Die structure for preventing 750kV cable accessory from being extruded and broken during forming

Abstract

The utility model discloses a die structure for preventing a 750kV cable accessory from being extruded to be broken during forming, which comprises a lower die, a lower die, a lower die, a lower die, a lower die, a lower die, a lower die, a lower die, a lower die and an upper die, the lower die is provided with a lower cavity, and the upper end face of the lower die is provided with recesses which are distributed along the circumferential direction of the lower cavity and communicated with the lower cavity; the pressing ring is located in the concave position, the center line of the pressing ring is vertically distributed, an opening is formed in the pressing ring in the circumferential direction of the pressing ring, an inclined face is arranged between the upper end face of the pressing ring and the outer circumferential face of the pressing ring, the inclined face is distributed in the circumferential direction of the pressing ring and inclines outwards and downwards, and the pressing ring can elastically deform under the action of external force; the upper mold is arranged on the upper side of the lower mold, the upper mold is provided with an upper cavity, the upper mold is provided with a glue injection runner, the glue injection runner forms an outlet in the lower end face of the upper mold, the outlet is located over the inclined face, and the lower end face of the upper mold is concavely provided with a glue inlet communicated with the upper cavity and the outlet. According to the utility model, the solution pressure of a material at the glue inlet can be effectively released in the vulcanization process, and the defects of extrusion breakage, breakage and the like of the part of a product are prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of cable accessory production, in particular to a die structure for preventing 750kV cable accessories from being crushed during molding. Background Art

[0002] Many cable accessories are made of rubber. Rubber molding, particularly of EPDM rubber products, is plagued by the inherently poor tear resistance of EPDM, and the problem of material inlet crushing is a major issue. Larger products require higher injection volume accuracy and mold inlet structure. Too little injection volume results in an underfilled product, while too much injection volume can lead to significant thermal expansion during the high-temperature vulcanization process, forcing the material toward the mold inlet, resulting in crushing. A new mold structure is urgently needed to address this issue. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a mold structure that prevents crushing during the molding of 750kV cable accessories. This structure effectively releases the melt pressure of the material at the glue inlet during the vulcanization process, preventing defects such as crushing and cracking in the product at this location.

[0004] According to an embodiment of the present invention, a mold structure for preventing 750kV cable accessories from being crushed during molding comprises:

[0005] A lower mold having a lower cavity, wherein an upper end surface of the lower mold is provided with recesses, the recesses being distributed along the circumference of the lower cavity and communicating with the lower cavity;

[0006] A pressing ring, wherein the pressing ring is located in the recess and the center line of the pressing ring is vertically distributed. An opening is provided on the pressing ring along the circumference of the pressing ring. An inclined surface is provided between the upper end surface of the pressing ring and the outer circumferential surface of the pressing ring. The inclined surface is distributed along the circumference of the pressing ring and is inclined outward and downward. The pressing ring is configured to be elastically deformable under the action of an external force;

[0007] The upper mold is arranged on the upper side of the lower mold, and the upper mold has an upper cavity. The upper mold is provided with a glue injection channel, and the glue injection channel is formed with an outlet on the lower end surface of the upper mold. The outlet is located directly above the inclined surface, and a glue inlet is concavely formed on the lower end surface of the upper mold to connect the upper cavity and the outlet.

[0008] The mold structure for preventing 750kV cable accessories from being crushed during molding according to the embodiment of the present invention has at least the following beneficial effects:

[0009] During operation, the upper mold and the lower mold are first closed, and then the rubber raw material is injected through the glue injection channel. After the rubber raw material flows out from the outlet of the glue injection channel, it will flow to the inclined surface of the pressure ring. Since the inclined surface of the pressure ring is inclined outward and downward, the rubber raw material will generate an extrusion pressure on the pressure ring toward the center line of the pressure ring. At this time, since an opening is provided on the pressure ring, the pressure ring will shrink inward under the extrusion of the rubber raw material to make the opening smaller or even closed. As the rubber raw material continues to enter the molding cavity from the glue inlet until the molding cavity is filled, the rubber raw material gradually enters the vulcanization process. The thermal expansion force formed during the vulcanization process will cause the pressure ring to expand outward, and the opening of the pressure ring will gradually expand. In the process of the pressure ring expanding outward, it can release the vulcanization pressure and effectively release the melt pressure of the material at the glue inlet, thereby avoiding defects such as squeezing and rupture of the product at the glue inlet due to excessive extrusion pressure.

