KR20220099512A - Damping force adjustable shock absorber, shock absorber control system of vehicle, and vehicle - Google Patents

Abstract

Embodiments of the present invention provide a damping force adjustable shock absorber, which comprises: a hollow cylinder portion in which a viscous fluid is enclosed; a piston portion slidably disposed within the cylinder portion with a gap through which the viscous fluid passes between inner surfaces of the cylinder portion; and a piston rod portion connected to the piston portion and configured to be drawn into or drawn out of the cylinder portion. The piston portion divides an inner space of the cylinder portion into a first zone and a second zone, and a first flow path through which the viscous fluid flows is formed in the piston portion. The piston rod portion includes: a piston rod body extending from the piston portion; an elongated valve rod slidably formed inside the piston rod body in a longitudinal direction of the piston rod body; a valve member formed at one end of the valve rod in the longitudinal direction and opening and closing the first flow path as the valve rod slides; and a piezo actuator formed at the other end of the valve rod in the longitudinal direction and sliding the valve rod toward the first flow path as a voltage is applied. An acceleration sensor unit is provided on the piston rod body, and when an acceleration value detected by the acceleration sensor unit exceeds a predetermined reference value, voltage applied to the piezo actuator is limited. The present invention can improve the accuracy of damping force control.

Description

DAMPING FORCE ADJUSTABLE SHOCK ABSORBER, SHOCK ABSORBER CONTROL SYSTEM OF VEHICLE, AND VEHICLE

Embodiments of the present disclosure relate to a damping force adjustable shock absorber, a shock absorber control system for a vehicle, and a vehicle, and more particularly, to a damping force adjustable shock absorber capable of largely adjusting the damping force according to a use environment, a shock absorber control system for a vehicle, and a vehicle.

In general, the suspension of a vehicle is equipped with a shock absorber in order to improve the riding comfort of the occupant. Such a shock absorber is compressed or expanded up and down to absorb vibration or shock generated by the height difference of the road surface. In addition, the buffer is divided into an oil buffer using oil as a working fluid and a gas buffer using gas as a working fluid.

However, in the conventional case, since the damping force of the shock absorber was adjusted by simply adjusting the opening degree of the piston valve, the range of damping force adjustment had to be locally limited.

In addition, in the case of a conventional shock absorber, the damping force adjustment performance and the damping force adjustment range are limited according to the structure of the previously designed piston valve, and this does not reflect the optimal damping force according to the driving environment of the vehicle, and thus the user's riding comfort And there was a problem causing inconvenience in convenience.

Korean Patent Publication No. 10-0745004 (2007.08.02)

Embodiments of the present disclosure are to provide a damping force adjustable shock absorber that solves the problems of the conventional shock absorber described above, and the damping force of the shock absorber can be largely adjusted and the damping force can be adjusted according to the driving environment of the vehicle and the user's intention. This is to provide a buffer with

The technical problems to be achieved in the embodiments of the present disclosure are not limited to the matters mentioned above, and other technical problems not mentioned are to those of ordinary skill in the art from the various embodiments to be described below. can be considered by

According to the embodiments of the present disclosure, a hollow cylinder part with a viscous fluid enclosed therein; a piston part slidably disposed in the cylinder part with a gap through which the viscous fluid can pass between the inner surfaces of the cylinder part; and a piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part, wherein the piston part divides the inner space of the cylinder part into a first zone and a second zone, and the piston part A first flow path through which the viscous fluid flows is formed, and the piston rod part includes: a piston rod body extending from the piston part; an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body; a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and a piezo actuator formed at the other longitudinal end of the valve rod and sliding the valve rod toward the first flow path as a voltage is applied, wherein an acceleration sensor unit is provided on the piston rod body, and the acceleration sensor unit When the value of acceleration detected by , exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, it is possible to provide a damping force adjustable shock absorber.

In addition, according to the embodiments of the present disclosure, the cylinder portion is formed in a hollow cylinder having a predetermined length, the viscous fluid is enclosed therein; a piston part having a cylindrical shape slidably disposed in a longitudinal direction of the cylinder part in the cylinder part, wherein a gap through which the viscous fluid can pass is formed between an outer circumferential surface of the piston part and an inner circumferential surface of the cylinder part; and a piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part, wherein the piston part divides the inner space of the cylinder part into a first zone and a second zone, and the piston part A first flow path through which the viscous fluid flows is formed, and the piston rod part includes: a piston rod body extending from the piston part; an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body; a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and a piezo actuator formed at the other longitudinal end of the valve rod and sliding the valve rod toward the first flow path as a voltage is applied, wherein an acceleration sensor unit is provided on the piston rod body, and the acceleration sensor unit When the value of acceleration detected by , exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, it is possible to provide a damping force adjustable shock absorber.

In addition, according to the embodiments of the present disclosure, a hollow cylinder part with a viscous fluid enclosed therein; a piston part slidably disposed in the cylinder part with a gap through which the viscous fluid can pass between the inner surfaces of the cylinder part; and a piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part, wherein the piston part divides the inner space of the cylinder part into a first zone and a second zone, and the piston part is formed with a first flow path connecting the first zone and the second zone, and the viscous fluid flows from one zone to the other zone through the first flow pathway. It is movable, and the piston rod part includes: a piston rod body extending from the piston part; an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body; a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and a piezo actuator formed at the other longitudinal end of the valve rod and sliding the valve rod toward the first flow path as a voltage is applied, wherein an acceleration sensor unit is provided on the piston rod body, and the acceleration sensor unit When the value of acceleration detected by , exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, it is possible to provide a damping force adjustable shock absorber.

The acceleration sensor unit may be positioned on an outer circumferential surface of the piston rod body in contact with a third flange coupled to the distal end of the piston rod body, and the acceleration sensor unit may include an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic transmitter and the ultrasonic receiver may be disposed to face the second flange.

The damping force adjustable shock absorber described above may further include an electromagnet that is positioned on the outer surface of the cylinder and exhibits magnetism as a current is applied.

In the damping force adjustable shock absorber described above, the piston part includes a third formed along the longitudinal direction of the cylinder part between the longitudinal central axis of the cylinder part and the inner surface of the cylinder part so as to connect the first zone and the second zone. 2 euros; a block moving path formed to intersect the second flow path; and a magnetic block disposed in the block movement path and capable of opening and closing the second passage by the magnetism of the electromagnet unit.

In the damping force adjustable shock absorber described above, the piston part further includes an elastic member positioned in the block movement path to press the magnetic block toward the center of the piston part, and at least one guide part protrudes on the block movement path. and, in the magnetic block, a guide groove formed along the longitudinal direction of the block movement path and into which the at least one guide part is inserted and guided may be formed.

In the damping force adjustable shock absorber described above, the electromagnet part, in the longitudinal direction of the cylinder part, is located on the opposite side of the piston rod part with respect to the piston part, and the electromagnet part is radially spaced apart from the central axis of the cylinder part a plurality of electromagnets disposed; a fixing member of a non-magnetic material disposed on an outer surface of the cylinder part; and a magnetic cover member disposed on an outer surface of the plurality of electromagnets and configured to fix the plurality of electromagnets between the fixing member, wherein the viscous fluid is a magnetic viscous fluid, and a current is applied to the electromagnets In this case, the viscosity of the magneto-viscous fluid flowing into the gap between the piston part and the inner surface of the cylinder part may be increased.

In the damping force adjustable shock absorber described above, the cylinder portion may include a cylindrical cylinder body, a first flange and a second flange coupled to both ends in the longitudinal direction of the cylinder body.

The cylinder body is provided with a locking jaw formed by increasing the diameter of the outer circumferential surface, the outer circumferential surface of the cylinder body is formed to be stepped by the locking jaw, and a seating jaw portion having a shape complementary to that of the locking jaw is formed on the fixing member can be The seating jaw portion may be formed to protrude from the inner circumferential surface of the fixing member in the central axis direction of the cylinder, and the seating jaw portion may be formed to have a ring shape in cross section.

A first accommodating groove for accommodating the electromagnet may be formed on an outer peripheral surface of the fixing member, and a second accommodating groove for accommodating the electromagnet may be formed on an inner peripheral surface of the cover member. The electromagnet may be inserted into the first receiving groove and the second receiving groove to be fixed between the fixing member and the cover member.

An insertion groove formed by being depressed inwardly is formed on one side of the outer circumferential surface of the fixing member, the insertion groove is formed to have a ring shape in cross section, and a protrusion formed to protrude outwardly from one side of the inner circumferential surface of the cover member to be inserted into the insertion groove Ash may form.

