Hot runner system, hot nozzle assembly, nozzle core structure and processing method thereof

Abstract

The invention provides a hot runner system, a hot nozzle assembly, a nozzle core structure and a processing method thereof, the nozzle core structure comprises a nozzle tip body, a steel insert, a metal covering part and a nozzle tip pressing cap, a nozzle tip runner is arranged in the nozzle tip body, and the nozzle tip end part of the nozzle tip body is provided with a first assembly position and a nozzle tip via hole; the steel insert is embedded into the first assembly position in an interference assembly manner, and the steel insert is positioned around the nozzle tip via hole; the metal covering part covers the joint of the steel insert and the nozzle tip body; the nozzle tip pressing cap is internally provided with a second assembly position, the nozzle tip body is inserted into the second assembly position in an interference assembly mode, the nozzle tip body and the nozzle tip pressing cap are coaxially arranged, and a pressing cap glue sealing position is formed at the outer side end, close to the nozzle tip via hole, of the nozzle tip pressing cap. The nozzle core structure can solve the problem that a nozzle core structure in the prior art cannot give consideration to heat conductivity and wear resistance at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of hot runner injection molding, and in particular to a hot runner system, a hot nozzle assembly, a nozzle core structure and a processing method thereof. Background Art

[0002] Injection molds are tools for producing plastic products, and they are also tools for giving plastic products a complete structure and precise dimensions. After the injection mold injects the resin material into the metal model, a product with a certain shape is obtained; although the structure of the mold may vary due to the different types and properties of plastics, the shape and structure of plastic products, and the type of injection machine, the basic structure is the same. In order to make the size of the product more accurate, precision injection molds are often used to make products.

[0003] In the needle valve hot runner system, the valve needle is driven by the valve needle drive system, the valve needle moves in the hot nozzle assembly, and the end of the valve needle cooperates with the gate to open and close the gate. The main function of the nozzle core structure is to control the gate heat and help the valve needle to guide before entering the gate.

[0004] In the prior art, the gate heat is generally controlled by changing the thermal conductivity of the material of the nozzle core structure to adapt to the characteristics of different injection molding materials. The nozzle tip is generally made of copper or steel. Copper has better thermal conductivity while steel has poorer thermal conductivity. Usually, when the valve needle is open, the valve needle and the gate are not concentric. When the valve needle is closed, it is necessary to guide the nozzle tip through the hole to make the valve needle and the gate concentric to reduce the risk of collision between the valve needle and the gate. If there is no nozzle tip hole to guide, the gate is easily worn by the valve needle. Therefore, it is urgent to develop a nozzle core structure that has both good thermal conductivity and good wear resistance. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a hot runner system, a hot nozzle assembly, a nozzle core structure and a processing method thereof to solve the problem that the nozzle core structure in the prior art cannot take into account both thermal conductivity and wear resistance.

[0006] To achieve the above object, the present invention provides a nozzle core structure, the nozzle core structure comprising:

[0007] A nozzle tip body, wherein a nozzle tip flow channel is arranged in the nozzle tip body, and a nozzle tip portion of the nozzle tip body has a first assembly position and a nozzle tip through hole;

[0008] A steel insert, wherein the steel insert is embedded in the first assembly position by interference fitting, and the nozzle tip flow channel runs through the nozzle tip body and the steel insert, and the steel insert is located around the nozzle tip through hole;

[0009] A metal covering portion is disposed on the end surface of the nozzle tip, and the metal covering portion covers the junction between the steel insert and the nozzle tip body; and

[0010] A nozzle tip pressure cap is provided with a second assembly position, the nozzle tip body is inserted into the second assembly position by interference fitting, and the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and a pressure cap sealing position is formed at the outer end of the nozzle tip pressure cap adjacent to the nozzle tip through hole.

[0011] As an optional technical solution, the diameter of the nozzle tip through hole is 3.8 mm, and the tolerance of the nozzle tip through hole is 0-0.01 mm; the diameter of the pressure cap sealing position is 14.99 mm, and the tolerance of the pressure cap sealing position is 0-0.005 mm.

