Injection molding device for plastic panel and use method of injection molding device
By employing inner and outer ejection mechanisms and a variable-speed cooling design, the problems of pressure concentration and adhesion caused by the small contact area between the ejector pin and the plastic panel are solved, achieving efficient, low-resistance demolding and improved product quality.
Patent Information
- Application Number
- CN202610016979.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-07
- Publication Date
- 2026-02-17
AI Technical Summary
In existing injection molding equipment, the small contact area between the ejector pin and the plastic panel during demolding leads to pressure concentration, which can easily cause dents or cracks. If the ejector pin area is large, the separation becomes more difficult, and the traditional ejector pin and panel have high adhesion resistance.
The ejection mechanism adopts a two-layer structure, with an inner ejector rod and an ejector rod sleeve combined. The ejection speeds of the ejector rod sleeve and the inner ejector rod are made asynchronous through a drive mechanism and a speed change mechanism, so that the separation is completed step by step. Air holes are set on the inner side of the ejector rod sleeve for cooling.
It increases the dispersion area of the ejection force, reduces adhesion resistance, lowers the difficulty of separation, and improves product quality through cooling.
Smart Images
Figure CN121535933A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of injection molding equipment technology, specifically to an injection molding equipment for plastic panels and its usage method. Background Technology
[0002] Injection molding equipment is a molding device used for plastic processing. It injects high-temperature melt into a mold and cools it to form a plastic product that conforms to the shape of the mold cavity. It is the core equipment for mass production of thin-walled products such as plastic panels.
[0003] In existing technology, injection molding equipment typically consists of a hopper, a conveying mechanism, a moving mold, a fixed mold, and an ejection mechanism. During operation, the moving mold and fixed mold fit together to form a mold cavity. The conveying mechanism transports the plastic raw material from the hopper to the fixed mold. A temperature control system in the hopper and conveying mechanism heats the raw material, turning it into a melt. After being transported to the mold cavity, the melt is rapidly cooled by a cooling system, causing it to cool and form a plastic panel. The ejection mechanism then ejects the plastic panel from the moving mold, completing the demolding process and thus finishing the plastic panel production.
[0004] However, the demolding of plastic panels is achieved by extending and retracting the ejector pin in the ejection mechanism. The ejector pin first extends from the moving mold, pushing the plastic panel away from the surface of the moving mold. Then, the tip of the ejector pin retracts into the moving mold, separating the plastic panel from the tip of the ejector pin, thus completing the demolding operation. However, this process presents a significant contradiction: if the area of the ejector pin's ejection end is small, the ejection force will be concentrated at the smaller ejection end when lifting the plastic panel. A smaller contact area results in greater pressure per unit area, potentially causing dents or cracks at the contact point between the plastic panel and the ejector pin, affecting product quality. Conversely, increasing the area of the ejector pin's ejection end increases the adhesion resistance between the ejector pin and the plastic panel when the ejector pin retracts into the moving mold and separates from the plastic panel, increasing the difficulty of separating the ejector pin from the product. Therefore, this invention proposes an injection molding device for plastic panels and its method of use to effectively solve the above-mentioned drawbacks. Summary of the Invention
[0005] The purpose of this invention is to provide an injection molding apparatus for plastic panels and a method for using the same, in order to solve the problems mentioned in the background art.
[0006] This invention is achieved through the following technical solution: an injection molding apparatus for a plastic panel, comprising an injection molding machine body, the injection molding machine body including a hopper and a material conveying system connected to the hopper's outlet, the outlet end of the material conveying system being connected to a fixed mold, and the injection molding machine body further comprising a moving mold driven by a mold clamping system, and further comprising: An ejection mechanism, comprising at least one inner ejector rod and an ejector rod sleeve disposed inside the moving mold, wherein a plurality of inner ejector rods and a plurality of ejector rod sleeves correspond one-to-one, and the inner ejector rod is slidably nested inside the ejector rod sleeve along the ejection direction; A drive mechanism, comprising a drive rod, which is movably connected to an inner ejector rod via a speed-changing assembly. The drive rod is capable of driving the inner ejector rod to move toward the fixed mold at a first speed, and the speed-changing assembly is capable of driving the inner ejector rod to move away from the fixed mold at a second speed. The drive rod is provided with a connecting component, which can be connected to or separated from the ejector sleeve. When the connecting component is connected to the ejector sleeve, the drive rod can drive the ejector sleeve to move toward the fixed mold at a first speed. The first speed is greater than the second speed. When the driving rod drives the inner ejector rod and the ejector sleeve to move synchronously toward the fixed mold at the first speed, and the speed change assembly drives the inner ejector rod to move away from the fixed mold at the second speed, the ejector end of the inner ejector rod retracts into the inner side of the ejector sleeve and gradually moves away from the ejector end of the ejector sleeve.
[0007] Optionally, the moving mold has an ejection hole through which the ejector sleeve is slidably inserted along the ejection direction of the ejection mechanism. The ejector sleeve has an annular structure, and the outer contour of the ejector sleeve matches the inner contour of the ejection hole. The inner ejector has a cylindrical structure, and the outer contour of the inner ejector matches the inner contour of the ejector sleeve.
[0008] Optionally, the driving mechanism further includes a cylinder disposed on the side of the moving mold away from the fixed mold. The movable end of the cylinder can extend and retract along the ejection direction of the ejection mechanism and is fixedly connected to a push plate. One end of the driving rod is connected to the push plate, and the other end of the driving rod extends into the ejection hole along the ejection direction of the ejection mechanism.
