Magnetorheological Damper with Integrated Valve

Abstract

The present invention relates to a valve-integrated magnetorheological damper device, providing a structure that electronically controls damping force using magnetorheological fluid (MR fluid) while simultaneously mechanically and individually adjusting the extension and compression damping forces through an integrated valve unit installed at the end of the piston. The piston is equipped with a magnetic field generating unit including an electromagnet coil, so that when current is applied from an external control unit, the viscosity of the MR fluid changes, thereby allowing the damping force to be adjusted in real time. Additionally, a radially arranged T-shaped valve unit installed at the end of the orifice fully opens when the piston is compressed to facilitate fluid flow, and partially closes when it is extended to restrict fluid flow, thereby allowing the extension damping force to be set to be greater than the compression damping force. Accordingly, asymmetric damping characteristics can be realized independently of current control, and stable damping force control is possible even in the event of an electronic control malfunction. This enables the achievement of effects such as improved ride comfort, ensured driving stability, and enhanced durability in various driving environments.

Description

Technology Field

[0001] The present invention relates to a valve-embedded magnetorheological damper device, and more specifically, to a valve-embedded magnetorheological damper device that electronically controls the viscosity of an MR fluid by forming a magnetic field by providing an electromagnet coil inside a piston, and at the same time mechanically opens and closes the fluid path according to the direction of movement of the piston through an embedded valve installed at the end of an orifice, thereby individually adjusting the damping force on the rebound side and the compression side. Background Technology

[0002] An automotive suspension system is a key device that absorbs shocks and vibrations transmitted from the road surface while driving, thereby ensuring both ride comfort and driving stability. The springs and dampers that make up the suspension operate complementarily; while springs primarily play the role of absorbing shocks, dampers perform an important function in controlling excessive vibrations caused by the spring's restoring force and ensuring stability.

[0003] In particular, the setting of the damper's damping force is one of the key factors determining the vehicle's behavioral characteristics; generally, it has become a design principle to set a strong damping force on the rebound side and a weak damping force on the compression side. Through these settings, excessive shaking of the vehicle body is suppressed when passing over road irregularities or protrusions, and the tires are enabled to maintain stable grip with the road surface.

[0004] Recently, electronically controlled magneto-rheological (MR) dampers are being applied to various vehicles to enable more precise control while satisfying these design principles. MR dampers operate by changing the strength of the magnetic field to adjust the viscosity of the MR fluid in real time, thereby changing the damping force.

[0005] These MR fluids have the characteristic that when a magnetic field is formed, fine particles within the fluid align, causing viscosity to increase, and when the magnetic field disappears, viscosity decreases again. Therefore, they offer the advantage of enabling fast response and damping force control suitable for various driving situations through current control. For this reason, MR dampers are expanding their application range not only to luxury vehicles and sports cars but also, recently, to mid-size sedans and SUVs.

[0006] However, existing MR damper structures face the problem of being unable to simultaneously satisfy vehicle driving stability and ride comfort due to design limitations. Existing MR dampers are designed to form a single orifice inside the piston so that the MR fluid flows through the same path when the piston extends or compresses.

[0007] In such cases, it is impossible to control the damping force on the extension side and the compression side independently, and even if the viscosity of the MR fluid is controlled by changing the electromagnetic field strength, there is a structural constraint that the ratio of the change in damping force in both directions is applied equally.

[0008] Therefore, it is difficult to implement the asymmetric damping characteristics of "strong on the extension side and weak on the compression side" required by design principles, and consequently, a problem arises where it is difficult to secure both ride comfort and handling stability in certain driving environments.

[0009] In addition, conventional MR dampers adopt a structure containing high-pressure gas internally, and this gas pressure acts directly on the cross-section of the piston rod. This causes the damper to automatically be pushed in the extension direction, and as a result, a reversal phenomenon occurs in which the damping force on the compression side becomes greater than the damping force on the extension side, contrary to the intention.

[0010] This inversion phenomenon conflicts with the damping characteristics targeted by vehicle designers and causes increased body vibration and unstable road grip, particularly when passing over uneven surfaces. It is a serious problem in that it can significantly reduce driving stability by degrading body roll control performance during cornering at high speeds.

[0011] Furthermore, since conventional MR dampers are structured to control damping force solely through current control, there are limitations in precisely setting damping characteristics. Although the viscosity of the MR fluid changes with the strength of the magnetic field, it is virtually impossible to set different damping force ratios between the extension and compression sides using only current control.

[0012] This implies a structural limitation in that the same control strategy must be applied despite the fact that the required damping force characteristics differ depending on driving conditions, such as low speed, high speed, sudden braking, and sharp turning.

[0013] This problem is particularly pronounced in vehicles equipped with electronically controlled suspension and makes it difficult to ensure optimal ride comfort and stability in various driving environments.

