KR20210089457A - Shock absorber - Google Patents

Abstract

A shock absorber is disclosed. In accordance with an embodiment of the present invention, provided is a shock absorber comprising: a piston rod reciprocating inside a cylinder, and having a connecting passage formed on the outer circumferential surface thereof in a longitudinal direction; a piston valve mounted on the piston rod, having a compression passage and a tension passage penetrated therethrough, and dividing the cylinder into the compression chamber and the tension chamber; and a valve assembly mounted on the piston rod, and generating a damping force that changes in accordance with frequencies during a tensile course. The valve assemblies includes: a main retainer coupled to the piston rod, and having a main chamber formed therein to communicate with the connecting passage; a housing coupled to the piston rod, and having an internal space provided therein to communicate with the connecting passage; a pilot disk coupled to the piston rod, and dividing an inner space into a first pilot chamber and a second pilot chamber; and a pilot valve coupled to the piston rod, and provided between the pilot disk and the main retainer to partition the main chamber and the first pilot chamber. Therefore, the riding comfort and operating stability of a vehicle can be satisfied.

Description

Shock absorber {SHOCK ABSORBER}

The present invention relates to a shock absorber, and more particularly, to a shock absorber capable of simultaneously satisfying riding comfort and adjustment stability by implementing different damping forces for high and low frequencies during compression and tension strokes of a piston valve.

In general, a shock absorber is installed in a vehicle to improve riding comfort by buffering shock or vibration that an axle receives from a road surface during driving, and a shock absorber is used as one of such shock absorbers.

The shock absorber operates according to the vibration of the vehicle according to the road surface condition. At this time, the damping force generated by the shock absorber varies according to the operating speed of the shock absorber, that is, as the operating speed is fast or slow.

It is very important to control the damping force characteristics of the shock absorber when designing a vehicle because the ride comfort and driving stability of the vehicle can be controlled depending on how the damping force characteristics generated from the shock absorber are adjusted.

Such a shock absorber is typically a cylinder filled with a working fluid (oil), a piston rod connected to the body side to reciprocate, and a piston valve coupled to the lower end of the piston rod to slide in the cylinder and control the flow of the working fluid to provide

Since the piston valve is designed to have a constant damping characteristic at high speed, medium speed, and low speed using a single flow path, it may affect even the medium and high speed damping force when trying to improve riding comfort by lowering the low speed damping force. In addition, the conventional fast absorber has a structure in which the damping force changes according to the change in the speed of the piston regardless of the frequency or the stroke. As described above, the damping force that is changed only according to the change in the speed of the piston generates the same damping force in various road surface conditions, so it is difficult to satisfy both riding comfort and adjustment stability.

Accordingly, there is a need to continuously research and develop a valve structure for a shock absorber that can vary the damping force according to various road surface conditions, that is, the excitation frequency and stroke, so that the ride comfort and control stability of the vehicle can be simultaneously satisfied.

Japanese Public Utility Model Gazette Actual Publication Hei 5-36149 Patent Application No. 10-2011-0087171

This embodiment is to provide a shock absorber that can satisfy the ride comfort and control stability of the vehicle by installing a valve assembly together with a piston valve to generate a damping force that changes according to a change in frequency and speed.

The present embodiment intends to provide a shock absorber capable of preventing a decrease in the performance of adjustment stability by preventing a decrease in damping force in a low-speed section during a tensile stroke in a low-frequency region.

This embodiment aims to provide a shock absorber that reduces and simplifies the number of parts to reduce cost and improve mass productivity.

This embodiment aims to provide a shock absorber that can reduce the basic length of the product to improve the space utilization and secure the extended stroke.

According to an aspect of the present invention, the piston rod reciprocating inside the cylinder, the connecting flow path is recessed in the longitudinal direction on the outer circumferential surface; a piston valve mounted on the piston rod, the compression passage and the tension passage passing vertically, and partitioning the cylinder into a compression chamber and a tension chamber; and a valve assembly mounted on the piston rod and generating a damping force that changes according to a frequency during a tensile stroke, wherein the valve assembly is coupled to the piston rod and a main chamber communicating with the connection passage is formed. retainer; a housing coupled to the piston rod and having an inner space communicating with the connection passage; a pilot disk coupled to the piston rod and partitioning the inner space into a first pilot chamber and a second pilot chamber; and a pilot valve coupled to the piston rod and provided between the pilot disk and the main retainer to partition the main chamber and the first pilot chamber.

