JP6452502B2 - Magnetorheological fluid device - Google Patents

Description

  The present invention relates to a magnetorheological fluid device that changes the force transmitted between the members by changing the strength of a magnetic field applied to the magnetorheological fluid interposed between the members.

  Patent Document 1 discloses a magnetorheological fluid device that changes the rotational force transmitted between two members via a magnetorheological fluid by changing the strength of a magnetic field applied to the magnetorheological fluid. For example, the magnetorheological fluid device described in FIG. 1 of the same document includes a disk that is a transmission side of a rotational force, a member that is opposed to the disk and is a transmission side of the rotational force, A magnetorheological fluid sealed in a casing interposed in a gap between the plate and the member, and an electromagnet for applying a magnetic field to the magnetorheological fluid. In this apparatus, when an electric current is applied to the electromagnet, a viscosity (shear stress) appears in the magnetorheological fluid in accordance with the magnitude of the electric current, and the magnitude of the applied current is changed so that the disk and the member are not affected. The rotational force (torque) transmitted by can be changed.

  Further, Patent Document 2 discloses a force in a linear motion direction (hereinafter referred to as “direct power”) transmitted between a piston and a cylinder body via a magnetorheological fluid by changing the strength of a magnetic field applied to the magnetorheological fluid. A damper is disclosed which is a magneto-rheological fluid device capable of changing.

JP 2014-181778 A JP 2004-019741 A

  By the way, in the field of devices for controlling / adjusting the force transmitted between members, it may be required to simultaneously control / adjust both the rotational force and the direct force. However, it has been difficult for conventional magnetorheological fluid devices to meet such demands alone.

  The present invention has been made in view of such problems, and a magnetorheological fluid device that changes the force transmitted between the members by changing the strength of the magnetic field applied to the magnetorheological fluid interposed between the members. An object of the present invention is to provide a magneto-rheological fluid device that can control and adjust both the rotational force and the direct force.

  A magnetorheological fluid device according to the present invention includes a cylinder, a piston fitted in an internal space of the cylinder so as to be reciprocally movable, and is inserted into the cylinder so as to be rotatable and reciprocally movable from one of the cylinders. A first shaft connected to the piston, a second shaft connected to the piston from the other side of the cylinder so as not to rotate and reciprocate, and connected to the piston; and provided in the piston It is premised on what is provided with the coil provided. The piston has a concave portion formed on one side thereof, and is fitted to the outer portion to which the first shaft member is connected on the other side and the concave portion so as to be rotatable. An inner portion to which the second shaft member is connected, and an annular plate portion that projects from the concave portion forming surface of the outer portion toward the center and is inserted into the slit formed in the inner portion so as to be relatively rotatable. . In addition, the first fluid chamber and the second fluid chamber in which the internal space of the cylinder is partitioned by the piston communicate with each other, and the slit forming surface of the inner portion and the plate surface of the annular plate portion A communication path that passes through the gap is provided. Further, the coil is disposed so that a magnetic path that penetrates the gap between the slit forming surface of the inner portion and the plate surface of the annular plate portion is formed by applying a current to the coil. In addition, materials used for the outer portion, the inner portion, and the annular plate portion are set.

  In addition, another magnetorheological fluid device according to the present invention includes a cylinder, a piston fitted in the inner space of the cylinder so as to be reciprocally movable, and is rotatable and reciprocally movable with respect to the cylinder from one of the cylinders. A first shaft member that is inserted and connected to the piston; a second shaft member that is inserted through the other of the cylinders so as to be non-rotatable and reciprocally movable; and connected to the piston; And a coil provided in the piston. The piston has a concave portion formed on one side thereof, and the outer portion to which the second shaft member is connected on the other side. The piston is rotatably fitted to the concave portion, and the piston is provided on a surface opposite to the fitting side. An inner portion to which the first shaft member is connected, and an annular plate portion that protrudes from the concave portion forming surface of the outer portion toward the center and is inserted into the slit formed in the inner portion so as to be relatively rotatable. . In addition, the first fluid chamber and the second fluid chamber in which the internal space of the cylinder is partitioned by the piston communicate with each other, and the slit forming surface of the inner portion and the plate surface of the annular plate portion A communication path that passes through the gap is provided. Further, the coil is disposed so that a magnetic path that penetrates the gap between the slit forming surface of the inner portion and the plate surface of the annular plate portion is formed by applying a current to the coil. In addition, materials used for the outer portion, the inner portion, and the annular plate portion are set.

