High-precision injection molding device for automobile back door and process of high-precision injection molding device
By introducing a lifting mechanism and cooling water channel design into the automobile tailgate injection molding device, the problems of injection molding accuracy and incomplete cooling are solved, and high-precision and high-hardness undercut molding is achieved.
Patent Information
- Application Number
- CN202510965139.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-09-12
AI Technical Summary
When molding undercut parts in existing automobile tailgate injection molding devices, the core pulling mechanism is difficult to accurately close the mold, resulting in reduced injection precision, and incomplete cooling causes the undercut parts to have insufficient hardness.
A high-precision injection molding device for automobile tailgates was designed. The device adopts a lifting mechanism and cooling water channel design to ensure that the inserts accurately fill the cavity gap during mold closing, and accelerates the cooling of the undercut parts through the cooling water channel surrounding the mold cavity.
It improves the injection molding accuracy, enhances the hardness of the undercut parts, ensures the quality of the molded parts, simplifies the cooling water channel processing, and prevents the mold core from loosening.
Smart Images
Figure CN120620573A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of automobile parts processing, in particular to a high-precision injection molding device for an automobile back door and a process thereof. Background Art
[0002] The rear door of a car is also called the tailgate. Some rear doors are assembled from a front panel, a lining panel, and a rear panel. The front panel is often formed with a fastener for connecting to the rear panel. When the front panel is injection molded, in order to improve production efficiency and the strength of the fastener, the fastener is usually molded together with the panel body. Since the fastener has an irregular shape and is often tilted, traditional injection molding equipment is equipped with a core-pulling mechanism to separate the fastener from the cavity in advance. Although the core-pulling mechanism can achieve the separation of the fastener, the following problems may occur in actual use: First, the insert in the core-pulling mechanism will slide as the movable mold is pressed down. Since the stroke of the insert and the movable mold is difficult to coordinate, when the movable mold and the fixed mold are completely merged, the rising insert cannot be accurately merged with the cavity, resulting in concave and convex surfaces on the cavity that do not belong to its process structure, which in turn affects the accuracy of injection molding and reduces the quality of the molded part. Secondly, there is a mold cavity for the molding of the undercut part in the insert. During the cooling stage, cooling water is often introduced into the fixed mold and the movable mold to circulate and cool the mold cavity to speed up the molding of the injection molded parts. However, the independently set insert cannot be connected to the cooling water channel in the fixed mold because it needs to slide up and down. Then the undercut part will not only take more time to cool, but also will not be cooled completely, which will eventually lead to low hardness of the undercut part and fail to meet the corresponding quality standards.
[0003] Therefore, it is necessary to provide a high-precision injection molding device for automobile back door and its process to solve the above problems. Summary of the Invention
[0004] Based on this, it is necessary to provide a high-precision injection molding device and process for a car back door in response to the existing technical problems.
[0005] In order to solve the problems of the prior art, the technical solution adopted by the present invention is: a high-precision injection molding device for a rear tail door of an automobile, comprising a fixed mold and a movable mold arranged above the fixed mold, a No. 1 cavity being provided in the fixed mold, and a No. 2 cavity being provided in the movable mold, after the fixed mold and the movable mold are closed, the No. 1 cavity and the No. 2 cavity are merged into a panel mold cavity for molding the rear tail door panel, two through grooves in a symmetrical state are provided on the fixed mold and which cause a gap in the No. 1 cavity, an insert is provided in the through groove which fills the gap in the No. 1 cavity by rising, a button-shaped mold cavity for molding the rear tail door undercut is provided in the insert, a cooling water channel surrounding the button-shaped mold cavity is provided in the insert, a lifting mechanism is provided on the fixed mold for driving the two inserts to rise after the movable mold is pressed down, each lifting mechanism includes a ejector block which slides obliquely in the through groove, the insert is provided above the ejector block, an elastic member is provided between the insert and the ejector block, a limit member is provided in the through groove for limiting the upward movement of the insert, and an ejection mechanism for ejecting the rear tail door panel is provided in the fixed mold.
[0006] Furthermore, four limit pins distributed in a matrix are formed at the bottom of the insert, a support plate is formed at the upper end of the top block, and the limit part includes four limit sleeves distributed in a matrix and fixedly connected to the inner wall of the through groove. The lower end of each limit pin passes through the support plate and the limit sleeve in turn, and the bottom of each limit pin is coaxially fixedly connected to the limit cap. The elastic part includes four No. 1 springs respectively mounted on the limit pins.
