A hot runner nozzle

Abstract

The present invention relates to a hot runner nozzle, comprising a coaxially arranged nozzle body, a nozzle head, a fixed sleeve and a heater; a first flow channel hole is provided in the nozzle body and passes through its upper and lower ends; a nozzle head positioning sleeve is provided inside the fixed sleeve, and the upper end of the fixed sleeve is fixedly sleeved on the lower end of the nozzle body so that the top end of the nozzle head is abutted and fixed on the bottom end of the nozzle body, and a second flow channel hole is provided in the nozzle head and passes through its upper and lower ends and is connected to the first flow channel hole; the nozzle head comprises an inner peripheral wall and an outer peripheral wall, an annular closed cavity is formed between the inner peripheral wall and the outer peripheral wall, and a first annular gap with an open lower end is provided between the outer peripheral wall and the inner peripheral surface of the fixed sleeve. The present invention utilizes the formed closed cavity and the first annular gap to play a role in heat insulation and heat preservation, thereby preventing the temperature of the melt passing through the nozzle head from failing to meet the requirements and affecting the appearance of the molded product.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding, and in particular relates to a hot runner nozzle. Background Art

[0002] Existing valve needle hot runner nozzle structure (such as Figure 1 The hot runner nozzle is generally composed of a nozzle body 101, a nozzle head 102, a fixing sleeve 103, a heater 104 and a valve needle 105. The nozzle body 101 is provided with a flow channel hole for the melt to pass through. The nozzle head 102 is connected with the flow channel hole 106 and the mold core gate 108. The heater 104 is used to heat the melt in the flow channel hole 106. During injection molding, the valve needle 105 moves upward to open the ejection hole 107 of the hot runner nozzle. The melt is ejected from the ejection hole 107 and enters the mold cavity from the mold core gate 108. When the injection molding is completed, the valve needle 105 moves downward to the ejection hole for sealing.

[0003] During the specific injection molding process, there will be accumulated plastic in the space 109 between the nozzle head 102 and the mold core gate 108. After a certain heating time, the plastic accumulated in the space 109 (commonly known as the color-changing cap in this field) will change color or decompose. The nozzle head 102 and the fixed sleeve 103 are tightly matched. This design will cause serious temperature loss of the fixed sleeve 103 due to the different temperatures at the mold core, resulting in the temperature of the nozzle head 102 being unable to play a role in heat preservation, thereby affecting the surface appearance of the product because the melt temperature does not meet the requirements, increasing the product defect rate, increasing production costs and affecting production efficiency. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies in the prior art to at least a certain extent and to provide a hot runner nozzle.

[0005] To achieve the above-mentioned object, the present invention provides a hot runner nozzle, comprising a coaxially arranged nozzle body, a nozzle head, a fixing sleeve and a heater;

[0006] The nozzle body is provided with a first flow channel hole penetrating through the upper and lower ends thereof; the nozzle head positioning sleeve is arranged inside the fixing sleeve, the upper end of the fixing sleeve is sleeved and fixed to the lower end of the nozzle body, so that the top end of the nozzle head is abutted and fixed to the bottom end of the nozzle body; the nozzle head is provided with a second flow channel hole penetrating through the upper and lower ends thereof and connected to the first flow channel hole, the lower end of the nozzle head extends from the bottom end of the fixing sleeve and is formed with a spray hole connected to the second flow channel hole; the heater is sleeved on the nozzle body;

[0007] The nozzle head comprises an inner circumferential wall and an outer circumferential wall, an annular closed cavity is formed between the inner circumferential wall and the outer circumferential wall, and a first annular gap with an open lower end is provided between the outer circumferential wall and the inner circumferential surface of the fixing sleeve.

[0008] Optionally, the nozzle head includes a nozzle core formed with the first flow channel hole and an outer sleeve mounted outside the nozzle core, the closed cavity is formed between the nozzle core and the outer sleeve, and the first annular gap is formed between the outer circumference of the outer sleeve and the inner circumference of the fixed sleeve.

