Priority mechanical jacking mechanism, stamping die and die opening method

Abstract

The invention discloses a priority mechanical jacking-back mechanism, a stamping die and a die opening method, and aims to solve the problem that the reliability of a delay nitrogen cylinder and other existing schemes is affected by environment and abrasion. The mechanism comprises an independent driving unit, a sequential execution unit driven by the independent driving unit to move in the transverse direction, a lifting action part and a jacking connecting block connected with an upper die pressing core. When the die is opened, the driving unit pushes the execution unit to horizontally move from the separation position to the intervention position, the upper die pressing core is forcibly jacked back through mechanical interference, and the action is completed to form a forcible premise for ejection starting of the lower die. The mechanical logic of space decoupling and sequence forcing is used for replacing traditional time sequence control, a directly-linked mechanical state indicator is adopted, absolute reliability and failure safety of interference prevention are achieved, and a brand-new basic solution is provided for precision stamping.

Description

Technical Field

[0001] This invention relates to the field of stamping dies, and more specifically to a priority sequence mechanical ejection mechanism and a stamping die and mold opening method using the priority sequence mechanical ejection mechanism. Background Technology

[0002] In stamping dies for deep drawing and precision forming with elastic blank holders, the safe ejection of parts after die opening is a core aspect of ensuring product quality and production efficiency. The technical challenge lies in the fact that if the upper blank holder has not fully reset and detached from the part when the lower die ejection device begins to eject the part, the part will be clamped by the upper and lower dies, resulting in "clamping" interference, causing the part to twist, be crushed, or even damage the die.

[0003] In existing technologies, besides using high-cost electronic timing control systems, the industry generally adopts "delayed nitrogen cylinders" as a solution. A delayed nitrogen cylinder is a specially designed gas spring that uses a precision oil circuit for throttling. It is designed to move slowly during the compression stroke (mold closing) and extend quickly during the return stroke (mold opening), thus completing the reset before the lower mold ejects.

[0004] However, through long-term practice and in-depth analysis, the applicant discovered that existing technical solutions, represented by delayed nitrogen cylinders, are designed based on a "timing control" paradigm, which aims to "gain" time priority by precisely controlling the dynamic performance of the reset element. This paradigm suffers from the following insurmountable, fundamental flaws. First, the probabilistic nature of reliability: its "fast" or "slow" characteristic depends entirely on the viscosity of the internal fluid and the precise dimensions of the throttling orifice. Changes in ambient temperature, wear of seals, differences in installation angle, and load fluctuations can all significantly alter its operating characteristics, leading to "delayed" failure. Its reliability is a probabilistic outcome influenced by multiple variables and cannot provide deterministic guarantees under long-term harsh operating conditions.

[0005] Second, functional coupling and interference: As a reset element, its damping force directly constitutes part of the clamping force, and its performance fluctuations can interfere with the stability of the molding process. At the same time, it has a single function, providing only unidirectional reset force and lacking the ability to physically maintain the reset state. The pressure core is at risk of falling back due to its own weight or vibration.

[0006] Third, failures are insidious and maintenance is expensive: performance degradation is gradual and insidious, and failures are often only detected after causing mass quality incidents. As a high-precision hydraulic / pneumatic component, it has high purchase and maintenance costs and long maintenance cycles.

[0007] The above analysis reveals a fundamental problem: the evolution of existing technologies has always focused on optimizing the timing of reset components, whether through the use of more precise nitrogen cylinders, increased temperature compensation, or the introduction of sensor feedback. It hasn't escaped the mindset of relying on component performance stability. This leads to a simultaneous increase in the complexity and vulnerability of solutions. Therefore, there is an urgent need in the field for a new design concept that can provide absolute security guarantees at the logical level rather than the performance level. Summary of the Invention

[0008] This invention aims to completely transcend the existing "timing control" paradigm, providing an anti-interference mechanism and method based on the novel concepts of "sequence enforcement" and "functional decoupling." The purpose of this invention is not to create a more precise "timer," but to construct an inviolable "mechanical logic lock." It does not rely on the dynamic performance of any component, but rather physically enforces a preset, irreversible sequence of actions through an independent mechanical system, thereby eliminating any possibility of interference at its source.

