shock absorber

Abstract

A shock absorber is disclosed. According to an aspect of the present application, a shock absorber can be provided, which includes a cylinder filled with fluid and a piston valve coupled to an end of a piston rod to divide an inner portion of the cylinder into a stretch chamber and a compression chamber, wherein the shock absorber further includes a support member coupled to an end of the cylinder and provided with a connection flow path, a first guide member forming a first pressurization chamber and provided with a first flow path formed to penetrate the first guide member in an up-down direction, a second guide member forming a second pressurization chamber and provided with a second flow path connecting the second pressurization chamber and the compression chamber, an opening and closing member coupled to a lower end of the piston valve and capable of pressurizing the second guide member when the piston rod descends, a first elastic member provided between the first guide member and the support member, and a second elastic member provided between the first guide member and the second guide member.

Description

Technical Field

[0001] This invention relates to a shock absorber, and more specifically, to a shock absorber that can achieve stepped damping force based on the amount of impact transmitted from the road surface during the compression stroke, and can buffer impacts during extremely low-speed compression strokes, thereby improving ride comfort and ride stability. Background Technology

[0002] Typically, buffer devices are installed in vehicles to improve ride comfort by cushioning the impacts or vibrations received by the axles from the road surface during driving; shock absorbers are one such buffer device.

[0003] Shock absorbers work based on the vibrations of the vehicle according to the road conditions. The damping force generated by the shock absorber varies depending on the operating speed of the shock absorber, that is, it varies depending on whether the operating speed is fast or slow.

[0004] Since the ride comfort and driving stability of a vehicle can be controlled by adjusting the damping force characteristics generated in the shock absorber, it is very important to adjust the damping force characteristics of the shock absorber when designing a vehicle.

[0005] Such shock absorbers typically include a cylinder filled with working fluid (oil), a piston rod connected to the side of the vehicle body for reciprocating motion, and a piston valve attached to the lower end of the piston rod to slide within the cylinder and control the flow of the working fluid.

[0006] The piston valve is designed to use a single flow path to maintain constant damping characteristics at high, medium, and low speeds. However, such a piston valve has a structure where damping forces are difficult to apply during the compression stroke at extremely low speeds.

[0007] In addition, when the piston rod performs a compression stroke at a constant stroke or more, a cylinder of a certain length is required, which results in the disadvantage of excessively long and bulky shock absorbers.

[0008] Existing technical documents

[0009] Patent documents

[0010] Korean Patent Publication No. 10-2018-0083725 (July 23, 2018) Summary of the Invention

[0011] The problem the invention aims to solve

[0012] This embodiment aims to provide a shock absorber that prevents the length and volume of the device from becoming excessive by adding additional damping force during the compression stroke at a certain stroke or above.

[0013] This embodiment aims to provide a shock absorber that can improve vehicle ride comfort and ride stability by periodically increasing damping force during the compression stroke above a certain stroke.

[0014] means for solving problems

[0015] According to one aspect of the present invention, a shock absorber can be provided, comprising a cylinder filled with fluid and a piston valve coupled to a piston rod to divide the interior of the cylinder into a tension chamber and a compression chamber, wherein the shock absorber further comprises: a support member coupled to an end of the cylinder and provided with a connecting flow path; a first guide member forming a first pressurization chamber and provided with a first flow path, the first flow path being formed to penetrate the first guide member in a vertical direction; a second guide member forming a second pressurization chamber and provided with a second flow path connecting the second pressurization chamber and the compression chamber; an opening and closing member coupled to an end of the piston rod, capable of pressurizing the second guide member when the piston rod descends; a first elastic member disposed between the first guide member and the support member; and a second elastic member disposed between the first guide member and the second guide member.

[0016] The first guide member may be spaced apart from the support member, and the first pressurization chamber may be formed between the support member and the first guide member.

[0017] The second guide member may be spaced apart from the first guide member, and the second pressurization chamber may be formed between the first guide member and the second guide member.