[0010] According to some embodiments of the present invention, the inner circumference of the recess is in contact with the outer circumference of the pressure ring.

[0011] According to some embodiments of the present invention, a first chamfered corner is provided at the lower end of the outer circumferential surface of the pressure ring.

[0012] According to some embodiments of the present invention, the pressure ring is configured as a circular ring structure, and the inclined surface is configured as a conical surface.

[0013] According to some embodiments of the present invention, along the circumference of the pressure ring, the opening and the glue inlet are staggered.

[0014] According to some embodiments of the present invention, the angle D between the inclined plane and the horizontal plane ranges from 15 degrees to 25 degrees.

[0015] According to some embodiments of the present invention, the upper end surface of the pressing ring is flush with the upper end surface of the lower mold, and when the upper mold and the lower mold are closed, the lower end surface of the upper mold at least partially covers the upper end surface of the pressing ring.

[0016] According to some embodiments of the present invention, the upper end of the inner circumference of the pressing ring is provided with a second chamfered corner, and the lower end of the inner circumference of the pressing ring is provided with a third chamfered corner.

[0017] According to some embodiments of the present invention, the injection channel includes a transverse channel and a longitudinal channel, the transverse channel is horizontally arranged on the upper end surface of the upper mold, the longitudinal channel is arranged at one end of the transverse channel, and the longitudinal channel extends vertically to the lower end surface of the upper mold to form the outlet.

[0018] According to some embodiments of the present invention, the pressing ring is made of manganese steel or polytetrafluoroethylene.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0021] Figure 1 It is a schematic diagram of the internal structure of an embodiment of the utility model;

[0022] Figure 2 yes Figure 1 A in the middle is an enlarged schematic diagram;

[0023] Figure 3 It is a structural schematic diagram of the pressure ring of an embodiment of the utility model.

[0024] Figure Number:

[0025] Lower mold 100, lower cavity 101, recess 102, core 110;

[0026] Pressing ring 200, opening 201, inclined surface 202, first rounded corner 203, second rounded corner 204, third rounded corner 205;

[0027] Upper mold 300, upper cavity 301, glue injection channel 302, outlet 303, glue inlet 304, transverse flow channel 305, longitudinal flow channel 306;

[0028] A first rubber material 400 and a second rubber material 401 . DETAILED DESCRIPTION

[0029] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the description of this utility model, "a plurality" means more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0033] Many cable accessories are made of rubber. Rubber molding, particularly of EPDM rubber products, is plagued by the inherently poor tear resistance of EPDM, and the biggest challenge is crushing the inlet. Larger products require higher injection volume accuracy and mold inlet structure. Too little injection volume results in an incomplete product due to material shortages. Too much injection volume can lead to significant thermal expansion during the high-temperature vulcanization process, forcing the material toward the mold inlet, resulting in crushing and rupture.

[0034] In this regard, the utility model proposes a mold structure that prevents 750kV cable accessories from being crushed during molding, which can effectively improve the above-mentioned problem.

[0035] Refer to the following Figures 1 to 3 The following describes a mold structure for preventing 750kV cable accessories from being crushed during molding according to an embodiment of the present invention.

[0036] The mold structure for preventing 750kV cable accessories from being crushed during molding according to the embodiment of the present invention comprises: a lower mold 100 , a pressing ring 200 and an upper mold 300 .

[0037] The lower mold 100 has a lower mold cavity 101 . The upper end surface of the lower mold 100 is provided with a recess 102 . The recess 102 is located at the top of the lower mold cavity 101 and is distributed along the circumference of the lower mold cavity 101 . The inner side of the recess 102 is connected to the lower mold cavity 101 .

