A slurry dipping device and method for a lost wax shell making process

Abstract

A kind of slurry dipping device and method for shell production process of lost-wax casting, including outer cylinder, slurry cylinder and spoiler, the inside of slurry cylinder is also equipped with spoiler, spoiler includes spoiler cylinder cage partially submerged below slurry liquid level, the inside of spoiler cylinder cage has slurry dipping area for accommodating workpiece to be dipped, spoiler cylinder cage is configured to change the flow direction and flow speed of slurry in slurry cylinder in slurry dipping area, so that slurry in slurry dipping area forms multiple beams of different fluid with different directions and speeds to contact workpiece.The present application forms multiple beams of high-energy fluid with different directions and speed distribution by setting spoiler cylinder cage and using its inside different spatial orientation second hole and guide hole under the drive of negative pressure, realizes multi-angle dynamic flushing to complex features such as deep hole and narrow slot of workpiece, effectively eliminates contact blind area, can effectively strip the retained air bubble in the recess of workpiece, ensures that slurry dipping layer is uniform and dense, without blind area and air hole, improves shell quality.

Description

Technical Field

[0001] This invention belongs to the field of casting processing technology, specifically referring to a slurry application device and method for lost-wax casting shell making process. Background Technology

[0002] Investment casting, also known as lost-wax casting, is a crucial forming process for producing high-precision, highly complex metal castings. In its shell-making process, the slurry application stage involves immersing the wax model assembly into a slurry tank containing refractory slurry. This refractory slurry, primarily composed of zircon powder and silica sol, ensures uniform adhesion to the wax model surface. This is followed by sanding and drying. This cycle is repeated multiple times to ultimately form a multi-layered shell with a certain thickness and strength. The uniformity of the slurry application, especially the wetting and complete coverage of the slurry on the wax model surface, directly determines the interlayer bonding strength, surface finish, and the dimensional accuracy and yield of the final casting. Uneven slurry application can easily lead to serious defects such as cracking, bulging, or sparking during subsequent dewaxing or pouring processes.

[0003] Existing slurry dipping devices mainly use a built-in stirring mechanism or turbulence-inducing component in the slurry tank to create a vortex flow of the slurry. Some solutions also improve the dipping effect by driving the module to revolve and rotate within the slurry. However, because the flow pattern of the slurry in the slurry tank is singular, mostly exhibiting an overall vortex or circumferential flow, the contact angle and velocity between the slurry and the workpiece surface are relatively fixed. This makes it difficult to achieve multi-angle and multi-velocity scouring and coverage of workpieces with complex structures such as deep holes, narrow grooves, and corners. In addition, during the dipping process, the slurry easily traps air bubbles in the recesses or dead corners of the workpiece, forming localized slurry blind spots or porosity defects. How to eliminate slurry blind spots in workpieces with complex structures is a technical problem that urgently needs to be solved in this field.

[0004] In addition, although existing slurry-dipping devices have basic adjustable functions such as speed regulation, lifting regulation and negative pressure regulation, most of their execution units are independent open-loop control, lacking a collaborative linkage strategy based on the slurry-dipping process. This results in a narrow process window and poor adaptability to fluctuations in slurry characteristics, making it difficult to meet the higher requirements of intelligent casting for consistency of slurry quality and process adaptability. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the purpose of the present invention is to provide a slurry application device and method for lost-wax casting shell making process, so as to at least partially solve the problems mentioned in the background art.

[0006] The technical solution adopted in this invention is as follows: A slurry application device for lost-wax casting shell-making process is proposed, comprising: The outer cylinder is fixed to the top of the support; The slurry cylinder is coaxially mounted inside the outer cylinder and is driven to rotate about an axis. A baffle plate is installed inside the slurry cylinder to agitate the flow of slurry inside the cylinder, and its height is adjusted by the lifting frame. The slurry cylinder is equipped with a flow disruptor, which includes a flow disruptor cage partially submerged below the slurry surface. The inner side of the flow disruptor cage has a slurry-coating zone for accommodating the workpiece to be coated with slurry. The flow disruptor cage is configured to change the flow direction and flow speed of the slurry in the slurry cylinder within the slurry-coating zone, so that the slurry in the slurry-coating zone forms multiple streams of fluid with different directions and speeds that come into contact with the workpiece.

