CN111843379A

CN111843379A - Bus bar manufacturing method

Info

Publication number: CN111843379A
Application number: CN201910707990.5A
Authority: CN
Inventors: 金明壎; 徐宗德
Original assignee: Afa House Co ltd
Current assignee: Afa House Co ltd
Priority date: 2019-04-30
Filing date: 2019-08-01
Publication date: 2020-10-30
Anticipated expiration: 2039-08-01
Also published as: CN111843379B; KR102084949B1

Abstract

The present invention relates to a method for manufacturing a bus bar, which friction-welds a first conductor and a second conductor and minimizes a weld bead generated during friction welding, and which includes the steps of: a disposing step of disposing second conductors at both ends of the first conductor, respectively; a friction welding step of performing friction welding between the first conductor and the second conductor; and a bus bar forming step of pressing or rolling the first and second conductors friction-welded in the friction welding step to form a bus bar, the friction welding step including the steps of: an installation process of installing the first conductor and the second conductor on the friction welding machine with a preset interval; a friction heat generating step of generating friction heat by rotating the first conductor and the second conductor in opposite directions and bringing the first conductor and the second conductor into close contact with each other; and a minimizing process of minimizing a weld bead generated when the first and second electric conductors are melted by frictional heat.

Description

Bus bar manufacturing method

Technical Field

The present invention relates to a method of Manufacturing a bus bar, and more particularly, to a method of Manufacturing a bus bar in which a first conductor and a second conductor are friction-welded and a weld bead generated during friction welding can be minimized.

Background

Bus bars (Bus bars), which are media for transmitting electric energy, are used mainly as cables in power transmission lines, such as large power transmission and distribution lines, conductors for electrical equipment, and communication cables, which have large current capacities, in power plants, large buildings, large factories, large department stores, subways, and new airports.

As can be seen from a comparison of the bus bar and the cable in construction, the similarity is in having a conductor and an insulator, but the bus bar has the greatest advantage of being able to transfer more electrical energy with the same volume of conductor. Therefore, while the advantages of bus bars in large-capacity power distribution systems are known, the amount of bus bars used is rapidly increasing, and bus bars are considered to be parts that are very suitable for modern large-capacity power transmission systems because of the trend toward a rapid increase in the demand for large buildings, large factories, power plants, subways, and the like, which require large-capacity electric energy, because the bus bars are safe and have less energy loss than ever.

Korean patent No. 10-1844270 (granted on 03/27/2018) discloses a bus bar and a method for manufacturing the same, which is characterized by comprising the steps of: preparing a plurality of conductive metal members in a band shape; bending the plurality of metal members only in a direction of a small thickness, i.e., before and after bending, so that upper and lower surfaces thereof are kept flat; welding bent portions of the plurality of metal members; and a step of restraining an integrated operation of the plurality of metal members in a state where the plurality of metal members are closely attached to each other, the plurality of metal members being made of copper or aluminum.

Korean granted patent No. 10-1306914 (granted on 04/09/2013) describes a bead processing machine for improving stability. According to the disclosed technology, the bead processing machine is characterized by comprising: a pair of sliding plates which are arranged at intervals so that a welding bead advancing path which is opened to the front and the back is formed at the center, and fixed blocks are respectively connected and arranged at the front and the back of the upper surface; a body head disposed between the fixing blocks and having an open lower portion; a main cutter shaft rotatably provided at one side of the inside of the body head and integrally provided with a main gear at the outside of the center thereof; a driven cutter shaft rotatably arranged at the other side of the inner part of the body head, and a driven gear meshed with the main gear for rotation is integrally inserted and arranged at the outer side of the upper part of the driven cutter shaft; a helical gear integrally inserted into an upper outer side of the main cutter shaft and receiving rotational power input from a power shaft; a cutting depth adjusting device integrally formed on a rear surface of the body head in a protruding manner, the rotating bracket being rotatably coupled to a rear side fixing block to form a front surface provided on the body head, the cutting depth adjusting device including: an adjuster case attached to a front surface of the body head; a cutting depth adjuster which is rotatably provided to penetrate the upper and lower portions of the adjuster case and has a plurality of locking grooves formed in a radial shape on a central outer circumferential surface; a screw shaft having a lower side rotatably connected to the front side fixing block and an upper side penetrating the cutting depth adjusting member to form a screw connection; and a ball screw which is provided to penetrate the adjuster case, and a ball protruding from a front end of the ball screw in an accessible manner is inserted into any one of the locking grooves, thereby maintaining locking of the cutting depth adjuster.

