A mold and method for preparing cable insulation-shielding test specimens

Abstract

This invention relates to the field of cable test specimen preparation technology, and discloses a mold and method for preparing cable insulation-shielding test specimens. The preparation mold includes a lower plate, a first shaping component, a second shaping component, and an upper plate. The first shaping component includes a first plate with a first through hole on its surface. The lower plate and the first plate together form a shaping groove communicating with the first through hole. The second shaping component includes a detachably connected second plate and a third plate, and a sliding baffle disposed between them. The opposite ends of the second and third plates are provided with a sliding groove for the sliding baffle to slide. The second and third plates each have multiple second through holes at corresponding positions. When the second plate and the third plate are aligned, the second through holes form a channel that runs vertically through the channel. The sliding baffle closes the channel in the first position and avoids the channel in the second position, forming a test specimen with multiple shielding layers arranged on the same insulation layer surface.

Description

Technical Field

[0001] This invention relates to the field of cable test specimen preparation technology, and in particular to a mold and method for preparing cable insulation-shielding test specimens. Background Technology

[0002] Power cables are the lifeblood of power networks, and the long-term reliability of their insulation systems is crucial for ensuring the safe operation of the power grid. The cable shielding layer not only serves to uniform the electric field, but the interface performance between it and the insulation layer is also a weak point that determines the cable's lifespan. Early cable failures often originate from interface defects rather than the insulation itself. Therefore, it is necessary to simulate and prepare double-layer samples of the cable shielding and insulation layers in the laboratory to facilitate subsequent theoretical and experimental research on these layers.

[0003] Currently, the preparation of cable shielding and insulation layers in the laboratory mostly adopts a step-by-step hot-pressing composite method. Specifically, an insulation layer sample and a shielding layer sample are prepared independently using a flat vulcanizing machine. The shielding layer sample is then placed on the insulation layer sample and placed in a hot press for a second hot-pressing composite to form a test sample. The shortcomings of this method for preparing cable shielding and insulation layers are: the insulation layer and the shielding layer need to undergo three independent hot-pressing processes (insulation, shielding, and composite). After each pressing, the sample must be removed from the mold, transferred, and placed again. This process is cumbersome and inefficient. The composite process requires independent insulation sheets and shielding sheets, and the preparation of multiple sets of parallel samples requires at least multiple independent insulation sheets and multiple independent shielding sheets. Therefore, it is impossible to prepare multiple sets of parallel shielding layer samples on the same insulation layer substrate at one time, resulting in bulk differences in the insulation layer between different samples. This seriously interferes with high-precision interface comparison studies and affects subsequent test results. Summary of the Invention

[0004] The purpose of this invention is to provide a mold and method for preparing cable insulation-shielding test specimens. In the prior art, the preparation of cable insulation and shielding layers involves a complicated process and low efficiency, and it is impossible to prepare multiple sets of shielding layer specimens on the same insulation substrate at one time.

[0005] To achieve the above objectives, the present invention provides a mold for preparing cable insulation-shielding test specimens, comprising a lower plate, a first shaping component, a second shaping component, and an upper plate that are detachably connected from bottom to top. The first shaping component includes a first plate with a first through hole on its surface. The lower plate and the first plate together form a shaping groove communicating with the first through hole. The second shaping component includes a second plate and a third plate that are detachably connected, and a sliding baffle disposed between them. The second plate and the third plate have a sliding groove at opposite ends to allow the sliding baffle to slide. The second plate and the third plate each have multiple second through holes at corresponding positions. When the second plate and the third plate are aligned, the second through holes form a vertically penetrating channel. The sliding baffle has a first position and a second position. When the sliding baffle slides to the first position, it closes the channel. When the sliding baffle slides to the second position, it avoids the channel.

[0006] In one embodiment, the second shaping component further includes a pull rod, one end of which extends into the groove and connects to the sliding baffle, and the other end extends out of the groove. The pull rod is used to drive the sliding baffle to slide horizontally within the groove.