[0038] The pressure ring 200 is an annular structure. The pressure ring 200 is located in the recess 102 and the center line of the pressure ring 200 is distributed vertically. Along the circumference of the pressure ring 200, the pressure ring 200 is provided with an opening 201, that is, the pressure ring 200 is a discontinuous annular structure; an inclined surface 202 is provided between the upper end surface of the pressure ring 200 and the outer peripheral surface of the pressure ring 200, and the inclined surface 202 is distributed along the circumference of the pressure ring 200, and the inclined surface 202 is inclined outward and downward away from the center line of the pressure ring 200. The pressure ring 200 is configured to undergo elastic deformation under the action of external force, that is, the pressure ring 200 has elastic deformation ability.

[0039] The upper mold 300 is arranged on the upper side of the lower mold 100. The upper mold 300 has an upper cavity 301. When the upper mold 300 and the lower mold 100 are molded together, the upper cavity 301 cooperates with the lower cavity 101 to form a complete molding cavity; the upper mold 300 is provided with a glue injection flow channel 302. The glue injection flow channel 302 is formed with an outlet 303 on the lower end surface of the upper mold 300. The outlet 303 of the glue injection flow channel 302 is located just above the inclined surface 202, that is, the rubber raw material flowing out of the outlet 303 of the glue injection flow channel 302 can fall into the inclined surface 202. 2, it is obvious that the glue injection channel 302 is further formed with an inlet on one side of the upper mold 300. In addition, a glue inlet 304 is formed on the lower end surface of the upper mold 300 to connect the upper cavity 301 and the outlet 303 of the glue injection channel 302. When the mold is closed, the rubber raw material is injected through the inlet of the glue injection channel 302, and the rubber raw material flows to the inclined surface 202 of the pressure ring 200 through the outlet 303 of the glue injection channel 302, and at the same time enters the molding cavity formed by the combination of the upper cavity 301 and the lower cavity 101 through the glue inlet 304.

[0040] The mold structure for preventing 750kV cable accessories from being crushed during molding according to the embodiment of the present invention is as follows: when working, the upper mold 300 is first closed with the lower mold 100, and then the rubber raw material is injected through the glue injection flow channel 302. After the rubber raw material flows out from the outlet 303 of the glue injection flow channel 302, it will flow onto the inclined surface 202 of the pressing ring 200. Since the inclined surface 202 of the pressing ring 200 is inclined outward and downward, the rubber raw material will generate an extrusion force toward the center line of the pressing ring 200 on the pressing ring 200. At this time, since an opening 201 is provided on the pressing ring 200, the pressing ring 200 will be squeezed by the rubber raw material. Under the extrusion of the rubber raw material, it shrinks inward to make the opening 201 smaller or even closed. As the rubber raw material continues to enter the molding cavity from the rubber inlet 304 until the molding cavity is filled, the rubber raw material gradually enters the vulcanization process. The thermal expansion force generated during the vulcanization process will cause the pressing ring 200 to expand outward, and the opening 201 of the pressing ring 200 will gradually expand. In the process of the pressing ring 200 expanding outward, the vulcanization pressure can be released, and the melt pressure of the material at the rubber inlet 304 can be effectively released, thereby avoiding excessive extrusion pressure causing defects such as squeezing and rupture of the product at the rubber inlet 304.

[0041] In addition, it should be noted that the size of the opening 201 needs to be designed according to the size of different products, so the present invention does not limit the size of the opening 201.

[0042] Reference Figure 1 and Figure 2As shown, in some embodiments of the present invention, the inner circumference of the recess 102 is in contact with the outer circumference of the pressing ring 200. In this way, the recess 102 can be used to position the pressing ring 200 in a horizontal direction, preventing the pressing ring 200 from moving laterally at will. When the rubber material falls onto the inclined surface 202 of the pressing ring 200, the pressing ring 200 can be more smoothly contracted and deformed inward. In a further embodiment, the lower end of the outer circumference of the pressing ring 200 is provided with a first chamfered corner 203. By providing the first chamfered corner 203, the pressing ring 200 can be more smoothly placed in the recess 102 during assembly, thereby improving assembly efficiency.

