Clamping jig for rail bond welding

Abstract

By simplifying the structure, costs can be reduced, and a clamping jig for rail bond welding that can be used continuously for a long period of time without being affected by heat or alloying wax associated with welding is provided. [Solution] The rail 4 is provided with a pair of first legs 2a that are spaced apart along the length of the rail and each contacts the bottom surface 4b1 of the rail, and a pair of second legs 2b that are spaced apart along the length of the rail and each have a predetermined gap between them and the top surface 4b2 of the rail. The rail bond 5 is configured with a clamp member 2 that straddles the bottom 4b of the rail and the pair of first legs, and a terminal retaining member (low pack) 3 that is inserted into the gap formed between the top surface of the rail and the pair of second legs and holds the terminal 5B of the rail bond 5 along the top surface of the rail.

Description

Technical Field

[0001] This invention relates to a clamp jig for rail bond welding for attaching a rail bond that electrically connects between rail joints to a rail.

Background Art

[0002] In order to ensure electrical connection at the joints of railway rails, a rail bond that connects between the rail joints is used. That is, the rail not only serves as a track for trains to run, but also plays a role in transmitting various signal currents or return currents for switching operation displays and switching points. However, in order to absorb the thermal expansion of the rail due to exposure to direct sunlight or the like, a gap is provided at the joint between the rails, and the two rails are electrically separated by this gap. Therefore, by attaching a conductive rail bond to this joint portion, electrical connection between the rails is ensured.

[0003] This rail bond includes a conductor made of a stranded wire formed by aggregating about several tens of thin copper wires, and terminals (rail bond terminals) attached to both ends of this conductor for electrically connecting the conductor and the rail. Generally, a means of attaching the rail bond terminal to the end of the rail by welding using alloy wax is adopted.

[0004] Regarding this type of rail bond and its attaching means, several proposals have been made by the applicant in the past. Among them, a jig for attaching a rail bond terminal by welding along the upper surface of the bottom of the rail is disclosed in Patent Document 1. Figure 11 shows a rail bond welding jig 41 disclosed in Patent Document 1, which is shown mounted on the bottom upper surface 31a of the rail 31. According to this rail bond welding jig 41, a handle 45 is mounted on a base 42 positioned along the bottom upper surface 31a of the rail 31, and is rotated by support shafts 43 and 44. By operating this handle 45, a link arm 48 is made rotatable via support shafts 46 and 47, and a terminal retaining pin 52 and a heater retaining member 53, which are pressed by a spring 51, are attached to the link arm 48.

[0005] According to this jig 41, by operating the handle 45, the link arm 48 rotates, and the heater retaining member 53 presses the U-shaped heater 54 toward the bottom upper surface 31a of the rail 31, while the terminal retaining pin 52 acts to press against an alloy wax (not shown) placed in the central space of the U-shaped heater 54 and the rail bond terminal superimposed on this alloy wax. The U-shaped heater 54 contains copper oxide and aluminum powder (copper thermite), and when heated with a flame, the copper thermite ignites, and the heat of combustion causes the rail bond terminal to be welded (brazed) to the bottom upper surface 31a of the rail 31 with the alloy brazing wax. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-273403 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Incidentally, in the rail bond welding jig 41 disclosed in Patent Document 1, a handle 45 is movably mounted on a base 42 via a plurality of support shafts 43 and 44, and a mechanical link mechanism is employed that rotates a link arm 48 via a plurality of other support shafts 46 and 47 by operating the handle 45. Furthermore, the link arm 48 also needs to be provided with a mechanism such as a terminal retaining pin 52 that is biased by a spring 51. Consequently, the configuration is complicated, and the manufacturing cost of the jig 41 is inevitably high. Furthermore, the jig 41 is affected by the heat generated during welding, and components such as copper thermite and alloy wax are scattered and adhere to the link mechanism of the jig 41. As a result, rust is likely to occur, leading to malfunctions in the movable parts of the link mechanism.

[0008] This invention is based on the aforementioned technical considerations and aims to provide a clamping jig for rail bond welding that can reduce costs by simplifying the jig's structure and can be used continuously for a long period of time without being affected by heat or alloying wax associated with welding. [Means for solving the problem]

[0009] The clamping jig for rail bond welding according to this invention, made to solve the aforementioned problems, is a clamping jig for rail bond welding for attaching a rail bond, which has a conductor for electrically connecting rails and a terminal for connecting the conductor attached to the end of the conductor, to a rail joint, wherein the clamping jig is provided with a pair of first legs that are spaced apart in the longitudinal direction of the rail and each contacts the bottom surface of the rail, and a pair of second legs that are spaced apart in the longitudinal direction of the rail and each has a predetermined gap between them and the top surface of the rail, and the clamping jig is provided with a clamping member that is positioned to straddle the bottom of the rail between the pair of first legs and the pair of second legs, and a terminal holding member (hereinafter also called a low pack) that is inserted into the gap formed between the top surface of the rail and the pair of second legs and holds the terminal of the rail bond along the top surface of the rail.

