CN110722746A - Hot nozzle assembly and hot runner system - Google Patents

Abstract

The invention discloses a hot nozzle assembly and a hot runner system. The hot nozzle assembly includes a hot nozzle extending along a longitudinal axis, a valve needle, and a tip device partially located inside the hot nozzle. The hot nozzle defines a first nozzle. a flow channel, the tip device defines a second flow channel in communication with the first flow channel and a gate in communication with the second flow channel, the valve needle is movably disposed in the first flow channel along a longitudinal axis and the second runner to open or close the gate, wherein the nozzle tip device includes an upper nozzle tip contacting the hot nozzle and a lower nozzle tip defining the gate, the lower nozzle tip having a hardness greater than The hardness of the upper tip and the thermal conductivity of the lower tip are smaller than the thermal conductivity of the upper tip. The invention makes the tip device not only ensure the thermal conductivity, but also is more wear-resistant and less deformable.

Description

Hot Nozzle Assembly and Hot Runner System

technical field

The invention relates to the field of hot runner moulds, in particular to a hot nozzle assembly and a hot runner system.

Background technique

At present, the injection molds commonly used in the injection molding industry are hot runner injection molds. Compared with ordinary molds, the quality of plastic products injected through the hot runner system is higher, and the hot runner system has the advantages of saving raw materials, improving production efficiency, and high degree of automation.

The hot nozzle assembly usually includes a hot nozzle, a nozzle tip set in the hot nozzle and a valve needle. The valve needle can be driven to reciprocate in the flow channel formed by the hot nozzle and the nozzle tip, thereby opening or closing the gate formed on the nozzle tip for injection. Glue or stop injection, the valve needle will hit the tip of the nozzle during the movement of the valve. The tip of the nozzle is usually made of a material with good thermal conductivity to keep the molten material at a certain temperature, thereby ensuring the fluidity of the molten material. However, due to the material with good thermal conductivity, the hardness is low, it is not resistant to wear, and it is easy to deform.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a hot nozzle assembly and a hot runner system, so that the nozzle tip device can not only ensure thermal conductivity, but also be more wear-resistant and not easily deformed.

In order to achieve one of the above objectives of the invention, an embodiment of the present invention provides a hot nozzle assembly, the hot nozzle assembly includes a hot nozzle extending along a longitudinal axis, a valve needle, and a tip device partially located inside the hot nozzle, so The hot nozzle defines a first flow channel, the tip device defines a second flow channel in communication with the first flow channel and a gate in communication with the second flow channel, and the valve needle is movable along the longitudinal axis. provided in the first runner and the second runner to open or close the gate, wherein,

The nozzle tip device includes an upper nozzle tip in contact with the hot nozzle and a lower nozzle tip defining the gate, the hardness of the lower nozzle tip is greater than that of the upper nozzle tip, and the thermal conductivity of the lower nozzle tip is less than The thermal conductivity of the upper tip.

As a further improvement of an embodiment of the present invention, the mouth tip device further includes an outer mouth tip, a part of the outer mouth tip covers a part of the periphery of the upper mouth tip, and a part of the outer mouth tip covers at least a part of the lower mouth tip Part of the periphery, the thermal conductivity of the outer tip is greater than the thermal conductivity of the lower tip.

As a further improvement of an embodiment of the present invention, in the circumferential direction, part of the outer nozzle tip is located between the hot nozzle and the upper nozzle tip, and part of the outer nozzle tip is located between the hot nozzle and the lower nozzle tip .

As a further improvement of an embodiment of the present invention, in the extending direction of the longitudinal axis, the upper nozzle tip is in contact with the hot nozzle, the lower nozzle tip is in contact with the upper nozzle tip, and the outer nozzle tip is in contact with the hot nozzle. Both the upper tip and the lower tip are in contact with each other, and the outer tip is fixed relative to the hot nozzle.

As a further improvement of an embodiment of the present invention, the hot nozzle assembly further includes a pressure cap that is fixedly connected to the inner side of the hot nozzle through threads, and in the extension direction of the longitudinal axis, the pressure cap is connected to the pressure cap. The outer nozzle tips are abutted to fix the nozzle tip device on the inner side of the hot nozzle.

As a further improvement of an embodiment of the present invention, the end of the lower mouth tip protrudes from the end of the outer mouth tip.

As a further improvement of an embodiment of the present invention, the material of the lower tip is tungsten steel.

As a further improvement of an embodiment of the present invention, the hot nozzle assembly includes a heat insulating sleeve covering the outer periphery of the distal end of the lower nozzle tip and the outer periphery of the distal end of the outer nozzle tip, and the thermal conductivity of the lower nozzle tip and the The thermal conductivity of the outer tip is greater than the thermal conductivity of the heat insulating sleeve.

