Uniform heating type injection molding nozzle

Abstract

The utility model discloses a uniform heating type injection molding nozzle which comprises a nozzle body and a nozzle tip arranged in the nozzle body, and further comprises a heater arranged on the nozzle body in a sleeving manner, and the heater comprises a heat conduction sleeve and a graphene heating layer wrapped on the heat conduction sleeve; the graphene heating layer is provided with a pair of first contacts which extend in the radial direction of the graphene heating layer and protrude out of a body of the graphene heating layer, and the first contacts abut against second contacts arranged on a pair of wires of an external power source to be used for heating the graphene heating layer. According to the heater, electric connection is achieved in a contact mode, disassembly and assembly are convenient, the heating mode is optimized into a surface heating mode, better heating uniformity is achieved, needed heating power is reduced, and the transverse occupied space is saved through the small wall thickness.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding nozzle devices, in particular to a uniformly heated injection molding nozzle. Background Art

[0002] During the injection molding process, the nozzle and the molten material inside it usually need to be heated to ensure their fluidity. In the existing heating methods, if a copper tube is used as a heater, a heating wire groove needs to be milled on its side wall, and then the heating wire is wound into the heating wire groove, and the heating wire is heated after power is applied. In this method, the heating wire is wrapped to form an integrated structure; in another method, a groove is directly milled on the side wall of the nozzle, and the heating wire is directly embedded in the groove on the side wall of the nozzle, and then heating is achieved after power is applied.

[0003] In the above two commonly used heating methods, on the one hand, the integrated structure is not convenient for replacing the heater, and on the other hand, heating is performed through a heating wire. Even if there is a copper tube for heat conduction, the contact area between the heating wire and the copper tube is limited. Therefore, the above two heating methods are closer to wire heating methods, which may cause uneven heating, and the heating power required to achieve the same heating effect (temperature) is larger, and the heating energy consumption is higher. Utility Model Content

[0004] The purpose of the utility model is to provide a uniformly heated injection molding nozzle, in which the heater is electrically connected through contacts, which is convenient for disassembly and assembly, and the heating form is optimized to a surface heating form, which has better heating uniformity, reduces the required heating power, and saves lateral space through a smaller wall thickness.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a uniformly heated injection molding nozzle, including a nozzle body and a nozzle tip arranged in the nozzle body, and also including a heater sleeved on the nozzle body, the heater including a heat-conducting sleeve and a graphene heating layer wrapped on the heat-conducting sleeve, the graphene heating layer is provided with a pair of first contacts extending along its radial direction and protruding outward from its body, the first contacts are abutted against second contacts on a pair of wires arranged on an external power supply for heating the graphene heating layer.

[0006] As a further optimization, the graphene heating layer includes, from the inside to the outside, an inner insulating thermally conductive coating, a graphene coating and an outer insulating thermally conductive coating that are sequentially abutted against each other, the inner insulating thermally conductive coating is formed on the outer wall of the thermally conductive sleeve, the first contact is connected to the graphene coating, and protrudes outward from the outer insulating thermally conductive coating and does not protrude inward from the inner insulating thermally conductive layer.

[0007] As a further optimization, the first contact is arranged on the side wall of the graphene coating; the first contact and the second contact are made of silver, copper or graphite.

[0008] As a further optimization, the first contact and the second contact are both cylindrical structures, and the two form surface contact.

[0009] As a further optimization, the projection of the second contact is located within the plane of the first contact, which facilitates electrical contact between the two.

[0010] As a further optimization, a flange for nozzle installation is provided at the upper end of the nozzle body, a side through hole is provided on the flange, and the first contact is located within the projection surface of the side through hole on the heater.

[0011] As a further optimization, it also includes an elastic insert, which is fixedly mounted on the wire through a mounting hole thereof, and the second contact is located on one side of the elastic insert. The elastic insert is interference-fitted into the side through hole, and the wire can be positioned so that the second contact is in stable contact with the first contact.

[0012] As a further optimization, a guide surface is provided on one side of the elastic insert close to the second contact point or on the outer side wall of the flange at the side through hole to facilitate installation of the elastic insert in the side through hole.

[0013] As a further optimization, a plurality of elastic pads with heat conduction performance are symmetrically arranged at the bottom end of the inner wall of the heat-conducting sleeve, and the abutment between the elastic pads and the nozzle body can ensure that the heater is installed on the nozzle body more stably.

[0014] As a further optimization, the heat-conducting sleeve is made of steel, and its thickness is 0.2-2 mm, preferably 0.5 mm. Designing it to be thinner can avoid occupying lateral space.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. The graphene heating layer is carried by a heat-conducting sleeve, and the graphene heating layer is heated by contact between a first contact point electrically connected to the graphene heating layer and a second contact point connected to an external power source. The heater has a simple structure and is easy to disassemble for replacement and maintenance;

[0017] 2. The combination of graphene heating layer and heat-conducting sleeve realizes heating of the entire surface of the nozzle. Compared with the conventional heating wire, it has the characteristics of uniform heating and low required heating power;

[0018] 3. The heater can have a smaller wall thickness, saving lateral space, saving mold opening, and realizing the design of small-pitch injection molding products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the utility model.