[0014] Furthermore, since conventional MR dampers operate based on electronic control signals, they can cause serious problems in the event of electrical system malfunctions. In situations such as ECU (Electronic Control Unit) errors, sensor malfunctions, or power supply failures, the damper loses its damping control capability; in this case, the damper reverts to a state identical to that of a simple mechanical damper. Under these circumstances, the vehicle becomes unable to respond to various driving conditions, resulting in a problem where ride comfort deteriorates and driving stability declines simultaneously.

[0015] In order to overcome the limitations of such conventional technology, there is a need to develop a new structure of MR damper that can ensure both ride comfort and handling stability by providing optimal damping force in various driving environments such as high-speed driving, sudden braking, cornering, and passing over bumps, and can maintain stable damping characteristics with only a basic flow path design even if an electronic control system malfunctions, thereby significantly improving safety compared to existing MR dampers. Prior art literature

[0016] Republic of Korea Published Patent No. 10-2025-0025542 (Date of Publication: February 24, 2025) The problem to be solved

[0017] The present invention has been devised to solve the aforementioned problems, and the objectives of the present invention are as follows.

[0018] The objective of the present invention is to provide a valve-embedded magnetorheological damper device capable of implementing a dual damping force control function in which electrical control and mechanical control operate complementarily by providing a magnetic field forming part including an electromagnet coil inside the piston to control the viscosity of the magnetorheological fluid in real time depending on whether an external current is applied, and simultaneously mechanically controlling the opening and closing of the compression side and extension side flow paths through an embedded valve part disposed at the end of the piston.

[0019] In addition, another objective of the present invention is to provide a valve-embedded magnetorheological damper device that can set the damping force asymmetrically according to the direction of movement of the piston, thereby lowering the damping force by fully opening the valve to facilitate fluid flow during compression, and increasing the damping force by partially closing the valve to restrict fluid flow during extension.

[0020] Accordingly, the basic principle of strong extensional damping force and weak compressional damping force required in automotive suspension systems can be implemented solely through mechanical design, thereby ensuring both optimized ride comfort and stability under various driving conditions.

[0021] In addition, another objective of the present invention is to provide a valve-embedded magnetorheological damper device that can achieve predictable and stable damping characteristics even in the event of an electrical failure, because the built-in valve part is configured to operate independently of magnetic field control, thereby maintaining the difference in damping force between the extension side and the compression side by the valve structure itself even in a non-energized state.

[0022] In addition, another objective of the present invention is to provide a valve-embedded magnetorheological damper device capable of preventing component damage and maintaining consistent performance over a long period through a structure that draws a wire into the piston rod, a valve protection mechanism embedded in a valve cap, and a multi-flow structure formed by radially arranging a plurality of valves.

[0023] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0024] To achieve the above objectives, the present invention provides a valve-embedded magnetorheological damper device.

[0025] The above valve-embedded magnetorheological damper device comprises: a cylinder housing portion in which magnetorheological fluid is filled in an internal space; a piston portion arranged to be reciprocally movable within the internal space of the cylinder housing portion; a magnetic field forming portion provided in the piston portion, which forms a magnetic field by providing an external current to raise the viscosity of the magnetorheological fluid to a set level when the piston moves along the direction of compression; and a valve portion formed in the piston portion, which opens and closes a flow path formed to open both sides of the piston, and closes the flow path when the piston portion moves along the direction of compression.

[0026] Here, the magnetic field forming unit is,

[0027] It includes an electromagnet coil arranged along the outer circumference of the piston portion,

[0028] It is preferable to form the magnetic field by receiving the external current from a current provider driven by the control of the control unit.

[0029] And, the electromagnet coil is electrically connected to the current provider through a wire, and

[0030] It is preferable that the above wire be drawn into the interior of the piston rod through the other side of the inner core and drawn out to the outside.

[0031] In addition, the above piston part,

[0032] An inner core having a piston rod formed therein penetrating one side of the cylinder housing, and

[0033] It includes an outer core that is coupled to the inner core to surround the outer circumference of the inner core, and whose outer circumference contacts the inner circumference of the cylinder housing.

[0034] The above Euro is,

[0035] It is preferable that it be formed between the inner core and the outer core.

[0036] In addition, on one side of the above piston part,

[0037] The valve cap is attached,

[0038] It is preferable that the above valve part be located on the inner side of the valve cap.

[0039] In particular, the above valve part is,

[0040] A number of them are installed at intervals along the outer circumference of the above piston part, and

[0041] The above Euro is,

[0042] It is formed in a plurality by corresponding to each of the valve parts formed by the plurality of above.

[0043] In addition, the above control unit,

[0044] It is electrically connected to a sensor that detects that the electromagnet coil is magnetized by current supplied from the current provider, and

[0045] When the piston portion moves along the direction of compression, if the magnetization of the electromagnet coil is not detected through the sensor, the operation of the valve portion is controlled.

