Injection mold for a silicone-coated wire for a microphone

Abstract

This utility model relates to the technical field of injection molds, and in particular to an injection mold for silicone-coated metal wire for a microphone rod, comprising: a front template, a rear template, and a fixing assembly; the fixing assembly includes a fixing insert and a fixing core; the fixing insert is detachably installed on the rear template, and the fixing insert has a fixing structure to position and fix one end of the insert to a preset position in the injection cavity via a first bracket; one side of the fixing core is fixedly connected to the rear template, and the other side extends into the injection cavity to form a protrusion, and the fixing core has a core groove for fixing a second bracket to position and fix the other end of the insert to a preset position in the injection cavity via the second bracket. In summary, by using a double-end positioning of "fixed insert + fixing core", combined with a bracket, heat-conducting plug, and sealing structure, high-precision positioning of the insert is achieved, the lower end cap is prevented from deforming and silicone from flowing in, assembly efficiency is improved, and the defects of traditional molds are solved.

Description

Technical Field

[0001] This utility model relates to the technical field of injection molds, and in particular to an injection mold for silicone-coated metal wire for microphone rods. Background Technology

[0002] In the field of silicone-coated metal wire injection molding production of microphone booms, the microphone boom, as a key component of the microphone assembly, needs to be able to bend without damaging the internal cable wires. Therefore, a gooseneck tube is usually built into it. The gooseneck tube can be bent arbitrarily and fixed in direction to guide the bending direction of the microphone boom and protect the internal metal wires.

[0003] However, existing injection molding fixation methods for this type of "slender short-axis" gooseneck tube have significant drawbacks, mainly in the following two aspects: Gooseneck tubes are prone to deformation: Traditional injection molds use fixed pins or inserts to directly fix the gooseneck tube. Due to the extremely small contact area between the fixed pin and the gooseneck tube, the gooseneck tube is prone to bending and deformation under injection pressure (5-8MPa). The deformation amount usually exceeds 0.5mm, which seriously affects the subsequent bending accuracy of the microphone and causes the microphone to be unable to perform multi-angle adjustment function normally.

[0004] Insufficient positioning accuracy: The positioning of the fixing pin relies on manual placement, making it difficult to ensure precise alignment of both ends of the gooseneck tube. The positioning error is often greater than 1mm. This can cause uneven silicone coating thickness on the microphone rod, with some areas having excessively thin coatings or even exposed wires. This not only affects the product's appearance quality but also causes the internal metal wires to lose insulation protection, increasing the risk of short circuits and damage. Utility Model Content

[0005] To overcome the shortcomings mentioned above, this utility model aims to provide a technical solution that can solve the above problems.

[0006] This utility model provides an injection mold for silicone-coated metal wire for a microphone, comprising: a front template, a rear template, and a fixing assembly; the front template and the rear template are mated together, and the two form an injection cavity for accommodating an insert, wherein the insert is the metal wire of the microphone; the fixing assembly includes a fixing insert and a fixing mold core; the fixing insert is detachably mounted on the rear template, and the fixing insert has a fixing structure for fixing a first bracket fitted at one end of the insert, so that one end of the insert is positioned and fixed in a preset position in the injection cavity by the first bracket; one side of the fixing mold core is fixedly connected to the rear template, and the other side extends into the injection cavity to form a protrusion, and the fixing mold core has a mold core groove corresponding to the other end of the insert, the mold core groove being used to fix a second bracket fitted at the other end of the insert, so that the other end of the insert is positioned and fixed in a preset position in the injection cavity by the second bracket.

[0007] Furthermore: the protrusion of the fixed mold core is a mold core protrusion, which is used to position and cooperate with the lower end cover of the microphone rod; the lower end cover is a box-shaped structure with an opening on one side, and its interior forms a cavity for accommodating electronic components. The opening end of the cavity is provided with an opening groove, and the closed end is provided with an opening for installing the microphone; the mold core protrusion is adapted to the cavity of the lower end cover, so that the lower end cover part extends into the injection molding cavity, and the insert passes through the opening end of the cavity and exits through the opening at the closed end.

[0008] Furthermore: the inner wall of the cavity of the lower end cover is provided with at least two reinforcing ribs along its depth direction; the two sides of the mold core protrusion are provided with limiting grooves along the protrusion direction corresponding to the positions of the reinforcing ribs, and the reinforcing ribs are adapted to engage with the limiting grooves to limit the lateral and radial displacement of the lower end cover relative to the mold core protrusion.

[0009] Furthermore: the second bracket has a block-shaped structure with lateral locking strips extending radially outward on both sides; the edge of the opening end of the lower end cover cavity has a lateral locking groove corresponding to the position of the lateral locking strip, and the lateral locking strip engages with the lateral locking groove to block the opening end of the cavity and form an integral positioning structure with the lower end cover.

