Ejector head connecting sleeve and novel ejector rod assembly
By designing a new head joint and using the structure of the outlet tank and cooling water outlet holes, efficient cooling of the head and the improvement of the inner surface quality of the steel pipe are achieved, solving the problem of poor head cooling effect in the existing technology, extending the service life and reducing production costs and safety risks.
Patent Information
- Application Number
- CN202421526273.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-28
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-06-28
AI Technical Summary
In the prior art, the cooling effect of the head is poor, resulting in the head being prone to structural defects such as nose collapse and meat loss under high temperature and high pressure conditions, which in turn affects the inner surface quality and service life of the steel pipe.
A new head joint is designed, including the main body of the socket, the water outlet tank and the cooling water outlet hole. The cooling water forms a water spray effect through the water outlet tank and tilts the water toward the head direction, improving the cooling effect of the head and reducing the impact on the inner surface of the steel pipe.
It achieves efficient cooling of the head, extends the service life of the head, improves the inner surface quality and material yield of the steel pipe, and reduces production costs and on-site safety risks.
Smart Images
Figure CN222902155U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of equipment related to seamless steel pipe production, and more specifically, particularly relates to a mandrel sleeve and a novel mandrel assembly. Background Art
[0002] Please refer to Figure 1 , Figure 1 The present invention is a schematic diagram of the structure of the jack, jack socket and jack rod after being assembled in the prior art.
[0003] In the production process of seamless steel pipes, the push rod assembly is used to realize the perforation of solid billet, which includes a push rod a and a push rod c. The push rod a is installed on the push rod c through a push rod socket b. A cold water pipeline d is arranged along the central axis of the push rod c to realize the circulation and transportation of cooling water, so as to cool the push rod a, the push rod socket b and the push rod c.
[0004] The plug a is one of the important deformation tools in the production of seamless steel pipes. Its main function is to punch the solid billet into a hollow rough tube. The metal deformation produced by the solid billet is mainly concentrated on the plug a. During the oblique rolling and punching process, the plug a is in a complex stress state such as repeated alternating tensile and compressive stress and frequent cold and hot alternating stress. The plug a works under extremely harsh conditions of high temperature, high pressure, rapid cooling and rapid heating. At the same time, it plays a vital role in the inner surface quality and wall thickness of the rough tube. Since the plug a is in contact with the high-temperature solid billet, if the plug a is not cooled well, the nose of the plug a (that is, the front end of the plug a) is prone to collapse (depression), meat loss (partial structure detachment), etc. If the plug a with such structural defects is continued to be used for steel penetration, the inner surface of the steel pipe (rough tube) will have defects such as internal folds, pits, and large pieces of heavy skin, causing the steel pipe to be scrapped and reducing the yield rate of the product. Therefore, once the plug a has defects such as collapsed nose and flesh loss, it must be replaced with a new plug a, which increases production costs and reduces production efficiency (replacing the plug a takes a certain amount of time).
[0005] In the prior art, there are several typical ways to cool the plug a:
[0006] 1. Open a hole directly on the top a for cooling.
[0007] Please refer to Figure 2 , Figure 2 The present invention is a schematic diagram of the structure of the plug when water holes are directly opened on the plug for cooling in the prior art.
[0008] In this method, three ∮3mm water holes e are evenly drilled around the nose of the mandrel a at intervals of 120° to release the cooling water delivered by the mandrel c. This method of drainage cooling has little effect on carbon steel when rolling carbon steel because the cooling water in the mandrel a is sprayed toward the end of the billet. However, when rolling alloy steel and high-alloy steel, the billet head will be wet (the head temperature is low), which is easy to cause the entire length of the steel pipe to be folded inward, the mechanical properties are not compatible, and the head has a heavy skin defect, causing the steel pipe to be scrapped and reducing the yield rate.
[0009] 2. Make a hole on the top socket b for cooling.
[0010] Please refer to Figure 3 and Figure 4 ,in, Figure 3 It is a schematic diagram of the structure of the plug socket when a water hole is directly opened on the plug socket for cooling in the prior art; Figure 4 The present invention is a schematic structural diagram of the plug socket from another perspective when water holes are directly opened on the plug socket for cooling in the prior art.
