KR100430645B1 - Two Step Shock Absorber for Unseating Prevention - Google Patents

Abstract

The present invention consists of a two-stage shock absorber composed of a high speed-dependent cylindrical fluid attenuator and a strain hardening elastic support to prevent falling and overdisplacement, thereby contacting the displacement limiting device with the constant displacement absorbing capability of the fluid attenuator. By reducing the pre-collision speed during the earthquake and reducing the impact force by the excellent energy absorption capacity of the fluid reducer and the elastic bearing to prevent the breakage of the bridge and further to prevent falling. That is, when an impact occurs in the two-stage shock absorber of the present invention, the initial compression occurs in the elastic support until the impact force required for the compression of the fluid attenuator is reached. The two stages of force-displacement relationship are shown by a series of processes in which final compression occurs, thus showing excellent energy absorption. Furthermore, due to the velocity-dependent nature of viscous fluids, small resistive forces are generated when shrinking at low speeds to accommodate constant displacement. In addition, restoring rubber is installed on the outside of the fluid attenuator to prevent the outflow of viscous fluids and to facilitate the compression deformation of the fluid attenuator, and to restore the fluid attenuator itself after a constant displacement or impact as a shock absorber. The function can be performed again without artificial action.

Description

Two Step Shock Absorber for Unseating Prevention

The present invention relates to a two-stage shock absorbing device for preventing the fall of bridges and over-displacement, more specifically, installed as a cushioning material between the top of the bridge and the alternating or pier to prevent falling during the earthquake and over displacement of the bridge support The present invention relates to a two-stage shock absorbing device capable of exerting an excellent shock energy absorbing ability through a two-stage shock absorbing structure consisting of a double structure of a fluid attenuator and an elastic support.

In general, the basic principles of seismic design can be divided into two aspects. First, the structure should not be damaged for small earthquakes. Second, damage to the structure cannot be avoided for large earthquakes, but at least the loss of life due to the collapse of the structure. In the event of a large earthquake, excessive displacement of the bridge may cause the bridge support to fall off or fall into a bridge, causing the entire bridge to collapse. To prevent this, install a fall prevention device on the bridge.

The fall prevention device is divided into a connection method and a displacement limit method, and the connection method is a method of preventing falling by restraining each other by using a cable, a chain, or a pin between a bridge top plate or a top plate and a substructure (piers or alternations). . In case of the displacement limiting method, a displacement limiting device such as a shear key is installed on the upper plate and the alternating or pier to prevent excessive displacement by preventing displacement.

On the other hand, when a collision occurs between two rigid objects, a large load may be generated within a short time, thereby causing serious damage to the object. At this time, if the collision occurs through the buffer material having a small rigidity, the collision time is delayed and the collision force is reduced. Therefore, in order to reduce the collision force, a shock absorbing device such as a shock absorber is used for the contact surface between the collision bodies. The present invention is a shock absorbing device used as a shock absorbing material of the displacement limiting method for preventing falling.

The above-mentioned cushioning material can generally be classified into strain hardening type and carbon molding on the basis of the mechanical properties (force-displacement relationship). The cushioning material using rubber is a strain hardening type, and the energy absorption rate is lower than that of carbon molding. Therefore, high damping rubber can be used instead of general rubber, and the structure of the cushioning material is improved to a honeycomb structure or PRF (Poly Rubber Fiber) and FRP (Fiber). Products that increase energy absorption rate using materials such as Reinforced Plastic are being introduced in Japan. However, due to structural or material limitations, they have limitations on shock absorption.

In addition, the top plate of the bridge is stretched in the horizontal direction by temperature stretching, drying shrinkage and creep. This is called the permanent displacement of the bridge, and the movable bridge bearing is used to smoothly accommodate the constant displacement. In the case of the conventional displacement limiting device, since the displacement capacity is small, the gap between the shift or the pier and the collider (top plate or the displacement limiting device) should be kept above the normal displacement. This increase in the collision distance leads to an increase in the collision speed, and even though a shock absorber is used, the bridge may have a big impact and cause damage.

The present invention has been made to solve the above problems, the object of the present invention is installed as a cushioning material in the displacement limiting device for prevention of falling off, it always receives the constant displacement and during the earthquake excellent shock through two-stage shock absorption It is to provide a two-stage shock absorbing device for the fall prevention and over-displacement of the bridge that can protect the structure by having the absorption capacity.

