Mechanical system for a liquid die casting mold

Abstract

The present application relates to the technical field of liquid die forging, and particularly relates to a mechanical system of a liquid die forging die; comprising: a basic bearing and floating unit for providing installation reference and die closing counterforce of the die system, which comprises a base platform and a floating support mechanism arranged on the base platform, the floating support mechanism is configured to allow the die assembly to produce elastic displacement in the axial direction under pressure state; a vertical main drive forging unit arranged above the basic bearing and floating unit, comprising a main drive oil cylinder and an upper die rigidly connected to the output end of the main drive oil cylinder, through the synergistic effect of a nonlinear time sequence transmission unit and a basic floating bearing unit, the present application realizes absolute mechanical interlocking of "first die closing and locking, then lateral pressurization" by using a single vertical active power source, and completely eliminates the electrical timing risk of the traditional multi-source drive system.

Description

Technical Field

[0001] This invention relates to the field of liquid forging technology, and more specifically to a mechanical system for a liquid forging die. Background Technology

[0002] Liquid forging (also known as squeeze casting) technology has been widely used in the manufacturing of key structural components for aerospace and new energy vehicles because it can eliminate internal porosity and shrinkage in castings and obtain metal parts with properties close to those of forging. For irregularly shaped parts with complex lateral features (such as side holes and undercuts), a die system with lateral core pulling or lateral extrusion functions is usually used.

[0003] However, existing bidirectional or multidirectional liquid forging equipment and die systems still have the following significant technical shortcomings in practical engineering applications: 1. Risk of "Timing Loss" Due to Multi-Source Drives: Existing lateral extrusion typically relies on independent hydraulic cylinder drives, with the sequence of actions entirely determined by the electrical control system and position sensors. In the high-temperature, high-vibration casting environment, sensors are prone to drift or failure, causing the lateral cylinders to actuate prematurely before the main mold is fully closed, or to retract prematurely before the molten metal has solidified. This "soft logic connection" can easily lead to serious "aluminum runaway" accidents or even mold collision damage.

[0004] 2. Rigid Extrusion Leading to "Shrinkage Compensation Failure": Traditional lateral sliders often employ mechanical screws or hydraulic rigid connections. When the molten metal cools and solidifies within the mold cavity and undergoes volume shrinkage, the rigid slider cannot automatically follow up to compensate for the displacement, causing the extrusion head to lose contact with the casting surface, and the effective specific pressure to instantly drop to zero. This makes the laterally thick sections of the casting highly susceptible to secondary shrinkage porosity, failing to meet high airtightness requirements.

[0005] 3. "Parting Surface Overflow" under High Pressure: The specific pressure of liquid forging is typically over 100 MPa. Under such enormous internal pressure, even slight elastic deformation or assembly gaps in the clamping mechanism of traditional molds can cause the parting surface of the moving and fixed dies to "expand." Liquid metal under high pressure will instantly seep into the gap, forming flash, which not only wastes material but, more seriously, can lead to premature erosion and failure of the mold surface.

[0006] In summary, developing a liquid forging die system that can achieve absolute mechanical timing linkage using a single power source, has automatic compensation for solidification shrinkage, and can achieve self-reinforcing sealing using forging pressure is a key technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides a mechanical system for a liquid forging die, comprising: a base bearing and floating unit for providing an installation reference and mold closing reaction force for the die system, comprising a base platform and a floating support mechanism disposed on the base platform, the floating support mechanism being configured to allow the die assembly to generate axial elastic displacement under pressure; a vertical main drive forging unit disposed above the base bearing and floating unit, comprising a main drive cylinder and an upper die rigidly connected to the output end of the main drive cylinder, the upper die being configured to move downward along a vertical axis to close the cavity and apply main forging pressure to the liquid metal; and a cavity receiving and constraining unit disposed on the floating support mechanism and cooperating with the upper die, comprising a lower die base and a lower die fixed within the lower die base, the lower die and the upper die jointly defining a cavity. A forming cavity for accommodating liquid metal; a nonlinear timing drive unit, rigidly fixed to the side of the vertical main drive forging unit and rising and falling synchronously with it, the nonlinear timing drive unit having a drive profile surface extending laterally, the drive profile surface being divided in sequence along the vertical direction into an idle stroke segment parallel to the vertical axis and a force-increasing drive segment inclined relative to the vertical axis; an elastic energy-storing lateral compensation unit, slidably disposed on the side wall of the cavity receiving and constraining unit, its input end abutting against the drive profile surface of the nonlinear timing drive unit, and its output end extending into the forming cavity; the elastic energy-storing lateral compensation unit is configured to: remain stationary under the action of the idle stroke segment, and under the action of the force-increasing drive segment, convert the vertical motion into a lateral flexible extrusion force pointing towards the center of the forming cavity through an internally integrated elastic energy storage element.

