Large casting molding precision positioning closing device and method based on laser measurement

Abstract

The application belongs to the technical field of casting, in particular to a large casting molding precision positioning and closing device and method based on laser measurement, comprising: a frame body; a liftable beam mounted on the frame body; two spacing adjustable clamping arms slidingly mounted along the length direction of the liftable beam; a hanging mechanism fixedly installed in the middle of the liftable beam and having a hook capable of extending and retracting; a guide unit comprising a guide disc rotatably mounted on the frame body, two groups of guide wheels rotatably mounted on the guide disc in the radial direction of the guide disc, a chain of the hook passing through the middle of the two groups of guide wheels, a clamping disc rotatably mounted at the lower end of the clamping arm and matched with a sand box lifting pile, and a transmission wheel coaxially connected with the clamping disc. Through the synergistic effect of the frame body, the liftable beam, the clamping arm, the hanging mechanism and the guide unit, combined with laser measurement and automatic control mechanism, the application realizes the precise positioning and closing operation of the sand box, has the advantages of improving the closing precision, reducing the safety risk and improving the operation efficiency.

Description

Technical Field

[0001] This invention relates to the field of casting technology, and in particular to a device and method for precise positioning and assembly of large castings based on laser measurement. Background Technology

[0002] Resin sand casting, due to its good formability and high casting precision, is widely used in the production of large and medium-sized castings. Molding and box assembly, as the core process of resin sand casting, directly determines the molding quality of the casting. The safety and efficiency of the box assembly operation are also crucial to the overall production process. Currently, in the molding and box assembly operation of large resin sand castings, the leveling and alignment of the upper and lower sand boxes mainly relies on manual operation of a crane. During the operation, workers need to climb high and, through visual observation and manual control, align the positioning recess of the upper sand box with the box assembly positioning pin installed on the lower sand box, and then control the upper sand box to descend and assemble.

[0003] However, large resin sand casting sand boxes are large in volume, weight, and height, making them prone to visual errors when observed manually. The positioning accuracy of manually operated cranes is difficult to control, which can easily lead to positioning deviations and low box assembly accuracy. This not only affects the quality of casting but may also damage the sand box and mold due to inaccurate positioning. At the same time, manual close-range assistance in hoisting and assembling large sand boxes poses high safety hazards, and the labor intensity for workers is high, resulting in low efficiency in box assembly operations. This makes it difficult to meet the automation and intelligent development needs of modern casting production.

[0004] To address the problems existing in the above-mentioned technologies, there is an urgent need to develop a method for molding and positioning large resin sand castings that can achieve automatic leveling and precise positioning, improve the accuracy of mold assembly and operational safety, and reduce labor intensity, so as to meet the requirements of large-scale and intelligent production of large resin sand castings.

[0005] In existing sand box assembly processes, the upper sand box is typically hoisted by a chain with a flipping mechanism at its end. This mechanism allows for controlled flipping of the upper sand box before assembly, ensuring that its positioning recess faces downwards and meets the embedding requirements. However, during the flipping process, the upper sand box's center of gravity shifts significantly, resulting in high inertia and potential hoisting sway and loss of posture control. In particular, when the upper sand box is suspended and requires fine-tuning, traditional chain hoisting systems lack real-time posture feedback and closed-loop correction capabilities. This makes it difficult to stably control the axial coaxiality and radial clearance between the positioning recess and the positioning pin, thereby increasing the assembly embedding resistance and potentially causing localized crushing or pin hole misalignment and jamming of the sand mold.

[0006] Moreover, when the upper sand box is about to overturn the dead point, that is, the center of gravity of the upper sand box shifts instantaneously and the force on the lifting point changes abruptly. The upper part of the upper sand box accelerates from relying on one side of the chain to relying on the other side of the chain, which will cause an instantaneous change in force and dynamic instability. This will cause a sudden increase in the impact load on the lifting point and aggravate the shaking of the upper sand box's posture, which may lead to chain breakage in severe cases. Summary of the Invention

[0007] This invention provides a device and method for precise positioning and box closing of large castings based on laser measurement, which has the advantages of improving box closing accuracy, reducing safety risks, and improving operational efficiency.

[0008] This invention provides the following technical solution: On one hand, the present invention provides a precision positioning and box-closing device for large castings based on laser measurement, comprising: Frame; The liftable beam is installed on the frame; The clamping arms are slidably installed along the length of the lifting beam, with two adjustable clamping arms. The hanging mechanism is fixedly installed in the middle of the liftable beam and has a hook that can extend and retract. The guiding unit includes a guide plate rotatably mounted on the frame. Two sets of guide wheels are rotatably mounted on the guide plate radially. The chain of the hook passes through the middle of the two sets of guide wheels. A clamping plate matching the sand box pile is rotatably mounted on the lower end of the clamping arm. A transmission wheel is coaxially connected to the clamping arm. The transmission wheel is linked to a driven wheel mounted on the clamping arm via a transmission belt. A driving gear is coaxially connected to the driven wheel. The driving gear meshes with a driven gear mounted on the guiding rotating shaft. The driven gear is axially slidably connected to the guiding rotating shaft. An axial limiting structure is provided between the driven gear and the guiding rotating shaft so that the driven gear can only slide axially and cannot rotate relative to it. A limiting component is installed on the clamping arm, and the driven gear is accommodated between the limiting component and the clamping arm.

[0009] Optionally, the frame is a gantry-type rigid structure, with a set of wheels and a locking device at the bottom.

[0010] Optionally, the length direction of the liftable beam is consistent with the length direction of the top beam. A movable part is installed on the top beam of the frame. The movable part can move along the length direction of the top beam. The movable part is equipped with a vertically arranged linear driver. The output end of the linear driver is fixedly connected to the liftable beam.

[0011] Optionally, the liftable beam is provided with slide rails on both sides, and a movable trolley is embedded in the slide rail. The clamping arm is installed at the bottom of the movable trolley. The movable trolley forms a sliding pair with the slide rail through a wheel set. The liftable beam is rotatably mounted with a bidirectional screw along its length. The two ends of the bidirectional screw have opposite directions of rotation and respectively mesh with the nut seats of the movable trolleys on both sides. The bidirectional screw is connected to the output shaft of the rotary driver.

[0012] Optionally, the hanging mechanism is an electric hoist fixed to the middle of the lifting beam.

[0013] Optionally, the guide plate is fixedly connected to the guide rotating shaft, which is mounted on the lower support plate of the liftable beam via a bearing seat, with clamping arms extending from both ends of the guide rotating shaft.

[0014] Optionally, a total of four guide wheels are provided, arranged symmetrically in pairs at both ends of the guide plate. Each pair of guide wheels consists of two symmetrically arranged rollers with parallel and coplanar axes. The distance between the rollers is slightly greater than the thickness of the hook chain, so as to achieve clamping and guiding of the chain.

