Automatic semicircle notching device

Abstract

To provide an automatic semicircle notching device that can substantially reduce work labor and substantially shorten working time, so as to reduce construction costs.SOLUTION: The automatic semicircle notching device comprises a base part 2, a support part 3, a driving part 4, a torch 5 for gas-cutting, and a gas cylinder that supplies the torch 5 with gas for hydrogen gas-cutting. The base part 2 has: a side surface contact part that is contacted with a surface to be constructed; clamping means (a toggle clamp 23) that clamps the device to an object to be constructed; and adjusting means that enables the torch 5 to move in a direction that is parallel and orthogonal to the surface to be constructed. The driving part 4 has an electric motor 41 and a rotating shaft 44. A rotating arm 46 is attached to the rotating shaft 44 so that the arm extends toward outside in a radial direction of the rotating shaft 44, and the torch 5 is attached to the rotating arm 46, where the rotating arm 46 and the torch 5 revolve around an area outside in the radial direction of the rotating shaft 44.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for forming semicircular notches in steel members such as vertical stiffeners. [Background technology]

[0002] A typical road bridge is constructed so that the main girders are supported by piers, and the deck is supported on top of the main girders. When a steel deck plate using a steel deck plate is used as the deck plate, in addition to the main girders, trough ribs with a U-shaped cross section and vertical stiffeners are placed on the underside of the deck plate.

[0003] When vertical stiffeners are installed, their upper ends are welded to the underside of the deck plate. In recent years, however, it has been discovered that fatigue cracks are likely to occur near the welds. As a countermeasure, semicircular notches are being formed in the vertical stiffeners of existing road bridges (semicircular cut construction).

[0004] This semicircular cutting is often performed by drilling multiple holes using a drilling machine, as shown in Figure 4 (an explanatory diagram of a conventional semicircular cutting method). More specifically, a semicircular planned line (not shown) is drawn near the lower side of the deck plate 71, with its center at a point on one side edge of the vertical stiffener 73 (the side edge opposite the main girder web 72). Holes are then drilled along this planned line (for example, at the position indicated by the dashed line in Figure 4(1)) using a drilling machine, and a crescent-shaped piece 73a is cut from the vertical stiffener 73 as shown in Figure 4(2). The sawtooth portion of the cutout is then cut using a grinder or the like to create a smooth curve as shown in Figure 4(3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-223393 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional semicircular cutting work, such as that shown in Figure 4, is extremely laborious and requires a long working time. The present invention aims to solve these problems in the conventional technology and to provide an automatic semicircular cutting device that can significantly reduce the working effort and shorten the working time. [Means for solving the problem]

[0007] The automatic semicircular notching device of the present invention has a base portion, a support portion, a drive portion, a gas cutting torch, and a gas cylinder that supplies hydrogen gas cutting gas to the torch, and the base portion has a side abutment portion that abuts against the surface to be worked on, a fixing means that fixes the device to the surface to be worked on, and an adjustment means that allows the torch to be moved in directions parallel to and perpendicular to the surface to be worked on, and the drive portion has an electric motor and a rotating shaft that is poweredly connected to the electric motor, and a rotating arm is attached to the rotating shaft so that it extends radially outward from the rotating shaft, and a torch is attached to the rotating arm, and the device is configured so that the rotating arm and torch rotate in an area radially outward from the rotating shaft when the rotating shaft rotates.

[0008] In this automatic semicircular notching device, it is preferable that a side edge guide extend perpendicular to the side abutment portion and abut against the side edge of the vertical stiffener, and that the electric motor and the rotating shaft are operatively connected via a reduction gear. Furthermore, it is preferable that the fixing means is a toggle clamp, and that the rotating arm is configured so that the amount of protrusion from the rotating shaft can be changed.

[0009] Furthermore, it is preferable that the adjustment means has a first feed mechanism, a movable stage connected to the side abutment portion via the first feed mechanism, and a second feed mechanism fixed on the movable stage and having a support portion attached thereto, and that the first feed mechanism is configured to be able to move the movable stage in a direction parallel to or perpendicular to the surface to be worked on, and that the second feed mechanism is configured to be able to move the support portion in a direction perpendicular to or parallel to the surface to be worked on.

