KR200305766Y1 - Piston valve device of damper using magneto-rheological fluid - Google Patents

Abstract

The present invention relates to a piston valve device of a damper using a magnetofluidic fluid, and the apparent viscosity of the magnetofluidic fluid passing through the gap on the valve is changed every moment by the strength of the magnetic field generated by the solenoid according to the applied current. It is possible to obtain the damping performance by using this method, so that the riding comfort and the ride conditions of the road contacted by the vehicle can be maintained while maintaining the various characteristics of the magnetic fluid such as fast response, high yield stress, excellent wear resistance, and low viscosity. It is designed to provide a wide range of attenuation performances up to adjustment stability.

Description

PISTON VALVE DEVICE OF DAMPER USING MAGNETO-RHEOLOGICAL FLUID}

The present invention relates to a piston valve device of a damper using magnetofluidic fluid. More specifically, the instantaneous viscosity of the magnetofluidic fluid passing through the gap on the valve by the strength of the magnetic field generated by the solenoid according to the applied current is instantaneous. By allowing the damping performance to be obtained by changing the phenomenon, various situations of the road surface where the car contacts while maintaining various characteristics of the magnetic fluid such as fast response, high yield stress, excellent wear resistance and low viscousity The present invention relates to a piston valve device for a damper using a magnetic fluid that enables a wide range of damping performances ranging from ride comfort to adjustment stability.

In general, a suspension is installed between the vehicle body and the wheels of the vehicle to absorb vibrations or shocks received from the road surface while driving to prevent damage to the vehicle body or cargo and to improve a passenger's riding comfort.

Such suspension is a passive suspension that absorbs vibrations and shocks transmitted to the vehicle body by appropriately responding to the state of the vehicle body by using the mechanical characteristics of the component according to the road surface or the driving conditions of the vehicle. The vehicle is classified into an active suspension that measures the state of the vehicle body according to the change in the driving conditions of the vehicle using a sensor, and appropriately corresponds to the state of the vehicle body by the controller based on the measured data.

The main components of such suspension are dampers or shock absorbers. Until now, the concept of dampers or shock absorbers applied to the suspension of automobiles is a linear movement in a cylinder and a base valve device coupled to a cylinder. The oil passage hole through which oil or gas can escape is formed in the piston valve device. When the piston valve device is operated, various types of springs such as helical spring, conical spring and disc spring are used to measure the instantaneous cross-sectional area according to the speed. A control method was applied.

In this case, however, the range of damping performance for the combination of components used, from passive to continuous variable shock absorbers controlled by solenoid valves, must be clearly known or databased, so that it is suitable for the vehicle. There is a problem that it takes a long time to tune the damping performance.

In order to solve the above problems, ① a continuous force is generated while having a fast response characteristic of several ms or less, ② easy to design the application device, ③ a high electric field but low current, etc. A damper using Electro-Rheological Fluid with advantages has been proposed.

However, electrofluidic fluids have limited damping forces because they have relatively low yield strengths, despite having many of the characteristics described above, and are easily affected by contaminants and require a high electric field of high voltage. As a result, the control system becomes very complicated.

Accordingly, researches on magnetofluid fluids have been actively conducted in order to overcome the performance constraints of the electrofluidic fluids and the technical problems caused when manufacturing the dampers using the electrofluidic fluids.

Magnetofluidic fluids are suspensions of magnetizable particles of micron size (10 ^-6 ) size in synthetic oil. Magnetic fluids can be developed to precisely control yield stress by applying a magnetic field.

Such a magnetic fluid has a characteristic of fast response characteristics, high yield stress, and no degradation in performance due to contamination.

In addition, the magnetofluid fluid can utilize a magnetic field easily generated by a simple, low voltage electromagnetic coil, has excellent wear resistance, and has low viscosity.

In addition, the magnetofluid fluid has a wide operating temperature range of -40 ° C. to 150 ° C. and has excellent characteristics of easy remixing.

As such, when the magnetofluid fluid is applied to the damper, most of the problems posed by the electrofluid fluid are solved, and thus, the suspension of the automobile may be widely applied in various industrial fields.

The present invention solves such a conventional problem, and its purpose is to change the apparent viscosity of the magnetofluid fluid passing through the gap on the valve every moment by the strength of the magnetic field generated by the solenoid according to the applied current. It is possible to obtain a damping performance by using the magnetic fluid, so that it can be used for various situations on the road contacted by the vehicle while maintaining various characteristics of the magnetic fluid such as quick response, high yield stress, excellent wear resistance, and low viscosity. It is to provide a damper piston valve device using a new magneto-fluidic fluid that can exhibit a wide range of damping performance up to the adjustment stability.

1 is a front end perspective view showing a piston valve device of a damper using a magnetic fluid according to the present invention,

2 is a front cross-sectional view of FIG.