[0007] In one embodiment, the second plate has a positioning hole on its surface for a bolt to pass through, and the third plate has a threaded hole corresponding to the positioning hole, the threaded hole being used to engage the bolt.

[0008] In one embodiment, a plurality of channels are formed between the second plate and the third plate, and the plurality of channels are arranged at intervals along the central axis of the second plate.

[0009] In one embodiment, the cross-section of the channel in the horizontal direction has a predetermined shape.

[0010] Another aspect of the present invention provides a preparation method for preparing a mold based on the above-mentioned cable insulation-shielding test specimen, which includes the following steps; Step S1: Place the insulating material in the shaping groove of the first plate, and place the first plate between the lower plate and the upper plate, and perform the first hot pressing to form an insulating layer; Step S2: Remove the upper plate, place the third plate, the sliding baffle and the second plate on top of the first plate from top to bottom, slide the sliding baffle to the first position to close the channel, and add shielding material into the channel; Step S3: Assemble the upper plate and perform a second hot pressing and pressure holding to melt the shielding material; Step S4: Release the pressure and slide the sliding baffle to the second position to open the channel. The molten shielding material flows through the channel to the surface of the insulating layer under the action of gravity to form a shielding layer. After cooling, a double-layer sample is obtained.

[0011] Furthermore, in the above-mentioned method for preparing cable insulation-shielding test specimens, both the first and second hot pressing are performed using a flat vulcanizing machine.

[0012] In one embodiment, a first isolation layer is provided between the insulating layer and the upper plate in step S1.

[0013] In one embodiment, a second isolation layer is provided between the insulating layer and the second shaping component in step S2, and the surface of the second isolation layer has clearance holes that correspond one-to-one with the channels.

[0014] In one embodiment, in step S3, the temperature is heated to 140°C to 200°C, and the pressure is maintained at 0 MPa before the shielding material melts.

[0015] In one embodiment, in step S4, after opening the channel, a pressure of 0.5 to 2 MPa is applied and maintained for 5 to 15 minutes, and then a pressure of 2 to 5 MPa is applied and maintained for 5 to 10 minutes.

[0016] Compared with the prior art, the advantages of the cable insulation-shielding test specimen preparation mold and method of this invention are as follows: By sequentially and separably connecting the lower plate, the first shaping component, the second shaping component, and the upper plate, the preparation of the insulation layer and the shielding layer is integrated into a mold system. After the insulating material is placed in the shaping groove to form the insulation layer, there is no need to transfer the sample. The sliding baffle is directly operated to the second position to open the channel, and the shielding material can be injected into the channel to prepare the shielding layer. The whole process is completed continuously in one mold, which greatly reduces intermediate links and operation steps, significantly improves preparation efficiency, shortens the sample preparation cycle, and can meet the sample quantity requirements of large-scale testing and research and development. In the second shaping component, multiple spaced second through holes are set at corresponding positions on the second and third plates, forming multiple vertically penetrating channels and constituting multiple independent shielding material flow spaces. During the shielding layer preparation process, shielding material can be injected into multiple channels simultaneously, so that multiple shielding layers are formed on the same insulation layer substrate surface, and multiple sets of insulation-shielding samples can be prepared at one time. This multi-channel structure design makes full use of the space resources of the mold, avoids the time and material waste caused by repeatedly preparing the same sample, and realizes the batch and efficient production of cable insulation-shielding test sample preparation. Attached Figure Description

[0017] Figure 1 This is a step diagram illustrating the preparation process of the mold for the cable insulation-shielding test specimen according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second shaping component in the cable insulation-shielding test specimen preparation mold according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the first shaping component in the cable insulation-shielding test specimen preparation mold according to an embodiment of the present invention; Figure 4 This is a schematic diagram of Embodiment 1 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 5 This is an exploded view of Embodiment 1 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 6 This is a schematic diagram of the second shaping component in Embodiment 1 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 7 This is a schematic diagram of the test specimen in Embodiment 1 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 8 This is a schematic diagram of Embodiment 2 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 9 This is a schematic diagram of the second shaping component in Embodiment 2 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 10 This is a schematic diagram of the test specimen in Embodiment 2 of the cable insulation-shielding test specimen preparation mold of the present invention; Figure 11 This is a flowchart of the cable insulation-shielding test specimen preparation method according to an embodiment of the present invention.