[0012] As an optional technical solution, the metal covering portion is a three-dimensional printed layer.

[0013] As an optional technical solution, the nozzle tip via hole and the pressure cap sealing position are formed by the same processing step.

[0014] As an optional technical solution, the nozzle core structure is made of copper.

[0015] The present invention also provides a hot nozzle assembly, the hot nozzle assembly comprising:

[0016] A hot nozzle body, wherein a hot nozzle flow channel and a nozzle tip mounting groove are arranged in the hot nozzle body, and a gate is arranged at the end of the hot nozzle body;

[0017] The nozzle core structure as described above is installed in the nozzle tip installation groove, the nozzle tip pressure cap is arranged between the hot nozzle body and the nozzle tip body, the hot nozzle body, the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and the hot nozzle flow channel and the nozzle tip flow channel match each other and flow and connect the gate; and

[0018] A valve needle passes through the hot nozzle flow channel and the nozzle tip flow channel and is positioned through the nozzle tip through hole to control the opening and closing of the gate.

[0019] As an optional technical solution, it also includes a sealing sleeve, which is sleeved on the first end of the hot nozzle body adjacent to the nozzle tip through hole, and the sealing sleeve is provided with the gate, which is connected to the nozzle tip through hole.

[0020] As an optional technical solution, a heater is also included, which is fixedly arranged on the periphery of the hot nozzle body.

[0021] The present invention also provides a hot runner system, which includes the hot nozzle assembly as described above.

[0022] The present invention provides a method for processing the nozzle core structure as described above, and the method for processing the nozzle core structure comprises the following steps:

[0023] S1, forming a nozzle tip body blank, wherein the nozzle tip portion of the nozzle tip body blank has a first assembly position; and forming a steel insert matched with the first assembly position;

[0024] S2, embedding the steel insert into the first assembly position by interference fitting;

[0025] S3, forming a metal covering portion on the end surface of the nozzle tip to obtain a nozzle tip body semi-finished product, wherein the metal covering portion covers the junction between the steel insert and the first assembly position;

[0026] S4, rough-processing the nozzle tip body semi-finished product and rough-processing to form a nozzle tip pressure cap semi-finished product, wherein the nozzle tip pressure cap semi-finished product has a second assembly position;

[0027] S5, inserting the nozzle tip body semi-finished product obtained by rough machining into the second assembly position by interference fitting to form a nozzle core structure semi-finished product;

[0028] S6, fine-processing the semi-finished nozzle core structure to form a nozzle tip body, a nozzle tip pressure cap, a nozzle tip flow channel, a nozzle tip through hole and a pressure cap sealing position, the nozzle tip flow channel runs through the nozzle tip body and the steel insert, the steel insert is located around the nozzle tip through hole, the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and the pressure cap sealing position is formed at the outer end of the nozzle tip pressure cap adjacent to the nozzle tip through hole.

[0029] Compared with the prior art, the present invention ensures the heat conduction of the nozzle core structure through the optimized processing technology, while improving the strength of the nozzle tip through hole and the concentricity of the nozzle tip through hole, making the nozzle core structure more wear-resistant and reducing the wear of the valve pin on the gate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of a nozzle core structure according to an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a first state of a hot nozzle assembly according to an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a second state of a hot nozzle assembly according to an embodiment of the present invention;