[0008] Furthermore, the floating support mechanism specifically includes: a lower fixed base plate rigidly fixed to the base platform; floating load-bearing plates arranged parallel to each other above the lower fixed base plate, on which the lower mold base is mounted; and a high-pressure elastic support assembly evenly distributed between the lower fixed base plate and the floating load-bearing plate, the assembly being composed of a high-pressure nitrogen spring or a high-strength disc spring assembly, used to provide an initial preload force to support the weight of the floating load-bearing plate and the lower mold base.

[0009] Furthermore, the floating support mechanism also includes a precision guide and limiting assembly that vertically penetrates the floating support plate and connects to the lower fixed base plate; wherein the floating support plate is configured to have two position states: in the non-forging state, it is lifted by the high-pressure elastic support assembly and constrained to the upper limit position by the precision guide and limiting assembly; when the main forging pressure is applied and exceeds the initial preload, it overcomes the elastic resistance and sinks axially to the lower limit position, using this sinking displacement to eliminate the gap of the mold parting surface to achieve high-pressure sealing.

[0010] Furthermore, the vertical main drive forging unit further includes: The main drive slider is connected to the piston rod of the main drive cylinder and performs vertical reciprocating motion along the guide column of the frame. The nonlinear timing transmission unit is rigidly installed on the side of the main drive slider through a keyway or bolts. A quick-change connecting seat is provided on the lower surface of the main drive slider.

[0011] Furthermore, the vertical main drive forging unit also includes an upper die core with conformal cooling channels, which is installed via the quick-change connecting seat; wherein, the vertical main drive forging unit also integrates a central mechanical ejection mechanism, which includes an ejector rod passing through the center of the main drive slider and the upper die core, the ejector rod being configured to actuate at the end of the die opening stroke to forcibly peel the solidified workpiece from the surface of the upper die core.

[0012] Furthermore, the cavity receiving and constraining unit adopts a split-type inlay structure, specifically including: A universal lower mold base, the bottom of which is fixed to the floating support plate of the floating support mechanism by bolts, and the side wall of the universal lower mold base is provided with a precision guide window corresponding to the position of the lateral feeding unit; and a detachable molding insert is embedded in the central groove of the universal lower mold base, the inner surface of which defines the bottom and part of the side contour of the casting.

[0013] Furthermore, the sidewall of the detachable molded insert is provided with a lateral extrusion channel that communicates with the precision guide window. The inner wall of the lateral extrusion channel is hardened and ground, and is configured to form a precision sliding seal with the output end of the elastic energy storage lateral compensation unit. The radial clearance of the fit is limited to be less than the critical overflow clearance of the liquid metal under extrusion pressure, so as to establish a physical barrier to the liquid metal in the lateral extrusion channel.

[0014] Further, the nonlinear timing transmission unit specifically includes: a rigid mounting base, fastened to the side of the vertical main drive forging unit by a key or screw, and having a position adjustment function in the vertical direction; and a composite profile timing cam, detachably mounted on the rigid mounting base, with the driving profile surface formed on the side facing the lateral feeding unit; the driving profile surface is continuously and smoothly connected from top to bottom by a straight pressure holding section, a transition arc section, and an oblique pressure boosting section; wherein, the surface of the straight pressure holding section is parallel to the motion axis of the main drive cylinder, and its length corresponds to the main stroke required for the molten metal to fill the cavity after the mold is closed, and is configured to not generate a lateral displacement component when sliding past the lateral feeding unit; the angle between the oblique pressure boosting section and the motion axis of the main drive cylinder is... The angle is 15° to 25°, and it is configured to decompose the vertical clamping force into horizontal extrusion force at the end of the main forging process.