[0009] To achieve the above objectives, this invention proposes the core concept of "priority sequence mechanical return". The core of its technical solution is to construct an external sequence controller that is decoupled from the main mold system in terms of space, function, and logic.

[0010] The priority sequence mechanical return mechanism provided by the present invention includes: a drive unit independent of the mold ejection system, which is fixedly installed at the outer end of the lower pressure core; A sequential execution unit driven by the drive unit, the sequential execution unit being configured to reciprocate along a first direction different from the mold opening and closing direction under the drive of the drive unit; A lifting mechanism formed on the upper part of the sequential execution unit; And a lifting connecting block that is fixedly connected to the upper pressure core; The sequential execution unit has a disengagement position and an intervention position; When in the disengaged position, the lifting mechanism and the lifting connecting block do not interfere with each other in the mold opening and closing direction; When the drive unit drives the sequential execution unit to move from the disengagement position to the intervention position, the lifting action part mechanically interferes with the lifting connecting block, thereby forcibly resetting the upper pressure core into the upper mold; The completion of the action of the priority sequence mechanical return mechanism constitutes the mechanical prerequisite for allowing the lower mold ejection system to start.

[0011] The present invention is further configured such that: the first direction is a horizontal direction or a direction that forms an angle of less than 45 degrees with the horizontal direction.

[0012] The present invention is further configured such that: the sequential execution unit is a slider that slides in the horizontal direction, and the driving unit is a horizontally mounted cylinder or hydraulic cylinder.

[0013] The present invention is further configured such that: the lifting action part is an inclined surface, an arc surface, or a curved surface formed by a combination of an inclined surface and an arc surface on the sequential execution unit; The lower part of the lifting connecting block is formed with a lifting function part, which is an inclined surface, an arc surface, or a curved surface composed of an inclined surface and an arc surface.

[0014] The present invention is further configured such that when the sequential execution unit is in the intervention position, the lifting action part includes a holding surface for maintaining the reset state of the upper pressure core.

[0015] The present invention is further configured to include a mechanical status indicator, which is linked to the sequential execution unit. When the sequential execution unit reaches the intervention position, the mechanical status indicator provides a visible or perceptible arrival signal.

[0016] The present invention is further configured such that: during the mold closing and stamping process, the sequential execution unit is in a disengaged position and does not bear or transmit the forming load of the mold.

[0017] The essential difference between this invention and the delayed nitrogen cylinder solution is: First level: Logical paradigm shift—from "passive temporal sequence" to "active sequential enforcement" The delayed nitrogen cylinder solution is passive: after the upper mold opens, it "attempts" to quickly reset based on its own characteristics, while the lower mold ejection occurs after a preset delay. The two actions have a loose sequential relationship based on time estimation.

[0018] This invention is proactive and dominant: it defines a rigid "three-step sequential lock": ① Upper mold opening → ② This mechanism actively intervenes and "forces" the return → ③ Lower mold ejection is "permitted" to begin. The physical completion of the second step is the sole and mandatory prerequisite for the execution of the third step. This elevates the process from a "chronological order" to a "logical conditional relationship." This concept, which returns the problem of interference prevention from the realm of "cybernetics" to the realm of "mechanical logic design," is something that those skilled in the art cannot achieve under existing paradigms.

[0019] The second level: Structural paradigm innovation—from "axial coupling" to "spatial and functional decoupling." The delayed nitrogen cylinder and the pressure core are coaxially mounted, achieving deep spatial and functional coupling with the molding system.

[0020] This invention introduces a "first direction" (particularly the horizontal direction) to make the motion trajectory of the sequential execution unit orthogonal to the opening and closing mold direction space. This design brings disruptive advantages: Functional purity: During the mold closing and stamping stages, the sequential execution unit is in the "disengaged position" and has no contact with the upper mold. It absolutely does not bear or transmit the forming load of tens of thousands of tons, ensuring the purity and stability of the mold process system.

