KR20140028200A - Valve assembly of dual frequency sensitive type - Google Patents

Abstract

The present invention relates to a valve assembly in which the damping force is changed according to the frequency range of vibration or shock transmitted to the shock absorber or the flow rate of the working fluid when the vehicle is driven, and an embodiment of the present invention is coupled to the lower end of the piston rod in which the orifice hole is formed. A valve housing having a first space portion communicating with the orifice hole; A first frequency sensitive valve unit installed in the first space part and including a first free piston configured to vertically partition the first space part; An inner tube installed to penetrate the center of the first free piston and having a plurality of flow paths formed therethrough; And a second frequency sensitive valve unit installed in the second space part of the inner tube and configured to include a second free piston configured to vertically partition the second space part.

Description

VALVE ASSEMBLY OF DUAL FREQUENCY SENSITIVE TYPE

The present invention relates to a valve assembly, and more particularly, two frequency-sensitive valve units are provided in one valve housing so that the damping force varies depending on the frequency range of vibration or shock transmitted to the shock absorber or the flow rate of the working fluid. A dual frequency sensitive valve assembly configured.

In general, since the vehicle constantly receives vibrations or shocks from the road surface while the vehicle is running, a shock absorber is installed between the vehicle body and the axle to prevent shock or vibration from being transmitted directly to the vehicle body, thereby improving ride comfort. By suppressing irregular vibrations, driving stability is improved.

In this case, the suspension device is commonly referred to as the connection between the vehicle body and the axle including such a shock absorber, the device is a shock absorber for controlling the free vibration of the chassis spring, the shock absorber to control the free vibration of the chassis spring, And a stabilizer, rubber bushing, control arm, etc., to prevent rolling.

Among the suspension systems, shock absorbers, in particular, serve to suppress and attenuate vibrations from the road surface, and are mounted between the vehicle body or the frame and the wheels, and in particular, by absorbing the up and down vibration energy of the vehicle body, the vibration is suppressed and the riding comfort is improved. It also increases the service life by protecting the load and reducing the dynamic stress of each part of the body, and at the same time, restrains the movement of the mass under the spring to secure the tire's foldability and also suppresses the change of posture by the inertia force. Improve.

Therefore, the riding comfort and the adjustment stability can be appropriately adjusted according to the damping force characteristics of the shock absorber. That is, the damping force needs to be small in order to improve the riding comfort during normal driving of the vehicle, and the damping force needs to be large in order to improve the adjustment stability during rapid turning of the vehicle or during high speed driving.

1 shows a typical shock absorber.

As shown in FIG. 1, the shock absorber 1 has a cylinder 2 filled with a working fluid, and a piston rod 3 having one end inside the cylinder 2 and the other end extending out of the cylinder 2. And a piston valve 4 mounted on one end of the piston rod 3 to reciprocate in the cylinder 2.

At this time, the cylinder (2) may comprise an inner tube (2a) and the outer tube (2b), the inner tube (2a) by the piston valve (4) to the tension chamber (C1) and the compression chamber (C2) When the piston valve 4 reciprocates up and down within the cylinder 2, the working fluid is drawn from the tension chamber C1 through the orifice (not shown) formed in the piston valve 4 from the compression chamber C2. ), Or from the compression chamber C2 to the tension chamber C1 while generating a damping force.

By the way, the conventional shock absorber 1 comprised in this way generate | occur | produces a damping force using the pressure difference of the tension chamber C1 and the compression chamber C2 which generate | occur | produces according to the linear reciprocation motion of the piston rod 3 connected to the vehicle body. Since the piston rod 3 has a large moving stroke or a low damping force, an appropriate damping force can be generated to smoothly absorb vibration, but the piston rod 3 has a small moving stroke or a high frequency impact. There is a problem in the realm.

That is, for example, when a high amplitude vibration or shock with small amplitude and frequent vibration is applied, since the pressure difference generated in the tension chamber C1 and the compression chamber C2 is small, the operation of the piston valve 4 is not smooth. Appropriate damping forces cannot be obtained, and thus these vibrations are not absorbed completely and are transmitted to the occupant, which reduces the ride comfort.

Therefore, it is necessary to adjust the damping force according to the frequency difference as well as the input speed of the shock. For this purpose, a shock absorber additionally equipped with a frequency sensitive valve device in the lower part of the main valve unit for dividing the cylinder up and down is provided. It has been published in -1995-0011204 (patent document 1) etc.