[0015] Furthermore, the elastic energy storage lateral compensation unit adopts a coaxial telescopic sleeve structure, specifically including: an external transmission sliding sleeve, which is slidably installed in the slide groove of the lower mold base, and its tail end is rotatably connected to a follower roller, the follower roller being configured to roll contact with the drive contour surface of the nonlinear timing transmission unit. An internal extrusion punch is coaxially inserted into the inner cavity of the external transmission sleeve and can slide relative to it. Its front end extends out of the external transmission sleeve and enters the lateral extrusion channel. A high-load disc spring assembly is connected in series between the inner bottom surface of the outer transmission sleeve and the tail end face of the inner extrusion punch, for storing and releasing extrusion potential energy.

[0016] Furthermore, the elastic energy storage lateral feeding unit also includes a preload adjusting cover, threaded to the open end of the external transmission sleeve, used to limit the maximum extension displacement of the internal extrusion punch and adjust the initial preload of the high-load disc spring assembly; a vacuum cut-off step is also constructed on the outer circumferential surface of the front end of the internal extrusion punch, which is configured to: preferentially pass over and close the exhaust port in the cavity receiving and constraining unit in the initial stage when the external transmission sleeve is driven to start displacement, and then perform flexible feeding of the liquid metal in the cavity under the thrust of the high-load disc spring assembly.

[0017] Beneficial effects Compared with known public technologies, the technical solution provided by this invention has the following beneficial effects: This invention achieves absolute mechanical interlocking of "first mold closing and locking, then lateral pressure increase" by utilizing a single vertical active force source through the synergistic effect of a nonlinear timing transmission unit and a basic floating bearing unit, completely eliminating the electrical timing risks of traditional multi-source drive systems. At the same time, combined with the "rigid-flexible coupling" mechanism of the elastic energy storage lateral feeding unit, it not only achieves self-reinforcing sealing (zero flash) of the parting surface by floating and sinking using forging pressure, but also uses the stored elastic potential energy to continuously and flexibly feed the volume shrinkage during the metal solidification process. Thus, without the need for a complex control system, it significantly improves the internal density and dimensional accuracy of complex irregular liquid forgings. Attached Figure Description

[0018] Figure 1 This is a system diagram of the present invention.

[0019] Figure 2 This is a front view full sectional structural diagram of the basic support and floating unit of the present invention; Figure 3 This is a schematic diagram of the vertical main drive forging unit structure of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings: Example: This invention provides a mechanical system for a liquid forging die. like Figure 2 As shown, the basic bearing and floating unit is used to provide the installation reference and mold closing reaction force for the mold system. It includes a base platform and a floating support mechanism disposed on the base platform. The floating support mechanism is configured to allow the mold assembly to generate axial elastic displacement under pressure. Furthermore, the operational procedures for the foundation support and floating unit include: The basic support and floating unit 100 constitutes the base of the entire liquid forging system. It not only bears the weight of the mold, but is also a key dynamic link to achieve the "high-pressure self-tightening seal" function. This unit mainly consists of a base platform 110, a lower fixed seat plate 120, a floating support plate 130, a high-pressure elastic support component 140, and a precision guide and limit component 150.

[0023] 1. Structural Layout and Connection Relationship: The base platform 110 is made of high-rigidity cast steel and is anchored to the workshop foundation using anchor bolts. The lower fixed seat plate 120 is horizontally screwed onto the base platform. The floating load-bearing plate 130 is suspended parallel above the lower fixed seat plate 120, forming a variable floating gap between them. For example, 3mm - 5mm.