[0046] In addition, the valve section is a flow control valve that opens and closes the flow path according to the control of the control section. Effects of the invention

[0047] According to the present invention, through the means for solving the above problem, the damping force on the extension side and the compression side can be controlled independently. An integrated valve part installed at an orifice or the end of a fluid path is designed to automatically open and close according to the direction of movement of the piston, thereby implementing an asymmetric control characteristic in which the damping force is lowered by fully opening the valve to facilitate fluid flow during compression, and the damping force is increased by partially closing the valve to restrict fluid flow during extension. Accordingly, the ideal damping characteristics of strong damping force on the extension side and weak damping force on the compression side, which are required in an automotive suspension system, can be realized solely through a mechanical structure.

[0048] In addition, the present invention provides an electronic damping force control function utilizing MR fluid. When current is applied from an external control unit to an electromagnet coil provided inside a piston, the viscosity of the MR fluid changes due to the magnetic field formed around the coil. Since the viscosity of the fluid changes in real time according to the strength of the magnetic field, the damping force can be precisely controlled according to driving conditions. Through this, ride comfort and handling stability can be satisfied simultaneously.

[0049] In addition, the present invention enables stable damping force control independent of electronic control. Since the built-in valve unit operates mechanically using only the fluid pressure difference and flow direction, it can maintain basic damping characteristics even in a non-energized state where no current is supplied. Accordingly, predictable damping performance can be secured even in situations such as abnormalities in the electronic control system, power cutoff, or sensor errors, thereby significantly improving safety.

[0050] In addition, the present invention improves adaptability to changes in the driving environment. Since the damper device according to the present invention utilizes both electronic control and mechanical valve control, it can provide optimized damping force in real time under various driving conditions such as uneven road surfaces, high-speed driving, sudden braking, and cornering.

[0051] In addition, the present invention can have excellent durability and reliability. The built-in valve section is composed of a plurality of T-shaped valves arranged radially, and is designed so that the fluid flows uniformly in all directions (360 degrees), preventing excessive stress from concentrating in specific areas. Furthermore, since the valve is protected by a valve protection cap, it can maintain performance for a long period even during repeated operation.

[0052] In addition, the present invention may offer a higher degree of design freedom compared to conventional MR dampers. In conventional technology, it was difficult to implement asymmetric damping characteristics between the extension and compression sides because the damping force ratio was controlled solely by current control. However, by combining a mechanical valve structure with electronic control, the present invention allows damping characteristics to be set at a desired ratio from the design stage, thereby enabling customized design according to vehicle characteristics.

[0053] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0054] FIG. 1 is a partially cutaway perspective view showing the configuration of a valve-embedded magnetorheological damper device of the present invention. Figure 2 is a partially cutaway perspective view showing the piston part of Figure 1. FIG. 3 is a cross-sectional view showing a piston part according to the present invention. FIG. 4 is a drawing showing a piston part and a valve part equipped with an internal valve part according to the present invention. Figure 5 is a graph showing the change in damping force of a valve-embedded magnetorheological damper device according to the present invention. Specific details for implementing the invention

[0055] Hereinafter, embodiments of the present invention are described in detail with reference to the drawings so that those skilled in the art can easily implement the present invention.

[0056] The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0057] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0058] In the following description, the statement that any configuration is provided or arranged on the "upper (or lower) surface" or the "upper (or lower) surface" of the description means that any configuration is provided or arranged in contact with the upper (or lower) surface of the description.

[0059] Furthermore, it is not limited to not including any other configuration between the above description and any configuration provided or placed on (or under) the description.

[0060] The valve-embedded magnetorheological damper device of the present invention will be described below with reference to the attached drawings.

[0061] FIG. 1 is a partially cutaway perspective view showing the configuration of a valve-embedded magnetorheological damper device of the present invention. FIG. 2 is a partially cutaway perspective view showing the piston portion of FIG. 1. FIG. 3 is a cross-sectional view showing the piston portion according to the present invention. FIG. 4 is a drawing showing a piston portion and a valve portion equipped with an embedded valve portion according to the present invention.

[0062] Referring to FIGS. 1 to 4, the valve-embedded magnetorheological damper device of the present invention comprises: a cylinder housing portion (100) in which magnetorheological fluid is filled in an internal space; a piston portion (200) arranged to be reciprocally movable in the internal space of the cylinder housing portion (100); a magnetic field forming portion (300) provided in the piston portion (200) and, when the piston portion (200) moves along the direction of compression, forms a magnetic field by providing an external current to raise the viscosity of the magnetorheological fluid to a set level; and a valve portion (400) formed in the piston portion (200) and opening and closing a flow path (201) formed to open both sides of the piston portion (200), and, when the piston portion (200) moves along the direction of compression, closes the flow path (201).