[0009] Optionally, the lower end surface of the nozzle core and / or the outer sleeve is a plane, and the plane is used to fit with the core gate joint surface of the injection mold.

[0010] Optionally, the top end of the mouth core protrudes radially outward to form a first positioning protrusion ring, and the top end of the outer sleeve protrudes radially outward to form a second positioning protrusion ring. The outer sleeve is arranged on the outside of the mouth core from bottom to top, and the top surface of the second positioning protrusion ring abuts against the bottom surface of the first positioning protrusion ring.

[0011] Optionally, a circumference of the second positioning protrusion protrudes toward the nozzle body to form a positioning ring, and the positioning ring is sleeved outside the first positioning protrusion ring.

[0012] Optionally, a second annular gap is formed between the inner circumferential surface of the positioning ring and the outer circumferential surface of the first positioning protruding ring.

[0013] Optionally, a third annular gap is formed between the outer circumferential surface of the positioning ring and the inner circumferential surface of the fixing sleeve.

[0014] Optionally, the inner cavity of the fixing sleeve includes a sleeve hole and a receiving hole connected to each other up and down, and a limiting step facing the nozzle body is defined between the sleeve hole and the receiving hole; the fixing sleeve is sleeved on the lower end of the nozzle body through the sleeve hole, so that the first positioning protrusion ring and the second positioning protrusion ring are fixed to each other and clamped between the limiting step and the bottom surface of the nozzle body.

[0015] Optionally, the nozzle core and the outer sleeve are formed into an integral structure of the nozzle head by 3D printing; or the nozzle head and the fixed sleeve are formed into an integral structure by 3D printing.

[0016] Optionally, one end of the nozzle core away from the nozzle body protrudes from the outer sleeve in a tapered manner to form a cone, and at least two ejection holes are provided on the conical surface of the cone, and at least two ejection holes are evenly distributed around the circumference of the axis of the second flow channel hole, and the axis of each ejection hole forms an angle with the axis of the second flow channel hole.

[0017] According to the hot runner nozzle of the present invention, a closed cavity surrounding the second flow channel hole and a first annular gap are formed from the inside to the outside of the nozzle head, and the air in the sealed cavity is utilized to play a role in heat insulation and heat preservation, thereby preventing the temperature of the melt passing through the nozzle head from failing to meet the requirements and affecting the appearance of the molded product; and there is also a first annular gap outside the sealed cavity, and the utilization of this annular gap can further improve the heat insulation effect of the nozzle head. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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 those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a structural diagram of an existing hot runner nozzle;

[0020] Figure 2 Schematic diagram of the structure of the hot runner nozzle of the present invention;

[0021] Figure 3 for Figure 2 An exploded schematic diagram of the hot runner nozzle is shown;

[0022] Figure 4 for Figure 2 A magnified schematic diagram of part A;

[0023] Figure 5 It is a structural schematic diagram of another embodiment of the present invention;

[0024] Figure 6 It is a structural schematic diagram of a third embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the structure of the fourth embodiment of the present invention;

[0026] Figure 8 This is a schematic structural diagram of a fifth embodiment of the present invention;

[0027] Figure 9 Schematic diagram of the structure of the sixth embodiment of the present invention;

[0028] Figure 10 Schematic diagram of the structure of the seventh embodiment of the present invention;

[0029] Figure 11 Schematic diagram of the structure of an eighth embodiment of the present invention;

[0030] Figure 12Schematic diagram of the structure of the ninth embodiment of the present invention;

[0031] Figure 13 10th embodiment of the present invention;

[0032] Figure 14 11 is a schematic structural diagram of an eleventh embodiment of the present invention;

[0033] Description of main components:

[0034] 101. Nozzle body; 102. Nozzle tip; 103. Fixing sleeve; 104. Heater; 105. Valve needle; 106. Runner hole; 107. Ejection hole; 108. Mold gate; 109. Space;

