A hidden gate type injection mold

Abstract

The application discloses a hidden gate type injection mold, which comprises a male mold, a female mold, a first core-pulling mechanism, a second core-pulling mechanism and an ejection mechanism; the female mold is provided with a gate; the first core-pulling mechanism is provided with an injection inlet groove; one side of the injection inlet groove is communicated with an injection runner groove; and the ejection mechanism is provided with a vertical gap corresponding to the injection runner groove. The injection inlet groove is arranged on the first core-pulling mechanism, the injection runner groove communicated with the injection inlet groove is arranged on one side of the injection inlet groove, and the vertical gap is arranged on the ejection mechanism corresponding to the injection runner groove. When the male mold and the female mold are closed, an injection channel is formed among the injection inlet groove, the injection runner groove and the gap, the gate position of the plastic part is changed to the bottom of the plastic part by virtue of the unique design, and thus the situation that the mold line exists on the surface of the plastic part is avoided, the structure is ingenious, and the injection quality of the plastic part is improved.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and in particular to a hidden gate injection mold. Background Technology

[0002] Electroplated decorative strips require injection molding during production. Some automotive electroplated decorative strips have unique shapes and structures; after assembly with the radiator grille, the edges are directly exposed without the usual "brims" for concealment. This places high demands on the parting line quality, allowing no step differences, flash defects, or any other mold lines. Initially, our company designed molds using a conventional structure, with material feeding from the fixed mold side and employing independent slides or angled ejectors to achieve non-shearing latent gates. However, this resulted in additional mold lines at the rounded corners, affecting the appearance quality of the electroplated decorative strip parts and failing to meet customer requirements.

[0003] Based on the customer's needs, we began to improve the above mold by changing the mold to feed from the moving mold side, inverting the hot runner, and using an integral angled ejector or slider. There are no additional mold lines on the rounded corners, which can meet the appearance quality requirements. However, the customer does not accept the structure of the hot runner system on the moving mold side. The hot runner is under the angled ejector or slider, which requires high skills from the injection molding personnel and is prone to misoperation that could damage the mold by clamping the material.

[0004] Therefore, it is necessary to design a hidden gate injection mold to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to address the problem that the surface of the molded decorative strip has splicing lines when it is injected into the mold, which affects the aesthetics of the plastic part, and to propose a hidden gate injection mold.

[0006] The technical solution of the present invention is: a hidden gate injection mold, comprising a punch, a die, a first core-pulling mechanism, a second core-pulling mechanism, and an ejection mechanism; the die is provided with a gate; the first core-pulling mechanism is provided with an injection inlet groove; one side of the injection inlet groove is connected to an injection runner groove; the ejection mechanism is provided with a vertical notch corresponding to the injection runner groove; when the punch and die are closed: an injection cavity for a plastic part is formed between the punch, die, first core-pulling mechanism, second core-pulling mechanism, and ejection mechanism; the gate is connected to the injection inlet groove through a hot runner; an injection channel is formed between the injection inlet groove, the injection runner groove, and the notch.

[0007] The first core-pulling mechanism includes a first core-pulling slider; the first core-pulling slider is slidably connected to the punch; the die is provided with an inclined guide post that slidably engages with the first core-pulling slider; the injection inlet groove and the injection runner groove are both located on the upper end face of the first core-pulling slider near the plastic part.

[0008] The second core-pulling mechanism includes an inclined ejector movably mounted on the punch; a push plate is provided at the bottom of the punch; an inclined ejector slide is provided on the push plate; an inclined ejector rod that slides into the punch and is fixed to the inclined ejector is slidably connected in the inclined ejector slide; and a drive assembly for driving the push plate is fixed on the punch.

[0009] The ejection mechanism includes an ejection block movably mounted on the punch and an ejection rod mounted on the push plate; the ejection rod slides into the punch and is fixedly connected to the ejection block; the notch is located on the side wall of the ejection block and corresponds to the position of the injection runner groove on the first core-pulling slider.

[0010] The top of the inclined top is provided with a positioning cone that mates with the die.

[0011] The injection inlet groove is a tapered hole that is larger at the top and smaller at the bottom.

[0012] The driving component is a hydraulic cylinder symmetrically arranged on both sides of the punch; one end of the hydraulic cylinder is fixedly connected to the punch, and the other end is fixedly connected to the push plate.

[0013] The present invention has the following beneficial effects by adopting the above technical solution: (1) The present invention provides an injection inlet groove on the first core pulling mechanism, and provides an injection runner groove communicating with the injection inlet groove on one side of the injection inlet groove, and provides a vertical notch at the injection runner groove corresponding to the ejection mechanism; when the punch and die are closed, an injection channel is formed between the injection inlet groove, the injection runner groove and the notch. The unique design changes the gate position of the plastic part to the bottom of the plastic part, thereby avoiding the presence of splicing lines on the surface of the plastic part. The structure is ingenious and improves the injection quality of the plastic part.