[0034] Figure 4-Figure 9 FIG. 4 is a schematic flow chart of a method for processing a nozzle core structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0036] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0037] See also Figure 1 , Figure 1 Schematic diagram of a nozzle core structure of an embodiment of the present invention. The present invention provides a nozzle core structure, wherein the nozzle core structure 1 comprises a nozzle tip body 2, a steel insert 3, a metal covering part 4 and a nozzle tip pressure cap 5. A nozzle tip flow channel 21 is arranged in the nozzle tip body 2, and a nozzle tip portion 22 of the nozzle tip body 2 has a first assembly position 23 and a nozzle tip through hole 24. The steel insert 3 is embedded in the first assembly position 23 by interference fitting, and the nozzle tip flow channel 21 passes through the nozzle tip body 2 and the steel insert 3, and the steel insert 3 is located around the nozzle tip through hole 24, wherein the steel insert 3 has high hardness. The metal covering part 4 is arranged on the end face 221 of the nozzle tip portion 22, and the metal covering part 4 covers the joint between the steel insert 3 and the nozzle tip body 2. The nozzle tip pressure cap 5 has a second assembly position 51, the nozzle tip body 2 is inserted into the second assembly position 51 by interference fitting, and the nozzle tip body 2 and the nozzle tip pressure cap 5 are coaxially arranged, and the outer end of the nozzle tip pressure cap 5 adjacent to the nozzle tip through hole 24 is formed with a pressure cap sealing position 52. Moreover, the pressure cap sealing position 52 is directly formed on the nozzle tip pressure cap 5, so that less heat can be transferred out, avoiding the loss of heat energy, and ensuring that the heat at the end of the nozzle core structure is sufficient.

[0038] Preferably, the diameter D1 of the nozzle tip through hole 24 is 3.8 mm, and the tolerance of the nozzle tip through hole 24 is 0-0.01 mm; the diameter D2 of the pressure cap sealing position 52 is 14.99 mm, and the tolerance of the pressure cap sealing position 52 is 0-0.005 mm. Moreover, preferably, the nozzle tip through hole 24 and the pressure cap sealing position 52 are formed by the same process, because the nozzle tip through hole 24 and the pressure cap sealing position 52 are processed together, the tolerances of the two can be closer, the size is more accurate, the concentricity can be better guaranteed, and the nozzle tip through hole 24 is conducive to better guiding the valve needle.

[0039] In one embodiment, the metal covering portion 4 is a three-dimensional printed layer. The metal covering portion 4 is provided to prevent the steel insert 3 from falling off. Therefore, after the nozzle tip body 2 and the steel insert 3 are squeezed and fitted, a layer of metal material is printed on the end face 221 of the nozzle tip 22 using 3D printing technology.

[0040] In one embodiment, the nozzle structure is made of copper, for example. Copper has very good thermal conductivity.

[0041] In one embodiment, a guide surface 25 is provided inside the nozzle tip body 2 at least adjacent to the nozzle tip through hole 24, and the guide surface 25 is a curved surface or an inclined surface.

[0042] Also, see Figure 2 and Figure 3 , Figure 2 A schematic diagram of a first state of a hot nozzle assembly according to an embodiment of the present invention; Figure 3 Schematic diagram of the second state of a hot nozzle assembly according to an embodiment of the present invention. The present invention further provides a hot nozzle assembly 6, which includes a hot nozzle body 7, a nozzle core structure 1 as described above, and a valve needle 8. A hot nozzle flow channel 71 and a nozzle tip mounting groove 72 are arranged in the hot nozzle body 7, and a gate 73 is arranged at the end of the hot nozzle body 7. The nozzle core structure 1 is installed in the nozzle tip mounting groove 72, and the nozzle tip pressure cap 5 is arranged between the hot nozzle body 7 and the nozzle tip body 2. The hot nozzle body 7, the nozzle tip body 2 and the nozzle tip pressure cap 5 are coaxially arranged, and the hot nozzle flow channel 71 and the nozzle tip flow channel 21 are matched and flowed with each other and connected to the gate 73. The valve needle 8 passes through the hot nozzle flow channel 71 and the nozzle tip flow channel 21 and is positioned through the nozzle tip through hole 24 to control the opening and closing of the gate 73.

[0043] In one embodiment, the hot nozzle assembly 6 further includes a sealing sleeve 9, which is sleeved on the first end of the hot nozzle body 7 adjacent to the nozzle tip through hole 24, and the sealing sleeve 9 is provided with the gate 73, which is connected to the nozzle tip through hole 24.

[0044] In addition, in one embodiment, the hot nozzle assembly 6 further includes a heater 10, which is fixedly disposed on the periphery of the hot nozzle body 7, and specifically, for example, is fixed to the hot nozzle body 7 using a fixing member. After the molten rubber enters the hot nozzle flow channel 71, the heater 10 generates heat, so that the rubber in the hot nozzle flow channel 71 and the nozzle tip flow channel 21 remains in a molten state, and then the molten rubber passes through the nozzle tip through hole 24 and flows out from the gate 73.

