WO2017051669A1 - Amortisseur de fluide magnéto-visqueux - Google Patents

Amortisseur de fluide magnéto-visqueux Download PDF

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Publication number
WO2017051669A1
WO2017051669A1 PCT/JP2016/075171 JP2016075171W WO2017051669A1 WO 2017051669 A1 WO2017051669 A1 WO 2017051669A1 JP 2016075171 W JP2016075171 W JP 2016075171W WO 2017051669 A1 WO2017051669 A1 WO 2017051669A1
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WO
WIPO (PCT)
Prior art keywords
piston
temperature compensation
magnetorheological fluid
diameter portion
flow path
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Application number
PCT/JP2016/075171
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English (en)
Japanese (ja)
Inventor
睦 小川
康裕 米原
Original Assignee
Ｋｙｂ株式会社
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Publication of WO2017051669A1 publication Critical patent/WO2017051669A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/50—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics
    • F16F9/52—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics in case of change of temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/53—Means for adjusting damping characteristics by varying fluid viscosity, e.g. electromagnetically

Definitions

  • the present invention relates to a magnetorheological fluid shock absorber using a magnetorheological fluid whose apparent viscosity changes due to the action of a magnetic field.
  • a magnetic viscous fluid shock absorber that changes a damping force by applying a magnetic field to a flow path through which the magnetic viscous fluid passes and changing an apparent viscosity of the magnetic viscous fluid.
  • JP2014-181808A when a piston assembly including a piston core having a coil wound on the outer periphery and a piston ring disposed on the outer periphery of the piston core slides in the cylinder, the piston core and the piston ring A magnetorheological fluid shock absorber is disclosed in which a magnetorheological fluid passes through a flow path formed therebetween.
  • An object of the present invention is to generate a required damping force regardless of a temperature change of a magnetorheological fluid.
  • a magnetorheological fluid shock absorber includes a cylinder in which a magnetorheological fluid whose apparent viscosity is changed by the action of a magnetic field is sealed, a slidable arrangement in the cylinder, and a pair in the cylinder.
  • a piston core connected to the piston and extending to the outside of the cylinder, the piston being attached to the end of the piston rod and having a coil provided on the outer periphery thereof,
  • An annular ring body that surrounds the outer periphery of the piston core and forms a flow path with the piston core; an annular plate that supports the ring body and defines the width of the flow path;
  • FIG. 1 is a cross-sectional view of a magnetorheological fluid shock absorber according to a first embodiment of the present invention.
  • FIG. 2 is a left side view of the piston in FIG.
  • FIG. 3 is a sectional view taken along line III-III in FIG.
  • FIG. 4 is an enlarged cross-sectional view of the periphery of the temperature compensation unit, showing a state where the temperature of the magnetorheological fluid is high.
  • FIG. 5 is an enlarged cross-sectional view of the periphery of the temperature compensation unit, showing a state where the temperature of the magnetorheological fluid is low.
  • FIG. 6 is a cross-sectional view showing another form of the temperature compensation unit corresponding to FIG.
  • FIG. 7 is an enlarged cross-sectional view of a magnetorheological fluid shock absorber according to a second embodiment of the present invention.
  • the shock absorber 100 is a damper whose damping coefficient can be changed by using a magnetorheological fluid whose apparent viscosity changes due to the action of a magnetic field.
  • the shock absorber 100 is interposed, for example, between a vehicle body and an axle in a vehicle such as an automobile.
  • the shock absorber 100 generates a damping force that suppresses vibration of the vehicle body by an expansion and contraction operation.
  • the shock absorber 100 includes a cylinder 10 in which a magnetorheological fluid is sealed, a piston 20 that is slidably disposed in the cylinder 10, and a piston rod 21 that is connected to the piston 20 and extends to the outside of the cylinder 10. And comprising.
  • the piston rod 21 moves forward and backward with respect to the cylinder 10 as the piston 20 slides.
  • the cylinder 10 is formed in a bottomed cylindrical shape.
  • the magnetorheological fluid sealed in the cylinder 10 is a liquid whose apparent viscosity changes due to the action of a magnetic field.
  • a magnetorheological fluid can be obtained by dispersing fine particles having ferromagnetism in a liquid such as oil.
  • the apparent viscosity of the magnetorheological fluid changes according to the strength of the applied magnetic field, and returns to its original state when the magnetic field is no longer affected.
  • a gas chamber (not shown) in which gas is sealed is defined via a free piston (not shown).
  • the volume change in the cylinder 10 due to the advance / retreat of the piston rod 21 is compensated by the gas chamber.