[0007] Furthermore, the turbulence cage includes hollow guide rings, hollow guide rods, and guide arc plates. Multiple hollow guide rings are arranged vertically, and the multiple hollow guide rings are connected by multiple centrally symmetrical hollow guide rods. The hollow guide rings and hollow guide rods are in communication, and the hollow guide rings and hollow guide rods form a cage structure. The guide arc plates are fixed within a window-shaped structure formed between the hollow guide rings and hollow guide rods.

[0008] Furthermore, the hollow guide ring has a first hole on the outer side of the surface corresponding to the slurry-coating area, and the hollow guide rod has a second hole on the inner side of the surface corresponding to the slurry-coating area. The slurry is drawn in through the first hole and partially discharged from the second hole. The guide arc plate has a guide hole, and the discharge speed of the slurry from the second hole is greater than the speed through the guide hole.

[0009] Furthermore, the first holes are evenly distributed on the hollow guide ring, and the hollow guide rod is provided with guide plates corresponding to the second holes inside. The guide plates are configured to guide the slurry flowing inside the hollow guide rod to flow into the slurry-adhesive area through the hollow guide rod, and the slurry flowing out of the multiple second holes has different flow directions and angles.

[0010] Furthermore, the flow guide plate is configured as a rectangular arc plate, and the guide holes are distributed in a matrix on the flow guide plate, with the multiple guide holes having different flow directions and angles for guiding the slurry.

[0011] Furthermore, the spoiler also includes a guide pipe, one end of which is connected to the spoiler cage and the other end is connected to a negative pressure device to provide negative pressure to the spoiler cage, so that the output speed of the second hole is greater than the output speed of the guide hole. A manifold is fixedly installed at the middle position of the hollow guide ring at the bottom, and the manifold is connected to the hollow guide ring and the guide pipe is connected to the manifold.

[0012] Furthermore, the guide pipe includes a confluence section, a slurry suction section, and a slurry discharge section connected in sequence. The confluence section is connected to the confluence pipe. The slurry suction section is located at the bottom of the slurry cylinder. The slurry discharge section extends vertically upward. The slurry suction section is provided with multiple suction holes. The slurry discharge section is provided with multiple slurry outlet holes, and some of the slurry outlet holes are located above the slurry surface. The multiple slurry outlet holes guide the slurry in different directions.

[0013] Furthermore, a mounting base is fixedly installed on the top of the outer cylinder, and a negative pressure pump is fixedly installed on the mounting base. The negative pressure pump is configured to provide negative pressure to the tail end of the guide pipe, and the negative pressure end of the negative pressure pump is connected to the end of the slurry discharge section.

[0014] A second aspect of the present invention provides a slurry application method for lost-wax casting shell-making process, which utilizes the above-described slurry application apparatus for lost-wax casting shell-making process and includes the following steps: Step 1: Adjust the lifting frame to drive the baffle plate to descend, so that the baffle plate is immersed below the slurry liquid surface in the slurry cylinder, driving the slurry cylinder to rotate around its own axis. At the same time, the baffle plate generates a shearing and blocking effect on the rotating slurry, so that the slurry in the slurry cylinder generates basic circumferential turbulence. Step 2: Start the negative pressure pump to generate negative pressure inside the turbulence cage, and draw the slurry in the slurry cylinder into the turbulence cage through the outer wall of the turbulence cage. The drawn-in slurry is discharged into the slurry-adhesive zone through the second hole of the hollow guide rod and the guide hole of the guide arc plate, forming multiple high-energy fluid bundles with different flow directions and differentiated flow velocities. Step 3: Hoist or clamp the workpiece to be coated with slurry in the slurry-coating zone inside the turbulence cage. During the slurry coating process, continuously adjust the negative pressure of the negative pressure pump to make the flow direction and velocity of the fluid stream in the slurry-coating zone change periodically or intermittently. The slurry flow at different speeds and angles continuously washes the workpiece surface from all directions, eliminating contact blind spots caused by the complex structure of the workpiece, until a uniform slurry layer is attached to the workpiece surface. In step 3, the suction power of the negative pressure pump is controlled so that the flow rate of the slurry discharged from the second hole of the hollow guide rod is greater than that of the slurry discharged from the guide hole of the guide arc plate. The guide plates provided inside the hollow guide rod are used to spray the slurry discharged from the second hole into the workpiece surface in different directions: radially inward, obliquely upward, and obliquely downward. At the same time, some of the slurry outlet holes are located above the slurry surface, and the slurry is sprayed out above the liquid surface through the slurry outlet holes.

