Cable ballistic shock mitigation device

Abstract

The application relates to a kind of anti-bullet and damping devices for double-inclined-surface bridge expansion joints, which are simple in structure, small in space occupation and do not need to reserve space for control mechanism.The technical scheme is that a cable reciprocally rotates and keeps tension between the bottom support point of double-inclined-surface cover plate and the end support point of expansion joint or the bottom support point of V-shaped support rod, so that the inclined surfaces on both sides of the bottom of double-inclined-surface cover plate and the inclined surface of the top corner of the beam keep close and compact, thereby avoiding rebound or displacement of double-inclined-surface cover plate after vehicle impact load.

Description

Technical Field

[0001] This invention relates to a bridge expansion joint, particularly suitable for expansion joints on double-sloping bridges that provide bulletproof, centering, and vibration reduction functions. Background Technology

[0002] Currently, vibration reduction measures for bridge expansion joints mainly include: setting up elastic rubber blocks, springs, polyurethane, and magnetic attraction. While double-sloped bridge expansion joints can be used as a reference, their structure remains complex, making it difficult to fully utilize the advantages of the double-sloped design. For example, the "adjustable bridge expansion joint structure (CN205171360U)" uses springs and struts to keep the trapezoidal rubber block pressed against the inclined surface of the beam end, occupying a large space, increasing costs, and reducing structural safety. Furthermore, it cannot be directly applied to double-sloped bridge expansion joints. Rubber block and polyurethane solutions also suffer from large space requirements, causing the expansion joint width to increase exponentially and doubling costs. Magnetic attraction solutions, once springing up, experience a sharp decrease in attractive force, posing a safety hazard. It is necessary to further simplify the structure of double-sloped bridge expansion joints, reduce the space occupied between joints, eliminate the need for pre-reserved space for control mechanisms at the beam ends, avoid increasing the expansion joint size due to the installation of expansion joints, facilitate beam design, reduce costs, and improve vibration reduction and ballistic performance. Summary of the Invention

[0003] To overcome the problems of complex structure, large space occupation, and high cost, this invention provides a cable-stayed vibration damping device with simple structure, easy installation, easy maintenance, and good bulletproof and vibration reduction performance. It is particularly suitable for expansion joints of double-sloping bridges.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] The cable reciprocates between the bottom support of the double-sloped cover plate and the beam end support or the bottom support of the V-shaped strut in the expansion joint, and remains taut. This keeps the slopes on both sides of the bottom of the double-sloped cover plate in close contact with the top corner slopes of the beam end, so as to prevent the double-sloped cover plate from rebounding or shifting after the vehicle impact load.

[0006] To reduce friction between the cable and the fulcrum, preventing damage to the fulcrum or cable, the connection methods between the cable and the bottom of the double-sloping cover plate and the bottom fulcrum of the V-shaped strut include, but are not limited to, the following methods used individually or in combination: pulleys, PTFE plates, pull rings, and grease application. For example, pulleys made of PTFE material. Their fundamental function is to change the direction of the cable; this technical solution uses pulleys as an example.

[0007] The beam end pulleys are connected to the beam body via hinges. The bottom pulleys of the double-sloped cover plate are connected to the double-sloped cover plate via hinges.

[0008] The V-shaped struts are hinged on both sides to the lower part of the apex slope of the beam end, and hinged at the bottom with pulleys. The V-shaped struts are designed to bend outwards near the pulleys to avoid interference between the struts and pulleys when the expansion joint is closed.

[0009] There are various tensioning methods for cables. One end can be fixed and the other end tensioned; or the middle can be fixed and both ends tensioned. They can be tensioned by weights or by springs. Different tensioning methods can also be used in combination.

[0010] A double-sloping cover plate has three support points: one at the bottom and two at the ends of the adjacent beams. Alternatively, a double-sloping cover plate has three support points: one at the bottom and two at the bottom of the adjacent V-shaped strut (including two pulleys). Each double-sloping cover plate must have at least one bottom support point, spaced approximately one meter apart.