[0011] In this method, a through hole f with a diameter of ∮10 mm is opened on the upper and lower parts of the plug socket b to discharge cooling water. In this way of drainage and cooling, since the cooling water in the plug a is drained toward the two sides of the punching point of the plug socket b, the drainage effect of the internal cooling water is not good. During the production process, the cooling water in the push rod c is gasified due to the high temperature, resulting in poor cooling effect in the nose of the plug a, causing the nose of the plug a to collapse and lose flesh. If this happens, the inner surface of the steel pipe is prone to internal folds, pits, and large pieces of heavy skin defects, causing the steel pipe to be scrapped and the yield rate to decrease. The service life of the plug a is short, which directly affects the production efficiency and increases the production cost. It is also easy to wet the on-site electrical equipment and cause the electrical equipment to short-circuit. The high temperature of the discharged water is easy to scald the on-site supervisor and there is a certain safety risk. Utility Model Content
[0012] 1. Technical issues:
[0013] In summary, how to optimize the structure of the existing ejector pin assembly to achieve efficient cooling of the ejector pin while reducing the impact on the high-temperature blank has become an urgent problem to be solved by those skilled in the art.
[0014] (II) Technical solution:
[0015] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0016] The utility model provides a plug connector. In the utility model, the plug connector comprises a connector body, and the connector body comprises an intermediate body and a front end connector for assembling with a plug and a rear end connector for assembling with a push rod, which are arranged on both sides of the intermediate body;
[0017] A sleeve water passage hole penetrating through the intermediate body, the front joint and the rear joint is provided on the sleeve main body. An outlet groove and an avoidance space for forming water spraying in the direction towards the front joint are provided on the intermediate body. A cooling water outlet hole is further provided on the intermediate body, and the cooling water outlet hole is communicated with the outlet groove and the sleeve water passage hole.
[0018] Preferably, in the top head sleeve provided by the present utility model, the cooling water outlet hole is a long straight hole.
[0019] Preferably, in the top head sleeve provided by the present utility model, the cooling water outlet hole is inclined in the direction towards the front joint.
[0020] Preferably, in the top head sleeve provided by the present utility model, the bottom of the outlet groove is a smooth arc surface.
[0021] Preferably, in the top head sleeve provided by the present utility model, the opening of the cooling water outlet hole on the bottom of the groove is not lower than the outer side surface of the front joint.
[0022] Preferably, in the top head sleeve provided by the present utility model, along the axial direction of the sleeve main body, the overall length of the outlet groove is not less than one-half of the overall length of the intermediate body and not greater than two-thirds of the overall length of the intermediate body.
[0023] Preferably, in the top head sleeve provided by the present utility model, the sleeve main body, the front joint and the rear joint are all cylindrical structures, the diameters of the front joint and the rear joint are both smaller than the diameter of the sleeve main body, and the diameters of the front joint and the rear joint are the same.
[0024] Preferably, in the top head sleeve provided by the present utility model, the width dimension range of the outlet groove is 12 mm - 16 mm.
[0025] Preferably, in the top head sleeve provided by the present utility model, the number of the outlet grooves provided is not less than two, and all the outlet grooves are arranged at equal intervals around the intermediate body.
[0026] The present utility model further provides a new type of ejector rod assembly, including a top head, a top head sleeve and an ejector rod. Among them, the top head sleeve is the top head sleeve as described above;
[0027] The front end of the top head is a top head nose portion, the rear end of the top head is used for docking with the front joint of the top head sleeve, and the outer edge of the rear end of the top head does not exceed the water spraying path of the cooling water outlet hole provided on the top head sleeve;
[0028] The top head is a cone structure, and the outer side surface of the top head is a smooth curved surface.