[0007] Furthermore, two strip-shaped inclined grooves corresponding to the through grooves are provided on the fixed mold, and one end of each strip-shaped inclined groove is connected to the corresponding through groove. Each lifting mechanism also includes a strip-shaped push block slidably connected to the strip-shaped inclined groove, and the strip-shaped push block is formed with a No. 1 inclined surface at one end facing the through groove, and a No. 2 inclined surface is formed at the lower end of the top block to cooperate with the inclined wedge of the No. 1 inclined surface. The movable mold is fixed with plug-in columns corresponding to the two strip-shaped push blocks, and each plug-in column is in an inclined state. The other end of the strip-shaped push block is provided with a columnar inclined groove for inserting the plug-in column.
[0008] Furthermore, a strip accommodating groove is provided downward at the bottom of each strip inclined groove, and the strip accommodating groove is parallel to the corresponding strip inclined groove. A fixing rod is provided in the strip accommodating groove, and the axial direction is parallel to the sliding direction of the strip push block. A protrusion is formed at the bottom of the strip push block, and the fixing rod passes through the protrusion. A No. 2 spring is sleeved on the fixing rod, and the protrusion presses the No. 2 spring against the inner wall of the strip accommodating groove. A limiting nut is screwed on one end of the fixing rod to limit the protrusion.
[0009] Furthermore, a cavity-shaped missing surface is formed on the top of the insert. After the insert rises, the cavity-shaped missing surface fills the gap of the No. 1 cavity and forms a complete No. 1 cavity.
[0010] Furthermore, a groove is provided downward on the surface of the cavity, a mold core is embedded in the groove, a button-shaped mold cavity is provided in the mold core, a concave cavity No. 1 surrounding the mold core is provided on the outer wall of the mold core, a concave cavity No. 2 surrounding the groove is provided on the inner wall of the groove, and the concave cavity No. 1 and the concave cavity No. 2 are combined to form a cooling water channel, and a partition is formed on the outer wall of the mold core. The partition forms two ends of the closed-loop cooling water channel that are not connected at the head and tail, and a water inlet channel and a drainage channel leading to the two ends of the cooling water channel respectively are provided in the insert.
[0011] Furthermore, the bottom of the mold core is formed with a support bar that passes downward through the insert, and the bottom of the insert is provided with a locking rod that is slidably connected to it. One end of the locking rod is formed with two extension blocks located on both sides of the support bar, and each extension block is provided with an oblique sliding groove. The lower end of the support bar is formed with a guide pin that passes through the two oblique sliding grooves respectively, and the other end of the locking rod is formed with a locking block fixedly connected to the insert.
[0012] Furthermore, a support seat is provided under the fixed mold, the fixed mold is fixed to the top of the support seat, and a rectangular accommodating opening is opened in the support seat. The ejection mechanism includes a lifting plate and a plurality of ejectors. The lifting plate is horizontally slidable in the rectangular accommodating opening, and a plurality of vertical No. 3 springs are provided between the lifting plate and the fixed mold. A plurality of ejectors are vertically fixed to the top of the lifting plate. Each ejector passes through the fixed mold upward, and the top of each ejector is flush with the No. 1 cavity.
[0013] Furthermore, a vertical shooting cavity connected to the No. 2 cavity is provided in the movable mold, a horizontal template is fixed on the top of the movable mold, and an injection port connected to the shooting cavity is provided on the top of the template.
[0014] A high-precision injection molding process for a car back door, the process comprising the following steps: S1, mold closing drive; S2, injection molding; S3, accelerated cooling; S4, mold opening and separation; S5, eject and take out the parts.
