Connecting rod driven arc core-pulling device of large elbow

Abstract

The utility model belongs to the technical field of mold manufacturing, and discloses a connecting rod driven arc core-pulling device for a large elbow, which comprises a front mold part, a rear mold part, an arc core-pulling mechanism and a connecting rod driving mechanism, the front mold part comprises a panel, a plate A, a front mold core and an inclined guide column, the stability and functionality of all the parts are ensured in the aspects of material selection, processing technology and assembly relation, and the inclined guide column is used for guiding the rear mold to move; the rear mold part comprises a bottom plate, a plate B and a rear mold core and provides support and assistance for product forming and demolding; the arc core-pulling mechanism is composed of an arc core-pulling slide seat and other components, and flexible movement is achieved through specific structural design and a specific connection mode. And the connecting rod driving mechanism converts linear motion into arc motion so as to realize accurate demolding. Through multi-aspect structural improvement design and cooperation of all the parts, it is guaranteed that the mold operates stably, the cambered surface demolding requirement of a large bent pipe plastic part is met, the product forming quality is improved, and the service life of the mold is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of mold manufacturing technology, specifically to a connecting rod-driven arc core-pulling device for large bent pipes. Background Technology

[0002] In the plastics manufacturing industry, bent pipe-type plastic parts are widely used, with automotive exhaust pipes and air conditioning condenser pipes being particularly representative. Automotive exhaust pipes are directly related to engine performance and exhaust emissions. Their complex three-dimensional curved surfaces and internal inverted structures designed for sealing and connection require the core-pulling mechanism to precisely avoid these complex structures while ensuring sufficient core-pulling stroke for complete demolding. Air conditioning condenser pipes, on the other hand, are crucial to the heat exchange efficiency and operational stability of the refrigeration system, making them extremely sensitive to dimensional accuracy and surface quality. The demolding process cannot tolerate even the slightest deviation in the core-pulling mechanism.

[0003] Traditional core-pulling devices rely mainly on hydraulic cylinders or linear motors for demolding such curved plastic parts. However, these traditional methods have revealed many thorny problems.

[0004] Angled guide pillar core pulling, a common and traditional method, has a long history of application in plastic molds. However, in actual production, the limited internal space of the mold restricts the installation and extension of the angled guide pillars, resulting in a short core pulling stroke. For large-curvature bends, especially exhaust pipes for some high-performance automotive engines with deep internal cavities, angled guide pillar core pulling simply cannot meet demolding requirements, often leading to demolding failure and the scrapping of a large number of products. To compensate for this deficiency, some manufacturers have attempted to use multi-spindle combination structures, trying to solve the problem by increasing the core pulling direction and stroke. However, this approach brings new problems, increasing the number of parting surfaces to around five. Too many parting surfaces significantly increase the complexity and precision requirements of mold manufacturing, greatly increasing the probability of flash during plastic part molding, with a defect rate as high as 10%. Flash not only affects the appearance of the plastic part, but in products like automotive exhaust pipes that have extremely high airtightness requirements, it can also lead to exhaust leakage, seriously affecting engine performance.

[0005] While hydraulic core-pulling technology offers certain advantages, providing significant core-pulling force to meet the demolding requirements of large plastic parts to some extent, its drawbacks are also quite apparent in practical applications. The need for an additional hydraulic system significantly increases the cost of the entire production equipment. When faced with long-stroke core-pulling tasks, the slender hydraulic push rod is prone to bending and deformation under strong thrust. This deformation directly leads to deviations in the core-pulling direction, making it difficult to guarantee the dimensional accuracy of the plastic part. For products like air conditioner condenser pipes, which have extremely high requirements for pipe diameter accuracy, dimensional deviations will severely affect their heat exchange efficiency, thereby reducing the cooling performance of the air conditioner. Furthermore, the hydraulic system requires a continuous power supply to maintain pressure, resulting in huge energy consumption and high long-term operating costs. Moreover, the hydraulic system is prone to leakage. Once a leak occurs, it not only wastes a large amount of energy but may also pollute the production environment and even cause equipment failure, leading to production interruptions. Statistics show that to maintain the normal operation of the hydraulic system, seals need to be replaced regularly, with a maintenance frequency of up to twice a month, each maintenance taking at least 4 hours, significantly impacting production efficiency. Meanwhile, the hydraulic system has a response time delay of 0.8 to 1.2 seconds from receiving the core-pulling command to actually executing the action. This severely restricts the improvement of production capacity in modern plastic product manufacturing, which pursues high-speed and high-efficiency production.