[0009] Optionally, the drive rod is fixedly connected to the push plate, and the speed change assembly includes a drive source and a connecting rod. The drive source is fixedly mounted on the drive rod, and the connecting rod extends along the ejection direction of the ejection mechanism and is fixedly connected to the inner ejector rod. The drive source can drive the connecting rod to move along the ejection direction of the ejection mechanism and drive the inner ejector rod to move away from the fixed mold at a second speed.
[0010] Optionally, the drive rod is rotatably connected to the push plate via a damping bearing, and a threaded groove is provided at one end of the drive rod that extends into the ejection hole. The speed change assembly includes a lead screw threaded in the threaded groove. The lead screw extends along the ejection direction of the ejection mechanism and is fixedly connected to the inner ejector rod. The drive rod drives the inner ejector rod to move away from the fixed mold at a second speed by rotation.
[0011] Optionally, the outer side wall of the drive rod is fixedly provided with a flange, and the outer side wall of the flange protrudes outward to form a slider. The inner side wall of the ejection hole is provided with a sliding groove for the slider to slide and connect. The sliding groove is composed of a first horizontal section, a spiral section and a second horizontal section. The first horizontal section and the second horizontal section are both distributed along the ejection direction of the ejection mechanism. The two ends of the spiral section are respectively connected to the first horizontal section and the second horizontal section. When the slider slides in the first horizontal section and the second horizontal section, the inner push rod moves in the ejection direction at a first speed. When the slider slides in the spiral section, the drive rod drives the lead screw to move in the ejection direction of the ejection mechanism at a second speed by rotation.
[0012] Optionally, the outer side wall of the inner push rod protrudes outward to form a first limiting block, and the inner side wall of the push rod sleeve is provided with a first limiting groove for sliding connection of the first limiting block along its own pushing direction, and the width of the first limiting block and the width of the first limiting groove are adapted to each other. The outer side wall of the top rod sleeve protrudes outward to form a second limiting block. The inner side wall of the ejection hole is provided with a second limiting groove along the ejection direction of the ejection mechanism for sliding connection of the second limiting block. The width of the second limiting block and the width of the second limiting groove are adapted to each other.
[0013] Optionally, the connecting assembly is elastically connected to a connecting block inside the drive rod radially via a spring. The end of the connecting block away from the spring extends outward from the drive rod. An annular groove is formed inwardly on the inner wall of the top rod sleeve for the connecting block to be embedded. The connecting assembly also includes an electromagnet fixedly disposed inside the drive rod. The two ends of the spring abut against the connecting block and the electromagnet, respectively. In its natural state, the spring is in a compressed state and always applies a spring force to the connecting block toward the outside of the drive rod.
[0014] Optionally, an air hole is provided on the inner side of the ejector sleeve near the ejector end. When the ejector sleeve moves toward the fixed mold at a first speed and the inner ejector moves away from the fixed mold at a second speed, the air hole gradually changes from a fully closed state to a fully open state.
[0015] The present invention also proposes a method for using an injection molding apparatus for plastic panels, applicable to the aforementioned injection molding apparatus, comprising the following steps: First, the mold clamping system controls the moving mold to move closer to and fit with the fixed mold to form a mold cavity. Then, the material conveying system melts the plastic raw material in the hopper into a melt and conveys it to the injection port of the fixed mold. After passing through the injection port, the melt enters the mold cavity. Wait for the melt to cool and form a plastic panel that matches the shape of the mold cavity. Then, the mold closing system controls the moving mold to move away from the fixed mold and bring out the plastic panel. Subsequently, the inner ejector rod and ejector sleeve are controlled by the drive rod in the drive mechanism to move synchronously toward the fixed mold at the first speed, pushing the plastic panel away from the surface of the moving mold, thus completing the separation operation between the plastic panel and the moving mold; Then, using the drive rod, continue to control the inner ejector rod and ejector sleeve to move towards the fixed mold at the first speed. Using the speed change component, control the inner ejector rod to move away from the fixed mold at the second speed, so that the speed at which the inner ejector rod approaches the fixed mold is less than the speed at which the ejector sleeve approaches the fixed mold. The inner ejector rod can then retract into the inside of the ejector sleeve, completing the separation operation between the inner ejector rod and the plastic panel. Finally, the connecting component and the ejector sleeve separate. The drive rod no longer drives the ejector sleeve to move. Instead, the drive rod drives the inner ejector to move towards the fixed mold, causing the inner ejector to extend out of the ejector sleeve, thus completing the separation operation between the ejector sleeve and the plastic panel.
[0016] Compared with the prior art, the present invention provides an injection molding apparatus for plastic panels and a method for using the same, which has the following beneficial effects: 1. This invention designs the ejection structure as a two-layer structure, with the ejection end of the inner ejector rod and ejector sleeve combination increasing the contact area with the plastic panel, allowing the ejection force to be distributed over a larger area. Through the drive mechanism and speed change mechanism, the ejection speeds of the ejector sleeve and the inner ejector rod are different, so that the ejector sleeve and the inner ejector rod can complete the separation operation from the plastic panel in steps, thereby reducing the area of adhesion to the plastic panel during a single separation. This avoids the inner ejector rod and the ejector sleeve separating from the plastic panel at the same time, which would increase the adhesion resistance, thereby reducing the difficulty of separating the ejection mechanism from the plastic panel. 2. The present invention provides an air hole inside the top rod sleeve to blow cold air into the inside of the top rod sleeve. The air hole is gradually opened by the action of the inner top rod retracting into the top rod sleeve, so that the space inside the top rod sleeve that can accommodate cold air continuously increases, allowing more cold air to cool the plastic panel. As a result, the area of the plastic panel facing the inner top rod becomes harder, so that the inner top rod can push the product away from the top rod sleeve ejection end. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the moving mold and fixed mold structure of the present invention; Figure 3 This is a side sectional view of the moving mold and the fixed mold of the present invention; Figure 4 This is a schematic diagram of the side cross-sectional view of the moving mold and ejection mechanism of the present invention; Figure 5 This is a schematic diagram of the synchronous ejection state of the inner push rod and push rod sleeve of the present invention; Figure 6 This is a schematic diagram of the internal push rod retracting into the push rod sleeve state structure of the present invention; Figure 7 This is a schematic diagram of the structure of the inner push rod extending out of the push rod sleeve of the present invention; Figure 8 for Figure 4 Enlarged structural diagram at point A in the middle.
