A mold hot nozzle heat insulation device and an injection mold

Abstract

The present invention discloses a heat insulation device for a mold hot nozzle and an injection mold, which includes a heat insulation sleeve and a circulating cooling system. The heat insulation sleeve is fixed in the mold and sleeved on the outer periphery of the hot nozzle. The circulating cooling system includes a diversion pipe and a cooling pipe. The cooling pipe is arranged in the heat insulation sleeve and is communicated with an external coolant circulating system through the diversion pipe. The present invention can reduce the heat conduction from the hot nozzle to the mold, so as to reduce the phenomena of mold cracking and difficult demolding caused by thermal expansion, thereby improving the precision of the mold.

Description

Technical Field

[0001] The present invention relates to the technical field of molds, and particularly to a mold hot nozzle heat insulation device and an injection mold. Background Art

[0002] A hot runner keeps the plastic in the runner and gate in a molten state by heating. A hot runner system generally consists of several parts such as a hot nozzle and a manifold plate. Since heating rods and heating coils are provided near or at the center of the runner, the entire runner from the outlet of the injection machine nozzle to the gate is in a high-temperature state, keeping the plastic in the runner in a molten state. However, the high temperature of the hot nozzle causes heat conduction to the template, resulting in thermal expansion of the template, which affects the accuracy of the mold, making the produced products unusable and affecting the quality and qualification rate of the products.

[0003] Since the form of the hot nozzle directly determines the selection of the hot runner system and the manufacturing of the mold, in the prior art, a common hot runner system only has a heat insulation sleeve sleeved on the head of the hot nozzle. However, simply using the heat insulation sleeve cannot reduce the heat generated by the hot nozzle from being conducted to the template. Therefore, there is an urgent need for a mold hot nozzle heat insulation device and an injection mold that can reduce the heat conduction from the hot nozzle to the template to solve the above technical problems existing in the prior art. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a mold hot nozzle heat insulation device and an injection mold, which can reduce the heat conduction from the hot nozzle to the mold, so as to reduce the phenomena of cracking and difficult demolding of the mold caused by thermal expansion, thereby improving the precision of the mold.

[0005] To solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] In a first aspect, the present invention provides a mold hot nozzle heat insulation device, including a heat insulation sleeve and a circulating cooling system. The heat insulation sleeve is fixed in the mold and sleeved on the outer periphery of the hot nozzle. The circulating cooling system includes a diversion pipe and a cooling pipe. The cooling pipe is arranged in the heat insulation sleeve and is connected to an external coolant circulation system through the diversion pipe.

[0007] In some embodiments, it further includes a pressing plate fixedly connected to the mold. The heat insulation sleeve is provided with a convex ring, and the pressing plate is pressed against the convex ring to realize the fixed connection between the heat insulation sleeve and the mold.

[0008] In some embodiments, the pressing plate is fixedly connected to the mold by screws.

[0009] In some embodiments, the caliber of the cooling pipe gradually increases along the injection flow direction of the hot nozzle.

[0010] In some embodiments, an inclined portion is provided at the end of the cooling pipe.

[0011] In some embodiments, a sealing ring is provided at the connection between the heat insulation sleeve and the mold to prevent leakage of the guide tube.

[0012] On the other hand, the present invention also provides an injection mold, comprising the mold hot nozzle insulation device.

[0013] In some embodiments, the hot nozzle is a flow channel structure with a heating wire arranged inside.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention provides a mold hot nozzle insulation device comprising an insulation sleeve and a circulating cooling system. The insulation sleeve is fixed within the mold and sleeved around the outer periphery of the hot nozzle. The circulating cooling system comprises a guide tube and a cooling pipe. The cooling pipe is disposed within the insulation sleeve and communicates with an external coolant circulation system via the guide tube. The present invention injects cooling water into the guide tube and the cooling pipe, allowing the cooling water to remove heat from the hot nozzle, preventing heat generated by the hot nozzle from being transferred to the mold. This reduces mold cracking and difficulty in demolding due to thermal expansion, thereby improving mold precision.

[0016] 2. The present invention provides a mold hot nozzle insulation device, in which the diameter of the cooling tube gradually increases along the injection flow direction of the hot nozzle, and an inclined portion is provided at the end of the cooling tube, so that the cooling tube can use the difference in distance between the inclined portion and the open end of the cooling tube to form a resistance difference inside the insulation sleeve, thereby allowing cold water to circulate automatically in the cooling tube.

