KR100709511B1 - Continuous damping control shock-absorber for motor vehicle suspension by electro-magnetic solenoid - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable damping force variable shock absorber of a vehicle suspension system using an electromagnet solenoid. The present invention relates to a damping force according to a change in the apparent viscosity of a magnetic fluid fluid moved between a compression chamber and a tension chamber by the strength of an electromagnetic field formed by an electromagnet solenoid. This variable is variable, and the volume of the hollow rod during compression and tension stroke can be quickly compensated by the action of the floating piston and diaphragm installed in the compression chamber to provide faster time response characteristics of 10 ms or less, and changes in frictional force. It is to be minimized.

The present invention is a cylindrical cylinder having a diameter and a length of a predetermined size; A hollow rod (Hollow Rod) of a predetermined length, which is fitted into the cylinder from an upper outer side of the cylinder and has a cavity having a diameter in a longitudinal direction along an inner center line; A rod guide configured to guide the hollow rod in a linear state while being fitted and coupled to an upper end of the cylinder while maintaining an accurate straightness; Piston valve fixedly coupled to the inner end of the hollow rod partitions the cylinder into the lower compression chamber and the upper tension chamber, and controls the flow of the magnetic fluid fluid filled in the compression chamber and the tension chamber while generating an electromagnetic field during compression and tension stroke ( Piston valve; A floating piston coupled to the cylinder in the compression chamber so as to slide in the vertical direction and sliding the compression chamber in a predetermined direction according to the compression and tension stroke of the piston valve; It includes a high-pressure nitrogen gas filled in the inner cylinder corresponding to the bottom of the floating piston.

Electromagnetic Solenoid, Electromagnetic Field, Shock Absorber, Piston Valve, Floating Piston, Rod Guide, Hollow Rod

Description

CONTINUOUS DAMPING CONTROL SHOCK-ABSORBER FOR MOTOR VEHICLE SUSPENSION BY ELECTRO-MAGNETIC SOLENOID}

1 is a perspective view showing a partial cross-sectional view showing a variable damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid according to the present invention,

2 is a front cross-sectional view of FIG.

Figure 3 is an enlarged perspective view showing a partial cross-section showing a hollow rod in the continuous damping force variable shock absorber of the suspension device for a vehicle by an electromagnet solenoid according to the present invention,

Figure 4 is an enlarged perspective view showing a partial cross-sectional view showing a road guide in the continuous damping force variable shock absorber of the suspension device for vehicles by the electromagnet solenoid according to the present invention,

5 is a front sectional view of FIG. 4;

Figure 6 is an enlarged perspective view showing a partial cross-sectional view showing a piston valve in the continuous damping force variable shock absorber of the suspension device for vehicles by the electromagnet solenoid according to the present invention,

7 is a front sectional view of FIG. 6;

Figure 8 is a cross-sectional configuration showing a state of finishing the assembly of the piston valve using the roller in the present invention,

Figure 9 is an enlarged perspective view showing a partial cross-section showing the floating piston in the continuous damping force variable shock absorber of the suspension device for vehicles by the electromagnet solenoid according to the present invention,

10 is a front sectional view of FIG. 9;

11 is an enlarged cross-sectional view showing an operation state of a floating fluid and a flow of magnetofluidic fluid during the compression stroke of a piston valve in a continuous damping force variable shock absorber of a vehicle suspension by an electromagnet solenoid according to the present invention;

12 is an enlarged cross-sectional view showing the flow of a magnetic fluid and the operating state of the floating piston in the tension stroke of the piston valve in the continuous damping force variable shock absorber of the vehicle suspension by the electromagnet solenoid according to the present invention.

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

20: cylinder 30: hollow rod

32: cavity 33: electric wire

40: road guide 42: oil seal

50: piston valve 51: electromagnet solenoid core

52: solenoid coil 53: gap

55b, 56a: Orifice 60: Floating piston

63: diaphragm 70: rebound stopper

81: Roller.