In the damping force adjustable shock absorber described above, the piston part further comprises a valve seat formed on the first flow path and engaged with the valve member, the valve seat is formed of a resin material, the damping force adjustable shock absorber , a temperature sensor unit for detecting the temperature of the viscous fluid in the cylinder unit; a data storage unit storing expansion information indicating an expansion amount of the valve seat in the determined temperature condition; And based on the temperature of the viscous fluid detected by the temperature sensor unit and the expansion information stored in the data storage unit, it may further include a control unit for adjusting the magnitude of the voltage value applied to the piezo actuator.

The damping force adjustable shock absorber described above can be installed in a vehicle, and the damping force adjustable shock absorber further includes a control unit configured to acquire driving speed information of the vehicle, wherein the control unit includes: based on the acquired driving speed information, the piezo actuator It is possible to control at least one of whether a voltage is applied to, whether a current is applied to the electromagnet unit, a magnitude of a voltage value applied to the piezo actuator, and a magnitude of a current value applied to the electromagnet part.

In the damping force adjustable shock absorber described above, the control unit can control the piezo actuator and the electromagnet by dividing the piezo actuator and the electromagnet into a first speed mode, a second speed mode and a third speed mode according to the obtained travel speed information, , in the first speed mode, the control unit cuts off the voltage applied to the piezo actuator and the current applied to the electromagnet unit, and in the second speed mode, the control unit applies a voltage to the piezo actuator but to the electromagnet unit The applied current is cut off, and in the third speed mode, the control unit may apply a voltage to the piezo actuator and apply a current to the electromagnet unit.

When the control unit is controlling the piezo actuator and the electromagnet unit in the third speed mode, when the acceleration value detected by the acceleration sensor unit exceeds a predetermined reference value, the control unit controls the voltage applied to the piezo actuator and It is possible to block the current applied to the electromagnet unit.

In addition, according to embodiments of the present disclosure, as the damping force adjustable shock absorber described above, the damping force adjustable shock absorber is provided with a plurality of the damping force adjustable shock absorber to be mounted on the vehicle body; a control module provided in the vehicle and operable by a user; and a display unit provided in the vehicle to provide the user with information on the damping force of the damping force adjustable shock absorber.

In addition, according to embodiments of the present disclosure, the damping force adjustable shock absorber described above; and a seat seat on which the occupant can be seated, wherein the damping force adjustable shock absorber is mounted under the seat seat.

According to the embodiments of the present disclosure, when the shock absorber is compressed by an external shock between driving of the vehicle, the damping force may be gradually and continuously increased during compression of the shock absorber to provide a sense of stability to the user riding in the vehicle.

Further, according to the embodiments of the present disclosure, even when a large shock suddenly occurs to the vehicle body during high-speed driving of the vehicle, it is possible to provide stability to the vehicle occupant by momentarily reducing the damping force of the shock absorber to slowly absorb the amount of shock.

Further, according to the embodiments of the present disclosure, even when used in different temperature environments, it is possible to maintain the damping force control performance of the shock absorber uniformly and to improve the damping force control accuracy.

In addition, according to embodiments of the present disclosure, it is possible to provide a stable riding comfort to a vehicle occupant by automatically adjusting a damping force according to the driving speed of the vehicle, and at the same time provide improved driving stability.

In addition, according to the embodiments of the present disclosure, it is possible to provide riding comfort and driving feeling optimized for individual users.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description to aid understanding of the embodiments, provide various embodiments and, together with the detailed description, explain technical features of the various embodiments.
1 is a view schematically showing a longitudinal cross-section of a damping force adjustable shock absorber according to an embodiment of the present disclosure;
2 is a view showing an operation of opening and closing the first flow path of the damping force adjustable shock absorber according to an embodiment of the present disclosure;
Figure 3 is a partial enlarged view of the piston of the damping force adjustable shock absorber according to an embodiment of the present disclosure shown in Figure 1;
Figure 4 (a) is a view schematically showing the rear surface of the magnetic block of the damping force adjustable shock absorber according to an embodiment of the present disclosure;
Figure 4 (b) is a view schematically showing the side of the magnetic block of the damping force adjustable shock absorber according to an embodiment of the present disclosure;
Figure 5 is a view showing the II' section of Figure 1;
6 is a view showing the polarity of the electromagnet when a current is applied to the electromagnet shown in FIG. 5
7 is a partially enlarged view of the electromagnet of the damping force adjustable shock absorber according to an embodiment of the present disclosure shown in FIG.
8 is a view showing the movement of the piston to the electromagnet side when the damping force adjustable shock absorber is compressed according to an embodiment of the present disclosure;
9 is a view showing a state in which the volume of the valve seat of the damping force adjustable shock absorber according to an embodiment of the present disclosure is changed according to the temperature;
10 is a diagram schematically illustrating a control unit of a damping force adjustable shock absorber according to an embodiment of the present disclosure;
11 is a view schematically showing an acceleration sensor unit of a damping force adjustable shock absorber according to an embodiment of the present disclosure;
12 is a view schematically showing a control form of a damping force adjustable shock absorber according to an embodiment of the present disclosure according to acquired speed information
13 is a diagram schematically showing a shock absorber control system according to another embodiment of the present disclosure;

The following embodiments combine elements and features of the embodiments in a predetermined form. Each component or feature may be considered optional unless explicitly stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, various embodiments may be configured by combining some components and/or features. The order of operations described in various embodiments may be changed. Some features or features of one embodiment may be included in another embodiment, or may be replaced with corresponding features or features of another embodiment.

In the description of the drawings, procedures or steps that may obscure the gist of various embodiments are not described, and procedures or steps that can be understood at the level of those of ordinary skill in the art are also not described. did.

Throughout the specification, when a part is said to "comprising or including" a certain component, it does not exclude other components unless otherwise stated, meaning that other components may be further included. do. In addition, terms such as "... unit", "... group", and "module" described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. can be implemented as Also, "a or an", "one", "the" and like related terms are used herein in the context of describing various embodiments (especially in the context of the claims that follow). Unless otherwise indicated or clearly contradicted by context, it may be used in a sense including both the singular and the plural.

Hereinafter, embodiments according to various embodiments will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION The detailed description set forth below in conjunction with the appended drawings is intended to describe exemplary embodiments of various embodiments, and is not intended to represent the only embodiments.

In addition, specific terms used in various embodiments are provided to help the understanding of various embodiments, and the use of these specific terms may be changed to other forms without departing from the technical spirit of various embodiments. .

1 is a view schematically showing a longitudinal section of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure.

Referring to FIG. 1 , the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure includes a hollow cylinder part 10 , a piston part 20 slidably disposed within the cylinder part 10 , and It may include a piston rod part 30 connected to the piston part 20 .

A viscous fluid F may be enclosed in the cylinder part 10 . In addition, the cylinder part 10 may be formed in a hollow cylindrical shape having a predetermined length. Specifically, the cylinder part 10 is a first flange 130 for sealing the cylinder body 110 by being coupled to both ends of the cylinder body 110 in the longitudinal direction of the cylinder body 110 in the longitudinal direction of which both sides are open in the longitudinal direction, respectively. and a second flange 140 . The above-described first flange 130 may be coupled to one end in the longitudinal direction of the cylinder body 110 , and the second flange 140 may be coupled to the other end in the longitudinal direction of the cylinder body 110 .

The piston part 20 may be disposed with a gap through which the viscous fluid F can pass between the inner surface (ie, the inner peripheral surface) of the cylinder part 10 . In addition, the piston part 20 may be formed in a cylindrical shape, and the outer peripheral surface of the piston part 20 may be formed in a shape complementary to the inner peripheral surface of the cylinder part 10 . That is, the interval between the inner peripheral surface of the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 may be formed to be the same in the circumferential direction.

The above-described piston rod part 30 may be disposed such that at least a part thereof protrudes to the outside of the cylinder part 10 . Preferably, one end of the piston rod part 30 is connected to the piston part 20 so that the piston rod part 30 and the piston part 20 can slide integrally in the cylinder part 10 . In addition, the other end of the piston rod part 30 may protrude from the second flange 140 of the cylinder part 10 to the outside and be located outside the cylinder part 10 .

In addition, the piston rod part 30 may be configured to be drawn into or drawn out from the cylinder part 10 . Specifically, when an external force is applied to the piston rod part 30 to move the piston part 20 toward the first flange 130 , the piston rod part 30 may be introduced into the cylinder part 10 . In addition, when an external force for moving the piston part 20 toward the second flange 140 is applied to the piston rod part 30 , the piston rod part 30 may be drawn out to the outside of the cylinder part 10 .

Meanwhile, the aforementioned piston unit 20 may divide the inner space of the cylinder unit 10 into a first region 121 and a second region 122 . In the drawing, the inner space of the cylinder portion 10 adjacent to the first flange 130 may be divided into a first region 121 , and the inner space of the cylinder portion 10 adjacent to the second flange 140 is second. It may be divided into two zones 122 .