[0024] In this embodiment, the high-pressure elastic support assembly 140 preferably uses a large-tonnage nitrogen spring, which is evenly distributed in a matrix at the four corners and the center of the floating support plate 130. The cylinder of the nitrogen spring is fixed to the lower fixed base plate, and the plunger end lifts the floating support plate. The precision guide and limit assembly 150 includes four high-precision guide pillars and matching limit bolts, which are used to limit the horizontal degree of freedom of the floating support plate, retaining only the vertical degree of freedom of movement, and setting the upper limit non-working state and the lower limit forged and pressed state of the floating support plate. 2. Floating Working Principle and Mechanical Model The core of this embodiment lies in achieving passive sinking sealing by using the "overflow value" of the main forging pressure through reasonable mechanical parameter settings.

[0025] In the non-working state and at the initial stage of mold closing, the high-pressure elastic support component 140 provides initial preload. The floating support plate 130 is pushed to its upper limit. At this time, the lower mold 320 is in a "high-position waiting state".

[0026] As the vertical main drive forging unit descends, and the upper die contacts the liquid metal and begins to apply pressure, the system forces follow the following mechanical model. To ensure system stability during the filling stage and smooth sinking and sealing during the forging stage, the total preload of the high-pressure elastic support assembly... The following mechanical equilibrium formulas must be satisfied: in, The total weight of the floating support plate and all lower mold components. This refers to the dynamic impact force generated during liquid injection and mold closing. The minimum working pressure set for the main forging cylinder. That is, the sum of the elastic forces of all nitrogen springs.

[0027] 3. Adaptive sealing mechanism: As the main forging pressure continues to increase, the vertically downward clamping force... Exceed At this time, the floating support plate is forced to overcome the resistance of the nitrogen spring and sink downwards until it reaches the lower limit or the mold parting surface is completely in contact. During this process, the effective sealing force acting on the mold parting surface... The expression is: in, This represents the total vertical pressure applied by the main hydraulic cylinder at the current moment. The sliding friction resistance of the guide component.

[0028] This system possesses a self-locking characteristic of "positive pressure correlation". Because... It is approximately a constant value within the short stroke, but changes with the main forging pressure. The rapid increase in pressure enters the Pascal hydraulic transmission stage, effectively sealing the combined force. It will also rise sharply in tandem.

[0029] A vertical main drive forging unit is disposed above the foundation bearing and floating unit, and includes a main drive cylinder and an upper die rigidly connected to the output end of the main drive cylinder. The upper die is configured to move downward along the vertical axis to close the cavity and apply main forging pressure to the liquid metal. Furthermore, the operation process of the vertical main drive forging unit includes: like Figure 3 As shown, the vertical main drive forging unit 200 is the power input end and main forming execution end of this system. It mainly consists of a main drive cylinder 210, a main drive slide block 220, a quick-change connecting seat 230, an upper die core 240 with conformal cooling channels, and a central mechanical ejection mechanism 250. Furthermore, the rigid mounting seat 410 of the nonlinear timing transmission unit 400 is rigidly fixed to both sides of the main drive slide block 220 by a high-strength bolt group 221. Rigid transmission and pressure control model: The main drive cylinder 210 is inverted and mounted on the top of the frame, and its piston rod is connected to the main drive slider 220. Unlike the toggle mechanism of traditional die casting machines, this invention adopts a direct pressure drive to ensure that "compensation pressure" can be applied in the final stage of mold closing.

[0030] During the main forging stage, the upper die core 240 immerses in the liquid metal surface. To ensure a dense internal structure of the casting, sufficient specific pressure must be established before the metal solidifies. The pressure transmission of the system follows the formula: in, The effective specific pressure acting on the projected surface of the casting, The rated output force of the main drive cylinder, This is the pressure transmission efficiency coefficient of the hydraulic system. The frictional resistance of the guide post and the sealing ring. The force loss required to drive the lateral mechanism, This represents the projected area of ​​the casting in the vertical direction.

