Vacuum infusion and curing control system for epoxy resin insulation

Abstract

The utility model requests protecting a kind of vacuum infusion and solidification control system of epoxy resin insulating part, it includes three-phase power supply L1, L2, L3 and zero line N, three-phase power supply is connected to system through total circuit breaker QF;System includes vacuum pump control circuit, infusion metering pump control circuit, solidification furnace control circuit and sequence control circuit;Vacuum pump control circuit includes contactor KM1, thermal relay FR1 and transport motor M1;Infusion metering pump control circuit includes contactor KM2, thermal relay FR2 and metering pump M2;Solidification control circuit includes contactor KM3, thermal relay FR3 and solidification furnace.The mould of the application is before and after the time of injecting the mixed liquid of epoxy resin and curing agent, carries out a vacuumizing action, to better remove the air in mould, greatly reduce the bubble in insulating part, and second vacuumizing is carried out simultaneously when solidifying, accelerates circulation period.

Description

Technical Field

[0001] This utility model relates to the field of power distribution cabinet technology, specifically to a vacuum injection and curing control system for epoxy resin insulating components. Background Technology

[0002] Vacuum potting and curing of epoxy resin insulators (such as pot insulators, bushings, and instrument transformers in power equipment) is a core process to ensure their high performance and long-term reliability. This is a systematic and precise engineering process, and any mistake in any step may lead to internal defects in the product (such as bubbles, cracks, and delamination), thereby causing insulation failure. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention proposes a vacuum injection and curing control system for epoxy resin insulation components. By performing vacuuming before and after injection, defects such as bubbles or oxidation inside the insulation components are avoided, and production efficiency is greatly improved.

[0004] The technical solution of this utility model is as follows: A vacuum infusion and curing control system for epoxy resin insulation components includes a three-phase power supply L1, L2, L3 and a neutral line N, with the three-phase power supply connected to the system via a main circuit breaker QF. The system includes a vacuum pump control circuit, an infusion metering pump control circuit, a curing oven control circuit, and a sequence control circuit. The vacuum pump control circuit includes a contactor KM1, a thermal relay FR1, and a vacuum pump M1. The infusion metering pump control circuit includes a contactor KM2, a thermal relay FR2, and a metering pump M2. The curing control circuit includes a contactor KM3, a thermal relay FR3, and a curing oven H. The sequence control circuit includes a starting unit, a vacuum unit, an infusion unit, and a curing unit. The vacuum unit controls the vacuum pump M1 to evacuate the mold. The infusion unit controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold. The curing unit controls the curing oven H to start and cure the mixture inside the mold.

[0005] The present invention is further configured such that: the starting unit includes an energized switch SB1, a starting switch SB2, and a relay KA; the energized switch SB1 is used to energize the system; the starting switch SB2 is connected to the relay KA; when the starting switch SB2 is pressed, the relay KA is energized, and its auxiliary contacts 1-2, 3-4, 5-6, and 7-8 are all closed; when the auxiliary contact 1-2 is closed, the relay KA is self-locked, ensuring that the relay KA remains energized.

[0006] The present invention is further configured such that: the vacuum unit includes a time relay KT1, when the contacts 3-4 of the relay KA are closed, the coil of the time relay KT1 is energized and starts timing, and at the same time the contactor KM1 is energized and operates to control the vacuum pump M1 to evacuate the mold.

[0007] The present invention is further configured such that: the injection unit includes a time relay KT2; when the normally open contacts 13-14 of the time relay KT1 are closed, the coil of the time relay KT2 is energized and starts timing, and at the same time the contactor KM2 is energized and controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold.

[0008] The present invention is further configured such that: the curing unit includes a time relay KT3, a time relay KT4, a contactor KM3, and a curing oven H; when the normally open contacts 25-26 of the time relay KT2 are closed, the coils of the time relays KT3 and KT4 are energized and start timing, and at the same time the contactor KM3 is energized and closed, so that the curing oven H can cure the mixture in the mold.

[0009] In summary, the above technical solution has the following beneficial effects: This utility model automatically executes the processes of pouring, vacuuming, and curing. Each batch of products only needs to be started once before the system can automatically execute the steps according to the process, improving the automation and safety reliability of the system. The mold in this application undergoes a vacuuming operation before and after the injection of the epoxy resin and curing agent mixture, thereby better removing air from the mold and greatly reducing air bubbles inside the insulating parts. Furthermore, the second vacuuming is performed simultaneously during curing, accelerating the cycle time. Attached Figure Description

[0010] Figure 1 This is a circuit diagram of a vacuum potting and curing control system for epoxy resin insulation components. Detailed Implementation

[0011] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0012] like Figure 1As shown, a vacuum infusion and curing control system for epoxy resin insulation components includes a three-phase power supply L1, L2, L3 and a neutral line N, with the three-phase power supply connected to the system via a main circuit breaker QF. The system includes a vacuum pump control circuit, an infusion metering pump control circuit, a curing oven control circuit, and a sequence control circuit. The vacuum pump control circuit includes a contactor KM1, a thermal relay FR1, and a vacuum pump M1. The infusion metering pump control circuit includes a contactor KM2, a thermal relay FR2, and a metering pump M2. The curing control circuit includes a contactor KM3, a thermal relay FR3, and a curing oven H. The sequence control circuit includes a starting unit, a vacuum unit, an infusion unit, and a curing unit. The vacuum unit controls the vacuum pump M1 to evacuate the mold. The infusion unit controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold. The curing unit controls the curing oven H to start and cure the mixture inside the mold.

