KR100808404B1 - Inserting Type Sensing Apparatus for Magneto-Rheological Continuous Damping Control Damper - Google Patents

Abstract

According to the present invention, a variable variable damping force using a magnetofluid fluid is provided in a continuous damping force variable damper using a magnetic fluid to improve durability of a sensing device for measuring a relative displacement between a body and an axle. It relates to a built-in sensing device of the type damper.

The present invention provides a piston valve for controlling a viscosity of the magnetofluid fluid by forming an electromagnetic field by a cylinder tube of a predetermined size containing a magnetofluidic fluid and a vertically reciprocating motion inside the cylinder tube, and by an externally applied power source. In the continuous damping force variable damper using a magnetic fluid comprising an assembly, coupled to the upper end of the piston valve assembly while being fitted into the cylinder tube, a non-magnetic metal plating of a predetermined material is formed at regular intervals on the outer peripheral surface Hollow piston rod and sinusoidal input coil having a predetermined length, which functions as a core of the displacement sensor, including a non-magnetic metal protective tube press-fitted into an iron rod and an outer circumferential surface of the iron rod to protect the non-magnetic metal plating , Cosine input coil and output coil While chwidoen is securely fixed to the upper portion of the cylinder tube, it characterized by consisting of, including a transformer for measuring the displacement of the piston rod of the hollow.

Damper, Magnetic Flow, MR, Displacement, Sensor, Copper Plating, Wear, Metal, Sheath

Description

Integrated Type Sensing Apparatus for Magneto-Rheological Continuous Damping Control Damper

1 is a perspective view showing a mechanism configuration of a built-in sensing device of a continuous damping force variable damper using a conventional magnetic fluid;

Figures 2a to 2e is a view for explaining the manufacturing process of the piston rod in the sensing device shown in Figure 1, respectively,

3A and 3B are schematic diagrams and coil connection diagrams of a built-in sensing device in a continuous damping force variable damper using a magnetorheological fluid of the present invention;

4A to 4D are views for explaining the manufacturing process of the piston rod in the sensing device of the variable damping force variable damper using the magnetic fluid of the present invention, respectively;

5A and 5B are cross-sectional views of a continuous damping force variable damper using a magnetofluidic fluid in which the sensing device of the present invention is incorporated, respectively, and a cross-sectional view of a conventional type and a semi-strut type;

6A and 6B are a perspective view and a partially cutaway perspective view of a transformer portion in a built-in sensing device of a continuous damping force variable damper using the magnetic fluid of the present invention, respectively;

7A and 7B are an external perspective view and a cross-sectional view of a transformer portion in a built-in sensing device of a continuous damping force variable damper using the magnetofluidic fluid of the present invention, respectively.

8 is an electrical control block diagram of a continuous damping force variable damper using a magnetic fluid with a built-in sensing device of the present invention;

9 is a waveform diagram of an essential part of the sensing device shown in FIG. 8;

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

10, 110: transformer, 11: sinusoidal input coil,

12: cosine wave input coil, 13: output coil,

14: housing, 15: copper plate,

16: separating disc, 17: PCB,

18: bobbin, 19: cover

20, 120: piston rod, 21: steel rod,

21a: groove, 22: copper plating,

23: special surface treatment, 24: metal protective tube,

24a: welded portion, 24b: rolling portion,

25: abrasive tools, 30, 130: rod guide assembly,

40, 140: cylinder tube, 42, 142: tension chamber,

44, 144: compression chamber, 46, 146: volume compensation chamber,

50, 150: piston valve assembly, 60, 160: piston flotation assembly,

200: sinusoidal-square wave conversion circuit, 210: phase comparator,

220: output wave-to-distance conversion circuit, 230: microprocessor,

240: external interface

The present invention relates to a built-in sensing device of a variable damping variable damper using a magnetofluidic fluid, in particular a displacement (garage) is built into the continuous damping variable variable damper using a magnetic fluid that can be adopted in the electronically controlled suspension of the vehicle The present invention relates to a built-in sensing device of a continuous damping force variable damper using a magnetic fluid fluid having improved durability.