[0015] Optionally, the clamping disc has a groove structure on the side facing the sand box pile that matches the outline of the sand box pile, and a pressure sensor array is embedded at the bottom of the groove for real-time feedback on the clamping contact status.

[0016] Optionally, the sidewall of the groove is provided with a guide groove along the circumference. The guide groove extends in a spiral shape. The sand box pile is provided with a guide rib that cooperates with the guide groove. The guide rib extends along the axial direction of the sand box pile. When the clamping plate clamps the sand box pile, the clamping plate is guided to rotate through the engagement of the guide rib and the guide groove. This allows the clamping plate to complete the angle alignment synchronously during the clamping process. The rotation of the clamping plate drives the guide rotation shaft to rotate synchronously, thereby driving the initial angle alignment of the guide plate.

[0017] On the other hand, the present invention provides a method for precise positioning and assembly of large castings based on laser measurement. S1. At least three box-closing positioning pins and three box-closing positioning recesses are respectively provided on the top of the lower sand box and the bottom of the upper sand box. Laser reflective stickers are provided at the three box-closing positioning pins and three box-closing positioning recesses. A laser tracker is provided on one side of the frame. S2. The laser measurement system collects the coordinates of the positioning pit on the parting surface of the sand box in real time, calculates its actual posture, compares it with the preset horizontal reference, obtains the leveling deviation value, drives the hanging mechanism to adjust the chain length, corrects the tilt angle of the sand box, until it is completely parallel to the preset horizontal reference, and completes the aerial leveling. S3. Use a laser measuring instrument to perform laser scanning on the three box-closing positioning pins on the sand box placed horizontally on the ground, and collect and obtain the precise three-dimensional positioning coordinates of the three box-closing positioning pins. S4. Use a laser measuring instrument to perform laser scanning on the three box-closing positioning pits on the sand box that is horizontally suspended in the air after the box is flipped, and collect and obtain the precise three-dimensional positioning coordinates of the three box-closing positioning pits. S5. Transmit the two sets of three-dimensional positioning coordinates of the box-closing positioning pin and the box-closing positioning recess obtained in steps S3 and S4 to the control system in real time. S6. The control system calculates the movement path based on the two sets of positioning coordinates received, drives the frame and the lifting beam to move the upper sand box, so that the three box-closing positioning pits of the upper sand box are accurately positioned and aligned with the center line of the three box-closing positioning pins of the lower sand box. S7. The control system controls the upper sand box to slowly descend vertically, so that the three box-closing positioning pins are precisely positioned and embedded into the corresponding box-closing positioning recesses, completing the precise positioning and box-closing of the upper and lower sand boxes, realizing the molding and box-closing operation of large resin sand castings.

[0018] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the invention.

[0019] The beneficial effects of this invention are as follows: Through the coordinated action of the frame, lifting beam, clamping arm, hanging mechanism and guiding unit, combined with laser measurement and automatic control mechanism, the sand box is accurately positioned and closed, which has the advantages of improving the accuracy of closing, reducing safety risks and improving operational efficiency.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is one of the overall structural schematic diagrams of an embodiment of the present invention; Figure 2 This is a second schematic diagram of the overall structure of an embodiment of the present invention; Figure 3 This is one of the three-dimensional structural schematic diagrams of a liftable beam according to an embodiment of the present invention; Figure 4 This is a second three-dimensional structural schematic diagram of a liftable beam according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a guidance unit according to an embodiment of the present invention; Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure at point AA; Figure 7 This is a partial structural schematic diagram of the clamping arm according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a clamping disk according to an embodiment of the present invention; Figure 9 This is one of the structural schematic diagrams of the sand box according to an embodiment of the present invention; Figure 10 This is a second schematic diagram of the structure of the sand box according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of the lower sand box according to an embodiment of the present invention.

[0022] Figure label: 1. Frame; 2. Liftable beam; 3. Clamping arm; 4. Hanging mechanism; 5. Guide unit; 6. Upper sand box; 7. Laser tracker; 8. Lower sand box; 101. Moving wheel assembly; 102. Top beam; 103. Track; 201. Moving part; 202. Linear actuator; 203. Slide rail; 204. Drive wheel; 205. Limiting element; 206. Driven gear; 207. Driving gear; 208. Driven wheel; 209. Drive belt; 210. Clamping plate; 2101, Groove; 2102, Guide groove; 301. Mobile trolley; 302. Rotary actuator; 303. Bidirectional screw; 401. Electric hoist; 402. Chain; 403. Hook; 501. Guide rotation shaft; 502. Guide disk; 503. Guide wheel; 601. Hanging lug; 602. Sand box lifting pile; 603. Guide rib; 604. Closing box positioning recess; 801. Box locating pin. Detailed Implementation

[0023] The technical solutions of 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0028] To better understand the purpose, function, and specific design of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0029] Traditional large-scale casting molding and mold assembly operations mainly rely on manual operation of overhead cranes, which has many limitations. Workers must visually observe and manually operate the upper and lower sand boxes 8 for leveling and alignment, which is prone to visual errors and insufficient operational precision. This results in large positioning deviations and low mold assembly accuracy, which in turn affects the quality of the casting and may even damage the sand box or mold. In addition, manual close-range operation poses safety hazards, is labor-intensive, and inefficient. Especially when the upper sand box 6 is flipped and finely adjusted for alignment, the lack of real-time attitude feedback and closed-loop correction capabilities can easily cause hoisting swaying and attitude loss, making it difficult to control coaxiality and clearance, increasing embedding resistance, and even causing sand mold breakage or pin hole jamming. There is also a risk of sudden increase in impact load on the lifting points, aggravated attitude vibration, and even chain 402 breakage.

[0030] In response, this invention provides a method for precise positioning and assembly of large castings based on laser measurement. like Figures 1-11As shown, it includes a pre-set lower sand box 8, an upper sand box 6, a box closing device, and a laser tracker 7; in the first step, three box closing positioning pins 801 are set on the top parting surface of the lower sand box 8, and three box closing positioning recesses 604 are set on the bottom parting surface of the upper sand box 6, and laser reflective stickers are set at the three box closing positioning pins 801 and the three box closing positioning recesses 604. The locating pin 801 and the locating recess 604 are physical alignment features used for the precise mechanical fit of the upper sand box 6 and the lower sand box 8. They are typically high-precision frustum-shaped locating pins and matching frustum-shaped holes, ensuring a unique and repeatable relative position during closure.