[0013] The main circuit includes a vacuum pump M1, a metering pump M2, and a curing oven H. The vacuum system requires a sealed mold. The mold cavity is connected to the vacuum pump M1, which evacuates the mold to a high vacuum, typically 100 Pa (0.1 kPa) below atmospheric pressure or even lower. Epoxy resin and curing agent are usually a two-component system, such as anhydride-cured epoxy resin. Both components need to be preheated and vacuum-degassed separately in individual, heatable tanks. The high-precision metering pump M2 delivers the two components to a dynamic mixing head or static mixer in a precise ratio (e.g., epoxy resin 100: curing agent 30) for thorough mixing. While maintaining a high vacuum in the mold cavity, the mixed resin is injected from the bottom of the mold through a pipeline. Utilizing the pressure difference between the metering pump M2 and the inside and outside of the mold, the resin is smoothly and slowly "drawn" into the mold, filling it from bottom to top, effectively guiding air bubbles upwards and preventing air from being trapped in turbulence. The main circuit is also equipped with thermal relays FR1, FR2 and FR3, which are connected in series with vacuum pump M1, metering pump M2 and curing oven H respectively, to monitor the operating current and automatically disconnect the circuit when the equipment is overloaded to protect the equipment from damage.

[0014] The starting unit includes a power switch SB1, a start switch SB2, and a relay KA. The power switch SB1 is used to power the system. The start switch SB2 is connected to the relay KA. When the start switch SB2 is pressed, the relay KA is energized, and its auxiliary contacts 1-2, 3-4, 5-6, and 7-8 are all closed. When the auxiliary contact 1-2 is closed, the relay KA is self-locked, ensuring that the relay KA remains energized.

[0015] The vacuum unit includes a time relay KT1. When contacts 3-4 of the relay KA are closed, the coil of the time relay KT1 is energized and starts timing. At the same time, the contactor KM1 is energized and controls the vacuum pump M1 to evacuate the mold.

[0016] The time relay KT1 includes normally closed contacts 11-12 and normally open contacts 13-14. When the time relay KT1's delay ends, its normally open contact 13-14 closes, initiating the subsequent process; its normally closed contact 11-12 opens, controlling the vacuum pump M1 to stop evacuating. The specific delay time of the time relay KT1 is related to the vacuum pump's flow rate and the mold volume. It requires the mold to reach a vacuum state, such as below 100 Pa of atmospheric pressure. The subsequent process is only initiated after the first vacuum evacuation is completed and stabilized.

[0017] The injection unit includes a time relay KT2; when the normally open contacts 13-14 of the time relay KT1 are closed, the coil of the time relay KT2 is energized and starts timing, and at the same time the contactor KM2 is energized and controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold.

[0018] The time relay KT2 includes normally closed contacts 21-22, normally open contacts 23-24, and normally open contacts 25-26. When the time relay KT2 finishes its delay, its normally closed contact 21-22 opens, controlling the metering pump M2 to stop injecting the mixture. Its normally open contact 23-24 closes, energizing the contactor KM1 again, controlling the vacuum pump M1 to evacuate the mold. Its normally open contact 25-26 closes, starting the subsequent process.

[0019] After the infusion is completed, the mixture needs to be vacuumed a second time to maintain pressure. Continue to maintain the vacuum for a period of time. Before the resin reaches the initial gel point, close the valve, such as for 30-60 minutes, so that the trace gases dissolved in the resin and the tiny bubbles generated during the infusion process have enough time to rise to the surface and break, and to prevent excessive vacuuming from causing the resin to "boil over".

[0020] The curing unit includes time relay KT3, time relay KT4, contactor KM3, and curing oven H. When the normally open contacts 25-26 of time relay KT2 are closed, the coils of time relays KT3 and KT4 are energized and start timing. At the same time, contactor KM3 is energized and closed, allowing the curing oven H to cure the mixture in the mold.

[0021] Time relay KT3 includes normally closed contacts 31-32, and time relay KT4 includes normally closed contacts 41-42. When the delay of time relay KT3 ends, the normally closed contacts 31-32 of time relay KT3 open, controlling vacuum pump M1 to stop evacuating; the normally closed contacts 41-42 of time relay KT4 open, controlling contactor KA to de-energize, and the entire control circuit to de-energize, completing a complete vacuum infusion and curing cycle of epoxy resin insulation.

[0022] The delay time of time relay KT3 is 30-60 minutes, which serves to maintain pressure and close the valve before the resin reaches its initial gel point. The delay time of time relay KT4 is the running time of the curing oven, and its duration is longer. Because curing requires a longer time, the second vacuuming and curing can be performed simultaneously, greatly reducing the cycle time.