[0018] The outer peripheral surface of the first guide member can be in close contact with the inner peripheral surface of the cylinder, and the first flow path can be provided in the central part of the first guide member.

[0019] The first flow path may include: a first main flow path formed to pass through the center of the first guide member along the axial direction, and a first slit flow path formed to be recessed in the bottom surface of the first guide member in a direction perpendicular to the axial direction.

[0020] The outer peripheral surface of the second guide member can be in close contact with the inner peripheral surface of the cylinder, and the second flow path can be provided at the center of the second guide member.

[0021] The second flow path may include: a second main flow path formed to penetrate the center of the second guide member along the axial direction, and a second slit flow path formed to be recessed on the upper surface of the second guide member in a direction perpendicular to the axial direction.

[0022] The opening and closing member may include: a main body, a flange extending radially outward from the bottom surface of the main body, and a hole disposed in the main body, into which the end of the piston rod is inserted.

[0023] The outer diameter of the flange portion can be set to be larger than the inner diameter of the second main flow path, and smaller than the inner diameter of the second slit flow path.

[0024] One side of the first elastic member can be inserted into a first groove on the bottom surface of the first guide member, and the other side can be inserted into a second groove on the upper surface of the support member.

[0025] One side of the second elastic member can be coupled to a first protrusion disposed on the upper surface of the first guide member, and the other side can be coupled to a second protrusion disposed on the bottom surface of the second guide member.

[0026] The shock absorber may further include: an outer tube, configured to be spaced apart from the outer side of the cylinder, and a storage chamber provided between the outer tube and the cylinder.

[0027] The shock absorber may further include: a main valve, which is connected to the lower end of the support member, connects the connecting flow path and the storage chamber, and generates a damping force.

[0028] The elastic modulus of the first elastic member can be greater than that of the second elastic member.

[0029] The elastic modulus of the first elastic member may be less than that of the second elastic member.

[0030] Invention Effects

[0031] The shock absorber according to an embodiment of the present invention has the effect of preventing the length and volume of the device from becoming too large by adding additional damping force during the compression stroke at a certain stroke or above.

[0032] According to an embodiment of the present invention, the shock absorber has the effect of improving the ride comfort and stability of the vehicle by increasing the damping force in stages during the compression stroke above a certain stroke. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view showing a shock absorber according to an embodiment of the present invention.

[0034] Figure 2 This is an enlarged cross-sectional view showing a shock absorber according to an embodiment of the present invention.

[0035] Figure 3This is an exploded perspective view showing a portion of a shock absorber according to an embodiment of the present invention.

[0036] Figure 4 This is a perspective view of the opening and closing member and the second guide member of a shock absorber according to an embodiment of the present invention.

[0037] Figure 5 This is a perspective view showing the bottom surface of the first guide member of a shock absorber according to an embodiment of the present invention.

[0038] Figure 6 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the first section of a shock absorber according to an embodiment of the present invention.

[0039] Figure 7 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the second section of a shock absorber according to an embodiment of the present invention.

[0040] Figure 8 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the third section of a shock absorber according to an embodiment of the present invention.

[0041] Figure 9 This is an enlarged cross-sectional view showing a modified embodiment of the shock absorber of the present invention.

[0042] Figure 10 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the first section of a shock absorber according to a modified embodiment of the present invention.

[0043] Figure 11 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the second section of a shock absorber according to a modified embodiment of the present invention.

[0044] Figure 12 This is an operational diagram illustrating the movement of the valve assembly according to the stroke length of the piston rod during the compression stroke in the third section of a shock absorber according to a modified embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures

[0046] 1, 2: Shock absorbers; 10: Cylinder

[0047] 11: Tension chamber; 12: Compression chamber

[0048] 13: Second pressurization chamber 14: First pressurization chamber

[0049] 15: Connection chamber 20: External pipe

[0050] 30: Piston rod; 31: Piston valve

[0051] 40: Main valve; 50: Valve body

[0052] 100, 200: Valve assembly; 110: Support component

[0053] 111: Connecting flow path; 120: First guiding component

[0054] 121: First flow path; 130: Second guiding component

[0055] 131: Second flow path; 140, 240: Second elastic component

[0056] 150, 250: First elastic member Specific Implementation

[0057] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. The following embodiments are presented to fully convey the spirit of the invention to those skilled in the art. The invention is not limited to the embodiments presented herein and may be practiced in other forms. The drawings may omit illustrations of parts unrelated to the description to make the invention clear, and may slightly exaggerate the dimensions of constituent elements to aid understanding.