[0021] Independent and autonomous: The entire mechanism operates as a fully functional module, with its driving, execution, and intervention processes forming a self-contained whole. This "plug-and-play" modular design is fundamentally different from the delayed nitrogen cylinder, which is an internal "organ" of the system.

[0022] The third level: The philosophy of state assurance – from “signal monitoring” to “state-derived physical indication”. Existing high-end solutions monitor the reset state by adding proximity sensors, which introduces new electronic failure points.

[0023] This invention creatively proposes a "mechanical status indicator." This indicator (such as a pop-out mechanical pin) is directly mechanically linked to the sequential execution unit. The indicator passively changes its physical state (e.g., pops out) only when the execution unit moves to the "intervention position" and completes its return. This state change is not a "monitoring signal," but rather "direct physical evidence" and a "derivative" of the completion of the safety action. Even if the simple electrical switch connected in parallel fails, this mechanical indication still provides irrefutable evidence for visual inspection and fault diagnosis, achieving fail-safe and state self-proof, which is more robust and engineeringly intelligent than relying on independent electronic sensors.

[0024] A stamping die includes an upper die, a lower die, an upper blank holder and a lower blank holder, and further includes a pair of priority sequence mechanical return mechanisms symmetrically arranged on the outer side of the lower blank holder.

[0025] A mold opening method using a priority sequence mechanical ejection mechanism includes the following sequential steps: Step S1: The mold opens, and the upper mold drives the upper pressing core and the lifting connecting block to move upward; Step S2: After the upper pressure core moves to a predetermined height, the drive unit is triggered to drive the sequential execution unit to move from the disengagement position to the intervention position. Through the mechanical interference between the lifting action part and the lifting connecting block, the upper pressure core is forcibly reset. Step S3: After confirming that the sequential execution unit has reached the intervention position, start the lower mold ejection device to eject the part.

[0026] In step S3, the arrival signal provided by the mechanical status indicator is used to confirm that the sequential execution unit has reached the intervention position.

[0027] The outstanding effects of this invention are: Compared to the closest existing technology (delayed nitrogen cylinder), this invention brings not an improvement, but a systemic advantage resulting from a paradigm shift: this invention brings revolutionary improvement, realizing a paradigm shift from "depending on component performance" to "depending on structural logic": This elevates probabilistic "timing control" to deterministic "sequence enforcement." Through physical intervention and mechanical interlocking logic, the possibility of interference is fundamentally eliminated, and reliability is no longer affected by the environment or wear.

[0028] The mechanism completely disengages during mold closing, without interfering with the molding process; during mold opening, it operates as an independent sequence, with clear functional module boundaries and no mutual interference.

[0029] The failure modes of the mechanism are mostly "failure to move" or "jamming". In this case, the lower mold ejection cannot be started or can be detected immediately, avoiding batch damage caused by hidden failures and ensuring high safety.

[0030] All components are standard mechanical and pneumatic parts, resulting in low cost and easy and quick maintenance and replacement, which significantly reduces the cost of use and maintenance.

[0031] It is easy to integrate mechanical indicators, enabling visualization of operational status and providing a foundation for preventative maintenance and safety interlocks. Attached Figure Description

[0032] Figure 1 This is a partial schematic diagram of the stretching die of the present invention (the lower die ejection module is hidden). Figure 2 This is a schematic diagram of the priority sequence mechanical return mechanism of the present invention; Figure 3 This is a partial cross-sectional view of the stretching die of the present invention; Figure 4 This is a schematic diagram of the opening of the stretching die of the present invention.

[0033] Reference numerals: 10. Priority sequence mechanical jacking mechanism; 1. Drive unit; 2. Sequential execution unit; 21. Lifting action part; 3. Status indication unit; 31. Mechanical status indicator; 32. Micro switch; 33. Triggering protrusion; 4. Lifting connecting block; 41. Lifting action part; 7. Lower mold ejector module; 8. Upper pressure core; 9. Lower pressure core material; 91. Rectangular slide groove. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0035] The following is for reference Figures 1 to 4 The present invention will be described as follows: This embodiment provides a priority sequence mechanical ejection mechanism 10 for a large automotive body panel drawing die. The mechanism is a single, compact mechanical module fixed to the side of the pressure ring of the lower pressure core material 9. It mainly consists of four functional parts: a drive unit 1, a sequence execution unit 2, an ejection connecting block 4, and a status indication unit 3. The mold's PLC control system controls the drive unit, and the components achieve functional linkage through direct mechanical connections or cooperation. Its core lies in using a horizontally moving slider as an "active intervention device" to insert an action at a precise moment during the mold opening process, rigidly and mechanically forcibly changing the state sequence of the upper pressure core material.

