JPS6360628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for manufacturing cable connections for underwater motors.

Submersible motors are widely used to drive pumps in water treatment equipment, such as deep wells, rivers, sewage, and civil engineering work, and are mainly used by being immersed in water. Furthermore, due to its structure, the connection between the motor body and the power cable is made after the motor is assembled.

Conventionally, cable connections for underwater motors have been manufactured by winding unvulcanized rubber tape or uncured prepreg tape to the required thickness, and then curing the tape using an appropriate heating and pressurizing device. In this case, it is necessary to wrap the tape over every detail so that the internal voids are minimized, and it also needs to be wrapped around the mold, making the process extremely time consuming even for experienced workers. ing. Furthermore, even with the utmost care, voids remain between the tapes, and dielectric breakdown occurs in a short period of time in environments such as seawater, rivers, and sewage.

In the above-mentioned method of wrapping unvulcanized tape or prepreg, the adhesion at the interface between the cable and the tape portion is not good, and water penetrates into the interface due to poor adhesion, causing dielectric breakdown.

For this reason, in the conventional method, the surface of the cable is roughened by treatment such as chromium mixed acid or sanding to improve the adhesion of the connection part. However, the conventional method of processing cable connections involves many processing steps, and each step requires a relatively long time, and automation is almost impossible, and the processing is done manually. Furthermore, since the reliability of the processed connections varies widely, it takes a lot of time to insulate them more than necessary.

As a result of extensive research to overcome the above-mentioned problems, the inventors of the present invention have discovered a method for manufacturing cable connections for underwater motors that reduces work time, simplifies work, and has high reliability. I have completed my invention.

That is, the present invention involves a process of degassing a molding material made of a thermosetting resin and a curing agent that has a melting point of 40 to 130°C and is solid at room temperature by vacuum stirring, and preforming the molding material into the same shape as a mold. A process in which the preformed molded product is heated and melted using a mold preheated to 50 to 140°C, which is equipped with clamping bolts, nuts, and a temperature-adjustable rubber heater as a heat source for curing, and an underwater motor. The present invention relates to a method for producing a cable connection part for an underwater motor, which comprises the steps of placing the cable connection part in a mold, clamping the mold, and curing a molten molding material.

The mold used in the present invention is equipped with mold clamping bolts, nuts, and a temperature-adjustable rubber heater as a curing heater, and mold clamping can be sufficiently achieved with a low mold clamping force equivalent to that of an operator's manual effort. Adjustment can also be easily performed by voltage control.

The preforming molding material used in the present invention is a mixture of a thermosetting resin with a melting point of 40°C to 130°C and solid at room temperature and a curing agent. For example, an isocyanate compound is hardened to a hydrogenated polyhydroxybutadiene polymer. Examples include mixtures in which a complex salt obtained by blocking boron trifluoride with an amine is blended into an epoxy resin having two or more epoxy groups in the molecule as a curing agent.

Examples of the epoxy resin having two or more epoxy groups in the molecule, which is the main ingredient used in the present invention, include Epicote 1001 (manufactured by Ciel Chemical Co., Ltd.),
GY6071 (manufactured by Ciba Geigy) etc.
Furthermore, by blending Epicote 828, Epicote 1004, Epicote 1007, Epicote 1009 (all manufactured by Ciel Chemical Co., Ltd.), DER431, DER438 (all manufactured by Dow Chemical Company), the melting point can be increased from 40 to
Examples include those adjusted to 130℃.

Examples of the isocyanate compound as a curing agent used in the present invention include 3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanateethyl-
3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanatomethyl-3,5,5
Examples include triethylcyclohexyl isocyanate, and examples of complexes in which boron trifluoride is blocked with amines include Anchor 1170, Anchor 1171, Anchor 1040, Anchor 1115, and Anchor 1222 (all manufactured by Anchor Chemical). .

The hydrogenated product of the polyhydroxybutadiene polymer and the epoxy resin, which are the main ingredients of the molding material used in the present invention, are thermosetting resins, and the hydrogenated product of the polyhydroxybutadiene polymer, which is the main ingredient, and the isocyanate compound, which is the curing agent. The ratio of the number of moles of isocyanate groups in the curing agent to the number of moles of hydroxyl groups in the main agent is NCO/OH = 0.8 to 1.2.
The ratio of the epoxy resin as the main ingredient to the complex of boron trifluoride as a curing agent blocked with an amine is preferably such that the ratio of the curing agent is equivalent to the epoxy equivalent of the main ingredient. is preferred.