In order to achieve one of the above objects of the invention, an embodiment of the present invention further provides a hot runner system, the hot runner system includes a hot nozzle assembly for pouring molten plastic, the hot nozzle assembly includes a A hot nozzle, a valve needle, and a nozzle tip device partially located inside the hot nozzle, the hot runner system further includes a driving unit for driving the valve needle to reciprocate along the longitudinal axis, the hot nozzle defines a first flow channel, so The tip device defines a second flow channel in communication with the first flow channel and a gate in communication with the second flow channel, and the valve needle can be drivably moved along the inner edge of the first flow channel and the second flow channel. The extension of the longitudinal axis is moved to open or close the gate, wherein,

The nozzle tip device includes an upper nozzle tip in contact with the hot nozzle and a lower nozzle tip defining the gate, the hardness of the lower nozzle tip is greater than that of the upper nozzle tip, and the thermal conductivity of the lower nozzle tip is less than The thermal conductivity of the upper tip.

As a further improvement of an embodiment of the present invention, the mouth tip device further includes an outer mouth tip, a part of the outer mouth tip covers a part of the periphery of the upper mouth tip, and a part of the outer mouth tip covers at least a part of the lower mouth tip Part of the periphery, the thermal conductivity of the outer tip is greater than the thermal conductivity of the lower tip.

Compared with the prior art, the beneficial effect of the present invention is that: since the mouth tip device is provided with two parts, the upper mouth tip and the lower mouth tip, the hardness of the lower mouth tip is greater than that of the upper mouth tip, and the thermal conductivity of the lower mouth tip is higher than that of the upper mouth tip. less than the thermal conductivity of the upper tip. Therefore, the upper nozzle tip conducts heat transfer, which ensures the temperature of the molten material. When the valve needle moves downward, it hits the lower nozzle tip, and the lower nozzle tip has a higher hardness, is more wear-resistant and is not easily deformed. To sum up, the hot nozzle assembly provided by the present invention not only ensures the thermal conductivity of the nozzle tip device, but also is more wear-resistant and less deformable.

Description of drawings

FIG. 1 is a schematic diagram of a longitudinal cross-sectional structure of a hot nozzle assembly in a specific embodiment of the present invention;

FIG. 2 is a schematic view of the longitudinal cross-sectional structure of the hot nozzle assembly in the specific embodiment of the present invention, and the valve needle is removed at this time;

FIG. 3 is a partial enlarged schematic view of the position A in FIG. 2 .

Detailed ways

The present invention will be described in detail below with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and structural, method, or functional changes made by those skilled in the art according to these embodiments are all included in the protection scope of the present invention.

In various figures of the present application, some dimensions of structures or parts are exaggerated relative to other structures or parts for convenience of illustration, and thus, are only used to illustrate the basic structure of the subject matter of the present application.

In the description of specific embodiments of the present invention, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner" The orientation or positional relationship indicated by ” and “outer” is based on the orientation or positional relationship shown in the accompanying drawings, usually with reference to the normal installation state of the hot nozzle assembly, rather than indicating that the indicated position or component must have a specific position.

As shown in Figure 1, Figure 2 and Figure 3, a preferred embodiment of the hot nozzle assembly of the present invention, an embodiment of the present invention provides a hot runner system, the hot runner system includes a hot nozzle assembly, a temperature control box and at least The hot runner formed in the hot nozzle assembly, by means of heating and temperature control of the injection material, pours the molten plastic into the cavity of the mold through the hot nozzle assembly in turn to avoid the formation of congealing in the pouring system.

Specifically, the hot nozzle assembly is used for pouring molten plastic. The hot nozzle assembly includes a hot nozzle 12 extending along the longitudinal axis 24, a valve needle 14, and a tip device 16 partially located inside the hot nozzle 12. The hot runner system also includes a drive A drive unit (not shown) for the reciprocating movement of the valve needle 14 along the longitudinal axis 24, the hot nozzle 12 and the nozzle tip device 16 are both arranged as hollow structures, the hot nozzle 12 defines the first flow channel 18, and the nozzle tip device 16 defines the first flow channel. 18 communicated with the second flow channel 20 and the gate 22 communicated with the second flow channel 20, the valve needle 14 can be driven to move in the extension direction of the longitudinal axis 24 in the first flow channel 18 and the second flow channel 20 to open or close the gate 22.

In this embodiment, the hot nozzle assembly has a central axis. In order to clearly express the position and direction described in this application, generally refer to the upstream and downstream of the hot runner in the hot nozzle assembly, and the direction from the upstream of the hot runner to the downstream along the central axis Defined as "down", otherwise defined as "up". The injection molding material first enters the first runner 18 defined by the hot nozzle 12 , then flows downward into the second runner 20 , and finally flows out from the gate 22 and is injected into the cavity of the mold for casting. When the pouring is stopped, the valve needle 14 is driven to move downward to close the gate 22 . In this preferred embodiment, the gate 22 is disposed coaxially with the first flow channel 18 and the second flow channel 20 . Of course, the extension axis of the gate 22 can also be set to form a certain angle with the extension axes of the first runner 18 and the second runner 20. In this case, the gate 22 can be set to one or two or two or more.