[0018] In the diagram: 1. Injection molding machine body; 101. Fixed mold; 2. Moving mold; 201. Ejector hole; 202. Slide groove; 2021. First horizontal section; 2022. Spiral section; 2023. Second horizontal section; 203. Second limiting groove; 3. Ejection mechanism; 301. Inner ejector rod; 3011. First limiting block; 302. Ejector rod sleeve; 3021. First limiting groove; 3022. Second limiting block; 3023. Annular groove; 4. Drive mechanism; 401. Drive rod; 402. Cylinder; 403. Push plate; 404. Flange; 405. Slider; 5. Speed change assembly; 501. Lead screw; 6. Connecting assembly; 601. Connecting block; 602. Electromagnet; 7. Air hole. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] Example 1: Please refer to Figure 1 - Figure 8 This application provides an injection molding apparatus for a plastic panel, including an injection molding machine body 1. The injection molding machine body 1 includes a hopper and a material conveying system connected to the hopper outlet. The material conveying system outlet is connected to a fixed mold 101. The injection molding machine body 1 is also provided with a moving mold 2 driven by a mold closing system.
[0021] The material conveying system includes a material conveying cylinder connected to the hopper outlet and a screw conveying mechanism installed inside the material conveying cylinder. A temperature control system for heating the plastic raw material is located outside the material conveying cylinder, used to melt the solid plastic into molten plastic. The mold closing system includes a mold closing cylinder, the movable end of which is connected to the moving mold 2, used to drive the moving mold 2 closer to or further away from the fixed mold 101. After the moving mold 2 and the fixed mold 101 are fitted together, they enclose a mold cavity communicating with the injection port, allowing the molten material to be injected into the mold cavity. Multiple cooling channels are provided in the fixed mold 101 and the moving mold 2 for the flow of cooling water or cooling oil, thereby rapidly cooling the molten material within the mold cavity to form a solid plastic panel.
[0022] In this embodiment, the injection molding apparatus further includes an ejection mechanism 3. The ejection mechanism 3 includes at least one inner ejector rod 301 and an ejector rod sleeve 302 disposed inside the moving mold 2. A plurality of inner ejector rods 301 and a plurality of ejector rod sleeves 302 correspond one-to-one. The inner ejector rods 301 slide and nest inside the ejector rod sleeves 302 along the ejection direction. Therefore, the inner ejector rods 301 and ejector rod sleeves 302 combine to form an inner and outer double-layer structure. Compared with the traditional single-layer ejector pin, the annular surface area of the ejection end of the inner ejector rod 301 is smaller than the ejection end area of the traditional ejector pin, and the area of the ejection end of the ejector rod sleeve 302 is smaller than the ejection end area of the traditional ejector pin. However, when the inner ejector rods 301 and ejector rod sleeves 302 are combined, the ejection end area of the combined ejector rod is larger than the ejection end area of the traditional ejector pin. This allows the ejection mechanism 3 to increase the contact area when ejecting from the plastic panel, and to gradually separate the inner ejector rods 301 and ejector rod sleeves 302 from the plastic panel when separating from it, reducing the contact area of a single separation and reducing the difficulty of separation.
[0023] The number of inner ejector pins 301 and ejector pin sleeves 302 depends on the number of ejector pins in the existing injection molding machine. For example, when the existing equipment has only one ejector pin, an ejector plate is set at the ejector pin ejection end. Correspondingly, the number of inner ejector pins 301 and ejector pin sleeves 302 in this application is also one. It is only necessary to ensure that the ejection end area of inner ejector pins 301 and ejector pin sleeves 302 is smaller than the area of the existing ejector plate, and that the ejection end area of inner ejector pins 301 and ejector pin sleeves 302 after combination is larger than the ejection end area of the existing ejector plate.
[0024] On the other hand, an annular air groove is provided at the edge of the moving mold 2, which can inflate air between the moving mold 2 and the plastic panel when the plastic panel is ejected, thereby forming an air cushion to reduce the contact pressure. Combined with the ejection force of the ejection mechanism 3, the plastic panel and the moving mold 2 are separated. In some demolding operations, a release agent is also sprayed on the mold surface to assist in the separation of the mold and the plastic panel.
[0025] It should be noted that the moving mold 2 has an ejection hole 201 through it along the ejection direction of the ejection mechanism 3 for the ejector sleeve 302 to slide into. The ejector sleeve 302 has a ring structure, and the outer contour of the ejector sleeve 302 matches the inner contour of the ejection hole 201. The inner ejector 301 has a column structure, and the outer contour of the inner ejector 301 matches the inner contour of the ejector sleeve 302.
