Color changing structure, hot runner nozzle and hot runner system

Abstract

The utility model relates to the technical field of hot runner injection molds, in particular to a color changing structure, a hot runner nozzle and a hot runner system.The color changing structure is characterized in that an annular end cover annularly sleeves the periphery of a valve needle and is located in a gap between the outer end face of a flow guide shuttle and the inner wall of a mold open frame cavity; the sleeve part and the annular end cover are integrally formed, and the sleeve part is arranged on the periphery of the flow guide shuttle extending part in a sleeving mode. The annular end cover and the sleeve part are formed by solidifying molten plastic; according to the color changing structure formed by solidifying the molten plastic, an existing color changing cap is removed, the problems that the color changing cap is prone to damage and needs to be replaced frequently are solved, the product quality is greatly improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hot runner injection molds, in particular to a color changing structure, a hot runner nozzle and a hot runner system. Background Art

[0002] like Figure 1 As shown, the color-changing cap 7 is one of the parts of the hot runner nozzle, and the hot runner nozzle is an important part of the hot runner system. The existing color-changing cap 7 is generally sleeved on the outer periphery of the extension of the guide shuttle 6; the color-changing cap 7 is fixed by matching the groove structure provided on the inner wall of the color-changing cap 7 with the convex structure provided on the outer wall of the guide shuttle 6, and a hole is provided in the middle of the color-changing cap 7 for the valve needle 8 to pass through. However, during the long-term use of the color-changing cap 7, due to the effect of external pressure, the color-changing cap 7 is prone to cracking, resulting in black line defects on the corresponding mold frame 9 product, which seriously affects the color-changing effect. Utility Model Content

[0003] Therefore, the technical problem to be solved by the utility model is to overcome the defect that the color changing cap is prone to cracking due to external pressure during long-term use, resulting in black line defects on the corresponding mold frame product, seriously affecting the color changing effect.

[0004] In order to solve the above problems, the utility model provides a color changing structure, including:

[0005] An annular end cover is sleeved on the outer periphery of the valve needle, and the annular end cover is located in the gap between the outer end surface of the guide shuttle and the inner wall of the cavity of the mold opening frame; a flow channel for the molten plastic to flow is provided along the axis of the guide shuttle; the valve needle is suitable for reciprocating in the flow channel to open or close the flow channel;

[0006] The sleeve part is integrally formed with the annular end cover, and the sleeve part is sleeved on the outer circumference of the extending part of the guide shuttle; the annular end cover and the sleeve part are both formed by solidifying the molten plastic.

[0007] Optionally, the gap between the outer end surface of the guide shuttle and the inner wall of the cavity of the mold opening frame is no more than 0.1 mm.

[0008] Optionally, the gap between the outer end surface of the guide shuttle and the inner wall of the cavity of the mold opening frame is 0.1 mm.

[0009] Optionally, an annular groove is provided around the outer circumference of the guide shuttle near the outer end surface, and an annular boss solidified from the molten plastic is accommodated in the annular groove, and the annular boss is integrally formed with the sleeve portion.

[0010] Optionally, the cross-section of the annular groove is rectangular.

[0011] The utility model also provides a hot runner nozzle, comprising: the color changing structure.

[0012] Optionally, it also includes:

[0013] A flow guide shuttle, the color changing structure is arranged on the flow guide shuttle, and the flow channel of the flow guide shuttle near the outer end is a conical flow channel contracting outwards;

[0014] The valve needle is located in the flow channel of the guide shuttle, the size of the valve needle near the outer end is smaller than the size near the inner end, and the size of the valve needle near the inner end is larger than the size of the outer end of the tapered flow channel.

[0015] Optionally, it also includes:

[0016] The core body is provided with a flow channel along the axis for the molten plastic to flow;

[0017] A nozzle cap is disposed near a side of the core body into which the molten plastic flows;

[0018] A heating sleeve and a spacer sleeve are arranged outside the core body;

[0019] A heater is disposed in the heating sleeve, and the heater is suitable for heating the molten plastic flowing through the core;

[0020] The nozzle head is connected to the internal thread on the side of the core body where the molten plastic flows out through an external thread. The guide shuttle is sleeved in the nozzle head, and an annular platform is provided near the inner end of the guide shuttle. An annular groove is formed between the inner wall of the core and the inner end of the nozzle head, and the annular platform cooperates with the annular groove to axially position the guide shuttle.

