Injection mold gate breaking device and injection molding process

Abstract

The application provides an injection mold gate breaking device and an injection part forming process, and relates to the technical field of injection parts. The device comprises a sliding block, a core-pulling device, an oil cylinder and a motion conversion assembly. The sliding block is arranged on the side of the gate of the mold. The oil cylinder is connected to one end of the core-pulling device and is used to drive the core-pulling device to move along the axial direction. The sliding block and the motion conversion assembly are drivingly connected and are respectively connected to the other end of the core-pulling device. The motion conversion assembly is used to drive the sliding block to move along the direction perpendicular to the axial direction of the core-pulling device under the driving action of the core-pulling device, so as to cut off the redundant material at the gate. The application realizes the in-mold cutting of the redundant material, avoids the redundant process, and realizes the higher-quality cutting of the gate by using the pure mechanical structure. The gate position is more beautiful in shape, no heating element is lost, and energy is saved.

Description

Technical Field

[0001] This invention relates to the field of injection molded parts technology, and more specifically, to an injection mold gate break-off device and an injection molded part molding process. Background Technology

[0002] In the injection molding process of automotive interior panels, a closed mold cavity is formed by closing an upper mold and a lower mold with a cavity. Molten material in a hot state is then introduced into the mold cavity. After the molten material completely fills the mold cavity and cools and solidifies, the mold cavity is opened to obtain the interior panel part with the predetermined shape or structure. The opening on the mold that connects to the mold cavity and is used to introduce the molten material after mold closing is called the gate. During the manufacturing of injection-molded interior panels, some excess material often remains at the gate location. This excess material will fuse with the injection-molded part as it cools and is then removed in subsequent processes.

[0003] In existing technologies, workers often remove excess material formed at the gate by first opening the mold and then removing it. However, this method not only adds unnecessary processing steps, but also, because the excess material is cast integrally with the injection molded part, removing the excess material after the injection molded part has cooled and solidified can easily cause rigid damage to the injection molded part, affecting its physical properties and ultimately leading to an increase in the defect rate of the injection molded parts. Summary of the Invention

[0004] The problem solved by this invention is how to use a better method to remove the excess material formed at the gate position during injection molding, thereby avoiding the impact on the physical properties of the injection molded part caused by rigid removal of excess material, while optimizing the injection molding process and eliminating unnecessary steps.

[0005] To address the above problems, this invention provides a gate breakage device for injection molds and an injection molding process for injection molded parts.

[0006] In a first aspect, the present invention provides a gate breakage device for injection molds, which is arranged inside the mold and includes: a slider, a core puller, a hydraulic cylinder, and a motion conversion assembly. The slider is disposed around the gate of the mold. The hydraulic cylinder is connected to one end of the core puller and is used to drive the core puller to move along its axial direction. The slider and the motion conversion assembly are connected in a transmission connection and are respectively connected to the other end of the core puller. The motion conversion assembly is used to drive the slider to move in a direction perpendicular to the axial direction of the core puller under the action of the core puller, so as to cut off the excess material at the gate.

[0007] Optionally, the motion conversion component includes a T-shaped block and a stop block. The two flanges of the T-shaped block each have a ramp (first ramp) on the side furthest from the slider. The two stops are respectively connected to the slider and are symmetrically arranged. Each stop block has a second ramp that mates with the corresponding ramp (first ramp). When the T-shaped block moves upward under the action of the core-pulling mechanism, the T-shaped block, through the squeezing action between ramp (first ramp) and ramp (second ramp), drives the stop block to move the slider in a direction perpendicular to the core-pulling axis toward the gate position, thereby breaking off excess material at the gate.

[0008] Optionally, the motion conversion assembly further includes a positioning block, which is installed on the side of the core pull away from the T-shaped block, and a positioning bolt is threaded through the positioning block, the end of the positioning bolt passing through the core pull and threaded inside the T-shaped block.

[0009] Optionally, the inclination angle of the first ramp is set to be between 10° and 30°.

[0010] Optionally, the side of the slider facing the gate forms an angle with the plane where the gate is located, and the angle is not less than 3°.

[0011] Optionally, the slider is connected to a limit switch for detecting whether the slider has reached the limit position of breaking the redundant material, and the limit switch is electrically connected to the hydraulic cylinder.

[0012] Secondly, the present invention provides an injection molding process for a part, comprising the following steps: S1: The upper and lower molds of the mold are closed to form a closed mold cavity. Molten material is introduced into the mold cavity and formed into an injection molded part after it has been shaped and cooled. S2: Control the hydraulic cylinder to retract, so as to drive the core puller to move along its axial direction away from the slider; S3: The core pulling mechanism drives the slider to move horizontally along the location of the gate of the mold through the motion conversion component, so as to break the excess material at the gate location; S4: Open the upper mold and the lower mold, and remove the injection molded part.