[0031] Laser reflective tags are markers used in laser measurement systems for target identification and coordinate acquisition. They are typically made of highly reflective materials, enabling precise reflection of the laser beam back to the laser tracker 7, thus achieving high-precision three-dimensional coordinate measurement. These reflective tags are usually affixed to specific locations on the box-closing positioning pin 801 and the box-closing positioning recess 604 as measurement reference points. The laser tracker 7 is a high-precision three-dimensional coordinate measurement device that measures the three-dimensional coordinates of a target point in real time by emitting a laser beam and receiving the reflected signal. It has the advantages of high precision, a large measurement range, and non-contact measurement. In this method, it is used to acquire the coordinates of the laser reflective tags on the sand box in real time, providing data support for subsequent attitude calculation and motion control.

[0032] The second step is to perform an aerial flipping and leveling operation on the prepared sand box 6: Specifically, the closing device is moved to the horizontally placed upper sand box 6, and then the position of the lifting beam 2 on the frame 1 is adjusted so that the lifting beam 2 is roughly directly above the upper sand box 6. Then, the lifting beam 2 is driven down to the preset height, and the clamping arms 3 move closer together to clamp the main body parts on both sides of the upper sand box 6 to center the upper sand box 6. After centering, the position of the clamping arms 3 is readjusted so that the clamping disc 210 of the clamping arms 3 is directly opposite the sand box lifting pile 602. Then, the hook 403 is attached to the upper sand box 6. The lug 601 on one side is engaged, and then the clamping arm 3 is driven to clamp. During the clamping process, the guide rib 603 on the sand box pile 602 slides along the guide groove 2102 so that the clamping plate 210 rotates towards the side where the hook 403 is attached, and simultaneously drives the guide plate 502 to rotate in the opposite direction. Finally, the clamping plate 210 presses against the surface of the pile, triggering the built-in pressure sensor to provide real-time feedback of the clamping force. The guide plate 502 deflects at a certain angle towards the direction where the hook 403 is attached, and the angle corresponds to the inclination angle of the guide groove 2102. Then, the lifting beam 2 is driven to rise at a constant speed. After rising to the predetermined height, the hanging mechanism is activated to drive the upper sand box 6 to rotate 180°. After the rotation is completed, the laser measurement system collects the coordinates of the box positioning pit 604 on the parting surface of the upper sand box 6 in real time, calculates its actual posture, compares it with the preset horizontal benchmark, obtains the leveling deviation value, drives the hanging mechanism 4 to adjust the length of the chain 402, corrects the tilt angle of the upper sand box 6 until it is completely parallel to the preset horizontal benchmark, and completes the aerial leveling.

[0033] The third step involves using a laser measuring instrument to perform laser scanning on the three box-joining positioning pins 801 on the lower sand box 8 casting mold placed horizontally on the ground, and collecting and obtaining the precise three-dimensional positioning coordinates of the three box-joining positioning pins 801.

[0034] After the lower sand box 8 mold is placed on the ground and stabilized, a laser measuring instrument is used to scan the three locating pins 801 on it. The scanning process involves illuminating the laser reflective stickers on the locating pins with a laser beam and receiving the reflected signals. The laser measuring instrument converts the scanned data into high-precision three-dimensional coordinate information, which represents the precise spatial position of the locating pins 801 on the lower sand box 8 mold.

[0035] The fourth step involves using a laser measuring instrument to scan the three positioning recesses 604 on the upper sand box 6 mold that is horizontally suspended in the air after the box is flipped, and to collect and obtain the precise three-dimensional positioning coordinates of the three positioning recesses 604.

[0036] After the upper sand mold 6 completes the flipping operation and the second step of aerial leveling, it is in a horizontal suspended state. At this time, a laser measuring instrument is used to scan the three mold-closing positioning recesses 604 (marked by laser reflective stickers) on it. The laser measuring instrument obtains the precise three-dimensional coordinates of the upper sand mold 6 mold's mold-closing positioning recesses 604. These coordinates, together with the coordinates of the positioning pins of the lower sand mold 8 in the third step, constitute all the spatial information required for mold alignment.

[0037] Step 5: Transmit the two sets of three-dimensional positioning coordinates of the box-closing positioning pin 801 and the box-closing positioning recess 604 obtained in steps 3 and 4 to the control system in real time.

[0038] This step ensures that the control system can make decisions and control based on the latest measurement data. The three-dimensional coordinate data of the positioning features of the upper and lower sand boxes, acquired by the laser measuring instrument, are transmitted to the central control system in real-time or near real-time via wired or wireless means. Real-time transmission improves the system's response speed and alignment accuracy. The control system is typically an industrial PC or PLC running specialized motion control and data processing software.

[0039] Step 6: Based on the two sets of positioning coordinates received, the control system calculates the movement path through a motion control algorithm, drives the frame 1 and the lifting beam 2 to move the upper sand box 6 mold, so that the three box-closing positioning recesses 604 of the upper sand box 6 mold are precisely positioned and aligned directly above the center line of the three box-closing positioning pins 801 of the lower sand box 8 mold.

[0040] After receiving the precise three-dimensional coordinates of the positioning features of the upper and lower sand boxes 8, the control system will run a preset motion control algorithm. The goal of the algorithm is to calculate the three-dimensional movement trajectory and attitude adjustment required for the upper sand box 6 to move from its current position to precisely align with the lower sand box 8. This can be achieved through a combination of three types of algorithms: coordinate transformation, error calculation, and path planning.

[0041] For example, a three-point spatial coordinate registration method is used. A local coordinate system is constructed using three non-collinear feature points (positioning pins / dimples). The translation matrix (T) and rotation matrix (R) of the upper sand box 6 coordinate system relative to the lower sand box 8 coordinate system are calculated to obtain the pose deviation. If measurement noise or small deviations of feature points exist, the pose is iteratively optimized using the ICP algorithm until the error is less than a preset threshold (e.g., 0.1 mm), thus obtaining the final pose deviation. Based on the pose deviation, a smooth movement path for the upper sand box 6 from its current position to the target position is planned to avoid swaying / impact: the translation deviation (X / Y / Z) and rotation deviation (α, β, γ) are decomposed into several small steps, and the motion of each axis is executed synchronously at a fixed speed to ensure that the upper sand box 6 translates and rotates smoothly along a straight line; the maximum acceleration / velocity of each axis is limited (e.g., translation speed ≤ 50 mm / s, rotation speed ≤ 0.5° / s) to avoid swaying of the lifting device.

[0042] The control system converts the calculated movement path into control commands for the device's actuators. These commands drive the frame 1 to move horizontally and the lifting beam 2 to move vertically. Through the coordinated movement of the frame 1 and the lifting beam 2, the upper sand box 6 is precisely guided to be directly above the lower sand box 8, ensuring that the center lines of its three locating recesses 604 are perfectly aligned horizontally with the center lines of the corresponding three locating pins 801 on the lower sand box 8.

