A low-pressure injection molding device and method for an automotive interior part
By using an injection mold design with an undercut molding groove and a slider, combined with an electrode correction component, the problem of unstable demolding of car audio housing parts was solved, achieving a high-precision and low-cost demolding process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CIXI XINTONGDA MOLD
- Filing Date
- 2026-04-22
- Publication Date
- 2026-07-21
AI Technical Summary
During the demolding process, the undercut parts of the car audio housing are prone to deformation and tearing of existing injection molds, and the demolding is unstable, affecting the precision and consistency of the product. This is especially true for interior parts with complex undercut structures, resulting in high manufacturing and maintenance costs.
The design employs an inverted molding groove, combined with the precise matching of the slider and the core-pulling component. The electrode correction component automatically adjusts the position of the electrode sheet, and the movement of the core-pulling component is controlled by a hydraulic cylinder to achieve stable demolding.
It reduces deformation and tearing at the undercut parts of plastic parts, improves product molding accuracy and consistency, reduces mold manufacturing and maintenance costs, and simplifies the demolding process.
Smart Images
Figure CN122425852A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of injection mold technology, specifically to a low-pressure injection molding device and method for automotive interior parts. Background Technology
[0002] In the automotive manufacturing sector, the requirements for lightweight, precision, aesthetics, and environmental friendliness in interior components are becoming increasingly stringent. With the development of the circular economy in the automotive industry, the recycling and reuse of waste plastics has become an inevitable trend in the production of automotive interior components. However, recycled plastic raw materials have inherent defects such as poor flowability, large fluctuations in shrinkage rate, high impurity content, and unstable mechanical properties, which place higher demands on injection molding processes and equipment, especially for interior components with complex undercut, thin-walled, and curved surface structures, such as car audio housings, door panel trims, and dashboard sub-components.
[0003] Currently, such as Figure 11 The car audio housing shown features a socket-shaped undercut, making smooth demolding crucial during injection molding. Existing injection molds for undercut parts typically employ simple angled ejector mechanisms for demolding. For example, a guide post drives a slider to move outward during mold opening to demold the undercut. However, uneven stress on the undercut during demolding can easily lead to deformation and tearing, affecting the appearance and dimensional accuracy of the part. Furthermore, the movement precision of the slider or angled ejector is difficult to guarantee, resulting in an unstable demolding process and poor product consistency. Therefore, for the complex undercut structure in car audio housing parts, existing mold demolding mechanisms are complex to design, resulting in high manufacturing and maintenance costs.
[0004] Chinese invention patent application CN11009147921 discloses an undercut core-pulling injection mold, including a front mold assembly and a rear mold assembly. It employs a side-slider core-pulling and side-integral insert design, resulting in a compact product structure with very limited space for the insert's movement, requiring rotational ejection. While this patent utilizes the undercut core-pulling method, the installation of electrodes needs to be embedded in the undercut portion of the car audio housing. For example, the limited space for core-pulling necessitates manual insertion of the electrodes into the mold groove, followed by stabilization to align and insert them into the core, leading to low injection efficiency. Furthermore, to prevent displacement during injection, the electrodes must be tightly fitted to the core, which can cause uneven stress on the undercut portion of the car audio housing during demolding, resulting in deformation and damage. Summary of the Invention
[0005] The purpose of this invention is to solve the above problems by providing a low-pressure injection molding device and method for automotive interior parts.
[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution: A low-pressure injection molding device for automotive interior parts includes a moving mold assembly and a fixed mold assembly. Both the moving mold assembly and the fixed mold assembly have undercut molding grooves in their mold grooves and mold heads. The shape and size of the undercut molding grooves match the shape of the undercut portion of a car audio housing. A slider is slidably connected to the top of the moving mold assembly. A core-pulling component is fixedly installed at one end of the slider near the mold groove. The core-pulling component matches the inner cavity shape of the undercut portion. An electrode correction assembly is provided inside the core-pulling component. This electrode correction assembly can clamp the electrode sheet in the undercut portion and correct its position.
