Threaded mold demolding structure

Abstract

The utility model discloses a demoulding structure of a threaded mould, which belongs to the technical field of moulds and comprises an upper mould plate, an upper mould base plate, a front mould plate and a mould opening driving device, a threaded insert is mounted on the upper mould plate, an insert driving component for transmitting torsion with the threaded insert is mounted on the upper mould base plate, and the upper mould plate is provided with a vertical through hole. A threaded core part for injection molding is arranged at the lower part of the threaded insert, the threaded insert is mounted in the vertical through hole, and a torsion rod part which is combined with the insert driving assembly and has a non-circular cross section is arranged at the upper part of the threaded insert; the mold opening driving device is connected with the front mold plate and drives the mold opening driving device to be separated from or combined with the upper mold base plate, and the front mold plate is provided with a pressing-back component used for axially jacking the torsion rod part. According to the demoulding structure, the production efficiency is improved, the service life of the mould is prolonged, the maintenance cost is also reduced, and the demoulding structure is effectively innovated and improved on the traditional thread mould demoulding structure.

Description

Technical Field

[0001] This utility model belongs to the field of injection mold technology, and in particular relates to a thread mold ejection structure. Background Technology

[0002] Injection molds are used to heat plastic masterbatch to a flowable state, inject the molten plastic through a gate into a metal cavity, and then allow it to cool and solidify. The front-mold unscrewing structure in thread molds is a common thread mold design. For example... Figure 1 When the mold is opened, the double-threaded insert 8 is rotated, and the force generated by the relative rotation between the copper threaded sleeve 9 installed on the upper mold and the double-threaded insert drives the double-threaded insert to retract and disengage the threads on the plastic part. When the mold is closed, the double-threaded insert is rotated in the opposite direction, and the force between it and the copper threaded sleeve resets the double-threaded insert.

[0003] Currently, traditional front-mold core-removal structures have several problems and shortcomings in the injection mold production process. Firstly, due to excessive injection pressure, the mold sometimes locks too tightly, preventing smooth thread removal. This problem is particularly prominent during production because the injection pressure inside the mold cannot be effectively released, causing the threaded insert to fail to retract properly, affecting demolding performance and product quality. To alleviate this problem, a gap of approximately 0.5mm is usually created between the upper and lower molds to release pressure. However, controlling this gap is very difficult; the gap often exceeds 1mm during mold opening, resulting in excessive relative displacement between the double-threaded insert and the copper sleeve. This affects the accurate repositioning or movement of the threaded insert, making the entire demolding process unstable and inaccurate.

[0004] Furthermore, excessive relative movement between the double-threaded insert and the copper bushing can easily cause severe wear, especially on the copper bushing. Frequent wear and damage necessitate regular replacement of the copper bushing, increasing not only material costs but also additional labor and time costs. The frequent need to replace the copper bushing not only increases the company's operating costs but can also lead to production line downtime, impacting production efficiency and schedules, and potentially causing stagnation in large-scale production, thus reducing overall production capacity.

[0005] These accumulated problems lead to a shortened overall lifespan of the mold, requiring frequent maintenance and resulting in higher maintenance costs and production instability for the company. Frequent wear of the threaded inserts and copper bushings makes it difficult for the mold to maintain stable operation for extended periods. Frequent repairs and replacements not only increase production costs but also affect the mold's precision and reliability, reducing product yield. This problem is particularly severe in high-precision production.

[0006] Therefore, the shortcomings of traditional front mold core-removal structures significantly impact mold lifespan, production efficiency, and product quality. Frequent replacement of copper bushings and mold maintenance not only waste substantial resources but also increase operational costs for enterprises. There is an urgent need to optimize and improve this structure to address deficiencies in mold opening clearance control, wear issues, and thread removal accuracy, thereby enhancing mold durability, stability, and production efficiency. Utility Model Content

[0007] To address the problems of excessive injection pressure leading to tight mold clamping, difficulty in controlling mold opening gap, frequent wear and replacement of copper bushings, resulting in short mold life, low production efficiency, and increased costs in traditional front mold core removal structures, this utility model provides a thread mold core removal structure.

[0008] This utility model is implemented as follows: a threaded mold ejection structure includes an upper template, an upper mold pad, a front template, and an ejection drive device. The upper template, upper mold pad, and front template are arranged sequentially from bottom to top. A threaded insert is installed on the upper template, and an insert drive assembly that transmits torque to the threaded insert is installed on the upper mold pad. The upper template has a vertical through hole, the lower part of the threaded insert has a threaded core for injection molding, the threaded insert is installed in the vertical through hole, and the upper part of the threaded insert has a torsion bar with a non-circular cross-section that is connected to the insert drive assembly. The ejection drive device is connected to the front template and drives the ejection drive device to separate or connect with the upper mold pad. A push-back component for axially pressing the torsion bar is installed on the front template.

