JP2022156981A - Auxiliary tool for peening and peening method - Google Patents

Abstract

To make it possible to correctly and easily guide a peening formation jig to at least a prescribed peening area along a weld zone contour, and in addition to this, to reduce residual stress around the weld zone contour on a surface of a metal matrix, thereby suppressing deterioration of fatigue strength.SOLUTION: An auxiliary tool 1 for peening is configured from a plate-like body 6 having an inlet-like notch 61 that is formed into a shape with an inner contour 62 that surrounds a wire joint 5 comprising: a metal matrix 2; a wire 31; a wire 3 with terminal having a metal terminal 32 attached to a tip of the wire 31; and a weld zone 4 which is formed in such a manner that at least a tip side of the metal terminal 32 of the wire 3 with terminal is welded to a surface 21 of the metal matrix 2 by use of thermite welding method. The plate-like body 6 is detachably attached to the surface of the metal matrix 2 so that the inner contour 62 guides a peening formation jig 7 to at least a prescribed peening area P of the wire joint 5 to be formed on the surface of the metal matrix 2 along a contour of the weld zone 4.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a peening aid and a peening method, and in particular, a peening forming jig is attached to an appropriate area to be peened along the contour of a weld formed by thermite welding of a metal base material and a wire rod with a terminal. The present invention relates to a peening aid and a peening method that can be guided for accurate and convenient peening.

The railway rails are fixed to roadbed sleepers or the like by fixing means such as dog spikes, and a plurality of rails are arranged side by side along the extending direction. Rails arranged along the direction of extension have gaps between adjacent rails to allow for thermal expansion. Since it is also used as a wire rod with a terminal, it is often electrically connected to each other by a bonding wire composed of a wire rod with a terminal.

Here, the metal terminal attached to the tip of the terminal-attached wire is welded to the rail with a welding metal. Welding of the metal terminals to the rails by deposit metal is performed on site after the rails have been installed. Among these welding methods, the thermite welding method is widely used because the welded portion has high electrical conductivity and bonding strength, and the bonding does not require a high level of skill.

In the thermite welding method, a mixed powder of aluminum and copper oxide (or iron oxide) is ignited in a crucible near the surface of the base material, and the heat generated by the chemical reaction melts the copper (or iron). It is a method of welding by

This thermite welding method is a welding method that can easily achieve high strength. It may drop and crack the rail. Therefore, usually, after thermite welding, the area around the welded portion is hit with a peening jig such as a hammer to plastically deform the rail surface into a concave shape. A so-called hammer peening treatment is performed to suppress the decrease in fatigue strength due to welding by canceling out the tensile residual stress of .

For example, Patent Document 1 describes a process of welding a weld metal to a base material such as a rail, and plastically deforming the surface of the base material and the vicinity of the peripheral edge of the weld metal into a concave shape using a peening jig. A method of welding deposited metal to a base metal is described, comprising the steps of:

JP-A-2002-346771

In the hammer peening treatment described in Patent Document 1, when a worker uses a peening forming jig to hit the area to be peened around the contour of the weld on the rail surface to plastically deform it, the peening forming jig is used. Since there is no jig or the like to guide the region to be peened, it may not be possible to accurately strike the region to be peened to cause plastic deformation. In hammer peening, driving a peening jig into the boundary between the welded part and the base material surface may damage the welded part, so it is necessary to hit the area to be peened accurately. be. On the other hand, even if a position farther than necessary from the boundary between the welded part and the base metal surface is plastically deformed by the peening jig, the residual stress cannot be sufficiently removed by the hammer peening treatment. Therefore, unless the worker is skilled, the residual stress removal effect by hammer peening treatment cannot be stably obtained. It is desirable to develop a peening method that can accurately and simply strike the area to be peened around the contour of the weld to cause plastic deformation.

It is an object of the present invention to be able to accurately and simply guide a peening jig to a predetermined peening area to be formed on the surface of the base metal along at least the contour of the weld. An object of the present invention is to provide a peening aid and a peening method that effectively reduce the residual stress around the contour of the weld on the surface of the material to suppress the deterioration of the fatigue strength.