[0036] Drive unit 1 uses a hydraulic cylinder, which is horizontally fixed to the lower core material via an L-shaped mounting bracket. The air inlet of the hydraulic cylinder is connected to the independent air circuit of the mold via a quick-connect coupling, and is controlled by the main PLC of the mold. This hydraulic cylinder and its hydraulic circuit system are completely independent of the hydraulic or pneumatic system controlling the lower mold ejection device, thus achieving decoupling of the power source.

[0037] The sequential execution unit 2 is a rectangular steel slider, rigidly connected to the front end of the piston rod of the hydraulic cylinder via a connector such as a spherical joint, ensuring gapless power transmission. The rectangular steel slider is slidably connected within the rectangular groove 91 of the lower pressure core material 9, with its lower part abutting against the bottom surface of the rectangular groove 91. This design forces the rectangular steel slider to move in a strictly horizontal straight line (i.e., the "first direction" described in this invention), laying the foundation for subsequent force direction conversion.

[0038] A high-hardness, high-precision lifting part 21 is machined into the upper part of the rectangular steel slider. In this embodiment, the lifting part is an inclined surface and two arc surfaces connecting the upper and lower ends of the inclined surface. The inclination angle of the inclined surface is calculated to balance the lifting force and the thrust of the hydraulic cylinder. A short horizontal holding surface 22 extends from the end of the upper arc surface.

[0039] A lifting connecting block 4 is vertically fixed to the lower side wall of the upper pressure core 8 by an internal hexagon screw. A hardened lifting action part 41 is machined into the lower part of the lifting connecting block 4. In this embodiment, the lifting action part 41 is also an inclined surface and two arc surfaces connecting the upper and lower ends of the inclined surface, with a short horizontal support surface extending from the end of the lower arc surface. The inclined surface of the lifting action part 41 is parallel to the inclined surface of the rectangular steel slider to ensure surface contact and reduce pressure and wear. The lifting action part 21 and the lifting action part 41 together constitute a pair of curved surface interference pairs that convert horizontal motion into vertical motion.

[0040] The status indicator unit 3 includes a mechanical status indicator 31, a micro switch 32, and a trigger bump 33. The mechanical status indicator 31 is a cylindrical pin inserted into the lower pressure core material 9, with its rear end pre-compressed by a spring, causing its head to retract in the normal state. A standard micro switch 32 signal conversion switch is installed on its side and rear, and the micro switch 32 is electrically connected to the mold's PLC control system. A trigger bump 33 is fastened to the side of the rectangular steel slider. The mechanical status indicator 31 and the rectangular steel slider are directly mechanically linked: when the rectangular steel slider reaches its position, the trigger bump 33 pushes the tail of the mechanical status indicator 31 from the front, forcing it to pop outward against the spring force. The popped-out head forms a conspicuous visual mark, while its tail presses down on the contact of the micro switch 32, activating the micro switch.

[0041] Phase 1: Static separation of mold closing and stamping, functional decoupling. When the mold closes under the drive of the press, the upper mold drives the upper pressure core 8 downward, and finally presses it together with the lower pressure core 9 to stretch and form the sheet material.

[0042] At this critical stage, the hydraulic cylinder of drive unit 1 is in the retracted state, and the rectangular steel slider of drive sequence execution unit 2 moves horizontally to the outermost disengaged position. At this time, the inclined surface and arc surface of the lifting part 21 on the upper part of the rectangular steel slider completely avoid the lifting connecting block 4 fixed to the lower part of the upper pressure core 8 in the horizontal direction. Specifically, the projections of the two in the vertical Z direction do not overlap at all, and there is a clear safety gap.

