Description ROTATION TYPE OIL DAMPER

Technical Field

[1] The present invention relates to a damper, and more particularly, to a rotary-type oil damper that can damp a rotating force, which is generated when a door and a cover or lid are opened and closed, by using a blade rotating along a rotation axis and a flow resistance of a viscous fluid. Background Art

[2] Generally, in a process of opening and closing a door, a cover, a lid, and so on, a rotary-type damper is used in order to prevent the door or lid to be closed abruptly by controlling its rotating force. The related art rotary-type damper broadly includes an elastic member type damper, which uses an elastic member such as a spring, and a viscous fluid type damper, which uses a viscous fluid to provide a damping force.

[3] Among the two types, in the elastic member type, the damping force is generated with respect to both a clockwise direction and a counter-clockwise direction. Therefore, when the damping force is required in only one of the two directions, the elastic member type damper cannot be adopted. Also, as the usage of the damper becomes more frequent, the elasticity of the elastic member deteriorates, thereby becoming unable to maintain a constant damping force.

[4] Meanwhile, in the rotary-type oil damper using the viscous fluid, the inside of a housing is filled with viscous fluid. And, a blade rotating within the housing is operated while being closely pressed to an inner peripheral surface of the housing. Also, a fluid flow path allowing the viscous fluid to pass through is formed on the blade, thereby generating the damping force from the flow resistance of the viscous fluid.

[5] Such related art rotary-type oil damper is disclosed in the Korean Patent Application

No. 414520 or in the Korean Utility Model No. 422594. Disclosure of Invention

Technical Problem

[6] However, as opposed to the above-described oil damper that requires a control in the damping force in accordance with a rotation degree to which an object for application is rotated, the related art rotary-type oil damper is disadvantageous in that such control of the damping force is impossible. This is because the resistance applied to the blade formed inside the housing of the oil damper is equal to the resistance generated by the viscous fluid regardless of the rotation degree.

[7] Also, in the related art oil damper, a plurality of assembly parts is formed inside the

housing in order to generate the damping force from airtight sealing and rotation of the viscous fluid. Thus, the structure becomes complicated, and the assembly process also becomes complicated, thereby causing a decrease in productivity. Additionally, the fabrication cost increases due to this complicated structure, and the growth in the overall size of the oil damper leads to limitations in applying the oil damper in various fields of technology.

[8] Moreover, the related art oil damper could not provide a completely airtight structure inside the housing. Therefore, the viscous fluid within the housing leaked to the outside, thereby causing a gradual deterioration in the damping force with respect to the frequent usage of the oil damper. In addition, the leakage of the viscous fluid also caused the surroundings of the oil damper to be unclean.

[9] Furthermore, in the related art oil damper, the fluid flow path, through which the viscous fluid flows, is asymmetrically formed along the axial direction of the housing, which eventually leads to a concentration of the damping force in a particular area only, thereby causing the oil damper to have an unstable structure. More specifically, since the generation of the damping force is concentrated near the fluid flow path, the rotating structure of the valve, which rotates (or turns) around an axis, becomes unstable. The purpose of the present invention is to resolve the above-described problems. Technical Solution

[10] In an aspect of the present invention, a rotary-type oil damper includes a blade positioned in an airtight space, the airtight space being filled with a viscous fluid, a rotation axis being connected to an object for damping a rotating force and rotating the blade, and a first flow path being formed on the rotation axis so as to connect spaces divided by the blade, and having different cross-sections exposed to the divided spaces based upon rotating movements of the rotating axis.

[11] In the rotary-type oil damper according to an embodiment of the present invention, the first flow path may be formed along an edge of a bottom surface of the rotation axis, wherein the bottom surface is in contact with the airtight space.

[12] In the rotary-type oil damper according to an embodiment of the present invention, the first flow path may have a differently formed gap, wherein the gap is provided between the first flow path and the bottom surface of the airtight space based upon a rotating direction of the rotation axis.

[13] In the rotary-type oil damper according to an embodiment of the present invention, when the rotation axis rotates in one direction, the first flow path may reduce a flowing amount of the viscous fluid, and when the rotation axis rotates in an opposite direction, the first flow path may increase the flowing amount of the viscous fluid.

[14] The rotary-type oil damper according to an embodiment of the present invention, may further include a stopper extending from an inner wall of the airtight space to an outer peripheral surface of the rotation axis, so as to limit a rotating angle of the blade, and sequentially exposing the first flow path in a longitudinal direction.