Figure 3 is a cross-sectional view showing the magnetic flux flow in the piston valve device of the damper using a magnetic fluid according to the present invention,

4 is a schematic diagram showing a case where a magnetic field by a solenoid is not applied to a magnetic fluid;

5 is a schematic diagram showing a case where a magnetic field by a solenoid is applied to a magnetorheological fluid;

6 is a graph showing the magnetic flux density change in the annular gap when the cross-sectional area of the core is fixed in the piston valve device of the damper using the magneto-fluidic fluid according to the present invention,

7 is a graph showing a change in magnetic flux density in an annular gap when a cross section of a pole is fixed in a piston valve device of a damper using a magnetofluidic fluid according to the present invention and the cross section of a core is changed.

** Description of symbols for the main parts of the drawing **

10: piston valve device 13: core

14: solenoid 15: bobbin

16: wire passage 17: piston rod

19: Pole Piece 20: Upper plate

21: supporter 22: flux ring

26: annular clearance.

In order to achieve the above object, the present invention has a through hole of a predetermined diameter having a screw portion to a certain depth in the central portion, a flange portion is formed in the upper end and the lower end, and the body corresponding to the position spaced apart a certain distance upward from the lower end A core having a predetermined length having a locking jaw formed at a side thereof; A cylindrical bobbin installed around the outer periphery of the core corresponding to a line coinciding with the outer end of the flange portion; A solenoid which forms a magnetic field when a current is applied from the outside in a state in which it is installed on the inner side of the bobbin; A disk-shaped pole piece that supports the lower end of the bobbin while being inserted and engaged from the lower end of the core to the locking jaw position and controls the damping performance at the lower part while forming a magnetic path through which the magnetic field generated from the solenoid can flow. Pole Piece; A piston rod having a lower end fitted in a threaded portion formed in a through hole of the core, and having a wire passage formed at a center thereof with a wire passage of a predetermined diameter; The wire is drawn along the wire passage inside the piston rod and electrically connected to the solenoid through the inside of the through hole of the core. A plurality of oil through holes are formed on the upper surface at regular intervals, and are inserted into the upper surface of the flange of the upper end of the core. An upper plate for maintaining concentricity between the piston rod and the piston valve in a coupled state; An inner supporter (Inner Supporter) which serves to support the core and the pole piece in a state of being fitted into the lower end of the core corresponding to the lower portion of the pole piece; An outer supporter having a plurality of oil passing holes formed at regular intervals on an upper edge thereof and fitted to the outer circumferential surface of the inner supporter; A flux ring made of a cylindrical shape and having a magnetic ring generated from the solenoid in a state in which the magnetic field generated in the solenoid is maintained in a closed circuit while being covered by a cover from above the core; An upper seal preventing the flow of magnetic fluid in the assembled state by being fitted to the center edge of the upper plate corresponding to the upper end of the coupling portion of the core and the piston rod; A cap nut screwed to the lower end of the core to fasten the entire piston valve; A low seal preventing the flow of magnetofluidic fluid in the assembled state of the cap nut; A ring nut screwed to the lower end of the core at the bottom of the cap nut to fix the flux ring; It is characterized by consisting of a piston band which is fitted along the upper outer peripheral surface of the flux ring.

In this invention, the core and the flux ring has a feature made of a ferromagnetic material.

In the present invention, the solenoid has a feature in which a coil having a thickness of 0.3 to 05φ is wound 300 to 500 times.

In the present invention, an annular jaw of the same thickness as the thickness of the flange portion and the pole piece is integrally formed on the inner side of the flux ring corresponding to the assembly position of the upper flange portion and the pole piece of the core, thereby forming the flange portion and the upper annular shape. A gap is formed between the jaw, the pole piece, and the lower annular jaw, through which a magnetic fluid can flow.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a front sectional perspective view showing a piston valve device of a damper using a magnetic fluid according to the present invention, Figure 2 is a front sectional view of FIG.

Referring to this, the piston valve device of the damper using the magnetic fluid according to the present invention is made of a solenoid control method.

To this end, a circular flange portion 11 is formed at the top and the bottom of the piston valve device 10, and a core 13 having a predetermined length having a through hole 12 formed at the center circumference is disposed, and each plan The bobbin 15 in which the solenoid 14 is built is installed on the circumferential surface of the core 13 corresponding to the branches 11.

The solenoid 14 has a form in which a coil of 0.3 to 05φ thickness is wound 300 to 500 times.

The piston rod 17 of the structure in which the wire passage 16 is formed in the upper part of the through hole 12 of the core 13 is fitted by screwing, and the wire passage 16 on the piston rod 17 is coupled. The wire 18 drawn through is configured to be electrically connected to the solenoid 14 through the inside of the through hole 12 of the core.

