KR20220022698A - Damping force controlling shock absorber - Google Patents

Abstract

A damping force variable shock absorber is disclosed. According to an embodiment of the present invention, the damping force variable shock absorber comprises: a tube cylinder where fluid is charged; a valve housing coupled to a piston rod provided inside the tube cylinder and having a bypass flow passage therein; a first piston valve coupled to the outside of the valve housing to divide the tube cylinder into a compression chamber and a tension chamber; a second piston valve provided inside the valve housing; a solenoid provided inside the valve housing and generating electromagnetic force; a valve plate installed inside the valve housing and having at least one penetrated plate hole; and a plunger lifted by the electromagnetic force of the solenoid to open and close the plate hole.

Description

Damping force variable shock absorber {DAMPING FORCE CONTROLLING SHOCK ABSORBER}

The present invention relates to a damping force variable shock absorber provided in a vehicle in order to alleviate the impact transmitted from the ground.

In general, the shock absorber is installed in a moving means such as a vehicle to absorb and buffer vibrations or shocks received from the road surface during driving to improve riding comfort. The shock absorber generally includes a cylinder and a piston rod that is installed to be compressible and expandable in the cylinder. The cylinder and the piston rod are respectively coupled to the body or to the wheel or axle.

When the damping force is set low, the shock absorber can absorb vibrations caused by the unevenness of the road surface during driving to improve riding comfort.

Therefore, a damping force variable shock absorber that can appropriately adjust damping force characteristics to improve riding comfort and steering stability according to road surface and driving conditions has been developed by mounting a damping force variable valve on one side of the shock absorber to appropriately adjust damping force characteristics. became

Most conventional damping force variable shock absorbers selectively open and close a plurality of flow paths formed in the spool guide through variable position of the spool, and have a structure in which a hard flow path and a soft flow path are selected. That is, by selectively controlling the opening and closing states of the hard and soft passages formed in the spool guide, it is possible to selectively generate a hard damping force or a soft damping force.

To this end, in the conventional variable damping force shock absorber, a back pressure passage for forming a hard damping force and a soft passage for forming a soft damping force are separately formed.

Such a conventional variable damping force shock absorber is installed between a piston dividing a cylinder into a compression chamber and a tension chamber, a back pressure chamber for generating back pressure during compression and tension strokes, and the piston and the back pressure chamber, and has a bypass flow path. The main retainer is formed, a disk for generating a damping force between the back pressure chamber and the main retainer, and a sub retainer for controlling a flow path connected to the back pressure chamber.

In the conventional variable shock absorber, the spool moves according to the current input to the solenoid and the flow path is changed to implement various damping force performance curves to control the damping force in real time. However, there are disadvantages in that various sensors (Wheel G-sensor, Body G-sensor) are required to recognize vehicle behavior, have a complicated valve flow path, and the system is expensive.

Korean Patent Publication No. 10-2009-0003019 (2009.01.09)

This embodiment intends to provide a damping force variable shock absorber that can selectively use a soft or hard damping force as needed.

The present embodiment intends to provide a damping force variable shock absorber that is provided so that the damping force can be variously adjusted by changing the specifications of the parts.

According to one aspect of the present invention, a tube cylinder filled with a fluid; a valve housing coupled to a piston rod provided in the tube cylinder and forming a bypass flow path therein; a first piston valve coupled to the outside of the valve housing to partition the tube cylinder into a compression chamber and a tension chamber; a second piston valve provided inside the valve housing; a solenoid provided inside the valve housing and generating electromagnetic force; a valve plate installed inside the valve housing and having at least one plate hole formed therethrough; And a plunger for opening and closing the plate hole by lifting by the electromagnetic force of the solenoid; damping force variable shock absorber comprising a can be provided.

A damping force variable shock absorber further comprising a; a plunger guide provided to surround the outside of the plunger to guide the elevation of the plunger may be provided.

