JPH0660439B2 - Electrodeposition insulation method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrodeposition insulating method using an electrophoretic method. More specifically, the present invention relates to an electrodeposition insulation method in which the electrodeposition liquid is jetted from a nozzle of a jet pipe to a place where electrodeposition by the electrophoresis method is difficult due to the electrode position and the flow direction of the electrodeposition liquid.

[Prior Art] Conventional electrodeposition insulation method (Japanese Patent Laid-Open No. 53-921298,
JP-A-51-39178 and JP-A-51-114602) is a method in which an electrodeposition solution circulates in the electrodeposition tank. For example, for those having a relatively small electric conductor diameter, the inorganic powder is separated by electrophoresis. It was electrodeposited parallel to and uniformly on the surface of the electrical conductor.

FIG. 2 is a sectional view of a conventional electrodeposition insulating device. (1)
Is an electrodeposition tank, (8) is a partition plate, (2) is an electrodeposition tank nozzle provided on the partition plate (8), (3a) is an electrodeposition liquid circulation pump,
(3b) is an electrodeposition liquid circulation auxiliary pump, (4) is an electrodeposition liquid,
(5) is an electric conductor, (6) is a direct current power source, and the inner electrodeposition tank (9) and the outer electrodeposition tank (10) are divided by partition plates (8) in the electrodeposition tank (1). Is provided, and the inner electrodeposition tank (9) and the outer electrodeposition tank (10) are connected by the electrodeposition tank nozzle (2). The arrow indicates the circulation direction of the electrodeposition liquid.

[Problems to be Solved by the Invention] However, as the diameter of the electric conductor becomes larger and the area to be electrodeposited becomes wider, the inorganic powder is less likely to be electrodeposited. Therefore, it is preferable to use the inorganic powder and the water-dispersed varnish on the surface of the electric conductor. It was not possible to electrodeposit with a proper mixing ratio. This is because the inorganic powders that make up the electrodeposition liquid and the water-dispersion varnish have different specific gravities, so the inorganic powders flow in the electrodeposition tank while precipitating, and therefore the inorganic powders on the flat surface below the electrical conductors. Is hard to be electrodeposited,
It was difficult to deposit a uniform electrodeposition insulating layer.

The present invention has been made to solve such problems, and an object thereof is to obtain an electrodeposition insulating method capable of forming a uniform film.

[Means for Solving Problems] The present invention uses a conventional method in which an apparatus for circulating an electrodeposition liquid in an electrodeposition tank and a jet pipe are used in combination.

[Operation] In the present invention, if the electrodeposition liquid is jetted by the jet pipe above and below the flat surface portion or the curved surface portion having a large area, it is possible to prevent sedimentation and further accumulation of the inorganic powder. According to the present invention, it is possible to deposit parallel and uniform electrodeposition insulating layers with a suitable compounding ratio regardless of the shape and size of the electrodeposited body.

[Examples] Details will be described below with reference to Examples.

Example 1 Water dispersion type varnish (manufactured by Ryoden Kasei Co., Ltd., trade name: Sai 68)
43-1) 15 parts by weight and 85 parts by weight of soft mica flakes (those of 35 mesh sieve pass, manufactured by Okabe Mica Co., Ltd.) were used as the electrodeposition liquid solid content, and the solid content was 10% and ion-exchanged water (5 ×
90% (10 ⁵ Ω / cm) is used as an electrodeposition liquid. FIG. 1 shows a sectional view of an electrodeposition insulation device according to an embodiment of the present invention. An inner electrodeposition tank (9) and an outer electrodeposition tank (10) are provided by partitioning with a partition plate (8) in the electrodeposition tank (1). The tank (10) is in communication with the tank (2) provided on the partition plate (8) and the jet pipe (7). The electrodeposition liquid (4) is circulated by the circulation pumps (3a) and (3b) in the electrodeposition tank (1), and further the circulation pump (3c) is used, for example, a nozzle of a jet pipe (7) made of a hollow metal. The electrodeposition liquid (4) is jetted toward the curved surface of the electric conductor (5) provided in the inner electrodeposition tank (9) to perform electrodeposition (DC 80V, 75 sec application), and the mica content is 85%. An electrodeposition insulating layer having a varnish content of 15% and a film thickness of 500 μm was formed.