[0006] Rack and pinion core-pulling technology also faces significant challenges when demolding complex curved plastic parts. Demolding large curved pipes often requires multi-angle core-pulling operations to accommodate their intricate spatial structures. However, the insufficient structural rigidity of rack and pinion systems becomes apparent during complex movements. Independent drive units are prone to delays when performing multi-angle core-pulling actions, leading to chaotic core-pulling rhythms. Furthermore, jamming during transmission is frequent, making the core-pulling process extremely difficult and causing uneven stress on the plastic part within the mold. Over time, this makes it difficult to guarantee the dimensional accuracy of the plastic part, resulting in loose connections during subsequent assembly due to dimensional deviations. For example, in the case of large curved plastic parts such as marine fuel pipelines, loose connections could lead to fuel leaks, posing a serious threat to the ship's navigational safety.

[0007] In summary, existing traditional core-pulling devices based on hydraulic cylinders or linear motors suffer from numerous problems when demolding curved plastic parts, including limited core-pulling stroke, low precision, complex structure, high cost, and poor reliability. These issues severely restrict the development of the plastic products manufacturing industry and fail to meet the urgent demands of modern industrial production for high efficiency, high precision, and low cost. Therefore, developing a new type of core-pulling device to meet industry needs is extremely urgent. Utility Model Content

[0008] The purpose of this invention is to provide a linkage-driven arc core-pulling device for large bent pipes. Through multi-faceted structural improvements and a uniquely designed linkage mechanism, linear motion is efficiently converted into arc motion. In conjunction with other components, it breaks through the stroke limitations of traditional core-pulling devices, enabling it to have a larger core-pulling stroke, higher core-pulling accuracy, a simpler and more reliable structure, lower energy consumption and cost, and a faster response speed. This effectively solves the demolding problem of bent pipe plastic parts and promotes the high-quality development of related industries in the plastic product manufacturing sector.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] A linkage-driven arc core-pulling device for large-scale pipe bending includes a front mold section, a rear mold section, an arc core-pulling mechanism, and a linkage drive mechanism. The front mold section includes a face plate, an A-plate, a front mold core, and inclined guide pillars. The rear mold section includes a base plate, a B-plate, a rear mold core, pads, a support plate, an ejector plate, an ejector base plate, and guide pillars. The arc core-pulling mechanism includes an arc core-pulling slide seat, an arc core-pulling element, a limiting pin, a slide, and a pressure strip. The arc core-pulling mechanism is slidably connected to the B-plate via a groove in the B-plate. In the plate, the arc-shaped core puller is securely installed on the arc-shaped core puller slide seat by rear screws. The front circular protrusion of the arc-shaped core puller should be positioned opposite the front circular recess of the front mold core and the rear mold core. The limiting pin is installed below the arc-shaped core puller slide seat to precisely limit the movement range of the arc-shaped core puller mechanism and prevent excessive movement. The slide is installed on the arc-shaped core puller slide seat, and the arc-shaped core puller slide seat and the slide are connected by a sliding connection to ensure the flexibility of its movement. The slide positioning pin is installed in the reserved hole of the arc-shaped core puller slide seat for positioning the slide, providing double protection to prevent displacement. The pressure strip is installed above the protruding edge strip below the slide by pressure strip screws, used to press the slide to ensure stable forward and backward movement during operation and avoid shaking or deviation. The linkage drive mechanism includes a driving linkage, a driven linkage, an intermediate pin, a T-shaped guide rail slider, a hydraulic cylinder, a hydraulic cylinder support block, and a hydraulic cylinder connecting block. The hydraulic cylinder is fixedly installed on the support plate by the hydraulic cylinder support block pin, providing power to the entire linkage drive mechanism. The piston rod of the hydraulic cylinder is connected to the T-shaped guide rail slider through the hydraulic cylinder connecting block. The T-shaped guide rail slider is installed in the support plate of the rear mold part, and the support plate has a T-shaped guide rail identical to that of the hydraulic cylinder support block. Alignment is achieved by the protruding pin of the hydraulic cylinder support block, allowing the T-shaped guide rail slider to slide smoothly along the T-shaped guide rail between the support plate and the hydraulic cylinder support block. One end of the driving linkage is connected to the T-shaped guide rail by a pin. The guide rail and slider are connected at one end, and the other end is connected to the hole in the middle section of the driven link through the intermediate pin. The short end hole of the driven link is connected to the arc core-pulling seat through the limiting pin, and the long end hole of the driven link is connected to the bottom of the B plate through the pin. Through this connection method and the slide rail design of the support plate, the linear motion of the oil cylinder is cleverly transformed into the arc motion of the arc core-pulling mechanism, realizing precise demolding drive.

