A hot runner nozzle assembly and temperature controlled injection molding apparatus

Abstract

This invention discloses a hot runner nozzle assembly and a temperature-controlled injection molding device, relating to the field of injection molding technology. It includes a drive cylinder as a power source; a nozzle body as a mounting and supporting base, with a connected melt main channel inside; a heat-insulating protective sleeve fitted over the nozzle body for heat isolation and protection; a dual-segment elastic guide assembly coaxially fixed inside the nozzle body for providing dual-support radial limiting, and integrating a self-lubricating melt flow channel structure; and a spherical sealing assembly coaxially mounted at the lower end of the nozzle body for gate opening and closing and sealing. The spherical sealing assembly includes a valve needle rod connected to the drive cylinder. Through structural optimization of the dual-segment elastic guide assembly and the spherical sealing assembly, the inherent contradictions of short valve needle wear life, melt leakage and flash in conical seals, and high-temperature dry friction causing needle breakage in existing hot runner nozzles are resolved, improving the sealing reliability, operational stability, and mass production adaptability of the nozzle assembly.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, specifically to a hot runner nozzle assembly and a temperature-controlled injection molding apparatus. Background Technology

[0002] As the core actuator for conveying molten plastic and opening and closing the gate in injection molds, the hot runner nozzle assembly is a key component that determines the molding quality, production efficiency, mold life, and stability of automated operation of injection molded products.

[0003] Existing hot runner nozzle assemblies for small precision injection molds mostly adopt a single-stage rigid guide sleeve, conical hard seal, and split assembly technology. During operation, the drive unit drives the valve needle to reciprocate axially, and radial limiting is achieved through the guide sleeve. The gate opening and closing and sealing are completed by the conical surface cooperation between the valve needle and the gate sleeve. Under the conditions of high-speed precision injection molding, temperature difference alternation, and long-cycle continuous production, the operational stability is limited. First, the single-stage rigid guide forms a long cantilever beam structure, and the high-speed movement of the valve needle is prone to radial runout, causing uneven wear. The rigid structure is difficult to adapt to the difference in thermal expansion, and under temperature alternation... Stress concentration and guide surface wear are prone to occur. The reserved gap will increase the risk of radial wobble and limit failure, leading to bending and jamming of the valve needle. Secondly, the conical hard seal is a line contact, which requires high coaxiality. Assembly errors and thermal deformation can cause melt leakage, resulting in flash and stringing defects in the product. However, improving the sealing performance requires improving the processing accuracy, which will continuously increase the cost. At the same time, the valve needle mating surface is in a state of dry metal friction for a long time. The friction coefficient increases at high temperature. Conventional surface coatings or periodic lubrication methods are difficult to achieve continuous self-lubrication, which increases the probability of jamming and needle breakage. Summary of the Invention

[0004] The purpose of this invention is to provide a hot runner nozzle assembly and a temperature-controlled injection molding device. Through the synergistic structural optimization of the dual-segment elastic guide assembly and the spherical sealing assembly, it overcomes some limitations of existing hot runner nozzles, such as short lifespan due to valve needle wear, leakage and flash of the conical seal, and needle breakage due to high-temperature dry friction. This improves the sealing reliability, operational stability and mass production adaptability of the nozzle assembly.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a hot runner nozzle assembly, including a drive cylinder as a power source; The nozzle body serves as the mounting and supporting base, and has a connected main melt channel inside; A heat insulation protective sleeve is fitted over the outside of the nozzle body for heat insulation and protection; A dual-stage elastic guide assembly is coaxially fixed inside the nozzle body to provide dual support radial limiting for the valve needle rod body. Its interior is integrated with a melt self-lubricating flow channel structure. A spherical sealing assembly is coaxially mounted on the lower end of the nozzle body and is used for opening and closing the gate and sealing the sealant. The dual-segment elastic guide assembly includes a first guide sleeve and a second guide sleeve spaced apart along the axial direction. The inner wall of the first guide sleeve is evenly distributed with a plurality of first axial elastic guide ribs, and the inner wall of the second guide sleeve is evenly distributed with a plurality of second axial elastic guide ribs. Both the plurality of first axial elastic guide ribs and the plurality of second axial elastic guide ribs have elastic deformation capability, which is used to form radial elastic support for the valve needle rod body. The spherical sealing assembly includes a valve needle rod body that is connected to the drive cylinder, a spherical sealing gate sleeve, and a bellows-type elastic floating section and an outwardly convex spherical conical sealing head disposed at the lower end of the valve needle rod body. The spherical sealing gate sleeve is provided with an inwardly concave spherical conical sealing section that matches the outwardly convex spherical conical sealing head. The bellows-type elastic floating section is used to drive the outwardly convex spherical conical sealing head to float radially and align, forming a full-circumferential seal.