[0035] 10. Nozzle body; 11. First flow channel hole;

[0036] 20. Nozzle head; 21. Nozzle core; 211. Second flow channel hole; 212. First positioning protrusion; 213. Spray hole; 214. Cone; 22. Outer sleeve; 221. Positioning hole; 222. Second positioning protrusion; 23. Sealed cavity; 24. First annular gap; 25. Second annular gap; 26. Third annular gap; 27. Inner circumferential wall; 28. Outer circumferential wall; 29. ​​Flange;

[0037] 30. Fixing sleeve; 31. Sleeve hole; 32. Accommodating hole; 33. Limiting step;

[0038] 40. Heater; 50. Temperature sensing line; 60. Valve needle; 70. Manifold; 71. Mold core gate; 80. Overall structure. DETAILED DESCRIPTION

[0039] The following describes in detail embodiments of the present invention, examples of which 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 to be used to explain the present invention, and are not to be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or position relationship, are based on the orientation or position 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 operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0042] See also Figure 2-4 An embodiment of the present invention provides a hot runner nozzle for use in an injection mold, which includes a coaxially arranged nozzle body 10, a nozzle head 20, a fixing sleeve 30 and a heater 40.

[0043] The top of the nozzle body 10 is fixed to the bottom of the manifold 70, and a first flow channel hole 11 is formed therein, which passes through the upper and lower ends thereof. The first flow channel hole 11 is connected to the manifold in the manifold 70. The heater 40 is sleeved on the nozzle body and is used to heat the melt in the first flow channel hole 11.

[0044] The nozzle head 20 is positioned and sleeved inside the fixed sleeve 30. The upper end of the fixed sleeve 30 is sleeved and fixed to the lower end of the nozzle body 10 so that the top of the nozzle head 20 is fixed to the bottom end of the nozzle body 10. The nozzle head 20 is provided with a second flow channel hole 211 that passes through its upper and lower ends and is connected to the first flow channel hole 11. The lower end of the nozzle head 20 extends from the bottom end of the fixed sleeve 30 and is formed with a spray hole 213 that is connected to the second flow channel hole 211. The hot runner nozzle also includes a nozzle that can be inserted through the first flow channel hole 11, the second flow channel hole 211 and the spray hole 213. 13, the apertures of the first flow channel hole 11, the second flow channel hole 211 and the ejection hole 213 decrease in sequence, and the aperture of the ejection hole 213 is adapted to the outer diameter of the lower end of the valve needle 60, and the aperture of the upper end of the second flow channel hole 211 gradually increases to adapt to the aperture of the first flow channel hole 11 to ensure smooth flow of the molten material; when the valve needle 60 moves downward to the ejection hole 213, the ejection hole 213 can be blocked, that is, the valve needle 60 is in the closed position at this time; preferably, when the valve needle 60 is in the closed position, the mold core gate 71 can also be blocked to ensure that the connection between the ejection hole 213 and the molding cavity of the injection mold is completely cut off.

[0045] The nozzle head 20 includes a sealed annular cavity 23. A first annular gap 24, open at the lower end, is defined between the outer peripheral wall and the inner peripheral surface of the fixed sleeve 30. Specifically, in this embodiment, the nozzle head 20 is a split structure, comprising a nozzle core 21 with a first flow channel 11 formed therein, and an outer sleeve 22 that fits over the nozzle core 21. The sealed cavity 23 is formed between the nozzle core 21 and the outer sleeve 22, while the first annular gap 24 is formed between the outer peripheral surface of the outer sleeve 22 and the inner peripheral surface of the fixed sleeve 30. In other words, the first annular gap 24 is located outside the sealed cavity 23.