Further, the tip device 16 includes an upper tip 26 in contact with the hot nozzle 12 and a lower tip 28 defining the gate 22. The hardness of the lower tip 28 is greater than that of the upper tip 26, and the thermal conductivity of the lower tip 28 is smaller than that of the upper tip 28. Thermal conductivity of the tip 26 . The upper nozzle tip 26 defines part of the second runner 20 , and the lower nozzle tip 28 defines part of the second runner 20 . When the molten injection molding material flows out of the first runner 18 , it first enters the interior of the upper nozzle tip 26 , and then flows into the lower nozzle tip. 28, and finally flows out through gate 22.

In this preferred embodiment, since the mouth tip device 16 is provided with two parts, the upper mouth tip 26 and the lower mouth tip 28 , the hardness of the lower mouth tip 28 is greater than that of the upper mouth tip 26 , and the thermal conductivity of the lower mouth tip 28 is smaller than that of the upper mouth tip 26 . Therefore, the upper tip 26 conducts heat transfer to ensure the temperature of the molten material. When the valve needle 14 moves downward, it strikes the lower tip 28 , and the lower tip 28 has a higher hardness, is more wear-resistant and is not easily deformed. To sum up, the hot nozzle assembly provided by the present invention not only ensures the thermal conductivity of the nozzle tip device 16, but also is more wear-resistant and less deformable.

In order to further improve the heat transfer of the nozzle tip device 16, the melting temperature of the injection molding material is more ensured, so that the fluidity of the injection molding material is better. The mouth tip device 16 further includes an outer mouth tip 30 , a part of the outer mouth tip 30 covers part of the periphery of the upper mouth tip 26 , and part of the outer mouth tip 30 covers at least part of the outer periphery of the lower mouth tip 28 , and the thermal conductivity of the outer mouth tip 30 is greater than that of the lower mouth tip 28 thermal conductivity. In the circumferential direction, a part of the inner side of the outer tip 30 is abutted with a part of the outer side of the upper tip 26 , and a part of the inner side of the outer tip 30 is abutted with at least a part of the outer side of the lower tip 28 , so that the outer tip 30 transfers the heat of the hot nozzle 12 to the upper tip 26 and lower tip 28, and finally to the injection molding material.

Additionally, in the circumferential direction, a portion of the outer tip 30 is located between the hot tip 12 and the upper tip 26 , and a portion of the outer tip 30 is positioned between the hot tip 12 and the lower tip 28 .

In the extending direction of the longitudinal axis 24, the upper tip 26 abuts the hot nozzle 12, the lower tip 28 abuts the upper tip 26, and the outer tip 30 abuts both the upper tip 26 and the lower tip 28, and the outer tip 30 abuts against the upper tip 26 and the lower tip 28. The hot nozzle 12 is fixed. Specifically, the upper tip 26 includes a lower end abutting against the lower tip 28 and an upper end protruding from the lower end in the circumferential direction, and the outer tip 30 abuts the upper end. The outer tip 30 also has a first inner boss 32 extending inwardly, and the first inner boss 32 also abuts against the lower end. Further, the outer tip 30 also has a second inner boss 34 extending inward, the lower tip 28 has a first outer boss 36 extending outward, and the second inner boss 34 abuts against the first outer boss 36 , The movement of the lower tip 28 is thereby restricted in the axial direction.

In this preferred embodiment, the lower nozzle tip 28 is made of hard tungsten steel. Of course, the lower nozzle tip 28 can also be made of other hard materials. The upper tip 26 and the outer tip 30 are made of copper with better thermal conductivity. Of course, the upper tip 26 and the outer tip 30 can also be made of other materials with better thermal conductivity. In addition, the materials of the upper tip 26 and the outer tip 30 can be designed to be the same, and the materials of the upper tip 26 and the outer tip 30 can also be designed to be different.

The hot nozzle assembly also includes a pressure cap 38 that is fixedly connected to the hot nozzle 12. In this preferred embodiment, the pressure cap 38 is fixedly connected to the inner side of the hot nozzle 12 through threads, and in the extension direction of the longitudinal axis 24, the pressure cap 38 is connected to the inner side of the hot nozzle 12. The outer nozzle tips 30 are abutted to fix the nozzle tip device 16 on the inner side of the hot nozzle 12 . Specifically, in the circumferential direction, the outer tip 30 has a second outer boss 40 extending outward, the pressure cap 38 has a third inner boss 42 extending inward, the third inner boss 42 and the second outer boss 40 abut against each other, thereby restricting the movement of the outer tip 30 in the axial direction. The pressure cap 38 is usually made of W302 abrasive steel. Of course, the pressure cap 38 can also be made of other materials. The pressure cap 38 is used to fix the nozzle tip device 16 to the hot nozzle 12 .

