Injection mold for manufacturing high-voltage cable protection layer

Abstract

According to the injection mold for manufacturing the high-voltage cable protection layer, in the overall injection molding process, on the basis of shape-preserving sleeves, firstly, the arrangement mode of each single-section shape-preserving sleeve is limited, the injection molding process of each single-section shape-preserving sleeve is completed in a correlative mode, and the diameter mode of a glue pouring channel in each single-section shape-preserving sleeve is specifically limited; according to the invention, a pressure balance assembly is further arranged in the diameter shrinkage forming process of the glue overflowing part, so that the glue liquid is temporarily stored in the glue pouring channels in the corresponding glue returning part and part of the glue pouring part, and the traction action of the cable inner core and the flowing pressure of the glue liquid are utilized, and the key content is that the pressure balance assembly is further arranged in the diameter shrinkage forming process of the glue overflowing part; the method is characterized in that possible'overflowing glue pressure 'is transferred into the pressed sleeve through the air pressure conversion process in the hole shrinkage forming process, in the process, the interior of the glue return part actively bears the'overflowing glue pressure', specifically, balance is carried out according to the backflow mode of glue liquid, and the two purposes of pressure balance and glue outlet amount balance are achieved on the basis that the temperature is kept stable.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, and in particular to an injection mold for producing a protective layer of a high-voltage cable. Background Art

[0002] The high-voltage cable protective layer is mainly prepared by injection molding of materials such as PVC, XLPE, and PUR. In essence, the molten plastic material is injected into the corresponding mold. After heat exchange, the molten plastic material cools and solidifies to form a cable protection compartment. Please refer to the relevant content in the publication number CN101807457A.

[0003] The temperature, pressure and glue discharge speed during the injection molding process of the cable outer layer are one of the key factors affecting the injection molding quality. Too high a temperature may cause bubbles or deformation, while too low a temperature will affect the molding effect. Too high a pressure may cause glue rushing, while too low a pressure may cause glue shortage. Too fast a glue discharge speed may cause glue rushing and flashing, while too slow a speed may cause product shrinkage, affecting the molding effect. Because the cable outer layer injection molding process is continuous, if the above problems occur in a local position due to the influence of factors such as temperature, pressure, and glue discharge speed, it is necessary to stop the line urgently or repair the local position. This process will affect the production line efficiency and the quality of the finished product.

[0004] This application proposes a solution to this problem. Summary of the Invention

[0005] The purpose of the present invention is to provide an injection mold for the production of high-voltage cable protective layer. Regarding the injection molding process of the cable outer layer, because the entire production line is in a continuous state, the differences in temperature, pressure and glue discharge speed during the specific injection molding process directly affect the production line efficiency or the quality of the finished product.

[0006] The object of the present invention can be achieved by the following technical solution: an injection mold for producing a high-voltage cable protective layer, comprising a cable inner core, a driving structure and a plurality of shape-retaining sleeves, wherein the shape-retaining sleeves are sequentially connected along the traction of the cable inner core, and the shape-retaining sleeves are respectively provided with a glue return portion, a glue injection portion, a glue overflow portion and a cooling portion along the traction of the cable inner core, a glue injection component is provided on the glue injection portion, and a pressure balancing component is provided between the glue return portion and the glue overflow portion; An outer coordinating sleeve is provided in the glue return part, an inner coordinating sleeve is provided in the inner position of the outer coordinating sleeve, and a first spiral sheet is installed on the outer wall of the outer coordinating sleeve, and a second spiral sheet corresponding to the inner wall position of the outer coordinating sleeve is installed on the outer wall of the inner coordinating sleeve, and glue holes are provided on the ends of the inner coordinating sleeve and the outer coordinating sleeve away from the glue filling part, and the outer coordinating sleeve is rotatably connected to the shape-preserving sleeve in the glue return part through a driving structure.

[0007] It is further configured as follows: a glue pouring channel corresponding to the cable inner core is opened in the shape-retaining sleeve, the diameter of the glue pouring channel matches the cable inner core, and the diameter of the glue pouring channel decreases along the pulling direction of the cable inner core.