[0026] The outer wall of the push rod sleeve 302 and the inner wall of the ejector hole 201 are fitted with a precision clearance fit, with a clearance of 0.01 to 0.03 mm. The high viscosity of the molten plastic prevents it from entering the gap. If the gap needs to be eliminated, a sealing sleeve can be fixedly fitted onto the outer wall of the push rod sleeve 302 to achieve a sealing effect. Similarly, the inner push rod 301 and the push rod sleeve 302 are fitted with a precision clearance fit; a sealing sleeve can also be fitted onto the outer side of the inner push rod 301 to achieve a sealing effect.
[0027] On the other hand, the ejector surfaces of the inner ejector pin 301 and the ejector pin sleeve 302 can be flush with the mold cavity surface on the moving mold 2, so as to avoid affecting the appearance and quality of the product when the plastic panel is molded.
[0028] Furthermore, the injection molding apparatus also includes a drive mechanism 4 for controlling the movement of the ejection mechanism 3. The drive mechanism 4 includes a drive rod 401, which is movably connected to the inner ejector rod 301 via a speed change assembly 5. The drive rod 401 can drive the inner ejector rod 301 to move toward the fixed mold 101 at a first speed, and the speed change assembly 5 can drive the inner ejector rod 301 to move away from the fixed mold 101 at a second speed.
[0029] The first speed is greater than the second speed. Therefore, when the drive rod 401 drives the inner ejector rod 301 and the ejector sleeve 302 to move synchronously toward the fixed mold 101 at the first speed, the speed change assembly 5 can drive the inner ejector rod 301 to move away from the fixed mold 101 at the second speed. As a result, the ejector end of the inner ejector rod 301 retracts into the inner side of the ejector sleeve 302 and gradually moves away from the ejector end of the ejector sleeve 302, thereby enabling the ejector end of the inner ejector rod 301 to separate from the plastic panel first.
[0030] Specifically, the drive mechanism 4 also includes a cylinder 402 disposed on the side of the moving mold 2 away from the fixed mold 101. The movable end of the cylinder 402 can extend and retract along the ejection direction of the ejection mechanism 3 and is fixedly connected to a push plate 403. One end of the drive rod 401 is connected to the push plate 403, and the other end of the drive rod 401 extends into the ejection hole 201 along the ejection direction of the ejection mechanism 3. The cylinder 402 can also be replaced with other linear drive devices, as long as they can drive the drive rod 401 to move along the ejection direction of the ejection mechanism 3. In this embodiment, a mounting bracket is fixedly connected to the side of the moving mold 2 away from the fixed mold 101. The cylinder 402 is fixedly mounted on the mounting bracket. The movable end of the cylinder 402 faces the moving mold 2 and can extend and retract along the ejection direction of the ejection mechanism 3. The drive rod 401 is set on the side of the push plate 403 away from the cylinder 402. The number of drive rods 401 is at least one, corresponding to the number of inner ejector rods 301 and ejector sleeves 302. Therefore, when the drive rod 401 is connected to the ejection mechanism 3, the cylinder 402 can control the ejection mechanism 3 to move along the ejection direction at a first speed.
[0031] Furthermore, when the drive rod 401 is fixedly connected to the push plate 403, the speed change assembly 5 includes a drive source and a connecting rod. The drive source is fixedly mounted on the drive rod 401, and the connecting rod extends along the ejection direction of the ejection mechanism 3 and is fixedly connected to the inner ejector rod 301. The drive source can drive the connecting rod to move along the ejection direction of the ejection mechanism 3 and drive the inner ejector rod 301 to move away from the fixed mold 101 at a second speed. The drive source is a linear drive device such as a hydraulic cylinder, mounted on the drive rod 401, enabling the drive rod 401 to drive the speed change assembly 5 and the ejection mechanism 3 together to move along the ejection direction at a first speed. The drive end of the drive source is fixedly connected to the connecting rod. Therefore, the drive source can independently control the inner ejector rod 301 to move along the ejection direction of the ejection mechanism 3 at a second speed, creating a difference in ejection speed between the inner ejector rod 301 and the ejector sleeve 302. This allows the inner ejector rod 301 to retract into the inner side of the ejector sleeve 302, completing the separation operation from the plastic panel.
[0032] On the other hand, when the drive rod 401 is rotatably connected to the push plate 403 via the damping bearing, the end of the drive rod 401 that extends into the ejection hole 201 is provided with a threaded groove. The speed change assembly 5 includes a lead screw 501 threadedly connected in the threaded groove. The lead screw 501 extends along the ejection direction of the ejection mechanism 3 and is fixedly connected to the inner ejector rod 301. The drive rod 401 drives the inner ejector rod 301 to move away from the fixed mold 101 at a second speed by rotation. The drive rod 401 has a first threaded protrusion in its threaded groove, and the lead screw 501 also has a second threaded protrusion on its outer side. The cross-sectional shape of the second threaded protrusion and the lead screw 501 are both trapezoidal. The threaded groove and the lead screw 501 are tightly fitted together, and there is no loosening or slippage when transmitting axial force. This allows the cylinder 402 to drive the drive rod 401 and the lead screw 501 to move synchronously along the axial direction when the drive rod 401 is not rotating. This stabilizes the inner push rod 301 and allows it to withstand the pushing force of the plastic panel returning, so that the plastic panel can be stably pushed away.