[0063] Referring to FIGS. 1 to 4, magnetorheological fluid is filled inside the cylinder housing part (100), and the piston part (200) reciprocates inside the cylinder housing in response to external vibrations and shocks through the piston rod.

[0064] An annular flow path (201) is formed between the inner core (210) and the outer core (220) of the piston part (200), and an electromagnet coil (310) is disposed on the outer circumference of the piston part (200). When current is applied from the current provider (610), a magnetic field is formed in the electromagnet coil (310), and the viscosity of the magnetorheological fluid passing through it increases, thereby generating a damping force.

[0065] At this time, the control unit (600) changes the viscosity of the magnetorheological fluid in real time by adjusting the current intensity, so precise damping force control is possible according to various driving conditions.

[0066] The built-in valve section (400) is installed at the end of the flow path (201) and includes a plurality of T-shaped flow control valves (410) arranged radially.

[0067] When the piston part (200) moves in the compression direction, the valve (410) is fully opened to allow magnetorheological fluid to flow freely, thereby lowering the compression-side damping force, and when the piston moves in the extension direction, the valve is partially closed to restrict the flow of fluid, thereby setting the extension-side damping force to be large.

[0068] In this way, the built-in valve section (400) allows the damping force on the extension side and the compression side to be individually set using only the mechanical structure, regardless of electronic control.

[0069] The present invention provides a composite damping force control method combining electronic control and mechanical valve control. Precise damping force adjustment corresponding to various driving conditions is possible through magnetic field control via an electromagnet coil, and through the valve structure, the damping force on the extension side is maintained to be greater than that on the compression side even in a non-energized state.

[0070] In addition, a valve protection cap (250) is applied to prevent damage to the valve due to repeated operation or external impact, and the radial arrangement structure uniformly controls the fluid flow to improve durability.

[0071] Accordingly, the damper device according to the present invention has the effect of simultaneously improving ride comfort and driving stability by smoothly absorbing road surface shocks in various driving environments while rapidly suppressing body shaking.

[0072] In addition, predictable damping force characteristics can be maintained even when electronic control malfunctions occur, thereby overcoming the limitations of conventional MR dampers and ensuring both stability and reliability.

[0073] The following explains this in more detail.

[0074] Referring to FIGS. 1 to 4, the valve-embedded magnetorheological (MR) damper device of the present invention comprises a magnetic field forming part (300) including an electromagnet coil (310) arranged along the outer circumference of a piston part (200).

[0075] The electromagnet coil (310) receives current from a current provider (610) driven by the control of the control unit (600) to form a magnetic field, and this magnetic field changes the viscosity of the magnetorheological fluid passing through the annular flow path (201) of the piston unit (200).

[0076] When no external current is applied, the viscosity of the magnetorheological fluid is low, allowing the fluid to flow freely and the damping force to be relatively weak. However, when current is applied through the control unit (600), a strong magnetic field is formed around the electromagnet coil (310), and as magnetic particles within the magnetorheological fluid passing through the flow path (201) align, the viscosity increases rapidly. As the viscosity increases, the resistance to fluid flow increases, and consequently, the damping force increases. By controlling the magnitude of the current, the damping force can also be precisely adjusted in real time, thereby enabling the realization of optimal damping characteristics required under various driving conditions.

[0077] Additionally, the built-in valve part (400) installed at the end of the Euro (201) mechanically controls the flow of fluid according to the direction of movement of the piston part (200).

[0078] When the piston part (200) moves in the compression direction, the valve part (400) is fully opened to allow magnetorheological fluid to flow smoothly, thereby lowering the compression-side damping force, and when the piston moves in the extension direction, the valve is partially closed to restrict fluid flow, thereby setting the extension-side damping force to be large.

[0079] Through this structure, the damping forces on the extension and compression sides can be differentially set mechanically without electronic control, and stable damping characteristics can be maintained even in a non-energized state.

[0080] Accordingly, the damper device of the present invention combines magnetic field control through an electromagnetic coil with mechanical opening and closing control of a valve section to solve the problem of asymmetric damping control centered on current control, which was a limitation of existing MR dampers. Through this, it improves ride comfort and stability in various driving environments and provides high reliability and safety by maintaining predictable damping performance even in the event of electronic control malfunctions.

[0081] Additionally, referring to FIGS. 1 to 4, the piston portion (200) includes an inner core (210) having a piston rod (211) formed therein that penetrates one side of the cylinder housing portion (100), and an outer core (220) which is coupled to the inner core (210) to surround the outer circumference of the inner core (210) and whose outer circumference contacts the inner circumference of the cylinder housing portion (100). The fluid passage (201) is formed between the inner core (210) and the outer core (220).

[0082] The valve-embedded magnetorheological damper device of the present invention has a structure that generates damping force centered on the piston part (200).

