A mold for seamless demolding and trimming-free sprue and its usage method

Abstract

The present invention relates to the field of PVC pipe molds, and more specifically, to a mold with seamless demolding and gate-free trimming and its usage method. The present invention includes a fixed mold, a movable mold used in cooperation with the fixed mold, and a core provided in a cavity between the fixed mold and the movable mold. A secondary ejector floating assembly for seamless demolding and core-pulling operations of plastic parts is provided on the movable mold. The core is connected to the secondary ejector floating assembly, and a gate cutter for simultaneously performing gate trimming operations during core-pulling operations is provided on the secondary ejector floating assembly. The present invention overcomes the defects that the traditional structure of using ejector pins to eject the pipe body and then using a pneumatic mechanism to cut off the gate is complex and easy to damage the product, and the structure is not easy to maintain. It changes the traditional demolding sequence, and realizes the seamless demolding technology of first demolding the cavity and then demolding the core in the way of first ejecting and then core-pulling. It can eliminate the complex parts required by traditional molds and at the same time achieve seamless ejection and an integrated demolding and trimming process, making the product more competitive in the market.

Description

Technical Field

[0001] The invention relates to the field of PVC pipe molds, and more specifically, to a traceless demoulding and shear-free water outlet mold and a use method thereof. Background Art

[0002] For molds of PVC drainage pipe fittings, the glue inlet needs to be cut off after product injection molding. However, the existing methods of removing the water outlet have problems such as poor water outlet cutting, difficult flow pattern adjustment, and unsatisfactory product performance. To address these drawbacks, it is necessary to develop a water outlet cutting device with low cost, high efficiency, high quality and long life.

[0003] A Chinese patent document with publication number CN205767303U discloses a mold for automatically cutting off a water outlet. After the fixed mold and the movable mold are opened, the runner ejector pin is pressed against the runner, and the product ejector pin is pressed against the product. The air cylinder and the oil cylinder are respectively fixed on the baffle, and the air cylinder is hung with a knife rod, and the oil cylinder is hung with an oil cylinder hanging plate. The oil cylinder hanging plate is fixed behind the slider seat by screws. The knife rod slides through the hole of the slider seat, thereby driving the cutter fixed thereon to move. When the ejector plate is lifted by an external injection molding machine, the pressure block is lifted and the gate of the runner is lifted. At this time, the air cylinder drives the knife rod to move and drives the cutter to cut off the gate of the runner. In this way, the lifting and resetting of the ejector plate drives the lifting and resetting of the pressure block, thereby controlling the machine-controlled valve to control the advance and retreat of the air cylinder to achieve the purpose of automatically cutting off the gate in the mold.

[0004] However, the above scheme still has some problems: on the one hand, in terms of product appearance, the existing scheme adopts a needle plate ejection mechanism, which requires the introduction of a series of components such as cylinders, knife rods, guide rails, and air control. Not only is the production cost high, but also when some products are cut off from the water outlet, the loose products are easy to touch the sharp corners of the mold and cause damage. Generally, there will be ejector marks on the PVC drainage pipe fittings, which seriously affects the product appearance. On the other hand, the ejector and the mold are worn to a certain extent during the production process. In this way, over time, the ejector position is prone to problems such as peaking, ejection failure, and ejector burnout. In the long run, the replacement cost is high and maintenance is difficult. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned water gate cutting scheme that the pneumatic mechanism cuts off the gate after the ejector ejects the tube body, the structure is complex and easy to damage the product, and the structure is not easy to maintain, and to provide a traceless demoulding and water gate cutting-free mold and its use method. The present invention eliminates the need for the introduction of complex parts required by traditional molds and realizes traceless ejection and integrated demoulding and cutting process, making the product more competitive in the market.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A seamless demolding and gate - shearing - free mold, comprising a fixed mold, a moving mold used in cooperation with the fixed mold, and a core set in the cavity between the fixed mold and the moving mold. A secondary ejector floating assembly for seamless demolding and core - removing operations of plastic parts is provided on the moving mold. The core is connected to the secondary ejector floating assembly, and a gate cutter for performing gate - shearing operations simultaneously during core - removing operations is provided on the secondary ejector floating assembly.