[0045] Please continue to see Figure 2 and Figure 3 When the hot nozzle assembly is in the first state (such as Figure 2 As shown), that is, when the valve needle 8 is opened, the valve needle 8 and the gate 73 are not concentric. When the valve needle 8 is closed, it needs to be guided by the nozzle tip through hole 24 to make the valve needle 8 and the gate 73 concentric, so as to reduce the risk of collision between the valve needle 8 and the gate 73. Figure 3 As shown, the hot nozzle assembly is in the second state. At this time, the valve needle 8 is guided through the nozzle tip through hole 24 to block the gate 73, and the gate 73 is closed.

[0046] That is, in actual operation, the valve needle 8 occupies at most a portion of the nozzle tip through hole 24 and is separated from the gate 73, and the gate 73 is open; while the valve needle 8 penetrates the nozzle tip through hole 24 and blocks the gate 73, and the gate 73 is closed.

[0047] In addition, the present invention also provides a hot runner system, which includes the hot nozzle assembly 6 as described above. The hot runner system mainly consists of the structural design of the nozzle core structure 1 and the hot nozzle body 6, and the injection molding process belongs to the conventional process. The rubber material passes through the injection nozzle, the diverter plate, the hot nozzle body 7, and the nozzle tip body 2 in sequence, and the valve needle 8 moves downward to seal the rubber, and moves upward to complete the entire injection molding process.

[0048] In addition, if Figure 4-Figure 9 As shown, Figure 4-Figure 9 1 is a schematic flow chart of a method for processing a nozzle core structure according to an embodiment of the present invention. The present invention further provides a method for processing the nozzle core structure as described above, and the method for processing the nozzle core structure comprises the following steps:

[0049] S1, forming a nozzle tip body blank 211, wherein the nozzle tip portion of the nozzle tip body blank 211 has a first assembly position 212; and forming a steel insert 31 that matches the first assembly position 212, such as Figure 4 As shown;

[0050] S2, embed the steel insert 31 into the first assembly position 212 by interference fitting, such as Figure 5 As shown;

[0051] S3, forming a metal covering portion 41 on the end surface 213 of the nozzle tip to obtain a semi-finished nozzle tip body. The metal covering portion 41 covers the junction between the steel insert 31 and the first assembly position 212, such as Figure 4 and Figure 5 As shown;

[0052] S4, rough processing the nozzle tip body semi-finished product and rough processing to form a nozzle tip pressure cap semi-finished product, the nozzle tip pressure cap semi-finished product 511 has a second assembly position 512, such as Figure 6 and Figure 7 As shown;

[0053] S5, inserting the semi-finished nozzle tip body obtained by rough machining into the second assembly position 512 by interference fitting to form a semi-finished nozzle core structure, such as Figure 8 As shown;

[0054] S6, fine-processing the semi-finished product of the nozzle core structure to form a nozzle tip body 217, a nozzle tip pressure cap 513, a nozzle tip flow channel 214, a nozzle tip through hole 215 and a pressure cap sealing position 216, so as to obtain the nozzle core structure, wherein the nozzle tip flow channel 214 runs through the nozzle tip body 217 and the steel insert 31, the steel insert 31 is located around the nozzle tip through hole 215, the nozzle tip body 217 and the nozzle tip pressure cap 513 are coaxially arranged, and the pressure cap sealing position 216 is formed at the outer end of the nozzle tip pressure cap 513 adjacent to the nozzle tip through hole 215, as shown in FIG. Fig. 9 shown.

[0055] In summary, the present invention ensures the heat conduction of the nozzle core structure through the optimized processing technology, while improving the strength of the nozzle tip through hole, improving the concentricity of the nozzle tip through hole, making the nozzle core structure more wear-resistant, and reducing the wear of the valve pin on the gate.