[0043] Therefore, throughout the entire process of mold closing and bearing enormous molding pressure, this mechanism remains completely outside the force flow. The molding load, reaching hundreds or even thousands of tons, is entirely borne by the closed load-bearing system consisting of the upper mold base, upper pressure core 8, lower pressure core 9, and the mold body. This mechanism is static and unloaded, achieving complete decoupling from the core molding function of the mold, ensuring process stability is not affected by any additional interference. Simultaneously, the mechanical status indicator 31 is in a retracted state under the action of a spring.

[0044] Phase Two: Mold Opening and Active Forced Dynamic Intervention, Executed Sequentially After the stamping is completed, the upper die begins to rise, entering the die opening stage.

[0045] Preparing to create a safety window: The upper mold moves the upper pressure core 8 and the lifting connecting block 4 fixed thereto upwards together. When the lifting action part 41 at the bottom of the lifting connecting block 4, especially the lowest point of its lower arc surface, rises above the lifting action part 21 of the slider, especially the highest point of its upper arc surface, a sufficient "safety window" is formed between them in the vertical direction. At this time, the mold's PLC control system or the position sensor determines that the conditions are ripe and sends an action command to the hydraulic cylinder of the drive unit 1.

[0046] Active intervention in mechanical logic execution: The piston rod of the hydraulic cylinder extends rapidly, pushing the rectangular steel slider towards the lifting connecting block 4 along a strictly horizontal first direction, that is, moving from the disengaged position to the intervention position. The inclined surface of the lifting action part 21 of the rectangular steel slider begins to make rigid contact and slide interference with the inclined surface of the lifting action part 41 of the lifting connecting block 4.

[0047] Forced Return Motion and Force Conversion: As the rectangular steel slider continues to advance horizontally, the interference between the inclined planes converts the horizontal thrust of the hydraulic cylinder into a vertical upward lifting force acting on the lifting connecting block 4 without delay and with certainty. This force forcibly pushes the upper pressure core 8, overcoming its return spring force, causing it to generate additional upward relative motion with respect to the rising upper mold base, until it is completely pushed back to its initial return position inside the upper mold. When the rectangular steel slider moves to the intervention position at the end of its stroke, the lifting connecting block 4 is just lifted to its highest point and is supported and mechanically locked by the horizontal holding surface 22 on the upper part of the rectangular steel slider, thus ensuring that the upper pressure core 8 will not fall back for any reason in subsequent actions.

[0048] Physical evidence generation for status confirmation: As the rectangular steel slider moves to the intervention position, the trigger protrusion 33 on its side pushes the tail end of the mechanical status indicator 31, forcing the indicator pin to pop outward against the spring force. This popping action is a direct and inevitable mechanical consequence of the rectangular steel slider reaching its position. The popped-out indicator pin provides an intuitive visual signal, while its tail triggers the microswitch 32, generating an electrical signal indicating that the mechanism is fully in place.

[0049] Phase 3: Security clearance and unlocking of the ejection logic, safe operation. Only after receiving a confirmation electrical signal from the micro switch 32, i.e., the "mechanical precondition" has been physically confirmed to be met, will the PLC control system of the mold execute the final unlock: sending a start command to the independent lower mold ejection system.

[0050] At this point, since the upper pressure core 8 has been reliably forced back and mechanically locked at its highest point, the molded part has been completely detached from it. The lower mold ejection device, such as an ejector rod or cylinder, can smoothly eject the part from the lower mold cavity in an absolutely interference-free safe space, thus completely eliminating the risk of "butt-locking".

[0051] After ejection is completed, the lower mold ejection device resets. Then, the drive unit 1 retracts, driving the rectangular steel slider back to the disengaged position. The mechanical status indicator 31 retracts under the action of the spring, and the mechanism returns to the standby state, ready for the next work cycle.

[0052] Key Logic Summary and Fault Safety Analysis: The core of this workflow is the "condition-action" chain: the return mechanism completes the action condition → the lower die ejects the permitted action. This is fundamentally different from the delayed nitrogen cylinder solution's "delay time reaches the condition → lower die ejects the action".

