JPH03283510A - Transformer for welder - Google Patents

Abstract

PURPOSE:To make a reduced-size and light-weight transformer by making a primary coil from many pieces of insulated conductors, by holding a coil unit by a base material and by setting the base material on a substrate on which a plurality of circuits are formed for making a primary- or secondary-side coil. CONSTITUTION:To make a primary-side coil for a welder transformer, all that has to be done is to wind an insulated conductor around a base material 10 which has a ramp and to mount this winding on a board 30. The welder transformer can be simply structured since coil units 39a-39d are electrically connected on the substrate 30. It has a large surface area since a plurality of conductors are used for the primary coil. It also has a capability to cope with a large current. In other words, a large welding current is allowed to flow without yielding a skin effect since a conductor surface area is increase for the welding current.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welding transformer, and more specifically, for example, a high-frequency welding transformer used in an inverter-type resistance welding machine. The present invention relates to a welding transformer that can be made smaller and lighter.

[Prior Art] Conventionally, for example, welding robots that perform resistance welding have been frequently used on automobile production lines.

In this case, resistance welding is used because it is necessary to supply a large current to the object to be welded.

The welding machine for this welding robot first converts direct current into high-frequency alternating current, supplies this high-frequency alternating current to a welding transformer to step down the voltage, and then converts it to direct current again using a rectifier to feed the welding gun arm. Inverter-type DC resistance welding equipment is used. The reason for converting to high-frequency alternating current is to make the welding transformer relatively small and lightweight by utilizing the fact that the cross-sectional area of the transformer core that constitutes the welding transformer is inversely proportional to the frequency of the high-frequency alternating current.

This type of welding transformer is disclosed, for example, in Japanese Patent Laid-Open No. 180683/1983 filed by the present applicant. This welding transformer is composed of a single-layer coil wound with many turns, a transformer core, and a one-turn secondary coil.

[Problems to be Solved by the Invention] The present invention has been made in connection with such technology, and by focusing on the skin effect that occurs when high-frequency alternating current is applied, further miniaturization and weight reduction can be achieved. The purpose of this invention is to provide a welding transformer that can be used for welding.

[Means for Solving the Problems] In order to solve the above problems, the welding transformer of the present invention includes a coil unit around which a plurality of conductive wires are wound, and a support that holds the coil unit in a wound state. and a substrate to which ends of the windings of the coil units extending from the support body are fixed, the substrate having a circuit for interconnecting the windings of the plurality of coil units, A primary side coil or a secondary side coil is formed by arranging a plurality of coil units configured as shown in FIG. Features.

[Function] According to the present invention, by constructing the single-layer coil of the welding transformer with a large number of insulated conductive wires, compared to the conventional case in which the secondary coil was constructed with a single rectangular conductive wire, The surface area of this secondary coil is significantly increased, so that the overall cross-sectional area of the conductor can be made relatively small. Therefore, it is possible to flow a large amount of current while avoiding the occurrence of the skin effect, and it is also possible to suppress heat generation.

Moreover, in the present invention, the coil unit composed of the conductive wire is held by a support body, and by simply fitting this support body to a board on which a plurality of circuits are formed, the It can be the next coil. Therefore, the structure itself can be simplified, it can be manufactured at a low location, and maintenance management can also be facilitated.

[Example] Next, examples of the welding transformer according to the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2, reference numeral 1O indicates a support body, and the support body 10 has a first flange portion 12a.
a plate body 14a and a second plate body 14b having a flange portion 12b, the first plate body 14a and the second plate body 14b.
and are separated by a predetermined distance by bridge members 16a and 16b. A hole 18 having a rectangular cross section is defined between the first plate 14a and the second plate 14b. That is,
This hole 18 is substantially defined by a rectangular cylinder 20 having a rectangular cross section, and the rectangular cylinder 20 is substantially formed by the bridge member 1.
Together with 6a and 16b, the first plate 14a1 and the second plate 14
b are separated by a predetermined distance, and the first plate body 14a1 and the second plate body 14b are firmly held. Note that the first plate body 14a
and the second plate body 14b are the first plate body 14a and the second plate body 14b.
Inclined plates 22a to 22e are provided which are inclined at a predetermined angle with respect to the extending direction of the plate body 14b. Note that the first plate 1
4a, six holes 24 are bored along the extending direction of the flange portion 12a, and six holes 26 are similarly provided in the second plate 14b.

