阅读说明：本技术 一种高压电缆终端应力锥的生产方法 (Production method of high-voltage cable terminal stress cone ) 是由 王刚 王志明 孙国玉 于 2019-02-19 设计创作，主要内容包括：本发明公开了一种高压电缆终端应力锥的生产方法,具体涉及应力锥生产技术领域,包括以下步骤：步骤一,注射模具温度调节,将应力锥注射模具放置于操作台上,对注射模具进行加热,使注射模具受热均匀；步骤二,低压力小流量注射,调节硅橡胶注射机的注射压力至低压状态,将硅橡胶材料利用硅橡胶注射机注射至注射模具内,注射过程中保持注射速度均匀,待硅橡胶材料填充满注射模具的内壁后停止注射；步骤三,高压力大流量注射。本发明通过采用低温注射,注射时没有达到硅橡胶的硫化温度,所以硅橡胶不会开始硫化,没有过硫化现象,注射时设定温度为60-70℃,硅橡胶受热粘度变小,流动性变好,更有利于硅橡胶在模具里面流动。(The invention discloses a method for producing a stress cone of a high-voltage cable terminal, in particular to the technical field of stress cone production, which comprises the following steps: step one, adjusting the temperature of an injection mold, placing the stress cone injection mold on an operation table, and heating the injection mold to ensure that the injection mold is uniformly heated; injecting at low pressure and low flow, adjusting the injection pressure of the silicon rubber injection machine to a low pressure state, injecting the silicon rubber material into an injection mould by using the silicon rubber injection machine, keeping the injection speed uniform in the injection process, and stopping injection after the inner wall of the injection mould is filled with the silicon rubber material; and step three, injecting at high pressure and high flow rate. The invention adopts low-temperature injection, the vulcanization temperature of the silicon rubber is not reached during injection, so the silicon rubber can not start vulcanization and has no over-vulcanization phenomenon, the set temperature is 60-70 ℃ during injection, the heated viscosity of the silicon rubber is reduced, the fluidity is improved, and the silicon rubber can flow in a mold.)

1. A production method of a high-voltage cable terminal stress cone is characterized by comprising the following steps:

step one, adjusting the temperature of an injection mold, placing the stress cone injection mold on an operation table, and heating the injection mold to ensure that the injection mold is uniformly heated;

injecting at low pressure and low flow, adjusting the injection pressure of the silicon rubber injection machine to a low pressure state, injecting the silicon rubber material into an injection mould by using the silicon rubber injection machine, keeping the injection speed uniform in the injection process, and stopping injection after the inner wall of the injection mould is filled with the silicon rubber material;

injecting at high pressure and high flow rate, adjusting the injection pressure of a silicone rubber injection machine to a high pressure state, injecting the silicone rubber material into an injection mold by using the silicone rubber injection machine, keeping the injection speed uniform in the injection process, and stopping injection after the silicone rubber material is filled into an inner cavity of 80-90% of the injection mold;

injecting at high pressure and low flow rate, continuously keeping the injection pressure of the silicone rubber injection machine at a high pressure state, injecting the rest silicone rubber material into an injection mold by using the silicone rubber injection machine, and stopping injection after the silicone rubber material is filled into 95-100% of an inner cavity of the injection mold;

and step five, vulcanizing, namely heating the injection mold after injection is finished, heating the injection mold uniformly in the heating process, stopping heating after the temperature in the injection mold continuously rises to 105-plus-110 ℃ so as to vulcanize the silicon rubber material in the injection mold, and demolding the injection mold by using a demolding machine after vulcanization is finished to obtain a product, namely the high-voltage cable terminal stress cone.

2. The method for producing a stress cone for a high-voltage cable termination according to claim 1, wherein: in the first step, the heating is stopped after the temperature in the injection mould is continuously raised to 60-70 ℃.

3. The method for producing a stress cone for a high-voltage cable termination according to claim 1, wherein: in the second to fourth steps, the temperature in the injection mold is maintained at 60-70 ℃ during the injection process.

4. The method for producing a stress cone for a high-voltage cable termination according to claim 1, wherein: in the fifth step, the vulcanization time of the silicone rubber material in the injection mold is 4 to 6 hours.

Technical Field

The invention relates to the technical field of stress cone production, in particular to a method for producing a stress cone of a high-voltage cable terminal.