[0006] Preferably, the plurality of first axial elastic guide ribs and the plurality of second axial elastic guide ribs are integrally formed with the corresponding first guide sleeve and second guide sleeve, and a melt flow channel is formed between adjacent guide ribs. The outer wall of the nozzle body is provided with a heating element corresponding to the axial position of the dual-segment elastic guide assembly, and the temperature measuring element is embedded in one end of the nozzle body near the spherical sealing assembly.

[0007] Preferably, each of the first axial elastic guide ribs has a lubrication microhole on its inner end face, the first guide sleeve has an annular flow channel communicating with the lubrication microhole, and the top of the first guide sleeve has a micro-drainage groove communicating with the main melt channel of the nozzle body and the annular flow channel.

[0008] Preferably, the first guide sleeve is coaxially installed in the upper inner hole of the nozzle body, and the second guide sleeve is coaxially installed in the lower inner hole of the nozzle body, with their central axes being coaxial, forming a double support constraint on the valve needle rod.

[0009] Preferably, a micro one-way valve is embedded in the micro channel, which allows the high-pressure melt to flow unidirectionally from the main channel to the annular channel.

[0010] Preferably, the first axial elastic guide rib and the second axial elastic guide rib are three sets of odd-numbered guide ribs evenly distributed in the circumference. The inner end face of each first axial elastic guide rib and the second axial elastic guide rib is provided with a wear-resistant protective layer, which forms a sliding fit with the valve needle rod body.

[0011] Preferably, the spherical sealing gate sleeve is coaxially arranged with the nozzle body, and its interior is integrally machined from top to bottom with a smooth connection between a conical guide section and an inwardly concave spherical conical sealing section. The upper end of the conical guide section is coaxially connected with the main melt channel of the nozzle body.

[0012] Preferably, the spherical sealing assembly further includes a metal mounting base, and the spherical sealing gate sleeve is coaxially fixed to the lower end of the nozzle body via the metal mounting base.

[0013] Preferably, the lower end of the valve needle rod is also integrally provided with a conical transition section, which is located between the bellows-type elastic floating section and the convex spherical conical sealing head, and cooperates with the conical guide section to form a smoothly connected melt flow channel.

[0014] The present invention also provides a temperature-controlled injection molding apparatus.

[0015] Compared with the prior art, the beneficial effects of the present invention are: In this invention, the dual-segment elastic guide assembly and spherical sealing assembly effectively improve the existing hot runner nozzle valve needle wear-related short lifespan, conical seal leakage and flash, and high-temperature dry friction jamming and needle breakage problems, thereby enhancing the sealing reliability, operational stability, and mass production adaptability of the nozzle assembly. Firstly, in the dual-segment elastic guide assembly, the coaxially arranged double guide sleeves and axial elastic guide ribs provide dual support and guidance for the entire stroke of the valve needle rod, suppressing radial sway of the valve needle and improving the problems of easy wear and coaxiality failure in traditional rigid guides. Simultaneously, the melt self-lubricating flow channel and one-way valve structure integrated into the guide assembly utilize the high-pressure molten plastic from the injection molding process as a lubricating medium to achieve valve needle movement... The continuous lubrication throughout the entire process transforms dry metal friction into fluid lubrication, alleviating the contradiction between lubrication and anti-jamming under high-temperature conditions and reducing the risk of jamming and needle breakage. Secondly, in the spherical sealing assembly, the concave spherical conical sealing section and the convex spherical conical sealing head form a full-circumferential surface fit seal. Combined with the automatic alignment capability of the bellows-type elastic floating section, a tight fit of the sealing surface can be achieved, upgrading the traditional conical line seal to a surface seal. This improves the problem of low fault tolerance and single-sided contact leakage of conical seals. The integrated connection between the flow guiding section and the sealing section can reduce the dead angle of melt retention, reduce the risk of plastic part contamination caused by melt carbonization and degradation, and help extend the service life of the assembly and reduce production and maintenance costs. Attached Figure Description