[0015] Furthermore, in step 3, the negative pressure pump is controlled to operate in pulse mode, periodically releasing negative pressure during the slurry application process. This causes instantaneous backflow disturbance of the slurry inside the turbulence cage, which removes stagnant air bubbles adhering to the workpiece's depressions or dead corners. The workpiece is also rotated alternately in both directions within the slurry application zone, causing multiple streams of fluid within the slurry application zone to form a cross-directional scouring path on the workpiece surface. This ensures complete coverage of all exposed surfaces of the workpiece, guaranteeing no slurry residue in any blind spots.

[0016] Beneficial effects: This invention utilizes a turbulence-inducing cage and, under negative pressure, its inner second holes and guide holes with different spatial orientations to form multiple high-energy fluid jets with varying directions and velocities within the slurry-coating zone. This enables multi-angle dynamic scouring of complex features such as deep holes and narrow grooves in the workpiece, effectively eliminating contact blind spots. Simultaneously, the differentiated arrangement of guide vanes within the hollow guide rod allows the jet to be sprayed radially, obliquely upward, and obliquely downward in a three-dimensional cross pattern, comprehensively covering all aspects of the workpiece. Combined with the instantaneous backflow disturbance generated by pulsed negative pressure control, it can effectively remove trapped air bubbles in the workpiece's recesses, ensuring a uniform and dense slurry layer without blind spots or pores, thus improving the quality of the mold shell. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a slurry application device for a lost-wax casting shell-making process according to an embodiment of the present invention; Figure 2 This is a top view of a slurry application device for a lost-wax casting shell-making process according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the internal structure of a slurry application device for a lost-wax casting shell-making process according to an embodiment of the present invention. Figure 4 A three-dimensional structural schematic diagram of the spoiler is provided for an embodiment of the present invention; Figure 5 A cross-sectional structural diagram of the spoiler is provided for an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the flow of slurry within a slurry cylinder, as presented in an embodiment of the present invention.

[0018] Among them, 10 is the outer cylinder; 11 is the support; 12 is the mounting base; 20 is the slurry cylinder; 30 is the lifting frame; 31 is the baffle plate; 40 is the baffle; 400 is the slurry-adhesive zone; 401 is the guide hole; 402 is the suction hole; 403 is the slurry outlet hole; 41 is the baffle cage; 411 is the hollow guide ring; 412 is the hollow guide rod; 413 is the guide arc plate; 414 is the manifold; 42 is the guide pipe; 421 is the manifold section; 422 is the slurry suction section; 423 is the slurry discharge section; and 50 is the negative pressure pump.

[0019] The accompanying drawings are provided to further understand the embodiments and form part of the specification. They are used together with the embodiments for explanation and do not constitute a limitation on the embodiments. Detailed Implementation

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

[0021] In the description of the embodiments, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments.

[0022] like Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention provides a slurry dipping device for lost-wax casting shell making process, including an outer cylinder 10, a slurry cylinder 20 and a baffle plate 31.

[0023] The outer cylinder 10 is a cylindrical protective shell with an open top, and its bottom is fixed to the top of the support 11 by a flange or welding. The support 11 is a welded steel frame placed on the workshop floor to support the entire device at a suitable height for worker operation. The slurry cylinder 20 is a thin-walled cylindrical container for holding refractory slurry, with an outer diameter smaller than the inner diameter of the outer cylinder 10. It is coaxially mounted inside the outer cylinder 10 via a slewing bearing at the bottom and a drive shaft. The bottom center of the slurry cylinder 20 is connected to the output shaft of a geared motor mounted on the support 11 via a key, and is driven by the motor to rotate at a constant speed or according to a set speed curve around its own vertical axis. The rotational speed of the slurry cylinder 20 can be adjusted within the range of 5 to 40 rpm according to the viscosity of the slurry.

[0024] Furthermore, the baffle 31 is a long strip of metal plate extending radially along the slurry cylinder 20. The baffle 31 is vertically installed near the inner wall of the slurry cylinder 20, but a 10-20mm gap is left between its outer edge and the cylinder wall to avoid scratching. The top center of the baffle 31 is fixedly connected to the crossbeam of the lifting frame 30. The lifting frame 30 is a support spanning above the outer cylinder 10, and is equipped with an electric push rod or screw nut lifting mechanism, which can drive the baffle 31 to move vertically up and down, thereby adjusting its immersion depth below the slurry surface. When the baffle 31 is immersed in the slurry, its plate surface exerts a shearing and blocking effect on the slurry rotating with the slurry cylinder 20, breaking up the overall circumferential laminar flow of the slurry and forming basic circumferential turbulence, providing a macroscopic flow background for subsequent precise jet turbulence.

