A valve needle guide structure, a valve needle guide positioning method and an injection mold

Abstract

The present application relates to a kind of valve needle guide structure and valve needle guide positioning method, injection mold.The valve needle guide structure, including splitter, guide and cover, splitter is opened in the through hole of up and down, the top of through hole is formed with the first annular groove;Guide is the rotary body structure with central guide hole, the outer surface of guide is the convex arc surface, guide is partially housed in the first annular groove, and it can be axially deflected adjustment setting by the cooperation of arc surface and the first annular groove;Cover is opened in the through hole of up and down, the bottom of through hole is formed with the second annular groove opposite to the first annular groove, cover is set on guide, and is fixedly connected with splitter, to limit the axial deflection of guide.The present application can quickly fix guide in the position where central guide hole and the ejection hole of hot runner nozzle are in the same central axis, simple structure, low processing precision requirement, easy and fast installation.

Description

Technical Field

[0001] This invention belongs to the field of mold technology, and particularly relates to a valve needle guide structure and valve needle guide positioning method, and an injection mold. Background Technology

[0002] Hot runner systems are primarily used as part of injection molds. Their function is to keep the plastic in a molten state during the injection process, while guiding the molten plastic to different mold cavities. This eliminates waste of sprue material, reduces injection pressure, shortens the injection cycle, and improves product quality.

[0003] Existing hot runner system structures such as Figure 1 As shown, it mainly includes a guide body 102, a fixing sleeve 103, and a hot runner nozzle 104. The guide body 102 is fixedly installed on the top surface of the manifold 101 through the fixing sleeve 103. The hot runner nozzle 104 is disposed on the bottom surface of the manifold 101. A through hole 105 is formed between the top and bottom surfaces of the manifold 101, communicating with the guide body 102 and the hot runner nozzle 104. The valve needle 107 of the hot runner nozzle 104 passes through the through hole 105 and is slidably connected to the central guide hole of the guide body 102. A manifold 10 channel 10 is formed in the manifold 101, communicating with the through hole 105. 6. The molten material enters the hot runner nozzle 104 from the runner 106 through the through hole 105. During injection, the valve needle 107 moves upward to open the ejection hole 108 of the hot runner nozzle 104. The molten material is ejected from the ejection hole 108 and enters the mold cavity from the mold core gate 109. After injection is completed, the valve needle 107 moves downward to the ejection hole 108 to close it. When the valve needle 107 moves up and down between the open and closed positions, it is guided by the central guide hole of the guide body 102 to prevent the valve needle 107 from deviating and causing damage to the inside of the hot runner nozzle 104.

[0004] However, due to machining and assembly errors, it cannot be completely guaranteed that the central guide hole of the guide body 102 and the ejection hole 108 of the hot runner nozzle 104 are on the same axis. Figure 2 As shown, the valve needle 107 may swing and damage the ejection hole 108 of the hot runner nozzle 104 during the movement, or even damage the mold core gate 109, thereby affecting the surface appearance of the molded product, causing problems such as excessive gate height and unsmooth gate discharge, resulting in increased scrap rate, increased production costs and reduced production efficiency. Summary of the Invention

[0005] The purpose of this invention is to at least partially address the shortcomings of the prior art and provide a valve needle guiding structure, a valve needle guiding and positioning method, and an injection mold.

[0006] To achieve the above objectives, the present invention provides a valve needle guide structure for use in an injection mold, comprising:

[0007] The diverter plate has a through hole extending vertically, and a first annular groove is formed around the periphery of the through hole at the top of the through hole.

[0008] The guide is a rotating structure with a central guide hole, which guides the sliding direction of the valve needle. The outer circumferential surface of the guide is a convex arc surface. The guide is partially housed in the first annular groove and can be axially deflected and adjusted by the cooperation between the arc surface and the first annular groove.

[0009] The cover has a through hole that extends vertically and is used to avoid the valve needle. The bottom of the through hole has a second annular groove that surrounds the periphery of the through hole and is opposite to the first annular groove. The cover is placed on the guide and fixedly connected to the diverter plate, so that the first annular groove and the second annular groove clamp the arc surface from top to bottom to limit the axial deflection of the guide.

[0010] Optionally, the arc surface of the guide member is formed by rotating an arc around the central axis of the central guide hole.

[0011] Optionally, the center of the arc is located outside the central axis.