In general, a damper (Damper) is a device for damping the vibration or shock applied from the outside is used in various industries, including vehicle suspension system. For example, a damper used in a vehicle suspension system is installed between the vehicle body and the wheel to absorb vibrations or shocks received from the road surface while driving to prevent damage to the vehicle body or cargo and improve ride comfort.

The components that make up the electronically controlled suspension system of a conventional vehicle are mainly composed of an electronic control unit (ECU), a gravity sensor (G-sensor) and a height (height) sensor, a variable damper of continuous damping force by a hydraulic solenoid valve, and these parts electrically. It consists of a connecting cable. However, hydraulic solenoid valve type dampers perform better than discrete dampers with variable damping force driven by passive dampers or step motors using oil or gas, but are still priced by consumers due to their slow time response characteristics. It did not provide satisfactory performance quality.

 Thus, continuous damping control (hereinafter simply referred to as 'CDC') dampers have emerged using highly functional magnetofluidic fluids that respond faster to vibrations transmitted from the road surface. Here, a magneto-rhetic fluid (hereinafter simply referred to as 'MR') fluid refers to a synthetic oil containing suspended magnetized particles, and a damper using such MR fluid has an apparent viscosity when the MR fluid passes through a magnetic field. Is to take advantage of the phenomenon that increases. That is, when the MR fluid flows into the magnetic field formed by the solenoid, the magnetized particles dispersed in the MR fluid are arranged in a chain structure under the influence of the magnetic field, and thus the damping increases as the yield shear stress of the fluid increases. . Therefore, the damper using the MR fluid can freely control the apparent viscosity and attenuation of the fluid by arbitrarily changing the strength of the magnetic field. Therefore, the CDC damper using such MR fluid can be preferably used in an electronically controlled suspension system.

Meanwhile, various types of sensors are used in the electronically controlled suspension system to grasp the behavior of the vehicle. Among them, the height sensor that detects the relative displacement of the vehicle body and the axle to determine the height of the vehicle body indirectly measures the relative displacement in the structure where the vehicle body and the axle link are respectively connected from the outside. In this case, in the installation of the garage sensor in a conventional vehicle, not only there are limitations to consider the physical positioning and the interference between the structures, but also because the garage sensor is exposed to the external environment, there are many disadvantages in the durability of the sensor itself. In addition, the nonlinear error of the link should be compensated for in calculating the signal received from the height sensor as the relative displacement between the body and the axle.

Among the displacement sensors that can be used as garage sensors, the types and advantages and disadvantages of sensors that can be mounted on dampers are as follows. (1) LVDT: There is a limit to the long stroke because the length of the coil part must be increased to detect the long distance by the position detection method by the correlation between the primary coil and the secondary coil. There is a possibility of noise problems. (2) Magnet scale: As the magnetic material must be planted in the piston rod, the cost is excessively increased, and therefore, mass production is difficult. (3) Optical scale: It is possible to secure high resolution and precision, but it is vulnerable to noise and difficult to apply to dampers in shape.

In view of this, the present applicant has proposed a built-in sensing device. FIG. 1 is a perspective view illustrating a mechanism configuration of a built-in sensing device of a continuous damping force variable damper using such a conventional magnetic fluid, and FIGS. 2A to 2E are respectively shown in FIG. 1. It is a figure for demonstrating the manufacturing process of a piston rod in the sensing apparatus shown in FIG. First, as shown in FIG. 1, in the conventional sensing device, unlike the general displacement sensor, the core 20 in which copper plating 22 is inserted into the steel rod 21 at regular intervals is used, and the wear resistance thereof is guaranteed. In order to treat the surface of the copper rod (21) plated copper (22) is a special surface treatment. And in manufacturing this, first, as shown in Figure 2a, the steel bar 21 is cut to a suitable length, and again, as shown in Figure 2b performs the necessary both ends, roughing and finishing. Next, as shown in FIG. 2C. After processing a plurality of grooves 21a on which copper (copper) is to be plated at an outer diameter at predetermined intervals, copper plating 22 is performed as shown in FIG. 2D. As shown in FIG. 2E, a special surface treatment 23 is performed.