[0011] The front mold portion also includes a panel, an A plate, and a front mold core; the inclined guide post is fixedly installed in the A plate, and when the mold is opened and closed, the inclined guide post is used to guide the sliding movement of the rear mold portion.

[0012] The rear mold portion includes a base plate, a B plate, a rear mold core, pads, a support plate, an ejector plate, an ejector base plate, ejector pins, and guide pillars. The pads are positioned between the base plate and the support plate to provide support. The rear mold core is mounted on the B plate and is a key part for product molding. The support plate is installed below the B plate and between the pads. The ejector plate fixes and positions four guide pillars. The ejector base plate supports the ejector plate and the guide pillars. The ejector plate and the ejector base plate are sequentially arranged below the support plate.

[0013] The inclined guide post and the slide are provided with mutually cooperating inclined surfaces. The cooperating inclined surface of the inclined guide post and the cooperating inclined surface of the slide are closely fitted. The slide is accurately positioned on the arc core-pulling slide seat by the slide positioning pin. When the mold is opened, the inclined guide post pushes the slide to move backward in a straight line within the arc core-pulling slide seat by its cooperating inclined surface, thereby realizing the first-stage demolding action of the mold.

[0014] The arc core-pulling mechanism forms a straight inverted T-shaped groove through the cooperation of the arc core-pulling slide seat and the pressure strip. The shape of the slide is matched with the inverted T-shaped groove. The arc core-pulling slide seat can move along a predetermined straight trajectory through the precise cooperation between the inverted T-shaped groove and the slide, so as to satisfy the separation of plate A and plate B during demolding. The inclined guide post drives the movement of the slide.

[0015] The B plate is provided with an arc-shaped slide groove of a predetermined shape. The arc-shaped core-pulling slide seat is designed to match the arc-shaped slide groove. Through precise matching with the arc-shaped slide groove on the B plate, the arc-shaped core-pulling slide seat can move along a predetermined arc trajectory to meet the special requirements of demolding large curved plastic parts.

[0016] The T-shaped guide rail slider is connected to the hydraulic cylinder via the hydraulic cylinder connecting block. When the linkage drive mechanism is activated, the hydraulic cylinder pushes the T-shaped guide rail slider to move between the hydraulic cylinder support block and the support plate, thereby driving the active linkage and the driven linkage to move. The long end of the driven linkage is fixed to the bottom of the B plate by a pin, and the short end of the driven linkage is fixed to the lower part of the arc core-pulling position seat by the limiting pin. The support plate has a fan-shaped groove for the driven linkage to move, and the B plate has an arc-shaped groove for the arc core-pulling mechanism to move along an arc trajectory. Therefore, the driven linkage can drive the arc core-pulling mechanism to perform reciprocating motion along an arc trajectory.

[0017] The guide post on the ejector plate passes through the B plate. During the demolding process, the ejector base plate drives the ejector plate and ejector pin to move upward. The guide post guides the ejector plate to move in a straight line, preventing the ejector pin from deviating or tilting when ejecting the product, thereby assisting the product to leave the mold and allowing the ejector pin to eject the product smoothly.

[0018] The cylinder connecting block is made of high-strength alloy steel to ensure sufficient strength and durability.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. This utility model improves the structure in many ways, especially through a uniquely designed linkage mechanism, which efficiently converts linear motion into arc motion. In conjunction with other parts, it breaks through the stroke limitation of traditional core-pulling devices and gives it a larger core-pulling stroke, higher core-pulling accuracy, simpler and more reliable structure, lower energy consumption and cost, and faster response speed. This effectively solves the demolding problem of bent plastic parts and promotes the high-quality development of related industries in plastic product manufacturing.

[0021] 2. This utility model, through a uniquely designed linkage mechanism, can ingeniously and efficiently convert linear motion into arc motion. In conjunction with other parts, its arc motion transmission efficiency can reach about 92%, which can easily meet the deep cavity demolding requirements of large curvature bent pipes. It can effectively solve the problems of limited core pulling stroke, low precision, complex structure, high cost and poor reliability of traditional core pulling devices, and realize efficient and high-precision demolding of large bent pipe plastic parts.