[0010] The semicircular cutting method of the present invention is characterized by using the above-mentioned automatic semicircular notching device, and is characterized by first fixing the automatic semicircular notching device to the object to be cut, supplying hydrogen gas for cutting from a gas cylinder to the torch, spraying a combustion flame from the nozzle at the tip of the torch toward the surface of the object to be cut, and supplying power to the electric motor to rotate the rotating arm and torch around the rotation axis. [Effects of the Invention]

[0011] The automatic semicircular notching device of the present invention can significantly reduce the labor and time required for semicircular cutting compared to conventional methods, thereby reducing construction costs. Furthermore, the device can be very easily and securely fixed to the vertical stiffener to be cut, and after fixing, the relative position of the device to the vertical stiffener can be adjusted. Furthermore, because the device is configured to perform hydrogen gas cutting, the problem of paint burns can be avoided. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a side view of an automatic semicircular notching device 1 according to the present invention. [Figure 2] FIG. 2 is a plan view showing the planar shape of the base portion 2 of the automatic semicircular notching device 1 shown in FIG. 1 and a horizontal cross section of the support portion 3 at an intermediate height position. [Figure 3] FIG. 3 is a diagram showing the operation of the automatic semicircular notching device 1 shown in FIG. [Figure 4] FIG. 4 is an explanatory diagram of a conventional general semicircular cutting method. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a side view of an automatic semicircular notching device 1 according to the present invention. As shown in the figure, this automatic semicircular notching device 1 has a base unit 2, a support unit 3, a drive unit 4, a torch 5, and a gas cylinder (not shown) containing gas for gas cutting. Fig. 2 is a plan view showing the planar shape of the base unit 2 shown in Fig. 1 and a horizontal cross section of the support unit 3 at an intermediate height position.

[0014] The base portion 2 has a means (fixing means) for fixing the automatic semicircular notching device 1 to the vertical stiffener 73 (see Figure 2) to be worked on, and a means (adjusting means) for adjusting the relative position of the torch 5 and the vertical stiffener 73 by moving the torch 5 (and the support portion 3 and drive portion 4) within a certain range in directions parallel to and perpendicular to the side of the vertical stiffener 73 (the surface to be worked on) while the base portion 2 is fixed.

[0015] More specifically, as shown in Figure 2, the base portion 2 has a side abutment portion 21 that abuts against the side surface (construction surface) of the vertical stiffener 73 to be installed, a side edge guide 22 that extends in a direction perpendicular to the side abutment portion 21 and abuts against the side edge of the vertical stiffener 73, and a toggle clamp 23 (fixing means) fixed to the side edge guide 22.

[0016] Of these, the toggle clamp 23 is composed of a base 23a, a clamp arm 23b, a lever handle 23c, and a link 23d, and the base 23a and the clamp arm 23b, and the clamp arm 23b and the lever handle 23c are pivotally connected, respectively, and the base 23a and the lever handle 23c are connected by the link 23d.

[0017] As shown in Figure 2(1), when the clamp arm 23b is open, the side abutment portion 21 and side edge guide 22 of the base portion 2 are abutted against the side and side edge of the vertical stiffener 73, respectively, and the lever handle 23c is rotated in a predetermined direction, as shown in Figure 2(2), the clamp arm 23b closes and the vertical stiffener 73 is sandwiched between the side abutment portion 21 and the clamp arm 23b (the pressing portion attached to its tip).

[0018] When the clamp arm 23b of the toggle clamp 23 rotates in the closing direction and passes the dead point, the link 23d resists, restricting its rotation in the opening direction. As a result, unless the lever handle 23c is operated, the state shown in Figure 2 (2) (state in which the vertical stiffener 73 is sandwiched between the side contact portion 21 and the clamp arm 23b) is maintained, and the automatic semicircular notching device 1 can be securely fixed to the vertical stiffener 73. Furthermore, by operating the lever handle 23c from this state (rotating it in the opposite direction), the clamp arm 23b can be released, allowing the automatic semicircular notching device 1 to be quickly removed from the vertical stiffener 73.

[0019] 2, the base unit 2 has a movable stage 24, a first feed mechanism unit 25, and a second feed mechanism unit 26 (adjustment means). The movable stage 24 is connected to the side abutment unit 21 via the first feed mechanism unit 25. The first feed mechanism unit 25 has a built-in ball screw, and by rotating a knob 25a, the movable stage 24 can be moved in a direction parallel to the side surface of the vertical stiffener 73 (the direction of the arrow shown in FIG. 2(1)).

[0020] A second feed mechanism 26 is fixed on the movable stage 24. A support unit 3 is mounted on the second feed mechanism 26. The second feed mechanism 26 has a built-in ball screw, similar to the first feed mechanism 25, and by rotating the knob 26a, the support unit 3 (or the torch 5) can be moved in a direction perpendicular to the side surface of the vertical stiffener 73 (the direction of the arrow shown in FIG. 2(2)), and the relative positions of the torch 5 and the vertical stiffener 73 can be adjusted.