[0009] In the above technical solution, preferably, the middle part of the threaded insert is a smooth rod part located in the vertical through hole of the upper template, and the smooth rod part is a cylindrical rod structure; a flange part is provided above the smooth rod part of the threaded insert, a spring is fitted on the smooth rod part of the threaded insert, the upper end of the spring contacts and engages with the flange part, and the lower end of the spring presses against the inner shoulder part formed at the bottom of the vertical through hole.

[0010] In the above technical solution, preferably, the torsion bar is a square bar with a rectangular cross-section, the insert drive assembly includes a drive gear, the drive gear is mounted on the upper mold pad through a bearing, and the drive gear has a central square hole that engages with the torsion bar.

[0011] This novel thread mold ejection structure, through improvements over traditional technology, offers several significant advantages and benefits:

[0012] 1. Solve the problem of jamming during demolding of threaded inserts.

[0013] In traditional thread molds, excessive clamping and injection pressure often prevent threaded inserts from retracting smoothly. The new structure, through a pre-opening action, creates a 40mm gap between the front mold platen and the upper mold backing plate, effectively releasing clamping pressure and providing sufficient space for the threaded inserts to retract. This avoids jamming and prevents the inserts from retracting, ensuring smooth mold operation.

[0014] 2. Improve the mold release method to enhance the stability of the threaded insert.

[0015] By replacing the original double-threaded insert with a single-threaded insert and eliminating the copper bushing, the retraction of the threaded insert relies entirely on the rotation driven by the product's own thread. This avoids the problem of uneven mold removal caused by the double-threaded structure and copper bushing wear in traditional technology. This improvement not only ensures the stability of the mold removal action but also reduces friction and wear between the insert and the copper bushing, significantly extending the mold's service life.

[0016] 3. Reduce processing costs and time.

[0017] The elimination of threaded copper bushings and double-threaded inserts in traditional designs simplifies the structure of the threaded die, significantly reducing the processing cost and difficulty of the inserts. Simultaneously, the simpler structure greatly shortens the processing cycle, contributing to improved production efficiency and reduced manufacturing costs.

[0018] 4. Extend mold life and reduce maintenance frequency.

[0019] By eliminating the copper bushing and the double-threaded design, friction and wear between the threaded insert and the copper bushing are reduced. The new structure significantly reduces the wear of the insert, avoiding frequent replacement of damaged copper bushings, thus reducing the frequency of maintenance and replacement. The mold's lifespan is therefore greatly extended, reducing maintenance costs and downtime for businesses.

[0020] 5. Improved mold closing and push-back mechanism ensures smooth mold closing.

[0021] In the new structure, the threaded insert is pushed back by the push-back block on the front platen during mold closing. This improves the pressure relief and mold opening position, avoiding the problems of insert jamming or damage caused by uneven mold closing or pressure in the traditional structure. The improved push-back mechanism ensures smoother mold closing and improves production efficiency.

[0022] 6. The production process is stable, and the inserts are not easily damaged.

[0023] This structural improvement makes the retraction process of the threaded insert smoother, less prone to jamming or excessive friction during demolding, and reduces the risk of damage to the insert. This structural improvement significantly enhances production stability and the reliability of the threaded die.

[0024] 7. Improve production efficiency and eliminate the phenomenon of parts not being removed.

[0025] Because the front mold plate opens first, the injection pressure is relieved, reducing the resistance encountered by the threaded insert during the mold removal process. This ensures that the insert can be smoothly removed, eliminating the "insert not removable" phenomenon that may occur in traditional technology. The improved mold removal process is more efficient, further enhancing overall production efficiency.

[0026] 8. Environmental protection and resource conservation.

[0027] The elimination of the copper bushing design makes the use of raw materials more efficient and reduces waste caused by copper bushing wear, which helps to reduce resource waste and meets the requirements of environmental protection and resource conservation.

[0028] In summary, the improved thread mold ejection structure achieves the goals of cost reduction and efficiency improvement by simplifying the design, optimizing the ejection process, reducing wear, and extending mold life. It not only improves production efficiency and extends mold life but also reduces maintenance costs, representing an effective innovation and improvement over traditional thread mold ejection structures. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the existing technology structure;

[0030] Figure 2 This is a cross-sectional view of the present invention;

[0031] Figure 3 This is a perspective view of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0033] To address the problems of short lifespan, low production efficiency, and increased costs associated with current double-threaded mold release mechanisms, this utility model provides a threaded mold release structure. A detailed description of the structure of this utility model, in conjunction with the accompanying drawings, is provided below:

[0034] Please see Figure 2 and Figure 3A threaded mold ejection structure includes an upper template 1, an upper mold pad 2, a front template 3, and an ejection drive device. The upper template, upper mold pad, and front template are arranged sequentially from bottom to top. A threaded insert 4 is mounted on the upper template, and an insert drive assembly that transmits torque to the threaded insert is mounted on the upper mold pad. The functions of each component in the prior art are clearly defined: the upper template is used to mount the threaded insert and is a key part of the mold thread forming process; the upper mold pad is fixedly connected to the upper template and is used to mount the insert drive assembly, which, through cooperation with the threaded insert, achieves torque transmission, ensuring that the thread rotates and ejects during demolding; the front template is the mold's support structure, providing overall strength and working with other templates to form the cavity; the ejection drive device is responsible for providing the power to open and close the mold, realizing cavity opening and demolding of the plastic part; the threaded insert directly participates in the forming of the threaded plastic part and completes demolding through rotation.