[0012] Optionally, both the first annular groove and the second annular groove are arc-shaped grooves adapted to the arc surface, and the curvature of both the first annular groove and the second annular groove is less than 90°.

[0013] Optionally, one end of the guide member protrudes from the periphery of the central guide hole from the clearance hole to form a tubular first guide portion.

[0014] Optionally, the other end of the guide member protrudes from the periphery of the central guide hole to form a second guide portion that extends into the through hole.

[0015] Optionally, the top of the diverter plate is provided with a mounting hole communicating with the through hole, and the bottom surface of the mounting hole and the through hole form the first annular groove, and the cover is fixedly installed in the mounting hole.

[0016] Optionally, the cross-sectional dimensions of the cover are adapted to the cross-sectional dimensions of the mounting hole, and a flange protrudes radially outward from the top of the cover, the flange being fixed to the top surface of the diverter plate by fasteners.

[0017] Optionally, a flow channel is formed in the flow divider plate, one end of which is connected to the main flow channel of the injection mold, and the other end is connected to the through hole.

[0018] The present invention also provides an injection mold, including the valve needle guide structure as described above, wherein the bottom surface of the manifold is provided with a hot runner nozzle communicating with the through hole, and the valve needle of the hot runner nozzle passes through the central guide hole.

[0019] The present invention also provides a valve needle guiding and positioning method, applied to the valve needle guiding structure described above, wherein the bottom surface of the flow divider plate is provided with a hot runner nozzle communicating with the through hole, comprising the following steps:

[0020] The valve needle of the hot runner nozzle is sequentially inserted into the clearance hole, the central guide hole, and the through hole;

[0021] When the end of the valve needle slides to the ejection hole of the hot runner nozzle, the cover is fixed to the flow divider plate to press the guide member, so that the axial positioning of the central guide hole is coaxial with the ejection hole.

[0022] This invention utilizes a first annular groove and a second annular groove to clamp and fix the guide member, thereby fixing the guide member at a position where the central guide hole and the ejection hole are on the same central axis. This ensures that the valve needle can slide accurately into the ejection hole under the guidance of the central guide hole, thus avoiding gate damage and problems that affect the product appearance, improving the yield of injection molds, and having a simple structure, low requirements for processing precision, and convenient and quick installation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 For valve needle guide structures in existing hot runner systems;

[0025] Figure 2 for Figure 1 The diagram shows the valve needle deflection caused by machining or installation errors in the valve needle guide structure.

[0026] Figure 3 This is a cross-sectional view of an embodiment of the valve needle guide structure of the present invention;

[0027] Figure 4 for Figure 3 An enlarged schematic diagram of part A in the middle;

[0028] Main component description:

[0029] 101. Manifold; 102. Guide body; 103. Fixing sleeve; 104. Hot runner nozzle; 105. Through hole; 106. Manifold; 107. Valve pin; 108. Ejection hole; 109. Mold core gate;

[0030] 10. Diverter plate; 11. Through hole; 12. First annular groove; 13. Diverter channel; 14. Mounting hole;

[0031] 20. Guide component; 21. Central guide hole; 22. Arc surface; 23. First guide section; 24. Second guide section;

[0032] 30. Cover body; 31. Clearance hole; 32. Second annular groove; 33. Flange flange;

[0033] 40. Hot runner nozzle; 41. Runner hole; 42. Ejection hole; 50. Valve needle; 60. Mold core gate. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," and "radial," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] Please see Figure 3 and Figure 4This invention provides a valve needle guide structure for use in injection molds with hot runner systems, including a manifold 10, a guide 20, and a cover 30.

[0038] The manifold 10 has a through hole 11 extending vertically, and a flow channel 13 is formed inside the manifold 10. One end of the flow channel 13 is connected to the main flow channel of the injection mold, and the other end is connected to the through hole 11. A first annular groove 12 is formed on the top of the through hole 11, surrounding the periphery of the through hole 11.

[0039] The guide member 20 is a rotating structure with a central guide hole 21, which is used to guide the sliding direction of the valve needle 50. The outer peripheral surface of the guide member 20 is a convex arc surface 22. The guide member 20 is partially housed in the first annular groove 12 and can be axially deflected and adjusted by the cooperation between the arc surface 22 and the first annular groove 12.