[0011] The beneficial effects of this invention are: simple structure, reduced manufacturing cost, and even the ability to source components directly from the hardware market. Specifically designed for double-sloped bridge expansion joints, it fully considers the existing advantages of double-sloped bridge expansion joints, such as their centering and anti-displacement capabilities, and the strong deformation resistance of the thicker middle and thinner sides of the double-sloped cover plate. In contrast, applying existing centering and anti-vibration design methods is cumbersome, inefficient, and wasteful of resources. This structure eliminates the need to reserve space for control mechanisms at the beam ends, thus avoiding interference with the beam design. It allows for a reduction in the width of the expansion joint, lowering the cost of the expansion joint. More importantly, this solution addresses the root cause of vibration, striving to prevent it from occurring in the first place, rather than focusing on how to eliminate vibration after it has occurred. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is an end view showing the positional relationship between the bottom support point of the double-sloped cover plate and the beam end support point inside the expansion joint of the present invention.

[0014] Figure 2 This is a diagram showing the cable of the present invention reciprocating between the bottom support point of the double-sloped cover plate and the beam end support point inside the expansion joint.

[0015] Figure 3 This is an end view showing the positional relationship between the bottom support point of the double-sloped cover plate and the bottom support point of the V-shaped strut (two pulleys are parallel but not aligned).

[0016] Figure 4 This is a diagram showing the cable of the present invention reciprocating between the bottom support point of the double-sloping cover plate and the bottom support point of the V-shaped strut (two pulleys are parallel but not on the same axis).

[0017] Figure 5 This is an end view showing the positional relationship between the bottom support point of the double-sloped cover plate and the bottom support point of the V-shaped strut (two pulleys are coaxial and side by side) of the present invention.

[0018] Figure 6 This is a diagram showing the cable of the present invention reciprocating between the bottom support point of the double-sloping cover plate and the bottom support point of the V-shaped strut (two pulleys are coaxial and parallel).

[0019] In the figure: 1. Beam end A (partial), 2. Double inclined plate, 3. Beam end pulley, 4. Bottom pulley of double inclined plate, 5. Cable, 6. Beam end B (partial), 7. V-shaped strut, 8. Two pulleys on opposite axes, 9. Two pulleys on the same axis. Detailed Implementation

[0020] Figure 1 and Figure 2 The technical solution shown in Embodiment 1 is "the cable pulls down the double-sloping cover plate through the support point at the beam end of the expansion joint".

[0021] like Figure 1 As shown, a double-sloped cover plate bottom pulley (4) is provided at the bottom support point, and beam end pulleys (3) are provided in pairs at the support points of beam end A (1) and beam end B (6). The double-sloped cover plate bottom pulley (4) and the two beam end pulleys (3) on both sides of the adjacent expansion joint are located in the same plane. However, this plane should form an angle with the expansion direction to avoid the beam end pulleys (3) on both sides touching when the expansion joint is closed. The beam end pulleys (3) and the double-sloped cover plate bottom pulley (4) are hinged to beam end A (1), beam end B (6) and double-sloped cover plate (2) respectively to adapt to the changes in the relative position of the pulleys and the changes in the direction of the cable (5) during the expansion and contraction of the beam.

[0022] like Figure 2 As shown, along the length of the expansion joint, the cable (5) passes through pulleys 31-41-32-33-42-34-35-43-36... In the figure, 41 / 42 / 43 correspond to the bottom pulleys (4) of the double-sloped cover plate, and 31 / 33 / 35 and 32 / 34 / 36 correspond to the beam end pulleys (3) respectively set at beam end A (1) and beam end B (6). The cable (5) can also use another way of turning, such as passing through pulleys 31-41-32-34-42-33-35-43-36... Other ways of turning can also be used to pull the double-sloped cover plate downwards and keep it in contact with the top corner slope of the beam end. It is even possible to reduce the spacing between the bottom support points of the double-sloped cover plate and save half of the beam end support points. The cable passes through 31-41-34-42-35... but this scheme is not recommended.

[0023] Figure 3 and Figure 4 This illustrates the technical solution of Embodiment 2, "the cable pulls down the double-sloping cover plate through the bottom fulcrum of the V-shaped strut" (two pulleys are parallel but not on the same axis).

[0024] like Figure 3As shown, the V-shaped strut (7) is located below the double-sloped cover plate (2), with both ends of the strut hinged to beam end A (1) and beam end B (6) respectively. The two struts of the V-shaped strut (7) are hinged together by a pivot. Two pulleys (8) with different axes are arranged side by side along the length of the expansion joint and are fixed to the pivot connecting the two struts by a bracket and a pivot.

