Pre-branched cable injection molding mold

Abstract

A pre-branched cable injection molding mold is characterized by comprising an upper mold body, a lower mold body, a first wire clamping mold and a second wire clamping mold, and the first wire clamping mold and the second wire clamping mold are arranged at two ports of a cavity formed after the upper mold body and the lower mold body are closed; the liquid flow groove is connected with the injection molding hole, so that the injection molding material is prevented from being directly injected into and pushing the cable branch crimping part, the cable branch crimping part is prevented from displacing after being subjected to large injection molding pressure to the greatest extent, the original dislocation crimping branch line with the main cable is changed or loosened, the thickness of each side of the injection molding body is uniform, the injection molding body is not easy to wear and crack, and the service life of the injection molding body is prolonged. The accident rate is low, the overall size is small, the occupied laying space is small, construction is convenient, and the glue guide pipes are arranged in the injection molding holes, so that mold opening and residual glue cleaning are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of cable manufacturing, in particular to an injection molding die for a multi-core pre-branching cable. Background Art

[0002] At present, the multi-core pre-branched cables used in high-rise buildings are often installed in a way that the branch head section is too large and the laying space in the cable well and bridge is insufficient, which affects the construction of the line and the appearance of the line after installation. Therefore, the branch head section of the multi-core pre-branched power cable should not be too large. If it is too large, it will occupy a large laying space, which is not conducive to the laying of multiple groups of cables in the cable well.

[0003] During the use of existing prefabricated branch cables, short circuit accidents often occur in the branch head section. The reason is that during the production, the injection molding body of the branch head section is directly injected at the opening of the cavity during crimping injection molding. The injection molding machine directly pushes the injection material into the cable branch crimping part, causing the cable branch crimping part to be displaced after being subjected to a large injection pressure, causing the original crimped branch line that was misaligned with the main cable to change or loosen. At the same time, the thickness of the injection molding body is uneven. One side is thin and easy to wear and perforate, and the other side is too thick, resulting in insufficient flexibility and easy to break when bent, which will increase the short circuit and water seepage accident rate of the cable. Due to different processing methods, the main cable sheath material and the injection material at the connection of the two ends of the injection molding body directly crack when bent, causing the cable core to be directly exposed and lack of protection, resulting in a short circuit accident in the cable.

[0004] During the injection molding process of the cable's injection molded body, the rubber in the injection molding machine flows into the mold cavity through the injection hole. After the rubber is cooled, the injection rubber at the tail end will stick to the inner walls of the injection hole and the liquid flow channel due to the pressure of the injection molding machine or the physical properties of the material itself after melting, resulting in greater resistance during mold opening and demolding. It also takes time and effort to remove the residual rubber in the injection hole and the liquid flow channel. Summary of the invention

[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and to provide a pre-branching cable injection molding die, the product injection molding body has uniform thickness, is not easy to wear and tear, has a low accident rate, is small in overall size, occupies little laying space, and is convenient for construction.

[0006] The technical scheme of the utility model is: a pre-branch cable injection molding die, characterized in that it comprises an upper mold body, a lower mold body, a first wire clamping mold and a second wire clamping mold, wherein the first wire clamping mold and the second wire clamping mold are arranged at two ends of a cavity formed after the upper mold body and the lower mold body are molded together;

[0007] The upper mold body is provided with a rubber guide hole and a liquid flow groove, the liquid flow groove is arranged on the surface of the upper mold body outside the mold cavity, one end of the liquid flow groove is an injection hole, and the other end is connected to the mold cavity of one end of the first wire clamping mold of the upper mold body, and the injection hole is connected to the mold cavity of the upper mold body at one end of the first wire clamping mold through the liquid flow groove;

[0008] The first wire clamping mold is arranged at the main line port of the cavity, and is a hollow cylinder. A circle of bosses is arranged on the outer surface of the first wire clamping mold, and the bosses are fixed with the corresponding grooves in the cavity. The inner hole of the first wire clamping mold is a two-step hole, which is used to prevent the injection plastic from overflowing from this end during injection molding, and can form a two-level transition step at the main wire end of the injection molding body during injection molding, which is conducive to bending and facilitates the transition between different process sizes of the main cable sheath and the injection molding body;

[0009] The second wire clamping mold is arranged at the branching port of the cavity, and the second wire clamping mold includes two first split bodies and a second split body which are mirror images of each other. A number of small semicircular notches and a large semicircular notch are provided on one long side of the first split body according to the number of main wires and branch wires. The second split body is also provided with corresponding semicircular notches at a position relative to the notches of the first split body. After the first split body and the second split body are spliced ​​and combined, the notches thereon form a main wire clamping hole and a number of branch wire clamping holes. The outer sides of the upper semicircular notches of the two split bodies of the second wire clamping mold are also provided with symmetrically distributed fixing holes. After the mold is closed, the two split bodies are connected as a whole through the fixing holes through a cover plate with corresponding holes.

