A core pulling anti-retraction device for die casting mold

Abstract

The present application relates to die-casting machining technical field, specifically to a kind of die-casting die core-pulling anti-retreating device, including die-casting machine, and fixed die pin and movable die pin on die-casting machine, die pin and movable die pin cooperate to form die-casting cavity, top pin is arranged between die pin and movable die pin, one side of die pin is fixedly connected with hydraulic cylinder, by setting anti-push mechanism and using the cooperation relationship between inclined guide block, stop block, bevel stop groove and conical spring, guide support can be timely limited and stopped when reverse retreating tendency exists in guide support after hydraulic cylinder drive completes core-pulling action, stop block is continuously pressed to inclined guide block under the elastic action of conical spring, effective locking is formed, prevent guide support from happening back because of factors such as hydraulic fluctuation vibration impact inertia rebound or mechanism gap, compared with the mode that mainly relies on wedge or ordinary cooperation to maintain position stability in prior art, therefore, core-pulling position is more reliable, and anti-retreating effect is more direct.

Description

Technical Field

[0001] This invention relates to the field of die casting machining technology, specifically to a die casting mold core-pulling anti-backward device. Background Technology

[0002] Die casting molds are crucial tooling in the metal die casting process, used to shape the product's external form and internal structure. For die castings with side holes, recesses, undercuts, or irregular cavities, a core-pulling mechanism is typically required within the mold to facilitate lateral demolding during mold opening, ensuring smooth forming and removal of the die casting. A die casting machine is the machine used for pressure casting. These include both hot-chamber and cold-chamber types, the latter further divided into vertical and horizontal types. Under pressure, the die casting machine injects molten metal into the mold, where it cools and solidifies. After mold opening, a solid metal casting is obtained. It was initially used for die casting lettering.

[0003] A Chinese invention patent with publication number CN114951596A discloses a slider wedge clamping device and its usage method for die casting molds. The device includes: a fixed mold core and a fixed mold frame fixedly connected; a slider wedge clamping block fixed on the fixed mold frame; a slider seat engaging with the slider wedge clamping block; a slider fixedly connected to the slider seat; the slider seat connected to the slider cylinder piston rod via a slider cylinder connector; the slider cylinder fixed to the moving mold frame via a slider cylinder bracket; the moving mold core fixedly connected to the moving mold frame; a slanted core puller fixedly connected to the slanted core puller slider seat; the slanted core puller slider seat connected to the slanted core puller piston rod via a slanted core puller cylinder connector; and the slanted core puller cylinder fixedly connected to the moving mold frame. The slider seat has a slanted core puller wedge clamping device. While the slider wedge clamps the slider, the wedge clamping device simultaneously wedges the slanted core puller. This invention achieves precise positioning of the slider and the slanted core puller simultaneously within a limited space. Furthermore, when the slider mechanism retracts by 1mm, the slanted core puller mechanism will not retract by more than 0.1mm, ensuring the accuracy of the die casting and preventing aluminum leakage and jamming in the mold.

[0004] The aforementioned existing technology improves the positioning effect of the slider and the inclined core-pulling mechanism through the wedge-tightening structure, and to a certain extent improves the fitting accuracy problem in the working process of the die-casting mold. However, this technical solution mainly relies on the wedge-tightening fit to achieve positioning control of the slider and the inclined core-pulling mechanism. Its technical focus is on the linkage wedge-tightening and positional accuracy guarantee between the slider and the inclined core-pulling mechanism. After the core-pulling mechanism completes the core-pulling action, it may experience backward movement due to hydraulic shock, vibration, inertial reaction force, or increased clearance caused by long-term use. Under the working conditions of high-frequency opening and closing, thermal expansion, and repeated impact of the die-casting mold, if the core-pulling mechanism only relies on the wedge-tightening structure to maintain positioning, there may still be problems such as local loosening, unstable backward movement, or insufficient reliability of backlash prevention, which will affect the core-pulling accuracy, product molding quality, and mold service life.