[0010] In this case, it is desirable that the pair of first legs and the pair of second legs are each attached to a flat plate to form the clamp member, and that the length dimension L1 of the pair of first legs from the flat plate is set to be larger than the length dimension L2 of the pair of second legs from the flat plate. Furthermore, it is desirable that the length dimension L4 of the terminal retaining member (low pack) be the same as or larger than the dimension L3 between the outer sides of a pair of second legs that are spaced apart in the longitudinal direction of the rail.

[0011] In addition, in a preferred embodiment, the clamp member is configured such that the flat plate side serves as the base end, and the tips of the pair of second legs are spread apart at a predetermined angle θ relative to the pair of first legs. [Effects of the Invention]

[0012] The clamping jig for rail bond welding according to this invention consists of two members: a clamping member that is positioned to straddle the bottom of the rail and has a pair of first legs that contact the lower surface of the bottom of the rail and a pair of second legs that are positioned with a predetermined gap between them and the upper surface of the bottom of the rail; and terminal holding members (low packs) that are inserted into the gap formed between the pair of second legs of the clamping member and the upper surface of the bottom of the rail, and clamp the rail bond terminals along the upper surface of the bottom of the rail.

[0013] Therefore, the clamping jig for rail bond welding according to this invention simplifies its structure, reduces costs, and is less susceptible to the effects of heat and heated alloy wax associated with welding, making it possible to provide a clamping jig for rail bond welding that can be used repeatedly over a long period of time. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view showing the clamp jig for rail bond welding according to this invention attached to the upper bottom surface of the rail. [Figure 2] This is a side view of the jig, seen from the longitudinal direction of the rail. [Figure 3] This is a plan view of the jig, seen from the top of the rail. [Figure 4] This is a front view of the jig, taken from a direction perpendicular to the longitudinal direction of the rail. [Figure 5] This is a perspective view of the jig, again, but from a different angle, looking at it from the upper, diagonal side of the rail. [Figure 6] This is a perspective view showing the individual components of the clamp members that make up the jig. [Figure 7] This is also a plan view of the clamp member. [Figure 8] This is also a front view of the clamp member. [Figure 9] This is a perspective view showing the individual components of the low pack that make up the jig. [Figure 10]Also showing the single-piece structure of the wax pack, (A) is a plan view, (B) is a front view, (C) is a bottom view, (D) is a left side view, and (E) is a right side view. [Figure 11] It is a side view showing an example of a conventional jig for rail bond welding.

Embodiments for Carrying out the Invention

[0015] Regarding the clamp jig for rail bond welding according to this invention, it will be described based on the embodiments shown in the drawings. FIGS. 1 to 5 show a state where the clamp jig 1 for rail bond welding is attached to the rail 4 and the rail bond 5 is set along the rail 4, that is, a state immediately before attaching the terminal 5B of the rail bond 5 to the rail 4 by welding (waxing).

[0016] As shown in FIG. 2, the portion of the rail 4 that contacts the wheel is called the head 4a, the portion that contacts the sleeper or the like on which the rail 4 is placed is called the bottom 4b, and the central portion connecting the head 4a and the bottom 4b is called the abdomen 4c. On the other hand, as already described, the rail bond 5 includes a conductor 5A formed by a stranded wire that aggregates about several tens of thin-diameter soft coppers, and terminals (rail bond terminals) 5B that are attached to both ends of the conductor 5A and electrically connect the conductor 5A and the rail 4 (see FIGS. 1 and 5). In the drawings, the conductor 5A formed by the stranded wire is described in a round bar state.

[0017] It has been proposed that the terminal 5B of this rail bond 5 be attached to the side surface of the head 4a of the rail, or the upper surface of the bottom 4b, or the side surface of the abdomen 4c, respectively, by welding (waxing). When the rail bond terminal 5B is attached to the side surface of the rail head 4a or the side surface of the abdomen 4c, the conductor 5A will be in a suspended state along the rail 4. In contrast, when the terminal 5B is attached to the upper bottom surface 4b2 of the rail, the conductor 5A of the rail bond 5 is kept in a state where it rests along the upper bottom surface 4b2 of the rail. Therefore, even if subjected to vibrations caused by the passage of trains over a long period of time, the degree to which the rail bond 5 is damaged is reduced.