[0015] Compared with the prior art, the present invention has the following beneficial effects: First, during the process of the movable mold descending and closing the fixed mold, the ejector block in the jacking mechanism will push the insert block to rise as the movable mold descends. When the insert block rises to the point where it is blocked by the limit sleeve, the insert block will completely fill the gap of the No. 1 cavity. After that, the movable mold continues to descend and the ejector block continues to rise. At this time, the ejector block will compress the No. 1 spring between it and the insert block. Through the No. 1 spring, the ejector block can continue to rise driven by the movable mold after the insert block rises to fill the gap of the No. 1 cavity. Finally, before the movable mold and the fixed mold are closed, it is ensured that the insert block has filled the gap of the No. 1 cavity, thereby improving the precision of injection molding and the quality of the molded parts. Secondly, a cooling water channel surrounding the button-shaped mold cavity is provided in the insert of the device. When the molded part cools, a circulating coolant is injected into the cooling water channel to accelerate the cooling and forming of the back door undercut, thereby improving the hardness of the undercut. Third, this device divides the cooling water channel for cooling the undercut into cavity No. 1 and cavity No. 2 formed on the embedding groove and the mold core respectively, so as to facilitate the milling of the cooling water channel, and the mold core is locked by a locking rod after being installed in the embedding groove, so as to prevent the mold core from loosening during the rising process of the insert, resulting in concave and convex surfaces in cavity No. 1 that do not belong to its process structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention when the mold is opened; Figure 2 yes Figure 1 A1 is a partial enlarged schematic diagram; Figure 3 yes Figure 2 A2 is a partial enlarged schematic diagram; Figure 4 It is a schematic diagram of the three-dimensional structure of the moving mold; Figure 5 This is a three-dimensional cross-sectional view of the present invention during mold closing. Figure 1 ; Figure 6 This is a three-dimensional cross-sectional view of the present invention during mold closing. Figure 2 ; Figure 7 It is a planar cross-sectional view of the present invention when the mold is closed; Figure 8 yes Figure 7 A3 is a partial enlarged schematic diagram; Figure 9 It is a plan view of the present invention when the mold is closed; Figure 10 yes Figure 9 A4 is a partial enlarged schematic diagram; Figure 11 This is a three-dimensional cross-section of the insert Figure 1 ; Figure 12 This is a three-dimensional cross-section of the insert Figure 2 ; Figure 13 It is a three-dimensional structural exploded view of the mold core and insert; Figure 14 It is a schematic diagram of the three-dimensional structure of the mold core and the locking rod; Figure 15 It is a schematic diagram of the three-dimensional structure of the automobile back door molding.
[0017] The numbers in the figure are: 1, fixed mold; 2, movable mold; 3, cavity No. 1; 4, cavity No. 2; 5, panel mold cavity; 6, through groove; 7, insert; 8, button mold cavity; 9, cooling water channel; 10, ejector block; 11, ejector mechanism; 12, limit pin; 13, support plate; 14, limit sleeve; 15, limit cap; 16, spring No. 1; 17, strip bevel; 18, strip push block; 19, inclined surface No. 1; 20, inclined surface No. 2; 21, plug column; 22, columnar bevel; 23, strip receiving groove; 24, fixing rod; 25 , protrusion; 26, No. 2 spring; 27, limit nut; 28, cavity shape defect; 29, embedding groove; 30, mold core; 31, No. 1 cavity; 32, No. 2 cavity; 33, spacer; 34, water inlet channel; 35, drainage channel; 36, support bar; 37, locking rod; 38, extension block; 39, oblique slide; 40, guide pin; 41, locking block; 42, support seat; 43, rectangular receiving port; 44, lifting plate; 45, ejector pin; 46, No. 3 spring; 47, shooting cavity; 48, template; 49, injection port. DETAILED DESCRIPTION
[0018] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0019] refer to Figures 1 to 15 The high-precision injection molding device for a car back door shown in the figure includes a fixed mold 1 and a movable mold 2 arranged above the fixed mold 1. The fixed mold 1 is provided with a No. 1 cavity 3, and the movable mold 2 is provided with a No. 2 cavity 4. After the fixed mold 1 and the movable mold 2 are closed, the No. 1 cavity 3 and the No. 2 cavity 4 are combined into a panel mold cavity 5 for molding the back door panel. The fixed mold 1 is provided with two symmetrical through grooves 6 that form a gap in the No. 1 cavity 3. The through groove 6 is provided with an insert 7 that fills the gap in the No. 1 cavity 3 by rising. A button-shaped mold cavity 8 is provided for forming the back door buckle, and a cooling water channel 9 surrounding the button-shaped mold cavity 8 is provided in the insert 7. A lifting mechanism is provided on the fixed mold 1 for driving the two inserts 7 to rise after the movable mold 2 is pressed down. Each lifting mechanism includes a top block 10 that slides obliquely in the through groove 6. The insert 7 is provided above the top block 10. An elastic member is provided between the insert 7 and the top block 10. A limit member is provided in the through groove 6 to limit the upward movement of the insert 7. An ejection mechanism 11 for ejecting the back door panel is provided in the fixed mold 1.