[0005] Therefore, it is still necessary to provide a die-casting mold core-pulling anti-backward device with a more compact structure that can cooperate with the core-pulling mechanism and effectively limit its backward tendency, so as to solve the technical problem of insufficient anti-backward performance of the existing core-pulling mechanism. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a die-casting mold core-pulling anti-backward device.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A die-casting mold core-pulling anti-backward device includes a die-casting machine, and a fixed mold core and a moving mold core fixed on the die-casting machine. The fixed mold core and the moving mold core cooperate to form a die-casting cavity. An ejector pin is provided through the fixed mold core and the moving mold core. A hydraulic cylinder is fixedly connected to one side of the fixed mold core. The output end of the hydraulic cylinder extends into the interior of the fixed mold core and is fixedly connected to a guide support. A threaded connection part is provided on the side of the guide support near the hydraulic cylinder. A spiral core-pulling mechanism is connected to the threaded connection part. The spiral core-pulling mechanism includes a receiving cavity sleeve connected to the guide support. An inclined groove is opened on the inner arc surface of the receiving cavity sleeve. A shaft core rod is inserted into the inclined groove. One end of the shaft core rod extends into the interior of the fixed mold core. An anti-backward mechanism abuts against the inner side wall of the moving mold core. The anti-backward mechanism includes a limiting base fixed to the inner bottom wall of the fixed mold core. A transverse opening groove is opened on the limiting base. The bottom of the guide support is slidably engaged with the surface of the limiting base.

[0008] In a preferred embodiment, one side surface of the guide support is provided with an inclined guide block, a fixing plate is fixedly connected to the inner side wall of the fixed mold core, and a conical spring is connected to the side of the fixing plate near the limiting base.

[0009] In a preferred embodiment, one end of the conical spring is connected to a stop block, the stop block has a beveled groove that matches the inclined guide block, and the end of the inclined guide block extends through a transverse opening groove and abuts against the beveled groove.

[0010] In a preferred embodiment, the bottom of the lower surface of the receiving cavity sleeve is provided with a tapered thread, and the receiving cavity sleeve is threadedly connected to the threaded connection part through the tapered thread. The lower surface of the shaft core rod is an eccentric shaft structure so that the shaft core rod forms a core-pulling action when moving along the inclined groove.

[0011] In a preferred embodiment, the transverse opening groove extends along the movement direction of the guide support and is used to guide and limit the movement trajectory of the guide support.

[0012] In a preferred embodiment, the inclined guide block is fixedly disposed on the side wall of the guide support, and the inclined surface of the inclined guide block is in contact with the groove wall of the inclined stop groove.

[0013] In a preferred embodiment, the anti-reverse block moves toward the inclined guide block under the elastic action of the conical spring, thereby keeping the inclined stop groove in contact with the inclined guide block to limit the guide support from retracting in the opposite direction.

[0014] In a preferred embodiment, the fixing plate is vertically disposed on the inner side wall of the fixed mold core, and the conical spring is disposed between the fixing plate and the anti-reverse block.

[0015] In a preferred embodiment, the guide support moves linearly along the limiting base under the drive of the hydraulic cylinder, and the core is pulled out by the core pulling mechanism. The anti-retraction mechanism is configured in conjunction with the core pulling mechanism, and the anti-retraction mechanism is used to stop and limit the guide support after the core is pulled out.

[0016] The beneficial effects of this invention are:

[0017] 1. By setting up an anti-retraction mechanism and utilizing the cooperation between the inclined guide block, the anti-retraction block, the inclined stop groove, and the conical spring, the guide support can be promptly limited and stopped after the core-pulling action is completed by the hydraulic cylinder. When the guide support has a tendency to retract, the anti-retraction block continues to press against the inclined guide block under the elastic action of the conical spring, thereby forming an effective lock and preventing the guide support from retracting due to hydraulic fluctuations, vibration impacts, inertial rebounds, or mechanism clearances. Compared with the existing technology that mainly relies on wedging or ordinary cooperation to maintain position stability, it can continuously constrain the state after the core-pulling is completed. Therefore, the core-pulling position is maintained more reliably, and the anti-retraction effect is more direct.

[0018] 2. The guide support is directly driven by a hydraulic cylinder, and the movement is guided and the trajectory is constrained by the limiting base and the transverse opening slot. This allows the guide support to move stably in a straight line in a predetermined direction during operation, avoiding problems such as uneven local force. At the same time, the receiving cavity sleeve, inclined groove and shaft core rod in the spiral core pulling mechanism cooperate with each other to effectively convert the linear motion of the guide support into core pulling motion, so that the shaft core rod completes the exit action according to the predetermined trajectory. Since both the guiding process and the core pulling process are subject to structural constraints, the core pulling component is not prone to positional deviation during operation. Therefore, it can better ensure the forming accuracy of side holes, side recesses, undercuts or irregular cavities, thereby improving the dimensional consistency and product quality of die castings.

[0019] 3. By organically combining functions such as hydraulic drive, guide support, spiral core pulling, and anti-backward limit, the anti-backward mechanism is mainly arranged inside the fixed mold core. It forms a relatively compact assembly structure through a fixed plate, conical spring, and anti-backward block. It can automatically stop the guide support without the need for additional complex large locking components. Furthermore, the receiving cavity sleeve is connected to the guide support through a conical thread, which ensures a stable connection and convenient assembly, which is beneficial for later installation, maintenance, and replacement. Attached Figure Description

[0020] Figure 1 This is a perspective view of the overall die-casting structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the overall structure of the mold core of the present invention;

[0022] Figure 3 This is a cross-sectional view of the internal structure of the present invention.

