A mold core insert core structure

Abstract

The application discloses a mold core insert structure, which comprises a sliding block, a hollow core, a rotary driving mechanism and a back driving mechanism, the front side of the sliding block is provided with a front mold, and an arc forming cavity is formed between the sliding block and the front mold; a sliding channel is formed in the sliding block and penetrates through the front and back ends; a forming screw thread is formed at the front end of the core; the core penetrates through the sliding channel, and the forming screw thread is located in the arc forming cavity; an insert needle is arranged in the core and rotates with the core; the front end of the insert needle is fixed with an insert; the insert extends to the front side of the core; and an arc-shaped end surface matched with the front mold is formed at the front end of the insert; the rotary driving mechanism is used for driving the core to rotate in the direction of unscrewing the screw hole of the workpiece in the arc forming cavity after the workpiece is injection molded; and the back driving stress is used for driving the core and the insert to move backward synchronously. The application has the characteristics of high matching precision, non-standard geometric surface forming, small mold design difficulty and simple structure.

Description

Technical Field

[0001] This invention relates to injection molds, and more particularly to a core-pulling structure for a mold core insert. Background Technology

[0002] For injection-molded workpieces with threaded holes, the industry generally adopts a process where the threaded core extends into the mold cavity, integrally forming the threaded hole during the injection molding stage. However, existing mold structures exhibit significant adaptation differences: if the inner surface of the workpiece corresponding to the threaded hole is flat, the mold only needs a simple planar-to-planar interlocking structure, resulting in a simple overall design, a straightforward threaded core movement path, and no special precision requirements for the threaded core's rotation stopping position; but when the inner surface around the threaded hole is curved, the mold must employ a curved / irregular surface interlocking structure, with the forming surface being a non-standard geometric surface, demanding extremely high precision in the fit of each component. If the threaded core's forming end is not properly positioned, misalignment and deformation defects will occur on the inner curved surface of the threaded hole after injection molding, significantly increasing the design difficulty and structural complexity of the entire mold. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a mold tooth core insert core-pulling structure that has high matching accuracy, can realize non-standard geometric surface forming, has low mold design difficulty, and has a simple structure, in order to overcome the shortcomings of the existing technology.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0005] A core-pulling structure for a mold core insert includes a slider, a hollow core, a rotary drive mechanism, and a retraction drive mechanism. A front mold is located on the front side of the slider, forming an arc-shaped forming cavity between them. A slide rail extends through both ends of the slider. A forming thread is formed at the front end of the core, passing through the slide rail and located within the arc-shaped forming cavity. An insert pin is inserted into the core, and the two are rotatably engaged. An insert is fixed to the front end of the insert pin, extending forward of the core. The front end of the insert has an arc-shaped end face that abuts against the front mold. The retraction drive mechanism applies a backward retraction stress to the core and the insert. The rotary drive mechanism, after injection molding of the workpiece within the arc-shaped forming cavity, drives the core to rotate in the direction of loosening the forming thread relative to the screw hole of the workpiece, using the retraction stress to drive the core and the insert to move backward synchronously.

[0006] Preferably, the insert includes a stepped portion that seals the front opening of the dental core.

[0007] Preferably, the slider has two parallel slides, and a tooth core is inserted in each slide.

[0008] Preferably, it includes a gearbox provided at the rear side of the slider. A driving motor is fixed to the rear end of the gearbox. Inside the gearbox, there is a driving gear and two driven gears distributed in a "pin" shape. A driving gear is provided on the driving shaft of the driving motor. The driving gear and the two driven gears are respectively meshed with the driving gear. Two core shafts respectively pass through the two driven gears. The core shaft can slide back and forth relative to the driven gear and the driven gear is used to drive the core shaft to rotate.

[0009] Preferably, the core shaft includes a square prism-shaped portion. A square sliding groove is provided at the center of the driven gear. The square prism-shaped portion passes through the square sliding groove and the two are in sliding fit.

[0010] Preferably, end shafts are respectively provided at the front and rear ends of the driven gear. Two bearings are provided inside the gearbox. The two end shafts respectively pass through the two bearings.

[0011] Preferably, an abutting sleeve is fixed to the rear end of the slider. A convex ring is formed on the outer side of the core shaft. The convex ring is used for abutting and cooperating with the front end of the abutting sleeve.

[0012] Preferably, a U-shaped support arm is fixed to the rear end of the gearbox. The retraction driving mechanism includes a sliding component and an elastic component. The rear end of the core shaft is in rotational cooperation with the sliding component. The rear end of the insert pin is fixedly connected to the sliding component. The elastic component is used to apply a retraction stress for sliding backward to the sliding component.

