Hot nozzle with valve needle self-guiding function

Abstract

The utility model provides a hot nozzle with an automatic guide valve needle. The hot nozzle comprises an HD body, a valve needle assembly arranged in the HD body, a hot nozzle body, a nozzle core sleeve, a sealing ring and a heat insulation cap, wherein the sealing ring and the heat insulation cap are located at one end of the HD body; a conical sealing surface and a ceramic lining are arranged at the outlet end of the hot nozzle body; the valve needle assembly is provided with a stepped shaft structure, a conical sealing head and a split type guide sleeve. A graphite self-lubricating layer is arranged on the inner wall of the split type guide sleeve, and the thickness is 0.05-0.2 mm; the dynamic compensation assembly comprises an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1 mm, and radial fine adjustment of the guide sleeve is achieved through melt pressure; the elastic compensation ring is a high-temperature alloy spring, and the adjustable range of the pre-tightening force is 50-200N; the spiral angle of the spiral flow guide groove in the inner wall of the ceramic lining is 15-45 degrees, and in practical application, the production and machining time and the system maintenance time can be effectively saved, the valve needle is effectively prevented from being deviated, the overall service life of a system is guaranteed, and the production efficiency of customers is improved.

Description

[Technical Field]

[0001] This utility model relates to the technical field of hot nozzle components for cylinders, and in particular to a hot nozzle with valve needle self-guiding that can be quickly replaced, saving system maintenance time and improving production efficiency. [Background Technology]

[0002] Traditional hot runner nozzles rely on external guide sleeves or linear bearings for valve needle movement, which has at least the following drawbacks:

[0003] A. The guide structure is prone to wear: Under long-term high temperature, the guide sleeve is prone to deformation, which can cause the valve needle to deviate, leading to material leakage or sealing failure.

[0004] B. Low alignment accuracy: The coaxiality of the valve needle and the inner wall of the hot nozzle depends on the assembly accuracy. Accumulated tolerances can easily cause jamming or local wear.

[0005] C. High maintenance costs: Guide components need to be replaced frequently, which affects production efficiency.

[0006] In the prior art, for example, the invention patent with patent number CN201910651794.0 and patent title "A Single-Piston Multi-Valve-Needle Hot Runner Nozzle" specifically discloses a single-piston multi-valve-needle hot runner nozzle: it includes a piston body and valve needles, the piston body is provided with 3-6 valve needles, the number of piston bodies is 1, and the valve needles penetrate the piston body and the nozzle body, the diameter of each valve needle is 1 / 7-9 / 1 of the inner diameter of the piston body. This invention, by reducing the diameter of the valve needles in the prior art and increasing the density of valve needles within the piston body, enables one piston to drive multiple valve needles. The more pistons there are, the higher the cost and the greater the maintenance difficulty. Reducing the number of pistons can reduce production and maintenance costs. Its technical method uses a multi-segment guiding structure, but it does not solve the problem of high-temperature thermal expansion and dynamic compensation of the valve needles.

[0007] Therefore, there is an urgent need for a hot nozzle solution that can achieve autonomous dynamic guidance of the valve needle and reduce wear. [Utility Model Content]

[0008] The problem addressed by this application in the prior art is:

[0009] A. The guide structure is prone to wear: Under long-term high temperature, the guide sleeve is prone to deformation, which can cause the valve needle to deviate, leading to material leakage or sealing failure.

[0010] B. Low alignment accuracy: The coaxiality of the valve needle and the inner wall of the hot nozzle depends on the assembly accuracy. Accumulated tolerances can easily cause jamming or local wear.

[0011] C. High maintenance costs: Guide components need to be replaced frequently, which affects production efficiency.

[0012] The solution to the technical problem of this utility model is:

[0013] A self-guided hot nozzle with a valve needle is provided, comprising an HD body, a valve needle assembly disposed inside the HD body, a hot nozzle body, a nozzle core sleeve, and a sealing ring and a heat insulation cap located at one end of the HD body; the outlet end of the hot nozzle body is provided with a conical sealing surface and a ceramic bushing; the valve needle assembly has a stepped shaft structure, a conical sealing head, and a split guide sleeve; the inner wall of the split guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; it also includes a dynamic compensation component, which contains an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is achieved by melt pressure; the elastic compensation ring is a high-temperature alloy spring with an adjustable preload range of 50-200N; the helix angle of the spiral guide groove on the inner wall of the ceramic bushing is 15-45°.