[0010] A further technical solution of the utility model is: a rubber guide tube is provided on the lower mold body at a position corresponding to the injection hole of the upper mold body, the rubber guide tube is cylindrical, the lower end of the rubber guide tube is fixedly connected to the lower mold body, a strip-shaped notch extending vertically is provided on the tube wall of the rubber guide tube along the axial direction, a notch is provided on one side of the connection between the lower end of the rubber guide tube and the lower mold body, which is aligned with the notch of the liquid flow groove after mold closing, the upper end passes through the injection hole for connection with the injection port of the injection molding machine, the injection rubber is injected into the liquid flow groove through the rubber guide tube and then enters the cavity, which can effectively reduce the adhesion of the injection rubber to the inner wall of the injection hole for easy mold opening, and the tube wall of the rubber guide tube is provided with a strip-shaped notch extending vertically for easy insertion of tools to clean residual rubber.

[0011] A further technical solution of the utility model is that positioning pin holes are respectively arranged at the diagonal positions of the upper mold body, and positioning pin holes are also arranged at corresponding positions of the lower mold body for the upper and lower mold bodies to be molded and positioned.

[0012] A further technical solution of the utility model is that a semicircular notch used as an exhaust hole is provided between the semicircular notch of the main wire clamping hole and the semicircular notch of the branch wire clamping hole on the two split bodies of the second wire clamping mold.

[0013] A further technical solution of the utility model is that mold opening grooves are arranged on the opposite side edges of the lower mold body for mold opening.

[0014] A further technical solution of the utility model is that the upper mold body, the lower mold body, the first wire clamping mold and the second wire clamping mold are made of 4Cr13 stainless steel material.

[0015] The usage of the technical solution of the utility model is: a method for injection molding of a multi-core pre-branching cable, which is characterized by comprising the following process steps:

[0016] 1. Wiring: According to the number of branch lines, connect the branch cable conductor with the end stripped of sheath and insulation to the conductor surface of the main line, then tighten the connection with a C-shaped copper buckle and put it into a press for further compression;

[0017] 2. Wrapping: Wrap the exposed part of each conductor of the tightly crimped conductor assembly with insulating tape, then bundle all the wires together, put them into the groove of the lower mold body of the injection molding mold, put a split of the second wire clamping mold into the groove corresponding to the groove of the lower mold body, and then put the main wire and branch wire at one end of the second wire clamping mold into the corresponding semicircular notches respectively, then pass the main wire at one end of the first wire clamping mold through the inner hole of the first wire clamping mold, and then put the first wire clamping mold into the groove corresponding to the groove of the lower mold body, apply force to tighten the two ends of the wire, and ensure that the compressed C-shaped copper buckle connection is not loose;

[0018] 3. Mold closing and injection molding: align the locating pin hole with the locating pin, cover the upper mold body on the lower mold body, ensure that the upper end of the rubber guide tube passes through the injection hole and is connected to the injection molding machine, and then fix the cover plate of the second clamping mold to the two parts by bolts to connect the second clamping mold as a whole, and then press the upper mold body and the lower mold body tightly, and use the injection molding machine to inject the molten injection plastic into the injection hole. The injection time is 200 seconds to 400 seconds;

[0019] 4. Mold opening, cooling and packaging: After removing the upper mold, wait for the injection molded body to cool to room temperature, then take out the injection molded body, wrap each end with insulating tape, and then package it into a product.

[0020] In order to increase the waterproof performance of the cable, it is characterized in that before the mold closing and injection molding step, 5-8 layers of high-temperature resistant water-blocking tape with a line length of not less than 50mm are overlapped and wrapped around the two ends of the main cable and the branch line ends of the branch cable inside the cavity 30-40mm away from each end clamping mold.