The plunger guide may be provided with a damping force variable shock absorber having at least one slot that is formed through the inside from the outside to form the bypass flow path.

a tube cylinder filled with a fluid; a valve housing coupled to a piston rod provided in the tube cylinder and forming a bypass flow path therein; a first piston valve coupled to the outside of the valve housing to partition the tube cylinder into a compression chamber and a tension chamber; a second piston valve provided inside the valve housing; a solenoid provided inside the valve housing to generate electromagnetic force; a valve plate installed inside the valve housing and having at least one plate hole penetrating vertically; a plunger provided between the valve plate and the solenoid so as to be raised and lowered by the electromagnetic force of the solenoid; and a plunger guide disposed between the plunger and the valve housing to guide the plunger and having at least one slot that is opened and closed by the plunger; a damping force variable shock absorber comprising a.

An elastic member interposed between the plunger and the valve plate to elastically support the plunger toward the solenoid; a damping force variable shock absorber further comprising a shock absorber may be provided.

The valve housing includes an upper valve housing coupled to the piston rod, a lower valve housing fastened to a lower end of the upper valve housing, the first piston valve being installed on the outside, and a center hole penetrating vertically inside the valve housing. A damping force variable shock absorber including the may be provided.

The upper valve housing has a housing hole penetrating the outside and the inside, and the bypass flow path is formed to pass through the housing hole, the slot, the plate hole, the second piston valve, and the center hole. A damping force variable shock absorber may be provided.

The plunger guide may be provided with a non-magnetic material, the plunger and the valve plate may be provided with a damping force variable shock absorber provided with a magnetic material at an outer end of the plunger and a non-magnetic material at the inner end of the plunger.

The slot may be provided with a damping force variable shock absorber that is recessed in the bottom surface of the plunger guide.

The slot may be provided with a damping force variable shock absorber that is formed through the side of the plunger guide.

The valve plate may be provided with a damping force variable shock absorber interposed between an inner protrusion protruding from the inner circumferential surface of the valve housing and the plunger guide.

The solenoid is provided with a guide groove recessed in the central axis, and the plunger is formed to protrude from the upper surface, and a damping force variable shock absorber having an inner protrusion that is provided to be able to move up and down in the guide groove may be provided.

In the hard mode, the solenoid lowers the plunger by electromagnetic force to close the bypass flow path, and in the soft mode, a damping force variable shock absorber for opening the bypass flow path by positioning the plunger at its original position may be provided.

The damping force variable shock absorber according to the embodiment of the present invention opens and closes the flow path through which the fluid passes while the plunger ascends and descends the inside of the tube cylinder by a solenoid. can be used

The damping force variable shock absorber according to an embodiment of the present invention is manufactured because the first piston valve is provided on the outside of the valve housing of the tube cylinder and the second piston valve is provided inside the valve housing so that the volume is not large and it is not complicated. cost can be reduced.

In the damping force variable shock absorber according to an embodiment of the present invention, since the first piston valve and the second piston valve are configured separately, they can be tuned independently, and each bidirectional (tension/compression direction) can be controlled simultaneously, so design freedom is very high high.

The damping force variable shock absorber according to an embodiment of the present invention can form two modes of damping force (soft/hard) to increase ride comfort and adjustment stability compared to the existing ones.

1 is a partial cross-sectional view of a damping force variable shock absorber according to an embodiment of the present invention.
2 is an enlarged view showing a solenoid and a piston valve of the damping force variable shock absorber according to an embodiment of the present invention.
FIG. 3 is an enlarged view of a part of FIG. 2 .
Figure 4 is an enlarged view of a part of Figure 2 to explain a modified example of the plunger guide of the damping force variable shock absorber of the present invention.
5 is a cross-sectional view for showing a stroke state in a state in which the plunger is moved to the hard mode in the damping force variable shock absorber according to an embodiment of the present invention.
6 is a cross-sectional view for showing a stroke state in a state in which the plunger is moved to the soft mode in the damping force variable shock absorber according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples 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 described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals refer to like elements throughout.