[0033] It should be noted that the outer wall of the inner push rod 301 protrudes outward to form a first limiting block 3011, and the inner wall of the push rod sleeve 302 has a first limiting groove 3021 for sliding connection of the first limiting block 3011 along its own pushing direction. The width of the first limiting block 3011 and the width of the first limiting groove 3021 are adapted to each other. Therefore, the first limiting block 3011 can only move in the first limiting groove 3021 along the pushing direction of the inner push rod 301, and cannot shake or rotate, so that the inner push rod 301 and the lead screw 501 cannot rotate. As a result, when the drive rod 401 rotates, it can drive the lead screw 501 to move along the pushing direction of the inner push rod 301 through the thread, and finally make the inner push rod 301 move axially inside the push rod sleeve 302 to achieve the purpose of separating from the plastic panel.
[0034] The first limiting block 3011 is radially elastically connected to the side of the inner push rod 301. When the inner push rod 301 is being assembled, the first limiting block 3011 can be pressed against the inner side wall of the push rod sleeve 302, causing the first limiting block 3011 to retract into the inner push rod 301. When the first limiting block 3011 and the first limiting groove 3021 are aligned, the first limiting block 3011 will be ejected into the first limiting groove 3021, thus realizing the assembly operation.
[0035] In order for the drive rod 401 to rotate, in this application, such as Figure 8 As shown, a flange 404 is fixedly provided on the outer wall of the drive rod 401. A slider 405 protrudes outward from the outer wall of the flange 404. A groove 202 is provided on the inner wall of the ejection hole 201 for the slider 405 to slide. The groove 202 consists of a first horizontal section 2021, a spiral section 2022, and a second horizontal section 2023. The first horizontal section 2021 and the second horizontal section 2023 are both distributed along the ejection direction of the ejection mechanism 3. The two ends of the spiral section 2022 are respectively connected to the first horizontal section 2021 and the second horizontal section 2023. In this embodiment, the slider 405 is radially elastically connected to the side of the flange 404. When assembling the drive rod 401, the slider 405 can be pressed against the inner wall of the ejection hole 201, causing the slider 405 to retract into the flange 404 until the slider 405 and the first horizontal section 2021 are aligned, at which point it can be springed into the flange 2021 to achieve assembly.
[0036] When the slider 405 slides in the first horizontal section 2021, the drive rod 401 does not rotate. The drive rod 401 drives the inner ejector rod 301 to move towards the fixed mold 101 at a first speed via the lead screw 501. When the slider 405 enters the spiral section 2022 from the first horizontal section 2021, the slider 405 will slide along the spiral trajectory of the spiral section 2022. This causes the drive rod 401 to rotate as it moves towards the fixed mold 101. However, the lead screw 501 and the inner ejector rod 301 cannot rotate due to the limiting cooperation of the first limiting block 3011 and the first limiting groove 3021. Therefore, the lead screw 501 will move away from the fixed mold 101 at a second speed inside the drive rod 401. At this time, the inner ejector rod 301 will retract into the inside of the ejector sleeve 302 to separate from the plastic panel. When the slider 405 enters the second horizontal section 2023 from the spiral section 2022, the drive rod 401 will stop rotating and continue to move toward the fixed mold 101 at the first speed, driving the inner ejector rod 301 to move toward the fixed mold 101 in sync.
[0037] It should be noted that the inner wall surface of the slide groove 202 is smooth, and the connection between the first horizontal section 2021, the spiral section 2022 and the second horizontal section 2023 is rounded. The slider 405 is cylindrical or spherical so that the slider 405 can slide smoothly in the slide groove 202.
[0038] Furthermore, the drive rod 401 is provided with a connecting component 6, which can be connected to or separated from the ejector sleeve 302. When the connecting component 6 is connected to the ejector sleeve 302, the drive rod 401 can drive the ejector sleeve 302 to move towards the fixed mold 101 at a first speed. Therefore, after the inner ejector 301 retracts into the inner side of the ejector sleeve 302 to complete the separation operation from the plastic panel, the connecting component 6 needs to be separated from the ejector sleeve 302, so that the drive rod 401 no longer drives the ejector sleeve 302 to move in the ejection direction. At this time, the slider 405 moves within the second horizontal section 2023, so that the drive rod 401 drives the inner ejector 301 to move synchronously towards the fixed mold 101 at a first speed through the lead screw 501. Finally, the ejection end of the inner ejector 301 will extend out of the outer side of the ejector sleeve 302, thereby pushing the plastic panel away from the ejection end of the ejector sleeve 302, completing the separation operation between the ejector sleeve 302 and the plastic panel.
[0039] Specifically, such as Figure 7 and 8 As shown, the connecting assembly 6 is elastically connected to the connecting block 601 inside the driving rod 401 radially via a spring. The end of the connecting block 601 away from the spring extends outward from the driving rod 401. An annular groove 3023 is formed inwardly on the inner wall of the top rod sleeve 302 for the connecting block 601 to be embedded. The connecting assembly 6 also includes an electromagnet 602 fixedly disposed inside the driving rod 401. The two ends of the spring abut against the connecting block 601 and the electromagnet 602 respectively. In its natural state, the spring is in a compressed state, and the spring always applies a spring force to the connecting block 601 to move outward from the driving rod 401. One end of the connecting block 601 located inside the drive rod 401 is fixed with an iron block or a magnetic block. Therefore, the connecting block 601 can be attracted by the energization of the electromagnet 602, so that the connecting block 601 is moved away from the annular groove 3023. This prevents the drive rod 401 from driving the push rod sleeve 302 to move in the pushing direction. The annular groove 3023 is annular in shape. Therefore, when the connecting block 601 is embedded in the annular groove 3023, the connecting block 601 can rotate within the annular groove 3023 without hindering the rotation of the drive rod 401.
