Three-way pipe arc core pulling structure, injection mold and demolding method

Abstract

The invention discloses a three-way pipe arc core-pulling structure, an injection mold and a demolding method.The arc core-pulling structure comprises a driving rack and a sliding limiting seat, an arc-shaped sliding block is arranged on the sliding limiting seat, an arc-shaped core-pulling insert is arranged on the arc-shaped sliding block, the arc-shaped core-pulling insert and the arc-shaped sliding block are the same in bending rate, and the circle centers of the arc-shaped core-pulling insert and the arc-shaped sliding block coincide; a rotatable transmission gear is arranged on the sliding limiting base, arc-shaped meshing teeth are arranged on the arc-shaped sliding block, and the transmission gear is connected with the driving rack and the arc-shaped meshing teeth in an engaged mode. The driving rack is driven to move linearly to drive the transmission gear to rotate, and then the transmission gear is matched with the arc-shaped meshing teeth to drive the arc-shaped sliding block to rotate and slide on the sliding limiting seat, so that the arc-shaped core-pulling insert can stretch into or stretch out of a product cavity. Core pulling of the arc hole is achieved through mold opening force, an external oil cylinder is not needed, the manufacturing cost of the mold can be reduced, the injection molding period can be shortened, and therefore the machining efficiency of the mold is improved.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, and in particular to a three-way pipe arc core-pulling structure, an injection mold and a demoulding method. Background Art

[0002] With the continuous development of society, the shapes of plastic products are becoming more and more complex. Figure 1 As shown, the product is a three-way pipe roughly in the shape of a "7", two of which are regular through holes; the other is an arc-shaped through hole. In order to realize the core pulling of the arc tube 302, the traditional solution is to use a cylinder to drive the rack transmission, and then drive the gear and the arc-shaped core pulling insert to rotate through the rack, so as to realize the arc-shaped core pulling function. This method requires an external cylinder, which will inevitably increase the overall production cost of the mold. In addition, the use of a cylinder drive often prolongs the injection cycle of the mold, thereby reducing the processing efficiency of the mold. Summary of the invention

[0003] In order to solve some or all of the problems existing in the above-mentioned prior art, on the one hand, the present invention provides a three-way pipe circular arc core pulling structure for being installed on an injection mold, wherein the injection mold comprises a movable mold and a fixed mold, the movable mold and the fixed mold can be connected in an opening and closing manner, and a product cavity is arranged on the parting surface of the movable mold and the fixed mold, and the three-way pipe circular arc core pulling structure comprises a driving rack and a sliding limit seat, the driving rack is connected to the movable mold, the sliding limit seat is connected to the fixed mold, an arc-shaped slider is arranged on the sliding limit seat, the arc-shaped slider and the sliding limit seat can be slidably limited, and an arc-shaped core pulling insert is arranged on the arc-shaped slider. The curvature of the arc-shaped core-pulling insert is the same as that of the arc-shaped slider, and the centers of the two circles coincide with each other. A rotatable transmission shaft is provided on the sliding limit seat, and a transmission gear is sleeved on the transmission shaft. An arc-shaped engaging tooth is provided on the end face of the arc-shaped slider, and the transmission gear is respectively meshed with the driving rack and the arc-shaped engaging tooth. The movable mold can drive the driving rack to move linearly, and the driving rack drives the transmission gear to rotate, and then the cooperation of the transmission gear and the arc-shaped engaging tooth drives the arc-shaped slider to rotate and slide on the sliding limit seat, so that the arc-shaped core-pulling insert can extend into or out of the product cavity.

[0004] As a further improvement of the present invention, the transmission gear includes a first gear and a second gear, the first gear and the second gear are respectively sleeved on the periphery of the transmission shaft, the diameter of the first gear is larger than the diameter of the second gear, the first gear is meshed with the driving rack, and the second gear is meshed with the arc-shaped meshing teeth.

[0005] As a further improvement of the present invention, the left and right sides of the arc-shaped sliding block are respectively provided with limiting protrusions, the inner side wall of the sliding limiting seat is provided with limiting sliding grooves, and the limiting protrusions are slidably engaged with the limiting sliding grooves.

[0006] As a further improvement of the present invention, a stop seat is provided on the movable mold, and the stop seat can abut against one end of the arc-shaped sliding block away from the arc-shaped core-pulling insert, and the stop seat is detachably connected to the sliding limit seat.