[0023] Figure 4 This is a three-dimensional structural diagram of the spiral core-pulling mechanism of the present invention;

[0024] Figure 5 This is a schematic diagram of the disassembled structure of the limiting base of the present invention;

[0025] Figure 6 This is a planar sectional view of the cavity sleeve of the present invention;

[0026] Figure 7 This is a diagram illustrating the inclined groove structure of the present invention;

[0027] Figure 8 This is a schematic diagram of the disassembly structure of the anti-retraction mechanism of the present invention;

[0028] Figure 9 This is a schematic diagram of the overall structure of the upper and lower mold core linkage device of the present invention.

[0029] In the diagram: 1. Fixed mold core; 2. Moving mold core; 3. Ejector pin; 4. Hydraulic cylinder; 5. Guide support; 51. Angled guide block; 6. Spiral core pulling mechanism; 61. Receiving cavity sleeve; 62. Angled groove; 63. Shaft core rod; 7. Anti-reverse mechanism; 71. Limiting base; 72. Horizontal opening groove; 73. Fixing plate; 74. Conical spring; 75. Anti-reverse block; 751. Angled stop groove. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0033] This embodiment provides: a die-casting mold core-pulling anti-reverse device according to... Figures 1 to 9 The die casting cavity includes a fixed mold core 1 and a movable mold core 2, which cooperate to form a die casting cavity. An ejector pin 3 is provided through the fixed mold core 1 and the movable mold core 2. A hydraulic cylinder 4 is fixedly connected to one side of the fixed mold core 1. The output end of the hydraulic cylinder 4 extends into the interior of the fixed mold core 1 and is fixedly connected to a guide support 5. The guide support 5 has a threaded connection on the side near the hydraulic cylinder 4. The threaded connection is connected to a spiral core pulling mechanism 6. The spiral core pulling mechanism 6 includes a receiving cavity sleeve 61 connected to the guide support 5. The inner arc surface of the cavity sleeve 61 is provided with an inclined groove 62, and a shaft core rod 63 is inserted into the inclined groove 62. One end of the shaft core rod 63 extends into the interior of the fixed mold core 1. An anti-retraction mechanism 7 is abutted on the inner side wall of the moving mold core 2. The anti-retraction mechanism 7 includes a limiting base 71 fixed to the inner bottom wall of the fixed mold core 1. A transverse opening groove 72 is provided on the limiting base 71. The bottom of the guide support 5 is slidably engaged with the surface of the limiting base 71. The anti-retraction mechanism 7 is located on one side between the fixed mold core 1 and the moving mold core 2.

[0034] according to Figure 1 and Figure 2In the die-casting machine, the fixed mold core 1 and the moving mold core 2 close together to form a die-casting cavity. An ejector pin 3 is inserted between the fixed mold core 1 and the moving mold core 2 to eject the casting after die-casting is completed and the mold is opened. A hydraulic cylinder 4 is fixedly installed on one side of the fixed mold core 1. The output end of the hydraulic cylinder 4 extends into the fixed mold core 1 and is fixedly connected to the guide support 5. Therefore, the linear extension and retraction motion of the hydraulic cylinder 4 can be directly transmitted to the guide support 5, driving the guide support 5 to reciprocate in a predetermined direction. The bottom of the guide support 5 is slidably engaged with the surface of the limiting base 71. The limiting base 71 is fixedly installed on the inner bottom wall of the fixed mold core 1. The limiting base 71 has a transverse opening groove 72, which extends along the movement direction of the guide support 5. During the movement of the guide support 5, its bottom is in sliding contact with the limiting base 71. The transverse opening groove 72 provides transverse constraint and guides the movement trajectory of the guide support 5, so that the guide support 5 moves stably mainly in a straight line under the drive of the hydraulic cylinder 4, reducing swaying, tilting or force deviation, and ensuring the stability of the subsequent core pulling action.