The lower end of the core 13 is inserted into the pole piece 19 in the form of a disc to be coupled to support the bobbin 15, the upper plate 20 is inserted from above the core 13 to the piston rod 17 It is configured to maintain concentricity.

An inner supporter 21 of a disc shape is fitted to the lower portion of the pole piece 19 to support the core 13 and the pole piece 19, and the circumference of the assembly is generated from the solenoid 14. A flux ring 22 is formed to form a magnetic path so that the magnetic field can maintain a closed circuit.

The outer surface of the inner porter is fitted with a disc-shaped outer supporter 24 having a plurality of oil passing holes 23 at regular intervals on the upper surface edge, the lower end of the flux ring 22 to the edge of the outer support Is supported.

In the present invention, the flux ring 22 is made of a ferromagnetic material cylindrical.

On the inner circumferential surface of the flux ring 22 corresponding to the edge of the upper flange portion 12 and the edge of the pole piece 19 of the core 13 and the thickness of the flange portion 12 and the pole piece 19, An annular jaw 25 having the same thickness is formed, and an annular gap through which oil can flow between the upper annular jaw 25 and the flange portion 12, the lower annular jaw 25, and the edge of the pole piece 19. (Annular Gap: 26) is formed.

In the present invention as described above, at the center edge of the upper plate 20, a threaded mounting groove 28 into which the upper chamber 27 is fitted is formed.

A predetermined portion of the outer circumferential surface of the flux ring 22 is fitted with a piston band 29 for assembling the damper or shock absorber to maintain airtightness with the inner wall of the cylinder, and the assembly of the flux ring 22 is performed. After completion, the cap nut 30 is screwed to the lower end of the core 13, and the ring nut 31 for fixing the flux ring 22 is coupled to the lower portion of the cap nut 30.

The lower chamber 32 is fitted to the inner central edge of the cap nut to prevent the magnetic fluid from flowing out.

Referring to the operating state of the present invention made as described above are as follows.

Figure 3 is a cross-sectional view showing the magnetic flux flow in the piston valve device of the damper using a magnetic fluid according to the present invention.

Referring to this, when a damper using a magnetic fluid having a piston valve device 10 according to the present invention is applied to the suspension of the vehicle, if vibration or shock is transmitted from the road surface when the vehicle is driven, the impact force detection signal is controlled. The controller controls to apply a proper current set according to the strength of the impact force.

At this time, the proper current flows through the wire drawn through the wire passage 16 on the piston rod 17 to the coil constituting the solenoid 14 to form a magnetic field around the solenoid 14.

As such, the magnetic field formed around the solenoid 14 flows along a path formed by the core 13 and the flux ring 22 to maintain a closed circuit.

At the same time, the piston valve device 10 is linearly moved along the inner wall of the cylinder constituting the damper or shock absorber, the magnetic fluid is filled in the compression chamber or the tension chamber inside the cylinder upper plate 20 and the outer supporter 24 After flowing into the oil through hole 23 formed in the annular jaw 25 on the flux ring 22 and the flange portion 12 of the core 13 and formed between the annular jaw 25 and the pole piece 19 It flows in the opposite direction through the annular gap 26.

As such, the magnetofluid fluid flowing through the annular gap 26 formed inside the flux ring 22 inevitably passes through the moving magnetic field while maintaining the closed circuit, and at this time, the magnetic fluid fluid As the apparent viscosity changes instantaneously, the desired damping performance is obtained.

4 is a schematic diagram showing a case where a magnetic field due to a solenoid is not applied to the magnetic fluid, and FIG. 5 is a schematic diagram showing a case where a magnetic field due to the solenoid is applied to the magnetic fluid.

Referring to FIG. 4, when the magnetic field is not applied to the magnetofluid fluid, particles of the magnetofluid fluid are loosely distributed.

However, as shown in FIG. 5, when the magnetofluidic fluid passes between magnetic fields, the fluid particles are instantaneously arranged to form a chain structure, and when the chain structure is broken, the flow occurs only when the viscosity changes every moment. Can be.

In this case, breaking the chain structure of the magnetofluidic fluid means that the yield shear stress of the fluid must be overcome.

6 is a graph showing a change in magnetic flux density in an annular gap when the cross sectional area of the core is fixed in the piston valve device of the damper using the magneto-fluidic fluid according to the present invention, 7 is a graph showing a change in magnetic flux density in an annular gap when a cross section of a pole is fixed in a piston valve device of a damper using a magnetofluidic fluid according to the present invention and the cross section of a core is changed.

In the case of Figure 6, the smaller the cross-sectional area of the pole can be seen that the magnetic flux density is larger. Therefore, the smaller the cross-sectional area of the pole within the limit that the damping performance of the annular gap 26 inside the flux ring 22 is stable in the automobile damper, the better.