[0007] Furthermore, the moving mold assembly includes a moving mold fixing plate mounted on the telescopic device of the injection molding machine. A moving mold plate is fixedly mounted on the top of the moving mold fixing plate. A moving mold groove is opened on the top of the moving mold plate. A moving mold core is fixedly mounted inside the moving mold groove. A fixed guide is provided on the top of the moving mold groove. Two sets of mold slots are opened on the top of the moving mold core. Multiple ejector pin holes are circumferentially opened around the mold slots. Multiple ejector pins fixed on the ejection device of the injection molding machine are provided inside the moving mold fixing plate. The ejector pins can pass through the corresponding ejector pin holes and eject the car audio housing part. The fixed guide can guide the ejected car audio housing part.
[0008] Furthermore, a lower ejector plate is slidably connected inside the moving mold fixing plate, an upper ejector plate with a flat contact is fixedly installed on the top of the lower ejector plate, an installation plate is provided at the bottom of the ejector pin, an installation groove is opened at the bottom of the upper ejector plate, the installation plate is tightly inserted into the installation groove, and the lower ejector plate is fixedly connected to the ejection device of the injection molding machine.
[0009] Furthermore, the fixed mold assembly includes a fixed mold fixing plate installed on the injection molding machine. A fixed mold template is fixedly installed at the bottom of the fixed mold fixing plate. A fixed mold groove is opened at the bottom of the fixed mold template. A fixed mold core is fixedly installed inside the fixed mold groove. Two sets of mold heads are provided at the bottom of the fixed mold core. A sprue sleeve is provided at the top of the fixed mold fixing plate.
[0010] Furthermore, an installation frame is fixedly installed on the outer side of the moving template, and an external telescopic drive unit is fixedly installed on the outer side of the installation frame. The telescopic end of the external telescopic drive unit is connected to the slider. A sliding groove is provided on the top of the moving template, and the slider is slidably connected in the sliding groove.
[0011] Furthermore, the core-pulling component has an electrode insertion hole at one end near the moving mold core. The electrode correction assembly includes an inner telescopic drive unit, a sliding plate, a positioning swing plate, and a limiting block. The inner telescopic drive unit is fixedly installed inside the core-pulling component. The sliding plate is fixedly installed at the telescopic end of the inner telescopic drive unit. The limiting block is fixedly installed at the inner top of the electrode insertion hole. The thickness of the limiting block is the same as the thickness of the insertion end of the electrode sheet. A guide gap is provided between the limiting block and the inner bottom of the electrode insertion hole. The sliding plate is slidably connected in the guide gap. The positioning swing plate is hinged on the sliding plate. Two sets of electrode slots are provided inside the positioning swing plate. The two insertion ends of the electrode sheet can be inserted into the electrode slots.
[0012] Furthermore, the electrode groove is provided with two alternating corrective springs. Each corrective spring is formed by an upper protrusion and a vertical part, which are inverted L-shaped. The upper protrusion is fixed to the top of the electrode groove facing outward. When the upper protrusion is not compressed, the distance between the two vertical parts is greater than the width of the electrode sheet. When the upper protrusion is compressed, the two vertical parts clamp the electrode sheet.
[0013] Furthermore, a torsion spring is provided at the hinge of the positioning swing plate. When the positioning swing plate slides completely out of the electrode insertion hole, the torsion spring causes the positioning swing plate to swing downward by 60°.
[0014] Furthermore, both the outer telescopic drive unit and the inner telescopic drive unit are hydraulic cylinders.
[0015] A low-pressure injection molding method for automotive interior parts includes the following steps: S1. Injection Molding: First, the electrode sheet is inserted into the undercut molding groove. Then, the external telescopic drive unit is controlled to run. The external telescopic drive unit drives the core-pulling part to move inward and approach the electrode sheet through the slider. Under the action of the electrode correction component, the electrode sheet can be smoothly inserted into the designated position inside the core-pulling part. When the core-pulling part is inserted into the undercut molding groove, the electrode sheet completes automatic positioning. Then, the moving mold assembly moves to the fixed mold assembly. The fixed mold core and the moving mold core close and form an injection cavity. The plastic melt is injected into the injection cavity through the sprue sleeve. After cooling and solidification, it is formed into multiple car audio housing parts. S2, Core pulling: When the mold is opened, the moving mold assembly first separates from the fixed mold assembly, and then controls the operation of the external telescopic drive unit. The external telescopic drive unit drives the core pulling part to move outward through the slider. The electrode correction assembly releases the electrode sheet, and then the core pulling part can easily detach from the undercut part. S3. Ejection: The ejection device of the injection molding machine pushes the lower ejector plate and the upper ejector plate upward, and causes the ejector pins to eject the plastic part from the moving mold core. During the ejection process, the fixed guide ensures the stability of the plastic part in the ejection direction, thus completing the injection molding.