[0035] The guide support 5 has a threaded connection on the side near the hydraulic cylinder 4. This threaded connection is connected to the spiral core-pulling mechanism 6. The spiral core-pulling mechanism 6 includes a receiving cavity sleeve 61. The receiving cavity sleeve 61 is threaded to the threaded connection on the guide support 5 through a tapered thread on its lower surface. The tapered thread connection facilitates a more secure assembly, making the receiving cavity sleeve 61 less prone to loosening during operation. It also helps to ensure the coaxiality and connection stability between the receiving cavity sleeve 61 and the guide support 5. The receiving cavity sleeve 61 forms a receiving space for installing and constraining the core rod 63. Its inner arc surface has an inclined groove 62. The core rod 63 is inserted into the inclined groove 62, and one end of the core rod 63 extends into the fixed mold core 1 and faces the part to be pulled out. The lower surface of the core rod 63... Since the surface is an eccentric shaft structure, the core rod 63 does not simply slide in a single straight line. Instead, when the guide support 5 moves and drives the receiving cavity sleeve 61 to move relative to it, the core rod 63 changes position along the inclined groove 62 with the help of the inclined guiding action of the inclined groove 62 and the cooperation of the eccentric shaft structure. Specifically, when the receiving cavity sleeve 61 moves forward with the guide support 5, the inclined groove 62 forms an inclined guide for the core rod 63. Under the constraint of the groove wall, the core rod 63 generates a relative displacement along the inclined groove 62. Since the lower surface of the core rod 63 is set as an eccentric shaft structure, it will convert the linear pushing motion of the guide support 5 into a composite displacement required for core pulling during the relative movement. This causes the core rod 63 to exit the original core mating position in the demolding direction, thereby completing the core pulling action for the side holes, side recesses, undercuts, or irregular cavities of the die casting.

[0036] Furthermore, in the initial stage of core pulling, (such as...) Figure 5 and Figure 6Hydraulic cylinder 4 starts and pushes guide support 5 to move linearly along limit base 71. When guide support 5 moves, it drives receiving cavity sleeve 61 to move synchronously. The inclined groove 62 in receiving cavity sleeve 61 then generates a guiding effect relative to shaft core rod 63. Since the inclined groove 62 is inclined, shaft core rod 63 no longer just maintains its original position after being subjected to the force of the groove wall, but moves along the inclined direction of inclined groove 62. Under the action of eccentric structure, it forms the core pulling stroke of exiting the side part of the cavity. In this process, the linear feed of guide support 5 is the power input, the cooperation between inclined groove 62 and shaft core rod 63 is the motion conversion mechanism, and the eccentric shaft structure further enhances the core pulling displacement formation effect, making the core pulling action smoother.

[0037] When the guide support 5 moves to the set core-pulling position, the core rod 63 completes the corresponding core-pulling stroke. At this time, the lateral clamping structure of the casting is released, creating conditions for subsequent mold opening and ejection. To prevent the guide support 5 from retracting after core pulling due to hydraulic pulsation, mold vibration, residual force of molten metal impact, inertial rebound of the mechanism, or the existence of fitting clearance, the present invention sets a special anti-retraction mechanism 7 inside the fixed mold core 1. In addition to the limiting base 71, the anti-retraction mechanism 7 also includes a fixed plate 73, a conical spring 74, and a backstop block 75. The fixed plate 73 is vertically fixed on the inner side wall of the fixed mold core 1. The conical spring 74 is set between the fixed plate 73 and the backstop block 75. An inclined guide block 51 is fixed on one side surface of the guide support 5. The backstop block 75 has an inclined stop groove 751 that cooperates with the inclined guide block 51. The end of the inclined guide block 51 passes through the transverse opening groove 72 and abuts against the inclined stop groove 751.

[0038] During the forward movement of the guide support 5, the inclined guide block 51 moves forward synchronously with the guide support 5. Since the anti-reverse block 75 always tends to move towards the inclined guide block 51 under the elastic force of the conical spring 74, the inclined stop groove 751 will continue to be close to the inclined surface of the inclined guide block 51. When the inclined guide block 51 is pushed forward, the inclined surface of the inclined guide block 51 and the groove wall of the inclined stop groove 751 slide relative to each other. This sliding will drive the anti-reverse block 75 to overcome the elastic force of the conical spring 74 and make adaptive clearance, thereby ensuring that the guide support 5 can continue to move forward to complete the core pulling stroke. In other words, in the forward direction, the inclined guide block 51 and the anti-reverse block 75 are in a sliding and overstepping fit, which will not hinder normal core pulling.

[0039] exist Figure 3 and Figure 4As shown, when the guide support 5 shows a tendency to retract in the opposite direction after the core pulling is completed, the inclined guide block 51 will move in the opposite direction. At this time, since the anti-retraction block 75 has been reset towards the inclined guide block 51 under the continuous pushing of the conical spring 74, the fit between the inclined stop groove 751 and the inclined guide block 51 is closer. The inclined surface of the inclined guide block 51 will form a top pressure and limit fit with the groove wall of the inclined stop groove 751. Since the relative inclined surface fit direction of the two is set to limit the reverse retraction, once the guide support 5 shows a tendency to move in the opposite direction, the inclined guide block 51 will be blocked by the anti-retraction block 75, thereby preventing the guide support 5 from continuing to retract. In this way, the guide support 5 can be stably maintained in the target position after the core pulling is completed, avoiding uncontrolled reset or dislocation of the core pulling component.

