Curing method of three-post insulator and three-post insulator mold

Abstract

The invention relates to a curing method of a three-post insulator and a three-post insulator mold, and belongs to the technical field of power transmission and transformation insulator forming. According to the method, in the curing process when a pouring material in a three-post insulator mold is in a curing stage, the heating temperature for heating the three-post insulator mold is adjusted in real time according to the temperature change of the pouring material adopted by the three-post insulator in the curing process; the difference value between the temperature of the inner wall of the three-post insulator mold and the temperature of a pouring material in the mold is kept at 0-3 DEG C all the time, the quality problems that a pouring body in the mold cracks due to the difference of internal and external thermal expansion coefficients in the curing stage and the like are solved, and the possibility of residual stress when the pouring material in the mold is cured and formed is effectively reduced. And residual stress in the pouring body is eliminated.

Description

Technical Field

[0001] The invention relates to a curing method for a three-pillar insulator and a three-pillar insulator mould, belonging to the technical field of power transmission and transformation insulation component forming. Background Art

[0002] The main raw materials of ultra-high voltage transmission and transformation insulation parts are generally epoxy resin / alumina composite materials. During the casting process, due to the influence of various factors, the insulation parts are prone to internal stress during the curing process. Practice has proved that internal stress is the main reason for microcracks, gaps, and strength reduction in epoxy resin castings. When the internal stress is large, composite components frequently suffer mechanical damage and insulation failure under operating conditions, which in turn causes system power outages, quenching, and even fires caused by power failures. Especially for three-pillar insulators, due to their irregular shape, complex component shapes, multiple cross-sections, and easy stress concentration during the molding process, which ultimately leads to quality problems such as deformation and cracking of the insulators.

[0003] The traditional method to eliminate residual stress is heat treatment, but the heat treatment process is prone to oxidation of the workpiece surface, changes in hardness and strength, high energy consumption and low efficiency. Therefore, how to regulate the curing stress distribution state of insulating parts and eliminate residual stress is a difficult problem that needs to be solved urgently.

[0004] Experiments have shown that the temperature requirements for epoxy resin curing process are relatively strict. The temperature during the curing process will directly affect the quality of the insulator curing. Due to the rapid cooling of the thick section, the solidification rate of the composite material surface is significantly faster than the core. The subsequent cooling will cause the core to solidify and shrink. The shrinkage of the core is restricted by the already solidified outer layer, forming tensile residual stress in the center of the component and large compressive stress near the surface.

[0005] As a key tool for epoxy casting molding, the mold plays a vital role in the quality of epoxy castings. The structure of the mold ensures the shape and size of the epoxy casting. When the mold structure is constant, the temperature field distribution of the mold determines the quality of the epoxy casting. For a mold with a certain structure, the heating method determines the distribution of its temperature field. At present, when the insulating part is cured, the insulating part mold is placed in an oven, and the oven provides a heating environment for the curing reaction of the insulating part. The temperature provided by the oven is relatively constant, but the constant temperature environment is not conducive to the release of stress in the insulating part. Therefore, the epoxy casting still has residual stress after curing. Summary of the invention

[0006] The purpose of the present invention is to provide a curing method for a three-pillar insulator to solve the problem of residual stress during curing molding of the existing mold; to provide a three-pillar insulator mold to solve the problem of residual stress during curing molding of the existing mold.

[0007] To achieve the above object, the solution of the present invention includes: A curing method for a three-pillar insulator of the present invention includes the following steps: During the curing process of pouring materials in the three-pillar insulator mold, according to the temperature change of the pouring materials used for the three-pillar insulator during the curing process, the heating temperature for heating the three-pillar insulator mold is controlled in real time, so that the temperature difference between the inner wall temperature of the three-pillar insulator mold and the temperature of the pouring materials in the mold is always maintained at 0 to 3 °C.

[0008] Further, the temperature of the pouring materials in the three-pillar insulator mold is taken as the temperature of the pouring materials at the central position in the mold.

[0009] Further, the heating is realized by covering heating sheets on the inner wall of the three-pillar insulator mold. The inner cavity of the mold covered with heating sheets has the same shape as the inner cavity of the mold body. The control of the temperature of the inner wall of the three-pillar insulator mold is realized by controlling the heating temperature of the heating sheets through a temperature control system.

[0010] Further, the mold is preheated before pouring the pouring materials into the three-pillar insulator mold.

[0011] Further, the preheating is realized by covering heating sheets on the inner wall of the three-pillar insulator mold. The inner cavity of the mold covered with heating sheets has the same shape as the inner cavity of the mold body. The control of the temperature of the inner wall of the three-pillar insulator mold is realized by controlling the heating temperature of the heating sheets through a temperature control system.