[0016] Figure 1 This is a perspective view of the main structure in this invention; Figure 2 This is a partial internal sectional view of the structure from a side view angle in this invention; Figure 3 This is a partial internal sectional view of the structure from a frontal viewing angle in this invention; Figure 4 This is a schematic diagram of the installation position structure of the dual-segment elastic guide assembly in this invention; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6This is a schematic diagram of the installation position structure of the spherical sealing assembly in this invention; Figure 7 This is a schematic diagram showing the installation positions of the bellows-type elastic floating section, the conical transition section, and the convex spherical conical sealing head in this invention. Figure 8 for Figure 7 Enlarged view of section B in the middle.

[0017] In the diagram: 100, drive cylinder; 200, heat insulation sleeve; 300, nozzle body; 400, dual-section elastic guide assembly; 401, first guide sleeve; 402, first axial elastic guide rib; 403, lubrication micro-hole; 404, micro-drainage groove; 405, micro-check valve; 406, annular flow channel; 407, second guide sleeve; 408, second axial elastic guide rib; 500, spherical sealing assembly; 501, metal mounting base; 502, spherical sealing gate sleeve; 503, conical guide section; 504, concave spherical conical sealing section; 505, valve needle rod; 506, bellows-type elastic floating section; 507, conical transition section; 508, convex spherical conical sealing head. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figures 1-2 As shown, this embodiment provides a hot runner nozzle assembly, including a drive cylinder 100 as a power source. The drive cylinder 100 can be pneumatically or hydraulically driven. Its piston rod is rigidly connected to the valve needle rod body 505 to provide a stable driving force for the reciprocating motion of the valve needle rod body 505. The nozzle body 300 is a mounting and bearing base with a connected melt main channel inside. The nozzle body 300 is integrally machined from H13 hot work die steel and has high-temperature strength and wear resistance after tempering and nitriding treatment. Its internal melt main channel has a smooth conical transition structure without steps. In addition to the dead zone, the heat insulation protective sleeve 200 is used to stably transport molten plastic from the manifold to the gate position. It is fitted on the outside of the nozzle body 300 for heat isolation and protection. The heat insulation protective sleeve 200 is a multi-layer air insulation structure with a closed air insulation cavity inside. It is fitted on the upper outer wall of the nozzle body 300. On the one hand, it can reduce the radial heat loss of the nozzle body 300 and reduce the energy consumption of injection molding production. On the other hand, it can isolate the high-temperature nozzle from the external mold, avoid the mold template from heat deformation, and reduce the heat transfer of the nozzle body 300 to the drive cylinder 100.

[0020] like Figure 3 As shown, the dual-segment elastic guide assembly 400 is coaxially fixed inside the nozzle body 300 and is used to provide dual-support radial limiting for the valve needle rod 505. It integrates a melt self-lubricating flow channel structure. The dual-segment elastic guide assembly 400 transforms the traditional long cantilever valve needle rod 505 into a dual-support structure through the first guide sleeve 401 and the second guide sleeve 407, which are coaxially spaced apart, thereby suppressing the radial sway of the valve needle rod 505 and effectively improving the problems of easy wear and coaxiality failure of the traditional single-segment rigid guide.

[0021] like Figure 3 As shown, the spherical sealing assembly 500 is coaxially mounted on the lower end of the nozzle body 300 and is used for gate opening and closing and sealing. The spherical sealing assembly 500 forms a full circumferential seal by means of the bellows-type elastic floating section 506 at the lower end of the valve needle rod 505 and the convex spherical conical sealing head 508, which cooperates with the concave spherical conical sealing section 504 of the spherical sealing gate sleeve 502. This can effectively improve the problems of low fault tolerance and single-sided contact leakage of traditional conical seals.

