CN215588225U

CN215588225U - Electromagnetic welding head

Info

Publication number: CN215588225U
Application number: CN202121302324.2U
Authority: CN
Inventors: 尹聪; 马昂; 余峰; 冯维一
Original assignee: Ningbo Weie Electronics Technology Ltd
Current assignee: Ningbo Weie Electronics Technology Ltd
Priority date: 2021-06-10
Filing date: 2021-06-10
Publication date: 2022-01-21
Anticipated expiration: 2031-06-10

Abstract

The utility model relates to an electromagnetic welding head, which comprises a middle magnetic core and a side magnetic core arranged on one side of the middle magnetic core at intervals, wherein a coil is wound on the middle magnetic core, and the coil is configured to generate a magnetic field after being electrified. The middle magnetic core is contacted with the welding position during electromagnetic welding, and the side magnetic core is used for generating induced electromotive force in the direction opposite to that of the middle magnetic core, so that the product is prevented from being burnt out.

Description

Electromagnetic welding head

Technical Field

The utility model relates to the technical field of electromagnetic welding, in particular to an electromagnetic welding head.

Background

In the existing photovoltaic bus bar welding technology, the bus bar and the welding strip are welded together by adopting electromagnetic welding, and the welding strip is easily blown when the welding power is too high and/or the welding time is too long.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide an electromagnetic welding head, which can effectively prevent a product from being burned out during welding.

The electromagnetic welding head of the embodiment of the utility model comprises: the middle magnetic core is wound with a coil; the side magnetic cores are arranged on one side of the middle magnetic core at intervals; the coil is configured to generate a magnetic field upon energization.

In some embodiments, the middle magnetic core is configured to solder a bus bar and a solder strip, wherein a photovoltaic cell piece is disposed on a side of the bus bar, the solder strip is disposed on the photovoltaic cell piece and extends to the bus bar, the photovoltaic cell piece further has a grid line electrically connected to the solder strip, the bus bar, the solder strip, and the grid line form a conductive branch, and the side magnetic core is configured to excite an induced current in the conductive branch.

In some embodiments, the coil is located at an end of the center core facing the bus bar.

In some embodiments, the center core and the side cores are plate-shaped, and the center core and the side cores are arranged in parallel with each other; the electromagnetic welding head further comprises: and the first top magnetic core is positioned on one side of the middle magnetic core and one side of the side magnetic core and fixedly connected with the middle magnetic core and the side magnetic core.

In some embodiments, the first top core and the center and side cores are all disposed perpendicular to each other.

In some embodiments, the center core, the side cores, and the first top core are integrally formed.

In some embodiments, the center core is cylindrical and the side cores are bent pieces; the electromagnetic welding head further comprises: and the second top magnetic core is in a disc shape, is positioned on one side of the middle magnetic core and one side of the side magnetic core, and is fixedly connected with the middle magnetic core and the side magnetic core.

In some embodiments, the center core, the side cores, and the second top core are integrally formed.

In some embodiments, there are two side cores, two side cores are located on two opposite sides of the middle core, and the two side cores are spaced apart from each other by a gap.

In some embodiments, the coil is a litz wire coil.

According to the electromagnetic welding head disclosed by the embodiment of the utility model, the edge magnetic cores generate induced electromotive force in the direction opposite to that of the middle magnetic core during electromagnetic welding, so that the product is prevented from being burnt out.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a schematic side view of an electromagnetic welding head of a first embodiment of the utility model;

FIG. 2 is a schematic top view of an electromagnetic welding head of a second embodiment of the utility model;

FIG. 3 is a schematic view of an exemplary photovoltaic module suitable for use in an electromagnetic welding head for welding in accordance with an embodiment of the present invention;

fig. 4 is a schematic view of an electromagnetic welding head welding product according to the first embodiment of the present invention.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details. Well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

Meanwhile, it should be understood that, in the following description, a "circuit" refers to a conductive loop constituted by at least one element or sub-circuit through electrical or electromagnetic connection. When an element or circuit is referred to as being "connected to" another element or element/circuit is referred to as being "connected between" two nodes, it may be directly coupled or connected to the other element or intervening elements may be present, and the connection between the elements may be physical, logical, or a combination thereof. In contrast, when an element is referred to as being "directly coupled" or "directly connected" to another element, it is intended that there are no intervening elements present.

Unless the context clearly requires otherwise, throughout the description, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, what is meant is "including, but not limited to".