[0012] Further, the three-pillar insulator mold filled with pouring materials is placed in an oven to keep the temperature of the three-pillar insulator mold through the oven, so as to reduce the influence of the ambient temperature on the curing of the pouring materials.

[0013] Further, a high-energy sound beam is applied to the pouring materials in the three-pillar insulator mold during the curing process to change the potential energy field of the pouring materials in the mold.

[0014] A three-pillar insulator mold of the present invention includes a mold body, heating sheets are covered on the inner wall of the mold body. The inner cavity of the mold covered with heating sheets has the same shape as the inner cavity of the mold body. The heating sheets are controlled and connected to a temperature control system; The temperature control system is used to, during the curing process of the pouring materials in the inner cavity of the mold, according to the temperature change of the pouring materials during the curing process, control in real time the heating temperature of the heating sheets for heating the pouring materials in contact with the inner wall of the heating sheets, so that the temperature difference between the outer surface temperature of the pouring materials and the temperature inside the pouring materials is always maintained at 0 to 3 °C.

[0015] Further, the temperature inside the pouring materials is taken as the temperature of the pouring materials at the central position in the mold.

[0016] Furthermore, a protective layer is also covered on the heating sheet. The protective layer is used to prevent the heating sheet from overheating and the casting material from adhering to the protective layer. The inner cavity of the mold covered with the protective layer has the same shape as the inner cavity of the mold body. The temperature control system is used to separately control the heating temperature at different positions on the heating sheet. A high-energy acoustic beam unit is also provided on the outer wall of the mold body. The high-energy acoustic beam unit is used to externally connect a multi-channel converter.

[0017] Advantages of the present invention: The present invention provides a curing method for a three-pillar insulator, which belongs to a pioneering invention. Specifically, during the curing process of the casting material in the three-pillar insulator mold in the curing stage, according to the temperature change of the casting material used in the three-pillar insulator during the curing process, the heating temperature for heating the three-pillar insulator mold is adjusted in real time, so that the temperature difference between the inner wall temperature of the three-pillar insulator mold and the temperature of the casting material in the mold is always maintained between 0 and 3 °C, making the temperature difference between the inner wall temperature of the three-pillar insulator mold and the temperature of the casting material in the mold as small as possible, reducing the different degrees of the internal and external thermal expansion coefficients of the casting body in the mold during the curing stage, avoiding quality problems such as cracking of the casting body in the mold due to the difference in its internal and external thermal expansion coefficients, effectively reducing the possibility of stress residue during the curing and forming of the casting material in the mold, and eliminating the residual stress in the casting body.

[0018] The present invention provides a three-pillar insulator mold, which belongs to an improved invention. By covering a heating sheet on the inner wall of the mold body, the heating sheet is controlled and connected to the temperature control system; the temperature control system is used to, during the curing process of the casting material in the inner cavity of the mold, according to the temperature change of the casting material during the curing process, control and adjust in real time the heating temperature of the heating sheet for heating the casting material in contact with the inner wall of the heating sheet, so that the temperature difference between the outer surface temperature of the casting material and the temperature inside the casting material is always maintained between 0 and 3 °C, making the temperature difference between the inner wall temperature of the three-pillar insulator mold and the temperature of the casting material in the mold as small as possible, reducing the different degrees of the internal and external thermal expansion coefficients of the casting body in the mold during the curing stage, avoiding quality problems such as cracking of the casting body in the mold due to the difference in its internal and external thermal expansion coefficients, effectively reducing the possibility of stress residue during the curing and forming of the casting material in the mold, and eliminating the residual stress in the casting body. Among them, the inner cavity of the mold covered with the heating sheet has the same shape as the inner cavity of the mold body to ensure that the addition of the heating sheet does not change the shape of the mold, and the adjustment of the mold size can be ignored or the mold specifications can be readjusted. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the mold body of the three-pillar insulator mold; Figure 2 It is a schematic structural diagram of the central insert; Figure 3 It is a schematic structural diagram of a molding system for casting body molding.

[0020] Explanation of reference numerals: 1. Central insert; 11. Protective layer; 12. Heating sheet; 13. Mold layer; 2. Mold body; 3. High-energy sound beam unit; 4. Insulation box. Specific embodiments

[0021] To solve the problems in the background art, the present invention changes the temperature of the outer surface of the casting body formed by the casting material in the mold, so that the temperature difference between the outer surface temperature and the temperature inside the casting body is as small as possible, thereby ensuring that the internal and external thermal expansion coefficients of the casting body in the mold are as consistent as possible during the curing stage, reducing the possibility of stress residue when the casting material in the mold is cured and formed, and achieving the elimination of residual stress in the casting body.

