JP2005349469A - Rail bond terminal welding method and impression tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rail bond terminal welding method and an impression tool in which a rail surface need not be hit by a hammer or the like, no damages or cracks are caused in a rail by a static pressurization means, the work is not noisy, the working amount can be reduced, the work is simplified, and performed in a comfortable attitude, the quality is consistent and uniform, the positioning and the shape of impression are uniform, and impression capable of demonstrating uniform effect can be applied to a correct position. <P>SOLUTION: A recessed plastically deformed area is formed by a step of welding a rail bond terminal to a rail through the copper-thermit welding in a nearly parallel state to the surface of a body part of the rail along the longitudinal direction of the rail, and a static pressurizing step by a predetermined static pressurizing means at four predetermined parts on the line in the radial direction of about 45° diagonally in the vertical direction from a nearly parallel line around the rail bond terminal of an outer welded edge of the rail bond terminal welded in the first step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of welding rail bond terminals and an indentation tool which are designed to reduce a decrease in fatigue strength of rails.

In recent years, various methods have been proposed for attaching rail bond terminals, etc. on conventional rails (ordinary rails, heat-treated rails). Especially, welding joints have high joint strength and require advanced skills. A relatively large number of copper thermite welding methods are used.
This copper thermite welding method is a welding method that applies a thermochemical reaction (thermit reaction). The principle is that a mixed powder of copper oxide and aluminum (copper thermite agent) is burned in a crucible constituting a jig, The rail bond terminal is welded to the surface of the body portion of the rail using the heat generated by.

However, such a copper thermit welding method is a welding method that is simple and can achieve high strength, but it is said that residual stress remains at the outer edge of the weld, and therefore the fatigue strength of the rail is lowered. For example, in order to improve the fatigue strength of the welded joint, as described in “Method of improving fatigue strength by improving weld toe” by Miki et al. It is known that it is effective to reduce the stress concentration at the weld toe and to reduce the tensile residual stress caused by welding.
The paper also describes that hammer peening is effective to some extent in combination with TIG treatment and grinder treatment as a stress relaxation method.

By the way, the hammer peening treatment means that the welding toe is hit with a hammer to plastically deform the rail, and the residual stress on the pressing side caused by the deformation is relieved of the tensile residual stress at the time of welding. This reduces the decrease in fatigue strength due to welding.
In addition, as described in the same paper, the hammer peening treatment improves the fatigue strength to some extent by applying a hammer hit to the peripheral portion where the residual tensile stress is the highest, On the other hand, it is known that scratches are generated on the rail, and fatigue cracks are generated based on the scratches.

Further, it is known that tensile stress remains in the peripheral portion of the heat-affected zone surrounding the melted portion by welding, and this tensile stress is related to the decrease in fatigue strength and the occurrence of cracks.
Furthermore, not the welded peripheral edge of the heat-affected zone where the residual tensile stress is considered to be the highest, but the peripheral edge of the rail bond terminal causes a plastic deformation with a concave shape due to the dome-shaped hammer hitting, and the fatigue strength due to welding is increased. The decrease can also be prevented.

In particular, when the welding is performed by a copper thermite welding method, the welded portion of the rail and the heat affected zone are hidden under the weld metal of the rail bond, so that the peripheral portion of the heat affected zone is directly pressed or peened. However, it is possible to form a concave plastic deformation by hammering the surface of the rail along the periphery of the portion of the rail bond that is not covered with the weld metal. It is known as shown in Japanese Patent Publication No. 2002-346771.
JP-A-2002-346771

  However, hitting the surface of the rail with a hammer as in the above-described prior art results in noise, and the hitting work is performed along the periphery of the portion of the rail bond that is not covered by the weld metal. There is a problem that the increase in the amount of work and the work becomes troublesome, and it is difficult to keep the strength of the hitting uniform, the shape of the indentation is uneven, and the indentation that can exert a uniform effect cannot be performed. It was.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and in the invention according to claim 1, the rail bond terminal is welded to the rail by copper thermite welding in a substantially parallel state along the longitudinal direction of the rail on the surface of the body of the rail. And at the predetermined four positions on the line in the radial direction of approximately 45 ° obliquely up and down from the substantially parallel line centering on the rail bond terminal at the welded outer edge portion of the rail bond terminal welded by the process. A concave plastic deformation region is formed by a static pressure step by a static pressure means.