[0018] In the diagram, 1. Lower plate; 2. First shaping component; 21. First plate; 211. First through hole; 3. Second shaping component; 31. Second plate; 311. Positioning hole; 32. Third plate; 321. Threaded hole; 33. Sliding baffle; 34. Tie rod; 35. Second through hole; 36. Slide groove; 4. Upper plate body; 5. First isolation layer; 6. Second isolation layer; 7. Insulation material; 8. Shielding material. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0020] In the description of this invention, it should be understood that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to that other element. The terms "mounted," "connected," and "attached" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In the description of this invention, it should be understood that the terms "height," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this invention to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0023] Example 1 like Figures 1 to 7As shown, a preferred embodiment of the present invention provides a mold for preparing a cable insulation-shielding test sample, which includes a lower plate 1, a first shaping component 2, a second shaping component 3, and an upper plate 4 that are detachably connected from bottom to top; the first shaping component 2 includes a first plate 21, the surface of which has a first through hole 211, and the lower plate 1 and the first plate 21 enclose a shaping groove communicating with the first through hole 211; the second shaping component 3 includes a second plate 31 and a third plate 32 that are detachably connected. And a sliding baffle 33 is provided between the two. The second plate 31 and the third plate 32 are provided with a sliding groove for the sliding baffle 33 to slide at opposite ends. The second plate 31 and the third plate 32 are provided with multiple second through holes 35 at corresponding positions. When the second plate 31 and the third plate 32 are connected, the second through holes 35 form a channel that runs through in the vertical direction. The sliding baffle 33 has a first position and a second position. When the sliding baffle 33 slides to the first position, it closes the channel. When the sliding baffle 33 slides to the second position, it avoids the channel.

[0024] Based on the above technical features, this embodiment of the invention integrates the preparation of the insulating layer and the shielding layer into a single mold system by sequentially and separably connecting the lower plate 1, the first shaping component 2, the second shaping component 3, and the upper plate 4. After the insulating material 7 is placed in the shaping groove to form the insulating layer, there is no need to transfer the sample. The sliding baffle 33 is directly operated to the second position to open the channel, and the shielding material 8 can be injected into the channel to prepare the shielding layer. The entire process is completed continuously within a single mold, greatly reducing intermediate steps and operations, significantly improving preparation efficiency, shortening the sample preparation cycle, and meeting the requirements of large-scale testing and research and development. The requirement for the number of samples; in the second shaping component 3, the second plate 31 and the third plate 32 are provided with multiple mutually spaced second through holes 35 at corresponding positions, forming multiple channels that run through the vertical direction, constituting multiple independent shielding material 8 flow spaces. During the shielding layer preparation process, shielding material 8 can be injected into multiple channels at the same time, so that multiple shielding layers are formed on the same insulating layer substrate surface, and multiple sets of insulating-shielding samples are prepared at one time. This multi-channel structure design makes full use of the space resources of the mold, avoids the time and material waste caused by repeatedly preparing the same sample, and realizes the batch and high efficiency of sample preparation.

[0025] As some embodiments of the present invention, such as Figure 2 and Figure 6As shown, the second shaping component 3 also includes a pull rod 34. One end of the pull rod 34 extends into the groove and connects to the sliding baffle 33, while the other end extends outside the groove. The pull rod 34 is used to drive the sliding baffle 33 to slide horizontally within the groove. The pull rod 34 provides the operator with a clear point of force application and a control handle, allowing for more precise control of the sliding baffle 33's movement distance and speed. During sample preparation, the position of the sliding baffle 33 in the first position (blocking the channel) and the second position (away from the channel) has a crucial impact on the sample preparation effect. Through the pull rod 34, the operator can slowly and steadily push or pull the sliding baffle 33 according to actual needs, ensuring it accurately reaches the required position and avoiding incomplete opening or closing of the channel due to inaccurate operation, thereby guaranteeing the quality of the insulation and shielding layer preparation.