[0022] 3. This utility model utilizes a hydraulic cylinder to drive the connecting rod and combines it with a guide rail mechanism to achieve a slider positioning accuracy of ±0.05mm, effectively improving the dimensional accuracy of the plastic parts and enhancing product quality.

[0023] 4. Compared with traditional hydraulic core-pulling devices, this utility model reduces the reliance on complex external equipment and reduces the mold volume by more than 30%. At the same time, it avoids the positional deviation problem caused by pressure fluctuations in hydraulic core pulling, making the mold structure more stable and reliable.

[0024] 5. The rigidity of the linkage transmission structure of this utility model is significantly enhanced, effectively avoiding the occurrence of slider jamming, extending the service life of the mold to more than 500,000 cycles, and reducing the maintenance cost and replacement frequency of the equipment.

[0025] 6. Compared with traditional hydraulic systems, this utility model reduces energy consumption by 42% and further improves positioning accuracy to ±0.03mm, achieving the dual goals of energy saving and high precision.

[0026] 7. The present invention has a simple structural design, reduces the number of transmission parts, simplifies the assembly process, thereby reducing the manufacturing cost of the mold and improving production efficiency. Attached Figure Description

[0027] Figure 1This is a schematic diagram of the overall external structure of the connecting rod-driven arc core-pulling device for a large bent pipe according to an embodiment of this utility model.

[0028] Figure 2 This is a schematic diagram of the front mold portion in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the rear mold portion in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the arc core-pulling mechanism according to an embodiment of the present invention;

[0031] Figure 5 This is a three-dimensional structural diagram of the arc core-pulling mechanism in an embodiment of the present invention, showing the cooperation state between the sliding position and the arc core-pulling seat.

[0032] Figure 6 This is a top view of the arc core-pulling mechanism in an embodiment of the present invention, showing the cooperative state between the sliding position and the arc core-pulling sliding position seat.

[0033] Figure 7 This is a schematic diagram of the linkage drive mechanism according to an embodiment of the present utility model;

[0034] Figure 8 This is a top view of the rear mold portion in an embodiment of the present invention.

[0035] Figure 9 This is a top view of the overall structure of the connecting rod-driven arc core-pulling device for a large bent pipe according to an embodiment of the present utility model.

[0036] Figure 10 This is a top view of the arc core-pulling mechanism according to an embodiment of the present invention;

[0037] Figure 11 This is a schematic diagram of the internal structure of the rear mold portion in an embodiment of this utility model.

[0038] In the diagram: 1. Front mold section; 101. Panel; 102. A plate; 103. Front mold core; 104. Angled guide pillar; 2. Rear mold section; 201. Base plate; 202. B plate; 203. Rear mold core; 204. Pad; 205. Support plate; 206. Ejector plate; 207. Ejector base plate; 208. Guide pillar; 209. Ejector pin; 3. Arc core pulling mechanism; 301. Arc core pulling slide seat; 302. Arc core pulling element; 303. Limiting pin; 304. Slide; 305. Pressure strip; 306. Slide positioning pin; 4. Linkage drive mechanism; 401. Driving link; 402. Driven link; 403. Intermediate pin; 404. T-shaped guide rail slider; 405. Hydraulic cylinder; 406. Hydraulic cylinder support block; 407. Hydraulic cylinder connecting block. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] Example

[0041] Please see Figure 1-9 The large-scale bending pipe connecting rod driven arc core pulling device provided in this embodiment includes a front mold part 1, a rear mold part 2, an arc core pulling mechanism 3, and a connecting rod drive mechanism 4. The front mold part 1 includes a panel 101, an A plate 102, a front mold core 103, and an inclined guide post 104. The rear mold part 2 includes a base plate 201, a B plate 202, a rear mold core 203, a pad 204, a support plate 205, an ejector plate 206, an ejector base plate 207, and a guide post 208. The arc core pulling mechanism 3 includes an arc core pulling slide seat 301, an arc core pulling element 302, a limiting pin 303, a slide 304, and a pressure strip 305. The arc core pulling mechanism 3 is slidably connected to the B plate 202 via a groove in the B plate 202. In plate 202, the arc core puller 302 is securely mounted on the arc core puller slide seat 301 by rear screws. The circular protrusion at the front end of the arc core puller 302 corresponds to the circular recess at the front end of the front mold core 103 and the rear mold core 203 for positioning. The limiting pin 303 is installed below the arc core puller slide seat 301 to precisely limit the movement range of the arc core puller mechanism and prevent excessive movement. The slide 304 is mounted on the arc core puller slide seat 301. The arc core puller slide seat 301 and the slide 304 are connected by a sliding connection to ensure the flexibility of their movement. The slide positioning pin 306 is installed in the reserved hole in the arc core puller slide seat 301 for positioning the slide 304, providing double protection to prevent displacement. The pressure strip 305 is installed above the protruding edge strip below the slide 304 by pressure strip screws, and is used to press the slide 304 to ensure that it moves smoothly back and forth during movement and avoids shaking or deviation.