[0058] Figure 1 This is a cross-sectional view showing a shock absorber according to an embodiment of the present invention. Figure 2 This is an enlarged cross-sectional view showing a shock absorber according to an embodiment of the present invention. Figure 3 This is an exploded perspective view showing a portion of a shock absorber according to an embodiment of the present invention. Figure 4 This is a perspective view of the opening and closing member and the second guide member of a shock absorber according to an embodiment of the present invention. Figure 5 This is a perspective view showing the bottom surface of the first guide member of a shock absorber according to an embodiment of the present invention.

[0059] Reference Figures 1 to 5 A shock absorber 1 according to an embodiment of the present invention may include: a piston rod 30 that reciprocates inside a cylinder 10 filled with fluid; a piston valve 31 installed on the piston rod 30 to divide the interior of the cylinder 10 into a tension chamber 11 and a compression chamber 12; and a valve assembly 100 coupled to the end of the cylinder 10 to change the damping force according to the displacement of the piston rod 30. Additionally, a shock absorber 1 according to an embodiment of the present invention may further include: an outer tube 20 disposed outside the cylinder 10 to form a storage chamber 21; and a main valve 40 coupled to the lower end of the valve assembly 100 to connect the storage chamber 21 and the valve assembly 100 and generate a damping force.

[0060] The cylinder 10 can be configured as a cylinder with an internal space, and the working fluid (oil) is filled inside the cylinder 10. In addition, the interior of the cylinder 10 can be divided into a lower compression chamber 12 and an upper tension chamber 11 by a piston valve 31.

[0061] One end of the piston rod 30 is located inside the cylinder 10, and the other end extends to the outside of the cylinder 10 and is connected to the vehicle body (not shown) or wheel side. At this time, the piston valve 31 and the opening and closing member 32 are installed at one end of the piston rod 30.

[0062] The piston valve 31 is configured to reciprocate within the fluid-filled cylinder 10 together with the piston rod 30 when the piston rod 30 is inserted through the piston valve 31. At this time, at least one compression flow path and one extension flow path are respectively formed to extend through the piston valve 31 in the vertical direction, allowing fluid movement during the compression or extension stroke. During the compression or extension stroke within the cylinder 10, the piston valve 31 generates a damping force due to fluid resistance as fluid flows into the compression chamber 12 or extension chamber 11.

[0063] Valve assembly 100 can be coupled to the end of cylinder 10 to change the damping force according to the displacement of piston rod 30. Specifically, during the compression stroke of piston valve 31, valve assembly can generate additional damping force according to the stroke length of piston rod 30. Details of valve assembly 100 will be described later.

[0064] The main valve 40 can be coupled to the lower end of the valve assembly 100 and generate additional damping force. Specifically, the main valve 40 may include: a main body portion, located between the valve assembly 100 and the valve housing 50, and forming at least one flow path, the at least one flow path being formed to extend through the main body portion in a vertical direction; a plurality of discs, respectively disposed at the upper and lower ends of the main body portion, regulating the flow of fluid through the flow path to generate damping force; and fastening members for fastening the plurality of discs to the main body portion.

[0065] The outer tube 20 can be configured as a cylinder with an internal space, and the inner diameter of the outer tube 20 is larger than that of the cylinder 10 to accommodate the cylinder 10 inside. In this case, a storage chamber 21 filled with working fluid (oil) is formed between the inner side of the outer tube 20 and the outer side of the cylinder 10. The storage chamber 21 is configured to communicate with the cylinder 10 through the main valve 40 and the valve assembly 100.