  According to the magnetorheological fluid device according to the present invention or the other magnetorheological fluid device according to the present invention, after the magnetorheological fluid is filled in the internal space and the communication path of the cylinder, an electric current is applied to the coil, When a magnetic field is applied to the magnetorheological fluid interposed in the gap between the slit forming surface and the plate surface of the annular plate portion, a viscosity (shear stress) corresponding to the strength of the magnetic field (applied current) appears in the magnetorheological fluid. The gap in which the magnetorheological fluid intervenes forms part of the communication path that connects the first fluid chamber and the second fluid chamber to each other, and at the same time, the magnetorheological fluid intervening in the gap The rotational force is transmitted between the part and the outer part. For these reasons, it is possible to control / adjust the rotational force transmitted between the first shaft member and the cylinder by changing the strength (applied current) of the magnetic field applied to the magnetorheological fluid. At the same time, the direct power transmitted between them can be controlled and adjusted.

  The said structure WHEREIN: The said coil is arrange | positioned inside the said cyclic | annular board part, and the said communicating path is one surface of the slit formation surface of the said inner part, and the board surface of the said cyclic | annular plate part facing this. It passes through the gap, the gap between the inner peripheral surface of the annular plate portion and the coil, and the gap between the other surface of the slit forming surface of the inner portion and the plate surface of the annular plate portion facing this. Is desirable.

  In this case, after filling the internal space and the communication path of the cylinder with a magnetorheological fluid and applying a current to the coil, the two portions formed between the slit forming surface of the inner portion and both surfaces of the annular plate portion are respectively formed. A magnetic field is applied to the magnetorheological fluid interposed in the gap, and a viscosity (shear stress) corresponding to the strength of the magnetic field (applied current) appears in the magnetorheological fluid interposed in each gap. The gap in which the two magnetorheological fluids intervene forms a communication path that connects the first fluid chamber and the second fluid chamber to each other, and at the same time, the magnetorheological fluid intervening in the gaps in the two sites. These all transmit rotational force between the inner part and the outer part. From these facts, it can be expected to improve the transmission efficiency of the rotational force and the direct power, and to suppress the power consumption.

  According to the present invention, it is possible to control and adjust the rotational force transmitted between the first shaft member and the cylinder by changing the strength of the magnetic field applied to the magnetorheological fluid. It is also possible to control / adjust the direct power transmitted between them.

It is sectional drawing which shows the magnetorheological fluid apparatus which concerns on embodiment of this invention. It is sectional drawing which showed the construction example of the cylinder and the piston. However, the painting for expressing the magnetorheological fluid is omitted. It is a partial expanded sectional view of pistons. It is sectional drawing which shows the state which the piston moved to the opposite side from the state shown in FIG. It is a partial expanded sectional view of pistons. It is a partial expanded sectional view of the piston etc. of the magnetorheological fluid device concerning other embodiments of the present invention. It is sectional drawing which shows the magnetorheological fluid apparatus which concerns on other embodiment of this invention.

  Hereinafter, a magnetorheological fluid device according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a magnetorheological fluid device 1 according to an embodiment of the present invention includes a cylinder 2, a piston 3, a rotatable rod 4, a nonrotatable rod 6, a magnetic field generating means 7, a magnetorheological fluid 8, and the like. Has been.

  The cylinder 2 is composed of a cylindrical member whose both ends are closed by end walls 9 and 10, and an internal space 12 for reciprocating the piston 3 is formed therein. One end wall 9 is formed with a rod hole 9 a for inserting the rotatable rod 4. Two grooves are formed on the inner peripheral surface of the rod hole 9a, and a bush 13 and a U packing 14 are fitted in each groove. The other end wall 10 is formed with a rod hole 10a through which the non-rotatable rod 6 is inserted. Two grooves are also formed on the inner peripheral surface of the rod hole 10a, and a bush 13 and a U packing 14 are fitted in each groove. The cylinder 2 is preferably made of a nonmagnetic material such as stainless steel (SUS304).

