WO2017047360A1 - Amortisseur - Google Patents

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Publication number
WO2017047360A1
WO2017047360A1 PCT/JP2016/075062 JP2016075062W WO2017047360A1 WO 2017047360 A1 WO2017047360 A1 WO 2017047360A1 JP 2016075062 W JP2016075062 W JP 2016075062W WO 2017047360 A1 WO2017047360 A1 WO 2017047360A1
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WO
WIPO (PCT)
Prior art keywords
piston
flow path
core
thermal expansion
shock absorber
Prior art date
Application number
PCT/JP2016/075062
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English (en)
Japanese (ja)
Inventor
康裕 米原
睦 小川
Original Assignee
Ｋｙｂ株式会社
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Filing date
Publication date
Application filed by Ｋｙｂ株式会社 filed Critical Ｋｙｂ株式会社
Publication of WO2017047360A1 publication Critical patent/WO2017047360A1/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 shock absorber.
  • JP2009-228861A includes a piston core, a piston ring, and a piston core that includes a piston core having a coil wound around the outer periphery and a piston ring disposed on the outer periphery of the piston core.
  • a shock absorber in which a magnetorheological fluid passes through a flow path formed between the two is disclosed.
  • the working fluid of the shock absorber including the magnetorheological fluid generally changes in viscosity due to a change in temperature. For this reason, in the shock absorber described in JP2009-228861A, a temperature compensation valve is provided in the bypass flow path in order to obtain a stable damping force even when the temperature of the magnetorheological fluid changes.
  • the bypass channel is configured by connecting a plurality of orthogonal holes. For this reason, the man-hour which processes a bypass flow path increases, and there exists a possibility that manufacturing cost may rise as a result.
  • An object of the present invention is to generate a required damping force regardless of a temperature change of a working fluid with a simple configuration.
  • the shock absorber includes a cylinder in which a working fluid is sealed, a piston that is slidably disposed in the cylinder, and that defines a pair of fluid chambers in the cylinder, and the piston A piston rod connected to the cylinder and extending to the outside of the cylinder.
  • the piston communicates with the pair of fluid chambers, and the working fluid circulates by the movement of the piston and resists the circulated working fluid.
  • a main flow path that provides the flow path
  • a bypass flow path that is provided in parallel with the main flow path and communicates with a pair of the fluid chambers, and is inserted into the bypass flow path, and the bypass flow path according to the temperature of the working fluid
  • a temperature compensation unit that changes the flow passage area of the bypass flow passage by being deformed in a direction orthogonal to the first flow passage.
  • FIG. 1 is a front sectional view of a magnetorheological fluid shock absorber according to an embodiment of the present invention.
  • FIG. 2 is a sectional view taken along line II-II in FIG.
  • FIG. 3 is an enlarged view of a portion III in FIG.
  • FIG. 4 is an enlarged view of a magnetorheological fluid shock absorber according to a modification of the embodiment of the present invention.
  • the shock absorber is a shock absorber 100 whose damping coefficient can be changed by using a magnetorheological fluid whose apparent viscosity is changed by the action of a magnetic field as a working fluid.
  • 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 has an apparent viscosity that is changed by the action of a magnetic field, and is a liquid in which fine particles having ferromagnetism are dispersed in a liquid such as oil.
  • the 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 main channel 22 and a bypass channel 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.
  • the piston 20 includes a piston core 30 attached to the piston rod 21, an annular flux ring 35 as a ring body surrounding the outer periphery of the piston core 30, and an annular plate 40 provided on the piston core 30 and supporting 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.
  • 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.
  • An end surface of the plate 40 through which the first small diameter portion 31 a is inserted comes into contact with the step portion 31 h, and the step portion 31 h sandwiches the plate 40 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 and the second core 32.
  • 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 part 33b in which a coil 33a is provided, a columnar part 33d fitted to the first core 31, and a radially inward direction from one end of the coil mold part 33b. And a pair of connecting portions 33c that extend linearly and connect the coil mold portion 33b and the cylindrical portion 33d.