[0016] The beneficial effects of this invention are as follows: 1. This invention effectively reduces deformation and tearing of the undercut parts of plastic parts through the design of the undercut molding groove, improves the molding accuracy and product qualification rate of the product, and makes the demolding process more stable through the precise cooperation of the slider and core pulling parts, significantly improving the consistency of the product and reducing the defect rate.
[0017] 2. This invention simplifies the design of the demolding mechanism, reduces the number of parts, and lowers the manufacturing and maintenance costs of the mold.
[0018] 3. The present invention can automatically adjust the position of the electrode sheet by setting the electrode correction component and tightly clamp the electrode sheet in the core pulling part, which simplifies the demolding process; during demolding, the electrode sheet is released, and no tension is generated during the demolding process, resulting in high demolding quality. Attached Figure Description
[0019] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the structure of the moving mold assembly of the present invention; Figure 4 yes Figure 3 Schematic diagram of the structure of the moving mold core; Figure 5 yes Figure 2 Schematic diagram of the structure of the central mold core; Figure 6 yes Figure 3 Schematic diagram of the structure of the core-pulling component; Figure 7 yes Figure 3 Schematic diagram of the cross-sectional structure of the core-pulling component; Figure 8 yes Figure 7 Exploded view of the middle skateboard and positioning pendulum; Figure 9 yes Figure 8 A schematic diagram of the structure of the central positioning swing plate; Figure 10 yes Figure 9 A schematic diagram of the cross-section of the corrective spring when it is not compressed; Figure 11 This is a structural schematic diagram of an existing car audio housing component.
[0020] Reference numerals: 1. Moving mold fixing plate; 2. Lower ejector plate; 3. Upper ejector plate; 4. Ejector pin; 5. Moving mold plate; 51. Fixed guide component; 6. Moving mold core; 61. Undercut forming groove; 7. Fixed mold fixing plate; 8. Fixed mold plate; 9. Fixed mold core; 10. Sprue bushing; 11. Mounting bracket; 12. External telescopic drive unit; 13. Slider; 14. Core pulling component; 141. Internal telescopic drive unit; 142. Slide plate; 143. Positioning swing plate; 144. Limiting block; 145. Electrode groove; 146. Correcting spring; 21. Undercut part; 22. Electrode plate. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.
[0022] Example like Figures 1-11 As shown, a low-pressure injection molding device for automotive interior parts includes a moving mold assembly and a fixed mold assembly. Both the mold groove of the moving mold assembly and the mold head of the fixed mold assembly have undercut molding grooves 61. The shape and size of the undercut molding grooves 61 match the shape of the undercut portion 21 of the car audio housing. A slider 13 is slidably connected to the top of the moving mold assembly. A core-pulling component 14 is fixedly installed at one end of the slider 13 near the mold groove. The core-pulling component 14 matches the inner cavity shape of the undercut portion 21. An electrode correction assembly is provided inside the core-pulling component 14. The electrode correction assembly can clamp the electrode piece 22 of the undercut portion 21 and correct the position of the electrode piece 22.
[0023] The moving mold assembly includes a moving mold fixing plate 1 installed on the telescopic device of the injection molding machine. A moving mold plate 5 is fixedly installed on the top of the moving mold fixing plate 1. A moving mold groove is opened on the top of the moving mold plate 5. A moving mold core 6 is fixedly installed inside the moving mold groove. A fixed guide 51 is provided on the top of the moving mold groove. The fixed guide 51 can guide the ejected car audio housing part. Two sets of mold slots are opened on the top of the moving mold core 6. Multiple ejector pin holes are opened around the mold slots. An ejector pin 4 is provided inside the moving mold fixing plate 1. The ejector pin 4 is fixedly connected to the ejection device of the injection molding machine. The ejector pin 4 passes through the ejector pin hole and ejects the car audio housing part.