  The piston 3 is fitted in the internal space 12 of the cylinder 2 so as to be able to reciprocate. The outer diameter of the piston 3 and the inner diameter of the cylinder 2 are set so that the magnetorheological fluid does not pass through the gap as much as possible when the piston 3 moves in the internal space 12 of the cylinder 2. The detailed structure of the piston 3 will be described later.

  The rotatable rod 4 is inserted through a rod hole 9 a formed in the end wall 9 of the cylinder 2, and one end thereof is connected to the piston 3. A button 16 is fixed to the other end of the rotatable rod 4. The button 16 has a cylindrical shape that can be easily grasped by a general person. The rotatable rod 4 is provided with a return means 17 that urges the rod 4 in a direction in which the rod 4 extends from the cylinder 2. The return means 17 includes a disk-like spring retainer 18 fixedly provided in the middle of the rotatable rod 4 and a coil spring interposed between the spring retainer 18 and the end wall 9 of the cylinder 2 in a compressed state. 19. It is desirable to use a nonmagnetic material such as stainless steel for the rotatable rod 4.

  The non-rotatable rod 6 is inserted through a rod hole 10 a formed in the end wall 10 of the cylinder 2 and connected to the piston 3. The non-rotatable rod 6 is provided so as not to rotate with respect to the cylinder 2 and to be movable in the axial direction. The means for making the non-rotatable rod 6 non-rotatable with respect to the cylinder 2 includes a pin 21 diametrically penetrating the non-rotatable rod and a pin formed on the end wall 10 of the cylinder 2 in parallel with the moving direction of the non-rotatable rod. 21 guide grooves 10b. Inside the non-rotatable rod 6, a conductor hole 6 a is formed for inserting a conductor 23 for supplying a current to a coil 22 described later. The non-rotatable rod 6 is desirably made of a nonmagnetic material such as stainless steel.

  Next, the piston 3 will be described in more detail. The piston 3 mainly includes an outer portion 31, an inner portion 32, and an annular plate portion 33.

  A concave portion 31 a is formed on one side of the outer portion 31. The inner portion 32 is fitted into the recess 31a so as to be relatively rotatable. The other end of the outer portion 31 is connected to the end of the rotatable rod 4. A nonmagnetic material such as stainless steel is used for the outer portion 31 (excluding the outer diameter side portion of the annular plate portion 33).

  The inner portion 32 is fitted to the concave portion 31a of the outer portion 31 so as to be rotatable via two bearings 34 and 35 and not to be relatively movable in the axial direction. One bearing 34 is fitted in a deep position of the recess 31a, and the other bearing 35 is fitted in a shallow position of the recess 31a. In the inner portion 32, a bobbin 36 and a coil 22 wound around the bobbin 36 are installed. The coil 22 is wound in a cylindrical shape around the axis of the inner portion 32. Moreover, in the inner part 32, the edge part of the non-rotatable rod 6 is connected to the surface 32a on the opposite side to the fitting side to the recessed part 31a. In the inner portion 32, a conductor hole 32 b for inserting the conductor 23 is formed from the conductor hole 6 a formed in the non-rotatable rod 6 to the coil 22 continuously. In addition, since the inner part 32 functions also as a yoke, the magnetic body is used as the material.

  The annular plate portion 33 projects from the formation surface of the concave portion 31 a of the outer portion 31 toward the center side and is inserted into a slit 32 c formed in the inner portion 32 so as to be relatively rotatable. A minute gap 37 (see FIG. 3) is secured between the front surface 33a and back surface 33b of the portion inserted into the inner portion 32 of the annular plate portion 33 and the two slit forming surfaces 32c1 and 32c2 of the inner portion 32. ing. Further, a gap 38 (see FIG. 3) is also secured between the inner peripheral surface of the annular plate portion 33 and the coil 22. Note that a magnetic material is used for the annular plate portion 33.

