Sprue bush capable of reducing flow velocity and injection mold

Abstract

A sprue bush and an injection mold capable of reducing flow velocity are characterized in that the sprue bush is mounted on an upper mold plate of the injection mold, a hot runner is arranged on the sprue bush, a hot nozzle is mounted in the hot runner, the sprue bush, the hot nozzle, the upper mold plate and a lower mold plate of the injection mold jointly define a forming cavity, one end of the sprue bush is provided with an inlet sprue, and the other end of the sprue bush is provided with an outlet sprue. The sprue is communicated with the hot runner in a stepped manner, is trumpet-shaped, is communicated with the hot nozzle and the forming cavity, expands outwards from the hot nozzle to the forming cavity, and is provided with a first end and a second end, the first end of the sprue is arranged on the end surface of the sprue bush, and the second end of the sprue is arranged on the end surface of the sprue bush; the second end of the pouring gate is arranged at the joint of the pouring gate and the hot runner, the diameter of a circle defined by the first end of the pouring gate is larger than that of a circle defined by the second end of the pouring gate, and a chamfering structure is arranged on the edge of the first end of the pouring gate.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to a sprue sleeve and an injection mold for reducing flow rate. Background Art

[0002] At present, the injection molding technology commonly used in the injection molding industry is hot runner technology. Hot runner technology specifically uses heating technology to make the rubber flow into the mold cavity along the runner in a molten state, thereby injection molding a plastic product.

[0003] For certain products, such as battery covers, the appearance is required to be intact and without defects. Usually, the industry will use inverted hot runner technology, in which the mold is an inverted mold and the casting is carried out from the middle point. Due to the fast injection speed, the gate is directly facing the appearance surface, causing the rubber to impact the cavity surface and fail to achieve the effect of reducing the speed. The gate is perpendicular to the product surface. The sudden turn of the rubber causes the rubber to generate a large amount of shear heat, and the local temperature is too high, resulting in sun patterns on the appearance, affecting the appearance of the product.

[0004] Therefore, in view of the problem that the current inverted hot runner technology causes sun streaks in products, it is urgent to develop a new machine or new technology to solve the above problem. Utility Model Content

[0005] The utility model aims to provide a sprue sleeve and an injection mold for reducing flow rate, so as to solve the problem that the product generates sun streaks due to the inverted hot runner technology.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A gate sleeve for reducing flow rate, the gate sleeve is installed on the upper template of the injection mold, a hot runner is arranged on the gate sleeve, a hot nozzle is installed in the hot runner, the gate sleeve, the hot nozzle, the upper template and the lower template of the injection mold together form a molding cavity, one end of the gate sleeve is provided with an inlet gate, the inlet gate is connected to the hot runner in a stepped manner, the inlet gate is trumpet-shaped, the inlet gate is connected to the hot nozzle and the molding cavity and expands outward from the hot nozzle toward the molding cavity, the inlet gate has a first end and a second end, the first end of the inlet gate is arranged on the end face of the gate sleeve, the second end of the inlet gate is arranged at the connection between the inlet gate and the hot runner, the diameter of the circle surrounded by the first end of the inlet gate is greater than the diameter of the circle surrounded by the second end of the inlet gate, and the edge of the first end of the inlet gate is provided with a chamfer structure.

[0008] Furthermore, at the connection between the inlet gate and the hot runner, the aperture of the inlet gate is larger than the aperture of the hot runner.

[0009] Furthermore, the distance between the first end of the inlet gate and the second end of the inlet gate is 5 mm to 7 mm.

[0010] Furthermore, the inlet gate has an inclined surface expanding outward from the second end to the first end, and the angle between the generatrix of the inclined surface and the central axis of the inlet gate is 12 degrees.

[0011] Furthermore, the ratio of the area of ​​the circle enclosed by the first end edge of the inlet gate to the area of ​​the circle enclosed by the second end edge of the inlet gate is 2:1.

[0012] Furthermore, the chamfered structure is a rounded corner.

[0013] Furthermore, the radius of the fillet is 0.8 mm to 1.0 mm.

[0014] An injection mold comprises a hot runner plate and the above-mentioned sprue sleeve for reducing flow rate, wherein the hot runner plate is provided with a hot runner, and a hot nozzle is connected to a flow channel in the hot runner.

[0015] Furthermore, the injection mold also includes a lower mold core and an upper mold core. The lower mold core is installed on the lower mold plate, the upper mold core is installed on the upper mold plate, and the gate sleeve is installed on the upper mold core. The gate sleeve, hot nozzle, upper mold core and lower mold core together form a molding cavity.

[0016] The utility model has the beneficial effects of a sprue sleeve and an injection mold for reducing flow rate: not only the structure is simple, but also the sun pattern on the appearance surface of the product is avoided, thereby improving the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a cross-sectional view of an injection mold.