[0013] Preferably, the sliding component includes a first sliding plate, a second sliding plate and a third sliding plate which are fixedly laminated in sequence from front to back. A square card slot is provided at the rear side of the second sliding plate. A square end is formed at the rear end of the insert pin. The square end is clamped in the square card slot. Guide grooves are respectively provided on the left and right sides of the first sliding plate, the second sliding plate and the third sliding plate. Two opposite guide rails are formed on the inner side of the U-shaped support arm. The two guide rails respectively pass through the two guide grooves, and the guide rails are in sliding fit with the guide grooves. Preferably, the elastic component includes a vertical support arm. The vertical support arm is fixedly connected to the rear end of the third sliding plate. Springs are respectively clamped between the upper and lower ends of the vertical support arm and the rear end of the gearbox.

[0014] In the core-pulling structure for the mold core insert disclosed in this invention, when the workpiece enters the mold opening process after injection molding, the rotary drive mechanism drives the core to rotate along the loosening direction of the forming thread relative to the workpiece thread hole; under the retraction stress provided by the retraction drive mechanism, the core and insert are synchronously displaced backward. During this movement, only the core rotates, while the insert pin and insert maintain a linear translation state, which can prevent the arc-shaped end face from shifting or misaligning relative to the irregular surface of the workpiece. Compared with the existing curved surface insertion mold structure, this structure can adapt to the forming requirements of non-standard geometric arc surfaces, the fitting accuracy between components is stable, and it can reduce the complexity of the overall mold design and processing, simplifying the mold structure. Attached Figure Description

[0015] Figure 1 Three-dimensional core-pulling structure for mold tooth core inserts Figure 1 ; Figure 2 for Figure 1 Enlarged view of section A; Figure 3 Three-dimensional core-pulling structure for mold tooth core inserts Figure 2 ; Figure 4 A 3D view of the workpiece; Figure 5 Exploded view of the core-pulling structure of the mold core insert; Figure 6 A three-dimensional view of the rotary drive mechanism; Figure 7 This is an exploded view of the rotary drive mechanism; Figure 8 Top view of the core-pulling structure of the mold core insert; Figure 9 for Figure 8 Sectional view along the BB line; Figure 10 This is a structural diagram of the U-shaped support arm and sliding assembly; Figure 11 This is an exploded view of the sliding component. Detailed Implementation

[0016] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0017] This invention discloses a core-pulling structure for a mold core insert, combined with... Figures 1 to 11As shown, it includes a slider 1, a hollow tooth core 2, a rotary drive mechanism 3, and a retraction drive mechanism 4. The front side of the slider 1 is provided with a front mold, and an arc-shaped forming cavity is formed between the two. The slider 1 has a slide rail 10 that runs through both the front and rear ends. The front end of the tooth core 2 is formed with a forming thread 20. The tooth core 2 passes through the slide rail 10, and the forming thread 20 is located in the arc-shaped forming cavity. The tooth core 2 is provided with a pin 5, and the two are rotatably engaged. The front end of the pin 5 is fixed with an insert 6. The insert 6 extends towards the front side of the tooth core 2, and the front end of the insert 6 forms an arc-shaped end face 60 that abuts and matches the front mold. The retraction drive mechanism 4 is used to apply a retraction stress to the tooth core 2 and the insert 6 to move backward; The rotary drive mechanism 3 is used to drive the tooth core 2 to rotate in the direction of loosening the forming thread 20 relative to the screw hole 101 of the workpiece 100 after the workpiece 100 in the arc forming cavity is injection molded, and to drive the tooth core 2 and the insert 6 to move backward synchronously by means of the back stress.

[0018] In the above structure, the slider 1 and the front mold together form an arc-shaped forming cavity for injection molding of the workpiece 100; the front end of the core 2 is provided with a forming thread 20, which is arranged inside the arc-shaped forming cavity. The insert 5 passes through the inside of the core 2 and rotates with the core 2. The insert 6 fixed at the front end of the insert 5 extends forward of the core 2, and the front end of the insert 6 is provided with an arc-shaped end face 60 that can abut and match the front mold. During the injection molding stage, the arc-shaped end face 60 abuts and limits the front mold, which can ensure that the irregular surface of the corresponding position of the screw hole 101 of the workpiece 100 is formed smoothly; at the same time, the retraction drive mechanism 4 continuously applies a backward retraction stress to the core 2 and the insert 6.

[0019] When the workpiece 100 completes injection molding and enters the mold opening process, the rotary drive mechanism 3 drives the core 2 to rotate along the loosening direction of the forming thread 20 relative to the threaded hole 101 of the workpiece 100; under the retraction stress provided by the retraction drive mechanism 4, the core 2 and the insert 6 move backward synchronously. During this movement, only the core 2 rotates, while the insert pin 5 and insert 6 maintain a linear translation state, which can prevent the arc-shaped end face 60 from shifting or misaligning relative to the irregular surface of the workpiece 100. Compared with the existing curved surface insertion mold structure, this structure can adapt to the forming requirements of non-standard geometric arc surfaces, the fitting accuracy between components is stable, and it can reduce the complexity of the overall mold design and processing, simplifying the mold structure.