[0026] As some embodiments of the present invention, such as Figure 2 As shown, the second plate 31 has a positioning hole 311 for the bolt to pass through, and the third plate 32 has a threaded hole 321 corresponding to the positioning hole 311. The threaded hole 321 is used to mate with the bolt. Through the design of the positioning hole 311, when the bolt passes through the positioning hole 311 of the second plate 31 and is screwed into the threaded hole 321 of the third plate 32, the threads of the bolt and the threads of the threaded hole 321 are tightly engaged, generating a huge frictional force and mechanical interlocking force. This strong fixing effect ensures that the second plate 31 and the third plate 32 are tightly connected. During sample preparation, the mold needs to withstand the pressure, temperature changes, and possible mechanical vibrations of the upper plate 4. A stable connection can prevent relative movement or separation between the second plate 31 and the third plate 32, ensuring the integrity of the mold structure and thus ensuring the smooth progress of sample preparation.

[0027] As some embodiments of the present invention, such as Figures 1 to 7 As shown, multiple channels are formed between the second plate 31 and the third plate 32, and these channels are spaced apart along the central axis of the second plate 31. Specifically, the multiple channels are evenly distributed circumferentially, allowing the mold to simultaneously prepare multiple shielding layers. In the traditional process of preparing insulation-shielding samples, only one insulation layer or shielding layer can be prepared at a time, and then the two are hot-pressed together to form an insulation-shielding sample, which is a cumbersome and time-consuming process. However, with this multi-channel design, the operator can inject shielding material 8 into multiple channels at once, forming multiple parallel shielding layers on the surface of an insulation layer substrate, thus forming multiple insulation-shielding samples. This greatly shortens the overall production cycle, improves production efficiency, and meets the needs of large-scale production.

[0028] As some embodiments of the present invention, the cross-section of the channel along the horizontal direction has a predetermined shape. The predetermined shape of the channel cross-section can be specifically designed according to the mechanical performance requirements of the sample. For example, by using a predetermined shape with reinforcing ribs or a specific curvature, the insulation material 7 and shielding material 8 can be orderly distributed according to this shape during sample preparation, forming a sample with a more rational internal structure. This structure can enhance the tensile, bending, and impact resistance of the sample, enabling the sample to more realistically reflect the mechanical properties of the cable in tests simulating actual usage environments, thus improving the effectiveness and practicality of the test.

[0029] Another aspect of the present invention is as follows Figure 11 As shown, a preparation method is also provided, which prepares a mold based on the above-mentioned cable insulation-shielding test specimen, and includes the following steps; Step S1: Place the insulating material 7 in the shaping groove of the first plate 21, and place the first plate 21 between the lower plate 1 and the upper plate 4, and perform the first hot pressing to form an insulating layer; specifically, weigh the insulating material 7 according to the required weight of the insulating layer, first place a 0.1mm thick polyimide film and the first plate 21 on the lower plate 1 in sequence, place the weighed insulating material 7 evenly in the shaping groove of the first plate 21, and then place a 0.1mm thick polyimide film and the upper plate 4 on top in sequence, and put it into a flat vulcanizing machine for pressing. Set the temperature of the flat vulcanizing machine to 180℃, and preheat the upper plate 4, the first plate 21, the lower plate 1 and the insulating material 7 on the machine for 5~10 minutes. Afterwards, three exhausts are performed simultaneously. After sufficient preheating, the sample is pressed for 5 minutes under a pressure of 10 MPa. Then, the upper plate 4, the first shaping component 2, and the lower plate 1 are cooled and removed from the vulcanizer. The insulation layer sample is pressed. The upper plate 4 and the polyimide film are then removed.

