A structure of undercut core-pulling and demolding for injection mold

Abstract

The utility model discloses an injection mold is used to the structure of core pulling of reverse buckle core pulling, and the utility model relates to mould equipment technical field. Including bottom mould seat, be provided with the demoulding mechanism for injection mold buckle core pulling off on the bottom mould seat, and the demoulding mechanism includes: locking assembly, including the upper die holder of bottom mould seat upper end setting, the utility model connecting rod drives both ends lifting plate synchronous rising, and the first push rod on the lifting plate pushes the top plate of both sides of mould core, makes mould core preliminary separation bottom mould seat, and mould core preliminary separation product reverse buckle, and connecting rod continues to rise, and the second push rod in the shell is contacted mould core bottom, and shock absorber spring and damping support pole buffer impact force, and the second push rod stably completes final ejection, thereby through the side of first push rod and the bottom of second push rod push to form the synergistic effect, avoid the sticking problem of mould core because of uneven stress of single point, avoid the single ejection force too big and lead to product deformation or reverse buckle fracture, and improve demoulding success rate.

Description

Technical Field

[0001] This utility model relates to the field of mold equipment technology, specifically to an undercut core-pulling demolding structure for injection molds. Background Technology

[0002] In the field of injection mold making, the demolding problem of products with undercut structures has always been a key focus. While undercut structures are a common functional feature in product design and can enhance structural strength or fulfill specific assembly requirements, they also present significant challenges to mold demolding.

[0003] Existing side-pulling core mechanisms mostly rely on independent driving devices such as hydraulic cylinders and pneumatic cylinders to lock and unlock the mold core. The hydraulic cylinder pushes the inclined guide post, which indirectly drives the slider to complete the side-pulling core. Existing demolding mechanisms mostly use a single ejector rod or ejector plate to directly push the bottom of the mold core to separate the product from the mold. However, the single-point force method is prone to local stress concentration in the mold core. Especially when dealing with undercut structures, the adhesion force between the mold core and the undercut of the product is large. Single-point pushing may cause the undercut to break or the product surface to be indented. Moreover, the instantaneous contact between the ejector rod and the mold core is prone to generating impact force, which may damage the mold core or the product. Therefore, this utility model provides an undercut core-pulling demolding structure for injection molds. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an undercut core-pulling demolding structure for injection molds. It solves the problems of existing side-pulling mechanisms that rely on independent driving devices such as hydraulic cylinders or pneumatic cylinders to lock and unlock the mold core, indirectly driving the slider to complete the side-pulling by pushing the inclined guide post with a hydraulic cylinder, and existing demolding mechanisms that often use a single ejector rod or ejector plate to directly push the bottom of the mold core to separate the product from the mold. However, this single-point force application method easily causes localized stress concentration in the mold core, especially when dealing with undercut structures. The adhesion force between the mold core and the undercut at the product is relatively large, and single-point pushing may lead to undercut breakage or indentation on the product surface. Furthermore, the instantaneous contact between the ejector rod and the mold core can easily generate impact force, leading to damage to the mold core or the product.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a backing core-pulling demolding structure for injection molds, comprising a bottom mold base, wherein the bottom mold base is provided with a demolding mechanism for backing cores out of the injection mold, the demolding mechanism comprising: The locking assembly includes an upper mold base disposed at the upper end of the bottom mold base, a pair of inclined rods fixed inside the upper mold base, sliding grooves opened on both sides inside the bottom mold base, a slider slidably connected inside the sliding groove, a locking rod fixed at one end of the slider, and a mold core disposed at the center inside the bottom mold base; The demolding assembly includes a vertical groove formed inside the lower part of the bottom mold base. A connecting rod connected by a push assembly is provided inside the vertical groove. A push housing is fixed at the center of the upper end face of the connecting rod. A second push rod connected by a shock-absorbing assembly is provided inside the push housing. Lifting plates are fixed at both ends of the connecting rod. A first push rod is fixed at the upper end face of the lifting plate.

[0006] Preferably, the bottom mold base is fixed with first hydraulic rods on both sides, the upper mold base is fixedly connected to the telescopic end of the first hydraulic rods, the upper end of the upper mold base is fixed with a first positioning rod, and the lower end of the first positioning rod is engaged with the lower end face of the bottom mold base.

[0007] Preferably, four sets of second positioning rods are fixed inside the upper mold base, and the second positioning rods are engaged with the bottom mold base.

[0008] Preferably, the push assembly includes a second hydraulic rod fixed inside the lower part of the bottom mold base, the connecting rod is slidably connected to the inner wall of the vertical groove, and the telescopic end of the second hydraulic rod is fixedly connected to the connecting rod.

