JPS6210973Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a tap lead-out device in a molded transformer.

Generally, the tap switching device of a molded transformer is the first
As shown in the figure and FIG. 2, a plurality of tap terminals 3 are arranged in a circular shape at equal intervals on a circular terminal seat 2 formed on the outer peripheral surface of the molded winding 1, and the required distance between the tap terminals 3 is It is constructed so that a desired tap voltage can be obtained by changing the connection using a tap switching piece 4. However, each of the tap terminals 3 has a tap lead 5 connected thereto and is screwed into an embedded metal fitting 6 embedded in the terminal seat 2, and when switching the tap voltage, the tap switching piece 4 is attached to the embedded metal fitting 6. Since the embedded metal fitting 6 is firmly fastened through the tap terminal 3,
There is a risk that the force transmitted each time the metal fitting 6 is tightened may cause cracks in the resin layer 7 around the embedded fitting 6, deteriorating the insulation of the molded winding 1, or the embedded fitting 6 may become loose, making it impossible to attach the tap terminal 3. It was hot. In addition, the embedded metal fittings 6 connected to the tap lead 5 must be arranged in a circle at the terminal seat 2 on the outer circumferential surface of the molded winding 1 with equal spacing from each other and molded with resin together with the bare coil of the molded winding, otherwise the tap switching will not be possible. There was a drawback that the mounting position with piece 4 was shifted, making it impossible to make a tap-switching connection. Furthermore, each time the tap is to be switched and connected, the tap terminal 3 must be removed from the embedded fitting 6, the tap switching piece 4 must be passed between the specified embedded fittings 6, and the tap terminal 3 must be tightened again. was extremely time-consuming and troublesome.

The present invention eliminates the above-mentioned drawbacks, allows the tap conductors connected to the tap leads to be pulled out from the outer peripheral surface of the molded winding without causing cracks in the resin layer, and allows these tap conductors to be separated from the molded transformer. This device is connected to a tap changer installed at a certain location, and the tap change operation can be performed quickly and easily by operating the handle.
In the figure, reference numeral 11 is formed by alternately winding a coil conductor 12 and an interlayer insulating material 13 by a predetermined number of layers, and at a predetermined number of turns midway through the winding, a tap lead 14 is pulled out onto the outer peripheral surface of the coil on an outer insulation 15. The element coil 16 is an insulator molded from thermosetting resin such as epoxy resin, and as shown in FIG.
A plurality of guide grooves 8 are protruded horizontally at regular intervals in the vertical direction, and on the back side of the mounting seat 17, a guide groove 20 is provided horizontally for each lead-out tube 18, with the through hole 19 sandwiched therebetween. It is drilled in. Reference numeral 21 denotes a tap conductor wire attached to the insulator 16 and drawn out from the lead-out tube 18. The tap conductor wire 21 is a flexible insulated wire with a core wire 22 covered with an insulator. To install, insert one end of the tap conductor into the lead-out tube 18 and insert only the core wire 22 into the lead-out tube 1.
8 to the back side of the insulator 16, as shown in FIG. The base of the tap conductor 21 is fixed to the insulator 16 by the adhesive layer 23 which is solidified by the adhesive layer 23, and the tap conductor 21 is pulled out from the lead-out tube 18. Reference numeral 24 denotes an insulating thread made of glass fiber or the like that is wound around the outer peripheral surface of the element coil 11 to fix the insulator 16 to the element coil 11. As shown in FIG. After brazing the tap leads 14, the core wire 22 is fitted into the guide groove 20 of the insulator 16, and the insulator 16 is brought into contact with the outer peripheral surface of the element coil 11 with the lead-out tubes 18 facing outward and arranged in tandem. After that, a non-woven fabric 25 such as glass fiber with good resin impregnation is attached to the outer insulation 15 on both sides of the insulator 16, and in this state, a plurality of insulating threads 24 are threaded from the insulator 16 to the outer peripheral surface of the element coil 11. Tighten the insulator 16 to the bare coil 1
It is fixed together with the nonwoven fabric 25 at a predetermined position on the outer peripheral surface of 1. Reference numeral 26 denotes a resin layer formed on the outer peripheral surface of the bare coil 11. The resin layer 26 is inserted into a mold (not shown) coated with a mold release agent on the inside, and then tapped with the lead-out cylinder 18 of the insulator 16. The conductive wire 21 is led out of the mold, and the gap between the through hole through which the lead-out tube 18 of the mold passes and the lead-out tube 18 is sealed with putty, and then the mold is placed in a vacuum drying chamber (not shown). After the vacuum is drawn, when a thermosetting resin such as epoxy resin is injected into the mold, this resin impregnates between the layers of the bare coil 11 and the entire coil (at this time, the resin is impregnated between the layers of the bare coil 11 and the entire coil
The resin impregnating the outer periphery of the tap conductor 21 tries to leak out from the lead-out tube 18 of the insulator 16 from which the tap lead wire 21 is led out, but this is prevented by the adhesive layer 23 that fixes the tap lead wire 21. However, of the guide grooves 20 provided on the back surface of the insulator 16, the resin enters the remaining half of the guide grooves 20 in which the core wire 22 is not fitted. After injecting the resin, the impregnated resin is heated and cured to form the resin layer 26 on the outer periphery of the bare coil 11.
is molded with the base of the insulator 16 (the part of the mounting seat 17) buried and the lead-out tube 18 protruding from the surface of the resin layer 26, and by providing the resin layer 26 around the outer periphery of the element coil 11, the mold winding is performed. The production of line 27 is completed. 28 connects the molded winding 27 to the iron core 2
Molded transformer installed in the leg of 9, 30
is a support stand extending from the lower core clamping fitting of the molded transformer 28 to the front of the molded transformer 28, and this support stand 30 has a movable contact that is rotationally driven by a drive shaft, and a movable contact that is rotated by a drive shaft. A tap changer 31 containing fixed contacts that are sequentially switched and connected is installed at a distance from the molded winding 27. The tap conductor 21 drawn out from the line 27 is connected. 32 is an operating handle attached to the drive shaft of the tap changer 31. 33 is a protective frame made of wire mesh or the like surrounding the molded transformer 28 and the tap changer 31 of the molded transformer 28.