  In addition, the piston 3 is formed with a communication passage 29 that communicates the first fluid chamber 27 and the second fluid chamber 28 in which the internal space 12 of the cylinder 2 is partitioned by the piston 3. This communication path 29 is formed in the outer part 31, the inner part 32, between the outer part 31 and the inner part 32, and the like. In the outer portion 31, a first through hole 31 b formed from the first fluid chamber 27 to the recess 31 a constitutes the communication passage 29. Further, in the inner portion 32, the second through hole 32d formed from the position facing the concave portion 31a of the outer portion 31 to the slit forming surface 32c1, the two minute gaps 37, the gap 38, and the slit formation. A communication passage 29 is constituted by the third through hole 32e formed from the surface 32c2 to the second fluid chamber 28. The second through hole 32d and the third through hole 32e are preferably formed at the same position when viewed from the moving direction of the piston 3. In the present embodiment, one each of the first through hole 31b, the second through hole 32d, and the third through hole 32e are formed, but a plurality of these are formed at intervals in the circumferential direction. May be.

  In addition, a communication path 39 with a check valve that penetrates the outer portion 31 from the first fluid chamber 27 to the second fluid chamber 28 is formed in the piston 3. The check valve 39a of the communication passage 39 with a check valve blocks the flow of the magnetorheological fluid that tries to move from the second fluid chamber 28 to the first fluid chamber 27 when the button 16 is pushed to the cylinder 2 side. It is installed to do. Reference numeral 39b is a member that prevents the ball of the check valve 39a from being detached from the communication path 39 without hindering the flow of the magnetorheological fluid in the communication path 39, and is constituted by, for example, a thin bar. Yes.

  The magnetic field generation means 7 includes a coil 22 wound around a bobbin 36, an inner part 32 of the piston 3 that functions as a yoke, and a current supply device that supplies current to the coil 22. (Not shown). When a current is supplied to the coil 22, two gaps 37 between the yoke (inner portion 32) and the annular plate portion 33 and a magnetic path that penetrates the annular plate portion 33 are formed. In addition, the conducting wire 23 extended from the coil 22 is connected to the current supply device through the conducting wire holes 6a and 32b.

  The magnetorheological fluid 8 is sealed in the internal space 12 of the cylinder 2 and spreads not only in the first fluid chamber 27 and the second fluid chamber 28 but also in the communication passage 29 and the gaps between the respective portions. The magnetorheological fluid 8 is a liquid in which magnetic particles are dispersed in a dispersion medium, and in particular, a liquid in which the magnetic particles are made of 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, and a hydrophobic silicone oil can be given as an example. 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 in order to obtain various desired properties.

  FIG. 2 shows a construction example of the cylinder 2 and the piston 3 of the magnetoviscous fluid device 1 described above. For the cylinder 2, a non-magnetic disk member 2B having a rod hole 9a formed at one end of a cylindrical member 2A made of a non-magnetic material is fitted and fixed, and a rod hole 10a is formed at the other end of the cylindrical member 2A. It can be constructed by fitting and fixing a cylindrical member 2C made of a magnetic material. Fixing after fitting can be performed by, for example, bolt fastening, welding, or the like. As for the outer portion 31 of the piston 3, the thick plate ring members 3A and 3B made of two nonmagnetic materials sandwich the outer diameter side of the annular plate member forming the annular plate portion 33, and further the thick plate ring member 3B. The disc 3C made of a non-magnetic material can be superposed on the side surfaces of the two and fixed together. These fixations can also be performed by, for example, bolt fastening, welding, or the like. For the inner portion 32 of the piston 3, as shown in FIG. 2, two members 3D and 3E made of a magnetic material previously processed so as to form a slit 32c, a coil 22, a bobbin 36, and the like are combined in the axial direction. Can be constructed.