[0022] like Figure 4 As shown, the dual-segment elastic guide assembly 400 includes a first guide sleeve 401 and a second guide sleeve 407 spaced apart along the axial direction. The inner wall of the first guide sleeve 401 is circumferentially distributed with multiple first axial elastic guide ribs 402, and the inner wall of the second guide sleeve 407 is circumferentially distributed with multiple second axial elastic guide ribs 408. Both the first axial elastic guide ribs 402 and the second axial elastic guide ribs 408 have elastic deformation capabilities, forming radial elastic support for the valve needle rod body 505. The first guide sleeve 401 is installed in the upper inner hole of the nozzle body 300, and the second guide sleeve 407 is installed in the lower inner hole of the nozzle body 300. Their central axes are coaxial. The first axial elastic guide ribs 402 and the second axial elastic guide ribs 408 are three sets of odd-numbered guide ribs evenly distributed circumferentially, integrally formed with the corresponding guide sleeves. A melt flow channel is formed between adjacent guide ribs to ensure smooth melt flow, while also reserving sufficient space for the elastic deformation of the guide ribs.

[0023] like Figure 7As shown, the spherical sealing assembly 500 includes a valve needle rod 505, a spherical sealing gate sleeve 502, and a bellows-type elastic floating section 506 and an outwardly convex spherical conical sealing head 508 disposed at the lower end of the valve needle rod 505. The spherical sealing gate sleeve 502 is provided with an inwardly concave spherical conical sealing section 504 that matches the outwardly convex spherical conical sealing head 508. The bellows-type elastic floating section 506 is used to drive the outwardly convex spherical conical sealing head 508 to float radially and align, forming a full-circumferential seal. The valve needle rod 505 is integrally formed from powder metallurgy high-speed steel and has high hardness and high-temperature wear resistance after vacuum quenching and wear-resistant coating treatment. The bellows-type elastic floating section 506 at its lower end has an annular thin-walled groove structure, which allows the outwardly convex spherical conical sealing head 508 to produce a small amount of radial floating, automatically aligning the sealing surface when the valve is closed, thereby compensating for the coaxiality error caused by assembly and thermal deformation.

[0024] Furthermore, such as Figure 4 As shown, multiple first axial elastic guide ribs 402 and multiple second axial elastic guide ribs 408 are integrally formed with the corresponding first guide sleeve 401 and second guide sleeve 407, and a melt flow channel is formed between adjacent guide ribs. This integrally formed structure avoids the coaxiality error and loosening risk caused by split assembly. The fan-shaped gap between adjacent guide ribs has sufficient flow area to ensure that the melt flows without throttling or stagnation.

[0025] like Figure 5 As shown, each first axial elastic guide rib 402 has a lubrication micro-hole 403 on its inner end face. The first guide sleeve 401 has an annular flow channel 406 communicating with the lubrication micro-hole 403 inside. The top of the first guide sleeve 401 has a micro-drainage groove 404 connecting the main melt channel of the nozzle body 300 and the annular flow channel 406. This self-lubricating structure uses the high-pressure molten plastic of the injection molding process as a lubricating medium. When the melt pressure reaches the set value, the melt enters the annular flow channel 406 through the micro-drainage groove 404, and then is sprayed onto the surface of the valve needle rod 505 through the lubrication micro-hole 403, forming a full-circumference lubrication film. This transforms metal dry friction into fluid lubrication, which can effectively improve the problems of easy jamming and needle breakage of traditional guide structures at high temperatures.

[0026] like Figure 4 As shown, the first guide sleeve 401 is coaxially installed in the upper inner hole of the nozzle body 300, and the second guide sleeve 407 is coaxially installed in the lower inner hole of the nozzle body 300. Their central axes are coaxial, forming a double-support constraint on the valve needle rod 505. This double-support structure transforms the traditional single-segment rigid guide cantilever beam structure into a double-support structure, reducing the maximum radial deflection of the valve needle rod 505. This effectively suppresses radial wobble during the movement of the valve needle rod 505 and avoids unilateral wear between the valve needle rod 505 and the spherical sealing gate sleeve 502.