The maximum distance between the electrodeposition tank (1) and the electric conductor (5) during electrodeposition was 300 mm, and the minimum distance was 100 mm. The closest distance between the jet pipe (7) and the electric conductor (5) is 15
It was mm. Further, the discharge rate of the electrodeposition liquid (4) from the nozzle of the jet pipe (7) was 0.5 / min. The discharge rate is preferably 0.1 / min to 10 / min.

The jet pipe (7) has the same electric potential as the electrodeposition tank (1) or supplies an electric charge equivalent to that of the electric conductor (5).

Example 2 15 parts by weight of an alumina (Al ₂ O ₃ ) powder having a particle size of 5 μm and 85 parts by weight of a varnish were used as an electrodeposition liquid solid content in an inorganic powder,
The composition of the electrodeposition liquid was 10% of the solid content and 90% of ion-exchanged water, and electrodeposition (DC 80V 75se) was performed on the electric conductor.
c) Then, an electrodeposition insulating layer having an alumina content of 15%, a varnish content of 85% and a film thickness of 500 μm was formed.

Comparative Example 1 Using the same electrodeposition liquid as in Example 1, the field coil (320 ^l × 60 w) of the electric motor was used in the electrodeposition apparatus (conventional method) shown in FIG.
Electrodeposited (DC 80V) on × 30h ring-shaped electric conductor
After 75 seconds), there was no uniformity (uniformity of 100 μm to 500 μm) in the film thickness of the flat surface portion, and no electrodeposition coating was formed on the curved surface portion inside the conductor. Furthermore, electrodeposition could not be carried out on the curved surface portion, the corner portion, etc. with a suitable mixing ratio of the electrodeposition liquid.

In the table, the examples of the present invention and the conventional examples are compared mainly in terms of film thickness.

The film thickness was measured at points (A) to (D) in the front view of the electrodeposited insulation test coil shown in FIG.

From the table, according to the embodiment of the present invention, from the electrodeposition liquid containing the inorganic powder, parallel to the electric conductor at a ratio close to the liquid composition,
It is also clear that a uniform film thickness can be obtained.

[Effects of the Invention] As described above, according to the present invention, an aqueous dispersion containing an inorganic powder and a water-dispersed varnish is used as an electrodeposition solution, and an electrodeposition layer is formed on an electric conductor surface to a desired film thickness by electrophoresis. In order to achieve electrodeposition, a jet pipe is provided, the above electrodeposition liquid is jetted from the device onto the surface of the electric conductor, and an insulating layer is formed by electrodeposition by the electrophoretic method to obtain a uniform film. You can

[Brief description of drawings]

FIG. 1 is a sectional view of an electrodeposition insulation device according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional electrodeposition insulation device, and FIG. 3 is a front view of a test coil insulated by electrodeposition. In the figure, (1) is an electrodeposition tank, (2) is an electrodeposition tank nozzle,
(5) is an electric conductor, (7) is a jet pipe, (8) is a partition plate, (9) is an inner electrodeposition tank, and (10) is an outer electrodeposition tank. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] 1. An electrodeposition insulation in which an aqueous dispersion containing an inorganic powder and a water-dispersed varnish is used as an electrodeposition solution, and an electrodeposition layer is electro-deposited to a desired film thickness on an electric conductor surface by an electrophoresis method. The method uses an electrodeposition tank in which an inner electrodeposition tank and an outer electrodeposition tank formed by partitioning with a partition plate are connected through a nozzle and a jet pipe provided on the partition plate. An electrodeposition insulation method characterized in that the electrodeposition liquid in the deposition tank is jetted toward an electric conductor provided in the inner electrodeposition tank through a jet pipe. 2. The jet pipe according to claim 1, wherein the jet pipe is made of a hollow metal, a nozzle is provided at an arbitrary position of the jet pipe, and the electrodeposition liquid is jetted from the nozzle at an appropriate speed. Electrodeposition insulation method. 3. The electrodeposition insulation method according to claim 1, wherein the discharge amount of the electrodeposition liquid jetted from the nozzle of the jet pipe is 0.1 / min to 10 / min. 4. The electrodeposition insulation method according to any one of claims 1 to 3, wherein the jet pipe has the same electric potential as that of the electrodeposition tank, or an electric charge is supplied to the electric conductor.