Additionally, the distal end of the lower tip 28 protrudes from the tip of the outer tip 30 . And the end of the lower mouth tip 28 and the end of the outer mouth tip 30 are both set as cones with a certain angle to the longitudinal axis 24. The angle of inclination between the tip and the longitudinal axis 24 is the same. In the direction of extension of the longitudinal axis 24 , the ends of the lower tip 28 and the tip of the outer tip 30 protrude beyond the pressure cap 38 .

The hot nozzle assembly includes an insulating sleeve 44 covering the outer periphery of the end of the lower tip 28 and the outer periphery of the outer tip 30. The thermal conductivity of the lower tip 28 and the thermal conductivity of the outer tip 30 are both greater than the thermal conductivity of the insulating sleeve 44. Rate. The heat insulating sleeve 44 is usually a plastic piece and is pressed against the outer ends of the lower tip 28 and the outer tip 30 . Insulation jacket 44 serves to reduce heat transfer to the mold.

It should be understood that although this specification is described in terms of embodiments, not every embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole, and each The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

The series of detailed descriptions listed above are only specific descriptions for the feasible embodiments of the present invention, and they are not used to limit the protection scope of the present invention. Changes should all be included within the protection scope of the present invention.

Claims (10)

1. A hot nozzle assembly comprising a hot nozzle extending along a longitudinal axis, a valve pin, and a tip device located partially inside the hot nozzle, the hot nozzle defining a first flow passage, the tip device defining a second flow passage in communication with the first flow passage and a gate in communication with the second flow passage, the valve pin being movably disposed within the first and second flow passages along the longitudinal axis to open or close the gate,

the tip device includes an upper tip in contact with the hot nozzle and a lower tip defining the gate, the lower tip having a hardness greater than a hardness of the upper tip and a thermal conductivity less than a thermal conductivity of the upper tip.

2. A hot nozzle assembly as claimed in claim 1, wherein said tip means further comprises an outer tip, part of said outer tip being wrapped around part of the periphery of said upper tip and part of said outer tip being wrapped around at least part of the periphery of said lower tip, said outer tip having a thermal conductivity greater than the thermal conductivity of said lower tip.

3. A hot nozzle assembly according to claim 2, wherein, in the circumferential direction, a portion of the outer tip is located between the hot nozzle and the upper tip, and a portion of the outer tip is located between the hot nozzle and the lower tip.

4. A hot nozzle assembly according to claim 2, wherein in the direction of extension of the longitudinal axis the upper tip abuts the hot nozzle, the lower tip abuts the upper tip, and the outer tip abuts both the upper tip and the lower tip, the outer tip being stationary relative to the hot nozzle.

5. A hot nozzle assembly according to claim 4, further comprising a pressing cap fixedly attached to the inside of the hot nozzle by threads, and wherein the pressing cap abuts the outer nozzle tip in the direction of extension of the longitudinal axis to secure the nozzle tip device to the inside of the hot nozzle.

6. The hot nozzle assembly of claim 2, wherein a distal end of the lower tip protrudes beyond a distal end of the outer tip.

7. The hot nozzle assembly of claim 1, wherein the lower nozzle tip is tungsten steel.

8. A hot nozzle assembly as claimed in claim 1, including an insulating sleeve covering a distal periphery of said lower tip and a distal periphery of said outer tip, said lower tip and said outer tip each having a thermal conductivity greater than a thermal conductivity of said insulating sleeve.

9. A hot-runner system including a hot-nozzle assembly for pouring a plastic in a molten state, the hot-nozzle assembly including a hot nozzle extending along a longitudinal axis, a valve pin, and a tip device located partially inside the hot nozzle, the hot-runner system further including a drive unit for driving the valve pin to reciprocate along the longitudinal axis, the hot nozzle defining a first flow passage, the tip device defining a second flow passage communicating with the first flow passage and a gate communicating with the second flow passage, the valve pin being drivingly movable within the first and second flow passages in a direction extending along the longitudinal axis to open or close the gate,

the tip device includes an upper tip in contact with the hot nozzle and a lower tip defining the gate, the lower tip having a hardness greater than a hardness of the upper tip and a thermal conductivity less than a thermal conductivity of the upper tip.

10. The hot-runner system of claim 9, wherein the tip arrangement further comprises an outer tip, a portion of the outer tip being wrapped around a portion of an outer periphery of the upper tip and a portion of the outer tip being wrapped around at least a portion of an outer periphery of the lower tip, the outer tip having a thermal conductivity greater than a thermal conductivity of the lower tip.

Images