JPS59117080A - Molding step automating controller of crosslinked polyethylene insulated cable connector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device used when forming a connection part of a crosslinked polyethylene insulated cable (hereinafter referred to as CV cable) by molding a polyolefin insulator in a mold and crosslinking it by heating.

Molded joints using polyolefin insulators for CV cables are used for ultra-high voltage lines of 154 KV or higher. Molded joints can be made by wrapping the connection part in layers with polyolefin insulating tape containing a cross-linking agent, extrusion molding of polyolefin containing a cross-linking agent, attaching integral or split blocks made of such materials, or laminated wrapping of molded sheets made of such materials, etc. It is formed by providing a polyolefin insulator containing a crosslinking agent, crosslinking it by heating, and then molding it. When manufacturing mold joints, it is desirable to automate the heating, pressurizing, and cooling processes of materials. Furthermore, in ultra-high voltage Cv cables, the insulator thickness at the joint is large, and the conductor size is also large (for example, the cross-sectional area of the conductor is about 200,018 m2 or 300,0711 m2), so when heating the bridge, heat dissipation through the conductor is significantly lower than the cross-linking temperature. It becomes difficult to raise the insulator temperature to For this reason, it is necessary to effectively raise the temperature near the conductor connecting pipe of the joint and to control this so that the mold of the polyolefin insulator forms a constant pattern.

An object of the present invention is to provide a mold control device that can effectively raise the temperature of the insulator when molding a joint using a polyolefin insulator, and also allows the molding to be performed automatically and uniformly. be.

The purpose of this is to have a cable auxiliary heating device and a mold heating device used for molding, the latter being made into blocks as the center and end portions, and heating with constant pressure applied between the mold and the entire insulator inside the mold. The central block of the device is activated to heat the end portion to the crosslinking temperature and this state is maintained for a predetermined period of time, and after this time has elapsed, the end block is activated to heat the end portion to the crosslinking temperature and the end portion heating is continued for a predetermined period of time. , the cable auxiliary heating device is operated after a predetermined period of time after heating by the end block, and after the completion of cross-linking, the connection part insulator is cooled while maintaining the above-mentioned pressurized state, and the cable is heated after a predetermined time after completion of cross-linking. This is achieved by a mold process automation control device configured to stop the operation of the auxiliary heating device.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram of the automation control device of the present invention, and FIG.
The figure shows a part of the operation pattern.

In FIG. 1, the connecting portion of the cable 7 is constructed of a polyolefin insulator 5 as in the prior art, and this is placed in a mold 3. The mold 3 may be a split mold, and has a mold center heating device 1 and a mold end heating device 2, and is provided with a pressure detector 1o and a temperature detector 12 inside as in the conventional case. Furthermore, a pressurizing hole 11 and other detectors are provided. An automation control device 8 according to the present invention is connected to the mold 3. The automation control device 8 mainly includes an auxiliary heating control device 18 that is a high-frequency induction heating power source, a pressure control device 19, and a main body heating control device 20.

The auxiliary heating control device 18 connects the CV cable 7 at both ends of the mold 3.
Although it is used in connection with the auxiliary heating device 4 which is a pipe-shaped high frequency coil for auxiliary heating, an electric heater, an infrared heater, etc. may be used depending on the case. The auxiliary heating control device 18 includes a temperature sensor 13 for the cable end.
It receives temperature condition information from a temperature control device 31 connected to the temperature sensor 14 for the high-frequency coil 4, and has a heating time control device 32 having a timer to maintain the temperature for a predetermined time when a predetermined temperature is reached. are doing.

The automation control device 8 furthermore has a device 34 for detecting the insulation thickness of the connections in the mold 3.

The pressure control device 19 may be provided with a pressure alarm device 38 that gives an alarm in case of abnormal pressure.

A further coil cooling control device 33 is provided to supply refrigerant to the high frequency coil 4 after completion of crosslinking.

The main body heating control device 2o is a heating time control device that has a temperature control device 35 that operates in conjunction with a temperature sensor 12 that measures the end temperature and center temperature of the mold 3, and a timer that controls the heating time of each part. 37, and may further include an alarm device 36 for giving a warning in the event of an abnormal operation.

The main operations of the automation control device 8 of the present invention configured as described above will be described below with reference to FIG.

FIG. 2 is an explanatory diagram of the operation, with time on the horizontal axis and temperature and pressure on the vertical axis.