[0029] (3) Beneficial effects:
[0030] The utility model provides a plug adapter, which includes an adapter body. The adapter body includes an intermediate body, a front joint disposed on both sides of the intermediate body for assembling with the plug, and a rear joint for assembling with the ejector rod. A water passage hole of the adapter is provided on the adapter body, passing through the intermediate body, the front joint, and the rear joint. An outlet groove and an avoidance space for forming water spraying in the direction of the front joint are provided on the intermediate body. A cooling water outlet hole is also provided on the intermediate body, and the cooling water outlet hole is communicated with the outlet groove and the water passage hole of the adapter. The utility model also provides a new type of ejector rod assembly, including a plug, a plug adapter, and an ejector rod, wherein the plug adapter is the above-mentioned plug adapter; the front end of the plug is the nose of the plug, the rear end of the plug is used to dock with the front joint of the plug adapter, and the outer edge of the rear end of the plug does not exceed the water spraying path of the cooling water outlet hole provided on the plug adapter; the plug is a conical structure, and the outer side surface of the plug is a smooth curved surface.
[0031] The utility model provides a plug adapter with a new structure. Through the above structural design, the utility model has at least the following beneficial effects: 1. The processing technology of the plug adapter is simple, and it will not change the original connection structure, and its installation operation is convenient; 2. It can quickly release cooling water to the plug, improving the cooling effect of the plug; 3. It changes the release direction of the cooling water through the plug adapter, and the cooling water is inclined to flow out in the direction of the plug, which can not only effectively cool the plug, but also reduce the contact between the cooling water and the inner surface of the capillary tube, reducing the influence on the capillary tube; 4. The discharge of high-temperature cooling water during the production process is controlled, and the high-temperature cooling water is released in the capillary tube, avoiding the splashing of high-temperature cooling water and effectively reducing the safety risk of scalding the on-site guardians; 5. It improves the surface quality of the steel pipe and the service life of the plug. Description of the Drawings
[0032] The schematic diagrams in the specification, which form a part of this application, are used to provide a further understanding of the utility model. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an improper limitation to the utility model. Among them:
[0033] Figure 1 is a schematic diagram of the structure after assembling the plug, the plug adapter, and the ejector rod in the prior art;
[0034] Figure 2 is a schematic diagram of the structure of the plug when directly opening a water hole on the plug for cooling in the prior art;
[0035] Figure 3 is a schematic diagram of the structure of the plug adapter when directly opening a water hole on the plug adapter for cooling in the prior art;
[0036] Figure 4 It is a schematic structural diagram of the top socket in another perspective when directly opening a water hole on the top socket for cooling in the prior art;
[0037] In Figures 1 to 4 the correspondence between the component names and the reference numerals is as follows:
[0038] top head a, top socket b, ejector rod c, cold water pipeline d, water through hole e, through hole f.
[0039] Figure 5 It is a schematic structural diagram of the top socket in an embodiment of the present invention;
[0040] Figure 6 It is a schematic structural diagram of the top socket in another perspective in an embodiment of the present invention;
[0041] Figure 7 It is a comparison diagram of the product quality between the present invention and the prior art products.
[0042] In Figure 5 and Figure 6 the correspondence between the component names and the reference numerals is as follows:
[0043] socket body 1, intermediate body 11, front end joint 12, rear end joint 13, socket water through hole 2,
[0044] water outlet groove 3, cooling water outlet hole 4.
[0045] In Figure 7 it is divided into two comparative embodiments of carbon structural steel and alloy steel. Among them, the light color represents the product defects produced by the prior art, and the dark color represents the product defects produced by the technology of the present invention. Product defect refers to the number of defective products produced per ton of raw materials. Detailed implementation manners
[0046] Hereinafter, the present invention will be described in detail with reference to the drawings and in conjunction with the embodiments. Each example is provided by way of explanation of the present invention rather than a limitation of the present invention. In fact, those skilled in the art will appreciate that modifications and variations can be made to the present invention without departing from the scope or spirit thereof. For example, features shown or described as part of one embodiment can be used in another embodiment to yield yet another embodiment. Therefore, it is desirable that the present invention includes such modifications and variations that fall within the scope of the appended claims and their equivalents.
[0047] In the description of the present utility model, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and does not require the present utility model to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. The terms "connected" and "coupled" used in the present utility model should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.
