A needle valve type hot runner with temperature sensing function

Abstract

This utility model relates to a needle valve-type hot runner with temperature sensing function. Heating wires are wound around the head, middle, and tail ends of the hot nozzle. A first temperature sensor and a second temperature sensor are respectively provided at the head and tail ends of the hot nozzle. The hot nozzle further includes a first hot nozzle segment and a second hot nozzle segment joined together along its length. The first hot nozzle segment forms the head end of the hot nozzle, and the second hot nozzle segment forms the middle and tail ends. The first hot nozzle segment includes a joint end face opposite to the second hot nozzle segment. The first hot nozzle segment also includes a first mounting groove recessed from the joint end face in a direction away from the second hot nozzle segment. The first temperature sensor is embedded in the first mounting groove. The first temperature sensor of this utility model can penetrate deeper into the interior of the hot nozzle, closer to the dispensing channel, improving its temperature sensing accuracy. The first mounting groove can be better heat-sealed by the relative joint of the first and second hot nozzle segments, avoiding the problem of low temperature sensing accuracy due to large heat loss at this point.

Description

Technical Field

[0001] This utility model relates to the field of hot runner technology for injection molds. Background Technology

[0002] The working principle of a hot runner system in injection molds is as follows: molten plastic is first heated to a suitable temperature by the heating elements of the hot runner system, and then injected into the mold cavity through hot nozzles to achieve product injection molding. Among these, the needle valve hot runner is a common type of hot runner system. Its characteristic is the presence of a needle valve at the injection port. Precise control of the molten plastic is achieved by controlling the opening and closing of the needle valve. The needle valve hot runner system can precisely control the amount of molten plastic injected by controlling the opening degree of the needle valve, thereby achieving precise filling of each mold cavity.

[0003] Some injection-molded products require high temperature precision during injection molding. The maximum temperature difference from the inlet to the outlet of the hot runner cannot exceed 5°C. This necessitates that the hot runner design incorporates multiple heating elements and can sense the temperature of the hot runner's flow path, with higher accuracy being better. The tail end of the hot runner, being deeply embedded in the mold core, experiences less heat loss and is easier to sense precisely. However, the head end of the hot runner often suffers from significant heat loss, and previous technologies have consistently failed to achieve precise temperature sensing at the head end of the hot runner's flow path. Utility Model Content

[0004] To address the aforementioned problems, this invention proposes a needle valve-type hot runner with optimized structure and temperature sensing function.

[0005] This utility model is achieved using the following technical solution: This utility model proposes a needle valve type hot runner with temperature sensing function, including a hot nozzle. An injection channel is provided inside the hot nozzle, extending from the head end to the tail end. Heating wires are wound around the head end, middle section, and tail end of the hot nozzle. A first temperature sensor and a second temperature sensor are also provided at the head end and tail end of the hot nozzle, respectively, and are embedded inside the hot nozzle. The hot nozzle further includes a first hot nozzle segment and a second hot nozzle segment spliced ​​together along its length. The first hot nozzle segment forms the head end of the hot nozzle, and the second hot nozzle segment forms the middle section and tail end of the hot nozzle. The first hot nozzle segment includes a splicing end face opposite to the second hot nozzle segment. The first hot nozzle segment also includes a first mounting groove recessed from the splicing end face in a direction away from the second hot nozzle segment, and the first temperature sensor is embedded in the first mounting groove.

[0006] Preferably, the first hot nozzle section and the second hot nozzle section are fixedly connected by screws.

[0007] Preferably, the second hot nozzle section includes a second mounting groove formed on its outer peripheral surface, and the second temperature sensor is embedded in the second mounting groove.

[0008] Preferably, the device also includes a mold core, in which the hot nozzle is inserted and fixed. The second hot nozzle section is also provided with an anti-rotation protrusion extending radially outward. The mold core is provided with an anti-rotation groove, in which the anti-rotation protrusion is inserted to limit the rotation of the hot nozzle.

[0009] Preferably, the second hot nozzle section is further provided with a heat sealing sleeve, which is located on the outer side of the heating wire in the middle section of the corresponding hot nozzle, and the mold core is provided with a stepped hole that abuts against the heat sealing sleeve.

[0010] The present invention has the following advantages: the first temperature sensor of the present invention can penetrate deeper into the interior of the hot nozzle and get closer to the glue injection channel, thereby improving its temperature sensing accuracy. At the same time, the first mounting groove can be better heat-sealed by the relative splicing of the first hot nozzle section and the second hot nozzle section, avoiding the problem of low temperature sensing accuracy caused by large heat loss at this location. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a needle valve-type hot runner with temperature sensing function in the embodiment; Figure 2 This is a three-dimensional schematic diagram of the hot nozzle in the embodiment; Figure 3 This is a cross-sectional view of the hot nozzle in the embodiment. Detailed Implementation

