Core-pulling device for injection mold

Abstract

This invention provides a core-pulling device for injection molds, belonging to the field of injection mold technology. The device includes a base and a guide assembly mounted on the base. A lower slide block and an upper slide block are slidably mounted on the guide assembly. It also includes a demolding assembly mounted on the upper slide block. The demolding assembly includes multiple demolding modules slidably mounted within the upper slide block. The upper slide block has a demolding cavity that cooperates with the demolding modules. Guide teeth are provided at the lower end of each demolding module, and push blocks that cooperate with the guide teeth are provided on the upper surface of the lower slide block. By incorporating retractable demolding modules, this invention transforms the continuous contact interface between the slide block and the product from a large-area surface contact to a localized discrete contact during the initial core-pulling stage. Combined with air duct ventilation to break down interface negative pressure and adhesion effects, this invention solves the problems of difficulty in effectively breaking the contact interface between the slide block and the product, concentrated initial demolding resistance, and uneven release in existing technologies, significantly reducing the initiation resistance of core-pulling.

Description

Technical Field

[0001] This invention belongs to the field of injection mold technology, and specifically relates to an injection mold core-pulling device. Background Technology

[0002] In the molding of plastic parts with lateral structures, such as air conditioner housings, the core-pulling mechanism is a key component for demolding these laterally molded structures. It primarily drives a slider to move in a predetermined direction during mold opening, allowing the molded plastic part to smoothly detach from the mold cavity. This mechanism plays a crucial role in ensuring the molding accuracy, smooth demolding, and overall stability of complex plastic parts.

[0003] Air conditioner volute structures typically feature curved flow channels and partial undercuts, requiring a slider core-pulling mechanism for lateral demolding during injection molding. The basic principle is as follows: after injection molding and cooling, a drive mechanism moves the slider in a set direction, pulling it out of the product and achieving demolding. Because the volute structure strongly encloses the slider, and the plastic shrinks during cooling, it creates a clamping effect on the slider, resulting in significant contact pressure and friction between the slider and the product. Simultaneously, a sealed contact interface easily forms between the slider and the product, generating negative pressure or adhesion, further increasing the resistance during core-pulling, thus affecting demolding stability and potentially causing surface scratches or localized deformation of the product.

[0004] Most existing core-pulling structures use an integral rigid slider, which forms a large area of ​​continuous contact with the product. During the core-pulling process, separation is usually achieved by forced separation of the whole. In the early stage of demolding, this structure is difficult to effectively destroy the contact interface between the slider and the product, so that the interface is always under the overall stress, resulting in large static friction and uneven release. It is difficult to achieve gradual separation of the contact interface, thus affecting the smoothness of core pulling and the molding quality of the product. Summary of the Invention

[0005] The purpose of this invention is to provide a core-pulling device for injection molds, which aims to solve the problems in the prior art where the interface between the slider and the product is difficult to break, resistance is concentrated in the early stage of demolding, and effective release is difficult to achieve.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a core-pulling device for injection molds, comprising: a base and a guide assembly disposed on the base, wherein a lower slider and an upper slider are slidably disposed on the guide assembly, and further comprising: A demolding assembly is provided on the upper slider. The demolding assembly includes multiple demolding modules that are slidably disposed in the upper slider. A demolding cavity that cooperates with the demolding modules is provided on the upper slider. A guide tooth is provided at the lower end of the demolding module. A push block that cooperates with the guide tooth is provided on the upper surface of the lower slider. First elastic elements are provided on both sides of the demolding modules. An air passage that communicates with the demolding cavity is provided inside the upper slider. A support assembly is provided on the upper slider. The support assembly includes multiple sets of support blocks that are slidably disposed within the upper slider. The detachable module and the support blocks are spatially offset. The upper slider has a support cavity that mates with the support blocks. The support cavity has a support groove. The upper surface of the lower slider has a drive block that mates with the support groove. Second elastic elements are provided on both sides of the support blocks.