The present invention has the above-described configuration, and the tap conductors 21 connected to the tap lead 14 and drawn out from the molded winding 27 are each led out from the lead-out cylinder 18 of the insulator 16, so that the tap conductors 21
Even if the tap conductor 21 is bent up and down or left and right when connecting it to the tap changer 31, the tap conductor 21 uses a flexible insulated wire;
The base of the tap conductor 21 is the lead-out tube 1 of the insulator 16.
8 and is bent, the force generated when bending the tap conductor 21 is not transmitted to the resin layer 26 of the molded winding 27 at all, and as a result, when connecting the tap conductor 21 to the tap changer 31, The resin layer 26 is not damaged at all. Further, when changing the taps, the tap voltage can be easily changed to a desired tap voltage simply by rotating the operation handle 32 of the tap changer 31 within the protective frame 33 in a non-voltage state.

In this case, an embodiment in which the insulator 16 has lead-out tubes 18 arranged in tandem has been described.
The insulator may be provided in an arc shape along the outer peripheral surface of the elementary coil 11 and have a plurality of lead-out tubes arranged horizontally, or an insulator with a plurality of lead-out tubes arranged in a circular manner may be used as the insulator for the elementary coil 11. It is also possible to use one formed in an arc shape along the outer circumferential surface.

Moreover, when molding the bare coil 11, without using a mold, the bare coil 11 is placed on a sheet-like metal material (not shown) coated with a mold release agent, and the inner and outer peripheries of the raw coil 11 are coated with the mold release agent. The coated sheet-like metal material (not shown) is wound around the insulator 16 with the lead-out tube 18 protruding, and in this state, molding resin is injected from the top surface of the raw coil to form the raw coil 11.
Of course, the sheet-like metal material may be removed after the resin impregnated therein is cured by heating, and the element coil 11 may be molded.

Furthermore, instead of using an insulated wire for the tap conductor 21, a bare conductor is used, which is connected to the tap lead and pulled out from the lead-out tube of the insulator 16.
It is also possible to use a tap conductor wire which is provided by covering the bare conducting wire portion pulled out from the tap with an insulating tube, fitting one side of the insulating tube into the lead-out tube 18, and fixing it integrally with the lead-out tube 18 with resin.

As mentioned above, the present invention has a lead-out tube for leading out the tap conductor protruding from the front surface, and a guide groove is provided on the back side of the lead-out tube across the through-hole of the lead-out tube. Insert one end into the lead-out tube, pull out the tap conductor to the back side of the insulator, fix the tap conductor and the insulator with the same resin as the molding resin, and then connect the tap conductor to the tap lead led out to the outer peripheral surface of the bare coil. The insulator is tied and fixed to the outer circumferential surface of the bare coil with insulating thread, and in this state, the outer circumferential surface of the bare coil is covered with resin, except for the insulator lead-out tube and the tap conductor wire led out from this lead-out tube. Since a molded winding is formed by molding, and a tap conductor led out from the molded winding is connected to a tap changer provided close to the molded winding, the following effects are obtained.