The present invention relates to a variable damping force variable shock absorber of a vehicle suspension system using an electromagnet solenoid, and more particularly, a compression chamber and a tension in a process in which a compression and tension stroke is performed by an impact continuously applied from the outside such as vibration transmitted from a road surface. The apparent viscosity of the magnetic fluid flowing between the chambers is controlled by the strength of the electromagnetic field formed by the electromagnet solenoid so that the damping force is variable, and the volume of the rod during compression and tension stroke inside the compression chamber affects the action of the diaphragm. By installing a floating piston to be compensated more quickly by the sliding action of the body when the volume changes excessively to provide a fast response time of less than 10ms, and to minimize the change in friction force To help It relates to a continuously variable damping force shock absorber for a vehicle suspension device according to the solenoid electromagnet.

In general, the suspension of the vehicle connects the axle and the body so that vibrations or shocks transmitted from the road surface to the axle during the driving are not transmitted directly to the body, thereby preventing damage to the cargo loaded on the vehicle and the passengers. It is one of the important devices to give a ride.

In addition, the suspension system acts to transmit the driving force generated from the driving wheel or the braking force of each wheel during braking to the vehicle body, to withstand the centrifugal force during the turning, and to maintain each wheel in the correct position with respect to the vehicle body. .

Suspension device to achieve such an action is made of an electronic control method, the chassis spring to mitigate the vibration or shock applied from the road surface, a stabilizer (Stabilizer) to prevent the rolling phenomenon of the vehicle, and It includes a shock absorber that controls free vibration of the chassis spring to give an improved ride comfort.

On the other hand, the shock absorber constituting the suspension device of the vehicle absorbs the free vibration generated by the shock applied to the chassis spring and at the same time to attenuate quickly serves to convert the energy of the vertical motion into thermal energy.

Suspension system of electronically controlled vehicle is mainly applied with hydraulic damping force variable shock absorber for automatically or arbitrarily converting damping force to improve driving stability, maneuvering stability and riding comfort.

As an example of such a conventional hydraulic damping force variable shock absorber, a hydraulic solenoid valve type has been applied.

The time response characteristic of the conventional hydraulic solenoid valve type shock absorber is 30 to 50ms, which shows better performance than the discrete damping force variable damper driven by a passive damper or step motor using oil or gas, but still has a time response characteristic. The problem is that it is relatively slow.

In this case, when the time response characteristic is slow, the shock absorber does not absorb the vibration transmitted from the road surface in a short time and is transmitted to the vehicle as it is, or it only serves to attenuate the aftershock after the main vibration. There is a problem that causes consumers to be dissatisfied with the price-performance ratio.

In addition, the conventional hydraulic solenoid valve type shock absorber has a problem that the structure is quite complicated and it is difficult to adjust the damping performance because it is formed in the form of mounting the hydraulic solenoid valve to the existing gas damper.

In order to improve the performance of the electronically controlled suspension system, a shock absorber that exhibits a fast response time of less than 10 ms is required.

The present invention is to solve such a conventional problem, the object is that the magnetic fluidity that is moved between the compression chamber and the tension chamber in the process of compression and tension stroke by the impact continuously applied from the outside, such as vibration transmitted from the road surface The apparent viscosity of the fluid is controlled by the strength of the electromagnetic field formed by the electromagnet solenoid so that the damping force is variable, and the volume of the rod is compensated more quickly by the action of the diaphragm during compression and tension stroke in the compression chamber. At the same time, a floating piston is installed to allow volume compensation by the sliding action of the main body in case of excessive volume change, providing a fast response time of less than 10ms, and a new electromagnet solenoid that minimizes the change in frictional force. Suspension for vehicles To provide a continuous damping force variable shock absorber of the device.

