A full-automatic film-coated sand mold shell line uses a shell grabbing robot

Abstract

The application relates to the technical field of mechanical hand equipment, and discloses a full-automatic film-coated sand mold shell line shell grabbing robot, which comprises a mechanical hand, a positioning frame installed at the tail end of the mechanical hand, two clamping jaw assemblies movably installed on the positioning frame, servo air cylinders fixedly installed on the positioning frame and used for driving the two clamping jaw assemblies to move, and a visual detection assembly. The visual detection assembly comprises a first camera fixedly installed at the middle of the bottom end of the positioning frame and a second camera installed at the bottom end of the two clamping jaw assemblies. The image of the film-coated sand mold shell is collected, the position and posture of the film-coated sand mold shell are recognized and positioned, the clamping jaw assemblies are driven by the respective mechanical hands to move to a grabbing position according to the positioning result, the two clamping jaw assemblies embrace the film-coated sand mold shell, the film-coated sand mold shell is ensured to be clamped on the outside of the film-coated sand mold shell, the servo air cylinders are controlled to drive the two clamping jaw assemblies to move towards each other to grab the film-coated sand mold shell, and the film-coated sand mold shell can be accurately grabbed.

Description

Technical Field

[0001] This application relates to the field of robotic arm equipment technology, and in particular to a fully automatic shell-grabbing robot for coated sand mold shell lines. Background Technology

[0002] Coated sand mold shells are thin-shell-shaped molds or sand cores formed by heating and curing coated sand (sand grains pre-coated with resin film). This process combines the high precision of precision casting with the flexibility of sand casting and is widely used in the production of small and medium-sized castings such as automobiles, motorcycles, internal combustion engines, valves and hardware.

[0003] However, existing gripping robots have difficulty in accurately positioning and grasping, and because the coated sand mold shell is a thin-walled brittle structure composed of resin-bonded sand particles, its tensile and bending strength is much lower than that of metal or plastic parts. When existing robotic arms grasp the coated sand mold shell, they are prone to causing the coated sand shell to crack and the rigid clamping tool to leave gaps at some points. If force sensors are equipped to monitor the bearing force and stop or retract immediately once abnormal resistance (such as jamming) is detected to prevent damage to the coated sand mold shell, the cost would be high. Summary of the Invention

[0004] This application proposes a fully automated shell-grabbing robot for coated sand mold shell lines, in order to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, this application adopts the following technical solution: a fully automated shell-grinding robot for coated sand molds, comprising:

[0006] A robotic arm, and a positioning frame installed at the end of the robotic arm, wherein two gripper assemblies are movably mounted on the positioning frame, and servo cylinders that drive the two gripper assemblies to move are fixedly mounted on the positioning frame.

[0007] The visual inspection component includes a first camera fixedly mounted at the bottom center of the positioning frame, and a second camera mounted on both sides of the bottom of the two gripper assemblies.

[0008] The control unit is communicatively connected to the robotic arm, servo cylinder, and vision inspection component. The vision inspection component identifies and locates the position of the coated sand mold shell. The control unit controls the robotic arm to drive the two gripper assemblies to move to the outside of the coated sand mold shell, and then controls the servo cylinder to drive the two gripper assemblies to move towards each other to grasp the coated sand mold shell.

[0009] Furthermore, the gripper assembly includes an arc-shaped shell. Several equidistantly arranged lower and upper rotating blocks are movably sleeved at the top and bottom ends of the arc-shaped shell, respectively. The lower rotating blocks are located directly below the upper rotating blocks. The lower and upper rotating blocks are movably sleeved with the arc-shaped shell via bearings, facilitating their rotation relative to the arc-shaped shell. A through-slot of the same size is provided in the middle of the lower and upper rotating blocks. A clamping band is movably sleeved between the through-slots of the lower and upper rotating blocks. A positioning cylinder is fixedly installed at the top of the upper rotating block. A piston is movably sleeved inside the positioning cylinder. The top of the clamping band extends into the interior of the positioning cylinder and is fixedly connected to the bottom of the piston. Above the piston is a negative pressure chamber. The specific negative pressure value is determined based on the weight of the coated sand mold shell to be gripped, ensuring that the negative pressure allows the clamping bands on the two arc-shaped shells to adhere to the surface of the coated sand mold shell, enabling the gripping and movement of the coated sand mold shell. A second camera is fixedly installed at both ends of the bottom of the arc-shaped shell.