[0043] Step 7: The control system controls the upper sand box 6 mold to slowly descend vertically, so that the three mold-closing positioning pins 801 are precisely positioned and embedded into the corresponding mold-closing positioning recesses 604, completing the precise positioning and closure of the upper sand box 6 and lower sand box 8 molds, realizing the molding and closure operation of large resin sand castings.

[0044] After the upper sand box 6 mold is horizontally aligned, the control system instructs the lifting beam 2 to slowly descend, causing the upper sand box 6 mold to move vertically downwards at a controlled speed. This slow descent avoids impact and protects the sand box and positioning features. As the upper sand box 6 descends, its bottom positioning recess 604 precisely aligns with the positioning pin 801 on the top of the lower sand box 8 and gradually embeds itself. Thanks to the precise measurement and alignment beforehand, this embedding process is smooth and unobstructed, ensuring the positioning pin is fully inserted into the recess. Once the positioning pin is fully embedded, the upper and lower sand box 8 molds complete the high-precision mold assembly operation, achieving automation and high precision in the molding and assembly of large resin sand castings.

[0045] like Figure 2-4 As shown, this invention proposes a laser-based precision positioning and box-closing device for large castings, comprising: Frame 1; The liftable beam 2 is installed on the frame 1; Clamping arms 3 are slidably installed along the length of the lifting beam 2, with two adjustable clamping arms 3; The hanging mechanism 4 is fixedly installed in the middle of the liftable beam 2 and has a hook that can extend and retract. The guide unit 5 includes a guide plate 502 rotatably mounted on the frame 1. Two sets of guide wheels 503 are rotatably mounted on the guide plate 502 radially. The chain 402 of the hook passes through the middle of the two sets of guide wheels 503. A clamping plate 210 matching the sand box lifting pile 602 is rotatably mounted on the lower end of the clamping arm 3. A transmission wheel 204 is coaxially connected to the clamping plate 210. The transmission wheel 204 is linked to the driven wheel 208 mounted on the clamping arm 3 via a transmission belt 209. A drive gear 207 is coaxially connected to the guide rotating shaft 501. The drive gear 207 meshes with the driven gear 206 mounted on the guide rotating shaft 501. The driven gear 206 is axially slidably connected to the guide rotating shaft 501, and an axial limiting structure is provided between the driven gear 206 and the guide rotating shaft 501 so that the driven gear 206 can only slide axially and cannot rotate relative to it. A limiting member 205 is installed on the clamping arm 3, and the driven gear 206 is accommodated between the limiting member 205 and the clamping arm 3.

[0046] Specifically, the aforementioned frame 1 serves as the supporting skeleton of the entire device, and its structure can take various forms, such as a frame welded from steel structural components, a crane, or a column structure made of castings, to ensure the stability and load-bearing capacity of the device during operation.

[0047] A liftable beam 2 is installed on the frame 1. The liftable beam 2 can be a transverse beam structure, mounted on the column of the frame 1 via guide rails and a slider mechanism. Its vertical lifting movement can be driven by a hydraulic cylinder or a pneumatic cylinder. The piston rod of the hydraulic cylinder or pneumatic cylinder is connected to the liftable beam 2, and the vertical lifting is achieved through fluid pressure.

[0048] Two adjustable clamping arms 3 are slidably installed along the length of the lifting beam 2. These clamping arms 3 can be installed in the groove below the lifting beam 2. The distance adjustment of the clamping arms 3 can be achieved by various linear drive mechanisms, such as a servo motor driven screw and nut pair, a pneumatic push rod, a hydraulic cylinder, etc.

[0049] The lifting mechanism 4 is fixedly installed in the middle of the liftable beam 2 and has a hook that can extend and retract. The lifting mechanism 4 can be a simple winch system, with its motor and drum fixed in the middle of the liftable beam 2. The hook is connected to the drum via a wire rope or chain 402, and the extension and retraction of the hook are achieved by the forward and reverse rotation of the motor.

[0050] The guiding unit 5 includes a guide disc 502 rotatably mounted on the frame 1. The guide disc 502 can be a simple circular disc mounted on the frame 1 via a central bearing seat, allowing it to rotate freely. Two sets of guide wheels 503 are rotatably mounted on the guide disc 502 along its radial direction. The guide wheels 503 can be simple pins with guide wheels 503 mounted on them. The guide wheels 503 can be two simple cylindrical rollers with a spacing slightly larger than the width of the chain 402 to allow the chain 402 to pass through them. The hook chain 402 passes through the middle of the two sets of guide wheels 503, thereby guiding the chain 402.

[0051] A clamping disc 210, matching the sand box lifting pile 602, is rotatably mounted on the lower end of the clamping arm 3. The clamping disc 210 can be a circular disc with a central groove 2101, mounted on the lower end of the clamping arm 3 via bearings, allowing it to rotate freely. The shape of the groove 2101 of the clamping disc 210 can be simply designed as a circular hole that matches the outer contour of the sand box lifting pile 602, facilitating insertion and clamping.

[0052] A drive wheel 204 is coaxially connected to the clamping disc 210. A drive wheel 204, such as a pulley, can be fixed to the shaft of the clamping disc 210. The drive wheel 204 is linked to a driven wheel 208 mounted on the clamping arm 3 via a drive belt 209. The pulley is connected to another pulley (driven wheel 208) mounted on the clamping arm 3 via a V-belt or synchronous belt. A drive gear 207 is coaxially connected to the driven wheel 208. The drive gear 207 meshes with a driven gear 206 mounted on the guide rotating shaft 501, forming a simple gear transmission chain.

[0053] Driven gear 206 is axially slidably connected to guide rotating shaft 501. The inner hole of driven gear 206 can be machined into a splined hole or keyway to mate with the spline or key on guide rotating shaft 501. In this way, driven gear 206 can slide axially on guide rotating shaft 501, but cannot rotate relative to it. An axial limiting structure is provided between driven gear 206 and guide rotating shaft 501 so that driven gear 206 can only slide axially and cannot rotate relative to it.

[0054] For example, in this embodiment, a bar key is provided on the outer side wall of the guide rotating shaft 501 along the axial direction, and a matching bar groove is provided on the inner side wall of the driven gear 206 along the thickness direction. When the driven gear 206 is sleeved on the guide rotating shaft 501, the bar key extends into the bar groove so that the driven gear 206 can slide relative to the guide rotating shaft 501 without relative rotation.

[0055] A limiting member 205 is installed on the clamping arm 3, and the driven gear 206 is accommodated between the limiting member 205 and the clamping arm 3. The limiting member 205 can be a simple U-shaped bracket or cover plate, which is fixed to the clamping arm 3 by bolts. The internal space of the bracket or cover plate is designed to accommodate the driven gear 206, so that when the clamping arm 3 moves axially along the lifting beam 2, it can synchronously drive the driven gear 206 to move together, thereby ensuring that the driven gear 206 can always mesh with the driving gear 207.