[0040] The cover 30 has a through hole 31 that extends vertically and is used to avoid the valve needle 50. The bottom of the through hole 31 has a second annular groove 32 that surrounds the periphery of the through hole 31 and is opposite to the first annular groove 12. The cover 30 is placed on the guide member 20 and fixedly connected to the diverter plate 10, so that the first annular groove 12 and the second annular groove 32 clamp the arc surface 22 from top to bottom to limit the axial deflection of the guide member 20.

[0041] The injection mold with a hot runner system has a hot runner nozzle 40 on the bottom surface of the manifold 10 that communicates with the through hole 11. The hot runner nozzle 40 has a runner hole 41 for the molten material to pass through. The upper end of the runner hole 41 is connected to the through hole 11 so that the molten material injected from the main runner can pass through the manifold 13 and the through hole 11 in sequence and enter the runner hole 41. The lower end of the runner hole 41 tapers to form an ejector hole 42. The ejector hole 42 communicates with the mold core gate 60 of the injection mold. The molten material in the flow hole can be injected into the molding cavity of the injection mold through the ejector hole 42 from the mold core gate 60. After the molten material in the molding cavity cools and solidifies, the mold can be opened and the molded product can be taken out.

[0042] In this embodiment, the outer diameter of the valve needle 50 of the hot runner nozzle 40 is adapted to the diameter of the ejection hole 42. When the lower end of the valve needle 50 slides downward and is located inside the ejection hole 42, the valve needle 50 blocks the ejection hole 42 to cut off the connection between the runner hole 41 and the mold core gate 60. When injection molding is required, the valve needle 50 is driven to move upward to open the ejection hole 42, so that the molten material in the runner hole 41 can be ejected from the ejection hole 42 and injected into the molding cavity from the mold core gate 60 to realize the injection molding of the product.

[0043] It should be understood that the injection mold is provided with a drive device (not shown) above the manifold 10. The upper end of the valve needle 50 is connected to the drive device, and the lower end passes through the central guide hole 21 and extends into the flow channel hole 41. The central guide hole 21 provides guidance for the valve needle 50 so that the drive device can accurately insert into the ejection hole 42 to achieve the purpose of sealing when driving the valve needle 50 to move downward.

[0044] It should be noted that, Figure 3 The structure of the lower end of the valve needle 50 shown in the figure has two position states. The position state of the valve rod 50 shown to the left of the center line is the closed position state. The lower end of the valve rod 50 simultaneously blocks the ejector hole 42 and the mold core gate 60 to close the connection between the runner hole 41 and the molding cavity. The position state of the valve rod 50 shown to the right of the center line is the open position state. That is, the lower end of the valve rod 50 moves upward and retracts into the runner hole 41 to open the ejector hole 42 and the mold core gate 60. At this time, the molten material can enter the molding cavity from the runner hole 41 through the ejector hole 42 and the mold core gate 60 in sequence to achieve injection molding.

[0045] According to the valve needle guide structure of the present invention, in practical applications, the guide member 20 is first installed on the first annular groove 12 of the flow divider plate 10, and then the lower end of the valve needle 50 is passed sequentially through the clearance hole 31 of the cover 30, the central guide hole 21 of the guide member 20, the through hole 11 of the flow divider plate 10, and the flow channel hole 41 of the hot runner nozzle 40 until it extends into the ejection hole 42. At this time, by utilizing the cooperation between the arc surface 22 of the guide member 20 and the first annular groove 12, the axial deflection of the guide member 20 can be adjusted so that the central guide hole 21 and the ejection hole 42 are aligned. On the central axis, the cover 30 is then fixed on the manifold 10. The guide member 20 is clamped and fixed by the first annular groove 12 and the second annular groove 32, so that the guide member 20 is fixed at the position where the central guide hole 21 and the ejection hole 42 are on the same central axis. This structure ensures that the valve needle 50 can slide accurately into the ejection hole 42 under the guidance of the central guide hole 21, thereby avoiding gate damage and affecting the appearance of the product, improving the yield of injection mold products, and the structure is simple, with low requirements for processing accuracy, and is convenient and quick to install.