[0021] In order to improve the corrosion resistance and wear resistance of the injection mold, the invention is characterized in that before the wrapping step, the inner cavity of the upper mold body, the inner cavity of the lower mold body and the surface of the first clamping mold and the surface of the second clamping mold are treated with chrome plating and nitriding processes in sequence.

[0022] Compared with the prior art, the utility model has the following advantages: a liquid flow trough is used to connect the injection holes to avoid the injection plastic being directly injected into and pushing the cable branch crimping part, and the displacement of the cable branch crimping part after being subjected to a large injection pressure is avoided to the greatest extent, so that the original branch line that was crimped misaligned with the main cable will change or loosen; the thickness of each side of the injection molding body is uniform, not easy to wear or break, with a low accident rate, a small overall volume, a small laying space occupied, and convenient construction; a rubber guide tube is arranged in the injection hole to facilitate mold opening and cleaning of residual rubber.

[0023] The utility model is further described below in conjunction with the figures and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the upper mold structure of the injection mold of the utility model;

[0025] Figure 2 This is a schematic diagram of the lower mold structure of the injection mold of the utility model;

[0026] Figure 3 This is a schematic diagram of the mold clamping structure of the utility model;

[0027] Figure 4 for Figure 3 AA section view;

[0028] Figure 5 This is a schematic diagram of the installation structure of the rubber guide tube of the utility model;

[0029] Figure 6 This is a schematic diagram of the structure of the first wire clamping mold of the utility model;

[0030] Figure 7 This is a schematic diagram of the structure of the second wire clamping mold of the utility model;

[0031] Figure 8 This is a schematic diagram of the structure of the rubber guide hose of the utility model. DETAILED DESCRIPTION Example

[0032] As shown in the figure, a pre-branch cable injection molding mold includes an upper mold body 1, a lower mold body 2, a first wire clamping mold 3 and a second wire clamping mold 4, and the first wire clamping mold 3 and the second wire clamping mold 4 are arranged at two ends of a cavity 6 formed by the upper mold body 1 and the lower mold body 2 being molded together;

[0033] The upper mold body 1 is provided with an injection hole 11 and a liquid flow groove 12, wherein the liquid flow groove 12 is arranged on the surface of the upper mold body 1 outside the mold cavity 6, one end of the liquid flow groove 12 is the injection hole 11, and the other end is connected to the mold cavity 6 at one end of the first clamping mold 3 of the upper mold body 1, and the injection hole 11 is connected to the mold cavity 6 of the upper mold body 1 at one end of the first clamping mold 3 through the liquid flow groove 12;

[0034] The first wire clamping mold 3 is arranged at the main line port of the cavity 6, and is a hollow cylinder. A circle of bosses 31 are arranged on the outer surface of the first wire clamping mold 3. The bosses 31 are fixed with the corresponding grooves in the cavity. The inner hole of the first wire clamping mold 3 is a two-step hole, which is used to prevent the injection plastic from overflowing from this end during injection molding, and can form a two-level transition step at the main line end of the injection molding body during injection molding, which is conducive to bending;

[0035] The second wire clamping mold 4 is arranged at the branching port of the cavity 6, and the second wire clamping mold 4 includes two first split bodies 41 and a second split body 42 which are mirror images of each other. A plurality of small semicircular notches 411 and a large semicircular notch 412 are provided on one long side of the first split body 41 according to the number of main conductors and branch conductors. The second split body 42 is also provided with corresponding semicircular notches at a position relative to the notches of the first split body 41. After the first split body 41 and the second split body 42 are spliced ​​and combined, the notches thereon form a main wire clamping hole and a plurality of branch wire clamping holes. The outer sides of the upper semicircular notches of the two split bodies of the second wire clamping mold are also provided with symmetrically distributed fixing holes. After the mold is closed, the two split bodies are connected as a whole through the fixing holes 413 through a cover plate 5 with corresponding holes.