[0056] For example, in this embodiment, the limiting member 205 is an L-shaped plate, one end of which is fixedly connected to the clamping arm 3 by bolts, and the other end is provided with a through hole for guiding the rotating shaft 501 to pass through. The driven gear 206 is located between the L-shaped plate and the outer wall of the clamping arm 3.

[0057] In some embodiments, the frame 1 is designed as a gantry-type rigid structure. A gantry-type rigid structure typically consists of two uprights and a crossbeam forming a portal frame. This ensures that it provides sufficient strength and stability when serving as the main support for the entire device.

[0058] Meanwhile, the bottom of the frame 1 is equipped with a set of moving wheels 101 and a locking device. The moving wheels 101 are designed to facilitate convenient movement of the device at the work site. They typically consist of multiple load-bearing wheels, which can be heavy-duty swivel casters or fixed casters, made of wear-resistant, high-load-bearing cast iron to accommodate the weight of large castings and varying ground conditions. The locking device is used to securely fix the device in its predetermined position after it has been moved, preventing accidental movement or shaking during operation. The locking device can be implemented in various ways, including but not limited to ground anchors and ground locks, to fix the device to the ground. These components together ensure that the device can be moved flexibly when needed and remains stable and reliable after being positioned.

[0059] For example, in this embodiment, a crane is used as the frame 1. The crane can move back and forth along a preset track 103 and lock itself after moving to the target position.

[0060] The length direction of the liftable beam 2 is aligned with the length direction of the top beam 102. To enable horizontal movement of the liftable beam 2, a moving part 201 is installed on the top beam 102. The moving part 201 can be a trolley or carriage with a guiding mechanism, for example, by cooperating with the guide rail on the top beam 102 via rollers or sliders to ensure its stability and accuracy during movement. The moving part 201 can move along the length direction of the top beam 102, thereby allowing the liftable beam 2 and the clamping arm 3, hanging mechanism 4, and guiding unit 5 it carries to make a wide range of horizontal displacements. This mobility greatly expands the working area of ​​the device, enabling it to cover different assembly points of large castings.

[0061] Furthermore, a vertically positioned linear actuator 202 is mounted on the moving part 201. The linear actuator 202 is a device capable of directly converting electrical energy or other forms of energy into linear motion; for example, it can be an electric actuator, hydraulic cylinder, or pneumatic cylinder. Its vertical orientation means that its output shaft extends and retracts in the vertical direction, specifically for controlling the vertical position of the lifting beam 2. The output end of the linear actuator 202 is fixedly connected to the lifting beam 2, ensuring that the vertical thrust or pull generated by the actuator can be stably and accurately transmitted to the lifting beam 2, thereby achieving smooth lifting and lowering of the lifting beam 2.

[0062] In this embodiment, the device not only enables precise vertical lifting of the lifting beam 2, but more importantly, through the horizontal movement of the moving part 201 on the top beam 102, the lifting beam 2 gains the ability to move horizontally along the length of the top beam 102. This significantly improves the flexibility and coverage of the device for assembling large castings. Operators can precisely move the upper sand box 6 above any designated position of the lower sand box 8 according to the size of the casting and the assembly requirements, greatly improving the accuracy and efficiency of assembly, reducing the difficulty and labor intensity of manual intervention, and thus effectively solving the problem of limited operating range of traditional devices.

[0063] In some embodiments, such as Figures 3-4 As shown, the liftable beam 2 has slide rails 203 on both sides, and a movable trolley 301 is embedded in the slide rails 203. The clamping arm 3 is installed at the bottom of the movable trolley 301. The movable trolley 301 forms a sliding pair with the slide rails 203 through the wheel set.

[0064] Specifically, the slide 203 is formed by the concave sides of the liftable beam 2. The moving trolley 301 is usually equipped with a roller assembly that cooperates with the slide 203 to achieve low-friction, high-load linear motion.

[0065] The clamping arm 3 is fixed to the bottom of the moving trolley 301 by bolts or other reliable connection methods, so that the movement of the clamping arm 3 is consistent with the movement of the moving trolley 301. At the same time, the liftable beam 2 is rotatably mounted with a bidirectional screw 303 along its length. The two ends of the bidirectional screw 303 have opposite directions of rotation and respectively engage with the nut seats of the two sides of the moving trolley 301. The bidirectional screw 303 is connected to the output shaft of the rotary driver 302.

[0066] The double-ended screw 303 is a special type of screw with opposite thread directions at both ends (e.g., one end is a left-hand thread and the other end is a right-hand thread). The double-ended screw 303 is mounted on the lifting beam 2 via bearings and other support structures, allowing it to rotate freely along its own axis. The nut seat is a component fixed to the moving trolley 301, and its internal threads match those of the double-ended screw 303. When the double-ended screw 303 rotates, due to the opposite thread directions at both ends, the nut seats on both sides (and the moving trolley 301 and clamping arms 3 on them) will move in opposite directions at the same speed, i.e., simultaneously moving closer or further apart.

[0067] The rotary driver 302 can be a servo motor or a stepper motor, connected to the output shaft of the bidirectional screw 303 via a coupling, gear drive, or other transmission mechanism. The rotary driver 302 provides precise rotational power, and by controlling its rotation direction and rotation angle, the rotation of the bidirectional screw 303 can be precisely controlled, thereby achieving precise adjustment of the distance between the two clamping arms 3.

[0068] In this embodiment, when the rotary driver 302 drives the bidirectional screw 303 to rotate, since the two sections of the bidirectional screw 303 rotate in opposite directions, the moving carriages 301 on both sides and the clamping arms 3 mounted on them can move synchronously and at the same speed relative to each other, thereby precisely adjusting the distance between the two clamping arms 3. This ensures the symmetry and accuracy of the clamping arm 3 distance adjustment and avoids synchronization errors and positioning deviations that may be caused by independent driving. It significantly improves the positioning accuracy, operating efficiency, and automation level of the device, and ensures the stability and reliability of the box closing process.

[0069] In some embodiments, such as Figure 4 As shown, the hanging mechanism 4 is specifically an electric hoist 401 fixed in the middle of the liftable beam 2.

[0070] The electric hoist 401 is a common type of electric lifting equipment. Its core components typically include a motor, reducer, brake, and drum or sprocket. It uses a motor to drive the drum or sprocket to rotate, which in turn drives the wire rope or chain 402 to raise or lower heavy objects. The electric hoist 401 features a compact structure, small size, light weight, easy operation, and safe and reliable use. It provides stable vertical lifting power, and its centrally mounted design effectively prevents the lifting beam 2 from tilting or twisting under heavy loads.