[0027] like Figure 5 As shown, a miniature check valve 405 is embedded within the miniature flow channel 404. The miniature check valve 405 allows the high-pressure melt to flow unidirectionally from the main flow channel to the annular flow channel 406. The miniature check valve 405 consists of a stainless steel ball and a miniature spring. During the injection molding stage, the melt pressure pushes the ball open to inject the lubricating medium. After the pressure holding period, the spring pushes the ball back to close the flow channel, preventing melt backflow and cooling solidification from clogging the lubricating micropores 403.

[0028] Furthermore, such as Figure 4 As shown, both the first axial elastic guide rib 402 and the second axial elastic guide rib 408 are three sets of odd-numbered guide ribs evenly distributed circumferentially. Each first axial elastic guide rib 402 and second axial elastic guide rib 408 has a wear-resistant protective layer on its inner end face, forming a sliding fit with the valve needle rod body 505. The wear-resistant protective layer uses a nano-ceramic coating, which, together with the wear-resistant coating on the surface of the valve needle rod body 505, forms a low-friction pair, significantly reducing wear on the guide mating surfaces and extending the service life of the dual-segment elastic guide assembly 400 and the valve needle rod body 505.

[0029] like Figure 8 As shown, the spherical sealing gate sleeve 502 is a cylindrical base coaxially arranged with the nozzle body 300. Inside, from top to bottom, are integrally machined conical guide sections 503 and concave spherical conical sealing sections 504 that smoothly connect to each other. The upper end of the conical guide section 503 is coaxially connected to the main melt channel of the nozzle body 300. The conical guide section 503 is a smooth conical surface that transitions tangentially with the concave spherical conical sealing section 504, eliminating dead zones for melt stagnation and preventing carbonization and degradation of the melt inside the gate sleeve.

[0030] Furthermore, such as Figures 6-7 As shown, the spherical sealing assembly 500 also includes a metal mounting base 501, and the spherical sealing gate sleeve 502 is coaxially fixed to the lower end of the nozzle body 300 through the metal mounting base 501. The metal mounting base 501 is threaded to the nozzle body 300 and is provided with a positioning stop. The stop and the inner hole of the nozzle body 300 adopt a high-precision clearance fit to ensure the basic coaxiality of the spherical sealing gate sleeve 502 and the valve needle rod 505. At the same time, it is easy to disassemble and assemble, and no disassembly of the core structure of the nozzle is required for later maintenance. The lower end of the valve needle rod 505 is also integrally provided with a conical transition section 507. The conical transition section 507 is located between the bellows-type elastic floating section 506 and the convex spherical conical sealing head 508, and cooperates with the conical flow guide section 503 to form a smoothly connected melt flow channel. The conical transition section 507 is a smooth conical surface that transitions tangentially with the convex spherical conical sealing head 508. In the open valve state, it forms a streamlined flow channel together with the conical guide section 503, reducing melt flow resistance, avoiding shear heat concentration, and ensuring stable melt injection molding performance.

[0031] like Figures 1-2As shown, the outer wall of the nozzle body 300 is provided with a heating element corresponding to the axial position of the dual-section elastic guide assembly 400, and a temperature sensing element is embedded in the end of the nozzle body 300 near the spherical sealing assembly 500. The temperature sensing element, located at the end of the nozzle body 300 near the spherical sealing assembly 500, can be an armored thermocouple. Its probe extends into the nozzle body 300 and is located near the melt flow channel to collect the temperature signal at the nozzle tip in real time. The temperature sensing element is electrically connected to an external temperature control box. The temperature control box adjusts the heating power of the heating element according to the signal fed back by the temperature sensing element to achieve closed-loop constant temperature control of the melt temperature inside the nozzle body 300. The heat insulation protective sleeve 200 is fitted on the upper section of the outer wall of the nozzle body 300. Its multi-layer air insulation structure can effectively reduce heat loss and ensure the stable operating temperature of the drive cylinder 100.