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

Firstly, referring to fig. 3, the principle of photovoltaic power generation is generally that a photovoltaic cell sheet 6 is arranged on one side of a bus bar 4, a plurality of photovoltaic modules (not shown in the figure) are arranged on the photovoltaic cell sheet 6, the photovoltaic modules are used for converting light energy into electric energy, a solder strip 5 (single-dot chain line) and a grid line 7 (double-dot chain line) are further arranged on the photovoltaic cell sheet, the solder strip 5 and the grid line 7 can be provided with a plurality of solder strips 5, the solder strips 5 are respectively and electrically connected with the grid line 7, the solder strips 5 extend from the photovoltaic cell sheet 6 to be connected to the bus bar 4, the grid line 7 is arranged on the photovoltaic cell sheet 6, the electric energy generated by the photovoltaic modules is transmitted to each solder strip 5 through the grid line 7 gathered on the photovoltaic cell sheet 6, the solder strips 5 transmit current to the bus bar 4, and the bus bar 4 collects current to other electronic components (not shown in the figure).

The solder strip 5 and the bus bar 4 are usually welded, the conventional electromagnetic welding head is usually a structure in which a coil is sleeved on a magnetic core, the magnetic core is used for pressing the solder strip 5 onto the bus bar 4, the coil on the magnetic core is electrified to generate a magnetic field, eddy current is generated in the bus bar 4, and heat is generated, so that the solder strip 5 and the bus bar 4 are welded together. However, in electromagnetic welding, in addition to the eddy currents generated in the bus bar 4 for welding, induced currents are also generated in the parallel branch consisting of the bus bar 4, the solder ribbon 5 and the grid lines 7, and when the welding power is too high and/or the welding time is too long, the currents in the parallel branch risk to blow the solder ribbon 5 due to the poor current resistance of the solder ribbon 5. The embodiment of the utility model provides an electromagnetic welding head which can be used for welding a welding strip 5 and a bus bar 4:

fig. 1 is a schematic side view of an electromagnetic welding head according to a first embodiment of the utility model. The electromagnetic welding head of the first embodiment of the present invention is symmetrical in the left and right viewing directions. As shown in fig. 1, the electromagnetic welding head includes a middle core 1 and a side core 3 disposed at an interval on one side of the middle core 1. The middle magnetic core 1 is wound with a coil 2, and the coil 2 is configured to generate a magnetic field after being energized.

As shown in fig. 1, 3 and 4, the solder ribbon 5 (single-dot chain line) extends from the photovoltaic cell sheet 6 and is connected to the bus bar 4, and the electromagnetic welding head of the present embodiment can be used for welding the solder ribbon 5 and the bus bar 4. During welding, the end of the middle magnetic core 1 pressed against the welding strip 5 is fixed on the bus bar 4 (see fig. 4), and alternating current is supplied to the coil 2, so that the magnetic field B1 (see fig. 3) is excited in space by the electromagnetic induction coil 2, and the eddy current I1 (dotted line) is generated in the bus bar 4 by the magnetic field B1. The heat generated by the current I1 is used to weld the solder strip 5 and the bus bar 4. However, since the solder ribbon 5 is also pressed against the bus bar 4, the current I2 (solid line) also flows through the branch composed of the solder ribbon 5 and the grid line 7 (two-dot chain line) and connected in parallel with the current I1. The current I2 may cause the solder strip 5 to be at risk of burning out, and especially the overhead section of the solder strip 5 led out from the photovoltaic cell sheet 6 to the bus bar 4 is easier to burn out.

Therein, the direction of the magnetic field B1 in FIG. 3 is shown as dots, the dots representing directions pointing perpendicular to the drawing plane to the reader. It should be understood that, because the winding directions of the coil 2 are different, the direction of the magnetic field B1 may be perpendicular to the drawing and toward the reader, or may be perpendicular to the drawing and away from the reader, for illustration, this embodiment takes one of them, and in actual circumstances, the direction of the magnetic field B1 may also be opposite to this embodiment. Fig. 4 is a schematic welding diagram of an electromagnetic welding head, in fig. 4, one end of the welding strip 5 extending to the bus bar 4 is tilted, the tilted portion is pressed against the bus bar 4 by the middle core 1 during welding, and the tilted portion is welded to the bus bar 4 under the heat of the current I1 so that the welding strip 5 is welded to the bus bar 4.

As shown in fig. 3, in the present embodiment, when a current I2 is generated in the parallel branch where the solder ribbon 5 and the grid line 7 are located, the magnetic core 3 excites a reverse magnetic field B2 in space to generate a sensing current (not shown in the figure) opposite to the current I2 in the parallel branch where the solder ribbon 5 and the grid line 7 are located, so as to at least partially cancel the current I2, so that the current I2 is not enough to burn out the solder ribbon 5. Therein, the direction of the magnetic field B2 is shown in fig. 3 as several crosses, which represent the direction away from the reader perpendicular to the drawing plane. That is, regardless of the winding direction of the coil 2, the directions of the magnetic field B1 and the magnetic field B2 are always opposite, and the induced currents generated in the parallel branch formed by the solder ribbon 5 and the grid line 7 can be at least partially cancelled, so as to protect the solder ribbon 5 from being blown due to the excessive current I2.