The present inventors have found that, in a wire joined body in which a wire rod with a terminal is welded to a metal base material, at least the periphery of the welded portion is surrounded by a cove-shaped notch portion of the plate-like body, and the inner side of the notch portion is By guiding the peening forming jig to the peening region formed by the contour and the contour of at least the welded part of the wire rod joined body, at a predetermined position along at least the contour of the welded part on the surface of the metal base material, The inventors have found that peening can be performed, and have completed the present invention.

That is, the gist and configuration of the present invention are as follows.
(1) a metal base material, a wire, and a wire with a terminal having a metal terminal attached to the tip of the wire; A plate-like body having a cove-shaped notch portion formed in a shape having an inner contour surrounding a wire rod joined body comprising a weld portion formed by welding using a welding method, said plate-like body the inner contour guides the peening jig to a predetermined peening area to be formed on the surface of the metal base material along at least the contour of the welded portion of the wire rod joined body; A peening aid characterized by being detachably attached to the surface of a material.
(2) The peening aid according to (1) above, wherein the inner contour guides the peening jig to the predetermined peening region along contours of the weld and the metal terminal of the wire rod assembly. equipment.
(3) The peening aid according to (1) or (2) above, wherein the auxiliary tool has a mounting member configured to be detachable from the surface of the metal base material on the back surface of the plate-shaped body. equipment.
(4) The peening aid according to (3) above, wherein the mounting member is a magnet.
(5) The plate-shaped body has a pair of opposite ends that are positioned to face each other with a space therebetween and form inlets and outlets of the notch, and the pair of opposite ends meet the The auxiliary tool is formed with a gap that can sandwich the wire rod portion forming a boundary with the base end of the metal terminal, and the auxiliary tool is attached to the wire rod assembly by fitting the pair of opposing end portions into the wire rod portion. The peening aid according to any one of (1) to (4) above, which is positioned and mounted.
(6) The peening aid according to any one of (1) to (5) above, wherein the metal base material is a railway rail, and the wire rod is a bond wire attached to the rail.
(7) The plate-like body is configured so that the inner contour is symmetrical with respect to the center line of the wire of the wire rod joint when viewed with the auxiliary tool attached to the surface of the metal base material. The peening aid according to any one of (1) to (6) above, which is formed in the
(8) A peening aid according to any one of (1) to (7) above is used to form on the surface of the metal base material along at least the contour of the welded portion of the wire rod joined body. A peening method for performing peening in a predetermined peening region to be peened, wherein the auxiliary tool is mounted on the surface of the metal base material in a positional relationship in which the notch portion of the plate-like body surrounds the wire rod joined body, a peening area defining step of forming a groove defining a peening area by the inner contour of the notch and the contour of at least the welded portion of the wire rod joined body; A peening method, comprising: a peening step in which peening is performed by repeatedly hitting the peening jig with the tip inserted and moving the peening jig guided by the slot.

According to the present invention, it is possible to accurately and simply guide a peening forming jig to a predetermined peening area to be formed on the surface of the base metal, along at least the contour of the weld. It is possible to provide a peening aid and a peening method that effectively reduce the residual stress around the contour of the weld on the surface of the material and suppress the deterioration of the fatigue strength.

FIG. 1 is a perspective view of an auxiliary tool for peening according to one embodiment of the present invention, in which the auxiliary tool is attached around the welded part of a wire rod joint welded to the surface of a metal base material (railway rail). 3 shows a state in which peening is performed by inserting the tip of a peening forming jig into a cutout portion of a plate-like body that constitutes the auxiliary tool. FIG. 2 is a perspective view of the state shown in FIG. 1 with the peening aid and the peening forming jig removed. 3 shows the peening aid of FIG. 1, FIG. 3(a) being a top view, FIG. 3(b) being a right side view, and FIG. 3(c) being a bottom view. FIG. 4 is a perspective view showing a state in which a peening aid of another embodiment is provided so as to surround a wire joined body attached to the head side surface of a railway rail. FIG. 5 shows a peening aid according to another embodiment in which the plate-shaped notch portion of the peening aid surrounds the wire rod assembly attached to the top surface of the bottom of the railway rail. It is a perspective view showing. FIG. 6 is a flow diagram showing steps in a peening method according to the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited to the following embodiments, and various modifications are possible without changing the gist of the present invention.