However, according to the conventional sensing device of the continuous damping force variable damper using the above-described magnetofluidic fluid, even if a special surface treatment is applied to the piston rod, the specially treated surface may be peeled off due to vibration, and thus copper plating There was a problem that the durability is not good, such as the area is worn out.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is incorporated in a continuous damping force variable damper using magnetofluidic fluid and is a non-linearity in a measurement result of a sensing device for measuring a relative displacement between a body and an axle. It is an object of the present invention to provide a built-in sensing device of a continuous damping force variable damper using a magnetofluidic fluid that can reduce the number of elements and improve durability.

The present invention for achieving the above object is a cylinder tube of a predetermined size containing a magnetofluidic fluid and the reciprocating motion up and down inside the cylinder tube and form an electromagnetic field by the power applied from the outside to form the magnetofluidic fluid A variable damping force variable damper using a magneto-fluidic fluid comprising a piston valve assembly for controlling the viscosity of the piston, which is coupled to the upper end of the piston valve assembly while being fitted into the cylinder tube, the predetermined material at regular intervals on the outer peripheral surface A hollow piston rod having a predetermined length that serves as a core of the displacement sensor, including a non-magnetic metal plate formed with a non-magnetic metal plate and a non-magnetic metal protective tube press-fitted to an outer circumferential surface of the iron rod to protect the non-magnetic metal plating And sine wave input coil, Yeo Hyun (Cos) while the input coil and the output coil is wound is fixed to the upper portion of the cylinder tube, characterized by consisting of, including a transformer for measuring the displacement of the piston rod of the hollow.

Hereinafter, with reference to the accompanying drawings it will be described in detail the built-in sensing device of the sensor built-in continuous damping variable variable damper using a magnetic fluid according to a preferred embodiment of the present invention.

3A and 3B are schematic diagrams and coil connection diagrams of a built-in sensing device in a continuous damping force variable damper using a magnetorheological fluid of the present invention. As shown in FIG. 3, according to the sensing device of the present invention, a sinusoidal input coil 11 is included in a core 20 of copper plating 22, that is, a circular transformer 10 in which a piston rod is inserted and moved. Cosine input coil 12 and output coil 13 are wound to detect phase change in induced electromotive force generated when copper-plated 22 passes through transformer 10. The change in distance is calculated based on the phase difference. That is, the core 20 passing through the transformer 10 in a state where a sinusoidal sin and a cosine wave are respectively applied to the sinusoidal input coil 11 and the cosine wave input coil 12 wound on the transformer 10. Change the position of. Then, the output waveform of the output coil 13 generated by the positional change of the core 20 becomes a waveform having a phase corresponding to the middle of the sin or cosine wave. The reason why the output waveform is changed is that the copper core 20 is plated with copper having different transmittances at regular intervals.

Figures 4a to 4d is a view for explaining the manufacturing process of the piston rod in the sensing device of the variable damping force variable damper using the magnetic fluid of the present invention, respectively. In manufacturing a piston rod in a built-in sensing device of a variable damping force variable damper using a magnetofluidic fluid of the present invention, as shown in FIG. 4A, first, a steel rod 21 in which copper plating 22 is completed by the process of FIG. 2D is completed. Metal protective tube 24 to be inserted to the outside of the), preferably STS304 stainless steel pipe, which is a non-magnetic material is manufactured to a predetermined length by the tubing or drawing. Next, as shown in FIG. 4B, the metal protective tube 24 manufactured as described above is forcibly inserted, that is, press-fitted into the outside of the steel rod 21 manufactured by the process of FIG. 2D, and again shown in FIG. 4C. In order to maintain the seal, the lower end of the metal protection tube 24 is welded to the steel rod 21, preferably argon welding 24a, and the upper part is rolled 24b for firm bonding and finishing. Finally, the surface of the metal protective tube 24 thus bonded is polished by the polishing tool 25 to complete its manufacture.