  • the coil assembly 33 is formed by molding a resin in a state where the coil 33a is inserted.
  • the 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 of the second core 32, 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 has an outer diameter that is substantially the same as the inner diameter of the large-diameter portion 31c of the first core 31, 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 the female screw 31f and the male screw 21d, but 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 flux ring 35 is formed so that the outer diameter is substantially the same as the inner diameter of the 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 the main flow path 22 through which the magnetorheological fluid flows.
  • the coil mold part 33 b faces the main flow path 22. Therefore, the magnetic field generated by the coil 33a acts on the magnetorheological fluid flowing through the main flow path 22. That is, the main 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.
  • a current is supplied to the coil 33a to form a magnetic field, the apparent viscosity of the magnetorheological fluid flowing through the main flow path 22 changes.
  • the 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.
  • a bypass channel 23 is formed so as to sandwich the coil 33a between the piston core 30 and the main channel 22.
  • the bypass channel 23 is a through-hole penetrating the piston core 30 in the axial direction, and two bypass channels 23 are formed at intervals of 180 °.
  • the bypass flow path 23 is provided at a position where the influence of the magnetic field generated by the coil 33 a is smaller than that of the main flow path 22.
  • the number of bypass channels 23 and the arrangement of the bypass channels 23 are not limited to this, and can be arbitrarily set according to required attenuation characteristics, workability, and the like.
  • a single bypass channel 23 may be provided near the axial center of the piston core 30.
  • the bypass channel 23 is a hole having a circular cross section having 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.
  • the first through hole 23a and the second through hole 23b are formed to have substantially the same diameter.
  • the first through hole 23 a and the second through hole 23 b are formed avoiding the connecting portion 33 c of the coil assembly 33.
  • a housing hole 23c having an inner diameter larger than that of the other part is formed in a part of the second through hole 23b.
  • One end of the accommodation hole 23 c opens to the end surface 32 e of the second core 32 that contacts the end surface 31 d of the first core 31.
  • a step portion 23d is formed on the inner peripheral surface of the second through hole 23b.
  • a cylindrical temperature compensation unit 60 that changes the flow passage area of the bypass flow passage 23 by being deformed according to the temperature of the magnetorheological fluid is inserted into the accommodation hole 23c. The temperature compensation unit 60 will be described in detail later.
  • the flow passage area in the second through hole 23b is determined by the size of the flow passage defined in the accommodation hole 23c by the temperature compensation unit 60, and this flow passage area is obtained when the temperature compensation unit 60 is deformed. Is set to be smaller than the flow path area of the first through hole 23a. Therefore, the attenuation characteristic when the piston 20 moves is determined by the flow passage area of the second through hole 23b, and the hole diameter of the first through hole 23a does not affect the attenuation characteristic.
  • 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.
  • the plate 40 is formed with a plurality of flow paths 24 that are through holes communicating with the main flow path 22.
  • 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.
  • 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 main 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 the distance (the width of the main 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 main 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 main flow path 22 is reduced, and the resistance imparted to the magnetorheological fluid passing through the main flow path 22 can be reduced.
  • FIG. 2 is a sectional view taken along line II-II in FIG. In FIG. 2, members other than the piston 20 are omitted for explanation.
  • FIG. 3 is an enlarged view in which a portion indicated by III in FIG. 2 is enlarged.
  • the temperature compensation unit 60 inserted into the accommodation hole 23 c includes a thermal expansion member 61 having a large coefficient of thermal expansion, and a protection member 62 that covers the surface of the thermal expansion member 61.
  • the thermal expansion member 61 is formed of a material having a larger coefficient of thermal expansion than the second core 32, for example, a resin material such as polyethylene and polyethylene terephthalate, or a metal material such as aluminum.
  • the protective member 62 is provided to prevent the thermal expansion member 61 made of resin from being in direct contact with the magnetorheological fluid and being worn by particles contained in the magnetorheological fluid.
  • the protection member 62 is formed of a wear-resistant material, for example, a metal material such as stainless steel.
