Hot runner structure of injection mold

Abstract

The utility model relates to a hot runner structure of an injection mold, which comprises two first hot runners arranged at the top of an upper mold, an injection molding cavity is arranged at the bottom of the upper mold, a second hot runner is arranged in the upper mold, the first hot runners are communicated with the second hot runner, and a heating part is arranged on the outer side of the second hot runner. And a discharging opening is formed in the inner top wall of the injection molding cavity and communicates with the second hot runner, side grooves are formed in the two opposite side walls of the discharging opening, the two inner side walls in the width direction of the side grooves are coplanar with the inner side wall of the discharging opening, and heat insulation baffles are slidably connected into the side grooves. The utility model relates to the technical field of injection molding. A worker rotates the two rotating rods to drive the two heat insulation baffles to be attached to each other and shield the discharging opening, so that the second hot runner is separated from the injection molding cavity, and demolding of a plastic workpiece is facilitated; and before the injection molding liquid is added next time, the heating pipe is started to work, so that plastic in the second hot runner is molten.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding, in particular to a hot runner structure of an injection mold. Background Art

[0002] Injection molds are tools for producing plastic products and also tools for giving plastic products complete structures and precise dimensions. Injection molding is a processing method used in mass production of certain parts with complex shapes. Specifically, it refers to the process of injecting heated and melted plastic into the mold cavity under high pressure by an injection molding machine, and then cooling and solidifying to obtain a molded product.

[0003] For example, the Chinese patent with publication number CN213618105U discloses a hot runner system structure of an injection mold, including a first mounting plate, a lower mold fixedly connected to the top of the first mounting plate, a first injection cavity formed at the top of the lower mold, an upper mold provided at the top of the lower mold, and a second injection cavity formed at the bottom of the upper mold. The utility model achieves the advantage of preventing the hot runner system structure from being blocked by arranging the first hot runner, the second hot runner, the injection joint, the servo motor, the rotating column, the anti-blocking auger, the heating cavity, the heating mechanism, the heat absorbing plate, the heat conducting column, the heating plate and the high temperature resistant sealing ring to cooperate with each other, so that the hot runner system structure can effectively heat the inside of the hot runner when used for a long time, and can also rotate to feed the inside of the hot runner to prevent the inside of the hot runner from being blocked, thereby improving the injection efficiency of the injection mold and meeting the needs of users.

[0004] This patent can heat the inside of the hot runner to prevent the hot runner from being blocked when adding molten plastic to the injection cavity. However, when the injection cavity is filled with injection liquid, some excess plastic liquid will remain in the second hot runner. If the second hot runner is not heated, the plastic in the second hot runner will stick to the curved anti-blocking dragon after cooling and solidifying, thereby hindering the normal demolding of the finished plastic product; and if the second hot runner is heated, heat will also be transferred near the second hot runner in the injection cavity, resulting in the inability of the finished plastic product to be completely solidified, reducing the quality of injection molding. For this reason, we propose a hot runner structure for injection molds. Utility Model Content

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a hot runner structure for an injection mold so as to solve the technical problems mentioned in the above background technology.

[0006] The above technical objectives of the utility model are achieved through the following technical solutions:

[0007] A hot runner structure for an injection mold comprises two first hot runners opened at the top of an upper mold, an injection cavity is opened at the bottom of the upper mold, a second hot runner is opened in the upper mold, the first hot runner is communicated with the second hot runner, a heating portion is arranged on the outer side of the second hot runner, a discharge port is opened on the top wall of the injection cavity, the discharge port is communicated with the second hot runner, side grooves are opened on the opposite side walls of the discharge port, the two inner side walls in the width direction of the side grooves are coplanar with the inner side walls of the discharge port, a heat insulation baffle is slidably connected in the side groove, and an adjustment portion is arranged on one side of the heat insulation baffle.

[0008] Furthermore, the adjusting part includes a rotating rod rotatably penetrated through the top of the upper mold, the bottom end of the rotating rod extends into the side groove, a screw is horizontally rotatably connected in the side groove, the screw is threadedly connected to the corresponding heat insulation baffle, and the rotating rod is transmission-connected to the corresponding screw through a bevel gear set.

[0009] Furthermore, a shield is fixedly sleeved on the upper half of the outer circumference of the rotating rod, and the bottom surface of the shield is in contact with the top surface of the upper mold.

