JP2004082140A - Welding method and welding terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding method and a welding terminal for preventing an electric wire from breaking through the release of a residual stress when the wire is vibrated. <P>SOLUTION: This welding method includes the steps of: preparing a welding terminal having a welding terminal body 4 formed with a through-hole opened to a first and second end faces and a sleeve 3 projecting from the first end face and with an introducing hole in communication with the through-hole; inserting a conductor 2 from the opened end of the second end face to near the opened end of the communicative hole of the sleeve 3; plastically deforming around the opened end of the sleeve 3 and making the sleeve 3 hold the conductor 2; and welding the conductor 2 and the welding terminal to base material by thermit welding of deposited metal so as to store at least the sleeve and the proximity to the first end face of the welding terminal body 4. The welding terminal is composed of the welding terminal body 4 formed with the through-hole opened to two end faces and the two or more sleeves 3 projecting from the end face and having the introducing hole in communication with the through-hole. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of welding a base material and a conductor or conductors to each other, and more particularly, to a thermite welding method for improving deformation strength and vibration strength near a welded end of a conductor using a welding terminal, and to be used in the welding method. It relates to a welding terminal that can be used.
[0002]
[Prior art]
As an example, the connection of bond wires for railway rails is generally performed by soldering or thermite welding, but thermite welding has a high joint strength at the welded parts and does not require advanced skills. In recent years, it has been widely used because it can ensure the welding performance of the steel.
[0003]
Thermite welding, which is mainly used in the present invention, means that a mixed powder of aluminum and copper oxide (or iron oxide) is ignited near the surface of a base material, and copper (or iron) is mixed with copper (or iron) by heat generated by the chemical reaction. The welding is performed by melting a part of the material.
[0004]
In the process of thermit welding, a conductor or an electric wire is fixed to a welding terminal, the welding terminal is arranged at a predetermined position of a thermit welding apparatus, and after locating these at a welding position, the mixed powder is ignited and welding is performed. Become. Generally, the electric wire is fixed to the welding terminal by pressing and deforming a sleeve provided on the welding terminal to grip a conductor housed therein.
[0005]
A procedure for fixing a wire terminal and a welding terminal and a method for inserting a welding terminal into a crucible in conventional thermit welding will be described below with reference to FIGS.
[0006]
FIG. 1 illustrates a process of fixing a wire terminal to a welding terminal in conventional thermite welding. The welding terminal is composed of a welding terminal body 4 having a through-hole formed in the first and second end faces, and a sleeve 3 having an introduction hole protruding from the first end face and communicating with the through-hole. The welding terminal body 4 and the sleeve part 3 are formed with through holes that can accommodate the conductor part 2 of the electric wire 1 and that are open at their respective end surfaces.
[0007]
The covering of the electric wire 1 is removed so that the conductor part 2 is exposed, and the conductor part 2 is inserted from the sleeve part 3 of the welding terminal in the direction of the welding terminal body 4, and the conductor part 2 is inserted 5 mm from the outer end face of the welding terminal body 4. The conductor portion 2 is fixed by pressing and deforming the sleeve portion 3 with a crimping tool at a position protruding by about 8 mm.
[0008]
FIG. 2 is a top view showing a state in which the electric wire in which the terminal of the conductor portion 2 is fixed to the sleeve portion 3 of the welding terminal according to the above-described procedure is arranged in the thermite welding apparatus 5. As shown in FIG. 2, the welding terminal body 4 is inserted into the welding device so that the boundary surface between the welding terminal body 4 and the sleeve portion 3 is located in the same plane as the end surface of the thermite welding device 5. I do. Therefore, after welding, most of the welding terminal body 4 is covered with the welding metal and is welded to the base material, so that it cannot be seen from the outside, but the sleeve portion 3 protrudes from the welding portion to the outside. .
[0009]
The reason why the electric wire 1 is fixed to the sleeve portion 3 of the welding terminal before welding in the above-described procedure and then the welding terminal body 4 and the base material are welded is that the electric wire 1 is fixed in advance so that the position of the electric wire during welding is fixed. This is mainly due to the requirement in terms of workability, such as preventing displacement.
