Hot nozzle assembly and hot runner mold

Abstract

The present invention belongs to the technical field of hot runners, and discloses a hot nozzle assembly and a hot runner mold. The hot nozzle assembly includes a hot nozzle body, a pressure cap and a nozzle tip, the pressure cap has an inner cavity, and can be sleeved on the outside of the nozzle tip; the pressure cap can be connected to the hot nozzle body to fix the nozzle tip between the two; the part of the inner cavity of the pressure cap not occupied by the nozzle tip forms a gap portion; the glue outlet end of the nozzle tip is provided with a diverter, the diverter is connected to the outer wall of the glue outlet end of the nozzle tip and is connected to the gap portion, and the part of the gap portion connected to the diverter forms a glue outlet passage; the glue outlet end of the nozzle tip is also provided with a filling portion, and the filling portion completely or partially fills the gap portion except the glue outlet passage. The hot nozzle assembly adopts an open point gate form, and can be applied to hot runner point gate injection molding of crystalline plastics or plastics with poor fluidity, and is not limited to whether there is a plane at the pouring point of the injection molded product or whether a "circle mark" is allowed to be formed.

Description

Technical Field

[0001] The invention relates to the technical field of hot runners, and in particular to a hot nozzle assembly and a hot runner mold. Background Art

[0002] Open point gate hot runner molds have the advantages of simple structure, low cost, and can be directly molded on the product surface without the need for cold runner transition, making them the most commonly used gate method in hot runner molds.

[0003] Generally, open point gate hot runner molds include two structures: open point gate with gate bushing and open point gate without gate bushing, where:

[0004] like Figure 1 As shown, the open point gate hot runner mold with a gate sleeve is provided with a gate sleeve 4 at its gate, and the gate sleeve 4 is used to fix and surround the nozzle tip 3, and the molten plastic flowing out of the hot nozzle assembly is insulated and kept warm by the gate sleeve 4, so that the heat at the gate is high, which is suitable for injection molding forms that require a "hot gate", such as injection molding materials such as crystalline plastics and plastics with poor fluidity. However, due to the presence of the gate sleeve, the pouring point of the injection molded product 300 needs to be flat, and the surface of the product will be pressed by the gate sleeve to form a "circle mark", which cannot be applied to products with irregular shapes and products with high surface quality requirements.

[0005] like Figure 2 As shown, the open point gate hot runner mold without a gate sleeve does not have a gate sleeve 4 at its gate, but uses a pressure cap 2 to fix the nozzle tip 3, and the tip of the nozzle tip 3 extends out of the pressure cap 2. Therefore, the heat at the gate is relatively low, which is suitable for "cold gate" injection molding that requires cold and hot separation, such as amorphous plastics, plastics with good fluidity and easy drawing, etc. Accordingly, since the gate sleeve 4 is not provided, the pouring point of the injection-molded product 300 does not need to be flat, and no "circle mark" will appear.

[0006] In view of the above, when crystalline plastics or plastics with poor fluidity need to be injection molded using hot runner point gates, and the product being injection molded does not have a large flat surface at the gate entry or does not allow "circle printing", the current hot runner point gate structure cannot solve this problem, and can only be prepared using a complex and costly needle valve hot runner mold. Summary of the invention

[0007] The object of the present invention is to provide a hot nozzle assembly and a hot runner mold, which adopts an open point gate form and can be suitable for hot runner point gate injection molding of crystalline plastics or plastics with poor fluidity, and is not limited by whether there is a plane at the pouring point of the injection molded product or whether a "circle mark" is allowed to form.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] A hot nozzle assembly comprises a hot nozzle body, a pressure cap and a nozzle tip, wherein the pressure cap has an inner cavity and can be sleeved on the outside of the nozzle tip; the pressure cap can be connected to the hot nozzle body to fix the nozzle tip between the two;

[0010] The portion of the inner cavity of the pressure cap not occupied by the nozzle tip forms a gap portion;

[0011] The glue outlet end of the nozzle tip is provided with a branch channel, the branch channel is connected to the outer wall of the glue outlet end of the nozzle tip and is connected to the gap portion, and the portion of the gap portion connected to the branch channel forms a glue outlet passage;

[0012] The glue outlet end of the nozzle tip is also provided with a filling part, and the filling part completely or partially fills the gap part except the glue outlet passage.