[0035] The upper template has a vertical through hole. The lower part of the threaded insert has a threaded core 4-1 for injection molding, and the threaded insert is installed in the vertical through hole. The upper part of the threaded insert has a torsion bar 4-2 with a non-circular cross-section, which is connected to the insert drive assembly. The middle part of the threaded insert is a smooth rod 4-3 located in the vertical through hole of the upper template; the smooth rod has a cylindrical structure. A flange 4-4 is located above the smooth rod of the threaded insert. A spring 5 is fitted onto the smooth rod of the threaded insert. The upper end of the spring contacts the flange, and the lower end of the spring presses against the inner shoulder formed at the bottom of the vertical through hole. The spring fitted onto the smooth rod of the threaded insert, with the flange contacting the upper end of the spring, provides a rebound force, preventing incomplete demolding of the threaded insert due to gravity or other factors, ensuring automatic reset of the threaded insert, improving work efficiency, and adding a linear spring to assist the threaded insert in retraction, preventing the product from having insufficient threads due to thread breakage. The torsion bar is a rectangular bar with a rectangular cross-section. The insert drive assembly includes a drive gear 6, which is mounted on the upper mold plate via bearings. The drive gear has a central square hole that engages with the torsion bar. Furthermore, the insert drive assembly also includes a rack and a transmission gear. The rack is connected to the drive gear via the transmission gear. This structure is existing and describes the structure of the insert drive assembly and its method of driving the threaded insert. The flange of the threaded insert has a clearance fit with the vertical through hole of the upper mold plate to ensure the stability of its rotational movement and avoid wear caused by eccentricity or wobbling. Simultaneously, the flange fixing spring effectively limits the axial displacement of the smooth bar, increasing overall durability.

[0036] The front template and the upper mold pad are vertically separable. The mold opening drive device is connected to the front template and drives the mold opening drive device to separate or connect with the upper mold pad. The front template is equipped with a push-back component 7 for axially pressing the torsion bar.

[0037] In existing technologies, mold opening drive devices typically employ hydraulic, pneumatic, mechanical, or electric drive structures. Hydraulic drive devices utilize hydraulic cylinders to provide powerful thrust, suitable for large-tonnage molds; pneumatic drive devices provide smaller thrust through air cylinders, offering fast response and suitable for small molds; mechanical drive structures use gear or screw transmissions, suitable for small to medium-sized molds, with lower cost but limited driving force; electric drive structures combine servo motors or stepper motors, providing precise control through precision transmission devices, suitable for molds requiring high precision. Among these drive methods, the mold opening drive device can effectively drive the separation or engagement of the front mold platen and the upper mold base plate, meeting the opening and closing requirements of different molds. The push-back component is usually installed at the lower part of the front mold platen as a removable insert, facilitating replacement and maintenance, and ensuring long-term stable operation of the mold.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A threaded die ejection structure, comprising an upper template, an upper die pad, a front template, and a die opening drive device, wherein the upper template, the upper die pad, and the front template are arranged sequentially from bottom to top; a threaded insert is mounted on the upper template; and an insert drive assembly that transmits torque to the threaded insert is mounted on the upper die pad, characterized in that: The upper template is provided with a vertical through hole, and the lower part of the threaded insert is provided with a threaded core for injection molding. The threaded insert is installed in the vertical through hole, and the upper part of the threaded insert is provided with a torsion bar with a non-circular cross section that is combined with the insert driving assembly. The mold opening driving device is connected to the front template and drives the mold opening driving device to separate or connect with the upper mold pad. A push-back component for axially pressing the torsion bar is installed on the front template.

2. The threaded die ejection structure according to claim 1, characterized in that: The center of the threaded insert is a smooth rod located in the vertical through hole of the upper template, and the smooth rod has a cylindrical rod structure; a flange is provided above the smooth rod of the threaded insert, and a spring is fitted on the smooth rod of the threaded insert, with the upper end of the spring contacting and engaging with the flange, and the lower end of the spring pressing against the inner shoulder formed at the bottom of the vertical through hole.

3. The threaded die ejection structure according to claim 2, characterized in that: The torsion bar is a rectangular bar with a rectangular cross-section. The insert drive assembly includes a drive gear, which is mounted on the upper mold plate via a bearing. The drive gear has a central square hole that engages with the torsion bar.

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