[15] The rotary-type oil damper according to an embodiment of the present invention may further include a second flow path formed from an outer peripheral surface of the rotation axis and inwards and being connected with the first flow path.

[16] In the rotary-type oil damper according to an embodiment of the present invention, the second flow path may be positioned to be in close contact with a ceiling of the airtight space.

[17] The rotary-type oil damper according to an embodiment of the present invention may further include a regulating valve being positioned in the second flow path and regulating an open surface of the second flow path based upon a flowing pressure of the viscous fluid passing through the second flow path.

[18] The rotary-type oil damper according to an embodiment of the present invention may further include an elastic member elastically pushing and applying pressure to the regulating valve, so as to enable the regulating valve to block or narrow down the second flow path.

[19] In the rotary-type oil damper according to an embodiment of the present invention may further include a via hole passing through the rotation axis in a longitudinal direction so as to connect the second flow path with the outside, and having the regulating valve and the elastic member inserted therein, and a fixing member being fit around the via hole so as to seal the via hole, and being supported by the elastic member.

[20] In the rotary-type oil damper according to an embodiment of the present invention, the fixing member may be connected to the via hole by being screwed to the via hole, thereby being capable of regulating an applied pressure of the elastic member.

[21] The rotary-type oil damper according to an embodiment of the present invention may further include a via hole passing through the rotation axis in a longitudinal direction so as to connect the second flow path with the outside, and a fixing member being screwed to the via hole so as to seal the via hole, and having its lower end positioned to flow across the second flow path, thereby enabling an opening surface of the second flow path to be regulated, when the fixing member rotates.

[22] In the rotary-type oil damper according to an embodiment of the present invention, the second flow path may include a bent portion, and the regulating valve may be positioned to open and close the bent portion.

[23] The rotary-type oil damper according to an embodiment of the present invention may further include, when the regulating valve minimizes the second flow path, a bypass

formed on an outer surface of the regulating valve or formed to pass through the regulating valve, so as to allow a small amount of the viscous fluid to pass through the second flow path.

[24] The rotary-type oil damper according to an embodiment of the present invention may further include a supporting protrusion protruding from the bottom of the airtight space, so as to be inserted in a hollow groove formed on the lower end of the rotation axis.

[25] In the rotary-type oil damper according to an embodiment of the present invention, it is preferable that a gap is provided between an upper end of the supporting protrusion and a surface of the groove, and that the gap is connected with the first flow path.

[26] The rotary-type oil damper according to an embodiment of the present invention may further include a third flow path being formed to flow across the supporting protrusion, and being connected with the first flow path within a predetermined angle range, when the rotation axis rotates.

[27] In the rotary-type oil damper according to an embodiment of the present invention, it is preferable that the blade and the stopper are each formed in pairs and positioned to face into one another, and that the first flow path is also formed in pairs, wherein each path is positioned between the pair of blades.

[28] In the rotary-type oil damper according to an embodiment of the present invention, a cylindrical surface of the rotation axis positioned between each of the blades may be provided within a range of 140° with respect to a pivot of the rotation axis, each of the first flow paths may be provided on the bottom surface of the rotation axis adjacent to the side (or lateral) surface of the each blade within a range of 110° with respect to the pivot of the rotation axis, and each of the stoppers may be positioned so as to be provided within a range of 40° with respect to the pivot of the rotation axis.

[29] In another aspect of the present invention, a rotary-type oil damper includes a housing accommodating a viscous fluid therein and being covered by a cover, the cover including an opening, a rotation axis inserted in the housing and connected to an object for damping a rotating force, thereby being rotated, a compartment being extended from a mid-portion of the rotation axis to an inner side surface of the housing, thereby forming an airtight space being filled with the viscous fluid, a blade being extended from a lower portion of the rotation axis so as to divide the airtight space, and rotating along with the rotation axis, a stopper being extended from an inner surface of the housing to an outer surface of the rotation axis, and a first flow path being formed on the rotation axis and having cross-sections differently formed based upon a rotating direction of the rotation axis, so as to allow the viscous fluid to pass through.

Advantageous Effects

[30] The rotary-type oil damper according to the present invention having the above- described structure has the following effects.