The valve assembly may further include a buffer member provided in the inner space and closely attached to the pilot disk to maintain a seal between the first pilot chamber and the second pilot chamber.

The housing includes a partition wall dividing the second pilot chamber up and down, and a plurality of internal flow passages formed through the partition wall, and the shock absorber is seated on the partition wall to support the pilot disk. can

The valve assembly may be provided with a shock absorber further comprising a spacer coupled to the piston rod and provided between the pilot disk and the pilot valve.

The spacer may be provided with a shock absorber having at least one slot for communicating the connection passage and the first pilot chamber.

The valve assembly may further include an inlet disk interposed between the spacer and the pilot valve and having at least one opening for communicating the connection passage and the first pilot chamber.

The main retainer includes a first seat portion protruding at regular intervals along an inner edge and a second seat portion protruding along an outer edge, and the main chamber is disposed between the first seat portion and the second seat portion. A shock absorber to be formed may be provided.

The main retainer may be provided with a shock absorber provided between the first seat portion and a main passage for communicating the connection passage and the main chamber.

The pilot valve may be provided with a shock absorber that is provided to be elastically deformable by a pressure difference between the main chamber and the first pilot chamber.

The pilot valve may be provided with a shock absorber including a body portion provided in the form of a disk, and a wing portion protruding along the outer edge of the body portion to be in close contact with the inner circumferential surface of the housing.

The valve assembly may be provided with a shock absorber further comprising an auxiliary disk coupled to the piston rod and in close contact with one side of the housing to open and close the second pilot chamber.

The auxiliary disk may be provided with a shock absorber comprising a disk-S in close contact with the housing and having at least one slit at an outer edge thereof, and a support disk in close contact with the disk-S to elastically support the disk-S. have.

The valve assembly may be provided with a shock absorber coupled to the piston rod and further comprising at least one disk interposed between the body portion and the main retainer.

Each of the at least one disk may be provided with a shock absorber provided with at least one inner slot at an inner edge thereof.

The pilot valve may be provided with a shock absorber elastically deformed in a direction in close contact with the main retainer during a low frequency stroke and elastically deformed in a direction spaced from the main retainer during a high frequency stroke.

The shock absorber according to an embodiment of the present invention has an effect that can satisfy the ride comfort and control stability of the vehicle by installing a valve assembly together with a piston valve to generate a damping force that changes according to a change in frequency and speed.

The shock absorber according to an embodiment of the present invention has an effect of preventing a decrease in the performance of adjustment stability by preventing a decrease in the damping force in the low-speed section during the tensile stroke in the low-frequency region.

The shock absorber according to an embodiment of the present invention has the effect of improving the riding comfort by generating damping force performance in the middle and high speed section during the tensile stroke in the high frequency region.

The shock absorber according to an embodiment of the present invention has the effect of reducing and simplifying the number of parts, thereby reducing cost and improving mass productivity.

The shock absorber according to an embodiment of the present invention has the effect of reducing the basic length of the product to improve the space utilization and secure the extension of the stroke.

1 is a cross-sectional view showing a shock absorber according to an embodiment of the present invention.
2 is an exploded perspective view illustrating a valve assembly provided in a shock absorber according to an embodiment of the present invention.
3 is a perspective view illustrating a main retainer of a shock absorber according to an embodiment of the present invention.
4 is a perspective view illustrating a spacer of a shock absorber according to an embodiment of the present invention.
5 is an operation diagram illustrating an operating state of a valve assembly during a low-frequency tensile stroke of a shock absorber according to an embodiment of the present invention.
6 is an enlarged view showing the operating state of the valve assembly during the low-frequency tension stroke of the shock absorber according to an embodiment of the present invention.
7 is an operation diagram illustrating an operating state of a valve assembly during a high-frequency tensile stroke of a shock absorber according to an embodiment of the present invention.
8 is an enlarged view showing the operating state of the valve assembly during the high-frequency tension stroke of the shock absorber according to an embodiment of the present invention.
9 is a graph for explaining a change in damping force using a shock absorber according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented in order to sufficiently convey the spirit of the present invention to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments presented herein and may be embodied in other forms. The drawings may omit the illustration of parts irrelevant to the description in order to clarify the present invention, and may slightly exaggerate the size of the components to help understanding.