It should be noted that only one possible branch of the current I2 (hereinafter referred to as I2 branch) is shown in fig. 3, and the I2 branch may have several branches (two or more). For example, referring to fig. 3, the photovoltaic cell sheet 6 has a plurality of grid lines 7 arranged horizontally and a plurality of solder strips 5 arranged vertically, each solder strip 5 is electrically connected to each grid line 7, and each grid line 7 is electrically connected to each solder strip 5. The photovoltaic cell sheet 6 further has at least one photovoltaic module (not shown) thereon for converting light energy into electric energy, and each photovoltaic module is electrically connected to at least one grid line 7. The grid lines 7 can conduct the electrical energy collected by the photovoltaic module to the respective solder strips 5 in the form of electrical current, the solder strips 5 can collect and conduct the electrical current in the grid lines 7 to the bus bars 4, and the bus bars 4 can conduct the electrical current in the solder strips 5 to other components (not shown in the figure). Therefore, it is easy to understand that each grid line 7 can form an I2 conductive branch with any two solder strips 5, and the solder strips 5 in the state of conducting current are exposed to the risk of being blown. In fig. 3, five solder strips 5 and ten grid lines 7 are shown, which are only used for illustration, and as known to those skilled in the art, in practical cases, the number of the solder strips 5 and the grid lines 7 on the photovoltaic cell sheet 6 may be any number (two or more).

As shown in fig. 1, in some embodiments, the coil 2 is located at an end of the middle core 1 facing the bus bar 4. This makes the intensity of the induced current excited in the bus bar 4 by the magnetic field generated after the coil 2 is energized higher, and the amount of heat generated at the weld is higher, contributing to the improvement of the welding efficiency.

As shown in fig. 1, in some embodiments, two side cores 3 are provided, two side cores 3 are respectively located at two opposite sides of the middle core 1, and the two side cores 3 are spaced apart from each other by a gap. This is a photovoltaic power generation apparatus provided with photovoltaic cell pieces 6 corresponding to both sides of the bus bar 4, the photovoltaic cell pieces 6 are shown only on one side of the bus bar 4 in fig. 3, in practical cases, the other side of the photovoltaic cell pieces 6 may also be provided with the photovoltaic cell pieces 6, and the photovoltaic cell pieces 6 on both sides of the bus bar 4 have the same arrangement of the solder strips 5 and the grid lines 7. Thereby, the side cores 3 on both sides of the center core 1 generate back-induced electromotive forces in the conductive branches I2 on both sides of the bus bar 4, respectively, thereby preventing the solder ribbon 5 from being burned out.

That is, the photovoltaic power generation apparatus (not shown) includes a form in which the photovoltaic cell sheet 6, the solder ribbon 5, and the grid line 7 are provided on both sides of the bus bar 4, respectively, or further includes a form in which the photovoltaic cell sheet 6, the solder ribbon 5, and the grid line 7 are provided on one side of the bus bar 4. Correspondingly, the side cores 3 may be disposed in two ways, i.e., one on one side of the middle core 1 or one on each of the two opposite sides of the middle core 1.

As shown in fig. 1, in some embodiments, the middle core 1 and the side cores 3 have a plate shape, and the middle core 1 and the side cores 3 are disposed parallel to each other. The electromagnetic welding head further comprises a first top magnetic core 8, wherein the first top magnetic core 8 is positioned on one side of the middle magnetic core 1 and the side magnetic core 3 and fixedly connected with the middle magnetic core 1 and the side magnetic core 3. In other words, this is similar to the structure of an E-core, as known to those skilled in the art. The electromagnetic welding head can be connected to other structures of the electromagnetic welding head through the first top magnetic core 8, the plate-shaped middle magnetic core 1 and the plate-shaped side magnetic core 3 are simple in manufacturing process and low in cost, and the winding of the coil 2 is simple.

Further, in some embodiments, the first top core 8 is perpendicular to the middle core 1 and the side cores 3, which may make the magnetic field generated by the cores in space more uniform and better magnetic conductive.

The middle magnetic core 1, the side magnetic core 3 and the first top magnetic core 8 may be integrally formed or may be formed by connecting the respective parts. Wherein, if integrated into one piece can improve electromagnetic welding head's structural strength, improve life. If each part is connected, the parts can be connected by gluing, so that the processing difficulty of the electromagnetic welding head can be reduced, and the production cost is reduced. The above can be selected according to actual needs.

