JP2001241486A - Viscous magnetic fluid flowing type electromagnetically vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic viscous fluid flowing type vibration control device attaining reduction of a cost and improvement of reliability by a relative ly simple constitution also permitting very slow displacement to be capable of obtaining a proper damping effect relating to the other vibration. SOLUTION: This vibration control device is constituted by a cylinder 1, a piston rod 2, a piston 3, a communication pipe 4, and a reservoir 5. The cylinder 1 and the communication pipe 4 are charged with a magnetic viscous fluid, it is received to the reservoir 5. Circulation of the magnetic viscous fluid by very slow displacement of the piston 3 is performed in a side of the reservoir 5 by opening/closing action of a puppet valve 10, thermal displacement of a pipe or the like is permitted. Circulation of the magnetic viscous fluid by displacement of the piston 3 except the above is performed in a side of the communication pipe 4 through an orifice 11, viscosity of the fluid is increased in a magnetic field with the orifice 11 by an electromagnet 15, flow resistance is increased, vibration due to a wind, an earthquake, etc., is damped. The orifice 11 is formed by a pair of magnetic bodies 12, 12 provided to make a space changeable to be opposed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a magnetorheological fluid having a characteristic of increasing the viscosity and increasing the flow resistance when a magnetic field is applied, and flowing the magnetorheological fluid in a magnetic field by an electromagnet by moving a piston due to vibration. The present invention relates to a magneto-rheological fluid flow type vibration damping device for damping vibration by its flow resistance.

[0002]

2. Description of the Related Art Conventionally, a cylinder is connected to one of a supporting member and a supported member, and a piston rod is inserted into the cylinder so as to be freely inserted into and removed from the cylinder. Is fixed, and the inside of the cylinder is filled with a magnetorheological fluid. An electromagnet is fixed to the piston, and a magnetorheological fluid flows between the compartments through a gap with the cylinder. Then, the magnetorheological fluid flows due to the reciprocation of the piston accompanying the vibration, but the flow resistance increases due to the magnetic field of the electromagnet, and the vibration is attenuated. In this case, the damping characteristic can be changed according to the vibration of the vibration damping target by changing the strength of the magnetic field by the electromagnet.

[0003]

In the above-mentioned conventional vibration damping device, since an electromagnet is provided in the cylinder, it is necessary to supply electric power to the movable portion from the outside, and the magnetic field is adjusted according to the degree of vibration. Control unit is required, the configuration of the device becomes complicated, and there are difficulties in terms of cost and reliability.

On the other hand, if permanent magnets are used in place of electromagnets, a damping load close to the rating will be applied to vibrations in a low-speed range. If applied, extremely gradual displacement due to thermal change is prevented, resulting in damage to piping and the like. Also,
The attenuation characteristics cannot be changed according to the installation situation.

Further, heat is easily stored in the cylinder due to heat generated by energization of the electromagnet, which causes deterioration of characteristics of the magnetorheological fluid. In addition, when the magnetorheological fluid deteriorates, it separates into base oil and iron powder, causing a phenomenon in which the base oil appears as a supernatant near the liquid surface, which adversely affects the performance of the apparatus.

Accordingly, the present invention aims at reducing the cost and improving the reliability with a relatively simple structure, and allows extremely slow displacement such as thermal displacement of the piping. The present invention provides an electromagnet type magnetorheological fluid flow type vibration damping device that can appropriately attenuate the vibration and easily adjust the damping characteristics according to the installation condition, and furthermore, prevent the deterioration of the magnetorheological fluid and reduce the influence of the deterioration. That is the task.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a cylinder 1 is connected to one of a supporting member and a supported member, and a magnetic viscous fluid is filled therein.
A piston rod 2 is connected to the other end and inserted into the cylinder 1 so as to be able to move in and out of the cylinder 1.
The inside is partitioned into first and second compartments 8 and 9, and a communication pipe 4 is connected to the first and second compartments 8 and 9 to fill the inside with a magnetic viscous fluid. Orifice 11 on the way
And the electromagnet 15 is fixed to the communication pipe 4 so that the orifice 1
1 is a poppet that provides a flow resistance to the magnetorheological fluid by forming a magnetic field, and allows the first and second compartments 8 and 9 of the cylinder 1 to flow the magnetorheological fluid due to extremely slow displacement of the piston 3. The reservoir 5 containing the magnetorheological fluid is communicated through the valve 10 to allow a very slow relative displacement of the piston 3 by the flow of the magnetorheological fluid to the reservoir 5 side. An electromagnet type magnetorheological fluid flow type vibration damping device is configured so as to attenuate vibration by imparting resistance by the flow of the magnetorheological fluid to the communication pipe 4 side.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a magnetic viscous fluid flow type vibration damping device according to the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. 1 and 2, the vibration damping device is a cylinder 1
A piston rod 2 inserted into the cylinder 1 so as to be able to move in and out in the axial direction; a piston 3 fixed on the piston rod 2; a communication pipe 4 provided at a lower part of the cylinder 1; And a reservoir 5 provided. The cylinder 1 is connected to one of a support such as a construction (not shown) or a supported body such as piping via a pull 6, and the piston rod 2 is connected to the other via a pull 7. The interior of the cylinder 1 is partitioned by the piston 3 into compartments 8 and 9. The inside of the cylinder 1 and the communication pipe 4 is filled with a magnetorheological fluid.

The reservoir 5 communicates with the compartments 8 and 9 of the cylinder 1 via a poppet valve 10, and contains a magnetorheological fluid therein. The poppet valve 10 opens and closes so as to allow only the flow of the magnetic viscous fluid due to the extremely slow relative displacement of the piston 3. That is, the poppet valve 10 is configured such that a valve body having a flow hole on a side portion is pushed by a spring in a direction away from a valve seat, and is always kept open to allow a slight flow. Close the valve at a pressure higher than the force.