[0083] The piston part (200) reciprocates within the internal space of the cylinder housing (100), and an inner core (210) with a piston rod (211) integrally formed therein is located at the center thereof, and an outer core (220) is coupled to surround the outer circumference of the inner core (210). Since the outer circumference of the outer core (220) contacts the inner circumference of the cylinder housing (100) and maintains a state of close contact, the piston part (200) can stably perform linear motion.

[0084] An annular flow path (201) is formed between the inner core (210) and the outer core (220), and magnetorheological fluid passes through this flow path when the piston part (200) moves.

[0085] A magnetic field forming unit (300) including an electromagnet coil (310) is arranged along the outer circumference of a piston unit (200), and receives current from a current provider (610) under the control of a control unit (600).

[0086] When current is applied, a magnetic field is formed in the electromagnet coil (310), and as magnetic particles inside the magnetorheological fluid passing through it align, the viscosity increases. The magnetorheological fluid with increased viscosity increases flow resistance when passing through the flow path (201), thereby increasing the damping force, and conversely, when the current is reduced, the viscosity decreases, and the damping force decreases. In this way, the damping force can be precisely controlled in real time by controlling the intensity of the current.

[0087] Additionally, at the end of the Euro (201), an internal valve section (400) is installed in which a plurality of T-shaped valve members are arranged radially.

[0088] When the piston part (200) moves in the compression direction, the valve part (400) is fully opened to allow magnetorheological fluid to flow freely, thereby lowering the compression-side damping force, and conversely, when the piston part (200) moves in the extension direction, the valve part (400) is partially closed to restrict fluid flow, thereby setting the extension-side damping force to be large.

[0089] Accordingly, the present invention provides a dual control method that combines magnetic field control through an electromagnet coil and mechanical control of an integrated valve unit, thereby enabling independent setting of damping forces on the extension side and the compression side.

[0090] This allows the vehicle suspension system to smoothly absorb road shocks while rapidly suppressing body roll, thereby simultaneously improving ride comfort and driving stability. Furthermore, since the valve structure itself can maintain asymmetric damping characteristics even in the event of electronic control malfunctions, it offers the effect of significantly enhancing system reliability and safety.

[0091] And, referring to FIGS. 1 to 4, the electromagnet coil (310) is electrically connected to the current provider (610) through a wire (611).

[0092] The above wire (611) is drawn into the interior of the piston rod through the other side of the inner core and drawn out to the outside.

[0093] The valve-embedded magnetorheological (MR) damper device of the present invention is equipped with a magnetic field forming part (300) including an electromagnet coil (310), and the electromagnet coil (310) is electrically connected to a current provider (610) via a wire (611). The wire (611) is fed into the interior of the piston rod (211) via the other side of the inner core (210) of the piston part (200) and is drawn out to the outside along the hollow part of the piston rod (211). This wire arrangement method ensures that the wire is flexibly protected even as the piston part reciprocates inside the cylinder housing, thereby effectively preventing wear, breakage, and insulation damage of the wire that may occur during repeated operation.

[0094] The control unit (600) supplies current to the electromagnet coil (310) through the current provider (610) and forms a magnetic field around the coil. This magnetic field acts on the magnetorheological fluid passing through the annular flow path (201) of the piston unit (200) to align magnetic particles within the fluid, thereby increasing the viscosity of the fluid.

[0095] The magnetorheological fluid with increased viscosity increases flow resistance when passing through the flow path (201), thereby increasing the damping force, and the damping force can be controlled in real time by adjusting the viscosity according to the current intensity.

[0096] This wire entry structure ensures a stable and continuous current supply to the electromagnet coil, thereby enabling the formation of a constant magnetic field even during the reciprocating motion of the piston.

[0097] Additionally, an internal valve section (400) installed at the end of the fluid path (201) mechanically controls the fluid flow according to the direction of movement of the piston section (200). When the piston section (200) moves in the compression direction, the valve section (400) is fully opened to allow magnetorheological fluid to flow freely, thereby lowering the compression damping force, and conversely, when the piston moves in the extension direction, the valve section (400) is partially closed to restrict the fluid flow, thereby setting the extension damping force to be large.

[0098] Through this, the present invention provides a dual control function in which the electronic control and the mechanical control of the valve operate complementarily, allowing the damping forces on the extension and compression sides to be set independently.

[0099] Therefore, the present invention enables a stable current supply even during the reciprocating motion of the piston through the internal insertion structure of the wire (611), so the magnetic field formation of the electromagnet coil can always be maintained at a constant level.

[0100] Based on this, the viscosity of the MR fluid can be precisely controlled according to the current intensity, and combined with mechanical flow control of the built-in valve section, optimal damping characteristics can be achieved even under various driving conditions.

