Mounting device for steel bracket

Abstract

To safely and efficiently perform mounting work of a steel bracket to a bridge.SOLUTION: A mounting device is composed of a rail 30 extending to a steel bracket mounting position from the ground and a loading truck 10 capable of traveling along the rail 30 in a state of mounting a steel bracket 3. The loading truck 10 is provided with a steel bracket mounting part 20 in which a large number of steel balls 19 are arranged in a receiving pan 18, the steel bracket 3 is mounted on the large number of steel balls 19, and an elevating device 24 capable of moving the steel bracket 3 in the vertical direction at the steel bracket mounting position is provided. A wire 31 is connected to the loading truck 10, and the loading truck 10 can travel along the rail 30 by winding the wire 31 with a winch 32.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a mounting device for steel brackets in a bridge fall prevention device that prevents bridge girders from falling from piers and abutments during earthquakes and other events. [Background technology]

[0002] Known bridge fall prevention devices that prevent bridge girders from falling from piers or abutments (substructure) when large relative displacement occurs between the piers or abutments and the bridge girders (superstructure) during earthquakes, etc., include displacement limiting devices consisting of a protruding stopper and a pot portion with which it engages, as disclosed in Patent Document 1 below, horizontal force sharing structures (lateral displacement restraint structures) that share horizontal forces with fixed walls installed on movable fulcrums, and bridge seat widening works that widen the girder contact length of piers or abutments.

[0003] In the displacement limiting device, the stopper is often installed on a steel bracket fixed to the pier or abutment, and the pot portion is installed on the bridge girder. Also, in the horizontal force distribution structure, a steel bracket is installed that protrudes from the underside of the bridge girder while ensuring a gap between the pier or abutment, and a concrete block is installed that protrudes from the bridge seat of the pier or abutment while ensuring a gap between the pier or abutment. In the bridge seat widening work, multiple steel brackets are installed on the front of the pier or abutment to widen the girder contact length of the pier or abutment.

[0004] As such, the installation of bridge fall prevention devices involves attaching steel brackets to the piers, abutments, and girders. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-184567 Summary of the Invention [Problem to be solved by the invention]

[0006] The steel brackets are very heavy, weighing between several hundred kilograms and several tons, and their inverted trapezoidal shape makes it difficult to find the center of gravity. Furthermore, because the steel brackets are attached below the girders, they cannot be directly attached using a large crane or similar device for lifting. For this reason, conventional steel brackets have been attached manually using a chain block or similar device, which is time-consuming and laborious, as shown in Figures 6 to 8.

[0007] To explain a specific conventional installation method, as shown in Figure 6, a steel bracket 50 is carried onto the scaffolding using a lifting device 51 such as a truck crane, and then, as shown in Figure 7, it is moved horizontally on the scaffolding to the vicinity of the installation position using a low-floor cart 52 or the like, and as shown in Figure 8, it is transferred to a support stand 53 whose height has been adjusted using a small lifting device such as a chain block, winch, or jack fixed to the underside of the girder, and then it is set in a predetermined fixed position and fixed in place.

[0008] However, the drawback of this method is that it takes time and effort to manually handle heavy objects in the narrow space under the girder. Fine adjustments are also required during installation, and skill is required to guide the chain block or winch. Furthermore, because the steel brackets are suspended by chain blocks or other equipment anchored to the underside of the girder, there are also problems with the risk of damage due to contact with the superstructure or substructure, and the risk of people (such as fingers) getting caught.

[0009] SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a steel bracket mounting device that can safely and efficiently perform the work of mounting steel brackets on bridges. [Means for solving the problem]

[0010] In order to solve the above problem, the present invention according to claim 1 provides a mounting device for a steel bracket in a bridge fall prevention device, A steel bracket mounting device is provided, which is characterized by comprising a rail extending from the ground to the steel bracket mounting position, and a loading cart that can run along the rail with the steel bracket mounted thereon.

[0011] In the invention described in claim 1 above, the steel bracket mounting device is composed of a rail extending from the ground to the steel bracket mounting position, and a loading cart that can run along the rail with the steel bracket loaded.Therefore, by loading the steel bracket onto the loading cart on the ground and running the loading cart with the steel bracket loaded along the rail, the steel bracket can be transported to the mounting position, making it possible to perform the work of mounting steel brackets on bridges safely and efficiently.

[0012] As a second aspect of the present invention, the loading cart is provided with a steel bracket mounting portion in which a number of steel balls are arranged in a tray, and the steel bracket is mounted on the number of steel balls, A steel bracket mounting device according to claim 1 is provided, in which, when the steel bracket is set in the mounting position, the steel bracket is manually moved on the steel ball to adjust the installation position.