[0048] Please refer to Figures 5 to 7 , wherein, Figure 5 is a schematic structural view of the top head socket in an embodiment of the present utility model; Figure 6 is a schematic structural view of the top head socket in another perspective in an embodiment of the present utility model; Figure 7 is a comparison chart of the product quality between the present utility model and the prior art product.
[0049] The present utility model provides a top head socket, which belongs to a component of the top rod assembly and is used to realize the assembly of the top head and the top rod. In the present utility model, the top head socket includes a socket main body 1. The socket main body 1 includes an intermediate body 11 (the intermediate body 11 is preferably a cylindrical structure), and a front end joint 12 and a rear end joint 13 which are respectively arranged on both sides of the intermediate body 11 (along the axial direction of the intermediate body 11, both sides of the intermediate body 11, or understood as both ends of the intermediate body 11) for assembling with the top head and the top rod. Preferably, the front end joint 12, the intermediate body 11, and the rear end joint 13 are coaxially arranged and are of an integral structure.
[0050] During the actual production operation process, the top rod assembly needs to be inserted into the blank. The outer periphery of the top rod assembly is a circular curved surface. Therefore, the outer periphery of the intermediate body 11 of the top head socket needs to be designed as a circular curved surface (for the intermediate body 11, its overall shape is approximately a cylinder). The shapes of the front end joint 12 (fitted with the top head by insertion) and the rear end joint 13 (fitted with the top rod by insertion) can be diversified, and can be either a cylindrical structure or a regular prism (triangular prism, quadrangular prism, hexagonal prism, etc.). Correspondingly, the shapes of the jacks (holes fitted with the front end joint 12 and the rear end joint 13 by insertion) provided on the top head and the top rod are the same as the shapes of the front end joint 12 and the rear end joint 13. Further, the front end joint 12 and the rear end joint 13 are coaxially arranged with the intermediate body 11.
[0051] In order to achieve the transportation of cooling water within the ejector rod assembly, the present utility model is provided with a sleeve water passage hole 2 on the sleeve main body 1 that penetrates through the intermediate body 11, the front end joint 12, and the rear end joint 13. In this way, the cooling water transported from the ejector rod (a water delivery channel is provided on the ejector rod, and the cooling water can be transported through the water delivery channel of the ejector rod) can enter the sleeve main body 1 through the sleeve water passage hole 2.
[0052] The present utility model cools the tip by means of the sleeve main body 1 releasing cooling water. Different from the traditional structure, the present utility model is provided with a water outlet groove 3 on the intermediate body 11 (there is no such water outlet groove 3 structure in the existing structure) and a relief space for forming a water spray towards the direction of the front end joint 12. Specifically, the bottom of the water outlet groove 3 is a smooth arc surface.
[0053] In a preferred embodiment of the present utility model, the water outlet groove 3 is a fan-shaped groove body structure extending from the front end face of the intermediate body 11 along the axis of the intermediate body 11 towards the rear end of the intermediate body 11. The two side faces of the water outlet groove 3 are flat surfaces (the two side faces are parallel to each other), and the bottom surface of the water outlet groove 3 is a gradually rising slope surface. In order to achieve the extraction of cooling water, a cooling water outlet hole 4 is also provided on the intermediate body. The cooling water outlet hole 4 is communicated with the water outlet groove 3 and the sleeve water passage hole 2. The cooling water passes through the cooling water outlet hole 4 and sprays out after passing through the water outlet groove 3 to achieve the cooling of the tip.
[0054] In an embodiment of the present utility model, the cooling water outlet hole 4 is a long straight hole (the long straight hole design has a small water outlet pressure).
[0055] In order to avoid the flushing pressure of the cooling water on the inner wall of the capillary tube, the present utility model optimizes the structure of the cooling water outlet hole 4: the cooling water outlet hole 4 is inclined towards the direction of the front end joint 12. On the basis of the structure where the cooling water outlet hole 4 is a long straight hole, the included angle range between the hole axis of the cooling water outlet hole 4 and the axis of the intermediate body is: 30° - 60°, preferably 45°. Further, the opening of the cooling water outlet hole 4 on the bottom of the groove is not lower than the outer side face of the front end joint 12.