[0007] Its effects are as follows: by retracting the module to destroy the contact interface and using the air channel to break the adhesion, the support block maintains dynamic support for the product during the core pulling process, effectively reducing the core pulling resistance and preventing the product from being stretched and deformed.

[0008] A further technical solution of the present invention is that the guiding component includes guide blocks disposed on both sides of the base, guide grooves are inclinedly disposed on the guide blocks, guide strips are disposed on both sides of the lower slider that slide in cooperation with the guide grooves, and a driving device is disposed on the upper surface of the base that can control the lower slider to slide back and forth along the guide grooves.

[0009] A further technical solution of the present invention is that the guide block is provided with an L-shaped guide groove, and the upper slider is provided with guide posts on both sides that slide in cooperation with the L-shaped guide groove.

[0010] A further technical solution of the present invention is that the demolding cavity penetrates the upper and lower end faces of the upper slider, the upper side of the demolding module can be flush with the upper side of the upper slider, the guide teeth are evenly arranged along the moving direction of the lower slider, the push block is located below the guide teeth, and the upper end of the push block is provided with a conical surface adapted to the guide teeth, and the other end of the first elastic element is connected to the inside of the demolding cavity.

[0011] Its effect is that, through the matching and cooperation of the conical surface at the upper end of the push block and the guide teeth, the ejector module is precisely lifted and made flush with the upper slide block during mold closing, ensuring the flatness of the forming surface and reliable switching between mold closing and core pulling states.

[0012] A further technical solution of the present invention is that the air passage and the demolding cavity are connected at the side of the demolding cavity near the injection surface, and a control valve connected to the air passage is provided on the upper slider, which can control the opening and closing of the air passage.

[0013] A further technical solution of the present invention is that the support cavity penetrates the upper and lower end faces of the upper slider, the upper side of the support block can be flush with the upper side of the upper slider, the support groove is divided into a front section and a rear section, the inclination direction of the front section of the support groove is parallel to the movement direction of the lower slider, and the inclination direction of the rear section of the support groove is opposite to the direction of the front section.

[0014] Its effect is that, through the design of the opposite tilting direction of the front and rear sections of the support groove, the drive block gradually releases its lifting effect on the support block during core pulling, so that the support block automatically retracts with the core pulling process, and the action is smooth.

[0015] A further technical solution of the present invention is that the bottom surface of the support block is inclined, and the inclination direction is parallel to the inclination direction of the front section of the support groove. The length of the bottom inclined surface of the support block is greater than the length of the front section of the support groove, and the other end of the second elastic member is connected to the inside of the support groove.

[0016] A further technical solution of the present invention is that the first elastic element is configured as a spring, and the second elastic element is configured as a spring.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. By setting a retractable demolding module, the continuous contact interface between the slider and the product changes from a large-area surface contact to a local discrete contact in the early stage of core pulling. Combined with air passage ventilation to break the interface negative pressure and adhesion effect, this invention solves the problems of the slider-product contact interface being difficult to effectively destroy, the initial demolding resistance being concentrated and unevenly released in the prior art, and significantly reduces the core pulling start resistance.

[0018] 2. This invention provides dynamic following support to the product during the core-pulling process through a support component. While the demolding module retracts to form a gap, the support block remains in contact with the product, preventing the product from being stretched and deformed under the demolding force due to local loss of support. This solves the problem of the product being easily stuck and damaged when the upper slider moves down first to remove interference, ensuring the molding quality of thin-walled or deep-cavity structures. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the core-pulling device in an embodiment of the present invention; Figure 3 This is a side view of the core-pulling device in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the guide component in an embodiment of the present invention; Figure 5 This is a schematic diagram of the installation structure of the upper slider and the lower slider in an embodiment of the present invention; Figure 6 This is a schematic diagram of the demolding component in an embodiment of the present invention; Figure 7 This is a schematic diagram of the installation structure of the detachable module and the upper slider in an embodiment of the present invention; Figure 8 This is a schematic diagram of the supporting component in an embodiment of the present invention; Figure 9 This is a schematic diagram of the installation structure of the support block and the upper slider in an embodiment of the present invention.