[0025] Furthermore, a flow deflector 40 is fixedly installed inside the slurry cylinder 20. The flow deflector 40 is fixed to the inner wall of the outer cylinder 10 by multiple horizontal support rods, or suspended by the top mounting base 12. It does not contact the inner wall or bottom of the slurry cylinder 20, and therefore does not rotate with the slurry cylinder 20. The main body of the flow deflector 40 is a cylindrical or frustoconical flow deflector cage 41. The flow deflector cage 41 is partially submerged below the slurry liquid surface in the vertical direction, and its upper end may be slightly above the liquid surface. The cavity formed by the inner side of the flow deflector cage 41 is the slurry-coating area 400 for accommodating the workpiece to be coated with slurry.

[0026] In some embodiments, the turbulence cage 41 is configured as an element capable of actively changing the flow characteristics of the slurry. It is connected to a negative pressure source through a pipeline and can actively draw in the slurry outside the cage and redirect it through the internal guiding structure. The slurry is then discharged into the slurry-coating zone 400 at a predetermined spatial angle and velocity gradient. This results in the slurry in the slurry-coating zone 400 no longer being a unidirectional vortex, but rather forming multiple bundles of differentiated fluids with different directions and velocities in three-dimensional space. These fluids exert a dynamic impact on the workpiece from the periphery to the center.

[0027] like Figure 4 and Figure 5As shown, in this embodiment, the turbulence cage 41 is specifically composed of three basic components: hollow guide rings 411, hollow guide rods 412, and guide arc plates 413. The hollow guide rings 411 are made of seamless stainless steel tubing and have a closed annular hollow inner cavity. In this embodiment, four hollow guide rings 411 are evenly spaced along the vertical direction. Adjacent hollow guide rings 411 are fixedly connected by six hollow guide rods 412 evenly distributed along the circumference. The hollow guide rods 412 are straight stainless steel tubes, with both ends welded to the outer walls of the upper and lower hollow guide rings 411, respectively. The welded joints have connecting holes, allowing the inner cavities of all hollow guide rings 411 and all hollow guide rods 412 to communicate with each other, forming a hollow cage with a three-dimensional mesh structure. Adjacent hollow guide rings 411 and adjacent hollow guide rods 412 naturally form multiple approximately rectangular windows. In each window, a flow guide arc plate 413 is welded. The flow guide arc plate 413 is an arc plate that is concentrically bent with the hollow flow guide ring 411, and its concave surface faces the slurry-adhesive area 400 inside the cage.

[0028] Further as Figure 5 As shown, the outer wall of the hollow guide ring 411, i.e., the side facing away from the center of the slurry zone 400 and towards the inner cavity of the slurry cylinder 20, has multiple first holes evenly distributed around its circumference (not shown in the figure). These first holes serve as suction inlets, connecting the slurry body inside the slurry cylinder 20 with the inner cavity of the hollow guide ring 411. The inner wall of the hollow guide rod 412, i.e., the side directly facing the center of the slurry zone 400, has multiple second holes distributed along its length. When the negative pressure pump 50 is started, the slurry is drawn into the hollow guide ring 411 through the first holes and flows into the hollow guide rod 412. Some of the slurry is ejected at high speed into the slurry zone 400 through the second holes. Simultaneously, the guide arc plate 413 has multiple guide holes 401 arranged in a matrix. Since the equivalent flow area of ​​the second hole is much smaller than the total flow area of ​​the guide hole 401, and a guide plate with increased resistance is provided at the outlet of the second hole, while the guide hole 401 is a straight hole with very little resistance, the speed at which the slurry is ejected from the second hole is designed to be significantly greater than the speed at which the slurry seeps out of the guide hole 401, thereby obtaining a speed difference.

[0029] More specifically, the diameter of the first orifice is 6-8 mm, and its uniform distribution ensures a balanced suction flow. Inside the hollow guide rod 412, corresponding to the position of each second orifice, a guide vane is welded. This guide vane has different tilt angles relative to the axis of the hollow guide rod 412; for example, the upper guide vane guides the slurry to be sprayed obliquely downwards, the lower guide vane guides the slurry to be sprayed obliquely upwards, and the middle guide vane guides the slurry to be sprayed horizontally radially. This differentiated arrangement ensures that the slurry exiting from multiple second orifices flows in different directions and impact angles in space, forming a three-dimensional, intersecting high-speed jet network. The guide arc plate 413 is a rectangular arc plate, and the guide holes 401 are distributed in a multi-row, multi-column matrix. Due to the change in the curvature of the arc plate surface, the axial direction of each guide hole 401 also changes, allowing the low-speed slurry seeping out to cover large areas at different angles.