  • the piston 20 defines a fluid chamber 11 and a fluid chamber 12 in the cylinder 10.
  • the fluid chamber 11 and the fluid chamber 12 communicate with each other through a flow path 22 and a bypass flow path 23 formed in the piston 20.
  • the configuration of the piston 20 will be described later in detail.
  • the piston rod 21 is formed coaxially with the piston 20, and one end 21 a of the piston rod 21 is fixed to the piston 20.
  • the other end 21 b of the piston extends to the outside of the cylinder 10.
  • the piston rod 21 has a cylindrical shape in which a through hole 21c is formed across one end 21a and the other end 21b.
  • a male screw 21 d that is screwed with the piston 20 is formed on the outer peripheral surface of the piston rod 21.
  • FIG. 2 is a left side view of the piston 20.
  • the piston 20 includes a piston core 30 attached to the piston rod 21, an annular flux ring 35 as a ring body that surrounds the outer periphery of the piston core 30, and an annular plate 40 that is provided on the piston core 30 and supports the flux ring 35. And a fixing nut 50 that is attached to the outer peripheral surface of the piston core 30 and fixes the plate 40 to the piston core 30.
  • the piston core 30 is formed by being divided into a coil assembly 33 provided with a coil 33a and first and second cores 31 and 32 sandwiching the coil assembly 33.
  • the first and second cores 31 and 32 are fastened by a pair of bolts (not shown) with the coil assembly 33 sandwiched therebetween.
  • the first core 31 has a cylindrical first small-diameter portion 31a, a cylindrical second small-diameter portion 31b formed with a larger diameter than the first small-diameter portion 31a, and a second small-diameter portion 31b. And a cylindrical large-diameter portion 31c formed to have a large diameter. A cylindrical portion 31e is formed on the outer peripheral edge of the end surface 31d of the large diameter portion 31c.
  • the first core 31 is formed of a magnetic material.
  • a female screw 31f that is screwed with the male screw 21d of the piston rod 21 is formed on the inner peripheral surface of the first small diameter portion 31a.
  • the first core 31 is fastened to the piston rod 21 by screwing the female screw 31 f of the first small diameter portion 31 a and the male screw 21 d of the piston rod 21.
  • a male screw 31g to which the fixing nut 50 is screwed is formed on the outer peripheral surface at the tip of the first small diameter portion 31a.
  • the second small diameter portion 31b is formed coaxially with the first small diameter portion 31a in the axial direction, and forms a step portion 31h between the first small diameter portion 31a and the first small diameter portion 31a.
  • the step portion 31 h is configured such that the inside of the end face of the plate 40 abuts and the plate 40 is sandwiched between the fixing nut 50.
  • the large-diameter portion 31 c is formed coaxially with the second small-diameter portion 31 b in the axial direction and is in contact with the coil assembly 33.
  • the cylindrical portion 31e extends toward the plate 40 from the outer peripheral edge of the end surface 31d of the large diameter portion 31c.
  • a temperature compensation unit 60 is disposed between the inner peripheral surface 31i of the cylindrical portion 31e and the outer peripheral surface 31j of the second small diameter portion 31b. The cylindrical part 31e and the temperature compensation part 60 will be described in detail later.
  • the second core 32 of the piston core 30 has a columnar large diameter portion 32a and a columnar small diameter portion 32b formed to have a smaller diameter than the large diameter portion 32a.
  • the large diameter portion 32 a has an end surface 32 c that faces the fluid chamber 12.
  • the small diameter portion 32b is formed coaxially with the large diameter portion 32a continuously in the axial direction.
  • a plurality of tool holes 32d are formed in the end surface 32c of the large diameter portion 32a.
  • the tool holes 32d are holes into which tools are fitted when the piston 20 is screwed onto the piston rod 21, and are formed at intervals of 90 °.
  • the second core 32 is formed of a magnetic material in the same manner as the first core 31.
  • the coil assembly 33 of the piston core 30 includes a cylindrical coil mold portion 33b provided with a coil 33a therein, a connecting portion 33c extending radially inward from one end of the coil mold portion 33b, and an axial direction from the connecting portion 33c. And a cylindrical portion 33d extending to the center.
  • the coil assembly 33 is formed by molding a resin in a state where the coil 33a is inserted.
  • the cylindrical coil mold portion 33b is formed so that the inner diameter is substantially the same as the outer diameter of the small diameter portion 32b, and is fitted to the outer peripheral surface of the small diameter portion 32b.