[0020] During the process of the movable mold 2 descending and closing with the fixed mold 1, the top block 10 in the jacking mechanism will push the insert 7 to rise as the movable mold 2 descends. When the insert 7 rises to be blocked by the limiter, the insert 7 completely fills the gap of the No. 1 cavity 3. Thereafter, the movable mold 2 continues to descend and the top block 10 continues to rise. At this time, the top block 10 will compress the elastic member between it and the insert 7. Through the elastic member, the top block 10 can be driven by the movable mold 2 to continue to rise after the insert 7 rises to fill the gap of the No. 1 cavity 3. Finally, before the movable mold 2 and the fixed mold 1 are closed, it is ensured that the insert 7 has filled the gap of the No. 1 cavity 3. When the flow plastic is injected into the panel cavity 5, Part of the plastic will flow into the button-shaped cavity 8, and the plastic that enters the panel cavity 5 will form the back door panel after cooling. The plastic that enters the button-shaped cavity 8 will form the back door undercut after cooling. When the molded part is cooled, a circulating coolant will be injected into the cooling water channel 9 to accelerate the cooling and forming of the back door undercut. When the entire car back door is cooled and formed, the movable mold 2 begins to rise and separate from the fixed mold 1. During this process, the insert 7 and the top block 10 will fall by themselves due to their own gravity. At this time, the back door undercut will separate from the button-shaped cavity 8, and as the insert 7 falls, the through groove 6 will cause a notch to be generated on the No. 1 cavity 3 (such as Figure 2 As shown), when the movable mold 2 and the fixed mold 1 are completely separated, the ejection mechanism 11 will eject the back door panel embedded in the No. 1 cavity 3.
[0021] In order to show how the top block 10 drives the insert 7 to slide obliquely in a specified direction, the following features are set: Four limit pins 12 distributed in a matrix are formed at the bottom of the insert 7, and a support plate 13 is formed at the upper end of the top block 10. The limit parts include four limit sleeves 14 distributed in a matrix and fixedly connected to the inner wall of the through groove 6. The lower end of each limit pin 12 passes through the support plate 13 and the limit sleeve 14 in sequence, and the bottom of each limit pin 12 is coaxially fixedly connected to the limit cap 15. The elastic part includes four No. 1 springs 16 respectively mounted on the limit pins 12.
[0022] Since the rear door panel of the car is a curved surface and the rear door buckle is in an inclined state, in order to enable the rear door buckle to be pulled out of the inlay 7, the sliding direction of the inlay 7 needs to be oblique. At this time, the cooperation between the limit pin 12 and the limit sleeve 14 enables the top block 10 to drive the inlay 7 to slide in the through groove 6 along the axial direction (i.e. oblique direction) of the limit pin 12. When the top block 10 drives the inlay 7 to rise, the inlay 7 will drive the corresponding limit cap 15 to gradually approach the limit sleeve 14 through the limit pin 12. When the positioning cap 15 conflicts with the limiting sleeve 14 upward, the insert 7 rises to the limit and fills the gap of the No. 1 cavity 3. After that, the movable mold 2 continues to descend and the top block 10 continues to rise. At this time, the top block 10 will compress several No. 1 springs 16 until the movable mold 2 and the fixed mold 1 are completely closed. When the top block 10 and the insert 7 descend by their own gravity, the support plate 13 on the top block 10 will gradually move downward and approach the four limiting sleeves 14. When the support plate 13 conflicts with the limiting sleeve 14 downward, the top block 10 falls to the limit.
[0023] In order to show how the top block 10 is driven by the passive mold 2 to drive the insert 7 to rise, the following features are set: Two strip-shaped inclined grooves 17 corresponding to the through-slot 6 are provided on the fixed mold 1, and one end of each strip-shaped inclined groove 17 is connected to the corresponding through-slot 6. Each lifting mechanism also includes a strip-shaped push block 18 that is slidably connected to the strip-shaped inclined groove 17. The strip-shaped push block 18 is formed with a No. 1 inclined surface 19 at one end facing the through-slot 6, and a No. 2 inclined surface 20 is formed at the lower end of the ejector block 10, which is wedge-matched with the No. 1 inclined surface 19. Plug columns 21 corresponding to the two strip-shaped push blocks 18 are fixed on the movable mold 2, and each plug column 21 is in an inclined state. The other end of the strip-shaped push block 18 is provided with a columnar inclined groove 22 for inserting the plug column 21.