[0017] 3. The present invention provides an injection mold comprising the aforementioned mold nozzle insulation device. The nozzle is a flow channel structure with a heating wire disposed therein. By providing an insulation sleeve and a circulating cooling system on the exterior of the nozzle, the injection mold provided by the present invention can remove heat from the nozzle, preventing heat generated therefrom from being transferred to the mold. This can thereby reduce mold cracking and mold release difficulties caused by thermal expansion, thereby increasing the mold's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view of a mold hot nozzle insulation device provided by an embodiment of the present invention;

[0019] Figure 2 This is a schematic structural diagram of a mold hot nozzle insulation device provided by an embodiment of the present invention;

[0020] Figure 3 yes Figure 1 Enlarged view of point A in the middle;

[0021] Figure 4 This is a structural schematic diagram of a heat insulation sleeve and a circulating cooling system of a mold hot nozzle heat insulation device provided by an embodiment of the present invention;

[0022] In the figure: 1, mold; 11, cylinder plate; 12, manifold plate; 13, female template; 14, hot runner system; 2, hot nozzle; 3, heat insulation sleeve; 4, circulating cooling system; 41, diversion pipe; 42, cooling pipe; 5, pressing plate; 6, convex ring; 7, screw; 8, sealing ring; 9, product. Specific implementation mode

[0023] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0025] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0026] Embodiment 1:

[0027] The present invention provides a heat insulation device including a hot nozzle of a mold. Refer to Figures 1 to 4, including a heat insulation sleeve 3 and a circulating cooling system 4. The heat insulation sleeve 3 is fixed inside the mold 1. The mold 1 includes a cylinder plate 11, a manifold plate 12, and a female mold plate 13 arranged in sequence from top to bottom. A hot runner system 14 is provided on the manifold plate 12, and the hot runner system 14 is used to heat the nozzle 2. The height of the heat insulation sleeve 3 is lower than the height of the nozzle 2 to increase the heat exchange area between the cooling water and the nozzle 2. At the same time, the heat insulation sleeve 3 does not prevent the normal operation of the nozzle 2. The heat insulation sleeve 3 is sleeved on the outer periphery of the nozzle 2. Among them, the circulating cooling system 4 includes a guiding pipe 41 and a cooling pipe 42. The cooling pipe 42 is arranged inside the heat insulation sleeve 3, and the cooling pipe 42 is communicated with an external coolant circulation system through the guiding pipe 41. The guiding pipe 41 includes an inlet guiding pipe and an outlet guiding pipe, and the inlet guiding pipe and the outlet guiding pipe are respectively arranged on both sides of the nozzle 2.

[0028] When it is necessary to cool down the nozzle 2, it is only necessary to inject cooling water at the inlet guiding pipe. Correspondingly, the cooling water flowing into the inlet guiding pipe flows through the cooling pipe 42 to the outlet guiding pipe, which can take away the heat generated by the nozzle 2. That is to say, after the cooling water is injected into the cooling pipe 42, the cooling water surrounds the whole nozzle 2, and then the cooling water with heat is discharged into the external coolant circulation system through the outlet guiding pipe, so that the cooling effect of the nozzle 2 is obvious, and the heat generated on the nozzle 2 is prevented from being conducted to the mold 1, thereby reducing the phenomena of mold 1 cracking and difficult demolding caused by thermal expansion and improving the precision of the mold 1.

[0029] Preferably, the caliber of the cooling pipe 42 gradually increases along the injection flow direction of the nozzle 2. That is to say, the upper caliber of the cooling pipe 42 is smaller than the lower caliber of the cooling pipe 42. In addition, an inclined part is provided at the end of the cooling pipe 42. The cooling pipe 42 can form a resistance difference inside the heat insulation sleeve 3 by using the distance difference between the inclined part and the opening end of the cooling pipe 42, so that the resistance in the upper part of the cooling pipe 42 is greater than the resistance in the lower part of the cooling pipe 42, so that the cooling water can automatically circulate and flow inside the cooling pipe 42 to take away the heat on the nozzle 2, preventing the heat generated on the nozzle 2 from being conducted to the mold 1, thereby reducing the phenomena of mold 1 thermal expansion cracking and difficult demolding and improving the service life of the mold 1. However, it should be understood that the shape of the cooling pipe 42 described in the present invention is not limited to this. For example, the upper and lower calibers of the cooling pipe 42 can be the same, and the upper caliber of the cooling pipe 42 can also be larger than the lower caliber of the cooling pipe 42, as long as the cooling water can circulate in the cooling pipe 42 to take away the heat generated on the nozzle 2.