In order to achieve the above object, the continuous damping force variable shock absorber of the suspension device for a vehicle by an electromagnet solenoid according to the present invention includes a cylindrical cylinder having a diameter and a length of a predetermined size; A hollow rod (Hollow Rod) of a predetermined length, which is fitted into the cylinder from an upper outer side of the cylinder and has a cavity having a diameter in a longitudinal direction along an inner center line; A rod guide configured to guide the hollow rod in a linear state while being fitted and coupled to an upper end of the cylinder while maintaining an accurate straightness; Piston valve fixedly coupled to the inner end of the hollow rod partitions the cylinder into the lower compression chamber and the upper tension chamber, and controls the flow of the magnetic fluid fluid filled in the compression chamber and the tension chamber while generating an electromagnetic field during compression and tension stroke ( Piston valve; A floating piston coupled to the cylinder in the compression chamber so as to slide in the vertical direction and sliding the compression chamber in a predetermined direction according to the compression and tension stroke of the piston valve; It includes a high-pressure nitrogen gas filled in the cylinder corresponding to the bottom of the floating piston.

In the present invention, the fastening screw portion is formed on the outer circumferential surface of the hollow rod, and the cavity formed along the longitudinal center line is wrapped with insulating material to supply external power, and the connector is coupled to the lower end. The electric wire is inserted and installed, while a grommet seal is fitted around the connector.

In the present invention, the rod guide is formed in the shape of a disc having a predetermined diameter and height, the coupling groove is formed in the upper end of the outer peripheral surface is fitted with an annular fastening rib protruding along the inner peripheral surface of the upper end of the cylinder, the hollow rod in the center A rod insertion hole into which a rod insertion hole is inserted, and a rod guide body having a receiving groove of a predetermined depth upward from a bottom surface thereof; An oil seal fitted into a receiving groove formed at a bottom of the rod guide main body and having a through hole formed at a central portion thereof; A support plate which is fixed by bending at a lower edge of the rod guide body in a state of being fitted into a receiving groove corresponding to a lower side of the oil seal to support the oil seal; Leakage prevention O-ring (O-Ring) is inserted into the lower portion of the outer peripheral surface of the rod guide body is installed.

In the present invention, the piston valve is formed with a rod fixing groove having a predetermined depth into which the hollow rod is fitted in the center of the upper surface, and a coil chamfering groove having a predetermined depth is formed along the outer circumferential surface, between the rod fixing groove and the coil winding groove. An axisymmetric electromagnet solenoid core having a connection passage of a predetermined size; Solenoid is sealed by the injection molding in the wound state and mounted in the coil winding groove, one end of which is drawn through the connecting passage and electrically connected to the connector of the electric wire through the lower end of the hollow rod fitted in the rod fixing groove. A coil (Solenoid coil); A flux ring covering a gap at a predetermined interval from an outer circumferential surface of the electromagnet solenoid core; A through-hole is formed in the center of the hollow rod, and a plurality of orifices having a predetermined angular range are formed at an upper surface edge corresponding to a gap formed between an outer circumferential surface of the electromagnet solenoid core and an inner circumferential surface of the flux ring. An upper plate formed with; Coupled in close contact with the bottom surface of the electromagnet solenoid core, a plurality of orifices having a predetermined angle range at the upper surface edge corresponding to the gap formed between the outer circumferential surface of the electromagnet solenoid core and the inner circumferential surface of the flux ring A bottom plate formed; And a Teflon band fitted to the center of the outer circumferential surface of the flux ring.

In the present invention, the floating piston is formed in the shape of a disc having a predetermined diameter and height, and the piston body inserted into the injection core inserted into the circumferential surface; A diaphragm having a membrane shape integrally formed from an inner circumferential surface of the piston body and having a central portion curved upward; A wear ring installed to be wrapped around upper and lower portions of an outer circumferential surface of the piston body; And a seal formed annularly between the wear rings.