[0056] In the preferred embodiment of the present utility model, along the axial direction of the sleeve main body 1, the overall length of the water outlet groove 3 is not less than one-half of the overall length of the intermediate body and not greater than two-thirds of the overall length of the intermediate body.
[0057] Further, the width dimension range of the water outlet groove 3 is 12mm - 16mm, preferably 14mm.
[0058] In order to ensure the cooling effect on the top, the number of water outlet grooves 3 is not less than two, and all water outlet grooves 3 are arranged at equal intervals around the intermediate body. In a specific embodiment of the utility model, the water outlet grooves 3 are designed to be two, and the two water outlet grooves 3 are arranged symmetrically up and down (or left and right symmetrically). In another specific embodiment of the utility model, the water outlet grooves 3 are designed to be three, and the three water outlet grooves 3 are arranged at intervals of 120°. The water outlet grooves 3 can also be designed to be four, and the four water outlet grooves 3 are arranged in a cross distribution.
[0059] Based on the above-mentioned plug socket, the utility model also provides a new type of ejector assembly, including a plug, a plug socket and a ejector, wherein the plug socket is the above-mentioned plug socket. In the utility model, no water outlet is provided on the plug, the plug is a cone structure, the outer side surface of the plug is a smooth curved surface (the plug structure in the utility model is basically the same as the plug structure in the prior art), the front end of the plug is the plug nose, the rear end of the plug (the rear end surface is a plane, and the rear end surface of the plug is provided with a hole for plugging with the front end joint 12) is used to dock with the front end joint 12 of the plug socket, and the outer edge of the rear end of the plug (using a smooth chamfer structure) does not exceed the water spray path of the cooling water outlet hole 4 provided on the plug socket. After the water supply pressure of the ejector assembly is set, the spray path of the cooling water sprayed out through the cooling water outlet hole 4 on the ejector sleeve is a nearly stable waterway, so that the structure of the ejector head can be optimized according to the waterway, especially the rear end of the ejector head can be optimized, so as to avoid the ejector head from affecting the ejection of the cooling water. Of course, under the premise that the ejector head structure cannot be optimized, the utility model can also change the waterway by changing the setting position and setting angle of the cooling water outlet hole 4, and the ultimate goal is to avoid the cooling water from directly hitting the ejector head after being sprayed out (of course, the premise is that the cooling water flow is ejected at an angle).
[0060] The utility model provides a plug adapter, which solves the cooling problem of the plug better and increases the service life of the plug in the punching process by strengthening the exploration of the cooling inside the plug and optimizing the design of the plug adapter.
[0061] The structure of the plug socket of the utility model is as follows: the plug socket is symmetrically processed with water outlet grooves 3 on the upper and lower parts, the width of the water outlet grooves is 14mm, and holes are punched in the water outlet grooves. During the punching process, high-temperature cooling water is continuously discharged through the water outlet grooves 3 at the connection between the plug and the socket, ensuring a good cooling effect inside the plug. The utility model has been successfully used in the on-site production process. By comparing the traditional plug socket with the plug socket of the new utility model, the use of the plug socket of the new utility model improves the service life of the plug, improves the quality of the inner and outer surfaces of the steel pipe, improves the yield rate of the steel pipe, improves production efficiency, reduces production costs, reduces the safety risks of on-site supervisors, and further enhances the competitiveness of the enterprise in the market. The comparison of the service life effect of the plug passing the number of steel pipes is shown in the following table:
[0062] Steel grade 27SiMn 45 42CrMo Specification 159*19 136*13 178*20 Average number of steel billets passed before the utility model (pcs) 20 140 60 Average number of steel billets passed after the utility model (pcs) 40 160 90 Comparison effect (%) ↑100％ ↑14％ ↑50％
[0063] Note: The above data are based on plugs of the same steel grade, specification, billet length and produced in the same batch.