[0020] Figure 2 It is a schematic diagram of the connection between the heater and the wire of the utility model.

[0021] Figure 3 This is a structural diagram of another embodiment of the heater of the present utility model.

[0022] Figure 4 This is a structural diagram of the utility model in which the wire is installed on the elastic insert. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0024] like Figures 1 to 2 As shown, a uniform heating type injection molding nozzle at least includes a nozzle body 11 and a nozzle tip 12 arranged in the nozzle body 11, and also includes a heater 2 sleeved on the nozzle body 11, the heater 2 includes a heat-conducting sleeve 21, and a graphene heating layer 22 wrapped on the heat-conducting sleeve 21, the heat-conducting sleeve 21 can be made of steel, which has good thermal conductivity and can also be close to the required expansion coefficient of the graphene heating layer 22, so that the adhesion stability of the graphene heating layer 22 thereon can be ensured, and the thickness is preferably 0.5mm, and the thinner design will not take up more space, and the graphene heating layer 22 is provided with a pair of first contacts 211 extending along the radial direction thereof and protruding outward from the body thereof, the first contacts 211 are abutted with second contacts 311 on a pair of wires 31 arranged on an external power supply for heating the graphene heating layer 22, that is, the conductive part 3 is formed by the wire 31 and the second contact 311 at the front end thereof for abutting with the first contact 211 to achieve conductive connection.

[0025] In the present invention, the nozzle body 11 is wrapped by the middle cavity 20 of the heat-conducting sleeve 21, the heat-conducting sleeve 21 capable of heat conduction is wrapped by the graphene heating layer 22, and the graphene heating layer 22 is electrically heated by the conductive connection between the first contact 211 and the second contact 311, and the nozzle body is heated by heat transfer through the heat-conducting sleeve 21. The heater 2 composed of the heat-conducting sleeve 21 and the graphene heating layer 22 can be conveniently installed on the nozzle body 11, and it is connected to the external power supply through the wire 31 in the form of contact connection, so that the overall installation is more convenient, and the whole set of heating and heat preservation structure is easy to disassemble. For example, when the heater 2 needs to be replaced or maintained, it only needs to be pulled out from the nozzle body 11, which improves the convenience and efficiency of disassembly and assembly of the heater 2. Moreover, the graphene heating layer 22 can heat the position where it is located (i.e. the entire annular surface) after being powered on for heating, thereby realizing the surface heating of the nozzle body 11 after heat conduction through the heat-conducting sleeve 21. On the one hand, it can ensure the uniformity of heating, and on the other hand, the optimization from the line heating form to the surface heating form can reduce the heating power by more than 50% under the premise of achieving the same heating effect. In addition, by using a heat-conducting sleeve 21 with a thinner wall thickness, the lateral space occupied by the heater can be reduced. The diameter of the heater 2 is much smaller than that of the existing form, which can save the mold frame, so that the mold point can be smaller, realizing the design of small-pitch injection molding products, reducing the mold size and reducing costs.

[0026] Continue as Figure 2 As shown, the graphene heating layer 22 includes, from the inside to the outside, an inner insulating thermal conductive coating 221, a graphene coating 222 and an outer insulating thermal conductive coating 221′ which are abutted against each other in sequence. The inner insulating thermal conductive coating 221 is formed on the outer wall of the thermal sleeve 21. For the specific forming of the graphene heating layer 22, the inner insulating thermal conductive coating 221 can be first sprayed (or printed) on the outer wall of the thermal sleeve 21. The specific material can be a high-temperature resistant insulating material with thermal conductivity such as ceramic glaze. After forming, graphene material is sprayed (or printed) on the inner insulating thermal conductive coating 221 to form a graphene coating 222. After forming, the same material as the inner insulating thermal conductive coating 221 is sprayed (or printed) on the graphene coating 222 again to form the outer insulating thermal conductive coating 221′.

[0027] As for the molding position of the first contact 211, it can be molded on the outer wall of the inner insulating thermal conductive coating 221 and then pass through the graphene coating 222 and the outer insulating thermal conductive coating 221′ to achieve connection with the graphene coating 222. It can also be molded on the outer wall of the graphene coating 222 and then pass through the outer insulating thermal conductive coating 221′. The latter design is preferred.

[0028] Furthermore, in order to ensure the precise connection between the first contact 211 and the second contact 311, the first contact 211 and the second contact 311 may be both configured as cylindrical structures, so that the two form surface contact to ensure the precision and stability of the contact.

