Demolding mechanism for plastic injection mold
By designing a mold release mechanism including ejection rod and current-changing liquid in plastic injection molds, the problem of stress concentration of plastic products during mold release is solved, uniform force application and flexible adaptation to different shapes of products are achieved, and the product is improved Quality and productivity.
Patent Information
- Application Number
- CN202420707483.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-08
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-08
AI Technical Summary
When the mold release mechanism of existing plastic injection molds is ejected from the molded plastic products, it may cause stress concentration, resulting in cracks, deformation or damage to the product, affecting product quality and increasing production costs.
A mold release mechanism including a top plate, a base, a support rod, a moving piece, a fixing plate, an ejection box and an air intake assembly is designed. Through the cooperation of a plurality of dispersed ejection rods and an electric liquid, force is applied evenly and avoided. Concentrate the force, and use the design of the cylinder and airbag to reduce the difficulty of mold release.
It effectively avoids deformation or damage caused by force concentration of finished products, improves product integrity and aesthetics, reduces production costs, and improves mold release efficiency and production efficiency.
Smart Images
Figure CN222201539U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of plastic injection molds, in particular to a demoulding mechanism for plastic injection molds. Background Art
[0002] Injection molding is a method of producing industrial products. Products usually use rubber injection molding and plastic injection molding. Injection molding can also be divided into injection molding and die casting. Injection molding machine is the main molding equipment that uses plastic molding molds to make plastic products of various shapes from thermoplastics or thermosetting materials. Injection molding is achieved through injection molding machines and molds.
[0003] After searching, a rapid prototyping injection mold with a publication number of CN220280362U includes a bottom plate, a top plate is fixedly connected to the top of the bottom plate, a liquid storage cavity is fixedly connected to one side of the top of the top plate, two electric telescopic rods are fixedly connected to the middle of the top of the bottom plate, a rubber sleeve is threadedly connected to the surface of the top block, and the surface and back of the molding cavity are fixedly connected to the connecting cavity, and the inner bottom wall of the molding groove is provided with two circular holes. The scheme uses the electric telescopic rod, the top block, the rubber sleeve, the circular hole, the cutting blade and the telescopic cylinder together, so that after adding a certain amount of molten plastic into the molding groove, it can avoid the plastic from flowing directly downward through the circular hole, thereby improving its sealing performance, and the molded product can still be ejected, which is convenient for the staff to take the molded product. However, the above technical scheme still has the following deficiencies in actual use:
[0004] In this solution, the ejector block can eject the molded plastic under the action of the electric telescopic rod, and the contact area between the ejector block and the plastic product is small. Since a relatively large force is required to form a closed space between the plastic product and the mold after plastic molding, this concentrated force may cause stress concentration on the plastic product, especially in the weak parts of the product, such as thin walls, sharp corners or slender parts. This stress concentration may cause cracks, deformation or other types of damage to the plastic product, affecting the quality of the injection molded product and increasing production costs.
[0005] Therefore, it is necessary to design a demoulding mechanism for the plastic injection mold to solve the above problems. Utility Model Content
[0006] The utility model aims to solve the shortcomings in the prior art and provides a demoulding mechanism for a plastic injection mold.
[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0008] A demoulding mechanism for a plastic injection mold comprises a top plate, a base and four support rods, one end of the support rod is fixed to the lower surface of the top plate, the other end of the support rod is fixed to the upper surface of the base, an upper mold is fixed to the lower surface of the top plate, a lower mold is arranged below the upper mold, a moving part for moving the lower mold is arranged on the base, a fixed plate is arranged below the lower mold, the support rod passes through the fixed plate, and the support rod is fixedly connected to the fixed plate, an ejection box is fixed on the fixed plate, a plurality of ejection rods are arranged in the ejection box, a fixing assembly for fixing the position of the ejection rods is arranged in the ejection box, and an air intake assembly for intake air into the lower mold is also arranged on the fixed plate.
[0009] As a preferred technical solution of the utility model, the movable part includes a cylinder fixedly connected to the base, a pressure plate is fixed to the telescopic end of the cylinder, the support rod passes through the surface of the pressure plate, and the support rod is slidably connected to the pressure plate, a plurality of connecting rods are fixedly connected to the pressure plate, the connecting rods pass through the lower surface of the fixed plate, and the connecting rods are slidably connected to the fixed plate, and the connecting rods are fixed to the lower mold.