Also, a first flow path 220 connecting the first region 121 and the second region 122 may be formed in the piston unit 20 . The first flow path 220 may be formed along the longitudinal direction of the cylinder part 10 , and the viscous fluid F flows through the first flow path 220 in the first zone 121 and the second zone 122 . It can flow from one zone to the other. That is, the viscous fluid F flows through the first flow path 220 and the gap C between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10, the first region 121 and the second Two zones 122 can be moved to each other.

The above-described piston rod unit 30 is a hollow piston rod body 310 having a predetermined length, and a valve rod 320 formed to be slidable in the longitudinal direction of the piston rod body 310 inside the piston rod body 310 . ), a valve member 330 formed at one end in the longitudinal direction of the valve rod 320 , and a piezo actuator formed at the other end in the longitudinal direction of the valve rod 320 .

Specifically, the piston rod body 310 has a first bore 311a formed along the longitudinal direction of the cylinder unit 10 to have a coaxial axis with the cylinder unit 10, and a first flow path of the first bore 311a ( 220) may include a second bore (311b) extending from the side end and formed to have a larger diameter than the first bore (311a). In this case, the valve rod 320 may be located in the first bore 311a, and the valve member 330 may be located in the second bore 311b.

The piston rod body 310 may extend from the piston unit 20 , and the valve member 330 may open and close the first flow path 220 as the valve rod 320 slides. In addition, the piezo actuator 340 may slide the above-described valve rod 320 toward the first flow path 220 as a voltage is applied.

In addition, at one end of the piston rod body 310 , a bore flow path 312 communicating the second region 122 and the second bore 311b may be formed. The bore flow path 312 may be composed of four, and the four bore flow paths 312 may be radially disposed with respect to the central axis of the cylinder part 10 . Through this, the viscous fluid F in the second zone 122 may flow to the second zone 122 through the four bore flow paths 312 , the second bore 311b and the first flow path 220 . .

Meanwhile, the piston rod unit 30 may further include a third flange 350 coupled to the other end in the longitudinal direction of the piston rod body 310 . The third flange 350 may be formed in a disk shape having a diameter greater than that of the piston rod body 310 . Also, the second flange 140 and the third flange 350 may be disposed to face each other, and a spring member S may be disposed between the second flange 140 and the third flange 350 .

The above-described spring member (S) may elastically support the position of the piston rod part 30 with respect to the cylinder part (10). Specifically, when an external force is applied to the piston rod part 30 and the piston rod part 30 is pressed into the cylinder part 10, when the external force is released, the spring member (S) moves the piston rod back into the cylinder part. (10) It can be drawn out. Similarly, when an external force is applied to the piston rod part 30 and the piston rod part 30 is pressed to the outside of the cylinder part 10 and is withdrawn, the spring member (S) moves the piston rod back into the cylinder when the external force is released. The part 10 may be drawn into the inside.

On the other hand, in the gap C formed between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10, the cross-sectional area of a plane perpendicular to the longitudinal central axis of the cylinder part 10 (that is, the cross-sectional area) is, It may be formed in a size smaller than the cross-sectional area of the first flow path 220 . That is, due to the gap C formed between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 , a ring-shaped gap C is formed between the piston part 20 and the cylinder part 10 . In the ring-shaped gap C, the size of the cross-sectional area of the cross-sectional area of the plane perpendicular to the longitudinal central axis of the cylinder part 10 is smaller than the size of the cross-sectional area of the first flow path 220. can

Preferably, the size of the cross-sectional area of the first flow path 220 may be 5 to 20 times the size of the cross-sectional area of the gap C formed between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10, and more Preferably, the size of the cross-sectional area of the first flow path 220 may be 10 to 15 times the size of the cross-sectional area of the gap C formed between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 . Through this, the flow rate of the viscous fluid F flowing between the first section 121 and the second section 122 in the cylinder part 10 can be significantly different depending on whether the first flow path 220 is opened or closed. have.

2 is a view showing an operation of opening and closing the first flow path 220 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure. Figure 2 (a) is a view showing a state in which the first flow path 220 is opened, Figure 2 (b) is a view showing a state in which the first flow path 220 is closed.

1 and 2 , the piezo actuator 340 may be formed by stacking piezo elements in the longitudinal direction of the piston rod body 310 , and the piezo actuator 340 has a volume stacked when a voltage is applied. It can be formed to increase in the direction. That is, when a voltage is applied, the volume or volume of the piezo actuator 340 in the longitudinal direction of the piston rod body 310 may be increased, through which the valve rod 320 slides toward the first flow path 220 . can be moved Conversely, when the voltage application to the piezo actuator 340 is released, the volume or volume of the piezo actuator 340 in the longitudinal direction of the piston rod body 310 can be reduced again, and as the piezo actuator 340 is compressed, Accordingly, the valve rod 320 may be moved in a direction away from the first flow path 220 .

On the other hand, when the first flow path 220 is closed by the valve member 330 due to voltage application to the piezo actuator 340 , the viscous fluid F in the cylinder part 10 flows into the first region 121 and Between the second region 122 , it can flow only through the gap C between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 .

As described above, the cross-sectional area of the gap C formed between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 is formed to be very small compared to the cross-sectional area of the first flow path 220 , the first The flow amount of the viscous fluid F flowing between the zone 121 and the second zone 122 is also greatly reduced. Accordingly, when an external force acts on the piston rod part 30 , the movement of the piston part 20 may be restricted compared to the state in which the first flow path 220 is opened, and the damping force by the shock absorber may be further improved. That is, when the same external force is applied, when the first flow path 220 is closed, the damping force can be significantly exerted compared to the case where the first flow path 220 is opened, and the piston rod part 30 with respect to the cylinder part 10 . ) can be made smaller.

In addition, an acceleration sensor unit 50 may be provided on the outer peripheral surface of the piston rod body 310 . Furthermore, when the acceleration value detected by the acceleration sensor unit 50 exceeds a predetermined reference value, the voltage applied to the piezo actuator 340 may be limited.

The acceleration value measured by the aforementioned acceleration sensor unit 50 may mean a relative displacement change occurring during a specific time in the relative displacement of the piston rod unit 30 with respect to the cylinder unit 10 . That is, when the acceleration value measured by the acceleration sensor unit 50 is high, it may mean that the magnitude of the relative displacement of the piston rod unit 30 with respect to the cylinder unit 10 is rapidly changed.

On the other hand, when the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure is mounted on a vehicle, the acceleration value measured by the above-described acceleration sensor unit 50 is a damaged part of the road surface between driving of the vehicle. It may mean a sudden relative displacement change of the piston rod part 30 with respect to the cylinder part 10 due to an impact generated when passing.

Through this, in the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure, even when a sudden large shock occurs to the vehicle body during driving, the voltage application to the piezo actuator 340 is released and the first flow path Since 220 is opened to reduce the damping force of the shock absorber, it is possible to provide a sense of stability to the vehicle occupant by absorbing the amount of shock slowly.

3 is a partial enlarged view of the piston part 20 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure shown in FIG. 1 . Here, (a) of FIG. 3 is a diagram schematically illustrating a state in which the second flow path 230 is opened, and FIG. 3 (b) is a diagram schematically illustrating a state in which the second flow path 230 is closed.

1 and 3, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure is located on the outer surface of the cylinder part 10 and magnetic as a current is applied. may include more. The electromagnet unit 40 may be installed in surface contact with the outer peripheral surface of the cylinder unit 10 . In addition, when an external force is not applied to the cylinder part 10 and the piston rod part 30 and in a normal state in which the relative displacement of the cylinder part 10 and the piston rod part 30 is maintained, the electromagnet part ( 40 may be positioned between the first flange 130 and the piston part 20 in the longitudinal direction of the cylinder part 10 .

In addition, the aforementioned piston unit 20 includes a second flow path 230 connecting the first region 121 and the second region 122 , and a block movement path 240 formed to intersect the second flow path 230 . , and a magnetic block 250 disposed in the block movement path 240 .

The second flow path 230 may be formed along the longitudinal direction of the cylinder unit 10 between the central axis of the longitudinal direction of the cylinder unit 10 and the inner surface of the cylinder unit 10 , preferably, the first It may be formed parallel to the flow path 220 .

In addition, the block moving path 240 may extend inwardly from the outer circumferential surface of the piston body 210 to be formed in a radial direction with respect to the central axis of the cylinder part 10, and the block moving path 240 may include a second flow path ( 230) and may be disposed to intersect. The magnetic block 250 may move in the block movement path 240 by the magnetism of the electromagnet unit 40 when a current is applied to the electromagnet unit 40 , and as it moves within the block movement path 240 , The second flow path 230 may be opened and closed.