[0022] To make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0023] An embodiment of a curing method for a three-pillar insulator: A curing method for a three-pillar insulator includes the following steps: During the curing process of the casting material in the three-pillar insulator mold, according to the temperature change of the casting material during the curing process, the heating temperature for heating the three-pillar insulator mold is adjusted in real time, so that the temperature difference between the inner wall temperature of the three-pillar insulator mold and the temperature of the casting material in the mold is always maintained between 0 and 3 °C, that is, to ensure that the temperature difference between the outer surface temperature of the casting body formed by the casting material in the three-pillar insulator mold and the temperature inside the casting body is as small as possible, to avoid quality problems such as cracking of the casting body in the mold due to different internal and external thermal expansion coefficients during the curing stage, effectively reducing the possibility of stress residue when the casting material in the mold is cured and formed, and eliminating the residual stress in the casting body.

[0024] Specifically, considering the uneven temperature distribution inside the casting body, the uneven distribution is specifically reflected in that the temperature at the central position is relatively high, that is, the temperature is lower towards the outside. And the reason for the formation of stress is that the internal and external thermal expansion coefficients of the casting body in the mold are inconsistent during the curing stage. Therefore, the temperature of the casting material at the central position in the mold is taken as the temperature of the casting material in the three-pillar insulator mold, to ensure that the temperature difference between the outer surface temperature of the casting body formed by the casting material in the three-pillar insulator mold and the temperature at the central position of the casting body is always maintained between 0 and 3 °C.

[0025] Among them, the center position of the casting body is around the central cylinder of the three-pillar insulator, and specifically can be determined near the central insert of the three-pillar insulator mold. The temperature at the center position of the casting body can be collected by a temperature sensor set at this center position.

[0026] As other embodiments, the temperature of the casting material in the three-pillar insulator mold can also be the average temperature at multiple positions in the casting body. Of course, it can also be set according to needs.

[0027] Specifically, heating can be achieved by placing the three-pillar insulator mold in an oven. However, since the oven has a low precision in temperature control, although the temperature difference between the outer surface temperature of the casting body formed by the casting material in the three-pillar insulator mold and the temperature at the center position of the casting body has decreased, there is still an inconsistent difference. Therefore, during the curing stage of the casting body in the mold, quality problems such as cracking will still occur due to the different thermal expansion coefficients inside and outside, and there will still be residual stress when the mold cures and forms.

[0028] In response to this, the heating of the present invention is achieved by covering heating sheets on the inner wall of the three-pillar insulator mold, and the control of the temperature of the inner wall of the three-pillar insulator mold is achieved by controlling the heating temperature of the heating sheets through a temperature control system. Among them, the temperature control system has a high precision in controlling the heating temperature of the heating sheets and can at least achieve the temperature change during the curing stage of the casting body.

[0029] Among them, the temperature control system includes a temperature sensor, a control circuit, and a relay. The temperature sensor is used to detect the temperature of the inner wall of the mold body in real time and convert the temperature signal into an electrical signal; the control circuit is used to receive the electrical signal output by the temperature sensor, perform signal processing and analysis, and judge whether the current temperature of the inner wall of the mold body is within the set temperature range. The set temperature range is set according to the change of the internal temperature of the casting material in the mold body during the curing process. If the current temperature of the inner wall of the mold body is lower than the lower limit of its corresponding set temperature range, the control circuit will issue a corresponding control signal according to a preset program, and the relay will control the heating sheet to start heating according to the control signal to increase the temperature of the inner wall of the mold body. The control circuit continuously monitors the temperature change of the inner wall of the mold body through the temperature sensor and adjusts the control strategy according to the feedback information to ensure that the temperature of the inner wall of the mold body is always stable within the changing set temperature range. The temperature control system can also adopt other existing temperature control systems.

[0030] Among them, the inner cavity of the mold covered with heating sheets has the same shape as the inner cavity of the mold body to ensure that the addition of the heating sheets does not change the shape of the mold, and the adjustment of the mold size can be ignored or the mold specifications can be readjusted.

[0031] Specifically, the three-pillar insulator mold is preheated before pouring the casting material into it, so as to narrow the temperature difference between the mold and the casting material during pouring and reduce the influence of the mold temperature on the curing of the casting material.

[0032] Among them, the preheating is realized by covering heating sheets on the inner wall of the three-pillar insulator mold. The inner cavity of the mold covered with heating sheets has the same shape as the inner cavity of the mold body. The temperature of the inner wall of the three-pillar insulator mold is controlled by controlling the heating temperature of the heating sheets through a temperature control system.