However, in the case of the conventional shock absorber equipped with the frequency sensitive valve device, there is a disadvantage that there is no means for controlling the pressure generated in addition to the speed change in addition to the main valve unit.

In addition, in the conventional frequency sensitive valve device, springs are provided on both upper and lower sides of the free piston, and the variable flow path is opened and closed by lifting the free piston. However, in order to see a large effect in the high frequency region, the rigidity of the spring must be low. On the other hand, in order for the operability of the free piston to be made smoothly, the rigidity of the spring needs to be high, but there is a problem that it is difficult to simultaneously satisfy these requirements.

Patent Document 1: Korean Utility Model Publication No. 20-1995-0011204 (published 1 January 15, 1995)

The present invention has been made to solve the above problems, an embodiment of the present invention, a dual frequency sensitive valve assembly that provides different damping force characteristics for each frequency range of vibration or shock delivered to shock absorber; Related.

In addition, one embodiment of the present invention relates to a dual frequency sensitive valve assembly having three variable flow paths that operate in high, medium, and low frequency ranges for vibration or shock transmitted to a shock absorber.

In addition, one embodiment of the present invention relates to a dual frequency sensitive valve assembly capable of controlling the additional pressure generated by the speed change by providing a sub valve unit in addition to the pressure sensitive main valve unit.

In addition, one embodiment of the present invention relates to a dual frequency sensitive valve assembly capable of preventing spring friction noise in a frequency sensitive valve.

According to a preferred embodiment of the present invention, the valve housing is coupled to the lower end of the orifice hole formed piston rod, the first space portion in communication with the orifice hole formed therein; A first frequency sensitive valve unit installed in the first space part and including a first free piston configured to vertically partition the first space part; An inner tube installed to penetrate the center of the first free piston and having a plurality of flow paths formed therethrough; And a second frequency sensitive valve unit installed in the second space part in the inner tube and configured to include a second free piston configured to vertically partition the second space part.

Here, the sub-valve unit is coupled to the lower end of the first space portion, the compression orifice and the tension orifice is further formed.

At this time, the first variable flow path and the second variable flow path which are opened and closed by the lifting and lowering of the second free piston are formed on the outer circumferential surface of the inner tube to be spaced apart from each other up and down.

In addition, the first free piston is elastically supported by a pair of first springs respectively installed on both upper and lower sides, and the second free piston is elastically supported by a pair of second springs respectively provided on both the upper and lower sides.

In this case, it is preferable that the elastic coefficients of the first spring and the second spring are different from each other.

According to the dual frequency sensitive valve assembly according to the preferred embodiment of the present invention, the first frequency sensitive valve unit and the second frequency sensitive valve unit are provided together in the valve housing, thereby varying each of the high frequency, mid frequency, and low frequency ranges. By operating the flow path, the damping force characteristics are maximized and the riding comfort is improved.

In addition, since the pressure generated additionally according to the speed change can be controlled through the sub-valve unit, the riding comfort is improved.

In addition, by the application of the truncated coil spring, the spring friction noise in the frequency-sensitive valve is prevented, there is an effect that the sensitivity quality is improved.

1 is a cross-sectional view of a typical shock absorber.
Figure 2 is a cross-sectional view showing the mounting state of the dual frequency sensitive valve assembly according to an embodiment of the present invention.
Figure 3 is a cross-sectional view showing the operating state of the dual frequency sensitive valve assembly according to an embodiment of the present invention during high frequency input.
Figure 4 is a cross-sectional view showing the operating state of the dual frequency sensitive valve assembly according to an embodiment of the present invention when the medium frequency input.
5 is a cross-sectional view showing an operating state of a dual frequency sensitive valve assembly according to an embodiment of the present invention at a low frequency input.

Hereinafter, a preferred embodiment of a dual frequency sensitive valve assembly according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

In addition, the following examples are not intended to limit the scope of the present invention, but are merely illustrative of the zero component elements set forth in the claims of the present invention, and are included in the technical idea throughout the specification of the present invention and constitute the claims. Embodiments that include a substitutable component as an equivalent in the element may be included in the scope of the present invention.

Example

Figure 2 is a cross-sectional view showing the mounting state of the dual frequency sensitive valve assembly according to an embodiment of the present invention.

As shown in FIG. 2, the dual frequency sensitive valve assembly (hereinafter, 'valve assembly') 100 according to an embodiment of the present invention is coupled to the lower end of the piston rod 10, and the frequency sensitive valve unit ( 300 and 500 and the sub valve unit 600 are disposed up and down.