[0007] As a further improvement of the present invention, a guide block is provided on the fixed mold at a position corresponding to the driving rack, a sliding slot is provided on the driving rack, and the guide block is slidably engaged with the sliding slot.

[0008] As a further improvement of the present invention, the three-way pipe arc core pulling structure also includes a limit plate, which is slidably connected to the movable mold and the fixed mold respectively, and a limit slot hole is provided on the limit plate. Limit bolts are provided at positions corresponding to the movable mold and / or fixed mold and the limit slot holes, and the limit bolts are slidably engaged with the limit slot holes.

[0009] On the other hand, the present invention also provides an injection mold including the above-mentioned three-way pipe arc core pulling structure, and also includes a front mold, a rear mold, a first core pulling structure and a second core pulling structure. The movable mold and the fixed mold can be connected in an opening and closing manner, and a product cavity is provided on the parting surface of the movable mold and the fixed mold. The first core pulling structure is provided with a first core pulling insert, and the first core pulling structure is used to drive the first core pulling insert to extend into or extend out of the product cavity. The second core pulling structure is provided with a second core pulling insert, and the second core pulling structure is used to drive the second core pulling insert to extend into or extend out of the product cavity. One end of the first core pulling insert can abut against one end of the arc core pulling insert, and one end of the second core pulling insert can abut against the outer wall of the first core pulling insert.

[0010] As a further improvement of the present invention, the first core pulling structure includes a first core pulling slide and a first core pulling slider, the first core pulling slide is connected to the fixed mold, the first core pulling slider is slidably connected to the first core pulling slide, a core pulling drive is provided on the first core pulling slide, the output end of the core pulling drive is connected to the first core pulling slider, the first core pulling insert is connected to the first core pulling slider, and the core pulling drive can drive the first core pulling slider to slide on the first core pulling slide, thereby driving the first core pulling insert to extend into or out of the product cavity.

[0011] As a further improvement of the present invention, the second core pulling structure includes a second core pulling slide and a second core pulling slider, the second core pulling slide is connected to the fixed mold, the second core pulling slider is slidably connected to the second core pulling slide, the second core pulling insert is connected to the second core pulling slider, the movable mold is provided with an inclined guide column, the second core pulling slider is provided with an inclined guide hole, the inclined guide column can be inserted into the inclined guide hole and slidably cooperate with the inclined guide hole, the inclined guide column can drive the second core pulling slider to slide on the second core pulling slide, and then drive the second core pulling insert to extend into or out of the product cavity.

[0012] On the other hand, the present invention also provides a method for demoulding a plastic product processed by the above injection mold, comprising the following steps:

[0013] S1: Drive the movable mold to move away from the fixed mold, so that the movable mold is separated from the fixed mold and the mold is opened;

[0014] During the mold opening process, the movable mold will drive the inclined guide column to slide in the inclined guide hole, drive the second core pulling slider to slide on the second core pulling slide seat, so that the second core pulling slider drives the second core pulling insert to extend out of the product cavity, completing the first straight tube core pulling of the plastic product;

[0015] At the same time, during the mold opening process, the movable mold will also drive the driving rack to move, and the driving rack will drive the transmission gear to rotate, and then the transmission gear and the arc-shaped meshing teeth will drive the arc-shaped slider to rotate and slide on the sliding limit seat, so that the arc-shaped core-pulling insert extends out of the product cavity, completing the arc core-pulling;

[0016] S2: Control the core pulling drive to work, and the core pulling drive drives the first core pulling slider to slide on the first core pulling slide seat, so that the first core pulling slider drives the first core pulling insert to extend out of the product cavity, completing the second straight tube core pulling;

[0017] S3: Drive the ejector plate on the fixed mold to move, and the ejector plate drives the ejector to extend into the product cavity, ejecting the plastic product in the product cavity out of the product cavity, and completing the demoulding of the plastic product.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention can directly use the mold opening force of the injection mold to realize the core pulling of the arc hole, without the need for an external oil cylinder, which can reduce the production cost of the mold; moreover, directly using the mold opening force to perform arc core pulling allows the mold opening and arc core pulling to be performed synchronously, reducing waiting time, shortening the injection molding cycle, and thus improving the processing efficiency of the mold. When the mold is closed, the arc core pulling insert extends into the product cavity, and the injection mold forms the plastic product outside the arc core pulling insert; when the mold is opened, the injection molding machine drives the movable mold to move in a direction away from the fixed mold, and the movable mold drives the driving rack to move synchronously, and the driving rack drives the transmission gear to rotate, and then the transmission gear and the arc meshing teeth cooperate to drive the arc slider to rotate and slide on the sliding limit seat, so that the arc core pulling insert extends out of the product cavity, realizing the arc core pulling process of the plastic product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the present invention or the solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic diagram of the structure of a plastic product processed by an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the structure of the movable mold in an embodiment of the present invention;