<About peening aids>
FIG. 1 is a perspective view of an auxiliary tool for peening according to one embodiment of the present invention, in which the auxiliary tool is attached around the welded part of a wire rod joint welded to the surface of a metal base material (railway rail). 3 shows a state in which peening is performed by inserting the tip of a peening forming jig into a cutout portion of a plate-like body that constitutes the auxiliary tool. 2 is a perspective view of the state shown in FIG. 1 with the peening aid and the peening forming jig removed. 3 shows the peening aid of FIG. 1, wherein FIG. 3(a) is a top view, FIG. 3(b) is a right side view, and FIG. 3(c) is a bottom view. .

As shown in FIG. 1, the peening aid 1 includes a metal base material 2, a wire 31, a wire 3 with a terminal having a metal terminal 32 attached to the tip of the wire 31, and a metal terminal of the wire 3 with a terminal. 32 is formed into a shape having an inner contour 62 surrounding the wire rod joined body 5 provided with the weld 4 formed by welding at least the tip side of 32 to the surface 21 of the metal base material 2 using the thermite welding method. It is composed of a plate-like body 6 having a cove-shaped notch portion 61, and the inner contour 62 of the plate-like body 6 is formed on the surface of the metal base material 2 along at least the contour of the welded portion 4 of the wire rod joined body 5. It is detachably attached to the surface of the metal base material 2 so as to guide the peening forming jig 7 to the predetermined peening region P to be formed.

As a result, of the surface 21 of the metal base material 2, the periphery of the predetermined peening region P such as the vicinity of the contour of the welded portion 4 is covered with the plate-like body 6 of the peening aid 1 shown in FIG. 3(a). Surrounding the cove-shaped notch 61 makes it possible to guide the peening forming jig 7 to the peening region P formed along the inner contour 62 of the notch 61 . As a result, the peening forming jig can be accurately and easily guided to the predetermined peening area P, and thus the residual stress around the contour of the weld 4 on the surface 21 of the metal base material 2 can be effectively reduced, It is possible to provide a peening aid and a peening method capable of suppressing a decrease in fatigue strength.

As shown in FIG. 3( a ), the peening aid 1 is composed of a plate-like body 6 having a cove-shaped notch 61 formed in a shape having an inner contour 62 surrounding the wire rod joined body 5 . be.

Here, as the wire joined body 5 to which the peening aid 1 is attached, one having a metal base material 2, a wire 3 with a terminal, and a welded portion 4 as shown in FIG. 2 can be mentioned. Among these, the terminal-equipped wire 3 includes at least a wire 31 and a metal terminal 32 attached to the tip of the wire 31 . The welded portion 4 is formed by welding at least the tip side of the metal terminal 32 at the tip of the wire rod 3 with a terminal to the surface of the metal base material 2 using the thermite welding method. can.

The plate-like body 6 of the peening aid 1 is detachably attached to the surface 21 of the metal base material 2, as shown in FIG. As a result, the plate-like body 6 surrounds the wire rod assembly 5 including the metal base material 2, the terminal-equipped wire 3, and the welded portion 4 by the inner contour 62 of the cove-shaped notch 61, so that the metal base material 2 can be attached to the surface 21 of the

The inner contour 62 of the notch portion 61 of the plate-like body 6 is in a predetermined peening region P to be formed on the surface of the metal base material 2 along at least the contour of the welded portion 4 of the wire rod joined body 5. It is configured to guide the peening jig 7 . In particular, this inner contour 62 is preferably configured to guide the peening jig 7 to a predetermined peening area P along the contours of the weld 4 and metal terminal 32 of the wire rod assembly 5 . Thereby, the peening forming jig 7 is guided to the peening region P formed along the contour of the welded portion 4 of the wire rod joined body 5 which is thermite welded to the metal base material 2 . Therefore, peening can be performed accurately and easily at an appropriate position at least around the contour of the welded portion 4, more preferably around the contours of the welded portion 4 and the metal terminal 32 in the wire rod joined body 5.

