JPH063782B2 - Method for manufacturing resin-molded induction device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a resin-molded induction device used in an environment where seawater splashes such as a power transformer of a refrigerating container for marine transportation, and particularly embedded support. The present invention relates to a method for forming a mold resin layer having no metal fitting.

[Conventional technology]

Frozen containers for marine transportation have a wide range of routes from the tropical to the boreal zone, so the temperature range that electric appliances can handle is wide, and they are installed on the deck where seawater splashes. It is exposed to a harsh environment that is unthinkable on land, such as repeated exposure. Therefore, the power transformer is entirely resin-molded to block the permeation of salt water into the main body portion and to be firmly formed to withstand a thermal cycle and mechanical shock.

FIG. 4 is a partially crushed side cross-sectional view showing an example of a conventional device, and an iron core 2 covered with a cushioning coating 4 having rubber elasticity,
The transformer main body 1 including the winding 3 wound around the winding 3 and the lead wire (not shown) drawn from the winding 3 is
It is integrally cast in a thick mold insulating layer 5 such as an epoxy resin. Further, in order to fix the above-mentioned resin mold transformer to a container or a hull, a plurality of embedded support metal fittings 7 having an outer peripheral surface subjected to knurling are embedded in the mold insulating layer 5. One end of the transformer penetrates the buffer coating 4 and is fixed to the tightening plate of the iron core 2, and the other end is fixed to the mold during the casting operation of the mold insulating layer 5, so that the transformer main body 1 is set at a predetermined position in the mold. Hold it, and at the time of completion of the resin-molded transformer, mount the embedded support metal 7 on the bolt 8
The transformer is firmly fixed to the container or the hull via the support base 9 by being connected to the support base 9.

[Problems to be solved by the invention]

However, after the resin molded transformer that has been firmly formed as described above is subjected to stress such as vibration, shock, cooling / heating cycle, and seawater immersion assuming practical conditions, the insulation resistance of the winding, change in appearance, and overhaul inspection. As a result of performing a verification test such as, the mold insulating layer is peeled around the embedded support fitting 7, and the peeling progresses to cause cracks in the mold insulating layer reaching the iron core 2. Has penetrated into the transformer body 1 to cause rusting of the iron core and decrease in insulation resistance of the winding.

An object of the method of the present invention is to provide a manufacturing method capable of obtaining a resin-molded electric induction machine that withstands harsh environmental conditions by eliminating embedded support metal fittings, which are weak points of the sealing performance of the mold insulating layer.

[Means for solving problems]

In order to solve the above problems, according to the method of the present invention,
An iron core having a buffer coating and an induction-electric body mainly composed of a winding wound around the core are housed in a mold, and the tip penetrates the buffer coating and engages with the core, and the other end is detachable from the mold. It is held in place by a plurality of fixed temporary bosses, the casting resin composition is cast, the mold is released after the curing treatment, and the temporary bosses are pulled to remove the holes remaining in the mold insulating layer. The through hole portion of the buffer coating is filled with a rubber adhesive to repair the through hole of the buffer coating, and the hole portion corresponding to the mold insulating layer on the outside is filled with a room temperature curing type adhesive agent for sealing. I will.

[Action]

In the above means, when accommodating the induction body into the casting mold, rod-shaped temporary bosses detachably fixed to the mold are provided at a plurality of locations, and the tip of the rod-shaped temporary boss penetrates the buffer coating to form, for example, an iron core. By embedding the temporary boss by engaging with the recess and holding the body of the induction machine in place in the mold, and performing the steps of casting, curing, and releasing the mold insulation layer, and pulling out the temporary boss. It is possible to form a mold insulating layer that tightly adheres to and surrounds the entire body of the induction electric device without using a support metal fitting. Further, by pulling out the temporary boss, a hole reaching the iron core remains in the mold insulating layer, but the hole of the buffer coating is repaired by the sealing agent having rubber elasticity filled in this hole and further filled in the outside thereof. By repairing the holes in the mold insulation layer with a sealing layer made of putty-like room temperature curing adhesive, a mold insulation layer without localized stress concentration is formed, and vibration, shock, thermal cycling, seawater immersion, etc. It is possible to obtain a resin-molded induction electric machine having a mold insulating layer that withstands severe usage conditions.