[0010]
[Problems to be solved by the invention]
However, for example, in order to connect the railway rails with each other with a wire-like conductor for electrical connection, when the wire-like conductor is thermite-welded to the base rail, when the vehicle passes, the sleeve portion is It will receive a large mechanical load. This corresponds to a portion where the sleeve portion is a fixing portion for gripping the internal conductor and at the same time receives an external force applied from the conductor. This is because stress remains. Since the electric wires are firmly fixed, the electric wires are easily broken by vibration (see FIG. 3).
[0011]
[Means for Solving the Problems]
In view of the above problems, the inventors focused on the position of the wire support portion, and changed the position of the sleeve portion 3 for crimping the conductor from the outside of the thermite welded portion near the wire receiving portion of the conventional welding terminal. It has been discovered that the above-mentioned problem can be solved by changing the position near the wire outlet of the welding terminal, that is, inside the welded portion 9 of the thermite weld. In other words, the part where the fixing part of the electric wire is placed inside the welding point, and as a result, the part where the residual stress when the electric wire is fixed to the welding terminal remains, and the part where mechanical external force from the electric wire is applied after the welding is completed Was separated. Thus, since the portion where the wire breakage has occurred conventionally (see FIG. 3) is not fixed, the durability of the wire can be improved, and the problem of wire breakage due to vibration has been solved.
[0012]
Based on a number of welding tests, tensile tests, and fatigue tests, the inventors have found that by using the welding terminal and / or the welding method according to the present invention, it is possible to break the wire while maintaining the same or better welding performance as before. It was confirmed that no abnormalities such as disconnection and terminal disconnection occurred.
[0013]
Specifically, according to one embodiment of the present invention, in the step of welding an electric wire using a welding terminal,
A step of joining the electric wire and the welding terminal;
Welding at least a joint between the electric wire and the welding terminal so as to be covered by a welded portion.
[0014]
According to the above-described method, the connection portion connecting the conductor and the terminal is accommodated in the weld metal, and the connection portion and the welded portion are integrated. As a result, the joint portion receiving the external force concentrated on the conductor is fixed by the entire welded portion, so that it has a function of alleviating the cause such as the breakage of the conductor wire due to the displacement that occurs when used in a railway rail.
[0015]
According to another embodiment of the present invention, the welding method is thermite welding.
[0016]
In recent years, thermite welding method has been the mainstream of the fusion welding method for welding a conductor and a base body, and has obtained high reliability in terms of finished quality and durability.
[0017]
According to yet another embodiment of the present invention, a welding terminal main body having a through-hole opening in the first and second end faces,
A thermit welding terminal having a sleeve portion having an introduction hole communicating with the through hole, protruding from the first end surface,
A welding terminal is proposed in which a chamfer in which the diameter of the introduction hole increases toward the opening end is formed near the opening end of the introduction hole on the second end surface.
[0018]
According to the above-described embodiment, the conductor is exposed from the second end surface when the conductor is inserted from the through hole of the second end surface to the end of the through hole of the sleeve portion of the first end surface regardless of before and after welding. When the conductor is displaced with respect to the welding terminal, the concentration of stress generated on both the conductor and the second end surface of the welding terminal body at the open end position of the second end surface can be reduced.
[0019]
According to still another embodiment of the present invention, the above-described welding terminal has one sleeve portion on each of both end surfaces of the welding terminal body where the through hole is opened, and the through hole and the introduction hole have a diameter. Are identical and formed coaxially.
[0020]
According to the above-described embodiment, the conductor can be smoothly inserted from one opening of the sleeve to the vicinity of the opening of the other sleeve.
[0021]
According to still another embodiment of the present invention, two sleeve portions formed on both end surfaces of the welding terminal body have different lengths.
[0022]
According to the above-described embodiment, according to the size of the weld metal portion determined by the conditions of the thermite welding or the shape of the base material, or the length of the sleeve to be projected from the weld metal, either the long or short sleeve is fixed to the conductor. It is possible to select as appropriate whether it is a part or which sleeve is projected.