As described above, conventionally, the bus bar is generally manufactured by using a copper or aluminum material, but in the case of copper, it is expensive and heavy, and thus there is a problem in durability against products, and in the case of aluminum, its electric conductivity is lower than that of a copper material, and thus it is necessary to have a volume 2 times or more larger than that of copper, otherwise heat is generated at the time of energization, and thus there is a problem in that a cooler is required depending on a use environment, and since an arc possibly generated at the time of energization, a problem in that an aluminum material having a low melting point is easily melted occurs, and thus there is a problem in that it is not suitable for a heavy electrical equipment or equipment having a capacity more than that.

Further, even when aluminum and copper are welded to manufacture a bus bar, a problem of poor bonding between aluminum and copper or poor bonding between aluminum and copper often occurs, and therefore, not only is there a problem that a bonded portion is cracked by external impact or the like, but also a post-processing step is necessary to remove a weld bead generated when welding is performed by the above-described weld bead processing machine, and therefore, there is a disadvantage that the manufacturing process is complicated.

Prior art documents

Patent document

(patent document 1) Korean patent laid-open No. 10-1844270

(patent document 2) Korean patent laid-open No. 10-1306914

Disclosure of Invention

Technical problem to be solved

The present invention is directed to solving the above-described problems, and therefore, to provide a bus bar manufacturing method that friction welds a first conductor and a second conductor, minimizes a weld bead generated during friction welding, and can omit a separate weld bead removal process.

Technical scheme for solving problems

In order to solve these problems, according to one feature of the present invention, there is provided a bus bar manufacturing method including the steps of: a configuration step of configuring second conductors at both ends of the first conductor, respectively; a friction welding step of performing friction welding between the first conductor and the second conductor; and a bus bar forming step of pressing or rolling the first and second conductors friction-welded in the friction welding step to form a bus bar, wherein the friction welding step includes the steps of: a mounting step of mounting the first conductor and the second conductor to a friction welder with a predetermined gap therebetween; a frictional heat generating step of generating frictional heat by bringing the first conductor and the second conductor into close contact with each other while rotating the first conductor and the second conductor in opposite directions to each other; and a minimizing process of minimizing a weld bead generated when the first and second electric conductors are melted by the frictional heat.

In one embodiment, in the minimizing, a bead expansion phenomenon is prevented by a bead prevention portion formed to be spaced apart from an abutting surface of the first conductor and the second conductor.

In one embodiment, the minimizing process moves the bead prevention part in an up-down direction using a cylinder connected to the bead prevention part.

In one embodiment, the minimizing process includes the following processes: a sensing process of sensing an amount of current applied to the friction welder; the judgment process compares the sensed current amount with a preset reference current amount, so that when the sensed current amount is more than the reference current amount, the overload is judged; and a control process of controlling the cylinder to move in a downward direction when it is judged that the overload is generated.

In one embodiment, after the friction welding step, a cooling step is further included, in which a coolant is applied to the friction welded portion of the first and second electrical conductors and is cooled.

Effects of the invention

According to the present invention, the bus bar is manufactured by friction welding copper as the second conductor to both ends of aluminum as the first conductor, thereby reducing cost, reducing weight, and improving performance. That is, the bus bar according to the present invention can be used in various transportation devices such as automobiles requiring light weight and strength because the bus bar can be greatly reduced in weight, and has the effect of facilitating storage and transportation and improving workability.