Background

In the manufacture of the cable head, the electric field distribution in the three ends of the cable is greatly changed compared with the cable itself due to the reasons that the metal shield (or sheath) and the insulation need to be cut off, the section of the conductor junction is enlarged, the thickness and the dielectric constant e of the additional insulation are different from the insulation of the cable body, and the like. This variation is mainly manifested in the generation of axial electric field strength, or axial stress, in the direction of the cable insulation surface, and the stress cone is the functional element for relieving this stress.

In the production of stress cones, a process of raising the temperature of a mold to a vulcanization temperature and then starting injection and vulcanization is adopted by many domestic and foreign manufacturers at present, because the viscosity of rubber is reduced after the rubber is heated, the rubber is easier to flow and has good fluidity, and the defects of injection by adopting the process are as follows: by adopting the injection at the vulcanization temperature, the silicon rubber injected firstly slowly starts to be vulcanized, if the product volume is larger, the over-vulcanization phenomenon can be generated, and if part of the over-vulcanized silicon rubber is stored in the product, the hidden danger can be caused.

Disclosure of Invention

In order to overcome the defects in the prior art, the embodiment of the invention provides a production method of a high-voltage cable terminal stress cone, low-temperature injection is adopted, and the vulcanization temperature of silicon rubber is not reached during injection, so that the silicon rubber cannot be vulcanized and the over-vulcanization phenomenon does not occur, the set temperature during injection is 60-70 ℃, the heated viscosity of the silicon rubber is reduced, the fluidity is improved, the silicon rubber can flow in a mold, a three-section injection process is adopted, low-pressure and small-flow injection is adopted, and no bubbles are generated during injection; the high-pressure high-flow injection is carried out quickly, the injection time is reduced, and the productivity is improved; high pressure and small flow injection are carried out, so that the silicon rubber can be ensured to fill the die, and the transition part of the insulating rubber and the semi-conductive rubber can reach the designed part.

In order to achieve the purpose, the invention provides the following technical scheme: a production method of a high-voltage cable terminal stress cone comprises the following steps:

step one, adjusting the temperature of an injection mold, placing the stress cone injection mold on an operation table, and heating the injection mold to ensure that the injection mold is uniformly heated;

injecting at low pressure and low flow, adjusting the injection pressure of the silicon rubber injection machine to a low pressure state, injecting the silicon rubber material into an injection mould by using the silicon rubber injection machine, keeping the injection speed uniform in the injection process, and stopping injection after the inner wall of the injection mould is filled with the silicon rubber material;

injecting at high pressure and high flow rate, adjusting the injection pressure of a silicone rubber injection machine to a high pressure state, injecting the silicone rubber material into an injection mold by using the silicone rubber injection machine, keeping the injection speed uniform in the injection process, and stopping injection after the silicone rubber material is filled into an inner cavity of 80-90% of the injection mold;

injecting at high pressure and low flow rate, continuously keeping the injection pressure of the silicone rubber injection machine at a high pressure state, injecting the rest silicone rubber material into an injection mold by using the silicone rubber injection machine, and stopping injection after the silicone rubber material is filled into 95-100% of an inner cavity of the injection mold;

and step five, vulcanizing, namely heating the injection mold after injection is finished, heating the injection mold uniformly in the heating process, stopping heating after the temperature in the injection mold continuously rises to 105-plus-110 ℃ so as to vulcanize the silicon rubber material in the injection mold, and demolding the injection mold by using a demolding machine after vulcanization is finished to obtain a product, namely the high-voltage cable terminal stress cone.

In a preferred embodiment, in the first step, the heating is stopped after the temperature inside the injection mold continuously rises to 60-70 ℃.

In a preferred embodiment, in the second to fourth steps, the temperature inside the injection mold is maintained at 60-70 ℃ during the injection.

In a preferred embodiment, in the fifth step, the vulcanization time of the silicone rubber material in the injection mold is 4 to 6 hours.

The invention has the technical effects and advantages that:

1. according to the invention, low-temperature injection is adopted, and the vulcanization temperature of the silicon rubber is not reached during injection, so that the silicon rubber cannot start vulcanization and has no over-vulcanization phenomenon, the set temperature during injection is 60-70 ℃, the heated viscosity of the silicon rubber is reduced, the fluidity is improved, and the silicon rubber can flow in a mold;

2. the three-stage injection process is adopted, low-pressure and small-flow injection is carried out, and no bubbles are generated during injection; the high-pressure high-flow injection is carried out quickly, the injection time is reduced, and the productivity is improved; high-pressure low-flow injection is carried out, so that the silicon rubber can be filled in the mold, and the transition part of the insulating rubber and the semi-conductive rubber can reach the designed part;

3. the method has the advantages of simple process, low equipment requirement, strong operability and good social popularization and application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.