[0033] As another implementation, the preheating is realized by placing the three-pillar insulator mold in an oven.

[0034] Specifically, the three-pillar insulator mold filled with the casting material is also placed in an oven or a heat preservation box, so as to keep the three-pillar insulator mold warm through the oven or the heat preservation box, and reduce the influence of the ambient temperature lower than the temperature of the casting material in the curing stage on the curing of the casting material. Of course, the oven or the heat preservation box has the function of fixing the three-pillar insulator mold.

[0035] Specifically, considering that there are also residual stresses caused by stress concentration during the curing process, high-energy acoustic beams (also known as ultrasonic waves) are also applied to the casting material in the three-pillar insulator mold during the curing process, so as to change the potential energy field of the casting material in the mold, and make the propagation of the sound wave, the law of the microscopic movement of the material molecules and the curing law of the casting part all proceed from the inside to the outside, reducing the possibility of stress residues when the casting material in the mold is cured and formed, and realizing the elimination of the residual stress in the casting body. The ultrasonic wave of this scheme propagates inside the three-pillar insulator casting body, and the ultrasonic wave acts on the material molecules inside the casting body, which can cause the microscopic movement of the material molecules inside the casting body, thereby weakening the force between molecules and releasing the internal stress generated by the casting body in the mold during the curing process, and effectively reducing the internal stress generated inside the casting body.

[0036] Among them, the high-energy acoustic beam can be output through a high-energy acoustic beam unit. Specifically, a high-energy acoustic beam unit can be set on the outer wall of the mold body. The high-energy acoustic beam unit is used to connect to a multi-channel converter, and the potential energy field of the casting material in the mold during the curing process is changed by the sound wave output by the high-energy acoustic beam unit. The outer wall of the mold body includes the cylindrical inner wall of the central insert of the mold body.

[0037] Specifically, the high-energy acoustic beam units 3 are evenly distributed along the axial direction and / or the circumferential direction on the cylindrical inner wall of the central insert 1.

[0038] When the high-energy acoustic beam units 3 are only evenly distributed along the axial direction on the cylindrical inner wall of the central insert 1, the sound wave or the high-energy acoustic beam can be relatively evenly distributed in the casting body in the mold to a certain extent, so as to further improve the ability to reduce the internal stress generated inside the casting body.

[0039] When the high-energy acoustic beam units 3 are only evenly distributed circumferentially on the inner wall of the cylinder of the central insert 1, referring to Figure 2 and Figure 3 , the sound waves or high-energy acoustic beams can be relatively evenly distributed in the casting body within the mold to a certain extent, so as to further improve the ability to reduce the internal stress generated in the casting body.

[0040] When the high-energy acoustic beam units 3 are evenly distributed both axially and circumferentially on the inner wall of the cylinder of the central insert 1, the sound waves or high-energy acoustic beams can be evenly distributed in the casting body within the mold to a greater extent, improving the ability to reduce the internal stress generated in the casting body.

[0041] Among them, the number of high-energy acoustic beam units 3 is considered for uniform distribution when it is 2, 3 or even more, and the specific value can be selected according to the actual situation.

[0042] Specifically, the mold body 2 has three column legs, and the high-energy acoustic beam units 3 are arranged on the central axis extending from any one of the three column legs or on the central axes extending from any two of the three column legs or on the central axes extending from all the column legs, so that the sound waves or high-energy acoustic beams extend from the inside to the outside in the casting body within the mold, further improving the ability to reduce the internal stress generated in the casting body.

[0043] When the high-energy acoustic beam units 3 are arranged on the central axis extending from any one column leg of the mold body 2, the number of high-energy acoustic beam units 3 is 1 or 2; when the high-energy acoustic beam units 3 are arranged on the central axes extending from any two column legs of the mold body 2, the number of high-energy acoustic beam units 3 is 2, 3 or 4; when the high-energy acoustic beam units 3 are arranged on the central axes extending from the three column legs of the mold body 2, that is, on the central axes extending from all the column legs, the number of high-energy acoustic beam units 3 is 3, 4, 5 or 6. When the high-energy acoustic beam units 3 are arranged on the central axes extending from the three column legs of the mold body 2 and the number of high-energy acoustic beam units 3 is 3, as Figure 3 shown.

[0044] Among them, the number of high-energy acoustic beam units 3 can be 1, 2, 3 or even more, and the specific value is selected according to the needs.