[0021] Optionally, it also includes:

[0022] A thermocouple is located in the heating sleeve and is arranged in close contact with the outer wall of the core. The thermocouple is suitable for measuring the temperature of the surface of the core.

[0023] The utility model also provides a hot runner system, comprising: the hot runner nozzle.

[0024] The above technical solution of the utility model has the following advantages compared with the prior art:

[0025] 1. The color-changing structure provided by the utility model comprises: an annular end cover, which is sleeved on the outer periphery of the valve needle, and the annular end cover is located in the gap between the outer end surface of the guide shuttle and the inner wall of the cavity of the mold opening frame; a flow channel for the circulation of molten plastic is provided along the axis of the guide shuttle; the valve needle is suitable for reciprocating in the flow channel to open or close the flow channel; a sleeve part, which is integrally formed with the annular end cover, and the sleeve part is sleeved on the outer periphery of the protruding part of the guide shuttle; the annular end cover and the sleeve part are both solidified by the molten plastic; the present application adopts the above-mentioned technical scheme, and removes the existing color-changing cap through the color-changing structure formed by solidifying the molten plastic, thereby avoiding the problem that the color-changing cap is easily damaged and needs to be frequently replaced, greatly improving product quality and reducing production costs; at the same time, due to the removal of the color-changing cap, the processing accuracy requirement of the cavity of the mold opening frame can be reduced by one level, reducing the processing difficulty and saving processing costs. In addition, since there is no restriction on the color-changing cap, the gap problem that may exist between the sleeve part of the color-changing structure and the guide shuttle is minimized, which is more conducive to rapid color change and greatly improves the color-changing efficiency. Since the color-changing structure is a solidified layer formed by filling molten plastic, it can fit perfectly with the guide shuttle to ensure the optimization of the color-changing effect.

[0026] 2. The gap between the outer end surface of the guide shuttle of the utility model and the inner wall of the cavity of the mold opening frame is not greater than 0.1 mm; the present application adopts the above technical solution, and since the gap is set very small, a solidification layer can be quickly formed after the molten plastic fills the gap, thereby constructing a color-changing structure and improving production efficiency.

[0027] 3. The utility model has an annular groove around the outer circumference of the guide shuttle close to the outer end surface, and the annular boss solidified from the molten plastic is accommodated in the annular groove, and the annular boss is integrally formed with the sleeve portion; the present application adopts the above technical solution, and through the cooperation of the annular groove and the annular boss, the color-changing structure is firmly fixed to ensure production stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the cross-sectional structure of an existing color-changing cap during installation;

[0030] Figure 2 It is a schematic cross-sectional structure diagram of a hot runner nozzle provided in an embodiment of the utility model;

[0031] Figure 3 for Figure 2 Schematic diagram of the local enlarged structure at point A in the middle.

[0032] Description of reference numerals:

[0033] 1. Core body; 2. Nozzle cap; 3. Heating sleeve; 4. Heater; 5. Thermocouple; 6. Guide shuttle; 7. Color changing cap; 8. Valve needle; 9. Mold opening frame; 10. Nozzle head. DETAILED DESCRIPTION

[0034] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] like Figure 1As shown, when the hot runner system is maintained, the damaged color-changing cap 7 is difficult to reuse and needs to be replaced, which results in high maintenance costs. In addition, when the cavity processing at the position near the outer wall of the color-changing cap 7 on the mold opening frame 9 is positive deviation, there is a gap between the mold opening frame 9 and the color-changing cap 7, and it is easy for glue to be stored in the gap; in addition, the color-changing cap 7 itself has no adhesion, and when the mold opening frame 9 is taken out, it is easy to bring out the stored glue, resulting in different color defects on the product surface. In order to reduce the gap between the mold opening frame 9 and the color-changing cap 7, it is necessary to improve the dimensional accuracy of the cavity processing of the mold opening frame 9, thereby increasing the processing cost. In addition, in order to make the color-changing cap 7 fit with the guide shuttle 6, the processing accuracy of the fitting surface of the color-changing cap 7 and the guide shuttle 6 is required to be high. A slight deviation will result in a gap, and high processing accuracy will also increase production costs. Based on the above-mentioned various current situations, the present application provides an improved color-changing structure.