[0066] The valve assembly 100 of the shock absorber 1 according to an embodiment of the present invention will be described in detail below.

[0067] A valve assembly 100 according to an embodiment of the present invention may include: a support member 110, which is coupled to the end of a cylinder 10 and is provided with a connecting flow path 111; a first guide member 120, which forms a first pressurization chamber 14 between the first guide member 120 and the support member 110 and has a first flow path 121, the first flow path 121 passing through the first guide member 120; a second guide member 130, which forms a second pressurization chamber 13 between the second guide member 130 and the first guide member 120 and has a second flow path 131 connecting the second pressurization chamber 13 and the compression chamber 12; an opening and closing member 32, which is coupled to the end of a piston rod 30 and is capable of pressurizing the second guide member 130 when the piston rod 30 descends; a first elastic member 150, which is disposed between the first guide member 120 and the support member 110; and a second elastic member 140, which is disposed between the first guide member 120 and the second guide member 130.

[0068] During the compression stroke, the valve assembly 100 can additionally increase the damping force according to the stroke length of the piston rod 30. The operation of the valve assembly 100 will be described in detail later in the operation-related section.

[0069] The support member 110 can be configured such that one side is coupled to the end of the cylinder 10 to support the lower end of the first elastic member 150, and the other side is coupled to the main valve 40.

[0070] Specifically, the support member 110 may include: a small-diameter portion 110a, which is pressed into and coupled to the end of the cylinder 10; and a large-diameter portion 110b, which has a radius greater than that of the small-diameter portion 110a, has a hollow connecting chamber 15 formed at its lower end, and is coupled to the main valve 40.

[0071] The support member 110 may be provided with a connecting flow path 111, which is formed to pass through the center of the support member 110 in the vertical direction to allow fluid to flow. Therefore, the connecting flow path 111 connects the first pressurization chamber 14 and the connecting chamber 15.

[0072] The support member 110 may have a groove 112 on its upper surface to accommodate and support the lower end of the first elastic member 150. For example, the groove 112 may be configured to be recessed in the circumferential direction on the upper surface of the support member 110.

[0073] The first guide member 120 is disposed between and spaced apart from the support member 110 and the second guide member 130, so as to form a first pressurization chamber 14 between the support member 110 and the first guide member 120, and a second pressurization chamber 13 between the first guide member 120 and the second guide member 130.

[0074] The first guide member 120 includes a first flow path 121 for connecting the first pressurization chamber 14 and the second pressurization chamber 13.

[0075] Specifically, the first flow path 121 may include: a first main flow path 121a, configured to penetrate the first guide member 120 in a vertical direction and in the form of a plurality of radially arranged cylindrical holes; and a first slit flow path 121b, formed to be recessed into the bottom surface of the first guide member 120 to communicate with the first main flow path 121a and extending toward the center of the first guide member 120 in the form of a slit. In this case, the first slit flow path 121b may be configured to connect at least a portion of the first main flow path 121a to each other.

[0076] Therefore, the first guide member 120 connects the first pressurization chamber 14 and the second pressurization chamber 13. Even when in close contact with the support member 110, the fluid can flow through the first slit flow path 121b, thus preventing negative pressure from being generated in the first pressurization chamber 14.

[0077] The lower end of the first guide member 120 is elastically supported by the first elastic member 150, and the upper end is elastically supported by the second elastic member 140.

[0078] The elastic modulus of the first elastic member 150 can be set to be smaller than that of the second elastic member 140. Therefore, during the compression stroke, when the opening and closing member 32 connected to the end of the piston rod 30 pressurizes the second guide member 130, the second guide member 130 descends, while the second elastic member 140 acts as a medium to pressurize the first guide member 120, so that the first elastic member 150 can be compressed and elastically deformed.

[0079] The bottom surface of the first guide member 120 may be provided with a groove 122 for accommodating the upper end of the first elastic member 150, and the upper surface of the first guide member 120 may be provided with a protrusion 123 for inserting the lower end of the second elastic member 140.