[0045] Considering that the casting material is generally an epoxy resin / aluminum oxide composite material, in order to avoid the situation that the casting material adheres to the heating sheet, a protective layer can be covered on the heating sheet. The protective layer should have an anti-adhesion function, and the protective layer can also prevent the heating sheet from overheating. The inner cavity of the mold covered with the protective layer has the same shape as the inner cavity of the mold body to ensure that the addition of the heating sheet does not change the shape of the mold, and the adjustment of the mold size can be ignored or the mold specifications can be readjusted.

[0046] Specifically, the temperature control system can also separately control the heating temperature and heating time of the heating elements covering different positions on the mold body, so as to adjust the heating temperature of the heating elements at different positions according to actual needs.

[0047] An embodiment of a three-pillar insulator mold: A three-pillar insulator mold, as Figure 1 shown, includes a mold body, the mold body includes a mold main body 2 and a central insert 1, the inner wall of the mold body is covered with heating elements 12, that is, both the mold main body 2 and the central insert 1 are covered with heating elements 12, and the inner cavity of the mold covered with heating elements 12 has the same shape as the inner cavity of the mold body. The heating elements 12 are controlled and connected to a temperature control system. The wall layer of the three-pillar insulator mold from the outside to the inside has two layers, namely the mold layer 13 where the mold body is located and the heating layer where the heating elements 12 are located.

[0048] Among them, the temperature control system is used to, during the curing process of the material poured into the mold cavity, according to the temperature change of the poured material during the curing process, in real time control the heating temperature of the heating elements for heating the poured material in contact with the inner wall of the heating elements, so that the difference between the temperature of the outer surface of the poured material and the temperature inside the poured material is always maintained between 0 and 3 °C.

[0049] Of course, the heating elements can also be used to preheat the mold before pouring the poured material into the three-pillar insulator mold, so as to reduce the influence of the temperature of the mold body, which is lower than the temperature of the poured material in the curing stage, on the curing of the poured material.

[0050] Among them, the actual heating area of the heating elements can completely cover the inner wall of the mold body to optimize the heating efficiency. Of course, the actual heating area of the heating elements can also be spaced and evenly distributed by using heat conduction.

[0051] Considering the uneven temperature distribution inside the poured body, the uneven distribution is specifically reflected in that the temperature at the central position is relatively high, that is, the temperature is lower towards the outside. The reason for the formation of stress is that the internal and external thermal expansion coefficients of the poured body in the mold are inconsistent during the curing stage. Therefore, the temperature of the poured material at the central position inside the mold is taken as the temperature of the poured material in the three-pillar insulator mold, so as to ensure that the difference between the temperature of the outer surface of the poured body formed by the poured material in the three-pillar insulator mold and the temperature at the central position of the poured body is always maintained between 0 and 3 °C.

[0052] Among them, the central position of the poured body is around the central cylinder of the three-pillar insulator, and specifically can be determined near the central insert of the three-pillar insulator mold. The temperature at the central position of the poured body can be collected by a temperature sensor arranged at this central position.

[0053] As other embodiments, the temperature of the casting material in the three-pillar insulator mold can also be the average temperature at multiple positions within the casting body. Of course, the temperature sensors can be set as needed.

[0054] Considering that the casting material is generally an epoxy resin / aluminum oxide composite material, to avoid the situation where the casting material adheres to the heating sheet, a protective layer 11 can be covered on the heating sheet 12. The protective layer 11 should have an anti-sticking function, and this protective layer 11 can also prevent the heating sheet 12 from overheating. The inner cavity of the mold covered with the protective layer 11 has the same shape as the inner cavity of the mold body to ensure that the addition of the heating sheet does not change the shape of the mold, and the adjustment of the mold size can be ignored or the mold specifications can be readjusted. Refer to Figure 2 and Figure 3 , the three-layer structure of the wall layer of the three-pillar insulator mold from the outside to the inside is the mold layer 13 where the mold body is located, the heating layer where the heating sheet 12 is located, and the protective layer 11.

[0055] Specifically, the temperature control system is used to separately control the heating temperature at different positions on the heating sheet, that is, the temperature control system can also separately control the heating temperature and heating time of the heating sheets covering different positions on the mold body, so as to adjust the heating temperature of the heating sheets at different positions according to actual needs.

[0056] Specifically, considering that there are also residual stresses caused by stress concentration during the curing process, therefore, refer to Figure 2 and Figure 3 , a high-energy acoustic beam unit 3 is also provided on the outer wall of the mold body. The high-energy acoustic beam unit 3 is used to externally connect a multi-channel converter, and ultrasonic waves are output to the casting material in the three-pillar insulator mold during the curing process through the high-energy acoustic beam unit 3 to change the potential energy field of the casting material in the mold, and make the propagation of the sound wave, the law of microscopic movement of the material molecules, and the curing law of the casting part all proceed from the inside to the outside, reducing the possibility of stress residues when the casting material in the mold is cured and formed, and realizing the elimination of residual stresses in the casting body. The ultrasonic wave in this solution propagates inside the three-pillar insulator casting body, and the ultrasonic wave acts on the material molecules inside the casting body, which can cause microscopic movement of the material molecules inside the casting body, thereby weakening the force between molecules and releasing the internal stress generated during the curing process of the casting body in the mold, and effectively reducing the internal stress generated inside the casting body.