[0046] Of course, in other embodiments, the cover 30 can be pre-connected to the diverter plate 10 so that the guide 20 can be movably accommodated between the first annular groove 12 and the second annular groove 32. When the valve needle 50 passes through the central guide hole 21 and the ejection hole 42, concentric positioning calibration is achieved. Then, the cover 30 is locked onto the diverter plate 10 so that the first annular groove 12 and the second annular groove 32 clamp and fix the guide 20 from above and below. For example, the cover 30 can be connected to the diverter plate 10 by a threaded connection. During installation, the guide 20 is in a relaxed state relative to the first annular groove 12 and the second annular groove 32. After the axial deflection of the guide body is adjusted by the valve needle 50, the cover 30 is tightened to fix the guide 20.

[0047] In one embodiment, the arc surface 22 of the guide member 20 is formed by rotating an arc around the central axis of the central guide hole 21, that is, the outer diameter of the guide member 20 has a structure that is large in the middle and small at both ends; preferably, the first annular groove 12 and the second annular groove 32 are both arc-shaped grooves adapted to the arc surface 22, and the curvature of the first annular groove 12 and the second annular groove 32 is less than 90°.

[0048] Thus, when the guide member 20 is in a relaxed state relative to the diverter plate 10 and the cover 30, the arc surface 22 can be axially deflected through the cooperation between the first annular groove 12 and the second annular groove 32, so as to quickly adjust the guide member 20; when the cover 30 is locked onto the diverter plate 10 so that the first annular groove 12 and the second annular groove 32 clamp and fix the guide member 20, the first annular groove 12 fits against the lower half of the arc surface 22 of the guide member 20, and the second annular groove 32 fits against the upper half of the arc surface 22 of the guide member 20.

[0049] To ensure the stability of the clamping of the guide member 20 by the cover 30 and the diverter plate 10, in this embodiment, the center of the arc is located outside the central axis; that is, the arc surface 22 of the guide member 20 is aspherical. This allows the guide member 20 to deflect axially when it is in a relaxed state relative to the diverter plate 10 and the cover 30. When the cover 30 and the diverter plate 10 clamp and fix the guide member 20, it prevents the guide member 20 from deflecting axially due to vibration during use, thus ensuring guiding stability. In other embodiments, the center of the arc can also be located on the central axis, that is, the arc surface 22 on the outer periphery of the guide member 20 is spherical. This also allows the guide member 20 to achieve axial deflection adjustment in a relaxed state. However, this method requires a higher strength from the cover 30 to press the guide member 20 to prevent the guide member 20 from deflecting axially when it is fixed.

[0050] In one embodiment, one end of the guide member 20 protrudes from the periphery of the central guide hole 21 through the vent hole 31 to form a tubular first guide portion 23, and the other end protrudes from the periphery of the central guide hole 21 to form a second guide portion 24 extending into the through hole 11.

[0051] Thus, by providing the first guide portion 23 and / or the second guide portion 24, the axial length of the central guide hole 21 can be extended, further improving the guiding accuracy of the guide member 20 for the valve needle 50; in this embodiment, the diameter of the clearance hole 31 is larger than the outer diameter of the first guide portion 23, and the diameter of the through hole 11 is larger than the outer diameter of the second guide portion 24, so that the guide member 20 can achieve axial deflection adjustment within a certain range.

[0052] In one embodiment, the top of the manifold 10 has a mounting hole 14 communicating with the through hole 11. A first annular groove 12 is formed between the bottom surface of the mounting hole 14 and the through hole 11. The cover 30 is fixedly installed in the mounting hole 14. This allows the guide 20 to be closer to the position of the ejection hole 42, reduces the distance between the central guide hole 21 and the ejection hole 42, improves the guiding accuracy of the guide 20, and allows the guide 20 and the cover 30 to be accommodated in the mounting hole 14, thereby optimizing the structure of the injection mold.

[0053] Furthermore, to improve the fixing strength between the cover 30 and the diverter plate 10, in this embodiment, the cross-sectional dimensions of the cover 30 are adapted to the cross-sectional dimensions of the mounting hole 14. A flange 33 is formed by radially outward protrusion of the top of the cover 30, and the flange 33 is fixed to the top surface of the diverter plate 10 by fasteners. Of course, an external thread can also be provided on the outer periphery of the cover 30, and a matching internal thread can be provided on the inner peripheral wall of the mounting hole 14, so that the cover 30 can be fixed in the mounting hole 14 by threaded connection, so as to achieve compression and fixation of the guide member 20.