In the present invention, a separate cap is covered on the upper outer side of the cylinder, and a spring seat supporting the upper end of the spring is fixedly installed on a predetermined height of the outer circumferential surface of the cap, and is fixed to a predetermined height upward of the piston valve. The outer circumferential surface of the hollow rod corresponding to the spaced apart position has a feature that a rebound stopper is coupled to be bound downward when it collides with the rod guide at the maximum height of the tension stroke.

In the present invention, in the final assembly of the piston valve, the piston valve is inserted into a separate pedestal in the state coupled with the hollow rod and rotated in place, and the upper end and the lower end of the flux ring constituting the piston valve are in contact with the outer circumferential surface thereof. It is characterized in that it is configured to be bent inward by the rotation action of the roller rotated to.

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

1 is a perspective view showing a partial cross-sectional view showing a variable damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid according to the present invention, Figure 2 is a front sectional view of FIG.

3 is an enlarged perspective view showing a partial cross-sectional view of a hollow rod in the continuous damping force variable shock absorber of the vehicle suspension device according to the present invention, Figure 4 is a suspension device for a vehicle vehicle by the electromagnet solenoid according to the present invention An enlarged perspective view showing a partial cross section showing a rod guide in the continuous damping force variable shock absorber, Figure 5 is a front sectional view of FIG.

6 is an enlarged perspective view showing a partial cross-sectional view showing a piston valve in a continuous damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid according to the present invention, Figure 7 is a front sectional view of FIG. It is sectional drawing which shows the state which finishes assembly of a piston valve using a roller.

9 is an enlarged perspective view showing a partial cross-sectional view of the floating piston in the continuous damping force variable shock absorber of the suspension device for a vehicle by the electromagnet solenoid according to the present invention, Figure 10 is a front sectional view of FIG.

11 is an enlarged cross-sectional view showing the flow of the magneto-fluidic fluid and the operating state of the floating piston in the compression stroke of the piston valve in the continuous damping force variable shock absorber of the vehicle suspension system by the electromagnet solenoid according to the present invention, FIG. In the continuous damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid according to the present invention is an enlarged cross-sectional view showing the flow of magnetofluidic fluid and the operating state of the floating piston during the tension stroke of the piston valve.

Referring to this, the continuous damping force variable shock absorber 10 of the suspension device for a vehicle by the electromagnet solenoid according to the present invention is the apparent viscosity of the magnetic fluid fluid moved between the compression chamber and the tension chamber by the strength of the electromagnetic field formed by the electromagnet solenoid The damping force is variable according to the change of, the volume of the hollow rod during compression and tension stroke is quickly compensated by the action of the floating piston and diaphragm installed in the compression chamber to provide faster response and frictional force. This is to minimize the change.

To this end, the continuous damping force variable shock absorber 10 of the suspension device for a vehicle using an electromagnet solenoid according to the present invention is a cylindrical cylinder 20 having a predetermined size and a predetermined length fitted into the cylinder 20. Hollow rod 30, a rod guide 40 coupled to the upper inner side of the cylinder 20, a piston valve 50 installed at an inner end of the hollow rod 30, and the piston valve 50. It consists of a floating piston 60 is installed in the cylinder 20 corresponding to the bottom of the).

In the present invention, the interior of the cylinder 20 is divided into a compression chamber 21 and a tension chamber 22 by the piston valve 50 and the floating piston (60).

The compression chamber 21 and the tension chamber 22 are filled with a magnetic fluid 23, and a high pressure nitrogen gas 24 is provided inside the cylinder 20 corresponding to the lower portion of the floating piston 60. Is filled.

The cylinder 20 has a cylindrical shape having a predetermined diameter and length, the lower end of which is closed and the upper end is opened, and an annular fastening rib 25 is formed along the inner circumferential surface of the upper end.

In addition, a separate cap 20a may be covered on the outer side of the upper end of the cylinder 20 if necessary, and a spring seat that supports the upper end of the spring 20c at a predetermined height on the outer circumferential surface of the cap 20a. 20b) can be fixed and installed.