[0024] Figure 4 It is a structural schematic diagram of a fixed mold in an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the combined state of the first core pulling structure, the second core pulling structure and the arc core pulling structure in the embodiment of the present invention;

[0026] Figure 6 2 is a schematic structural diagram of the arc core pulling structure in an embodiment of the present invention;

[0027] Figure 7 It is a structural schematic diagram of the arc core pulling structure from another perspective in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs; the terms used in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0029] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0030] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0031] like Figure 1-7 As shown, an injection mold comprises a movable mold 100, a fixed mold 200, a first core pulling structure 1, a second core pulling structure 2 and an arc core pulling structure 3. The movable mold 100 and the fixed mold 200 can be connected in an opening and closing manner, and a product cavity 300 is provided on the parting surface of the fixed mold 200 and the movable mold 100; the injection mold is used to be installed on an injection molding machine for processing, and the injection molding machine can drive the movable mold 100 to move toward or away from the fixed mold 200, thereby realizing mold opening and closing; and the injection molding machine can inject rubber into the product cavity 300 through the feeding system of the injection molding machine, thereby forming a three-way pipe in the product cavity 300.

[0032] The arc core pulling structure 3 includes a driving rack 31 and a sliding stopper 32. One end of the driving rack 31 is fixedly connected to the movable mold 100, and the other end can extend into the fixed mold 200. The sliding stopper 32 is fixedly connected to the fixed mold 200. The sliding stopper 32 is provided with an arc-shaped slider 33. The arc-shaped slider 33 is slidably and stopperedly connected to the sliding stopper 32. The arc-shaped core pulling insert 34 is provided on the arc-shaped slider 33. The arc-shaped core pulling insert 34 has the same curvature as the arc-shaped slider 33, and the centers of the two coincide, so that when the arc-shaped slider 33 slides in an arc shape in the sliding stopper 32, the arc-shaped core pulling insert 34 can rotate and swing along the same curvature. A rotatable transmission shaft 35 is provided on the sliding limit seat 32, a transmission gear 36 is sleeved on the transmission shaft 35, an arc-shaped meshing tooth 331 is provided on the end surface of the arc-shaped slider 33, and the transmission gear 36 is respectively meshed with the driving rack 31 and the arc-shaped meshing tooth 331. The movable mold 100 can drive the driving rack 31 to move linearly, and the transmission gear 36 is driven to rotate by the driving rack 31, and then the arc-shaped slider 33 is driven to rotate and slide on the sliding limit seat 32 through the cooperation of the transmission gear 36 and the arc-shaped meshing tooth 331, so that the arc-shaped core-pulling insert 34 can extend into or out of the product cavity 300.

[0033] During the injection molding process, the movable mold 100 and the fixed mold 200 are molded together, the arc-shaped core-pulling insert 34 extends into the product cavity 300, and one end of the driving rack 31 extends into the fixed mold 200 to mesh with the transmission gear 36. After the plastic part is formed, the injection molding machine drives the movable mold 100 to move away from the fixed mold 200; the movable mold 100 drives the driving rack 31 to move synchronously, and the driving rack 31 drives the transmission gear 36 to rotate, and then the transmission gear 36 and the arc-shaped meshing teeth 331 cooperate to drive the arc-shaped slider 33 to rotate and slide on the sliding limit seat 32, so that the arc-shaped core-pulling insert 34 extends out of the product cavity 300, and the core-pulling process of the arc tube 302 of the plastic product is realized.