[0031] 2. Thermodynamic Design of Conformal Cooling: Given that liquid forging involves high-temperature molten metals such as aluminum alloys (650℃-700℃), the thermal fatigue of the upper die core (240mm) is a key factor affecting its lifespan. This embodiment abandons traditional direct drilling cooling and adopts a conformal cooling channel manufactured by 3D printing. To ensure thermal balance during continuous production, the heat exchange area of ​​the cooling channel is... Design based on a variant of Newton's law of cooling: in, The total latent heat and sensible heat released during a single injection of molten metal. For safety reasons, The convective heat transfer coefficient of the cooling medium. The maximum allowable operating temperature of the mold. This refers to the cooling water inlet temperature. This refers to the die-casting cycle time.

[0032] 3. Quick-change and ejection linkage: The quick-change connecting seat 230 adopts a T-slot and hydraulic clamping structure, which reduces the time for changing the upper mold core to less than 15 minutes. The ejector rod of the central mechanical ejection mechanism 250 passes through the center of the mold core.

[0033] Action Logic: When the main drive slider 220 returns upwards, causing the upper mold core to leave the casting, the upper end of the ejector rod is blocked by the fixed stop on the frame, thus moving downwards relative to the upper mold core and forcibly peeling the casting tightly wrapped on the male mold. This purely mechanical action is completely synchronized with the hydraulic return stroke, requiring no additional electrical control, which greatly improves the reliability of the system.

[0034] The cavity receiving and constraining unit is disposed on the floating support mechanism and cooperates with the upper mold. It includes a lower mold base and a lower mold fixed in the lower mold base. The lower mold and the upper mold together define a forming cavity for receiving liquid metal.

[0035] Furthermore, the operation process of the cavity receiving and constraining unit includes: The cavity support and constraint unit adopts a modular "outer bundle and inner support" split structure, which mainly consists of a universal lower mold base, a detachable molding insert and a precision guide window hole on the side wall; 1. Thermodynamic fit design of the insert structure: The detachable forming insert is embedded in the central groove of the universal lower die base. During liquid forging, the forming insert directly contacts the high-temperature molten metal. The universal lower mold base is heated only through heat conduction. There is a huge temperature gradient between the two.

[0036] To prevent the insert from expanding at high temperatures and causing the mold base to crack, or to prevent the insert from loosening due to mold base constraint failure, the assembly clearance / interference in the cold state is set according to the thermoelastic fit formula. : in, The nominal diameter of the mating surface between the insert and the mold base These are the coefficients of thermal expansion for the insert and the mold base, respectively. At room temperature This is to allow for high-pressure elastic compression.

[0037] 2. Critical sealing mechanism of the lateral channel: The precision guide window extends laterally through the die base and the insert. To achieve "flash-free" lateral extrusion, an extremely narrow gap must be maintained between the inner wall of the lateral extrusion channel and the punch of the lateral feeding unit. .

[0038] This embodiment does not aim for zero clearance, but rather, based on fluid mechanics and solidification principles, it considers the fit clearance. Limited to the allowable range of critical overflow thickness: in, This refers to the critical thickness at which liquid metal can penetrate a gap. The surface tension of liquid metal; To moisten the corner, This represents the maximum extrusion pressure.

[0039] It has been theoretically proven that as long as the gap is smaller than... By utilizing the surface tension and rapid solidification characteristics of molten metal, high-temperature resistant liquid-solid dynamic sealing can be achieved without relying on rubber sealing rings.

[0040] For the aluminum alloy A356 working condition, this embodiment controls the single-sided fitting clearance of the lateral channel to 0.03mm - 0.05mm.

[0041] 3. Surface hardening treatment: The inner surface of the lateral extrusion channel is treated with ion nitriding or PVD coating, and the surface hardness reaches HV900 or above.

[0042] A nonlinear timing transmission unit is rigidly fixed to the side of the vertical main drive forging unit and rises and falls synchronously with it. The nonlinear timing transmission unit has a drive profile surface extending to the side, which is divided into an idle stroke segment parallel to the vertical axis and a force-increasing drive segment inclined relative to the vertical axis in sequence along the vertical direction. Furthermore, the operation flow of the nonlinear timing transmission unit includes: The nonlinear timing transmission unit is a "logic converter" connecting the main drive end and the lateral execution end. Its core function is to achieve absolute timing of "first mold closing and locking, then lateral extrusion" through a single power source using purely mechanical means. This unit mainly consists of a rigid mounting base and a compound surface timing cam.

