Casting method of low-voltage straight-through current transformer secondary coil

Abstract

The invention discloses a casting method of a low-voltage straight-through current transformer secondary coil, which casts the secondary coil twice and comprises the following steps of: putting the secondary coil and an insert into a mould cavity of a primary casting mould and carrying out primary casting; removing the primary casting mould and obtaining the secondary coil and the insert which are cast together, namely a semi-finished product; then putting the semi-finished product into a secondary casting mould, fixing the secondary coil in the mould cavity of the secondary casting mould by utilizing the insert, thus ensuring a safety wall thickness between the surface of the secondary coil and the inner wall of the mould cavity of the secondary casting mould to carry out secondary casting; and removing the secondary casting mould, and obtaining a finished product of the straight-through current transformer. The casting method facilitates the casting production, the package of the product is not exposed, and the transformer has big capacity.

Description

technical field [0001] The invention relates to the technical field of current transformers, and relates to a casting method for a secondary coil of a low-voltage through-core current transformer. Background technique [0002] In the processing and molding of current transformers with low-voltage through-cores (generally annular cores) in the prior art, the secondary coil 20 (such as figure 1 Shown) there are two pouring methods for hoisting in the mold: one is to bind the secondary coil 20 on the support 10, and then fix the support 10 bound with the secondary coil 20 in the mold cavity of the mold (such as figure 2 As shown), pouring is carried out to make a through-core current transformer; the other is to tie several cloth tapes directly on the secondary coil 20, and hang the secondary coil 20 in the cavity of the mold with the help of cloth tapes for casting , Made into a feedthrough current transformer. [0003] Regardless of the above-mentioned casting methods, the...

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Problems solved by technology

[0003] Regardless of the above-mentioned casting methods, there are defects that the secondary coil 20 is difficult to hoist and unstable, and the secondary coil 20 is prone to offset in the mold cavity, resulting in uneven wall thickness after casting, and even after demoulding. Therefore, in order to avoid the uneven wall thickness and the occurrence of exposed pockets, the design size of each part of the secondary coil 20 is usually reduced so that there is a large enough gap between the secondary coil 20 and the inner wall of the mold cavity. distance, to ensure that the secondary coil 20 is completely covered, so that the surface of the secondary coil 20 has a safe wall thickness, but such a small secondary coil 20 results in a small transformer capacity

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