[0021] As shown in Fig. 1, a drive unit 4 is fixed to the upper end of the support unit 3. This drive unit 4 includes an electric motor 41, a metal cover 42 that covers the electric motor 41, a gear box 43 that houses a reduction gear, and a rotating shaft 44. The rotating shaft 44 is operatively connected to the electric motor 41 via a reduction gear in the gear box 43, and when power is supplied via control means (not shown), the output shaft of the electric motor 41 rotates in a predetermined direction, and this rotational driving force is reduced by the reduction gear and transmitted to the rotating shaft 44, causing the rotating shaft 44 to rotate at a low speed (e.g., 0.6 rpm).

[0022] A rotating arm 46 is attached to the tip of the rotating shaft 44 via a socket 45. This rotating arm 46 is attached so as to extend radially outward from the rotating shaft 44, and a torch 5 is attached to its tip. Therefore, when the rotating shaft 44 rotates, the rotating arm 46 and the torch 5 at its tip revolve in the area radially outward from the rotating shaft 44.

[0023] In this embodiment, the amount of protrusion of the rotating arm 46 (the dimension from the rotating shaft 44 to the tip of the rotating arm 46) can be changed by loosening the bolt 45a of the socket 45. Therefore, the radius of rotation of the torch 5 around the rotating shaft 44 can be adjusted appropriately within the range of the length of the rotating arm 46.

[0024] The torch 5 is a gas cutting torch, and is configured to receive gas from a gas cylinder (not shown) and release it from a nozzle at the tip, allowing the object to be cut by the combustion flame of the gas. In this embodiment, the torch 5 is configured to be supplied with hydrogen gas cutting gas.

[0025] Here, we will explain how to use the automatic semicircular cutting device 1 according to the present invention (semicircular cutting construction method). First, as shown in Figure 3(1), the automatic semicircular cutting device 1 is fixed to the vertical stiffener 73 of an existing road bridge. Specifically, the automatic semicircular cutting device 1 is placed in an appropriate position, and the lever handle 23c of the toggle clamp 23 is operated to clamp and fix the vertical stiffener 73 (see Figure 2).

[0026] Next, as necessary, the knob 25a of the first feed mechanism 25 and the knob 26a of the second feed mechanism 26 are rotated to appropriately move the support part 3 or the torch 5 in a direction parallel to and perpendicular to the side surface of the vertical stiffener 73, thereby adjusting the relative position with respect to the vertical stiffener 73. In addition, the amount of protrusion of the rotating arm 46 (the radius of rotation of the torch 5) is adjusted as necessary.

[0027] Furthermore, if necessary, a heat-transfer-preventing heat-insulating agent is applied in advance to the surface of the vertical stiffener 73. For example, if an epoxy resin adhesive for concrete / steel joints has been applied to the upper surface of the deck plate 71, it is effective to apply a heat-transfer-preventing heat-insulating agent to the upper part of the vertical stiffener 73 (the region between the position where gas cutting is performed and the deck plate 71, the position indicated by the dashed line in Figure 3(1)) in order to minimize the effects of the heat generated during gas cutting.

[0028] The term "thermal conduction preventing and heat insulating agent" used here refers to a paste or gel-like insulating agent whose main component is a material with heat insulating and heat absorbing properties (such as silicon dioxide). When this insulating agent is applied, it absorbs and dissipates heat, suppressing heat conduction. It is originally used to avoid problems such as distortion caused by heat during welding, etc.

[0029] As shown in Figure 3(1), when the torch 5 is in the starting position at the lower end and a switch of a control means (not shown) is turned on, hydrogen gas cutting gas is supplied from a gas cylinder to the torch 5 via a hose (not shown), a combustion flame is sprayed from the nozzle at the tip of the torch 5 toward the vertical stiffener 73, and power is supplied to the electric motor 41, causing the output shaft of the electric motor 41 and the rotating shaft 44 to rotate, and the rotating arm 46 and torch 5 to rotate around the rotating shaft 44 as shown in Figure 3(2).

[0030] The combustion flame of the rotating torch 5 performs gas cutting on the vertical stiffener 73, and the cut (crack) progresses along the arc-shaped path of the torch 5. When the torch 5 reaches the upper end position (the position indicated by the dashed line in Figure 3(2)), the crescent-shaped fragment is completely cut off from the vertical stiffener 73, forming a semicircular notch. Then, the supply of power to the electric motor 41 and the supply of gas to the torch 5 are stopped, and the operation is completed.

[0031] As described above, the automatic semicircular notching device 1 according to the present invention can significantly reduce the labor and time required for semicircular cutting compared to the conventional method (see FIG. 4), thereby reducing construction costs. Furthermore, the device can be very easily and reliably fixed to the vertical stiffener to be cut, and after fixing, the relative position of the device to the vertical stiffener can be adjusted.