[0020] In the diagram: 1. Base; 2. Guide assembly; 21. Guide block; 211. Guide groove; 212. L-shaped guide groove; 22. Drive device; 3. Lower slider; 31. Guide bar; 32. Push block; 33. Drive block; 4. Upper slider; 41. Guide post; 42. Demolding cavity; 43. Air passage; 44. Control valve; 45. Support cavity; 451. Support groove; 5. Demolding assembly; 51. Demolding module; 52. Guide tooth; 53. First elastic element; 6. Support assembly; 61. Support block; 62. Second elastic element. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-9 The present invention provides the following technical solution: a core-pulling device for injection molds, comprising a base 1, a guide assembly 2, a lower slider 3, an upper slider 4, a demolding assembly 5, and a support assembly 6.

[0023] The base 1 is mounted on the template of the injection mold, and the guide assembly 2 is mounted on the base 1. The lower slider 3 and the upper slider 4 are slidably mounted on the guide assembly 2, with the upper slider 4 positioned above the lower slider 3. The guide assembly 2 guides the movement of the lower slider 3 and the upper slider 4, while the base 1 supports the movement of the lower slider 3 and the upper slider 4 and serves as the foundation for their movement. The demolding assembly 5 is mounted on the upper slider 4. During the demolding of the injection molded workpiece, the lower slider 3 first pulls out the core and detaches from the workpiece. At this time, the demolding assembly 5 can slide and disengage from the workpiece, while simultaneously assisting the upper slider 4 in smoothly pulling out the core. The support assembly 6 is mounted on the upper slider 4. The support assembly 6 can maintain contact with the workpiece and support it during the movement of the upper slider 4 to pull out the core, preventing the workpiece from sticking to the upper slider 4 during the core-pulling process and causing tensile deformation.

[0024] like Figures 1-4 As shown, the guide assembly 2 includes guide blocks 21 disposed on both sides of the upper surface of the base 1. Guide grooves 211 are inclinedly disposed on the guide blocks 21. Guide strips 31 that slide in slidably with the guide grooves 211 are disposed on both sides of the lower slider 3. A drive device 22 is disposed on the upper surface of the base 1. The output end of the drive device 22 is connected to the side of the lower slider 3 away from the injection molded workpiece. The drive device 22 can control the lower slider 3 to slide back and forth along the guide grooves 211. When the lower slider 3 moves towards the drive device 22, under the action of the guide grooves 211, the lower slider 3 gradually demolds and approaches the base 1. An L-shaped guide groove 212 is disposed on the guide blocks 21. Guide posts 41 that slide in slidably with the L-shaped guide grooves 212 are disposed on both sides of the upper slider 4. The L-shaped guide grooves 212 can limit the guide posts 41 and allow the upper slider 4 to move along the shape of the L-shaped guide grooves 212.

[0025] After the workpiece injection is completed, the lower slider 3 is first controlled to slide along the guide groove 211 towards the drive device 22 (i.e., away from the core-pulling direction of the workpiece). Since there is no interference between the contact position of the lower slider 3 and the workpiece, the side of the lower slider 3 away from the drive device 22 disengages from the workpiece, realizing the core-pulling and demolding of the lower slider 3. The upper side of the upper slider 4 is in contact with the injection-molded workpiece, and there is interference due to the workpiece structure. When the upper slider 4 is pulling the core, it needs to move downward along the L-shaped guide groove 212 to remove the interference, and then move together with the lower slider 3 to demold.