  In the magnetorheological fluid device 1 described above, when a current is applied to the coil 22 by a current supply device (not shown), the inside of the inner portion 32 and the annular plate portion 33 along the direction indicated by the arrow P in FIG. A magnetic path is formed. This magnetic path passes through the magnetorheological fluid 8 interposed in the minute gaps 37, 37 between the annular plate portion 33 and the slit forming surfaces 32 c 1, 32 c 2 of the inner portion 32. For this reason, the viscosity (shear stress) corresponding to the strength of the magnetic field appears in the magnetorheological fluid 8 on the magnetic path, and as a result, the annular plate portion 33 (button 16, rotatable rod 4) and the inner portion 32 ( The rotational force transmitted to and from the cylinder 2) increases in accordance with the strength of the magnetic field (the magnitude of the current supplied to the coil 22).

  When the button 16 is pushed by the user and the piston 3 moves from the state shown in FIG. 1 to the state shown in FIG. 4, the check valve 39a is closed as shown in FIG. The magnetorheological fluid in the second fluid chamber 28 moves exclusively to the first fluid chamber 27 through the communication path 29. At this time, the magnetorheological fluid passing through the communication passage 29 has a magnetic field strength when passing through the minute gaps 37 and 37 between the both surfaces 33a and 33b of the annular plate portion 33 and the slit forming surfaces 32c1 and 32c2 of the inner portion 32. Viscosity (shear stress) corresponding to Therefore, direct power corresponding to the strength of the magnetic field (the magnitude of the current supplied to the coil 22) is transmitted from the button 16 side to the cylinder 2 side. Thereafter, when the user releases his / her hand from the button 16, the return means 17 applies a force in the return direction to the rotatable rod 4, and the button 16 returns to its original position. At this time, as shown in FIG. 5, the check valve 39 a is opened by the flow of the magnetorheological fluid from the first fluid chamber 27 to the second fluid chamber 28, so whether or not current is applied to the coil 22. Regardless, the button 16, piston 3, etc. quickly return to their original positions.

  The magnetorheological fluid device 1 described above can be applied to various usage forms. As one of the usage forms, it is conceivable to use the cylinder 2 while being fixed at a predetermined place. In this case, by controlling the current supplied to the coil 22, the load that the user feels when pushing the button 16 and the rotation load that the user feels when the button 16 is rotated can be freely controlled. It can be controlled and adjusted. Of course, since the responsiveness of the viscosity of the magnetorheological fluid to the change in the current value supplied to the coil 22 is excellent, the present apparatus 1 can freely express even a minute load change or a complicated load change. can do.

<Other embodiments>
The magnetorheological fluid device 1 according to the above-described embodiment includes the return means 17 and the communication passage 29 with a check valve. However, one or both of them may be omitted as necessary in applying the present invention. Also good. In particular, if the communication passage 29 with a check valve is omitted, when the button 16 is pulled with a current applied to the coil 22, the magnetorheological fluid in the first fluid chamber 27, as shown in FIG. It moves to the second fluid chamber 28 exclusively through the communication passage 29. At this time, the viscosity (shear stress) corresponding to the strength of the magnetic field is applied to the magnetorheological fluid passing through the minute gaps 37 and 37 between the both surfaces 33a and 33b of the annular plate portion 33 and the slit forming surfaces 32c1 and 32c2 of the inner portion 32. Because of this expression, the load when the user pulls the button 16 can be freely controlled and adjusted.

  In the above-described embodiment, the rotatable rod 4 and the outer portion 31 of the piston 3 are connected, and these are configured to be rotatable, while the non-rotatable rod 6 and the inner portion 32 of the piston 3 are connected, However, as shown in FIG. 7, the piston 3 is reversely arranged to connect the rotatable rod 4 and the inner portion 32 of the piston 3 so that they can rotate. The impervious rod 6 and the outer portion 31 of the piston 3 may be connected, and the magnetorheological fluid device 1A may be configured such that they cannot be rotated.

  In the embodiment described above, a sliding bearing such as a bush may be provided in place of the two bearings 34 and 35.

  In the above-described embodiment, when the piston 3 moves, the magnetorheological fluid may pass through the bearings 34 and 35. If it is necessary to prevent this passage, the bearings 34 and 35 Rubber packing may be arranged on the side surface (upper and lower surfaces of the bearing in the figure).