[0024] The fixed mold assembly includes a fixed mold fixing plate 7 installed on the injection molding machine. A fixed mold plate 8 is fixedly installed at the bottom of the fixed mold fixing plate 7. A fixed mold groove is opened at the bottom of the fixed mold plate 8. A fixed mold core 9 is fixedly installed inside the fixed mold groove. Two sets of mold heads are opened at the bottom of the fixed mold core 9. A sprue sleeve 10 is provided at the top of the fixed mold fixing plate 7.
[0025] An installation frame 11 is fixedly installed on the outside of the moving template 5. An external telescopic drive unit 12 is fixedly installed on the outside of the installation frame 11. The telescopic end of the external telescopic drive unit 12 is connected to the slider 13. A sliding groove is provided on the top of the moving template 5, and the slider 13 is slidably connected in the sliding groove.
[0026] The surface treatment of the aforementioned undercut forming groove 61 can be achieved by processes such as hard chrome plating and nitriding to improve wear resistance and corrosion resistance, and extend the service life of the mold.
[0027] Based on the above embodiment, a lower ejector plate 2 is slidably connected inside the moving mold fixing plate 1. The lower ejector plate 2 is fixedly connected to the ejection device of the injection molding machine. An upper ejector plate 3 with a flat contact is fixedly installed on the top of the lower ejector plate 2. An installation plate is provided at the bottom of the ejector pin 4. An installation groove is opened at the bottom of the upper ejector plate 3. The installation plate is tightly inserted into the installation groove, so that multiple ejector pins 4 can be installed quickly, improving installation efficiency.
[0028] like Figure 10 As shown, the electrode sheet 22 includes a base plate, and the base plate has a vertically arranged insertion part on its plane, which will not be described in detail here.
[0029] The workflow of using this invention is as follows: Injection molding: First, the electrode plate 22 is inserted into the undercut molding groove 61. Then, the external telescopic drive unit 12 is controlled to run. The external telescopic drive unit 12 drives the core-pulling part 14 to move inward and approach the electrode plate 22 through the slider 13. Under the action of the electrode correction component, the electrode plate 22 can be smoothly inserted into the designated position inside the core-pulling part 14. When the core-pulling part 14 is inserted into the undercut molding groove 61, the electrode plate 22 completes automatic positioning. Then, the moving mold assembly moves to the fixed mold assembly. The fixed mold core 9 and the moving mold core 6 close and form an injection cavity. The plastic melt is injected into the injection cavity through the sprue sleeve 10. After cooling and solidification, it is formed into multiple car audio housing parts.
[0030] Core pulling: When the mold is opened, the moving mold assembly first separates from the fixed mold assembly, and then controls the operation of the external telescopic drive unit 12. The external telescopic drive unit 12 drives the core pulling part 14 to move outward through the slider 13. The electrode correction assembly releases the electrode plate 22, and then the core pulling part 14 can easily disengage from the undercut part 21.
[0031] Ejection: The ejection device of the injection molding machine pushes the lower ejector plate 2 and the upper ejector plate 3 upward, and causes the ejector pin 4 to eject the plastic part from the moving mold core 6. During the ejection process, the fixed guide 51 ensures the stability of the plastic part in the ejection direction and prevents deviation.
[0032] Based on the above embodiments, the core-pulling component 14 has an electrode insertion hole at one end near the moving mold core 6. The electrode correction assembly includes an inner telescopic drive part 141, a slide plate 142, a positioning swing plate 143, and a limiting block 144. The inner telescopic drive part 141 is fixedly installed inside the core-pulling component 14. The slide plate 142 is fixedly installed at the telescopic end of the inner telescopic drive part 141. The limiting block 144 is fixedly installed at the inner top of the electrode insertion hole. The thickness of the limiting block 144 is the same as the thickness of the insertion end of the electrode piece 22. A guide gap is provided between the limiting block 144 and the inner bottom of the electrode insertion hole. The slide plate 142 is slidably connected in the guide gap. The positioning swing plate 143 is hinged on the slide plate 142. Two sets of electrode grooves 145 are provided inside the positioning swing plate 143. The two insertion ends of the electrode piece 22 can be inserted into the electrode grooves 145.