[0030] To provide a continuous negative pressure to the aforementioned turbulence cage 41, the turbulence generator 40 also includes a guide pipe 42. One end of the guide pipe 42 is connected to the interior of the turbulence cage 41 via a manifold 414, and the other end is connected to the suction port of the negative pressure pump 50. Specifically, a vertical manifold 414 is welded to the middle of the bottom hollow guide ring 411. The upper end of the manifold 414 is connected to the inner cavity of the bottom hollow guide ring 411, and the lower end extends downward and connects to the confluence section 421 of the guide pipe 42. All the slurry collected by the entire turbulence cage 41 flows into the guide pipe 42 through the manifold 414.

[0031] like Figure 3 , Figure 4 and Figure 5 As shown, the guide pipe 42 includes a confluence section 421, a suction section 422, and a discharge section 423 connected in sequence. The confluence section 421 is horizontally arranged and connected to the confluence pipe 414. The suction section 422 is horizontally laid at the bottom of the slurry cylinder 20 and has multiple downward-facing suction holes 402 for sucking up the high-density slurry settled at the bottom of the cylinder under negative pressure to prevent slurry stratification. The discharge section 423 extends vertically upward from the outer end of the suction section 422, passing through the top opening of the slurry cylinder 20 and the top wall of the outer cylinder 10 in sequence. The wall of the discharge section 423 has multiple discharge holes 403, some of which are significantly higher than the static liquid level inside the slurry cylinder 20. These slurry outlet holes 403 have different opening directions (upward, downward, inclined). When the negative pressure pump 50 is working, some slurry can be sprayed from the slurry outlet holes 403 above the liquid surface to the upper part of the liquid surface, wetting the part of the workpiece on the liquid surface and eliminating foam on the liquid surface.

[0032] A mounting base 12 is welded or bolted to the top of the outer cylinder 10, and a negative pressure pump 50 is fixedly mounted on the mounting base 12. The negative pressure pump 50 is a variable frequency speed-regulating rotary vane vacuum pump, and its suction port is sealed to the top pipe port of the discharge section 423 through a quick-connect coupling. After the negative pressure pump 50 is started, it provides an adjustable negative pressure environment to the entire guide pipe 42 and the interior of the turbulence cage 41.

[0033] As a preferred collaborative control scheme of the present invention, the drive motor of the slurry cylinder 20, the lifting drive component of the lifting frame 30, and the negative pressure pump 50 are all adjustable speed or adjustable stroke actuators. Through the preset linkage adjustment sequence, the rotation speed of the slurry cylinder 20, the immersion depth of the baffle plate 31, and the suction power of the negative pressure pump 50 are coordinated and changed according to the set curve during the slurry application process. Thus, without adding any additional detection components, the dynamic reconstruction and adaptive matching of the fluid bundle morphology in the slurry application zone 400 can be achieved by utilizing the parameter adjustment margin of the existing actuator.

[0034] In actual operation, the rotational speed of the slurry cylinder 20, the height of the lifting frame 30, and the frequency of the negative pressure pump 50 are not adjusted independently, but are coupled together through a preset linkage logic curve. For example, in the initial stage of slurry application, a lower cylinder rotational speed and a higher negative pressure are used to enhance the jet impact force and quickly wet the workpiece surface; as the slurry application time progresses, the negative pressure is gradually reduced while the cylinder rotational speed is increased simultaneously, so that the basic circumferential turbulence generated by the baffle plate 31 is superimposed with the jet field of the baffle cage 41, forming a composite flow field that transitions from strong impact to smooth uniform coating.

[0035] A second aspect of the present invention provides a slurry application method for lost-wax casting shell-making process, which utilizes the above-described slurry application apparatus for lost-wax casting shell-making process and includes the following steps: Step 1: Adjust the lifting frame 30 to drive the baffle 31 to descend, so that the baffle 31 is immersed below the slurry liquid surface in the slurry cylinder 20, driving the slurry cylinder 20 to rotate around its own axis. At the same time, the baffle 31 generates shearing and blocking effects on the rotating slurry, so that the slurry in the slurry cylinder 20 generates basic circumferential turbulence. This basic turbulence enhances the turbulence diffusion coefficient of the entire slurry system, providing favorable conditions for the subsequent jet to propagate further and mix more fully with the surrounding slurry.