[0008] It is further configured that: the glue pouring channel is respectively configured with a large diameter and a small diameter along the pulling direction of the cable inner core, and the setting position of the glue pouring component corresponds to the middle position between the large diameter and the small diameter.

[0009] It is further configured as follows: the pressure balancing assembly includes a pressure connecting sleeve, a return glue insulation pipe and a pressure sleeve, the return glue part and the overflow glue part are respectively provided with a return glue port and an overflow glue port, the return glue insulation pipe is used to be connected to the return glue port and the overflow glue port, and the pressure sleeve is installed in the middle position of the return glue insulation pipe.

[0010] It is further configured as follows: the pressure-connecting sleeve is respectively installed on the upper side of the return glue part and the overflow glue part, and a heat-resistant rubber sheet is installed in the internal position of the pressure-connecting sleeve, and the lower internal position of the pressure-connecting sleeve corresponding to the heat-resistant rubber sheet is connected to the inside of the shape-retaining sleeve.

[0011] It is further configured as follows: a directional movable block is installed inside the pressure sleeve for sliding in the vertical direction, and the inside of the pressure sleeve is divided into an upper air chamber and a lower air chamber by the directional movable block, and a glue hole is opened in the internal position of the directional movable block corresponding to the glue return insulation pipe.

[0012] It is further configured as follows: ventilation hoses are provided between the inside of the pressure-connecting sleeve in the overflow part and the upper air chamber, and between the inside of the pressure-connecting sleeve in the return part and the lower air chamber.

[0013] It is further configured as follows: the spiral diameter of the first spiral sheet matches the inner wall diameter of the corresponding large diameter, and the spiral angles of the first spiral sheet and the second spiral sheet are opposite and the pitches are different.

[0014] It is further configured as follows: the inner core of the cable passes through the outer coordination sleeve and the inner coordination sleeve respectively, and the setting position of the glue return port corresponds to the setting position of the first spiral sheet.

[0015] Further settings are: The present invention has the following beneficial effects: 1. For the injection molding process of the cable protective layer, multiple retaining sleeves are used as the basis. Each retaining sleeve cooperates with each other to complete the injection molding process. To this end, the diameter of the glue filling channel in each retaining sleeve is first limited, so that the glue filling channels in the corresponding glue return part and part of the glue filling part temporarily store the glue. This is mainly used to maintain the quantity and pressure during the shrinkage molding process at small diameters. Specifically, the pulling action of the cable core and the flow pressure of the glue are used to continuously inject and mold the high-voltage cable covered with the outer protective layer. 2. Based on the above content, the key is to add and improve the conformal sleeves at the glue return part and the glue overflow part to obtain a pressure balancing component. The pressure balancing component specifically uses the pressure receiving sleeve to sense the glue pressure changes in the glue overflow part in real time and convert it into air pressure. The pressure difference between the glue pressure and the air pressure is specifically used to transfer the "overflowing glue pressure" that may occur during the shrinkage forming to the pressure sleeve through the air pressure conversion process. The glue return part actively bears the "overflowing glue pressure" and drives the directional movement of the directional movable block. Its purpose is to control the flow amount and flow direction in the glue liquid reflux mode. On the basis of maintaining temperature stability, the two purposes of pressure balance and glue output balance are achieved through the glue pressure-air pressure balance method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a structural schematic diagram of an injection mold for producing a high-voltage cable protective layer proposed by the present invention; Figure 2 The present invention proposes an injection mold for producing a high-voltage cable protective layer Figure 1 Split diagram of ; Figure 3 The present invention proposes an injection mold for producing a high-voltage cable protective layer Figure 2 Front view of Figure 4 This is a schematic structural diagram of a pressure balancing component in an injection mold for producing a high-voltage cable protective layer, as proposed by the present invention; Figure 5 This is a disassembled diagram of the glue return part in an injection mold for manufacturing a high-voltage cable protective layer proposed by the present invention; Figure 6 The figure is a cross-sectional view of the glue return portion in an injection mold for producing a high-voltage cable protective layer proposed by the present invention.