  • the coil mold part 33 b and the connecting part 33 c are sandwiched between the first and second cores 31 and 32.
  • the cylindrical part 33d is located on the opposite side to the coil mold part 33b with respect to the connecting part 33c.
  • the cylindrical portion 33d is formed so that the outer diameter is substantially the same as the inner diameter of the cylindrical large diameter portion 31c, and is fitted to the large diameter portion 31c.
  • the tip 33e of the cylindrical portion 33d is inserted into the through hole 21c of the piston rod 21.
  • An O-ring 34 is provided on the outer peripheral side of the distal end portion 33e of the cylindrical portion 33d.
  • the O-ring 34 is compressed in the axial direction by the large diameter portion 31 c of the first core 31 and the piston rod 21, and is compressed in the radial direction by the tip portion 33 e of the coil assembly 33 and the piston rod 21. This prevents the magnetorheological fluid flowing between the piston rod 21 and the first core 31 or between the first core 31 and the coil assembly 33 from leaking into the through hole 21 c of the piston rod 21.
  • the piston core 30 is formed by being divided into three members of the first core 31, the second core 32, and the coil assembly 33. Therefore, it is only necessary to form only the coil assembly 33 provided with the coil 33 a by molding and to sandwich the coil assembly 33 between the first core 31 and the second core 32.
  • the piston core 30 formed by dividing into three members can easily form the piston core 30 as compared with the case where the piston core 30 is formed as a single body and the molding operation is performed.
  • the first core 31 is fixed to the piston rod 21 by screwing of the female screw 31f and the male screw 21d, while the coil assembly 33 and the second core 32 are only fitted in the axial direction. .
  • the second core 32 and the coil assembly 33 are fixed so as to be pressed against the first core 31. Therefore, the piston core 30 can be easily assembled.
  • the outer diameter of the large diameter portion 32 a and the coil mold portion 33 b of the second core 32 is formed to be the same as the large diameter portion 31 c of the first core 31. Since the outer diameters of the large diameter portions 31c and 32a and the coil mold portion 33b are the same, in the following, the portion composed of the large diameter portions 31c and 32a and the coil mold portion 33b is referred to as the “large diameter portion 30a” of the piston core 30. Called.
  • the flux ring 35 of the piston 20 is made of a magnetic material.
  • One end 35a of the flux ring 35 is provided with an annular recess 35e recessed in the axial direction.
  • the other end 35b of the flux ring 35 is formed so as to be flush with the end surface 32c of the large diameter portion 32a.
  • the annular flux ring 35 is formed so that the outer diameter is substantially the same as the inner diameter of the cylindrical cylinder 10, and the inner diameter is larger than the outer diameter of the large-diameter portion 30 a of the piston core 30. Accordingly, an annular gap is formed between the inner peripheral surface 35c of the flux ring 35 and the outer peripheral surface 30b of the large diameter portion 30a of the piston core 30 over the entire length in the axial direction. This gap functions as a flow path 22 through which the magnetorheological fluid flows.
  • the coil mold part 33 b faces the flow path 22. Therefore, the magnetic field generated by the coil 33a acts on the magnetorheological fluid flowing through the flow path 22. That is, the flow path 22 functions as a magnetic gap through which the magnetic flux generated around the coil 33a passes.
  • the coil 33a forms a magnetic field by a current supplied from the outside.
  • the strength of the magnetic field increases as the current supplied to the coil 33a increases.
  • an electric current is supplied to the coil 33a to form a magnetic field, the apparent viscosity of the magnetorheological fluid flowing through the flow path 22 changes.
  • the apparent viscosity of the magnetorheological fluid increases as the magnetic field generated by the coil 33a increases.
  • a pair of wires (not shown) for supplying a current to the coil 33a is routed inside the connecting portion 33c and the cylindrical portion 33d.
  • the pair of wires are drawn from the tip of the cylindrical portion 33 d and passed through the through hole 21 c of the piston rod 21.
  • bypass channel 23 that penetrates in the axial direction is formed at a position where the influence of the magnetic field generated by the coil 33 a is smaller than that of the channel 22.
  • Two bypass channels 23 are formed at intervals of 180 °.
  • the number of bypass channels 23 is not limited to this, and the bypass channels 23 may not be provided.
  • the bypass flow path 23 includes a first through hole 23 a that penetrates the first core 31 and a second through hole 23 b that penetrates the second core 32 and the coil assembly 33.
  • the hole diameter of the first through hole 23a is small enough to give sufficient resistance to the magnetorheological fluid.