[0080] The second guide member 130 is disposed on the upper side of the first guide member 120 to form a second pressurization chamber 13 between the second guide member 130 and the first guide member 120.

[0081] The second guide member 130 includes a second flow path 131 for connecting the compression chamber 12 and the second pressurization chamber 13.

[0082] Specifically, the second flow path 131 may include: a second main flow path 131a, which is formed in a cylindrical shape and passes through the center of the second guide member 130 in the vertical direction; and a second slit flow path 131b, which is formed to be recessed in the upper surface of the second guide member 130 in a direction perpendicular to the axial direction and extends radially.

[0083] At this time, the inner diameter r1 of the second main flow path 131a is set to be smaller than the outer diameter r3 of the bottom surface of the opening and closing member 32, and the inner diameter r2 of the second slit flow path 131b is set to be larger than the outer diameter r3 of the bottom surface of the opening and closing member 32. Therefore, even when the opening and closing member 32 descends and comes into close contact with the second guide member 130, the second guide member 130 can still connect the compression chamber 12 and the second pressurization chamber 13 through the second slit flow path 131b, and can prevent negative pressure from being generated in the second pressurization chamber 13 when the opening and closing member 32 returns (see reference). Figure 4 ).

[0084] The bottom surface of the second guide member 130 may be provided with a protrusion 132 for receiving the upper end of the second elastic member 140. For example, the protrusion 132 may be formed to protrude circumferentially in the bottom surface of the second guide member 130 to be inserted into the upper end of the second elastic member 140.

[0085] The second guide member 130 is spaced apart from the first guide member 120, such that its lower end is elastically supported by the second elastic member 140. During the compression stroke, the second guide member 130 can be lowered by the pressure of the opening and closing member 32, and can return to its original position by the elastic force of the second elastic member 140. The detailed operation of the second guide member 130 will be described later.

[0086] The opening and closing member 32 can be disposed in the compression chamber 12, configured to be spaced apart from the second guide member 130 and pressurized by the piston rod 30.

[0087] The opening and closing member 32 is attached to the end of the piston rod 30, configured to move up and down together with the piston rod 30, and configured to pressurize the second guide member 130.

[0088] The opening and closing member 32 may include: a main body portion 32a; a flange portion 32b formed to extend radially outward from the main body portion 32a; and a hole 32c provided in the main body portion 32a, into which the end of the piston rod 30 can be inserted.

[0089] The outer diameter r3 of the flange portion 32b of the opening / closing member 32 can be set to be larger than the inner diameter r1 of the second main flow path 131a and smaller than the inner diameter r2 of the second slit flow path 131b. Therefore, even when the opening / closing member 32 is in close contact with the second guide member 130 during descent, the compression chamber 12 and the second pressurization chamber 13 can still be connected through the second slit flow path 131b.

[0090] The operation of the shock absorber 1 during the compression stroke according to an embodiment of the present invention will be described below.

[0091] Figures 6 to 8This is an operational diagram showing the operation of the valve assembly 100 according to the stroke length of the piston rod 30 during the compression stroke of the shock absorber 1 according to an embodiment of the present invention.

[0092] Reference Figures 6 to 8 During the compression stroke of the shock absorber 1 according to an embodiment of the present invention, different damping forces are generated according to the stroke length or displacement of the piston rod 30.

[0093] The shock absorber 1 can operate to increase the damping force according to the stroke length (displacement) of the piston rod 30 as it descends. Specifically, the damping force can be gradually increased in the stroke interval before the opening / closing member 32 contacts the second guide member 130 (i.e., the first interval), the stroke interval before the first guide member 120 contacts the support member 110 as the second guide member 130 descends (i.e., the second interval), and the stroke interval before the second guide member 130 contacts the first guide member 120 (i.e., the third interval).

[0094] refer to Figure 6 This explains that during the compression stroke, the piston rod 30 descends in the cylinder 10, and the shock absorber 1 operates in the displacement range, i.e., the first range, before the opening and closing member 32 contacts the second guide member 130.