The two ends of the communication pipe 4 are connected to the compartments 8 of the cylinder 1,
9 in communication. The communication pipe 4 is located below the cylinder 1 and is made of a substantially rectangular nonmagnetic material, and a flow passage having a circular cross section in the longitudinal direction penetrates. The communication pipe 4 has an orifice 11 substantially at the center in the longitudinal direction. The orifice 11
It is formed by a pair of opposing magnetic bodies 12 inserted into the communication pipe 4 from the lateral direction. The distance between the orifices 11 of the magnetic body 12 can be adjusted by the fixing position of the bolt 13 by tightening the nut to the mounting piece 14 fixed to the cylinder 1. The mounting piece 14 is made of a magnetic material.

An electromagnet 15 for forming a magnetic field in the orifice 11 is fixed to the communication pipe 4 via a mounting piece 14. The electromagnet 15 includes an iron core 15a that forms a magnetic path together with the magnetic bodies 12, 12 and the mounting piece 14, and an annular coil 15b wound around the iron core 15a.
The coil 15b is connected to an external power supply (not shown).

This vibration damping device is applied, for example, to support a pipe of a power generation facility. When thermal displacement occurs in the pipe, the piston 3 moves relatively slowly with respect to the cylinder 1. When the piston 3 moves, the volumes of the compartments 8 and 9 change, so that the magnetorheological fluid inside the compartments enters and exits the cylinder 1. When the piston 3 moves leftward (or rightward) in FIG.
And is pushed out from the compartment 8 (or 9) to the reservoir 5 side, and the shortage flows into the compartment 9 (or 8) from the reservoir 5 side. Therefore, extremely slow movement of the piston 3 is not hindered, and the displacement of the damping target is allowed without exerting a damping force.

On the other hand, when vibration is applied to the vibration damping object due to a wind, an earthquake, or the like, the piston 3 moves leftward (or rightward) at a higher moving speed than the previous example, and the magnetic viscous fluid is moved by the piston 3 to the compartment 8
(Or 9). At this time, poppet valve 1
Since 0 is closed, the magnetorheological fluid does not enter or leave the reservoir 5 side, and flows through the communication pipe 4. The flow of this magnetorheological fluid is restricted by the orifice 11, and the viscosity increases due to the magnetic field of the electromagnet 15, so that the flow resistance increases and free flow is hindered. Accordingly, resistance is generated in the movement of the piston 3, and the vibration is attenuated. Since the flow resistance of the magnetorheological fluid changes depending on the distance between the orifices 11 and the magnetic field strength at the orifices 11, the damping load is reduced by the magnetic members 12, 12.
Can be adjusted by adjusting the fixing position of the coil or by changing the current flowing through the coil 15b. In particular, since the interval between the orifices 11 can be freely changed depending on the fixing position of the bolt 13 by tightening the nut, there is no need for precise finishing or assembling work of the member for finely adjusting the gap. Since the electromagnet 15 is exposed to the outside and is not in contact with the magnetorheological fluid, the magnetorheological fluid does not deteriorate due to heat generated by energization. Further, even if the magnetic viscous fluid deteriorates and the base oil and the iron powder are separated and the base oil becomes a supernatant, the orifice 11 is submerged in the normal magnetic viscous fluid at the lower position. Therefore, the performance of the apparatus is not affected.

[0014]

As described above, in the present invention, the piston and the electromagnet are separated and the magnetorheological fluid is circulated outside the cylinder, so that the cost can be reduced as a whole with a relatively simple structure. Can be planned. In addition, since the electromagnet is provided outside the cylinder, power supply becomes easy, a control unit for changing the magnetic field is not required, the configuration of the device is simplified, cost is reduced, and reliability is improved. be able to. For example, extremely slow relative displacement of the piston due to thermal changes in pipes and the like is reasonably permitted to prevent equipment damage, but it can reliably attenuate vibrations caused by wind and earthquakes, improving performance and reliability. Can be planned. Further, even if the electromagnet generates heat, the characteristics of the magnetorheological fluid do not deteriorate.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a magnetic viscous fluid flow type vibration damping device according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston rod 3 Piston 4 Communication pipe 5 Reservoir 8 Compartment 9 Compartment 10 Poppet valve 11 Orifice 12 Magnetic body 13 Bolt 15 Electromagnet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuaki Sunoda 6-5-19 Minamishinagawa, Shinagawa-ku, Tokyo Sanwa Tekki Co., Ltd. (72) Inventor Hiroshi Sodeyama 2703 Nakaokamoto Nakaokamoto, Kawachi-gun, Kawachi-gun Tochigi F-term in the Utsunomiya Plant of Tech Co., Ltd. (reference) 3J069 AA36 AA55 CC10 DD25 EE62

Claims (1)

[Claims] Claims: 1. A method according to claim 1, further comprising:
A cylinder filled with a magnetorheological fluid, a piston rod connected to the other side and inserted into and out of the cylinder, and fixed to the piston rod;
A piston which divides the inside of the cylinder into first and second compartments, and which is movable in the cylinder in the axial direction, and a first and second compartments of the cylinder, each of which has a magnetic viscosity due to a slow relative displacement of the piston. A reservoir containing a magnetorheological fluid that communicates through a poppet valve that allows fluid to flow therethrough, and a magnetorheological fluid filled therein and communicates with the first and second compartments, and an orifice is provided on the way A communication pipe through which the magnetorheological fluid flows, and an electromagnet fixed to the communication pipe to form a magnetic field at the orifice, allowing extremely slow relative displacement of the piston, but resisting relative displacement at other speeds. An electromagnet type magnetorheological fluid flow type vibration damping device characterized in that vibration is attenuated by being applied.