[0042] The linkage drive mechanism (4) includes an active linkage 401, a driven linkage 402, an intermediate pin 403, a T-shaped guide rail slider 404, a hydraulic cylinder 405, a hydraulic cylinder support block 406, and a hydraulic cylinder connecting block 407. The hydraulic cylinder 405 is fixedly mounted on the support plate 205 via a pin in the hydraulic cylinder support block 406, providing power to the entire linkage drive mechanism. The piston rod of the hydraulic cylinder 405 is connected to the T-shaped guide rail slider 404 via the hydraulic cylinder connecting block 407. The T-shaped guide rail slider 404 is installed in the support plate 205 of the rear mold section, and the support plate 205 has a T-shaped guide rail identical to that of the hydraulic cylinder support block 406. The T-shaped guide rail slider 404 is aligned with the protruding pin of the hydraulic cylinder support block 406, allowing the T-shaped guide rail slider 404 to move along the T-shaped guide rail. The T-shaped guide rail slides smoothly between the support plate 205 and the cylinder support block 406. One end of the active connecting rod 401 is connected to the T-shaped guide rail slider 404 via a pin, and the other end is connected to the hole in the middle section of the driven connecting rod 402 via the intermediate pin 403. The short end hole of the driven connecting rod 402 is connected to the arc core-pulling seat 301 via the limiting pin 303, and the long end hole of the driven connecting rod 402 is connected to the bottom of the B plate 202 via a pin. Through this connection method and the slide rail design of the support plate 205, the linear motion of the cylinder 405 is cleverly transformed into the arc motion of the arc core-pulling mechanism, achieving precise demolding drive.

[0043] The front mold portion 1 further includes a panel 101, an A plate 102, and a front mold core 103; the inclined guide post 104 is fixedly installed in the A plate 102, and during mold opening and closing operations, the inclined guide post 104 is used to guide the sliding movement of the rear mold portion; the rear mold portion 2 includes a base plate 201, a B plate 102, and a B plate 103. The system comprises a base plate 202, a rear mold core 203, feet 204, a support plate 205, an ejector plate 206, an ejector base plate 207, guide pillars 208, and ejector pins 209. The feet 204 are positioned between the base plate 201 and the support plate 205 to provide support. The rear mold core 203 is mounted on the B plate 202 and is a key component in product molding. The support plate 205 is mounted below the B plate 202 and between the feet 204. The ejector plate 206 fixes and positions four guide pillars 208. The ejector base plate 207 supports the ejector plate 206 and the guide pillars 208. The ejector plate 206 and the ejector base plate 207 are sequentially positioned below the support plate 205.