[0040] In this embodiment, a power supply for powering the electromagnet 602 is installed on the push plate 403. A miniature Hall effect switch or other switch, controlled by an external magnetic field signal or Wi-Fi signal, is provided in the circuit between the power supply and the electromagnet 602. A wire connected to the electromagnet 602 passes through the inside of the drive rod 401, extends to the push plate 403, and connects to the switch. The opening logic is pre-set by an external control system; for example, when the slider 405 first moves to the connection end of the second horizontal segment 2023 and the spiral segment 2022... When the trigger switch is turned on, the electromagnet 602 is energized to attract the connecting block 601, thereby causing the connecting block 601 to disengage from the annular groove 3023. When the slider 405 moves again to the connection end of the second horizontal section 2023 and the spiral section 2022, the connecting block 601 and the annular groove 3023 are aligned. The trigger switch is turned off, de-energizing the electromagnet 602. The spring then pushes the connecting block 601 into the annular groove 3023, allowing the drive rod 401 to retract the push rod sleeve 302 back into the moving mold 2, completing the reset operation.
[0041] To ensure that the push rod sleeve 302 can only move horizontally in the pushing direction and cannot rotate, in this application, as follows: Figure 6 The outer wall of the push rod sleeve 302 protrudes outward to form a second limiting block 3022. The inner wall of the ejection hole 201, along the ejection direction of the ejection mechanism 3, has a second limiting groove 203 for sliding connection with the second limiting block 3022. The width of the second limiting block 3022 is matched with the width of the second limiting groove 203. This ensures that the push rod sleeve 302 can only move along its own axial direction, preventing the inner push rod 301 from rotating together when the push rod sleeve 302 rotates or shakes. Figure 6 As shown, one end of the second limiting groove 203 is connected to the outer wall of the moving mold 2 so that the second limiting block 3022 can be assembled from the outer surface of the moving mold 2 inward. In this embodiment, a limiting plug is fixedly installed in the space of the second limiting groove 203 near the outer wall of the moving mold 2. After the second limiting block 3022 is assembled into the second limiting groove 203, the limiting plug is fixed in the second limiting groove 203 by a fixed adhesive. The second limiting block 3022 is limited to prevent it from falling out of the second limiting groove 203 and is flush with the outer surface of the moving mold 2 so that the surface of the plastic panel is flat.
[0042] The second limiting block 3022 is a magnet. When the second limiting block 3022 moves as follows... Figure 6In the state shown, the ends of the second limiting block 3022 and the second limiting groove 203 are fitted together and can be firmly adsorbed onto the ends of the second limiting groove 203. In practical applications, an iron sheet can be fixedly installed at the ends of the second limiting groove 203. The magnetic attraction between the ends of the second limiting block 3022 and the second limiting groove 203 is greater than the frictional force between the inner ejector rod 301 and the ejector sleeve 302, so that when the inner ejector rod 301 retracts from the outside of the ejector sleeve 302 to the inside of the ejector sleeve 302, it cannot drive the ejector sleeve 302 to move away from the fixed mold 101. Only when the connecting block 601 is re-embedded in the annular groove 3023, the ends of the second limiting block 3022 and the second limiting groove 203 are separated by the cooperation of the connecting block 601 and the annular groove 3023.
[0043] It is worth mentioning that an air hole 7 is provided on the inner side of the ejector sleeve 302 near the ejector end. When the ejector sleeve 302 moves towards the fixed mold 101 at a first speed, and the inner ejector 301 moves away from the fixed mold 101 at a second speed, the air hole 7 gradually changes from a fully closed state to a fully open state. Figure 6 As shown, when the inner push rod 301 separates from the plastic panel, the air hole 7 is gradually opened, allowing cold air to be continuously supplied between the inner push rod 301 and the plastic panel. This achieves the purpose of cooling the area of the plastic panel facing the inner push rod 301, making the area harder and facilitating the subsequent removal of the plastic panel from the push rod sleeve 302 by the inner push rod 301.
[0044] In this embodiment, the inner ejector rod 301 and the ejector sleeve 302 move synchronously toward the fixed mold 101. However, under the action of the speed-changing component 5, the speed at which the inner ejector rod 301 moves toward the fixed mold 101 is slower than the speed at which the ejector sleeve 302 moves toward the fixed mold 101. Compared to the method where the inner ejector rod 301 remains stationary while the ejector sleeve 302 continuously moves toward the fixed mold 101, the opening speed of the vent 7 will also be slower, rather than suddenly opening over a large area. Therefore, in this application, the opening method of the vent 7 is gradual and small-area exposure, and the airflow will enter the end space smoothly, greatly weakening the impact force and avoiding the hard impact of the airflow on the plastic panel. This is especially suitable for products with high appearance precision, such as high-gloss and transparent products. Secondly, the space at the end of the inner ejector rod 301 expands slowly, so that the internal pressure changes linearly and smoothly. Neither the negative pressure will increase the adsorption force, nor will the product stick to the ejector rod due to a sudden increase in pressure. The force during the demolding process is more controllable, which can reduce abnormal situations such as jamming and product displacement.
[0045] The top rod sleeve 302 has an internal air guide channel for supplying cold air to the air hole 7. The end of the air guide channel away from the air hole 7 is connected to a gas delivery hose. The gas delivery hose passes through the flange 404. The flange 404 has an arc-shaped space for the gas delivery hose to move, so that when the flange 404 rotates, the rotation amplitude of the gas delivery hose will be reduced, and the gas can still be continuously and normally delivered by utilizing its own flexibility.