[0020] To ensure a good fit with the front end of the core 2 and reduce sprue formation, please refer to [link / reference needed]. Figure 7 The insert 6 includes a stepped portion 61, which seals the front opening of the core 2.

[0021] This embodiment preferably adopts a double-row core 2 structure. Specifically, two mutually parallel slideways 10 are provided in the slider 1, and a core 2 is disposed in each slideway 10.

[0022] Regarding the preferred driving mode of the rotary driving mechanism 3, in combination with Figures 5 to 7 and Figure 9 As shown, this embodiment includes a gearbox 7 provided at the rear side of the slider 1. A driving motor 8 is fixed to the rear end of the gearbox 7. The rotary driving mechanism 3 includes a transmission gear 70 and two driven gears 71 distributed in a "pin" shape in the gearbox 7. A driving gear 80 is provided on the driving shaft of the driving motor 8. The driving gear 80 and the two driven gears 71 are respectively engaged with the transmission gear 70. The two cores 2 respectively pass through the two driven gears 71. The core 2 can slide back and forth relative to the driven gear 71, and the driven gear 71 is used to drive the core 2 to rotate. In the above structure, based on the gear transmission structure distributed in a "pin" shape, one driving motor 8 can drive the two cores 2 to rotate synchronously.

[0023] To enable the core 2 to slide back and forth and be driven to rotate by the driven gear 71, in this embodiment, the core 2 includes a square prism-shaped portion 21. A square chute 72 is provided at the center of the driven gear 71. The square prism-shaped portion 21 passes through the square chute 72 and the two are in sliding fit. Further, to ensure the good rotation of the driven gear 71, end shafts 73 are respectively provided at the front and rear ends of the driven gear 71. Two bearings 74 are provided in the gearbox 7, and the two end shafts 73 respectively pass through the two bearings 74.

[0024] As a preferred method, please refer to Figure 5 and Figure 9 , in this embodiment, an abutting sleeve 12 is fixed to the rear end of the slider 1. A convex ring 22 is formed on the outer side of the core 2. The convex ring 22 is used to abut and cooperate with the front end of the abutting sleeve 12. After the mold is closed in this embodiment, the abutting sleeve 12 abuts against the convex ring 22 to keep the core 2 in the forward-in-place state. During the mold opening process, the slider 1 is driven to move backward by the ejector base, providing a backward movement space for the core 2.

[0025] Please refer to Figure 1 , Figure 5 and Figure 10 , in this embodiment, a U-shaped support arm 9 is fixed to the rear end of the gearbox x7. The retraction driving mechanism 4 includes a sliding component 40 and an elastic component 41. The rear end of the core 2 is in rotational cooperation with the sliding component 40. The rear end of the ejector pin 5 is fixedly connected to the sliding component 40. The elastic component 41 is used to apply a retraction stress for sliding backward to the sliding component 40.

[0026] Specifically, the sliding assembly 40 includes a first sliding plate 400, a second sliding plate 401, and a third sliding plate 402, which are stacked and fixed from front to back. A square slot 403 is provided on the rear side of the second sliding plate 401. A square end 50 is formed at the rear end of the insert pin 5. The square end 50 is engaged in the square slot 403. Guide grooves 404 are provided on the left and right sides of the first sliding plate 400, the second sliding plate 401, and the third sliding plate 402. Two opposing guide rails 90 are formed on the inner side of the U-shaped support arm 9. The two guide rails 90 pass through the two guide grooves 404 respectively, and the guide rails 90 slide in cooperation with the guide grooves 404. In the above structure, based on the front and rear stacked and fixed cooperation of the first sliding plate 400, the second sliding plate 401 and the third sliding plate 402, it can not only rotate with the rear end of the tooth core 2, but also fix the insert 5, so that the tooth core 2 keeps rotating during the retraction process while the insert 5 remains straight.

[0027] In order to continuously apply elastic retraction stress to the sliding component 40, the tooth core 2, and the insert pin 5, in this embodiment, the elastic component 41 includes a vertical support arm 410, which is fixedly connected to the rear end of the third sliding plate 402. Springs 411 are respectively clamped between the upper and lower ends of the vertical support arm 410 and the rear end of the gearbox 7. During the actual mold closing process, under the push of the slider 1, the sliding component 40, the tooth core 2, and the insert pin 5 move forward synchronously to their positions. This process requires overcoming the retraction stress of the elastic component 41 to ensure the continuous existence of the retraction stress.