In addition, not only the bonding force between aluminum and copper is strong and has high strength, but also the welding bead generated during friction welding is minimized, so that a separate post-processing process for removing the welding bead after welding can be omitted, thereby the manufacturing process becomes simple, and thus not only mass production is possible, but also troublesome effects such as metal debris splashing or the need to collect the removed welding bead during the removal of the welding bead can be solved.

Drawings

Fig. 1 and 2 are flowcharts illustrating a bus bar manufacturing method according to a first embodiment of the present invention.

Fig. 3 is a sectional view illustrating a minimization process shown in fig. 1 by another example.

Fig. 4 is a flow chart illustrating the minimization process shown in fig. 1 by way of yet another example.

Fig. 5 is a flowchart illustrating a bus bar manufacturing method according to a second embodiment of the present invention.

Reference numerals

100: first conductor

200: second conductor

300: friction welding machine

400: weld bead prevention part

500: cylinder

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the invention. However, the description of the present invention is intended to be illustrative only of structural or functional descriptions, and thus, the scope of the present invention should not be construed as being limited by the embodiments described herein. That is, the embodiments can be variously modified and have various forms, and therefore, it should be understood that the scope of the claims of the present invention includes equivalents capable of realizing the technical idea. Further, the purpose or effect suggested in the present invention does not mean that a specific embodiment includes all or only that effect, and therefore, it should not be construed that the scope of the right of the present invention is limited by the specific embodiment.

On the other hand, the meanings of the terms described in the present invention should be understood as follows.

The terms "first", "second", and the like are used to distinguish one constituent element from another constituent element, and the scope of the claims should not be limited by these terms. For example, the first component can be named as the second component, and similarly, the second component can also be named as the first component.

When a certain component is referred to as being "connected" to another component, this includes not only a case where the component is directly connected but also a case where the component is indirectly connected with the other component interposed therebetween. In contrast, when a component is referred to as being "directly connected" to another component, it is to be understood that no other component is present therebetween. Similarly, other expressions for explaining the relationship between the respective constituent elements, that is, expressions such as "between" and "immediately between" or "adjacent to" and "directly adjacent to" may be similarly interpreted.

It will be understood that the terms "comprises" and "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a term includes a reference to a "or" including "or" having "or any other variation thereof, unless the context clearly dictates otherwise.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Terms defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

A bus bar manufacturing method according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to fig. 1 and 2, the second conductor 200 is disposed at both ends of the first conductor 100 by the conveyance device (S100).

In step S100, the first conductor 100 is a strip of aluminum, and the second conductor 200 is a strip of copper. In this case, a copper material having relatively high conductivity and a relatively high melting point is preferably provided in a portion where electrical contact is made.

The friction welding is performed between the first conductor 100 and the second conductor 200 disposed in the step S100 by the friction welder 300 (S200).

In step S200, first, the first conductor 100 and the second conductor 200 are attached to the friction welder 300 with a predetermined distance (for example, approximately 1cm) therebetween (S210).

The first conductor 100 and the second conductor 200 are mounted on each other in the step S210 by rotating in opposite directions, and the first conductor 100 and the second conductor 200 are brought into close contact with each other to generate frictional heat (S220).

In step S220, the first conductor 100 and the second conductor 200 are fused and bonded to each other by frictional heat generated at the contact surfaces. At this time, by rotating and closely contacting the first conductor 100 and the second conductor 200 in opposite directions, not only the relative speed can be increased to the sum of the rotational speeds of the first conductor 100 and the second conductor 200, but also even in the absence of an external braking force, the inertia can be cancelled by the force combination between the couple of the first conductor 100 rotating in the normal direction and the couple of the second conductor 200 rotating in the opposite direction on the closely contacting surface, thereby providing a braking effect.

In step S220, the first conductor 100 and the second conductor 200 can be rotated in opposite directions at a predetermined rotational speed (for example, 1600 to 2200 rpm) and the first conductor 100 and the second conductor 200 can be rotated until the contact surfaces thereof are in a gel state which is a semi-solid state, thereby generating frictional heat.