Fig. 2 is a schematic top view of an electromagnetic welding head according to a second embodiment of the utility model. As shown in fig. 2, the electromagnetic welding head of the present embodiment is different from the electromagnetic welding head of the first embodiment in that the center core 1 of the present embodiment has a cylindrical shape and the side core 3 has a bent sheet shape. And the electromagnetic welding head of the embodiment includes a second top core 9 in a circular sheet shape, and the second top core 9 is located at one side of the middle core 1 and the side core 3 and fixedly connects the middle core 1 and the side core 3. In other words, this is similar to a pot core structure, as known to those skilled in the art. The electromagnetic shielding effect of the pot-shaped magnetic core is better.

In addition, in some other optional implementation manners, the side cores 3 may have a plurality of plate shapes, the plurality of side cores 3 are disposed in a ring shape surrounding the middle core 1, and each adjacent plate-shaped side cores 3 may be connected to each other or spaced apart from each other, thereby having a better electromagnetic shielding effect. The adjacent side magnetic cores 3 are separated by a distance (namely, a gap exists) so that the coil 2 is more convenient to wind to the middle magnetic core 1, and a conducting wire can enter the magnetic cores from the gap and wind.

The electromagnetic welding head of the present embodiment may be integrally formed, or may be formed by connecting the middle core 1, the side core 3, and the second top core 9.

As shown in fig. 2, the two side cores 3 of the present embodiment may also be disposed on two sides of the middle core 1, respectively, and the two side cores 3 are circumferentially disposed around the middle core 1, and the two side cores 3 are spaced apart from each other. This is a photovoltaic apparatus provided with photovoltaic cells 6 corresponding to both sides of the bus bar 4, similarly to the electromagnetic welding head of the first embodiment.

The coil 2 of the present embodiment may be a litz wire coil or a copper coil. Preferably a litz wire coil, a wire twisted or braided from a plurality of individually insulated conductors. The litz wire coil is simple to wind, and can effectively reduce the high-frequency skin effect or the proximity effect, thereby reducing the loss and having high transmission efficiency.

The electromagnetic welding head of the embodiment of the utility model welds the product through the middle magnetic core, and avoids the product from being burnt out by the induced electromotive force generated by the side magnetic core in the direction opposite to the middle magnetic core, thereby ensuring the welding quality of the product.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electromagnetic welding head, comprising:

the magnetic core comprises a middle magnetic core (1), wherein a coil (2) is wound on the middle magnetic core (1);

the side magnetic cores (3) are arranged on one side of the middle magnetic core (1) at intervals;

the coil (2) is configured to generate a magnetic field upon energization.

2. Electromagnetic welding head according to claim 1, characterized in that the middle magnetic core (1) is arranged to weld a bus bar (4) with a solder ribbon (5), wherein a photovoltaic cell strip (6) is arranged laterally to the bus bar (4), the solder ribbon (5) is located on the photovoltaic cell strip (6) and extends to the bus bar (4), the photovoltaic cell strip (6) is further provided with a grid line (7) electrically connected to the solder ribbon (5), the bus bar (4), the solder ribbon (5) and the grid line (7) constitute a conductive branch, and the side magnetic core (3) is arranged to excite an induced current in the conductive branch.

3. Electromagnetic welding head according to claim 2, characterized in that the coil (2) is located at the end of the center core (1) facing the bus bar (4).

4. Electromagnetic welding head according to any of the claims 1-3 characterized in that the middle magnetic core (1) and the side magnetic core (3) are plate-shaped and the middle magnetic core (1) and the side magnetic core (3) are arranged parallel to each other;

the electromagnetic welding head further comprises:

and the first top magnetic core (8) is positioned on one side of the middle magnetic core (1) and the side magnetic core (3) and fixedly connected with the middle magnetic core (1) and the side magnetic core (3).

5. Electromagnetic welding head according to claim 4 characterized in that said first top magnetic core (8) is arranged perpendicular to each other both said middle magnetic core (1) and said side magnetic core (3).

6. Electromagnetic welding head according to claim 5 characterized in that said middle magnetic core (1), said side magnetic core (3) and said first top magnetic core (8) are integrally formed.

7. Electromagnetic welding head according to any of the claims 1-3 characterized in that the middle magnetic core (1) is cylindrical and the side magnetic cores (3) are bent sheets;

the electromagnetic welding head further comprises:

and the second top magnetic core (9) is in a disc shape, is positioned on one side of the middle magnetic core (1) and the side magnetic core (3), and is fixedly connected with the middle magnetic core (1) and the side magnetic core (3).

8. Electromagnetic welding head according to claim 7 characterized in that said middle magnetic core (1), said side magnetic core (3) and said second top magnetic core (9) are integrally formed.

9. An electromagnetic welding head according to claim 1, characterized in that said side cores (3) are provided in two, two of said side cores (3) being located on opposite sides of said middle core (1), and said side cores (3) being spaced apart.

10. Electromagnetic welding head according to claim 1, characterized in that the coil (2) is a litz wire coil.