[0018] In the figure: 1. Conformal sleeve; 101. Glue return unit; 102. Glue filling unit; 103. Glue overflow unit; 104. Cooling unit; 2. Driving structure; 3. Pressure-connecting sleeve; 4. Glue return insulation pipe; 5. Pressure sleeve; 6. Glue filling assembly; 7. External positioning sleeve; 8. Heat-resistant rubber sheet; 9. Directional movable block; 10. Glue hole; 11. Internal positioning sleeve; 12. First spiral sheet; 13. Second spiral sheet. DETAILED DESCRIPTION

[0019] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Example 1: Regarding the injection molding process of the cable outer layer, since the entire production line is in a continuous state, the differences in temperature, pressure, and glue discharge speed during the specific injection molding process directly affect the production line efficiency or the quality of the finished product. In this regard, the following technical solutions are proposed: Reference Figures 1 to 6 In this embodiment, an injection mold for producing a high-voltage cable protective layer includes a cable inner core, a driving structure 2, and multiple retaining sleeves 1. The retaining sleeves 1 are connected in sequence along the traction of the cable inner core, and the retaining sleeves 1 are respectively provided with a glue return part 101, a glue injection part 102, a glue overflow part 103, and a cooling part 104 along the traction of the cable inner core. A glue injection component 6 is provided on the glue injection part 102, and a pressure balancing component is provided between the glue return part 101 and the glue overflow part 103. An outer coordinating sleeve 7 is provided in the glue return part 101, an inner coordinating sleeve 11 is provided in the inner position of the outer coordinating sleeve 7, and a first spiral piece 12 is installed on the outer wall position of the outer coordinating sleeve 7, and a second spiral piece 13 corresponding to the inner wall position of the outer coordinating sleeve 7 is installed on the outer wall position of the inner coordinating sleeve 11, and glue holes are opened on the end position of the inner coordinating sleeve 11 and the outer coordinating sleeve 7 away from the glue filling part 102, and the outer coordinating sleeve 7 is rotatably connected to the shape-preserving sleeve 1 in the glue return part 101 through the driving structure 2.

[0021] Basic Principle: A brief description of the injection molding process of the outer protective layer of the high-voltage cable is given. First, a suitable plastic raw material is selected and melted under high pressure and high temperature to obtain a glue liquid, which is then injected into the inner part of the shape-contained sleeve 1 through high-pressure injection and the glue potting component 6; by Figure 3 For example, the cable core is continuously pulled and moved from left to right by a traction machine and other equipment. During this process, the glue is first squeezed into the glue pouring channel in each section of the retaining sleeve 1 by the glue pouring component 6, so that the cable core is completely covered with the glue. During the whole process, the temperature is controlled according to the physical properties of the plastic raw material to ensure that the glue fully covers the cable core and solidifies it by cooling to form an outer protective layer. This part is not explained in detail in the present invention. It should be noted that: Improvements are made to the glue pouring channels inside each section of the conformal sleeve, wherein the diameter of the glue pouring channels inside the conformal sleeve 1 in the glue pouring section 102, the glue overflow section 103 and the cooling section 104 is equal to the outer diameter of the high-voltage cable, but the diameter of some glue pouring channels in the glue return section 101 and the glue pouring section 102 is larger than the outer diameter of the high-voltage cable. Therefore, during the real-time glue pouring process, the glue pouring channels in the glue return section 101 and the glue pouring section 102 serve as temporary storage space for the glue liquid, specifically to maintain the quantity and pressure of the subsequent molding process in the glue overflow section 103 and the cooling section 104. The overall process specifically utilizes the traction action of the traction equipment and the glue pressure during the glue injection.

[0022] Example 2: Explanation of the overall injection molding process: A glue pouring channel corresponding to the cable inner core is opened in the conformal sleeve 1. The diameter of the glue pouring channel matches the cable inner core, and the diameter of the glue pouring channel decreases along the pulling direction of the cable inner core. The glue pouring channel is set to a large diameter and a small diameter along the pulling direction of the cable inner core, and the setting position of the glue pouring component 6 corresponds to the middle position between the large diameter and the small diameter.