[31] Firstly, when the rotation axis and the blades rotate, the cross-section of the first flow path allowing the viscous fluid to pass through is formed differently based upon the rotating direction of the rotation axis. And, accordingly, the flowing amount of the viscous fluid through the first flow path changes with respect to the rotating angle. This signifies that the damping force of the oil damper varies depending upon the rotating degree of the rotation axis. Therefore, according to the present invention, the level of the damping force of the oil damper can be controlled with respect to the object of application, by designing the oil damper so that the damping force has barely any influence at the beginning of the rotation of the object for damping the rotating force. However, the damping force gradually increases as the rotation progresses.

[32] Secondly, according to the present invention, by optimizing a rotation axis structure, which is mounted in the housing and generates a damping force by sealing the space accommodating the viscous fluid and by using the blades and the flow paths, the structure can be simplified and the number of assembly parts can be minimized, thereby enhancing productivity.

[33] Thirdly, according to the present invention, either a regulating valve that can regulate the flowing amount of the viscous fluid based upon the oil pressure is installed on the second flow path, or a lower end of a fixing member that can manually regulate the flowing amount of the viscous fluid is placed on the second flow path. In the former case, when the rotating force of the object for damping the rotating force is larger than usual, the regulating valve can double the opening of the second flow path, thereby decreasing the damping force. Accordingly, when the oil damper according to the present invention is applied to a door, the present invention is advantageous in that, when a person quickly (or abruptly) closes or opens the door, an adequate damping force is provided while the response to the person s operation is enhanced. In the latter case, even after the installation of the oil damper according to the present invention, the damping force of the oil damper can be adequately regulated based upon the object of application.

[34] Fourthly, according to the present invention, by preventing the viscous fluid from leaking to the outer side of the oil damper, the deterioration of the damping performance caused by frequent usage can be prevented, thereby maintaining a stable damping performance. Additionally, by preventing the leakage of the viscous fluid, the surroundings of the oil damper may be prevented from becoming unclean and dirty by the viscous fluid, thereby maintaining a level of cleanness in the oil damper.

[35] And, finally, by symmetrically designing the blades, the stoppers, and the first flow path, the damping force generated from an airtight space, which accommodates the viscous fluid, can be prevented from being concentrated onlyin one specific area, thereby enabling the oil damper to be designed with stability. Brief Description of Drawings

[36] Fig. 1 illustrates a perspective view of an oil damper according to an embodiment of the present invention;

[37] Fig. 2 illustrates a disassembled perspective view of the oil damper shown in Fig. 1;

[38] Fig. 3 illustrates a cross-sectional view taken along line I-I of Fig. 1;

[39] Fig. 4 illustrates a perspective cross-sectional view taken along line II-II of Fig. 1;

[40] Fig. 5 illustrates a schematic view of a partial lateral face (or side) (from 0° to 140°) of the rotation axis shown in Fig. 4;

[41] Fig. 6 and Fig. 7 illustrate perspective cross-sectional views showing the rotation axis in normal rotation, when the oil damper is operated;

[42] Fig. 8 illustrates a partial cross-sectional view showing the viscous fluid pushing a regulating valve while flowing, when the rotation axis of the oil damper is in reverse rotation; and

[43] Fig. 9 illustrates a cross-sectional view of an oil damper according to another embodiment of the present invention cut along line I-I of Fig. 3. Best Mode for Carrying out the Invention

[44] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, in the description of the present invention, the same reference numbers will be used throughout the drawings to refer to the same or like parts, and detailed description of the same will be omitted for simplicity.

[45] First of all, Fig. 1 illustrates a perspective view of an oil damper according to an embodiment of the present invention. Fig. 2 illustrates a disassembled perspective view of the oil damper shown in Fig. 1. Fig. 3 illustrates a cross-sectional view taken along line I-I of Fig. 1. Fig. 4 illustrates a perspective cross-sectional view taken along line II-II of Fig. 1. Fig. 5 illustrates a schematic view of a partial lateral face (or side) (from 0° to 140°) of the rotation axis shown in Fig. 4. Fig. 6 and Fig. 7 illustrate perspective cross-sectional views showing the rotation axis in normal rotation, when the oil damper is operated. Fig. 8 illustrates a partial cross-sectional view showing the viscous fluid pushing a regulating valve while flowing, when the rotation axis of the oil damper is in reverse rotation. And, Fig. 9 illustrates a cross-sectional view of an oil damper according to another embodiment of the present invention cut along line I-I of Fig. 3.