[0040] in Figure 7 As shown, the inclined guide block 51 is fixedly mounted on the side wall of the guide support 5, and its inclined surface is in contact with the groove wall of the inclined stop groove 751. This contact relationship gives the anti-reverse action a clear force path: the reverse thrust of the guide support 5 is first transmitted to the inclined guide block 51, and then the inclined guide block 51 acts on the anti-reverse block 75. The anti-reverse block 75 further transmits the force to the conical spring 74 and the fixing plate 73. Finally, the fixing plate 73 and the fixed mold core 1 body bear the reaction force. Since the anti-reverse block 75 is not a simple point contact, but forms a surface contact or near-surface contact with the inclined guide block 51 through the inclined stop groove 751, therefore... This can improve stress stability, reduce local wear, and enhance the reliability of backlash prevention. The role of the conical spring 74 in this device is not only to push the backlash block 75 to automatically reset, but also to use its elastic preload to eliminate the fit gap between the backlash block 75 and the inclined guide block 51. In this way, after the guide support 5 completes its forward stroke, the backlash block 75 can press against the inclined guide block 51 in time and enter the effective backlash position, thereby avoiding the increase in backlash caused by excessive gap. The use of conical spring 74 can also obtain better compression stroke and elastic recovery ability within a limited installation space, making it more suitable for installation inside the fixed mold core 1.

[0041] After the mold enters the mold opening stage, since the core rod 63 has already completed the core pulling and withdrawal action, the lateral clamping of the die casting is released. Subsequently, the fixed mold core 1 and the moving mold core 2 separate, and the ejector pin 3 can eject the casting from the cavity under the drive of the subsequent ejection mechanism. At this time, since the anti-retraction mechanism 7 has stopped and limited the guide support 5, the core rod 63 can maintain a stable position after core pulling during the mold opening and ejection process, and will not re-enter the lateral area of ​​the cavity due to vibration or collision, thereby avoiding interference with the demolding of the casting.

[0042] according to Figure 8 and Figure 9When a reset is required, the guide support 5 can be reversed by the hydraulic cylinder 4 to return according to the set program. During the return process, the output force of the hydraulic cylinder 4 can be adjusted to make the guide support 5 overcome the limiting effect of the anti-reverse block 75. The structural design reserves the separation guide relationship between the inclined guide block 51 and the anti-reverse block 75 so that the two can re-slide relative to each other when a specific force condition is reached, thereby realizing the controlled return of the guide support 5. After the guide support 5 returns to its original position, the receiving cavity sleeve 61 drives the shaft core rod 63 to move in the opposite direction along the inclined groove 62, so that the shaft core rod 63 returns to the initial standby position for the next die casting cycle.

[0043] After the hydraulic cylinder 4 is started, its output end pushes the guide support 5 to move linearly along the transverse opening groove 72 of the limiting base 71. Since the transverse opening groove 72 extends along the movement direction of the guide support 5, it can guide and limit the movement trajectory of the guide support 5, preventing the guide support 5 from swaying or being overloaded during movement, thereby ensuring the linearity and stability of the movement of the guide support 5.

[0044] In this embodiment, the inclined guide block 51 and the inclined stop groove 751 adopt an asymmetrical inclined surface mating structure. Specifically, the inclined guide block 51 has a first guide inclined surface on the forward direction side of the guide support 5 and a second stop inclined surface on the backward direction side of the guide support 5. Correspondingly, the inclined stop groove 751 has a guide groove wall that mates with the first guide inclined surface and a stop groove wall that mates with the second stop inclined surface. The inclination angle of the first guide inclined surface is greater than the inclination angle of the second stop inclined surface, so that when the guide support 5 moves forward, the stop block 75 can compress the conical spring 74 and retract under the action of the inclined surface. When the guide support 5 retracts, the second stop inclined surface and the stop groove wall form a limiting fit, thereby restricting the reverse movement of the guide support 5.