〔Example〕

 The present invention will be described below based on examples.

FIG. 1 is a partial crush side sectional view of a resin-molded transformer manufactured according to the embodiment method of the present invention, and FIG. 2 is a sectional view showing a state where the transformer main body is housed in a casting mold. In all of these, detailed structures such as the lead wire and the lead terminal portion thereof are omitted. In the figure, an iron core 2 having a buffer coating 4
At the time of casting the mold insulating layer 5, the main body 1 of the induction electric device, which is mainly composed of the winding 3 wound around it, is first housed in the mold 21 as shown in FIG. The tip of the die 21 is engaged with the iron core 2 of the induction machine body 1 so that the induction machine body 1
A plurality of rod-shaped temporary bosses 22 for positioning and holding the mold in a predetermined position in the mold 21 are provided. In the case of FIG. 2, the temporary boss 22 is formed in a rod shape having a flange 23, and the mold 2
In order that the tip of the temporary boss 22 penetrating the hole 21A provided in the first part penetrates the buffer coating 4 and engages with the recess 2A on the iron core 2 side, the flange 23 is provided on the outer wall of the mold 21 via a gasket or the like. It is fixed airtight by the screw 24.

As described above, the whole induction housing body 1 is held in a predetermined position in the mold 21 by the temporary boss 22 and is housed in a vacuum casting tank, and a liquid casting resin composition containing an inorganic filler and the like, For example, an epoxy resin composition is cast, further transferred to a heating and curing tank to be subjected to a curing treatment, and then released from the mold, whereby a temporary boss extraction hole 11 as shown in FIG.
The mold insulating layer 5 having the is formed. Therefore, a putty-like rubber adhesive (or sealing material) such as silicone rubber, urethane rubber, or thiochol rubber is filled in the inner part of the pull-out hole 11 of the temporary boss, and the recess 2 of the iron core is filled.
A repair layer 12 having rubber elasticity is formed to fill the extraction hole of the temporary boss 22 remaining in A and the buffer coating 4. further,
The provisional boss drawing hole 11 is formed by filling the hole portion of the mold insulating layer 5 on the outside thereof with a room-temperature-curing putty-like epoxy resin adhesive (for example, trade name Araldite AV138, manufactured by Ciba) and solidifying. The sealing layer 13 is formed. Needless to say, the release agent adhering to the inner peripheral surface of the extraction hole 11 is removed when the sealing layer 13 is formed, and the adhesive surface is roughened if necessary.

As described above, in the embodiment method of the present invention, by using the temporary boss, the casting work of the mold insulating layer 5 can be performed without using the embedded supporting metal fitting in the conventional technique, and the temporary boss extraction hole can be formed. The portion corresponding to the buffer coating 4 is repaired and sealed by the repair layer 12 having rubber elasticity, and the portion corresponding to the mold insulating layer 5 is repaired and sealed by the sealing layer 13 having the same quality as the mold insulating layer. In addition, the main body 1 of the resin-molded inductor is covered with a homogeneous mold insulating layer that does not have embedded support metal fittings that are sources of weak points such as thermal stress and cracks and peeling caused by it, and is rigid. The core 2 having high strength and the mold insulating layer 5 are separated by the buffer coating 4 having the repair layer 12, and the thermal stress acting between the two is almost completely absorbed. Virtual specific resin mold type having a sealing structure induction apparatus is obtained. Therefore, as shown in FIG. 1, if the resin-molded induction machine is fixed to the support base 9 by using the tightening band 18 surrounding the mold insulating layer 5 via the vibration-proof rubber 19, it is possible to move the hull. A resin having excellent performance capable of absorbing shock of waves and waves by the anti-vibration rubber 19 and locally concentrating the acceleration applied to the induction electric device on the mold insulating layer 5, and therefore sufficiently enduring severe operating conditions. A molded induction device can be obtained.