[0034] In this embodiment, the transmission gear 36 includes a first gear 361 and a second gear 362, which are respectively sleeved on the periphery of the transmission shaft 35, and the diameter of the first gear 361 is larger than the diameter of the second gear 362. The first gear 361 meshes with the driving rack 31, and the second gear 362 meshes with the arc-shaped meshing teeth 331. By setting the first gear 361 and the second gear 362 as two gears with different diameters, the strokes and speeds of the arc-shaped core-pulling insert 34 and the driving rack 31 are different during the mold opening and closing process, so as to achieve precise control. In this embodiment, the stroke of the arc-shaped core-pulling insert 34 is greater than the stroke of the driving rack 31, so the diameter of the first gear 361 is set to be larger than the diameter of the second gear 362. In other embodiments, if the stroke of the arc-shaped core-pulling insert 34 is smaller than the stroke of the driving rack 31, the first gear 361 can also be adaptively set to be smaller than the second gear 362.

[0035] In order to ensure a stable connection between the arc-shaped slider 33 and the sliding limit seat 32, limit protrusions 332 are respectively provided on the left and right sides of the arc-shaped slider 33, and limit grooves 321 adapted to the limit protrusions 332 are provided on the inner side wall of the sliding limit seat 32. The limit protrusions 332 are respectively inserted into the corresponding limit grooves 321 and are respectively slidably engaged with the corresponding limit grooves 321. During the sliding process of the arc-shaped slider 33, the limit protrusions 332 will slide in the limit grooves 321; the cooperation between the limit protrusions 332 and the limit grooves 321 can limit and guide the movement direction of the arc-shaped slider 33, and can also prevent the arc-shaped slider 33 from falling out of the sliding limit seat 32, thereby improving the stability of the transmission and the stability of the structure.

[0036] In order to prevent the arc-shaped core-pulling insert 34 from sliding out of the product cavity 300 during the injection molding process, a backstop seat 37 is provided on the movable mold 100. The backstop seat 37 can abut against the end of the arc-shaped slider 33 away from the arc-shaped core-pulling insert 34, and the backstop seat 37 is detachably connected with the sliding limit seat 32. When the injection molding machine drives the movable mold 100 to move toward the fixed mold 200 for mold closing, the movable mold 100 will drive the backstop seat 37 to move together, and the backstop seat 37 will be inserted into the sliding limit seat 32; after the mold closing is completed, the backstop seat 37 can abut against the end of the arc-shaped slider 33 away from the arc-shaped core-pulling insert 34; through the cooperation of the backstop seat 37 and the arc-shaped core-pulling insert 34, the problem of the arc-shaped slider 33 retreating due to excessive injection pressure can be avoided, the processing stability is improved, and the processing yield rate is guaranteed.

[0037] In order to limit and guide the movement direction of the driving rack 31, a guide block 38 is provided at a position corresponding to the driving rack 31 on the fixed mold 200, and a sliding slot 311 is provided on the driving rack 31, and the guide block 38 is slidably engaged with the sliding slot 311. During the mold opening or closing process, the driving rack 31 moves, so that the guide block 38 slides in the sliding slot 311; the movement direction of the driving rack 31 can be limited and guided by the cooperation of the guide block 38 and the sliding slot 311, thereby improving the stability and transmission accuracy of the transmission.

[0038] The arc core pulling structure 3 also includes a limit plate 39, which is connected to the movable mold 100 and the fixed mold 200 respectively. A limit slot 391 is provided on the limit plate 39. The movable mold 100 and the fixed mold 200 are provided with limit bolts 310 at positions corresponding to the limit slot 391, respectively. The limit bolts 310 are slidably engaged with the limit slot 391. During the mold opening process, the movable mold 100 moves to drive the limit bolt 310 to slide in the limit slot 391. When the mold is opened to the limit position, the limit bolt 310 will abut against one end of the limit slot 391; the cooperation between the limit bolt 310 and the limit slot 391 can limit the movement stroke of the driving rack 31, thereby preventing the driving rack 31 from driving the arc slider 33 to fall out of the sliding limit seat 32, thereby improving the stability of the structure.