[0023] Solution Description: Refer to Figure 5 and Figure 6 To illustrate, the cable core will first pass through the outer matching sleeve 7 and the inner matching sleeve 11, and the intersection of the outer matching sleeve 7 and the inner matching sleeve 11 with the cable core will be sealed. The overall shape-preserving sleeve 1 is in a fixed connection, but the outer matching sleeve 7 can be directional rotated by the driving structure 2. In this process, the synchronous rotation of the first spiral piece 12 can provide pressure from left to right on the glue in the glue return part 101 and the glue filling part 102. On the basis of the glue pressure of the glue, further pressure can be applied to the overall molding process to ensure that the glue is fully attached to the cable core. The inner coordinating sleeve 11 and the outer coordinating sleeve 7 adaptively rotate, but it needs to be further explained that the inner coordinating sleeve 11 will not rotate in the same direction due to the rotation of the outer coordinating sleeve 7. On the contrary, the inner coordinating sleeve 11 is mainly subjected to the glue pressure of the glue liquid itself and the second spiral piece 13 to rotate in a directional manner, and its rotation speed is related to the glue pressure of the glue liquid. The specific reason is that when the glue liquid is continuously injected into the glue return part 101 and the glue filling part 102, and the first spiral piece 12 further applies pressure, the pressure in the internal glue filling channels of the two is significantly increased. In this process, the glue liquid will also provide reverse glue pressure to the second spiral piece 13 in the inner coordinating sleeve 11 and drive the inner coordinating sleeve 11 to rotate in a directional manner. The purpose is to balance the glue pressure of the glue liquid inside the glue part 101 and the glue filling part 102, so as to avoid affecting the glue output speed due to excessive glue pressure.

[0024] Example 3: Based on Example 1 and Example 2, it can be seen that the overall injection molding process is supplemented with relevant instructions for the pressure balancing component: The pressure balancing assembly includes a pressure-connecting sleeve 3, a return glue insulation pipe 4, and a pressure sleeve 5. The return glue portion 101 and the overflow glue portion 103 are respectively provided with a return glue port and an overflow glue port. The return glue insulation pipe 4 is used to connect to the return glue port and the overflow glue port. The pressure sleeve 5 is installed in the middle of the return glue insulation pipe 4. The pressure-connecting sleeve 3 is respectively installed on the upper side of the return glue portion 101 and the overflow glue portion 103. A heat-resistant rubber sheet 8 is installed inside the pressure-connecting sleeve 3. The pressure-connecting sleeve 3 is connected to the interior of the conformal sleeve 1 in the lower internal position corresponding to the heat-resistant rubber sheet 8, and a directional movable block 9 is slidably installed in the pressure sleeve 5 in the vertical direction, and the interior of the pressure sleeve 5 is divided into an upper air chamber and a lower air chamber by the directional movable block 9. A glue hole 10 is opened in the internal position of the directional movable block 9 corresponding to the return glue insulation pipe 4, and a ventilation hose is provided between the interior of the pressure-connecting sleeve 3 in the overflow glue part 103 and the upper air chamber, and between the interior of the pressure-connecting sleeve 3 in the return glue part 101 and the lower air chamber. The spiral diameter of the first spiral piece 12 matches the inner wall diameter of the corresponding large diameter, and the spiral angles of the first spiral piece 12 and the second spiral piece 13 are opposite and the pitches are different. The inner core of the cable passes through the outer matching sleeve 7 and the inner matching sleeve 11 respectively, and the setting position of the return glue port corresponds to the setting position of the first spiral piece 12.