[0033] Each electrode groove 145 is provided with two alternating corrective springs 146. Each corrective spring 146 is formed by an upper protrusion and a vertical part in an inverted L shape. The upper protrusion is fixed to the top of the electrode groove 145 facing outward. When the upper protrusion is not compressed, the distance between the two vertical parts is greater than the width of the electrode sheet 22. When the upper protrusion is compressed, the two vertical parts clamp the electrode sheet 22.
[0034] A torsion spring is provided at the hinge of the positioning swing plate 143. When the positioning swing plate 143 slides completely out of the electrode insertion hole, the torsion spring causes the positioning swing plate 143 to swing downward by 60°.
[0035] Specifically, during the injection molding process, the electrode plate 22 is first inserted into the undercut molding groove 61. At this time, the insertion end of the electrode plate 22 is in a drooping state under the action of gravity and rests obliquely on the undercut molding groove 61. Then, the outer telescopic drive unit 12 is controlled to run. The outer telescopic drive unit 12 drives the core-pulling component 14 to move inward and approach the electrode plate 22 through the slider 13. At this time, the inner telescopic drive unit 141 is controlled to run. The inner telescopic drive unit 141 pushes the slide plate 142 to slide outward. The slide plate 142 drives the positioning swing plate 143 to slide outward. When the positioning swing plate 143 slides out of the electrode insertion hole completely, the torsion spring causes the positioning swing plate 143 to swing downward by 60°. Since the correcting spring 146 is not squeezed, the upper protrusion of the correcting spring 146 is a round shape that bulges upward. In the arc state (natural state), the vertical part is attached to the inner wall of the electrode groove 145. The distance between the two vertical parts in the electrode groove 145 is greater than the width of the electrode piece 22. Then, the core puller 14 continues to approach the electrode piece 22, so that the positioning swing plate 143 moves to the bottom of the electrode piece 22. Then, the inner telescopic drive part 141 is controlled to pull back. The positioning swing plate 143 can swing upward under the action of the electrode insertion hole. The positioning swing plate 143 pushes the insertion part of the electrode piece 22 to swing upward to the horizontal. The correction spring 146 approaches the electrode piece 22 from bottom to top. Under the guidance of the upper protrusion, the electrode piece 22 can smoothly enter between the two vertical parts in the electrode groove 145. Therefore, when placing the electrode piece 22, it is only necessary to place it roughly in the middle of the undercut forming groove 61. When the positioning swing plate 143 swings to the horizontal, it is pulled back into the electrode insertion hole. At this time, the upper protrusion of the correcting spring 146 is flattened by the top wall of the electrode insertion hole, and the vertical part moves away from the inner wall of the corresponding electrode groove 145. The vertical part clamps the electrode piece 22. Then the inner telescopic drive unit 141 and the outer telescopic drive unit 12 continue to run, and the electrode piece 22 is pulled into the electrode insertion hole until the end of the electrode piece 22 hits the limiting block 144 and the inner end of the core puller 14 hits the bottom plate plane of the electrode piece 22, thus completing the automatic positioning of the electrode piece 22.
[0036] During the core-pulling and mold-opening process, the moving mold assembly first separates from the fixed mold assembly, and then controls the operation of the outer telescopic drive unit 12. The outer telescopic drive unit 12 drives the core-pulling component 14 to move outward through the slider 13. At this time, the inner telescopic drive unit 141 pushes the slide plate 142 and the positioning swing plate 143 to extend from between the core-pulling component 14 and the electrode insertion hole, so that the electrode plate 22 and the positioning swing plate 143 remain in the same position. That is, the output end stroke of the outer telescopic drive unit 12 is consistent with the output end stroke of the inner telescopic drive unit 141. The position of the positioning swing plate 143 is relatively fixed. The core-pulling component 14 moves outward relative to the positioning swing plate 143. When the positioning swing plate 143 slides out of the electrode insertion hole completely, the torsion spring causes the positioning swing plate 143 to swing downward by 60°. At this time, the electrode plate 22 is released, allowing the core-pulling component 14 to easily disengage from the undercut part 21.
[0037] During the above-described process, the electrode plate 22 will not be displaced within the inverted portion 21, and the electrode correction assembly can stably position and clamp the electrode plate 22, making the operation simple.