The plate-like body 6 preferably has a pair of opposed ends 63a, 63b that are positioned facing each other with a distance d therebetween and form inlets and outlets of the notch 61. As shown in FIG. At this time, the pair of opposed ends 63a and 63b are formed with a distance d between them so that the portion of the wire 31 forming the boundary with the base end of the metal terminal 32 can be sandwiched between the pair of opposed ends 63a and 63b. It is preferable that the peening aid 1 is positioned and attached to the wire joined body 5 by fitting into the portion 31 . As a result, the wire rod 31 of the wire rod 3 with terminals is sandwiched between the opposing ends 63a and 63b, so that the inlet/outlet of the notch 61 of the plate-like body 6 substantially overlaps with the extending direction of the wire rod 31, and the peening is performed. Since the peening aid 1 is fitted into the portion of the wire rod 31, the peening aid 1 can be positioned more accurately.

The distance d between the pair of opposing ends 63a and 63b is preferably wider than the thickness of the wire 31 from the viewpoint of facilitating the sandwiching of the wire 31 therebetween. In addition, the cove-shaped notch 61 having a pair of opposed ends 63a and 63b at both ends is provided so that the metal terminal 32 faces the metal terminal 32 from the viewpoint of ensuring the positioning and attachment of the peening aid 1 to the wire rod joined body 5. It is preferable that the end portions 63a and 63b be located closer to the cove.

On the other hand, as shown in FIG. 3( a ), the plate-like body 6 has an inner contour 62 are preferably formed so as to be symmetrical with respect to the center line C of the wire rod 31 of the wire rod joined body 5 . As a result, when the peening aid 1 is inverted vertically or horizontally, peening of the wire rod 31 extending toward the opposite side can be performed in the same manner as before the inversion, thereby improving workability in peening. can be further enhanced.

The material of the plate-like body 6 is not particularly limited, but from the viewpoint of reducing breakage and wear of the plate-like body 6 due to sliding of the peening forming jig 7 during peening, a material such as steel is used. It is preferably made of metal. In addition, the size of the inner contour 62 of the notch 61 of the plate-like body 6 is such that it can surround the wire rod assembly 5 and that the peening forming jig 7 can be inserted into the gap between the wire rod assembly 5 and the wire rod assembly 5 . is preferably More specifically, the inner contour 62 of the notch 61 preferably has a size that forms a gap of 7 mm or more and 12 mm or less with respect to the wire joined body 5 .

The peening aid 1 preferably has a mounting member 8 on the back surface of the plate-like body 6 that is detachably attached to the surface of the metal base material 2 . As a result, the positional relationship between the peening aid 1 and the metal base material 2 can be fixed by the mounting member 8, so that the peening forming jig 7 can be guided more accurately and simply.

Here, it is preferable that the mounting member 8 includes a magnet from the viewpoint of being easily attached and detached and being able to adhere to the railroad rail. In particular, when the mounting member 8 is provided with a magnet, from the viewpoint of preventing damage to the magnet due to sliding of the peening forming jig 7 during peening and maintaining adhesion to the surface of the metal base material 2, the magnet It is more preferable to use the mounting member 8 whose outer periphery is covered with a metal cover such as steel. Note that the mounting member 8 may be made of another material such as an adhesive material.

In addition, from the viewpoint of increasing the fixing force to the surface of the metal base material 2, the mounting member 8 is preferably provided on at least one of the corners of the plate-like body 6. More preferably.

The mounting member 8 may be attached to the plate-like body 6 by screwing as shown in FIGS. 3(a) to 3(c), or may be attached to the plate-like body 6 by other means. .