[0057] Among them, as Figure 2 shown, the outer wall of the mold body includes the inner wall of the cylinder of the central insert 1.

[0058] Specifically, the mold body 2 has three column legs, and the high-energy acoustic beam unit 3 is arranged on the central axis extending from any one of the three column legs, or on the central axes extending from any two of the three column legs, or on the central axes extending from all of the three column legs, so that the sound wave or high-energy acoustic beam extends from the inside to the outside in the casting body within the mold, further improving the ability to reduce the internal stress generated inside the casting body.

[0059] Among them, the number of the high-energy acoustic beam units 3 can be 1, 2, 3 or even more, and is specifically selected according to needs.

[0060] When the high-energy acoustic beam unit 3 is arranged on the central axis extending from any one of the column legs of the mold body 2, the number of the high-energy acoustic beam units 3 is 1 or 2; when the high-energy acoustic beam unit 3 is arranged on the central axes extending from any two of the column legs of the mold body 2, the number of the high-energy acoustic beam units 3 is 2, 3 or 4; when the high-energy acoustic beam unit 3 is arranged on the central axes extending from the three column legs of the mold body 2, that is, all of the column legs, the number of the high-energy acoustic beam units 3 is 3, 4, 5 or 6. When the high-energy acoustic beam unit 3 is arranged on the central axes extending from the three column legs of the mold body 2 and the number of the high-energy acoustic beam units 3 is 3, as Figure 3 shown.

[0061] Specifically, the high-energy acoustic beam units 3 are uniformly distributed along the axial direction and / or along the circumferential direction on the inner wall of the cylinder of the central insert 1.

[0062] When the high-energy acoustic beam units 3 are only uniformly distributed along the axial direction on the inner wall of the cylinder of the central insert 1, the sound wave or high-energy acoustic beam can be relatively uniformly distributed in the casting body within the mold to a certain extent, so as to further improve the ability to reduce the internal stress generated inside the casting body.

[0063] When the high-energy acoustic beam units 3 are only uniformly distributed along the circumferential direction on the inner wall of the cylinder of the central insert 1, referring to Figure 2 and Figure 3 , the sound wave or high-energy acoustic beam can be relatively uniformly distributed in the casting body within the mold to a certain extent, so as to further improve the ability to reduce the internal stress generated inside the casting body.

[0064] When the high-energy acoustic beam units 3 are uniformly distributed along both the axial direction and the circumferential direction on the inner wall of the cylinder of the central insert 1, the sound wave or high-energy acoustic beam can be uniformly distributed in the casting body within the mold to a greater extent, improving the ability to reduce the internal stress generated inside the casting body.

[0065] Among them, uniform distribution is considered only when the number of the high-energy acoustic beam units 3 is 2, 3 or even more, and can be specifically selected according to the actual situation.

[0066] Specifically, as Figure 3As shown in the figure, it further includes an incubator 4. The mold body is placed in the incubator 4 during the pouring and curing stage to keep the three-pillar insulator mold warm through the incubator 4, so as to reduce the influence of the ambient temperature lower than the temperature of the pouring material in the curing stage on the curing of the pouring material. Of course, the incubator 4 has the function of fixing the three-pillar insulator mold.

[0067] The incubator 4 is also equipped with a temperature control system to keep the temperature difference between the insulation temperature of the incubator 4 and the temperature of the outer surface of the pouring material at 0 to 3°C at all times, ensuring insulation while not affecting the curing of the pouring material. Of course, the incubator 4 can also be used to preheat the mold before pouring the pouring material into the three-pillar insulator mold, so as to reduce the influence of the mold body temperature lower than the temperature of the pouring material in the curing stage on the curing of the pouring material.

[0068] As another embodiment, it further includes an oven, and the oven is also used to preheat the mold before pouring the pouring material into the three-pillar insulator mold, so as to reduce the influence of the mold body temperature lower than the temperature of the pouring material in the curing stage on the curing of the pouring material. Of course, the oven has the function of fixing the three-pillar insulator mold.