[0038] Based on the above embodiments, both the outer telescopic drive unit 12 and the inner telescopic drive unit 141 employ hydraulic cylinders, which enables more precise control of the movement speed and position of the core-pulling component 14, further improving demolding accuracy. The inner telescopic drive unit 141 can employ a miniature hydraulic cylinder, with an installation cavity provided inside the core-pulling component 14, allowing direct installation inside the core-pulling component 14.
[0039] Based on the above embodiments, a low-pressure injection molding method for automotive interior parts is provided, comprising the following steps: S1. Injection Molding: First, the electrode plate 22 is inserted into the undercut molding groove 61. Then, the external telescopic drive unit 12 is controlled to run. The external telescopic drive unit 12 drives the core-pulling part 14 to move inward and approach the electrode plate 22 through the slider 13. Under the action of the electrode correction component, the electrode plate 22 can be smoothly inserted into the designated position inside the core-pulling part 14. When the core-pulling part 14 is inserted into the undercut molding groove 61, the electrode plate 22 completes automatic positioning. Then, the moving mold assembly moves to the fixed mold assembly. The fixed mold core 9 and the moving mold core 6 close and form an injection cavity. The plastic melt is injected into the injection cavity through the sprue sleeve 10. After cooling and solidification, it is formed into multiple car audio housing parts. S2, Core pulling: When the mold is opened, the moving mold assembly first separates from the fixed mold assembly, and then controls the operation of the external telescopic drive unit 12. The external telescopic drive unit 12 drives the core pulling part 14 to move outward through the slider 13. The electrode correction assembly releases the electrode sheet 22, and then the core pulling part 14 can easily disengage from the undercut part 21. S3, Ejection: The ejection device of the injection molding machine pushes the lower ejector plate 2 and the upper ejector plate 3 upward, and causes the ejector pin 4 to eject the plastic part from the moving mold core 6. During the ejection process, the fixed guide 51 ensures the stability of the plastic part in the ejection direction, thus completing the injection molding.
[0040] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A low-pressure injection molding device for automotive interior parts, comprising a moving mold assembly and a fixed mold assembly, characterized in that, The moving mold assembly and the fixed mold assembly both have undercut forming grooves (61). The shape and size of the undercut forming grooves (61) match the shape of the undercut part (21) of the car audio housing. The top of the moving mold assembly is slidably connected to a slider (13). A core-pulling component (14) is fixedly installed at one end of the slider (13) near the mold groove. The core-pulling component (14) matches the inner cavity shape of the undercut part (21). An electrode correction component is provided inside the core-pulling component (14). The electrode correction component can clamp the electrode piece (22) in the undercut part (21) and correct the position of the electrode piece (22).
2. The low-pressure injection molding device for automotive interior parts according to claim 1, characterized in that, The moving mold assembly includes a moving mold fixing plate (1) installed on the telescopic device of the injection molding machine. A moving mold plate (5) is fixedly installed on the top of the moving mold fixing plate (1). A moving mold groove is opened on the top of the moving mold plate (5). A moving mold core (6) is fixedly installed inside the moving mold groove. A fixed guide (51) is provided on the top of the moving mold groove. Two sets of mold slots are opened on the top of the moving mold core (6). Multiple ejector pin holes are opened around the mold slots. Multiple ejector pins (4) are fixed on the ejection device of the injection molding machine inside the moving mold fixing plate (1). The ejector pins (4) can pass through the corresponding ejector pin holes and eject the car audio housing. The fixed guide (51) can guide the ejected car audio housing.
3. The low-pressure injection molding device for automotive interior parts according to claim 2, characterized in that, The moving mold fixing plate (1) is internally slidably connected to a lower ejector plate (2). The top of the lower ejector plate (2) is fixedly installed with a plane abutting upper ejector plate (3). The bottom of the ejector (4) is provided with a mounting plate. The bottom of the upper ejector plate (3) is provided with a mounting groove. The mounting plate is tightly inserted into the mounting groove. The lower ejector plate (2) is fixedly connected to the ejection device of the injection molding machine.
4. The low-pressure injection molding device for automotive interior parts according to claim 3, characterized in that, The fixed mold assembly includes a fixed mold fixing plate (7) installed on the injection molding machine. A fixed mold plate (8) is fixedly installed at the bottom of the fixed mold fixing plate (7). A fixed mold groove is opened at the bottom of the fixed mold plate (8). A fixed mold core (9) is fixedly installed inside the fixed mold groove. Two sets of mold heads are provided at the bottom of the fixed mold core (9). A sprue sleeve (10) is provided at the top of the fixed mold fixing plate (7).