[0036] A rubber guide tube 13 is provided on the lower mold body 2 at a position corresponding to the injection hole 11 of the upper mold body 1. The rubber guide tube 13 is cylindrical, and the lower end of the rubber guide tube 13 is fixedly connected to the lower mold body 2. A strip-shaped notch that runs through the tube wall of the rubber guide tube 13 is axially provided thereon, and a notch that is aligned with the notch of the liquid flow groove 12 after the mold is closed is provided on one side of the connection between the lower end of the rubber guide tube 13 and the lower mold body 2. The upper end passes through the injection hole 11 for connection with the injection port of the injection molding machine. The injection rubber material is injected into the liquid flow groove 12 through the rubber guide tube 13 and then enters the cavity 6, which can effectively reduce the adhesion of the injection rubber material to the inner wall of the injection hole 11 and facilitate mold opening. The tube wall of the rubber guide tube 13 is provided with a strip-shaped notch that runs through the tube wall to facilitate the insertion of tools to clean up the residual rubber material.

[0037] Positioning pin holes 14 are respectively provided at the diagonal positions of the upper mold body 1, and positioning pin holes are also provided at the corresponding positions of the lower mold body 2, which are used for the upper and lower mold bodies to be molded and positioned.

[0038] A semicircular notch used as an exhaust hole 44 is further provided between the semicircular notch 411 of the main wire clamping hole and the semicircular notch 412 of the branch wire clamping hole on the two split bodies of the second wire clamping mold 4 .

[0039] The lower mold body 2 has mold opening grooves 21 on opposite sides of its edges for mold opening.

[0040] The upper mold body 1, the lower mold body 2, the first wire clamping mold 3 and the second wire clamping mold 4 are made of 4Cr13 stainless steel material.

[0041] A multi-core pre-branching cable injection molding method based on the above-mentioned injection molding mold, comprising the following process steps:

[0042] 1. Wiring: According to the number of branch lines, connect the branch cable conductor with the end stripped of sheath and insulation to the conductor surface of the main line, then tighten the connection with a C-shaped copper buckle and put it into a press for further compression;

[0043] 2. Wrapping: Wrap the exposed part of each conductor of the tightly crimped conductor assembly with insulating tape, then bundle all the wires together, put them into the groove of the lower mold body of the injection molding mold, put a split of the second wire clamping mold into the groove corresponding to the groove of the lower mold body, and then put the main wire and branch wire at one end of the second wire clamping mold into the corresponding semicircular notches respectively, then pass the main wire at one end of the first wire clamping mold through the inner hole of the first wire clamping mold, and then put the first wire clamping mold into the groove corresponding to the groove of the lower mold body, apply force to tighten the two ends of the wire, and ensure that the compressed C-shaped copper buckle connection is not loose;

[0044] 3. Mold closing and injection molding: align the locating pin hole with the locating pin, cover the upper mold body on the lower mold body, ensure that the upper end of the rubber guide tube passes through the injection hole and is connected to the injection molding machine, and then fix the cover plate of the second clamping mold to the two parts by bolts to connect the second clamping mold as a whole, pass the locating pin through the diagonal locating pin hole, press the upper mold body and the lower mold body, and use the injection molding machine to inject the molten injection plastic into the injection hole. The injection time is 400 seconds;

[0045] 4. Mold opening, cooling and packaging: After removing the upper mold, wait for the injection molded body to cool to room temperature, then take out the injection molded body, wrap each end with insulating tape, and then package it into a product.

[0046] In order to increase the waterproof performance of the cable, it is characterized in that before the mold closing and injection molding step, 5-8 layers of high-temperature resistant water-blocking tape with a line length of not less than 50 mm are overlapped and wrapped around the two ends of the main cable and the branch line ends of the branch cable inside the cavity 35 mm away from each end clamping mold.

[0047] In order to improve the corrosion resistance and wear resistance of the injection mold, the invention is characterized in that before the wrapping step, the inner cavity of the upper mold body, the inner cavity of the lower mold body and the surface of the first clamping mold and the surface of the second clamping mold are treated with chrome plating and nitriding processes in sequence.