1 is a partial cross-sectional view of a damping force variable shock absorber according to an embodiment of the present invention.

1, the damping force variable shock absorber according to the present embodiment is provided in the form of a cylinder and filled with a fluid, and is provided inside the tube unit 100 to selectively open and close the fluid to compress or and a valve unit 200 for performing a tension stroke.

The tube unit 100 includes a tube cylinder 110 having an inner tube 111 and an outer tube 112 filled with a fluid, and a piston rod 120 disposed in parallel with the tube inside the inner tube 111 . ), the fluid storage chamber 130 provided in the space between the inner tube 111 and the outer tube 112, and the body valve 140 located at the lower end of the inner tube 111 and the outer tube 112. may include

The tube cylinder 110 includes an inner tube 111 forming a space therein, and an outer tube 112 provided outside the inner tube 111 . However, the shape of the tube cylinder 110 is not limited to the twin-tube form, and may be provided in the form of a mono-tube in which only one tube is formed and the piston rod moves forward and backward. If the cylinder is filled with a fluid inside and generates a damping force by the movement of the valve unit 200, it will be understood the same.

The inner tube 111 may have a cylindrical shape in which an inner space is long, and a fluid (oil, etc.) is filled in the inner tube 111 . The outer tube 112 has an outer diameter greater than that of the inner tube 111 and is provided to surround the inner tube 111 , and similarly, a fluid is filled therein and may have a shape corresponding to the inner tube 111 . The inside of the inner tube 111 may be divided into a compression chamber 113 and a tension chamber 114 by the first piston valve 250 of the valve unit 200 to be described later.

One end of the outer tube 112 and the piston rod 120 omitted from the upper side in FIG. 1 is connected to the vehicle body side and the other end of the outer tube 112 and the piston rod 120 provided with the body valve 140 is They are respectively connected to the wheel side and can perform compression and tension strokes of fluid for shock absorption. In addition, the respective couplings of the vehicle body side and the wheel side may be connected in opposite directions, and separate coupling portions (not shown) for connecting to the vehicle body side or the wheel side may be provided at both ends, respectively.

The piston rod 120 is provided with a valve housing 210 of the valve unit 200 at one end as shown, and the other end, not shown, extends to the outside of the outer tube 112 to the body side or wheel side of the vehicle. can be connected to

The fluid storage chamber 130 is provided in a predetermined space between the inner tube 111 and the outer tube 112 , and the storage chamber 130 is connected to the compression chamber 113 and the inner tube 111 by the body valve 140 . are separated For example, during the compression stroke of the piston rod 120 , the fluid in the compression chamber 113 may be moved to the storage chamber 130 through the flow path 141 on one side of the body valve 140 , and conversely, the tension of the piston rod 120 . During the stroke, the fluid in the storage chamber 130 may be moved to the compression chamber 113 through the other side flow path 142 of the body valve 140 .

The body valve 140 is installed at the lower end of the compression chamber 113 to separate the compression chamber 113 and the fluid storage chamber 130 . A resistance force is formed while the fluid moves in the direction of the tension and compression strokes through the narrow passages 141 and 142 of the body valve 140 , and the damping force of the shock absorber is generated by this resistance force.

Disks 143 and 144 for opening and closing the flow paths 141 and 142 in a selected direction are provided on the upper and lower portions of the body valve 140 . The disks 143 and 144 are, for example, when the piston rod 120 and the first piston valve 250 perform a compression stroke (down in the direction shown), the fluid flows into the storage chamber 130 through the flow path of the body valve 140 . The piston rod 120 and the first piston valve 250, on the other hand, are opened to move in the opposite direction to the above-described operation during the tension stroke (rising in the direction shown).