More specifically, the valve assembly 100 according to an embodiment of the present invention, the valve housing 200 coupled to the lower end of the piston rod 10, the first space portion 210 in the valve housing 200 It includes a first frequency sensitive valve unit 300 and the inner tube 400, the second frequency sensitive valve unit 500 is installed in the second space portion 410 in the inner tube 400, the valve housing ( It may further include a sub valve unit 600 coupled to the lower end of the first space portion 210 of the 200.

At this time, the main valve unit 700 is coupled to the outer circumferential surface of the piston rod 10 to be positioned above the valve assembly 100.

Here, the piston rod 10 is axially installed in the cylinder 20 filled with a working fluid such as oil, and reciprocates, and has an orifice hole (11) to communicate with the first space portion 210 of the valve housing 200. 11) is formed.

The main valve unit 700 has a valve body 710 whose outer circumferential surface is in close contact with the inner circumferential surface of the cylinder 20 so as to vertically divide the cylinder 20 into a tension chamber 21 and a compression chamber 22. A compression flow path 711 and a tension flow path 712 formed to penetrate the valve body 710 in the up and down direction, and a leaf valve 720 provided on the upper and lower surfaces of the valve body 710 to open and close the flow path, respectively. It is made to include.

In addition, the valve housing 200 is a cylindrical shape in which the first space portion 210 is formed therein, and the coupling hole 221 is coupled to the lower end of the piston rod 10 at the upper end by a press-fit or screw coupling method. Exciting coupling portion 220 is formed projecting, the lower end is open.

At this time, the outer circumferential surface of the valve housing 200 is coupled to the inner circumferential surface of the valve housing 200 by a press-fit method, and the like, so that the outer circumferential surface of the outer tube 230 and the inner circumferential surface of the valve housing 200 are in close contact with each other.

The first frequency sensitive valve unit 300 and the second frequency sensitive valve unit 500 are installed in the first space portion 210 of the valve housing 200, and the first frequency sensitive valve unit 300 is provided in the first space. A first free piston 310 for vertically dividing the portion 210 and a pair of first springs 320 interposed on the upper and lower sides of the first free piston 310 to elastically support the first free piston 310. ).

In this case, the first free piston 310 has a disc-shaped central portion 311 in which the through hole 311a is formed, an inclined portion 312 formed to be inclined upward and outward along the edge of the central portion 311, and an inclined portion. And a contact portion 313 protruding radially outward from the top of 312.

Here, the contact portion 313 is raised and lowered in close contact with the inner circumferential surface of the valve housing 200, or the inner circumferential surface of the outer tube 230, the ring-shaped solid on the outer circumferential surface of the contact portion 313 for abrasion prevention and sealing (sealing) The lubricant 314 is preferably coupled. At this time, a solid lubricant 314 such as teflon may be coupled to the coupling groove 313a formed in the circumferential direction on the outer circumferential surface of the contact portion 313.

In addition, the first spring 320 is made of a truncated coil spring having a wider width at the top than a width at the bottom to prevent noise from the impact or friction between the windings during extension and compression, and to secure additional free field. desirable.

In this case, the first spring 320 above the first free piston 310 has a wide upper end supported on the ceiling of the first space portion 210, and a narrow lower end supported on the upper side of the central portion 311. The first spring 320 under the first free piston 310 has a wide upper end supported on the bottom surface of the contact portion 313, and a narrow lower end supported on an upper side of the coupling pin 660 which will be described later. 1 Free piston 310 is stably supported at both the upper and lower sides.

Since the outer circumferential surface of the first free piston 310 is in close contact with the inner circumferential surface of the outer tube 230, the first free piston 310 partitions the first space portion 210 into the upper and lower chambers 211 and the lower chamber 212. As a result of the lifting and lowering of the 310, the low frequency variable channel 240 communicating with the loss 211 and the base 212 of the first space part 210 is opened and closed.

To this end, one side of the inner circumferential surface of the outer tube 230 is formed with a protrusion 231 protruding inward along the circumferential direction, the upper side and the lower side of the protrusion 231 is inclined outward to widen the first free piston 310, the outer circumferential surface of the contact portion 313 is initially in close contact with the protrusion 231 of the outer tube 230. On the other hand, it is also possible to form a protrusion 231 on the inner peripheral surface of the valve housing 200 without separately engaging the outer tube 230.