[0045] During linear movement, the guide support 5 drives the spiral core-pulling mechanism 6 to move synchronously. Specifically, the receiving cavity sleeve 61 is threadedly connected to the threaded connection part through a tapered thread, thereby forming a stable assembly positioning relationship. An inclined groove 62 is formed inside the receiving cavity sleeve 61, and the shaft core rod 63 is inserted into the inclined groove 62. Furthermore, the lower surface of the shaft core rod 63 has an eccentric shaft structure. Thus, when the guide support 5 drives the receiving cavity sleeve 61 to undergo linear displacement, the shaft core rod 63 generates a combined axial and radial displacement under the inclined guiding action of the inclined groove 62, causing the shaft core rod 63 to gradually withdraw towards the cavity side, thereby realizing the core-pulling action. To prevent the guide support 5 from retracting due to pressure rebound, inertial reaction, or vibration impact after core pulling is completed, this invention provides… An anti-retraction mechanism 7 is provided, which includes a limiting base 71 fixed to the inner bottom wall of the fixed mold core 1, a fixing plate 73, a conical spring 74, and an anti-retraction block 75. The fixing plate 73 is vertically arranged on the inner side wall of the fixed mold core 1. The conical spring 74 is arranged between the fixing plate 73 and the anti-retraction block 75, and one end of the conical spring 74 always applies an elastic preload to the anti-retraction block 75. A slanted guide block 51 is provided on one side surface of the guide support 5. The anti-retraction block 75 has a slanted stop groove 751 that cooperates with the slanted guide block 51. The end of the slanted guide block 51 passes through the transverse opening groove 72 and abuts against the slanted stop groove 751. It should be noted that the slanted guide block 51 and the slanted stop groove 751 are not simply rigidly locked together. Instead of a simple relationship, this invention features inclined guide and elastic clearance characteristics. In this invention, the inclined surface of the inclined guide block 51 and the groove wall of the inclined stop groove 751 are both mutually cooperating inclined structures. The inclination angle of the two inclined surfaces is comprehensively set according to the anti-reverse self-locking requirements and hydraulic reset requirements. The inclination angle can be understood as the angle between the inclined surface and the direction of movement of the guide support 5. It is preferably set to 10°-35°, and more preferably 15°-25°. The reason for adopting the above angle range is that when the inclination angle is too large, the axial component of the force between the inclined guide block 51 and the inclined stop groove 751 increases, and the anti-reverse block 75 is more easily pushed open, which is not conducive to forming a stable anti-reverse effect. When subjected to hydraulic fluctuations, inertial rebound or mold vibration, the reliability of anti-reverse may be affected. In the case of descent; when the slope angle is too small, although the self-locking tendency is enhanced, the guide support 5 needs to overcome greater frictional resistance and extrusion force when resetting, which can easily lead to an increase in the resetting load of the hydraulic cylinder 4, affecting the smoothness of the mechanism's return stroke. In severe cases, it may also cause increased local wear or jamming. Therefore, setting the slope angle within the above range can enable the inclined guide block 51 to be smoothly guided and moved along the inclined stop groove 751 when the guide support 5 moves forward. At the same time, when the guide support 5 has a tendency to retreat in the opposite direction, the preload provided by the conical spring 74 can be used to form a stable abutment and anti-retreat relationship between the inclined stop groove 751 and the inclined guide block 51, thereby taking into account the forward passability, backward restriction and resetting feasibility.

[0046] When the guide support 5 moves forward under the action of the hydraulic cylinder 4, the inclined guide block 51 enters or slides along the inclined surface of the inclined stop groove 751. The anti-reverse block 75 is forced to produce a short stroke retraction under the action of the conical spring 74, thereby allowing the guide support 5 to continue to move forward without affecting the normal core pulling.

[0047] If the guide support 5 shows a tendency to retreat after the core is pulled out, the conical spring 74 will push the anti-reverse block 75 to automatically press back, so that the groove wall of the inclined stop groove 751 and the inclined guide block 51 form a reverse blocking engagement, thereby restricting the guide support 5 from retreating. In other words, the core principle of the anti-reverse mechanism 7 is to use the synergistic effect of the inclined surface self-guided, spring pre-tightening, and reverse anti-reverse to allow passage in the forward direction and form a blockage in the backward direction, thereby achieving reliable locking after the core is pulled out.

[0048] In addition, the tapered spring 74 adopts a tapered structure, which can provide a longer compression stroke and a more stable elastic recovery capability within a limited installation space. This allows the anti-reverse block 75 to always maintain a pre-tightened state facing the inclined guide block 51. This ensures smooth clearance when the core is pulled forward and timely restoration of the anti-reverse position after the core is pulled. It avoids the reduced anti-reverse effect caused by the instability of ordinary straight column springs under high-frequency compression, large space occupation, or untimely recovery. The cooperation between the tapered spring 74, the fixed plate 73, and the anti-reverse block 75 not only achieves elastic pre-tightening but also takes into account the structural adaptability under the condition of limited internal space of the mold.