[0023]
According to still another embodiment of the present invention, at least one of the two sleeve portions can be plastically deformed by an external pressing force to grip the conductor accommodated in the introduction hole.
[0024]
According to the above-described embodiment, the conductor can be fixed to the welding terminal by pressing the sleeve portion from the outside and plastically deforming the sleeve portion, so that a quick fixing operation is possible.
[0025]
According to yet another embodiment of the present invention, the welding terminal body has a flat side surface.
[0026]
According to the above embodiment, the welding strength can be increased by increasing the contact area between the welding terminal main body and the base material.
[0027]
According to still another embodiment of the present invention, a chamfer in which the diameter of the introduction hole increases toward the opening end is formed near the opening of at least one introduction hole of each of the sleeves.
[0028]
According to the above-described embodiment, regardless of before and after welding, when the conductor is displaced with respect to the welding terminal, stress concentration generated in both the conductor and the sleeve at the open end position of the sleeve can be reduced.
[0029]
According to still another embodiment of the present invention, the welding terminal is made of copper or a copper alloy.
[0030]
The material of the welding terminal is selected mainly from the viewpoint of the affinity for thermit welding and the plastic deformation ability required when holding the conductor by plastic deformation, for example, copper, copper alloy, aluminum, aluminum alloy, steel material, etc. Among them, copper and copper alloy are preferable.
[0031]
According to still another embodiment of the present invention, a welding terminal main body having a through-hole opened in the first and second end faces,
A step of preparing a welding terminal having a sleeve portion projecting from the first end face and having an introduction hole communicating with the through hole;
Inserting a conductor from the open end of the second end surface to the vicinity of the open end of the communication hole of the sleeve portion;
A step of plastically deforming the vicinity of the open end of the sleeve portion and causing the sleeve portion to grip the conductor;
Welding the conductor and the welding terminal to the base metal by thermit welding of the welding metal so as to accommodate at least the vicinity of the first end surface of the sleeve and the welding terminal body;
Is proposed.
[0032]
According to the welding method, since the sleeve portion is housed in the weld metal by thermite welding, external force applied from the conductor during vibration is not directly applied to the sleeve portion, so that fatigue damage or the like may occur in the sleeve portion. However, the durability of welding is significantly improved as compared with the conventional method.
[0033]
According to another embodiment of the present invention, the welding terminal used in the welding method,
A welding terminal main body having a through hole opened in the first and second end faces;
A thermit welding terminal having a sleeve portion having an introduction hole communicating with the through hole, protruding from the first end surface,
A chamfer in which the diameter of the introduction hole increases toward the opening end is formed near the opening end of the introduction hole on the second end surface.
[0034]
According to the above-described embodiment, since the chamfered portion is formed on the inner surface of the end opening where the conductor is inserted, the conductor is displaced with respect to the end opening by external force such as vibration. Also, stress concentration occurring at the position of the opening end is reduced, and as a result, durability is improved.
[0035]
According to another embodiment of the present invention, the conductor and the welding terminal are welded to the base material by thermit welding of the welding metal so as to accommodate all except the vicinity of the second end face of the welding terminal body.
[0036]
According to the method, since all except the vicinity of the second end face of the welding terminal into which the conductor is inserted is accommodated in the weld metal, it is possible to realize extremely strong and highly durable welding.
[0037]
According to yet another embodiment of the present invention, there is provided a method for thermit welding a conductor and a base material using any of the aforementioned welding terminals according to the present invention,
Inserting the conductor from the communication hole of the first sleeve portion of the welding terminal to the vicinity of the open end of the communication hole of the second sleeve portion;
A step of plastically deforming the vicinity of the open end of the second sleeve portion and causing the second sleeve portion to grip a conductor;
Welding the conductor and the welding terminal to the base material by thermit welding of the welding metal so as not to accommodate at least the vicinity of the opening end of the first sleeve;
Is proposed.
[0038]
According to the welding method, the second sleeve portion plastically deformed so as to grip the internal conductor is buried in the weld metal by thermite welding, and a first sleeve different from that protrudes from the weld metal to the outside. Therefore, a portion where a residual stress is generated due to plastic deformation is different from a portion which receives an external force during vibration through a conductor. Therefore, welding having excellent proof stress against vibration and external force after welding can be realized.