[0025] like Figure 4 As shown, along the length of the expansion joint, the cable (5) passes around pulleys 81-41-82-83-42-84-85-43-86... In the figure, 41 / 42 / 43 correspond to the bottom pulleys (4) of the double-sloped cover plate, and 81 and 82, 83 and 84, 85 and 86 correspond to the two pulleys (8) on different axes on each V-shaped strut (7). Other winding methods can also be used to pull the double-sloped cover plate downwards and keep it in contact with the top corner of the beam. It is worth noting that the V-shaped strut (7) should have a certain width to prevent it from tipping over and failing under the action of the cable (5). In addition, the V-shaped strut (7) is designed to be bent outwards near the pulley to avoid the V-shaped strut squeezing the pulley when the beam stretches and the expansion joint shrinks.

[0026] Figure 5 and Figure 6 This illustrates the technical solution of Embodiment 3, "the cable pulls down the double-sloping cover plate through the bottom fulcrum of the V-shaped strut" (two pulleys are coaxial and parallel). Unlike Embodiment 2, the pair of pulleys at the bottom of the V-shaped strut (7) use the same pivot, i.e., two pulleys (9) are coaxial and parallel. The two coaxial and parallel pulleys (9) and the bottom pulley (4) of the double-sloping cover plate are not located on the same plane, making it easy for the cable (5) to come out of the pulley groove. Moreover, the torsional torque generated relative to the V-shaped strut (7) accelerates its wear.

[0027] The V-shaped strut (7) should have a certain width along the length of the expansion joint, especially at the hinge point with the beam, to prevent lateral tilting due to the influence of the cable. A large axial allowance should be reserved at the hinge point between the V-shaped strut (7) and the beam to prevent lateral displacement of the beam from damaging the V-shaped strut. Option 2 is preferred, although it increases the cost of the strut compared to Option 1, the effect is much better. Option 3, with its two wheels on the same axle, is more compact than Option 2 and slightly reduces cost, but it increases the risk of the cable coming off the pulley.

[0028] There are various methods for tensioning cables, which will not be repeated here. Refer to the counterweights used for guy wires in electrified railways. The counterweight should be placed in a safe area at one end of the expansion joint to prevent cable failure and breakage, which could cause secondary damage. During routine maintenance, special attention should be paid to the corrosion of each component.

[0029] The bottom support points of the double-sloped cover plate and the bottom support points of the V-shaped strut are used in pairs, and the line connecting them is basically perpendicular to the bridge surface. Considering the influence of factors such as the direction of traffic and the slope of the bridge surface, the double-sloped cover plate may slide to one side, and the bottom support points of the V-shaped strut may be offset in the opposite direction relative to the bottom support points of the double-sloped cover plate, so the line connecting them may not be completely perpendicular to the bridge surface.

Claims

1. A bulletproof and shock-absorbing device for a double-bevel bridge expansion joint, characterized by: The cable reciprocally rotates between the bottom support point of the double-inclined cover plate and the bottom support point of the V-shaped support rod and keeps tension, so that the inclined surfaces on both sides of the bottom of the double-inclined cover plate keep close contact with the inclined surfaces at the top corners of the beam, wherein the V-shaped support rod is hingedly connected below the inclined surfaces at the top corners of the beam and is hingedly connected with a pulley at the bottom as the bottom support point of the V-shaped support rod.

2. The dual-ramp bridge expansion joint bullet-resistant and vibration-damping device of claim 1, wherein: The connection mode of the cable with the bottom of the double-inclined cover plate and the bottom support point of the V-shaped support rod includes but is not limited to the following modes used alone or in combination: pulley, Teflon plate, pull ring, and lubricating grease.

3. The dual-ramp bridge expansion joint bullet-resistant and vibration-damping device of claim 1, wherein: The V-shaped support rod is designed to be outwardly curved near the pulley part.

4. The dual ramp bridge expansion joint bullet-resistant and vibration-damping device of claim 1, wherein: The pulley at the bottom of the double-inclined cover plate is connected with the beam body through a hinged mode between the double-inclined cover plate and the beam body.

5. The dual ramp bridge expansion joint bullet-resistant and vibration-damping device of claim 1, wherein: At least one bottom support point is arranged on each double-inclined cover plate, and the interval is about one meter.

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