In order to achieve the above object, the present invention provides an elastic material 202 laminated between the upper and lower plates 201 and 204 and the upper and lower plates 201 and 204 used in the displacement limiting device for preventing falling. In the shock absorbing device comprising a deformation-hardening elastic support 304 made of an internal reinforcing steel plate 203, the upper surface in contact with the impact body is spherical so as to minimize the impact force acts as an eccentricity and does not contact the impact body And a contact plate 101 which is a plane; a hollow-clamp-type fastening plate 103 having fastening holes to be fastened by a part of the upper plate 201 of the elastic bearing and the fastening bolt 112; and an overall trapezoidal cylindrical upper end. Is bonded to the contact plate 101 and the lower end is bonded to the fastening plate 103 to restore the compression deformation under the pressure acting on the contact plate Radish 102; and the upper surface is attached to the center of the plane of the lower surface of the contact plate 101, the orifice 106 is installed through the upper and the cylindrical cylinder 105 of the lower surface is open; The upper end of the cylindrical The piston 107 is inserted into the cylinder 105 through its open bottom surface and the lower end is bolted by the circular bolt 113 in the form of a socket with the center of the upper plate 201 of the elastic bearing and the contact plate upon impact. And a cylindrical fluid attenuator comprising viscous fluids (110, 110 ') that are compressed and sealed to distribute the inside and the outside of the cylinder (105) by the impact force applied to the restoring rubber. It is characterized by.

1 is a cross-sectional view of a two-stage shock absorbing device according to the present invention,

2 is a view showing an installation example of a two-stage shock absorbing device according to the present invention,

3 is a step-by-step deformation of the two-stage shock absorbing device according to the present invention,

Figure 4 is a force-displacement relationship diagram of a two-stage shock absorbing device according to the present invention,

Figure 5 is a force-displacement relationship diagram according to the impact speed of the two-stage shock absorbing device according to the present invention,

6 is a velocity dependent characteristic diagram of a viscous fluid used in the present invention,

7 is a collision time-load relationship diagram with or without a buffer material,

8 is a force-displacement relationship diagram of the strain hardening shock absorber according to the existing method,

9 is a force-displacement relationship diagram of the carbon shaping shock absorber according to the conventional method.

※ Explanation of codes for main parts of drawing

101: contact plate 102: restoring rubber

103: Restoration rubber fastening plate 104, 104`: fluid inlet

105: cylinder 106: orifice

107: piston 108, 108`: guide ring

109: movable sealing material 110, 110`: viscous fluid

111, 111`: Fixing sealing material 112: Fastening bolt

113: round bolt

201: upper plate 202: elastic material

203: internal reinforcing steel sheet 204: lower plate

205: fastener

301: two-stage shock absorber according to the present invention

302: displacement limiting device (shear key) 303: bridge deck

304: Bridge support (elastic support) 305: Pier or shift

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a cross-sectional view of a two-stage shock absorbing device according to the present invention.

Depending on the rigidity of the two objects, the magnitude of the force generated during the collision changes. Therefore, when the cushioning material is inserted between the two objects, the impact force is reduced, and the cause of the decrease in the collision force is the delay of the contact time when the two objects collide. In other words, it is no exaggeration to say that the performance of the shock absorber depends on the delay of the collision time. Therefore, in order to delay the impact time described above, the present invention provides a bridge from the impact through the two-stage shock absorption by the dual structure of the cylindrical fluid attenuator having the carbon forming dynamics and the elastic bearing having the deformation hardening dynamics. A shock absorber was developed to protect the system.

As shown, the present invention is installed as a cushioning material in the contact with the impact body such as the displacement limiting device 302 to accommodate the constant displacement as well as to prevent falling off due to the excellent energy absorption capacity through two-stage shock absorption in the event of an earthquake In order to prevent the bridge from being damaged, the contact plate 101 and the fastening plate 103, which are in contact with the colliding body, are integrally manufactured with the restoring rubber 102. At this time, the contact surface of the contact plate 101, which collides with the colliding body, is spherical so that the impact force acts as an eccentricity. In addition to preventing the external leakage of the fluid ( 110, 110`), the normal displacement is reduced or restored to the original state after the collision. Restoration rubber 102 is preferably used to creep small rubber material, it can be produced by inserting the fiber and the like to increase the restoring force.

A cylinder 105 is attached to the bottom surface of the contact plate 101 and several orifices 106 are disposed on the upper side of the cylinder 105 so that the viscous fluid 110 is discharged to the outside of the cylinder 105 in the event of a collision. The piston 107 is inserted into the inner lower surface of the 105. The piston 107 is bolted by the round bolt 113 in the form of a socket on the upper plate 201 of the elastic bearing, the guide ring 108 of solid lubrication material on the contact surface of the piston 107 and the cylinder 105 , 108 'to facilitate the vertical movement of the piston, as well as to protect the inner surface of the cylinder 105, and to install the movable sealing member 109 between the guide rings 108, 108` cylinder (105) It prevents the inside of the viscous fluid 110 to flow out to the side of the piston (107). A groove is provided in the upper edge of the piston 107 so that the fluid attenuator contracts so that the orifice 106 is not blocked when the piston 107 comes into contact with the inner bottom surface of the cylinder 105. In addition, the fixing sealing members 111 and 111 'are installed at the joints between the fluid damper metals to prevent the viscous fluids 110 and 111' from leaking out.