[0008] It should be noted that, generally, according to the injection requirements of different plastic parts, fixed - mold inserts and moving - mold inserts of different specifications can be installed on the fixed mold and the moving mold. The fixed - mold insert and the moving - mold insert are detachably connected to form the cavity for plastic part injection molding. Using fixed - mold inserts and moving - mold inserts of different specifications or using an integrally - formed moving mold and fixed mold to form the cavity does not affect the achievement of the purpose of the present invention.

[0009] In this way, by adding a secondary ejector floating assembly, seamless demolding and core - removing of plastic parts are realized, replacing the traditional ejector plate ejection mechanism. That is, a series of traditional mold parts such as spacer blocks, ejector plates, top plates, support columns, front plates, back plates, and ejector pins do not need to be manufactured, changing the traditional demolding sequence. The seamless demolding technology of first demolding the cavity and then demolding the core is realized in the way of first ejecting and then core - pulling. At the same time, the gate cutter is directly set on the secondary ejector floating assembly. During the core - removing process, the gate is cut off by the gate cutter, replacing the existing pneumatic gate - cutting mechanism. A series of components such as cylinders, tool bars, guide rails, and pneumatic controls do not need to be introduced, further simplifying the design structure and reducing the manufacturing difficulty and cost of the mold.

[0010] Furthermore, the secondary ejector floating assembly includes a secondary ejector rod demolding mechanism for the plastic part to be separated from the moving mold in the parting direction, a core - removing mechanism connected to the secondary ejector rod demolding mechanism and used for the plastic part to be separated from the core in the core - pulling direction, and the gate cutter is arranged on the core - removing mechanism. In this way, a corresponding secondary ejector rod demolding mechanism capable of ejecting in the parting direction and a core - removing mechanism for core - pulling of the plastic part in the core - pulling direction are designed, realizing the movement mode of first ejecting and then core - pulling.

[0011] Furthermore, the secondary ejector rod demolding mechanism includes a secondary ejector link movably penetrating through the moving mold, a pushing block fixed to one end of the secondary ejector link close to the core, a guiding assembly fixed to the moving mold and used for restricting the movement of the pushing block in the parting direction, and an ejection system connected to the other end of the secondary ejector link and used for driving the secondary ejector link to perform reciprocating motion. The core is fixed to the pushing block.

[0012] Furthermore, the secondary ejector link is connected to the ejection system through a secondary ejector rod.

[0013] It should be noted that there are generally clearance holes for the secondary ejector link rods designed on the moving mold, enabling the pushing block to be ejected and retracted in the parting direction through the ejection system of the injection molding machine. In this way, the ejection system first drives the secondary ejector rod, which drives the secondary ejector link rod to move. The secondary ejector link rod is directly connected to the pushing block, and the secondary ejector link rod synchronously drives the pushing block to move in the parting direction. The guiding assembly restricts the movement route of the pushing block in the parting direction. At this time, the entire secondary ejector mechanism moves a distance S towards the parting surface together, and the plastic part wrapped around the core is separated from the cavity of the moving mold insert along with the secondary ejector mechanism, realizing demolding on the parting surface.

[0014] Furthermore, the core-pulling mechanism includes a link rod passing through the pushing block. The link rod is parallel to the core. One end of the link rod is connected with a push plate sleeved on the core, and the other end of the link rod is connected with a driving device for providing reciprocating power. The push plate is provided with a limiting device for restricting the movement distance between the push plate and the pushing block. In this way, after the plastic part is separated from the cavity of the moving mold along with the secondary ejector mechanism, the plastic part is pushed out from the core-pulling direction by the push plate arranged between the pushing block and the plastic part, enabling the plastic part to be separated from the mold independently, realizing complete separation from the core, and falling outside the mold.

[0015] Furthermore, the gate cutter is arranged on the side of the push plate far from the pushing block. In this way, the gate cutter is fixed on the push plate and corresponds to the position of the gate of the plastic part on the core. Then, the link rod of the driving oil cylinder pushes the push plate to move in the direction of core-pulling of the plastic part. In this way, the gate cutter fixed on the push plate first reaches the position of the gate of the plastic part. Since the plastic part is still wrapped around the core at this time, the gate cutter will cut off the gate position, and the runner will fall naturally after being cut off, realizing the integrated in-mold gate shearing operation.