[0071] In some embodiments, the guide plate 502 is fixedly connected to the guide rotating shaft 501, which is mounted on the lower support plate of the liftable beam 2 via a bearing seat, and the clamping arms 3 extend from both ends of the guide rotating shaft 501.

[0072] Specifically, the fixed connection between the guide plate 502 and the guide rotation shaft 501 is designed to ensure that the rotational motion is transmitted to the guide plate 502 via the guide rotation shaft 501, achieving precise angle alignment. The guide rotation shaft 501 is mounted on the lower support plate of the liftable beam 2 via a bearing seat, providing stable and low-friction rotational support for the guide rotation shaft 501. Furthermore, the design of clamping arms 3 extending from both ends of the guide rotation shaft 501 ensures that the length of the guide rotation shaft 501 is sufficient to span the distance between the two clamping arms 3, preventing interference from the clamping and releasing actions of the clamping arms 3.

[0073] In this embodiment, it is ensured that when the clamping plate 210 clamps the sand box pile 602, its rotation angle can be accurately transmitted and drive the guide plate 502 to perform initial angle alignment without the need for additional power source or additional control method to adjust the guide plate 502. This greatly simplifies the structural design and control system, and reduces the equipment manufacturing cost and maintenance difficulty.

[0074] In some embodiments, such as Figures 5-6 As shown, there are four guide wheels 503 in total, arranged symmetrically in pairs at both ends of the radial direction of the guide plate 502. Each pair of guide wheels 503 consists of two symmetrically arranged rollers with parallel and coplanar axes. The distance between the rollers is slightly greater than the thickness of the chain 402 of the hook, so as to achieve clamping and guiding of the chain 402.

[0075] Specifically, the four guide wheels 503 work together to provide multi-point support and constraint for the hook chain 402, aiming to provide sufficient contact area and support force to ensure the stability of the chain 402 during movement and prevent unnecessary displacement or swaying in the radial direction of the guide plate 502. They also provide guidance when the upper sand box 6 flips over the dead point. These four guide wheels 503 are organized into two groups, each containing two guide wheels 503, and these two groups of guide wheels 503 are symmetrically arranged at both ends of the guide plate 502. Each group of guide wheels 503 consists of two symmetrically arranged rollers. The symmetrically arranged rollers can clamp the chain 402 from both sides, providing stable support and guidance. Furthermore, the axes of the two rollers in each group are parallel to each other and lie in the same plane. This avoids chain jamming, uneven wear, or guidance failure caused by non-parallel axes or not being in the same plane. At the same time, the spacing between the two rollers in each group is designed to be slightly larger than the thickness of the hook chain 402. The gap allows the chain 402 to pass freely between the rollers while providing sufficient constraint to prevent excessive lateral swaying of the chain 402.

[0076] In this embodiment, four guide wheels 503 are precisely configured and arranged symmetrically in two sets at both ends of the guide plate 502. Each set consists of two parallel and coplanar rollers, and the distance between the rollers is set to be slightly greater than the thickness of the chain 402 of the hook. This refined guide wheel 503 structure can form a stable and precise clamping and guiding of the chain 402 of the hook.

[0077] In some embodiments, such as Figures 7-8 As shown, the clamping disc 210 has a groove 2101 structure that matches the outer contour of the sand box pile 602 on the side facing the sand box pile 602. A pressure sensor array is embedded at the bottom of the groove 2101 to provide real-time feedback on the clamping contact status.

[0078] Specifically, the clamping disc 210 has a groove 2101 structure on the side facing the sand box pile 602, which matches the outer contour of the sand box pile 602. The groove 2101 structure is designed to provide a precise mechanical fit with the sand box pile 602, ensuring that the clamping disc 210 can firmly and without shaking grip the sand box pile 602 during the clamping process. In this embodiment, the groove 2101 structure is a cylindrical groove 2101, and its inner diameter is adapted to the outer diameter of the sand box pile 602.

[0079] Furthermore, a pressure sensor array is embedded in the bottom of the groove 2101. The pressure sensor array consists of multiple independent pressure sensing elements, which can be distributed in a matrix or a specific pattern in the bottom region of the groove 2101. These pressure sensors can be piezoresistive, capacitive, or strain gauge sensors, and they can sense and quantify the local pressure when the clamping disc 210 contacts the sand box pile 602.

[0080] In this embodiment, the groove 2101 structure of the clamping disc 210 can precisely match the outer contour of the sand box lifting pile 602, thereby ensuring stability and positioning accuracy during the clamping process. Simultaneously, the pressure sensor array embedded at the bottom of the groove 2101 can monitor the contact pressure and distribution between the clamping disc 210 and the sand box lifting pile 602 in real time, providing immediate feedback to the control system. This significantly improves the reliability and safety of the box closing operation, ensuring precise positioning of large castings.

[0081] In some embodiments, such as Figure 8 As shown, a guide groove 2102 is provided circumferentially on the side wall of the groove 2101 of the clamping disc 210. The guide groove 2102 extends in a spiral shape. The sand box lifting pile 602 is provided with a guide rib 603 that cooperates with the guide groove 2102. The guide rib 603 extends axially along the sand box lifting pile 602. When the clamping disc 210 clamps the sand box lifting pile 602, the engagement of the guide rib 603 with the guide groove 2102 guides the clamping disc 210 to rotate, so that the clamping disc 210 can synchronously complete the angle alignment during the clamping process. The rotation of the clamping disc 210 drives the guide rotation shaft 501 to rotate synchronously, thereby driving the initial angle alignment of the guide disc 502.

[0082] Specifically, the clamping disc 210 has a groove 2101 structure on the side facing the sand box pile 602, which matches the outer contour of the sand box pile 602. A guide groove 2102 is provided on the inner wall of this groove 2101 along its circumference. The guide groove 2102 is usually machined and its function is to provide a sliding path for the guide ribs 603 on the sand box pile 602, so as to achieve mechanical engagement and relative motion guidance between the two. The guide groove 2102 is not a simple straight groove or annular groove, but extends on the side wall of the groove 2101 in the form of a spiral. The spiral guide groove 2102 can convert the axial movement of the clamping disc 210 (i.e., the direction of movement when clamping the sand box pile 602) into its own rotational movement. The pitch and direction of the spiral determine the speed and direction of rotation of the clamping disc 210 during the clamping process, thereby achieving automatic angle adjustment.