[0039]
According to still another embodiment of the present invention, in particular, the conductor and the welding terminal are formed on the base metal by thermit welding of the welding metal so as not to accommodate the sleeve portion having the chamfered portion formed on the inner surface of the open end of the sleeve. Weld.
[0040]
According to the above welding method, since the chamfered portion is formed on the inner surface of the end of the sleeve portion into which the conductor is inserted, when the conductor is displaced with respect to the sleeve by external force such as vibration. Also, the concentration of stress generated at the tip of the sleeve portion is reduced, and as a result, the durability is improved.
[0041]
According to still another embodiment of the present invention, the plastic deformation near the open end of the second sleeve portion is performed by a crimping means.
[0042]
Means for fixing the tip of the conductor to the sleeve portion include, in addition to crimping, welding, a method using a specific fixing device, and the like. The simplest method is to crush the sleeve portion using a pliers-like crimping device. .
[0043]
According to still another embodiment of the present invention, the conductor and at least a part of the welding terminal, for example, the vicinity of the first sleeve portion are covered with an insulating material.
[0044]
The conductor and the sleeve are preferably covered by the insulating material in terms of appearance, and furthermore, oxidization and electrical protection due to external impact or rain can be achieved.
[0045]
According to yet another embodiment of the present invention, the insulating material thermally shrinks.
[0046]
According to the above-described embodiment, if a tube-shaped material in which the insulating material thermally shrinks is selected, if the heat treatment is performed after covering the conductive wire portion and the sleeve portion with the tube after the welding process, the conductive wire portion and the sleeve portion can be formed. It can be easily fixed tightly.
[0047]
Features and effects other than the above of the present invention will be clarified by the following description of embodiments of the present invention.
[0048]
Embodiment
Hereinafter, the first embodiment of the thermite welding process according to the present invention will be described with reference to FIGS. 3 and 4 by taking welding of a base material and an electric wire as an example.
[0049]
FIG. 4 is a top view illustrating a process of performing a terminal process for fixing an electric wire and a welding terminal in thermit welding according to the present invention. The welding terminal body described in the prior art and having a through-hole formed in first and second end faces, and a sleeve part having an introduction hole protruding from the first end face and communicating with the through-hole. The covering of the electric wire 1 is removed by using a welding terminal having the above, the conductor portion 2 is exposed, and the conductor portion 2 is moved from the opening end of the second end face to the vicinity of the opening end of the communication hole of the sleeve as shown in FIG. Insert up to. The conductor portion 2 is fixed by pressing and deforming the sleeve portion 3 with a crimping tool at a position where the conductor tip portion protrudes to some extent from the outer end surface of the sleeve. More preferably, if the vicinity of the introduction hole of the conductor 1 is chamfered, it is possible to flexibly cope with the stress concentration with respect to the displacement of the conductor 2 (see the position 7 in FIG. 4).
The conductor 2 can maintain a certain free state by having a free space with the inner surface inside the welding terminal through hole.
[0050]
FIG. 5 is a top view showing a state in which the electric wire in which the terminal of the conductor portion 2 is fixed to the sleeve portion 3 of the welding terminal by the above-described procedure is arranged in the thermite welding apparatus. As shown in FIG. 5, the sleeve part 3 and at least the vicinity of the first end face of the terminal main body 4 are inserted into the welding device so as to be accommodated therein, and thermit welding is performed. Therefore, after welding, most of the welding main body 4 and the sleeve portion 3 are covered with the weld metal and are welded to the base material, so that they cannot be seen from the outside (see FIG. 6).
[0051]
According to the welding method, the sleeve portion is housed in the welded metal by thermite welding, so that the workability is not inferior to the conventional one, and the fixed portion of the electric wire is only one portion of the welded portion, and the displacement of the electric wire is large. The wires remain relatively free on the inlet side.
[0052]
Further, the first embodiment is subjected to thermit welding of the weld metal so that the second end face is located substantially in the same plane as the end face of the thermite welding apparatus, and the weld metal is entirely accommodated to the vicinity of the second end face. Further, if the welding terminal is welded to the base material, all except for the vicinity of the second end face where the conductor is inserted is accommodated in the welded metal, so that an extremely strong and highly durable welding method can be realized.