[0026] like Figure 2 and Figures 5-7As shown, the demolding assembly 5 includes demolding modules 51 slidably disposed within the upper slider 4. Multiple sets of demolding modules 51 are evenly arranged. The upper slider 4 has a demolding cavity 42 that cooperates with the demolding modules 51. The demolding cavity 42 extends through the upper and lower end faces of the upper slider 4. The demolding modules 51 can reciprocate along the demolding cavity 42. The upper side of the upper slider 4 contacts the injection molded workpiece, and the upper side of the demolding modules 51 can remain flush with the upper side of the upper slider 4, ensuring contact between the upper side of the demolding modules 51 and the workpiece during injection molding. A guide tooth 52 is provided at the lower end of the demolding module 51. The guide teeth 52 are evenly arranged along the moving direction of the lower slider 3. A push block 32 that cooperates with the guide teeth 52 is provided on the upper surface of the lower slider 3. The push block 32 is located below the guide teeth 52, and its upper end has a conical surface adapted to the guide teeth 52. When injection begins, the push block 32 moves along the inside of the demolding cavity 42 to the side closest to the workpiece. At this time, the top of the push block 32 contacts the bottom of the demolding module 51 and pushes the upper end of the demolding module 51 upward until it is flush with the upper side of the upper slider 4. The demolding module 51 is provided with first elastic elements 53 on both sides. The other end of the first elastic element 53 is connected to the inside of the demolding cavity 42. When the push block 32 disengages from the demolding module 51, the first elastic element 53 pulls the demolding module 51 into the demolding cavity 42 and slides the demolding module 51 into the demolding cavity 42. In this embodiment, the first elastic element 53 is set as a spring.

[0027] The upper slider 4 has an air passage 43 inside, which communicates with the demolding cavity 42. The communication point is located on the side of the demolding cavity 42 closest to the injection surface. When the upper end of the demolding module 51 is flush with the upper side of the upper slider 4, the side of the demolding module 51 can block the communication point between the air passage 43 and the demolding cavity 42, thus completely separating the air passage 43 and the demolding cavity 42. When the upper end of the demolding module 51 moves downward below the communication point between the air passage 43 and the demolding cavity 42, the air passage 43 and the demolding cavity 42 communicate with each other again. The upper slider 4 is equipped with a control valve 44 that communicates with the air passage 43, which can control the opening and closing of the air passage 43.

[0028] During the injection molding stage, with the mold in the closed state, the lower slider 3 moves to the side closest to the injection molded workpiece under the action of the drive mechanism. The push block 32 enters the position below the demolding cavity 42, and through the engagement of its upper conical surface with the guide teeth 52 at the bottom of the demolding module 51, it lifts the demolding module 51 upward, making the upper end surface of the demolding module 51 flush with the upper side surface of the upper slider 4. At this time, the upper slider 4 and the demolding module 51 together form a complete cavity surface, which is in direct contact with the injection molded workpiece, ensuring the complete molding of the product structure.

[0029] After injection molding is completed and cooled, the mold opening and core pulling stage begins. The lower slide block 3 drives the push block 32 to be pulled out synchronously and gradually disengage from the guide teeth 52. The demolding module 51 retracts into the demolding cavity 42 under the action of the first elastic element 53. Its upper end face is lower than the upper side of the upper slide block 4, creating multiple local gaps between the upper slide block 4 and the workpiece, thus transforming the original continuous contact interface into a discrete contact state. As the demolding module 51 retracts below the position where the air passage 43 passes through, the air passage 43 and the demolding cavity 42 are reconnected. Gas is introduced through the control valve 44, and the gas enters the contact interface through the gaps to break the negative pressure and adhesion. During the core pulling process, the inclined surfaces of the push block 32 and the guide teeth 52 make periodic contact and disengagement during relative sliding, thereby driving the demolding module 51 to produce a slight reciprocating motion. At this time, the control valve 44 remains open, causing the contact pressure to change and promoting interface loosening. Subsequently, the lower slide block 3 continues to be pulled out and drives the upper slide block 4 to move. Since the contact interface has been reduced and the adhesion has weakened, the upper slide block 4 can complete the core pulling with less resistance, achieving smooth demolding of the product.