[0014] Preferably, the outer surface of the valve needle is plated with a hard chrome structural layer, and the outer surface of the hard chrome structural layer is coated with a heat-resistant and non-stick layer; the outer surface of the hard chrome structural layer is covered with nanopores to form a nanopore surface, and the heat-resistant and non-stick layer is tightly bonded to the nanopore surface of the hard chrome structural layer by an integral injection molding method to form an integral structure.

[0015] Preferably, the valve needle assembly is located at the center of the inner side of the cylinder unit.

[0016] The technical effects achieved by this application in solving the technical problem are as follows:

[0017] Compared with existing technologies, this utility model provides an integrated body structure with a valve needle self-guided hot nozzle, which saves production and processing time, system maintenance time, effectively avoids valve needle misalignment, ensures the overall service life of the system, and improves the customer's production efficiency. [Image Description]

[0018] Figure 1 This is a three-dimensional structural diagram of a valve needle self-guided hot nozzle according to the present invention.

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of a valve needle self-guided hot nozzle according to the present invention. [Detailed Implementation]

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0021] It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0022] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] Please see Figure 1 and Figure 2 This utility model discloses a valve needle self-guided hot nozzle 1, comprising an HD body 11, a valve needle assembly 12 disposed inside the HD body 11, a hot nozzle body, a nozzle core sleeve, and a sealing ring and a heat insulation cap 13 located at one end of the HD body 11; the outlet end of the hot nozzle body 11 is provided with a conical sealing surface and a ceramic bushing; the valve needle assembly 12 has a stepped shaft structure, a conical sealing head, and a split guide sleeve; the inner wall of the split guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; it also includes a dynamic compensation component, which contains an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is achieved by melt pressure; the elastic compensation ring is a high-temperature alloy spring with an adjustable preload range of 50-200N; the helix angle of the spiral guide groove on the inner wall of the ceramic bushing is 15-45°.

[0028] In some other embodiments, the outer surface of the valve needle is plated with a hard chrome structural layer, and the outer surface of the hard chrome structural layer is coated with a heat-resistant and non-stick layer; the outer surface of the hard chrome structural layer is covered with nanopores to form a nanopore surface, and the heat-resistant and non-stick layer is tightly bonded to the nanopore surface of the hard chrome structural layer by an integral injection molding method to form an integral structure.

[0029] The valve needle assembly 12 is located at the center of the inner side of the cylinder unit.

[0030] This utility model relates to a self-guided hot nozzle with a valve needle, comprising an HD body 11, a nozzle core, a nozzle core sleeve, a sealing ring, and a heat insulation cap 13. The nozzle core and nozzle core sleeve are assembled by a tight fit, and the nozzle core assembly is assembled to the body by cold fitting. A threaded section is provided on the lower inner wall of the body, and the sealing ring is connected to the body by a threaded connection. The body, nozzle core assembly, and sealing ring are made with precision machining to achieve concentricity and perpendicularity. In this patented structure, the valve needle can effectively avoid deviation by being self-guided by the steel nozzle core when moving up and down. The nozzle core is made of steel and the nozzle core sleeve is made of copper, which increases the hardness of the inner wall of the nozzle core compared to a single copper core, thus increasing wear resistance and corrosion resistance. The high thermal conductivity of the copper nozzle core can quickly increase the temperature of the inner plastic wall and the valve needle head. This patented structure is an integrated structure, which can be quickly replaced during system maintenance, saving system maintenance time and improving production efficiency.

[0031] The integrated body structure saves production and processing time and system maintenance time, effectively avoids valve needle misalignment, ensures the overall service life of the system, and improves the customer's production efficiency.

[0032] By incorporating a built-in guiding structure and dynamic compensation mechanism, the problems of valve needle misalignment, wear, and seal failure are solved, thereby improving injection molding stability and hot nozzle life.