At this time, when a low-frequency shock having a large amplitude while driving the vehicle is transmitted to the shock absorber and the contact portion 313 of the first free piston 310 is out of the protrusion 231, the outer circumferential surface of the first free piston 310 and the outer tube ( The working fluid of the chamber 211 flows to the base 212 through the low frequency variable flow path 240, which is a gap generated between the inner circumferential surfaces of the 230, which will be described later with reference to FIG. 5.

The inner tube 400 is installed in the first space portion 210 so as to pass through the through hole 311a of the first free piston 310. At this time, the upper end of the inner tube 400 is supported along the outer edge of the coupling hole 221, the orifice hole 11 of the piston rod 10 to the second space portion 410 inside the inner tube 400 Communicate. In addition, the lower end of the inner tube 400 is supported on the upper side of the coupling pin 660, which will be described later, the first free piston 310 and the first spring 320 surrounds the outer circumferential surface of the inner tube 400 Will be achieved.

The second frequency sensitive valve unit 500 is installed in the second space portion 410 inside the inner tube 400, and the second free piston 510 of the disk shape to partition the second space portion 410 up and down; And a pair of second springs 520 interposed on both upper and lower sides of the second free piston 510 to elastically support the second free piston 510.

Here, the second free piston 510 is divided up and down the second space portion 410 by the outer peripheral surface is in close contact with the inner peripheral surface of the inner tube 400, hereinafter, the second space partitioned by the second free piston 510 An upper space of the unit 410 will be referred to as an 'upper chamber 411', and a lower space will be referred to as a 'lower chamber 412'.

At this time, the first variable flow path 420 and the second variable flow path 430 are formed through the outer peripheral surface of the inner tube 400 spaced apart from each other in the vertical direction. These variable flow paths 420 and 430 are opened and closed by lifting and lowering the second free piston 510 according to the frequency range of the shock or vibration inputted to the second space portion 410, so that the upper chamber 411 of the second space portion 410 is opened. ) Working fluid flows into the loss 211 of the first space portion 210, or the working fluid from the lower chamber 412 of the second space portion 410 into the base 212 of the first space portion 210. While the damping force is generated, this will be described later with reference to FIGS. 3 to 5.

The second spring 520 elastically supporting the second free piston 510 may have a smaller elastic modulus than the first spring 320 elastically supporting the first free piston 310. This is for the second frequency sensitive valve unit 500 to operate according to the frequency range of the shock or vibration, or to operate the first frequency sensitive valve unit 300 together with the second frequency sensitive valve unit 500. .

On the other hand, the sub-valve unit 600 is coupled to the lower end of the first space 210, the valve body 610, the tension orifice 621 and the compression orifice (through) formed in the vertical direction through the valve body 610 ( 622, a damping force is generated during the passage of the working fluid through these orifices 621, 622.

Here, the valve body 610 is coupled to the lower end of the first space portion 210 of the valve housing 200 by press fitting or screwing, and the compression orifice 622 on the upper side and the lower side of the valve body 610, respectively. And a multi-plate disc 630 for opening and closing the tension orifice 621 together with the retainer 640 and the washer 650. At this time, the multi-disc disk 630, retainer 640 and washer 650 is fixed to the valve body 610 by a coupling pin 660.

Hereinafter, the operating state of the dual frequency sensitive valve assembly 100 according to the frequency region of the shock or vibration will be described by taking the tension stroke as an example.

Figure 3 is a cross-sectional view showing an operating state of the dual frequency sensitive valve assembly according to an embodiment of the present invention at the time of high frequency input.

When the high frequency residual vibration with low amplitude is transmitted to the shock absorber while the vehicle is traveling, the upper stroke of the second space portion 410 through the orifice hole 11 is small since the operating stroke of the piston rod 10 is small. The flow rate of the working fluid flowing into 411 is also low.

Accordingly, the second free piston 510 slides in the inner tube 400 while the first variable flow path 420 is closed, and the working fluid of the lower chamber 412 passes through the second variable flow path 430. Flow to the basement 212.

At this time, after the working fluid flows through the orifice hole 11 into the upper chamber 411, the second free piston 510 is pressurized to elastically deform the second spring 520 and the lower chamber 412. Damping force is generated while the working fluid flows through the second variable flow path 430 to reduce residual vibration.

Figure 4 is a cross-sectional view showing the operating state of the dual frequency sensitive valve assembly according to an embodiment of the present invention when the medium frequency input.