[0013] Preferably, the filling portion and the nozzle tip are an integrated structure.

[0014] Preferably, a guide groove is further provided at the glue outlet end of the nozzle tip, the guide groove is connected to the branch channel in a one-to-one correspondence, and the guide groove extends to the tip of the nozzle tip.

[0015] Preferably, the number of the branch channels is 1-6.

[0016] Preferably, the tip of the nozzle protrudes out of the pressure cap.

[0017] To achieve this object, the present invention also adopts the following technical solutions:

[0018] A hot runner mold, comprising an upper mold and a lower mold, wherein the upper mold and the lower mold can form a mold cavity when the upper mold and the lower mold are combined, wherein a hot nozzle assembly for injecting molten plastic into the mold cavity and a heating part for heating the hot nozzle assembly are arranged in the upper mold; the hot nozzle assembly comprises a hot nozzle body, a pressure cap and a nozzle tip, wherein the pressure cap has an inner cavity and can be sleeved on the outside of the nozzle tip; the pressure cap can be connected to the hot nozzle body to fix the nozzle tip between the two;

[0019] The portion of the inner cavity of the pressure cap not occupied by the nozzle tip forms a gap portion;

[0020] The glue outlet end of the nozzle tip is provided with a branch channel, the branch channel is connected to the outer wall of the glue outlet end of the nozzle tip and is connected to the gap portion, and the portion of the gap portion connected to the branch channel forms a glue outlet passage;

[0021] The glue outlet end of the nozzle tip is also provided with a filling portion, and the filling portion completely or partially fills the gap portion except the glue outlet passage.

[0022] Preferably, the filling portion and the nozzle tip are an integrated structure.

[0023] Preferably, a guide groove is further provided at the glue outlet end of the nozzle tip, the guide groove is connected to the branch channel in a one-to-one correspondence, and the guide groove extends to the tip of the nozzle tip.

[0024] Preferably, the number of the branch channels is 1-6.

[0025] Preferably, the tip of the nozzle protrudes out of the pressure cap.

[0026] Beneficial effects of the present invention:

[0027] The hot nozzle assembly provided in the present application has a filling portion that can solidly fill the gap portion during the injection molding operation except for the glue outlet passage portion, so that the portion can transfer the heat of the nozzle tip to the molten plastic flowing out of the branch channel, so that the molten plastic is kept at a high temperature, thereby being suitable for hot runner injection molding operations of crystalline plastics or plastics with poor fluidity. Furthermore, since the hot nozzle assembly in this embodiment does not need to adopt a gate sleeve for thermal insulation, no "print ring" will be formed on the surface of the molded product produced, so that the hot nozzle assembly and the hot runner mold equipped with the hot nozzle assembly have a wider range of production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of the hot nozzle assembly of a traditional open point gate hot runner mold with a gate sleeve;

[0029] Figure 2 It is a schematic diagram of the structure of the hot nozzle assembly of a traditional open point gate hot runner mold without a sprue sleeve;

[0030] Figure 3 is a schematic structural diagram of a hot runner mold in an embodiment of the present application;

[0031] Figure 4 is a partial enlarged view of the hot nozzle assembly in the embodiment of the present application;

[0032] Figure 5 It is a schematic diagram of the structure of the mouth tip in the embodiment of the present application.

[0033] In the figure:

[0034] 100, upper mold; 200, hot nozzle assembly; 300, product;

[0035] 1. Hot nozzle body; 11. First flow channel; 2. Pressing cap; 21. Gap portion; 3. Nozzle tip; 31. Second flow channel; 32. Branch flow channel; 33. Filling portion; 34. Guide groove; 4. Gate sleeve. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0037] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0040] See also Figures 3 to 5 The present embodiment provides a hot runner mold, which includes an upper mold 100 and a lower mold. When the upper mold 100 and the lower mold are combined, a cavity can be formed. A hot nozzle assembly for injecting molten plastic into the cavity and a heating part for heating the hot nozzle assembly are provided in the upper mold 100.

[0041] The hot nozzle assembly includes a hot nozzle body 1, a pressure cap 2 and a nozzle tip 3. The pressure cap 2 has an inner cavity and can be sleeved on the outside of the nozzle tip 3. The pressure cap 2 can be connected to the hot nozzle body 1 to fix the nozzle tip 3 therebetween.