Figure 2 is an enlarged view showing a solenoid and a piston valve of the damping force variable shock absorber according to an embodiment of the present invention, Figure 3 is an enlarged view of a part of Figure 2, Figure 4 is a damping force variable type of the present invention It is an enlarged view of a part of FIG. 2 in order to explain a modified example of the plunger guide of the shock absorber.

2 to 4 , the valve unit 200 of the damping force variable shock absorber according to the present embodiment includes a valve housing 210 connected to the piston rod 120, and the valve housing 210 is raised and lowered inside. It may include a plunger 220 provided as possible, a solenoid 230 that includes an electromagnetic force, a first piston valve 250 , and a second piston valve 260 .

The valve housing 210 is made of a metal material, and the upper valve housing 211 is coupled to the piston rod 120 , and the lower valve housing 211 is coupled to the upper valve housing 211 and the first piston valve 250 is provided therein. A valve housing 216 may be included.

The upper valve housing 211 is connected to the piston rod 120 using the rod fastening protrusion 213 provided thereon. The upper valve housing 211 has a 'U'-shaped cup shape that is opened downward, and may communicate with the outside and the internal space through the housing hole 214 formed on the side surface.

The housing hole 214 is formed through the side surface of the upper valve housing 211 , and may be provided with a plurality of circular or slit-shaped holes along the circumferential direction. The housing hole 214 connects the tension chamber 114 of the inner tube 111 and the inside of the valve housing 210 in a horizontal direction, and the fluid passing through the housing hole 214 includes the plunger guide 270 and the open It moves in the vertical direction towards the lower valve housing 216 through the plunger 220 and the valve plate 280 .

An inner protrusion 215 is provided on an inner surface adjacent to the housing hole 214 of the upper valve housing 211 to support the upper end of the second piston valve 260 . In addition, the valve plate 280 may be seated on the upper end of the inner protrusion 215 .

The lower valve housing 216 is screw-coupled or press-fitted from the lower side of the upper valve housing 211, and is integrally provided with a large-diameter valve seat 216a and a small-diameter lower valve seat 216a to the outside. One piston valve 250 may include a valve guide (216b) is coupled. The first piston valve 250 may be constrained and fastened by a nut 217 coupled to a lower side thereof while being interposed between the upper and lower washers.

In addition, the lower valve housing 216 has a center hole 218 formed in a vertical direction therein, so that the compression chamber 113 and the flow path may be connected.

The center hole 218 may be provided to form a right angle with the housing hole 214 on the inside along the longitudinal direction of the valve guide 216b. In this case, the center hole 218 may have a larger cross-sectional area than the first valve passage 252 of the first piston valve 250 .

When the plunger 220 is opened, the fluid flows through the housing hole 214 provided in the upper valve housing 211 , the second valve passage 262 provided in the second piston valve 260 , and the lower valve housing 216 . ) is sequentially passed through the center hole 218 provided in, hereinafter, the passages 214 , 262 , and 218 connecting them are referred to as a bypass passage P1 . More specifically, the bypass flow path P1 sequentially passes through the housing hole 214 , the slot 272a , the plate hole 281 , the second valve flow path 262 , and the center hole 218 to communicate with each other. am. The bypass flow path P1 is formed inside the valve housing 210 to communicate the compression chamber 113 and the tension chamber 114 through the second piston valve 260 when the plunger 220 is opened. .

The solenoid 230 is coupled to the piston rod 120 located inside the inner tube 111 and electrically moves the plunger 220 to open and close the bypass passage P1 selectively.

To this end, the solenoid 230 may include a magnet 232 that generates a magnetic field with electricity transmitted from the wire 231 as a power supply means.