Figure 1 is a cross-sectional view showing a shock absorber according to an embodiment of the present invention, Figure 2 is an exploded perspective view showing a valve assembly provided in the shock absorber according to an embodiment of the present invention, Figure 3 is an embodiment of the present invention A perspective view illustrating a main retainer of a shock absorber according to an example, and FIG. 4 is a perspective view illustrating a spacer of the shock absorber according to an embodiment of the present invention.

1 and 2, the shock absorber 1000 according to the present embodiment includes a piston rod 1100 that reciprocates inside the cylinder 100, and a piston valve 1200 mounted on the piston rod 1100, and and a valve assembly 1300 .

The cylinder 100 may have a cylindrical shape forming a space therein, and a working fluid (oil) is filled in the cylinder 100 . Here, the inside of the cylinder 100 may be divided into a compression chamber 110 and a tension chamber 120 by a piston valve 1200 to be described later.

One end of the piston rod 1100 is located inside the cylinder 100 , and the other end is extended to the outside of the cylinder 100 to be connected to the vehicle body side or the wheel side.

One end of the piston rod 1100 is provided with a mounting portion 1111 having a smaller radius by forming a step 1112 so that the piston valve 1200 and the valve assembly 1300 are easily mounted. At this time, a portion of the connection passage 1111 communicating with the tension chamber 120 may be provided in the form of a recess 1111b on the surface of the step 1112 , and the recess 1111b may be formed to be rounded.

An upper washer 210 , a piston valve 1200 , a valve assembly 1300 , and a lower washer 220 are coupled through the mounting portion 1111 of the piston rod 1100 and are sequentially assembled and fixed by a nut 230 . do. However, the mounting order may be reversed, and should be understood as the same.

At least one connection flow path 1111 is recessed in the outer peripheral surface of the piston rod 1100 in the longitudinal direction. At this time, a plurality of connection passages 1111 may be provided radially on the outer circumferential surface of the piston rod 1100 , or may be provided as a pair as shown in FIG. 2 .

The connection passage 1111 is recessed from the step 1112 to the portion where the auxiliary disk 1370 is mounted along the outer circumferential surface of the mounting part 1111 . That is, the connection passage 1111 may be formed of a groove 1111b formed on the surface of the step 1112 and a groove 1111a formed on the outer circumferential surface of the mounting part 1111 . Accordingly, the connection flow path 1111 may introduce the working fluid of the tension chamber 120 into the main chamber 1315 and/or the first pilot chamber 1322a and/or the second pilot chamber 1322b during the tension stroke. have. The structure in which the working fluid flows through the connection passage 1111 will be described again below.

The length of the connection passage 1111 can be changed according to the specifications of products such as the piston valve 1200 and the valve assembly 1300, and if the tension chamber 120 and the inside of the valve assembly 1300 communicate with each other, it should be understood in the same way. something to do.

The piston valve 1200 is provided to reciprocate inside the cylinder 100 filled with the working fluid together with the piston rod 1100 in a state in which the piston rod 1100 is coupled therethrough. In the piston valve 1200 , a plurality of compression passages 1210 and a plurality of tension passages 1220 penetrate vertically so that the working fluid moves during compression and tension strokes.

The piston valve 1200 generates a damping force due to the resistive force of the working fluid while reciprocating in the compression and tension stroke directions within the cylinder 100 .

For example, when the piston valve 1200 performs a compression stroke, the pressure of the lower compression chamber 110 is increased compared to the upper tension chamber 120 . In this process, the working fluid filled in the compression chamber 110 by the pressure increase of the compression chamber 110 moves to the tension chamber 120 while pushing the valve means through the compression passage 1210 of the piston valve 1200 to open it. do.

Conversely, when the piston valve 1200 performs a tension stroke, the pressure of the upper tension chamber 120 rises higher than that of the lower compression chamber 110, and in this process, the working fluid of the tension chamber 120 is It moves to the compression chamber 110 while pushing and opening the valve means through the tension passage 1220 .

The valve assembly 1300 is mounted to the piston rod 1100 to be disposed under the piston valve 1200 . The valve assembly 1300 may serve to generate a damping force that varies according to a frequency during a tensile stroke.