[0053] During normal operation, this logic ensures absolute safety.

[0054] In fault scenarios: If the mechanism fails to reach its designated position due to jamming, the indicator will not pop out, the microswitch will not give a signal, and the PLC will determine that the preconditions are not met, prohibiting the ejection and triggering an alarm, thus achieving "failure-safety". Maintenance personnel can quickly locate whether the fault lies in the mechanism itself or the signal switch based on whether the indicator pin pops out, greatly improving maintainability.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications assumed above should also be considered within the scope of protection of the present invention.

Claims

1. A priority sequence mechanical return mechanism, characterized in that, include: A drive unit (1) independent of the mold ejection system is fixedly installed at the outer end of the lower pressure core; A sequential execution unit (2) driven by the drive unit (1) is configured to reciprocate in a first direction different from the mold opening and closing direction under the drive of the drive unit (1); The lifting action part (21) is formed on the upper part of the sequential execution unit (2); And a lifting connection block (4) that is fixedly connected to the upper pressure core; The sequential execution unit (2) has a disengagement position and an intervention position; When in the disengaged position, the lifting action part (21) and the lifting connecting block (4) do not interfere with each other in the mold opening and closing direction; When the driving unit (1) drives the sequential execution unit (2) to move from the disengagement position to the intervention position, the lifting action part (21) and the lifting connecting block (4) mechanically interfere with each other, thereby forcibly resetting the upper pressure core to the inside of the upper mold; The completion of the action of the priority sequence mechanical return mechanism constitutes the mechanical prerequisite for allowing the lower mold ejection system to start.

2. The priority sequence mechanical return mechanism according to claim 1, characterized in that: The first direction is a horizontal direction or a direction that forms an angle of less than 45 degrees with the horizontal direction.

3. The priority sequence mechanical return mechanism according to claim 2, characterized in that: The sequential execution unit (2) is a slider that slides in the horizontal direction, and the drive unit (1) is a horizontally mounted cylinder or hydraulic cylinder.

4. The priority sequence mechanical return mechanism according to claim 1, characterized in that: The lifting action part (21) is an inclined surface, an arc surface, or a curved surface formed by a combination of inclined surface and arc surface on the sequential execution unit (2); The lower part of the lifting connecting block (4) is formed with a lifting action part (41), which is an inclined surface, an arc surface or a curved surface composed of an inclined surface and an arc surface.

5. A priority sequence mechanical return mechanism according to claim 4, characterized in that: When the sequential execution unit (2) is in the intervention position, the lifting action part (21) includes a holding surface (32) for maintaining the reset state of the upper pressure core.

6. The priority sequence mechanical return mechanism according to claim 1, characterized in that: It also includes a mechanical status indicator that is linked to the sequential execution unit (2). When the sequential pressing core execution unit (2) reaches the intervention position, the mechanical status indicator provides a visible or perceptible arrival signal.

7. The priority sequence mechanical return mechanism according to claim 1, characterized in that: During the mold closing and stamping process, the sequential execution unit (2) is in a disengaged position and does not bear or transmit the forming load of the mold.

8. A stamping die, comprising an upper die, a lower die, an upper blank holder, and a lower blank holder, characterized in that, It also includes a pair of priority mechanical return mechanisms as described in any one of claims 1 to 7, symmetrically arranged on the outside of the lower pressure core.

9. A mold opening method using a priority sequence mechanical ejection mechanism, characterized in that, Includes the following sequential steps: Step S1: The mold opens, and the upper mold drives the upper pressing core and the lifting connecting block (4) to move upward; Step S2: After the upper pressing core moves to a predetermined height, the drive unit (1) is triggered to drive the sequential execution unit (2) to move from the disengagement position to the intervention position. Through the mechanical interference between the lifting action part (21) and the lifting connecting block (4), the upper pressing core is forcibly reset. Step S3: After confirming that the sequential execution unit (2) has reached the intervention position, start the lower mold ejection device to eject the part.

10. The method according to claim 9, characterized in that, In step S3, the arrival signal provided by the mechanical status indicator is used to confirm that the sequential execution unit (2) has reached the intervention position.

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