[46] The housing 110 has one open side, in which an accommodation space is formed.

The outer surface of the housing 110 has the shape similar to a rectangular parallelepiped (or a rectangular box), as shown in Fig. 1. However, the overall shape of the housing will not be limited only to the rectangular box-like figure and may vary depending upon the object that is to be mounted on the housing 110. The housing 110 may be fixed in a variety of methods in accordance with the mounting object. For example, the housing 110 may be inserted in and fixed to the mounting object, or, as shown in Fig. 1 to Fig. 3, the housing 110 may be stably fixed to the mounting object by using a flange 111 and a fastening element (not shown), which are formed on the outer surface of the housing 110 in order to be coupled with the mounting object. Herein, the flange 111 is provided with fastening apertures I l ia enabling the fastening element to pass through.

[47] The accommodation space is formed in a cylindrical shape, as shown in Fig. 2 and

Fig. 3, wherein its lower part is blocked by the housing 110 and its upper part is open. A viscous fluid such as oil is filled in the lower part of the accommodation space within the housing 110. Additionally, a rotation axis 130, which is connected to an object for damping the rotating force and rotates, is placed in the accommodation space. Then, the open upper part of the accommodation space is covered by a cover 120.

[48] The cover 120 is coupled with the open upper portion of the housing 110. More specifically, a fastening hole 124 is formed in each corner portion of the cover 120, as shown in Fig. 2. And, a coupling hole 114 corresponding to each fastening hole 124 is formed in each upper corner portion of the housing 110. Then, a fastening element 126 is formed to pass through each fastening hole 124 and coupling hole 114, thereby enabling the cover 120 to be coupled with the housing 110. Thus, the housing 110 is covered.

[49] An opening 121 is formed in the center portion of the cover 120, as shown in Fig. 1 and Fig. 2. Herein, the axis of the object for damping the rotating force is introduced inside the housing 110 by passing through the opening 121, so as to be connected with the rotation axis 130 provided inside the housing 110. Conversely, the rotation axis 130 may be exposed to the outside through the opening 121 and may be equipped so that the axis of the object for damping the rotating force can be connected with the end portion of the exposed rotation axis 130.

[50] The rotation axis 130 is placed on the central axis of the accommodation space in a longitudinal direction. At the mid-portion of the rotation axis 130, a compartment 140 is protruded, as shown in Fig. 3, so as to form an airtight space A at the lower portion of the accommodation space, which is filled with the viscous fluid. Also, a lower portion of the rotation axis 130 placed in the airtight space A is provided with a blade

150, which is positioned to be submerged in the viscous fluid, thereby damping the rotating force of the corresponding object by rotating along the rotation axis 130 and using the flow resistance of the viscous fluid. Hereinafter, the rotation axis 130, the compartment 140, and the blade 150 will be described in more detail with reference to the accompanying drawings.

[51] As shown in Fig. 2 and Fig. 3, the compartment 140 is placed at the mid-portion of the rotation axis 130. The compartment 140 is extended in all directions from the outer peripheral surface of the rotation axis 130 to the inner suface of the housing 110, thereby dividing the accommodation space into an upper portion and a lower portion. Accordingly, an airtight space A, which is surrounded by the compartment 140 and the bottom of the housing 110, is formed in the lower portion of the housing 110. The airtight space A formed as described above is then filled with a viscous fluid, i.e., oil.

[52] In order to enhance the airtight sealing force between the compartment 140 and the inner surface of the housing 110, a hollow (or concave) groove 141 is provided on the outer peripheral surface of the compartment 140, as shown in Fig. 2 and Fig. 3, and a ring-shaped sealing 145 is provided around the groove 141. The sealing 145 is in close contact with the outer peripheral surface of the compartment 140 and with the inner surface of the housing 110, thereby effectively preventing the oil filling the airtight space A from leaking.

[53] The rotation axis 130 is, for example, shaped like a long cylindrical bar and placed inside the accommodation space. The lower end of the rotation axis 130 is fixed to be in contact with the bottom of the housing 110, i.e., the bottom of the airtight space A. Since the compartment 140, which is extended from the mid-portion of the rotation axis 130, comes in contact with the inner surface of the housing 110, the rotation axis 130 stably placed in the center of the accommodation space within the housing 110 in the longitudinal direction, as shown in Fig. 3.