  • the second through hole 23b is formed to have a larger diameter than the first through hole 23a. Therefore, the damping characteristic when the piston 20 slides is determined by the hole diameter of the first through hole 23a. The hole diameter of the second through hole 23b does not affect the damping characteristics when the piston 20 slides.
  • Two of the above-mentioned four tool holes 32d formed on the end face 32c of the second core 32 are formed at the end of the second through hole 23b.
  • the tool hole 32d is shared with the second through hole 23b.
  • the plate 40 is an annular flat plate member made of a nonmagnetic material.
  • the outer peripheral surface 40b which is an outer edge is press-fitted into the annular recess 35e of the flux ring 35, so that the plate 40 is accommodated in the annular recess 35e and supports the flux ring 35.
  • a plurality of flow paths 24 that are through holes communicating with the flow path 22 are formed.
  • the flow paths 24 are formed in an arc shape and are arranged at equiangular intervals. Specifically, four flow paths 24 are formed at 90 ° intervals.
  • the flow path 24 is not limited to an arc shape, and may be a circular through hole, for example.
  • the flow path 24 has a port 24 a that opens to one end surface of the plate 40.
  • the port 24a faces the end surface 31d of the large diameter portion 31c.
  • the port 24 a is provided in the axial direction and is disposed radially inward with respect to the flow path 22.
  • An annular gap is formed between the plate 40 and the large diameter part 31 c of the first core 31.
  • This gap functions as a bypass branch 25 that branches and guides the magnetorheological fluid flowing from the channel 24 into the channel 22 and the bypass channel 23. Since the bypass branch path 25 is formed in an annular shape around the second small diameter portion 31b, it is not necessary to align the circumferential positions of the flow path 24 and the bypass flow path 23 when the piston 20 is assembled, and the piston 20 can be easily Can be assembled.
  • the plate 40 is formed with a through hole 40a into which the first small diameter portion 31a of the first core 31 is fitted. By fitting the first small diameter portion 31a into the through hole 40a, the coaxiality between the plate 40 and the first core 31 is ensured. As a result, the plate 40 defines an interval (width of the flow path 22) between the inner peripheral surface 35c of the flux ring 35 and the outer peripheral surface 30b of the large diameter portion 30a.
  • the plate 40 is pressed and clamped against the step portion 31h by the fastening force of the fixing nut 50 with respect to the first small diameter portion 31a of the piston core 30.
  • the position of the axial direction with respect to the piston core 30 of the flux ring 35 fixed to the plate 40 will be prescribed
  • the fixing nut 50 is formed in a substantially cylindrical shape, and is attached to the outer periphery of the first small diameter portion 31a of the piston core 30.
  • the fixing nut 50 is in contact with the plate 40 at the tip 50a.
  • the fixing nut 50 is formed with an internal thread 50c that is engaged with the external thread 31g of the first core 31 on the inner periphery of the base end 50b. Thereby, the fixing nut 50 is screwed to the first small diameter portion 31a.
  • the flux ring 35 and the piston core 30 are coupled via the plate 40 provided on the one end 35a side of the flux ring 35 so that the center axis of the flux ring 35 and the center axis of the piston core 30 coincide with each other. Is done. Further, the axial position of the flux ring 35 with respect to the piston core 30 is defined by the plate 40. For this reason, it is not necessary to provide the member which couple
  • the member for connecting the flux ring 35 and the piston core 30 is not disposed on the other end 35 b side of the flux ring 35, the flow path 22 is continuously opened in an annular shape with respect to the fluid chamber 12. As a result, the flow resistance of the flow path 22 is reduced, and the resistance imparted to the magnetorheological fluid passing through the flow path 22 can be reduced.
  • FIG. 3 is a sectional view taken along line III-III in FIG.
  • members other than the piston 20 are omitted for explanation.
  • the cylindrical portion 31e extends from the outer peripheral edge of the end surface 31d of the large diameter portion 31c toward the plate 40.
  • the cylindrical portion 31 e does not reach the plate 40, and a gap is provided between the cylindrical portion 31 e and the plate 40. Therefore, the magnetorheological fluid goes back and forth between the bypass branch 25 and the flow path 22 through this gap.
  • the cylindrical portion 31e is formed of a material having a high rigidity and a low coefficient of thermal expansion, for example, a metal such as stainless steel.
  • the cylindrical portion 31 e may be formed integrally with the first core 31, or may be formed separately from the first core 31 and attached to the first core 31.
  • the temperature compensation unit 60 includes a thermal expansion member 61 and a protection member 62.