[0010] Furthermore: the top of the mold core protrusion extending into the injection cavity has a slot extending along its long side, the slot being for the passage of metal wires; the top of the mold core protrusion is also provided with a heat-conducting plug, the heat-conducting plug being adapted to and detachably connected to the slot to close the slot; the heat-conducting plug is made of stainless steel, and its side facing the lower end cover is fitted with the top of the cavity of the lower end cover to support the lower end cover and conduct heat to the rear mold plate.

[0011] Furthermore: the fixed insert includes a first insert and a second insert that can be mated and fastened together; the first insert has a first groove on its mating surface facing the second insert, and the second insert has a second groove on its mating surface facing the first insert; after the first groove and the second groove are mated together, a cavity is formed for accommodating and positioning the first bracket, the shape of the cavity is adapted to the first bracket, and one end of the cavity is provided with an opening to avoid the joint portion of the first bracket.

[0012] Furthermore: the first bracket has an annular groove on the outer periphery of one end near the fixed insert; the cavity formed after the first groove and the second groove are connected has an annular insert retaining ring at the position corresponding to the annular groove; the insert retaining ring is adapted to engage with the annular groove to limit the displacement of the first bracket along its axial direction.

[0013] Compared with the prior art, the beneficial effects of this utility model are: ① High-precision positioning solves the problems of deformation and exposed wires. The double-end positioning structure of "fixed insert + fixed mold core" is adopted, and with the first bracket (microphone tail connector) and the second bracket (dedicated positioning component), the gooseneck tube-hardware wire insert is fixed in all dimensions, with a positioning error ≤0.2mm and radial runout ≤0.1mm. The deformation of the gooseneck tube during injection molding is less than 0.1mm, and the thickness deviation of the silicone coating is less than 0.1mm, completely eliminating the problem of exposed wires and ensuring the bending accuracy and insulation performance of the microphone rod.

[0014] ② The lower end cover positioning and protection have been upgraded to improve assembly stability. The design incorporates a matching structure between the mold core protrusion and the lower end cap cavity (gap 0.1mm), combined with the snap-fit ​​of the reinforcing ribs and the limiting groove (lateral and radial offset ≤0.05mm), which increases the pull-out resistance of the lower end cap from 30N to 80N, completely resisting the injection molding impact force. The stainless steel heat plug (thermal conductivity 16.2W / (m・K)) has a raised groove in the closed mold core, which not only provides stable support for the lower end cover, but also conducts heat quickly, keeping the temperature of the lower end cover below 80℃ during injection molding and the deformation ≤0.05mm, ensuring the installation accuracy of electronic components (error ≤0.1mm).

[0015] ③ Improve sealing and process optimization to increase production efficiency The second bracket and the lower end cover are fitted together by a lateral locking strip and a lateral locking groove (gap 0.1mm) to form a double seal. After 1000 tests, the probability of molten silicone flowing into the lower end cover cavity is 0, eliminating the need for subsequent cleaning procedures. The split-type fixed insert is compatible with the L-shaped first bracket, which can be assembled without forced deformation, improving assembly efficiency by 30%. At the same time, the first bracket, as a finished part of the microphone rod, does not need to be removed after injection molding, reducing an assembly process and improving overall production efficiency by 15%-20%.

[0016] ④ Enhanced structural strength and stability, extending product lifespan The engagement of the first bracket's annular groove with the insert retaining ring (gap 0.01mm) increases the axial pull-out resistance of the first bracket from 20N to 80N, and the circumferential anti-rotation angle is ≤0.2°, ensuring the alignment accuracy of the microphone tail connector with the external equipment (error ≤0.1mm). The reinforcing ribs inside the lower end cap cavity improve the cavity's resistance to deformation by 50%. The second bracket and the lower end cap work together to position the insert, ensuring that the straightness error is ≤0.1mm / m (better than the traditional 0.5mm / m), thus guaranteeing the stability of the microphone signal transmission and extending the product's service life.

[0017] In summary, this injection mold achieves high-precision positioning of the insert, prevents deformation of the lower end cap and prevents silicone from flowing in through a double-end positioning system of "fixed insert + fixed mold core", combined with a bracket, heat-conducting plug and sealing structure. It also improves assembly efficiency and solves the defects of traditional molds.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the front and rear templates of this utility model; Figure 2 This is a schematic diagram of the fixed mold core and the lower end cap of this utility model; Figure 3 This is a schematic diagram of the insert and heat plug of this utility model; Figure 4 This is a schematic diagram of the insert retaining ring and insert groove of this utility model; Figure 5 This is a schematic diagram of the structure of the first and second supports of this utility model; Figure 6This is a structural schematic diagram of the lower end cover and the second bracket of this utility model in a separated state; Figure 7 This is a schematic diagram of the structure of the insert of this utility model in a separated state from the first bracket and the second bracket.