[54] A mounting groove 131 is formed on the upper end of the rotation axis 130, as shown in Fig. 3, so that the rotation axis 130 can be connected with a rotation axis of an external device (i.e., the axis of the object for damping the rotating force). Since the upper end of the rotation axis 130, which is placed so as to be connected with the outside through the opening 121, is connected to the object for damping the rotating force, the rotation axis 130 can rotate within the housing 110. While the rotation axis 130 rotates, a friction may be generated between the upper end of the rotation axis 130 and the cover 120. Therefore, as shown in Fig. 2 and Fig. 3, a washer 125 may be provided between the cover 120 and the upper end of the rotation axis 130.

[55] As shown in Fig. 3, a hollow groove 137 is formed on the lower end of the rotation axis 130, which comes in contact with the bottom of the airtight space A. A supporting protrusion 117 protrudes from the bottom of the airtight space A so as to be inserted in

the groove 137. Accordingly, the rotation axis 130 can stably rotate along a pivot of the rotation axis 130 without shaking. Meanwhile, a gap is formed between the supporting protrusion 117 and the upper inner surface of the groove 137 formed on the lower end of the rotation axis 130, as shown in Fig. 3. Herein, the gap is connected with a first flow path 101 and a second flow path 102, which will be described later on.

[56] The blade 150 is placed below the compartment 140 and is extended from the lower outer peripheral surface of the rotation axis 130 towards the inner side wall of the airtight space A. As shown in FIG. 4, the blade 150 is in close contact with the inner side wall of the airtight space A, thereby dividing the airtight space A into a plurality of unit spaces.

[57] According to an embodiment of the present invention, the blade 150 is provided in pairs, as shown in Fig. 2 and Fig. 4, and placed symmetrically with respect to the rotation axis 130. As described above, by symmetrically placing the blades 150, the damping force may be prevented from being concentrated in only a specific area, thereby stabilizing the structure of the oil damper. Conversely, however, in configuring the blade 150, only a single blade or at least three blades may be provided, which is/are arranged at a constant angle depending upon the rotating direction.

[58] As shown in Fig. 4, a stopper 115 is protruded from the inner side wall of the airtight space A. The stopper 115 is extended towards the rotation axis 130, so as to limit the rotating movements of the blade 150 when the rotation axis 130 is rotated. With the above-described structure, the rotation angle of the object for damping the rotating force, such as a door, a cover, or a lid, which is fixed to the oil damper 100 according to the present invention, may be limited.

[59] The stopper 115 may be formed to be extended to the outer peripheral surface of the rotation axis 130. Accordingly, by touching the outer peripheral surface of the rotation axis 130, the stopper 115 along with the blade 150 divides the airtight space A into a plurality of unit spaces. The stopper 115 having the above-described structure is also formed in pairs, just as the blades 150, which are arranged to symmetrically face into each other within the airtight space A.

[60] Meanwhile, a first flow path 101 connecting the unit spaces divided by the blades

150 is formed on the rotation axis 130. When the object for damping the rotating force rotates the rotaion axis 130, the blades 150 also rotate within the airtight space A. At this point, the viscous fluid within a unit space that is placed before the rotating direction of the blades 150 shifts to a unit space that is placed after the rotating direction through the first flow path 101. Due to a resistance of the viscous fluid generated during this process, the rotating force of the rotation axis 130 and the rotating force of the object for damping the rotating force are damped.

[61] Depending upon the rotating movement of the rotation axis 130, the cross-sections of

the first flow path 101 that are exposed to the divided unit spaces may be formed differently. More specifically, the first flow path 101 may have different cross-sections wherein the viscous fluid can flow based upon the rotating direction of the rotation axis 130. Therefore, the amount of the viscous fluid flowing from any one unit space to another unit space through the first flow path 101 may vary depending upon the rotating direction of the rotation axis 130. Accordingly, the damping force of the oil damper 100 may also vary depending upon the rotating direction of the rotation axis 130. Therefore, it can be advantageous in that the damping force of the oil damper 100 according to the present invention may be freely adjusted depending upon the subject to which the oil damper 100 is to be applied.