[0013] Optionally, in step S1, the excess material at the gate location remains molten and connected when the injection molded part is under pressure.

[0014] Optionally, in step S1, the pressure holding and cooling time of the injection molded part is within 0.5s-3s.

[0015] Optionally, the following steps are included after step S3: S31: After the excess material at the gate position is broken, the hydraulic cylinder continues to maintain pressure for 0.2s-0.5s.

[0016] The beneficial effects of the injection mold gate break-off device and injection molding process of the present invention are: 1. This application improves the structure of the injection molded part gate break-off device, and realizes gate cutting through a purely mechanical structure. It not only eliminates the loss of heating element, but also makes the cross-section at the gate break-off position smoother, eliminating the need for further processing. 2. In this application, the excess material at the gate position of the injection molded part is cut off in the mold through process improvement. Compared with the existing technology, it is not only more convenient to operate, but also saves the operation step of manually removing the excess material at the gate position after mold opening, thereby improving production efficiency and yield. 3. This application achieves pure mechanical control of injection molding by using process clamps and hydraulic cylinder drive, which not only saves manpower but also avoids structural damage caused by human error. Attached Figure Description

[0017] Figure 1 This is an overall structural view of the injection mold gate break-off device and injection molding process embodiment one of this application.

[0018] Figure 2 This is a cross-sectional view of the structure of the gate break-off device for injection molds and the first embodiment of the injection molding process of injection molded parts according to this application.

[0019] Figure 3 This is a partial structural view of the position of the motion conversion component in Embodiment 1 of the injection mold gate break-off device and injection molding process of this application.

[0020] Figure 4 This is an exploded view of the structure of a motion conversion component of an injection mold gate break-off device and an injection molding process embodiment 1 of this application.

[0021] Figure 5 for Figure 1 A magnified view of point A in the middle.

[0022] Figure 6 This is a process flow diagram of the tear-off process in Embodiment 2 of the injection mold gate tear-off device and injection molding process of this application.

[0023] Explanation of reference numerals in the attached figures: 1. Slider; 2. Injection molded part; 21. Process clamp; 22. Precast groove; 3. Core pulling; 4. Hydraulic cylinder; 5. Motion conversion assembly; 51. T-block; 511. Ramp one; 52. Positioning block; 53. Positioning bolt; 54. Stop block; 541. Ramp two. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0025] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0026] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0027] Example 1 Reference Figures 1 to 5 This application provides a gate breakage device for injection molds, which is used to reliably break off excess material at the gate position from the injection molded part 2 during the injection molding process, thereby avoiding excess material remaining on the surface of the injection molded part 2 or at the gate position, and improving the molding quality and appearance consistency of the injection molded part 2.

[0028] The injection mold gate break-off device includes a mold, a slider 1, an injection molded part 2, a connecting cylinder, a core puller 3, and a motion conversion component 5. The mold is composed of a detachably connected upper and lower mold, which together form a cavity for forming the injection molded part 2. The mold has a gate communicating with the cavity. Molten material enters the cavity through the gate, cools and solidifies to form the injection molded part 2, and excess material forms at the gate location. The slider 1 is located at the gate location and can slide horizontally along the gate location. It is used to break the excess material at the gate location by moving horizontally after the injection molded part 2 is formed. The connecting cylinder has a hydraulic cylinder 4 and a motion conversion component 5 at each end. The core puller 3 slides through the connecting cylinder, and its two ends are connected to the hydraulic cylinder 4 and the motion conversion component 5 respectively. The two ends of the motion conversion component 5 are connected to the core puller 3 and the slider 1 respectively. When the hydraulic cylinder 4 is activated, the core puller 3 moves axially. The motion conversion component 5 converts the axial motion of the core puller 3 into the horizontal motion of the slider 1, causing the slider 1 to move at the gate position and break off the excess material.

[0029] In this embodiment, the motion conversion component 5 includes a T-shaped block 51 and a positioning block 52. The two ends of the T-shaped block 51 are respectively connected to the core puller 3 and the slider 1 for transmission. When the core puller 3 moves axially, the T-shaped block 51 drives the slider 1 to move horizontally.