The metal base material 2 to which the peening aid 1 is attached is preferably a railway rail. That is, it is preferable that the metal base material 2 is a rail that constitutes a train or a running surface of the train. Since such rails are also used as circuits for passing return currents from trains, etc., and signal currents, it is important to provide electrical connections between adjacent rails from the perspective of eliminating electrolytic corrosion and leakage currents in underground equipment. In many cases, a rail bond that connects to the rail and a transfer bond that electrically connects the rail to an external signal circuit or the like are provided. The peening aid 1 of the present embodiment can be suitably used for peening railway rails to which bond wires such as rail bonds and transfer bonds are attached by welding as the wire rods 32 of the wire rods 3 with terminals. In addition, the term "rail" in this specification includes a train or a turnout that branches the course of the train.

In the above-described embodiment, the notch 61 of the plate-like body 6 of the peening aid 1 is arranged so as to surround the wire rod joined body 5 attached to the surface of the abdomen of the railway rail, which is the metal base material 2. Although the case where it is provided is shown, it is not limited only to such a configuration. For example, as shown in FIG. 4, the notch portion 61 of the plate-like body 6 of the peening aid 1 is attached to a portion of the head side surface of the railway rail that does not constitute the running surface of the train or the train. , may be provided so as to surround the wire rod joined body 5 . Further, as shown in FIG. 5, the notch portion 61 of the plate-like body 6 of the peening aid 1 may be provided so as to surround the wire joined body 5 attached to the bottom upper surface of the railway rail.

<Regarding the peening method>
FIG. 6 is a flow diagram showing steps in a peening method according to the present invention. The peening method of the present invention uses the peening aid 1 described above to form a predetermined peening region P on the surface 21 of the metal base material 2 along at least the contour of the welded portion 4 of the wire rod assembly 5. It is a peening method for peening. More specifically, the peening aid 1 is attached to the surface of the metal base material 2 in such a positional relationship that the notch 61 of the plate-like body 6 surrounds the wire joined body 5 , and the inner contour of the notch 61 is 62 and the outline shape of at least the welded portion 4 of the wire rod joined body 5 in a peening area defining step (ST1) of defining and forming a slot defining a peening area P, and inserting the tip of the peening forming jig 7 into the slot A peening step (ST2) is provided in which peening is performed by repeatedly striking the peening jig 7 and moving the peening jig 7 guided by the grooves.

By using such a peening method, after the peening region P is formed in a predetermined region such as the vicinity of the wire rod assembly 5 by the peening region defining step (ST1), the peening forming jig is formed by the peening step (ST2). 7 is performed in the peening region P. As a result, since the peening forming jig 7 can be accurately and simply guided to the predetermined peening region P, the residual stress around the contour of the thermite weld on the surface of the metal base material 2 can be reduced, thereby reducing the fatigue strength. can be suppressed.

As the wire rod joined body 5 used in the peening method, one obtained by welding at least the tip side of the metal terminal 32 of the wire rod 3 with a terminal to the surface 21 of the metal base material 2 using the thermite welding method can be used. Here, as the thermite welding method, a mixed powder of aluminum and copper oxide (or iron oxide) is ignited in a crucible provided near the surface 21 of the metal base material 2, and the heat generated by the chemical reaction A method of welding the surface 21 of the metal base material 2 and the front end side surface of the wire rod 3 with a terminal using molten copper (or iron) can be used. In the wire rod assembly 5 welded by such a thermite welding method, tensile residual stress tends to remain in the vicinity of the welded portion 4 formed by welding due to heating and cooling during welding.