[0024] When the movable mold 2 is separated from the fixed mold 1, the insert 7 is in a descending state, and the strip push block 18 is in a state away from the through slot 6. In the process of the movable mold 2 descending and closing with the fixed mold 1, each plug post 21 will be inserted downward into the corresponding columnar inclined groove 22. Thereafter, as the plug post 21 is inserted, the strip push block 18 will slide toward the through slot 6 through the oblique wedge cooperation between the plug post 21 and the columnar inclined groove 22. When the strip push block 18 approaches the top block 10, the number one inclined surface 19 on the strip push block 18 will align with the number one inclined surface 19 on the top block 10. The No. 2 inclined surface 20 conflicts with each other. Thereafter, as the strip push block 18 is continuously pushed in, the top block 10 will drive the insert 7 to rise through the wedge cooperation of the No. 1 inclined surface 19 and the No. 2 inclined surface 20. Finally, the insert 7 will fill the gap of the No. 1 cavity 3. When processing the columnar inclined groove 22 and the plug column 21, the top of the columnar inclined groove 22 is processed into a flared shape, and the lower end of the plug column 21 is processed into a round head shape, so that the plug column 21 can pass through the flared end at the top of the columnar inclined groove 22 and smoothly insert into the columnar inclined groove 22.
[0025] In order to enable the strip push block 18 to reset itself when the movable mold 2 is separated from the fixed mold 1, the following features are set: A strip receiving groove 23 is provided downwardly at the bottom of each strip inclined groove 17, and the strip receiving groove 23 is parallel to the corresponding strip inclined groove 17. A fixing rod 24 is provided in the strip receiving groove 23, and the axial direction is parallel to the sliding direction of the strip push block 18. A protrusion 25 is formed at the bottom of the strip push block 18, and the fixing rod 24 passes through the protrusion 25. A No. 2 spring 26 is sleeved on the fixing rod 24, and the protrusion 25 presses the No. 2 spring 26 against the inner wall of the strip receiving groove 23. A limiting nut 27 is screwed on one end of the fixing rod 24 to limit the protrusion 25.
[0026] In the process of the strip push block 18 sliding toward the through groove 6, the protrusion 25 provided at the bottom of the strip push block 18 will slide on the fixed rod 24, and the protrusion 25 will compress the No. 2 spring 26, so that the No. 2 spring 26 generates elastic force. When the movable mold 2 is separated from the fixed mold 1, the plug 21 gradually slides out of the columnar inclined groove 22. During this process, the No. 2 spring 26 will gradually release the elastic force and drive the strip push block 18 to slide in the opposite direction through the protrusion 25 until it is reset. When the protrusion 25 slides to conflict with the limit nut 27, the strip push block 18 stops moving and is completely reset.
[0027] In order to show how the insert 7 fills the gap of the No. 1 cavity 3, the following features are set: A cavity-shaped missing surface 28 is formed on the top of the insert 7. After the insert 7 rises, the cavity-shaped missing surface 28 fills the gap of the No. 1 cavity 3 and forms a complete No. 1 cavity 3.
[0028] When the insert 7 is inserted into the through groove 6, the outer wall of the insert 7 fits with the inner wall of the through groove 6. When the insert 7 rises, the cavity-shaped missing surface 28 provided on the top of the insert 7 will fill the gap of the No. 1 cavity 3 and finally form a complete No. 1 cavity 3, and there is no gap between the insert 7 and the through groove 6. Then, when the flow plastic is injected into the merged No. 1 cavity 3 and No. 2 cavity 4, the flow plastic will only fill the panel mold cavity 5 and the button mold cavity 8.
[0029] In order to facilitate the processing of the cooling water channel 9, the following features are set: A groove 29 is provided downwardly on the cavity-shaped surface 28, and a mold core 30 is embedded in the groove 29. The button-shaped mold cavity 8 is provided in the mold core 30. A No. 1 concave cavity 31 surrounding the mold core 30 is provided on the outer wall of the mold core 30, and a No. 2 concave cavity 32 surrounding the groove 29 is provided on the inner wall of the groove 29. The No. 1 concave cavity 31 and the No. 2 concave cavity 32 are combined to form a cooling water channel 9. A partition 33 is formed on the outer wall of the mold core 30. The partition 33 forms two ends of the closed-loop cooling water channel 9 that are not connected at the head and tail. A water inlet channel 34 and a drainage channel 35 leading to the two ends of the cooling water channel 9 are provided in the insert 7.