The present invention has a plurality of tap conductor lead-out tubes protruding from the front surface, and an insulator with horizontal guide grooves on both sides of the through hole for each lead-out tube on the back surface, and the tap conductor wire is molded and wound. When connecting this tap conductor to the tap changer, the force generated when it is bent vertically, horizontally, or accidentally pulled toward the front is absorbed by the tap conductor. It is not transmitted at all to the resin layer in the vicinity, that is, in the vicinity of the connection part with the tap lead on the outer periphery of the element coil. By embedding the mounting seat part of the insulator in the outer periphery of the bare coil, this insulator itself plays the role of reinforcing the tap conductor and the resin layer, and the mechanical strength of this part can be maintained. Even if an external force is applied to the tap conductor, the resin layer will not be damaged at all.

In addition, the base end of the tap conductor drawn out from the lead-out tube of the insulator is integrally bonded to the insulator with resin, so it cannot be pulled out from the insulator when the tap conductor is connected to the tap changer. Connection work can be done quickly and easily.

Furthermore, the insulator is provided with guide grooves in the lateral direction on both sides of the through-hole for each lead-out pipe on the back surface opposite to the protruding direction of the lead-out pipe from which the tap conductor is drawn out, so that multiple wires can be drawn out. The base ends of the tap conductors can be fitted and fixed in their respective predetermined positions, and
Casting resin is injected into the guide groove on the opposite side where the base end of the tap conductor is not fitted, and the resin solidifies, so the insulator is used in the empty space of the guide groove where the tap conductor is not fitted. By doing so, the mechanical strength can be increased and fixed with a large contact area to the resin layer around the outer periphery of the elementary coil.

In addition, since the above insulator has a simple structure with a lead-out tube on the front surface and a guide groove on the back surface,
It has excellent mass productivity and can be manufactured economically.

In addition, the tap conductors are connected to a tap changer attached to the molded transformer, and when changing taps, it is only necessary to operate the tap changer, so the connection of the tap changer piece can be changed as in the conventional method. At this time, there is no possibility that excessive force is applied to the embedded metal fitting, causing cracks or the like in the resin layer and deteriorating the insulation of the molded winding.

As explained above, in the present invention, it is only necessary to connect the flexible tap conductor drawn out from the molded winding to the tap changer, and the base of the tap conductor is buried in the outer periphery of the molded winding. The insulator prevents the wire from coming off, and it is constructed to strengthen the mechanical strength of the base of the tap conductor, so even if external force is applied when connecting the tap conductor, the resin layer on the surface of the molded winding will not crack. It has many excellent effects in practical use, such as completely eliminating the occurrence of.

[Brief explanation of the drawing]

Fig. 1 is a front view of a molded transformer equipped with a conventional tap changer, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 shows the usage state of the molded transformer equipped with the device of the present invention. 4 is a side view, FIG. 4 is a perspective view of the molded winding, FIG. 5 is a perspective view showing the molded winding in the middle of production, FIG. 6 is a plan view showing the main parts of the device according to the present invention, and FIG. 7 is a perspective view of the molded winding. FIG. 3 is a perspective view of an insulator. 11: Bare coil, 14: Tapered lead, 16:
Insulator, 18: Lead-out tube, 21: Tap conductor, 2
6: Resin layer, 27: Mold winding, 31: Tap changer.

Claims (1)

[Scope of utility model registration request] The required number of tap leads 1 are placed around the outer circumference of the bare coil 11.
4, and a lead-out tube 18 that leads out the tap conductor 21 connected to the tap lead 14 is attached to the mounting seat 1.
Multiple protrusions are provided on the surface of 7 at regular intervals,
On the back surface of the mounting seat 17, the tap conductor 21 is connected to the insulator 16, which has guide grooves 20 formed laterally on both sides of the through hole 19 for each lead-out pipe 18.
A part of the tap conductor 21 leading out to the back side of the insulator 16 is inserted into the guide groove 20.
The above insulator 16 fitted into and fixed with resin,
The element coil 11 is connected to the outer periphery of the element coil 11 at right angles to the winding direction of the coil conductor 12 and bound by an insulating thread 24, and the tap lead 14 is connected to the tap conductor 21 drawn out from the guide groove 20 of the insulator 16. A molded winding 27 is formed by resin molding with casting resin so that the lead-out tube 18 of the insulator 16 protrudes from the surface of the resin layer 26, and the tap conductor 21 pulled out from the lead-out tube 18 is inserted into the molded winding 27. A tap conductor drawing device for a molded transformer, which is connected to a tap changer 31 provided in close proximity to the tap changer 31.