[0042] Specifically, the hot nozzle body 1 is provided with a first flow channel 11 connected to the glue outlet of the upstream manifold, and the end of the first flow channel 11 is provided with a plug-in slot, and the inner wall of the plug-in slot is provided with an internal thread. The nozzle tip 3 is provided with a second flow channel 31, and the glue inlet end of the nozzle tip 3 can be plugged into the plug-in slot of the hot nozzle body 1. The pressure cap 2 has an external thread adapted to the internal thread provided on the inner wall of the plug-in slot. When the hot nozzle body 1 and the pressure cap 2 are screwed and assembled, the pressure cap 2 presses the nozzle tip 3 tightly against the plug-in slot of the hot nozzle body 1, and connects the first flow channel 11 and the second flow channel 31, so that the molten plastic flowing out of the manifold can flow out of the nozzle tip 3 through the first flow channel 11 and the second flow channel 31, and then flow to the mold cavity. At the same time, the heating part heats the hot nozzle body 1, and the hot nozzle body 1 conducts heat to the nozzle tip 3, so that the molten plastic flowing through the hot nozzle body 1 and the nozzle tip 3 is kept at a high temperature.

[0043] The part of the inner cavity of the pressure cap 2 not occupied by the nozzle tip 3 forms a gap portion 21. The glue outlet end of the nozzle tip 3 is provided with a diverter 32, which is connected to the outer wall of the glue outlet end of the nozzle tip 3 and is connected to the gap portion 21, and the part where the gap portion 21 is connected to the diverter 32 forms a glue outlet passage.

[0044] Please refer to Figure 2 and Figure 4 , and please refer first to Figure 2 In the conventional open dispensing port hot runner mold, the inner cavity of the pressure cap 2 not occupied by the nozzle tip 3 also forms a gap 21, which is formed into a ring-shaped flow chamber for the molten plastic to flow. After the injection molding operation begins, the molten plastic flowing out of the branch channel 32 of the nozzle tip 3 will fill the gap 21. After the gap 21 is substantially filled, the glue outlet passage portion of the gap 21 will form a continuous molten plastic flow state, and after the gap 21 is filled with molten plastic except for the glue outlet passage portion, the molten plastic in this portion will generally remain in a relatively stable retention state, that is, the retention portion does not actually participate in the circulation transfer of the molten plastic, and, based on the poor thermal conductivity of plastic, the molten plastic in the retention portion will also affect the heat transfer from the nozzle tip 3 to the molten plastic flowing out of the branch channel 32.

[0045] In this embodiment, if Figure 4 As shown, a filling portion 33 is provided at the glue outlet end of the nozzle tip 3, and the filling portion 33 completely or partially fills the gap portion 21 except for the glue outlet passage.

[0046] By means of the above structure, the filling portion 33 can solidly fill the gap portion 21 except the glue outlet passage portion during the injection molding operation, so that this portion can transfer the heat of the nozzle tip 3 to the molten plastic flowing out of the branch channel 32, so that the molten plastic is kept at a high temperature state, thereby being suitable for hot runner injection molding operations of crystalline plastics or plastics with poor fluidity. Based on this, the hot nozzle assembly in this embodiment does not need to adopt a gate sleeve for insulation and heat preservation, and no "print ring" will be formed on the surface of the molded product produced, so that the hot nozzle assembly and the hot runner mold equipped with the hot nozzle assembly have a wider range of production applications.

[0047] Specifically, if Figure 4 and Figure 5 As shown, when the hot nozzle body 1 and the pressure cap 2 are screwed and assembled, the tip of the nozzle tip 3 extends out of the pressure cap 2, so that the gate formed at the tip of the nozzle tip 3 of the hot nozzle assembly is point-shaped, that is, the structural form of the gate sleeve is avoided, so that the surface of the molded product produced by the hot nozzle assembly will not form a "print circle".

[0048] Preferably, the filling portion 33 is an integrated structure with the nozzle tip 3. That is, during the production of the nozzle tip 3, the filling portion 33 structure can be directly formed on the nozzle tip 3, that is, the filling portion 33 can be understood as a part of the nozzle tip 3.