In addition, the piston part 20 may further include a side cover part 260 installed on the outer peripheral surface of the piston body 210 to form the outer peripheral surface of the piston part 20 . The block movement path 240 may be shielded by the side cover part 260 . In addition, the piston unit 20 may further include an elastic member 270 positioned in the block movement path 240 to press the magnetic block 250 toward the center of the piston unit 20 . One end of the elastic member 270 may be coupled to the inner surface of the side cover part 260 , and the other end of the elastic member 270 may be coupled to the magnetic block 250 . The magnetic block 250 may be pressed and supported in the central axis direction of the cylinder part 10 by the elastic member 270 .

Accordingly, in a state in which no current is applied to the electromagnet unit 40 , the magnetic block 250 is pressed toward one end of the block movement path 240 adjacent to the central axis of the cylinder unit 10 by the elastic member 270 . can be Through this, the second flow path 230 may be maintained in an open state, and the viscous fluid F in any one of the first zone 121 and the second zone 122 is transferred to the second flow path 230 . can flow to the other zone through That is, as the flow area of the viscous fluid F between the first zone 121 and the second zone 122 is increased, the damping force of the buffer may be decreased. Therefore, when an external force such as an external shock is applied, the relative displacement of the piston rod part 30 with respect to the cylinder part 10 during compression of the shock absorber can be reduced at a relatively high speed compared to the case where the damping force is high, and the shock absorber When the is mounted on the vehicle, the length change of the entire shock absorber from one end of the cylinder part 10 to the other end of the piston rod part 30 can be made relatively quickly.

On the other hand, when a current is applied to the electromagnet unit 40 to make the electromagnet unit 40 magnetic, the magnetic block 250 overcomes the elastic support force of the elastic member 270 by attraction with the electromagnet unit 40 and It may move toward the electromagnet part 40 located on the outer peripheral surface of the cylinder part 10 . In this case, the second flow path 230 may be closed by the magnetic block 250 , and the flow path of the viscous fluid F through the second flow path 230 may be blocked. That is, since the flow area of the viscous fluid F between the first zone 121 and the second zone 122 is reduced, the damping force of the buffer may be increased. Therefore, when an external force such as an external shock is applied, the relative displacement of the piston rod part 30 with respect to the cylinder part 10 during compression of the shock absorber may be reduced at a relatively slow speed compared to the case where the damping force is low, and the shock absorber When the is mounted on the vehicle, the length change of the entire shock absorber from one end of the cylinder part 10 to the other end of the piston rod part 30 may be made relatively slowly.

Meanwhile, the above-described second flow path 230 , block moving path 240 , magnetic block 250 , and elastic member 270 may be provided by four each, and each of the second flow path 230 and block moving member 270 may be provided. The furnace 240 , the magnetic block 250 , and the elastic member 270 may form one second flow path 230 opening/closing structure. That is, a total of four second flow passages 230 opening/closing structures may be provided. At this time, the four second flow path 230 opening/closing structure may be radially disposed with respect to the longitudinal central axis of the cylinder part 10 , and the four second flow path 230 opening/closing structure may be formed of the piston part 20 . They may be disposed to be spaced apart from each other while forming an angle of 90 degrees in the circumferential direction.

On the other hand, in all the four second flow paths 230 , the sum of the cross-sectional areas of the plane perpendicular to the longitudinal central axis of the cylinder part 10 (that is, the sum of the cross-sectional areas of all the second flow paths 230 ) is, It may be formed in a size smaller than the cross-sectional area of the first flow path 220 .

Preferably, the size of the cross-sectional area of the first flow path 220 may be 2 to 5 times the sum of the cross-sectional areas of all the second flow paths 230 , and more preferably, the size of the cross-sectional area of the first flow path 220 is The sum of the cross-sectional areas of all the second flow paths 230 may be 3 to 4 times.

It is possible to sequentially and/or selectively determine whether to open or close the first flow path 220 and the second flow path 230 by the control unit 70 to be described later, the damping force adjustable shock absorber ( The damping force of 1) can be adjusted step by step in a wide range.

Figure 4 (a) is a view schematically showing the rear surface of the magnetic block 250 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure, Figure 4 (b) is an embodiment of the present disclosure It is a view schematically showing the side of the magnetic block 250 of the damping force adjustable shock absorber (1) according to. The rear surface of the magnetic block 250 described above means the outer surface of the magnetic block 250 arranged to face the central axis of the cylinder part 10 in the magnetic block 250 arranged in the block movement path 240 . have.

3 and 4 , the above-described block moving path 240 may have a circular cross-section, and the magnetic block 250 has a predetermined length to have an outer circumferential surface complementary to the inner circumferential surface of the block moving path 240 . It may be formed in a cylindrical shape having

In addition, at least one guide part 241 may protrude from the block moving path 240 described above, and the magnetic block 250 has a guide groove 251 into which at least one guide part 241 is inserted and guided. can be formed.

At least one guide part 241 may be provided two by two in each block movement path 240 , and the two guide parts 241 form a pair to be disposed to face each other in the block movement path 240 . can That is, each guide part 241 may be formed to protrude in the longitudinal direction of the cylinder part 10 on the inner circumferential surface of the block movement path 240 .

Two guide grooves 251 may be provided in each magnetic block 250 , and the two guide grooves 251 may form a pair to face each other in the magnetic block 250 . That is, each guide groove 251 may be formed by recessing the outer peripheral surface of each magnetic block 250 toward the central axis in the longitudinal direction of the magnetic block 250 .

In addition, the guide groove 251 may be formed to extend from one end in the longitudinal direction of the magnetic block 250 toward the other side in the longitudinal direction. That is, one end 251a in the longitudinal direction of the guide groove 251 may be opened, and the other end 251b in the longitudinal direction of the guide groove 251 may be closed. On the other hand, the open end 251a of the guide groove 251 may be located on one end side of the block movement path 240 adjacent to the central axis of the cylinder part 10, and the other closed end of the guide groove 251 . The 251b may be positioned toward the other end of the block moving path 240 adjacent to the inner surface of the cylinder part 10 . When assembling the above-described piston unit 20, before the side cover unit 260 is coupled to the piston body 210, the magnetic block 250 moves through the opening of the block moving path 240 through the block moving path 240. ), and the guide part 241 may be inserted into the guide groove 251 through the open end 251a of the guide groove 251 .

In a state in which the magnetic block 250 is disposed on the block movement path 240 , the pair of guide parts 241 are inserted into the pair of guide grooves 251 , and the magnetic block 250 is the block movement path. It can be moved without twisting within 240 , and in particular, the magnetic block 250 is twisted along the block moving path 240 even when passing through a portion where the block moving path 240 intersects the second flow path 230 . However, it can be moved in a straight line without deviation from the path.

5 is a view showing a cross section I-I' of FIG. 1 , and FIG. 6 is a view showing the polarity of the electromagnet 420 when a current is applied to the electromagnet unit 40 shown in FIG. 5 .

5 and 6 , the above-described electromagnet unit 40 may be located on the opposite side of the piston rod unit 30 with respect to the piston unit 20 in the longitudinal direction of the cylinder unit 10 . . That is, the electromagnet part 40 may be disposed between the first flange 130 and the piston part 20 .

In addition, the electromagnet unit 40 includes a plurality of electromagnets 420 that are radially spaced apart from the central axis of the cylinder unit 10 , and a fixing member 410 of a non-magnetic material disposed on the outer surface of the cylinder unit 10 . , and a magnetic cover member 430 disposed on the outer surface of the plurality of electromagnets 420 . The cover member 430 may fix the plurality of electromagnets 420 between the fixing member 410 and the fixing member 410 . The cover member 430 may be coupled to the fixing member 410 to prevent the electromagnet 420 from being exposed to the outside.

The above-described electromagnets 420 may be provided in four, and the four electromagnets 420 may be radially disposed with respect to the longitudinal central axis of the cylinder unit 10 . In addition, each of the electromagnets 420 may be formed in a circular arc shape with a cross section on a plane orthogonal to the central axis of the cylinder part 10 .

The above-described fixing member 410 may be formed in a hollow cylindrical shape, and a first receiving groove 411 for accommodating the electromagnet 420 may be formed on an outer circumferential surface of the fixing member 410 . Four first receiving grooves 411 may be provided to correspond to the four electromagnets 420 , and each of the first receiving grooves 411 has the shape of the outer surface of the electromagnet 420 , preferably of the electromagnet 420 . It may be formed in a shape complementary to the shape of the radially inner outer circumferential surface. That is, each of the first receiving grooves 411 may be formed in a circular arc shape with a cross section on a plane perpendicular to the central axis of the cylinder part 10 . On the other hand, the groove depth of the first receiving groove 411 may be formed smaller than the radial width of the electromagnet 420 , the electromagnet 420 accommodated in the first receiving groove 411 of the fixing member 410 . The outer circumferential surface may protrude radially outward from the outer circumferential surface of the fixing member 410 .