Claims

1. A pre-branch cable injection molding mold, characterized in that It includes an upper mold body, a lower mold body, a first wire clamping mold and a second wire clamping mold, wherein the first wire clamping mold and the second wire clamping mold are arranged at two ends of the mold cavity formed after the upper mold body and the lower mold body are molded together; The upper mold body is provided with a rubber guide hole and a liquid flow groove, the liquid flow groove is arranged on the surface of the upper mold body outside the mold cavity, one end of the liquid flow groove is an injection hole, and the other end is connected to the mold cavity of one end of the first wire clamping mold of the upper mold body, and the injection hole is connected to the mold cavity of the upper mold body at one end of the first wire clamping mold through the liquid flow groove; The first wire clamping mold is arranged at the main line port of the cavity, and is a hollow cylinder. A circle of bosses is arranged on the outer surface of the first wire clamping mold, and the bosses are fixed with the corresponding grooves in the cavity. The inner hole of the first wire clamping mold is a two-step hole, which is used to prevent the injection plastic from overflowing from this end during injection molding, and can form a two-level transition step at the main wire end of the injection molding body during injection molding, which is conducive to bending and facilitates the transition between different process sizes of the main cable sheath and the injection molding body; The second wire clamping mold is arranged at the branching port of the cavity, and the second wire clamping mold includes two first split bodies and a second split body which are mirror images of each other. A number of small semicircular notches and a large semicircular notch are provided on one long side of the first split body according to the number of main wires and branch wires. The second split body is also provided with corresponding semicircular notches at a position relative to the notches of the first split body. After the first split body and the second split body are spliced ​​and combined, the notches thereon form a main wire clamping hole and a number of branch wire clamping holes. The outer sides of the upper semicircular notches of the two split bodies of the second wire clamping mold are also provided with symmetrically distributed fixing holes. After the mold is closed, the two split bodies are connected as a whole through the fixing holes through a cover plate with corresponding holes.

2. A pre-branch cable injection molding mold as claimed in claim 1, characterized in that A rubber guide tube is provided on the lower mold body at a position corresponding to the injection hole of the upper mold body. The rubber guide tube is cylindrical, and the lower end of the rubber guide tube is fixedly connected to the lower mold body. A strip notch is axially provided on the tube wall of the rubber guide tube, which passes through the upper and lower mold bodies. A notch is provided on one side of the connection between the lower end of the rubber guide tube and the lower mold body, which is aligned with the notch of the liquid flow groove after the mold is closed. The upper end passes through the injection hole for connection with the injection port of the injection molding machine. The injection rubber is injected into the liquid flow groove through the rubber guide tube and then enters the cavity.

3. A pre-branch cable injection molding mold as described in claim 1 or 2, characterized in that Positioning pin holes are respectively arranged at the diagonal positions of the upper mold body, and positioning pin holes are also arranged at the corresponding positions of the lower mold body, which are used for the mold closing and positioning of the upper and lower mold bodies.

4. A pre-branch cable injection molding mold as claimed in claim 1 or 2, characterized in that A semicircular notch used as an exhaust hole is also provided between the semicircular notch of the main wire clamping hole and the semicircular notch of the branch wire clamping hole on the two split bodies of the second wire clamping mold.

5. A pre-branch cable injection molding mold as claimed in claim 3, characterized in that A semicircular notch used as an exhaust hole is also provided between the semicircular notch of the main wire clamping hole and the semicircular notch of the branch wire clamping hole on the two split bodies of the second wire clamping mold.

6. A pre-branch cable injection molding mold as described in claim 1, 2 or 5, characterized in that The opposite side edges of the lower mold body are provided with mold opening grooves for mold opening.

7. The pre-branch cable injection molding mold according to claim 3 is characterized in that The opposite side edges of the lower mold body are provided with mold opening grooves for mold opening.

8. The pre-branch cable injection molding mold according to claim 4, characterized in that The opposite side edges of the lower mold body are provided with mold opening grooves for mold opening.

9. The pre-branch cable injection molding mold according to any one of claims 1, 2, 5, 7, or 8, characterized in that The upper mold body, the lower mold body, the first wire clamping mold and the second wire clamping mold are made of 4Cr13 stainless steel material.

10. The pre-branch cable injection molding mold according to claim 3, characterized in that The upper mold body, the lower mold body, the first wire clamping mold and the second wire clamping mold are made of 4Cr13 stainless steel material.

11. The pre-branch cable injection molding mold according to claim 4, characterized in that The upper mold body, the lower mold body, the first wire clamping mold and the second wire clamping mold are made of 4Cr13 stainless steel material.

12. The pre-branch cable injection molding mold according to claim 6, characterized in that The upper mold body, the lower mold body, the first wire clamping mold and the second wire clamping mold are made of 4Cr13 stainless steel material.

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