[0010] As a preferred technical solution of the utility model, the fixing assembly includes a storage tank arranged in the ejection box, the interior of the storage tank is filled with electrorheological fluid, one end of the ejection rod is fixedly connected to a mounting plate, the other end of the ejection rod extends to the outside of the ejection box, a spring is provided on the mounting plate, the spring is fixed to the inner top surface of the ejection box, an airbag 1 is also fixed on the mounting plate, the airbag 1 is fixed to the inner top surface of the ejection box, a liquid inlet pipe is connected to the airbag 1, and all of the liquid inlet pipes are connected to the storage tank.
[0011] As a preferred technical solution of the utility model, the air intake assembly includes an airbag 2 mounted on one of the connecting rods, one end of the airbag 2 is fixed to the bottom of the lower mold, and the other end of the airbag 2 is fixed to the upper surface of the fixed plate. A ventilation pipe is connected to the airbag 2, and a plurality of air holes are provided on the ejector rod. The interior of the ejector rod is hollow, and the air holes are connected to the interior of the ejector rod, and all the ejector rods are connected to the ventilation pipe.
[0012] As a preferred technical solution of the utility model, the ejection box is arranged opposite to the lower mold.
[0013] As a preferred technical solution of the utility model, the spring and the airbag are both sleeved on the ejection rod.
[0014] The utility model has the following beneficial effects:
[0015] 1. Ejection uniformity: Multiple dispersed ejector rods can evenly apply force to the bottom of the finished product, effectively avoiding deformation or damage of the finished product due to concentrated force, ensuring the integrity and aesthetics of the product, ensuring the structural stability of the product, and reducing the production cost of the product due to damage;
[0016] 2. Flexibility: Under the action of the spring, the position of the ejector rod can be moved according to the shape of the finished product, and then fixed by the electrorheological fluid, which can ensure that each ejector rod can contact the bottom of the finished product, ensure the uniformity of the force applied by the ejector rod to the finished product, and make the device suitable for products of different shapes, improving the practicality and flexibility of the device;
[0017] 3. Improvement of demoulding efficiency: The moving mechanism of the mold driven by the cylinder, the compression of the airbag 2 and the design of the vent pipe jet effectively solve the problem of the possible formation of a closed space between the finished product and the mold, reduce the demoulding difficulty, reduce the force required for the finished product to be ejected, speed up the smooth separation of the finished product, improve production efficiency, and also prevent the finished product from being damaged by excessive force. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of the structure of the demoulding mechanism for the plastic injection mold proposed by the utility model;
[0019] Figure 2 An exploded view of the demoulding mechanism for the plastic injection mold proposed by the utility model;
[0020] Figure 3 The figure is a schematic diagram of the internal structure of the ejector box, including an enlarged view of the local structure of the ejector rod, spring 1 and airbag;
[0021] Figure 4 Exploded view of ejector rod, spring and airbag.
[0022] In the figure: 1 ejector plate, 2 base, 3 support rod, 4 upper mold, 5 lower mold, 6 pressure plate, 7 cylinder, 8 connecting rod, 9 ejector box, 10 ejector rod, 11 mounting plate, 12 spring, 13 airbag 1, 14 electrorheological fluid, 15 storage tank, 16 liquid inlet pipe, 17 airbag 2, 18 ventilation pipe, 19 air hole, 20 fixing plate. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.
[0024] Reference Figure 1-4A demolding mechanism for a plastic injection mold comprises a top plate 1, a base 2 and four support rods 3, one end of the support rod 3 is fixed to the lower surface of the top plate 1, and the other end of the support rod 3 is fixed to the upper surface of the base 2. An upper mold 4 is fixed to the lower surface of the top plate 1, a lower mold 5 is arranged below the upper mold 4, a moving part for moving the lower mold 5 is arranged on the base 2, a fixed plate 20 is arranged below the lower mold 5, the support rod 3 passes through the fixed plate 20, and the support rod 3 is fixedly connected to the fixed plate 20, an ejection box 9 is fixed on the fixed plate 20, a plurality of ejection rods 10 are arranged in the ejection box 9, a fixing assembly for fixing the position of the ejection rod 10 is arranged in the ejection box 9, and an air intake assembly for intake air into the lower mold 5 is also arranged on the fixed plate 20.