On the other hand, the important design factor of the piston rod is a continuous cycle interval and plating depth between the magnetic rod 21 and the non-magnetic copper plating (22), the size and shape of the induction waveform depending on the design factor. For example, if the periodic interval is wider, the generation of the induced waveform is better but the accuracy of the sensor is lowered. On the contrary, if the periodic interval is narrowed, the voltage of the induced waveform is smaller but the accuracy of the sensor is improved.

5A and 5B are cross-sectional views of a continuous damping force variable damper using a magnetofluidic fluid in which a sensing device of the present invention is incorporated, respectively, as a cross-sectional view of a conventional type and a semi-strut type. FIG. 5A shows a conventional type, and FIG. 5B shows a semi-strut type, which is a built-in sensing device manufactured by the process of FIG. 4D as a displacement (garage) sensor. In FIG. 5, reference numerals 40 and 140 denote cylinder tubes of a predetermined size, respectively, and 20 and 120 serve as cores of the displacement sensor, respectively, inserted into the cylinder tubes 40 and 140, respectively, and copper plating is periodically inserted. And a piston rod having a metal protection tube inserted in the outside thereof, and 10 and 110 are transformers in which the sine wave input coil 11, the cosine wave input coil 12, and the output coil 13 are wound, respectively, in the displacement sensor. Is a rod guide assembly coupled to the upper inside of the cylinder tubes 40 and 140 to guide the piston rods 20 and 120, respectively, and 50 and 150 are the lower ends of the piston rods 20 and 120, respectively. A piston valve assembly coupled to the piston valve for reciprocating up and down in the interior of the cylinder tubes 40 and 140, and 60 and 160 are respectively installed in the lower side of the cylinder tubes 40 and 140, respectively. Floating Pis that Supports 150 Flexiblely ton assembly).

In the above-described configuration, the piston rod 20, 120 is made of a hollow hollow rod so that the (+) (-) wire for applying electricity to the solenoid coil to be described later can pass through. Further, the transformer 10, 110 is preferably fixed to the upper portion of the rod guide assembly 30, 130, respectively. On the other hand, the interior of the cylinder tube 40, 140, the upper tension chamber 42, 142 and the lower compression chamber 44, 144 around the piston valve assembly 50, 150, respectively The tension chambers 42 and 142 and the compression chambers 44 and 144 are filled with a magnetorheological fluid containing floating magnetized particles. In the drawings, reference numerals 46 and 146 denote volumetric chambers formed by the piston support assemblies 60, 160.

6A and 6B are respectively a perspective view and a partially cutaway perspective view of a transformer portion in a built-in sensing device of a variable damping force variable damper using the magneto-fluidic fluid of the present invention, and FIGS. 7A and 7B are respectively views of the magneto-fluidic fluid of the present invention. In the built-in sensing device of the continuous damping force variable damper, a perspective view and a cross-sectional view of a transformer part are given, for convenience, the reference type is given by taking the conventional type damper shown in FIG. 5A as an example. In the sensing device of the present invention, the transformer 10 is wound around the sinusoidal and cosine wave input coils and the output coils at regular intervals to form an induction waveform according to the magnetic flux.

Specifically, in the sensing device of the present invention, as shown in FIGS. 6 and 7, the transformer 10 may be, for example, a total of four sets of primary coils wound around the bobbin 18 in and out, that is, It comprises two sets of sine wave input coils 11, two sets of cosine wave input coils 12, and a total of four sets of secondary coils, that is, output coils 13 wound thereon. Furthermore, a non-magnetic copper plate 15 is interposed between the primary coils 11, 12 and the secondary coils 13, and a thin separating disk 16 is interposed between each pair of coils. These are all secured to the top of the rod guide assembly 30 of the damper by the cover 19, all embedded in the housing 14.