  Further, the invention according to claim 2 is the method for welding rail bond terminals according to claim 1, wherein the concave plastic deformation regions are formed at predetermined four locations on the line in the approximately 45 ° radial direction obliquely up and down. Is characterized in that each line is formed to have a required length and a required depth in a state of crossing at a required angle.

  A third aspect of the present invention is the method of welding rail bond terminals according to the first or second aspect of the present invention, wherein the plastic deformation region is a concave shape formed at four predetermined positions on the diagonally approximately 45 ° radial line. Is characterized in that it is formed simultaneously at four locations by a static pressure step by a required static pressure means.

  A fourth aspect of the present invention is the method of welding rail bond terminals according to any one of the first to third aspects, wherein the plastic deformation region is a concave shape formed at four predetermined positions on the diagonally approximately 45 ° radial line. Includes the step of simultaneously forming two of the four locations by the static pressure step by the required static pressure means, and further forming the remaining two locations at the same time.

  Further, the invention according to claim 5 is provided with a pair of indentation-forming claws having an arcuate tip shape on the front lower surface of the substrate, provided symmetrically with an angle of approximately 45 ° with respect to the longitudinal center line of the handle. A contact stabilization protrusion is provided on the lower surface of the handle side.

  According to the rail bond terminal welding method of the first aspect of the present invention, the concave plasticity is generated without generating noise by the static pressure action by the static pressure means without hitting the surface of the rail with a hammer or the like. Since the deformation area is formed, the rails are not damaged or cracked, the work is quiet, the quality is stable and uniform, the work amount is reduced, the work is simplified, and the work can be done in an easy posture. In addition, when forming the indentation, the strength, length, depth, shape, etc. of the indentation can be selectively adjusted and determined each time in accordance with the indentation formation conditions, and the work can be properly performed. Therefore, there is an effect that the indentation and the shape are not uneven, and an indentation capable of exhibiting a uniform effect at an accurate position can be surely applied.

  According to the rail bond terminal welding method according to claim 2 of the present invention, the concave plastic deformation regions formed at predetermined four locations on the line in the radial direction of approximately 45 ° obliquely up and down are each Since it is formed in the required length and required depth in a state where it intersects with each line at a required angle, it is performed along the periphery of the portion of the conventional rail bond that is not covered with the weld metal. The indentation work is extremely easy as compared with the conventional one, and there is an effect that the fatigue strength can be sufficiently prevented from being lowered by welding.

  Further, according to the rail bond terminal welding method of the third aspect of the present invention, the concave plastic deformation regions formed obliquely at the predetermined four locations on the line in the approximately 45 ° radial direction have the required static electricity. Since four places are formed simultaneously by the pressurizing means, there is an effect that the operation is simple and accurate.

  According to the rail bond terminal welding method according to claim 4 of the present invention, the concave plastic deformation regions formed obliquely at predetermined four locations on the line in the radial direction of approximately 45 ° have the required static electricity. Since two of the four places are formed simultaneously by the pressurizing means, and the remaining two places are formed at the same time, the static pressurization of the static pressurizing means is reduced in size and size, and is convenient for carrying. There is an effect that can be.

  Further, according to the indentation tool of claim 5 of the present invention, the pair of indentation claws having the arcuate tip shape is formed on the front lower surface of the substrate with an angle of about 45 ° with respect to the longitudinal center line of the handle. Since the contact stabilization protrusion is provided on the lower surface on the handle side of the substrate, the tip of the indentation claw at the time of formation of the indentation is placed at a predetermined place where the indentation is formed on the surface of the body of the rail. There is an effect that the indentation can be accurately positioned by the contact stabilizing protrusion.