The magnet 232 generates a magnetic force by power supplied from the outside and converts the variable shock absorber into a soft mode or a hard mode through magnetic coupling with the magnetic plunger 220 . That is, the solenoid 230 causes the plunger 220 to rise or fall depending on the direction in which the magnetic force is formed, so that the fluid passes or blocks the second piston valve 260 through the bypass flow path P1 to reduce the damping force. can be converted

The central axis 233 of the magnet 232 may be provided with a guide groove 233a which is recessed inward to guide the elevation of the plunger 220 . The guide groove 233a is provided in a shape corresponding to the inner protrusion 223 protruding from the upper end of the plunger 220, and the inner protrusion 223 is recessed deeper than the movable range up and down to form the plunger 220. It may be provided so that the inner protrusion 223 does not deviate from the guide groove 233a during the elevating of the .

The plunger 220 is provided to move up and down by the electromagnetic force of the solenoid 230 to open and close the bypass flow path P1. Specifically, the plunger 220 closes the bypass flow path P1 when operating in the hard mode so that the fluid passes only the first piston valve 250, and opens the bypass flow path P1 when operating in the soft mode. It also allows fluid to pass through the second piston valve 260 .

The plunger 220 is a metal material with a disk-shaped plunger body 221, an inner protrusion 223 protruding from the upper portion of the plunger body 221 and inserted into the guide groove 233a of the solenoid 230, and the plunger body An outer protrusion 222 formed to protrude on the upper portion of the solenoid 230 and surrounding the lower end of the central axis 233 of the solenoid 230, and a depression formed in the bottom surface of the plunger body 221 to constrain the elastic member 290 It may include an inner groove 225 . In addition, the plunger body 221 may include at least one drain hole 224 in the thickness direction.

When the plunger 220 is lowered by the electromagnetic force of the solenoid 230 , the bottom surface of the plunger body 221 may be in close contact with the valve plate 280 to close the plate hole 281 . At the same time, the side of the plunger 220 may close the slot 272a of the plunger guide 270 .

The plunger 220 maintains the housing hole 214 in an open state due to the resistance by the elastic member 290 when the solenoid 230 does not operate, and the elastic member 290 when the solenoid 230 operates. The housing hole 214 is closed while resisting the restoring force of the pull-out type.

The plunger guide 270 is provided inside the upper valve housing 211 , and is provided to surround the outside of the plunger 220 in a ring shape to guide the lifting and lowering of the plunger 220 . Specifically, the outer peripheral surface of the plunger guide 270 is in close contact with the inner peripheral surface of the upper valve housing 211, the inner peripheral surface is in close contact with the outer peripheral surface of the plunger (220).

In addition, the plunger guide 270 is provided with a step inward on the bottom surface and a stepped portion 271 forming a ring-shaped space, and is formed through the stepped portion 271 to communicate the housing hole 214 and the plunger 220. and at least one slot 272a. The slot 272a is provided on the bottom surface of the plunger guide 270, is formed through the inside from the outside, and may be disposed at a position opposite to the housing hole 214. (See FIG. 3) Also, the slot 272b Silver may be formed to penetrate the side surface of the plunger guide 270 , and specifically, may be formed to penetrate the stepped portion 271 (see FIG. 4 ).

However, the position, size, and number of the slots 272a and 272b may be variously changed, and may be adjusted according to the required damping force specification and packaging size. At this time, when the slot 272a is recessed in the bottom surface, injection molding of the plunger guide 270 is easy and processing is simple, so that the cost can be reduced, and when the slot 272b is formed through the side, the slot ( Since it becomes easy to close the slot 272b when the plunger 220 of 272b is lowered, there is an advantage in that the performance of blocking the bypass passage P1 is improved.

At least one plate hole ( 281) is formed through the top and bottom.

The plate hole 281 is provided in a portion opposite to the plunger 220 so as to be opened and closed by the plunger 220, for example, a plurality of circular holes may be provided and radially disposed on the central side. At this time, the position, size, and number of the plate holes 281 can be variously changed and can be adjusted according to the required damping force specifications.

Accordingly, when the plunger 220 is lowered, the valve plate 280 and the plunger 220 may be in close contact, the plate hole 281 may be blocked, and the bypass flow path P1 may be blocked. On the other hand, when the plunger 220 rises, the valve plate 280 and the plunger 220 may be spaced apart to open the plate hole 281 and the bypass flow path P1 may be opened.