[0021] The reference numerals and names in the figure are as follows: 10 Front template; 11 Rear template; 20 Fixed insert; 21 Insert retaining ring; 22 Insert groove; 23 First insert; 24 Second insert; 30 Fixed mold core; 31 Mold core groove; 32 Limiting groove; 33 Slot; 34 Heat-conducting plug; 40 Lower end cover; 41 Opening groove; 42 Side retaining groove; 43 Opening; 44 Reinforcing rib; 50 Insert; 51 First bracket; 52 Annular retaining groove; 53 Auxiliary hole; 54 Auxiliary plug; 55 Second bracket; 56 Side retaining strip. Detailed Implementation

[0022] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] Please see Figures 1 to 7 In this embodiment of the present invention, an injection mold for silicone-coated metal wire for a microphone rod includes a front template 10 and a rear template 11 that are assembled together, forming an injection cavity between the front template 10 and the rear template 11 for injection molding an insert 50 pre-placed in the injection cavity; it also includes a fixing assembly, which has a fixing insert 20 and a fixing core 30. The fixing insert 20 is detachably mounted on the rear template 11 and is used to support a first bracket fitted onto one end of the insert 50. 51 is fixed so that one end of the insert 50 is fixed in a preset position in the injection cavity by the support of the first bracket 51; one side of the fixed insert 30 is fixed to the rear template 11, and the other side forms a protrusion extending into the injection cavity. The fixed insert 30 is provided with a insert groove 31 corresponding to the part of the insert 50. The insert groove 31 is used to fix the second bracket 55 sleeved on the other end of the insert 50 so that the other end of the insert 50 is fixed in a preset position in the injection cavity by the support of the second bracket 55.

[0024] Specifically, the insert 50 molding process is an injection molding technology that involves placing a pre-made insert 50 (such as metal, plastic, or glass) into a mold and injecting injection molding material (silicone) to form a product with integrated materials. This process is widely used in the electrical, automotive, medical, and consumer electronics fields. It combines the plasticity of molten silicone with the rigidity of the insert 50 to achieve integrated insulation and conductivity, meeting the requirements of complex structures. The microphone boom is a key component in microphone assemblies, typically a bendable or rotatable rod-shaped structure used to fix the microphone head and adjust its position. To improve the bending performance of the microphone boom, allowing it to bend arbitrarily without damaging the internal cables, a gooseneck tube is preferably installed inside the microphone boom. The gooseneck tube's ability to bend arbitrarily and determine direction guides and limits the bending of the microphone boom, while protecting the internal cables during bending. However, in the injection molding production of microphone booms, the gooseneck tube has a small diameter and a long length, making traditional fixing pins or inserts inconvenient for fixing during the injection molding process; therefore, improvement is necessary.

[0025] This invention uses a fixing component between the front template 10 and the rear template 11 to fix the insert 50 in a preset position, ensuring accurate fixation for injection molding of the gooseneck tube and internal wires. For the relatively long length of the gooseneck tube, a first bracket 51 and a second bracket 55 are preferably provided at both ends, allowing them to be fitted onto the ends of the gooseneck tube for support and positioning. The first bracket 51 and the second bracket 55 are pre-produced plastic parts. They can be accessories required for the microphone rod itself, or special accessories configured to fix the insert 50. For example, the first bracket 51 can be configured using the tail connector of the microphone rod. That is, the tail connector of the microphone rod is produced and used as the first bracket 51, which is fitted onto one end of the gooseneck tube. Then, the tail connector of the microphone rod is fixed by the fixed insert 20, so that it is fixed in the preset position of the injection cavity. This allows for simultaneous injection molding of the insert 50 with the tail connector of the microphone rod, and it can also be used as the first bracket 51 to support the insert 50 and keep it in the preset position. The second bracket 55 can be a special accessory, that is, a component that is not part of the microphone rod itself, but is pre-injected and molded to support and position the insert 50. For example, a small silicone block is set with a through hole corresponding to the installation position of the insert 50, so that it is fitted onto the other end of the insert 50. A mold core groove 31 (3-5mm deep, 0.1mm wider than the second bracket 55) is provided on the side of the mold core protrusion corresponding to the other end of the insert 50, so that the silicone block of the second bracket 55 can be inserted into the mold core groove 31 to form a fixation.

[0026] 1. In existing microphone rods, silicone-coated wires require an internal gooseneck tube to ensure bending performance (gooseneck tube diameter 3-5mm (typical value 4mm), length 150-190mm (typical value 165mm), belonging to the "slender short shaft component" category). Traditional injection molds use fixing pins or inserts to directly fix the gooseneck tube, which has two major drawbacks: ① The contact area between the fixing pin and the gooseneck tube is small, making it prone to bending and deformation under injection pressure (deformation > 0.5mm), affecting the bending accuracy of the microphone rod; ② The positioning of the fixing pin relies on manual placement, resulting in large positioning errors at both ends of the gooseneck tube (> 1mm), leading to uneven silicone coating thickness and even exposed wire.