In addition, the cover member 430 may be formed in a hollow cylindrical shape, and a second accommodation groove 431 for accommodating the electromagnet 420 may be formed on an inner circumferential surface of the cover member 430 . Four second receiving grooves 431 may be provided to correspond to the four electromagnets 420 , and each of the second receiving grooves 431 has the shape of the outer surface of the electromagnet 420 , preferably of the electromagnet 420 . It may be formed in a shape complementary to the shape of the outer peripheral surface in the radial direction. That is, each of the second receiving grooves 431 may be formed in a circular arc shape with a cross section on a plane orthogonal to the central axis of the cylinder part 10 . On the other hand, the groove depth of the second receiving groove 431 may be formed to be smaller than the radial width of the electromagnet 420 , and the electromagnet 420 accommodated in the second receiving groove 431 of the cover member 430 is formed. The outer circumferential surface may protrude radially outward from the inner circumferential surface of the cover member 430 .

In addition, each of the first receiving groove 411 and the second receiving groove 431 may be disposed to face each other in the radial direction of the electromagnet unit 40 .

As described above, the electromagnet 420 is accommodated and fixed in the fixing member 410 on the inner circumferential side and is received and fixed in the cover member 430 at the outer circumferential side, so that the position with respect to the cylinder portion 10 is firmly maintained. can

On the other hand, when a current is applied to the above-described electromagnet 420, the electromagnet 420 becomes magnetic, and preferably, the electromagnet 420 is arranged so that the inner peripheral surface side has an N pole and the outer peripheral surface side has an S pole. can At this time, all of the four electromagnets 420 may be arranged such that the inner peripheral surface side has an N pole and the outer peripheral surface side has an S pole when current is applied. That is, the four electromagnets 420 may be arranged to be symmetrical with respect to the central axis of the cylinder part 10 . Through this, a magnetic field along the radial direction from the inside to the outside of the cylinder part 10 may be generated.

In addition, the above-described fixing member 410, the cylinder body 110, and the piston body 210 may be formed of a non-grown material. Therefore, the fixing member 410 and the cylinder body 110 are not formed as a magnetic path when a current is applied to the electromagnet 420, and the magnetic field generated by the electromagnet 420 can be effectively applied to the above-described magnetic block 250 and , the movement control of the magnetic block 250 by the electromagnet unit 40 can be easily made.

Since the above-described cover member 430 is formed of a magnetic material, the magnetic field directed toward the outer peripheral surface of the electromagnet 420 may pass through the inside of the cover member 430 without divergence. Accordingly, the magnetic field generated by the electromagnet 420 can be effectively applied to the above-described magnetic block 250 .

Meanwhile, the four electromagnets 420 may be disposed to face each of the four block movement paths 240 and the four magnetic blocks 250 described above. That is, each of the block movement path 240 , the magnetic block 250 , and the electromagnet 420 may be aligned in a radial direction with respect to the longitudinal central axis of the cylinder unit 10 .

7 is a partially enlarged view of the electromagnet 40 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure shown in FIG. 1 .

Referring to FIG. 7 , the cylinder body 110 may be provided with a locking protrusion 111 formed with an increased diameter of the outer circumferential surface. The outer circumferential surface of the cylinder body 110 may be formed to be stepped by the locking jaw portion 111 .

In addition, the above-described fixing member 410 may be formed with a seating jaw portion 412 having a shape complementary to the above-described locking jaw portion 111 . The seating jaw part 412 may be formed to protrude from the inner circumferential surface of the fixing member 410 in the central axis direction of the cylinder part 10 , and the seating jaw part 412 may be formed to have a ring shape in cross section.

In addition, an insertion groove 413 formed by being depressed inwardly may be formed on one side of the outer circumferential surface of the fixing member 410 . The insertion groove 413 may be formed to have a ring shape in cross section, and the insertion groove 413 may be disposed at the same radial position as the seating jaw portion 412 in the longitudinal central axis of the cylinder portion 10 . have.

Meanwhile, a protrusion member 432 protruding outwardly and inserted into the above-described insertion groove 413 may be formed on one side of the inner circumferential surface of the cover member 430 . The protruding member 432 may be formed to have a ring shape in its cross section, and the protruding member 432 has the same radius as the seating jaw part 412 in the longitudinal central axis of the cylinder part 10 like the insertion groove 413 . It may be disposed in a directional position.

As the protrusion member 432 of the cover member 430 is inserted in the insertion groove 413 of the fixing member 410 in the radial direction of the cylinder part 10 , the cylinder between the cover member 430 and the fixing member 410 . A locking structure is formed in the longitudinal direction of the part 10, and even when an external impact in the longitudinal direction continuously acts on the cylinder part 10, the coupling structure between the cover member 430 and the protruding member 432 is can be kept strong.

In addition, the fixing member 410 and the cover member 430 may be coupled to the cylinder body 110 by a fastening member 440 inserted and fastened in a radial direction from the outside of the cylinder part 10 . The fastening member 440 may pass through the fixing member 410 , the cover member 430 , and the cylinder body 110 at the same time to be coupled thereto. In addition, the fastening member 440 is inserted and fastened in the radial direction of the cylinder part 10, and even when an external impact is applied in the longitudinal direction of the cylinder part 10, the fastening member 440 is separated in the radial direction. It is possible to prevent the problem of separation, and the fixing member 410 and the cover member 430 can be firmly coupled to the cylinder body 110 .

Furthermore, a plurality of fastening members 440 may be provided, and preferably, eight coupling members 440 may be provided and positioned radially with respect to the central axis of the cylinder part 10 . The plurality of fastening members 440 may be spaced apart at an equal angle with respect to the central axis of the cylinder part 10 to couple the fixing member 410 and the fastening member 440 to the cylinder body 110 .

In addition, a connector (not shown) spaced apart from the insertion groove 413 may be formed inside the insertion groove 413 of the fixing member 410 in the radial direction. The connector may be formed by penetrating the fixing member 410 in the longitudinal direction of the cylinder part 10 , and one side of the first insertion groove 413 may communicate with the outside through the connector. The connector may be formed corresponding to the number of the electromagnets 420 , and a wire (not shown) for applying a current to the electromagnet 420 may be connected to the electromagnet 420 through the connector.

On the other hand, when the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure is vertically disposed on the ground, the engaging jaw portion 111 may be formed in the lower portion of the cylinder body 110 . That is, when the cylinder part 10 is vertically disposed on the ground, the diameter of the outer circumferential surface of the cylinder body 110 may be formed to be smaller in the upper part than the lower part. In addition, the electromagnet unit 40 may be stably seated on the engaging jaw portion 111 of the cylinder body 110 through the above-described seating jaw portion 412 .

In addition, when the cylinder part 10 is disposed perpendicular to the ground, the fastening member 440 may be positioned under the electromagnet part 40 , and the protruding member 432 and the insertion groove 413 are the fastening member ( 440). That is, when the cylinder part 10 is disposed perpendicular to the ground, the electromagnet 420 in the longitudinal direction of the cylinder part 10 may be positioned between the fastening member 440 and the protruding member 432 , and The fixing of the electromagnet 420 by the fixing member 410 and the cover member 430 can be firmly maintained.

8 is a view illustrating the movement of the piston unit 20 toward the electromagnet unit 40 when the damping force adjustable shock absorber 1 is compressed according to an embodiment of the present disclosure. Figure 8 (a) is a view showing a state before the piston rod part 30 is pressurized and drawn into the cylinder part 10, Figure 8 (b) is the piston rod part 30 is pressurized to the cylinder part (10) It is a view showing the state drawn into the interior.

Referring to FIG. 8 , the viscous fluid F enclosed in the cylinder part 10 may be a magnetic viscous fluid F, and when a current is applied to the electromagnet 420 described above, the piston part 20 and the cylinder The viscosity of the magneto-viscous fluid F located between the inner surfaces of the part 10 may be increased.

The above-described magneto-viscous fluid F may have a change in viscosity depending on the strength of an applied magnetic field, and for example, the magneto-viscous fluid F may be formed of a viscous fluid F containing fine particles having ferromagnetic properties. .

Meanwhile, as described above, since the four electromagnets 420 are radially disposed with respect to the central axis of the cylinder unit 10 , magnetic force in a radial direction may be generated from the central axis of the cylinder unit 10 . When a current is applied to the electromagnet 420 described above, the magnetic force generated in the electromagnet 420 flows in the gap C between the outer circumferential surface of the piston part 20 and the inner circumferential surface of the cylinder part 10. A magnetic viscous fluid ( F) may be uniformly applied, and the viscosity of the magnetic viscous fluid F may be increased to increase the damping force between the cylinder part 10 and the piston part 20 .