[0101] As a result, the vehicle suspension system smoothly absorbs road shocks while rapidly suppressing body roll to improve ride comfort, and even in the event of controller malfunction or power failure, it can maintain basic damping characteristics solely through the valve structure in a non-energized state, significantly enhancing driving stability and reliability.

[0102] Also, referring to FIGS. 1 to 4, a valve cap (250) is attached to one side of the piston part (200).

[0103] The above valve part (400) is located inside the valve cap (250).

[0104] In the valve-embedded magnetorheological (MR) damper device of the present invention, a valve cap (250) is attached to one side of the piston part (200), and the embedded valve part (400) is placed in the internal space of the valve cap (250). The valve cap (250) protects the embedded valve part (400) and performs the role of fixing and supporting the valve part so that it can operate stably by being precisely aligned with the annular flow path (201).

[0105] The valve section (400) located inside the valve cap (250) is composed of a plurality of T-shaped valve members arranged radially and mechanically controls the fluid flow according to the direction of movement of the piston section (200).

[0106] When the piston part (200) moves in the compression direction, the valve part (400) is fully opened so that the magnetorheological fluid flows freely, thereby lowering the compression damping force, and when the piston part (200) moves in the extension direction, the valve part (400) is partially closed to restrict the flow of the magnetorheological fluid, thereby setting the extension damping force to be large.

[0107] Since this valve control operates solely in a mechanical manner regardless of electronic control, it can maintain differential damping forces on the extension and compression sides even in a non-energized state without current supply.

[0108] The valve cap (250) plays an important role in ensuring the stability and durability of the valve part (400).

[0109] The valve part (400) is protected from fluid shock, vibration, and repeated opening and closing operations that may occur during the process of the piston part (200) moving back and forth at high speed, and the valve is prevented from being damaged by external impact.

[0110] In addition, the valve cap (250) maintains the precise position of the valve section so that each radially arranged valve member can operate at the same spacing and pressure conditions, thereby enabling uniform fluid flow control across the entire piston section.

[0111] Accordingly, the structural combination of the valve cap (250) and the built-in valve part (400) of the present invention provides a basis for stably and precisely controlling the flow of MR fluid.

[0112] As a result, the vehicle suspension system can simultaneously achieve contrasting performance characteristics: smooth shock absorption during compression and suppression of body roll during extension. Furthermore, the protective function provided by the valve cap ensures the durability of the valve section even in repetitive operating environments, allowing for the maintenance of consistent damping performance over a long period.

[0113] In particular, referring to FIGS. 1 to 4, the valve portion (400) is installed in multiple numbers at intervals along the outer circumference of the piston portion (200).

[0114] The above Euro (201) is formed in a plurality by corresponding to each of the valve parts (400) formed in the plurality.

[0115] In the valve-embedded magnetorheological (MR) damper device of the present invention, the embedded valve portion (400) is arranged in a radially spaced manner along the outer circumference of the piston portion (200). Corresponding to each valve portion (400), annular flow paths (201) are also formed in a plurality and are uniformly distributed across the entire cross-section of the piston.

[0116] This structure allows the flow of MR fluid to be controlled through multiple independent paths, thereby significantly improving the precision of flow control and damping force responsiveness compared to the existing single-path method.

[0117] When the piston part (200) moves in the compression direction, all of the valve parts (400) are fully opened so that the MR fluid flows freely through each flow path (201).

[0118] This minimizes fluid flow resistance during the compression process, allowing the compression-side damping force to be set low, and enables the vehicle suspension to smoothly absorb road shocks.

[0119] Conversely, when the piston part (200) moves in the extension direction, the multiple valve parts (400) are partially closed to simultaneously limit the amount of MR fluid flowing through each path (201).

[0120] At this time, as the flow resistance of the MR fluid increases, the damping force on the extension side is set to be greater than that on the compression side, and the effect of quickly suppressing excessive shaking of the vehicle body occurs.

[0121] Multiple valve sections and corresponding multi-flow structures have a significant advantage in that they enable uniform flow control across the entire piston cross-section.

[0122] In a single-flow system, local pressure variations may occur inside the piston due to fluid flow constraints in a specific direction, but in the present invention, the valve section and the flow path are distributed into multiple sections, so the pressure distribution is maintained uniformly. As a result, the flow of the MR fluid is controlled smoothly and precisely, and the response characteristics of the damping force are improved.

[0123] In addition, by arranging multiple valve sections radially, the entire piston is uniformly covered 360 degrees, thereby achieving the effect of evenly dispersing and recovering fluid from the center of the piston outwards. This not only maximizes vibration control performance by maintaining pressure balance on both sides of the piston, but is also advantageous in preventing uneven valve wear or piston deformation that may occur during repeated operation.

[0124] Therefore, the multi-valve and multi-flow structure of the present invention implements asymmetric damping force characteristics, thereby setting the damping force on the extension side to be greater than that on the compression side, which rapidly suppresses vehicle body shaking during driving and improves driving stability.