Meanwhile, since the transformer 10 shown in FIGS. 6 and 7 is mounted inside the suspension system, the outer diameter and thickness of the input coils 11 and 12 and the output coil 13 may be limited depending on the size of the suspension system. Will receive. Therefore, it is necessary to select an appropriate outer diameter and thickness of the transformer 10 after using the number of turns of each coil and the shape dimension to obtain the required output as the limiting factor. Furthermore, the transformer 10 may be manufactured in a bobbin type and a bobbinless type without a bobbin. In the case of the bobbin type, the bobbin mold should be added separately, but the assembly is easy, while in the case of the bobbinless type, the component can be reduced. However, there are also wiring difficulties in final assembly of the transformer.

8 is an electrical control configuration diagram of a continuous damping force variable damper using a magnetic fluid in which the built-in sensing device of the present invention is incorporated. As shown in FIG. 8, the electrical configuration of the variable damping force variable damper using the magnetic fluid having the sensing device according to the present invention includes the sine wave input coil 11, the cosine wave input coil 12, and the output coil ( A transformer 10 having a 13) and a copper plating 22 are periodically installed and a piston rod 20 moving through the transformer 10, a sinusoidal input coil 11, a cosine wave input coil 12. And a sine wave and an output wave for a sine wave as a reference among the sine wave-square wave conversion circuit 200 and the sine wave-square wave conversion circuit 200 for converting the waveform of the output coil 13 into corresponding square waves, respectively. A phase comparator 210 that calculates displacement within a period of copper plating 22, that is, a movement distance by comparing phases between square waves with respect to the output wave, and an output wave-to-distance conversion circuit 220 that calculates the total movement distance of the sensor device from the output wave. , Phase Gyoki 210 and the output wave-converts the data output from the distance transform circuit 220 to the physical distance from the external interface circuit 240 may comprise a microprocessor 230 for an output to the outside.

Meanwhile, in order to apply the sensing device of the present invention to an automobile damper, the geometric information of the damper, that is, the measuring range of the sensing device, the frequency of the sinusoidal and cosine wave inputs 11 and 12, the input frequency ), The pitch of the copper plating 22, the carrier frequency, the diameter of the piston rod, the seating portion of the sensing device and its inner diameter, and the like.

FIG. 9 is a waveform diagram of an essential part of the sensing device shown in FIG. 8. In FIG. 9, signals A and B represent sinusoidal sin and cosine signals, which are input signals applied to the sinusoidal input coil 11 and the cosine wave input coil 12, respectively. There is also a phase difference. The signal C represents a signal guided to the piston rod 20. When the signals A, B, and C are converted by the sinusoidal-square wave conversion circuit 200, respectively, the signals D, E, and F become the same.

On the other hand, when the signal D and the signal F pass through an exclusive OR circuit (not shown) inside the phase comparator 210, the signal G comes out, which is the pulse width of the signal G when the piston rod 20 moves. The change is proportional to the moving distance. Next, the signal H is a reference square wave clock signal that divides the frequency, and is generated in an oscillator (not shown) of 50 MHz, for example, and the signal G and the clock signal H are ANDed in the phase comparator 210. Passing through a circuit (not shown) results in signal I. Since the width of the signal I varies with the characteristics of the signal G, it is represented by the multiple of the reference square wave clock signal. Therefore, the signal I periodically outputs is counted by a counter (not shown) inside the phase comparator 210 and transmitted to the microprocessor 230 so that the microprocessor 230 transmits it to the actual moving distance (displacement) within the copper plating 22 cycle. Convert. The microprocessor 230 also calculates the actual moving distance, i.e., the total moving distance, out of the period of copper plating 22 of the sensing device by the data calculated by the output wave-to-distance conversion circuit 220.