[0032] During assembly, the pre-processing and precision testing of each core component are completed first. After deburring and cleaning, the machined first guide sleeve 401, second guide sleeve 407, valve needle rod 505, spherical sealing gate sleeve 502, and other components undergo form and position tolerance and dimensional accuracy testing. Once qualified, they are transferred to the assembly process. During assembly, the heat insulation protective sleeve 200 is pre-fitted onto the corresponding position on the outer wall of the nozzle body 300. Then, the first guide sleeve 401, with the embedded miniature one-way valve 405, is coaxially pressed into the upper inner hole step of the nozzle body 300 using a heat-fitting method. Subsequently, the second guide sleeve 407 is coaxially pressed into the lower inner hole step of the nozzle body 300. Throughout the pressing process, the coaxiality of the two guide sleeves is continuously checked to ensure that the form and position tolerances meet the design requirements. After the guide sleeves are properly fitted, the valve needle rod 505 is inserted from the upper end of the nozzle body 300, and then sequentially passes through the first guide sleeve 401, second guide sleeve 407, valve needle rod 505, and spherical sealing gate sleeve 502. The valve needle rod 505 is manually pushed and pulled to test the center hole of the first guide sleeve 401, the inner cavity of the nozzle body 300, and the second guide sleeve 407 to ensure smooth reciprocating movement without jamming or abnormal resistance. Then, the metal mounting base 501 with the pre-pressed spherical sealing gate sleeve 502 is locked to the lower end of the nozzle body 300 by thread locking. During the locking process, the coaxiality of the spherical sealing gate sleeve 502 and the valve needle rod 505 is ensured to complete the assembly of the nozzle body 300. Then, the drive cylinder 100 is locked to the upper flange of the nozzle body 300, and the piston rod of the drive cylinder 100 is rigidly connected to the upper end of the valve needle rod 505. Finally, the heating element and the temperature measuring element are installed on the outer wall of the nozzle body 300 to complete the overall assembly of the nozzle assembly. After the assembly is completed, the valve needle rod 505 passes the action test, pressure test, and insulation test, and can then be transferred to the final assembly process of the injection molding device.

[0033] Once the injection molding device is debugged, it can enter the continuous production process. At the start of the injection cycle, the injection molding machine control system sends a valve opening signal, and then the drive cylinder 100 drives the valve needle rod 505 to move upward. At this time, the gate is fully opened, the injection molding machine screw advances, and the high-pressure molten plastic enters the main melt channel of the nozzle body 300 through the manifold. During the valve opening process, the first axial elastic guide rib 402 and the second axial elastic guide rib 408 in the first guide sleeve 401 and the second guide sleeve 407 elastically hold the valve needle rod 505 throughout the entire process, forming a double-support radial constraint to suppress the radial sway of the valve needle rod 505. At the same time, the high-pressure melt in the main melt channel pushes open the micro one-way valve 405 and is sprayed onto the surface of the valve needle rod 505 through the micro drainage groove 404, the annular flow channel 406, and the lubrication microhole 403, forming a continuous lubrication film and converting dry friction into fluid lubrication. During the injection stage, the melt... The melt is injected into the mold cavity through the annular gap between the conical guide section 503, the valve needle rod 505, and the spherical sealing gate sleeve 502. The conical transition section 507 and the conical guide section 503 form a smooth flow channel, reducing melt retention and shear degradation. During the holding pressure stage, the drive cylinder 100 remains open, and the dual-section elastic guide component 400 continuously provides radial support and self-lubricates continuously to ensure smooth movement of the valve needle rod 505. After the holding pressure is completed, the control system sends a valve closing signal, and the drive cylinder 100 drives the valve needle rod 505 to move downward. The bellows-type elastic floating section 506 drives the convex spherical conical sealing head 508 to float radially and align, forming a full circumferential seal with the concave spherical conical sealing section 504, cutting off the gate and effectively suppressing leakage and flash. Subsequently, the plastic part in the mold cools and solidifies, the mold opens, and the plastic part is ejected, completing a complete injection cycle. This cycle is repeated to achieve continuous and stable production.