[0036] The rotation speed of the slurry cylinder 20 is selected according to the slurry viscosity grade according to the preset gear, and is adjusted in conjunction with the power of the negative pressure pump 50 during the slurry application process to match the slurry application requirements at different stages.

[0037] Step 2: Start the negative pressure pump 50 to generate negative pressure inside the turbulence cage 41. Driven by this pressure difference, a large amount of slurry in the slurry cylinder 20 is rapidly drawn into the hollow mesh cage structure through the first hole on the hollow guide ring 411. The slurry fills the inner cavity of the hollow guide ring 411 and the hollow guide rod 412. When a portion of the slurry flows inside the hollow guide rod 412, it encounters guide plates with different inclination angles, and its flow direction is forcibly changed. It is then ejected at high speed through the second hole towards the slurry-coated area 400. Another portion of the slurry passes through the window between the hollow guide rings 411, is blocked by the guide arc plate 413, and seeps out at low speed in a divergent manner from the guide hole 401. Thus, within the slurry-coated area 400, there is both a high-speed impact jet and a large-area low-speed seepage, forming a high-energy fluid jet composite field with velocity gradient differences and spatial direction differences.

[0038] In this step, by changing the operating frequency of the negative pressure pump 50, the velocity gradient between the jet from the second hole and the seepage from the guide hole 401 can be steplessly adjusted, so that the impact momentum and coating softness can be matched as needed, and the adhesive strength can be intelligently controlled.

[0039] Step 3: The wax model tree workpiece is vertically hoisted using the pneumatic chuck at the top and slowly lowered to the center of the slurry application zone 400 inside the turbulence cage 41, ensuring the workpiece is completely enclosed by the cage and does not contact the cage wall. During the slurry application process, the frequency converter of the negative pressure pump 50 is continuously adjusted according to a preset curve via the PLC controller, for example, with a cycle of 30 seconds. The fluctuation of the negative pressure causes the impact force of the jet in the second hole and the seepage flow rate of the guide hole 401 to change synchronously and periodically, resulting in dynamic switching of the scouring angle and intensity of the fluid jet acting on the workpiece surface. Specifically, when the negative pressure increases, the horizontal radial jet is enhanced, mainly attacking the outer circumferential surface of the workpiece; when the negative pressure decreases, due to the influence of gravity, the oblique jet component is relatively prominent, mainly attacking the upper and lower end faces of the workpiece. This dynamically changing scouring effect can continuously force fresh slurry into the bottom of the deep hole and the sidewall of the narrow groove, displacing the old slurry and air in the dead zone, effectively eliminating the contact blind zone. Continue applying the slurry dynamically for about 60 to 90 seconds, until the workpiece surface is visually inspected and found to be evenly covered with a complete slurry film.

[0040] Throughout the slurry application process, the negative pressure fluctuation cycle of the negative pressure pump 50, the forward and reverse rotation switching sequence of the slurry cylinder 20, and the micro-lifting and micro-lowering actions of the lifting frame 30 are executed in coordination according to the set logic. This enables dynamic interference and complementarity between the basic circumferential flow and the jet composite field. With limited degrees of freedom of the actuator, the multi-modal intelligent switching of the slurry application flow field is achieved, ensuring that the optimal coverage effect can be obtained for workpieces with different structural features.

[0041] During step 3 above, it is essential to ensure that the slurry jet velocity exiting through the second hole of the hollow guide rod 412 is always greater than the slurry seepage velocity exiting through the guide hole 401 of the guide arc plate 413, thereby guaranteeing sufficient impact momentum. Simultaneously, by utilizing the spatial angle difference of the guide plates inside the hollow guide rod 412, it is ensured that the slurry exiting from multiple second holes is continuously sprayed in different directions: radially inward, obliquely upward, and obliquely downward. Furthermore, controlling the suction flow rate of the negative pressure pump 50 ensures that the slurry outlet holes 403 above the liquid surface on the slurry discharge section 423 maintain continuous spraying, forming a slurry curtain covering the liquid surface. When the workpiece is lifted or rotated, this curtain can replenish the slurry on the exposed upper part of the workpiece, preventing the upper coating from thinning due to gravity flow.