In the peening region definition step (ST1), the peening aid 1 is attached to the surface of the metal base material 2 of the wire rod joined body 5 . More specifically, in the peening area defining step (ST1), the peening aid 1 is attached to the surface of the metal base material 2 in such a positional relationship that the notch 61 of the plate-like body 6 surrounds the wire joined body 5. , the inner contour 62 of the cutout portion 61 and the contour shape of at least the welded portion 4 of the wire rod assembly 5 define a groove defining the peening region P. As a result, the region of the slot sandwiched between the inner contour 62 of the notch 61 and the contour shape of at least the welded portion 4 of the wire rod joined body 5 is defined as the peening region P, so that the peening forming jig 7 can be guided along this peened region P.

In the subsequent peening step (ST2), peening is performed with the tip of the peening forming jig 7 inserted into the slot. Here, the peening process can be performed by repeating the impact of the peening jig 7 and the movement of the peening jig 7 guided by the slot in the peening region P. As a result, the peening treatment is performed by the peening forming jig 7 whose tip position is guided along the peening region P, so that the residual stress around the contour of the welded portion 4 on the surface 21 of the metal base material 2 is reduced, thereby reducing fatigue. A decrease in strength can be suppressed.

As a specific method of peening treatment, it is preferable to perform hammer peening treatment in which the vicinity of the welded portion is hit with a peening forming jig such as a hammer to plastically deform the base material into a concave shape. 7 is not limited to this.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes various aspects within the scope of the present invention, including all aspects included in the concept of the present invention and the scope of claims. can be modified to

REFERENCE SIGNS LIST 1 peening aid 2 metal base material 21 surface of metal base material 3 wire rod with terminal 31 wire rod 32 metal terminal 4 welded portion 5 wire rod assembly 6 plate-like body 61 notch portion 62 inner contour of notch portion 63a, 63b facing each other End portion 7 Peening forming jig 8 Mounting member 9 Peening method d Interval between opposing ends C Center line of wire P Peening area ST1 Peening area definition step ST2 Peening step

Claims (8)

a metal base material;
a wire and a wire with a terminal having a metal terminal attached to the tip of the wire;
and a weld portion formed by welding at least the tip side of the metal terminal of the wire rod with a terminal to the surface of the metal base material using a thermite welding method. Consists of a plate-shaped body having a cove-shaped notch formed,
The plate-shaped body is arranged such that the inner contour guides the peening forming jig to a predetermined peening region to be formed on the surface of the metal base material along at least the contour of the welded portion of the wire rod joined body. , an auxiliary tool for peening, which is detachably attached to the surface of the metal base material. 2. The peening aid of claim 1, wherein the inner contour guides the peening tool to the predetermined peening area along the contour of the weld and the metal terminal of the wire assembly. The auxiliary tool is
3. The peening aid according to claim 1, wherein the back surface of the plate-like body has a mounting member that is detachable from the surface of the metal base material. 4. A peening aid according to claim 3, wherein said mounting member is a magnet. The plate-shaped body has a pair of opposite ends that are positioned facing each other with a gap therebetween and form inlets and outlets of the notch,
The pair of opposed end portions are formed at a distance capable of sandwiching the portion of the wire forming a boundary with the base end of the metal terminal. The auxiliary tool for peening according to any one of claims 1 to 4, wherein the auxiliary tool is positioned and attached to the wire joined body. The metal base material is a railway rail,
The peening aid according to any one of claims 1 to 5, wherein said wire is a bond wire attached to said rail. The plate-like body is formed such that the inner contour is symmetrical about the center line of the wire rod of the wire rod joined body when viewed with the auxiliary tool mounted on the surface of the metal base material. 7. A peening aid according to any one of claims 1 to 6, comprising: Using the peening aid according to any one of claims 1 to 7, a predetermined peening region to be formed on the surface of the metal base material along at least the contour of the welded portion of the wire rod joined body A peening method for peening to
The auxiliary tool is attached to the surface of the metal base material in such a positional relationship that the notch portion of the plate-like body surrounds the wire rod joined body, and the inner contour of the notch portion and the wire rod joined body a peening area defining step of defining a slot defining a peening area with at least the contour of the weld;
The peening treatment is performed by repeatedly striking the peening jig and moving the peening jig guided by the groove while the tip of the peening jig is inserted into the groove. A peening method, comprising:

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