[0030] When the mold core 30 is inserted downward into the embedding groove 29, the No. 1 cavity 31 and the No. 2 cavity 32 are merged to form the cooling water channel 9. The cooling water channel 9 is split to facilitate the processing of the cooling water channel 9. When the plastic flows into the button-shaped mold cavity 8 and is cooled, the coolant flows into the cooling water channel 9 through the water inlet channel 34. Thereafter, the coolant will surround the mold core 30 and finally be discharged from the drainage channel 35.
[0031] In order to facilitate the removal of the mold core 30 and prevent the mold core 30 from loosening, the following features are provided: The bottom of the mold core 30 is formed with a support bar 36 that passes downward through the insert 7. The bottom of the insert 7 is provided with a locking rod 37 that is slidably connected to it. One end of the locking rod 37 is formed with two extension blocks 38 located on both sides of the support bar 36. Each extension block 38 is provided with an oblique sliding groove 39. The lower end of the support bar 36 is formed with a guide pin 40 that passes through the two oblique sliding grooves 39 respectively. The other end of the locking rod 37 is formed with a locking block 41 that is fixedly connected to the insert 7.
[0032] When the mold core 30 is fully inserted into the embedding groove 29, the lower end of the support bar 36 passes downwardly outside the insert 7. At this time, the locking rod 37 is pushed toward the support bar 36, and the guide pin 40 slides in the oblique slide groove 39 toward the lowest end of the oblique slide groove 39. In this process, the guide pin 40 cooperates with the oblique wedge of the oblique slide groove 39 to drive the mold core 2 to slide downward in the embedding groove 29 until the mold core 30 is fully embedded in the embedding groove 29. Thereafter, the locking block 41 is fixed to the insert 7, and finally the mold core 30 can be locked in the current position to prevent the mold core 30 from loosening during the lifting of the insert 7. When removing the mold core 30 from the embedding groove 29, first unlock the locking block 41 and the insert 7, and then pull the locking rod 37 outward. During this process, the guide pin 40 will slide from the lowest end of the oblique slide groove 39 to the highest end of the oblique slide groove 39, so that the support bar 36 will drive the mold core 2 to extend from the embedding groove 29. When processing the oblique slide groove 39, the highest end of the oblique slide groove 39 will penetrate the top of the extension block 38. When the mold core 30 extends from the embedding groove 29, the guide pin 40 will slide out along the highest end of the oblique slide groove 39, and finally the mold core 30 can be completely pulled out of the embedding groove 29.
[0033] In order to show the specific structure of the ejection mechanism 11, the following features are set: A support seat 42 is provided below the fixed mold 1, and the fixed mold 1 is fixed to the top of the support seat 42. A rectangular accommodating opening 43 is opened in the support seat 42. The ejection mechanism 11 includes a lifting plate 44 and a plurality of ejector pins 45. The lifting plate 44 is horizontally slidable in the rectangular accommodating opening 43. A plurality of vertical No. 3 springs 46 are provided between the lifting plate 44 and the fixed mold 1. A plurality of ejector pins 45 are vertically fixed to the top of the lifting plate 44. Each ejector pin 45 passes through the fixed mold 1 upward, and the top of each ejector pin 45 is flush with the No. 1 cavity 3.
[0034] In actual use, a cylinder (not shown in the figure) is provided under the fixed mold 1 for driving the lifting plate 44 to rise. When the movable mold 2 rises and separates from the fixed mold 1, the cylinder will drive the lifting plate 44 to rise. During this process, the lifting plate 44 will drive several ejector pins 45 to eject the back door panel from the No. 1 cavity 3. At the same time, the lifting plate 44 will compress the No. 3 spring 46 upward, so that the No. 3 spring 46 generates elastic force. When the output end of the cylinder retracts, the lifting plate 44 will be driven down by the No. 3 spring 46 until it is reset.
[0035] To demonstrate how the plastic is injected into the panel cavity 5, the following features are set: A vertical shot cavity 47 communicating with the second cavity 4 is provided in the movable mold 2 . A horizontal template 48 is fixed on the top of the movable mold 2 . An injection port 49 communicating with the shot cavity 47 is provided on the top of the template 48 .