[0046] On the other hand, the end of the gas delivery hose away from the gas guide channel is connected to a split pipe, a gas source, and a gas pump. A gas valve is installed on the split pipe. When the inner push rod 301 is retracted into the push rod sleeve 302, the gas pump is turned on and the gas valve is closed, and the gas flows from the gas source to the gas hole 7. When the inner push rod 301 is extended out of the push rod sleeve 302, the gas pump is turned off and the gas valve is turned on, and the gas flows from the gas hole 7 to the gas delivery hose, then to the split pipe, and is finally discharged.
[0047] It should be noted that the distance between the air hole 7 and the protruding end of the push rod sleeve 302 is within 1mm, making the space between the inner push rod 301 and the plastic panel very small, forming a thin air cushion. Without affecting the pushing force of the inner push rod 301, it can also reduce the difficulty of separating the plastic panel and the push rod sleeve 302.
[0048] Example 2: Please refer to Figure 1 - Figure 8 A method for using an injection molding apparatus for a plastic panel, applicable to the injection molding apparatus in Embodiment 1, includes the following steps: First, the mold-closing cylinder in the mold-closing system controls the moving mold 2 to move closer to and fit against the fixed mold 101, so that a mold cavity is formed between the fixed mold 101 and the moving mold 2. Then, the plastic raw material in the hopper is introduced into the material barrel through the screw conveying mechanism in the material barrel of the material conveying system. The temperature control system on the outside of the material barrel is activated to heat the raw material and melt it into a melt, which is then conveyed to the injection port of the fixed mold 101. After injection through the injection port, the melt enters the mold cavity.
[0049] Subsequently, the cooling water in the cooling circuit of the cooling system accelerates the cooling of the melt, causing the melt to cool and form a plastic panel that matches the shape of the mold cavity. Then, the mold closing cylinder in the mold closing system controls the moving mold 2 to move away from the fixed mold 101. Because the moving mold 2 has a core, the plastic panel will naturally hug the core when it cools and shrinks, so that the moving mold 2 can take the plastic panel out of the fixed mold 101.
[0050] At this time, the electromagnet 602 is de-energized, the connecting block 601 is embedded in the annular groove 3023, and the slider 405 is located at the end of the first horizontal section 2021 away from the spiral section 2022. The cylinder 402 in the drive mechanism 4 can drive the cylinder 402 and the drive rod 401 to move towards the fixed mold 101 at the first speed. The drive rod 401 will drive the ejector sleeve 302, the lead screw 501 and the inner ejector 301 to move towards the fixed mold 101 at the first speed. With the help of the annular air groove on the edge of the moving mold 2 and the release agent, the plastic panel is pushed away from the surface of the moving mold 2, and the separation operation of the plastic panel and the moving mold 2 is completed.
[0051] When the slider 405 moves to the spiral section 2022, the cylinder 402 continues to control the drive rod 401, inner ejector rod 301, and ejector sleeve 302 to move towards the fixed mold 101 at the first speed. The slider 405 will move spirally along the trajectory of the spiral section 2022, so that the flange 404 and the drive rod 401 can rotate while moving horizontally. This causes the drive rod 401 to drive the lead screw 501 to move away from the fixed mold 101 at the second speed through the inner thread groove, which in turn drives the inner ejector rod 301 to move away from the fixed mold 101. At this time, the speed at which the inner ejector rod 301 approaches the fixed mold 101 is less than the speed at which the ejector sleeve 302 approaches the fixed mold 101. The inner ejector rod 301 can then retract into the inner side of the ejector sleeve 302, completing the separation operation between the inner ejector rod 301 and the plastic panel.
[0052] Finally, when the slider 405 moves to the connection end of the second horizontal section 2023 and the spiral section 2022, the electromagnet 602 is energized, attracting the connecting block 601 and moving the connecting block 601 away from the annular groove 3023. At this time, the drive rod 401 can no longer drive the ejector sleeve 302 to move, and the drive rod 401 can still drive the inner ejector 301 to move towards the fixed mold 101, so that the inner ejector 301 extends out of the outside of the ejector sleeve 302, completing the separation operation of the ejector sleeve 302 and the plastic panel, thereby completing the injection molding, molding and demolding operation of the plastic panel.
[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.
[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A plastic panel injection molding device, comprising an injection molding machine body, the injection molding machine body comprising a hopper and a material conveying system connected with a hopper discharge port, a fixed mold connected with a discharge end of the material conveying system, and a movable mold driven by a mold clamping system, characterized in that, Also include: The ejection mechanism includes at least one set in the inner die ejector rod and ejector rod sleeve, several said inner ejector rod and several ejector rod sleeve one-to-one, the inner ejector rod along the ejection direction sliding nested inside the ejector rod sleeve; The driving mechanism includes a driving rod, the driving rod is movably connected with the inner ejector rod through a variable speed assembly, the driving rod can drive the inner ejector rod to move towards the fixed mold direction at a first speed, the variable speed assembly can drive the inner ejector rod to move away from the fixed mold direction at a second speed; The driving rod is provided with a connecting assembly, the connecting assembly can be connected or separated with the ejector rod sleeve, when the connecting assembly and the ejector rod sleeve are connected, the driving rod can drive the ejector rod sleeve to move towards the fixed mold direction at a first speed; The first speed is greater than the second speed, when the driving rod drives the inner ejector rod and the ejector rod sleeve to move towards the fixed mold direction at a first speed synchronously, the variable speed assembly drives the inner ejector rod to move away from the fixed mold direction at a second speed, the inner ejector rod retracts into the inside of the ejector rod sleeve and gradually moves away from the ejector rod sleeve top end.