[62] As shown in Fig. 2 and Fig. 4, the first flow path 101 is formed along the edge of the bottom of the rotation axis 130, which contacts the bottom of the airtight space A. Since the cross-section of the first flow path 101 is formed differently depending upon the rotating direction of the rotation axis 130, the gap formed between the first flow path 101 and the bottom surface of the airtight space A may also be formed differently depending upon the rotating direction of the rotation axis 130.

[63] The cross-section of the first flow path 101 may either grow smaller or larger as it develops to one direction, as shown in Fig. 5. Herein, Fig. 5 illustrates a schematic view of the outer peripheral surface of the rotation axis 130 between a pair of blades 150, as shown in Fig. 4. In the oil damper 100 according to the embodiment of the present invention, a range of approximately 140° with respect to the center point of the rotation axis 130 is ensured as a cylindrical surface of the rotation axis 130, which is located between the side walls of each blade 150. Accordingly, Fig, 5 illustrates a schematic view of the outer peripheral surface of the rotation axis 130 starting from a point corresponding to 0° to a point corresponding to about 140° with respect to the pivot of the rotation axis 130. Also, in the embodiment of the present invention, each stopper 115 is arranged to be spaced apart by 40° with respect to the pivot of the rotation axis 130, as shown in Fig. 4. Additionally, the upper portion of Fig. 5 corresponds to the lower end of the rotation axis 130, which contacts the bottom of the airtight space A, and the lower portion of Fig. 5 corresponds to the upper end of the rotation axis 130, which contacts the ceiling of the airtight space A, i.e., the compartment 140.

[64] As shown in Fig. 4 and Fig. 5, for example, the cross-section of the first flow path

101, which contacts the side wall of any one blade 150 at an angle of 0° may have a larger surface. And, the cross-section of the first flow path 101 corresponding to a point closest to the side wall of the other blade 150, i.e., the cross-section formed at an angle of 110° may gradually decrease (or decrease step by step). Also, from the point corresponding to the angle of 110° to the point corresponding to an angle of 140°

which contacts the other blade 150, the first flow path 101 is not formed, and the respective surface is blocked. The first flow path 101 having the above-described structure is formed at both sides of the rotation axis 130 based upon the blades 150, as shown in Fig. 4.

[65] As described above, a range of about 40° with respect to the rotation axis 130 is ensured for the stopper 115, and a range of about 110° with respect to the rotation axis 130 is ensured for the first flow path 101. With the above-described structure, when the rotation axis 130 rotates, the first flow path 101 may be able to either separate or connect the unit spaces divided by the stopper 115, the rotation axis 130, and the blades 150.

[66] Meanwhile, as shown in Fig. 3 and Fig. 4, a second flow path 102 may further be formed on the rotation axis 130. The second flow path 102 is internally formed starting from the outer peripheral surface of the rotation axis 130, so as to be connected with the first flow path 101. For example, as shown in Fig. 3, the second flow path 102 is formed to be adjacent to the ceiling of the airtight space A, thereby allowing the viscous fluid to pass through when the rotation axis 130 rotates.

[67] As shown in Fig. 3, a regulating valve 165 may be formed within the second flow path 102. The regulating valve 165 moves along a pressure of the viscous fluid, which passes through the second flow path 102 when the rotation axis 130 rotates, thereby regulating the opening surface of the second flow path 102. For example, as shown in Fig. 3, the regulating valve 165 may be formed to be inserted and fit in a via hole 135, which passes through the rotation axis 130.

[68] When the viscous fluid is completely introduced, the regulating valve 165 is inserted in the via hole 135, as shown in Fig. 3. Thereafter, a lower end of the regulating valve 165 is formed to entirely or partially block the second flow path 102, which is formed in the rotation axis 130. Herein, a bent section is formed on the second flow path 102, and the regulating valve 165 is placed to open and close the bent section.

[69] More specifically, the second flow path 102 is vertically extended upwards from a groove 137 formed at the lower end of the rotation axis 130, as shown in Fig. 3. Then, the second flow path 102 is bent towards the side wall, so as to be connected with the airtight space A. Thereafter, the regulating valve 165, which is inserted in the via hole 135, is placed to block the area vertically formed in the second flow path 102.