[0046] According to the hot runner nozzle of the present invention, a sealed cavity 23 and a first annular gap 24 surrounding the second flow channel hole 211 are formed from the inside to the outside of the nozzle head 20. The sealed cavity is filled with air that cannot flow. The thermal conductivity of air is 0.026W / (m·K). Since the thermal conductivity of air is extremely low, it can play a role in heat insulation and heat preservation, thereby preventing the temperature of the melt passing through the nozzle head 20 from failing to meet the requirements and affecting the appearance of the molded product. There is also a first annular gap 24 outside the sealed cavity. The thermal insulation effect of the nozzle head 20 can be further improved by utilizing the annular gap.

[0047] It should be noted that the aperture of the lower end of the second flow channel hole 211 gradually shrinks and extends to the same diameter as the ejection hole 213 to ensure smooth flow of the molten material from the second flow channel hole 211 to the ejection hole 213; correspondingly, the lower end of the closed cavity 23 extends to a position adjacent to the ejection hole 213 and gradually shrinks inward to shorten the distance between the ejection hole 213 and the closed cavity 23, so as to achieve the purpose of maximizing thermal insulation of the ejection hole 213 position.

[0048] In one embodiment, a first positioning protrusion 212 is formed radially outwardly on the top of the nozzle core 21, and a second positioning protrusion 222 is formed radially outwardly on the top of the outer sleeve 22. The outer sleeve 22 is fitted over the nozzle core 21 from bottom to top, with the top surface of the second positioning protrusion 222 abutting against the bottom surface of the first positioning protrusion 212. The lower end of the outer sleeve 22 has a positioning hole 221 that fits tightly around the outer circumference of the lower end of the nozzle core 21. The first positioning protrusion 212 and the second positioning protrusion 222 can be secured together by clamping, snapping, fasteners, or the like, thereby securing the nozzle core 21 and the outer sleeve 22 to each other to form a nozzle head 20 having a sealed cavity 23.

[0049] In this embodiment, the inner cavity of the fixing sleeve 30 includes a connecting hole 31 and a receiving hole 32 that communicate with each other vertically. A stop step 33 facing the nozzle body 10 is defined between the connecting hole 31 and the receiving hole 32. The fixing sleeve 30 is mounted on the lower end of the nozzle body 10 through the connecting hole 31, so that the first positioning protrusion 212 and the second positioning protrusion 222 are fixedly clamped between the stop step 33 and the bottom surface of the nozzle body 10. In other words, the diameter of the connecting hole 31 is larger than that of the receiving hole 32, and the outer circumferences of the first and second positioning protrusions 212, 222 can form a seal with the inner circumference of the connecting hole 31. The outer diameter of the main portion of the outer sleeve 22 is smaller than the diameter of the receiving hole 32. The outer diameter of the second positioning protrusion 222 forms a first annular gap 24 between the outer circumference of the outer sleeve 22 and the inner circumference of the receiving hole 32.

[0050] The fixing sleeve 30 can be sleeved on the lower end of the nozzle body 10 by plugging. During assembly, the mouth core 21, the outer sleeve 22, and the fixing sleeve 30 can be assembled to the bottom of the nozzle body 10 in sequence. Such a structure is simple and convenient to assemble, and can be automated and assembled in batches through equipment, thereby improving production efficiency and reducing costs. Of course, in other embodiments, the fixing sleeve 30 can also be fixed to the lower end of the nozzle body 10 by a threaded connection, that is, an internal thread is provided in the sleeve hole 31, and a matching external thread is provided at the lower end of the nozzle body 10, thereby realizing a threaded connection and fixation between the fixing sleeve 30 and the nozzle body 10.

[0051] In one embodiment, Figure 5As shown, a positioning ring is formed on the periphery of the second positioning protrusion 222 of the outer sleeve 22, protruding toward the nozzle body 10. The positioning ring is sleeved outside the first positioning protrusion 212. Preferably, the top surface of the positioning ring is flush with the top surface of the first positioning protrusion 212 and is in contact with the bottom surface of the nozzle body 10, thereby making the split-structure nozzle head 20 more stable and reliable after assembly.

