JPH0543459Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fixed contact device for a tap selector used in an on-load tap switching device.

[Conventional technology]

Conventionally, a transformer is equipped with an on-load tap switching device for maintaining the supply voltage at a required voltage in response to frequently changing amounts of power. As shown in the figure, there is a switching switch S that cuts off the load current and generates an arc between movable and fixed contacts, and an adjustment winding connected in series to the main winding T of the transformer via a polarity switching switch Sa. A tap selector Sb that selects the tap to be switched in advance in a no-voltage state among the taps T ₁ , T _{2 .} . . of the line Ta, and an operating device (not shown) that operates the switching switch S and the tap selector Sb. The tap selector is provided such that a movable contact sequentially contacts a plurality of fixed contacts connected to the tap winding to selectively switch the tap.

As the fixed contact to which the lead wire from the tap winding is connected, for example, the one shown in FIG. 6 is used. That is, in FIG.
1 is an insulating plate, and a fixed contact 3 in the shape of a round bar with a collar piece 2 is provided through the insulating plate 1, and a nut 4 is attached to the opposite side of the fixed contact 3 across the insulating plate 1. , the fixed contact 3 was fixed to the insulating plate 1. When fixing the fixed contact 3,
Shield rings 5 and 6 are inserted between the collar piece 2 and the insulating plate 1, and between the nut 4 and the insulating plate 1, respectively, to relieve the electric field around the fixed contact 3. Further, one end of the fixed contact 3 is formed into a flat plate shape, and a connecting terminal 7 for a lead wire is attached to the end part 8, which is drawn out from the tap winding of the transformer, and the other end part 8 is formed into a round bar shape, and a connecting terminal 7 for a lead wire is attached thereto. , movable contacts 9 and 10 are provided below so as to be able to slide toward and away from each other.

Moreover, FIGS. 7 and 8 show other mounting examples of the fixed contact 3, in which the fixed contact 3 is sandwiched between two insulating cylinders 11 and 12, and in this state, the two insulating cylinders are 11 and 12 sandwich the fixed contact 3 from above and below, and attach the four tightening fittings 13 to the tightening screws 14.
The fixed contact 3 was installed by tightening with.

[The problem that the idea aims to solve]

In the above-mentioned mounting structure of the fixed contact 3, the former requires a threaded part for screwing the collar piece 2 and the nut 4 onto the fixed contact 3 itself, and when mounting, the nut 4 is tightened and fixed. The contact point 3 is fixed, and the latter is also connected to two insulating tubes 11, 1 like the former.
Since the fixed contact 3 was held between the two and fixed by tightening the clamping metal 13, many parts such as the nut 4 and the clamping metal 13 were required to install the fixed contact 3. Therefore, there were problems in that the installation required time and effort, and the mounting structure of the fixed contact 3 became complicated due to the increase in the number of parts.

In addition, since the fixed contact 3 uses parts with many sharp parts such as the collar piece 2, nut 3, and fastening metal fitting 13, shield rings 4 and 5 are used to alleviate the electric field surrounding the fixed contact 3. However, if the shield rings 4 and 5 are not installed, the surrounding electric field will be biased, and there is a risk of creepage failure of the insulating plate 1 surface due to abnormal voltage. was absolutely necessary in order to protect the insulating plate 1. However, for example, the sixth
As shown in the figure, if shield rings 5 and 6 are used to shield the sharp parts of the mounting parts, the mounting interval of the fixed contacts 3 will inevitably become large, and the tap selector using this type of fixed contacts 3 will become large. shape,
The increase in the number of parts together with the problem of increasing the manufacturing cost of the tap selector has arisen.

In view of the above-mentioned problems, the present invention simply configures the mounting part of the fixed contact with an insulator, thereby increasing the dielectric strength and mechanical strength, and quickly and reliably attaching the fixed contact with almost one operation. An object of the present invention is to provide a fixed contact device for a tap selector that can be attached.