[0014] (2) The first core-pulling slider of the present invention is driven by the inclined guide post set on the die, which not only ensures its motion stability, but also eliminates the need for an additional drive structure for the first core-pulling slider, simplifying the overall structure of the mold and reducing the manufacturing cost of the mold.

[0015] (3) The inclined pusher of the present invention is driven by an inclined pusher rod that is slidably connected to the push plate, which can ensure the stability of the inclined pusher movement.

[0016] (4) The ejection mechanism of the present invention uses an ejection rod on the push plate to drive the ejection block to eject the plastic part. The ejection block not only forms the injection channel, but also ejects the plastic part. The structure is ingenious.

[0017] (5) The present invention provides a positioning cone at the top of the inclined top to cooperate with the die, so as to facilitate its precise cooperation with the die.

[0018] (6) The injection inlet groove of the present invention is a tapered hole with a larger upper part and a smaller lower part, so as to facilitate its precise fit with the hot runner and avoid material leakage.

[0019] (7) The drive assembly of the present invention uses hydraulic cylinders symmetrically arranged on both sides of the punch to ensure the stability of the push plate operation. Attached Figure Description

[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a cross-sectional view of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the first core-pulling mechanism of the present invention.

[0024] Figure 4 This is a schematic diagram of the ejection mechanism of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure of the plastic part of the present invention.

[0026] The labels in the attached diagram are:

[0027] 1. Punch; 2. Die; 3. First core-pulling mechanism; 3-1. First core-pulling slider; 3-2. Angled guide post; 4. Second core-pulling mechanism; 4-1. Angled ejector; 4-2. Push plate; 4-3. Angled ejector slide; 4-4. Angled ejector rod; 4-5. Drive assembly; 4-6. Positioning cone; 5. Ejection mechanism; 5. Ejection block; 5-1. Ejection rod; 5-2. Gate; 6. Injection inlet groove; 7. Injection runner groove; 8. Notch; 9. Detailed Implementation

[0028] (Example 1)

[0029] See Figures 1 to 5 This embodiment of a hidden gate injection mold includes a punch 1, a die 2, a first core-pulling mechanism 3, a second core-pulling mechanism 4, and an ejector mechanism 5. The die 2 is provided with a gate 6. The first core-pulling mechanism 3 is provided with an injection inlet groove 7. One side of the injection inlet groove 7 is connected to an injection runner groove 8. The ejector mechanism 5 is provided with a vertical notch 9 corresponding to the injection runner groove 8. When the punch 1 and the die 2 are closed, an injection cavity for the plastic part is formed between the punch 1, the die 2, the first core-pulling mechanism 3, the second core-pulling mechanism 4, and the ejector mechanism 5. The gate 6 is connected to the injection inlet groove 7 through a hot runner. An injection channel is formed between the injection inlet groove 7, the injection runner groove 8, and the notch 9. This embodiment adopts a two-cavity injection molding, that is, the first core-pulling mechanism 3, the second core-pulling mechanism 4, and the ejector mechanism 5 are symmetrically arranged, and each first core-pulling mechanism 3 is symmetrically provided with two injection inlet grooves 7.

[0030] Furthermore, the first core-pulling mechanism 3 includes a first core-pulling slider 3-1; the first core-pulling slider 3-1 is slidably connected to the punch 1; the die 2 is provided with an inclined guide post 3-2 that slidably engages with the first core-pulling slider 3-1; the injection inlet groove 7 and the injection runner groove 8 are both located on the upper end face of the first core-pulling slider 3-1 near the plastic part. In this embodiment, the inclined guide post 3-2 is used to drive the first core-pulling slider 3-1 to move, which not only ensures its movement stability, but also eliminates the need for an additional drive structure for the first core-pulling slider 3-1, simplifying the overall structure of the mold and reducing the manufacturing cost of the mold.

[0031] Furthermore, the second core-pulling mechanism 4 includes an inclined ejector 4-1 movably mounted on the punch 1; a push plate 4-2 is provided at the bottom of the punch 1; an inclined ejector slide 4-3 is provided on the push plate 4-2; an inclined ejector rod 4-4 is slidably connected inside the inclined ejector slide 4-3, extending into the punch 1 and fixed to the inclined ejector 4-1; a driving assembly 4-5 for driving the push plate 4-2 is fixed on the punch 1. In this embodiment, the inclined ejector 4-1 is driven by the inclined ejector rod 4-4 slidably connected to the push plate 4-2, which can ensure the stability of the movement of the inclined ejector 4-1.

[0032] Furthermore, the ejection mechanism 5 includes an ejection block 5-1 movably mounted on the punch 1 and an ejection rod 5-2 mounted on the push plate 4-2; the ejection rod 5-2 slides into the punch 1 and is fixedly connected to the ejection block 5-1; the notch 9 is located on the side wall of the ejection block 5-1 and corresponds to the position of the injection runner groove 8 on the first core-pulling slider 3-1. In this embodiment, the ejection mechanism 5 uses the ejection rod 5-2 mounted on the push plate 4-2 to drive the ejection block 5-1 to eject the plastic part. The ejection block 5-1 not only forms the injection channel but also ejects the plastic part, which is ingenious in structure.