The valve assembly 1300 includes a housing 1330 having a main retainer 1310 in which a main chamber 1315 communicating with the connection passage 1111 is formed, and an internal space 1332 in communication with the connection passage 1111, and , a pilot disk 1350 dividing the inner space 1332 into a first pilot chamber 1322a and a second pilot chamber 1322b, and a main chamber 1315 provided between the pilot disk 1350 and the main retainer 1310 ) and a pilot valve 1320 partitioning the first pilot chamber 1322a.

1 and 3 , the main retainer 1310 is coupled to the piston rod 1100 and is disposed below the piston valve 1200 . In addition, the main retainer 1310 has an open lower portion and a main chamber 1315 is formed in the opened portion.

More specifically, as for the main retainer 1310 , the piston rod 1100 passes through the center, and the first sheet portion 1311 protruded at regular intervals along the inner edge and the main retainer 1310 are stepped from the outer edge of the main retainer 1310 . It includes a ring-shaped second sheet portion 1312 formed to protrude. In this case, the main chamber 1315 is formed between the first sheet part 1311 and the second sheet part 1312 .

The bottom surfaces of the first and second seat portions 1311 and 1312 are in contact with a disk or pilot valve 1320 positioned below. In addition, as the first seat portion 1311 is formed to protrude at regular intervals along the inner edge of the hollow main retainer 1310 by the piston rod 1100, a connection between the first seat portions 1311 spaced apart from each other A main flow passage 1313 communicating with the flow passage 1111 is provided.

A plurality of main flow paths 1313 may be provided in a radial direction, and the flow of the working fluid flowing from the connection flow path 1111 to the main chamber 1315 can be controlled according to the cross-sectional area and number of the main flow paths 1313 formed. and, ultimately, enables damping force control.

1 and 2 , the housing 1330 is coupled to the piston rod 1100 , and an internal space 1332 communicating with the connection passage 1111 is provided inside the housing 1330 . In this case, the inner space 1332 of the housing 1330 is divided into a first pilot chamber 1322a and a second pilot chamber 1322b by the pilot disk 1350 .

The housing 1330 is provided in a cylindrical shape through which the piston rod 1100 passes through the center, and a hollow inner space 1332 is provided, and the inner space 1332 is partitioned up and down by a partition wall 1331. have. In this case, the inner space 1332 may be provided with a larger space on the side of the pilot valve 1320 , that is, the upper space with respect to the partition wall 1331 .

In the housing 1330 , the height of the inner diameter portion may be lower than the height of the outer diameter portion to accommodate the pilot disk 1350 and the spacer 1360 , which will be described later.

At least one internal flow path 1333 penetrating vertically is provided in the partition wall 1331 . Also, the partition wall 1331 is provided in the second pilot chamber 1322b to vertically partition the second pilot chamber 1322b.

The pilot disk 1350 is provided in the form of a disk to which the piston rod 1100 is coupled through the center, and divides the inner space 1332 into a first pilot chamber 1322a and a second pilot chamber 1322b, and the inner space (1332) accepted.

The pilot disk 1350 may be made of an elastically deformable material, for example, made of steel. In addition, the pilot disk 1350 may have an inner edge interposed between the spacer 1360 and an inner diameter portion of the housing 1330 , and an outer edge interposed between the pilot valve 1320 and the buffer member 1340 . Accordingly, when the pilot valve 1320 is elastically deformed, the inner edge of the pilot disk 1350 is fixed and the outer edge is pressed to elastically deform.

The buffer member 1340 is in close contact with the bottom surface of the pilot disk 1350 to maintain the seal between the first pilot chamber 1322a and the second pilot chamber 1322b. At the same time, the buffer member 1340 may be seated on the partition wall 1331 to elastically support the pilot disk 1350 .

The buffer member 1340 is made of an elastically deformable material, and may be made of, for example, rubber or synthetic resin. In addition, the buffer member 1340 may be provided in a ring shape, and since the cross-sectional thickness is large, the outer diameter of the buffer member 1340 may be provided to correspond to the inner diameter of the inner space 1332 of the housing 1330 .

Preferably, the thickness of the buffer member 1340 is formed to be the same as the interval between the partition wall 1331 and the pilot disk 1350 .

The pilot valve 1320 is interposed between the main retainer 1310 and the housing 1330, and the upper and lower portions are in close contact with the main retainer 1310 and the housing 1330, respectively, so that the main chamber 1315 and the first pilot chamber ( 1322a) is partitioned.