[0023] Curing is the process by which epoxy resin forms a three-dimensional network structure through chemical reactions, achieving its final mechanical and electrical properties. This is a multi-step heating and staged holding process, with temperature control achieved by the curing oven. It generally includes: a low-temperature curing stage (e.g., 80-90℃, held for several hours): allowing the resin to flow fully at low viscosity, completing final wetting, and initiating a gentle initial cross-linking reaction. A main curing stage (e.g., 110-130℃, held for 10-20 hours): in this stage, most of the cross-linking reaction is completed, achieving a high degree of curing. This is the critical stage determining the product's glass transition temperature (Tg) and mechanical strength. A post-curing stage (e.g., 10-20℃ above Tg, held for several hours): the purpose is to further react unreacted groups, maximizing the degree of curing, eliminating internal stress, and stabilizing the microstructure, thereby significantly improving the product's thermal stability, aging resistance, and dimensional stability.

[0024] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. A vacuum infusion and curing control system for epoxy resin insulation components, characterized in that, It includes three-phase power supply L1, L2, L3 and neutral line N, and the three-phase power supply is connected to the system through the main circuit breaker QF; the system includes a vacuum pump control circuit, a filling metering pump control circuit, a curing oven control circuit and a sequence control circuit; The vacuum pump control circuit includes a contactor KM1, a thermal relay FR1, and a vacuum pump M1. The injection metering pump control circuit includes contactor KM2, thermal relay FR2 and metering pump M2; The curing oven control circuit includes contactor KM3, thermal relay FR3, and curing oven H; The sequential control loop includes a start-up unit, a vacuum unit, a filling unit, and a curing unit. The vacuum unit controls the vacuum pump M1 to evacuate the mold; the filling unit controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold; and the curing unit controls the curing oven H to start and cure the mixture in the mold.

2. The epoxy resin insulation vacuum infusion and curing control system according to claim 1, characterized in that: The starting unit includes a power switch SB1, a start switch SB2, and a relay KA; the power switch SB1 is used to power the system; the start switch SB2 is connected to the relay KA; when the start switch SB2 is pressed, the relay KA is energized, and its auxiliary contacts 1-2, 3-4, 5-6, and 7-8 are all closed; when the auxiliary contact 1-2 is closed, the relay KA is self-locked, ensuring that the relay KA remains energized.

3. The epoxy resin insulation vacuum infusion and curing control system according to claim 2, characterized in that: The vacuum unit includes a time relay KT1. When contacts 3-4 of the relay KA are closed, the coil of the time relay KT1 is energized and starts timing. At the same time, the contactor KM1 is energized and controls the vacuum pump M1 to evacuate the mold.

4. The epoxy resin insulation vacuum infusion and curing control system according to claim 3, characterized in that: The time relay KT1 includes normally closed contacts 11-12 and normally open contacts 13-14. When the time relay KT1 finishes its delay, its normally open contacts 13-14 close, starting the subsequent process; its normally closed contacts 11-12 open, controlling the vacuum pump M1 to stop evacuating.

5. The epoxy resin insulation vacuum infusion and curing control system according to claim 4, characterized in that: The injection unit includes a time relay KT2; when the normally open contacts 13-14 of the time relay KT1 are closed, the coil of the time relay KT2 is energized and starts timing, and at the same time the contactor KM2 is energized and controls the metering pump M2 to inject a mixture of epoxy resin and curing agent into the mold.

6. The epoxy resin insulation vacuum infusion and curing control system according to claim 5, characterized in that: The time relay KT2 includes normally closed contacts 21-22, normally open contacts 23-24, and normally open contacts 25-26. When the time relay KT2 finishes its delay, its normally closed contacts 21-22 open, controlling the metering pump M2 to stop injecting the mixture. Its normally open contacts 23-24 close, energizing the contactor KM1 again, controlling the vacuum pump M1 to evacuate the mold. Its normally open contacts 25-26 close, starting the subsequent process.

7. The epoxy resin insulation vacuum infusion and curing control system according to claim 6, characterized in that: The curing unit includes a time relay KT3, a time relay KT4, a contactor KM3, and a curing oven H. When the normally open contacts 25-26 of the time relay KT2 are closed, the coils of the time relays KT3 and KT4 are energized and start timing. At the same time, the contactor KM3 is energized and closes, allowing the curing oven H to cure the mixture in the mold.

8. The epoxy resin insulation vacuum infusion and curing control system according to claim 7, characterized in that: The time relay KT3 includes normally closed contacts 31-32, and the time relay KT4 includes normally closed contacts 41-42. When the time relay KT3 finishes its delay, the normally closed contacts 31-32 of the time relay KT3 open, controlling the vacuum pump M1 to stop evacuating. The normally closed contacts 41-42 of the time relay KT4 open, controlling the contactor KA to de-energize, and the entire control circuit to de-energize, thus completing a complete vacuum infusion and curing cycle of the epoxy resin insulation component.

Images