[0013] In the invention described in claim 2 above, the loading cart is provided with a steel bracket mounting section in which a large number of steel balls are arranged in a tray, and the steel bracket is mounted on top of the large number of steel balls.Therefore, after the steel bracket is loaded onto the loading cart and transported to the installation position, when the steel bracket is set at the installation position, the steel bracket can be moved over the steel balls by hand, and the steel bracket can be installed while making fine adjustments in the horizontal direction.

[0014] As the present invention according to claim 3, there is provided a steel bracket mounting device according to claim 1, in which the loading cart is equipped with a lifting device that enables the steel bracket to be moved up and down at the steel bracket mounting position.

[0015] In the invention described in claim 3 above, the loading cart is equipped with a lifting device that enables the steel bracket to be moved up and down at the steel bracket mounting position, making it possible to mount the steel bracket while making fine adjustments in the up and down direction using the lifting device.

[0016] The present invention according to claim 4 provides a steel bracket mounting device according to claim 1, in which a wire is connected to the loading cart, and by winding up the wire with a winch, the loading cart can run along the rails.

[0017] The invention described in claim 4 above prescribes specific means for enabling the loading cart to travel along the rails, and a wire is connected to the loading cart, and the wire is wound up with a winch to enable the cart to travel. [Effects of the Invention]

[0018] As explained above in detail, according to the present invention, the work of attaching steel brackets to bridges can be carried out safely and efficiently. [Brief explanation of the drawings]

[0019] [Figure 1] This is an enlarged side view of the main parts of the substructure and superstructure to which the steel bracket 3 is attached. [Figure 2] This is a cross-sectional view of the substructure and superstructure to which steel brackets 3 are attached. [Figure 3] FIG. 2 is a side view showing how to attach the steel bracket 3. [Figure 4] FIG. 2 is a perspective view of the loading cart 10. [Figure 5] FIG. 2 is a side view showing a state in which a steel bracket 3 is mounted on a loading platform 10. [Figure 6] FIG. 1 is a front view showing a first procedure for attaching a conventional steel bracket 50. [Figure 7] FIG. 10 is a side view showing a second procedure for attaching a conventional steel bracket 50. [Figure 8] FIG. 10 is a side view showing a third procedure for attaching a conventional steel bracket 50. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0021] The steel bracket mounting device 1 according to the present invention is a device used to secure steel brackets used in bridge fall prevention devices P to piers, abutments, bridge girders, etc. By using this device, the heavy steel brackets can be safely transported from the ground to the mounting position, and the mounting work to piers, abutments, bridge girders, etc. can be carried out simply and efficiently. This device 1 is not limited to the following embodiment, but can be widely applied to any known form of bridge fall prevention device P equipped with a steel bracket.

[0022] 1 and 2 is a displacement restriction device in which a steel bracket 3 is fixed to a pier 2, a protruding stopper 4 is installed on the upper surface of the steel bracket 3, and a pot portion 6 that engages with this stopper 4 is fixed to a bridge girder 5. A plurality of anchor bolts 7 are embedded in the pier 2 with one end protruding, and the steel bracket 3 is provided with a plurality of insertion holes through which the anchor bolts 7 can be inserted. The anchor bolts 7 are inserted into the insertion holes and tightened with nuts, thereby fixing the steel bracket 3 to the pier 2.

[0023] The procedure for installing the bridge fall prevention device P is generally as follows: after fixing the steel bracket 3 to the pier 2, a stopper 4 is attached to the top surface of the steel bracket 3, and a pot portion 6 that engages with the stopper 4 is attached to the bridge girder 5. In addition, in the preparation stage before installing the bridge fall prevention device P, a scaffolding 23 is set up for workers to use in setting up the steel bracket 3 on the pier 2.

[0024] As shown in Figures 1 and 2, the steel bracket 3 has a fixed surface 3a that is fixed to the pier 2, an upper surface 3b that faces the bridge girder 5 when fixed to the pier 2 and to which the stopper 4 is attached, an inclined surface 3c that is the opposite side of the fixed surface 3a and whose separation distance from the fixed surface 3a increases toward the upward side, and a lower surface 3d that is the opposite side of the upper surface 3b.

[0025] As shown in Figure 3, the mounting device 1 for a steel bracket 3 according to the present invention (hereinafter also referred to simply as "mounting device 1") is composed of a rail 30 extending from the ground to the steel bracket mounting position, and a loading cart 10 that can run along the rail 30 with the steel bracket 3 loaded on it.