[0125] In addition, since the MR fluid is distributed and controlled through multiple Euros, it offers excellent responsiveness and a wide control range, and can achieve optimized damping characteristics under various driving conditions.

[0126] In addition, uniform flow control based on the radial arrangement enables the generation of the same damping force across the entire piston cross-section, providing consistent performance even under repetitive impact situations.

[0127] In addition, the multi-valve and multi-flow design minimizes pressure variations inside the piston, thereby improving the durability of the valve and maintaining stable damping performance even during long-term use.

[0128] As a result, the present invention can provide the effect of significantly improving the damping force control range, responsiveness, and durability compared to conventional MR dampers by finely controlling the flow of MR fluid through a plurality of valve parts (400) and a plurality of annular flow paths (201) arranged radially along the outer circumference of the piston.

[0129] Additionally, referring to FIGS. 1 to 4, the control unit (600) is electrically connected to a sensor (620) that detects when current is supplied from the current provider (610) and the electromagnet coil (310) is magnetized.

[0130] The control unit (600) controls the operation of the valve unit (400) when the piston unit (200) moves along the direction of compression and the magnetization of the electromagnet coil (310) is not detected through the sensor (620).

[0131] Additionally, the valve unit (400) is a flow control valve (410) that opens and closes the flow path according to the control of the control unit (600).

[0132] Referring to FIGS. 1 to 4, in the valve-embedded magnetorheological (MR) damper device of the present invention, the control unit (600) is electrically connected to a current provider (610) and a sensor (620) to detect the magnetization state of the electromagnet coil (310) in real time and, as needed, controls the operation of the built-in valve unit (400).

[0133] The electromagnet coil (310) forms a magnetic field by the current supplied from the current provider (610), and the sensor (620) detects whether the electromagnet coil (310) is properly magnetized and transmits a signal to the control unit (600).

[0134] If the magnetization of the electromagnet coil (310) is not detected through the sensor (620) while the piston part (200) is moving in the compression direction, it is determined that there is an abnormality in the electronic control system or a failure in current supply.

[0135] In this case, the control unit (600) automatically drives the built-in valve unit (400) to change the open / closed state of the flow control valve (410), thereby supplementing the damping force control. Since the control unit (600) directly controls the valve unit (400) even if the electronic control does not operate normally, vehicle driving stability can be maintained even in emergency situations.

[0136] In particular, the built-in valve unit (400) is composed of a flow control valve (410) that operates according to a control signal from the control unit (600).

[0137] This valve (410) directly controls the flow of magnetorheological fluid passing through the path (201) and can also implement a hybrid control method in which electronic control and mechanical control are applied simultaneously.

[0138] For example, normally, current is supplied to the electromagnet coil (310) to change the viscosity of the MR fluid and set the damping force, but in the event of a current supply failure or non-energy state, the control unit (600) can drive the flow control valve (410) to directly restrict the flow of the MR fluid, thereby maintaining the desired damping force characteristics.

[0139] Through such a control structure, the present invention can enable stable and predictable damping force control in various situations.

[0140] First, when the electronic control is operating normally, real-time damping force control can be performed by precisely adjusting the viscosity of the MR fluid according to the current intensity.

[0141] Second, even in the event of magnetization abnormalities in the electromagnet coil or power supply failures, the control unit directly controls the valve unit, enabling the maintenance of a stable basic damping force even in a non-energized state.

[0142] Third, since multiple flow paths (201) are finely controlled through the flow control valve (410) and the valve structure of the radial arrangement, the responsiveness of the damping force is improved and the road surface shock can be effectively absorbed during vehicle driving.

[0143] Fourth, through the dual control method, the vehicle suspension system can simultaneously improve ride comfort and driving stability in various driving environments.

[0144] As a result, the present invention can implement a high-stability MR damper device that provides reliable damping force control even in electronic control abnormal situations by combining sensor-based state detection and control unit-valve unit interlocking control.

[0145] This enables predictable vibration control performance even under various conditions such as high-speed driving, sudden braking, and cornering, and effectively overcomes the current dependency problem of existing MR dampers.

[0146] Figure 5 is a graph showing the change in damping force of a valve-embedded magnetorheological damper device according to the present invention.

[0147] Referring to FIG. 5, the valve-embedded magnetorheological (MR) damper device of the present invention shows damping force characteristics according to current intensity (A) and piston speed (m / s). As can be seen in the graph, the present invention has the characteristic that the damping force on the rebound side and the compression side changes differently depending on the magnitude of the current applied to the electromagnet coil (310) and the piston movement speed.

[0148] First, the damping force on the elongation side increases significantly as the current increases. Even in the non-energized state (0A), a certain level of initial damping force exists, and as the current is gradually increased, the viscosity of the magnetorheological fluid (MR fluid) increases rapidly, causing the resistance of the fluid flowing through the flow path (201) to increase.