[0039] The first core pulling structure 1 is provided with a first core pulling insert 11, which is used to drive the first core pulling insert 11 to extend into or extend out of the product cavity 300; the second core pulling structure 2 is provided with a second core pulling insert 21, which is used to drive the second core pulling insert 21 to extend into or extend out of the product cavity 300, one end of the first core pulling insert 11 can abut against one end of the arc-shaped core pulling insert 34, and one end of the second core pulling insert 21 can abut against the outer wall of the first core pulling insert 11. When closing the mold, first control the first core pulling structure 1 to drive the first core pulling insert 11 to extend into the product cavity 300; then control the second core pulling structure 2 and the arc core pulling structure 3 to work respectively, the second core pulling structure 2 drives the second core pulling insert 21 to extend into the product cavity 300 until one end of the second core pulling insert 21 abuts against the outer wall of the first core pulling insert 11; the arc core pulling structure 3 drives the arc-shaped core pulling insert 34 to extend into the product cavity 300 until one end of the arc-shaped core pulling insert 34 abuts against one end of the first core pulling insert 11. When opening the mold and pulling the core, first control the second core pulling structure 2 and the arc core pulling structure 3 to work, the second core pulling structure 2 drives the second core pulling insert 21 to extend out of the product cavity 300, and the arc core pulling structure 3 drives the arc core pulling insert 34 to extend out of the product cavity 300; at this time, since the plastic product is wrapped on the first core pulling insert 11, the plastic product will not move with the second core pulling insert 21 and the arc core pulling insert 34. After the second core pulling insert 21 and the arc core pulling insert 34 are completed, the first core pulling structure 1 is controlled to work, drive the first core pulling insert 11 to extend out of the product cavity 300, complete the three connected through-hole core pulling work of the plastic product, and then drive the plastic product to be demolded by the injection molding machine.

[0040] The first core-pulling structure 1 includes a first core-pulling slide 12 and a first core-pulling slider 13. The first core-pulling slide 12 is connected to the fixed mold 200. The first core-pulling slider 13 is slidably connected to the first core-pulling slide 12. A core-pulling driving member 14 is provided on the first core-pulling slide 12. The output end of the core-pulling driving member 14 is connected to the first core-pulling slider 13. The first core-pulling insert 11 is connected to the first core-pulling slider 13. The core-pulling driving member 14 can drive the first core-pulling slider 13 to slide on the first core-pulling slide 12, thereby driving the first core-pulling insert 11 to extend into or extend out of the product cavity 300. During operation, the first core-pulling slider 13 is driven to slide on the first core-pulling slide 12 by the core-pulling driving member 14, and the first core-pulling slider 13 will drive the first core-pulling insert 11 to move synchronously, so that the first core-pulling insert 11 extends into or extends out of the product cavity 300.

[0041] In this embodiment, the core-pulling driving member 14 is a hydraulic cylinder; in other embodiments, other mechanical structures or devices capable of driving linear motion may also be used, such as an electric cylinder.

[0042] The second core pulling structure 2 includes a second core pulling slide 22 and a second core pulling slider 23. The second core pulling slide 22 is connected to the fixed mold 200. The second core pulling slider 23 is slidably connected to the second core pulling slide 22. The second core pulling insert 21 is connected to the second core pulling slider 23. The movable mold 100 is provided with an inclined guide column 24. The second core pulling slider 23 is provided with an inclined guide hole 25. The inclined guide column 24 can be inserted into the inclined guide hole 25 and slidably cooperate with the inclined guide hole 25. The inclined guide column 24 can drive the second core pulling slider 23 to slide on the second core pulling slide 22, thereby driving the second core pulling insert 21 to extend into or out of the product cavity 300. During the process of opening or closing the mold, the movable mold 100 moves relative to the fixed mold 200, and the inclined guide column 24 on the movable mold 100 will extend into or out of the inclined guide hole 25 and slide in the inclined guide hole 25; through the cooperation between the inclined guide column 24 and the inclined guide hole 25, the second core pulling slider 23 can be pulled or pushed to slide on the second core pulling slide 22, and the second core pulling slider 23 will drive the second core pulling insert 21 to move synchronously, so that the second core pulling insert 21 extends into or out of the product cavity 300, thereby realizing mold closing or through-hole core pulling.

[0043] The processing process of the above injection mold is as follows:

[0044] During processing, the movable mold 100 and the fixed mold 200 are respectively connected to the injection molding machine, and the movable mold 100 and the fixed mold 200 are clamped and fixed to achieve mold closing; then the rubber is injected into the product cavity 300 through the feeding system of the injection molding machine, and after pressure-maintaining cooling, the three-way pipe plastic product is formed in the product cavity 300.