[0053]
Hereinafter, an embodiment of the thermite welding terminal according to the present invention of FIG. 7 will be described.
[0054]
FIG. 7 is a perspective view of a thermite welding terminal according to one embodiment of the present invention. The welding terminal includes a welding terminal body 4 having a through hole formed at two end surfaces thereof, and two or more sleeve portions 3 and 3 ′ having an introduction hole protruding from the end surface and communicating with the through hole. It is configured.
[0055]
The above-mentioned welding terminal further has one sleeve portion 3 and 3 ′ on both end surfaces of the welding terminal body 4 where the through hole is opened, and the through hole and the introduction hole have the same diameter and are coaxial. May be formed.
[0056]
The two sleeve portions 3 and 3 ′ formed on both end surfaces of the welding terminal body 4 may have different lengths.
[0057]
At least one of the two or more sleeve portions may be plastically deformed by an external pressing force, and may be capable of gripping the conductor accommodated in the introduction hole.
[0058]
The welding terminal body may have a flat side surface.
[0059]
In the vicinity of the opening of at least one introduction hole of each of the sleeves, a chamfer in which the diameter of the introduction hole increases toward the opening end may be formed. As a result, the wires are not firmly fixed and the wires are free to move with respect to the displacement of the wires, which helps to further prevent breakage of the wires.
[0060]
The above welding terminal may be made of copper or a copper alloy.
[0061]
Hereinafter, the welding of the base material and the electric wire will be described as an example using the second embodiment of the thermite welding process using the above-described thermite welding terminal according to the present invention.
[0062]
Using any of the above-described thermite welding terminals according to the present invention shown in FIG. 7, the coating of the electric wire 1 is removed so that the conductor 2 is exposed, and the conductor 2 is connected to the first sleeve 3. The second sleeve 3 'is inserted from the hole to the vicinity of the open end of the communication hole of the second sleeve 3'. The conductor portion 2 is fixed by pressing and deforming the sleeve portion 3 'at an appropriate position with a crimping tool.
[0063]
The electric wire in which the terminal of the conductor portion 2 is fixed to the sleeve portion of the welding terminal by the above procedure is arranged in the thermite welding apparatus. At this time, at least the vicinity of the opening end of the first sleeve 3 is arranged so as not to be accommodated in the welding device. Then, the deposited metal is subjected to thermite welding together with the second sleeve 3 ′ to weld the conductor and the welding terminal to the base material (see FIG. 8).
[0064]
According to this welding method, the second sleeve portion 3 'plastically deformed so as to grip the inner conductor is buried in the weld metal by thermite welding, and the other first sleeve projects outward from the weld metal. Therefore, by applying the coating 6 of FIG. 8 to the protruding portion, the electric wire can be fixed in a preferable state in appearance.
[0065]
A chamfer may be formed on the inner surface of the open end of the sleeve, and the conductor and the base may be welded by thermit welding of the weld metal so as not to accommodate the sleeve.
[0066]
The plastic deformation in the vicinity of the opening end of the second sleeve portion may be performed by crimping means.
[0067]
The vicinity of the conductor and the first sleeve portion may be covered with an insulating material, and the insulating material may be a material that thermally shrinks.
[0068]
As described above, the preferred embodiments of the present invention have been specifically described with reference to the drawings. However, the drawings and the above description are examples, and the present invention is not limited to these embodiments.
[0069]
【The invention's effect】
As described above, in the thermite welding of the electric wire, the base material, and the electric wires according to the present invention, the vibration strength of the terminal compression portion is significantly improved, and the wire strength of the crimped portion temporarily reduced by crimping is reduced to the welding portion. At the same time, it was confirmed that welding substantially restored the actual strength of the electric wire.
[Brief description of the drawings]
FIG. 1 is a top view of a conventional terminal treatment of electric wires and welding terminals in thermite welding.
FIG. 2 is a top view in which terminals are inserted into a conventional welding device in thermite welding.