The hollow rod 30 is fitted to the inside of the cylinder from the upper outer side of the cylinder 20, the fastening screw portion 31 is formed on the outer peripheral surface of the upper end.

In addition, a cavity 32 having a predetermined diameter is formed in the hollow rod 30 along a longitudinal center line, and an electric wire 33 for supplying external power is provided in the cavity 32. It is fitted and installed.

The outer circumferential surface of the wire 33 is wrapped with an insulating material 34, the connector 35 is coupled to the lower end. The grommets seal 36 is installed around the connector 35 to prevent leakage.

On the other hand, the rod guide 40 is fitted inside the upper end of the cylinder 20 in order to guide the hollow rod 30 to move linearly while maintaining the correct straightness.

The rod guide 40 is a disk-shaped rod guide main body 41 having a predetermined diameter and height, and a magneto-fluid fluid buried on the outer surface of the hollow rod 30 by being fitted to the bottom surface of the rod guide main body 41. 23) The oil seal 42 to remove the oil to prevent leakage, the support plate 43 for supporting the oil seal 42, the oil leakage which is installed on the outer peripheral surface of the bushing 44 and the rod guide body 41 of the Teflon material It consists of a protective O-ring 45.

A coupling groove 46 into which an annular fastening rib 25 protrudes along the inner circumferential surface of the upper end of the cylinder 20 is formed at the upper end of the outer circumferential surface of the rod guide body 41, and the oil seal is upwardly from a bottom surface thereof. A storage groove 47 having a predetermined depth on which the 42 and the support plate 43 are seated is formed.

In addition, a rod insertion hole 48 into which the hollow rod 30 is fitted is formed at the center of the rod guide body 41, and a bushing 44 of Teflon material having excellent wear resistance is formed on an inner circumferential surface of the rod insertion hole 48. It is fitted and installed.

The oil seal 42 made of a rubber material has a through hole 42a into which the hollow rod 30 is fitted, and a center of the inner circumferential surface of the through hole 42a has a wedge shape protruding inward.

The support plate 43 is formed in a disc shape having a through hole 43a into which the hollow rod 30 is fitted at the center thereof, and is inserted into an accommodating groove 47 corresponding to the lower side of the oil seal 42 to seal the oil seal 42. It serves to support.

The edge of the support plate 43 is fixed without being separated downward as the bottom edge of the rod guide body 41 is bent.

The leakage preventing O-ring 45 serves to prevent the magnetic fluid 23 in the tension chamber 22 from leaking to the outside of the cylinder 20 during the tension stroke.

In the present invention, the piston valve 50 fixed and coupled to the inner end of the hollow rod 30 partitions the inside of the cylinder 20 into a lower compression chamber 21 and an upper tension chamber 22. The damping force is varied in such a way that the apparent viscosity of the magnetofluidic fluid 23 flowing between the compression chamber 21 and the tension chamber 22 is changed by generating an electromagnetic field during the tension stroke.

The piston valve 50 has an electromagnet solenoid core 51 formed in an axisymmetric type, a solenoid coil 52 provided on an outer circumferential surface of the electromagnet solenoid core 51, and a circumference of the electromagnet solenoid core 51. A flux ring 54 covered with a gap 53 at a predetermined interval, and an upper plate 55 and a lower plate 56 which are tightly coupled to the upper and lower surfaces of the electromagnet solenoid core 51; , Teflon band 57 is provided on the outer peripheral surface of the flux ring 54.

The electromagnet solenoid core 51 has a rod fixing groove 51a having a predetermined depth into which the lower end of the hollow rod 30 is fitted in the center of the upper surface thereof, and a coil groove groove 51b having a predetermined depth along the outer circumferential surface thereof. Is formed.

A connection passage 51c of a predetermined size is formed between the rod fixing groove 51a and the coil winding groove 51b.