In the above configuration, the insulated conductive wire 28 is first inserted through the hole 24 and wound between the inclined plates 22a to 22e, and the end thereof is led out from the hole 26, and this is repeated six times. By doing this, a shape wound in six layers is obtained. Therefore, as can be easily understood from FIG. 2, the coil unit 39a is divided into six pieces and has five turns. This coil unit) 39a is then connected to the substrate 3.
Inserted into 0. That is, the flange portions 12a, 12b
is attached to the substrate 30 via an adhesive or the like, and
The conductive wire 28 on the hole 24 side is inserted into the hole 32a bored in the substrate 30. The conductive wire 28 on the hole 26 side is inserted into a hole 32b bored in the substrate 30.

Similarly, coil units 39b, 39c, and 39d are fixed to the holes drilled in the substrate 30.

Next, the back surface of the substrate 30 on which the coil units 39a to 39d are mounted will be explained.

That is, on the back surface of the substrate 30, in the figure, four terminals 31a to 31d are formed on the upper side, and four terminals 35a to 35d are formed on the lower side. As can be understood from the figure, terminal 31a and terminal 35b are connected by a conductor, and terminal 3
The same applies to terminal 1b and terminal 35C1 and terminal 31C and terminal 35d. The terminal 31d and the terminal 35a are electrically connected to an inverter section to be described later.

As shown in FIG. 4, the cores 40 and 42 are mounted on the substrate to which the coil units 39a to 39d are fixed in this way using the holes 18.

Then, the coil unit configuring this -order coil) 39
A conductor having a rectangular cross section constituting a secondary coil is engaged with a to 39d. That is, the conductor 52 having a rectangular cross section and electrically connected to the main surface of the first diode 50 held by the plate 48 extends horizontally toward the substrate 30 side, and after passing through the space of the core 40 . , - is bent and directed downward, and is further bent and extends back toward the first diode 50 side. Then, the end portion extends parallel to the substrate 30, rises upward again, and further extends parallel to the substrate 30.

Furthermore, after extending toward the substrate 30 and descending again, it contacts a hexagonal plate 56 that contacts the second diode 54 . In this case, a bolt is inserted between the plate 56 and the plate 48 to firmly sandwich the first diode 50 and the second diode 54. Note that the center tap 58 is raised at the middle portion of the conductor 52.

Next, as explained in the longitudinal cross-sectional view of FIG. 7, the transformer can be effectively cooled by forming a hole 59 in the conductor 52 in advance and allowing cooling water to flow through the hole 59.

FIG. 8 shows the circuit configuration of the transformer constructed as described above. Reference numeral 60 is a control circuit. For example, a three-phase AC 400V power source is connected to this control circuit 60, and after obtaining DC in this control circuit 60, the inverter section 6
2 to obtain a square wave, then a predetermined direct current is taken out from the secondary side and supplied to the welding gun 64.

As described above, according to this embodiment, the single-layer coil of the welding transformer is formed by simply winding the insulated conductive wire around the support 10 on which the inclined plate is formed and then attaching it to the substrate 30. . That is, since it is possible to electrically connect each coil unit (39a to 39d) to the board 30, the configuration is simple, and since a plurality of conductive wires are used as the coil side, the surface area is large. A welding transformer that can handle a large amount of current can be obtained. In other words, the surface area of the conductor through which welding current flows is increased, and a large welding current can be passed without producing a skin effect.

Next, another embodiment of the present invention is shown in FIG. 9 and FIG. 1O. In this embodiment, the same reference numerals as in the previous embodiment indicate the same components, and the same applies hereinafter.