[0083] like Figures 9-10As shown, the sand box hoisting pile 602 is a structure on the sand box used for clamping and hoisting. To mate with the guide groove 2102 on the clamping disc 210, raised ribs, i.e., guide ribs 603, are correspondingly provided on the outer surface of the sand box hoisting pile 602. The shape, size, and position of these guide ribs 603 need to precisely match the guide groove 2102 to ensure smooth entry and sliding along the guide groove 2102 during clamping. The guide ribs 603 extend along the central axis of the sand box hoisting pile 602. When the clamping disc 210 moves downward to clamp the sand box hoisting pile 602, the guide ribs 603 first contact the entrance of the guide groove 2102, and as the clamping disc 210 further descends, the guide ribs 603 slide within the guide groove 2102, thereby generating a rotational torque.

[0084] In this embodiment, when the clamping disc 210 clamps the sand box hoisting pile 602, the clamping disc 210 is guided to rotate by the engagement of the guide rib 603 with the guide groove 2102, so that the clamping disc 210 synchronously completes angle alignment during the clamping process. The clamping disc 210 is coaxially connected to a transmission wheel 204, which is linked to a driven wheel 208 mounted on the clamping arm 3 via a transmission belt 209. The driven wheel 208 is coaxially connected to a driving gear 207, which meshes with a driven gear 206 mounted on the guide rotating shaft 501. Therefore, when the clamping disc 210 rotates during the clamping process due to the cooperation of the guide groove 2102 and the guide rib 603, its rotational motion is synchronously transmitted to the guide rotating shaft 501 through this series of transmission mechanisms, thereby causing the guide disc 502 to also perform corresponding angle adjustments, so that it reaches the preset initial angle alignment state. This significantly improves the automation and efficiency of the box closing operation.

[0085] Specifically, the process of the above-mentioned box-closing device flipping the upper sand box 6 is as follows: First, the equipment is positioned and locked for the first time.

[0086] The box-closing device is moved to the working area of ​​the sand box 6 to be hoisted. The moving wheel set 101 at the bottom of the frame 1 travels along the preset track 103. When the position sensor on the frame 1 detects that the device has reached the preset work position directly above the sand box 6, the signal is transmitted to the control system in real time. The control system immediately sends a start command to the locking device at the bottom of the frame 1. The electric hydraulic lock / ground lock is activated to rigidly lock the frame 1 to the ground foundation, preventing the frame 1 from shifting during subsequent clamping and hoisting, and providing a stable equipment foundation for subsequent operations. After locking is completed, the locking device sends a position signal back to the control system.

[0087] Secondly, the sand box 6 clamping and pressure sensor linkage clamping are completed.

[0088] The control system drives the lifting beam 2 to descend to a preset height, and at the same time starts the rotary driver 302 to drive the bidirectional screw 303 to rotate. The two moving trolleys 301 on both sides move synchronously towards each other along the slide of the lifting beam 2. The clamping arms 3 move closer with the moving trolleys 301 until the clamping plate 210 at the lower end of the clamping arms 3 contacts the main body on both sides of the upper sand box 6 and continues to clamp until the distance between the clamping arms 3 matches the preset size of the main body of the upper sand box 6, thereby completing the centering operation of the upper sand box 6. Then the hook 403 is hung on the lug 601 on the side away from the sand box hoisting pile 602 to be clamped. Subsequently, clamping arm 3 resets and moves to both sides of the upper sand box 6 to lift the pile, until the clamping plate 210 at the lower end of clamping arm 3 is precisely aligned with the upper sand box 6 to lift the pile. After alignment, the moving trolley 301 stops moving. Then, the control system sends a command to the clamping drive assembly of clamping arm 3, driving the clamping plate 210 to move closer to the sand box to lift the pile 602. The groove 2101 of the clamping plate 210 gradually fits into the sand box to lift the pile 602. The guide rib 603 on the sand box to lift the pile 602 engages with the guide groove 2102. As it continues to extend, the guide rib 603 pushes the clamping plate 210 to rotate towards the sand box to lift the pile 602 on the other side. Figures 3-4 - Figure 8 From the perspective of the clamping disc 210, it rotates clockwise (towards the direction shown in the diagram), which synchronously drives the transmission wheel 204 to rotate clockwise. The transmission wheel 204, through the transmission belt 209, synchronously drives the driven wheel 208 to rotate clockwise. The clockwise rotation of the driven wheel 208 synchronously drives the driving gear 207 to rotate clockwise. The clockwise rotation of the driving gear 207 drives the driven gear 206 to rotate counterclockwise. The counterclockwise rotation of the driven gear 206 synchronously drives the guide rotating shaft 501 and the guide disc 502 to rotate counterclockwise, that is, as shown in the diagram. Figure 6 The channel through which the chain 402 passes along the dotted line will gradually deflect from a vertical position toward the side of the hook 601 on which the hook 403 is attached.

[0089] Finally, when the clamping disc 210 completes the clamping action, the pressure sensor array embedded in the bottom of the groove 2101 begins to collect clamping contact pressure data in real time and feeds the data back to the control system at a millisecond frequency. A preset safe clamping pressure threshold and an overload protection threshold are established. When the pressure value collected by any sensing element in the pressure sensor array reaches the safe clamping pressure threshold, the control system determines that the sand box lifting pile 602 has been securely clamped, immediately sends a stop command, the clamping drive assembly stops operating, and the clamping disc 210 locks its current position. If the pressure value exceeds the overload protection threshold, the control system immediately triggers an emergency brake, the clamping drive assembly stops operating, and an audible and visual alarm is issued to prevent damage to the sand box lifting pile 602 or the clamping disc 210 due to overpressure.

[0090] Next, the sand box 6 was hoisted and rotated.

[0091] After the clamping disc 210 completes clamping and the pressure feedback reaches the target, the control system sends a command to the hanging mechanism 4 (electric hoist 401) on the lifting beam 2. The chain 402 of the electric hoist 401 retracts until it is taut. Then, the control system controls the lifting beam 2 to rise, lifting the upper sand box 6 off the ground to the preset flipping height. During this process, the clamping arm 3 remains clamped. After the upper sand box 6 is suspended at the flipping height, the electric hoist 401 continues to retract the chain 402. Under the pulling force of the hook 403, the upper sand box 6 begins to flip around the clamped pile as the rotation center. At this time, the clamping disc 210... A rigid connection is formed between the upper sand box 602 and the sand box pile 602. Therefore, the clamping plate 210 will rotate synchronously, thereby driving the guide rotating shaft 501 and the guide plate 502 to rotate together. By controlling the initial angle of the guide plate 502 to be less than 90 degrees, it is ensured that when the upper sand box 6 is flipped to the vertical position, the channel of the guide plate 502 has deflected to the other side, thereby driving the upper sand box 6 to flip around the pile axis past the dead point. During this process, the upper sand box 6 is always constrained, so there will be no shaking, slippage or loss of attitude of the upper sand box 6 due to inertia or center of gravity shift during the flipping process. After the upper sand box 6 flips past the dead point, the control system controls the electric hoist 401 to release the chain 402. As the chain 402 is gradually released, the upper sand box 6 continues to flip downward under its own weight until the upper sand box 6 flips to a horizontal position. The detection of the upper sand box 6 overturning beyond the dead point can be achieved by a high-precision rotary encoder installed on the shaft of the clamping plate 210 to monitor the rotation angle change in real time. When the encoder feedback angle increment reaches the preset dead point threshold (±0.5°), the control system determines that the overturning has passed the mechanical dead point and simultaneously triggers the release command of the chain 402 of the electric hoist 401. Through the real-time feedback of the rotation angle by the encoder, when the rotation reaches 180°, the motor immediately stops and the brake locks, ensuring that the parting surface of the upper sand box 6 faces downward. Subsequently, aerial leveling is performed. The laser tracker 7 on one side of the frame 1 performs laser scanning on the box-closing positioning recess 604 of the bottom parting surface of the sand box, collects coordinate data and calculates the actual posture of the upper sand box 6, and compares it with the preset horizontal reference to obtain the leveling deviation value. The control system sends a command to the hanging mechanism 4 according to the deviation value to adjust the extension length of the chain 402 of the electric hoist 401 and correct the tilt angle of the upper sand box 6 until the upper sand box 6 is completely parallel to the preset horizontal reference. During the leveling process, the clamping plate 210 always remains in a clamped and locked state.