[0016] Furthermore, the guiding assembly includes a guide rail fixed on the moving mold, and the guide rail is slidably connected with the pushing block.

[0017] Furthermore, the guiding assembly includes a guide post fixed on the moving mold and passing through the pushing block, and the guide post is slidably connected with the pushing block.

[0018] Furthermore, the guiding assembly includes a guide rail fixed on the moving mold and a guide post fixed on the moving mold and passing through the pushing block, and the guide rail and the guide post are respectively slidably connected with the pushing block.

[0019] It should be noted that the guiding assembly is mainly used to limit the stability of the movement direction of the pushing block on the parting surface. The movement direction can be restricted by using the guide rail or the guide post alone, or both the guide rail and the guide post can be used simultaneously to further strengthen the movement stability of the pushing block. The use of any one of the guiding assemblies does not affect the realization of the purpose of the present invention.

[0020] Further, the limiting device includes a limiting guide post with one end fixedly connected to the push plate and passing through the pushing block, and a limiting block is fixedly connected to the other end of the limiting guide post. In this way, the limiting device is mainly used to ensure the stability of the movement direction of the push plate in the plastic part core-pulling direction and the movement orientation. The vertical reciprocation of the push plate relative to the pushing block is limited by the guide post, and the reciprocating distance of the push plate relative to the pushing block is fixed by the limiting block, ensuring that the push plate can completely push the plastic part away from the core and limiting the reciprocating distance reasonably.

[0021] Further, locking blocks are also provided at the positions on the fixed mold and the moving mold that are in contact with the pushing block to prevent the pushing block from loosening during mold clamping and injection molding. In this way, after the fixed mold and the moving mold of the mold are closed, the pushing blocks are locked by the locking blocks fixed on the fixed mold and the moving mold respectively, preventing them from loosening when subjected to the injection pressure.

[0022] A method for using a traceless demolding and gate-free shearing mold specifically includes the following steps:

[0023] S1 Mold separation: After the injection molding machine completes injection molding, the locking blocks are loosened, and the injection molding machine drives the moving mold to separate from the fixed mold. The moving mold drives the core and the plastic part to synchronously separate from the fixed mold and reach the designated position;

[0024] S2 Plastic part demolding: The ejection system of the secondary ejector rod demolding mechanism drives the secondary ejecting connecting rod to push the pushing block a certain distance in the parting direction out of the moving mold. The core connected to the pushing block and the entire core-pulling mechanism synchronously separate from the moving mold, and the plastic part separates from the cavity of the moving mold along with the core, completing the parting and demolding of the plastic part;

[0025] S3 Plastic part core-pulling and gate shearing: After the plastic part is parted and demolded, the driving device of the core-pulling mechanism drives the connecting rod to move a certain distance in the plastic part core-pulling direction. The push plate and the gate cutter connected to the connecting rod move a certain distance relative to the core in the plastic part core-pulling direction. During the movement of the push plate, the gate cutter first reaches the corresponding glue injection position of the plastic part, and the gate cutter cuts off the gate. As the push plate further advances, the push plate reaches the port of the plastic part, and then the push plate completely pushes the plastic part away from the core, completing the core-pulling and synchronous gate shearing of the plastic part;

[0026] S4 Mold clamping: After completing one demolding, core-pulling and gate-shearing operation, the moving mold is reset according to the reverse steps of S3 and S2. The injection molding machine pushes the moving mold to close with the fixed mold, and the locking blocks are locked, preparing for the next cycle of injection molding operation.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) The present invention realizes seamless demoulding and core removal of plastic parts by adding a secondary ejector floating component, and uses a secondary ejector rod directly connected to the push block to replace the traditional needle plate ejection mechanism, so that demoulding can be achieved without using an ejector pin. The product appearance will not have the defect of the ejector pin mark, and there will be no original ejector pin life problem.