[0149] When the speed is 0.1 m / s, the damping force increases to a maximum of approximately 80 N or more, and when the speed is 0.05 m / s, it increases to approximately 60 N. When the current reaches 2.5 A or more, the damping force reaches a saturation state and is maintained stably. These characteristics mean that the extensional damping force can be precisely controlled in real time by adjusting the current according to driving conditions.

[0150] On the other hand, the absolute value of the damping force on the compression side is smaller than that on the extension side even under the same current conditions. It operates at a maximum level of about -80N under a speed of 0.1 m / s and about -60N under a speed of 0.05 m / s, and the range of change in damping force with increasing current is relatively gradual.

[0151] This is because the valve structure of the present invention and MR fluid control are combined to realize asymmetric damping force characteristics.

[0152] That is, when the piston moves in the compression direction, the valve part (400) is fully opened to facilitate fluid flow and reduce the compression damping force, and when the piston moves in the extension direction, the valve part is partially closed to restrict fluid flow, thereby allowing the extension damping force to be set to be large.

[0153] In addition, as shown in the graph, the range of change in damping force increases as the piston speed increases.

[0154] While the change in damping force responds sensitively to the increase in current at a speed of 0.1 m / s, the range of change is gradual at 0.05 m / s, thereby providing speed-dependent damping force control characteristics that ensure ride comfort in low-speed driving environments and enhance driving stability in high-speed driving environments.

[0155] Therefore, the valve-embedded MR damper of the present invention combines MR fluid viscosity control through an electromagnet coil and mechanical flow rate control using an embedded valve, so that the damping force can be finely and stably controlled according to the current intensity and piston speed.

[0156] This allows for the smooth absorption of road shocks while rapidly suppressing body roll, providing the effect of simultaneously improving ride comfort and driving stability under various driving conditions.

[0157] In addition, since a certain level of damping force is maintained solely by the built-in valve structure even in a non-energized state, predictable damping performance can be achieved even in the event of electronic control malfunctions or power failures.

[0158] In conclusion, the damper device of the present invention provides four key technical effects: implementation of asymmetric damping force, real-time current-based control, velocity-dependent damping characteristics, and stability in a non-energized state, and can provide excellent performance in terms of control range, responsiveness, and durability compared to existing MR dampers.

[0159] The present invention is not limited to the specific preferred embodiments described above, and anyone with ordinary knowledge in the art to which the invention pertains can make various modifications without departing from the essence of the invention as claimed in the claims, and such modifications will be within the scope of the claims. Explanation of the symbols

[0160] 100: Cylinder housing part 200: Piston part 201 : Euro 210 : Inner Core 211: Piston rod 220: Outer core 250: Valve cap 300: Magnetic field forming part 310: Electromagnet coil 400: Valve part 410: Flow control valve 600: Control unit 610: Current supply unit 611: Wire 620 : Sensor

Claims

Claim 1 A cylinder housing portion in which magnetorheological fluid is filled in an internal space; a piston portion arranged to be capable of reciprocating movement in the internal space of the cylinder housing portion; and a magnetic field forming portion provided in the piston portion, which, when the piston portion moves along the direction of compression, forms a magnetic field by providing an external current to increase the viscosity of the magnetorheological fluid to a set level. and, the device includes a valve portion that opens and closes a fluid passage formed in the piston portion and formed to open both sides of the piston portion, and closes the fluid passage when the piston portion moves along the direction of compression; the magnetic field generating portion includes an electromagnet coil arranged along the outer circumference of the piston portion, and forms the magnetic field by receiving the external current from a current provider driven according to the control of the control portion; the piston portion includes an inner core having a piston rod formed penetrating one side of the cylinder housing portion, and an outer core coupled to the inner core to surround the outer circumference of the inner core, with the outer circumference in contact with the inner circumference of the cylinder housing; the fluid passage is formed between the inner core and the outer core; the electromagnet coil is electrically connected to the current provider through a wire; the wire is drawn into the interior of the piston rod through the other side of the inner core and drawn out to the outside; the valve portion is installed in multiple numbers at intervals along the outer circumference of the piston portion, and the fluid passage is the A valve-embedded magnetorheological damper device characterized by being formed in a plurality corresponding to each of the valve parts formed in a plurality, wherein the control unit is electrically connected to a sensor that detects that the electromagnet coil is magnetized when current is supplied from the current provider, and when the piston part moves along the direction of compression, the magnetization of the electromagnet coil is not detected through the sensor, thereby controlling the operation of the valve part, and wherein the valve part is a flow control valve that opens and closes the flow path according to the control of the control unit. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A valve-embedded magnetorheological damper device according to claim 1, characterized in that a valve cap is coupled to one side of the piston portion, and the valve portion is located inside the valve cap.

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