[0025] Reference Figure 1 and Figure 2 The movable part includes a cylinder 7 fixedly connected to the base 2, a pressing plate 6 is fixed to the end of the telescopic end of the cylinder 7, a support rod 3 penetrates the surface of the pressing plate 6, and the support rod 3 is slidably connected to the pressing plate 6, a plurality of connecting rods 8 are fixedly connected to the pressing plate 6, the connecting rod 8 penetrates the lower surface of the fixed plate 20, and the connecting rod 8 is slidably connected to the fixed plate 20, and the connecting rod 8 is fixed to the lower mold 5. During the downward movement of the lower mold 5, the connecting rod 8 will also move downward, and the fixed plate 20 can guide the connecting rod 8. At the same time, the pressing plate 6 moves downward, and the support rod 3 can guide the pressing plate 6, so that the lower mold 5 can always maintain a horizontal state, so that the lower mold 5 can contact the ejector rod 10, and at the same time, it can also ensure that the upper mold 4 and the lower mold 5 can be completely closed, thereby ensuring the stability of the overall structure of the device.
[0026] Reference Figure 3 and Figure 4The fixed component includes a storage tank 15 arranged in the ejection box 9, and the interior of the storage tank 15 is filled with an electrorheological fluid 14. It is worth mentioning that the electrorheological fluid 14 is a suspension under normal conditions. It can transform from liquid to solid under the action of an electric field. The viscosity of this suspension increases with the increase of the electric field strength. Its internal specific structure and working principle are all prior art and will not be described in detail here. One end of the ejection rod 10 is fixedly connected to a mounting plate 11, and the other end of the ejection rod 10 extends to the outside of the ejection box 9. A spring 12 is provided on the mounting plate 11, and the spring 12 is fixed to the inner top surface of the ejection box 9. An airbag 13 is also fixed on the mounting plate 11, and the airbag 13 is fixed to the inner top surface of the ejection box 9. The airbag 1 13 is connected with a liquid inlet pipe 16, and all the liquid inlet pipes 16 are connected to the storage tank 15. As the shape of the finished product is different, the ejector rod 10 will move under the action of the spring 12. When moving downward, the electrorheological fluid 14 will be sucked into the airbag 13. On the contrary, when moving upward, the electrorheological fluid 14 in the airbag 13 will be squeezed into the storage tank 15. Electricity is applied to the electrorheological fluid 14 to make the electrorheological fluid 14 change from liquid to solid, thereby achieving the fixation of the ejector rod 10. In this way, under the action of all the ejector rods 10, the force on the finished product can be dispersed to prevent deformation, breakage and other problems caused by concentrated force, and the position of the ejector rod 10 can be flexibly adjusted according to the shape of the finished product, which improves the practicability and flexibility of the device.
[0027] Reference Figure 1-3 The air intake assembly includes an airbag 17 sleeved on one of the connecting rods 8, one end of the airbag 17 is fixed to the bottom of the lower mold 5, and the other end of the airbag 17 is fixed to the upper surface of the fixing plate 20. The airbag 17 is connected to a vent pipe 18, and the ejector rod 10 is provided with a plurality of air holes 19. The interior of the ejector rod 10 is hollow, and the air holes 19 are connected to the interior of the ejector rod 10. All the ejector rods 10 are connected to the vent pipe 18. When the lower mold 5 moves downward to squeeze the airbag 17, the air in the airbag 17 will be sprayed between the lower mold 5 and the finished product through the air holes 19, so that a closed space can be prevented from being formed between the finished product and the mold to cause demoulding difficulties, and the force required for ejecting the finished product is reduced, thereby reducing the load of the device, ensuring that the finished product can be quickly and smoothly separated from the lower mold 5.
[0028] Reference Figure 1 and Figure 2 The ejector box 9 is arranged opposite to the lower mold 5, and the lower mold 5 is provided with a through hole adapted to the ejector rod 10, so that when the lower mold 5 moves downward, the ejector rod 10 can be located inside the through hole, ensuring that the ejector rod 10 can eject the finished product.
[0029] Reference Figure 3 and Figure 4The spring 12 and the airbag 13 are both mounted on the ejector rod 10, so that the spring 12 and the airbag 13 can exert the same force on the mounting plate 11, so that the ejector rod 10 can always be perpendicular to the lower mold 5, ensuring the stability of the overall structure of the device.