[0043] Reference Figure 2 and Figure 3 As shown, in some embodiments of the present invention, the pressing ring 200 is configured as a circular ring structure, and the inclined surface 202 is configured as a conical surface. In this way, when the pressing ring 200 is squeezed by the rubber material, the pressing ring 200 can shrink and deform smoothly.

[0044] In some embodiments of the present invention, the opening 201 of the pressing ring 200 is staggered with the glue inlet 304 along the circumference of the pressing ring 200, that is, the opening 201 of the pressing ring 200 is not directly below the glue inlet 304, so as to avoid the rubber raw material directly squeezing the pressing ring 200 open instead of slowly shrinking and closing the pressing ring 200 when the rubber raw material is injected.

[0045] Reference Figure 2 As shown, in some embodiments of the present invention, the angle D between the inclined surface 202 and the horizontal plane ranges from 15 degrees to 25 degrees, that is, the angle D between the inclined surface 202 and the horizontal plane is not less than 15 degrees and not greater than 25 degrees. It can be understood that when the rubber material is pressed on the inclined surface 202, a horizontal force toward the center line of the pressing ring 200 can be decomposed through the inclined surface 202. This force can cause the pressing ring 200 to shrink inward. If the angle D between the inclined surface 202 and the horizontal plane is less than If the angle D between the inclined surface 202 and the horizontal plane is greater than 15 degrees, the angle is too small, and the force applied by the rubber material to the pressing ring 200 horizontally toward the center line of the pressing ring 200 will be too small, insufficient to cause the pressing ring 200 to shrink inward. If the angle D between the inclined surface 202 and the horizontal plane is greater than 25 degrees, the angle is too large, which can easily cause the pressing ring 200 to be subjected to excessive force and deform, and increase the resistance to the subsequent rebound of the pressing ring 200. Therefore, in this embodiment, the angle D between the inclined surface 202 and the horizontal plane is designed to be in the range of 15 degrees to 25 degrees. It should be noted that in some embodiments, the pressing ring 200 is configured as an annular structure and the inclined surface 202 is configured as a conical surface. When the rubber material is pressed on the inclined surface 202, this inclined surface 202 can decompose a force inward along the radial direction of the pressing ring 200.

[0046] Reference Figure 2As shown, in some embodiments of the present invention, the upper end surface of the pressure ring 200 is flush with the upper end surface of the lower mold 100, that is, the pressure ring 200 is completely located in the recess 102 and does not protrude upward from the lower mold 100, and when the upper mold 300 and the lower mold 100 are closed, the lower end surface of the upper mold 300 at least partially covers the upper end surface of the pressure ring 200. In this way, when the upper mold 300 and the lower mold 100 are closed, the pressure ring 200 can be prevented from vertically moving, thereby playing a role of vertically limiting the pressure ring 200.

[0047] Reference Figure 2 As shown, in some embodiments of the present invention, the upper end of the inner circumference of the pressing ring 200 is provided with a second chamfer 204, and the lower end of the inner circumference of the pressing ring 200 is provided with a third chamfer 205, so as to avoid the occurrence of sharp corners on the product and cause excessive stress concentration, thereby ensuring the quality of the product.

[0048] Reference Figure 1 As shown, in some embodiments of the present invention, the injection channel 302 includes a transverse channel 305 and a longitudinal channel 306. The transverse channel 305 is horizontally arranged on the upper end surface of the upper mold 300, and the longitudinal channel 306 is arranged at one end of the transverse channel 305. The longitudinal channel 306 extends vertically to the lower end surface of the upper mold 300 to form an outlet 303. Since the outlet 303 is located directly above the inclined surface 202, when the rubber material is injected, the rubber material can be injected vertically into the inclined surface 202 of the pressing ring 200, ensuring that a sufficient amount of rubber material falls on the inclined surface 202 of the pressing ring 200 to elastically shrink and deform the pressing ring 200. In some embodiments, the material of the pressing ring 200 is manganese steel or polytetrafluoroethylene.