Meanwhile, the above-described electromagnet unit 40 may be positioned so as to be radially aligned with the piston unit 20 when the piston rod unit 30 is drawn into the cylinder unit 10 as much as possible. That is, the viscosity of the magneto-viscous fluid F in the cylinder part 10 may be formed differently depending on the longitudinal position of the cylinder part 10, and as shown in FIG. 8(b), the piston part ( As 20) is positioned adjacent to the electromagnet part 40, the viscosity of the magneto-viscous fluid F flowing in the gap C between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 may increase. .

As described above, when a current is applied to the electromagnet 420 , the viscosity of the magneto-viscous fluid F is linear as the piston rod part 30 is drawn in and the piston part 20 moves toward the electromagnet part 40 side. It can be improved, and when the piston part 20 is positioned closest to the electromagnet part 40, the viscosity of the magneto-viscous fluid F can be formed to be the highest. Through this, when an external shock is applied to the shock absorber while current is being applied to the electromagnet 420 , the damping force between the cylinder part 10 and the piston rod part 30 may be gradually and continuously increased, and through this, the external Even when a shock is generated and the shock absorber is compressed, the stability felt by the user in the vehicle may be improved.

On the other hand, as described above, the fixing member 410 and the cylinder body 110 are formed of a non-ferrous material, and the cover member 430 is formed of a magnetic material, and the fixing member 410 and the cylinder body 110 are formed of a magnetic material. While no magnetic path is formed when current is applied to the electromagnet 420 , the magnetic field directed toward the outer peripheral surface of the electromagnet 420 may pass through the inside of the cover member 430 without divergence. Through this, the magnetic field generated by the electromagnet 420 can be effectively applied to the magneto-viscous fluid F enclosed in the cylinder part 10, and the damping force adjustment by the electromagnet part 40 and the magneto-viscous fluid F is controlled. can be done effectively.

9 is a view showing a state in which the volume of the valve seat 280 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure is changed according to the temperature. Specifically, (a) of Figure 9 is a view showing the shape when the ambient temperature of the valve seat 280 is at approximately room temperature, Figure 9 (b) is the ambient temperature of the valve seat 280 is at a high temperature. It is a diagram showing the shape when

10 is a diagram schematically showing the control unit 70 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure.

9 and 10 , the aforementioned piston unit 20 may further include a valve seat 280 formed on the first flow path 220 and engaged with the valve member 330 . The valve seat 280 may be coupled to the piston body 210 so as to be positioned at an end of the first flow path 220 on the second region 122 side of the first flow path 220 . In addition, the valve seat 280 may be formed in an open cone shape by cutting the tip portion, and the inner diameter of one end of the valve seat 280 on the first flow path 220 side is the same as the diameter of the first flow path 220 . can be formed. In addition, the inner diameter of the other end of the valve member 330 side of the valve seat 280 may be formed larger than the diameter of the first flow path 220 .

In addition, the inner circumferential surface of the valve seat 280 may be formed in a shape complementary to the outer surface of the first flow path 220 of the valve member 330 , and the valve member 330 aligns the longitudinal direction of the cylinder part 10 . Accordingly, when moving toward the first flow path 220 , the valve member 330 may be engaged with the inner circumferential surface of the valve seat 280 to close the first flow path 220 .

The above-described valve seat 280 may be formed of a resin material. Through this, the valve seat 280 may be formed to have a predetermined elasticity, and when the valve member 330 is engaged with the valve seat 280 , the airtightness between the valve member 330 and the valve seat 280 will be improved. can

On the other hand, as the valve seat 280 is formed of a resin material, the volume of the valve seat 280 may be changed by a change in ambient temperature.

For example, when the ambient temperature of the valve seat 280 is room temperature (approximately 25° C.) as shown in FIG. 9 (a), no substantial change occurs in the volume of the valve seat 280, but the ambient temperature And when the ambient temperature of the valve seat 280 is raised to a high temperature of about 40 to 60°C due to the heating of the surrounding parts by the repeated use of the shock absorber, the valve seat 280 is shown in FIG. As it expands, its volume can be increased.

When the valve seat 280 is expanded due to the high ambient temperature, the valve seat 280 is expanded toward the valve member 330, and accordingly, the separation distance between the valve seat 280 and the valve member 330 is the valve seat It may be formed differently depending on the ambient temperature of 280 . That is, when the valve member 330 is positioned with the same spacing with respect to the piston body 210 , the viscous fluid F flowing through the first flow path 220 according to the ambient temperature of the valve seat 280 . The flow rate can be varied.

The damping force adjustable shock absorber 1 according to an embodiment of the present disclosure includes a temperature sensor unit 60 that detects the temperature of the viscous fluid F enclosed in the cylinder unit 10, and a valve seat at a predetermined temperature condition ( The control unit 70 may further include a data storage unit 80 in which expansion information indicating an expansion amount of the 280 is stored, and a control unit 70 for adjusting a magnitude of a voltage value applied to the piezo actuator 340 .

The above-described temperature sensor unit 60 may be disposed on the side into which the piston rod unit 30 is inserted in the longitudinal direction of the cylinder unit 10 , and specifically, the electromagnet unit 40 and the second flange 140 . ) may be located adjacent to the second flange 140 between. In addition, the temperature sensor unit 60 is coupled to the outer circumferential surface of the cylinder body 110 , and a part thereof may be installed to be inserted into the cylinder unit 10 .

In addition, the control unit 70, based on the temperature of the viscous fluid F detected by the temperature sensor unit 60 and the expansion information stored in the data storage unit 80, the voltage value applied to the piezo actuator 340 You can resize it. At this time, the expansion information stored in the data storage unit 80 may mean volume information of the valve seat 280 according to the temperature of the viscous fluid F flowing in the valve seat 280 .

That is, when the ambient temperature of the valve seat 280 becomes a low temperature of -20 to 0 ° C, a room temperature of about 25 ° C, or a high temperature of about 40 to 60 ° C, the valve seat ( The volume information of 280 may be stored in the data storage unit 80 . On the other hand, the expansion information of the valve seat 280 for each temperature stored in the data storage unit may be stored together with the material information of the resin material valve seat 280, and even if the material of the valve seat 280 is changed, the corresponding valve The temperature-specific expansion information corresponding to the material of the sheet 280 may be used to adjust the voltage value of the piezo actuator 340 by the controller 70 .

On the other hand, the ambient temperature of the valve seat 280 may be replaced with the temperature of the viscous fluid (F) detected by the above-described temperature sensor unit 60, and the valve seat for each temperature section stored in the data storage unit 80 ( 280) may be calculated and stored based on the temperature of the viscous fluid F detected by the above-described temperature sensor.

That is, the control unit 70, based on the volume change of the valve seat 280 according to the ambient temperature of the actual valve seat 280 through the temperature detection of the viscous fluid F, the voltage applied to the piezo actuator 340 You can adjust the value.

Through this, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure includes preset control information of a voltage level applied to the piezo actuator 340 to open and close the first flow path 220 and the actual first flow path. It is possible to prevent an error from occurring between the magnitude of the voltage to be applied to the piezo actuator 340 to open and close 220 . That is, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may suppress a change in the opening degree or a change in flow rate of the first flow path 220 according to thermal expansion of the valve seat 280 due to a change in temperature.

Accordingly, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure can improve the accuracy of damping force control.

The above-described control unit 70, whether voltage is applied to the piezo actuator 340, and/or the magnitude of the voltage value applied to the piezo actuator 340, and/or whether current is applied to the plurality of electromagnets 420, and / Alternatively, the piezo actuator 340 and/or the electromagnet 420 may be controlled by determining the magnitude of the current value applied to the plurality of electromagnets 420 .

In addition, the control unit 70 may acquire vehicle speed information from the vehicle system control unit 3a provided in the vehicle equipped with the shock absorber according to an embodiment of the present disclosure, and based on the acquired vehicle speed information, the piezo actuator ( 340) and whether or not the electromagnet 420 operates and the operating strength can be adjusted. Specific details thereof will be described in the description of FIG. 12 . The vehicle system control unit 3a may be a vehicle integrated control unit 70 provided in the vehicle to detect and calculate vehicle fuel information, vehicle speed information, and vehicle state information, or a VSM (Vehicle Stability Management) system. can

In addition, the control unit 70 may acquire the temperature information of the viscous fluid F in the cylinder unit 10 from the above-described temperature sensor unit 60 , and the control unit 70 may be configured for each temperature section from the data storage unit 80 . Information on the degree of expansion of the valve seat 280 may be acquired. Through this, the control unit 70, based on the temperature of the viscous fluid F detected by the temperature sensor unit 60 and the expansion information stored in the data storage unit 80, whether a voltage is applied to the piezo actuator 340 and / or the voltage strength can be controlled.