The pilot valve 1320 is coupled to the piston rod 1100 through a body portion 1321 provided in the form of a disk, and a wing portion that is formed to protrude along the edge of the body portion 1321 and is in close contact with the inner circumferential surface of the housing 1330 . (1322). The body part 1321 and the wing part 1322 may be provided integrally, and may be made of rubber or synthetic resin to be elastically deformable. Accordingly, the wing part 1322 and/or the body part 1321 may be elastically deformed by a pressure difference according to the inflow amount of the working fluid flowing into the main chamber 1315 and the first pilot chamber 1322a, for example. It may be elastically deformed downward to press the pilot disk 1350 .

The valve assembly 1300 may further include a spacer 1360 and an inlet disk 1390 provided between the pilot disk 1350 and the pilot valve 1320 .

Referring to FIG. 4 , the spacer 1360 is provided in the form of a ring through which the piston rod 1100 is coupled through the center to maintain a gap between the pilot disk 1350 and the pilot valve 1320 . At the same time, the spacer 1360 includes at least one slot 1361 for communicating the connection passage 1111 and the first pilot chamber 1322a. In this case, a plurality of slots 1361 may be provided in a radial direction, and may be recessed in the bottom surface of the spacer 1360 . In addition, according to the cross-sectional area and number of slots 1361 formed, the flow of the working fluid flowing from the connection flow path 1111 to the first pilot chamber 1322a may be adjusted, which ultimately enables the damping force adjustment.

The inlet disk 1390 is coupled to the piston rod 1100 and interposed between the spacer 1360 and the pilot valve 1320, and at least one opening ( 1391) are provided. At this time, a plurality of openings 1391 may be provided in a radial direction, and the flow of the working fluid flowing from the connection passage 1111 to the first pilot chamber 1322a according to the cross-sectional area and number of the openings 1391 are formed. can be adjusted, which ultimately makes it possible to adjust the damping force.

In other words, according to the shape of the slot 1361 of the spacer 1360 and the opening 1391 of the inlet disk 1390, the flow of the working fluid flowing from the connection passage 1111 to the first pilot chamber 1322a is adjusted. can

The valve assembly 1300 may further include at least one disk 1380 coupled to the piston rod 1100 and interposed between the pilot valve 1320 and the main retainer 1310 and provided to be elastically deformable. Specifically, the disk 1380 is installed to adjust the elastic deformation coefficient of the pilot valve 1320, and the degree of elastic deformation of the pilot valve 1320 can be adjusted by increasing or decreasing the number of disks 1380 according to design requirements. have. In addition, at least one inner slot 1381 may be provided at an inner edge of each disk 1380 .

The valve assembly 1300 may further include an auxiliary disk 1370 coupled to the piston rod 1100 and in close contact with the lower side of the housing 1330 to open and close the second pilot chamber 1322b.

Specifically, the auxiliary disk 1370 is in close contact with the housing 1330 and is provided with at least one slit 1371a on the outer edge of the disk-S (1371), and the disk-S (1371) is a support disk in close contact with the lower end of the disk-S (1371). (1372). In this case, the slit 1371a may be formed in a T-shape along the outer edge of the disk-S 1371 .

The support disk 1372 may be provided with the same size as the disk-S 1380 , and while preventing the flow of the working fluid passing through the slit 1371a, the pressure of the second pilot chamber 1322b is excessive. When it rises, it is elastically deformed downward to relieve pressure.

Such a shock absorber 1000 is securely assembled by predetermined components so that the piston valve 1200 and the valve assembly 1300 move together with the piston rod 1100 to implement the damping force generation performance. As shown, the upper washer 210 is mounted on the piston rod 1100 on the upper part of the piston valve 1200, the valve assembly 1300 is mounted on the lower part of the piston valve 1200, and the valve assembly 1300 A lower washer 220 is mounted on the piston rod 1100 with the ring member interposed therebetween. In addition, a nut 230 is mounted on the lower portion of the lower washer 220 and is fastened to the piston rod 1100 . Accordingly, the piston valve 1200 and the valve assembly 1300 mounted on the piston rod 1100 maintain a tightly coupled state in the axial direction of the piston rod 1100 and may be provided to move together with the piston rod 1100. have.

Hereinafter, an operation state in which a damping force is generated according to the operation of the shock absorber according to an embodiment of the present invention will be described.