[Means to solve the problem]

In this invention, an insulating mounting part is integrally molded with synthetic resin on the outer circumference near the axial center of a hollow cylindrical fixed contact, and when molding this insulating mounting part, the fixed contact When mounted on an insulating plate, there is a large-diameter flange that prevents the fixed contact from moving in one axial direction, a mounting body that fits into the mounting hole of the insulating plate, and a mounting body that fits into the mounting hole of the insulating plate. A locking protrusion on the periphery that engages with a locking groove provided in the mounting hole of the insulating plate to prevent rotation of the mounting body, and a C-shaped edge protruding from the insulating plate of the mounting body. A fixed contact device is constructed by integrally molding a fitting groove into which a retaining ring is fitted.

[Effect]

When a fixed contact is installed, the flange of the insulating mounting part provided on the outer periphery of the central part of the fixed contact is positioned on the movable contact side, and the mounting body of the insulating mounting part is inserted into the mounting hole of the insulating plate. and the protruding edge of the mounting body that protrudes from the end face of the insulator after the locking protrusion provided on the mounting body is engaged with the locking groove recessed in the mounting hole of the insulating plate. The fixed contact is attached to the insulating plate by attaching a C-shaped retaining ring to the fitting groove formed in the insulating plate with one end in contact with the end face of the insulating plate. Movement of the insulating plate in the axial direction is restricted by the flange of the insulating mounting part and the C-shaped retaining ring fitted in the fitting groove, and the locking protrusion on the mounting body restricts the movement of the insulating plate in the axial direction. Since rotation with respect to the mounting hole can be restricted, the fixed contact of the present invention can be mounted to the insulating plate in one action, and its removal prevention and fixing are C-shaped. The use of a retaining ring ensures reliability, and since the resin insulating mounting part is formed to protrude from the surface of the insulating plate, there is no need for a shield ring to alleviate the surrounding electric field. The present invention is characterized by improving dielectric strength and mechanical strength with a small number of parts, and also by allowing the installation work to be performed in almost one operation.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

In FIG. 2, reference numeral 20 denotes an insulating plate for mounting a fixed contact device 22, which will be described later, which has a circular mounting hole 21 opened therein. A locking groove 23 is integrally formed orthogonally to each other. Reference numeral 24 denotes a hollow cylindrical fixed contact that serves as the current-carrying part of the fixed contact device 22, and an insulator on its outer periphery that fixes and supports the fixed contact 24 on the insulating plate 20, as shown in FIGS. 1 and 2. Mounting part 2
5 is made of a thermosetting resin such as epoxy resin, leaving the current-carrying parts at both ends of the fixed contact 24.
4 and is formed by integral molding.

Next, the detailed structure of the insulating mounting portion 25 will be explained with reference to FIG.

In FIG. 1, 26 is a flange edge formed at the end of the insulating mounting part 25 with a diameter larger than the mounting hole 21 of the insulating plate 20, leaving the current-carrying part 24a at one end of the fixed contact 24, and 27 is the flange edge. At the front part of the section 26 (on the left side in FIG. 1), a hole is formed that is integral with the flange part 26 and has the same diameter as the mounting hole 21 of the insulating plate 20, and the length of the body matches the thickness of the insulating plate 20. The mounting body 27 has a locking protrusion 2 on its circumferential edge that engages with a locking groove 23 provided in the mounting hole 21 along the axial direction.
8 is formed integrally with the mounting body 27.
29 is a fitting groove recessed in the front side of the mounting body 27 formed to have the same length as the thickness of the insulating plate 20 and has a smaller diameter than the mounting body 27; 30 is a fitting groove in front of the fitting groove 29; The insulating part is formed to have approximately the same diameter as the mounting body part 27, and the current-carrying part 24b on the other end side of the fixed contact 24 protrudes from the end face of the insulating part.

The insulating mounting portion 25 is connected to the flange portion 2.
6, mounting body 27, locking protrusion 28, fitting groove 29,
The current-carrying portions 24 at both ends are provided on the outer periphery of the fixed contact 24 so that the insulating portion 30 can be integrally formed.
With a and 24b exposed to the outside, resin molding is performed using a mold (not shown).