[0030] Specifically, the T-shaped block 51 includes a middle block and two wing plates. The two wing plates are symmetrically and integrally connected to the middle block on the side near the slider 1, and both wing plates have a ramp 511 on their back sides. The slider 1 has two stops 54 symmetrically connected to the side of the two wing plates away from the slider 1, and each of the stops 54 has a ramp 541 on its lower side near the wing plate that matches the shape of the ramp 511. When the T-shaped block 51 moves vertically upward along the axis of the core-pulling 3 under the drive of the core-pulling 3, the ramp 511 on its upper side will continuously squeeze the ramp 541, forcing the stops 54 to move towards the core-pulling 3, and driving the slider 1 to move, so as to break the excess material at the gate position.

[0031] The positioning block 52 is installed on the side of the core puller 3 away from the T-shaped block 51. A positioning bolt 53 is threaded through the positioning block 52, and the end of the positioning bolt 53 passes through the core puller 3 and is threaded inside the T-shaped block 51. The positioning bolt 53 reliably connects the T-shaped block 51 and the core puller 3, ensuring the stability of power transmission and facilitating disassembly and maintenance.

[0032] Preferably, the inclination angle of ramp 511 is set between 10-30°. Due to the presence of ramp 511, the axial displacement of core puller 3 can be converted into the horizontal displacement of slider 1, and as core puller 3 continues to move, the displacement of slider 1 gradually increases. This gradually increasing displacement causes the excess material to be subjected to a gradually increasing tensile force at the gate position, which is beneficial to a more clean separation between the excess material and the injection molded part 2, while reducing the risk of damage to the surface of the injection molded part 2 due to excessive instantaneous tensile force.

[0033] An angle of not less than 3° is provided between the surface of slider 1 and the surface of the gate location along the horizontal direction. This angle between slider 1 and the surface of the gate location allows slider 1 to form a certain shearing tendency with the gate location when moving horizontally, which is beneficial to the breaking of excess material and makes the fracture surface smoother.

[0034] The injection molded part 2 has a process clamp 21 on a non-surface location for gripping by a robotic arm. The process clamp 21 has a pre-formed groove 22 for easy detachment from the mold. The process clamp 21 facilitates stable gripping and removal of the injection molded part 2 by the robotic arm after injection molding. The pre-formed groove 22 makes it easier for the process clamp 21 to detach from the injection molded part 2 during subsequent processing, without affecting the performance of the injection molded part 2. At the same time, the process clamp 21 also prevents direct contact between human hands and the injection molded part 2, thus avoiding accidental damage to the surface of the injection molded part 2.

[0035] The slider 1 is connected to a limit switch for detecting whether the slider 1 has reached the limit position to break the excess material. The limit switch is electrically connected to the hydraulic cylinder 4. When the slider 1 moves to the set position, the limit switch sends a signal to control the hydraulic cylinder 4 to stop or maintain pressure, ensuring that the excess material is completely broken while avoiding excessive movement of the slider 1 that could damage the mold or injection part 2.

[0036] Example 2 Reference Figure 6 This application also provides an injection molding process applicable to the aforementioned injection mold gate break-off device. The process includes the following steps: First, the upper and lower molds are closed to form a sealed cavity. Molten material is then poured into the cavity, and after it cools and solidifies, it forms part 2. In this step, the excess material at the gate remains molten and connected under pressure while part 2 is in the injection molding state. This means that neither the excess material nor the injection molding part has completely cooled and solidified, maintaining a certain bond strength, but not yet fully hardened. The pressure-holding and cooling time of part 2 is controlled within 0.5-3 seconds to ensure the excess material is in a suitable state for tearing—neither too soft, causing stringing during tearing, nor too hard, leading to difficulty in tearing or a rough fracture surface.

[0037] Subsequently, the hydraulic cylinder 4 contracts, causing the core puller 3 and the T-block 51 to move away from the slider 1. During this movement, the T-block 51 pulls the slider 1 horizontally along the gate location. As the slider 1 moves, it gradually breaks off the excess material at the gate location. Because the excess material remains molten and connected under pressure, its bond strength with the injection molded part 2 is relatively low, and the horizontal movement of the slider 1 can easily separate the excess material from the injection molded part 2.

[0038] As the T-block 51 gradually moves, the displacement of the slider 1 gradually increases under the influence of the ramp 511 of the T-block 51, and the breaking force gradually increases until the excess material at the gate position is completely broken. Since the inclination angle of the ramp 511 is set between 10-30°, the displacement change of the slider 1 is relatively gentle, the breaking process is stable, the cross-section of the excess material is relatively flat, and it is not easy to leave obvious residues on the surface of the injection molded part 2.