[0030] In order to firmly fix the heat insulation sleeve 3 to the mold 1, the heat nozzle 2 heat insulation device of the mold 1 further includes a pressing plate 5 fixedly connected to the mold 1. A convex ring 6 is provided on the heat insulation sleeve 3, and the size of the convex ring 6 can be arranged according to the size of the heat insulation sleeve 3. The pressing plate 5 is pressed against the convex ring 6, and the pressing plate 5 fixedly connects the convex ring 6 to the mold 1 through screws 7, so as to realize the fixed connection between the heat insulation sleeve 3 and the mold 1. Of course, those skilled in the art can also use other methods to fixedly connect the heat insulation sleeve 3 to the mold 1. For example, the heat insulation sleeve 3 can be pasted to the mold 1 using an adhesive. In order to prevent the diversion pipe 41 from leaking liquid, a sealing ring 8 is also provided at the connection between the heat insulation sleeve 3 and the mold 1. The size and thickness of the sealing ring 8 can be set according to the size of the diversion pipe 41. It should be noted that the sealing ring 8 is a high-temperature resistant sealing ring 8, and the minimum heat resistance temperature of the sealing ring 8 is 250 °C.

[0031] Embodiment 2:

[0032] The present invention also provides an injection mold 1. Refer to Figure 1 、 Figure 2 , the injection mold includes the mold heat nozzle heat insulation device described in Embodiment 1. It should be noted that the heat nozzle 2 is a runner structure with heating wires arranged inside. Specifically, the inside of the heat nozzle 2 is filled with heating wires. When the hot runner system 14 heats the heat nozzle 2, the heat nozzle 2 can quickly heat up. The heated heat nozzle 2 can melt the plastic granules, so that the melted plastic liquid can flow to the female mold core through the bottom of the heat nozzle 2, and finally a product 9 is manufactured.

[0033] When the temperature of the heat nozzle 2 is too high, the heat of the heat nozzle 2 is easily conducted to the mold 1, causing the mold 1 to expand thermally, and then the mold 1 thermally expands and cracks, and the manufactured product 9 is also prone to problems such as difficult demolding. Therefore, for the mold 1 that needs to use the hot runner system 14, in order to reduce the heat conduction from the heat nozzle 2 to the mold 1 and affect the precision of the mold 1.

[0034] In the present invention, a heat insulation sleeve 3 is sleeved on the outer periphery of the hot nozzle 2. By arranging the heat insulation sleeve 3 and the circulating cooling system 4 outside the hot nozzle 2, the heat on the hot nozzle 2 can be taken away. At the same time, a pressing plate 5 fixedly connected to the female template 13 presses the convex ring 6 of the heat insulation sleeve 3. Correspondingly, screws 7 are used to fix the pressing plate 5 of the heat insulation sleeve 3 on the manifold plate 12, that is, the pressing plate 5 fixedly connected to the female template 13 is fixedly connected to the mold 1 through the screws 7 with the convex ring 6, so as to realize the fixed connection between the heat insulation sleeve 3 and the mold 1. By designing a diversion pipe 41 capable of water inlet and outlet on the manifold plate 12, cooling water is injected into the cooling pipe 42 inside the heat insulation sleeve 3, so that the cooling water can circulate inside the cooling pipe 42 and take away the heat on the hot nozzle 2, avoiding the conduction of the heat generated on the hot nozzle 2 to the mold 1, thereby reducing the phenomena of cracking and difficult demolding of the mold 1 caused by thermal expansion and improving the service life of the mold 1.

[0035] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can still be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A mold hot nozzle heat insulation device, characterized in that It includes a heat insulation sleeve and a circulating cooling system. The heat insulation sleeve is fixed inside the mold and sleeved around the outer periphery of the hot nozzle. The circulating cooling system includes a diversion pipe and a cooling pipe. The cooling pipe is arranged inside the heat insulation sleeve and is communicated with an external coolant circulation system through the diversion pipe. The caliber of the cooling pipe gradually increases along the injection molding flow direction of the hot nozzle. An inclined part is provided at the end of the cooling pipe. The height of the heat insulation sleeve is lower than the height of the hot nozzle.

2. The mold hot nozzle heat insulation device according to claim 1, characterized in that, It further includes a pressing plate fixedly connected to the mold. A convex ring is provided on the heat insulation sleeve, and the pressing plate is press-connected to the convex ring to realize the fixed connection between the heat insulation sleeve and the mold.

3. The mold hot nozzle heat insulation device according to claim 2, characterized in that, The pressing plate is fixedly connected to the mold by screws.

4. The mold hot nozzle heat insulation device according to claim 1, characterized in that, A sealing ring for preventing liquid leakage of the diversion pipe is provided at the connection between the heat insulation sleeve and the mold.

5. An injection mold, characterized in that, It includes the mold hot nozzle heat insulation device according to any one of claims 1 to 4.

6. The injection mold according to claim 5, wherein, The hot nozzle is a runner structure with heating wires arranged inside.

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