Further, if the melting point of the hydrogenated polyhydroxybutadiene polymer and epoxy resin used in the present invention is lower than 40°C, it is not preferable because the molding material tends to flow easily at room temperature and becomes sticky. Further, if the temperature is higher than 130°C, the fluidity of the molding material will be poor and the molded appearance will be poor, which is not preferable.

Next, the method of the present invention will be explained in detail based on the drawings, but the present invention is not limited thereto.

Fig. 1 is an explanatory diagram of a method of preforming a molding material, Fig. 2 is a sectional view taken along line A-A in Fig. 1,
FIG. 3 is a plan view when the mold is closed, FIG. 4 is a plan view when the mold is opened, FIG. FIG. 6 is a process explanatory diagram of the manufacturing method of the present invention.

In FIGS. 1 and 2, 1 is a molding material to be preformed, and 2 is a mold for the preform. The mold may be made of metal, plastic, or wood as long as it has excellent mold releasability. By preforming the molding material into a shape similar to that of the curing mold using the mold, it is possible to eliminate waste of molding material and the generation of voids after curing, and furthermore, the heat conduction during curing becomes uniform. .

In this example, the molding material 1 is adjusted so that the number of moles of isocyanate groups in the curing agent is equal to the number of moles of hydroxyl groups in the base resin, and the molding material is sufficiently defoamed by vacuum stirring treatment and then molded. Preformed in mold.

In FIGS. 3 and 4, 3 is the mold body;
4 is a bolt and nut for clamping the mold, and 5 is a hinge. Reference numeral 6 designates a cable support stopper to prevent the cable from shifting when it is set, 7 a curing rubber heater whose temperature can be adjusted, and 8 a lead wire of the curing rubber heater. It is preferable to use a mold made of aluminum, which is significantly lighter than conventional molds. Further, the mold is equipped with bolts and nuts for mold clamping, and mold clamping can be sufficiently achieved with a low mold clamping force input by the operator. Furthermore, the mold is equipped with a curing rubber heater, and the temperature can be easily adjusted by voltage control.

In FIG. 5, 9 is a cable line, 11 is a lead wire of the underwater motor body, and 10 is a connecting portion.

FIG. 6 is a process explanatory diagram of the manufacturing method of the present invention.

An example of the procedure of the manufacturing method of the present invention is as follows. In other words, by adjusting the voltage of the curing rubber heater, the melting point of the molding material is increased by 10 to 20 degrees Celsius, or 50 to
Preheat to 140℃. Next, with the mold open, the preformed molding material was set in the mold, and the underwater motor cable connection section to be insulated after melting was quickly set, then the mold was closed and mold clamped, and the mold was heated at 150℃ for 1 hour. By heating and curing for ~2 hours and demolding after curing, the method for manufacturing a cable connection part for an underwater motor of the present invention can be achieved.

Since the manufacturing method of the underwater motor cable connection part of the present invention is carried out by integral melting molding, highly reliable insulation treatment is possible without the occurrence of voids or poor adhesion as in the case of conventional taping work. It is possible. Furthermore, the working time can be surprisingly shortened, and workability can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a method of preforming a molding material, Fig. 2 is a sectional view taken along line A-A in Fig. 1,
FIG. 3 is a plan view when the mold is closed, FIG. 4 is a plan view when the mold is opened, FIG. FIG. 6 is a process explanatory diagram of the manufacturing method of the present invention. (Symbols in the drawing), 1: Molding material, 2: Preform mold, 3: Mold, 4: Mold clamping bolts and nuts, 5: Hinge, 6: Supporting stopper,
7: Rubber heater for curing, 8: Lead wire of rubber heater for curing, 9: Cable wire, 10: Connection part, 11: Lead wire of underwater motor.

Claims (1)

[Claims] 1. A step of defoaming a molding material made of a thermosetting resin and a curing agent that has a melting point of 40 to 130°C and is solid at room temperature by vacuum stirring, and shaping the molding material into the same shape as a mold. A step of preforming, a step of heating and melting the preformed molded product in a mold preheated to 50 to 140 degrees Celsius, equipped with clamping bolts, nuts, and a temperature-adjustable rubber heater as a heat source for curing; A method for manufacturing a cable connection part for an underwater motor, which comprises the steps of arranging the cable connection part of the underwater motor in a mold, clamping the mold, and curing the molten molding material. 2. The manufacturing method according to claim 1, wherein the molding material is a mixture of a hydrogenated polyhydroxybutadiene polymer and an isocyanate compound. 3. The manufacturing method according to claim 1, wherein the molding material is a mixture of an epoxy resin having two or more epoxy groups in the molecule and a complex of boron trifluoride blocked with an amine.