[0027] 2. Specific implementation methods of mold components In this embodiment, the insert 50 is specifically a combination of "outer gooseneck tube + inner hardware wire" (the gooseneck tube is coaxially sleeved on the outside of the hardware wire, the total diameter of the insert 50 is 3-5mm (typical value 4mm), and the length is 150-190mm (typical value 165mm); the first bracket 51 and the second bracket 55 are both pre-injection molded auxiliary positioning parts, as detailed below: The first bracket 51 (microphone stem end connector): made of ABS plastic, one end of which has a blind hole adapted to the gooseneck tube (blind hole diameter 2.1-4.1mm, depth 5-8mm, interference fit with the gooseneck tube), and the other end has a retaining ring structure adapted to the fixed insert 20; the fixing structure of the fixed insert 20 is a "slot adapted to the retaining ring of the first bracket 51". During assembly, the blind hole of the first bracket 51 is fitted onto one end of the gooseneck tube (interference fit fixation), and then the retaining ring of the first bracket 51 is inserted into the slot of the fixed insert 20 to achieve positioning of one end of the insert 50 (positioning error ≤0.2mm); at the same time, the first bracket 51 is a necessary component of the finished microphone stem. After injection molding, it does not need to be removed and directly becomes the connector structure of the microphone stem end, simplifying the production process.

[0028] The second support 55 (dedicated silicone block): made of silicone with a Shore hardness of 50-60, with a through hole in the center that matches the insert 50 (gooseneck tube) (through hole diameter 3.1-4.1mm, depth 3-5mm, clearance fit with insert 50, clearance 0.1-0.2mm); the depth of the mold core groove 31 of the fixed mold core 30 is the same as the thickness of the second support 55 (3-5mm), and the width is 0.1mm larger than the second support 55. During assembly, the through hole of the second support 55 is fitted onto the other end of the insert 50, and then the second support 55 is inserted into the mold core groove 31 of the fixed mold core 30 to achieve positioning of the other end of the insert 50 (positioning error ≤0.2mm); the second support 55 is a dedicated positioning part, which is removed from the finished product manually or by a robot after injection molding (the silicone material is easy to peel off and does not damage the silicone coating of the injection-molded micrometer).

[0029] The protrusion of the fixed mold core 30: The protrusion extends along the length of the injection cavity (parallel to the axis of the insert 50), with a height of 1-5mm. It is used to form a preset cavity structure on the silicone coating of the microphone rod (to meet the needs of subsequent assembly of other parts of the microphone rod). At the same time, the protrusion abuts against the side of the second bracket 55, further restricting the radial displacement of the insert 50.

[0030] 3. Injection Molding Process ① Pre-treatment of insert 50: The gooseneck tube is coaxially sleeved on the outside of the hardware wire to form the insert 50 to be injection molded; ② Bracket assembly: Fit the first bracket 51 (microphone rod tail connector) onto one end of the insert 50 (interference fit), and fit the second bracket 55 (silicone block) onto the other end of the insert 50 (clearance fit). ③ Mold positioning before mold closing: Place the insert 50 with the assembled bracket into the preset position of the rear template 11, so that the first bracket 51 is inserted into the slot of the fixed insert 20 and the second bracket 55 is inserted into the mold core groove 31 of the fixed mold core 30, thus completing the positioning of the insert 50 (at this time, the axis of the insert 50 coincides with the axis of the injection cavity, and the radial runout is ≤0.1mm). ④ Mold closing and injection molding: The front mold plate 10 and the rear mold plate 11 are aligned to form the mold, and molten silicone is injected into the injection cavity (injection temperature 160-180℃, pressure 5-8MPa). The silicone fills the cavity and wraps the insert 50 and the first support 51 (the second support 55 is not wrapped). ⑤ Demolding and post-processing: After cooling and molding (cooling time 10-15s), open the mold, take out the finished product, peel off the second bracket 55, and obtain the finished product of the silicone-coated hardware wire of the microphone rod with the first bracket 51 (tail connector).

[0031] 4. Implementation Results The following effects can be achieved by adopting the solution of this embodiment: ① The gooseneck tube is free from bending deformation (deformation amount < 0.1mm), solving the deformation problem caused by traditional fixing pins; ② The positioning error of the insert 50 is ≤ 0.2mm, the silicone coating thickness of the microphone rod is uniform (deviation < 0.1mm), and there is no exposed wire problem; ③ The first bracket 51 is a finished component, reducing one assembly process and increasing production efficiency by 15%-20%.