First, as described above, the piston valve 1200 has a compression passage 1210 and a tension passage 1220 in which the working fluid of the compression chamber 110 and the tension chamber 120 is formed in the piston valve 1200 during the compression and tension strokes. The damping force is generated by moving through the At this time, since the valve assembly 1300 has little effect on the damping force during the compression stroke, the operation of the valve assembly 1300 during the tension stroke will be described with reference to FIGS. 5 to 8 .

5 is an operation diagram illustrating the operation of the valve assembly during the low-frequency tensioning stroke of the shock absorber according to an embodiment of the present invention, and FIG. 6 is the operation of the valve assembly during the low-frequency tensioning stroke of the shock absorber according to an embodiment of the present invention. It is an enlarged view showing

5 and 6 , during the low frequency (large amplitude) tension stroke, the working fluid flows into the pilot chamber and the main chamber 1315 through the connection passage 1111 of the piston rod 1100 . That is, the working fluid flows into the first pilot chamber 1322a through the opening 1391 of the inlet disk 1390 and the slot 1361 of the spacer 1360 , and simultaneously flows through the main flow path 1313 of the main retainer 1310 . through the main chamber 1315 . At this time, as the piston rod 1100 operates at a low frequency, the working fluid may be smoothly introduced into the first pilot chamber 1322a through the opening 1391 and the slot 1361 . Accordingly, the pressure of the working fluid introduced into the first pilot chamber 1322a and the main chamber 1315 is balanced, so that the pilot valve 1320 or the disk 1380 is almost in contact with the lower portion of the main retainer 1310 . will keep That is, since the main chamber 1315 is closed or hardly opened during the low-frequency tensile stroke, the connection passage 1111 and the compression chamber 110 do not communicate smoothly.

On the other hand, when the pressure of the connection passage 1111 increases to a predetermined pressure or more as the inflow amount of the working fluid into the first pilot chamber 1322a and the main chamber 1315 increases, the auxiliary disk provided in the lower part of the housing 1330 As the 1370 elastically deforms, the working fluid may be discharged. More specifically, as the disk-S 1371 and the support disk 1372 are elastically deformed, pressure may be released through the second pilot chamber 1322b and the slit. Accordingly, it is possible to prevent a continuous increase in pressure inside the valve assembly 1300 such as the first pilot chamber 1322a, the main chamber 1315, and the second pilot chamber 1322b.

7 is an operation diagram illustrating the operation of the valve assembly during the high-frequency tensioning stroke of the shock absorber according to an embodiment of the present invention, and FIG. 8 is the operation of the valve assembly during the high-frequency tensioning stroke of the shock absorber according to an embodiment of the present invention. It is an enlarged view showing

7 and 8 , during a high frequency (small amplitude) tension stroke, the working fluid flows into the pilot chamber and the main chamber 1315 through the connection passage 1111 of the piston rod 1100 . At this time, an inflow resistance of the working fluid occurs due to the narrow cross-sectional area of the opening 1391 of the inlet disk 1390 and the slot 1361 of the spacer 1360 , and the inflow amount flowing into the first pilot chamber 1322a is reduced, so that the pressure ascent is limited. Accordingly, the pilot valve 1320 is elastically deformed due to a pressure difference (the pressure of the main chamber 1315 is greater than the pressure of the first pilot chamber 1322a) due to the inflow amount of the working fluid flowing into the main chamber 1315 . and is spaced apart from the upper portion of the main retainer 1310 or the disk 1380 to open the main chamber 1315 .

That is, the working fluid flowing into the main chamber 1315 during the high-frequency tensioning stroke flows into the compression chamber 110 while the pilot valve 1320 is opened toward the first pilot chamber 1322a, and ultimately, compared to the low-frequency tensioning stroke. damping force may be reduced.

Hereinafter, the damping force change according to the speed change of the shock absorber of the present invention will be described by dividing it into low frequency and high frequency cases.

9 is a graph showing the change in the damping force according to the speed change of the shock absorber according to the present invention.

Referring to FIG. 9 , in the shock absorber 1000 according to the present embodiment, the inflow amount and pressure of the working fluid passing through the connection passage according to the frequency during the tensile stroke into the first pilot chamber 1322a and the main chamber 1315 . By this change, a similar damping force is realized at low and high frequencies in the low-speed section, and the damping force is lowered at the high frequency in the middle-and high-speed section, so that it is possible to satisfy both ride comfort and steering stability.