When the middle frequency, which is a frequency range lower than the high frequency described above, is input while driving the vehicle, since the amplitude is larger than that of the high frequency input, the first variable flow path 420 is opened by the second free piston 510 as shown in FIG. 5. .

However, there is no opening of the low frequency variable flow path 240 (refer to FIG. 5) by the first free piston 310, and the first free piston 310 maintains close contact with the protrusion 231 of the outer tube 230. As it slides slightly, elastic deformation occurs in the first spring 320.

That is, as shown in FIG. 4, when a working fluid of a certain flow rate flows into the upper chamber 411 of the second space part 410 through the orifice hole 11 of the piston rod 10, the pressure is applied to the pressure. As a result, the second free piston 510 is lowered to open the first variable flow path 420.

When the working fluid flows from the upper chamber 411 into the upper chamber 211 through the open first variable flow path 420, the first free piston 310 slides due to the inflow pressure. 310 maintains the outer circumferential surface of the outer tube 230 in close contact with the protruding portion 231 of the outer tube 230, so that the low frequency variable channel 240 is not opened.

On the other hand, the damping force at this time is mainly affected by the elastic deformation of the first spring 320 due to the sliding of the first free piston 310, with the effect of reducing the residual vibration by the elastic deformation of the second spring (520) Since the elastic modulus of the first spring 320 is greater than the elastic modulus of the second spring 520, a larger damping force is generated than the high frequency input shown in FIG. 3.

5 is a cross-sectional view showing an operating state of a dual frequency sensitive valve assembly according to an embodiment of the present invention at a low frequency input.

If the low frequency vibration or instantaneous large shock transmitted to the shock absorber while driving the vehicle is transmitted to the shock absorber, the operating stroke of the piston rod 10 rises, and the sliding amount of the second free piston 510 also increases. do.

At this time, when the working fluid flows into the upper chamber 411 of the second space portion 410 through the orifice hole 11 of the piston rod 10, as shown in Figure 5, the pressure of the second free piston 510 is lowered to open the first variable passage 420, and the second variable passage 430 is closed by the second free piston 510.

The working fluid exiting the upper chamber 411 from the upper chamber 411 through the open first variable flow passage 420 presses down the first free piston 310 and lowers the outer peripheral surface of the first free piston 310. It flows to the base 212 through the low-frequency variable flow path 240 formed as a gap between the inner peripheral surface of the outer tube (230).

The working fluid flowing to the base 212 is pushed through the tension orifice 621 of the sub-valve unit 600 to the compression chamber 22 outside the valve housing 200 by pushing the multi-disc disk 630, in the process 감쇠 The damping force of the shock absorber increases, and the stability of the body behavior can be maximized.

That is, according to the dual frequency sensitive valve assembly 100 according to an embodiment of the present invention, it shows different attenuation characteristics according to the frequency (high frequency, medium frequency, low frequency) region of the vibration or shock transmitted to the shock absorber, As the shock absorber improves performance, the ride comfort of the vehicle is maximized.

100 valve assembly 200 valve housing
210: first space portion 230: outer tube
240: low frequency variable flow path 300: the first frequency response valve unit
310: first free piston 320: first spring
400: inner tube 410: second space part
420: first variable flow path 430: second variable flow path
500: second frequency sensitive valve unit 510: second free piston
520: second spring 600: sub-valve unit
700: main valve unit

Claims (5)

A valve housing coupled to a lower end of the piston rod having an orifice hole formed therein and having a first space portion communicating therewith;
A first frequency sensitive valve unit installed in the first space part and including a first free piston configured to vertically partition the first space part;
An inner tube installed to penetrate the center of the first free piston and having a plurality of flow paths formed therethrough; And
And a second frequency sensitive valve unit installed in the second space part of the inner tube and including a second free piston configured to vertically partition the second space part.
The method according to claim 1,
And a sub-valve unit coupled to a lower end of the first space and having a compression orifice and a tension orifice penetrating therethrough.
The method according to claim 1,
Dual frequency sensitive valve assembly, characterized in that the outer periphery of the inner tube, the first variable flow path and the second variable flow path which is opened and closed by the lifting of the second free piston is formed through the spaced apart from each other up and down.
The method according to claim 1,
The first free piston is elastically supported by a pair of first springs respectively installed on both upper and lower sides, and the second free piston is elastically supported by a pair of second springs respectively installed on both the upper and lower sides. Dual frequency sensitive valve assembly.
The method of claim 4,
Dual frequency sensitive valve assembly, characterized in that the elastic modulus of the first spring and the second spring are different from each other.

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