31 is the bottom of the fitting groove 29 of the insulating mounting portion 25;
It is a C-shaped retaining ring that is fitted and engaged across the plate surface of the insulating plate 20, and the small diameter portion a that is engaged on the fitting groove 29 side is approximately the same diameter as the fitting groove 29, Insulating plate 2
The large diameter portion b that locks on the 0 side is slightly larger in diameter than the diameter of the mounting hole 21, and is molded into a truncated conical shape using polyacetal resin or the like having excellent heat resistance and elasticity.

In FIG. 1, 32 is an insulating part 30 of the insulating mounting part 25.
The other current-carrying part 24b of the fixed contact 24 protrudes from the
A through hole 33 for insulating oil, etc., is a connection terminal screwed onto the current-carrying portion 24b so as not to close the through hole 32, and is used to connect a lead 34 drawn out from a tap winding of a transformer (not shown). 35 is a fixed contact 24 protruding from the flange portion 26 of the insulating mounting portion 25
These are a pair of movable contacts that slide toward and away from one current-carrying portion 24a from above and below.

Next, the case of assembling the fixed contact device 22 will be explained.

When assembling the fixed contact device 22, the other current-carrying part 24b of the fixed contact 24 is directed toward the mounting hole 21 side of the insulating plate 20, and the locking groove 23 provided in the mounting hole 21 is connected to the fixed contact 24 side. Align the locking protrusions 28 formed on the mounting body 26 of the insulating mounting portion 25 to the same position, and insert the fixed contact 24 into the mounting hole 2 of the insulating plate 20.
Insert into 1. Then, the mounting body 27 of the insulated mounting part 25, which is molded except for the current-carrying parts 24a and 24b at both ends of the outer periphery of the fixed contact 24, fits into the mounting hole 21, and at the same time, the locking protrusion 28 locks. Groove 2
3. In this state, when the fixed contact 24 is further pushed to a position where the edge of the flange 26 comes into contact with the plate surface of the insulating plate 20, the engagement provided on the mounting body 27 of the insulating mounting part 25 of the fixed contact 24 With the locking protrusion 28 engaged with the locking groove 23 of the mounting hole 21 of the insulating plate 20, the mounting body 27 is fitted and held in the mounting hole 21. After the fixed contact 24 is fitted and held on the insulating plate 20 via the insulating mounting portion 25 as described above, the fitting groove of the insulating mounting portion 25 that protrudes toward the other current-carrying portion 24b side of the fixed contact 24 is inserted. As shown in FIG. 1, when the C-shaped retaining ring 31 is expanded and fitted into the fitting groove 29 with its small diameter portion a side positioned in the fitting groove 29, as shown in FIG. Due to its own elastic force, the retaining ring 31 has a small diameter portion a that fits into the fitting groove 29, and a large diameter portion b that is in contact with the plate surface of the insulating plate 20 on the outside of the mounting hole 21. Thus, the insulating mounting portion 25 is engaged and held.

As described above, when the fixed contact 24 is attached to the mounting hole 21 of the insulating plate 20 via the insulating mounting part 25 formed by resin molding on the outer periphery, the fixed contact 24 is attached to the edge of the flange part 26. The movement in the axial direction is restricted by the retaining ring 31 fitted in the fitting groove 29, and the locking protrusion 28 provided on the mounting body 27 is locked in the locking groove 23 of the mounting hole 21. By matching, it becomes possible to restrict movement in the circumferential direction. As a result, just by fitting the fixed contact 24 into the mounting hole 21 of the insulating plate 20 via the insulating mounting part 25 and fitting and engaging the retaining ring 31 into the fitting groove 29 of the insulating mounting part 25, as in the conventional case, To quickly, easily, and reliably attach an insulating plate 20 to an insulating plate 20 without using tightening parts such as nuts or tightening fittings, and without pulling out or rotating in a state close to one movement. Can be done. Further, the portion of the fixed contact 24 that protrudes from the mounting hole 21 of the insulating plate 20 is a current-carrying portion 24a,
With the exception of 24b, the metal parts are covered by the flange 26 of the insulating mounting part 25 and the insulating part 39, so the surrounding electric field can be alleviated to make it difficult to discharge without providing a special shield ring. Therefore, when a plurality of fixed contacts 24 are mounted on the insulating plate 20, even if the fixed contacts 24 are mounted close to each other to some extent, a sufficient insulation distance can be ensured by the insulating mounting portion 25. Therefore, creeping damage to the insulating plate 20 can be prevented, and the tap selector itself can be made smaller.