[0032] like Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 7As shown, preferably, the protrusion of the fixed mold core 30 is a mold core protrusion, which is used to position and cooperate with the lower end cover 40 of the microphone rod; the lower end cover 40 is a box-shaped structure with an opening on one side, and its interior forms a cavity for accommodating electronic components. The opening end of the cavity is provided with an opening groove 41, and the closed end is provided with an opening 43 for installing the microphone; the mold core protrusion is adapted to the cavity of the lower end cover 40, so that the lower end cover 40 partially extends into the injection molding cavity, and the insert 50 passes through the opening end of the cavity and exits through the opening 43 of the closed end.

[0033] This embodiment designs a dedicated positioning scheme for the box-shaped structure of the lower end cover 40, solving the problem of insufficient positioning accuracy caused by its large size (70mm long × 12mm deep × 27mm wide): Lower end cover 40 structure: Made of POM plastic (Shore hardness 85), with an opening on one side (opening size adapted to the second bracket 55), an internal cavity depth of 12mm (along the injection direction), a length of 70mm (along the axis of insert 50), and a width of 27mm (radial). A φ24mm opening 43 is provided at the center of the closed end (for the gooseneck tube and hardware wire to pass through and assemble the connecting microphone); Mold core protrusion design: A rectangular structure adapted to the cavity (69.9mm long × 11.9mm deep × 26.9mm wide), with a gap between the core and the cavity... The gap is 0.1mm, extending along the axis of insert 50; positioning logic: the opening end of the lower end cover 40 faces the side of insert 50 (gooseneck tube), the cavity is fitted after the mold core protrusion, the closed end (with microphone opening 43) extends into the injection cavity (length 20mm), the opening end and the remaining cavity (length 50mm) fit with the fixed mold core 30, realizing axial (error ≤0.1mm) and radial (error ≤0.05mm) bidirectional positioning; insert 50 path: the gooseneck tube (diameter 3mm) and the hardware wire (diameter 0.8mm) pass into the cavity from the opening end of the lower end cover 40, extend along the slot 33 on the top surface of the mold core protrusion to the closed end opening 43 to pass out, ensuring the connection accuracy with the microphone (alignment error ≤0.2mm).

[0034] like Figure 2 , Figure 3 and Figure 6 As shown, preferably, the inner wall of the cavity of the lower end cover 40 is provided with at least two reinforcing ribs 44 along its depth direction; the two sides of the mold core protrusion are provided with limiting grooves 32 along the protrusion direction corresponding to the positions of the reinforcing ribs 44, and the reinforcing ribs 44 are adapted to engage with the limiting grooves 32 to limit the lateral and radial displacement of the lower end cover 40 relative to the mold core protrusion.

[0035] To prevent the lower end cap 40 from shifting laterally and radially under injection pressure (5-8MPa), this embodiment designs a mating structure between the reinforcing rib 44 and the limiting groove 32: Reinforcing rib 44 configuration: Two reinforcing ribs 44 (10mm long, consistent with the cavity depth) are symmetrically arranged on the inner wall of the lower end cap 40 cavity. They have a U-shaped cross-section and are integrally formed with the lower end cap 40, enhancing the cavity rigidity (increasing deformation resistance by 50%) and serving as a positioning reference; Limiting groove 32 design: U-shaped limiting grooves are provided at corresponding positions on both sides of the mold core protrusion. Groove 32, height 10mm (consistent with the height of the mold core protrusion); Fitting effect: When the lower end cover 40 is fitted onto the mold core protrusion, after the reinforcing rib 44 slides into the limiting groove 32, the lateral offset is ≤0.05mm and the radial offset is ≤0.05mm, ensuring the relative position accuracy (error ≤0.1mm) of the subsequent installation position of electronic components inside the cavity and the insert 50; Process advantages: Compared with the traditional planar fit, this structure increases the pull-out resistance of the lower end cover 40 from 30N to 80N, completely resisting the impact force during injection molding.

[0036] like Figures 5 to 7 As shown, preferably, the second bracket 55 is provided with lateral retaining strips 56 on both sides, and the lower end cover 40 is provided with lateral retaining grooves 42 corresponding to the positions of the lateral retaining strips 56 on both sides of the second bracket 55. The lower end cover 40 covers the mold core protrusion, so that the lateral retaining grooves 42 are fitted onto the lateral retaining strips 56, thereby assisting in the positioning of the second bracket 55.

[0037] Specifically, in another embodiment, since the lower end cap 40 needs to be injection molded inside the silicone outer skin of the microphone, the second bracket 55 can be set to be non-removable, so that it can be directly injection molded at the end of the lower end cap 40 near the cavity of the gooseneck tube, to assist the injection molding of the injection cavity, that is, to seal the flow path of the molten silicone between the injection cavity and the lower end cap 40, and to prevent the molten silicone from flowing into the cavity of the lower end cap 40.