[0045] After the plastic part is formed, the mold is opened by driving the injection molding machine, so that the movable mold 100 moves away from the fixed mold 200 to realize the mold opening. During the mold opening process, the movable mold 100 will drive the inclined guide column 24 to slide in the inclined guide hole 25, and drive the second core-pulling slider 23 to slide on the second core-pulling slide seat 22, so that the second core-pulling slider 23 drives the second core-pulling insert 21 to extend out of the product cavity 300, and complete the core pulling of the first straight tube 301 of the plastic product; at the same time, during the mold opening process, the movable mold 100 will also drive the driving rack 31 to move, and drive the transmission gear 36 to rotate through the driving rack 31, and then drive the arc slider 33 to rotate and slide on the sliding limit seat 32 through the cooperation of the transmission gear 36 and the arc-shaped meshing tooth 331, so that the arc-shaped core-pulling insert 34 extends out of the product cavity 300, and completes the core pulling of the arc tube 302 of the plastic product. After the core pulling of the first straight tube 301 and the arc tube 302 is completed, the core pulling driving member 14 is controlled to work, and the core pulling driving member 14 drives the first core pulling slider 13 to slide on the first core pulling slide seat 12, so that the first core pulling slider 13 drives the first core pulling insert 11 to extend out of the product cavity 300, and the second straight tube 303 of the plastic product is pulled out. Then, the ejector plate on the fixed mold 200 is lifted by the ejector rod of the injection molding machine, and the ejector plate drives the ejector to extend into the product cavity 300, and the plastic product in the product cavity 300 is ejected from the product cavity 300, thereby completing the demoulding of the entire plastic product.

[0046] When closing the mold, the ejector rod of the injection molding machine is controlled to retract, so that the ejector plate drives the ejector to re-extend into the fixed mold 200 and withdraw it from the product cavity 300. Then the first core-pulling structure 1 is controlled to reset, and the first core-pulling insert 11 is driven to re-extend into the product cavity 300. Then the injection molding machine drives the movable mold 100 to move toward the fixed mold 200, so that the movable mold 100 and the fixed mold 200 are closed; during the process of closing the mold, the movable mold 100 will drive the second core-pulling structure 2 and the arc core-pulling structure 3 to work respectively, and the second core-pulling structure 2 drives the second core-pulling insert 21 to extend into the product cavity 300 until the second core-pulling insert 21 abuts against the side wall of the first core-pulling insert 11; the arc core-pulling structure 3 will drive the arc-shaped core-pulling insert 34 to extend into the product cavity 300 until one end of the arc-shaped core-pulling insert 34 abuts against one end of the first core-pulling insert 11.

[0047] The above-mentioned specific implementation is a preferred implementation of the present invention, and is not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to this specific implementation. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A three-way pipe arc core-pulling structure, used for installation on an injection mold, the injection mold includes a movable mold and a fixed mold, the movable mold and the fixed mold are openably connected, and a product cavity is provided on the parting surface between the movable mold and the fixed mold, characterized in that: The arc core-pulling structure of the three-way pipe includes a driving rack and a sliding limit seat, wherein the driving rack is connected to the movable mold, the sliding limit seat is connected to the fixed mold, an arc-shaped slider is provided on the sliding limit seat, and the arc-shaped slider is slidably and limitably connected to the sliding limit seat, an arc-shaped core-pulling insert is provided on the arc-shaped slider, and the curvature of the arc-shaped core-pulling insert and the arc-shaped slider are the same, and the centers of the two coincide, a rotatable transmission shaft is provided on the sliding limit seat, a transmission gear is sleeved on the transmission shaft, an arc-shaped meshing tooth is provided on the end surface of the arc-shaped slider, and the transmission gear is meshed with the driving rack and the arc-shaped meshing tooth respectively; The movable mold can drive the driving rack to move linearly, and the driving rack drives the transmission gear to rotate, and then the transmission gear and the arc-shaped meshing teeth cooperate to drive the arc-shaped slider to rotate and slide on the sliding limit seat, so that the arc-shaped core-pulling insert can extend into or out of the product cavity.

2. The three-way pipe arc core pulling structure according to claim 1, characterized in that: The transmission gear includes a first gear and a second gear, the first gear and the second gear are respectively sleeved on the periphery of the transmission shaft, the diameter of the first gear is larger than the diameter of the second gear, the first gear is meshed with the driving rack, and the second gear is meshed with the arc-shaped meshing teeth.