[0030] Step S2: Remove the upper plate 4, place the third plate 32, sliding baffle 33 and second plate 31 from top to bottom on top of the insulating layer, and slide the sliding baffle 33 to the first position to block the channel. Add shielding material 8 into the channel. Specifically, calculate the amount of shielding material 8 according to the required shielding layer thickness, place the assembled second shaping component 3 on top of the first shaping component 2, and place the weighed shielding material 8 into the second through hole 35. At this time, the sliding baffle 33 closes the channel in the first position. Then, place a 0.1mm polyimide film and the upper plate 4 on top of the second plate 31 in sequence.

[0031] Step S3: Assemble the upper plate 4 and perform a second hot pressing and pressure holding to melt the shielding material 8; set the temperature of the plate vulcanizing machine to 180℃, preheat the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4, and the shielding material 8 in the vulcanizing machine for 10 minutes, set the pressure of the vulcanizing machine to 0Mpa, and wait for the shielding material 8 to melt completely.

[0032] Step S4: Release the pressure and slide the sliding baffle 33 to the second position to open the channel. The molten shielding material 8 flows through the channel to the surface of the insulating layer under the action of gravity to form a shielding layer. After cooling, a double-layer sample is obtained. After step S3 is completed, the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4 and the shielding material 8 are cooled. The pressure is maintained at 2MPa during cooling. After complete cooling, the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4 and the shielding material 8 are removed. The excess part of the sample is cut off to obtain the insulation-shielding test sample. The dimensions of the insulation layer and the shielding layer are 100×100×1mm and φ50×2mm, respectively.

[0033] As some embodiments of the present invention, such as Figure 5 As shown, a first isolation layer 5 is provided between the insulation layer and the upper plate 4 in step S1. During the preparation of the cable insulation-shielding test specimen, the insulation material 7 will come into direct contact with the upper plate 4 during high-temperature molding. After cooling, it may be difficult to remove it completely from the mold due to adhesion, resulting in specimen damage. After setting the first isolation layer 5, it acts as an isolation layer between the insulation layer and the upper plate 4, effectively preventing the two from sticking together. After the specimen preparation is completed, the specimen can be easily removed from the mold, ensuring the integrity and appearance quality of the specimen, providing a good foundation for subsequent accurate testing and analysis.

[0034] As some embodiments of the present invention, such as Figure 5 As shown, in step S2, a second isolation layer 6 is provided between the insulating layer and the second shaping component 3, and the surface of the second isolation layer 6 is provided with clearance holes corresponding to the channels.

[0035] The design of the second insulating layer 6 effectively isolates the insulating layer from the second shaping component 3, preventing adhesion. During demolding, the sample can be easily removed from the mold, ensuring the integrity of the sample's appearance and structure, providing a good foundation for subsequent accurate testing and analysis.

[0036] As some embodiments of the present invention, in step S3, the temperature is heated to 140°C to 200°C, and the pressure is maintained at 0 MPa before the shielding material 8 melts.

[0037] As some embodiments of the present invention, in step S4, after the channel is opened, a pressure of 0.5~2 MPa is applied and maintained for 5~15 minutes, and then a pressure of 2~5 MPa is applied and maintained for 5~10 minutes.