[0052] Further, if Figure 6 As shown, a second annular gap 25 is formed between the inner circumference of the positioning ring and the outer circumference of the first positioning convex ring 212. The second annular gap 25 is also a closed space, that is, the closed cavity 23 is the lower half portion sleeved outside the second flow channel hole 211, and the second annular gap 25 is the upper half portion sleeved outside the second flow channel hole 211, so that the cooperation of the second annular gap 25 and the closed cavity 23 provides heat insulation for the melt in the entire second flow channel hole 211, so that the melt in the first flow channel hole 11 can reduce heat loss as much as possible when passing through the second flow channel hole 211, so that the temperature of the melt when it is ejected from the ejection hole 213 reaches or exceeds the required requirement, so as to ensure that the appearance of the final injection molded product will not be flawed or waste due to the low temperature of the melt.

[0053] In an alternative embodiment, Figure 7 As shown, in this embodiment, a third annular gap 26 is formed between the outer circumference of the positioning ring and the inner circumference of the sleeve hole 31 of the fixing sleeve 30. The third annular gap 26 is also a closed space, so that the cooperation of the third annular gap 26 and the closed cavity 23 can provide heat insulation for the melt in the entire second flow channel hole 211, so that the melt in the first flow channel hole 11 can reduce heat loss as much as possible when passing through the second flow channel hole 211, so that the temperature of the melt when it is ejected from the ejection hole 213 reaches above the required requirement, so as to ensure that the appearance of the final injection molded product will not be flawed or waste due to the low temperature of the melt.

[0054] It should be noted that, in actual application of the hot runner nozzle of the present invention, the second annular gap 25 or the third annular gap 26 can be defined separately in the nozzle head 20 according to actual needs, or the second annular gap 25 and the third annular gap 26 can be formed at the same time. The present invention does not impose any special restrictions on this.

[0055] Preferably, the hot runner nozzle of the present invention also includes a temperature sensing line 50 arranged on the nozzle head 20, through which the temperature of the melt in the second flow channel hole 211 is detected, and the heating power of the heater 40 is controlled according to the detected temperature to adjust the temperature of the melt when it is ejected from the nozzle head.

[0056] In one embodiment, Figure 8 As shown, the hot runner nozzle provided in this embodiment is the same as the above Figure 4 The difference between the illustrated embodiments is that the nozzle head 20 in this embodiment is an integrated structure formed by 3D printing, that is, the nozzle core 21 and the outer sleeve 22 are formed into an integrated nozzle head 20 through the 3D printing process, and the integrated nozzle head 20 has an inner circumferential wall 27 and an outer circumferential wall 28, a second flow channel hole 211 is formed inside the inner circumferential wall 27, and an annular closed cavity 23 is formed between the inner circumferential wall 27 and the outer circumferential wall 28; the upper end of the integrated nozzle head 20 has a radially protruding flange 29, which is clamped between the limiting step 33 and the nozzle body 10, thereby forming a first annular gap 24 between the outer circumferential wall 28 and the accommodating hole 32.

[0057] Specifically, in this embodiment, the upper end of the closed cavity 23 extends to a position adjacent to the top, and the lower end extends to a position adjacent to the ejection hole 213, so that the closed cavity 23 is used to provide heat insulation for the melt in the entire second flow channel hole 211, so that the melt in the first flow channel hole 11 can reduce heat loss as much as possible when passing through the second flow channel hole 211, so that the temperature of the melt when ejected from the ejection hole 213 reaches or exceeds the required requirements, so as to ensure that the appearance of the final injection molded product will not be flawed or cause waste due to the low temperature of the melt. Of course, in other embodiments, the upper end of the closed cavity 23 can also extend only to the middle of the nozzle head 20, such as Figure 9 As shown, it is located approximately flush with the bottom end of the heater 40.