[0029] (2) The present invention directly sets the gate cutter on the additional sub-top floating assembly. During the core stripping process, the gate cutter is used to cut off the gate, replacing the existing pneumatic gate cutting mechanism. There is no need to add complex in-mold cutting parts. The production cost is much lower than that of the original mold. When the gate cutter cuts the gate, the product will not hit the mold to cause damage to the plastic part, resulting in a high defective rate.

[0030] (3) The present invention adds a secondary ejector floating assembly to the movable mold, and the fixed mold does not need to vacate the ejector plate ejection space. The entire fixed mold is directly fixed to the injection molding machine panel, eliminating the warping of the mold parting surface, solving the problem of deformation of the mold under stress, reducing the occurrence of peaks, and extending the life of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a front view of the surface where the dynamic model cavity of Example 1 is located.

[0032] Figure 2 It is a schematic structural diagram of the movable mold of Example 1.

[0033] Figure 3 for Figure 2 Schematic diagram of the cross section at AA in FIG.

[0034] Figure 4 This is a schematic structural diagram of the fixed mold of Example 1.

[0035] Figure 5 Schematic diagram of the connection structure of the auxiliary top connecting rod of Example 1.

[0036] Figure 6 This is a schematic diagram of the connection structure of the limiting guide column of Example 1.

[0037] The illustrations are as follows:

[0038] 1-movable mold, 2-auxiliary ejector connecting rod, 3-lower locking block, 4-pushing block, 5-upper locking block 5, 6-fixed mold, 7-fixed mold insert, 8-movable mold insert, 9-, 10-core, 11-push plate, 12-driving cylinder, 13-auxiliary ejector rod, 14-limiting guide column, 15-guide column, 16-limiting block, 17-guide rail, 18-sprue cutter. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with specific embodiments. Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to this patent; in order to better illustrate the embodiments of the present invention, some components in the attached drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0040] Embodiment 1

[0041] As Figures 1 to 6 shown, a seamless demolding and gate-free trimming mold includes a fixed mold 6, a fixed mold insert 7 fixed on the fixed mold 6, a moving mold 1 used in cooperation with the fixed mold 6, a moving mold insert 8 fixed on the moving mold 1, the fixed mold insert 7 and the moving mold insert 8 are detachably connected to form a cavity for plastic part injection molding, and a core 10 arranged in the cavity between the fixed mold insert 7 and the moving mold insert 8. A secondary ejector floating assembly for seamless demolding and core-pulling operation of the plastic part is arranged on the moving mold 1. The core 10 is connected to the secondary ejector floating assembly, and a gate cutter 18 for gate trimming operation during core-pulling operation is arranged on the secondary ejector floating assembly.

[0042] In this way, by adding a secondary ejector floating assembly, seamless demolding and core-pulling of the plastic part are realized, replacing the traditional ejector plate ejection mechanism, that is, a series of traditional mold parts such as spacer blocks, ejector plates, face ejector plates, support columns, mold plates, bottom plates, ejector pins, etc. do not need to be made, changing the traditional demolding sequence, and realizing the seamless demolding technology of first demolding the cavity and then demolding the core in the way of first ejecting and then core-pulling. At the same time, the gate cutter 18 is directly arranged on the secondary ejector floating assembly. During the core-pulling process, the gate is cut off by the gate cutter, replacing the existing pneumatic gate-cutting mechanism, eliminating the need to introduce a series of components such as cylinders, tool bars, guide rails, and pneumatic controls, further simplifying the design structure, and at the same time reducing the manufacturing difficulty and cost of the mold.

[0043] As Figures 1 to 3 shown, the secondary ejector floating assembly includes a secondary ejector rod demolding mechanism for the plastic part to be separated from the moving mold in the parting direction, a core-pulling mechanism connected to the secondary ejector rod demolding mechanism and used for the plastic part to be separated from the core in the core-pulling direction, and the gate cutter 18 is arranged on the core-pulling mechanism. In this way, a corresponding secondary ejector rod demolding mechanism capable of ejecting in the parting direction and a push plate core-pulling mechanism for core-pulling of the plastic part in the core-pulling direction are designed, realizing the movement mode of first ejecting and then core-pulling.