[0039] After the excess material is completely broken, the hydraulic cylinder 4 maintains pressure for 0.2-0.5 seconds to ensure a complete cut without leaving any residue. This pressure-holding process keeps the slider 1 in the broken position for a period of time, which compresses and trims the cross-section at the gate position to a certain extent, thereby further reducing the possibility of residue formation.

[0040] Finally, the upper and lower molds are opened, and injection molded part 2 is removed. Since the excess material has been reliably broken off before mold opening, injection molded part 2 will not have surface defects due to excess material adhesion when removed from the mold cavity, significantly improving the overall appearance quality of injection molded part 2. Furthermore, the breaking process is completed inside the mold, eliminating the need for an additional excess material removal process after mold opening, thus improving production efficiency.

[0041] With the cooperation of the above-mentioned device and process, the excess material is broken off in time during the pressure holding stage. The breaking process is stable and controllable, and the surface of the injection molded part 2 is not prone to leaving gate marks, which effectively improves the appearance quality of the injection molded part 2 and reduces the amount of subsequent repair work.

[0042] The beneficial effects of the injection mold gate breakage device and injection molding process of this embodiment compared with the prior art are the same as those of the injection mold gate breakage device and injection molding process described above, and will not be repeated here.

[0043] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A gate break-off device for injection molds, used for placement inside the mold, characterized in that, include: The components include a slider (1), a core puller (3), a hydraulic cylinder (4), and a motion conversion assembly (5). The slider (1) is positioned around the gate of the mold. The hydraulic cylinder (4) is connected to one end of the core puller (3) and is used to drive the core puller (3) to move along its axial direction. The slider (1) and the motion conversion assembly (5) are connected by a transmission and are respectively connected to the other end of the core puller (3). The motion conversion assembly (5) is used to drive the slider (1) to move in a direction perpendicular to the axial direction of the core puller (3) under the driving action of the core puller (3) so as to break the excess material at the gate.

2. The injection mold gate breakage device according to claim 1, characterized in that, The motion conversion component (5) includes a T-shaped block (51) and a stop block (54). The two wings of the T-shaped block (51) are provided with ramp one (511) on the side away from the slider (1). The two stops (54) are respectively connected to the slider (1) and are arranged symmetrically. Each of the two stops (54) is provided with ramp two (541) that fits against the corresponding ramp one (511). When the T-shaped block (51) moves upward under the action of the core puller (3), the T-shaped block (51) drives the stop block (54) to drive the slider (1) to move towards the gate position in a direction perpendicular to the axis of the core puller (3) through the squeezing action between ramp one (511) and ramp two (541) so as to break the excess material at the gate.

3. The injection mold gate breakage device according to claim 2, characterized in that, The motion conversion component (5) further includes a positioning block (52), which is installed on the side of the core puller (3) away from the T-shaped block (51), and a positioning bolt (53) is threaded through the positioning block (52). The end of the positioning bolt (53) passes through the core puller (3) and is threaded through the T-shaped block (51).

4. The injection mold gate breakage device according to claim 2, characterized in that, The inclination angle of the slope one (511) is set to be between 10° and 30°.

5. The injection mold gate breakage device according to claim 1, characterized in that, The side of the slider (1) facing the gate forms an angle with the plane where the gate is located, and the angle is not less than 3°.

6. The injection mold gate break-off device according to claim 1, characterized in that, The slider (1) is connected to a limit switch for detecting whether the slider (1) has reached the limit position of breaking the redundant material, and the limit switch is electrically connected to the oil cylinder (4).

7. An injection molding process, applicable to the injection mold gate break-off device according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: The upper and lower molds of the mold are closed to form a closed mold cavity. Molten material is introduced into the mold cavity and formed into an injection molded part after it is shaped and cooled (2). S2: Control the oil cylinder (4) to retract so as to drive the core puller (3) to move along its axis in a direction away from the slider (1); S3: The core-pulling (3) drives the slider (1) to move horizontally along the gate location of the mold through the motion conversion component (5) to break the excess material at the gate location; S4: Open the upper mold and the lower mold, and take out the injection molded part (2).

8. The injection molding process for a part according to claim 7, characterized in that, In step S1, the excess material at the gate position remains in a molten connection state when the injection molded part (2) is under pressure.

9. The injection molding process for a part according to claim 7, characterized in that, In step S1, the pressure holding and cooling time of the injection molded part (2) is within 0.5s-3s.

10. The injection molding process for a part according to claim 7, characterized in that, Following step S3, the following steps are also included: S31: The oil cylinder (4) continues to hold pressure for 0.2s-0.5s after the excess material at the gate position is broken.

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