[0044] The inclined guide post 104 and the slide 304 are provided with mutually cooperating inclined surfaces. The cooperating inclined surface of the inclined guide post 104 and the cooperating inclined surface of the slide 304 are closely fitted. The slide 304 is accurately positioned on the arc-shaped core-pulling slide seat 301 by the slide positioning pin 306. When the mold opens, the inclined guide post 104 pushes the slide 304 to move backward in a straight line within the arc-shaped core-pulling slide seat 301 by its cooperating inclined surface, thereby realizing the first-stage demolding action of the mold. The B plate 202 is provided with an arc-shaped slide of a predetermined shape. The arc-shaped core-pulling slide seat 301 is designed to match the arc-shaped slide groove. Through precise matching with the arc-shaped slide groove on the B-plate 202, the arc-shaped core-pulling slide seat 301 can move along a predetermined arc trajectory to meet the special requirements of demolding large curved plastic parts with curved surfaces. The T-shaped guide rail slider 404 is connected to the hydraulic cylinder 405 via the hydraulic cylinder connecting block 407. When the connecting rod drive mechanism 4 is activated, the hydraulic cylinder 405 pushes the T-shaped guide rail slider 404 between the hydraulic cylinder support block 406 and the support plate 205. The guide rail moves, driving the active connecting rod 401 and the driven connecting rod 402 to move. The long end of the driven connecting rod 402 is fixed to the bottom of the B plate 202 by a pin, and the short end of the driven connecting rod 402 is fixed to the lower part of the arc core-pulling mechanism 301 by the limiting pin 303. The support plate 205 has a fan-shaped groove for the driven connecting rod 402 to move, and the B plate 202 has an arc-shaped groove for the arc core-pulling mechanism 3 to move along an arc trajectory. Therefore, the driven connecting rod 402 can drive the arc core-pulling mechanism 3. The ejector plate 206 performs a reciprocating motion along an arc trajectory. The guide post 208 on the ejector plate 206 passes through the B plate 202. During the demolding process, the ejector base plate 207 drives the ejector plate 206 and ejector pin 209 to move upward. The guide post 208 guides the ejector plate 206 to move in a straight line, preventing the ejector pin 209 from deviating or tilting when ejecting the product, thereby assisting the product to leave the mold and allowing the ejector pin 209 to eject the product smoothly. The hydraulic cylinder connecting block 407 is made of high-strength alloy steel to ensure sufficient strength and durability.

[0045] The working principle of this utility model is as follows:

[0046] The core working principle of this large-scale bent pipe connecting rod-driven arc core-pulling device is that multiple parts work together to convert the linear motion of the hydraulic cylinder into the arc motion of the arc core-pulling mechanism, so as to achieve precise demolding of large-scale bent pipe plastic parts.

[0047] Mold opening and closing guiding principle: The inclined guide pillars of the front mold and the slide of the rear mold are connected by mutually cooperating inclined surfaces. When the mold opens, the inclined guide pillars push the slide to make a linear motion, completing the first demolding action and preparing for the subsequent arc core pulling demolding.

[0048] Power conversion principle: The linkage drive mechanism uses a hydraulic cylinder as the power source. The piston rod of the hydraulic cylinder pushes the T-shaped guide rail slider to make linear motion. Through the connection and transmission of the active and driven linkages, the linear motion is converted into the arc motion of the arc core pulling slide seat, which meets the special requirements of demolding large curved plastic parts.

[0049] Demolding assistance principle: The ejector plate and ejector base plate of the rear mold part move upward under the action of the ejection device of the injection molding machine. The ejector base plate drives the ejector pins of the ejector plate to move upward. The guide post guides the ejector plate to move in a straight line, avoiding the ejector pins from deviating or tilting when ejecting the product, thereby assisting the product to leave the mold and allowing the ejector pins to eject the product smoothly.

[0050] The typical work steps are as follows:

[0051] S1. Mold Closing Stage

[0052] 1. Mold Closure: The injection molding machine drives the front mold and rear mold to close, the panel 101 and the base plate 201 gradually approach each other, the A plate 102 and the B plate 202 fit together, and the front mold core 103 and the rear mold core 203 close to form a complete product molding cavity.

[0053] 2. Slide Reset: During mold closing, the connecting rod drive mechanism 4 is activated, the piston rod in the oil cylinder 405 extends, pushing the active connecting rod 401 forward, driving the driven connecting rod 402, so that the arc core-pulling slide seat 301 is also reset. The inclined guide post 104 is inserted into the mating inclined surface of the slide 304, guiding the slide 304 to move forward to the initial position. The slide 304 is accurately positioned on the arc core-pulling slide seat 301 by the slide positioning pin 306, preparing for injection molding.

[0054] S2. Injection Molding Stage

[0055] 1. Plastic injection: The injection molding machine injects molten plastic through the gate into the cavity formed by the front mold core 103 and the rear mold core 203. The plastic cools and solidifies in the cavity to form a large curved plastic part.

[0056] 2. Pressure holding and cooling: After injection molding, maintain a certain pressure to allow the plastic to fully fill the cavity and cool and solidify, ensuring the shape and dimensional accuracy of the product.

[0057] S3. Mold Opening Stage

[0058] 1. First-level demolding linear motion

[0059] The injection molding machine drives the front mold and rear mold to separate. As the front mold moves, the inclined guide post 104, through its mating inclined surface with the slide 304, pushes the slide 304 to move backward in a straight line, realizing the first demolding action of the mold and initially separating the plastic part from the front mold.