[0018] Figure 2 for Figure 1 A cross-sectional view of a sprue bushing of an injection mold is shown.

[0019] Figure 3 for Figure 2 An enlarged cross-sectional view of point A in the sprue bushing is shown.

[0020] Figure 4 for Figure 3 Cross-section of the gate shown Figure 1 .

[0021] Figure 5 for Figure 3 Cross-section of the gate shown Figure 2 . DETAILED DESCRIPTION

[0022] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] The terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", etc. in the specification and claims of the utility model indicate directions or position relationships based on the directions or position relationships shown in the drawings, and are only for the clarity of expressing the technical solutions and the convenience of description, and therefore cannot be understood as limitations on the present application.

[0024] See also Figure 1-Figure 3 A sprue bushing for reducing flow rate, wherein the sprue bushing 10 is installed on an upper mold plate 40 of an injection mold, a hot runner 20 is arranged on the sprue bushing 10, a hot nozzle 21 is installed in the hot runner 20, and the sprue bushing 10, the hot nozzle 21, the upper mold plate 40, and the lower mold plate 50 of the injection mold together form a molding cavity 100. One end of the sprue bushing 10 has an inlet gate 11, and the inlet gate 11 is connected to the hot runner 20 in a stepped manner. The hot nozzle 21 is arranged at the connection between the inlet gate 11 and the hot runner 20, and the aperture of the inlet gate 11 is larger than the aperture of the hot nozzle 21 of the hot runner 20, so that it can ensure that the rubber flows directly from the hot nozzle 21 to the inlet gate 11.

[0025] The inlet gate 11 is trumpet-shaped, and the inlet gate 11 is connected to the hot nozzle 21 and the molding cavity 100. More specifically, the inlet gate 11 has a first end 111 and a second end 112, the first end 111 of the inlet gate 11 is arranged on the end surface of the sprue bushing 10, and the second end 112 of the inlet gate 11 is arranged at the connection between the inlet gate 11 and the hot runner 20. The diameter of the circle surrounded by the first end 111 of the inlet gate 11 is greater than the diameter of the circle surrounded by the second end 112 of the inlet gate 11.

[0026] The rubber material flows into the molding cavity 100 from the hot nozzle 21 along the inlet gate 11 in a molten state. When the rubber material flows through the inlet gate 11, since the inlet gate 11 is trumpet-shaped and expands outward toward the molding cavity 100, the aperture of the inlet gate 11 gradually increases in the direction toward the molding cavity 100, so that the flow rate of the rubber material is reduced, thereby achieving the effect of reducing the speed.

[0027] In the prior art, the gate 11 is perpendicular to the appearance surface of the product, and the rubber is filled from the gate 11 directly onto the appearance surface of the product. Since the flow rate of the rubber is relatively fast during injection molding, when the rubber flows to the first end 111 of the gate 11, the rubber suddenly turns to be filled along the four sides of the molding cavity 100, causing the rubber to generate a large amount of shear heat and the local temperature to be too high, resulting in sun patterns on the appearance, affecting the appearance of the product.

[0028] The edge of the first end 111 of the inlet gate 11 is provided with a chamfer structure. The chamfer structure can prevent the rubber from suddenly turning when it flows to the first end 111 of the inlet gate 11, so that the rubber can turn more smoothly and flow around the molding cavity 100, thereby avoiding the generation of sun streaks.

[0029] As described above, the gate sleeve for reducing the flow rate proposed in the utility model, by providing the gate sleeve 10 with the inlet gate 11 which has the function of reducing the speed and steering the rubber material, not only has a simple structure, but also avoids the generation of sun streaks on the product and improves the product yield.

[0030] See also Figure 5 The inlet gate 11 has an inclined surface 113 expanding from the second end 112 to the first end 111, and the angle α between the generatrix of the inclined surface 113 and the central axis 115 of the inlet gate 11 is 12 degrees. When the angle α is 12 degrees, the inlet gate 11 has a moderate effect of slowing down the rubber material, and will neither make the flow rate of the rubber material too fast to cause sun patterns on the product, nor make the flow rate of the rubber material too slow to reduce production efficiency.

[0031] The distance L between the first end 111 of the inlet gate 11 and the second end 112 of the inlet gate 11 is 5mm to 7mm. It can be understood that the longer the distance L is, the more obvious the deceleration effect on the rubber material is, but if the distance L is too long, the production efficiency will be reduced. After many tests, the distance is 5mm to 7mm, which can be compatible with the requirements of the deceleration effect and production efficiency. Preferably, those skilled in the art can specifically set the distance L to 5mm, 5.5mm, 6mm, 6.5mm, 7mm, etc., which is not limited here.