[0026] First, to explain the loading cart 10 in detail, as shown in Figures 4 and 5, the loading cart 10 is mainly composed of a base frame 11, a hydraulic jack 13 and a support plate 15 that are provided on the base frame 11 and support the inclined surface 3c of the steel bracket 3, a steel bracket mounting portion 20 in which a number of steel balls 19 are arranged in a tray 18, and a lifting device 24 that enables the steel bracket mounting portion 20 to move up and down.

[0027] The base platform 11 is a cart on which all of the elements that make up the loading cart 10 are mounted, and its bottom surface is equipped with running means (not shown) such as wheels, tires, and gears that enable smooth running along the rails 30.

[0028] The hydraulic jack 13 and support plate 15 that support the inclined surface 3c of the steel bracket 3 are such that the support plate 15 directly supports the inclined surface 3c of the steel bracket 3, and the hydraulic jack 13 supports the back surface of the support plate 15.

[0029] The hydraulic jack 13 is a piston-type jack having one end connected to a base 14 provided on the base frame 11 that receives a reaction force, and the other end connected to the back of a support plate 15 that directly supports the inclined surface 3c of the steel bracket 3.

[0030] The support plate 15 is a steel plate that is approximately rectangular when viewed from above, and its front surface is formed flat to support the inclined surface 3c of the steel bracket 3, while its back surface is provided with a connection portion to which the hydraulic jack 13 is connected.

[0031] The lower end of the support plate 15 is supported so as to be rotatable about a through shaft 17 extending in the left-right direction (horizontal direction) and inserted between bearing portions 16, 16 protruding upward from the base frame 11. By extending or retracting the hydraulic jack 13, the support plate 15 rotates about the through shaft 17 at the lower end. In this way, by extending or retracting the hydraulic jack 13, the support plate 15 can be tilted to any angle in accordance with the angle of inclination of the inclined surface 3c of the steel bracket 3, so that a wide variety of steel brackets 3 with different angles of inclination of the inclined surface 3c can be mounted on the loading cart 10.

[0032] The steel bracket mounting portion 20 is configured by arranging a large number of steel balls 19 in a tray 18 with an open top, which is made up of a bottom plate that is roughly rectangular in plan view and side plates that surround the periphery of the bottom plate. The steel balls 19 have a diameter that causes their upper parts to protrude beyond the side plates of the tray 18, and are formed in a size that prevents them from climbing over the side plates and rolling out. The steel balls 19 are not packed tightly inside the tray 18, but are arranged so that some space is left so that they can roll within the tray.

[0033] The steel bracket mounting portion 20 supports the underside 3d of the steel bracket 3. In other words, the steel bracket 3 is mounted on a large number of steel balls 19 arranged in a tray 18. As a result, when a force is applied to the steel bracket 3 in the horizontal direction, the steel balls 19 roll within the tray 18, causing the steel bracket 3 to move, making it possible to move the steel bracket 3 with a small force. Therefore, when setting the steel bracket 3 in the mounting position, the steel bracket 3 can be manually moved on the steel balls 19 to fine-tune the installation position in the horizontal direction (left-right and front-back directions).

[0034] The lifting device 24 that moves the steel bracket mounting portion 20 in the vertical direction is disposed between the tray 18 and the base stand 11, and moves the steel bracket mounting portion 20 including the tray 18 in the vertical direction, thereby moving the steel bracket 3 mounted on the steel bracket mounting portion 20 in the vertical direction. A jack, for example, can be used as the lifting device 24.

[0035] As shown in Figure 5, a buffer material 21 such as hard rubber is provided at the front end of the loading cart 10 (the end of the base frame 11 on the pier 2 side), protruding forward from all components arranged on the base frame 11, such as the steel bracket mounting part 20 and the steel bracket 3 mounted thereon. Because the buffer material 21 is provided in a state of protruding forward, when the steel bracket 3 is set in a fixed position, the buffer material 21 comes into contact with the pier 2, preventing the steel bracket 3 and the like from accidentally colliding with the pier 2 and damaging the pier 2.

[0036] As shown in Figure 5, in order to prevent the steel bracket 3 mounted on the loading cart 10 from moving or falling while the steel bracket 3 is traveling along the rail 30, it is preferable to fasten the steel bracket 3 to the loading cart 10 using a fastener 22 such as a wire, rope, band, or chain. It is preferable to apply tension to the fastener 22 with a lever block (registered trademark) or the like so that the steel bracket 3 is firmly fixed to the loading cart 10.