[0044] As Figure 5As shown, the deputy ejector rod demolding mechanism includes a deputy ejector rod 2 movably arranged on the movable mold, a push block 4 is fixed to one end of the deputy ejector rod 2 close to the core, a guide component is fixed to the movable mold and used to limit the movement of the push block 4 in the parting direction, and an ejection system is connected to the other end of the deputy ejector rod 2 and used to drive the deputy ejector rod 2 to do reciprocating motion. The core 10 is fixed on the push block 4, the deputy ejector rod 2 and the ejection system are connected by a deputy ejector rod 13, and an air avoidance hole for the deputy ejector rod 2 is opened on the movable mold 1, so that the push block 4 can be ejected and pulled back in the parting direction through the ejection system of the injection molding machine.

[0045] In this way, the auxiliary ejector link 2 is driven by the ejection system, and the auxiliary ejector link 2 is directly connected to the push block 4. The auxiliary ejector link 2 synchronously drives the push block 4 to move in the parting direction. The guide component limits the movement path of the push block 4 in the parting direction. At this time, the entire auxiliary ejector demoulding mechanism is ejected together toward the parting surface for a distance S, and the plastic part wrapped on the core 10 is separated from the cavity of the movable mold insert 8 together with the auxiliary ejector demoulding mechanism, thereby realizing demoulding on the parting surface.

[0046] like Figure 2 As shown, the guide assembly includes a guide rail 17 fixed on the movable mold, and a guide column 15 fixed on the movable mold and penetrating the push block 4, and the guide rail 17 and the guide column 15 are respectively slidably connected with the push block 4. In this way, the guide assembly is mainly used to limit the stability of the movement direction of the push block 4 on the parting surface, and the guide rail 17 and the guide column 15 are used to limit the movement direction, so as to further enhance the movement stability of the push block 4.

[0047] like Figure 2 and Figure 6 As shown, the core-ejecting mechanism includes a connecting rod passing through the push block 4, the connecting rod is parallel to the core, one end of the connecting rod is connected to a push plate 11 sleeved on the core, the other end of the connecting rod is connected to a driving device 12 for providing reciprocating power, and a limit device for limiting the movement distance between the push plate 11 and the push block 4 is provided on the push plate 11. In this way, when the plastic part is separated from the cavity of the movable mold insert 8 together with the auxiliary ejector demoulding mechanism, the push plate 11 provided between the push block 4 and the plastic part pushes the plastic part out from the core-pulling direction, so that the plastic part is separated from the mold alone, completely separated from the core, and falls outside the mold.

[0048] like Figure 6As shown in the figure, the limiting device includes a limiting guide post 14 with one end fixedly connected to the push plate 11 and passing through the pushing block 4 at the same time, and a limiting block 16 is fixedly connected to the other end of the limiting guide post 14. In this way, the limiting device is mainly used to ensure the stability of the movement direction of the push plate 11 in the plastic part core-pulling direction. The vertical reciprocation between the push plate 11 and the pushing block 4 is limited by the guide post 14, and the reciprocating distance between the push plate 11 and the pushing block 4 is limited by the limiting block 16, ensuring that the push plate 11 can completely push the plastic part away from the core and ensuring that the reciprocating distance is reasonable.

[0049] As Figure 3 shown in the figure, the gate cutter 18 is arranged on the side of the push plate 11 away from the pushing block 4. In this way, the gate cutter 18 is fixed on the push plate 11 and corresponds to the position of the injection gate of the plastic part on the core 10. Then, the connecting rod of the driving oil cylinder 12 pushes the push plate 11 to move in the direction of the plastic part core-pulling 9, so that the gate cutter 18 fixed on the push plate 11 first reaches the position of the injection gate corresponding to the plastic part 9. Since the plastic part 9 is still wrapped on the core 10 at this time, the gate cutter 18 will cut off the injection gate position, and the runner will naturally fall after being cut off, realizing the integrated in-mold gate shearing operation.