[0018] The clamp jig 1 for rail bond welding according to the present invention, described below, attaches the terminal 5B of the rail bond 5 to the bottom upper surface 4b2 of the rail by welding (brazing). This jig 1 consists of two members: a clamp member 2 positioned to straddle the bottom 4b of the rail 4, and a terminal retaining member (brazing pack) 3 inserted between the bottom upper surface 4b2 of the rail 4 and the clamp member 2, which functions to hold the rail bond terminal 5B along the bottom upper surface 4b2 of the rail 4.

[0019] Figures 6 to 8 show the individual components of the clamp member 2 that make up the jig 1. The clamp member 2 is provided with a pair of first legs 2a that are spaced apart along the length of the rail 4 and each contacts the bottom surface 4b1 of the rail 4, and a pair of second legs 2b that are spaced apart along the length of the rail 4 and each have a predetermined gap between them and the top surface 4b2 of the rail 4. The pair of first legs 2a and the pair of second legs 2b are positioned to straddle the bottom 4b of the rail.

[0020] In this embodiment, the clamp member 2 is prepared as a set in which a first leg portion 2a, which is formed in the shape of a rectangular prism, is integrally molded in a U shape with a second leg portion 2b, which is also formed in the shape of a rectangular prism. The outer sides of the central parts of the U-shaped bends of each are attached to one side of the longitudinal end of a flat plate 2c, respectively. The first leg portion 2a and the second leg portion 2b, and the plate 2c, which are integrally molded in a U-shape, are preferably made of stainless steel (SUS), and are joined together by means such as welding as shown in the illustrated example. Furthermore, a cylindrical grip 2d is attached to the center of the back side of plate 2c, facing in the opposite direction to the extension direction of the first leg 2a and the second leg 2b.

[0021] As shown in Figure 8, the clamp member 2 has a flat plate 2c side as its base end, and the tips of a pair of second legs 2b are arranged to be spread apart at a predetermined angle θ relative to a pair of first legs 2a, in this embodiment the angle θ is set to 14°. With this configuration, in the state shown in Figure 2, for example, where the first legs 2a and the second legs 2b are arranged straddling the bottom 4b of the rail, a substantially parallel gap can be formed between the bottom upper surface 4b2 of the rail 4 and the second legs 2b. This allows the low pack 3 and the rail bond terminal 5B, which is pressed against the bottom upper surface 4b2 of the rail 4 via the low pack 3, to be held stably in the gap between the bottom upper surface 4b2 of the rail 4 and the second leg portion 2b.

[0022] Furthermore, as shown in Figure 8, it is desirable that the clamp member 2 has a length dimension L1 of the pair of first legs 2a extending from the plate 2c that is larger than the length dimension L2 of the pair of second legs 2b extending from the plate 2c. In this embodiment, the length dimension L2 of the second legs 2b is set to 65 mm, and the length dimension L1 of the first legs 2a is set to 80 mm. In this configuration, the length dimension L2 of the second leg portion 2b is limited because its tip abuts against the body 4c of the rail 4, whereas the length dimension L1 of the first leg portion 2a can be set to be larger. By positioning a pair of first legs 2a with a larger length dimension L1 in close contact with the bottom surface 4b1 of the rail 4, it is possible to attach the clamp jig 1 to the rail 4 in a stable state.

[0023] Next, Figures 9 and 10 show the individual components of the low pack 3 that make up the jig 1. The Low Pack 3 is inserted into the gap formed between the pair of second legs 2b of the clamp member 2 and the bottom upper surface 4b2 of the rail 4, and functions as a terminal retaining member that presses the terminal 5B of the rail bond 5 along the bottom upper surface 4b2 of the rail 4. Therefore, it is desirable that the length dimension L4 (see Figure 10(A)) of the low pack 3, which is positioned between the pair of second legs 2b of the clamp member 2, be the same as or larger than the dimension L3 (see Figure 7) between the outer sides of the pair of second legs 2b of the clamp member 2.

[0024] The Low Pack 3 is made of a metal material such as an aluminum alloy, and as shown in Figure 9, a nearly rectangular parallelepiped L-shaped bent portion 3b is integrally molded to one end of the nearly rectangular parallelepiped main body portion 3a. On both ends of the upper surface, a lower surface is formed on both sides facing outwards via stepped portions 3c, and the pair of second legs 2a of the clamp member 2 come into contact with the lower surface formed by the stepped portions 3c, so that the Low Pack 3 is inserted into the gap formed between the pair of second legs 2b and the bottom upper surface 4b2 of the rail 4 and clamped. Therefore, the dimension between the stepped portions 3c at both ends along the longitudinal direction of the low pack 3 is set to be slightly smaller than the dimension between the inner sides of the pair of second legs 2b in the clamp member 2.