The valve plate 280 may be seated on the inner protrusion 215 and interposed between the plunger guide 270 and the inner protrusion 215 . In addition, the valve plate 280 may be fastened to a screw thread (not shown) provided on the inner circumferential surface of the upper valve housing 211 provided with a screw thread (not shown) on the outer circumferential surface.

The plunger 220 and the valve plate 280 may have a central portion provided with a non-magnetic material and an outer portion provided with a magnetic material. Also, the plunger guide 270 may be formed of a non-magnetic material. Accordingly, when a current is applied to the solenoid 230, the electromagnetic force of the magnet 232 is induced in a direction to sequentially pass through the outer portion of the plunger 220, the outer portion of the valve plate 280, and the valve housing 210, the plunger 220 can be lowered. (See FIG. 3)

The elastic member 290 is interposed between the plunger 220 and the valve plate 280 . Therefore, when a current is applied to the solenoid 230, the plunger 220 resists the elastic force of the elastic member 290 and descends, and when no current is applied to the solenoid 230, the plunger 220 is caused by the elastic force of the elastic member 290. rises

The second piston valve 260 communicates with the compression chamber 113 and the tension chamber 114 through the second valve passage 262 . The second piston valve 260 may generate relatively less flow resistance than the first piston valve 250 in fluid movement between the compression chamber 113 and the tension chamber 114 . The second piston valve 260 may be inserted between the bottom surface of the inner protrusion 215 and the valve seat 216a of the lower valve housing 216 to be firmly positioned.

In a state in which the bypass flow path P1 is opened, the second piston valve 260 transfers the fluid in the compression chamber 113 to the tension chamber 114 through the second valve flow path 262 during the compression stroke of the piston rod 120 . ), and the fluid in the tension chamber 114 may be moved to the compression chamber 113 through the second valve passage 262 during the tension stroke of the piston rod 120 .

On the other hand, the first piston valve 250 divides the inside of the inner tube 111 into a compression chamber 113 and a tension chamber 114 as described above, and is formed while reciprocating inside the inner tube 111 . A damping force is generated using the resistive force of the fluid. For example, when the first piston valve 250 performs a compression stroke, since the pressure of the lower compression chamber 113 is increased compared to the upper tension chamber 114 , the fluid filled in the compression chamber 113 is transferred to the first valve It moves to the tension chamber 114 while pushing and opening a valve means (not shown) such as a disk through the flow path 252 , and in this process, a damping force due to the resistance of the fluid is generated. Conversely, when the first piston valve 250 performs a tension stroke, the fluid moves in the opposite direction to the above-described compression stroke process.

When the plunger 220 is closed, the fluid flows from the compression chamber 113 to the tension chamber 114 only through the first valve passage 252 of the first piston valve 250, or from the tension chamber 114 to the compression chamber ( 113), and this flow path is referred to as a main flow path P2.

A gap ring 254 may be interposed between the first piston valve 250 and the inner tube 111 . The gap ring 254 is made of a plastic material to prevent damage or deformation caused by direct contact between the inner tube 111 made of a metal material and the first piston valve 250 , respectively.

Hereinafter, the operation of the damping force variable shock absorber will be described with reference to FIGS. 5 and 6 .

5 is a cross-sectional view for showing a stroke state in a state in which the plunger 220 is moved to a hard mode in the damping force variable shock absorber according to the present embodiment, and FIG. 6 is a damping force variable type according to the present embodiment. It is a cross-sectional view for showing a stroke state in a state in which the plunger 220 is moved to the soft mode in the shock absorber.