  In the present invention, the rail surface is not struck with a hammer or the like, the rail is not damaged or cracked, the operation is quiet, and because of the static pressure means, no noise is generated and the work amount is reduced. The work is simple, you can work in an easy posture, the quality is stable and uniform, the indentation positioning is not uneven, the uniform effect can be exerted on the accurate position and the indentation can be applied reliably Provided is a rail bond terminal welding method and an indentation tool.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a rail bond terminal welding method and an indentation tool according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a partially cutaway perspective view showing an example of a crucible constituting a general jig to which a copper thermit welding method is applied. FIG. 2 is a perspective view showing an embodiment of the rail bond terminal. FIG. 3 is a front view of a jig for explaining the rail bond terminal welding method according to the present invention, and shows an example in which the static pressure means is a hydraulic or pneumatic cylinder. . FIG. 4 shows an example when the static pressure means is a screw-type cylinder. FIG. 5 is a right side view of FIG. 3 and shows an example of a usage state of the indentation tool. FIG. 6 is an explanatory view showing a completed indentation formation according to the present invention. FIG. 7 is a perspective view showing an example of a state in which the rail bond terminal is welded to one side of the rail body. 8, (a)-(c) is explanatory drawing which shows an example of an indentation formation process. 9 is a plan view showing an example of an indentation tool, FIG. 10 is a side view thereof, and FIG. 11 is a perspective view thereof. FIG. 12 is an explanatory view showing an example of use of the indentation tool. 13 and 14 are plan views showing other examples.

In FIG. 1, reference numeral 1 denotes a rail welding terminal welding jig to which a conventionally used copper thermite welding method is applied.
The jig 1 is composed of a crucible body 2 having a recess 2a, a runner 3, and a copper weld 4 having a semicircular cut 4a connected to the runner 3.
In the recess 2a of the crucible body 2, a thermite agent 5 and an igniter 6 are placed so as to cover it.
At the initial stage, the bottom opening of the recess 2 a is closed with the steel disk 7.

Using such a jig 1, a tubular rail bond terminal 8 (shown in FIG. 2) having substantially the same shape as the semicircular cut 4 a is formed on the surface of the body portion 10 a of the rail 10 by a copper thermite welding method. Weld (11).
A rail bond (electric wire) 8a is fixed to the cylindrical rail bond terminal 8 by caulking or the like. Reference numeral 8b denotes a fixing portion which is positioned and welded to the copper welded portion 4.

  More specifically, first, the cylindrical rail bond terminal 8 is inserted into the semicircular cut 4a of the crucible body 2 in the longitudinal direction of the rail 10 (for example, a normal rail or a heat-treated rail) (for example, the surface of the rail body 10a). When the rail bond terminal 8 is welded to the body 10a of the rail 10 by the crucible body 2, the inside of the crucible body 2 is heated by a gas burner (not shown).

Next, the rail 10 is preheated as necessary. There may be no residual heat.
Subsequently, the part which welds the rail bond terminal 8 to the trunk | drum 10a of the rail 10 with a gas burner is heated. At that time, the flame of the gas burner is applied at right angles to the welding surface and heated uniformly while moving the blowing tube in a circular shape.

Next, the jig 1 is temporarily attached to the rail 10 by opening a handle (not shown) and placing a bond fitting (not shown) on the rail head 10b.
Next, when the rail bond terminal 8 is inserted into the semicircular cut 4a of the crucible body 2 along the surface of the body portion 10a of the rail 10, the fixing portion 8b provided on the rail bond terminal 8 is positioned at the copper welded portion 4. Stop on.

Here, the handle (not shown) is closed and firmly fixed to the rail 10, and is securely attached so that there is no gap or play between the rail 10 and the crucible body 2.
In this state, the steel disk 7 is set in the middle of the crucible body 2 from above the crucible body 2, that is, the upper portion of the runner 3, and the copper thermite agent 5 is introduced.

  Furthermore, when the igniter 6 is introduced and ignited with a lighter with a long handle, it reacts almost simultaneously with the ignition. After the copper thermite agent 5 burns for a few seconds, the steel disk 7 is also melted and the molten copper passes through the runner 3. If the rail bond terminal 8 to be welded in the copper welded portion 4 and the rail 10 are brought into close contact with each other, the rail bond terminal 8 that is stopped at an appropriate position of the copper welded portion 4 is passed. The fixed portion 8b is securely welded (11) to the trunk portion 10a of the rail 10 by molten copper.