[0049] The inclined groove 62 provides radial guidance and positional constraint for the shaft core 63, ensuring that its center position is always limited by the groove wall when it moves within the receiving cavity 61, preventing significant radial movement or swaying. The eccentric shaft structure causes a shift between the force center and geometric center of the shaft core 63 when guided, resulting in a controlled eccentric displacement of the shaft core 63 under the constraint of the groove wall as the guide support 5 pushes the receiving cavity 61. Essentially, the core-pulling motion converts the linear thrust output by the hydraulic cylinder 4 into the shaft core... The lateral exit displacement of 63 relative to the cavity is transformed as follows: the hydraulic cylinder 4 pushes the guide support 5 to move linearly along the limiting base 71, and the guide support 5 then drives the receiving cavity sleeve 61, which is threaded to it, to move forward synchronously. Since the receiving cavity sleeve 61 is provided with an inclined groove 62, and the shaft core rod 63 is inserted into the inclined groove 62, when the receiving cavity sleeve 61 makes a linear displacement, the inclined groove wall of the inclined groove 62 will apply a decomposition force to the shaft core rod 63, decomposing the original single linear motion into a component that propagates along the groove direction and a displacement component that is perpendicular to the groove direction.

[0050] Specifically, after the mold is closed, the hydraulic cylinder 4 actuates, driving the guide support 5 to move forward along the extension direction of the transverse opening groove 72. Since the bottom of the guide support 5 is slidably engaged with the limiting base 71, the movement trajectory of the guide support 5 is constrained by the limiting base 71. When the guide support 5 moves forward, the receiving cavity sleeve 61 moves synchronously with the guide support 5. Since the eccentric section of the shaft core rod 63 is inserted into the inclined groove 62, and the inclined groove 62 is inclined relative to the movement direction of the guide support 5, when the receiving cavity sleeve 61 makes a linear displacement along the movement direction of the guide support 5, the groove wall of the inclined groove 62 applies a constraint force to the eccentric section of the shaft core rod 63. This force can be decomposed into a component force along the extension direction of the inclined groove 62 and a constraint component force perpendicular to the groove wall of the inclined groove 62. Affected by this constraint relationship, the shaft core rod 63 generates a guided displacement relative to the receiving cavity sleeve 61.

[0051] Because the core rod 63 has an eccentric section, when the eccentric section moves within the inclined groove 62, its center of force is offset relative to the main axis of the core rod 63. Therefore, in addition to displacement along the direction of movement of the guide support 5, the core rod 63 also generates a retraction component relative to the side of the cavity. Thus, the linear thrust output by the hydraulic cylinder 4 is transmitted to the receiving cavity sleeve 61 via the guide support 5, and then, with the guidance and constraint of the inclined groove 62 on the eccentric section, it is converted into a composite displacement of the core rod 63, causing the core rod 63 to gradually detach from the lateral forming part of the die-casting, completing the core-pulling action. It should be noted that in this embodiment, the spiral core-pulling mechanism mainly refers to the motion conversion structure formed between the receiving cavity sleeve 61 and the core rod 63 through inclined guidance and eccentric cooperation. Its core lies in the motion conversion structure formed by the receiving cavity sleeve 61 and the core rod 63 through inclined guidance and eccentric cooperation. The displacement of the cavity sleeve 61 drives the shaft core rod 63 to exit along a predetermined trajectory. It is not limited that the shaft core rod 63 must make a continuous full-circle rotation. In some embodiments, the shaft core rod 63 may also be accompanied by a limited angular displacement. In other embodiments, the shaft core rod 63 may also mainly exhibit lateral exit displacement. During the forward movement of the guide support 5, the inclined guide block 51 moves forward synchronously. Since the first guide inclined surface of the inclined guide block 51 is in contact with the guide groove wall of the inclined stop groove 751, when the inclined guide block 51 continues to move forward, it pushes the anti-retraction block 75 to overcome the elastic force of the conical spring 74 and retract along the guide limiting structure, thereby providing clearance space for the guide support 5 to move forward. In this state, the anti-retraction mechanism 7 does not form a rigid block on the forward stroke of the guide support 5.

[0052] When the guide support 5 moves to the core-pulling position, if the guide support 5 has a tendency to move in the opposite direction due to hydraulic fluctuations, mold vibration, or mechanical inertia, the anti-reverse block 75 is reset towards the inclined guide block 51 under the pre-tightening action of the conical spring 74, so that the anti-reverse groove wall of the inclined stop groove 751 abuts against the second anti-reverse inclined surface of the inclined guide block 51. At this time, the reverse force of the guide support 5 is transmitted to the anti-reverse block 75 through the inclined guide block 51, and then to the fixed plate 73 and the fixed mold core 1, thereby forming a mechanical limit on the backward stroke of the guide support 5.