Referring to FIG. 5 , in the hard mode, current is applied to the solenoid 230 to generate electromagnetic force, and the plunger 220 overcomes the elastic force of the elastic member 290 and is in close contact with the valve plate 280 . Accordingly, the bypass flow path P1 passing through the inside of the valve housing 210 is closed, and the fluid movement between the compression chamber 113 and the tension chamber 114 during compression and tension strokes causes the first piston valve 250 to move. done through

During the compression stroke of the piston rod 120 in the state in which the plunger 220 is lowered by the solenoid 230 (hard mode), the fluid in the compression chamber 113 flows to the first piston as indicated by a dotted line in FIG. It moves to the tension chamber 114 through the first valve flow path 252 of the valve 250 , for example, the main flow path P2 . The fluid moving to the tension chamber 114 through the first piston valve 250 generates a hard damping force.

Conversely, during the tension stroke of the piston rod 120 in a state in which the plunger 220 is lowered by the solenoid 230 (hard mode), the fluid in the tension chamber 114 is discharged as indicated by a solid line in FIG. 1 While moving to the compression chamber 113 through the main flow path P2 of the piston valve 250, a hard damping force is generated.

Referring to FIG. 6 , in the soft mode, no current is applied to the solenoid 230 to generate electromagnetic force, and the plunger 220 is spaced apart from the valve plate 280 by the elastic force of the elastic member 290 . Accordingly, the bypass flow path P1 passing through the inside of the valve housing 210 is opened, and the fluid movement between the compression chamber 113 and the tension chamber 114 during compression and tension strokes is performed by the first piston valve 250 as well as the first piston valve 250 . No, this is done through the second piston valve 260 .

On the other hand, during the compression stroke of the piston rod 120 in the state in which the plunger 220 is raised by the elastic member 290 (soft mode), the fluid in the compression chamber 113 is as indicated by the dotted line in FIG. 6 . The fluid flowing into the center hole 218 and moving the bypass passage P1 through the center hole 218 is the second valve passage 262 of the second piston valve 260, for example, the auxiliary passage and the housing hole ( 214) to generate a soft damping force while moving to the tension chamber 114.

Conversely, during the tension stroke of the piston rod 120 in a state in which the plunger 220 is raised by the elastic member 290 (soft mode), the fluid in the tension chamber 114 is as indicated by the solid line in FIG. A soft damping force is generated while moving to the compression chamber 113 through the housing hole 214 and the second valve passage 262 and the center hole 218 of the second piston valve 260 .

As described above, in the damping force variable shock absorber according to an embodiment of the present invention, the second piston valve 260 (Soft Valve) is located in the valve housing 210 , and the first piston valve is located on the outside of the valve housing 210 . (250) (Hard Valve) is located. In addition, the plunger 220 located in the valve housing 210 selectively opens and closes the plate hole 281 or the slot 272a while moving up and down according to the current input to the solenoid 230 .

When the plunger 220 moves downward to block the plate hole 281 or the slot 272a, the bypass flow path P1 is blocked and the fluid flows into the main flow path P2 of the first piston valve 250 side. It causes hard damping force. Conversely, when the plunger 220 moves upward and the plate hole 281 or the slot 272a is opened, the fluid flows into the bypass flow path P1 and the introduced oil flows through the flow path on the second piston valve 260 side. It moves through and causes a soft damping force.

Therefore, the damping force variable shock absorber according to the present embodiment can form two modes of damping force (soft damping force / hard damping force) to increase riding comfort and adjustment stability compared to the existing ones, and furthermore has a simple structure. In addition, the first piston valve 250 and the second piston valve 260 are separately configured so that they can be tuned independently, and each can be controlled in both directions (tension/compression direction) at the same time, so that the degree of freedom of tuning is high.

As mentioned above, although the present invention has been described with reference to an embodiment shown in the accompanying drawings, this is merely exemplary, and various modifications and equivalent other embodiments are possible by those skilled in the art. will be able to understand Accordingly, the true scope of the present invention should be defined only by the appended claims.