Specifically, in the low-speed section, the damping force is prevented from lowering regardless of the frequency to prevent the deterioration of the vehicle's steering stability, and in the middle-speed section, the damping force is lowered only for high-frequency vibrations caused by foreign substances on the road surface, thereby improving the riding comfort of the vehicle. have.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

100: cylinder 110: compression chamber
120: tension chamber 210: upper washer
220: lower washer 230: nut
1000: shock absorber 1100: piston rod
1110: mounting part 1111: connection passage
1112: step 1200: piston valve
1210: compressed oil passage 1220: tension passage
1300: valve assembly 1310: main retainer
1311: first seat portion 1312: second seat portion
1313: main euro 1315: main chamber
1320: pilot valve 1321: body portion
1322: wings 1330: housing
1331: bulkhead 1332: interior space
1332a: first pilot chamber 1332b: second pilot chamber
1340: buffer member 1350: pilot disk
1360: spacer 1361: slot
1370: secondary disk 1380: disk
1390: inlet disk 1391: opening

Claims (15)

a piston rod reciprocating inside the cylinder and having a connection passage recessed in the outer circumferential surface in the longitudinal direction;
a piston valve mounted on the piston rod, the compression passage and the tension passage passing vertically, and partitioning the cylinder into a compression chamber and a tension chamber; and
A valve assembly mounted on the piston rod and generating a damping force that changes according to a frequency during a tensile stroke; includes,
the valve assembly
a main retainer coupled to the piston rod and having a main chamber communicating with the connection passage;
a housing coupled to the piston rod and having an inner space communicating with the connection passage;
a pilot disk coupled to the piston rod and partitioning the inner space into a first pilot chamber and a second pilot chamber; and
and a pilot valve coupled to the piston rod and provided between the pilot disk and the main retainer to partition the main chamber and the first pilot chamber. According to claim 1,
the valve assembly
and a buffer member provided in the inner space and closely attached to the pilot disk to maintain a seal between the first pilot chamber and the second pilot chamber. 3. The method of claim 2,
the housing is
a partition wall dividing the second pilot chamber up and down, and a plurality of internal flow paths penetrating through the partition wall;
The buffer member is
A shock absorber seated on the bulkhead to support the pilot disk. According to claim 1,
the valve assembly
and a spacer coupled to the piston rod and provided between the pilot disk and the pilot valve. 5. The method of claim 4,
The spacer is
A shock absorber having at least one slot for communicating the connection passage and the first pilot chamber. 6. The method of claim 5,
the valve assembly
and an inlet disk interposed between the spacer and the pilot valve and having at least one opening for communicating the connection passage and the first pilot chamber. According to claim 1,
The main retainer is
It includes a first sheet portion protruding at regular intervals along the inner edge, and a second sheet portion protruding along the outer edge,
The main chamber is
A shock absorber formed between the first sheet portion and the second sheet portion. 8. The method of claim 7,
The main retainer is
A shock absorber provided with a main flow path for communicating the connection flow path and the main chamber between the first sheet part. According to claim 1,
The pilot valve is
A shock absorber provided to be elastically deformable by a pressure difference between the main chamber and the first pilot chamber. 10. The method of claim 9,
The pilot valve is
A shock absorber comprising a body portion provided in the form of a disk, and a wing portion protruding along the outer edge of the body portion to be in close contact with the inner circumferential surface of the housing. 11. The method of claim 10,
the valve assembly
and an auxiliary disk coupled to the piston rod and in close contact with one side of the housing to open and close the second pilot chamber. 12. The method of claim 11,
The secondary disk is
A shock absorber comprising: a disk-S in close contact with the housing and having at least one slit at an outer edge thereof; and a support disk in close contact with the disk-S to elastically support the disk-S. 13. The method of claim 12,
the valve assembly
The shock absorber further comprising at least one disk coupled to the piston rod and interposed between the body portion and the main retainer. 14. The method of claim 13,
the at least one disk
A shock absorber each having at least one inner slot on the inner edge. According to claim 1,
The pilot valve is
A shock absorber elastically deformed in a direction in close contact with the main retainer during a low frequency stroke and elastically deformed in a direction spaced from the main retainer during a high frequency stroke.

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