First, time 1. ), the pressure control device 19 pressurizes the inside of the mold 3 through the pressure hole 11, and the pressure sensor 10 indicates that the mold internal pressure reached a predetermined pressure P at time 11.
When detected, the pressure is maintained for a predetermined period of time by operating a suitable timer.

After the pressure P is achieved, at time t2, the main body heating device 2° is activated, and the central heating device 1 is energized by the heating time control device 37 to bring the temperature of the center of the mold to a predetermined value T, and the polyethylene is crosslinked. Keep it for as long as you need. The temperature at the center and both ends of the mold is sent to the temperature control device 35 by the sensor 12 and constantly monitored to maintain a predetermined value.

When the central part monitor indicates that the central part temperature T has been achieved, the mold end heating device 2 is activated at time t3 to heat the mold to the same temperature T, and the temperature is maintained at the end of the central part temperature maintenance time. Try to maintain the same.

During the time required for this crosslinking, when the temperature of the entire mold rises to a predetermined value and the cable temperature rises by a predetermined temperature, this is detected by the cable temperature sensor 13, and the auxiliary heating control device 18 detects this at the time t4. The heating time control device 32 operates to raise the temperature by the cable auxiliary heating device 4 to a predetermined temperature 1=lower than the mold temperature,
At the same time as this predetermined temperature is achieved, the timer of the heating time control device 32 is activated to continue heating at the diameter where the mold temperature has sufficiently decreased. The temperature of the auxiliary heating device 4 is monitored by a sensor 14 and adapted to maintain it at a constant temperature. In order to cool the auxiliary heating device 4, which is a high-frequency coil, the coil cooling control device 33 allows gas such as air or nitrogen gas, or liquid such as water or silicone oil to pass through the coil.

Cooling of the mold body starts when the heating of the mold body is stopped by the timer end 15 of the heating/time control device 37 of the main body heating/cooling device 20, but in this case, cooling of the mold is started by using an appropriate means if necessary. Cooling may also be performed. The operation of the auxiliary heating device ends at time t6 when the temperature of the mold falls to a predetermined temperature.

Then, after the mold temperature and the pull end temperature have been cooled down to a predetermined value, the operation of the pressurization control device 19 is canceled to terminate the molding.

Note that the insulator thickness sensor 9 disposed inside the mold measures the thickness of the insulator before raising the temperature to the crosslinking temperature when the mold is completely filled with the connection insulator. This is to prevent eccentricity of the insulation thickness.

According to the control device of the present invention configured and operated in this manner, it is possible to automate the heat molding of the molded connection part using the polyolefin insulator of the cross-linked polyethylene insulated vinyl sheath cable in a fixed pattern, thereby eliminating variations in product quality. disappears.

In the device of the present invention, the mold is heated from the center to the ends, so cable deformation due to expansion of the insulator due to heating is avoided.
Since the pressure can be monitored by a pressure sensor, deformation can be prevented by providing an appropriate expansion pressure absorber.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the control device of the present invention, and FIG. 2 is a diagram illustrating a part of the operation of the device shown in FIG. 1 Mold central heating device, 2 Mold end heating device, 3 Mold, 4 Cable auxiliary heating device (high frequency coil), 5
Connection insulator, 7-CV cable, 8 Automation control device, 9 Insulation thickness sensor, '1° pressure detection sensor, 11
Pressure hole, 12, 13゜14 Temperature sensor, 18/Auxiliary heating control device, 19 Pressure control device, 20 Main unit heating device, 31゜35 Temperature control device, 32.37 Heating/
Time control device, 33 Coil cooling control device, 36.38
Alarm device. 387

Claims (1)

[Claims] A cable auxiliary heating device, a mold center heating device, a mold end heating device, a mold pressure control device that keeps the inside of the mold at a predetermined pressure for a certain period of time, and a specified mold pressure control device. After the pressurization is achieved, the mold center heating device is activated to maintain the mold center at a constant temperature necessary for crosslinking the polyolefin for a predetermined period of time, and after the mold center reaches the constant temperature, the mold is heated. a main body heating control device for operating an end heating device to maintain the end of the mold at the constant temperature at the end of the predetermined time period; An auxiliary heating control device for operating a heating device to keep the end of the cable at a temperature lower than the above-mentioned constant temperature for a predetermined period of time that ends after the above-mentioned end time, and automation of the molding process of a connection part of a cross-linked polyethylene insulated cable. Control device.