[0033] Heating nozzle body:

[0034] It has an internal melt channel, and the outlet end of the channel is equipped with a conical sealing surface.

[0035] The hot nozzle head integrates a high-temperature resistant ceramic bushing, and the inner wall of the bushing is provided with a spiral guide groove to help the melt be evenly distributed.

[0036] Autonomous Guided Valve Needle Mechanism:

[0037] The valve needle body has a stepped shaft structure, and the front end is a conical sealing head that mates with the hot nozzle sealing surface.

[0038] The valve needle is equipped with a split guide sleeve in the middle section. The guide sleeve is embedded with a graphite self-lubricating layer, which allows the valve needle to deflect slightly at high temperatures.

[0039] The valve needle is connected to a drive rod at its tail, and the drive rod is linked with an external cylinder / servo motor.

[0040] Dynamic compensation component:

[0041] The valve needle is equipped with an elastic compensation ring at the tail end, which uses a high-temperature alloy spring or a disc spring to compensate for axial displacement caused by thermal expansion.

[0042] A floating gap is provided between the guide sleeve and the inner wall of the hot nozzle. The guide sleeve is radially fine-tuned by the melt pressure to achieve dynamic centering of the valve needle.

[0043] Technical effect:

[0044] The valve needle's self-guiding structure reduces the skew error to ≤0.02mm and increases the sealing life by more than 2 times.

[0045] The graphite self-lubricating layer has a friction coefficient of ≤0.1 at 300℃, reducing the risk of jamming.

[0046] The dynamic compensation mechanism can absorb ±0.15mm of thermal expansion, adapting to continuous high-temperature operating conditions;

[0047] Example 1:

[0048] The hot nozzle is installed on the mold, and the valve needle is driven by a servo motor with a stroke accuracy controlled to ±0.01mm.

[0049] During injection molding, the melt pressure (80MPa) acts on the floating gap (11), pushing the guide sleeve (7) to move radially and correcting the valve needle position.

[0050] The elastic compensation ring (10) is compressed by 0.1 mm during thermal expansion to prevent the valve needle from getting stuck axially.

[0051] Example 2:

[0052] For glass fiber reinforced materials, the ceramic bushing (3) is replaced with tungsten carbide material, and the depth of the spiral guide groove (4) is increased to 0.5 mm to reduce shear heat;

[0053] Dynamic alignment and thermal expansion compensation of the valve needle are achieved through a split guide sleeve, floating gap and elastic compensation ring, which significantly improves sealing reliability and injection precision, and is suitable for high-requirement injection molding scenarios such as automotive electronics and medical devices.

[0054] Compared with the prior art, the present invention provides an integrated body structure with a valve needle self-guided hot nozzle 1, which saves production and processing time, system maintenance time, effectively avoids valve needle misalignment, ensures the overall service life of the system, and improves the customer's production efficiency.

[0055] The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A valve having a self-guiding needle with a hot tip, characterized by: The HD body, the valve needle assembly arranged inside the HD body, the hot nozzle body, the nozzle core sleeve, the sealing ring and the heat insulation cap at one end of the HD body; the outlet end of the hot nozzle body is provided with a conical sealing surface and a ceramic bushing; the valve needle assembly has a stepped shaft structure, a conical sealing head and a split type guide sleeve; the inner wall of the split type guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; further comprising a dynamic compensation assembly containing an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is realized by the melt pressure; the elastic compensation ring is a high-temperature alloy spring, and the pre-tightening force can be adjusted in the range of 50-200N; the spiral angle of the spiral flow guide groove in the inner wall of the ceramic bushing is 15-45°.

2. A valve needle with self-guiding hot tip as defined in claim 1, characterized in that: The outer surface of the valve needle is plated with a hard chromium structural layer, and the outer surface of the hard chromium structural layer is coated with a heat-resistant anti-sticking layer; the outer surface of the hard chromium structural layer is covered with nano-pores to form a nano-pore surface, and the heat-resistant anti-sticking layer is tightly combined with the nano-pore surface of the hard chromium structural layer by one-piece injection molding to form an integrated structure.

3. A valve needle with self-guiding hot tip as defined in claim 1, characterized in that: The valve needle assembly is located at the center of the inside of the HD body.

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