[0053] To achieve subsequent reset, when the hydraulic cylinder 4 reverses and drives the guide support 5 back, the guide support 5 applies a reverse thrust to the anti-reverse block 75. When the reverse thrust and the inclined guide relationship work together and reach the set value, the anti-reverse block 75 compresses the conical spring 74 and retracts again. The inclined guide block 51 disengages from the anti-reverse limit area of ​​the inclined stop groove 751, and the guide support 5 can continue to return. Correspondingly, the receiving cavity sleeve 61 drives the shaft core rod 63 to move along a trajectory opposite to the core pulling process, so that the shaft core rod 63 returns to the initial position.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A die-casting mold core-pulling anti-reverse device, comprising a die-casting machine, and a fixed mold core (1) and a movable mold core (2) fixed on the die-casting machine, wherein the fixed mold core (1) and the movable mold core (2) cooperate to form a die-casting cavity, and an ejector pin (3) is provided through the fixed mold core (1) and the movable mold core (2), characterized in that: A hydraulic cylinder (4) is fixedly connected to one side of the fixed mold core (1), and the output end of the hydraulic cylinder (4) extends into the interior of the fixed mold core (1) and is fixedly connected to a guide support (5). The guide support (5) is provided with a threaded connection on the side near the hydraulic cylinder (4), and the threaded connection is connected to a spiral core pulling mechanism (6). The spiral core pulling mechanism (6) includes a receiving cavity sleeve (61) connected to the guide support (5). The inner arc surface of the receiving cavity sleeve (61) is provided with an inclined groove (62). A shaft core rod (63) is inserted into the inclined groove (62). One end of the shaft core rod (63) extends into the interior of the fixed mold core (1). The inner wall of the moving mold core (2) is abutted by an anti-retraction mechanism (7). The anti-retraction mechanism (7) includes a limiting base (71) fixed to the inner bottom wall of the fixed mold core (1). The limiting base (71) has a transverse opening groove (72). The bottom of the guide support (5) is slidably engaged with the surface of the limiting base (71).

2. The die-casting mold core-pulling anti-reverse device according to claim 1, characterized in that, The guide support (5) has an inclined guide block (51) on one side surface, and a fixing plate (73) is fixedly connected to the inner side wall of the fixed mold core (1). A conical spring (74) is connected to the side of the fixing plate (73) near the limiting base (71).

3. The die-casting mold core-pulling anti-reverse device according to claim 2, characterized in that, One end of the conical spring (74) is connected to a stop block (75), and the stop block (75) has a beveled stop groove (751) that cooperates with the beveled guide block (51). The end of the beveled guide block (51) passes through a transverse opening groove (72) and abuts against the beveled stop groove (751).

4. The die-casting mold core-pulling anti-reverse device according to claim 3, characterized in that, The lower surface of the receiving cavity sleeve (61) is provided with a tapered thread, and the receiving cavity sleeve (61) is threadedly connected to the threaded connection part through the tapered thread. The lower surface of the shaft core rod (63) is an eccentric shaft structure so that the shaft core rod (63) forms a core pulling action when it moves along the inclined groove (62).

5. The die-casting mold core-pulling anti-reverse device according to claim 3, characterized in that, The transverse opening groove (72) extends along the movement direction of the guide support (5) and is used to guide and limit the movement trajectory of the guide support (5).

6. The die-casting mold core-pulling anti-reverse device according to claim 3, characterized in that, The inclined guide block (51) is fixedly installed on the side wall of the guide support (5), and the inclined surface of the inclined guide block (51) is in contact with the groove wall of the inclined stop groove (751).

7. The die-casting mold core-pulling anti-reverse device according to claim 6, characterized in that, The anti-reverse block (75) moves toward the inclined guide block (51) under the elastic action of the conical spring (74), thereby keeping the inclined stop groove (751) in contact with the inclined guide block (51) to limit the guide support (5) from retracting in the opposite direction.

8. The die-casting mold core-pulling anti-reverse device according to claim 7, characterized in that, The fixing plate (73) is vertically disposed on the inner side wall of the fixed mold core (1), and the conical spring (74) is disposed between the fixing plate (73) and the anti-reverse block (75).

9. A die-casting mold core-pulling anti-reverse device according to claim 8, characterized in that, The guide support (5) moves linearly along the limiting base (71) under the drive of the hydraulic cylinder (4), and drives the core rod (63) to pull the core through the spiral core pulling mechanism (6). The anti-retraction mechanism (7) is set in cooperation with the spiral core pulling mechanism (6). The anti-retraction mechanism (7) is used to stop and limit the guide support (5) after the core is pulled.

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