[0038] This embodiment solves two core problems through the snap-fit ​​connection between the second bracket 55 and the lower end cover 40: ① sealing the opening of the cavity (preventing silicone from flowing in); ② coordinated positioning of the second bracket 55 and the lower end cover 40. The specific solution is as follows: Second bracket 55 structure: Made of POM material (same as the lower end cover 40), in the shape of a cuboid block (11mm long × 9mm wide × 8mm thick), with a φ4.5mm through hole in the center (for the insert 50 to pass through), and symmetrically arranged side retaining strips 56 (2.5mm long × 1.5mm wide × 7mm high) on both sides, with a 0.2mm chamfer at the end of the retaining strips (for easy assembly); Side retaining groove 42 design: A side retaining groove 42 (2.6mm long × 1.6mm wide × 7.1mm deep) is provided at the corresponding position on the edge of the opening of the lower end cover 40, with a 0.1mm gap from the side retaining strip 56, and a chamfer is also provided at the opening of the side retaining groove 42 (for easy assembly); Assembly and sealing: The second bracket 55... After the side clip 56 of the bracket 55 is engaged with the side slot 42, the engagement force reaches 10N (to prevent it from falling off during injection molding). Its end face fits with the opening end of the lower end cover 40 (gap ≤ 0.05mm). At the same time, the outer periphery of the second bracket 55 fits with the injection molding cavity wall (gap ≤ 0.05mm), forming a double seal and completely blocking the flow of molten silicone into the cavity (after 1000 tests, the inflow rate is 0). Cooperative positioning: After the second bracket 55 and the lower end cover 40 are engaged, the coaxiality of their axes is ≤ 0.05mm. After the insert 50 (gooseneck tube) passes through the through hole of the second bracket 55, the straightness error is ≤ 0.1mm / m, which is better than the traditional solution (0.5mm / m), ensuring the stability of subsequent electronic component welding.

[0039] like Figure 2 , Figure 3 and Figure 5 As shown, preferably, the mold core protrusion extends into the top of the injection cavity and is also provided with a heat-conducting plug 34. The heat-conducting plug 34 extends along the long side of the mold core protrusion and is used to support and conduct heat to the lower end cover 40.

[0040] Specifically, because the top of the mold core protrusion has a slot 33 to facilitate the passage of metal wires, the supporting area of ​​the mold core protrusion for the lower end cover 40 is reduced. Since the lower end cover 40 is a pre-injected plastic part, during in-mold injection molding, it is susceptible to hollow deformation due to insufficient support caused by the high temperature (160-180℃) of the molten silicone. Therefore, a heat-conducting plug 34 can be installed on the top of the mold core protrusion. The heat-conducting plug 34 seals the slot 33 and provides support for the lower end cover 40, preventing deformation. Simultaneously, the heat-conducting plug 34, made of stainless steel, can also conduct heat from the lower end cover 40 to the rear mold plate 11, protecting it from high temperatures.

[0041] After injection molding is completed, the heat-conducting plug 34 can be demolded synchronously with the lower end cover 40. Then, the gooseneck tube and the hardware wire are bent to remove the heat-conducting plug 34 from the cavity of the lower end cover 40 for reuse.

[0042] This embodiment addresses the hollow deformation problem of the lower end cap 40 caused by high injection molding temperature (silicone melting temperature 170~180℃). The heat-conducting plug 34 structure is designed as follows: The slot 33 design: A rectangular slot 33 (50mm long × 10mm wide × 8mm deep) is cut along the long side of the mold core protrusion, maintaining a certain gap with the metal wire to ensure smooth wire passage; The heat-conducting plug 34 structure: Made of 304 stainless steel (thermal conductivity 16.2W / (m·K)), it is machined into a rectangular block (50mm long × 10mm wide × 2mm thick) that matches the slot 33. Anti-slip texture is provided on the side, and an interference fit (interference amount) is used. 0.05mm) Embedded in slot 33; Support and heat conduction effect: The heat conduction plug 34 is fully fitted with the top of the cavity of the lower end cover 40 (POM material, thermal conductivity 0.25W / (m·K)), and can withstand the injection pressure (8MPa) of the lower end cover 40 and silicone without deformation; At the same time, it quickly conducts the heat of the lower end cover 40 (the surface temperature reaches 150℃ during injection) to the rear template 11 (aluminum alloy material, thermal conductivity 237W / (m·K)), so that the actual temperature of the lower end cover 40 is controlled within 80℃, and the deformation is ≤0.05mm (the deformation reaches 0.5mm when there is no heat conduction plug 34 in the traditional case).

[0043] like Figures 2 to 4 As shown, preferably, the fixed insert 20 is provided with a first insert 23 and a second insert 24 that are connected and engaged with each other, and a first groove and a second groove for accommodating the first support 51 are respectively opened on the mating surfaces of the first insert 23 and the second insert 24, so that the first groove and the second groove are connected to each other to form a cavity for accommodating and positioning the first support 51.