Thus, in this invention, when welding the rail bond terminal 8 to the trunk | drum 10a of the rail 10, as shown in FIG. 7, the above copper thermite welding methods are applied.
First, a cylindrical rail bond terminal 8 formed so as to stop at an appropriate position of the copper weld portion 4 is inserted into the semicircular cut 4a of the crucible body 2 along the surface of the body portion 10a of the rail 10, When the copper thermite agent 5 is ignited above the crucible body 2, the copper passes through the runner 3, and the fixing portion 8 b of the rail bond terminal 8 is reliably welded to the trunk portion 10 a of the rail 10 at the copper welded portion 4.

  Thus, it is known that the outer stress of the welded portion of the rail bond terminal 8 welded to the body portion 10a of the rail 10 remains in the residual stress, and the fatigue strength decreases. It is known that the hammering is applied to the outer edge portion of the rail bond terminal to cause a concave plastic deformation, thereby preventing a decrease in fatigue strength due to welding.

  In FIG. 3 to FIG. 5, reference numeral 12 denotes an indentation forming jig body, which is formed in a bifurcated shape so as to be able to straddle the rail 10, and one of the bifurcated portions, that is, a body portion of the rail 10. On the side located on the side surface (rail bond terminal welding side surface), required static pressure means by, for example, a hydraulic or pneumatic cylinder 13 or a screw pressure type 14 is detachably provided by a screw 13a. On the other side of the crotch portion, a receiving body 15 that receives a static pressure by the static pressure means is detachably provided by a screw 15a, 13b is an operating handle for a hydraulic or pneumatic cylinder 13, and 13c is an operating release lever. It is. Reference numeral 16 denotes a screw body for attaching the indentation forming jig main body 12 to the rail 10, and reference numerals 17 and 18 denote the same stopper, which cooperates with the screw body 16 to connect the indentation forming jig main body 12 to the rail. 10 is provided so that it can be attached to 10 stably. Reference numeral 19 denotes a hand lowering handle.

9 to 11, reference numeral 20 denotes an indentation tool substrate. On the front lower surface of the substrate 20, a pair of indentation claws 21 whose tip shape is an arc shape 21a is approximately 45 with respect to the longitudinal center line a ′. In addition, the indentation claw 21 is stably brought into contact with the indentation formation portion of the body portion of the rail 10 on the lower surface of the substrate 20 on the handle 22 side when the indentation is formed. A contact stabilizing protrusion 23 is provided. In FIG. 12, 21b shows an indentation.
FIG. 13 shows the case where the indentation claw 21 is provided above the longitudinal center line a ′, and the contact stabilization protrusion 23 is provided below. FIG. 14 shows the indentation claw 21 and the contact claw 21. The contact stabilization protrusions 23 are provided so as to face each other at an angle of approximately 45 ° with respect to the longitudinal center line a ′.

When forming the indentation, the indentation forming jig main body 12 is positioned so as to straddle the head of the rail 10 as shown in FIG. 8A, and then the screw 15a is used as shown in FIG. 8B. The receiving body 15 is brought into contact with the side surface of the body portion of the rail 10, and the indentation forming jig main body 12 is attached to a predetermined position of the rail 10 with a screw body 16 and stoppers 17 and 18. Next, as shown in (first time) in FIG. 12 and (c) in FIG. 8, the indentation claw 21 is positioned at a predetermined indentation position on the body of the rail 10, and in this state, the hydraulic or pneumatic cylinder 13 is used. A predetermined indentation 21b is formed by a static pressure.
In addition, after the formation of the indentation, the pressurizing force of the hydraulic or pneumatic cylinder 13 is released by the operation release lever 13c, and the indentation forming claw 21 is placed on the opposite side as shown in FIG. 12 (second time). The predetermined indentation 21b is formed by the same action as described above.

In addition, using two indentation tools of the same shape, as shown in FIG. 12, each indentation claw 21 can be located at a predetermined indentation forming position, and indentations 21b can be formed simultaneously at four places.
Of course, the indentation tool 21 provided with the indentation claw 21 as shown in FIGS. 13 and 14 can also form the predetermined indentation 21b.