[0043] 1. Kinematic Definition of Mechanical Hysteresis and Timing Control: The driving profile of the compound-surface timing cam is the core feature of this system. To achieve precise "what you see is what you get" timing control, we design the profile as a piecewise function.

[0044] Let the vertical downward displacement of the main drive slider be... Taking the moment of contact with the liquid surface as zero point, the horizontal displacement of the lateral feeding unit is... The length of the cam's idle stroke is The included angle of the inclined booster section is Phase 1 As long as the vertical displacement Less than the preset idle travel No matter how high the pressure of the main hydraulic cylinder is, the lateral displacement is strictly zero.

[0045] Phase Two Once the critical point is crossed, the horizontal movement immediately stops. Proportional linear triggering.

[0046] 2. Calculation of Adjustability of Delay Time: In actual production, castings with different wall thicknesses require different solidification waiting times. This embodiment adjusts the vertical position of the rigid mounting base or replaces different... A cam of varying length is used to precisely control the mechanical delay time. The calculation formula is: in, This is the set downward speed for the die-casting machine during the pressurization phase.

[0047] 3. Optimization of Vector Force Amplification and Self-Locking Angle: In the force amplification drive section, we will optimize the vertical clamping force. Transformed into horizontal extrusion pressure To achieve the maximum extrusion ratio while ensuring mold release, the tilt angle... The selection of [the appropriate component] is crucial.

[0048] For example, it is determined based on force transmission efficiency and self-locking criticality. Scope: And the output force relationship is: in, The static friction coefficient is The coefficient of kinetic friction is . For the target boost coefficient, To prevent jamming safety factor.

[0049] Specific implementation parameters: Taking into account the frictional characteristics of the mold steel, this embodiment selects... Substituting into the formula, we can see that... After deducting frictional losses, the system can amplify the vertical clamping force by approximately 2.8 times and output it to the side.

[0050] Impact smoothing in the transition zone: At the junction of a straight line segment and an oblique line segment, if they intersect directly, the theoretical acceleration abruptly changes to infinity, instantly shattering the roller. Therefore, this embodiment designs a high-order polynomial transition curve at the junction, with a radius of curvature... satisfy: .

[0051] An elastic energy-storing lateral compression unit is slidably disposed on the side wall of the cavity receiving and constraining unit. Its input end abuts against the driving contour surface of the nonlinear timing transmission unit, and its output end extends into the molding cavity. The elastic energy-storing lateral compression unit is configured to remain stationary under the action of the idle stroke section, and under the action of the force-increasing drive section, convert the vertical motion into a lateral flexible extrusion force pointing towards the center of the molding cavity through the internally integrated elastic energy storage element.

[0052] Furthermore, the operation procedure of the elastic energy storage lateral compensation unit includes: The elastic energy storage lateral compensation unit adopts an innovative coaxial telescopic design, integrating the dual functions of a vacuum valve and a compensation pin. It mainly consists of an external transmission sleeve, an internal extrusion punch, a high-load disc spring assembly, a preload adjusting cover, and a tail-end follower roller.

[0053] 1. Structural nesting and degree of freedom analysis: The external transmission sleeve acts as the driving component, making linear reciprocating motion in the mold base slide groove; the internal extrusion punch is coaxially nested in the sleeve, and the two are not rigidly connected, but are connected in series through a high-load disc spring group.

[0054] Relative displacement was introduced When the outer sliding sleeve is pushed forward by the cam At that time, the actual displacement of the internal punch Not necessarily equal Instead, it follows the formula for calculating displacement difference: in, This is the reaction force of the liquid metal on the tip of the punch. This is the equivalent stiffness of the disc spring assembly.

[0055] 2. Constant Pressure Feeding and Energy Release Model: The most challenging problem in liquid forging is the volume shrinkage during metal solidification, which leads to internal shrinkage cavities. This unit utilizes a high-load disc spring assembly as an energy storage device.