[0060] 2. Arc-shaped core pulling and demolding motion

[0061] When the hydraulic cylinder 405 is activated, the piston rod retracts, pushing the T-shaped guide rail slider 404 to move linearly along the guide rail on the support plate 205. The T-shaped guide rail slider 404 drives the driven link 402 to move through the active link 401. The driven link 402 then drives the arc core pulling slide seat 301. The arc core pulling slide seat 301 moves along the predetermined arc trajectory of the B plate 203. The arc core pulling part 302 is pulled out from the arc-shaped part of the plastic part, completing the arc core pulling demolding action.

[0062] 3. Final demolding and ejection

[0063] The ejection device of the injection molding machine acts on the ejector base plate 207, pushing the ejector plate 206, the ejector base plate 207 and the ejector 209 to move upward. The guide post 208 guides the ejector plate 206 to move in a straight line, preventing the ejector 209 from deviating or tilting when ejecting the product, thereby assisting the product to leave the mold and completing the final separation of the product from the mold.

[0064] S4. Part Retrieval and Reset Phase

[0065] 1. Removal: The operator removes the large bent plastic part from the mold.

[0066] 2. Reset and prepare for the next cycle: The piston rod of the hydraulic cylinder 405 extends, driving the T-shaped guide rail slider 404, the driving connecting rod 401, the driven connecting rod 402 and the arc core pulling slide seat 301 to reset; the injection molding machine drives the mold to close again and enter the next injection cycle.

[0067] In this embodiment, the front mold portion, including the panel, A-plate, front mold core, and inclined guide pillars, ensures stability and functionality through material selection, processing technology, and assembly relationships. The inclined guide pillars guide the movement of the rear mold slide. The rear mold portion, including the base plate, B-plate, and rear mold core, provides support and assistance for product molding and demolding. Components such as the arc core-pulling mechanism's arc core-pulling slide seat achieve flexible movement through a combination of specific shapes and connection methods. The linkage drive mechanism utilizes hydraulic cylinders to provide power, converting linear motion into arc motion for precise demolding. Furthermore, mutually cooperating inclined surfaces, arc-shaped grooves, and sliders are incorporated to ensure stable mold operation. This utility model, through multifaceted structural improvements and coordinated cooperation among components, meets the demolding requirements of large curved plastic parts with curved surfaces, improving product molding quality and mold lifespan.

[0068] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A link driven arc core pulling device for large radius bends, characterized by, It includes a front mold part (1), a rear mold part (2), an arc core pulling mechanism (3), and a linkage drive mechanism (4); The front mold part (1) includes a panel (101), an A plate (102), a front mold core (103), and an inclined guide post (104). The rear mold part (2) includes a B plate (202), a rear mold core (203), and a support plate (205); The arc core-pulling mechanism (3) includes an arc core-pulling position seat (301) and a limiting pin (303). The linkage drive mechanism (4) includes an active linkage (401), a driven linkage (402), an intermediate pin (403), a T-shaped guide rail slider (404), a hydraulic cylinder (405), a hydraulic cylinder support block (406), and a hydraulic cylinder connecting block (407). The hydraulic cylinder (405) is fixedly mounted on the support plate (205) via a pin in the hydraulic cylinder support block (406), providing power to the entire linkage drive mechanism. The piston rod of the hydraulic cylinder (405) is connected to the T-shaped guide rail slider (404) via the hydraulic cylinder connecting block (407). The T-shaped guide rail slider (404) is installed in the support plate (205) of the rear mold section, and the support plate (205) has a T-shaped guide rail identical to that of the hydraulic cylinder support block (406). The T-shaped guide rail slider (404) is aligned with the protruding pin of the hydraulic cylinder support block (406), allowing the T-shaped guide rail slider (404) to move along the T-shaped guide rail. The guide rail slides smoothly between the support plate (205) and the cylinder support block (406); one end of the active connecting rod (401) is connected to the T-shaped guide rail slider (404) through a pin, and the other end is connected to the hole in the middle section of the driven connecting rod (402) through an intermediate pin (403); the short end hole of the driven connecting rod (402) is connected to the arc core pulling seat (301) through a limiting pin (303); the long end hole of the driven connecting rod (402) is connected to the bottom of the B plate (202) through a pin.