Claims

1. A hot runner nozzle assembly, characterized in that, include: The drive cylinder (100) is the power source; The nozzle body (300) serves as the mounting base, with a connected melt main channel inside; A heat insulation protective sleeve (200) is fitted over the outside of the nozzle body (300) for heat insulation and protection; A dual-segment elastic guide assembly (400) is coaxially fixed inside the nozzle body (300) to provide dual-support radial limiting, and its interior integrates a melt self-lubricating flow channel structure; A spherical sealing assembly (500) is coaxially mounted on the lower end of the nozzle body (300) and is used for gate opening and closing and sealing. The spherical sealing assembly (500) includes a valve needle rod body (505) that is connected to the drive cylinder (100), a spherical sealing gate sleeve (502), and a bellows-type elastic floating section (506) and an outwardly convex spherical conical sealing head (508) disposed at the lower end of the valve needle rod body (505). The spherical sealing gate sleeve (502) is provided with an inwardly concave spherical conical sealing section (504) that matches the outwardly convex spherical conical sealing head (508). The bellows-type elastic floating section (506) is used to drive the outwardly convex spherical conical sealing head (508) to float radially and align, forming a full circumferential seal. The dual-segment elastic guide assembly (400) includes a first guide sleeve (401) and a second guide sleeve (407) spaced apart along the axial direction. The inner wall of the first guide sleeve (401) is evenly distributed with a plurality of first axial elastic guide ribs (402), and the inner wall of the second guide sleeve (407) is evenly distributed with a plurality of second axial elastic guide ribs (408). Both the plurality of first axial elastic guide ribs (402) and the plurality of second axial elastic guide ribs (408) have elastic deformation capabilities and are used to form radial elastic support for the valve needle rod body (505). Multiple first axial elastic guide ribs (402) and multiple second axial elastic guide ribs (408) are integrally formed with the corresponding first guide sleeve (401) and second guide sleeve (407), and a melt flow channel is formed between adjacent guide ribs; Each of the first axial elastic guide ribs (402) has a lubrication microhole (403) on its inner end face. The first guide sleeve (401) has an annular flow channel (406) that communicates with the lubrication microhole (403) inside. The top of the first guide sleeve (401) has a micro-drainage groove (404) that communicates with the melt main channel of the nozzle body (300) and the annular flow channel (406).

2. The hot runner nozzle assembly according to claim 1, characterized in that: The outer wall of the nozzle body (300) is provided with a heating element corresponding to the axial position of the dual-segment elastic guide assembly (400), and the heating element is embedded in one end of the nozzle body (300) near the spherical sealing assembly (500).

3. The hot runner nozzle assembly according to claim 1, characterized in that: The first guide sleeve (401) is coaxially installed in the upper inner hole of the nozzle body (300), and the second guide sleeve (407) is coaxially installed in the lower inner hole of the nozzle body (300), with their central axes being coaxial.

4. The hot runner nozzle assembly according to claim 1, characterized in that: The micro-channel (404) is equipped with a micro-check valve (405), which allows the high-pressure melt to flow unidirectionally from the main channel to the annular channel (406).

5. The hot runner nozzle assembly according to claim 3, characterized in that: The first axial elastic guide rib (402) and the second axial elastic guide rib (408) are three sets of odd-numbered guide ribs evenly distributed in the circumference. The inner end face of each first axial elastic guide rib (402) and the second axial elastic guide rib (408) is provided with a wear-resistant protective layer, which forms a sliding fit with the valve needle rod body (505).

6. The hot runner nozzle assembly according to claim 1, characterized in that: The spherical sealing gate sleeve (502) is coaxially arranged with the nozzle body (300). The inside of the sleeve is integrally machined from top to bottom with a conical guide section (503) and an inwardly concave spherical conical sealing section (504). The upper end of the conical guide section (503) is coaxially connected with the melt main channel of the nozzle body (300).

7. The hot runner nozzle assembly according to claim 6, characterized in that: The spherical sealing assembly (500) also includes a metal mounting base (501), and the spherical sealing gate sleeve (502) is coaxially fixed to the lower end of the nozzle body (300) via the metal mounting base (501).

8. The hot runner nozzle assembly according to claim 7, characterized in that: The lower end of the valve needle rod body (505) is also integrally provided with a conical transition section (507). The conical transition section (507) is located between the bellows-type elastic floating section (506) and the convex spherical conical sealing head (508), and cooperates with the conical guide section (503) to form a smoothly connected melt flow channel.

9. A temperature-controlled injection molding device, characterized in that: The hot runner nozzle assembly as described in any one of claims 1-8 is provided.

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