FIG. 3 is a characteristic table showing the verification test results of the power supply transformer for the refrigerating container according to the above-mentioned embodiment in comparison with that of the conventional technique, both having a capacity of 12 KVA and a voltage of 400 V /
22V, 90kg total weight made of resin molded transformer,
After conducting vibration test and heat shock test (temperature range -30 ℃ to 100 ℃, 5 cycles) simulating practical conditions, appearance change in seawater immersion for 500 to 5000 hours, insulation between winding and support base It shows the results of resistance and overhaul inspection after 5000 hours. In the figure, in the comparative example based on the prior art, although the appearance of the resin mold layer is not abnormal, the insulation resistance rapidly decreases to 50 MΩ after 500 hours of immersion and 0 MΩ after 2000 hours.
It shows that seawater has penetrated to the winding part of the transformer body through the interface of the embedded support metal fittings.
During overhaul, it was confirmed that the iron core was corroded. On the other hand, in the embodiment, the insulation resistance is maintained at 2000 MΩ or more even after being immersed for 5000 hours, which shows that seawater does not penetrate into the winding portion.
In the overhaul inspection after a lapse of time, no abnormality was found in the mold insulating layer and the iron core, and it was proved that the mold insulating layer and the iron core have sufficient reliability to withstand a harsh environment as compared with the prior art.

〔The invention's effect〕

As described above, according to the present invention, an iron core having a cushioning coating and an induction body mainly composed of a winding wound around the core are positioned in a mold by using a temporary boss to cast a mold insulating layer and A hardening treatment was performed, and the extraction hole of the temporary boss was configured to be sealed by a repair layer of a buffer coating having rubber elasticity and a sealing layer of the same quality as the mold insulating layer. As a result, casting can be performed without using the embedded support metal fittings, and the extraction holes of the temporary boss are sealed by the buffer coating and the repair layer and sealing layer of the same quality as the mold insulating layer to form a homogeneous mold insulating layer. Since a resin-molded induction machine in which the body of the induction machine is completely embedded can be obtained, the iron core based on the cracks and delaminations that occur at the interface between the embedded support bracket and the mold insulating layer in the conventional method, and the resulting penetration of seawater. Problems such as corrosion of the wire and deterioration of winding insulation performance are almost completely eliminated,
(EN) It is possible to provide a manufacturing method by which a resin-molded induction machine having sufficient reliability against harsh environmental conditions such as a marine transportation refrigeration container can be easily obtained.

[Brief description of drawings]

FIG. 1 is a partially crushed sectional view showing a resin-molded induction machine according to an embodiment method of the present invention, and FIG. 2 is a sectional view showing a positioning state of an induction machine body in a mold according to the embodiment method. FIG. 4 is a characteristic table showing the results of verification tests of resin-molded induction electrical appliances according to the example method and the comparative example method, and FIG. 4 is a partially crushed sectional view showing the conventional structure. DESCRIPTION OF SYMBOLS 1 ... Inductor body, 2 ... Iron core, 3 ... Winding, 4 ... Buffer coating, 5 ... Mold insulating layer, 7 ... Embedded support metal fitting, 11 ...
Temporary boss drawing hole, 12 ... Repair layer (rubber adhesive), 13
... Sealing layer (room temperature curing adhesive), 21 ... Mold, 21A ...
Holes, 22 ... Temporary boss, 18 ... Tightening band, 19 ... Anti-vibration rubber, 9 ... Support base.

Claims (1)

[Claims] Claim: What is claimed is: 1. An iron core having a shock-absorbing coating and an induction electric device main body comprising a winding wound around the shock-absorbing coating are housed in a mold, the tip of which penetrates the shock-absorbing coating to engage with the iron core and the other end of which is made of metal. Mold insulating layer by holding in place with a plurality of temporary bosses that are detachably fixed to the mold, casting a casting resin composition, performing curing treatment, and then releasing the temporary boss. The through hole portion of the buffer coating of the remaining hole is filled with a rubber adhesive to repair the through hole of the buffer coating, and the room temperature curing type adhesive agent is applied to the hole portion corresponding to the outer mold insulating layer. A method for manufacturing a resin-molded induction electric device, which comprises filling and sealing a resin.