FIG. 3 is a view showing a state of electric wire breakage caused by electric wire displacement in conventional thermite welding.
FIG. 4 is a top view of a terminal treatment of a welding terminal in thermite welding according to the present invention.
FIG. 5 is a top view in which terminals are inserted into a welding device in thermite welding according to the present invention.
FIG. 6 is an outline view after thermite welding according to the present invention.
FIG. 7 is a perspective view of a welding terminal for thermite welding according to the present invention.
FIG. 8 is a schematic view after thermite welding using the welding terminal for thermite welding according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electric wire 2 ... Conductor part 3 and 3 '... 1st and 2nd sleeve part 4 ... Weld terminal main body 5 ... Thermit welding apparatus 6 ... Coating 7 ... Chamfering part 9 ... welding part

Claims (17)

In the process of welding using electric wires and welding terminals,
A step of joining the electric wire and the welding terminal;
A step of welding so that at least a connection portion between the electric wire and the welding terminal is covered by a welding portion,
A welding method comprising: The welding method according to claim 1, wherein the welding method is thermit welding. A welding terminal main body having a through hole opened at two end faces,
A welding terminal protruding from a first end face and having a sleeve portion having an introduction hole communicating with the through hole,
A welding terminal, wherein a chamfered portion in which the diameter of the introduction hole increases toward the opening end is formed near the opening end of the second end surface. A welding terminal having one sleeve portion on each of both end surfaces of a welding terminal body in which the through hole is opened, wherein the through hole and the introduction hole have the same diameter and are formed coaxially. The welding terminal according to claim 4, wherein the two sleeve portions formed on both end surfaces of the welding terminal body have different lengths. The welding terminal according to claim 4, wherein at least one of the two sleeve portions is plastically deformed by an external pressing force and is capable of gripping a conductor housed in the introduction hole. The welding terminal according to any one of claims 4 to 6, wherein the welding terminal body has a flat side surface. The chamfer in which the diameter of the introduction hole increases toward the opening end near the opening of at least one introduction hole of each of the sleeves. The welding terminal according to the item. The welding terminal according to any one of claims 4 to 8, wherein the welding terminal is made of copper or a copper alloy. A step of preparing a welding terminal body having a through-hole formed in the first and second end surfaces and a sleeve terminal having a sleeve portion projecting from the first end surface and having an introduction hole communicating with the through-hole; When,
Inserting a conductor from the open end of the second end surface to the vicinity of the open end of the communication hole of the sleeve portion;
A step of plastically deforming the vicinity of the open end of the sleeve portion and causing the sleeve portion to grip the conductor;
Welding the conductor and the welding terminal to the base metal by thermit welding of the welding metal so as to accommodate at least the vicinity of the sleeve and the first end surface of the welding terminal body;
A welding method comprising: The welding method according to claim 10, wherein the step of preparing the welding terminal is a step of preparing the welding terminal according to claim 3. The welding method according to claim 10 or 11, wherein the conductor and the welding terminal are welded to the base metal by thermit welding of the weld metal so as to accommodate all except for the vicinity of the second end surface of the welding terminal body. A method for performing thermite welding of a conductor and a base material using the welding terminal according to any one of claims 4 to 9,
Inserting the conductor from the communication hole of the first sleeve portion of the welding terminal to the vicinity of the open end of the communication hole of the second sleeve portion;
A step of plastically deforming the vicinity of the open end of the second sleeve portion and causing the second sleeve portion to grip a conductor;
Welding the conductor and the welding terminal to the base metal by thermit welding of the welding metal so as not to accommodate at least the vicinity of the opening end of the first sleeve;
A welding method comprising: 14. The conductor and the welding terminal are welded to the base material by thermit welding of the welding metal so as not to accommodate the sleeve portion in which the chamfered portion is formed, using the welding terminal described in claim 8. Welding method. The method according to claim 10, wherein the plastic deformation near the open end of the sleeve portion is performed by a crimping unit. The method according to claim 10, wherein the conductor and at least a part of the welding terminal are covered with an insulating material. 17. The method of claim 16, wherein said insulating material thermally shrinks.

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