  • the thermal expansion member 61 is formed of a material having a larger coefficient of thermal expansion than the first core 31, for example, a resin material such as polyethylene and polyethylene terephthalate, or a metal material such as aluminum.
  • the protection member 62 is formed of a material having wear resistance, for example, a metal material such as stainless steel.
  • the thermal expansion member 61 and the protection member 62 are formed in an annular shape.
  • the thermal expansion member 61 is disposed between the inner peripheral surface 31i of the cylindrical portion 31e and the outer peripheral surface 31j of the second small diameter portion 31b.
  • the protection member 62 sandwiches the thermal expansion member 61 between the end surface 31d of the large diameter portion 31c and partially faces the port 24a.
  • the bypass branch 25 is formed between the plate 40 and the protection member 62.
  • the thermal expansion member 61 and the protection member 62 have a through hole 23c penetrating in the axial direction.
  • the bypass branch channel 25 and the bypass channel 23 communicate with each other through the through hole 23c.
  • the inner diameter of the through hole 23 c is preferably larger than the inner diameter of the bypass flow path 23 when the thermal expansion member 61 is at the maximum expansion.
  • the thermal expansion member 61 expands and contracts in the axial direction as the temperature changes.
  • the protective member 62 has an end surface fixed to the thermal expansion member 61, while an outer peripheral surface and an inner peripheral surface are not fixed to the cylindrical portion 31e and the second small diameter portion 31b. Therefore, the protection member 62 moves relative to the large-diameter portion 31c as the thermal expansion member 61 expands and contracts, and moves forward and backward with respect to the port 24a. As the protective member 62 advances and retreats, the opening degree of the flow path 22 changes and the flow resistance changes.
  • the protective member 62 is provided to prevent the resin thermal expansion member 61 from coming into direct contact with the magnetorheological fluid and wearing out. If there is no fear that the thermal expansion member 61 is worn by the magnetorheological fluid, it is not necessary to provide the protection member 62, and the thermal expansion member 61 may be configured to advance and retract directly with respect to the port 24a. Further, since the protective member 62 is a flat member, the opening degree can be easily adjusted by the advancement and retreat of the thermal expansion member 61.
  • the volume of the thermal expansion member 61 expands, so that the protection member 62 advances toward the port 24a along the direction of arrow A shown in FIG.
  • the opening degree of the flow path 22 is reduced, the flow path 22 is narrowed, and as a result, the flow resistance increases.
  • the second small diameter portion 31b and the cylindrical portion 31e are formed of a material having high rigidity and a low coefficient of thermal expansion, the second small diameter portion 31b and the cylindrical portion 31e function as a guide portion that restricts expansion of the thermal expansion member 61 in the radial direction. Therefore, the expansion of the thermal expansion member 61 is allowed only in the direction toward the port 24a. In this way, the expansion direction of the thermal expansion member 61 is not dispersed and is regulated in one direction, so that the change in the volume of the thermal expansion member 61 can be efficiently reflected in the change in the opening degree of the flow path 22. .
  • the temperature compensation unit 60 (thermal expansion member 61) is not limited to a configuration that expands and contracts only in a direction that advances and retreats with respect to the port.
  • the temperature compensation unit 60 may be configured to expand and contract in the direction of advancing and retreating with respect to the port and to expand and contract in the radial direction of the piston core 30.
  • “expansion / contraction” of the temperature compensation unit 60 (thermal expansion member 61) means expansion and contraction in a direction at least moving forward and backward with respect to the port.
  • the port 24a Since the protective member 62 partially faces the port 24a, even if the thermal expansion member 61 expands and the protective member 62 reaches the plate 40, the port 24a is not completely closed. Since the port 24a is not completely closed, the communication between the fluid chambers 11 and 12 through the port 24a can be maintained even during the maximum expansion of the thermal expansion member 61.
  • the volume of the thermal expansion member 61 contracts, so that the protection member 62 moves backward from the port 24a toward the large diameter portion 31c along the direction of arrow B shown in FIG.
  • the opening degree of the flow path 22 is increased, the flow path 22 is not restricted, and as a result, the flow resistance is reduced.
  • the temperature compensation unit 60 is not limited to an annular member.
  • FIG. 6 is a cross-sectional view showing another form of the temperature compensation unit 60 corresponding to FIG. As shown in FIG. 6, the temperature compensation unit 60 may be formed in an arc shape. Further, a plurality of arc-shaped temperature compensation units 60 may be arranged in the circumferential direction.