  • the protection member 62 does not need to be provided on all surfaces of the thermal expansion member 61, and may be provided on a portion where the magnetorheological fluid mainly circulates. If the thermal expansion member 61 is made of metal and is not likely to be worn by the magnetorheological fluid, the protection member 62 may not be provided. Even when a magnetorheological fluid is not used as the working fluid, particles such as iron powder may be present in the working fluid, and thus it is preferable to provide the protective member 62.
  • the thermal expansion member 61 is a member having a C-shaped cross section that is inserted in the axial direction along the accommodation hole 23c.
  • the thermal expansion member 61 is disposed so as to contact the stepped portion 23d and the end surface 31d of the first core 31 in the axial direction. For this reason, the movement of the thermal expansion member 61 in the axial direction is limited by the step portion 23d and the end surface 31d.
  • the outer peripheral surface of the thermal expansion member 61 abuts on the inner peripheral surface of the accommodation hole 23c, the outward movement in the radial direction is limited by the inner peripheral surface of the accommodation hole 23c.
  • the thermal expansion member 61 expands radially inward and circumferentially where movement is not restricted when the temperature of the magnetorheological fluid increases.
  • the thermal expansion member 61 expands radially inward and circumferentially, which is a direction orthogonal to the bypass flow path 23, the flow area of the second through hole 23b is reduced, and the flow resistance of the bypass flow path 23 is increased. To do.
  • the thermal expansion member 61 contracts and the flow path area of the second through hole 23b increases. As a result, the flow resistance of the bypass flow path 23 decreases.
  • the protective member 62 is an elastic body having a force that presses the thermal expansion member 61 radially outward so that the flow passage area of the second through hole 23b is quickly expanded. It may be formed.
  • the protection member 62 has a C-shaped main body 62a provided along the inner peripheral surface of the thermal expansion member 61, and an end extending radially outward from the opening end of the main body 62a. 62b.
  • the radial length of the end portion 62b is such that the outer diameter side end of the end portion 62b is located radially outside the second through-hole 23b even when the thermal expansion member 61 is most expanded.
  • the outer diameter side end of the end portion 62b is set so as not to contact the inner peripheral surface of the accommodation hole 23c.
  • the assembly of the temperature compensation unit 60 to the piston 20 is performed before the piston core 30 is assembled. Specifically, the temperature compensation unit 60 is inserted into the accommodation hole 23c formed in the second core 32 until one end thereof comes into contact with the stepped portion 23d. Then, the end face 32e of the second core 32 into which the temperature compensation unit 60 is inserted is pressed against the end face 31d of the first core 31, and the coil assembly 33 is sandwiched between the first core 31 and the second core 32. The piston core 30 is assembled. At this time, the temperature compensation unit 60 is restricted from moving in the axial direction by the step portion 23d and the end surface 31d, and is assembled in the accommodation hole 23c.
  • the temperature compensation unit 60 is assembled to the piston 20 by a very simple method of insertion into the accommodation hole 23c.
  • the position where the temperature compensation unit 60 is inserted that is, the position where the accommodation hole 23c is formed is not limited to the second core 32, but may be the first core 31 where the bypass flow path 23 is formed.
  • the accommodation hole 23c may be formed across a plurality of members.
  • 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 main flow path 22 and the bypass flow path. 23. 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 main 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 magnetorheological fluid flowing through the main flow path 22 during the expansion / contraction operation of the shock absorber 100.
  • the 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 main 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 viscosity of the magnetorheological fluid flowing through the main 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 viscosity of the magnetorheological fluid flowing through the bypass passage 23 does not change so 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 expands, the flow area of the second through hole 23b is decreased, and the flow resistance of the bypass flow path 23 is increased. That is, the temperature compensation unit 60 acts to suppress a decrease in damping force when the temperature of the magnetorheological fluid is high.
  • the temperature compensation unit 60 contracts, increasing the flow path area of the second through hole 23b and decreasing the flow resistance of the bypass flow path 23. That is, the temperature compensation unit 60 acts to suppress an increase in damping force when the temperature of the magnetorheological fluid is low.