  The present invention can be applied to a device (for example, an operation feeling variable device) that changes the transmission force between the members by changing the strength of the magnetic field applied to the magnetorheological fluid interposed between the members.

1, 1A Magnetorheological fluid device 2 Cylinder 3 Piston 4 Rotating rod (first shaft member)
6 Non-rotatable rod (second shaft)
8 Magnetorheological fluid 12 Cylinder internal space 22 Coil 27 First fluid chamber 28 Second fluid chamber 29 Communication path 31 Outer portion 31a Recessed portion 32 Inner portion 32a Surface opposite to the fitting side into the recessed portion 32c Slit 32c1, 32c2 Slit formation Surface 33 Annular plate portion 33a Surface of annular plate portion (plate surface)
33b Back surface of the annular plate (plate surface)
37 Minute gap (gap)
38 Clearance

Claims (4)

A cylinder,
A piston fitted in the internal space of the cylinder so as to be able to reciprocate;
A first shaft member, which is inserted in a rotatable and reciprocating manner with respect to the cylinder from one of the cylinders, and is connected to the piston;
A second shaft member that is inserted from the other side of the cylinder so as to be non-rotatable and reciprocable with respect to the cylinder, and connected to the piston;
A coil provided in the piston;
A magnetorheological fluid device comprising:
The piston is
An outer part in which a recess is formed on one side and the first shaft member is connected to the other side;
An inner portion in which the second shaft member is connected to a surface opposite to the fitting side, and is fitted to the recess so as to be rotatable.
An annular plate portion that protrudes from the concave portion forming surface of the outer portion toward the center, and is inserted so as to be relatively rotatable in a slit formed in the inner portion;
Have
A first fluid chamber and a second fluid chamber in which an internal space of the cylinder is partitioned by the piston communicate with each other, and a gap between a slit forming surface of the inner portion and a plate surface of the annular plate portion There is a communication path to go through,
While applying the current to the coil, the coil is disposed so that a magnetic path that penetrates the gap between the slit forming surface of the inner portion and the plate surface of the annular plate portion is formed, The material used for the outer part, the inner part and the annular plate part is set,
A magnetorheological fluid device characterized by the above. A cylinder,
A piston fitted in the internal space of the cylinder so as to be able to reciprocate;
A first shaft member, which is inserted in a rotatable and reciprocating manner with respect to the cylinder from one of the cylinders, and is connected to the piston;
A second shaft member that is inserted from the other side of the cylinder so as to be non-rotatable and reciprocable with respect to the cylinder, and connected to the piston;
A coil provided in the piston;
A magnetorheological fluid device comprising:
The piston is
An outer part in which a recess is formed on one side and the second shaft member is connected to the other side;
An inner part in which the first shaft member is connected to a surface opposite to the fitting side;
An annular plate portion that protrudes from the concave portion forming surface of the outer portion toward the center, and is inserted so as to be relatively rotatable in a slit formed in the inner portion;
Have
A first fluid chamber and a second fluid chamber in which an internal space of the cylinder is partitioned by the piston communicate with each other, and a gap between a slit forming surface of the inner portion and a plate surface of the annular plate portion There is a communication path to go through,
While applying the current to the coil, the coil is disposed so that a magnetic path that penetrates the gap between the slit forming surface of the inner portion and the plate surface of the annular plate portion is formed, The material used for the outer part, the inner part and the annular plate part is set,
A magnetorheological fluid device characterized by the above. The magnetorheological fluid device according to claim 1 or 2,
The coil is disposed inside the annular plate portion,
The communication path includes a gap between one surface of the slit forming surface of the inner portion and one plate surface of the annular plate portion opposed thereto, a gap between the inner peripheral surface of the annular plate portion and the coil, and It passes through the gap between the other surface of the slit forming surface of the inner portion and the other plate surface of the annular plate portion facing it.
A magnetorheological fluid device characterized by the above. In the magnetorheological fluid device according to any one of claims 1 to 3,
A magnetorheological fluid device in which the interior space of the cylinder and the communication path are filled with a magnetorheological fluid.

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