[70] As shown in Fig. 2 and Fig. 3, a bypass groove 167 may be formed on the surface of the regulating valve 165. A plurality of bypass grooves 167 may be may be positioned along the outer peripheral surface of the regulating valve 165. Accordingly, even when the regulating valve 165 is positioned to completely block the second flow path 102, as shown in Fig. 3, a bypass channel is formed between the inner surface of the second flow path 102 and the outer surface of the regulating valve 165. Therefore, even

though the regulating valve 165 blocks the second flow path 102, a small amount of the viscous fluid may be able to pass through the second flow path 102. In order to ensure a minimum flowing amount of the viscous fluid through the second flow path 102, a groove 139 corresponding to the bypass groove 167 is also formed in the inner wall of the second flow path 102, as shown in Fig. 3. Meanwhile, the bypass groove 167 may also be provided in the form of a hole that passes through (or penetrates) the regulating valve 165.

[71] When the regulating valve 165 is placed in the second flow path 102, as described above, the minimum flowing amount of the viscous fluid may be ensured when the rotation axis 130 rotates. Herein, when the rotation axis 130 rotates in one specific direction, the viscous fluid is unable to lift the regulating valve 165, as shown in Fig. 3, thereby causing limitations in the flowing amount of the viscous fluid. Conversely, when the rotation axis 130 rotates in the opposite direction with a greater rotating force, the viscous fluid may lift the regulating valve 165, as shown in Fig. 8, thereby enabling a larger amount of viscous fluid to pass through. Thus, the damping force of the oil damper 100 descreases, thereby enabling the rotation axis 130 to rotate more easily.

[72] The regulating valve 165 may be positioned to block the second flow path 102 with its own weight (or empty weight). However, as shown in Fig. 2 and Fig. 3, the regulating valve 165 may be elastically pressurized by an elastic member 163 so as to block or narrow down the second flow path 102. In the latter case, as shown in Fig. 3, the elastic member 163 is inserted in the via hole 135 after the regulating valve 165 is inserted.

[73] After the regulating valve 165 and the elastic member 163 are inserted in the via hole

135, a fixing member 161 is fit around the via hole 135 so that the via hole 135 can be completely sealed. At this point, the elastic member 163 supports the lower end of the fixing member 161, thereby elastically pushing the regulating valve 165 downwards. The regulating valve 165 is screwed on the via hole 135. And, by tighly screwing (or tightening) or loosening the regulating valve 165, the applied pressure of the elastic member 163 may be adjusted. Accordingly, the pressure of the viscous fluid that moves the regulating valve 165 may also be adjusted, which signifies that the damping force of the oil damper 100 can be managed by adjusting the regulating valve 165. Meanwhile, in order to completely seal the via hole 135, a sealing 162 is inserted between the fixing member 161 and the rotation axis 130, as shown in Fig. 2 and Fig. 3.

[74] The example presented above describes the regulating valve 165 being mounted in order to be moved by the pressure of the viscous fluid. However, the present invention is not limited only to the example described above. In another example, as shown in

Fig. 9, the regulating valve 165 may be formed so that the lower end of the fixing member 161, which is inserted in the via hole 135, can block or narrow down the bent portion of the second flow path 102. In this case, by tightening or loosening the fixing member 161, the lower end of the fixing member 161 is respectively elevated or descended, thereby regulating the opening surface of the second flow path 102. Accordingly, by using such structure, the damping force of the oil damper 100 may be minutely regulated.

[75] Meanwhile, as shown in Fig. 4, a third flow path 103 is formed on the supporting protrusion 117, so that the third flow path 103 can flow across the supporting protrusion 117. When the rotation axis 130 rotates, as shown in Fig. 6 and Fig. 7, the third flow path 103 is connected with the first flow path 101 within a predetermined angle range. Therefore, the viscous fluid may pass through the third flow path 103, when the rotation axis 130 rotates within the angle range, wherein the third flow path 103 is connected with the first flow path 101.

[76] Hereinafter, the process of damping the rotation force performed by the oil damper

100 according to an embodiment of the present invention, when the oil damper 100 is being operated, will now be described in detail. An example of the oil damper 100 according to the present invention being mounted on a home bar unit door (not shown) of a refrigerator will be given as an example, in order to simplify the understanding of the present invention. Herein, the home bar unit door is attached to the door of the refrigerator using a hinge, and the oil damper 100 according to the present invention is connected to an axis of the home bar unit door. However, it is apparent that the application of the oil damper 100 according to the present invention will not be limited only to the home bar unit door of a refrigerator.