[0095] In the first section, during the compression stroke, the damper 1 generates a damping force due to fluid resistance as the fluid contained in the compression chamber 12 passes through the piston valve 31 and moves to the tension chamber 11. Simultaneously, a portion of the fluid contained in the compression chamber 12, while being compressed, moves through the valve assembly 100 and the main valve 40 to the storage chamber 21 and is compressed, generating a damping force due to fluid resistance.

[0096] At this time, since the connecting flow path 111, the first flow path 121 and the second flow path 131 of the valve assembly 100 are in a fully open state, almost no additional damping force is added.

[0097] That is, in the shock absorber 1, only the damping force generated by the piston valve 31 and the main valve 40 plays a role, and the valve assembly 100 generates almost no damping force.

[0098] Reference Figure 7 During the compression stroke, the piston rod 30 descends within the cylinder 10, and the opening and closing member 32 pressurizes the second guide member 130. The descent of the second guide member 130 causes the shock absorber 1 to operate in the stroke interval before the first guide member 120 contacts the support member 110, i.e., the second interval.

[0099] In the second interval, during the compression stroke, the shock absorber 1 operates as follows: since the elastic modulus of the second elastic member 140 is set to be greater than that of the first elastic member 150, when the opening and closing member 32 presses on the second guide member 130, the second elastic member 140 presses on the first guide member 120, and the first elastic member 150 is compressed and elastically deformed until the first guide member 120 is in close contact with the support member 110.

[0100] At this time, as the opening and closing member 32 pressurizes the second guide member 130, the first pressurizing chamber 13 and the second pressurizing chamber 14 can be in a high-pressure state to apply additional damping force.

[0101] refer to Figure 8 This explains that during the compression stroke, the piston rod 30 descends within the cylinder 10, and the shock absorber 1 operates in the stroke interval before the second guide member 130 contacts the first guide member 120, i.e., the third interval.

[0102] In the third interval, the shock absorber 1 operates such that when the opening and closing member 32 applies pressure to the second guide member 130, the second guide member 130 compresses the second elastic member 140 while simultaneously descending.

[0103] At this time, in the third interval, since the first guide member 120 is in close contact with the support member 110, the flow path area of ​​the fluid through the first guide member 120 is reduced, thereby applying additional pressure between the first guide member 120 and the support member 110.

[0104] Specifically, when the first guide member 120 is in close contact with the support member 110, the first pressurization chamber 14 shrinks, and the fluid through the first guide member 120 flows only through the first main flow path 121a and through the first slit flow path 121b to the connection flow path 111.

[0105] Therefore, in the shock absorber 1, in the third interval, the damping force generated by the hydraulic pressure produced when the first guide member 120 and the support member 110 are in close contact plays an additional role.

[0106] Therefore, according to an embodiment of the present invention, the shock absorber 1 can apply a variable damping force by increasing an additional damping force according to the stroke length of the piston rod 30 during the compression stroke.

[0107] Hereinafter, a modified embodiment of the shock absorber 1 of the present invention, namely the shock absorber 2, will be described.

[0108] In the description of the shock absorber 2 of the modified embodiment of the present invention, in order to avoid repetition, the same content as the shock absorber 1 of the embodiment of the present invention described above is omitted.

[0109] Figure 9This is an enlarged cross-sectional view showing a modified embodiment of the shock absorber of the present invention.

[0110] refer to Figure 9 According to a modified embodiment of the present invention, the valve assembly 200 may include: a support member 110, coupled to the end of the cylinder 10 and provided with a connecting flow path 111; a first guide member 120, forming a first pressurization chamber 14 between the first guide member 120 and the support member 110, and forming a first flow path 121, the first flow path 121 penetrating the first guide member 120; a second guide member 130, forming a second pressurization chamber 13 between the second guide member 130 and the first guide member 120 and having a second flow path 131 communicating between the second pressurization chamber 13 and the compression chamber 12; an opening and closing member 32, coupled to the end of the piston rod 30, capable of pressurizing the second guide member 130 when the piston rod 30 descends; a first elastic member 250, disposed between the first guide member 120 and the support member 110; and a second elastic member 240, disposed between the first guide member 120 and the second guide member 130.

