Plastic part back-off demolding mechanism
By designing an undercut demolding mechanism for plastic parts, flexible demolding is achieved using elastic deformation components, which solves the problem of undercut deformation or breakage caused by traditional forced demolding, improves product yield, and reduces production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional demolding methods forcibly demold plastic parts with undercut structures can easily cause deformation or breakage of the undercut parts of the plastic material with poor elasticity, increasing production costs.
Design a plastic part undercut demolding mechanism, which uses a working head with an elastic deformable component such as a bellows structure to avoid damage to the undercut part through flexible demolding, and uses hydraulic drive and guide structure to ensure accuracy.
It improved the yield rate of plastic parts, avoided damage to the undercut parts, and reduced production costs.
Smart Images
Figure CN224116643U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of demolding device technology, specifically to a plastic part inverted demolding mechanism. Background Technology
[0002] In today's large-scale production of plastic products, in order to meet the diverse product functions and design requirements, more and more plastic parts are designed with undercut structures. Simply put, an undercut structure is a protrusion or depression on the product that interferes with the mold opening direction. Although this structure can give the product unique functions, such as enhancing connection stability and realizing special assembly methods, it also brings great challenges to the demolding process.
[0003] Traditional demolding methods for this type of undercut structure often employ forced demolding. For plastic materials with poor elasticity, the undercut part is prone to deformation or even breakage due to excessive external force during forced demolding, leading to product scrap and increased production costs. Therefore, a plastic part undercut demolding mechanism is proposed to solve the problems mentioned above. Utility Model Content
[0004] To solve the above-mentioned technical problems, a plastic part undercut demolding mechanism is provided. This technical solution solves the problem that the traditional demolding methods mentioned in the background technology often use forced demolding when dealing with such undercut structures. For plastic materials with poor elasticity, the undercut part is very easy to deform or even break due to excessive external force during the forced demolding process, resulting in product scrap and increased production costs.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A plastic part undercut demolding mechanism includes a mounting plate. Four evenly distributed guide pillars are fixedly connected to the upper end of the mounting plate. Limit blocks are fixedly connected to the upper ends of the four guide pillars. Push plates are slidably connected to the outer surfaces of the four guide pillars. Several evenly distributed fixing holes are opened at the upper end of the push plates. Ejector pin fixing plates are fixedly connected to the inside of the fixing holes by bolts. A pin rod is fixedly connected to the inner side of the ejector pin fixing plate. An elastic deformation part is fixedly connected to the upper end of the pin rod. A working head is fixedly connected to the upper end of the elastic deformation part.
[0007] Preferably, a hydraulic rod is fixedly installed at the upper center of the mounting plate, and the output end of the hydraulic rod is fixedly connected to the lower end of the push plate.
[0008] Preferably, a return spring is fitted on the outer surface of each of the four guide posts.
[0009] Preferably, the two ends of the reset spring are fixedly connected to the upper end of the push plate and the lower end of the limiting block, respectively.
[0010] Preferably, the working head is an irregularly shaped structure adapted to the shape of the inverted part.
[0011] Preferably, the elastic deformation part is a bellows structure.
[0012] Preferably, mounting holes are provided at all four corners of the upper end of the mounting plate.
[0013] The advantages of this utility model compared with the prior art are:
[0014] This solution proposes a plastic part undercut demolding mechanism. By setting an elastic deformation part, the working head can use its own elastic deformation characteristics to achieve flexible demolding when it comes into contact with the undercut part. This avoids the damage to the product caused by traditional forced demolding and helps to improve the product yield. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this utility model;
[0016] Figure 2 This is a structural schematic diagram of the present invention from another perspective.
[0017] The numbers on the map are:
[0018] 1. Mounting plate; 2. Guide post; 3. Push plate; 4. Ejector pin fixing plate; 5. Needle bar; 6. Elastic deformation part; 7. Working head; 8. Hydraulic rod; 9. Limiting block; 10. Return spring; 11. Mounting hole. Detailed Implementation
[0019] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.
[0020] Reference Figure 1 and Figure 2 As shown, a plastic part undercut demolding mechanism includes a mounting plate 1. Four evenly distributed guide pillars 2 are fixedly connected to the upper end of the mounting plate 1. Limiting blocks 9 are fixedly connected to the upper ends of the four guide pillars 2. Push plates 3 are slidably connected to the outer surfaces of the four guide pillars 2. Several evenly distributed fixing holes are opened at the upper end of the push plates 3. Ejector pin fixing plates 4 are fixedly connected to the inside of the fixing holes by bolts. A needle rod part 5 is fixedly connected to the inner side of the ejector pin fixing plate 4. An elastic deformation part 6 is fixedly connected to the upper end of the needle rod part 5. A working head 7 is fixedly connected to the upper end of the elastic deformation part 6.