The electromagnet solenoid core 51 is designed in an axisymmetric shape to minimize the magnetic losses, and to reduce the saturation of the magnetic flux density in the electromagnet solenoid core 51 in accordance with the induced power (Ampere × turns) The core 51 is constructed so that there is no hole in the center so that the cross-sectional area is maximized.

The solenoid coil 52 is configured to be mounted to the coil winding groove 51b after being sealed by an injection molded product in a wound state.

One end of the solenoid coil 52 is electrically connected to the connector 35 of the electric wire 33 through the lower end of the hollow rod 30 fitted through the connecting passage 51c and fitted into the rod fixing groove 51a. .

At this time, the (-) pole is drawn out through the connecting passage 51c in an insulated state by the injection molding, and then connected to the wire 33 inside the lower end of the hollow rod 30, and the (+) pole is the electromagnet solenoid core. 51 is grounded to itself.

The flux ring 54 is installed by covering a gap 53 at a predetermined interval from the outer circumferential surface of the electromagnet solenoid core 51.

The upper plate 55 is coupled in close contact with the upper surface of the electromagnet solenoid core 51, and a through hole 55a into which the hollow rod 30 is fitted is formed at the center thereof.

In addition, a plurality of orifices 55b (Orifice) having a predetermined angle range are formed at an upper surface edge corresponding to a position corresponding to the gap 53 formed between the outer circumferential surface of the electromagnet solenoid core 51 and the inner circumferential surface of the flux ring 54. Is formed.

Meanwhile, the lower plate 56 is coupled in close contact with the bottom surface of the electromagnet solenoid core 51 and coincides with the gap 53 formed between the outer circumferential surface of the electromagnet solenoid core 51 and the inner circumferential surface of the flux ring 54. A plurality of orifices 56a having a predetermined angle range are formed at an upper surface edge corresponding to the position.

The teflon band 57 is excellent in wear resistance, and is fitted in the center of the outer circumferential surface of the flux ring 54.

When the final assembly and fastening of the piston valve 50 is shown, as shown in FIG. 8, the piston valve 50 is inserted into a separate pedestal 80 in a state in which the piston valve 50 is coupled with the hollow rod 30 to rotate in place. At the same time, the upper and lower ends of the flux ring 54 are rotated inward by rotating the roller 81 in contact with the outer circumferential surface of the upper and lower ends of the flux ring 54 constituting the piston valve 50. Allow bending.

As such, the piston valve 50 is assembled and fastened by bending the upper end and the lower end of the flux ring 54 using the rotational force of the roller 81 while rotating the piston valve 50 coupled with the hollow rod 30 in place. In this case, it can be easily assembled with much smaller force than mold or press method, and it can be assembled and fastened precisely without tolerance of component dimension or cumulative error due to processing.

In the present invention, the floating piston 60 is coupled to slide in the up and down direction in the compression chamber 21 of the cylinder 20, and the volume compensation while sliding in a predetermined direction in accordance with the compression and tension stroke of the piston valve (50). It works.

The floating piston 60 is formed in a disc shape having a predetermined diameter and height, and the piston body 62 is inserted into the injection body 61 inserted into the circumferential surface as a basic component.

On the inner circumferential surface of the piston body 62, a diaphragm 63 having a membrane shape in which a central portion thereof is curved upward is integrally formed.

In addition, the upper and lower portions of the outer circumferential surface of the piston body 62 is provided so that the wear ring 64 is wrapped, and an annular seal 65 is formed between the wear rings 64.

On the other hand, in the present invention to the outer circumferential surface of the hollow rod 30 corresponding to the position spaced apart by a certain height upward of the piston valve 50 to be bound downward when colliding with the rod guide 40 at the maximum height of the tension stroke Rebound stopper 70 for fixing is installed.

The operation of the present invention made as described above is as follows.

