JPS584805B2 - Contact attachment device for tap changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a contact mounting device for a tap changer.

For example, one example of an on-load tap changer in a transformer is a column made of insulating material disposed in the center and having a fixed slit spring, and concentrically held by flanges at the upper and lower parts. It has an outer circular array of many rods made of hard paper laminate.

A fixed contact is attached to each rod.

Further, the fixed contact and the slip ring can be strongly contacted and connected by an elastically supported movable contact, and this contact is attached to a holding device consisting of a rotatable insulating rod and moves on a circular orbit. It is configured to rotate.

Therefore, when the movable contact contacts the next fixed contact during switching, a strong mechanical load is applied to it, so careful consideration of the material is required in order to attach the fixed contact to a support made of hard paper laminate. Installation work required large costs.

Furthermore, when a connecting conductor leading to the transformer winding is connected to this stationary contact using a clamping screw, a large mechanical load acts on the device for attaching this contact to the support.

Conventionally, when fixing a contact to a support made of a hard paper laminate, a tightening screw that is screwed into a hole provided in the lamination direction of the hard paper has been used.

However, it has been experimentally known that the thermal expansion and contraction of hard paper laminates is much more pronounced in the direction of lamination than in the direction in which the layers run, and especially at temperatures above about 110°C, thermal expansion in this direction is caused by an increase in temperature. It has been confirmed that the number of people living in Japan increases at an even more significant rate.

Therefore, with conventional screw fastening means, after heating and subsequent shrinkage, the threaded connection will break and the installation will be inadequate.

This becomes especially noticeable when the device is treated in a vacuum drying oven at 120-130 DEG C. in order to remove moisture from the hard paper laminate in order to achieve guaranteed insulation values in the tap changer.

The purpose of this invention is to provide a simple method for fixing contacts to a support made of a hard paper laminate in a manner that is safe against thermal expansion and contraction of the hard paper and does not loosen even after being exposed to high temperatures during the necessary drying operation. It provides the means.

That is, according to the present invention, the fixing element for attaching the contact to the support made of the hard paper laminate is formed in the form of a rod-shaped body and elastic in the radial direction with respect to its axis,
The fixing element is press-fitted into the support and the contact so that the fixation element is in pressure contact with each other, and the axial direction of the fixation element is arranged in the stacking direction of the support.

Suitable elastic rods are, for example, notched tubular bodies or notched solid rods, which are pressed against the hard paper laminate and the contact by the radial force of their spring properties.

If its setting is good, the bonding force of this element will therefore not loosen during and after expansion and contraction due to thermal effects, and thus the contact remains firmly fixed to the support.

And it is because the expansion in the stacking direction caused by the heat load in the hard paper laminate acts on the fixing element, but the action of fixing the contact to its support is due to the spring action of the fixing element in the radial direction, i.e. the layer of the hard paper laminate. This is because it is the direction in which the

That is, since the direction of force is in the direction of lamination of the hard paper laminate and there is no threaded portion, no loosening of the joint occurs.

In carrying out this invention, in order to cope with the large force acting on the contact and its fixing element, the fixing element is deeply plunged from the back side of the contact to the front, and the fixing element is placed on the back side of the contact and the support. It is good to support additionally.

As such an additional support structure, it is preferable to provide a hollow part on the back surface of the contact and provide a support plate that fits into the hole in the rear wall, and to insert the fixing element into the support plate and support it.

Note that in order to prevent branch current from flowing through the fixing element and this support plate, this support plate is preferably made of an insulating material.

If the contact is mounted with a single fixing element, at least one side of the contact must be pressed against the side of the support that is not in the stacking direction, so that the contact cannot rotate around the fixing element. is necessary.

In this case, by appropriately deviating the hole in the contact for the fixing element and the hole in the support, when the fixing element is press-fitted through both, one surface of the contact comes into pressure contact with the support. The contact is well secured and prevented from pivoting by the radial forces and additional pressure exerted by the fixing element.

In addition, when attaching a contact to a support with a small cross section, do not provide a hole for the fixing element in the center of the support, but provide semi-cylindrical holes in each side of the support opposite the contact. I can do it.

When the fixing element is press-fitted into this hole, a good connection between the contact and the support is achieved in this part by means of radial force, and furthermore, another part of the contact is formed on the support on the side opposite to the press-fitted part. It can be configured such that the surfaces are pressed together.