[0029] Since the heater 2 needs to be sleeved on the nozzle body 11 first, and then the second contact 311 is driven by the wire 31 to extend into the side through hole 130 of the flange 13 to abut against the first contact 211, the area of ​​the first contact 211 can be set larger, and the area of ​​the second contact 311 can be set smaller. The projection of the second contact 311 is located in the plane of the first contact 211, which makes it easier to achieve contact between the two. The flange 13 is sleeved on the upper end of the nozzle body 11 to install and fix the nozzle as a whole on the diverter plate. When the heater 2 is sleeved on the nozzle body 11, a pair of first contacts 211 need to be aligned with the side through hole 130 so that the wire 31 can be inserted and connected.

[0030] like Figure 3 As shown, further, a plurality of elastic pads 212 (such as thermally conductive silicone etc.) with heat conduction performance can be symmetrically provided at the bottom end of the inner wall of the middle cavity 20 of the heat-conducting sleeve 21, and the heater 2 can be fixed by at least partially contacting the nozzle body 11 with the elastic pads. Preferably, the portion of the heat-conducting sleeve 21 with the elastic pads 212 can have a slightly larger space by expanding outwards or the like so that after the elastic pads 212 are installed, the contact surface thereof will not protrude much from the inner wall of the heat-conducting sleeve 21, so that the portion of the heat-conducting sleeve 21 without the elastic pads 212 can still contact with the nozzle body 11, that is, after the elastic pads 212 and the nozzle body 11 are in interference contact, the contact between the heat-conducting sleeve 21 and the nozzle body 11 and the heat conduction between the two will not be affected.

[0031] like Figure 4 As shown, in another embodiment of the utility model, the conductive part 3 also includes an elastic insert 32, and the elastic insert 32 is fixedly mounted on the pair of wires 31 through the mounting hole 320 it has, and the second contact 311 is located on one side of the elastic insert 32, and the elastic insert 32 is interference-mounted in the side through hole 130. Due to the fixing and supporting function of the elastic insert 32, the positions of the pair of wires 31 and the pair of second contacts 311 can be relatively fixed to ensure the contact stability with the first contact 211; the elastic insert 32 can also be made of insulating material.

[0032] In addition, a guide surface may be provided on one side of the elastic insert 32 close to the second contact 311 or on the outer wall of the flange 13 at the side through hole 130 to facilitate installation of the elastic insert 32 in the side through hole 130 .

[0033] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A uniformly heated injection molding nozzle, comprising a nozzle body and a nozzle tip disposed in the nozzle body, characterized in that: It also includes a heater sleeved on the nozzle body, the heater includes a heat-conducting sleeve and a graphene heating layer wrapped on the heat-conducting sleeve, the graphene heating layer is provided with a pair of first contacts extending along its radial direction and protruding outward from its body, the first contacts abut against second contacts on a pair of wires provided on an external power supply for heating the graphene heating layer.

2. The uniformly heated injection molding nozzle according to claim 1, characterized in that: The graphene heating layer includes, from the inside to the outside, an inner insulating thermally conductive coating, a graphene coating and an outer insulating thermally conductive coating which are abutted against each other in sequence. The inner insulating thermally conductive coating is formed on the outer side wall of the thermally conductive sleeve. The first contact is connected to the graphene coating and protrudes outward from the outer insulating thermally conductive coating but does not protrude inward from the inner insulating thermally conductive layer.

3. The uniformly heated injection molding nozzle according to claim 2, characterized in that: The first contact is disposed on a side wall of the graphene coating; the first contact and the second contact are made of silver, copper or graphite.

4. The uniformly heated injection molding nozzle according to any one of claims 1 to 3, characterized in that: The first contact and the second contact are both cylindrical structures, and the two are in surface contact.

5. The uniformly heated injection molding nozzle according to claim 4, characterized in that: The projection of the second contact is located in the plane of the first contact.

6. The uniformly heated injection molding nozzle according to any one of claims 1 to 3, characterized in that: A flange for installing the nozzle is disposed at the upper end of the nozzle body, a side through hole is disposed on the flange, and the first contact point is located within the projection surface of the side through hole on the heater.

7. The uniformly heated injection molding nozzle according to claim 6, characterized in that: It also includes an elastic insert, which is fixedly sleeved on the wire through a mounting hole, and the second contact is located on one side of the elastic insert, and the elastic insert is interference-mounted in the side through hole.

8. The uniformly heated injection molding nozzle according to claim 7, characterized in that: A guide surface is provided on one side of the elastic insert close to the second contact point or on the outer side wall of the flange located at the side through hole.

9. The uniformly heated injection molding nozzle according to claim 1, characterized in that: A plurality of elastic pads with heat conduction performance are symmetrically arranged at the bottom end of the inner wall of the heat-conducting sleeve.

10. The uniformly heated injection molding nozzle according to claim 1, characterized in that: The heat-conducting sleeve is made of steel and has a thickness of 0.2-2 mm.

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