[0049] In one specific embodiment, the cable accessories to be produced include two rubber raw materials, which are named as the first rubber raw material 400 and the second rubber raw material 401 for the convenience of distinction. The first rubber raw material 400 is pre-made, and the core 110 is set in the lower cavity 101. The first rubber raw material 400 is pre-set on the core 110 before production. During production, the upper mold 300 and the lower mold 100 are molded together, and then the second rubber raw material 401 is injected through the injection channel 302. After the second rubber raw material 401 flows out from the outlet 303 of the injection channel 302, it will flow to the inclined surface 202 of the pressing ring 200. Since the inclined surface 202 of the pressing ring 200 is inclined outward and downward, the second rubber raw material 401 will press the pressing ring. 200 generates an extrusion pressure toward the center line of the pressing ring 200. At this time, since an opening 201 is provided on the pressing ring 200, the pressing ring 200 will shrink inward under the extrusion of the second rubber raw material 401 to make the opening 201 smaller or even closed. As the second rubber raw material 401 continues to enter the molding cavity from the glue inlet 304 until the remaining space in the molding cavity is filled, the material gradually enters the vulcanization process. The thermal expansion force generated during the vulcanization process will cause the pressing ring 200 to expand outward, and the opening 201 of the pressing ring 200 will gradually expand. In the process of the pressing ring 200 expanding outward, the vulcanization pressure can be released, thereby avoiding defects such as squeezing and rupture of the product at the glue inlet 304 caused by excessive extrusion force. In this embodiment, since the second rubber raw material 401 is manufactured in advance and mounted on the core 110, in order to make full use of the existing structure, the inner ring of the pressure ring 200 can be extended into the lower cavity 101 and downwardly abut the first rubber raw material 400, thereby acting as a vertical limit for the first rubber raw material 400.

[0050] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0051] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A mold structure for preventing 750kV cable accessories from being crushed during molding, characterized in that: include: A lower mold having a lower cavity, wherein an upper end surface of the lower mold is provided with recesses, the recesses being distributed along the circumference of the lower cavity and communicating with the lower cavity; A pressing ring, wherein the pressing ring is located in the recess and the center line of the pressing ring is vertically distributed. An opening is provided on the pressing ring along the circumference of the pressing ring. An inclined surface is provided between the upper end surface of the pressing ring and the outer circumferential surface of the pressing ring. The inclined surface is distributed along the circumference of the pressing ring and is inclined outward and downward. The pressing ring is configured to be elastically deformable under the action of an external force; The upper mold is arranged on the upper side of the lower mold, and the upper mold has an upper cavity. The upper mold is provided with a glue injection channel, and the glue injection channel is formed with an outlet on the lower end surface of the upper mold. The outlet is located directly above the inclined surface, and a glue inlet is concavely formed on the lower end surface of the upper mold to connect the upper cavity and the outlet.

2. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: The inner circumferential surface of the recess is in contact with the outer circumferential surface of the pressing ring.

3. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 2 is characterized in that: A first chamfered corner is provided at the lower end of the outer circumferential surface of the pressing ring.

4. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: The pressing ring is configured as a circular ring structure, and the inclined surface is configured as a conical surface.

5. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: Along the circumference of the pressing ring, the opening and the glue inlet are staggered.

6. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: The angle D between the inclined plane and the horizontal plane ranges from 15 degrees to 25 degrees.

7. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: The upper end surface of the pressing ring is flush with the upper end surface of the lower mold. When the upper mold and the lower mold are clamped, the lower end surface of the upper mold at least partially covers the upper end surface of the pressing ring.

8. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1 is characterized in that: The upper end of the inner circumference of the pressing ring is provided with a second chamfered corner, and the lower end of the inner circumference of the pressing ring is provided with a third chamfered corner.

9. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1, characterized in that: The injection channel includes a transverse channel and a longitudinal channel. The transverse channel is horizontally arranged on the upper end surface of the upper mold, and the longitudinal channel is arranged at one end of the transverse channel. The longitudinal channel extends vertically to the lower end surface of the upper mold to form the outlet.

10. The mold structure for preventing 750kV cable accessories from being crushed during molding according to claim 1, characterized in that: The material of the pressing ring is manganese steel or polytetrafluoroethylene.

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