[0044] Specifically, in order to accommodate and fix the first support 51 and keep it in a preset position in the injection cavity, a first insert 23 and a second insert 24 are preferably provided. The first and second grooves on their mating surfaces surround each other to form an insert groove 22, which clamps the first support 51, thereby accommodating and fixing the first support 51. Moreover, since the first support 51 is the tail connector of the microphone rod itself, and its shape is L-shaped, with one end of the L-shape being the connector part, which needs to be connected to external equipment and cannot be injection molded closed, the space formed by the first and second grooves is used to wrap the L-shaped connector part to avoid the influence of molten silicone.

[0045] Meanwhile, since the first support 51 is L-shaped, it is inconvenient to pass metal wires and gooseneck tubes through the mold. Therefore, an insert structure can be set to pre-fix the gooseneck tube in the blind hole of the first support 51. Then, the first insert 23 and the second insert 24 are used to clamp the first support 51, and the first insert 23 and the second insert 24 are fixed with bolts. Then, the fixed whole structure is assembled onto the rear template 11, thereby fixing one end of the insert 50. The other end of the insert 50 can be inserted into the second support 55 and fixed to the lower end cover 40. Since the second support 55 is provided with a through hole, it can be easily inserted. Similarly, the open end of the lower end cover 40 and the internal cavity can also be easily inserted.

[0046] In addition, after the gooseneck tube is pre-fixed into the blind hole at one end of the first bracket 51, the metal wire inside the gooseneck tube needs to be passed through the other end of the first bracket 51. To facilitate the passage of the metal wire, it is preferable to set an auxiliary hole 53 at the junction of the two ends of the L-shaped tail connector, so that the worker can pass the metal wire through the auxiliary hole 53 into the other end of the tail connector. An auxiliary plug 54 is set in the auxiliary hole 53 to seal the auxiliary hole 53, so that when the molten silicone is injection molded to wrap the tail connector, the auxiliary plug 54 is also wrapped inside. That is, the auxiliary plug 54 can prevent the molten silicone from entering the auxiliary hole 53 and avoid damaging the metal wire.

[0047] This embodiment solves the positioning problem of the L-shaped first bracket 51 (tail connector, 25mm long × 20mm wide × 20mm long bent section) by designing a split insert structure: Insert structure: The first insert 23 and the second insert 24 are made of ABS material (easy to process and meet the strength requirements). The mating surfaces are respectively provided with the first groove and the second groove. After mating, they are fastened together by bolts. Cavity adaptability: The cavity formed by mating has a gap of 0.1mm with the L-shaped bracket. One end of the cavity is provided with a 15mm×10mm opening (to avoid the joint part of the bracket, which needs to be exposed to connect external equipment). Assembly advantages: First, the hardware wire is inserted into the blind hole of the first bracket 51 (interference fit, fitting force 40N), then the first bracket 51 is placed into the first groove of the first insert 23, and after the second insert 24 is fastened, the whole is fixed to the rear template 11 with bolts. The assembly accuracy reaches ±0.05mm. Compared with the traditional integral insert, the assembly efficiency is improved by 30% (because the L-shaped bracket can be put into the split cavity without forced deformation).

[0048] like Figure 4 , Figure 6 and Figure 7As shown, preferably, the first bracket 51 has an annular groove 52 at one end near the fixed insert 20, and the first groove and the second groove are provided with insert retaining rings 21 corresponding to the positions of the annular groove 52. Through the cooperation between the annular groove 52 and the insert retaining rings 21, the first bracket 51 is securely fixed in the fixed insert 20.

[0049] Specifically, since one end of the first bracket 51 with the metal wire needs to extend into the injection molding cavity for injection molding, while the other end needs to remain in the first and second grooves of the fixed insert 20, in order to fix its position and prevent displacement during the injection molding process, insert retaining rings 21 can be set on the first and second grooves to limit and support the annular retaining groove 52 of the first bracket 51, thereby ensuring that the position of the first bracket 51 does not change.

[0050] This embodiment strengthens the axial positioning of the first bracket 51 through a ring-shaped snap-fit ​​structure, solving the bracket displacement problem caused by the impact force (5MPa) of silicone during injection molding: The ring groove 52 and retaining ring design: An annular groove 52 (groove width 1mm, groove depth 2mm, chamfer 0.5mm) is provided at the end of the first bracket 51; a ring insert retaining ring 21 (inner ring 6.2mm, lower outer ring 8.2mm, height 1mm, gap 0.01mm from the annular groove 52) is provided at the corresponding position of the cavity formed by the mating of the first groove and the second groove. ); Fixing effect: After the retaining ring is engaged in the annular groove 52, the axial pull-out force of the first bracket 51 reaches 80N (the pull-out force is only 20N when there is no retaining ring in the traditional case), and the circumferential anti-rotation angle is ≤0.2°, ensuring the alignment accuracy of the bracket joint with the external equipment (error ≤0.1mm); Synergistic effect: This snap-fit ​​structure cooperates with the above-mentioned "split insert fastening" to enable the first bracket 51 to be positioned in all dimensions of "axial + radial + circumferential" during the injection molding process, with a displacement of ≤0.05mm, which meets the high-precision assembly requirements of the microphone rod.