[0049] In order to ensure that the crystalline plastic or the plastic with poor fluidity can smoothly flow out of the nozzle tip 3 during the hot runner injection molding operation using the crystalline plastic or the plastic with poor fluidity as the injection medium, the nozzle tip 3 may also be provided with a guide groove 34 at the plastic outlet end, the guide groove 34 is connected with the branch channel 32 in a one-to-one correspondence, and the guide groove 34 extends to the tip of the nozzle tip 3. Thus, the molten plastic flowing out of the branch channel 32 is guided to the tip of the nozzle tip 3 through the guide groove 34, so as to smoothly flow into the mold cavity.

[0050] Specifically, the guide groove 34 is formed by the inward concave setting of the glue outlet end of the nozzle tip 3 and generally extends along the axial direction of the nozzle tip 3, so that the molten plastic can be generally kept surrounded by the solid part of the nozzle tip 3, and then continuously heated and maintained in a high-temperature molten state.

[0051] According to the requirements of specific application scenarios, the number of runners 32 can be 1-6 to meet most hot runner injection scenarios. Of course, in other optional embodiments, the number of runners 32 can also be other numbers, which is not specifically limited here.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A hot nozzle assembly, comprising a hot nozzle body (1), a pressure cap (2) and a nozzle tip (3), wherein the pressure cap (2) has an inner cavity and can be sleeved on the outside of the nozzle tip (3); the pressure cap (2) can be connected to the hot nozzle body (1) to fix the nozzle tip (3) therebetween; a portion of the inner cavity of the pressure cap (2) not occupied by the nozzle tip (3) forms a gap portion (21); a flow channel (32) is provided at a glue outlet end of the nozzle tip (3), the flow channel (32) is connected to an outer wall of the glue outlet end of the nozzle tip (3) and is connected to the gap portion (21), and a portion of the gap portion (21) connected to the flow channel (32) forms a glue outlet passage; Features: The glue outlet end of the nozzle tip (3) is also provided with a filling portion (33), and the filling portion (33) completely or partially fills the gap portion (21) except for the glue outlet passage; The filling portion (33) and the nozzle tip (3) are an integrated structure; The glue outlet end of the nozzle tip (3) is also provided with a guide groove (34), the guide groove (34) is connected to the branch flow channel (32) in a one-to-one correspondence, and the guide groove (34) extends to the tip of the nozzle tip (3).

2. The hot nozzle assembly according to claim 1, characterized in that: The number of the branch channels (32) is 1-6.

3. The hot nozzle assembly according to any one of claims 1 to 2, characterized in that: The tip of the mouth tip (3) protrudes from the pressing cap (2).

4. A hot runner mold, comprising an upper mold (100) and a lower mold, wherein the upper mold (100) and the lower mold are capable of forming a cavity when they are combined, wherein a hot nozzle assembly for injecting molten plastic into the cavity and a heating unit for heating the hot nozzle assembly are arranged in the upper mold (100); the hot nozzle assembly comprises a hot nozzle body (1), a pressure cap (2) and a nozzle tip (3); the pressure cap (2) has an inner cavity and can be sleeved on the outside of the nozzle tip (3); the pressure cap (2) The nozzle body (1) can be connected to the nozzle body (1) so as to fix the nozzle tip (3) therebetween; the portion of the inner cavity of the pressure cap (2) not occupied by the nozzle tip (3) forms a gap portion (21); the nozzle tip (3) is provided with a flow channel (32) at the glue outlet end, the flow channel (32) is connected to the outer wall of the glue outlet end of the nozzle tip (3) and is connected to the gap portion (21); the portion of the gap portion (21) connected to the flow channel (32) forms a glue outlet passage; Features: The glue outlet end of the nozzle tip (3) is also provided with a filling portion (33), and the filling portion (33) completely or partially fills the gap portion (21) except for the glue outlet passage; The filling portion (33) and the nozzle tip (3) are an integrated structure; The glue outlet end of the nozzle tip (3) is also provided with a guide groove (34), the guide groove (34) is connected to the branch flow channel (32) in a one-to-one correspondence, and the guide groove (34) extends to the tip of the nozzle tip (3).

5. The hot runner mold according to claim 4, characterized in that: The number of the branch channels (32) is 1-6.

6. The hot runner mold according to any one of claims 4 to 5, characterized in that: The tip of the mouth tip (3) protrudes from the pressing cap (2).

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