[0069] The curing method of the three-pillar insulator and the three-pillar insulator mold of the present invention can be applied to the forming and stress regulation of epoxy-poured three-pillar insulating parts for ultra-high voltage switchgear, and can be specifically applied to the pouring of three-pillar insulators with voltage levels such as 420 kV, 550 kV, 800 kV, and 1100 kV.

[0070] Taking the three-pillar insulator mold with heating and high-energy sound beams as an example, the following detailed description is given: The three-pillar insulator mold of the present invention can be used for stress regulation and gradient heating in the curing stage of the casting. Specifically, heating sheets are installed inside the mold, and in cooperation with the insulation device and the temperature control system, gradient heating is carried out on different parts of the insulator casting body to ensure the orderly curing of the insulator casting, and keep the temperature difference between the epoxy at the center position and the epoxy at the periphery of the three-pillar casting body at 0 to 3°C at all times, avoiding cracking and other phenomena caused by different thermal expansion coefficients at the center position and the periphery; at the same time, a high-energy sound beam transducer and a multi-channel adapter head are installed at the center cylinder position of the mold, and the high-energy sound beam is used to change the internal potential energy field of the casting body, so as to release the stress generated during the curing process of the three-pillar insulator casting while heating the insulating part, and solve the problems of mechanical damage and insulation failure caused by stress concentration due to uneven curing of the three-pillar insulator.

[0071] Among them, the mold is on the outermost side, the heating sheet is fixed in the middle by screws, and the protective layer is installed on the innermost side of the mold. The protective layer is used to prevent the heating sheet from overheating, thereby avoiding damage to the casting material. The high-energy acoustic beam transducer is fixed inside the central cylinder of the mold by screws and emits sound waves during the curing stage to relieve stress on the insulator casting.

[0072] The three-pillar insulator mold is used to achieve stress regulation and self-heating during the curing stage of the casting. That is, the stress regulation and self-heating curing device using the three-pillar insulator mold includes a heat preservation box and a gradient heating mold (three-pillar insulator mold). The heat preservation box serves as a heat preservation system to maintain a relatively high ambient temperature; the gradient heating mold is divided into a mold layer (insulating part forming mold), a heating layer, and a protective layer. The gradient heating mold ensures the orderly curing of the insulator casting. Among them, the mold layer is made of alloy steel to control the forming process of the three-pillar insulator casting; the heating layer uses silicon nitride ceramic heating sheets, and the temperature control system is used to achieve temperature regulation during the curing process of the three-pillar insulator; the protective layer uses a 0.4-mm polytetrafluoroethylene plastic film as an isolation layer to provide protection for the heating sheet. Among them, the shape of the heating sheet is designed to match the inner surface shape of the mold. A heating wiring with a heating function can be used, and different working times can be set for the power supply connected to each heating sheet, and an independent temperature control background can be set for each heating sheet to achieve individual control of the heating sheet; the local temperature during the curing process can be regulated through the insulating part temperature control module as the temperature control system, and the operation is simple.

[0073] It also includes a multi-channel stress regulation module. The multi-channel stress regulation module includes ultrasonic power units with different powers, a multi-channel adapter, and high-energy acoustic beam transducers (high-energy acoustic beam units). Among them, the number of high-energy acoustic beam transducers is 3, which are respectively placed at the inner wall of the central insert of the three-pillar insulator to release energy and achieve the regulation and elimination of stress during the curing process.

[0074] The specific usage steps of the stress regulation and self-heating curing device are as follows: 1) Preheat the inner cavity of the mold through the heating sheet before pouring; 2) Pour, and after pouring, fix the mold in the heat preservation box; 3) Connect the high-energy acoustic beam unit to the multi-channel converter; 4) According to the general law of the curing reaction, set the heating time and heating temperature of the heat preservation box and the gradient heating sheet in the insulating part temperature control module; 5) The control system turns on the ultrasonic power unit, connects the ultrasonic power unit and the high-energy acoustic beam transducer through the multi-channel converter, and releases energy to the three-pillar insulator casting; 6) Turn on the temperature control system, regulate the temperature control system, and keep the temperature difference between the outer surface temperature of the casting formed by the casting material in the three-pillar insulator mold and the temperature at the center position of the casting at 0 to 3°C at all times; 7) After curing is completed, open the oven and the mold, and take out the cured three-pillar insulator casting.

[0075] Among them, the heating time and heating temperature can be determined according to different epoxy resin formulations. Each formulation has its corresponding curing temperature and time. The heating sheet will increase the heating temperature and time for the epoxy resin that is relatively far from the metal insert (center insert) to enable uniform curing of the insulator casting.