1 to 12, the continuous damping force variable shock absorber 10 by the electromagnet solenoid according to the present invention is applied to the suspension of the vehicle wires inserted into the cavity 32 in the hollow rod 30 ( 33) As an external power source is applied to the solenoid coil 52 through an external electric field, an electromagnetic field directed inward to the outside between the solenoid coil 52 wound around the periphery of the electromagnet solenoid core 51 and the inner circumferential surface of the flux ring 54. Is formed.

 As the vehicle travels in such a state, as the shock and vibration transmitted from the road surface are transmitted to the cylinder 20, the hollow rod 30 and the piston valve 50 continuously repeat the compression stroke and the tension stroke.

In the compression stroke in which the hollow rod 30 and the piston valve 50 are moved to the compression chamber 21, as shown in FIG. 11, the magnetic fluid 23 in the compression chamber 21 is the piston valve 50. After entering the orifice 56a of the lower plate 56, the orifice on the upper plate 55 via the gap 53 formed between the outer circumferential surface of the electromagnet solenoid core 51 and the inner circumferential surface of the flux ring 54 55b) is moved into the tension chamber 22.

 In this way, the magnetic fluid 23 passes through the gap 53 between the electromagnet solenoid core 51 and the flux ring 54 and the orifices 55b and 56a formed on the upper and lower plates 55 and 56. When the apparent viscosity of the magnetofluid fluid 23 is changed by an electromagnetic field formed between the electromagnet solenoid core 51 and the flux ring 54, the damping is performed.

Further, in the tension stroke in which the hollow rod 30 and the piston valve 50 are moved to the tension chamber 22, as shown in FIG. 12, the magnetofluidic fluid 23 in the tension chamber 22 is a piston valve ( 50) flows into the orifice 55b of the upper plate 55 constituting the upper plate 55 on the lower plate 56 via a gap 53 formed between the outer circumferential surface of the electromagnet solenoid core 51 and the inner circumferential surface of the flux ring 54. It moves to the compression chamber 21 through the orifice 56a.

 In this manner, the magnetic fluid 23 passes through the gap 53 between the electromagnet solenoid core 51 and the flux ring 54 and the orifices 55b and 56a formed on the upper and lower plates 55 and 56. When the apparent viscosity of the magnetofluid fluid 23 is changed by an electromagnetic field formed between the electromagnet solenoid core 51 and the flux ring 54, the damping is performed.

On the other hand, the vibration is generated in the vertical direction according to the state of the road surface when the vehicle is running, and thus the volume compensation according to the vertical reciprocating movement of the hollow rod 30 and the piston valve 50 constituting the shock absorber is the cylinder 20 Compensated by the action of the floating piston 60 installed therein.

That is, when the volume change due to the entry and exit operation of the hollow rod 30 and the reciprocating movement of the piston valve 50 is insignificant, it is immediately compensated by the action of the diaphragm 63 constituting the floating piston 60. If the volume change is excessive, the floating piston 60 is to compensate for the pressure and the volume of the instantaneous change in a way that the entire floating piston (60).

The restoration of the diaphragm 63 constituting the floating piston 60 or the restoration of the floating piston 60 itself during the conversion from the compression stroke to the tension stroke is performed by the action of the high pressure nitrogen gas 24.

Meanwhile, as the vibration applied from the road surface increases, the width of the compression stroke and the tensile stroke increases. At the maximum end point of the tension stroke, the rebound stopper 70 installed at a predetermined height of the hollow rod 30 is provided with the rod guide 40. It collides with the lower part of the and then rebounds downward.

When the hollow rod 30 is moved in and out according to the compression and tension stroke, the magnetic fluid 23 buried on the surface of the hollow rod 30 is removed by the action of the oil seal 42 constituting the rod guide 40. It will not leak.

In addition, excessive pressure is formed inside the shock absorber in the course of the tension and compression stroke progressed by the up and down vibration transmitted from the road surface, and the leakage of the magnetofluidic fluid 23 may be expected, and in particular, to form an electromagnet solenoid Since the electric wire 33 is connected through the cavity 32 formed at the center of the rod 30, a phenomenon in which the magnetic fluid 23 may leak may occur.