[0037] Next, the rail 30 on which the loading cart 10 runs will be described. The rail 30 extends continuously from the ground to the steel bracket attachment position, and is an ascending road with an upward slope for the most part. The slope of the rail 30 rises almost linearly in the section extending from the ground outside the scaffolding 23, and in the vicinity of the scaffolding 23, the slope gradually becomes gentler as it approaches the scaffolding 23, and is almost horizontal near the steel bracket attachment position (preferably on the scaffolding 23). Outside the scaffolding 23, the rail 30 is supported by a framework 33 composed of frame materials, diagonal braces, baseboards, crosspieces, etc. assembled from the ground, and on the scaffolding 23, the rail 30 is supported by the scaffolding 23.

[0038] Since the rail 30 is arranged from the outside of the scaffolding 23, the steel bracket 3 can be installed from the outside of the scaffolding 23, eliminating the need for work such as rearranging the scaffolding 23, and enabling the work of attaching the steel bracket 3 to be carried out efficiently.

[0039] The rail 30 may be a single rail (monorail), but is preferably two parallel rails. The rail 30 is configured in a form that allows travel means provided on the bottom surface of the base frame 11 of the loading cart 10 to travel on it. That is, for example, if the travel means is a rubber tire, it is made of channel steel or the like having grooves on which the tire can roll, if the travel means is a steel wheel, it is made of I-beam or the like on which the wheel rolls, and if the travel means is a gear, it is made of a flat plate or straight bar (rack) or the like having a series of equally shaped teeth on one surface with which the gear meshes.

[0040] To run the loading cart 10 along the rails 30, any known means for enabling travel along the rails 30 can be used without limitation. For example, as shown in Fig. 3, a wire 31 is connected to the loading cart 10, and the wire 31 is wound up by a winch 32 installed on the ground, thereby enabling the loading cart 10 to run along the rails 30.

[0041] Next, a method for attaching the steel bracket 3 to the pier 2 using the attachment device 1 configured as described above will be described.

[0042] First, as shown in FIG. 3, a scaffold 23 for workers to install the steel bracket 3 is provided on the pier 2 on which the steel bracket 3 is to be installed.

[0043] Next, a rail 30 extending from the ground to the steel bracket mounting position is laid on a frame 33, and a wire 31 is placed along this rail 30.

[0044] The steel bracket 3 is placed on the loading cart 10 and fixed to the loading cart 10 with fasteners 22 .

[0045] The steel bracket 3 fixed to the loading cart 10 is placed on the rails 30 using a forklift or the like. Note that the steel bracket 3 may be fixed to the loading cart 10 in a state where the loading cart 10 is placed on the rails 30. The steel bracket 3 can be moved relatively easily because it is moved on the ground using a forklift or the like.

[0046] A wire 31 is connected to the loading cart 10 and the wire 31 is wound up by the winch 32, causing the loading cart 10 to run along the rail 30 with the steel bracket 3 fixed thereto, and transporting the steel bracket 3 to the mounting position.

[0047] At the steel bracket mounting position, the fastener 22 is removed to release the steel bracket 3 from the loading cart 10, and then the steel bracket 3 is manually moved over the steel ball 19 to make fine adjustments in the horizontal direction, and the lifting device 24 provided on the loading cart 10 is operated to make fine adjustments in the vertical direction, after which the anchor bolt 7 is inserted into the insertion hole of the steel bracket 3 and tightened with a nut to fix the steel bracket 3 to the pier 2. [Explanation of symbols]

[0048] 1...Steel bracket mounting device, 2...Pier, 3...Steel bracket, 4...Stopper, 5...Bridge girder, 6...Pot portion, 7...Anchor bolt, 10...Loading cart, 11...Base frame, 13...Hydraulic jack, 14...Pedestal portion, 15...Support plate, 16...Bearing portion, 17...Through shaft, 18...Receptacle, 19...Steel ball, 20...Steel bracket mounting portion, 21...Buffer material, 22...Fastener, 24...Lifting device, 30Rail, 31...Wire, 32...Winch, 33...Framework, P...Bridge fall prevention device

Claims

1. A mounting device for a steel bracket in a bridge fall prevention device, A steel bracket mounting device comprising a rail extending from the ground to the steel bracket mounting position, and a loading cart capable of running along the rail with the steel bracket mounted thereon.

2. The loading cart is provided with a steel bracket mounting portion in which a number of steel balls are arranged in a tray, and the steel bracket is mounted on the number of steel balls, 2. The steel bracket mounting device according to claim 1, wherein when the steel bracket is set in the mounting position, the steel bracket is manually moved on the steel balls to adjust the installation position.

3. 2. The steel bracket mounting device according to claim 1, wherein the loading platform is provided with a lifting device that enables the steel bracket to be moved up and down at the steel bracket mounting position.

4. 2. The steel bracket mounting device according to claim 1, wherein a wire is connected to the loading cart, and the loading cart can be moved along the rail by winding up the wire with a winch.

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