[0010] Furthermore, the heating part includes two side cavities opened in the upper mold, a heating tube is fixedly connected in the side cavity, a plurality of heat-conducting rods are fixedly penetrated through the inner wall of the side cavity, one end of the heat-conducting rod extends into the second hot runner, a first heat-conducting plate is fixedly connected to one end of the corresponding heat-conducting rods located in the side cavity, and a second heat-conducting plate is fixedly connected to one end of the corresponding heat-conducting rods located in the second hot runner.

[0011] Furthermore, the side wall of the second heat conducting plate is in contact with the inner wall of the second hot runner.

[0012] Furthermore, a motor is fixedly connected to the top of the upper mold, and an output shaft is transmission-connected to the output end of the motor. The output shaft extends into the second hot runner, and the bottom end of the output shaft is located above the discharge port. An anti-blocking dragon is fixedly provided on the outer peripheral surface of the output shaft.

[0013] In summary, the present invention includes at least one of the following beneficial technical effects:

[0014] 1. In this hot runner structure of an injection mold, after the injection liquid is added, the staff rotates the two rotating rods to drive the two heat insulation baffles to fit together and cover the discharge port, thereby separating the second hot runner from the injection cavity, which is convenient for demolding the plastic workpiece; before the next injection liquid is added, the heating tube is started to melt the plastic in the second hot runner and fall into the injection cavity to prevent the second hot runner from being blocked;

[0015] 2. In this injection mold hot runner structure, when the two heat insulation baffles are in contact with each other, the two baffles respectively cover the tops of the two first hot runners. Therefore, when the solidified plastic in the second hot runner is heated, the heat in the second hot runner will not be discharged to the external environment, thereby improving the heating effect and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a three-dimensional diagram of a hot runner structure of an injection mold in this embodiment;

[0018] Figure 2 is a front cross-sectional view of a hot runner structure of an injection mold in this embodiment;

[0019] Figure 3 This embodiment Figure 2 Enlarged view of point A in the middle.

[0020] In the figure, 1. upper mold; 2. first hot runner; 3. injection cavity; 4. second hot runner; 5. heating part; 51. heating tube; 52. side cavity; 53. heat conducting rod; 54. first heat conducting plate; 55. second heat conducting plate; 6. discharge port; 7. side groove; 8. heat insulating baffle; 9. adjustment part; 91. rotating rod; 92. screw; 93. shield; 10. motor; 11. output shaft; 12. anti-blocking dragon. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0022] Example:

[0023] Reference Figures 1 to 3 The utility model discloses a hot runner structure of an injection mold, comprising two first hot runners 2 opened on the top of an upper mold 1, an injection cavity 3 opened at the bottom of the upper mold 1, a second hot runner 4 opened in the upper mold 1, the first hot runner 2 is communicated with the second hot runner 4, a heating portion 5 is arranged on the outer side of the second hot runner 4, a discharge port 6 is opened on the top wall of the injection cavity 3, the discharge port 6 is communicated with the second hot runner 4, side grooves 7 are opened on the two opposite side walls of the discharge port 6, the two inner side walls of the side groove 7 in the width direction are coplanar with the inner side wall of the discharge port 6, a heat insulation baffle 8 is slidably connected in the side groove 7, and an adjustment portion 9 is arranged on one side of the heat insulation baffle 8.

[0024] In this embodiment, the injection liquid enters the second hot runner 4 through the first hot runner 2, and then enters the injection cavity 3 through the discharge port 6, and forms a plastic workpiece after being cooled and solidified.

[0025] The first hot runner 2 is set to have an inner diameter that gradually decreases from top to bottom. The inner bottom wall of the second hot runner 4 is set to be inclined downward on the side close to the discharge port 6. The heat insulation baffle 8 is a heat-resistant laminated board synthesized from a skeleton-like glass fiber and a high-heat-resistant composite material, and has a high heat insulation effect. In the initial state, the heat insulation baffle 8 is completely located in the corresponding side groove 7.