[0042] As a preferred embodiment of this method, in addition to step 3 above, the negative pressure pump 50 is further controlled to operate in pulse mode. Specifically, based on continuous negative pressure, every 10 seconds, the pressure is rapidly released for 0.5 seconds via a solenoid valve, causing the negative pressure inside the turbulence cage 41 to disappear instantaneously. At this time, due to inertia and the reverse pressure difference, the slurry inside the cage generates instantaneous backflow disturbance. The shock wave of this backflow acts on the workpiece surface, effectively pulling out and peeling off the tiny air bubbles trapped in the workpiece's cross holes and right-angle corners due to capillary action. Simultaneously, through the clamping device, the workpiece is alternately switched within the slurry-coated zone 400: 5 seconds of forward rotation, 1 second of stillness, and 5 seconds of reverse rotation. The forward and reverse rotation of the workpiece itself causes the jet beam, which was originally spatially fixed, to move relative to the workpiece surface, thereby forming a cross-directional sweeping and scouring path on the workpiece surface. Through the synergistic effect of the bubble peeling by the negative pressure pulse and the sweeping effect of the forward and reverse rotation of the workpiece, it is ensured that all exposed surfaces of the workpiece, especially complex structural areas, are free of any slurry-coated blind spots and air bubble residues, ultimately obtaining a high-quality, uniform slurry coating.

[0043] This invention, without adding any additional sensing and execution hardware, deeply explores the potential for coordinated adjustment among the slurry cylinder rotation speed, the immersion depth of the baffle plate, and the magnitude of negative pressure. This enables the slurry flow field to actively adapt to the process progress, effectively expanding the equipment's adaptability to slurry viscosity fluctuations and workpiece structural differences, reducing the frequency of manual intervention, and providing a low-cost, highly reliable technical solution for integrating the shell-making process of lost-wax casting into intelligent casting production lines. The device dynamically adapts the slurry flow field to the process progress by linking and adjusting the operating parameters of existing actuators, making it suitable for intelligent casting production modes.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] The embodiments have been described above, and such description is not restrictive. The figures shown are only one embodiment, and the actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit, such design should fall within the scope of protection.

Claims

1. A slurry application device for lost-wax casting shell-making process, characterized in that, include: The outer cylinder (10) is fixed to the top of the support (11); The slurry cylinder (20) is coaxially installed inside the outer cylinder (10) and is driven to rotate around the axis; A baffle plate (31) is installed on the inside of the slurry cylinder (20) to agitate the flow of slurry inside the slurry cylinder (20); The lifting frame (30) is configured to drive the drive to adjust the height; The slurry cylinder (20) is also equipped with a flow disruptor (40). The flow disruptor (40) includes a flow disruptor cage (41) that is partially submerged below the slurry surface. The inner side of the flow disruptor cage (41) has a slurry-coating zone (400) for accommodating the workpiece to be coated with slurry. The flow disruptor cage (41) is configured to change the flow direction and flow speed of the slurry in the slurry cylinder (20) in the slurry-coating zone (400), so that the slurry in the slurry-coating zone (400) forms multiple streams of different directions and speeds that come into contact with the workpiece.

2. The slurry application device for lost-wax casting shell-making process according to claim 1, characterized in that: The turbulence cage (41) includes a hollow guide ring (411), a hollow guide rod (412), and a guide arc plate (413). Multiple hollow guide rings (411) are arranged in the vertical direction. Multiple hollow guide rings (411) are connected by multiple centrally symmetrical hollow guide rods (412). The hollow guide rings (411) and hollow guide rods (412) are connected. The hollow guide rings (411) and hollow guide rods (412) form a cage structure. The guide arc plate (413) is fixed in the window-shaped structure formed between the hollow guide rings (411) and hollow guide rods (412).

3. The slurry application device for lost-wax casting shell-making process according to claim 2, characterized in that: The hollow guide ring (411) has a first hole on one side of its outer circumference corresponding to the slurry-coating area (400), and the hollow guide rod (412) has a second hole on one side of its outer circumference corresponding to the slurry-coating area (400). The slurry is drawn in through the first hole and partially discharged through the second hole. The guide arc plate (413) has a guide hole (401). The discharge speed of the slurry from the second hole is greater than the speed through the guide hole (401).

4. The slurry application device for lost-wax casting shell-making process according to claim 3, characterized in that: The first hole is evenly distributed on the hollow guide ring (411). The hollow guide rod (412) is provided with a guide plate corresponding to the second hole. The guide plate is configured to guide the slurry flowing inside the hollow guide rod (412) to flow into the slurry-adhesive area (400) through the hollow guide rod (412). The slurry flowing out of the multiple second holes has different flow directions and angles.