[0033] Furthermore, the top of the inclined top 4-1 is provided with a positioning cone 4-6 that mates with the die 2, so as to facilitate its precise mating with the die 2.

[0034] Furthermore, the injection inlet groove 7 is a tapered hole that is larger at the top and smaller at the bottom, so as to facilitate its precise fit with the hot runner and avoid material leakage.

[0035] Furthermore, the driving assembly 4-5 is a hydraulic cylinder symmetrically arranged on both sides of the punch 1; one end of the hydraulic cylinder is fixedly connected to the punch 1, and the other end is fixedly connected to the push plate 4-2 to ensure the stability of the push plate 4-2 during operation.

[0036] The working process of a hidden gate injection mold in this embodiment is as follows: First, the punch 1 and the die 2 are closed, and then injection, pressure holding, cooling, and mold opening are performed. After mold opening, the first core-pulling slider 3-1 pulls the core from one side of the plastic part under the action of the inclined guide post 3-2. The driving component 4-5 drives the push plate 4-2 to move and eject the inclined ejector 4-1. The inclined ejector 4-1 realizes the core-pulling of the other side of the plastic part. At the same time, the ejector block 5-1 ejects the plastic part, completing the demolding of the plastic part.

[0037] In this embodiment, the hidden gate injection mold is provided with an injection inlet groove 7 on the first core pulling mechanism 3, and an injection runner groove 8 communicating with the injection inlet groove 7 is provided on one side of the injection inlet groove 7. Moreover, a vertical notch 9 is provided on the ejector mechanism 5 corresponding to the injection runner groove 8. When the punch 1 and the die 2 are closed, an injection channel is formed between the injection inlet groove, the injection runner groove 8 and the notch 9. The unique design changes the position of the gate 6 of the plastic part to the bottom of the plastic part, thereby avoiding the presence of mold lines on the surface of the plastic part. The structure is ingenious and improves the injection quality of the plastic part.

[0038] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hidden gate injection mold characterized by: The utility model relates to a kind of injection molding machine, including punch (1), female die (2), first core-pulling mechanism (3), second core-pulling mechanism (4) and ejection mechanism (5);The female die (2) is equipped with sprue (6);The first core-pulling mechanism (3) is equipped with injection inlet slot (7);Injection inlet slot (7) side is communicated with injection runner slot (8);The ejection mechanism (5) is equipped with vertical direction notch (9) corresponding injection runner slot (8);When the punch (1) is closed with female die (2): the punch (1), female die (2), first core-pulling mechanism (3), second core-pulling mechanism (4) and ejection mechanism (5) form the injection molding cavity of plastic part between;The sprue (6) is communicated with injection inlet slot (7) by hot runner;Injection inlet slot (7), injection runner slot (8) and notch (9) form injection channel between;The first core-pulling mechanism (3) includes first core-pulling slider (3-1);The first core-pulling slider (3-1) is slidably connected on punch (1);The female die (2) is equipped with inclined guide pillar (3-2) with the sliding fit of first core-pulling slider (3-1);Injection inlet slot (7) and injection runner slot (8) are all equipped on the upper end surface of first core-pulling slider (3-1) close to plastic part one end;The second core-pulling mechanism (4) includes inclined ejector (4-1) movably arranged on punch (1);The bottom of punch (1) is equipped with push plate (4-2);The push plate (4-2) is equipped with inclined ejector slide (4-3);Inclined ejector slide (4-3) is slidably connected with inclined ejector rod (4-4) slidingly extended into punch (1) and fixed with inclined ejector (4-1);The punch (1) is fixed with drive assembly (4-5) for driving push plate (4-2) to move;The ejection mechanism (5) includes ejection block (5-1) movably arranged on punch (1) and ejection rod (5-2) arranged on push plate (4-2);The ejection rod (5-2) is slidably extended into punch (1) and fixedly connected with ejection block (5-1);The notch (9) is arranged on the side wall of ejection block (5-1) and position corresponding injection runner slot (8) on first core-pulling slider (3-1).

2. A hidden gate injection mold according to claim 1, characterized in that: The top of the inclined ejector (4-1) is provided with a positioning cone (4-6) matched with the female die (2).

3. A hidden gate injection mold according to claim 1, characterized in that: The injection inlet slot (7) is a tapered hole with a large upper part and a small lower part.

4. A hidden gate injection mold according to claim 1, characterized in that: The drive assembly (4-5) is a hydraulic cylinder symmetrically arranged on both sides of the punch (1), one end of which is fixedly connected with the punch (1), and the other end is fixedly connected with the push plate (4-2).

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