Furthermore, the control unit 70 may acquire acceleration information of the relative displacement of the piston rod unit 30 with respect to the cylinder unit 10 from the above-described acceleration sensor unit 50 . When the acceleration value detected by the acceleration sensor unit 50 exceeds a predetermined reference value, the control unit 70 limits the voltage application applied to the piezo actuator 340 and the current application applied to the electromagnet 420 . can do. Specific details thereof will be described in the description of FIG. 12 below.

11 is a diagram schematically illustrating the acceleration sensor unit 50 of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure.

Referring to FIG. 11 , the aforementioned acceleration sensor unit 50 may be positioned in contact with the third flange 350 on the outer circumferential surface of the piston rod body 310 , and the acceleration sensor unit 50 includes an ultrasonic transmitter 510 and An ultrasound receiver 520 may be included.

The ultrasonic transmitter 510 and the ultrasonic receiver 520 may be disposed to face the second flange 140 . The ultrasonic transmitter 510 may radiate ultrasonic waves of a predetermined speed from the third flange 350 side to the second flange 140 side, and the emitted ultrasonic waves are reflected from the second flange 140 to the third flange 350 . ) may be introduced into the ultrasonic receiver 520 of the side.

The acceleration sensor unit 50 may detect a separation distance between the second flange 140 and the third flange 350 and a required time from the ultrasound transmitter 510 to reception from the above-described ultrasound transmission/reception information. Also, the acceleration sensor unit 50 may calculate an acceleration for a displacement difference between the second flange 140 and the third flange 350 based on the above-described separation distance and required time.

Through this, when a change occurs in the relative displacement between the piston rod part 30 and the cylinder part 10 due to the action of an external force, the acceleration sensor part 50 is formed between the piston rod part 30 and the cylinder part 10 . It is possible to detect acceleration information about the relative displacement change of . Also, the acceleration sensor unit 50 may transmit the detected acceleration information to the control unit 70 .

12 is a diagram schematically showing a control form of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure according to the acquired speed information.

Referring to FIG. 12 , the control unit 70 divides the piezo actuator 340 and the electromagnet unit 40 into three speed modes based on the vehicle traveling speed information acquired from the above-described vehicle system control unit 3a. can Specifically, the controller 70 may control the piezo actuator 340 and the electromagnet 420 of the electromagnet unit 40 by dividing them into three speed modes according to the driving speed of the vehicle.

For example, the control unit 70 may control the piezo actuator 340 and the electromagnet 420 in the first speed mode M1 when the acquired vehicle traveling speed is greater than approximately 0 km/h and less than or equal to 40 km/h. , when the acquired vehicle traveling speed is approximately 40 km/h or less and 80 km/h or less, the piezo actuator 340 and the electromagnet 420 may be controlled in the second speed mode M2, and the acquired vehicle traveling speed is approximately 80 When the speed exceeds km/h, the piezo actuator 340 and the electromagnet 420 may be controlled in the third speed mode M3.

In the first speed mode M1 in which the vehicle travels at a relatively low speed, the control unit 70 may cut off the voltage applied to the piezo actuator 340 and the current applied to the electromagnet 420 , through which one of the present disclosure The damping force of the damping force adjustable shock absorber 1 according to the embodiment may act softly. That is, when an external shock is applied to the vehicle according to the road surface condition when the vehicle is traveling at a low speed, it is possible to provide a stable riding comfort to the vehicle occupants by absorbing the shock smoothly.

Also, in the second speed mode M2 in which the vehicle travels at a relatively medium speed, the controller 70 may apply a voltage to the piezo actuator 340 but block the current applied to the electromagnet 420 . Through this, the damping force of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may act as an intermediate damping force between the soft and hard ones. In other words, when an external shock is applied to the vehicle depending on the road surface condition when the vehicle is driving at medium speed, it can provide a stable ride comfort to the vehicle occupants by absorbing some of the shock, and also strengthen the shock absorber between driving of the vehicle or handling in a curve section rather firmly. It can provide stable driving performance to the vehicle. Alternatively, in the second speed mode M2 , the controller 70 may apply a current to the electromagnet 420 while blocking the voltage applied to the piezo actuator 340 .

Meanwhile, in the third speed mode M3 in which the vehicle travels at a relatively high speed, the controller 70 may apply a voltage to the piezo actuator 340 and apply a current to the electromagnet 420 . Through this, the damping force of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may act as a hard damping force. That is, when the vehicle is traveling at high speed, it is possible to provide stable driving performance to the vehicle by firmly holding the shock absorber between driving of the vehicle or handling of a curve section.

On the other hand, when the control unit 70 is controlling the piezo actuator 340 and the electromagnet 420 based on the third speed mode M3, the acceleration sensor unit 50 detects the sudden external shock caused by the road surface condition. When the determined acceleration value exceeds a predetermined reference value, the control unit 70 may immediately stop the operation of the piezo actuator 340 and the control unit 70 .

Through this, when the piston rod part 30 is drawn into the cylinder part 10 due to an external impact and the shock absorber is compressed, the damping force of the shock absorber can be reduced, and even when a sudden shock is applied during high-speed driving, through the shock absorber By absorbing external shocks more gently, it is possible to provide a stable ride comfort to vehicle occupants.

In this case, as the first flow path 220 and the second flow path 230 are closed, the damping force of the shock absorber is momentarily increased greatly, and the piston unit 20 is pressed toward the electromagnet unit 40 and moved. The viscosity of the magneto-viscous fluid F flowing in the gap C between the outer peripheral surface of the piston part 20 and the inner peripheral surface of the cylinder part 10 by the electromagnet 420 may be gradually and continuously increased. Through this, the stability felt by the user in the vehicle during the shock absorption process by the shock absorber may be improved.

As described above, in the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure, not only the damping force can be continuously increased or decreased, but also the operation of the piezo actuator 340 and/or the electromagnet 420 is controlled. Thus, the damping force magnitude of the shock absorber can be quickly adjusted in a stepwise manner.

13 is a diagram schematically showing a shock absorber control system 2 according to another embodiment of the present disclosure.

Referring to FIG. 13 , the shock absorber control system 2 according to another embodiment of the present disclosure includes the damping force adjustable shock absorber 1 according to the embodiment of the present disclosure described above, and a control module provided in the vehicle to be operated by the user. (3b) may be included. At this time, a plurality of the above-described damping force adjustable shock absorbers 1 may be provided and mounted on the vehicle body, and the damping force adjustable shock absorber 1 is configured to absorb changes in vehicle body height and external shocks according to road surface conditions between driving of the vehicle. can be configured.

The above-described control module 3b refers to a control module capable of inputting a command signal by direct manipulation by a user, and may be formed as a console module or a touchable display. However, this is not limited thereto by way of example, and the control module 3b may be formed of a manipulation module that can be directly manipulated by a user, such as a button-type manipulation unit and a rotation-type manipulation unit.

The user can half-manually operate the control unit 70 through the control module 3b built into the vehicle, and the control unit 70 controls the piezo actuator 340 and the electromagnet unit 40 as described above. to the third speed mode (M1, M2, M3), the user can control the intensity of the voltage applied to the piezo actuator 340 and/or the current applied to the electromagnet 40 through the control module 3b. By adjusting the strength, the damping force of the shock absorber can be finely manually manipulated.

In addition, the user can completely manually operate the control unit 70 through the control module 3b, and in this case, regardless of the first to third speed modes M1, M2, and M3, the user can operate the piezo actuator It is possible to directly determine whether the operation of the 340 and whether the electromagnet unit 40 is operated. As described above, by allowing the user to directly manipulate the magnitude of the damping force, it is possible to provide an optimized riding and driving feeling for individual users.

In addition, the shock absorber control system 2 according to another embodiment of the present disclosure may further include a display unit 3c provided in the vehicle to provide damping force information to the user. Specifically, the display unit 3c may output information on the speed mode in which the current control unit 70 operates. Furthermore, the display unit 3c may output information on whether the above-described piezo actuator 340 and the electromagnet 420 are operated and/or operation strength information.

In addition, the display unit 3c may provide information on the current damping force strength of the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure mounted on a vehicle. For example, the damping force information may be provided by being divided into 1 to 100, and the softer the damping force, the closer to 1, and the harder the damping force, the closer to 100.

Through this, the user can intuitively recognize the damping force information of the shock absorber currently applied to the vehicle, and can easily control the damping force strength of the shock absorber to a desired degree by manipulating the control module 3b as necessary.