[0030] The specific working principle of the utility model is as follows:
[0031] In the initial state, the ejector rod 10 passes through the bottom of the lower mold 5. Before the injection molding operation, the staff first puts the sample plastic product into the lower mold 5. The sample will press the ejector rod 10 downward, so that each ejector rod 10 can be displaced according to the shape of the sample, and the spring 12 is in a stretched state. The downward movement of the ejector rod 10 stretches the airbag 13 and forms a negative pressure state inside, so that the electrorheological fluid 14 can be sucked into the airbag 13. Then, the electrorheological fluid 14 is energized. The viscosity of the electrorheological fluid 14 will increase due to the electric field, and then it will change from liquid to solid, so that the position of the ejector rod 10 can be fixed. When the injection molding operation is performed, after the plastic is cooled and formed, the cylinder 7 is started, and the telescopic end of the cylinder 7 contracts to drive the pressing plate 6 and the connecting rod 8 to move downward, so that the lower mold 5 moves downward. The downward movement of the lower mold 5 allows the ejector rod 10 to pass through the lower mold 5 and exert an upward force on the finished product, so that the finished product can be ejected. Since a plurality of dispersed ejector rods 10 are provided, each ejector rod 10 is in contact with the bottom of the finished product, so that the force exerted by the device on the finished product can be dispersed, preventing the deformation and damage of the finished product caused by the concentrated force, and the position of the ejector rod 10 can be flexibly adjusted according to the shape of the finished product, which improves the practicality and flexibility of the device;
[0032] Furthermore, in the above-mentioned ejection process, when the cylinder 7 drives the lower mold 5 to move downward, the lower mold 5 will squeeze the airbag 2 17, and the air in the airbag 2 17 will be squeezed into the ventilation pipe 18, and then ejected through the air hole 19. The ejected air is located between the inner bottom surface of the lower mold 5 and the bottom of the finished product, which can prevent the formation of a closed space between the finished product and the mold, causing difficulty in demolding. Then, as the air enters, the air will generate a thrust on the finished product, so that the finished product can be quickly and smoothly separated from the lower mold 5.
[0033] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A demoulding mechanism for a plastic injection mold, comprising a top plate (1), a base (2) and four support rods (3), one end of each support rod (3) being fixed to the lower surface of the top plate (1), and the other end of each support rod (3) being fixed to the upper surface of the base (2). It is characterized in that An upper mold (4) is fixed on the lower surface of the top plate (1), a lower mold (5) is arranged below the upper mold (4), a moving part for moving the lower mold (5) is arranged on the base (2), a fixed plate (20) is arranged below the lower mold (5), the support rod (3) passes through the fixed plate (20), and the support rod (3) is fixedly connected to the fixed plate (20), an ejection box (9) is fixed on the fixed plate (20), a plurality of ejection rods (10) are arranged in the ejection box (9), a fixing assembly for fixing the position of the ejection rods (10) is arranged in the ejection box (9), and an air intake assembly for intake air into the lower mold (5) is also arranged on the fixed plate (20).
2. The demoulding mechanism for a plastic injection mold according to claim 1, It is characterized in that The movable part comprises a cylinder (7) fixedly connected to the base (2); a pressing plate (6) is fixedly provided at the telescopic end of the cylinder (7); the support rod (3) passes through the surface of the pressing plate (6), and the support rod (3) is slidably connected to the pressing plate (6); a plurality of connecting rods (8) are fixedly connected to the pressing plate (6); the connecting rods (8) pass through the lower surface of the fixed plate (20), and the connecting rods (8) are slidably connected to the fixed plate (20); and the connecting rods (8) are fixed to the lower mold (5).
3. The demoulding mechanism for a plastic injection mold according to claim 1, It is characterized in that The fixing assembly comprises a storage tank (15) arranged in the ejection box (9), the interior of the storage tank (15) is filled with electrorheological fluid (14), one end of the ejection rod (10) is fixedly connected to a mounting plate (11), the other end of the ejection rod (10) extends to the outside of the ejection box (9), a spring (12) is arranged on the mounting plate (11), the spring (12) is fixed to the inner top surface of the ejection box (9), an air bag (13) is also fixed on the mounting plate (11), the air bag (13) is fixed to the inner top surface of the ejection box (9), a liquid inlet pipe (16) is connected to the air bag (13), and all the liquid inlet pipes (16) are connected to the storage tank (15).
4. The demoulding mechanism for a plastic injection mold according to claim 2, It is characterized in that The air intake assembly comprises an air bag (17) sleeved on one of the connecting rods (8), one end of the air bag (17) being fixed to the bottom of the lower mold (5), and the other end of the air bag (17) being fixed to the upper surface of the fixing plate (20), a vent pipe (18) being connected to the air bag (17), a plurality of air holes (19) being provided on the ejector rod (10), the interior of the ejector rod (10) being hollow, the air holes (19) being connected to the interior of the ejector rod (10), and all the ejector rods (10) being connected to the vent pipe (18).
5. The demoulding mechanism for a plastic injection mold according to claim 1, It is characterized in that The ejection box (9) is arranged opposite to the lower mold (5).
6. The demoulding mechanism for a plastic injection mold according to claim 3, It is characterized in that The spring (12) and the air bag (13) are both sleeved on the ejection rod (10).