[0039] like Figure 2 A specific embodiment of the color-changing structure shown includes: an annular end cover and a sleeve portion. The annular end cover is sleeved on the outer periphery of the valve needle 8, and the annular end cover is located in the gap between the outer end surface of the guide shuttle 6 and the inner wall of the cavity of the mold opening frame 9; specifically, the gap between the outer end surface of the guide shuttle 6 and the inner wall of the cavity of the mold opening frame 9 is not greater than 0.1 mm; more specifically, the gap between the outer end surface of the guide shuttle 6 and the inner wall of the cavity of the mold opening frame 9 is 0.1 mm. A flow channel for the flow of molten plastic is provided along the axis of the guide shuttle 6; the valve needle 8 is suitable for reciprocating in the flow channel to open or close the flow channel. The sleeve portion is integrally formed with the annular end cover, and the sleeve portion is sleeved on the outer periphery of the protruding portion of the guide shuttle 6; the annular end cover and the sleeve portion are both solidified from the molten plastic. Furthermore, an annular groove is provided around the outer periphery of the guide shuttle 6 near the outer end surface, and an annular boss formed by solidification of the molten plastic is accommodated in the annular groove, and the annular boss is integrally formed with the sleeve portion. Specifically, the cross section of the annular groove is rectangular. Figure 1 The machining accuracy requirement of the existing color-changing cap 7 and the mold opening frame 9 can be reduced by one level, from the original positive and negative deviation of 0.02 mm to the current positive and negative deviation of 0.05 mm. In addition, due to the absence of the restriction of the color-changing cap 7, the possible gap problem at the matching point between the sleeve part of the color-changing structure and the guide shuttle 6 is minimized, which is more conducive to rapid color change. After experimental comparison with the technical solution of the existing color-changing cap 7, the average color-changing efficiency of the color-changing structure described in this application is improved by 15%.

[0040] When the injection molding product is formed, after the molten plastic enters the gap between the guide shuttle 6 and the mold opening frame 9, the gap can be 0.1 mm, combined with the effect of temperature difference, the molten plastic instantly solidifies into a thin solidified layer. Under the action of the annular groove, the solidified layer will be in a constant state, and the solidified layer also has a heat insulation effect; thereby realizing the function of the color change cap 7 in the prior art. When the hot runner system is maintained, the above solidified layer can be cleaned up; in the next production, the same principle can be used to form a new solidified layer; and the solidified layer is formed by filling the injection pressure and fits perfectly with the guide shuttle 6; there are no dead angles or gaps.

[0041] like Figure 2 and Figure 3 A specific embodiment of the hot runner nozzle shown includes: the color changing structure, the flow guide shuttle 6, the valve needle 8, the core body 1, the nozzle cap 2, the heating sleeve 3, the heater 4, the nozzle head 10 and the thermocouple 5. Specifically, the flow guide shuttle 6 is made of alloy steel, cast steel, titanium zirconium molybdenum alloy, copper alloy or tungsten steel.

[0042] like Figure 2 As shown, the color-changing structure is arranged on the guide shuttle 6, and the flow channel of the guide shuttle 6 near the outer end is a tapered flow channel that contracts outward. The valve needle 8 is located in the flow channel of the guide shuttle 6, and the size of the valve needle 8 near the outer end is smaller than the size near the inner end, and the size of the valve needle 8 near the inner end is larger than the size of the outer end of the tapered flow channel. The valve needle 8 reciprocates under the drive of the cylinder or the oil cylinder to open or close the tapered flow channel of the guide shuttle 6, that is, the valve needle 8 is used to open or close the glue port. The core body 1 is provided with a flow channel for the molten plastic to flow along the axis; the nozzle cap 2 is arranged near the side of the core body 1 where the molten plastic flows in. The heating sleeve 3 is sleeved on the outside of the core body 1 at intervals. The heater 4 is arranged in the heating sleeve 3, and the heater 4 is suitable for heating the molten plastic flowing through the core body 1. The nozzle head 10 is connected to the inner thread provided on the side of the core body 1 where the molten plastic flows out through an outer thread, the guide shuttle 6 is sleeved in the nozzle head 10, and an annular platform is provided near the inner end of the guide shuttle 6; an annular groove is formed between the inner wall of the core body 1 and the inner end of the nozzle head 10, and the annular platform cooperates with the annular groove to axially position the guide shuttle 6. The thermocouple 5 is located in the heating sleeve 3, and the thermocouple 5 is arranged in contact with the outer wall of the core body 1, and the thermocouple 5 is suitable for measuring the temperature of the surface of the core body 1.