In step S220, in a state where the first conductor 100 and the second conductor 200 are in close contact with each other, a welding force can be applied in a direction of the close contact surface in a range of 7 to 20 tons while rotating in opposite directions to each other.

The friction heat generated in step S220 melts the contact surfaces of the first conductor 100 and the second conductor 200, and at the same time, minimizes the weld bead (S230).

The bead (weld bead) is a band-like shape formed by bulging at a welded portion in a welding operation.

In step S230, the expansion of the weld bead can be prevented by one or more bead prevention portions 400 formed at a distance from the contact surfaces of the first conductor 100 and the second conductor 200.

In step S230, the bead prevention unit 400 is formed at a distance of 1mm to 5mm from the contact surface between the first conductor 100 and the second conductor 200. At this time, if the bead prevention portion 400 is completely in close contact with the close contact surfaces of the first conductor 100 and the second conductor 200, the rotation and adhesion of the first conductor 100 and the second conductor 200 are disturbed, and the welding cannot be performed normally, so that a defect occurs, and if the bead prevention portion 400 is formed apart from the close contact surfaces of the first conductor 100 and the second conductor 200 by an interval of 5mm or more, a bead flows out from between the intervals, and the expansion of the bead cannot be normally prevented.

In step S230, the bead prevention unit 400 has a pentagonal cross-sectional shape and is formed of a horizontally long blade, thereby preventing the expansion of the bead, and spreading the flowing-out portion to be flat and thin on both sides while guiding the fusion of the contact surfaces of the first and

second conductors

100 and 200.

That is, although the bead hardly generates a bead due to the bead prevention portion 400, when the amount of melted and flowed out is large during friction welding, the bead is spread flat and thinly on both sides of the bead prevention portion 400 and does not swell so as to bulge out, and therefore, a separate grinding operation is not required.

The first and

second conductors

100 and 200 friction-welded in the step S200 are pressed or rolled to form a bus bar (S300).

In step S300, the friction-welded first conductor 100 and second conductor 200 can be press-molded into a predetermined pattern (for example, a plate shape or a cylindrical shape) and thickness depending on the installation location.

In step S300, the first conductor 100 and the second conductor 200 that are friction welded can be roll-formed by a stitching roller device.

The bus bar formed in the step S300 can be cut into a desired size and both ends of the bus bar are punched, so that a hole for connecting the terminals can be formed.

The surface of the bus bar formed in the step S300 can be coated with a coating agent. In this case, the coating may be selected from calender coating, curtain coating, dip coating, electrodeposition coating, electrostatic coating, thermal spraying, fluid dip coating, roll coating, blade coating, and spray coating, as needed, and the coating agent may be polyvinyl chloride resin (PVC), epoxy resin, or silicone resin having excellent insulating properties against electricity discharged to the outside, or may be a material having an insulating function.

The bus bar manufacturing method having the above steps can reduce the cost, reduce the weight, and improve the performance by manufacturing the bus bar by friction-welding copper as the second conductor 200 to both ends of aluminum as the first conductor 100. That is, since the bus bar can be greatly reduced in weight, it can be used in various transportation vehicles including automobiles requiring light weight and strength, and is easy to store and transport and has improved workability.

In addition, not only the bonding force between aluminum and copper is strong and has high strength, but also the weld bead generated during friction welding is minimized, so that an additional post-processing process for removing the weld bead after welding can be omitted, thereby the manufacturing process becomes simple, and thus not only mass production is possible, but also the trouble of metal debris splashing or collecting the removed weld bead during removal of the weld bead, etc. can be solved.

Referring to fig. 3, in step S230, the bead prevention unit 400 can be moved in the vertical direction by the cylinder connected to the bead prevention unit 400.

In step S230, the cylinder 500 is formed at the lower portion of the bead prevention unit 400, and the interval between the contact surfaces of the first conductor 100 and the second conductor 200 and the bead prevention unit 400 can be adjusted by adjusting the height of the bead prevention unit 400 while reciprocating in the vertical direction. The cylinder 500 may be electrically driven, hydraulically driven, or compressed air driven, and may be adjusted in height in real time by an up/down switch.