3. The three-way pipe arc core pulling structure according to claim 1, characterized in that: The left and right sides of the arc-shaped sliding block are respectively provided with limiting protrusions, and the inner side wall of the sliding limiting seat is provided with limiting sliding grooves, and the limiting protrusions are slidably engaged with the limiting sliding grooves.

4. The three-way pipe arc core pulling structure according to claim 3, characterized in that: The movable mold is provided with a stop seat, which can abut against one end of the arc-shaped sliding block away from the arc-shaped core-pulling insert, and the stop seat is detachably connected with the sliding limit seat.

5. The three-way pipe arc core pulling structure according to claim 1, characterized in that: A guide block is provided at a position on the fixed mold corresponding to the driving rack, a sliding slot is provided on the driving rack, and the guide block is slidably engaged with the sliding slot.

6. The three-way pipe arc core pulling structure according to claim 1, characterized in that: The three-way pipe arc core pulling structure also includes a limit plate, which is slidably connected to the movable mold and the fixed mold respectively, and a limit slot is provided on the limit plate. The movable mold and / or the fixed mold are provided with limit bolts at positions corresponding to the limit slots, and the limit bolts are slidably engaged with the limit slots.

7. An injection mold comprising the three-way pipe arc core-pulling structure according to any one of claims 1 to 6, characterized in that: It also includes a front mold, a rear mold, a first core pulling structure and a second core pulling structure. The movable mold and the fixed mold can be connected in an opening and closing manner. A product cavity is provided on the parting surface between the movable mold and the fixed mold. The first core pulling structure is provided with a first core pulling insert. The first core pulling structure is used to drive the first core pulling insert to extend into or extend out of the product cavity. The second core pulling structure is provided with a second core pulling insert. The second core pulling structure is used to drive the second core pulling insert to extend into or extend out of the product cavity. One end of the first core pulling insert can abut against one end of the arc-shaped core pulling insert, and one end of the second core pulling insert can abut against the outer side wall of the first core pulling insert.

8. The injection mold according to claim 7, characterized in that: The first core pulling structure includes a first core pulling slide and a first core pulling slider, the first core pulling slide is connected to the fixed mold, the first core pulling slider is slidably connected to the first core pulling slide, a core pulling driving component is provided on the first core pulling slide, the output end of the core pulling driving component is connected to the first core pulling slider, the first core pulling insert is connected to the first core pulling slider, and the core pulling driving component can drive the first core pulling slider to slide on the first core pulling slide, thereby driving the first core pulling insert to extend into or out of the product cavity.

9. The injection mold according to claim 8, characterized in that: The second core pulling structure includes a second core pulling slide and a second core pulling slider, the second core pulling slide is connected to the fixed mold, the second core pulling slider is slidably connected to the second core pulling slide, the second core pulling insert is connected to the second core pulling slider, the movable mold is provided with an inclined guide column, the second core pulling slider is provided with an inclined guide hole, the inclined guide column can be inserted into the inclined guide hole and slidably cooperate with the inclined guide hole, the inclined guide column can drive the second core pulling slider to slide on the second core pulling slide, and then drive the second core pulling insert to extend into or out of the product cavity.

10. A demoulding method for processing a plastic product using the injection mold according to claim 9, characterized in that: The following steps are involved: S1: Drive the movable mold to move away from the fixed mold, so that the movable mold is separated from the fixed mold and the mold is opened; During the mold opening process, the movable mold will drive the inclined guide column to slide in the inclined guide hole, drive the second core pulling slider to slide on the second core pulling slide seat, so that the second core pulling slider drives the second core pulling insert to extend out of the product cavity, completing the first straight tube core pulling of the plastic product; At the same time, during the mold opening process, the movable mold will also drive the driving rack to move, and the driving rack will drive the transmission gear to rotate, and then the transmission gear and the arc-shaped meshing teeth will drive the arc-shaped slider to rotate and slide on the sliding limit seat, so that the arc-shaped core-pulling insert extends out of the product cavity, completing the arc core-pulling; S2: Control the core pulling drive to work, and the core pulling drive drives the first core pulling slider to slide on the first core pulling slide seat, so that the first core pulling slider drives the first core pulling insert to extend out of the product cavity, completing the second straight tube core pulling; S3: Drive the ejector plate on the fixed mold to move, and the ejector plate drives the ejector to extend into the product cavity, ejecting the plastic product in the product cavity out of the product cavity, and completing the demoulding of the plastic product.

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