[0050] As Figure 3 and Figure 4 shown in the figure, an upper locking block 5 for preventing the pushing block 4 from loosening during injection molding is also arranged at the position on the fixed mold 6 in contact with the pushing block 4, and a lower locking block 3 for preventing the pushing block 4 from loosening during injection molding is also arranged at the position on the moving mold 1 in contact with the pushing block 4. In this way, after the fixed mold plate 6 and the moving mold plate 1 of the mold are closed, the pushing block 4 is locked by the upper locking block 5 fixed on the fixed mold 6 and the lower locking block 3 fixed on the moving mold 1 respectively, preventing it from loosening under the injection pressure.

[0051] The working process of this embodiment is as follows:

[0052] After the mold injection molding is completed, the moving template 1 and the fixed template 6 are separated. At the same time of separation, the fixed mold insert 7 is disengaged from the plastic part 9, and other conventional core-pulling components are also pulled out of the plastic part 9. Then, the secondary ejector rod 13 of the injection molding machine pushes the secondary ejector connecting rod 2, and at the same time pushes out the pushing block 4. The core 10 and the entire secondary eject floating assembly connected to it are pushed out a distance S in the direction of the parting surface. At this time, the plastic part 9 is disengaged from the cavity of the moving mold insert 8 and wrapped around the core 10. Then, the driving link of the driving oil cylinder 12 pushes the push plate 11 to move in the core-pulling direction of the plastic part 9, so that the gate cutter 18 fixed on the push plate 11 first reaches the corresponding gate position of the plastic part 9. Since the plastic part 9 is still wrapped around the core 10 at this time, the gate cutter 18 will cut off the gate. After cutting off, the runner naturally falls. As the push plate 11 is further pushed forward until it reaches the port of the plastic part 9, at this time, the plastic part 9 is disengaged from the core 10 under the action of the thrust of the push plate 11. After the pushing stroke L, the limit block 16 slides behind the pushing block 4 to stop the push plate 11 from pushing. At this time, the plastic part 9 is completely disengaged from the core 10 and falls out of the mold.

[0053] After the ejection is completed, the driving oil cylinder 12 pulls the push plate 11 to reset during the mold closing process. Then, the secondary ejector rod 13 of the injection molding machine resets the entire secondary eject floating assembly and the core 10 connected to it together. Finally, the moving mold and the fixed mold are closed to perform the next cycle of injection molding.

[0054] Embodiment 2

[0055] This embodiment is similar to Embodiment 1. The difference is that in this embodiment, the guiding assembly includes a guide rail 17 fixed to the moving mold, and the guide rail 17 is slidably connected to the pushing block 4. The structures and working principles of other parts of this embodiment are the same as those of Embodiment 1.

[0056] Embodiment 3

[0057] This embodiment is similar to Embodiment 1. The difference is that in this embodiment, the guiding assembly includes a guide post 15 fixed to the moving mold and passing through the pushing block 4, and the guide post 15 is slidably connected to the pushing block 4. The structures and working principles of other parts of this embodiment are the same as those of Embodiment 1.

[0058] Embodiment 4

[0059] A method for using a mold for seamless demolding and gate-free trimming, specifically including the following steps:

[0060] S1 Mold separation: After the injection molding of the injection molding machine is completed, the upper locking block 5 on the fixed mold 6 is loosened from the lower locking block 3 on the moving mold 1. The injection molding machine drives the moving mold 1 to disengage from the fixed mold 6. The moving mold 1 drives the core 10 and the plastic part 9 to synchronously disengage from the fixed mold 6 and reach the designated position;

[0061] S2 Plastic part demoulding: The ejection system of the secondary ejector rod demoulding mechanism drives the secondary ejecting link 2 to push the pushing block 4 out of the moving die 1 by a certain distance in the parting direction. The core 10 connected to the pushing block 4 and the entire core-pulling mechanism are synchronously separated from the moving die 1, and the plastic part 9 is separated from the cavity of the moving die 1 along with the core 10, completing the parting and demoulding of the plastic part 9;