  • the temperature compensation part 60 When the temperature compensation part 60 is formed in an arc shape, it is preferable to provide a guide part 31k adjacent to the end face 60a of the temperature compensation part 60 in the circumferential direction on the end face 31d of the large diameter part 31c. Since the expansion of the temperature compensation unit 60 in the circumferential direction is regulated by the guide portion 31k, the change in the volume of the temperature compensation unit 60 can be efficiently reflected in the change in the opening degree of the flow path 22.
  • the shock absorber 100 expands and contracts and the piston rod 21 advances and retreats with respect to the cylinder 10, the magnetorheological fluid passes through the flow path 24 and the bypass branch path 25 formed in the plate 40, and the flow path 22 and the bypass flow path 23. And flow. Thereby, the piston 20 slides in the cylinder 10 as the magnetorheological fluid flows between the fluid chamber 11 and the fluid chamber 12.
  • the first core 31, the second core 32, and the flux ring 35 formed of a magnetic material constitute a magnetic path that guides a magnetic flux generated around the coil 33a.
  • the plate 40 is formed of a nonmagnetic material, the flow path 22 between the piston core 30 and the flux ring 35 becomes a magnetic gap through which the magnetic flux generated around the coil 33a passes.
  • the magnetic field of the coil 33a acts on the magnetic viscous fluid which flows through the flow path 22 at the time of expansion-contraction operation of the shock absorber 100.
  • Adjustment of the damping force generated by the shock absorber 100 is performed by changing the amount of current supplied to the coil 33a and changing the strength of the magnetic field acting on the magnetorheological fluid flowing through the flow path 22. Specifically, as the current supplied to the coil 33a increases, the strength of the magnetic field generated around the coil 33a increases. Therefore, the apparent viscosity of the magnetorheological fluid flowing through the flow path 22 increases, and the damping force generated by the shock absorber 100 increases.
  • the bypass flow path 23 is provided in a place that is not easily affected by the magnetic field of the coil 33a. For this reason, even if the energization amount to the coil 33a is changed, the apparent viscosity of the magnetorheological fluid flowing through the bypass passage 23 does not change much. As a result, the pressure fluctuation that occurs when the damping force is changed by changing the amount of current supplied to the coil 33a is alleviated by providing the bypass flow path 23.
  • the temperature compensation unit 60 advances toward the port 24a, reduces the opening degree of the flow path 22 and narrows the flow path 22 to increase the flow resistance. That is, the temperature compensation unit 60 suppresses a decrease in damping force when the temperature of the magnetorheological fluid is high.
  • the temperature compensation unit 60 moves backward from the port 24a, increases the opening degree of the flow path 22, releases the throttle of the flow path 22, and decreases the flow resistance. That is, the temperature compensation unit 60 suppresses an increase in damping force when the temperature of the magnetorheological fluid is low.
  • the temperature compensation unit 60 by providing the temperature compensation unit 60, the change in the damping force of the shock absorber 100 due to the viscosity change of the magnetorheological fluid due to the temperature change is compensated. As a result, a desired damping force can be generated by adjusting the amount of current supplied to the coil 33a regardless of the temperature change of the magnetorheological fluid.
  • the temperature compensation unit 60 moves back and forth with respect to the port 24a in accordance with the temperature of the magnetorheological fluid to change the flow resistance. For this reason, the change of the damping force of the shock absorber 100 due to the viscosity change of the magnetorheological fluid due to the temperature change is compensated. As a result, a desired damping force can be generated by adjusting the amount of current supplied to the coil 33a regardless of the temperature change of the magnetorheological fluid.
  • the cylindrical portion 31e restricts the expansion of the temperature compensation portion 60 in the radial direction of the piston core 30. For this reason, since the displacement direction of the temperature compensation part 60 is not disperse
  • the temperature compensation unit 60 partially faces the port 24a. For this reason, the temperature compensation unit 60 does not completely block the port 24a even during the maximum expansion. Thus, since the port 24a is not completely blocked, the communication between the pair of fluid chambers 11 and 12 through the port 24a can be maintained.
  • FIG. 7 is an enlarged cross-sectional view corresponding to FIG. 4 of the first embodiment.
  • a cylindrical portion 31e is provided in the piston core 30 as a guide portion that restricts expansion of the temperature compensation portion 60 in the radial direction (see FIG. 4).
  • the shock absorber 200 includes an annular member 70 as a guide member that moves relative to the piston core 30 as the temperature compensation unit 60 advances and retreats instead of the cylindrical portion 31e of the first embodiment.
  • the annular member 70 is formed of a material having high rigidity and a low coefficient of thermal expansion, for example, a metal such as stainless steel.