On the contrary, in the case of FIG. 7, the magnetic flux density in the annular gap increases as the cross-sectional area of the core increases while the cross-sectional area of the pole is fixed while the cross-sectional area of the pole is fixed.

Therefore, it can be seen that the design of the core and the pole piece, which acts as a magnet in the damper using the magneto-fluidic fluid, should achieve the maximum magnetic flux density when the minimum power is supplied.

The larger the cross-sectional area is, the better the core is in consideration of the piston valve device being engaged with the piston rod, and the pole piece is a damper for automobiles, considering the limitation of stable damping performance. .

In the case of the damper using the magnetofluidic fluid to which the piston valve device 10 according to the present invention is applied, the structure is very simple, the control method is easy, and the most important response time is 5 to 10ms compared with the conventional solenoid valve type shock absorber. Fast enough

Therefore, in the ECS system using the solenoid valve type shock absorber, it is possible to solve the complaints of consumers due to the response characteristics.

In the prior art, when tuning the shock absorber or damper for automobiles, it is difficult to adjust the performance because the ride stability is poor, whereas the ride stability is poor when the adjustment stability is improved, but the damper using the magnetic fluid fluid according to the present invention has been difficult. By applying this, it is possible to overcome the limitations of the existing contradictory performance, and thus it is possible to secure the adjustment stability while ensuring a good ride comfort, thereby obtaining excellent motor performance of the vehicle.

Applying the present invention as described above has the following effects.

First, as the cylindrical flux ring is applied, the magnetic flux forms a closed loop so that the magnetic flux loss hardly occurs, so the performance of the product is excellent.

Second, the annular gap and concentricity can be kept constant at all times, and the assembly is very excellent.

Third, when the cross sectional area of the core is increased and the cross sectional area of the pole piece is reduced within the limit in which the damping performance is stably exhibited, the maximum magnetic flux density can be obtained by the same power supply.

Claims (4)

A through hole of a predetermined diameter having a thread portion is formed in the central portion, and a flange portion is formed at the upper end portion and the lower end portion, and a core having a predetermined length having a locking jaw formed at an outer surface of the body corresponding to a position spaced apart from the bottom by a predetermined distance ( Core); A cylindrical bobbin installed around the outer periphery of the core corresponding to a line coinciding with the outer end of the flange portion; A solenoid which forms a magnetic field when a current is applied from the outside in a state in which it is installed on the inner side of the bobbin; A disk-shaped pole piece that supports the lower end of the bobbin while being inserted and engaged from the lower end of the core to the locking jaw position and controls the damping performance at the lower part while forming a magnetic path through which the magnetic field generated from the solenoid can flow. Pole Piece; A piston rod having a lower end fitted in a threaded portion formed in a through hole of the core, and having a wire passage formed at a center thereof with a wire passage of a predetermined diameter; An electric wire connected to the solenoid through the inside of the through hole of the core after being drawn along the electric wire passage inside the piston rod; An upper plate having a plurality of oil passing holes formed at regular intervals on an upper surface thereof and maintaining concentricity of the piston rod and the piston valve in a state of being fitted to the upper surface of the flange portion of the core; An inner supporter (Inner Supporter) which serves to support the core and the pole piece in a state of being fitted into the lower end of the core corresponding to the lower portion of the pole piece; An outer supporter having a plurality of oil passing holes formed at regular intervals on an upper edge thereof and fitted to the outer circumferential surface of the inner supporter; A flux ring made of a cylindrical shape and having a magnetic ring generated from the solenoid in a state in which the magnetic field generated in the solenoid is maintained in a closed circuit while being covered by a cover from above the core; An upper seal preventing the flow of magnetic fluid in the assembled state by being fitted to the center edge of the upper plate corresponding to the upper end of the coupling portion of the core and the piston rod; A cap nut screwed to the lower end of the core to fasten the entire piston valve; A lower seal preventing the flow of magnetofluidic fluid in the assembled state of the cap nut; A ring nut screwed to the lower end of the core at the bottom of the cap nut to fix the flux ring; And a piston band fitted and coupled along the upper outer circumferential surface of the flux ring. The method of claim 1, The core and the flux ring is a piston valve device of a damper using a magnetic fluid, characterized in that consisting of a ferromagnetic material. The method of claim 1, The solenoid is a piston valve device of a damper using a magnetic fluid fluid, characterized in that the coil of 0.3 ~ 05φ thickness is made 300 to 500 times wound. The method of claim 1, On the inner surface of the flux ring corresponding to the assembly position of the upper flange portion and the pole piece of the core, an annular jaw of the same thickness as the thickness of the flange portion and the pole piece is integrally formed so that the flange portion, the upper annular jaw, the pole piece and A piston valve device for a damper using a magnetic fluid fluid, characterized in that the gap formed between the lower annular jaw flows the magnetic fluid flow.