[0051] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A mould for injection moulding a silicone-coated wire for a microphone, characterised in that, include: The front template (10), the rear template (11), and the fixing assembly; the front template (10) and the rear template (11) are assembled together, and the two enclose each other to form an injection cavity for accommodating the insert (50); the fixing assembly includes a fixing insert (20) and a fixing mold core (30); the fixing insert (20) is detachably installed on the rear template (11), and the fixing insert (20) is provided with a fixing structure for fixing a first bracket (51) fitted at one end of the insert (50), so that the insert (50) is fixed by the first bracket (51). One end of the insert (50) is positioned and fixed in the preset position of the injection cavity; one side of the fixed insert (30) is fixedly connected to the rear template (11), and the other side extends into the injection cavity to form a protrusion. The fixed insert (30) is provided with a mold core groove (31) at the position corresponding to the other end of the insert (50). The mold core groove (31) is used to fix the second bracket (55) fitted on the other end of the insert (50) so that the other end of the insert (50) is positioned and fixed in the preset position of the injection cavity through the second bracket (55).

2. A mould for injection moulding a silicone overmoulding on a wire for a microphone according to claim 1, characterised in that, The protrusion of the fixed mold core (30) is a mold core protrusion, which is used to position and cooperate with the lower end cover (40) of the microphone rod; the lower end cover (40) is a box-shaped structure with an opening on one side, and a cavity for accommodating electronic components is formed inside. The opening end of the cavity is provided with an opening groove (41), and the closed end is provided with an opening (43) for installing the microphone head; the mold core protrusion is adapted to the cavity of the lower end cover (40), so that the lower end cover (40) partially extends into the injection molding cavity, and the insert (50) passes through the opening end of the cavity and exits through the opening (43) of the closed end.

3. A mould for injection moulding a silicone overmoulding on a wire for a reed according to claim 2, characterised in that, The inner wall of the cavity of the lower end cover (40) is provided with at least two reinforcing ribs (44) along its depth direction; the two sides of the mold core protrusion are provided with limiting grooves (32) along the protrusion direction corresponding to the position of the reinforcing ribs (44), and the reinforcing ribs (44) are adapted to engage with the limiting grooves (32) to limit the lateral and radial displacement of the lower end cover (40) relative to the mold core protrusion.

4. The injection mold for a silica gel package of a gold wire of a tweeter according to claim 3, wherein The second bracket (55) has a block structure with lateral locking strips (56) extending radially outward on both sides; the opening edge of the cavity of the lower end cover (40) is provided with a lateral locking groove (42) corresponding to the position of the lateral locking strip (56). The lateral locking strip (56) and the lateral locking groove (42) engage and cooperate, so that the second bracket (55) blocks the opening end of the cavity and forms an integral positioning structure with the lower end cover (40).

5. A mould for injection moulding a silicone overmoulding on a wire for a reed according to claim 2, characterised in that, The top of the mold core protrusion extending into the injection cavity has a slot (33) extending along its long side, which is used for the passage of metal wires; the top of the mold core protrusion is also provided with a heat-conducting plug (34), which is adapted to and detachably connected to the slot (33) to close the slot (33); the heat-conducting plug (34) is made of stainless steel, and its side facing the lower end cover (40) is in contact with the top of the cavity of the lower end cover (40) to support the lower end cover (40) and conduct heat to the rear template (11).

6. A mold for injection molding a silicone package of a wire for a tweeter according to claim 1, wherein The fixed insert (20) includes a first insert (23) and a second insert (24) that can be mated and fastened together; the first insert (23) has a first groove on the mating surface facing the second insert (24), and the second insert (24) has a second groove on the mating surface facing the first insert (23); after the first groove and the second groove are mated together, a cavity is formed for accommodating and positioning the first bracket (51), the shape of the cavity is adapted to the first bracket (51), and one end of the cavity is provided with an opening to avoid the joint portion of the first bracket (51).

7. A mould for injection moulding a silicone overmoulding on a wire for a reed according to claim 6, characterised in that, The first bracket (51) has an annular groove (52) on its outer periphery near the fixed insert (20); the cavity formed after the first groove and the second groove are connected has an annular insert retaining ring (21) at the position corresponding to the annular groove (52); the insert retaining ring (21) is adapted to engage with the annular groove (52) to limit the displacement of the first bracket (51) along its axial direction.

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