In addition, in order to prevent the fixed contact 24 from coming off the insulating plate 20, the present invention uses a flange 26 provided on one side of the insulating mounting part 25 and a retaining ring 31 that is fitted and engaged in the fitting groove 29. Although the embodiment described above has been described, instead of providing the flange portion 26, the mounting hole 2 of the insulating plate 20 is
A retaining ring 31 is attached to the insulating mounting portion 25 protruding from both sides of the
The present invention can also be achieved by engaging the fixed contact 24 with the insulating plate 20 to prevent the fixed contact 24 from coming off the insulating plate 20.

Further, although the present invention has been described with reference to an embodiment in which the fixed contact 24 is formed of a hollow conductor, the present invention is not limited to this, and a conductive round bar may also be used. The present invention can also be achieved even if a flattened material is used.

[Effect of idea]

Since the present invention is configured as described above, the following effects can be obtained.

(1) An insulating mounting part is integrally formed on the outer periphery of the fixed contact by resin molding, and using this insulating mounting part, the fixed contact is inserted into the mounting hole of the insulating plate and protrudes from the mounting hole of the insulating plate. C on the insulation mounting part
Since the shaped retaining ring is configured to be locked between the insulating plate, it is not possible to secure the fixed contact to the insulating plate using a tightening part such as a nut, tightening screw, or clamping fitting as in the conventional method. Compared to the case where the fixed contact is mounted, no fastening parts are required, so it can be done in almost a single operation.The fixed contact can be mounted quickly and easily without reducing mechanical strength by using a retaining ring. This can be done easily and reliably.

(2) Also, since the insulating mounting part is integrally formed on the outer periphery of the fixed contact with molded resin, it can be used in the same way as the shield ring described above, without using a shield ring to alleviate the surrounding electric field as in the past. It is possible to prevent disturbances in the electric field, and the presence of the insulated mounting part also makes it possible to reduce the insulation distance from other fixed contacts, making it possible to downsize the entire tap selector. .

(3) Furthermore, when installing fixed contacts, there is no need to use tightening parts such as nuts or shield rings for electric field mitigation, which is required in the past, so the number of parts can be reduced, and the installation work can be reduced. Coupled with the fact that this can be performed in almost one operation, the tap selector can be manufactured economically with a simple structure, and the manufacturing cost of the tap selector can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the main part showing the fixed contact device of the present invention, Fig. 2 is a perspective view showing the attachment relationship between the fixed contact device and the insulating plate, and Fig. 3 is taken along the line A-A in Fig. 1. 4 is a front view of the insulating plate, FIG. 5 is a connection diagram for explaining tap switching, FIG. 6 is a vertical sectional view of the main part showing a conventional fixed contact device, and FIG. 7 is a conventional contact A vertical sectional view of main parts showing another embodiment of the device,
FIG. 8 is a view taken along the X arrow in FIG. 20... Insulating plate, 21... Mounting hole, 22... Fixed contact device, 23... Locking groove, 24... Fixed contact, 25... Insulating mounting portion, 26... Flange edge, 27
... Mounting body, 29 ... Fitting groove, 31 ... Retaining ring.

Claims (1)

[Scope of utility model registration request] An insulating mounting part is integrally formed with the fixed contact using resin on the outer circumference of the fixed contact except for the current-carrying parts located at both axial ends of the fixed contact, and the insulating mounting part is inserted into the mounting hole of the insulating plate. A fixed contact, characterized in that a retaining ring for preventing the fixed contact from slipping out is engaged between the insulating mounting portion that is inserted through the insulating plate and protrudes from the mounting hole of the insulating plate, and the plate surface of the insulating plate. Device.