[0032] The ratio of the area of ​​the circle formed by the edge of the first end 111 of the inlet gate 11 to the area of ​​the circle formed by the edge of the second end 112 of the inlet gate 11 is 2:1. The inlet gate 11 has a moderate effect of reducing the speed of the rubber material, which will neither make the flow rate of the rubber material too fast to cause sun patterns on the product, nor make the flow rate of the rubber material too slow to reduce production efficiency.

[0033] See also Figure 4In the present embodiment, the chamfered structure is a fillet 114, and the radius R of the fillet 114 is 0.8 mm to 1.0 mm. It can be understood that the larger the radius R of the fillet 114, the smoother the turn of the rubber in the molding cavity 100 will be made by the fillet 114, but if the radius R is too large, more rubber will be wasted, which will increase the production cost. After many tests, the radius R is between 0.8 mm and 1.0 mm, which can be compatible with the requirements of smooth turn and production cost. Preferably, those skilled in the art can set the radius R specifically to 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, etc., which is not limited here.

[0034] See also Figure 1-Figure 3 In addition, the utility model also provides an injection mold, including a hot runner plate 30 and a gate sleeve for reducing the flow rate as described in any of the above embodiments, the hot runner plate 30 is provided with the hot runner 20, and the hot nozzle 21 is connected to the flow channel in the hot runner 20.

[0035] The injection mold also includes a lower mold core 51 and an upper mold core 41. The lower mold core 51 is installed on the lower mold plate 50, the upper mold core 41 is installed on the upper mold plate 40, and the gate sleeve 10 is installed on the upper mold core 41. The gate sleeve 10, the hot nozzle 21, the upper mold core 41 and the lower mold core 51 together surround the molding cavity 100.

[0036] The utility model has the beneficial effects of a sprue sleeve and an injection mold for reducing flow rate: not only the structure is simple, but also the sun pattern on the appearance surface of the product is avoided, thereby improving the product yield.

[0037] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A sprue bushing for reducing flow rate, the sprue bushing being mounted on an upper mold plate of an injection mold, the sprue bushing being provided with a hot runner, a hot nozzle being installed in the hot runner, the sprue bushing, the hot nozzle, the upper mold plate, and the lower mold plate of the injection mold jointly forming a molding cavity, characterized in that: One end of the sprue sleeve is provided with an inlet gate, the inlet gate is connected to the hot runner in a stepped manner, the inlet gate is trumpet-shaped, the inlet gate is connected to the hot nozzle and the molding cavity, the inlet gate has a first end and a second end, the first end of the inlet gate is arranged on the end surface of the sprue sleeve, the second end of the inlet gate is arranged at the connection between the inlet gate and the hot runner, the diameter of the circle surrounded by the first end of the inlet gate is larger than the diameter of the circle surrounded by the second end of the inlet gate, and the edge of the first end of the inlet gate is provided with a chamfered structure.

2. A sprue bushing for reducing flow rate as claimed in claim 1, characterized in that: At the connection between the inlet gate and the hot runner, the aperture of the inlet gate is larger than the aperture of the hot runner.

3. A sprue bushing for reducing flow velocity as claimed in claim 1, characterized in that: The distance between the first end of the inlet gate and the second end of the inlet gate is 5 mm to 7 mm.

4. A sprue bushing for reducing flow velocity as claimed in claim 1, characterized in that: The inlet gate has an inclined surface expanding outward from the second end to the first end, and the angle between the generatrix of the inclined surface and the central axis of the inlet gate is 12 degrees.

5. A sprue bushing for reducing flow velocity as claimed in claim 1, characterized in that: The ratio of the area of ​​the circle enclosed by the first end edge of the inlet gate to the area of ​​the circle enclosed by the second end edge of the inlet gate is 2:

1.

6. A sprue bushing for reducing flow velocity as claimed in claim 1, characterized in that: The chamfered structure is a rounded corner.

7. A sprue bushing for reducing flow velocity as claimed in claim 6, characterized in that: The radius of the fillet is 0.8 mm to 1.0 mm.

8. An injection mold, characterized in that: It comprises a hot runner plate and a sprue sleeve for reducing flow rate as described in any one of claims 1 to 7, wherein the hot runner is arranged on the hot runner plate, and the hot nozzle is connected to the flow channel in the hot runner.

9. An injection mold according to claim 8, characterized in that: The injection mold also includes a lower mold core and an upper mold core, the lower mold core is installed on the lower mold plate, the upper mold core is installed on the upper mold plate, the gate sleeve is installed on the upper mold core, and the gate sleeve, the hot nozzle, the upper mold core and the lower mold core together surround the molding cavity.

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