5. The slurry application device for lost-wax casting shell-making process according to claim 3, characterized in that: The flow guide plate (413) is configured as a rectangular arc plate, and the guide holes (401) are distributed in a matrix on the flow guide plate (413). The multiple guide holes (401) guide the slurry in different flow directions and angles.

6. The slurry application device for lost-wax casting shell-making process according to claim 2, characterized in that: The turbulence diffuser (40) also includes a guide pipe (42), one end of which is connected to the turbulence cage (41) and the other end is connected to a negative pressure device to provide negative pressure to the turbulence cage (41) so that the speed of the second hole is greater than the speed of the guide hole (401). A manifold (414) is fixedly installed in the middle position of the hollow guide ring (411) at the bottom. The manifold (414) is connected to the hollow guide ring (411) and the guide pipe (42) is connected to the manifold (414).

7. The slurry application device for lost-wax casting shell-making process according to claim 6, characterized in that: The guide pipe (42) includes a confluence section (421), a slurry suction section (422), and a slurry discharge section (423) connected in sequence. The confluence section (421) is connected to the confluence pipe (414). The slurry suction section (422) is located at the bottom of the slurry cylinder (20). The slurry discharge section (423) extends vertically upward. The slurry suction section (422) is provided with multiple suction holes (402). The slurry discharge section (423) is provided with multiple slurry outlet holes (403). Some of the slurry outlet holes (403) are located above the slurry surface. The multiple slurry outlet holes (403) guide the slurry in different directions.

8. The slurry application device for lost-wax casting shell-making process according to claim 7, characterized in that: A mounting base (12) is fixedly installed on the top of the outer cylinder (10), and a negative pressure pump (50) is fixedly installed on the mounting base (12). The negative pressure pump (50) is configured to provide negative pressure to the tail end of the guide pipe (42), and the negative pressure end of the negative pressure pump (50) is connected to the end of the discharge section (423).

9. A slip application method for lost-wax casting shell making process, characterized in that: The application of the slip-dipping apparatus for lost-wax casting shell-making process according to any one of claims 1 to 8 includes the following steps: Step 1: Adjust the lifting frame (30) to drive the baffle (31) to descend, so that the baffle (31) is immersed below the slurry liquid surface in the slurry cylinder (20), driving the slurry cylinder (20) to rotate around its own axis. At the same time, the baffle (31) generates shearing and blocking effect on the rotating slurry, so that the slurry in the slurry cylinder (20) generates basic circumferential turbulence. Step 2: Start the negative pressure pump (50) to generate negative pressure inside the turbulence cage (41), and draw the slurry in the slurry cylinder (20) into its interior through the outer wall of the turbulence cage (41). The drawn-in slurry is discharged into the slurry-adhesive zone (400) through the second hole of the hollow guide rod (412) and the guide hole (401) of the guide arc plate (413), forming multiple high-energy fluid bundles with different flow directions and differentiated flow velocities. Step 3: Hoist or clamp the workpiece to be coated with slurry in the slurry-coating zone (400) inside the turbulence cage (41). During the slurry coating process, continuously adjust the negative pressure of the negative pressure pump (50) so that the flow direction and velocity of the fluid stream in the slurry-coating zone (400) change periodically or intermittently. Slurry flows at different speeds and angles continuously scour various positions on the surface of the workpiece to eliminate contact blind spots caused by the complex structure of the workpiece until a uniform slurry layer is attached to the surface of the workpiece. In step 3, the suction power of the negative pressure pump (50) is controlled so that the flow rate of the slurry discharged from the second hole of the hollow guide rod (412) is greater than that of the slurry discharged from the guide hole (401) of the guide arc plate (413). The guide plate provided inside the hollow guide rod (412) is used to spray the slurry discharged from the second hole into the workpiece surface in different directions, namely radially inward, obliquely upward and obliquely downward. At the same time, some of the slurry outlet holes (403) are located above the slurry surface, and the slurry is sprayed out above the liquid surface through the slurry outlet holes (403).

10. The slurry application method for lost-wax casting shell making process according to claim 9, characterized in that: In step 3, the negative pressure pump (50) is controlled to work in pulse mode, and the negative pressure is periodically released during the slurry application process, so that the slurry inside the turbulence cage (41) generates instantaneous backflow disturbance, so as to peel off the stagnant air bubbles attached to the depressions or dead corners of the workpiece, and make the workpiece alternately switch forward and reverse in the slurry application zone (400), so as to cause multiple streams of fluid in the slurry application zone (400) to form a cross-directional flushing path on the surface of the workpiece, thereby fully covering all exposed surfaces of the workpiece.

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