Mould for preventing horn gate from falling off

Abstract

The utility model discloses a mould for preventing a horn gate from falling off, which relates to the technical field of injection moulds and comprises a horn insert provided with a horn pouring gate and an ejector pin used for ejecting the horn gate formed in the horn pouring gate, and the horn insert is provided with an ejector pin hole in sliding fit with the ejector pin. The ox-horn pouring gate comprises an ejection section located in the ejector pin hole, an ox-horn glue inlet section connected with the product cavity and a shunting section connected with the ox-horn glue inlet section and the ejection section, side grooves are formed in the two opposite side faces of the ejection end of the ejector pin, and the groove walls, opposite to the hole wall of the ejector pin hole, of the side grooves extend to the ejection end face of the ejector pin to form a channel communicated with the ox-horn pouring gate; and the distance from the ejection end surface of the ejector pin when the ejector pin returns to the zero position to the shunting section is greater than the runner depth of the ox horn glue feeding section. The utility model solves the problem that the horn gate of the existing mould with the horn glue feeding structure is easy to fall off in the ejection process, is clamped on a mould ejector pin or a horn insert and needs to be manually taken out.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to a mold capable of preventing a bull horn gate from falling off. Background Art

[0002] The bull horn gate is a common glue inlet structure in the molding process of plastic products. The molding mold with the bull horn gate is mainly used to mold some plastic products that require high appearance quality, special structural requirements or high precision requirements. Because the longitudinal section of the bull horn gate close to the glue inlet presents a smooth curved cone shape like a bull horn, its minimum diameter is used as the glue inlet of the plastic part, and the glue inlet is set in a hidden place of the plastic part. After the plastic part is molded, when the bull horn gate is ejected, the connection between the gate and the plastic part is very small, and it is easy to be separated from the plastic part. No traces of the gate can be seen on the appearance surface of the plastic part, so it can effectively improve the appearance quality of the product and help meet special structural and high precision requirements.

[0003] In the current injection mold with a bull horn glue inlet structure, the runner in the bull horn insert includes a bull horn glue inlet section, a diversion section and an ejection section. The diversion section is connected to the large end of the bull horn glue inlet section. The ejection section is located in the ejection hole of the ejector pin and is perpendicular to the diversion section. The ejection surface of the ejector pin is a plane, a slope or a curved surface. The cross-sections of all parts of the ejector pin in the ejection hole except the ejection surface are the same. When using a mold with this structure for injection molding, after the product is injection molded, the front and rear models of the mold are opened, the ejector performs an ejection action, the injection port of the bull horn gate is disconnected first, and the ejector continues to eject the bull horn gate. Since the ejector only contacts the bottom of the ejection section of the bull horn gate, after the bull horn gate is completely separated from the ejection hole, it is easy to deviate from the established ejection trajectory and cause abnormal falling off, and get stuck on the mold ejector or the bull horn insert, which needs to be removed manually, and fully automatic production of robot removal cannot be achieved. During the production process, there may be problems with the gate being missed and not removed manually, and there is a possibility of the next molded product being crushed, resulting in damage to the production mold and causing production safety problems. Utility Model Content

[0004] The utility model aims to provide a mold for preventing a bull horn gate from falling off. The device can solve the problem that the bull horn gate of the existing mold with a bull horn glue feeding structure is easy to fall off during the ejection process and gets stuck on the mold ejector pin or the bull horn insert, requiring manual removal.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is: the mold for preventing the bull horn gate from falling off includes a bull horn insert provided with a bull horn runner and an ejector pin for ejecting the bull horn runner formed in the bull horn runner, the bull horn insert is provided with an ejector hole slidably matched with the ejector, the bull horn runner includes an ejection section located in the ejector hole, a bull horn glue feeding section connected to the product cavity, and a diversion section connecting the bull horn glue feeding section and the ejection section, side grooves are provided on the opposite sides of the ejection end of the ejector pin, the groove wall of the side groove opposite to the hole wall of the ejector pin extends to the ejection end face of the ejector pin, forming a channel connecting the bull horn runner; the distance from the ejection end face of the ejector pin to the diversion section when the ejector pin is at the ejector return zero position is greater than the runner depth of the bull horn glue feeding section.

[0006] In the technical solution of the molding die of the above-mentioned bull horn gate, a more specific technical solution may also be: the side groove is an undercut groove that is engaged with the bull horn gate.

[0007] Furthermore, the diameter of the ejection section is greater than the runner depth of the diversion section.

[0008] Furthermore, the axial depth of the undercut groove is greater than the diameter of the ejector pin hole.