[0021] Furthermore, mounting holes 11 are provided at the four corners of the upper end of the mounting plate 1 for fixed connection with the mold base plate. The guide post 2 provides precise motion guidance for the push plate 3, ensuring that each component can move smoothly along the predetermined straight direction during the demolding process, avoiding deviation or shaking, thereby ensuring the accuracy and stability of the demolding action.
[0022] Furthermore, a hydraulic rod 8 is fixedly installed at the upper center of the mounting plate 1. The output end of the hydraulic rod 8 is fixedly connected to the lower end of the push plate 3. The hydraulic rod 8 serves as the power source for the entire demolding mechanism, providing demolding power to the push plate 3 and driving the entire demolding execution assembly to perform demolding and resetting actions.
[0023] Furthermore, a reset spring 10 is fitted on the outer surface of each of the four guide pillars 2. The two ends of the reset spring 10 are fixedly connected to the upper end of the push plate 3 and the lower end of the limit block 9, respectively. The reset spring 10 provides the power for automatic reset of the demolding mechanism. After demolding is completed, it can quickly push the push plate 3 and related components back to the initial position to prepare for the next production cycle.
[0024] Furthermore, the working head 7 is an irregularly shaped structure adapted to the shape of the undercut part. It is customized according to the specific shape of the undercut part of the product to ensure that it can fit tightly with the undercut part and achieve effective demolding.
[0025] Furthermore, the elastic deformation section 6 is a bellows structure. The outer diameter of the bellows is determined according to the diameter of the needle rod section 5 and the deformation requirements. The bellows structure has radial elastic deformation capability and can undergo controllable elastic deformation when subjected to lateral force.
[0026] Furthermore, during the demolding process, when the working head 7 moves along with the ejector pin fixing plate 4 and the push plate 3, and the working head 7 contacts the undercut part of the plastic part, the undercut part generates a lateral force on the working head 7. Under the action of this lateral force, the elastic deformation part 6 undergoes radial deformation, allowing the working head 7 to pass smoothly through the undercut part, achieving flexible demolding and effectively avoiding damage to the undercut part of the plastic part.
[0027] Working principle: When the injection mold is in the closed state, the working head 7 fits tightly with the mold cavity to form the undercut structure of the product. At this time, the hydraulic rod 8 is in the initial contracted state, the return spring 10 is in the naturally extended state, and the push plate 3 and the ejector pin fixing plate 4 are in the initial position. When the injection is completed, the mold begins to open. The main parting surface opens first. Then, the piston rod of the hydraulic rod 8 extends and pushes the push plate 3 to move along the guide post 2. During the movement of the push plate 3, the working head 7 gradually approaches the plastic part. As the push plate 3 and the ejector pin fixing plate 4 continue to move forward, the working head 7 gradually contacts the undercut part of the plastic part. Since the undercut part interferes with the mold opening direction, the working head 7 is subjected to lateral force. At this time, the elastic deformation part 6 begins to play its role and undergoes radial deformation under the action of lateral force, so that the working head 7 can pass smoothly through the undercut part and realize the flexible demolding of the undercut part of the plastic part.
[0028] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A plastic part undercut demolding mechanism, characterized in that, The system includes a mounting plate (1), on which four evenly distributed guide posts (2) are fixedly connected at the upper end. Each of the four guide posts (2) is fixedly connected to a limit block (9). A push plate (3) is slidably connected to the outer surface of the four guide posts (2). The upper end of the push plate (3) is provided with several evenly distributed fixing holes. A pin fixing plate (4) is fixedly connected to the inside of the fixing holes by bolts. A pin rod part (5) is fixedly connected to the inner side of the pin fixing plate (4). An elastic deformation part (6) is fixedly connected to the upper end of the pin rod part (5). A working head (7) is fixedly connected to the upper end of the elastic deformation part (6).
2. The plastic part undercut demolding mechanism according to claim 1, characterized in that: A hydraulic rod (8) is fixedly installed at the center of the upper end of the mounting plate (1), and the output end of the hydraulic rod (8) is fixedly connected to the lower end of the push plate (3).
3. The plastic part undercut demolding mechanism according to claim 1, characterized in that: Each of the four guide posts (2) is fitted with a return spring (10) on its outer surface.
4. The plastic part undercut demolding mechanism according to claim 3, characterized in that: The two ends of the reset spring (10) are fixedly connected to the upper end of the push plate (3) and the lower end of the limiting block (9), respectively.
5. The plastic part undercut demolding mechanism according to claim 1, characterized in that: The working head (7) is an irregularly shaped structure adapted to the shape of the undercut part.
6. The plastic part undercut demolding mechanism according to claim 1, characterized in that: The elastic deformation part (6) is a bellows structure.
7. The plastic part undercut demolding mechanism according to claim 1, characterized in that: Mounting holes (11) are provided at the four corners of the upper end of the mounting plate (1).