  • the viscosity of the magnetorheological fluid flowing through the bypass channel 23 is caused by both the magnetic force and the temperature. Change. For this reason, for example, when the viscosity of the magnetic viscous fluid increases when the temperature of the magnetic viscous fluid increases and the flow resistance of the bypass channel 23 increases, the damping force decreases due to the increased temperature of the magnetic viscous fluid. There is a possibility that a damping force larger than the damping force necessary to compensate for the above will be generated in the bypass channel 23.
  • the bypass flow path 23 in which the temperature compensation unit 60 is inserted is provided at a position where the influence of the magnetic field generated by the coil 33a is smaller than that of the main flow path 22. For this reason, the viscosity of the magnetorheological fluid flowing through the bypass flow path 23 changes substantially only by temperature. That is, in the bypass channel 23, the flow resistance is increased or decreased with respect to the magnetorheological fluid whose viscosity changes due to temperature alone. As a result, it is possible to generate a sufficient damping force in the bypass flow path 23 to compensate for a change in the damping force due to a viscosity change due to a temperature change.
  • 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 that is deformed according to the temperature of the magnetorheological fluid is inserted into the bypass passage 23 formed through the piston core 30.
  • the bypass flow path 23 into which the temperature compensation unit 60 is inserted is a simple through hole, it can be easily formed. As a result, an increase in manufacturing cost of the shock absorber 100 can be suppressed.
  • the temperature compensation unit 60 inserted into the bypass channel 23 is deformed in a direction perpendicular to the bypass channel 23 according to the temperature of the magnetorheological fluid, and changes the flow resistance of the bypass channel 23. 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.
  • FIG. 4 is a cross-sectional view corresponding to FIG. 3 of the above embodiment.
  • the cross-sectional shape of the accommodation hole 23c is circular.
  • the cross-sectional shape of the accommodation hole 223c in which the temperature compensation unit 260 is accommodated may be rectangular.
  • the cross-sectional shape of the accommodation hole 223c formed in a part of the second through hole 23b is formed in a rectangle having a long side whose length is longer than the diameter of the other part.
  • Two temperature compensation portions 260 having a rectangular cross-sectional shape are disposed in the housing hole 223c so as to face each other.
  • the flow passage area in the second through hole 23b is determined by the size of the flow passage defined by the two temperature compensation portions 260 and the accommodation hole 223c. This flow passage area is obtained when the temperature compensation portion 260 is deformed. Even if it exists, it sets so that it may become smaller than the flow-path area of the 1st through-hole 23a. Therefore, as in the above embodiment, the damping characteristic when the piston 20 moves is determined by the flow passage area of the second through hole 23b, and the hole diameter of the first through hole 23a does not affect the damping characteristic. .
  • the temperature compensation unit 260 includes a thermal expansion member 261 having a large coefficient of thermal expansion, and a protection member 262 that covers the surface of the thermal expansion member 261.
  • the thermal expansion member 261 and the protection member 262 are formed of the same material as the thermal expansion member 61 and the protection member 62 in the above embodiment.
  • the thermal expansion member 261 is disposed in the accommodation hole 223c so as to contact the stepped portion 223d and the end surface 31d of the first core 31 in the axial direction, similarly to the thermal expansion member 61 of the above embodiment. For this reason, the movement of the thermal expansion member 261 in the axial direction is limited by the step portion 223d and the end surface 31d. Further, since the thermal expansion member 261 is disposed in the accommodation hole 223c having a rectangular cross-sectional shape, the movement of the thermal expansion member 261 is allowed only in the direction orthogonal to the accommodation hole 223c.
  • the thermal expansion member 261 expands in a direction orthogonal to the accommodation hole 223c where movement is not restricted when the temperature of the magnetorheological fluid increases. As the thermal expansion member 261 expands, the flow passage area of the second through hole 23b decreases, and the flow resistance of the bypass flow passage 23 increases.