In this embodiment, the insulated conductor 70 is simply wound around the support 10 without using any inclined plate. With this configuration, further coil units) 39a to 39d
The configuration can be simplified.

Still another embodiment of the present invention is shown in FIG. 11 and FIG. 12. In this embodiment, coil units) 39a to 3
Five holes 72 are bored in the bridge member 16a of 9d, and holes (not shown) are similarly bored in the bridge member 16b. Insulating plates 80a to 80d are provided on the rectangular tube body 20 at equal intervals from each other.

Therefore, the first conductor 90a is connected to the first plate 14a and the insulating plate 8.
0a and inserted into the hole 100a of the substrate 30, and the other end of the conductor 90a is inserted into the hole 100b bored in the lower side of the substrate 30.

Hereinafter, the conductors 90b to 90e are similarly connected to the holes 1ooa and 1
Holes 102a to 108a, 102b adjacent to 00b
108b (hereinafter referred to as coil unit) 39b
The same applies to 39d to 39d. Note that the back side of the substrate 30 is
The wiring is substantially similar to the circuit diagram shown in FIG. 3. In this embodiment as well, the same effects as in the previous embodiment can be obtained.

[Effects of the Invention] As described above, according to the present invention, a part of the coil of the welding transformer is divided and made up of insulated conductive wires.

Furthermore, the structure is such that the coil unit including the support body can be easily attached to the substrate. For this reason, for example, in the conventional technology, compared to the case where the secondary coil is composed of a single rectangular conductor wire, the surface area of the multiple conductor wires becomes significantly larger as a whole, which causes the skin effect. It is possible to avoid the inconvenience that current flows only near the conductor surface.

That is, it becomes possible to efficiently flow current through the conductor as a whole. Moreover, by simply inserting and fixing the coil unit configured as described above to the board, a well-balanced single-layer coil can be obtained, allowing stable operation during welding. I can do it.

Moreover, since the structure is simple, failures are rare, and not only can it be manufactured at a low cost, but even if it breaks down, parts can be easily replaced. Therefore,
Not only can it be made smaller as a welding transformer, but it can also be extremely lightweight.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted perspective explanatory view showing the relationship between the coil unit and the substrate that constitute the welding transformer according to the present invention, Fig. 2 is a vertical cross-sectional explanatory view of the coil unit shown in Fig. 1, and Fig. 3 is the substrate. 4 is a perspective explanatory view when assembling a welding transformer consisting of a partial coil and a secondary coil with the coil unit attached to the board, and FIG. 5 is a wiring diagram on the back side of the 4 is a plan view of the welding transformer shown in FIG. 4, FIG. 6 is a front view of the welding transformer shown in FIGS. 4 and 5, FIG. 7 is a sectional view taken along line A-A in FIG. 5, and FIG. An electric circuit diagram of a welding transformer according to the present invention; FIG. 9 is a partially omitted perspective explanatory diagram of another embodiment of the present invention; FIG. 1O is a longitudinal sectional view of the coil unit shown in FIG. 9; 12 is a partially omitted perspective explanatory view of a coil unit constituting a welding transformer according to still another embodiment of the present invention, and FIG. 12 is a longitudinal sectional view of the coil unit shown in FIG. 11. 10...Support bodies 14a, 14b...=Plate bodies 16a, 16b...Bridge member 20...Square cylinder bodies 22a to 22e...Slanted plate 30...Substrates 39a to 39d...Coil unit 50. 54...Diode 60...Control circuit 62...Inverter part 64...Welding gun 70...Insulated conductor 6b

Claims (1)

[Claims] (1) A coil unit around which a plurality of conductive wires are wound, a support body that holds the coil unit in a wound state, and an end portion of the winding of the coil unit extending from the support body are fixed. The board has a circuit for interconnecting the windings of a plurality of coil units, and a plurality of coil units configured as described above are arranged on the board to form a primary side or a secondary side. A welding transformer, characterized in that a coil is formed, and a core member and a secondary coil or a primary coil are brought close to the coil unit.