[0009] Preferably, the shock absorption assembly includes a shock absorption spring fixed inside the push-out housing, the inner ring of the shock absorption spring is provided with a damping support rod, the damping support rod is fixedly connected to the push-out housing, the second push rod is fixedly connected to the upper end of the shock absorption spring, and the second push rod is slidably connected to the push-out housing.

[0010] Preferably, the lower ends of both sides of the mold core are provided with top plates, and a pair of guide rods are fixed to the lower ends of the top plates, the guide rods being slidably connected to the bottom mold base.

[0011] Beneficial effects This invention provides an undercut core-pulling demolding structure for injection molds. Compared with the prior art, it has the following advantages: Firstly, when the upper mold base and the lower mold base of this utility model are closed, the inclined rod fixed to the upper mold base is inserted into the mating hole of the slider, pushing the slider to slide along the slide groove towards the mold core until the locking rod is inserted into the locking holes on both sides of the mold core, thus completing the lateral locking of the mold core. This can withstand the lateral pressure of the molten plastic on the mold core during injection molding, avoiding the product size deviation caused by the mold core offset. The unlocking action is synchronized with the mold opening action of the upper mold base, without the need for an additional driving device, which simplifies the mold control logic.

[0012] Secondly, the connecting rod of this utility model drives the lifting plates at both ends to rise synchronously. The first push rod on the lifting plate pushes the top plates on both sides of the mold core, so that the mold core initially separates from the bottom mold base and the mold core initially separates from the product undercut. The connecting rod continues to rise, pushing the second push rod inside the outer shell to contact the bottom of the mold core. The shock-absorbing spring and the damping support rod buffer the impact force, and the second push rod smoothly completes the final ejection. Thus, the side push of the first push rod and the bottom push of the second push rod form a synergistic effect, avoiding the sticking problem caused by uneven force on a single point of the mold core, avoiding product deformation or undercut breakage due to excessive single ejection force, and improving the demolding success rate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the bottom mold base of this utility model; Figure 3 This is a schematic diagram of the slider connection structure of this utility model; Figure 4 This is a schematic diagram of the first push rod structure of this utility model.

[0014] In the diagram: 1. Bottom mold base; 2. Upper mold base; 201. First hydraulic rod; 202. First positioning rod; 3. Diagonal rod; 301. Slide groove; 302. Sliding block; 303. Locking rod; 304. Mold core; 4. Second positioning rod; 5. Vertical groove; 501. Second hydraulic rod; 502. Connecting rod; 503. Lifting plate; 504. First ejector rod; 505. Top plate; 506. Guide rod; 6. Pushing shell; 601. Shock-absorbing spring; 602. Damping support rod; 603. Second ejector rod. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figures 1-4 This utility model provides a technical solution: an undercut core-pulling demolding structure for injection molds, including a bottom mold base 1, wherein the bottom mold base 1 is provided with a demolding mechanism for removing the core from the injection mold, the demolding mechanism including: The locking assembly includes an upper mold base 2 disposed on the upper end of the bottom mold base 1. A pair of inclined rods 3 are fixed inside the upper mold base 2. Slide grooves 301 are opened on both sides inside the bottom mold base 1. A slider 302 is slidably connected inside the slide grooves 301. A locking rod 303 is fixed at one end of the slider 302. A mold core 304 is disposed at the center inside the bottom mold base 1. Locking holes corresponding to the locking rods 303 are opened on both sides of the mold core 304. When the inclined rods 3 rise through the upper mold base 2, the inclined rods 3 drive the sliders 302 away from the mold core 304. When the upper mold base 2 and the bottom mold base 1 are closed, the inclined rod 3 fixed to the upper mold base 2 is inserted into the mating hole of the slider 302, pushing the slider 302 to slide along the slide groove 301 towards the mold core 304 until the locking rod 303 is inserted into the locking holes on both sides of the mold core 304, thus completing the lateral locking of the mold core. This can withstand the lateral pressure of the molten plastic on the mold core 304 during injection molding, and prevent the mold core from shifting, which would cause product size deviation.

[0017] Furthermore, after injection molding is completed, the upper mold base 2 rises, and the inclined rod 3 moves upward accordingly. Its inclined structure generates a lateral pulling force on the slider 302, causing the slider 302 to move away from the mold core 304 along the slide groove 301. The locking rod 303 is pulled out from the locking hole, releasing the locking restriction on the mold core 304 and preparing for subsequent demolding.