  • the annular member 70 is formed so that the inner peripheral surface protrudes from the outer peripheral edge of the first annular portion 71 and the first annular portion 71 arranged along the outer peripheral surface 31j of the second small diameter portion 31b, and the inner peripheral surface has a large diameter.
  • a second annular portion 72 extending along the outer peripheral surface of the portion 31c.
  • a step portion 31m is formed along the circumferential direction on the outer peripheral surface 31n of the large diameter portion 31c of the first core 31, and an end surface of the second annular portion 72 faces the step portion 31m.
  • the thickness of the second annular portion 72 is preferably equal to or less than the thickness of the stepped portion 31m. By setting the thickness of the second annular portion 72 in this way, the second annular portion 72 prevents the flow path 22 from being hindered. be able to. Most preferably, the thickness of the second annular portion 72 is equal to the thickness of the step portion 31m. By setting the thickness of the second annular portion 72 in this way, the change in the opening degree of the flow path 22 is efficiently reflected. However, the obstruction of the flow path 22 by the second annular portion 72 can be prevented.
  • the first annular portion 71 sandwiches the temperature compensation portion 60 between the end surface 31d of the large diameter portion 31c.
  • the temperature compensation unit 60 is sandwiched between the outer peripheral surface 31j of the second small diameter part 31b. That is, the annular member 70 covers the temperature compensation unit 60 and prevents the magnetorheological fluid from contacting the temperature compensation unit 60. Therefore, even if the temperature compensation unit 60 is formed of a resin material, wear of the temperature compensation unit 60 due to the magnetorheological fluid can be prevented.
  • the end surface of the first annular portion 71 is fixed to the temperature compensation portion 60, while the inner peripheral surface is not fixed to the second small diameter portion 31b.
  • the inner peripheral surface of the second annular portion 72 is coupled to the first annular portion 71, but is not fixed to the large diameter portion 31c. Accordingly, the first and second annular portions 71 and 72 slide along the outer peripheral surface 31j of the second small diameter portion 31b and the outer peripheral surface 31n of the large diameter portion 31c, respectively, as the thermal expansion member 61 expands and contracts. .
  • the annular member 70 can be provided with a function of limiting the expansion of the temperature compensation unit 60 in the radial direction of the piston core 30 and a function of preventing the magnetic viscous fluid from contacting the temperature compensation unit 60. it can.
  • the second annular portion 72 is longer than the temperature compensation portion 60 when the temperature compensation portion 60 is at the maximum expansion. Therefore, even when the temperature compensation unit 60 is expanded, the temperature compensation unit 60 is not exposed to the flow path 22. Therefore, expansion of the temperature compensation unit 60 in the radial direction of the piston core 30 can be more reliably restricted, and contact of the magnetorheological fluid with the temperature compensation unit 60 can be more reliably prevented.
  • the temperature compensation unit 60 is made of metal, the first annular portion 71 need not be provided.
  • the temperature compensation unit 60 acts to increase the damping force when the temperature of the magnetorheological fluid is high, and when the temperature of the magnetorheological fluid is low, It acts to reduce the damping force. For this reason, the change of the damping force of the shock absorber 200 due to the viscosity change of the magnetorheological fluid due to the temperature change is compensated. As a result, a desired damping force can be generated by adjusting the amount of current supplied to the coil 33a regardless of the temperature change of the magnetorheological fluid.
  • the annular member 70 has a function of limiting expansion of the temperature compensation unit 60 in the radial direction of the piston core 30 and a function of preventing contact of the magnetorheological fluid with the temperature compensation unit 60. Therefore, the structure of the shock absorber 200 can be simplified.
  • the shock absorbers 100 and 200 are disposed in a cylinder 10 in which a magnetorheological fluid whose apparent viscosity is changed by the action of a magnetic field is sealed, and are slidably disposed in the cylinder 10. And a piston rod 21 connected to the piston 20 and extending to the outside of the cylinder 10. The piston 20 is attached to one end 21a of the piston rod 21, and a coil 33a is provided on the outer periphery.
  • a piston core 30 that surrounds the outer periphery of the piston core 30 and forms a flow path 22 between the piston core 30 and an annular plate that supports the flux ring 35 and defines the width of the flow path 22 40 and a magnetic viscous fluid which is formed on the plate 40 and moves between the pair of fluid chambers 11 and 12 through the flow path 22.
  • a port 24a that passes through, and a temperature compensation unit 60 that is provided in the piston core 30 so as to face the port 24a, and that moves forward and backward with respect to the port 24a to change the opening degree of the flow path 22 by expanding and contracting.