5. The low-pressure injection molding device for automotive interior parts according to claim 4, characterized in that, An installation frame (11) is fixedly installed on the outside of the moving template (5), and an external telescopic drive part (12) is fixedly installed on the outside of the installation frame (11). The telescopic end of the external telescopic drive part (12) is connected to the slider (13). A sliding groove is provided on the top of the moving template (5), and the slider (13) is slidably connected in the sliding groove.
6. The low-pressure injection molding device for automotive interior parts according to claim 5, characterized in that, The core-pulling component (14) has an electrode insertion hole at one end near the moving mold core (6). The electrode correction assembly includes an inner telescopic drive unit (141), a sliding plate (142), a positioning swing plate (143), and a limiting block (144). The inner telescopic drive unit (141) is fixedly installed inside the core-pulling component (14). The sliding plate (142) is fixedly installed at the telescopic end of the inner telescopic drive unit (141). The limiting block (144) is fixedly installed at the inner top of the electrode insertion hole. The thickness of the limiting block (144) is the same as the thickness of the insertion end of the electrode sheet (22). A guide gap is provided between the limiting block (144) and the inner bottom of the electrode insertion hole. The sliding plate (142) is slidably connected in the guide gap. The positioning swing plate (143) is hinged on the sliding plate (142). Two sets of electrode slots (145) are opened inside the positioning swing plate (143). The two insertion ends of the electrode sheet (22) can be inserted into the electrode slots (145).
7. The low-pressure injection molding device for automotive interior parts according to claim 6, characterized in that, The electrode groove (145) is provided with two alternating corrective springs (146). The corrective springs (146) are formed by an upper protrusion and a vertical part in an inverted L shape. The upper protrusion is fixed to the top of the electrode groove (145) facing outward. When the upper protrusion is not squeezed, the distance between the two vertical parts is greater than the width of the electrode sheet (22). When the upper protrusion is squeezed, the two vertical parts clamp the electrode sheet (22).
8. The low-pressure injection molding device for automotive interior parts according to claim 7, characterized in that, A torsion spring is provided at the hinge of the positioning swing plate (143). When the positioning swing plate (143) slides completely out of the electrode insertion hole, the torsion spring causes the positioning swing plate (143) to swing downward by 60°.
9. A low-pressure injection molding device for automotive interior parts according to claim 8, characterized in that, Both the outer telescopic drive unit (12) and the inner telescopic drive unit (141) are hydraulic cylinders.
10. A low-pressure injection molding method for automotive interior parts, using the low-pressure injection molding apparatus for automotive interior parts as described in claim 9, characterized in that, Includes the following steps: S1, Injection Molding: First, insert the electrode sheet (22) into the undercut molding groove (61), then control the operation of the external telescopic drive unit (12). The external telescopic drive unit (12) drives the core puller (14) to move inward and approach the electrode sheet (22) through the slider (13). Under the action of the electrode correction component, the electrode sheet (22) can be smoothly inserted into the designated position inside the core puller (14). When the core puller (14) is inserted into the undercut molding groove (61), the electrode sheet (22) completes automatic positioning. Then the moving mold assembly moves to the fixed mold assembly. The fixed mold core (9) and the moving mold core (6) close and form an injection cavity. The plastic melt is injected into the injection cavity through the sprue sleeve (10). After cooling and solidification, it is formed into multiple car audio housing parts. S2, Core pulling: When the mold is opened, the moving mold assembly first separates from the fixed mold assembly, and then controls the operation of the external telescopic drive unit (12). The external telescopic drive unit (12) drives the core pulling part (14) to move outward through the slider (13). The electrode correction assembly releases the electrode sheet (22), and then the core pulling part (14) can easily disengage from the undercut part (21). S3, Ejection: The ejection device of the injection molding machine pushes the lower ejector plate (2) and the upper ejector plate (3) upward, and causes the ejector pin (4) to eject the plastic part from the moving mold core (6). During the ejection process, the fixed guide (51) ensures the stability of the plastic part in the ejection direction and completes the injection molding.