[77] When the home bar unit door is closed, the blades 150 of the oil damper 100 are positioned as shown in Fig. 4. At this point, the second flow path 102 connects the unit spaces that are divided by the blades 150, the stoppers 115, and the rotation axis 130. In the position of Fig. 4, when the home bar unit door begins to open, the rotation axis 130 and the blades 150 rotate clockwise, as shown in Fig. 6. And, at this point, the viscous fluid moves by passing through the second flow path 102. Also, since the larger cross-section of the first flow path 101 is exposed to the airtight space A at the beginning of the rotating movements of the rotation axis 130, a large amount of viscous fluid pass through the first flow path 101 at the beginning of the opening of the home bar unit door. Accordingly, the damping force is small. Therefore, at the beginning, the home bar unit door begins to open with a swift rotation.

[78] When the rotating angle of the home bar unit door increases, the first flow path 101 gradually decreases, as shown in Fig. 6, and the flowing amount of the viscous fluid through the first flow path 101 also descreases, respectively. With the gradual opening

of the home bar unit door, the damping force of the oil damper 100 increases, respectively, thereby signifying that the opening speed of the home bar unit door is gradually decreasing. As described above, when opening the home bar unit door, the flowing amount of the viscous fluid through the first flow path 101 may gradually decrease. However, a constant amount of viscous fluid passes through the second flow path 102, as shown in Fig. 3. At this point, since the home bar unit door generally opens gradually due to its empty weight, a large rotating force is not generated. Accordingly, the regulating valve 165 is not lifted by the viscous fluid passing through the second flow path 102, and only a limited amount of viscous fluid passes through the bypass groove 167.

[79] Before the complete closing of the home bar unit door, the first flow path 101 is actually closed. Thus, the damping force of the oil damper 100 becomes considerably large. Accordingly, the home bar unit door may be open safely and smoothly without any impact. When the home bar unit door is completely open, the blades 150 are not supported by the stoppers 115, as shown in Fig. 7. Therefore, the rotation of the home bar unit door stops. At this point, the second flow path 102 is closed but the third flow path 103 connects the divided unit spaces.

[80] Meanwhile, when closing the home bar unit door, the viscous fluid flows in a direction opposite to the above-described direction. In the condition shown in Fig. 7, if the home bar unit door is rotated in a reversed direction, the viscous fluid flows through the third flow path 103 at the beginning of the reverse rotation. When the rotating angle of the rotation axis 130 increases, as shown in Fig. 6, the third flow path 103 closes, and the second flow path 102 and the first flow path 101 begin to open. However, since the open cross-section of the first flow path 101 is small at this point, only a small amount of the viscous fluid passes through the first flow path 101.

[81] However, if the force that closes the home bar unit door is large, a large amount of pressure is applied to the unit chamber accommodating the viscous fluid. And, accordingly, the viscous fluid is introduced to the second flow path 102 at a high pressure. Therefore, as shown in Fig. 8, the regulating valve 165 is lifted by the highly pressurized viscous fluid, thereby enlarging the open cross-section of the second flow path 102. Accordingly, a large amount of viscous fluid passes through the second flow path 102. Thereafter, since the damping force of the oil damper 100 decreases, the user is capable of rotating the home bar unit door in an opposite direction with a relatively small force, thereby closing the home bar unit door.

[82] As the rotating angle of the home bar unit door rotating in the opposite direction becomes larger, the exposed cross-section of the first flow path 101 also becomes larger. Thus, the damping force becomes smaller, thereby enabling the home bar unit door to be easily closed. When the home bar unit door is completely closed, the third

flow path 103 is closed, as shown in Fig. 4, the first flow path 101 is completely open, and the second flow path 102 maintains its closed state. Therefore, at the beginning of the opening of the home bar unit door, the viscous fluid passes through the first flow path 101, thereby enabling the rotation axis 130 and the blades 150 to rotate.

[83] As described above, when the rotary-type oil damper 100 according to the present invention is applied, it is very convenient in that the damping force can be regulated in accordance with the rotation or the degree of opening and closing an object for damping the rotating force. Also, when a person manually operates the object for damping the rotating force having the rotary-type oil damper 100 according to the present invention applied thereto, the damping force is damped by the action of the regulating valve 165, thereby facilitating manual operation. Meanwhile, in the rotary- type oil damper 100 according to the present invention, by regulating the fixing member 161 that blocks the via hole 135, the damping force may be regulated to a certain level even after installing the oil damper 100.

[84] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.