5A and 5B, the flow mechanism of the piston valve assembly 50 and 150 while the continuous damping force variable damper using the magnetic fluid in which the sensing device of the present invention is incorporated proceeds in tension and compression stroke. This is as follows. First, magnetofluidic fluid moving from compression chambers 44 and 144 to tension chambers 42 and 142 during the compression stroke is introduced into the annular orifice between the solenoid core (not shown) and the flux ring (not shown). As it passes through the annular orifice, an electromagnetic field is instantaneously formed, resulting in attenuation as the apparent viscosity of the fluid changes.

As described above, in the conventional hydraulic damper, the fluid passing through the annular orifice is controlled by various spring constants. In the damper of the continuous damping force variable by the solenoid of the present invention, the viscosity of the fluid passing through the annular orifice is controlled by the strength of the magnetic field. To control. The same principle of operation applies in tension strokes.

The sensing device for the continuous damping force variable damper using the magneto-fluidic fluid of the present invention can be implemented in various modifications within the range allowed by the technical idea of the present invention without being limited to the above-described embodiment. For example, instead of copper plating the piston rod, it is also possible to plate materials of different electrical conductivity and non-magnetic material for iron such as gold or silver.

According to the sensing device of the continuous damping force variable damper using the magneto-fluidic fluid of the present invention as described above, the piston rod surface by protecting copper plating periodically provided on the piston rod surface of the sensing device by a metal protective tube such as stainless pipe Wear resistance and surface hardness can be secured, and the durability of the sensing device can be improved.

Furthermore, by adopting a method of forcibly injecting a stainless pipe into the piston rod of the sensing device, it is possible to reduce environmental pollution by heavy metals that may be generated by special treatment of the conventional piston rod surface, and to simplify the manufacturing process of the piston rod. .

Claims (6)

Magnetic cylinder comprising a cylinder tube containing a magnetofluidic fluid and a piston valve assembly for reciprocating up and down inside the cylinder tube and forming an electromagnetic field by a power source applied from the outside to control the viscosity of the magnetofluidic fluid. In the built-in sensing device of the continuous damping force variable damper using a fluid fluid, A non-magnetic metal plate that is coupled to an upper end of the piston valve assembly while being inserted into the cylinder tube, and is pressed into an outer circumferential surface of the steel rod and a steel rod having a non-magnetic metal plating formed thereon at a predetermined interval on an outer circumferential surface thereof to protect the non-magnetic metal plating Hollow piston rod of predetermined length including the metal protective tube of the adult and serving as the core of the displacement sensor; A transformer comprising a sinusoidal input coil, a cosine input coil, and an output coil fixedly mounted on an upper portion of the cylinder tube to measure a displacement of the hollow piston rod. Built-in sensing device of continuous damping force variable damper using flowable fluid. The method of claim 1, wherein the non-magnetic metal plating is copper plating, a continuous damping variable variable damper built-in sensing device using a magnetic fluid, characterized in that the copper plating. According to claim 1, wherein the non-magnetic metal protective tube is a built-in sensing device of a continuous damping force variable damper using a magnetic fluid, characterized in that the stainless pipe. The apparatus of claim 2, wherein the copper plating is performed in grooves formed at regular intervals on an outer diameter of the hollow piston rod. 4. According to claim 1 or 3, wherein the lower end of the non-magnetic metal protective tube is welded and sealed to the steel rod, the upper portion of the non-magnetic metal protective tube is a continuous damping force variable using a magnetic fluid, characterized in that the rolling finish Built-in sensing device of the type damper. The method of claim 1, wherein the transformer, Protective housing; A bobbin installed in the housing; Two pairs of the sine wave input coils and the cosine wave input coils wound inside and outside the bobbin; A total of four sets of the output coils wound on the upper side of the bobbin; A copper plate interposed between the sine wave input coil and the cosine wave input coil and the output coil; Built-in sensing device of a continuous damping force variable damper using a magnetic fluid, characterized in that it comprises a separating disk interposed between the coil of each set.

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