[0012] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0013] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0014] See Figures 1-3As shown, in a preferred embodiment of this utility model, a needle valve-type hot runner with temperature sensing function is provided, including a hot nozzle 1 and a mold core 2. The hot nozzle 1 is inserted into the mold core 2, and glue is injected into the product molding cavity on the mold core 2 through the hot nozzle 1. From the length direction of the hot nozzle 1, the hot nozzle 1 has a head end 11, a middle section 12 and a tail end 13. The hot nozzle 1 has a hollow structure, and a glue injection channel 5 is provided inside the hot nozzle 1. The glue injection channel 5 extends from the head end 11 to the tail end 13 of the hot nozzle. A first heating wire 31, a second heating wire 32 and a third heating wire 33 are respectively wound around the head end 11, the middle section 12 and the tail end 13 of the hot nozzle. In addition, a first temperature sensor 41 and a second temperature sensor 42 are respectively provided at the head end 11 and the tail end 13 of the hot nozzle. The first temperature sensor 41 and the second temperature sensor 42 are embedded inside the hot nozzle.

[0015] The hot nozzle 1 further includes a first hot nozzle segment 101 and a second hot nozzle segment 102 spliced ​​together along its length. In this embodiment, the first hot nozzle segment 101 and the second hot nozzle segment 102 are fixedly connected by screws. The first hot nozzle segment 101 forms the head end 11 of the hot nozzle, and the second hot nozzle segment 102 forms the middle section 12 and the tail end 13 of the hot nozzle. The first hot nozzle segment 101 includes a splicing end face 103 opposite to the second hot nozzle segment 102. The first hot nozzle segment 101 also includes a first mounting groove 104 recessed from the splicing end face 103 in a direction away from the second hot nozzle segment 102. The first temperature sensor 41 is embedded in the first mounting groove 104.

[0016] With the above settings, the first temperature sensor 41 can penetrate deeper into the interior of the hot nozzle 1 and get closer to the glue injection channel 3, thereby improving its temperature sensing accuracy. At the same time, the first mounting groove 104 can be better heat-sealed by the relative splicing of the first hot nozzle section 101 and the second hot nozzle section 102, avoiding the problem of low temperature sensing accuracy caused by large heat loss at this location.

[0017] The second hot nozzle section 102 includes a second mounting groove 105 formed on its outer peripheral surface, into which the second temperature sensor 42 is embedded. Furthermore, the second hot nozzle section 102 is provided with an anti-rotation protrusion 106 extending radially outward, and an anti-rotation groove 21 is provided on the mold core. The anti-rotation protrusion 106 is inserted into the anti-rotation groove 21 to restrict the rotation of the hot nozzle 1 and improve the positional stability of the hot nozzle 1.

[0018] The second hot nozzle section 102 is also provided with a heat sealing sleeve 107. The heat sealing sleeve 107 is located on the outer side of the corresponding second heating wire 32. The mold core 2 of the heat sealing sleeve 107 is provided with a stepped hole 22 that abuts against the heat sealing sleeve 107. The heat sealing effect is further improved by the abutment between the heat sealing sleeve 107 and the stepped hole 22, thereby improving the temperature consistency of the injection channel 3.

[0019] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that any changes in form and detail made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims fall within the protection scope of the present invention.

Claims

1. A needle valve hot runner with temperature sensing function, comprising a hot nozzle, a glue injection runner is arranged in the inside of the hot nozzle, characterized in that: The glue injection channel extends from the head end of the hot nozzle to the tail end of the hot nozzle. Heating wires are wound around the head end, middle section and tail end of the hot nozzle respectively. A first temperature sensor and a second temperature sensor are also provided at the head end and tail end of the hot nozzle respectively. The first temperature sensor and the second temperature sensor are embedded inside the hot nozzle. The hot nozzle further includes a first hot nozzle segment and a second hot nozzle segment spliced ​​together along its length. The first hot nozzle segment forms the head end of the hot nozzle, and the second hot nozzle segment forms the middle and tail ends of the hot nozzle. The first hot nozzle segment includes a splicing end face opposite to the second hot nozzle segment. The first hot nozzle segment also includes a first mounting groove recessed from the splicing end face in a direction away from the second hot nozzle segment, and the first temperature sensor is embedded in the first mounting groove.

2. The needle valve type hot runner having a temperature sensing function according to claim 1, characterized in that: The first and second hot nozzle sections are fixedly connected by screws.

3. The needle valve type hot runner having a temperature sensing function according to claim 1, characterized in that: The second hot nozzle section includes a second mounting groove formed on its outer peripheral surface, and a second temperature sensor is embedded in the second mounting groove.

4. The needle valve type hot runner having a temperature sensing function according to claim 1, characterized in that: It also includes a mold core, in which the hot nozzle is inserted and fixed. The second hot nozzle section is also provided with an anti-rotation protrusion extending radially outward. The mold core is provided with an anti-rotation groove, in which the anti-rotation protrusion is inserted to limit the rotation of the hot nozzle.

5. The needle valve type hot runner having a temperature sensing function according to claim 4, characterized in that: The second hot nozzle section is also provided with a heat sealing sleeve, which is located on the outside of the heating wire in the middle section of the corresponding hot nozzle. The mold core is provided with a stepped hole that abuts against the heat sealing sleeve.

Images