In this case, a groove is provided on the opposite surface of the support body and a surface of the contactor facing thereto, and a groove is inserted into the groove to additionally hold the contactor and prevent its rotation. It is better to do so.

Note that when metal flanges are attached above and below this support, the same means as described above can be employed at the attachment portion between the support and the metal flange.

The invention will now be explained in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a contact, which is fixed to a support 2 made of a hard paper laminate by means of a fixing element 3 (the above-mentioned cylindrical body or rod-shaped body).

Further, the holes in the support body 2 for press-fitting the fixing elements 3 are provided in the stacking direction of the hard papers as shown.

The fixing element 3 presses and connects the support 2 and the contact 1 in the radial direction due to its spring property.

In order to further prevent the contact 1 from pivoting about the axis of the fixing element 3, the contact 1 is brought into contact with the support 2 at its longitudinally extending surface 4, as shown in FIG. ing.

Then, by press-fitting the fixing element 3 into the contact 1,
The support 2 is simultaneously pressed against the surface 4.

Note that a hollow portion is provided on the back side of the contactor 1, and a support plate 5 is mounted so as to fit into the hole in the rear wall and the fixing element 3.

Additional support and fixation on the back side of the contact 1 is thereby achieved.

Note that 6 is a tapped hole for attaching a connecting conductor to the transformer winding.

In the embodiment of FIG. 3, the support 2 is inserted into the groove of the contact 1.

At this time, by slightly deviating the hole of the contact 1 for press-fitting the fixing element 3 and the hole of the support body 2, the fixing element 3
When the contactor 10 is compressed, the surface 4 of the contactor 10 is brought into pressure contact with the support body, and rotation of the contactor is prevented.

Note that this figure shows the state in which the connecting conductor to the transformer winding is attached.

4 and 5 show an embodiment in which the contact 1 and the support 2 are each provided with a semi-cylindrical fixing element mounting hole.

When the fixing element 3, which in this case is formed as a tubular body with a cut, is pressed into the hole, its radial pressing force not only firmly connects the contact 1 with the support 2, but also at the same time The opposing member 4 on the opposite side is also pressed against the support.

In this case, rotation of the contact can be effectively prevented by providing opposing grooves in the facing surface 4 and the support body and inserting the wedge 7 into the groove to additionally support the contact.

In the embodiment according to FIG. 6, the carrier 2 is inserted into a deep groove of the contact and the contact 1 is fixed to the carrier 2 by two fastening elements 3.

Therefore, there is no need to specially provide the above-mentioned connection surface on the contact in order to prevent rotation of the contact.

[Brief explanation of drawings]

Fig. 1 is a side view showing one σ embodiment of the device of the present invention, Fig. 2 is a sectional view taken along the line A-B, Fig. 3 is a vertical sectional side view showing another embodiment, and Fig. 4 is a side view showing one σ embodiment of the device of the present invention. FIG. 5 is a side view showing another embodiment, FIG. 5 is a sectional view taken along line A-B, and FIG. 6 is a longitudinal sectional side view showing still another embodiment. In each figure, the same reference numerals are given to parts having the same function. In Figures 1 and 2, 1 is a contact, 2 is its support, 3 is a fixing element, 4 is a pressure contact surface of the contact to the support, 5 is a support plate, and 6 is a screw for attaching a connecting conductor. be.

Claims (1)

[Scope of Claims] 1. A fixing element for attaching a contact to a support made of a hard paper laminate is formed in the form of a rod and has elasticity in the radial direction with respect to its axis, and this fixing element 1. A contact mounting device for a tap changer, characterized in that the fixing element is press-fitted into a support and a contact so as to be in pressure contact with each other, and the axial direction of the fixing element is arranged in the stacking direction of the support. 2. A contact mounting device in a tag changer, characterized in that the fixing element is formed as a notched tubular body or a notched solid rod-like body. 3. In the device according to claim 1 or 2, the connection between the contact and the support is effected by press-fitting the fixing element due to its radial force, and the radial force of the fixing element is A contact attachment device for a tap changer, characterized in that a fixing element is disposed at a position where the other surface of the contact is pressed against one side of the support book by force. 4. A contact mounting device in a tap changer, characterized in that the device according to claim 3 is provided with a wedge that spans the surface of the contact to be pressed and one side of the support. .