[0062] S3 Plastic part core-pulling and gate shearing: After the plastic part 9 is parted and demoulded, the driving device of the core-pulling mechanism drives the connecting rod to move a certain distance in the core-pulling direction of the plastic part 9. The push plate 11 and the gate cutter 18 connected to the connecting rod move a certain distance relative to the core 10 in the core-pulling direction of the plastic part. During the movement of the push plate 11, the gate cutter 18 first reaches the corresponding glue injection position of the plastic part 9, and the gate cutter 18 cuts off the gate. With the further advancement of the push plate 11, the push plate 11 reaches the port of the plastic part, and then the push plate 11 completely pushes the plastic part 9 away from the core 10, completing the core-pulling and synchronous gate shearing of the plastic part 9;

[0063] S4 Mold closing: After completing one demoulding, core-pulling and gate-shearing operation, the moving die 1 is positioned according to the reverse steps of S3 and S2. The injection molding machine pushes the moving die 1 to close with the fixed die 6. The upper locking block 5 on the fixed die 6 is locked with the lower locking block 3 on the moving die 1, and preparations are made for the next cycle of injection molding operation.

[0064] The same or similar reference numerals correspond to the same or similar components.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A mold for mark - free demolding and trimming - free gate cutting, comprising a fixed mold (6), a moving mold (1) used in cooperation with the fixed mold (6), and a core (10) disposed in the cavity between the fixed mold (6) and the moving mold (1), characterized in that, On the moving mold (1), there is a secondary ejector floating component for the seamless demolding and core-pulling operation of the plastic part. The core (10) is connected to the secondary ejector floating component, and a gate cutter (18) for performing gate cutting operation simultaneously during the core-pulling operation is provided on the secondary ejector floating component. The secondary ejector floating component includes a secondary ejector rod demolding mechanism for the plastic part to separate from the moving mold in the parting direction, a core-pulling mechanism connected to the secondary ejector rod demolding mechanism for the plastic part to separate from the core in the core-pulling direction, and the gate cutter (18) is provided on the core-pulling mechanism. The secondary ejector rod demolding mechanism includes a secondary ejector connecting rod (2) movably penetrating through the moving mold (1), a pushing block (4) fixed to one end of the secondary ejector connecting rod (2) close to the core, a guiding component fixed to the moving mold (1) for limiting the movement of the pushing block (4) in the parting direction, and an ejecting system connected to the other end of the secondary ejector connecting rod (2) for driving the secondary ejector connecting rod (2) to perform reciprocating motion. The core (10) is fixed to the pushing block (4). The core-pulling mechanism includes a connecting rod penetrating through the pushing block (4), the connecting rod is parallel to the core, one end of the connecting rod is connected with a push plate (11) sleeved on the core, the other end of the connecting rod is connected with a driving device (12) for providing reciprocating power, and a limiting device for limiting the movement distance between the push plate (11) and the pushing block (4) is provided on the push plate (11). The gate cutter (18) is provided on the side of the push plate (11) far from the pushing block (4). The secondary ejector connecting rod (2) is connected to the ejecting system through a secondary ejector rod (13). At the positions on the fixed mold (6) and the moving mold (1) in contact with the pushing block (4), locking blocks are also provided to prevent the pushing block (4) from loosening during mold clamping and injection molding.

2. The seamless demolding and gate-free trimming mold according to claim 1, characterized in that, The guiding component includes a guide rail (17) fixed to the moving mold (1), and the guide rail (17) is slidably connected to the pushing block (4).

3. The seamless demolding and gate-free trimming mold according to claim 1, characterized in that, The guiding component includes a guide post (15) fixed to the moving mold (1) and penetrating through the pushing block (4), and the guide post (15) is slidably connected to the pushing block (4).

4. The markless demolding and gate-free trimming mold according to claim 1, characterized in that, The guiding component includes a guide rail (17) fixed to the moving mold (1), and a guide post (15) fixed to the moving mold (1) and penetrating through the pushing block (4). The guide rail (17) and the guide post (15) are respectively slidably connected to the pushing block (4).

5. The seamless demolding and gate-free shearing mold according to claim 1, wherein the limiting device includes a limiting guide post (14) with one end fixedly connected to the push plate (11) and penetrating through the pushing block (4), and a limiting block (16) is fixedly connected to the other end of the limiting guide post (14).

Images