[0025] Specifically, the overall injection molding process is described in detail with respect to the technical contents in Example 1 and Example 2: S1: Figure 3 To illustrate, continuous glue filling is performed through the glue filling component 6, so that the glue pressure inside the glue part 101 and the glue filling part 102 continues to rise. However, when the glue continues to flow into the glue filling channel in the glue overflow part 103, the glue pressure inside the glue overflow part 103 will be greater than the glue pressure in the glue part 101 and the glue filling part 102 due to the shortening of the glue filling channel diameter. On this basis, the adhesion rate of the glue to the cable core can be improved. However, excessive glue pressure will also affect the molding process of the cable outer protective layer. For this, it is necessary to monitor the glue pressure of the glue in real time with two pressure connecting sleeves 3. Its essence is: refer to Figure 4 Because the lower end of the pressure-connecting sleeve 3 is connected to the inside of the shape-retaining sleeve 1, the glue inside the shape-retaining sleeve 1 will continue to overflow into the pressure-connecting sleeve 3. However, this process will be blocked by the heat-resistant rubber sheet 8, causing the heat-resistant rubber sheet 8 to undergo directional deformation. It is necessary to briefly explain that the type of heat-resistant rubber sheet 8 is selected according to the temperature of the plastic glue used for injection molding. If the temperature range of the plastic glue used for injection molding is 125-130°C, then it is necessary to ensure that the heat-resistant rubber sheet 8 can withstand a minimum temperature of 135°C. Therefore, the type of heat-resistant rubber sheet 8 is selected based on this minimum tolerance temperature requirement. On the basis of ensuring real-time monitoring, the heat-resistant rubber sheet 8 is prevented from indirectly affecting the glue pressure and injection molding process. S2: Based on S1 and with reference to Figure 2 , a glue return insulation pipe 4 is connected between the glue filling channels inside the glue return part 101 and the glue overflow part 103. Theoretically, the glue liquid inside the glue return part 101 and the glue overflow part 103 can flow freely through the glue return insulation pipe 4, so that the glue pressure inside the glue return part 101 and the glue overflow part 103 always remains equal. However, this process is not conducive to the coating process of the cable inner core in the glue overflow part 103. For this purpose, a pressure sleeve 5 needs to be provided in the glue return insulation pipe 4, and the pressure sleeve 5 is also provided with a directional movable block 9 for sealing the glue return insulation pipe 4. When the glue opening 10 in the directional movable block 9 is not connected to the glue return insulation pipe 4, the glue pressure inside the glue return part 101 and the glue overflow part 103 will not interfere with each other. However, the interior of the pressure sleeve 5 is divided into an upper air chamber and a lower air chamber by a directional movable block 9, and ventilation hoses are provided between the inside of the pressure-receiving sleeve 3 in the overflow glue part 103 and the upper air chamber, and between the inside of the pressure-receiving sleeve 3 in the return glue part 101 and the lower air chamber. It can be understood that: the glue pressure inside the return glue part 101 and the overflow glue part 103 will be directly reflected in the upper air chamber and the lower air chamber, thereby further driving the directional movable block 9 to move in a directional manner according to the glue pressure inside the return glue part 101 and the overflow glue part 103. When part of the glue port 10 is connected to the return glue insulation pipe 4, the return glue part 101 and the overflow glue part 103 are in contact with each other. The internal glue is connected, which further affects the glue pressure inside the return glue part 101 and the overflow glue part 103. However, because the glue filling component 6 continues to fill the glue, the pressure environment in the return glue part 101 continues to rise, thereby causing the directional movable block 9 to move further, so that the return glue insulation pipe 4 is blocked again. To this end, it is necessary to control the glue filling amount per unit time in the glue filling component 6 according to the process parameters, and based on this, the size of the directional movable block 9 is limited. The specific content is not explained in detail in the present invention. On the basis of maintaining the glue temperature, the key is to control the glue output by balancing the glue pressure; S3: For Example 2 and Figure 5 To supplement, after the return glue part 101 receives the "backflow replenishment" of the glue from the overflow glue part 103, it still continues to flow from left to right through the first spiral sheet 12, and a part of the glue enters the inner matching sleeve 11. Because this part of the glue needs to flow further, the internal glue needs to be ensured to be discharged through the glue ports in the outer matching sleeve 7 and the inner matching sleeve 11. Based on this, the inner matching sleeve 11 performs an adaptive rotation action in the outer matching sleeve 7.

[0026] In summary, based on the retaining sleeve, the arrangement of each single section of the retaining sleeve is restricted so that each section can complete the injection molding process in an interconnected manner. The diameter of the glue filling channel is specifically restricted so that the glue filling channels in the corresponding glue return section and partial glue filling section can temporarily store the glue. This can utilize the traction action of the cable core and the glue flow pressure. The key points are: A pressure balancing component is further set up for the shrinkage molding process in the overflow glue section. Its essence is: to transfer the "overflowing glue pressure" that may occur during the shrinkage molding to the pressure sleeve through the air pressure conversion process. In this process, the return glue section actively bears the "overflowing glue pressure" and balances it according to the specific return flow method of the glue liquid, thereby achieving the two goals of pressure balance and glue output balance on the basis of maintaining temperature stability.