[0038] Example 2 like Figures 8 to 10 As shown, the difference between Embodiment 2 and Embodiment 1 is that: the second shaping component 3 has two sliding baffles 33, which are symmetrically arranged in the groove, and a pull rod 34 is provided at the ends of the two sliding baffles 33 that are far apart from each other. The embodiment includes the following steps: Step S1: Place the insulating material 7 into the shaping groove of the first plate 21, and place the first plate 21 between the lower plate 1 and the upper plate 4, and perform the first hot pressing to form an insulating layer; specifically, weigh the insulating material 7 according to the required weight of the insulating layer, first place a 0.1mm thick polyimide film and the first plate 21 on the upper plate 1 in sequence, evenly place the weighed insulating material 7 in the shaping groove of the first plate 21, and then place the 0.1mm thick polyimide film on top in sequence. The amine film and the upper plate 4 are placed in a flat vulcanizing machine for pressing. The temperature of the flat vulcanizing machine is set to 180℃. The upper plate 4, the first plate 21, the lower plate 1, and the insulating material 7 are preheated on the machine for 5~10 minutes. At the same time, three exhausts are performed. After sufficient preheating, the material is pressed for 5 minutes under a pressure of 10MPa. Then, the upper plate 4, the first shaping component 2, and the lower plate 1 are cooled with the sample and removed from the vulcanizing machine. The insulation layer sample is pressed. The upper plate 4 and the polyimide film are then removed.

[0039] Step S2: Remove the upper plate 4, place the second shaping component 3 above the insulating layer, and slide the sliding baffle 33 to the first position to block the channel. Add shielding material 8 into the channel of the second shaping component 3. Specifically, calculate the amount of shielding material 8 according to the required shielding layer thickness, place the assembled second shaping component 3 above the first shaping component 2, and place the weighed shielding material 8 into the second through hole 35. At this time, the sliding baffle 33 closes the channel at the first position. Then, place a 0.1mm polyimide film and the upper plate 4 on the second plate 31 in sequence.

[0040] Step S3: Assemble the upper plate 4 and perform a second hot press to melt the shielding material 8. Set the temperature of the plate vulcanizing machine to 180°C. Preheat the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4, and the shielding material 8 in the vulcanizing machine for 10 minutes. Set the pressure of the vulcanizing machine to 0 MPa. Wait for the shielding material 8 to melt completely. Before the second hot press, place the polyimide film between the first shaping component 2 and the second shaping component 3. The polyester film has openings with the same shape, size, and distribution as the second shaping component 3. When placing the film, the opening positions of the polyester film and the second through holes 35 of the second shaping component 3 must correspond one-to-one.

[0041] Step S4: Slide the sliding baffle 33 to the second position away from the channel. After melting, the shielding material 8 flows through the channel to the surface of the insulating layer to form a shielding layer. After cooling, a double-layer sample is obtained. After step S3 is completed, the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4, and the shielding material 8 are cooled. The pressure is maintained at 2MPa during cooling. After complete cooling, the lower plate 1, the first shaping component 2, the second shaping component 3, the upper plate 4, and the shielding material 8 are removed. The excess part of the sample is cut off to obtain the insulation-shielding test sample. The dimensions of the insulating layer and the shielding layer are 100×100×1mm and φ50×2mm, respectively.

[0042] In summary, the present invention provides a mold and method for preparing cable insulation-shielding test specimens. Compared with the prior art, its advantages lie in the fact that the preparation of the insulation layer and the shielding layer are integrated into a single mold system through the sequentially separable connection of the lower plate 1, the first shaping component 2, the second shaping component 3, and the upper plate 4. After the insulation material 7 is placed in the shaping groove to form the insulation layer, there is no need to transfer the specimen. The sliding baffle 33 is directly operated to the second position to open the channel, and the shielding material 8 can be injected into the channel to prepare the shielding layer. The entire process is completed continuously within a single mold, greatly reducing intermediate steps and operations, significantly improving preparation efficiency, and shortening the specimen preparation time. The cycle can meet the requirements of large-scale testing and R&D for the number of samples. In the second shaping component 3, the second plate 31 and the third plate 32 are provided with multiple mutually spaced second through holes 35, forming multiple vertically penetrating channels, which constitute multiple independent shielding material 8 flow spaces. During the shielding layer preparation process, shielding material 8 can be injected into multiple channels at the same time, so that multiple shielding layers are formed on the same insulating layer substrate surface, and multiple sets of insulation-shielding samples are prepared at one time. This multi-channel structure design makes full use of the space resources of the mold, avoids the time and material waste caused by repeatedly preparing the same sample, and realizes the batch and high efficiency of sample preparation.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A mold for preparing a cable insulation-shielding test sample, characterized in that, include: The components that can be detachably connected from bottom to top are: a lower plate (1), a first shaping component (2), a second shaping component (3), and an upper plate (4). The first shaping component (2) includes a first plate (21), and a first through hole (211) is provided on the surface of the first plate (21). The lower plate (1) and the first plate (21) are enclosed to form a shaping groove that communicates with the first through hole (211). The second shaping component (3) includes a second plate (31) and a third plate (32) that are detachably connected, and a sliding baffle (33) disposed between the two. The second plate (31) and the third plate (32) are provided with a sliding groove (36) for the sliding baffle (33) to slide at opposite ends. The second plate (31) and the third plate (32) are provided with a plurality of second through holes (35) at corresponding positions. When the second plate (31) and the third plate (32) are connected, the second through holes (35) form a channel that runs through in the vertical direction. The sliding baffle (33) has a first position and a second position. When the sliding baffle (33) slides to the first position, it closes the channel. When the sliding baffle (33) slides to the second position, it avoids the channel.