100: tube unit 110: tube cylinder
111: inner tube 112: outer tube
113: compression chamber 114: tension chamber
120: pisto rod 130: fluid storage compartment
140: body valve 200: valve unit
210: valve housing 211: upper valve housing
214: housing hole 216: lower valve housing
218: center hole 220: plunger
230: solenoid 232: magnet
250: first piston valve 252: first valve flow path
260: second piston valve 262: second valve passage
270: plunger guide 271: step part
272a, 272b: slot 280: valve plate
281: plate hole 290: elastic member

Claims (13)

a tube cylinder filled with a fluid;
a valve housing coupled to a piston rod provided in the tube cylinder and forming a bypass flow path therein;
a first piston valve coupled to the outside of the valve housing to partition the tube cylinder into a compression chamber and a tension chamber;
a second piston valve provided inside the valve housing;
a solenoid provided inside the valve housing and generating electromagnetic force;
a valve plate installed inside the valve housing and having at least one plate hole formed therethrough; and
Damping force variable shock absorber including; a plunger for opening and closing the plate hole by lifting by the electromagnetic force of the solenoid. According to claim 1,
Damping force variable shock absorber further comprising; a plunger guide provided to surround the outside of the plunger to guide the elevation of the plunger. 3. The method of claim 2,
The plunger guide is
A damping force variable shock absorber having at least one slot penetrating from the outside to the inside in a radial direction to form the bypass flow path. a tube cylinder filled with a fluid;
a valve housing coupled to a piston rod provided in the tube cylinder and forming a bypass flow path therein;
a first piston valve coupled to the outside of the valve housing to partition the tube cylinder into a compression chamber and a tension chamber;
a second piston valve provided inside the valve housing;
a solenoid provided inside the valve housing to generate electromagnetic force;
a valve plate installed inside the valve housing and having at least one plate hole penetrating vertically;
a plunger provided between the valve plate and the solenoid to ascend and descend by the electromagnetic force of the solenoid; and
A damping force variable shock absorber comprising a; disposed between the plunger and the valve housing to guide the plunger, the plunger guide having at least one slot that is opened and closed by the plunger. 5. The method of claim 1 to 4,
Damping force variable shock absorber further comprising; an elastic member interposed between the plunger and the valve plate to elastically support the plunger toward the solenoid. 5. The method of claim 3 or 4,
The valve housing is
an upper valve housing coupled to the piston rod;
A damping force variable shock absorber comprising a lower valve housing fastened to the lower end of the upper valve housing, the first piston valve being installed on the outside, and a center hole penetrating vertically on the inside. 7. The method of claim 6,
The upper valve housing is
and a housing hole penetrating the outside and the inside,
The bypass flow
A damping force variable shock absorber formed to pass through the housing hole, the slot, the plate hole, the second piston valve, and the center hole. 5. The method of claim 2 to 4,
The plunger guide is provided with a non-magnetic material,
The plunger and the valve plate are
A damping force variable shock absorber in which the radially outer end is provided with a magnetic material, and the inner end is provided with a non-magnetic material. 5. The method of claim 3 or 4,
the slot is
A damping force variable shock absorber that is recessed in the bottom surface of the plunger guide. 5. The method according to claim 3 or 4,
the slot is
A damping force variable shock absorber that is formed through the side of the plunger guide. 5. The method of claim 3 or 4,
the valve plate
A damping force variable shock absorber interposed between an inner protrusion protruding from the inner circumferential surface of the valve housing and the plunger guide. 5. The method of claim 1 to 4,
The solenoid is
A guide groove recessed in the central axis is provided;
The plunger is
A damping force variable shock absorber having an inner protrusion formed to protrude on the upper surface and provided to be liftable in the guide groove. 5. The method of claim 1 or 4,
The solenoid is
A damping force variable shock absorber for closing the bypass flow path by lowering the plunger by electromagnetic force in hard mode, and opening the bypass flow path by placing the plunger at its original position in soft mode.

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