[0009] Furthermore, the lateral distance from the ox-horn glue inlet section to the ejection section of the diversion section is greater than the lateral distance from the glue inlet of the ox-horn glue inlet section to the diversion section.

[0010] Furthermore, a trapezoidal groove is provided at the bottom of the diversion section, the large end of the trapezoidal groove is a notch, and each corner of the trapezoidal groove has an arc transition.

[0011] Furthermore, the lateral distance between the center of the trapezoidal notch and the glue inlet of the horn glue inlet section is less than or equal to the depth of the ejection section.

[0012] Due to the adoption of the above technical solution, the utility model has the following beneficial effects compared with the prior art:

[0013] 1. Side grooves are opened on the opposite sides of the ejection end of the ejector pin to make the bull horn gate intersect with the ejector pin part. The bull horn gate obtained after molding can be clamped on the ejector pin to prevent the bull horn gate from falling off during the ejection process. The distance from the ejection section of the bull horn gate from the zero-position end face of the ejector pin to the diversion section is greater than the gate depth of the bull horn glue feeding section, so that there is enough space for the bull horn gate to be ejected, which is convenient for using a robot to pick up parts, thereby realizing continuous production, improving production efficiency, ensuring production safety, and reducing labor costs.

[0014] 2. The side groove is set as an undercut groove, which improves the reliability of the bull horn gate to prevent ejection and falling off.

[0015] 3. The diameter of the ejector section is greater than the runner depth of the diversion section, which can improve the strength of the ejector section of the bull horn gate and reduce the risk of gate breakage.

[0016] 4. The axial depth of the undercut groove is greater than the diameter of the ejector hole, which can improve the reliability of the buckle between the bull horn gate and the ejector.

[0017] 5. The size limit of the diversion section and the gluing section of the bull horn runner can compress the lateral distance of the gluing section, improve the strength of the gate, reduce the risk of breakage, and make the gate easier to detach from the bull horn insert.

[0018] 6. Trapezoidal grooves with arc transitions at each corner are set in the diversion section, so that during the ejection process of the bull-horn gate, the main part can be bent and buffered at the trapezoidal groove to avoid breakage due to excessive bending stress.

[0019] 7. The distance between the bend of the bull horn gate and the glue inlet is less than or equal to the ejection section, which can ensure that when the ejection section is fully ejected, the main part of the bull horn gate is also fully ejected. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a mold for preventing a bull horn gate from falling off.

[0021] Figure 2 It is a schematic diagram of the undercut state of the bull horn gate and ejector pin.

[0022] Explanation of the accompanying numbers: 1. movable mold; 2. product cavity; 3. fixed mold; 4. bull horn insert; 5. ejector pin; 6. undercut groove; 7. ejector section; 8. diversion section; 9. trapezoidal groove; 10. bull horn glue inlet section; 11. glue inlet; 12. plastic product; 13. bull horn gate. DETAILED DESCRIPTION

[0023] The utility model is further described in detail below in conjunction with the accompanying drawings:

[0024] Figure 1 and Figure 2 The mold for preventing the bull horn gate from falling off shown includes a movable mold 1, a fixed mold 3, a bull horn insert 4 and an ejector 5. A product cavity 2 is provided in the movable mold 1, and a bull horn insert 4 is embedded in the fixed mold 3. A bull horn runner and an ejector hole are provided in the bull horn insert 4. The ejector 5 is inserted into the ejector hole to eject the bull horn gate 13 formed in the bull horn runner, and the ejector 5 is slidably matched with the ejector hole.

[0025] The bull horn runner includes an ejection section 7, a diverter section 8 and a bull horn glue inlet section 10. The ejection section 7 is located in the ejector hole and intersects with the ejection end of the ejector 5. The diverter section 8 is a transverse runner perpendicular to the ejection section 7. The diameter of the ejection section 7 is greater than the runner depth H1 of the diverter section 8. The distance H2 from the ejection end surface of the ejector 5 to the diverter section 8 when the ejector 5 is at the ejector return zero position is greater than the runner depth H4 of the bull horn glue inlet section 10. The ejection section 7 is connected to the bull horn glue inlet section 10 through the diverter section 8. The large end of the bull horn glue inlet section 10 is connected to the diverter section 8, and its small end is a glue inlet 11 connected to the product cavity 2. The lateral distance L1 of the diverter section 8 from the bull horn glue inlet section 10 to the ejection section 7 is greater than the lateral distance L2 from the glue inlet 11 of the bull horn glue inlet section 10 to the diverter section 7. A trapezoidal groove 9 is provided at the bottom of the diversion section 7, the large end of the trapezoidal groove 9 is a notch, the corners of the trapezoidal groove 9 are arc transitions, and the lateral distance between the center of the trapezoidal notch 9 and the glue inlet 11 of the horn glue inlet section 10 is less than or equal to the depth of the ejection section 7. The horn insert 4 of this embodiment is a single insert that is integrally cast, and the horn insert in other embodiments can also be composed of multiple inserts.