  • the temperature compensation unit 60 changes the flow resistance by moving forward and backward with respect to the port 24a and changing the opening degree of the flow path 22 in accordance with the temperature of the magnetorheological fluid. For this reason, the change of the damping force of the shock absorber 100 due to the viscosity change of the magnetorheological fluid due to the temperature change is compensated. As a result, a desired damping force can be generated by adjusting the amount of current supplied to the coil 33a regardless of the temperature change of the magnetorheological fluid.
  • the piston core 30 is formed with a cylindrical portion 31e that restricts expansion of the temperature compensation portion 60 in the radial direction of the piston core 30.
  • the cylindrical portion 31e restricts the expansion of the temperature compensation unit 60 in the radial direction of the piston core 30, so that the displacement direction of the temperature compensation unit 60 is not dispersed. Therefore, the change in the volume of the temperature compensation unit 60 due to expansion or contraction can be efficiently reflected in the change in flow resistance.
  • the shock absorber 200 is further provided with an annular member 70 that is provided outside the temperature compensation unit 60 and restricts the expansion direction of the temperature compensation unit 60, and the piston core 30 is provided with a coil 33 a on the outer periphery and a flux ring 35.
  • the temperature compensating portion 60 is formed between the first annular portion 71 that slides along the surface 31j and the outer peripheral surface 31j of the second small-diameter portion 31b that extends annularly from the outer peripheral edge of the first annular portion 71 to the large-diameter portion 30a.
  • the annular member 70 can be provided with a function of limiting the expansion of the temperature compensation unit 60 in the radial direction of the piston core 30 and a function of preventing the magnetic viscous fluid from contacting the temperature compensation unit 60. it can.
  • the port 24a is provided in the axial direction and is arranged radially inward with respect to the flow path 22, and the temperature compensation unit 60 partially faces the port 24a.
  • a pair of wires for supplying a current to the coil 33a passes through the inner periphery of the piston rod 21. Therefore, it is possible to eliminate the ground for allowing the current applied to the coil 33a to escape to the outside.
  • only one wire for applying a current to the coil 33a may pass through the inside of the piston rod 21 and be grounded to the outside through the piston rod 21 itself.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Fluid-Damping Devices (AREA)

Abstract

L'invention concerne un amortisseur (100) comprenant un cylindre (10), un piston (20) disposé de manière coulissante dans le cylindre (10), et une tige de piston (21) reliée au piston (20). Le piston (20) comporte : un noyau de piston (30) ayant une bobine (33a) prévue sur la périphérie externe du noyau de piston (30) ; une bague de flux (35) entourant la périphérie externe du noyau de piston (30) et formant un passage d'écoulement (22) entre la bague de flux (35) et le noyau de piston (30) ; une plaque annulaire (40) supportant la bague de flux (35) et définissant la largeur du passage d'écoulement (22) ; un orifice (24a) formé dans la plaque (40) ; et une section de compensation de température (60) prévue sur le noyau de piston (30) de manière à faire face à l'orifice (24a) et à se déplacer vers l'avant et l'arrière par rapport à l'orifice (24a) à mesure que la section de compensation de température (60) s'étend et se contracte en fonction de la température, modifiant ainsi le degré d'ouverture du passage d'écoulement (22).
PCT/JP2016/075171 2015-09-24 2016-08-29 Amortisseur de fluide magnéto-visqueux WO2017051669A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015187140A JP2017061979A (ja) 2015-09-24 2015-09-24 磁気粘性流体緩衝器
JP2015-187140 2015-09-24

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WO2017051669A1 true WO2017051669A1 (fr) 2017-03-30

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JP2020509919A (ja) * 2017-06-05 2020-04-02 南京中硼▲聯▼康医▲療▼科技有限公司Ｎｅｕｂｏｒｏｎ Ｍｅｄｔｅｃｈ Ｌｔｄ． 中性子捕捉治療用のビーム整形体

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6189539U (fr) * 1984-11-19 1986-06-11
JP2008101638A (ja) * 2006-10-17 2008-05-01 Honda Motor Co Ltd 液圧ダンパ
JP2014181808A (ja) * 2013-03-21 2014-09-29 Kayaba Ind Co Ltd 磁気粘性流体緩衝器

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6189539U (fr) * 1984-11-19 1986-06-11
JP2008101638A (ja) * 2006-10-17 2008-05-01 Honda Motor Co Ltd 液圧ダンパ
JP2014181808A (ja) * 2013-03-21 2014-09-29 Kayaba Ind Co Ltd 磁気粘性流体緩衝器

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