[0030] like Figure 2 , Figure 5 and Figures 8-9 As shown, the support assembly 6 includes a support block 61 slidably disposed within the upper slider 4. Multiple sets of support blocks 61 are evenly arranged, and the release module 51 is spatially offset from the support blocks 61. The upper slider 4 has a support cavity 45 that mates with the support block 61. The support cavity 45 extends through the upper and lower end faces of the upper slider 4. The support block 61 can slide back and forth along the support cavity 45, and its upper side surface can remain flush with the upper side surface of the upper slider 4, allowing the upper side surface of the support block 61 to contact the workpiece during injection molding. A support groove 451 is provided inside the support cavity 45. A drive block 33 that mates with the support groove 451 is provided on the upper surface of the lower slider 3. The drive block 33 can slide back and forth along the support groove 451, and its upper surface can contact the bottom surface of the support block 61. The support groove 451 is divided into a front section and a rear section. The inclination direction of the front section of the support groove 451 is parallel to the movement direction of the lower slider 3, and the inclination direction of the rear section of the support groove 451 is opposite to that of the front section. During injection molding, the drive block 33 is located in the front section of the support groove 451. At this time, the upper surface of the drive block 33 contacts the bottom surface of the support block 61, and keeps the upper side surface of the support block 61 flush with the upper side surface of the upper slider 4. The bottom surface of the support block 61 is inclined, and the inclination direction is parallel to the inclination direction of the front section of the support groove 451. The length of the inclined surface at the bottom of the support block 61 is greater than the length of the front section of the support groove 451. Second elastic members 62 are provided on both sides of the support block 61. The other end of the second elastic member 62 is connected to the inside of the support groove 451. In the initial state, under the action of the second elastic member 62, the upper side surface of the support block 61 is kept flush with the upper side surface of the upper slider 4. In this embodiment, the second elastic member 62 is set as a spring.

[0031] During the injection molding stage, the mold is in the closed state. The lower slider 3 moves to the side closer to the injection molded workpiece. The drive block 33 is located at the front of the support groove 451 and contacts the bottom surface of the support block 61. Under the combined action of the drive block 33 and the second elastic element 62, the upper end surface of the support block 61 is kept flush with the upper side surface of the upper slider 4, thereby providing support for the workpiece. At the same time, the push block 32 lifts the ejector module 51, so that it and the upper slider 4 together form a complete cavity surface to participate in the molding.

[0032] After injection molding is completed and cooled, the core-pulling stage begins. The lower slider 3 starts to be pulled out, and the drive block 33 moves from the front to the rear along the support groove 451. Since the rear section of the support groove 451 is inclined in the opposite direction to the front section, the supporting effect of the drive block 33 on the support block 61 gradually weakens, causing the support block 61 to be displaced relative to the upper slider 4 under the action of the second elastic element 62. At this time, the upper slider 4 begins to move downward along the L-shaped guide groove 212 and gradually releases the lateral interference with the workpiece. During this process, the upper end face of the support block 61 still maintains contact with the workpiece. The upper slider 4 moves downward, causing the support block 61 to gradually slide out from the upper surface of the upper slider 4, and can continue to provide local support to the workpiece when the demolding module 51 retracts to form a gap, preventing the workpiece from deforming due to tension during demolding due to loss of support. As the lower slider 3 continues to extend, the drive block 33 gradually disengages from the bottom of the support block 61. Under the action of the second elastic element 62, the support block 61 retracts into the support cavity 45, and simultaneously disengages from the workpiece, causing the upper side of the support block 61 to become flush with the upper side of the upper slider 4 again. The drive block 33 continues to slide to the end point at the rear of the support groove 451. At this point, the upper slider 4 and the lower slider 3 are relatively stationary. The lower slider 3 drives the upper slider 4 to move synchronously along the guide groove 211 and the L-shaped guide groove 212 to perform core pulling and completely disengage from the workpiece, thus achieving smooth core pulling and demolding of the product.

[0033] After the core is pulled out and the mold is opened to remove the part, the drive device 22 reverses its movement, driving the lower slide block 3 to move back towards the workpiece along the guide groove 211. During the resetting process, the push block 32 re-enters below the demolding cavity 42 and lifts the demolding module 51, restoring its upper surface to be flush with the upper side of the upper slide block 4. At the same time, the drive block 33 slides along the support groove 451 from the rear to the front and lifts the support block 61 again, making it flush with the upper side of the upper slide block 4. As the lower slide block 3 continues to reset, the upper slide block 4 synchronously returns to its initial position under the guidance of the L-shaped guide groove 212, completing the cavity reconstruction and entering the next injection molding cycle.