[0028] To achieve the rollback detection function, combined with Figures 1 to 5 As shown, a positioning switch 13 is fixed inside the U-shaped support arm 9, and a rearwardly extending trigger 14 is fixed on the elastic component 41. When the elastic component 41 moves backward until the tooth core 2 and the insert 6 are pushed out of the screw hole 101, the trigger 14 abuts against and triggers the positioning switch 13.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the technical scope of the present invention should be included within the scope of protection of the present invention.

Claims

1. A core-pulling structure for a mold core insert, characterized in that, It includes a slider (1), a hollow core (2), a rotation drive mechanism (3) and a retraction drive mechanism (4). A front mold is provided on the front side of the slider (1), and an arc-shaped molding cavity is formed therebetween. A slideway (10) penetrating through the front and rear ends is formed in the slider (1). A molding thread (20) is formed at the front end of the core (2). The core (2) passes through the slideway (10), and the molding thread (20) is located in the arc-shaped molding cavity. An insert pin (5) is inserted into the core (2) and they are rotationally matched. An insert (6) is fixed to the front end of the insert pin (5). The insert (6) extends forward from the front side of the core (2). An arc-shaped end face (60) that abuts and matches the front mold is formed at the front end of the insert (6). The retraction drive mechanism (4) is used to apply a retraction stress for the core (2) and the insert (6) to move backward. The rotation drive mechanism (3) is used to drive the core (2) to rotate in the direction of loosening the molding thread (20) relative to the screw hole (101) of the workpiece (100) after the workpiece (100) in the arc-shaped molding cavity is injection molded, and use the retraction stress to drive the core (2) and the insert (6) to move backward synchronously.

2. The core-pulling structure for the mold core insert as described in claim 1, characterized in that, The insert (6) includes a stepped portion (61), and the stepped portion (61) seals the front end opening of the core (2).

3. The core-pulling structure for the mold core insert as described in claim 1, characterized in that, Two mutually parallel slideways (10) are formed in the slider (1), and a core (2) is inserted into each slideway (10).

4. The mold core insert core-pulling structure as described in claim 3, characterized in that, It includes a gear box (7) provided at the rear side of the slider (1). A drive motor (8) is fixed to the rear end of the gear box (7). The rotation drive mechanism (3) includes a transmission gear (70) and two driven gears (71) arranged in a "pin" shape in the gear box (7). A driving gear (80) is provided on the drive shaft of the drive motor (8). The driving gear (80) and the two driven gears (71) are respectively meshed with the transmission gear (70). The two cores (2) respectively pass through the two driven gears (71). The core (2) can slide back and forth relative to the driven gear (71), and the driven gear (71) is used to drive the core (2) to rotate.

5. The core-pulling structure for the mold core insert as described in claim 4, characterized in that, The core (2) includes a square prism-shaped portion (21). A square chute (72) is provided at the center of the driven gear (71). The square prism-shaped portion (21) passes through the square chute (72) and they are slidably matched.

6. The core-pulling structure for the mold core insert as described in claim 4, characterized in that, End shafts (73) are respectively provided at the front and rear ends of the driven gear (71). Two bearings (74) are provided in the gear box (7). The two end shafts (73) are respectively inserted into the two bearings (74).

7. The core-pulling structure for the mold core insert as described in claim 1, characterized in that, An abutting sleeve (12) is fixed to the rear end of the slider (1). A convex ring (22) is formed on the outer side of the core (2). The convex ring (22) is used to abut and cooperate with the front end of the abutting sleeve (12).

8. The core-pulling structure for the mold core insert as described in claim 1, characterized in that, The rear end of the gearbox (7) is fixed with a U-shaped support arm (9). The retraction drive mechanism (4) includes a sliding component (40) and an elastic component (41). The rear end of the tooth core (2) is rotatably engaged with the sliding component (40). The rear end of the insert (5) is fixedly connected to the sliding component (40). The elastic component (41) is used to apply a retraction stress to the sliding component (40) to slide backward.

9. The mold core insert core-pulling structure as described in claim 8, characterized in that, The sliding assembly (40) includes a first sliding plate (400), a second sliding plate (401), and a third sliding plate (402) that are stacked and fixed from front to back. A square slot (403) is provided on the rear side of the second sliding plate (401). A square end (50) is formed at the rear end of the pin (5). The square end (50) is engaged in the square slot (403). Guide grooves (404) are provided on the left and right sides of the first sliding plate (400), the second sliding plate (401), and the third sliding plate (402). Two opposing guide rails (90) are formed on the inner side of the U-shaped support arm (9). The two guide rails (90) pass through the two guide grooves (404) respectively, and the guide rails (90) slide in cooperation with the guide grooves (404).

10. The core-pulling structure for the mold core insert as described in claim 9, characterized in that, The elastic component (41) includes a vertical support arm (410), which is fixedly connected to the rear end of the third sliding plate (402). Springs (411) are respectively clamped between the upper and lower ends of the vertical support arm (410) and the rear end of the gearbox (7).

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