  • the thermal expansion member 261 contracts, the thermal expansion member 261 is pressed in the direction of separating the two thermal compensation members 260 so that the flow passage area of the second through hole 23b is quickly expanded.
  • An elastic body 263 that exerts an urging force is provided.
  • the elastic body 263 also has a function of preventing the temperature compensation unit 260 from dropping from the accommodation hole 223c or tilting in the accommodation hole 223c.
  • the number of temperature compensation units 260 is not limited to two, and may be one. Also in this case, it is preferable to provide the elastic body 263 so that the flow passage area of the second through hole 23b is quickly expanded when the temperature compensation unit 260 contracts.
  • the cross-sectional shape of the accommodation hole 223c is not limited to a rectangle, and the length in the longitudinal direction is longer than the diameters of the first through hole 23a and the second through hole 23b, and between the second through hole 23b and the accommodation hole 223c. If the step 223d is formed, it may be an ellipse or a rounded rectangle.
  • the temperature compensation unit 260 that deforms according to the temperature of the magnetorheological fluid is inserted into the bypass channel 23 that is formed through the piston core 30 in the above modification.
  • the bypass flow path 23 into which the temperature compensation unit 260 is inserted is a through hole and can be easily formed. As a result, an increase in manufacturing cost of the shock absorber 100 can be suppressed.
  • the temperature compensation unit 260 inserted into the bypass channel 23 is deformed in a direction orthogonal to the bypass channel 23 according to the temperature of the magnetorheological fluid, and changes the flow resistance of the bypass channel 23. 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 shock absorber 100 is connected to the cylinder 10 in which the working fluid is sealed, the piston 20 that is slidably disposed in the cylinder 10, and that defines a pair of fluid chambers 11 and 12 in the cylinder 10, and the piston 20.
  • a piston rod 21 extending to the outside of the cylinder 10, and the piston 20 communicates with the pair of fluid chambers 11 and 12, and the working fluid circulates by the movement of the piston 20 and resists the circulated working fluid.
  • Temperature compensation units 60 and 260 that change the flow channel area of the bypass flow channel 23 by being deformed in a direction orthogonal to the bypass flow channel 23.
  • the temperature compensation units 60 and 260 that are deformed according to the temperature of the working fluid are inserted into the bypass channel 23 that is formed through the piston core 30.
  • the bypass flow path 23 into which the temperature compensation parts 60 and 260 are inserted is a simple through hole, it can be easily formed. As a result, an increase in manufacturing cost of the shock absorber 100 can be suppressed.
  • the temperature compensation units 60 and 260 inserted into the bypass channel 23 are deformed in a direction orthogonal to the bypass channel 23 according to the temperature of the working fluid, and change the flow resistance of the bypass channel 23. For this reason, the change in the damping force of the shock absorber 100 due to the change in the viscosity of the working fluid due to the temperature change is compensated. As a result, a desired damping force can be generated by adjusting the energization amount to the coil 33a regardless of the temperature change of the working fluid.
  • the temperature compensation units 60 and 260 include resin thermal expansion members 61 and 261 and metal protection members 62 and 262 that cover at least a part of the surface of the thermal expansion members 61 and 261.
  • the protective members 62 and 262 that cover the surfaces of the thermal expansion members 61 and 261 are disposed, and the resin thermal expansion members 61 and 261 are prevented from coming into direct contact with the working fluid. For this reason, it can suppress that the resin-made thermal expansion members 61 and 261 are worn by the working fluid.
  • the bypass flow path 23 is a hole having a circular cross section, and the thermal expansion member 61 is formed in a C-shaped cross section, and is provided so that the outer peripheral surface is in contact with the inner peripheral surface of the bypass flow path 23.
  • the member 62 is provided so as to cover at least a part of the inner peripheral surface of the thermal expansion member 61.