[0026] In order to make the ejection end of the ejector pin 5 intersect with the ejection section 7 of the bull horn runner without affecting the removal of the bull horn runner 13 from the ejector pin 5 after demolding, side grooves are provided on the two opposite sides of the ejection end of the ejector pin 5, and the groove wall of the side groove opposite to the wall of the ejector hole extends to the ejection end face of the ejector pin to form a channel connected to the bull horn runner. Preferably, the side groove is an undercut groove 6 that is engaged with the bull horn runner 13, and the undercut groove 6 has a radial plane and an inclined surface connecting the radial plane and the ejection end face of the ejector pin 5, and the inclined surface is inclined inwardly from the ejection end face of the ejector pin 5 toward the radial plane. The axial depth of the undercut groove 6, that is, the distance H3 between the ejection end face of the ejector pin 5 and the radial plane, is greater than the diameter of the ejector hole.

[0027] After the plastic product 12 is injection molded, the end of the horn gate 13 in the horn runner located in the ejection section 7 is buckled and connected with the undercut groove 6 of the ejector pin 5, which can prevent the horn gate 13 from falling off during the ejection process. After the mold is opened, the ejector pin 5 is in the process of ejecting the horn gate 13, and the glue inlet 11 is disconnected from the plastic product 12, and the horn gate 13 is bent at the groove corresponding to the trapezoidal groove 9. Since the distance H2 from the ejection section 7 of the horn runner from the zero-position end face of the ejector to the diversion section 8 is greater than the runner depth H4 of the horn glue inlet section 10, the ejector pin 5 can completely eject the main body of the horn gate 13 from the horn insert 4 when it does not extend out of the ejector hole. After the horn gate 13 is completely ejected from the horn insert 4, there is enough space between the main body of the horn gate 13 and the horn insert 4, which is convenient for using a robot to pick up the parts. When taking out the parts, the parts are taken out radially outward along the inclined surface of the undercut groove 9, so that the horn gate 13 can be separated from the ejector 5, and the horn gate 13 can be prevented from being stuck on the ejector 5 or the horn insert 4. In this way, the injection molding machine can continue to produce without opening the door, thereby improving production efficiency; in addition, since there is no need to manually take out the parts, production safety is guaranteed and labor costs are reduced.

Claims

1. A mold for preventing a bull horn gate from falling off, comprising a bull horn insert provided with a bull horn runner and an ejector pin for ejecting the bull horn gate formed in the bull horn runner, the bull horn insert being provided with an ejector pin hole for slidingly cooperating with the ejector pin, the bull horn runner comprising an ejection section located in the ejector pin hole, a bull horn glue feeding section connected to a product cavity, and a diversion section connecting the bull horn glue feeding section and the ejection section, characterized in that: Side grooves are provided on opposite sides of the ejection end of the ejector pin, and the groove walls of the side grooves opposite to the ejector hole walls extend to the ejection end surface of the ejector pin to form a channel connected to the bull horn runner; when the ejector pin is at the ejector pin return zero position, the distance from the ejection end surface to the diversion section is greater than the runner depth of the bull horn glue feeding section.

2. The mold for preventing the bull horn gate from falling off according to claim 1, characterized in that: The side groove is an undercut groove that is engaged with the bull horn gate.

3. The mold for preventing the bull horn gate from falling off according to claim 2, characterized in that: The diameter of the ejection section is greater than the runner depth of the diversion section.

4. The mold for preventing the bull horn gate from falling off according to claim 3 is characterized in that: The axial depth of the undercut groove is greater than the diameter of the ejector pin hole.

5. The mold for preventing the bull horn gate from falling off according to claim 4, characterized in that: The lateral distance of the diversion section from the ox horn glue feeding section to the ejection section is greater than the lateral distance from the glue inlet of the ox horn glue feeding section to the diversion section.

6. The mold for preventing the bull horn gate from falling off according to any one of claims 1 to 5, characterized in that: A trapezoidal groove is provided at the bottom of the diversion section, the large end of the trapezoidal groove is a notch, and each corner of the trapezoidal groove has an arc transition.

7. The mold for preventing the horn gate from falling off according to claim 6, characterized in that: The lateral distance between the center of the trapezoidal groove and the glue inlet of the horn glue inlet section is less than or equal to the depth of the ejection section.

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