[0036] When the movable mold 2 and the fixed mold 1 are closed, the upstream injection molding machine (not shown in the figure) will inject the plasticized material into the shot cavity 47 through the injection port 49. Thereafter, the plasticized material will be injected into the panel mold cavity 5 along the shot cavity 47. In the process of the plasticized material passing through the panel mold cavity 5, part of the plasticized material will be injected into the button-shaped mold cavity 8. Finally, the plasticized material will cool in the panel mold cavity 5 to form the rear door panel, and the plasticized material will cool in the button-shaped mold cavity 8 to form the rear door buckle.
[0037] A high-precision injection molding process for a car back door, the process comprising the following steps: S1, mold closing drive; The movable mold 2 descends, and the plug 21 pushes the strip push block 18 to slide along the strip inclined groove 17. The insert 7 is driven to rise by the cooperation of the top block 10 and the inclined wedge of the insert 7. The No. 1 spring 16 is compressed until the insert 7 is blocked by the limit piece, and finally the gap of the No. 1 cavity 3 is filled by the cavity-shaped missing surface 28 on the insert 7.
[0038] S2, injection molding; The plastic is injected into the panel mold cavity 5 and the button mold cavity 8 through the injection port 49 and the shot cavity 47, and after cooling, the rear door panel and the rear door buckle are formed respectively.
[0039] S3, accelerated cooling; The cooling water channel 9 is fed with circulating coolant to accelerate the cooling of the plastic flow in the button-shaped mold cavity 8 and promote the molding of the back door undercut.
[0040] S4, mold opening and separation; The movable mold 2 rises, and the insert 7 and the top block 10 fall down by their own gravity. During this process, the back door buckle is separated from the button-shaped mold cavity 8, and the descending insert 7 causes a gap in the No. 1 mold cavity 3.
[0041] S5, eject and take out the parts.
[0042] After the fixed mold 1 and the movable mold 2 are completely separated, the lift plate 44 drives a plurality of ejectors 45 to eject the rear door panel from the first cavity 3 .
[0043] The above embodiments merely represent one or several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.
Claims
1. A high-precision injection molding device for automobile back doors, characterized in that: The invention comprises a fixed mold (1) and a movable mold (2) arranged above the fixed mold (1), wherein a first cavity (3) is arranged in the fixed mold (1), and a second cavity (4) is arranged in the movable mold (2). After the fixed mold (1) and the movable mold (2) are closed, the first cavity (3) and the second cavity (4) are combined into a panel mold cavity (5) for forming a back door panel. The fixed mold (1) is provided with two through grooves (6) which are symmetrical and cause a gap in the first cavity (3). The through groove (6) is provided with an insert (7) which fills the gap of the first cavity (3) by rising. The insert (7) is provided with a back door panel. A button-shaped mold cavity (8) for forming a fastener is provided in the insert (7) with a cooling water channel (9) surrounding the button-shaped mold cavity (8). A lifting mechanism is provided on the fixed mold (1) for driving the two inserts (7) to rise after the movable mold (2) is pressed down. Each lifting mechanism includes a top block (10) that slides obliquely in the through groove (6). The insert (7) is provided above the top block (10). An elastic member is provided between the insert (7) and the top block (10). A limit member for limiting the upward movement of the insert (7) is provided in the through groove (6). An ejection mechanism (11) for ejecting the rear door panel is provided in the fixed mold (1).
2. The high-precision injection molding device for a car back door according to claim 1, characterized in that: The bottom of the insert (7) is formed with four limit pins (12) distributed in a matrix, the upper end of the top block (10) is formed with a support plate (13), the limit member includes four limit sleeves (14) distributed in a matrix and fixedly connected to the inner wall of the through groove (6), the lower end of each limit pin (12) passes through the support plate (13) and the limit sleeve (14) in sequence, the bottom of each limit pin (12) is coaxially fixedly connected to the limit cap (15), and the elastic member includes four No. 1 springs (16) respectively sleeved on the limit pins (12).