[0056] During the extrusion stage, the outer sleeve stops moving after reaching its position, at which point the disc spring assembly is compressed to its maximum energy storage state. As the molten metal cools and contracts, the pressure inside the cavity decreases, and the disc spring assembly releases its potential energy, propelling the internal extrusion punch forward. To eliminate shrinkage cavities, the disc spring assembly provides compensating pressure. It must always be greater than the interdendritic feeding resistance of the metal, and its design is based on the dynamic pressure balance calculation formula: in, To maximize the compression stroke, This refers to the interface retreat velocity caused by metal solidification shrinkage. Let be the cross-sectional area of ​​the punch tip. To prevent the critical pressure threshold caused by micro-shrinkage.

[0057] 3. Vacuum cut-off timing logic: The front end of the internal extrusion punch is equipped with a vacuum cut-off step, which must seal the exhaust channel before the molten metal arrives.

[0058] To ensure the logic holds true, this embodiment specifies the initial preload of the disc spring. A lower limit has been set, requiring the rigid transmission condition to be met. Must meet: in, The dynamic friction force of the punch seal ring. The suction force of the vacuum negative pressure on the punch.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mechanical system for a liquid forging die, characterized in that, include: The basic bearing and floating unit, used to provide the mounting reference and mold closing reaction force for the mold system, includes a base platform and a floating support mechanism disposed on the base platform. The floating support mechanism is configured to allow the mold assembly to generate axial elastic displacement under pressure. A vertical main drive forging unit is disposed above the foundation bearing and floating unit, and includes a main drive cylinder and an upper die rigidly connected to the output end of the main drive cylinder. The upper die is configured to move downward along the vertical axis to close the cavity and apply main forging pressure to the liquid metal. The cavity receiving and constraining unit is disposed on the floating support mechanism and cooperates with the upper mold. It includes a lower mold base and a lower mold fixed in the lower mold base. The lower mold and the upper mold together define a forming cavity for receiving liquid metal. A nonlinear timing transmission unit is rigidly fixed to the side of the vertical main drive forging unit and rises and falls synchronously with it. The nonlinear timing transmission unit has a drive profile surface extending to the side, which is divided into an idle stroke segment parallel to the vertical axis and a force-increasing drive segment inclined relative to the vertical axis in sequence along the vertical direction. An elastic energy-storing lateral compression unit is slidably disposed on the side wall of the cavity receiving and constraining unit. Its input end abuts against the driving contour surface of the nonlinear timing transmission unit, and its output end extends into the molding cavity. The elastic energy-storing lateral compression unit is configured to remain stationary under the action of the idle stroke section, and under the action of the force-increasing drive section, convert the vertical motion into a lateral flexible extrusion force pointing towards the center of the molding cavity through the internally integrated elastic energy storage element.

2. The mechanical system for a liquid forging die according to claim 1, characterized in that, The floating support mechanism specifically includes: a lower fixed base plate rigidly fixed to the base platform; floating load-bearing plates arranged parallel to each other above the lower fixed base plate, on which the lower mold base is mounted; and a high-pressure elastic support assembly evenly distributed between the lower fixed base plate and the floating load-bearing plate. This assembly is composed of high-pressure nitrogen springs or high-strength disc springs and is used to provide an initial preload force to support the weight of the floating load-bearing plate and the lower mold base.

3. The mechanical system for a liquid forging die according to claim 2, characterized in that, The floating support mechanism further includes a precision guide and limiting assembly that vertically penetrates the floating support plate and connects to the lower fixed base plate; wherein, the floating support plate is configured to have two position states: in the non-forging state, it is lifted by the high-pressure elastic support assembly and constrained to the upper limit position by the precision guide and limiting assembly; when the main forging pressure is applied and exceeds the initial preload, it overcomes the elastic resistance and sinks axially to the lower limit position, using this sinking displacement to eliminate the gap of the mold parting surface to achieve high-pressure sealing.