  • the thermal expansion member 61 inserted into the bypass channel 23 is formed in a C-shaped cross section. For this reason, when the temperature of the working fluid increases, the thermal expansion member 61 expands inward in the radial direction where movement is not limited. As a result, the flow path area of the bypass flow path 23 changes according to the temperature of the working fluid, so that the flow resistance of the bypass flow path 23 can be changed according to the temperature of the working fluid. Further, a protective member 62 is provided on the inner peripheral surface side of the thermal expansion member 61 through which the working fluid flows. For this reason, it is possible to prevent the resin thermal expansion member 61 from coming into direct contact with the working fluid, and to prevent the thermal expansion member 61 from being worn by the working fluid.
  • the working fluid is a magnetorheological fluid
  • the piston 20 has a piston core 30 attached to the end of the piston rod 21 and provided with a coil 33a on the outer periphery, and a flux ring 35 surrounding the outer periphery of the piston core 30.
  • the main flow path 22 is defined by the outer periphery of the piston core 30 and the inner periphery of the flux ring 35, and the bypass flow path 23 is formed in the piston core 30 so as to sandwich the coil 33 a between the main flow path 22.
  • the bypass flow path 23 in which the temperature compensation units 60 and 260 are inserted is provided at a position where the influence of the magnetic field generated by the coil 33a is smaller than that of the main flow path 22.
  • the temperature compensation units 60 and 260 are suppressed from being affected by the magnetic field generated by the coil 33a, it is possible to compensate for a change in damping force due to a viscosity change due to a temperature change. 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.
  • 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.
  • the temperature compensation units 60 and 260 are not limited to the shock absorber 100 using a magnetorheological fluid, and can be applied to a throttle channel of a general shock absorber using hydraulic oil.
  • the cross-sectional area of the flow path can be changed according to the temperature by a simple configuration in which a temperature compensation unit that deforms according to the temperature of the hydraulic oil is inserted into the flow path. As a result, it is possible to compensate for the change in the damping force of the shock absorber caused by the change in the viscosity of the hydraulic oil due to the temperature change.

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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, dans lequel un fluide de travail est enfermé hermétiquement ; un piston 20 disposé de manière coulissante à l'intérieur du cylindre 10 ; et une tige de piston 21 reliée au piston 20. Le piston 20 comporte : un passage d'écoulement principal 22 qui assure une communication entre une paire de chambres de fluide 11, 12, permet à un fluide de travail de s'écouler à travers celui-ci lorsque le piston 20 se déplace, et oppose une résistance à l'écoulement d'un fluide de travail à travers celui-ci ; un passage d'écoulement de dérivation 23 disposé parallèlement au passage d'écoulement principal 22 et assurant une communication entre la paire de chambres de fluide 11, 12 ; et une section de compensation de température 60, 260 qui est insérée dans le passage d'écoulement de dérivation 23 et qui, en fonction de la température d'un fluide de travail, se déforme dans la direction perpendiculaire au passage d'écoulement de dérivation 23, de façon à modifier ainsi la section d'écoulement du passage d'écoulement de dérivation 23.
PCT/JP2016/075062 2015-09-16 2016-08-26 Amortisseur WO2017047360A1 (fr)

Applications Claiming Priority (2)

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JP2015-182890 2015-09-16
JP2015182890A JP2017057921A (ja) 2015-09-16 2015-09-16 緩衝器

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5676743A (en) * 1979-11-22 1981-06-24 Showa Mfg Co Ltd Temperature characteristic compensator for hydraulic shock absorber
JPS5970945U (ja) * 1982-11-04 1984-05-14 トヨタ自動車株式会社 シヨツクアブソ−バ
JP2013167313A (ja) * 2012-02-16 2013-08-29 Kyb 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
JPS5676743A (en) * 1979-11-22 1981-06-24 Showa Mfg Co Ltd Temperature characteristic compensator for hydraulic shock absorber
JPS5970945U (ja) * 1982-11-04 1984-05-14 トヨタ自動車株式会社 シヨツクアブソ−バ
JP2013167313A (ja) * 2012-02-16 2013-08-29 Kyb Co Ltd 磁気粘性流体緩衝器

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