[0064] As can be seen from the above, the utility model provides a kind of top socket, which includes a socket body 1, and the socket body 1 includes an intermediate body 11 and a front end joint 12 for assembly with the top and a rear end joint 13 for assembly with the ejector rod, which are arranged on both sides of the intermediate body 11; a socket water hole 2 is arranged on the socket body 1, which passes through the intermediate body 11, the front end joint 12 and the rear end joint 13, and a water outlet trough 3 is arranged on the intermediate body 11 to form an escape space for spraying water toward the front end joint 12. A cooling water outlet hole 4 is also arranged on the intermediate body, and the cooling water outlet hole 4 is connected with the water outlet trough 3 and the socket water hole 2. The utility model also provides a novel ejector assembly, including a ejector head, an ejector head socket and an ejector head, wherein the ejector head socket is the ejector head socket as described above; the front end of the ejector head is the ejector head nose, the rear end of the ejector head is used to dock with the front end joint 12 of the ejector head socket, and the outer edge of the rear end of the ejector head does not exceed the water spray path of the cooling water outlet hole 4 arranged on the ejector head socket; the ejector head is a cone structure, and the outer side surface of the ejector head is a smooth curved surface.
[0065] The utility model provides a plug socket with a novel structure. Through the above structural design, the utility model has at least the following beneficial effects: 1. The processing technology of the plug socket is simple, and it will not change the original connection structure, and its installation operation is convenient; 2. It can quickly release cooling water to the plug, improving the cooling effect of the plug; 3. It changes the release direction of the cooling water through the plug socket, and the cooling water discharges obliquely towards the plug direction, which can not only effectively cool the plug, but also reduce the contact between the cooling water and the inner surface of the capillary tube, reducing the impact on the capillary tube; 4. The discharge of high-temperature cooling water during the production process is controlled, and the high-temperature cooling water is released in the capillary tube, avoiding the splash of high-temperature cooling water and effectively reducing the safety risk of scalding the on-site guardians; 5. It improves the surface quality of the steel pipe and the service life of the plug.
[0066] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A plug socket, characterized in that: It comprises a socket body (1), the socket body comprising an intermediate body (11) and a front end joint (12) for assembling with a mandrel and a rear end joint (13) for assembling with a mandrel, which are arranged on both sides of the intermediate body; The socket body is provided with a socket water hole (2) penetrating the intermediate body, the front end joint and the rear end joint, the intermediate body is provided with a water outlet groove (3) for forming an escape space for spraying water in the direction of the front end joint, and the intermediate body is also provided with a cooling water outlet hole (4), the cooling water outlet hole being connected with the water outlet groove and the socket water hole.
2. The plug socket according to claim 1, characterized in that: The cooling water outlet hole is a long straight hole.
3. The plug socket according to claim 2, characterized in that: The cooling water outlet hole is arranged obliquely toward the direction of the front end joint.
4. The plug socket according to claim 1, characterized in that: The bottom of the water outlet trough is a smooth arc surface.
5. The plug socket according to claim 4, characterized in that: The opening of the cooling water outlet hole located on the groove bottom is not lower than the outer side surface of the front end joint.
6. The plug socket according to claim 4, characterized in that: Along the axial direction of the socket body, the overall length of the water outlet groove is not less than one half of the overall length of the intermediate body and not more than two thirds of the overall length of the intermediate body.
7. The plug socket according to claim 1, characterized in that: The socket body, the front end joint and the rear end joint are all cylindrical structures, the diameters of the front end joint and the rear end joint are both smaller than the diameter of the socket body, and the diameters of the front end joint and the rear end joint are the same.
8. The plug socket according to claim 1, characterized in that: The width of the water outlet trough ranges from 12 mm to 16 mm.
9. The plug socket according to any one of claims 1 to 8, characterized in that: The number of the water outlet grooves is not less than two, and all the water outlet grooves are arranged at equal intervals around the intermediate body.
10. A novel ejector assembly, comprising an ejector head, an ejector head socket and an ejector rod, characterized in that: The top connector is the top connector according to any one of claims 1 to 9; The front end of the plug is a plug nose, the rear end of the plug is used to dock with the front end joint of the plug socket, and the outer edge of the rear end of the plug does not exceed the water spray path of the cooling water outlet hole set on the plug socket; The top head is a cone structure, and the outer side surface of the top head is a smooth curved surface.