  In this embodiment, in particular, the hammering of the welded outer edge portion of the rail bond terminal welded to the rail by the step of welding the rail bond terminal to the rail by copper thermit welding and the step of welding by this copper thermit welding. Because it includes a process of applying static pressure with the required static pressure means, it does not hit the rail surface with a hammer, so the rail is not damaged or cracked, the work is quiet, and the amount of work is reduced. In addition, the work is easy, the work can be done in an easy posture, the quality is stable and uniform, the indentation positioning and shape are not uneven, the uniform effect can be achieved at the exact position, and the indentation can be formed Of course, it can be applied to the welding method of the rail bond terminal.

  It is a partially notched perspective view which shows an example of the crucible which comprises the general jig | tool which applies a copper thermit welding method.   It is a perspective view which shows the Example of a rail bond terminal.   It is a front view of the jig | tool for demonstrating the welding method of the rail bond terminal which concerns on this invention.   It is a front view of the jig | tool for demonstrating the welding method of the rail bond terminal which concerns on this invention.   It is a figure explaining an example of the use condition of an impression tool.   It is explanatory drawing which shows the indentation formation state which concerns on this invention.   It is a perspective view which shows an example of the state which welded the rail bond terminal to the rail trunk | drum one side surface.   It is explanatory drawing which shows an example of an indentation formation process.   It is a figure explaining an example of an indentation tool.   It is the same side view.   It is the same perspective view.   It is a figure explaining an example of the use condition of an impression tool.   It is a top view which shows the other Example of an indentation tool.   It is a top view which shows the other Example of an indentation tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Jig for welding a rail bond terminal 2 Crucible body 2a Recess 3 Runway 4 Copper weld 4a Semi-circular cut 5 Thermite agent 6 Ignition agent 7 Steel disk 8 Tubular rail bond terminal 8a Rail bond (electric wire)
8b Adhering portion 10 Rail 10a Rail body portion 10b Rail head portion 11 Welding 12 Indentation forming jig body 13 Hydraulic or pneumatic cylinder 13a Screw 13b Actuating handle 13c Actuating release lever 14 Screw pressurization type 15 Receptacle 15a Screw 16 Screw body 17 Stopper 18 Stopper 19 Lowering handle 20 Substrate 21 Indentation claw 21
21a Arc shape 21b Indentation 22 Indentation handle 23 Contact stabilization protrusion aa Longitudinal centerline a′-a ′ of rail bond terminal Longitudinal centerline of substrate

Claims (5)

  Welding the rail bond terminal to the rail by copper thermite welding in a substantially parallel state along the longitudinal direction of the rail on the surface of the body of the rail, and the rail at the welded outer edge of the rail bond terminal welded by the process Concave plastic deformation regions are formed at predetermined four locations on a line in the radial direction approximately 45 ° obliquely from the substantially parallel line with the bond terminal as the center by a static pressure process by a required static pressure means. A method for welding rail bond terminals.   2. The welding method for rail bond terminals according to claim 1, wherein the concave plastic deformation regions formed at predetermined four locations on the line in the radial direction of approximately 45 ° obliquely in the vertical direction are respectively required for the lines. A rail bond terminal welding method, wherein the rail bond terminal is formed to have a required length and a required depth in a state of crossing with a corner.   3. The rail bond terminal welding method according to claim 1, wherein the concave plastic deformation regions formed at the predetermined four positions on the line in the radial direction of approximately 45 degrees are formed by a required static pressure means. A method for welding rail bond terminals, wherein four locations are formed simultaneously by a static pressure step.   4. The rail bond terminal welding method according to claim 1, wherein the concave plastic deformation regions formed at predetermined four locations on the oblique line in the radial direction are the required static pressure means. A method of welding rail bond terminals, comprising: simultaneously forming two of the four locations by the static pressure step according to, and further forming the remaining two locations simultaneously.   A pair of indentation nails having a circular arc shape on the front lower surface of the substrate is provided symmetrically with an angle of approximately 45 ° with respect to the longitudinal center line of the handle and is provided on the lower surface on the handle side of the substrate for stabilizing the contact. The indentation tool used for the welding method of the rail bond terminal of Claim 1 thru | or 4 provided with the protrusion.

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