However, in the present invention, as the grommet seal 36 is installed around the connector 35 formed at the lower end of the electric wire 33, leakage of oil is prevented.

 According to the present invention, the apparent viscosity of the magnetofluid fluid passing between the gap formed between the electromagnet solenoid core of the piston valve and the flux ring and the orifice on the upper and lower plates during compression and tension stroke is changed by the electromagnetic field. Therefore, the time response characteristic is very fast, less than 10ms.

In addition, since the floating piston has a double wear ring structure to smooth the diaphragm structure and sliding, the hollow rod volume is compensated faster according to the tension and compression stroke, resulting in faster mechanical time response and excessive volume change. In the floating piston itself, the volume compensation can be achieved by sliding, thereby minimizing the frictional force change.

In addition, when the cap type spring seat is additionally assembled, it can be made into a strut type. As the assembly and fastening of the piston valve are made by rolling the roller, the assembly is easy, Cumulative error can be eliminated.

Claims (7)

Cylindrical cylinder filled with magneto-fluidic fluid, Hollow rod (cavity) formed in the longitudinal direction of the cylinder, and Rod guide for guiding the hollow rod in the state coupled to the upper end of the cylinder And a piston valve fixed to an end of the hollow rod to partition the inside of the cylinder into a compression chamber and a tension chamber and generate an electromagnetic field to control the flow of the magnetic fluid, and slidably coupled to the compression chamber of the cylinder. A continuous damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid including a floating piston that performs a volume compensation action, The piston valve, a rod fixing groove is formed in the center of the upper surface coupled to the hollow rod is formed along the outer circumferential surface coil guiding groove and an electromagnet solenoid core (Solenoid core) is formed between the rod fixing groove and the coil winding groove And a solenoid coil mounted on the coil winding groove, one end of which is drawn out through the connecting passage and electrically connected to the connector of the electric wire through the lower end of the hollow rod, and from the outer circumferential surface of the electromagnet solenoid core. A flux ring is formed at a predetermined interval, and a through hole into which the hollow rod is fitted is formed to be tightly coupled to the upper surface of the electromagnet solenoid core, and is interposed between the outer circumferential surface of the electromagnet solenoid core and the inner circumferential surface of the flux ring. Upper part with orifice at the position coinciding with the formed gap On the lower plate of the orifice formed in a position in close contact with the plate, the bottom surface of the electromagnetic solenoid core and the gap formed between the outer peripheral surface of the electromagnet solenoid core and the inner peripheral surface of the flux ring, and the outer peripheral surface of the flux ring It is configured to include a Teflon band (Teflon band), the lower end of the rod fixing groove formed on the upper surface of the electromagnet solenoid core and the end of the hollow rod is formed so as not to reach the height of the top of the solenoid coil to the piston valve The through-hole through which the hollow rod penetrates is not formed in the center of the; The rod guide has a coupling groove into which a fastening rib protruding along the inner circumferential surface of the cylinder is fitted on an outer circumferential surface thereof, and a rod inserting hole into which a hollow rod is fitted into a central portion thereof, and a rod guide main body having an accommodating groove upward from a bottom surface thereof; The oil seal is inserted into the receiving groove formed in the rod guide main body and has a through hole formed at the center thereof, and is fixed to the bottom edge of the rod guide main body in the state of being fitted in the receiving groove corresponding to the lower side of the oil seal to support the oil seal. A plate and an O-ring fitted to the outer circumferential surface of the rod guide body; The flux ring which is covered on the outer circumferential surface of the piston valve is rotated by being inserted into a separate pedestal in the state that the hollow rod is coupled and rotated while the upper and lower ends of the flux ring are in contact with the outer circumferential surface thereof. A continuous damping force variable shock absorber of a suspension device for a vehicle by an electromagnet solenoid, characterized in that it is configured to be bent inward by action. delete delete delete delete delete delete

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