2. The link-driven arc core pulling device for large radius bends of claim 1, wherein, The arc core-pulling mechanism (3) further includes: an arc core-pulling element (302), a sliding element (304), a pressure strip (305), and a sliding element positioning pin (306); the arc core-pulling mechanism (3) is slidably connected to the B plate (202) via a groove in the B plate (202). In plate (202), the arc core puller (302) is firmly installed on the arc core puller slide seat (301) by rear screws. The circular protrusion at the front end of the arc core puller (302) corresponds to the circular recess at the front end of the front mold core (103) and the rear mold core (203) for positioning. The limiting pin (303) is installed below the arc core puller slide seat (301). The slide (304) is installed on the arc core puller slide seat (301), and the arc core puller slide seat (301) and the slide (304) are slidably connected. The slide positioning pin (306) is installed in the reserved hole of the arc core puller slide seat (301) to position the slide (304). The pressure strip (305) is installed above the protruding edge strip below the slide (304) by pressure strip screws to press the slide (304).

3. The link-driven arc core pulling device for large radius bends of claim 1, wherein, The inclined guide post (104) is fixedly installed in the A plate (102).

4. The link-driven arc core pulling device for large radius bends of claim 3, wherein, The rear mold part (2) also includes a base plate (201), a rear mold core (203), pads (204), an ejector plate (206), an ejector base plate (207), guide pillars (208), and ejector pins (209). The pads (204) are disposed between the base plate (201) and the support plate (205). The rear mold core (203) is installed on the B plate (202). The support plate (205) is installed below the B plate (202) and between the pads (204). The ejector plate (206) fixes and positions four guide pillars (208). The ejector base plate (207) supports the ejector plate (206) and the guide pillars (208). The ejector plate (206) and the ejector base plate (207) are disposed below the support plate (205) in sequence.

5. The link driven arc core pulling device for large radius bends of claim 4, wherein, The guide post (208) on the ejector plate (206) penetrates the B plate (202). During the demolding process, the ejector base plate (207) drives the ejector plate (206) and ejector pin (209) to move upward. The guide post (208) guides the ejector plate (206) to move in a straight line, so that the ejector pin (209) can smoothly eject the product.

6. The link-driven arc core pulling device for large radius bends of claim 3, wherein, The inclined guide post (104) and the slide (304) are provided with mutually cooperating inclined surfaces. The cooperating inclined surface of the inclined guide post (104) and the cooperating inclined surface of the slide (304) are closely fitted. The slide (304) is accurately positioned on the arc core-pulling slide seat (301) by the slide positioning pin (306). When the mold is opened, the inclined guide post (104) pushes the slide (304) to move backward in a straight line within the arc core-pulling slide seat (301) by relying on its cooperating inclined surface, thereby realizing the first-level demolding action of the mold.

7. The link activated arc core pulling device for large radius bends of claim 3 wherein, The arc core-pulling mechanism (3) forms a straight inverted T-shaped groove through the cooperation of the arc core-pulling slide seat (301) and the pressure strip (305). The shape of the slide (304) matches the inverted T-shaped groove. The arc core-pulling slide seat (301) cooperates with the slide (304) through the inverted T-shaped groove and moves according to a predetermined straight trajectory. When demolding, it separates plate A (102) from plate B (202). The inclined guide post (104) drives the slide (304) to move.

8. The link activated arc core pulling device for large radius bends of claim 2, wherein, The B plate (202) is provided with an arc-shaped slide groove, and the arc core-pulling seat (301) is shaped to match the arc-shaped slide groove. The arc core-pulling seat (301) moves along a predetermined arc trajectory by cooperating with the arc-shaped slide groove on the B plate (202), so that the arc surface of the large bent tube plastic part can be demolded.

9. The link activated arc core pulling device for large radius bends of claim 1, wherein, The T-shaped guide rail slider (404) is connected to the oil cylinder (405) through the oil cylinder connecting block (407). When the linkage drive mechanism (4) is started, the oil cylinder (405) pushes the T-shaped guide rail slider (404) to move on the T-shaped guide rail between the oil cylinder support block (406) and the support plate (205), thereby driving the active linkage (401) and the driven linkage (402) to move.

10. The link activated arc core pulling device for large radius bends of claim 9, wherein, The long end of the driven link (402) is fixed to the bottom of the B plate (202) by a pin, and the short end of the driven link (402) is fixed to the bottom of the arc core pulling seat (301) by a limiting pin (303). The support plate (205) has a fan-shaped groove for the driven link (402) to move, and the B plate (202) has an arc-shaped groove for the arc core pulling mechanism (3) to move along an arc trajectory, so that the driven link (402) drives the arc core pulling mechanism (3) to perform reciprocating motion along an arc trajectory.

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