[0054] The present invention also proposes an injection mold, which includes a valve needle guide structure. The specific structure of the valve needle guide structure is as described in the above embodiments. Since the injection mold adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0055] In addition, the present invention also provides a valve needle guiding and positioning method, applied to the above-mentioned valve needle guiding structure, comprising the following steps: with the guide member 20 in a state in which axial deflection adjustment is possible relative to the flow divider plate 10; the valve needle 50 of the hot runner nozzle 40 is inserted into the clearance hole 31, the central guide hole 21 and the through hole 11, and the lower end of the valve needle 50 passes through the through hole 11 and enters the flow channel hole 41; when the lower end of the valve needle 50 slides to the ejection hole 42 of the hot runner nozzle 40, the arc surface 22 of the guide member 20 and the first annular groove 12 are used to guide the valve needle 50 to be positioned. The axial deflection of guide member 20 is adjusted so that the central guide hole 21 and the ejector hole 42 are on the same central axis. Then, the cover 30 is fixed to the flow divider plate 10 to press the guide member 20, so that the axial positioning of the central guide hole 21 is on the same central axis as the ejector hole 42. This method is convenient and quick to install, and ensures that the valve needle 50 can slide accurately into the ejector hole 42 under the guidance of the central guide hole 21, thereby avoiding gate damage and affecting the appearance of the product, improving the yield of injection mold products, and having low requirements for the machining accuracy of the workpiece.

[0056] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0057] The above is a description of the technical solution provided by the present invention. For those skilled in the art, based on the ideas of the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A valve needle guide structure, applied in an injection mold, characterized in that, include: The diverter plate has a through hole extending vertically, and a first annular groove is formed around the periphery of the through hole at the top of the through hole. The guide is a rotating structure with a central guide hole, which guides the sliding direction of the valve needle. The outer circumferential surface of the guide is a convex arc surface, the center of which is located outside the central axis. The guide is partially housed in the first annular groove and can be axially deflected and adjusted by the cooperation between the arc surface and the first annular groove. The cover has a through-hole that allows the valve needle to pass through. A second annular groove is formed at the bottom of the through-hole, surrounding its periphery and opposite to the first annular groove. The cover is placed on the guide and fixedly connected to the flow divider, so that the first and second annular grooves clamp the arc surface, limiting the axial deflection of the guide. The arc surface of the guide is formed by rotating an arc around the central axis of the central guide hole. One end of the guide protrudes from the through-hole from the periphery of the central guide hole to form a tubular first guide portion; the other end of the guide protrudes from the periphery of the central guide hole to form a second guide portion extending into the through hole.

2. The valve needle guide structure according to claim 1, characterized in that, Both the first annular groove and the second annular groove are arc-shaped grooves adapted to the arc surface, and the curvature of both the first annular groove and the second annular groove is less than 90°.

3. The valve needle guide structure according to claim 1, characterized in that, The top of the diverter plate has a mounting hole that communicates with the through hole. The bottom surface of the mounting hole and the through hole form the first annular groove. The cover is fixedly installed in the mounting hole.

4. The valve needle guide structure according to claim 3, characterized in that, The cross-sectional dimensions of the cover are adapted to the cross-sectional dimensions of the mounting hole. The top of the cover protrudes radially outward to form a flange, which is fixed to the top surface of the diverter plate by fasteners.

5. The valve needle guide structure according to claim 1, characterized in that, The manifold has a manifold channel, one end of which is connected to the main flow channel of the injection mold, and the other end is connected to the through hole.

6. An injection mold, characterized in that, Includes the valve needle guide structure as described in any one of claims 1-5, wherein the bottom surface of the flow divider plate is provided with a hot runner nozzle communicating with the through hole, and the valve needle of the hot runner nozzle passes through the central guide hole.

7. A valve needle guiding and positioning method, characterized in that, Applied to the valve needle guide structure as described in any one of claims 1 to 5, wherein the bottom surface of the flow divider plate is provided with a hot runner nozzle communicating with the through hole, the method includes the following steps: The valve needle of the hot runner nozzle is sequentially inserted into the clearance hole, the central guide hole, and the through hole; When the end of the valve needle slides to the ejection hole of the hot runner nozzle, the cover is fixed to the flow divider plate to press the guide member, so that the axial positioning of the central guide hole is coaxial with the ejection hole.

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