2. The cable insulation-shielding test specimen preparation mold according to claim 1, characterized in that, The second shaping component (3) further includes a pull rod (34), one end of which extends into the groove (36) and connects to the sliding baffle (33), and the other end extends out of the groove (36). The pull rod (34) is used to drive the sliding baffle (33) to slide horizontally in the groove (36).

3. The cable insulation-shielding test specimen preparation mold according to claim 1, characterized in that, The second plate (31) has a positioning hole (311) through which the arch bolt passes, and the third plate (32) has a threaded hole (321) corresponding to the positioning hole (311) on its surface. The threaded hole (321) is used to fit the bolt.

4. The cable insulation-shielding test specimen preparation mold according to claim 1, characterized in that, A plurality of channels are formed between the second plate (31) and the third plate (32), and the plurality of channels are arranged at intervals along the axial direction of the second plate (31).

5. The cable insulation-shielding test specimen preparation mold according to claim 4, characterized in that, The cross-section of the channel in the horizontal direction has a predetermined shape.

6. A preparation method, based on the cable insulation-shielding test specimen preparation mold according to any one of claims 1-5, characterized in that, Includes the following steps: Step S1: Place the insulating material (7) in the shaping groove of the first plate (21), and place the first plate (21) between the lower plate (1) and the upper plate (4) for the first hot pressing to form an insulating layer; Step S2: Remove the upper plate (4), place the third plate (32), the sliding baffle (33) and the second plate (31) from top to bottom above the first plate (21), and slide the sliding baffle (33) to the first position to close the channel, and add shielding material (8) into the channel. Step S3: Assemble the upper plate (4) and perform a second hot pressing and pressure holding to melt the shielding material (8); Step S4: Remove the pressure and slide the sliding baffle (33) to the second position to open the channel. The molten shielding material (8) flows through the channel to the surface of the insulating layer under the action of gravity to form a shielding layer. After cooling, a double-layer sample is obtained.

7. The preparation method according to claim 6, characterized in that, In step S1, a first isolation layer (5) is provided between the insulating layer and the upper plate (4).

8. The preparation method according to claim 7, characterized in that, In step S2, a second isolation layer (6) is provided between the insulating layer and the second shaping component (3), and the surface of the second isolation layer (6) is provided with clearance holes corresponding to the channels.

9. The preparation method according to claim 8, characterized in that, In step S3, the temperature is heated to 140°C to 200°C, and the pressure is kept at 0 MPa before the shielding material (8) melts.

10. The preparation method according to claim 9, characterized in that, In step S4, after opening the channel, apply a pressure of 0.5~2 MPa and maintain it for 5~15 minutes, then apply a pressure of 2~5 MPa and maintain it for 5~10 minutes.

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