[0092] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. In the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A precision positioning and box-closing device for large castings based on laser measurement, characterized in that, include: Frame; The liftable beam is installed on the frame; The clamping arms are slidably installed along the length of the lifting beam, with two adjustable clamping arms. The hanging mechanism is fixedly installed in the middle of the liftable beam and has a hook that can extend and retract. The guiding unit includes a guide plate rotatably mounted on the frame. Two sets of guide wheels are rotatably mounted on the guide plate radially. The chain of the hook passes through the middle of the two sets of guide wheels. A clamping plate matching the sand box pile is rotatably mounted on the lower end of the clamping arm. A transmission wheel is coaxially connected to the clamping arm. The transmission wheel is linked to a driven wheel mounted on the clamping arm via a transmission belt. A driving gear is coaxially connected to the driven wheel. The driving gear meshes with a driven gear mounted on the guiding rotating shaft. The driven gear is axially slidably connected to the guiding rotating shaft. An axial limiting structure is provided between the driven gear and the guiding rotating shaft so that the driven gear can only slide axially and cannot rotate relative to it. A limiting component is installed on the clamping arm, and the driven gear is accommodated between the limiting component and the clamping arm.

2. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The frame is a gantry-type rigid structure, and the bottom is equipped with a set of moving wheels and a locking device.

3. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The length direction of the liftable beam is consistent with the length direction of the top beam. A movable part is installed on the top beam, which can move along the length direction of the top beam. The movable part is equipped with a vertically arranged linear actuator, and the output end of the linear actuator is fixedly connected to the liftable beam.

4. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The liftable beam has slides on both sides, and a movable trolley is embedded in the slide. The clamping arm is installed at the bottom of the movable trolley. The movable trolley forms a sliding pair with the slide through the wheel set. The liftable beam is rotatably mounted with a bidirectional screw along its length. The two ends of the bidirectional screw have opposite directions of rotation and respectively mesh with the nut seats of the movable trolleys on both sides. The bidirectional screw is connected to the output shaft of the rotary driver.

5. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The hoisting mechanism consists of an electric hoist, a matching chain, and a hook fixed to the middle of the lifting beam.

6. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The guide plate is fixedly connected to the guide rotating shaft, which is mounted on the lower support plate of the liftable beam through a bearing seat. Clamping arms extend from both ends of the guide rotating shaft.

7. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, There are four guide wheels in total, arranged symmetrically in pairs at both ends of the guide plate. Each pair of guide wheels consists of two symmetrically arranged rollers with parallel and coplanar axes. The distance between the rollers is slightly greater than the thickness of the hook chain to achieve clamping and guiding of the chain.

8. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The clamping disc has a groove structure on the side facing the sand box pile that matches the outline of the sand box pile. A pressure sensor array is embedded at the bottom of the groove to provide real-time feedback on the clamping contact status.

9. The laser-based precision positioning and box-closing device for large castings as described in claim 1, characterized in that, The groove sidewall is provided with a guide groove along the circumference. The guide groove extends in a spiral shape. The sand box pile is provided with a guide rib that cooperates with the guide groove. The guide rib extends along the axial direction of the sand box pile. When the clamping plate clamps the sand box pile, the clamping plate is guided to rotate through the engagement of the guide rib and the guide groove. This allows the clamping plate to complete the angle alignment synchronously during the clamping process. The rotation of the clamping plate drives the guide rotation shaft to rotate synchronously, thereby driving the initial angle alignment of the guide plate.

10. A method for precise positioning and assembly of large castings based on laser measurement, using the precise positioning and assembly device for large castings based on laser measurement as described in any one of claims 1-9, characterized in that: S1. At least three box-closing positioning pins and three box-closing positioning recesses are respectively provided on the top of the lower sand box and the bottom of the upper sand box. Laser reflective stickers are provided at the three box-closing positioning pins and three box-closing positioning recesses. A laser tracker is provided on one side of the frame. S2. The laser measurement system collects the coordinates of the positioning pit on the parting surface of the sand box in real time, calculates its actual posture, compares it with the preset horizontal reference, obtains the leveling deviation value, drives the hanging mechanism to adjust the chain length, corrects the tilt angle of the sand box, until it is completely parallel to the preset horizontal reference, and completes the aerial leveling. S3. Use a laser measuring instrument to perform laser scanning on the three box-closing positioning pins on the sand box placed horizontally on the ground, and collect and obtain the precise three-dimensional positioning coordinates of the three box-closing positioning pins. S4. Use a laser measuring instrument to perform laser scanning on the three box-closing positioning pits on the sand box that is horizontally suspended in the air after the box is flipped, and collect and obtain the precise three-dimensional positioning coordinates of the three box-closing positioning pits. S5. Transmit the two sets of three-dimensional positioning coordinates of the box-closing positioning pin and the box-closing positioning recess obtained in steps S3 and S4 to the control system in real time. S6. The control system calculates the movement path based on the two sets of positioning coordinates received, drives the frame and the lifting beam to move the upper sand box, so that the three box-closing positioning pits of the upper sand box are accurately positioned and aligned with the center line of the three box-closing positioning pins of the lower sand box. S7. The control system controls the upper sand box to slowly descend vertically, so that the three box-closing positioning pins are precisely positioned and embedded into the corresponding box-closing positioning recesses, completing the precise positioning and box-closing of the upper and lower sand boxes, realizing the molding and box-closing operation of large resin sand castings.

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