[0026] In a further preferred embodiment of the present invention, Figure 2 As shown, the adjusting part 9 includes a rotating rod 91 rotatably penetrated through the top of the upper mold 1, the bottom end of the rotating rod 91 extends into the side groove 7, a screw rod 92 is horizontally rotatably connected in the side groove 7, the screw rod 92 is threadedly connected to the corresponding heat insulation baffle 8, and the rotating rod 91 is transmission-connected to the corresponding screw rod 92 through a bevel gear set.

[0027] In this embodiment, after the injection liquid is added, the staff rotates the two rotating rods 91, drives the screw 92 to rotate through the bevel gear set, and the screw 92 drives the insulation baffle 8 to move horizontally. The two insulation baffles 8 enter the discharge port 6 and fit each other, thereby shielding the discharge port 6 and separating the injection liquid in the injection cavity 3 from the injection liquid in the second hot runner 4. Therefore, after the injection liquid in the injection cavity 3 is cooled and solidified, it can be easily demolded.

[0028] After the plastic workpiece is demoulded and before the next injection liquid is added, the heating unit 5 is started to melt the plastic in the second hot runner 4 to prevent the second hot runner 4 from being blocked.

[0029] In a further preferred embodiment of the present invention, Figure 1 As shown, a shield plate 93 is fixedly sleeved on the upper half of the outer circumference of the rotating rod 91, and the bottom surface of the shield plate 93 is in contact with the top surface of the upper mold 1.

[0030] In this embodiment, when the two heat insulation baffles 8 are in contact with each other, the shield 93 also shields the corresponding first hot runner 2. Therefore, when the plastic solidified in the second hot runner 4 is heated, the heat in the second hot runner 4 will not be discharged to the external environment, thereby improving the heating effect and reducing energy consumption.

[0031] In the initial state, the shielding plate 93 does not shield the first hot runner 2, and the heat insulation baffle 8 is completely located in the corresponding side groove 7 (such as Figure 2 Injection liquid can be added in this state.

[0032] In a further preferred embodiment of the present invention, Figure 2 and Figure 3As shown, the heating part 5 includes two side cavities 52 opened in the upper mold 1, a heating tube 51 is fixedly connected in the side cavity 52, a plurality of heat-conducting rods 53 are fixedly penetrated through the inner wall of the side cavity 52, one end of the heat-conducting rod 53 extends into the second hot runner 4, and a first heat-conducting plate 54 is fixedly connected to one end of the corresponding plurality of heat-conducting rods 53 located in the side cavity 52, and a second heat-conducting plate 55 is fixedly connected to one end of the corresponding plurality of heat-conducting rods 53 located in the second hot runner 4.

[0033] In this embodiment, the heating tube 51 is connected to an external power source through a circuit, and the heat-conducting rod 53, the first heat-conducting plate 54 and the second heat-conducting plate 55 are all made of copper material, and the heat-conducting effect is good. When the heating tube 51 is working, the air in the side cavity 52 is heated, and the hot air exchanges heat with the first heat-conducting plate 54. The heat enters the second hot runner 4 through the heat-conducting rod 53 and the second heat-conducting plate 55, and heats the solidified plastic in the second hot runner 4.

[0034] In a further preferred embodiment of the present invention, Figure 2 As shown, a motor 10 is fixedly connected to the top of the upper mold 1, and an output shaft 11 is transmission-connected to the output end of the motor 10. The output shaft 11 extends into the second hot runner 4, and the bottom end of the output shaft 11 is located above the discharge port 6. An anti-blocking dragon 12 is fixedly sleeved on the outer peripheral surface of the output shaft 11.

[0035] The side wall of the second heat conducting plate 55 is in contact with the inner wall of the second hot runner 4 to prevent the anti-blocking dragon 12 from colliding with the second heat conducting plate 55 when rotating.

[0036] In this embodiment, during the process of adding injection liquid, the heating tube 51 can also work to heat the inside of the second hot runner 4 to further prevent it from being blocked. At this time, the motor 10 drives the output shaft 11 and the anti-blocking dragon 12 to rotate, and the anti-blocking dragon 12 transports the injection liquid to move downward quickly into the injection cavity 3, reducing the residence time of the injection liquid in the first hot runner 2 and the second hot runner 4, thereby reducing the risk of blockage.