[0076] In the present invention, by installing heating sheets on the inner surface of the mold, configuring a heat preservation device and a temperature control system, gradient heating is performed on different parts of the insulator casting to ensure the orderly curing of the casting. By changing the heating temperature of the heating sheet, the temperature difference between the center position of the three-pillar insulator and the temperature of the peripheral epoxy is kept at 0 to 3°C at all times, which is beneficial to the release of internal stress in the insulator and avoids phenomena such as cracking caused by the difference in the thermal expansion coefficients of the center position and the surface layer of the casting. The present invention also installs a high-energy acoustic beam transducer and a multi-channel adapter head at the position of the central cylinder (center insert) of the mold, and uses the high-energy acoustic beam to improve the stress concentration that occurs during the curing process of the three-pillar casting to eliminate the stress generated during the curing process of the three-pillar casting.

[0077] While heating the insulator casting, the present invention changes the potential energy field of the epoxy material of the casting through a high-energy acoustic beam, thereby overall regulating the stress of the insulator, solving the problem that the temperature field is too constant during the traditional oven curing process, resulting in incomplete curing of the epoxy three-pillar insulator casting, improving quality problems such as deformation and cracking of the insulator caused by residual stress, and improving the operation reliability of UHV power transmission and transformation equipment. The present invention can provide support for the reliability analysis and improvement of three-pillar insulators, effectively reduce heat consumption, reduce the scrap rate, and improve product quality to ensure the operation reliability of UHV power transmission and transformation equipment, and is expected to save 2 million yuan in production costs and test expenses annually.

Claims

1. A curing method for a three-pillar insulator, characterized in that: The steps include: During the solidification process of the cast material in the three-pillar insulator mold, the heating temperature of the three-pillar insulator mold is controlled in real time according to the temperature change of the cast material used in the three-pillar insulator during the solidification process, so that the difference between the temperature of the inner wall of the three-pillar insulator mold and the temperature of the cast material in the mold is always maintained at 0 to 3°C.

2. The curing method of the three-pillar insulator according to claim 1, characterized in that: The temperature of the casting material in the three-pillar insulator mold is the temperature of the casting material at the center position of the mold.

3. The curing method of a three-pillar insulator according to claim 1, characterized in that: The heating is achieved by covering the inner wall of the three-pillar insulator mold with a heating plate. The mold cavity covered with the heating plate has the same shape as the inner cavity of the mold body. The temperature of the inner wall of the three-pillar insulator mold is controlled by controlling the heating temperature of the heating plate through a temperature control system.

4. The curing method of a three-pillar insulator according to claim 1, characterized in that: The three-post insulator mold is also preheated before pouring the casting material into the mold.

5. The curing method of the three-pillar insulator according to claim 4, characterized in that: The preheating is achieved by covering the inner wall of the three-pillar insulator mold with a heating plate. The mold cavity covered with the heating plate has the same shape as the inner cavity of the mold body. The temperature of the inner wall of the three-pillar insulator mold is controlled by controlling the heating temperature of the heating plate through a temperature control system.

6. The curing method of a three-pillar insulator according to claim 1, characterized in that: The three-pillar insulator mold poured with the casting material is also placed in an oven, so that the three-pillar insulator mold is kept warm by the oven to reduce the influence of the ambient temperature on the curing of the casting material.

7. The curing method of a three-pillar insulator according to claim 1, characterized in that: A high energy acoustic beam is also applied to the casting material in the solidification process in the three-pillar insulator mold to change the potential energy field of the casting material in the mold.

8. A three-pillar insulator mold, comprising a mold body, characterized in that: The inner wall of the mold body is covered with a heating plate, the inner cavity of the mold covered with the heating plate has the same shape as the inner cavity of the mold body, and the heating plate is controlled and connected to a temperature control system; The temperature control system is used to control the heating temperature of the heating plate to heat the casting material in contact with the inner wall of the heating plate in real time according to the temperature change of the casting material during the curing process of the casting material in the mold cavity, so that the difference between the temperature of the outer surface of the casting material and the temperature inside the casting material is always maintained at 0 to 3°C.

9. The three-pillar insulator mold according to claim 8, characterized in that: The temperature in the casting material is the temperature of the casting material at the center position in the mold.

10. The three-pillar insulator mold according to claim 8, characterized in that: The heating plate is also covered with a protective layer, which is used to prevent the heating plate from overheating and the casting material from adhering to the protective layer. The inner cavity of the mold covered with the protective layer has the same shape as the inner cavity of the mold body; The temperature control system is used to individually control the heating temperature at different positions on the heating plate; A high-energy sound beam unit is also arranged on the outer wall of the mold body, and the high-energy sound beam unit is used for connecting an external multi-channel converter.

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