[0018] The demolding assembly includes a vertical groove 5 formed at the bottom of the bottom mold base 1. A connecting rod 502 connected by a push assembly is provided inside the vertical groove 5. A push housing 6 is fixed at the center of the upper end face of the connecting rod 502. A second push rod 603 connected by a shock-absorbing assembly is provided inside the push housing 6. Lifting plates 503 are fixed at both ends of the connecting rod 502. A first push rod 504 is fixed at the upper end face of the lifting plate 503.

[0019] In a preferred embodiment, a first hydraulic rod 201 is fixed on both sides of the bottom mold base 1. The upper mold base 2 is fixedly connected to the telescopic end of the first hydraulic rod 201. A first positioning rod 202 is fixed at the upper end of the upper mold base 2. The lower end of the first positioning rod 202 is engaged with the lower end face of the bottom mold base 1. Four sets of second positioning rods 4 are fixed inside the upper mold base 2. The second positioning rods 4 are engaged with the bottom mold base 1. When the mold is closed, the first hydraulic rod 201 drives the upper mold base 2 to descend. The first positioning rod 202 and the second positioning rods 4 are engaged with the corresponding holes in the bottom mold base 1 to complete precise positioning.

[0020] In a preferred embodiment, the push assembly includes a second hydraulic rod 501 fixed inside the lower part of the bottom mold base 1, a connecting rod 502 slidably connected to the inner wall of the vertical groove 5, and the telescopic end of the second hydraulic rod 501 is fixedly connected to the connecting rod 502. When the second hydraulic rod 501 extends, it pushes the connecting rod 502 to rise.

[0021] In a preferred embodiment, the shock-absorbing assembly includes a shock-absorbing spring 601 fixed inside the push-out housing 6. The inner ring of the shock-absorbing spring 601 is provided with a damping support rod 602, which is fixedly connected to the push-out housing 6. A second push rod 603 is fixedly connected to the upper end of the shock-absorbing spring 601 and is slidably connected to the push-out housing 6. Top plates 505 are provided on the lower ends of both sides of the mold core 304. A pair of guide rods 506 are fixed on the lower ends of the top plates 505 and are slidably connected to the bottom mold base 1. When the lifting plate 503 is raised and lowered, the first push rod 504 is raised. The first push rod 504 pushes the top plate 505, and then the top plate 505 pushes the mold core 304. When the lifting and lowering continues, the second push rod 603 pushes the bottom of the mold core 304.

[0022] Furthermore, the connecting rod 502 drives the lifting plates 503 at both ends to rise synchronously. The first push rod 504 on the lifting plate 503 pushes the top plates 505 on both sides of the mold core 304, so that the mold core 304 initially separates from the bottom mold base 1 and the mold core 304 initially separates from the product undercut. The connecting rod 502 continues to rise, and the second push rod 603 inside the push housing 6 contacts the bottom of the mold core 304. The shock-absorbing spring 601 and the damping support rod 602 buffer the impact force, and the second push rod 603 smoothly completes the final ejection. Thus, the side push of the first push rod 504 and the bottom push of the second push rod 603 form a synergistic effect, avoiding the sticking problem caused by uneven force on a single point of the mold core 304, avoiding product deformation or undercut breakage due to excessive single ejection force, and improving the demolding success rate.

[0023] The vertical groove 5 limits the connecting rod 502 to ensure that the pushing force is transmitted in the vertical direction, thus preventing the mold core 304 from tilting and being damaged during demolding. The guide rod 506 limits the top plate 505 to ensure that the mold core 304 remains horizontal when pushed from the side, thus preventing tilting during demolding.

[0024] The first hydraulic rod can be model Y32-100, and the second hydraulic rod can be model Y32-50.