[0043] The utility model also provides a hot runner system, comprising: the hot runner nozzle.

[0044] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention of the utility model.

Claims

1. A color-changing structure, characterized in that: include: An annular end cover is sleeved on the outer periphery of the valve needle (8), and the annular end cover is located in the gap between the outer end surface of the flow guide shuttle (6) and the inner wall of the cavity of the mold opening frame (9); a flow channel for the molten plastic to flow is provided along the axis of the flow guide shuttle (6); the valve needle (8) is suitable for reciprocating in the flow channel to open or close the flow channel; The sleeve portion is integrally formed with the annular end cover, and the sleeve portion is sleeved on the outer periphery of the extended portion of the guide shuttle (6); the annular end cover and the sleeve portion are both formed by solidifying the molten plastic.

2. The color-changing structure according to claim 1, characterized in that: The gap between the outer end surface of the guide shuttle (6) and the inner wall of the cavity of the mold opening frame (9) is no greater than 0.1 mm.

3. The color-changing structure according to claim 2, characterized in that: The gap between the outer end surface of the guide shuttle (6) and the inner wall of the cavity of the mold opening frame (9) is 0.1 mm.

4. The color changing structure according to any one of claims 1 to 3, characterized in that: An annular groove is arranged around the outer circumference of the guide shuttle (6) near the outer end surface, and an annular boss formed by solidifying the molten plastic is accommodated in the annular groove, and the annular boss is integrally formed with the sleeve portion.

5. The color changing structure according to claim 4, characterized in that: The cross section of the annular groove is rectangular.

6. A hot runner nozzle, characterized in that: include: The color-changing structure according to any one of claims 1 to 5.

7. The hot runner nozzle according to claim 6, characterized in that: Also includes: A flow guide shuttle (6), wherein the color changing structure is arranged on the flow guide shuttle (6), and the flow channel of the flow guide shuttle (6) near the outer end is a conical flow channel that contracts outwards; The valve needle (8) is located in the flow channel of the guide shuttle (6), the size of the valve needle (8) near the outer end is smaller than the size near the inner end, and the size of the valve needle (8) near the inner end is larger than the size of the outer end of the tapered flow channel.

8. The hot runner nozzle according to claim 7, characterized in that: Also includes: The core (1) is provided with a flow channel along the axis for the molten plastic to flow; A nozzle cap (2) is arranged close to a side of the core (1) into which the molten plastic flows; A heating sleeve (3) is spaced apart and arranged outside the core (1); A heater (4) is disposed in the heating sleeve (3), and the heater (4) is suitable for heating the molten plastic flowing through the core (1); The nozzle head (10) is connected to the internal thread provided on the side of the core body (1) where the molten plastic flows out through an external thread. The guide shuttle (6) is sleeved in the nozzle head (10), and an annular platform is provided near the inner end of the guide shuttle (6). An annular groove is formed between the inner wall of the core body (1) and the inner end of the nozzle head (10), and the annular platform cooperates with the annular groove to axially position the guide shuttle (6).

9. The hot runner nozzle according to claim 8, characterized in that: Also includes: A thermocouple (5) is located inside the heating sleeve (3), and the thermocouple (5) is arranged in close contact with the outer wall of the core (1). The thermocouple (5) is suitable for measuring the temperature of the surface of the core (1).

10. A hot runner system, characterized in that: include: The hot runner nozzle according to any one of claims 6 to 9.

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