4. The mechanical system for a liquid forging die according to claim 3, characterized in that, The vertical main drive forging unit further includes: The main drive slider is connected to the piston rod of the main drive cylinder and performs vertical reciprocating motion along the guide column of the frame. The nonlinear timing transmission unit is rigidly installed on the side of the main drive slider through a keyway or bolts. A quick-change connecting seat is provided on the lower surface of the main drive slider.

5. The mechanical system for a liquid forging die according to claim 4, characterized in that, The vertical main drive forging unit also includes an upper die core with conformal cooling channels, which is installed via the quick-change connecting seat; wherein, the vertical main drive forging unit also integrates a central mechanical ejection mechanism, which includes an ejector rod passing through the center of the main drive slider and the upper die core, the ejector rod being configured to actuate at the end of the die opening stroke to forcibly peel the solidified workpiece from the surface of the upper die core.

6. The mechanical system for a liquid forging die according to claim 5, characterized in that, The cavity receiving and constraining unit adopts a split-type inlay structure, specifically including: A universal lower mold base, the bottom of which is fixed to the floating support plate of the floating support mechanism by bolts, and the side wall of the universal lower mold base is provided with a precision guide window corresponding to the position of the lateral feeding unit; and a detachable molding insert is embedded in the central groove of the universal lower mold base, the inner surface of which defines the bottom and part of the side contour of the casting.

7. The mechanical system for a liquid forging die according to claim 6, characterized in that, The sidewall of the detachable molded insert is provided with a lateral extrusion channel that communicates with the precision guide window. The inner wall of the lateral extrusion channel is hardened and ground, and is configured to form a precision sliding seal with the output end of the elastic energy storage lateral compensation unit. The radial clearance of the fit is limited to be less than the critical overflow clearance of the liquid metal under extrusion pressure, so as to establish a physical barrier to the liquid metal in the lateral extrusion channel.

8. The mechanical system for a liquid forging die according to claim 7, characterized in that, The nonlinear timing transmission unit specifically includes: A rigid mounting base, fastened to the side of the vertical main drive forging unit by a key or screw, has a vertical position adjustment function; and a composite profile timing cam, detachably mounted on the rigid mounting base, has a drive profile surface formed on its side facing the lateral feeding unit; the drive profile surface is continuously and smoothly connected from top to bottom by a straight pressure holding section, a transition arc section, and an oblique pressure boosting section; wherein, the surface of the straight pressure holding section is parallel to the motion axis of the main drive cylinder, its length corresponds to the main stroke required for the molten metal to fill the cavity after the mold closes, and is configured to not generate a lateral displacement component when sliding past the lateral feeding unit; the angle of the oblique pressure boosting section relative to the motion axis of the main drive cylinder is... The angle is 15° to 25°, and it is configured to decompose the vertical clamping force into horizontal extrusion force at the end of the main forging process.

9. The mechanical system for a liquid forging die according to claim 8, characterized in that, The elastic energy storage lateral compensation unit adopts a coaxial telescopic sleeve structure, specifically including: an external transmission sliding sleeve, which is slidably installed in the slide groove of the lower mold base, and its tail end is rotatably connected to a follower roller, which is configured to make rolling contact with the drive contour surface of the nonlinear timing transmission unit. An internal extrusion punch is coaxially inserted into the inner cavity of the external transmission sleeve and can slide relative to it. Its front end extends out of the external transmission sleeve and enters the lateral extrusion channel. A high-load disc spring assembly is connected in series between the inner bottom surface of the outer transmission sleeve and the tail end face of the inner extrusion punch, for storing and releasing extrusion potential energy.

10. The mechanical system for a liquid forging die according to claim 9, characterized in that, The elastic energy storage lateral feeding unit also includes a preload adjustment cover, which is threaded to the open end of the external transmission sleeve and is used to limit the maximum extension displacement of the internal extrusion punch and adjust the initial preload of the high-load disc spring assembly. The front end outer circumferential surface of the internal extrusion punch is also constructed with a vacuum cut-off step, which is configured to: in the initial stage when the external transmission sleeve is driven to start displacement, preferentially pass over and close the exhaust port in the cavity receiving and restraining unit, and then perform flexible feeding of the liquid metal in the cavity under the thrust of the high-load disc spring assembly.

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