[0025] Furthermore, as shown in Figure 10, a sloping portion 3d is formed on the inner corner side of the rectangular parallelepiped main body portion 3a and the L-shaped bent portion 3b toward the lower bottom surface of the Low Pack 3, and an overhanging terminal locking portion 3e is provided toward the upper surface of the L-shaped bent portion 3b. In this embodiment, the rail bond terminal 5B is configured as shown in Figure 5, comprising a metal cylindrical portion 5a that surrounds and attaches to the end of a conductor 5A made of assembled small-diameter soft copper, and an L-shaped conductor 5b that is integrally molded with the cylindrical portion 5a and has its tip bent. Therefore, the end face of the L-shaped conductor 5b of the rail bond terminal 5B is locked to the overhang-shaped terminal locking portion 3e formed on the wax pack 3, and a receiving portion 6 can be formed between it and the bottom upper surface 4b2 of the rail 4, as shown in Figure 5, into which molten alloy wax can be poured.

[0026] Furthermore, as shown in Figure 10, a rubber member (silicone rubber) 3f is housed and arranged along a groove formed from the main body 3a to the L-shaped bent portion 3b on the lower bottom surface of the Low Pack 3. The rubber member 3f is mounted so as to protrude slightly from the lower bottom surface of the Low Pack 3, for example, as shown in Figure 10(B). Therefore, the rubber member 3f provides a slight cushion when the wax pack 3 is placed on the bottom upper surface 4b2 of the rail 4, and also serves to prevent the molten alloy wax from leaking out when the alloy wax is filled into the tray portion 6 formed between the L-shaped conductor 5b constituting the rail bond terminal 5B and the bottom upper surface 4b2 of the rail 4, as shown in Figure 5.

[0027] As described above, the clamp jig 1 is set on the rail 4 as shown in Figure 5, and by filling the receiving portion 6 formed between the L-shaped conductor 5b constituting the rail bond terminal 5B and the bottom upper surface 4b2 of the rail 4 with molten alloy solder, the rail bond terminal 5B can be welded (brazed) to the bottom upper surface 4b2 of the rail 4.

[0028] Furthermore, the rail bond 5 described above also has a similar rail bond terminal 5B connected to the other end of the conductor 5A. Accordingly, the wax pack 3 used in the clamp jig 1 for welding the rail bond terminal 5B at the other end to the rail 4 will be a modified version of the wax pack 3 (left terminal wax pack) shown in Figures 9 and 10, with the L-shaped bend 3b replaced in the longitudinal direction of the main body 3a (right terminal wax pack). [Explanation of Symbols]

[0029] 1. Clamping jig 2 Clamp members 2a 1st leg 2b 2nd leg 2c plate 2D Grip 3. Terminal retaining member (low pack) 3a Main body 3b L-shaped bend 3c Step section 3d slope 3e Terminal locking part 3f Rubber components 4 rails 4a head 4b bottom 4b1 Bottom bottom surface 4b2 Bottom top surface 4c abdomen 5 Rail Bond 5A Conductor 5B Rail Bond Terminal 5a Cylindrical body part 5b L-shaped conductor 6. Receiving tray

Claims

1. A clamping jig for rail bond welding, for attaching a rail bond, which has a conductor for electrically connecting rails and a terminal for connecting the conductor attached to the end of the conductor, to a rail joint, The clamping jig comprises a pair of first legs, each spaced apart in the longitudinal direction of the rail and in contact with the lower surface of the bottom of the rail, and a pair of second legs, each spaced apart in the longitudinal direction of the rail and positioned with a predetermined gap between them and the upper surface of the bottom of the rail, and the pair of first legs and the pair of second legs are positioned across the bottom of the rail as a clamping member, A terminal retaining member is inserted into and clamped within the gap formed between the bottom upper surface of the rail and the pair of second legs, and presses the terminal of the rail bond along the bottom upper surface of the rail. A clamping jig for rail bond welding, characterized by being composed of the following.

2. The pair of first legs and the pair of second legs are each attached to a flat plate to form the clamp member. The clamping jig for rail bond welding according to claim 1, characterized in that the length dimension L1 of the pair of first legs from the flat plate is set to be larger than the length dimension L2 of the pair of second legs from the flat plate.

3. The clamping jig for rail bond welding according to claim 1, characterized in that the length dimension L4 of the terminal retaining member is set to be the same as or larger than the dimension L3 between the outer sides of a pair of second legs that are spaced apart in the longitudinal direction of the rail.

4. The clamping jig for rail bond welding according to claim 2, characterized in that the flat plate side serves as the base end, and the tips of the pair of second legs are arranged to be spread apart at a predetermined angle θ relative to the pair of first legs.

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