Claims

1. A core-pulling device for injection molds, comprising: The base (1) and the guide assembly (2) disposed on the base (1) are characterized in that a lower slider (3) and an upper slider (4) are slidably disposed on the guide assembly (2), and further include: The demolding assembly (5) is set on the upper slider (4). The demolding assembly (5) includes multiple demolding modules (51) slidably set in the upper slider (4). The upper slider (4) has a demolding cavity (42) that cooperates with the demolding modules (51). The lower end of the demolding module (51) is provided with guide teeth (52). The upper surface of the lower slider (3) is provided with push blocks (32) that cooperate with guide teeth (52). The demolding modules (51) are provided with first elastic elements (53) on both sides. The upper slider (4) has an air passage (43) that communicates with the demolding cavity (42). The support assembly (6) is set on the upper slider (4). The support assembly (6) includes multiple sets of support blocks (61) slidably set in the upper slider (4). The detachable module (51) and the support blocks (61) are spatially offset. The upper slider (4) has a support cavity (45) that cooperates with the support blocks (61). The support cavity (45) has a support groove (451) inside. The upper surface of the lower slider (3) has a drive block (33) that cooperates with the support groove (451). The support blocks (61) have second elastic members (62) on both sides.

2. The injection mold core-pulling device according to claim 1, characterized in that: The guide assembly (2) includes guide blocks (21) arranged on both sides of the base (1), guide grooves (211) are inclinedly arranged on the guide blocks (21), guide strips (31) are arranged on both sides of the lower slider (3) and slide in cooperation with the guide grooves (211), and a drive device (22) is provided on the upper surface of the base (1) to control the lower slider (3) to slide back and forth along the guide grooves (211).

3. The injection mold core-pulling device according to claim 2, characterized in that: The guide block (21) is provided with an L-shaped guide groove (212), and the upper slider (4) is provided with guide posts (41) on both sides that slide in cooperation with the L-shaped guide groove (212).

4. The injection mold core-pulling device according to claim 1, characterized in that: The demolding cavity (42) extends through the upper and lower end faces of the upper slider (4). The upper side of the demolding module (51) is flush with the upper side of the upper slider (4). The guide teeth (52) are evenly arranged along the moving direction of the lower slider (3). The push block (32) is located below the guide teeth (52), and the upper end of the push block (32) is provided with a conical surface that matches the guide teeth (52). The other end of the first elastic element (53) is connected to the inside of the demolding cavity (42).

5. A core-pulling device for injection molds according to claim 4, characterized in that: The air passage (43) and the demolding cavity (42) are connected at the side of the demolding cavity (42) close to the injection surface. The upper slider (4) is provided with a control valve (44) that communicates with the air passage (43). The opening and closing of the air passage (43) can be controlled by the control valve (44).

6. The injection mold core-pulling device according to claim 5, characterized in that: The support cavity (45) penetrates the upper and lower end faces of the upper slider (4). The upper side of the support block (61) can be flush with the upper side of the upper slider (4). The support groove (451) is divided into a front section and a rear section. The inclination direction of the front section of the support groove (451) is parallel to the movement direction of the lower slider (3), and the inclination direction of the rear section of the support groove (451) is opposite to that of the front section.

7. A core-pulling device for injection molds according to claim 6, characterized in that: The bottom surface of the support block (61) is inclined, and the inclination direction is parallel to the inclination direction of the front section of the support groove (451). The length of the bottom inclined surface of the support block (61) is greater than the length of the front section of the support groove (451). The other end of the second elastic member (62) is connected to the inside of the support groove (451).

8. The injection mold core-pulling device according to claim 7, characterized in that: The first elastic element (53) is configured as a spring, and the second elastic element (62) is configured as a spring.

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