2. A device for injection molding a plastic panel according to claim 1, characterized in that: The movable die is provided with an ejection hole along the ejection direction of the ejection mechanism, the ejector rod sleeve is slidably embedded in the ejection hole, the ejector rod sleeve has a ring structure, the outer profile of the ejector rod sleeve is matched with the inner profile of the ejection hole, the inner ejector rod has a cylindrical structure, the outer profile of the inner ejector rod is matched with the inner profile of the ejector rod sleeve.
3. A device for injection moulding a plastic panel according to claim 2, characterised in that: The driving mechanism further includes a cylinder arranged on the side of the movable die away from the fixed mold, the movable end of the cylinder is telescopically connected with a push plate, one end of the driving rod is connected with the push plate, the other end of the driving rod extends into the ejection hole along the ejection direction of the ejection mechanism.
4. A device for injection moulding a plastic panel according to claim 3, characterised in that: The driving rod is fixedly connected with the push plate, the variable speed assembly includes a driving source and a connecting rod, the driving source is fixedly arranged on the driving rod, the connecting rod extends along the ejection direction of the ejection mechanism and is fixedly connected with the inner ejector rod, the driving source can drive the connecting rod to move along the ejection direction of the ejection mechanism and drive the inner ejector rod to move away from the fixed mold direction at a second speed.
5. A device for injection molding a plastic panel as defined in claim 3, wherein: The driving rod is rotatably connected with the push plate through a damping bearing, one end of the driving rod extending into the ejection hole is provided with a threaded groove, the variable speed assembly includes a screw rod threaded in the threaded groove, the screw rod extends along the ejection direction of the ejection mechanism and is fixedly connected with the inner ejector rod, the driving rod drives the inner ejector rod to move away from the fixed mold direction at a second speed by rotating.
6. A device for injection moulding a plastic panel according to claim 5, characterised in that: The outer wall of the driving rod is fixedly provided with a flange, the outer wall of the flange protrudes outward to form a sliding block, the inner wall of the ejection hole is provided with a sliding groove for sliding connection of the sliding block, the sliding groove is composed of a first horizontal section, a spiral section and a second horizontal section, the first horizontal section and the second horizontal section are distributed along the ejection direction of the ejection mechanism, the two ends of the spiral section are respectively communicated with the first horizontal section and the second horizontal section; When the sliding block slides in the first horizontal section and the second horizontal section, the inner ejector rod moves along the ejection direction at a first speed, when the sliding block slides in the spiral section, the driving rod drives the screw rod to move along the ejection direction of the ejection mechanism at a second speed by rotating.
7. A device for injection moulding a plastic panel according to claim 6, characterised in that: The inner side wall of the inner ejector rod is outwardly convex and forms a first limiting block, and the inner side wall of the ejector rod sleeve is provided with a first limiting slot along the ejecting direction of the ejecting mechanism for sliding connection of the first limiting block, and the width of the first limiting block is matched with the width of the first limiting slot. The outer side wall of the ejector rod sleeve is outwardly convex and forms a second limiting block, and the inner side wall of the ejecting hole is provided with a second limiting slot along the ejecting direction of the ejecting mechanism for sliding connection of the second limiting block, and the width of the second limiting block is matched with the width of the second limiting slot.
8. A device for injection molding a plastic panel according to claim 6, wherein: The connecting assembly is elastically connected to a connecting block inside the driving rod in the radial direction of the driving rod through a spring, one end of the connecting block away from the spring extends outside the driving rod, and an annular groove is recessed inwardly on the inner side wall of the ejector rod sleeve for embedding the connecting block, the connecting assembly further comprises an electromagnet fixedly arranged inside the driving rod, and the two ends of the spring abut on the connecting block and the electromagnet respectively; in the natural state, the spring is in a compressed state, and the spring always applies a spring force to the connecting block to move towards the outside of the driving rod.
9. The apparatus for injection molding of plastic panels according to claim 1, wherein: The inner side wall of the ejector rod sleeve is provided with an air hole near the ejecting end, and when the ejector rod sleeve moves towards the fixed mold at a first speed and the inner ejector rod moves away from the fixed mold at a second speed, the air hole gradually changes from a fully closed state to a fully open state.
10. A method of using a plastic panel injection molding apparatus, suitable for use with the injection molding apparatus of any one of claims 1-9, the method comprising: The method comprises the following steps: Firstly, the fixed mold is moved towards the fixed mold by the mold closing system to form a mold cavity, and then the plastic raw material in the hopper is melted into a melt by the feeding system and then conveyed to the injection port of the fixed mold, and the melt enters the mold cavity after passing through the injection port; After waiting for the melt to cool and form a plastic panel that matches the shape of the mold cavity, the fixed mold is moved away from the fixed mold by the mold closing system to take out the plastic panel; Subsequently, the inner ejector rod and the ejector rod sleeve are moved towards the fixed mold at a first speed by the driving rod in the driving mechanism to separate the plastic panel from the surface of the movable mold; Then, the inner ejector rod and the ejector rod sleeve are moved towards the fixed mold at the first speed by the driving rod, and the inner ejector rod is moved away from the fixed mold at a second speed by the speed changing assembly, so that the speed of the inner ejector rod moving towards the fixed mold is less than the speed of the ejector rod sleeve moving towards the fixed mold, and the inner ejector rod can retract into the inner side of the ejector rod sleeve to separate the inner ejector rod and the plastic panel; Finally, the connecting assembly and the ejector rod sleeve are separated, the driving rod no longer drives the ejector rod sleeve to move, the driving rod drives the inner ejector rod to move towards the fixed mold, and the inner ejector rod extends outside the ejector rod sleeve to separate the ejector rod sleeve and the plastic panel.