[0032] In the above embodiment, hydrogen gas cutting gas is supplied to the torch 5, and hydrogen gas cutting is performed. However, it is also possible to supply the more commonly used acetylene gas. However, when gas cutting is performed on an existing vertical stiffener 73 using acetylene gas, the heat can burn the paint not only near the cut but also on the opposite side of the vertical stiffener 73 (the side opposite the side facing the torch 5). This requires repainting and the installation of scaffolding. As a result, time and cost savings cannot be expected. On the other hand, when hydrogen gas cutting is performed, problems such as paint burns can be avoided, and time and cost savings can be expected.

[0033] Furthermore, in the above embodiment, the first feed mechanism 25 is configured to be able to move the movable stage 24 in a direction parallel to the surface to be worked on, and the second feed mechanism 26 is configured to be able to move the support part 3 in a direction perpendicular to the surface to be worked on, but the first feed mechanism 25 may be configured to be able to move the movable stage 24 in a direction perpendicular to the surface to be worked on, and the second feed mechanism 26 may be configured to be able to move the support part 3 in a direction parallel to the surface to be worked on.

[0034] Furthermore, in the above embodiment, the toggle clamp 23 is used as a means for fixing the automatic semicircular notching device 1 to the vertical stiffener 73 (see Figure 2), but other fixing means, such as a screw-type clamp or a fixing means using a magnet, can also be used.

[0035] Furthermore, in the above embodiment, an example of performing semicircular cutting on the vertical stiffener 73 is described, but the construction target of the present invention is not limited to vertical stiffeners, and semicircular cutting can also be performed on other steel materials. [Explanation of symbols]

[0036] 1: Automatic semicircular notching device, 2: Base part, 21: Side contact portion, 22: Side edge guide, 23: Toggle clamp, 23a: bass, 23b: clamp arm, 23c: Lever handle, 23d: Links, 24: Movable stage, 25: First feed mechanism unit, 25a: knob, 26: second feed mechanism unit, 26a: knob, 3: Support part, 4: Drive unit, 41: electric motor, 42: Metal cover, 43: Gearbox, 44: Rotation axis, 45: Socket, 45a: Bolt, 46: Rotating arm, 5: Torch, 71: Deck plate, 72: Main girder web, 73: Vertical stiffener, 73a:Fragment, 74:Trough Rib,

Claims

1. The cutting tool has a base, a support, a drive, a gas cutting torch, and a gas cylinder that supplies hydrogen gas cutting gas to the torch; The base portion has a side abutment portion that abuts against the surface of the processing target, a fixing means that fixes the device to the processing target, and an adjustment means that allows the torch to move in a direction parallel to and perpendicular to the surface of the processing target, the drive unit has an electric motor and a rotary shaft power-connected to the electric motor; An automatic semicircular notching device characterized in that a rotating arm is attached to a rotating shaft so as to extend radially outward from the rotating shaft, and a torch is attached to the rotating arm, and that when the rotating shaft rotates, the rotating arm and the torch rotate in the radially outer area of ​​the rotating shaft.

2. 2. The automatic semicircular notching device according to claim 1, further comprising a side edge guide extending in a direction perpendicular to the side abutment portion and abutting against the side edge of the vertical stiffener.

3. 2. The automatic semicircular notching device according to claim 1, wherein the electric motor and the rotary shaft are operatively connected via a reduction gear.

4. 2. The automatic semicircular notching device according to claim 1, wherein the fixing means is a toggle clamp.

5. 2. The automatic semicircular notching device according to claim 1, wherein the rotating arm is configured so that the amount of protrusion from the rotating shaft can be changed.

6. the adjustment means includes a first feed mechanism, a movable stage connected to the side abutment portion via the first feed mechanism, and a second feed mechanism fixed on the movable stage and having a support portion attached thereto; The first feed mechanism is configured to move the movable stage in a direction parallel to or perpendicular to the surface to be processed, 2. The automatic semicircular notching device according to claim 1, wherein the second feed mechanism is configured to move the support part in a direction perpendicular to or parallel to the surface to be worked on.

7. A method for performing semicircular cutting using the automatic semicircular notching device according to any one of claims 1 to 6, An automatic semicircular notching device is fixed to the construction target, This method of cutting a semicircle is characterized by supplying hydrogen gas cutting gas from a gas cylinder to a torch, spraying a combustion flame from the nozzle at the tip of the torch toward the surface to be cut, and supplying power to an electric motor to rotate the rotating arm and torch around the rotation axis.

8. 8. The method for cutting semicircular sections according to claim 7, wherein a heat-transfer-preventing and heat-insulating agent is applied to the surface of the workpiece in advance.

Images