In step S230, the cylinder 500 is raised or lowered according to the size, rotation speed, and the like of the first and

second conductors

100 and 200, and the interval between the contact surfaces of the first and

second conductors

100 and 200 and the bead prevention unit 400 is appropriately adjusted so that the bead prevention unit 400 can prevent the phenomenon in which the rotation of the first and

second conductors

100 and 200 is disturbed or the phenomenon in which the bead expands.

Referring to fig. 4, the amount of current applied to the friction welder 300 is sensed using a sensing sensor provided to the friction welder 300 and transmitted to the control unit (S231).

The control unit compares the current amount received in the step S231 with a reference current amount preset in a memory, and determines that the load is excessive when the received current amount is equal to or greater than the reference current amount (S232).

When it is determined that the overload is generated in the step S232, the control unit generates a falling signal and transmits the falling signal to the cylinder 500 to move the cylinder 500 downward (S233).

Accordingly, the operator can immediately lower the cylinder 500 to cope with the overload without continuously monitoring whether the friction welder 300 is overloaded and accurately and rapidly determining the overload state of the friction welder 300, so that it is possible to prevent malfunctions such as malfunction and damage due to the overload and to greatly improve the work efficiency.

Referring to fig. 5, after the step S200, a coolant (e.g., cooling water, liquid nitrogen, etc.) is applied to the friction-welded portion of the first and second

electric conductors

100 and 200 to cool them (S400).

In the step S400, coolant is sprayed to the friction-welded portion using an injector to directly quench the friction-welded portion so as to prevent changes in the interior of the metal, thereby maintaining a stable state or an intermediate state at a high temperature, and thus, strength can be further improved.

In step S400, the friction-welded portion between the first conductor 100 and the second conductor 200 can be gradually cooled (slowly cooled) by the coolant to prevent deformation such as cracking or distortion from occurring on the surface and inside of the metal.

As described above, the embodiments of the present invention can be embodied not only by the above-described devices and/or operation methods but also by a program for realizing functions corresponding to the configurations of the embodiments of the present invention, a recording medium on which the program is recorded, and the like, and those skilled in the art can easily embody the embodiments based on the description of the embodiments described above.

Although the embodiments of the present invention have been described in detail, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the appended claims are also within the scope of the present invention.

Claims

1. A bus bar manufacturing method, characterized by comprising the steps of:

a configuration step of configuring second conductors at both ends of the first conductor, respectively;

a friction welding step of performing friction welding between the first conductor and the second conductor; and

a bus bar forming step of pressing or rolling the first and second conductors friction-welded in the friction welding step to form a bus bar,

wherein the friction welding step comprises the following processes:

a mounting step of mounting the first conductor and the second conductor to a friction welder with a predetermined gap therebetween;

a frictional heat generating step of generating frictional heat by bringing the first conductor and the second conductor into close contact with each other while rotating the first conductor and the second conductor in opposite directions to each other; and

a minimizing process of minimizing a weld bead generated when the first and second electric conductors are melted by the frictional heat.

2. The bus bar manufacturing method according to claim 1,

in the minimizing step, a bead expansion phenomenon is prevented by a bead prevention portion formed apart from the contact surface between the first conductor and the second conductor.

3. The bus bar manufacturing method according to claim 2,

in the minimizing, the welding bead preventing part is moved in an up-and-down direction by a cylinder connected to the welding bead preventing part.

4. The bus bar manufacturing method according to claim 3,

the minimization process includes:

a sensing process of sensing an amount of current applied to the friction welder;

a judgment process of comparing the sensed current amount with a preset reference current amount, thereby judging that the load is overloaded when the sensed current amount is greater than or equal to the reference current amount; and

and a control process of controlling the cylinder to move downwards when the overload is judged.

5. The bus bar manufacturing method according to claim 1,

after the friction welding step, a cooling step of applying a coolant to the friction-welded portion of the first and second electric conductors to cool the friction-welded portion is further included.