Meanwhile, according to another embodiment of the present disclosure, a vehicle including the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may be provided. At this time, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may be mounted on the vehicle body. In addition, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may be connected to a wheel of a vehicle to attenuate vibration and shock transmitted from the road surface during vehicle driving. In this case, the shock absorber applied to the vehicle according to another embodiment of the present disclosure is substantially the same as the damping force adjustable shock absorber 1 according to the embodiment of the present disclosure described above, and a detailed description thereof will be omitted.

Meanwhile, according to another embodiment of the present disclosure, a vehicle including the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may be provided. At this time, the damping force adjustable shock absorber 1 according to an embodiment of the present disclosure may be mounted on a lower portion of a seat seat of a vehicle in which an occupant can be seated. Through this, vibration transmitted to the seat seat of the vehicle during vehicle driving may be attenuated, and a stable riding comfort may be provided to vehicle occupants. In this case, the shock absorber applied to the vehicle according to another embodiment of the present disclosure is substantially the same as the damping force adjustable shock absorber 1 according to the embodiment of the present disclosure described above, and a detailed description thereof will be omitted.

The various embodiments described above may be embodied in other specific forms without departing from the technical idea and essential characteristics thereof. Accordingly, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the various embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the various embodiments are included in the scope of the various embodiments. In addition, claims that are not explicitly cited in the claims may be combined to form an embodiment or may be included as a new claim by amendment after filing.

1: Damping force adjustable shock absorber
10: cylinder part
110: cylinder body
111: jamming chin
121: Zone 1
122: second zone
130: first flange
140: second flange
20: piston unit
210: piston body
220: first euro
230: second euro
240: block movement path
241: guide unit
250: magnetic block
251: guide home
260: side cover part
270: elastic member
280: valve seat
30: piston rod part
310: piston rod body
311a: first bore
311b: second bore
312: bore euro
320: valve rod
330: valve member
340: piezo actuator
350: third flange
40: electromagnet
410: fixing member
411: first receiving groove
412: seating chin
413: insertion groove
420: electromagnet
430: cover member
431: second storage groove
432: protrusion member
440: fastening member
50: acceleration sensor unit
510: ultrasonic transmitter
520: ultrasonic receiver
60: temperature sensor unit
70: control unit
80: data storage unit
2: Buffer control system
3a: vehicle system control
3b: control module
3c: display unit
S: spring member
F: viscous fluid
C: gap

Claims (12)

A hollow cylinder part with a viscous fluid enclosed therein;
a piston part slidably disposed in the cylinder part with a gap through which the viscous fluid can pass between the inner surfaces of the cylinder part; and
A piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part
including,
The piston part divides the inner space of the cylinder part into a first zone and a second zone,
A first flow path through which the viscous fluid flows is formed in the piston part,
The piston rod part,
a piston rod body extending from the piston part;
an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body;
a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and
A piezo actuator formed at the other end of the valve rod in the longitudinal direction and sliding the valve rod toward the first flow path as a voltage is applied.
includes,
The piston rod body is provided with an acceleration sensor,
When the acceleration value detected by the acceleration sensor unit exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, the damping force adjustable shock absorber.
a cylinder part formed in a hollow cylinder having a predetermined length, and having a viscous fluid enclosed therein;
a piston part having a cylindrical shape slidably disposed in a longitudinal direction of the cylinder part in the cylinder part, wherein a gap through which the viscous fluid can pass is formed between an outer circumferential surface of the piston part and an inner circumferential surface of the cylinder part; and
A piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part
including,
The piston part divides the inner space of the cylinder part into a first zone and a second zone,
A first flow path through which the viscous fluid flows is formed in the piston part,
The piston rod part,
a piston rod body extending from the piston part;
an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body;
a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and
A piezo actuator formed at the other end of the valve rod in the longitudinal direction and sliding the valve rod toward the first flow path as a voltage is applied.
includes,
The piston rod body is provided with an acceleration sensor,
When the acceleration value detected by the acceleration sensor unit exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, the damping force adjustable shock absorber.
A hollow cylinder part with a viscous fluid enclosed therein;
a piston part slidably disposed in the cylinder part with a gap through which the viscous fluid can pass between the inner surfaces of the cylinder part; and
A piston rod part connected to the piston part and configured to be drawn into or drawn out from the cylinder part
including,
The piston part divides the inner space of the cylinder part into a first zone and a second zone,
A first flow path connecting the first zone and the second zone is formed in the piston part, and the viscous fluid flows from one of the first zone and the second zone to the other one through the first flow passage. can flow into the area of
The piston rod part,
a piston rod body extending from the piston part;
an elongate valve rod slidably formed in the piston rod body in the longitudinal direction of the piston rod body;
a valve member formed at one end in the longitudinal direction of the valve rod and opening and closing the first flow path as the valve rod slides; and
A piezo actuator formed at the other end of the valve rod in the longitudinal direction and sliding the valve rod toward the first flow path as a voltage is applied.
includes,
The piston rod body is provided with an acceleration sensor,
When the acceleration value detected by the acceleration sensor unit exceeds a predetermined reference value, the voltage applied to the piezo actuator is limited, the damping force adjustable shock absorber.
4. The method according to any one of claims 1 to 3,
Positioned on the outer surface of the cylinder portion and further comprising an electromagnet that exhibits magnetism as current is applied, damping force adjustable shock absorber.
5. The method according to claim 4,
The piston part,
a second flow path formed along the longitudinal direction of the cylinder part between the longitudinal central axis of the cylinder part and an inner surface of the cylinder part to connect the first zone and the second zone;
a block moving path formed to intersect the second flow path; and
a magnetic block disposed in the block movement path and capable of opening and closing the second flow path by the magnetism of the electromagnet part;
Which will further include, damping force adjustable shock absorber.
6. The method of claim 5,
The piston part further comprises an elastic member positioned in the block movement path to press the magnetic block toward the center of the piston part,
At least one guide part is formed to protrude on the block moving path,
In the magnetic block, the damping force adjustable shock absorber is formed along the longitudinal direction of the block movement path and the at least one guide part is formed with a guide groove to be inserted and guided.
5. The method according to claim 4,
The electromagnet part is located on the opposite side of the piston rod part with respect to the piston part in the longitudinal direction of the cylinder part,
The electromagnet unit,
a plurality of electromagnets radially spaced apart from the central axis of the cylinder part;
a fixing member of a non-magnetic material disposed on an outer surface of the cylinder part; and
A cover member of a magnetic material disposed on the outer surface of the plurality of electromagnets and for fixing the plurality of electromagnets between the fixing member and the fixing member
including,
The viscous fluid is a magneto-viscous fluid,
When a current is applied to the electromagnet, the viscosity of the magneto-viscous fluid flowing into the gap between the piston part and the inner surface of the cylinder part is increased.
4. The method according to any one of claims 1 to 3,
The piston part further includes a valve seat formed on the first flow path and engaged with the valve member,
The valve seat is formed of a resin material,
The damping force adjustable shock absorber,
a temperature sensor unit detecting a temperature of the viscous fluid in the cylinder unit;
a data storage unit storing expansion information indicating an expansion amount of the valve seat in a predetermined temperature condition; and
A control unit for adjusting the magnitude of a voltage value applied to the piezo actuator based on the temperature of the viscous fluid detected by the temperature sensor and the expansion information stored in the data storage unit
Which will further include, damping force adjustable shock absorber.
5. The method according to claim 4,
The damping force adjustable shock absorber can be installed in a vehicle,
The damping force adjustable shock absorber further comprises a control unit for acquiring the vehicle traveling speed information,
The control unit, based on the obtained traveling speed information, whether a voltage is applied to the piezo actuator, whether a current is applied to the electromagnet unit, a magnitude of a voltage value applied to the piezo actuator, and applied to the electromagnet unit and controlling at least one of the magnitude of the current value.
10. The method of claim 9,
The control unit may divide and control the piezo actuator and the electromagnet unit into a first speed mode, a second speed mode and a third speed mode according to the acquired travel speed information,
In the first speed mode, the control unit cuts off the voltage applied to the piezo actuator and the current applied to the electromagnet unit,
In the second speed mode, the control unit applies a voltage to the piezo actuator, but blocks the current applied to the electromagnet unit,
In the third speed mode, the control unit applies a voltage to the piezo actuator and applies a current to the electromagnet unit, the damping force adjustable shock absorber.
The damping force adjustable shock absorber according to any one of claims 1 to 3, wherein a plurality of the damping force adjustable shock absorbers are provided and mounted on a vehicle body, the damping force adjustable shock absorber;
a control module provided in the vehicle and operable by a user; and
A display unit provided in the vehicle to provide information on the damping force of the damping force adjustable shock absorber to the user
A vehicle shock absorber control system comprising a.
The damping force adjustable shock absorber according to any one of claims 1 to 3; and
Seats that can accommodate passengers
including,
The damping force adjustable shock absorber will be mounted on the lower portion of the seat seat, the vehicle.

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