[0056] The present invention has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present invention. In addition, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A nozzle core structure, characterized in that: The nozzle core structure comprises: A nozzle tip body, wherein a nozzle tip flow channel is arranged in the nozzle tip body, and a nozzle tip portion of the nozzle tip body has a first assembly position and a nozzle tip through hole; A steel insert, wherein the steel insert is embedded in the first assembly position by interference fitting, and the nozzle tip flow channel runs through the nozzle tip body and the steel insert, and the steel insert is located around the nozzle tip through hole; A metal covering portion is disposed on the end surface of the nozzle tip, and the metal covering portion covers the junction between the steel insert and the nozzle tip body; and A nozzle tip pressure cap is provided with a second assembly position, the nozzle tip body is inserted into the second assembly position by interference fitting, and the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and a pressure cap sealing position is formed at the outer end of the nozzle tip pressure cap adjacent to the nozzle tip through hole.

2. The tip structure according to claim 1, characterized in that: The diameter of the nozzle tip through hole is 3.8 mm, and the tolerance of the nozzle tip through hole is 0-0.01 mm; the diameter of the pressure cap sealing position is 14.99 mm, and the tolerance of the pressure cap sealing position is 0-0.005 mm.

3. The tip structure according to claim 1, characterized in that: The metal covering portion is a three-dimensional printing layer.

4. The tip structure according to claim 1, characterized in that: The nozzle tip through hole and the pressure cap sealing position are formed by the same process.

5. The tip structure according to claim 1, characterized in that: The nozzle core structure is made of copper.

6. A hot nozzle assembly, characterized in that: The hot nozzle assembly comprises: A hot nozzle body, wherein a hot nozzle flow channel and a nozzle tip mounting groove are arranged in the hot nozzle body, and a gate is arranged at the end of the hot nozzle body; The nozzle core structure according to any one of claims 1 to 5, wherein the nozzle core structure is installed in the nozzle tip installation groove, the nozzle tip pressure cap is arranged between the hot nozzle body and the nozzle tip body, the hot nozzle body, the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and the hot nozzle flow channel and the nozzle tip flow channel match each other and flow and connect the gate; and A valve needle passes through the hot nozzle flow channel and the nozzle tip flow channel and is positioned through the nozzle tip through hole to control the opening and closing of the gate.

7. The hot nozzle assembly according to claim 6, characterized in that: It also includes a sealing sleeve, which is sleeved on the first end of the hot nozzle body adjacent to the nozzle tip through hole, and the sealing sleeve is provided with the gate, which is connected to the nozzle tip through hole.

8. The hot nozzle assembly according to claim 6, characterized in that: It also includes a heater which is fixedly arranged on the periphery of the hot nozzle body.

9. A hot runner system, characterized in that: The hot runner system comprises the hot nozzle assembly as claimed in claim 6.

10. A method for processing a core tip structure according to any one of claims 1 to 5, characterized in that: The processing method of the nozzle core structure comprises the following steps: S1, forming a nozzle tip body blank, wherein the nozzle tip portion of the nozzle tip body blank has a first assembly position; and forming a steel insert matched with the first assembly position; S2, embedding the steel insert into the first assembly position by interference fitting; S3, forming a metal covering portion on the end surface of the nozzle tip to obtain a nozzle tip body semi-finished product, wherein the metal covering portion covers the junction between the steel insert and the first assembly position; S4, rough-processing the nozzle tip body semi-finished product and rough-processing to form a nozzle tip pressure cap semi-finished product, wherein the nozzle tip pressure cap semi-finished product has a second assembly position; S5, inserting the nozzle tip body semi-finished product obtained by rough machining into the second assembly position by interference fitting to form a nozzle core structure semi-finished product; S6, fine-processing the semi-finished nozzle core structure to form a nozzle tip body, a nozzle tip pressure cap, a nozzle tip flow channel, a nozzle tip through hole and a pressure cap sealing position, the nozzle tip flow channel runs through the nozzle tip body and the steel insert, the steel insert is located around the nozzle tip through hole, the nozzle tip body and the nozzle tip pressure cap are coaxially arranged, and the pressure cap sealing position is formed at the outer end of the nozzle tip pressure cap adjacent to the nozzle tip through hole.

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