[0025] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0026] During operation, the first hydraulic rods 201 on both sides of the bottom mold base 1 are activated first. Their telescopic ends push the upper mold base 2 down. During the process, the four sets of second positioning rods 4 fixed inside the upper mold base 2 are first inserted into the bottom mold base 1 to complete the initial positioning. Then, the lower ends of the first positioning rods 202 fixed at the upper end of the upper mold base 2 are engaged with the four ends of the lower end face of the bottom mold base 1 to achieve precise mold alignment. At the same time as the mold is closed, a pair of inclined rods 3 fixed inside the upper mold base 2 are inserted into the sliding holes of the sliders 302 in the sliding grooves 301 on both sides inside the bottom mold base 1. The sliders 302 are pushed to slide towards the mold core 304 at the center inside the bottom mold base 1 until the locking rods 303 fixed at one end of the sliders 302 are inserted into the corresponding locking holes on both sides of the mold core 304, completing the lateral locking of the mold core 304 to withstand the lateral pressure of the molten plastic on the mold core 304 during injection molding. After injection molding, the first hydraulic rod 201 drives the upper mold base 2 to rise, and the inclined rod 3 moves upward accordingly. Its inclined structure generates a lateral pulling force on the slider 302, causing the slider 302 to move away from the mold core 304 along the slide groove 301. The locking rod 303 is pulled out from the locking hole to release the locking restriction on the mold core 304. Then, the second hydraulic rod 501 fixed inside the lower part of the bottom mold base 1 extends, pushing the connecting rod 502 slidably connected to the inner wall of the vertical groove 5 to rise. The connecting rod 502 drives the lifting plates 503 fixed at both ends to rise synchronously. The first push rod 504 fixed on the upper end surface of the lifting plate 503 pushes the top plate 505 set on the lower end surface of both sides of the mold core 304. The top plate 505 is fixed on the lower end surface. The guide rod 506 slides along the bottom mold base 1 to push the mold core 304, so that the mold core 304 initially separates from the bottom mold base 1 and the product undercut. Then the connecting rod 502 continues to rise, and the push shell 6 fixed at the center of its upper end surface moves upward in sync. The second push rod 603 connected to the push shell 6 through the shock absorption component buffers the push impact force. The second push rod 603 smoothly completes the final ejection of the mold core 304. Through the synergistic action of the side push of the first push rod 504 and the bottom push of the second push rod 603, the mold core 304 is prevented from sticking due to uneven force at a single point or from product deformation and undercut breakage due to excessive single ejection force. Finally, the entire undercut core pulling and demolding process is completed.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reverse-outlet core-pulling demolding structure for injection molds, comprising a bottom mold base (1), characterized in that: The bottom mold base (1) is provided with a demolding mechanism for removing the core from the injection mold. The demolding mechanism includes: The locking assembly includes an upper mold base (2) provided on the upper end of the bottom mold base (1), a pair of inclined rods (3) fixed inside the upper mold base (2), sliding grooves (301) provided on both sides inside the bottom mold base (1), a slider (302) slidably connected inside the sliding groove (301), a locking rod (303) fixed at one end of the slider (302), and a mold core (304) provided at the center inside the bottom mold base (1). The demolding assembly includes a vertical groove (5) opened at the bottom of the bottom mold base (1). A connecting rod (502) connected by a push assembly is provided inside the vertical groove (5). A push housing (6) is fixed at the center of the upper end face of the connecting rod (502). A second push rod (603) connected by a shock-absorbing assembly is provided inside the push housing (6). Lifting plates (503) are fixed at both ends of the connecting rod (502). A first push rod (504) is fixed at the upper end face of the lifting plate (503).

2. The undercut core-pulling demolding structure for injection molds according to claim 1, characterized in that: The bottom mold base (1) is fixed with a first hydraulic rod (201) on both sides. The upper mold base (2) is fixedly connected to the telescopic end of the first hydraulic rod (201). The upper end of the upper mold base (2) is fixed with a first positioning rod (202). The lower end of the first positioning rod (202) is engaged with the lower end face of the bottom mold base (1).

3. The undercut core-pulling demolding structure for injection molds according to claim 1, characterized in that: The upper mold base (2) is internally fixed with four sets of second positioning rods (4), which are engaged with the bottom mold base (1).

4. The undercut core-pulling demolding structure for injection molds according to claim 1, characterized in that: The top-pushing assembly includes a second hydraulic rod (501) fixed inside the bottom mold base (1), and a connecting rod (502) is slidably connected to the inner wall of the vertical groove (5). The telescopic end of the second hydraulic rod (501) is fixedly connected to the connecting rod (502).

5. The undercut core-pulling demolding structure for injection molds according to claim 1, characterized in that: The shock absorption assembly includes a shock absorption spring (601) fixed inside the push-out housing (6). The inner ring of the shock absorption spring (601) is provided with a damping support rod (602). The damping support rod (602) is fixedly connected to the push-out housing (6). The second push rod (603) is fixedly connected to the upper end of the shock absorption spring (601). The second push rod (603) is slidably connected to the push-out housing (6).

6. The undercut core-pulling demolding structure for injection molds according to claim 1, characterized in that: The mold core (304) has a top plate (505) on both lower ends. A pair of guide rods (506) are fixed on the lower ends of the top plate (505). The guide rods (506) are slidably connected to the bottom mold base (1).

Images