[0111] According to a modified embodiment of the present invention, the elastic modulus of the first elastic member 250 of the shock absorber 2 can be set to be greater than the elastic modulus of the second elastic member 240.

[0112] Therefore, during the compression stroke, when the opening and closing member 32, which is coupled to the end of the piston rod 30, pressurizes the second guide member 130, the second guide member 130 descends, and at the same time the second elastic member 240 can be compressed and elastically deformed.

[0113] Therefore, in the shock absorber 2 according to a modified embodiment of the present invention, the compressive elastic deformation of the second elastic member 240 can be completed before the first guide member 120 and the support member 110 come into close contact.

[0114] Figures 10 to 12 This is an operational diagram showing the operation of the valve assembly 200 according to the stroke length of the piston rod during the compression stroke of the shock absorber 2 according to a modified embodiment of the present invention.

[0115] Reference Figures 10 to 12 During the compression stroke of the damper 2 according to a modified embodiment of the present invention, different damping forces are generated according to the stroke length or displacement of the piston rod 30.

[0116] The shock absorber 2 can operate according to the stroke length (displacement) of the piston rod 30 to increase the damping force. Specifically, as the piston rod 30 descends, the damping force can be gradually increased in the stroke interval before the opening / closing member 32 contacts the second guide member 130 (i.e., the first interval), the stroke interval before the second guide member 130 descends and contacts the first guide member 120 (i.e., the second interval), and the stroke interval before the first guide member 120 contacts the support member 110 (i.e., the third interval).

[0117] refer to Figure 10 This explains that during the compression stroke, the piston rod 30 descends in the cylinder 10, and the shock absorber 2 operates in the displacement range, i.e., the first range, before the opening and closing member 32 contacts the second guide member 130.

[0118] In the first section, during the compression stroke, the damper 2 generates a damping force due to fluid resistance as the fluid contained in the compression chamber 12 passes through the piston valve 31 and moves to the tension chamber 11. Simultaneously, a portion of the fluid contained in the compression chamber 12, while being compressed, moves through the valve assembly 200 and through the main valve 40 to the storage chamber 21 and is compressed, generating a damping force due to fluid resistance.

[0119] At this time, since the connecting flow path 111, the first flow path 121 and the second flow path 131 of the valve assembly 200 are in a fully open state, almost no additional damping force is added.

[0120] That is, in the shock absorber 2, only the damping force generated by the piston valve 31 and the main valve 40 plays a role, and the valve assembly 200 generates almost no damping force.

[0121] Reference Figure 11 During the compression stroke, the piston rod 30 descends within the cylinder 10, and the opening and closing member 32 pressurizes the second guide member 130. The second guide member 130 descends and contacts the shock absorber 2 in the stroke interval before contacting the first guide member 120, i.e., the second interval.

[0122] In the second interval, during the compression stroke, the shock absorber 2 operates as follows: since the elastic modulus of the second elastic member 240 is set to be less than that of the first elastic member 250, when the opening and closing member 32 applies pressure to the second guide member 130, the second elastic member 240 is compressed and elastically deformed until the second guide member 130 is in close contact with the first guide member 120.

[0123] At this time, as the opening and closing member 32 pressurizes the second guide member 130, the first pressurizing chamber 13 and the second pressurizing chamber 14 can be in a high-pressure state to apply additional damping force.

[0124] refer to Figure 12This explains that during the compression stroke, the piston rod 30 descends within the cylinder 10, and the shock absorber 2 operates in the stroke interval, i.e., the third interval, before the first guide member 120 contacts the support member 110.

[0125] In the third interval, the shock absorber 2 operates by the opening and closing member 32 pressing the second guide member 130, causing the second elastic member 240 to deform elastically, thereby moving downward while pressing the first guide member 120 and compressing the first elastic member 250.