[0058] Preferably, if Figure 10 As shown, in this embodiment, a third annular gap 26 is formed between the outer circumference of the upper end flange 29 of the integrated nozzle head 20 and the inner circumference of the sleeve hole 31. The third annular gap 26 can better improve the heat insulation effect of the nozzle head 20.

[0059] In one embodiment, Figure 11 As shown, the hot runner nozzle provided in this embodiment is the same as the above Figure 8 The difference between the shown embodiments is that the nozzle head and the fixed sleeve can be formed into an integrated overall structure 80 by 3D printing, that is, the 3D printed overall structure 80 includes the above-mentioned nozzle head structure and the fixed sleeve structure, forming a sleeve hole 31 connected and fixed to the nozzle body 10, a second flow channel hole 211 connected to the first flow channel hole 11, an annular closed cavity 23 sleeved outside the second flow channel hole 211, and a first annular gap 24 sleeved outside the closed cavity 23. Such a structure ensures the heat insulation effect of the melt in the second flow channel hole 211, while also improving the strength of the overall structure 80, making assembly more convenient and reliable.

[0060] It should be noted that Figure 4 and Figure 8-11The structure of the lower end of the valve needle 60 shown in the figure has two position states. The position state of the valve stem shown on the left side of the center line is the closed position state. The lower end of the valve stem simultaneously blocks the ejection hole 213 and the mold core gate 71 to close the connection between the runner hole and the molding cavity; the position state of the valve stem shown on the right side of the center line is the open position state, that is, the lower end of the valve stem moves upward and retracts into the second runner hole 211 to open the ejection hole 213 and the mold core gate 71. At this time, the molten material can pass through the ejection hole 213 and the mold core gate 71 from the second runner hole 211 in turn and enter the molding cavity to realize injection molding.

[0061] In one embodiment, Figure 12 As shown, the hot runner nozzle provided in this embodiment is the same as the above Figure 4 The difference between the illustrated embodiment and the nozzle core 21 is that the end away from the nozzle body 10 protrudes from the outer sleeve 22 to form a tapered cone 214. The cone 214 is provided with at least two ejection holes 213. These ejection holes 213 are evenly distributed around the circumference of the second flow passage 211, and the axis of each ejection hole 213 forms an angle with the axis of the second flow passage 211. When there are two ejection holes 213, the two ejection holes 213 are symmetrically arranged about the axis of the second flow passage 211. When there are multiple ejection holes 213, they are arranged in a circular array about the axis of the second flow passage 211.

[0062] Preferably, the bottom surface of the second flow channel hole 211 is a downwardly concave spherical surface or arc surface, the upper end of each ejection hole 213 passes through the spherical surface or arc surface to be connected with the second flow channel hole 211, and the lower end passes through the conical surface of the cone 214. The angle between the ejection hole 213 and the second flow channel hole 211 can be selected according to actual needs, preferably 5 to 20°. Such a structure allows the molten material in the second flow channel hole 211 to smoothly pass through each ejection hole 213 and enter the molding cavity of the mold through the mold core gate 71 to achieve injection molding.

[0063] In some embodiments, combined Figure 13 and Figure 14 As shown, the shape of the lower end of the nozzle head 20 can be adapted to the positioning space outside the mold core gate 71, and the lower end of the nozzle head 20 is fitted with the joint surface around the mold core gate 71 in the positioning space, so that there is no dead angle between the mold core gate 71 and the nozzle head 20, forming a color-changing cap-free design, which solves the problem of difficulty in changing product color and different color of the product due to material accumulation between the nozzle head 20 and the mold core gate 71.

[0064] For example, in this embodiment, the lower end surface of the outer sleeve 22 can be aligned with the joint surface of the mold core gate 71, and the lower end surface of the nozzle core 21 is located above the lower end surface of the outer sleeve 22. In other embodiments, the lower end surfaces of the nozzle core 21 and the outer sleeve 22 can be flush planes, which are used to align with the joint surface surrounding the mold core gate 71 in the positioning space. Alternatively, only the lower end surface of the nozzle core 21 can be aligned with the joint surface of the mold core gate 71, and the lower end of the nozzle core 21 can extend downwardly through the bottom surface of the outer sleeve 22.