And in the elastic support produced by laminating the elastic material 202 and the internal reinforcing steel plate 203 between the upper and lower plates 201, 204, the elastic material 202 may be a general-purpose rubber, high-damping rubber or other Elastic materials such as viscoelastic materials are used and the thickness of the elastic material 202 and the thickness and quantity of the internal reinforcing steel plate 203 are adjusted to match the vertical rigidity required for the elastic support. In addition, the fastening hole 205 is provided on the outer side of the lower plate 204 of the elastic support to be bolted when mounted on the bridge.

In addition, the fluid attenuator portion and the elastic bearing portion are fastened with the fastening bolts 112, and fastened with a high fastening force to bring the contact surface between the fastening plate 103 of the restorative rubber and the upper plate 201 of the elastic bearing close to each other. At the same time, pressure is applied to the fixing sealing material 111 to prevent the viscous material 110` inside the fluid attenuator from leaking out of the fluid attenuator.

In Figure 1, 104, 104` refers to the fluid inlet in which the viscous fluid (110, 110`) is injected, the fluid inlet is completely pressure-sealed to prevent leakage after the fluid is injected, the fluid is refilled It is opened when there is a need.

Hereinafter, with reference to the accompanying drawings will be described in more detail the operation of the present invention made under the above configuration.

2 is a view showing an installation example of a two-stage shock absorbing apparatus according to the present invention, Figure 3 is a step-by-step deformation of the two-stage shock absorbing apparatus according to the present invention, Figure 4 is a two-stage shock absorbing apparatus according to the present invention Figure 5 is a force-displacement relationship, Figure 5 is a force-displacement relationship according to the impact speed of the two-stage shock absorber according to the present invention, Figure 6 is a velocity-dependent characteristic of the viscous fluid used in the present invention, Figure 7 Is a collision time-load relationship chart with and without buffer.

As can be seen in Figure 2, the two-stage shock absorbing device composed of the cylindrical fluid damper and the elastic support portion of the present invention is installed as a cushioning portion at the contact with the displacement limiting device 302 installed on the bridge top plate 303, Since the contact with the displacement limiting device 302 is maintained through the displacement capacity, there is no gap with the displacement limiting device even in the event of an earthquake, so the pre-collision speed is reduced and the momentum before the collision can be greatly reduced. The energy absorbing capacity also greatly reduces the momentum after the collision. In FIG. 2, reference numeral 305 denotes a pier or an alternation, and reference numeral 304 denotes a bridge bearing installed between the bridge top plate 303 and the pier or alternate 305.

Referring to the deformation process during the impact of the two-stage shock absorbing device according to the present invention shown in Figure 3, the initial compression occurs in the elastic support until the impact force required to compress the fluid attenuator when a collision occurs, after which the fluid attenuator When the piston 107 is in contact with the inside of the cylinder 105 and the compression of the fluid attenuator is completed, final compression occurs in the elastic support. The force-displacement relationship of the two-stage shock absorber during impact by such a series of processes is shown in FIG. 4, and the impact energy absorption ability is excellent because the area under the force-displacement curve is large. In addition, since the viscous fluids 110 and 110` used in the fluid attenuator portion have high velocity dependency as shown in FIG. 6, the viscous fluid 110` inside the cylinder is discharged through the orifice 106 when the fluid attenuator is compressed. When a cylinder is attached to the lower surface of the contact plate 101 as shown in b, c, and d of FIG. 3, a small resistance occurs when contracted at a low speed and a large resistance occurs when contracted at a high speed. As the distance between the piston and the piston becomes shorter (insertion of the piston), the viscous fluid 110'in the cylindrical cylinder is subjected to greater pressure, and thus the viscous fluid to escape through the orifice 106 having a constant radius The extrusion speed is increased, and the increased extrusion speed of the viscous fluid and its viscosity characteristics further increase the damping force to alleviate the impact force. As a result, the impact force is primarily absorbed by the damping forces described above.

Accordingly, as shown in FIG. 5, since a small resistance is generated at a low speed during constant displacement, the permanent displacement is easily accommodated, and a large resistance is generated at high speed, thereby exhibiting excellent energy absorption ability.

And the capacity of the constant displacement of the shock absorber according to the present invention is due to the speed dependence of the fluid attenuator. This speed dependence arises from the characteristics of the viscous fluid used inside the fluid attenuator. In the case of viscous fluid, the resistance is small when moving to the slow speed because the velocity dependency is high, and the resistance increases greatly as the speed increases. Therefore, the constant displacement is the displacement of the slow speed, so the resistance of the fluid attenuator is small, so that the constant displacement can be easily accommodated. In addition, if the gap between the piston 107 and the cylinder 105 is manufactured to be equal to or greater than the normal displacement, all the normal displacement can be accommodated and the gap between the impactor and the shock absorbing device can be eliminated, thereby reducing the impact force during an earthquake.