[0126] At this time, in the third interval, the first pressurized chamber 13 and the second pressurized chamber 14 are under high pressure to increase additional damping force.

[0127] Therefore, according to a modified embodiment of the present invention, the shock absorber 2 can apply a variable damping force by increasing an additional damping force according to the stroke length of the piston rod 30 during the compression stroke.

[0128] 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 those skilled in the art can make various modifications and variations within the technical concept of the present invention and the equivalent scope of the appended claims.

Claims

1. A shock absorber comprising a cylinder filled with fluid and a piston valve coupled to a piston rod to divide the interior of the cylinder into a tension chamber and a compression chamber, wherein, The shock absorber also includes: A support member is attached to the end of the cylinder and is provided with a connecting flow path. A first guiding member forms a first pressurization chamber and is provided with a first flow path, the first flow path being formed to penetrate the first guiding member in a vertical direction. The second guiding member forms a second pressurization chamber and is provided with a second flow path connecting the second pressurization chamber and the compression chamber. The opening and closing component, coupled to the end of the piston rod, can pressurize the second guide component when the piston rod descends. A first elastic member is disposed between the first guide member and the support member, and A second elastic member is disposed between the first guide member and the second guide member. The outer peripheral surface of the first guide member is in close contact with the inner peripheral surface of the cylinder. The first flow path includes: Multiple primary main paths are formed to penetrate the first guide member in a vertical direction, and The first slit flow path is formed in a recess on the bottom surface of the first guide member to communicate with the first main flow path and extends toward the center of the first guide member in the form of a slit; The first slit flow path connects at least a portion of the first main flow path to each other.

2. The shock absorber according to claim 1, wherein, The first guide member is spaced apart from the support member, and the first pressurization chamber is formed between the support member and the first guide member.

3. The shock absorber according to claim 2, wherein, The second guide member is spaced apart from the first guide member, and the second pressurization chamber is formed between the first guide member and the second guide member.

4. The shock absorber according to claim 1, wherein, The first main channel is arranged in the form of radially arranged cylindrical holes on the first guide member.

5. The shock absorber according to claim 3, wherein, The outer peripheral surface of the second guide member is in close contact with the inner peripheral surface of the cylinder, and the second flow path is provided at the center of the second guide member.

6. The shock absorber according to claim 5, wherein, The second flow path includes: The second main path is formed to pass through the center of the second guide member axially, and The second slit flow path is formed by a recess on the upper surface of the second guide member in a direction perpendicular to the axial direction.

7. The shock absorber according to claim 6, wherein, The opening and closing component includes: Main body, The flange portion is formed to extend radially outward from the bottom surface side of the main body portion, and A hole is provided in the main body, and the end of the piston rod is inserted into the hole.

8. The shock absorber according to claim 7, wherein, The outer diameter of the flange is set to be larger than the inner diameter of the second main flow path, and smaller than the inner diameter of the second slit flow path.

9. The shock absorber according to claim 3, wherein, One side of the first elastic member is inserted into a first groove on the bottom surface of the first guide member, and the other side is inserted into a second groove on the upper surface of the support member.

10. The shock absorber according to claim 3, wherein, One side of the second elastic member is coupled to a first protrusion disposed on the upper surface of the first guide member, and the other side is coupled to a second protrusion disposed on the bottom surface of the second guide member.

11. The shock absorber according to claim 3, wherein, Also includes: The outer tube is configured to be spaced apart from the outer side of the cylinder. A storage chamber is provided between the outer tube and the cylinder.

12. The shock absorber according to claim 11, wherein, Also includes: The main valve is attached to the lower end of the support member, connecting the connecting flow path and the storage chamber and generating a damping force.

13. The shock absorber according to claim 3, wherein, The elastic modulus of the first elastic member is greater than that of the second elastic member.

14. The shock absorber according to claim 3, wherein, The elastic modulus of the first elastic member is less than that of the second elastic member.

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