[0065] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0066] The above is a description of the technical solution provided by the present invention. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A hot runner nozzle, characterized in that: It includes a coaxially arranged nozzle body, a nozzle head, a fixing sleeve and a heater; The nozzle body is provided with a first flow channel hole penetrating through the upper and lower ends thereof; the nozzle head positioning sleeve is arranged inside the fixing sleeve, the upper end of the fixing sleeve is sleeved and fixed to the lower end of the nozzle body, so that the top end of the nozzle head is abutted and fixed to the bottom end of the nozzle body; the nozzle head is provided with a second flow channel hole penetrating through the upper and lower ends thereof and connected to the first flow channel hole, the lower end of the nozzle head extends from the bottom end of the fixing sleeve and is formed with a spray hole connected to the second flow channel hole; the heater is sleeved on the nozzle body; The nozzle head includes an inner circumferential wall and an outer circumferential wall, an annular closed cavity is formed between the inner circumferential wall and the outer circumferential wall, and a first annular gap with an open lower end is provided between the outer circumferential wall and the inner circumferential surface of the fixed sleeve; the nozzle head includes a nozzle core formed with the first flow channel hole and an outer sleeve sleeved outside the nozzle core, the closed cavity is formed between the nozzle core and the outer sleeve, and the first annular gap is formed between the outer circumferential surface of the outer sleeve and the inner circumferential surface of the fixed sleeve.

2. The hot runner nozzle according to claim 1, characterized in that: The lower end surface of the nozzle core and / or the outer sleeve is a plane, and the plane is used to fit with the mold core gate joint surface of the injection mold.

3. The hot runner nozzle according to claim 1, characterized in that: The top of the mouth core protrudes radially outward to form a first positioning protrusion ring, and the top of the outer sleeve protrudes radially outward to form a second positioning protrusion ring. The outer sleeve is mounted on the outside of the mouth core from bottom to top, and the top surface of the second positioning protrusion ring abuts against the bottom surface of the first positioning protrusion ring.

4. The hot runner nozzle according to claim 3, characterized in that: The periphery of the second positioning protrusion protrudes toward the nozzle body to form a positioning ring, and the positioning ring is sleeved outside the first positioning protrusion.

5. The hot runner nozzle according to claim 4, characterized in that: A second annular gap is formed between the inner circumferential surface of the positioning ring and the outer circumferential surface of the first positioning protruding ring.

6. The hot runner nozzle according to claim 4, characterized in that: A third annular gap is formed between the outer circumferential surface of the positioning ring and the inner circumferential surface of the fixing sleeve.

7. The hot runner nozzle according to any one of claims 3 to 6, characterized in that: The inner cavity of the fixing sleeve includes a sleeve hole and a receiving hole connected to each other up and down, and a limiting step facing the nozzle body is defined between the sleeve hole and the receiving hole; the fixing sleeve is sleeved on the lower end of the nozzle body through the sleeve hole, so that the first positioning protrusion ring and the second positioning protrusion ring are fixedly clamped between the limiting step and the bottom surface of the nozzle body.

8. The hot runner nozzle according to claim 1, characterized in that: The nozzle core and the outer sleeve are formed into an integral structure of the nozzle head by 3D printing; or the nozzle head and the fixed sleeve are formed into an integral structure by 3D printing.

9. The hot runner nozzle according to claim 1, characterized in that: One end of the nozzle core away from the nozzle body protrudes from the outer sleeve in a tapered manner to form a cone, and at least two ejection holes are opened on the cone surface. The at least two ejection holes are evenly distributed around the circumference of the axis of the second flow channel hole, and the axis of each ejection hole forms an angle with the axis of the second flow channel hole.

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