In addition, the restoring rubber 102 not only prevents the outflow of viscous fluids and facilitates the compression deformation of the fluid attenuator, but also has a restoring function through the self restoring force after the constant displacement or the collision in the event of an earthquake, so that the gap with the colliding body is increased. It should be maintained at all times, and at the same time, it will be able to perform the function as a shock absorber without any artificial action.

In addition, the shock absorbing device according to the present invention is equipped with an elastic bearing having a deformation-curable mechanical characteristic under the fluid attenuator to provide a secondary shock absorbing function and a displacement limiting function through additional shock absorption other than the shock absorbing by the fluid attenuator. At the same time, a fluid attenuator including a piston 107 and a cylinder 105 made of steel is protected from impact.

Through the cylindrical fluid attenuator, the collision time is significantly delayed compared to the conventional deformation-hardening buffer material, and the cross-sectional area of the orifice 6 is reduced to increase the discharge time of the viscous fluid 110 during the collision or the piston 107 and the cylinder 105 The collision time can be further delayed by increasing the compression time by increasing the interval between them.

In the conventional displacement limiting method, the fall prevention device has to keep the gap between the cushioning material and the collider (top plate, alternating or pier) more than the normal displacement in order to prepare for the constant displacement, and the impact speed increases due to such a gap, which greatly impacts the bridge. May cause damage. However, the shock absorber according to the present invention can compensate for this disadvantage because there is no gap between the impactor and the shock absorber by absorbing the constant displacement in the fluid attenuator.

In addition, in the case of the conventional strain hardening buffer material, the impact energy absorption rate is lowered, and in the case of the carbon molding buffer material, there is no self-resilience, so it is difficult to perform the re-function after the impact. However, the shock absorbing device according to the present invention functions as a shock absorbing device because it combines the carbon-forming fluid attenuator and the deformation-curable elastic bearing to complement each other's shortcomings and gives the fluid attenuator a constant displacement capacity and self-resilience. Can be performed with excellent performance.

As described above, the two-stage shock absorber according to the present invention is installed as a buffer of the displacement limiting device for preventing falling, thereby reducing the pre-collision momentum during the earthquake by means of the constant displacement absorbing capacity, thereby greatly reducing the momentum before the collision. Due to the excellent energy absorption capacity and the delay of collision time, the momentum after the collision is greatly reduced, which not only protects the collision site of the bridge from an earthquake but also prevents falling.

Furthermore, it has the effect of deriving great economic value.

Claims (5)

Deformation consisting of an elastic material 202 and an internal reinforcing steel sheet 203 laminated between the upper and lower plates 201 and 204 and the upper and lower plates 201 and 204 used in the displacement limiting device for preventing falling. In the shock absorbing device comprising a curable elastic support 304, An upper surface contacting the colliding body is spherical so as to minimize impact force acting eccentrically, and a lower surface which is not in contact with the colliding body is a flat contact plate 101; A fastening plate 103 having a fastening hole to be fastened by a fastening bolt 112 and a portion of an upper surface of the elastic plate 201; An overall trapezoidal cylindrical upper end is bonded to the contact plate 101 and the lower end is bonded to the fastening plate 103, the restoring rubber 102 is subjected to compression deformation under pressure acting on the contact plate; A cylindrical cylinder 105 having an upper surface attached to a center of a plane below the contact plate 101 and having an orifice 106 penetrated thereon and having an open lower surface; The upper end is inserted into the cylindrical cylinder 105 through the open lower surface and the lower end of the piston 107 is bolted by the circular bolt 113 in the form of a socket with the center of the upper plate 201 of the elastic bearing and Cylindrical fluid comprising viscous fluids (110, 110 ') that are compressed and sealed to flow in and out of the cylinder (105) through an orifice (106) by an impact force applied to the contact plate and the restoring rubber upon impact. Two-stage shock absorbing device for preventing falling and over-displacement, characterized in that it comprises a damper. The guide ring (108, 108) of claim 1, wherein the vertical movement between the cylinder (105) and the piston (107) is smoothly formed around the piston (107) and the inner surface of the cylinder (105) is protected. Two-stage shock absorber to prevent falling and over displacement, characterized in that the `) is installed. According to claim 1 or 2, wherein the intermetallic portion of the fluid attenuator is characterized in that the fixing sealing material (111, 111`) is installed to prevent the viscous fluid (110, 110`) to leak to the outside. Two-stage shock absorber to prevent falling and over displacement. delete The movable sealing material 109 is installed between the guide rings 108 and 108` to prevent the viscous fluid 110 from leaking around the piston 107 other than the orifice 106. Two-stage shock absorption device for preventing falling and over displacement, characterized in that the.