3. The high-precision injection molding device for a car back door according to claim 1, characterized in that: The fixed mold (1) is provided with two strip-shaped inclined grooves (17) corresponding to the through grooves (6), one end of each strip-shaped inclined groove (17) is connected to the corresponding through groove (6), and each lifting mechanism further includes a strip-shaped push block (18) slidably connected to the strip-shaped inclined groove (17), and the strip-shaped push block (18) is formed with a first inclined surface (19) at one end facing the through groove (6), and the lower end of the top block (10) is formed with a second inclined surface (20) that is wedge-matched with the first inclined surface (19). The movable mold (2) is fixed with plug posts (21) corresponding to the two strip-shaped push blocks (18), and each plug post (21) is in an inclined state. The other end of the strip-shaped push block (18) is provided with a columnar inclined groove (22) for inserting the plug post (21).
4. The high-precision injection molding device for a car back door according to claim 3, characterized in that: Each strip-shaped inclined groove (17) is provided with a strip-shaped receiving groove (23) at the bottom thereof, and the strip-shaped receiving groove (23) is parallel to the corresponding strip-shaped inclined groove (17). A fixing rod (24) is provided in the strip-shaped receiving groove (23) whose axial direction is parallel to the sliding direction of the strip-shaped push block (18). A protrusion (25) is formed at the bottom of the strip-shaped push block (18). The fixing rod (24) passes through the protrusion (25). A second spring (26) is sleeved on the fixing rod (24). The protrusion (25) presses the second spring (26) on the inner wall of the strip-shaped receiving groove (23). One end of the fixing rod (24) is provided with a limit nut (27) for limiting the protrusion (25).
5. The high-precision injection molding device for a car back door according to claim 1, characterized in that: The top of the insert (7) is formed with a cavity-shaped missing surface (28). After the insert (7) rises, the cavity-shaped missing surface (28) fills the gap of the No. 1 cavity (3) and forms a complete No. 1 cavity (3).
6. The high-precision injection molding device for a car back door according to claim 5, characterized in that: The cavity-shaped defective surface (28) is provided with an embedding groove (29) downwardly, and a core (30) is embedded in the embedding groove (29). The button-shaped mold cavity (8) is provided in the core (30). A first concave cavity (31) surrounding the core (30) is provided on the outer wall of the core (30). A second concave cavity (32) surrounding the embedding groove (29) is provided on the inner wall of the embedding groove (29). The first concave cavity (31) and the second concave cavity (32) are combined to form a cooling water channel (9). A spacer (33) is formed on the outer wall of the core (30). The spacer (33) forms two ends of the closed-loop cooling water channel (9) that are not connected at the head and tail. A water inlet channel (34) and a drainage channel (35) leading to the two ends of the cooling water channel (9) are provided in the insert (7).
7. The high-precision injection molding device for a car back door according to claim 6, characterized in that: The bottom of the mold core (30) is formed with a support bar (36) that passes downward through the insert (7), and the bottom of the insert (7) is provided with a locking rod (37) that is slidably connected to it. One end of the locking rod (37) is formed with two extension blocks (38) respectively located on both sides of the support bar (36), and each extension block (38) is provided with an oblique sliding groove (39). The lower end of the support bar (36) is formed with a guide pin (40) that passes through the two oblique sliding grooves (39), and the other end of the locking rod (37) is formed with a locking block (41) fixedly connected to the insert (7).
8. The high-precision injection molding device for a car back door according to claim 1, characterized in that: A support seat (42) is provided below the fixed mold (1), the fixed mold (1) is fixed to the top of the support seat (42), a rectangular accommodating opening (43) is provided in the support seat (42), and the ejection mechanism (11) includes a lifting plate (44) and a plurality of ejector pins (45), the lifting plate (44) is horizontally slidably provided in the rectangular accommodating opening (43), a plurality of vertical No. 3 springs (46) are provided between the lifting plate (44) and the fixed mold (1), and a plurality of ejector pins (45) are vertically fixed to the top of the lifting plate (44), each ejector pin (45) passes through the fixed mold (1) upward, and the top of each ejector pin (45) is flush with the No. 1 cavity (3).
9. The high-precision injection molding device for a car back door according to claim 1, characterized in that: A vertical shot cavity (47) is provided in the movable mold (2) and is connected to the second mold cavity (4). A horizontal template (48) is fixed on the top of the movable mold (2). An injection port (49) is provided on the top of the template (48) and is connected to the shot cavity (47).
10. A high-precision injection molding process for a car back door, comprising a high-precision injection molding device for a car back door according to any one of claims 1 to 9, characterized in that: The process includes the following steps: S1, mold closing drive; S2, injection molding; S3, accelerated cooling; S4, mold opening and separation; S5, eject and take out the parts.