[0037] The implementation principle of the above embodiment is:

[0038] In the initial state, the shield 93 does not shield the first hot runner 2, and the heat insulation baffle 8 is completely located in the corresponding side groove 7. The staff adds the injection liquid into the first hot runner 2, and the injection liquid passes through the second hot runner 4 and the discharge port 6 in sequence and finally enters the injection cavity 3. At the same time, the heating pipe 51 works to heat the inside of the second hot runner 4, and the motor 10 works to drive the anti-blocking dragon 12 to rotate, and the injection liquid is transported to quickly enter the injection cavity 3.

[0039] After the injection liquid is added, the heating tube 51 and the motor 10 are turned off. The shield 93 is rotated so that the shield 93 shields the first hot runner 2, and the shield 93 drives the rotating rod 91 to rotate, and the rotating rod 91 drives the screw 92 to rotate, and the screw 92 drives the heat insulation baffle 8 to extend into the discharge port 6, and the two heat insulation baffles 8 fit together to shield the discharge port 6, and also separate the injection liquid in the injection cavity 3 from the injection liquid in the second hot runner 4, so that after the injection liquid in the injection cavity 3 is cooled and solidified, it can be easily demolded.

[0040] After the plastic workpiece is demoulded, before the next injection liquid is added, the heating unit 5 is started to melt the plastic in the second hot runner 4 to prevent the second hot runner 4 from being blocked. Then the shield 93 is rotated to expose the first hot runner 2, and the molten injection liquid in the second hot runner 4 enters the injection cavity 3.

[0041] The embodiments of this specific implementation method are all preferred embodiments of the utility model, and are not intended to limit the protection scope of the utility model. Therefore, all equivalent changes made based on the structure, shape, and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A hot runner structure of an injection mold, comprising two first hot runners (2) opened at the top of an upper mold (1), an injection cavity (3) opened at the bottom of the upper mold (1), characterized in that: A second hot runner (4) is provided in the upper mold (1), the first hot runner (2) is communicated with the second hot runner (4), a heating portion (5) is provided on the outer side of the second hot runner (4), a discharge port (6) is provided on the inner top wall of the injection cavity (3), the discharge port (6) is communicated with the second hot runner (4), side grooves (7) are provided on opposite side walls of the discharge port (6), the two inner side walls of the side groove (7) in the width direction are coplanar with the inner side walls of the discharge port (6), a heat insulation baffle (8) is slidably connected in the side groove (7), and an adjustment portion (9) is provided on one side of the heat insulation baffle (8).

2. The hot runner structure of an injection mold according to claim 1, characterized in that: The adjusting portion (9) comprises a rotating rod (91) rotatably arranged on the top of the upper mold (1), the bottom end of the rotating rod (91) extends into the side groove (7), a screw rod (92) is horizontally rotatably connected in the side groove (7), the screw rod (92) is threadedly connected to the corresponding heat insulation baffle (8), and the rotating rod (91) is transmission-connected to the corresponding screw rod (92) via a bevel gear set.

3. The hot runner structure of an injection mold according to claim 2, characterized in that: A shield plate (93) is fixedly sleeved on the upper half of the outer circumference of the rotating rod (91), and the bottom surface of the shield plate (93) is in contact with the top surface of the upper mold (1).

4. The hot runner structure of an injection mold according to claim 1, characterized in that: The heating portion (5) comprises two side cavities (52) opened in the upper mold (1), a heating tube (51) is fixedly connected in the side cavity (52), a plurality of heat-conducting rods (53) are fixedly penetrated through the inner wall of the side cavity (52), one end of the heat-conducting rod (53) extends into the second hot runner (4), one end of the corresponding plurality of heat-conducting rods (53) located in the side cavity (52) is fixedly connected to a first heat-conducting plate (54), and one end of the corresponding plurality of heat-conducting rods (53) located in the second hot runner (4) is fixedly connected to a second heat-conducting plate (55).

5. The hot runner structure of an injection mold according to claim 4, characterized in that: The side wall of the second heat conducting plate (55) is in contact with the inner wall of the second hot runner (4).

6. The hot runner structure of an injection mold according to claim 5, characterized in that: A motor (10) is fixedly connected to the top of the upper mold (1), and an output shaft (11) is drivingly connected to the output end of the motor (10). The output shaft (11) extends into the second hot runner (4), and the bottom end of the output shaft (11) is located above the discharge port (6). An anti-blocking dragon (12) is fixedly sleeved on the outer peripheral surface of the output shaft (11).

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