device according to claim 1,
The relative displacement portion is disposed between the other portion of the first magnetic path forming portion and the other portion of the second magnetic path forming portion, and rotates relative to the magnetic path forming portions. A magneto-rheological fluid device, characterized in that it is a disk portion provided so as to be capable of being provided. The magnetorheological fluid device according to claim 1 or 2,
When the magnet portion is located at a second position with respect to the first and second magnetic path forming portions, the magnet portion is disposed between the two magnetic pole portions of the magnet portion, and the magnet portion is arranged between the first and second magnetic path forming portions. A magnetorheological fluid device, comprising: a regulating member made of a non-magnetic material disposed at a position separated from a position between both magnetic pole portions of the magnet portion when the magnet portion is at a first position with respect to the magnetic path forming portion. . The magnetorheological fluid device according to any one of claims 1 to 3,
The part of the first magnetic path forming part arranged to face the one magnetic pole part and the part of the second magnetic path forming part arranged to face the other magnetic pole part And a regulating member made of a non-magnetic material disposed between the magnetic viscous fluid device. The magnetorheological fluid device according to any one of claims 1 to 4,
The magnet portion moving means is provided integrally with the male and female screw portions provided integrally with the magnet portion and the first and second magnetic path forming portions, and is screwed to the screw portion. And the other male or female screw portion,
A magnetic viscous fluid device characterized by the above.

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