[0027] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An injection mold for producing a high-voltage cable protective layer, comprising a cable inner core, a drive structure (2) and a plurality of shape-retaining sleeves (1), characterized in that: The shape-retaining sleeves (1) are connected in sequence along the pulling direction of the cable inner core, and the shape-retaining sleeves (1) are respectively provided with a glue return portion (101), a glue injection portion (102), a glue overflow portion (103) and a cooling portion (104) along the pulling direction of the cable inner core, a glue injection component (6) is provided on the glue injection portion (102), and a pressure balancing component is provided between the glue return portion (101) and the glue overflow portion (103); An outer coordinating sleeve (7) is provided in the glue return portion (101), an inner coordinating sleeve (11) is provided in an inner position of the outer coordinating sleeve (7), and a first spiral piece (12) is installed on the outer wall of the outer coordinating sleeve (7), a second spiral piece (13) corresponding to the inner wall position of the outer coordinating sleeve (7) is installed on the outer wall of the inner coordinating sleeve (11), and a glue opening is provided at one end of the inner coordinating sleeve (11) and the outer coordinating sleeve (7) away from the glue injection portion (102), and the outer coordinating sleeve (7) is rotatably connected to the shape-preserving sleeve (1) in the glue return portion (101) through the driving structure (2).

2. The injection mold for producing a high-voltage cable protective layer according to claim 1, characterized in that: The shape-retaining sleeve (1) is provided with a glue pouring channel corresponding to the cable inner core, the diameter of the glue pouring channel matches the cable inner core, and the diameter of the glue pouring channel decreases along the pulling direction of the cable inner core.

3. The injection mold for producing a high-voltage cable protective layer according to claim 2, characterized in that: The glue pouring channel is respectively arranged with a large diameter and a small diameter along the pulling direction of the cable inner core, and the setting position of the glue pouring component (6) corresponds to the middle position between the large diameter and the small diameter.

4. The injection mold for producing a high-voltage cable protective layer according to claim 1, characterized in that: The pressure balancing assembly comprises a pressure-connecting sleeve (3), a return glue insulation pipe (4) and a pressure sleeve (5); the return glue portion (101) and the overflow glue portion (103) are respectively provided with a return glue port and an overflow glue port; the return glue insulation pipe (4) is used to be connected to the return glue port and the overflow glue port; and the pressure sleeve (5) is installed in the middle of the return glue insulation pipe (4).

5. The injection mold for producing a high-voltage cable protective layer according to claim 4, characterized in that: The pressure-connecting sleeve (3) is respectively installed on the upper side of the return glue portion (101) and the overflow glue portion (103), and a heat-resistant rubber sheet (8) is installed in the inner position of the pressure-connecting sleeve (3). The lower inner position of the pressure-connecting sleeve (3) corresponding to the heat-resistant rubber sheet (8) is connected to the inner part of the shape-preserving sleeve (1).

6. The injection mold for producing a high-voltage cable protective layer according to claim 5, characterized in that: A directional movable block (9) is installed inside the pressure sleeve (5) so as to slide in the vertical direction, and the inside of the pressure sleeve (5) is divided into an upper air chamber and a lower air chamber by the directional movable block (9). A glue hole (10) is opened in the internal position of the directional movable block (9) corresponding to the glue return insulation pipe (4).

7. The injection mold for producing a high-voltage cable protective layer according to claim 6, characterized in that: A ventilation hose is provided between the interior of the pressure-connecting sleeve (3) in the overflow glue portion (103) and the upper air chamber, and between the interior of the pressure-connecting sleeve (3) in the return glue portion (101) and the lower air chamber.

8. The injection mold for producing a high-voltage cable protective layer according to claim 1, characterized in that: The spiral diameter of the first spiral sheet (12) matches the inner wall diameter of the corresponding large diameter, and the spiral angles of the first spiral sheet (12) and the second spiral sheet (13) are opposite and the pitches are different.

9. The injection mold for producing a high-voltage cable protective layer according to claim 4, characterized in that: The inner core of the cable passes through the outer matching sleeve (7) and the inner matching sleeve (11) respectively, and the setting position of the glue return port corresponds to the setting position of the first spiral sheet (12).

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