[0010] Furthermore, the openings of the through grooves are all designed with smooth chamfers. After the clamping band is attached to the coated sand mold shell, the surface of the clamping band fits into the chamfer of the through groove opening, thus preventing the clamping band from being excessively worn.

[0011] Furthermore, the clamping band is made of high-temperature resistant silicone material, which completely covers the temperature of the coated sand mold shell, and is soft and has good cushioning properties.

[0012] Furthermore, the bottom end of the clamping band is fixedly connected to a limiting shaft located below the lower rotating block. The outer diameter of the limiting shaft is greater than the width of the through groove of the lower rotating block. The lower rotating block limits the clamping band above the limiting shaft, preventing the bottom end of the clamping band from separating from the lower rotating block.

[0013] Furthermore, a sealing ring is fixedly fitted at the bottom of the arc-shaped shell above the lower rotating block. The inner side of the sealing ring is movably fitted with the outer side of the lower rotating block. The sealing ring seals the gap between the lower rotating block and the arc-shaped shell, preventing impurities from falling into the bearing in the gap and affecting the rotation of the lower rotating block relative to the arc-shaped shell.

[0014] Furthermore, the top of the positioning cylinder is connected to a three-way pipe, and two adjacent three-way pipes are connected to each other through an air guide pipe. One end of one of the outermost three-way pipes is connected to a one-way air outlet valve, and one end of the other outermost three-way pipe is fixedly fitted with a sealing plug. By drawing negative pressure into the inner cavity of the positioning cylinder at one end of the one-way air outlet valve, the air guide pipe connects the negative pressure chambers in each positioning cylinder on an arc-shaped shell. Based on the weight of the coated sand mold shell that needs to be grasped, negative pressure is drawn into the negative pressure chamber at one end of the one-way air outlet valve using a negative pressure drawing device.

[0015] Furthermore, tension springs are connected to both sides of the lower rotating block and the upper rotating block respectively. The end of the tension spring away from the upper rotating block is fixedly connected to the arc-shaped shell. By connecting tension springs to both sides of the lower rotating block and the upper rotating block respectively, the various clamping bands are kept in a flush state on the same plane under normal conditions. When controlling the two arc-shaped shells to move towards each other to grasp the coated sand mold shell, it is beneficial for the surface of the clamping band to adhere to the outer side of the coated sand mold shell.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. This application provides a fully automatic shell gripping robot for coated sand mold shell production lines. By acquiring images of coated sand mold shells, the robot identifies and locates the position and orientation of the coated sand mold shells. Based on the positioning results, each robotic arm drives the gripper assembly to move to the gripping position, so that the two gripper assemblies surround the coated sand mold shell, ensuring that the gripper is located on the outside of the coated sand mold shell. Then, the robot controls the servo cylinder to drive the two gripper assemblies to move towards each other to grip the coated sand mold shell, which facilitates precise gripping of the coated sand mold shell.

[0018] 2. By setting several equidistant clamping straps on two arc-shaped shells, and cooperating with the negative pressure suction of the positioning cylinder on the piston, the clamping straps tend to be straightened. When the two arc-shaped shells grip the coated sand mold shell, multiple clamping straps adhere to the surface of the coated sand mold shell. The negative pressure suction pulls the clamping straps to buffer and clamp the coated sand mold shell. Compared with existing gripping equipment, the soft gripping method can stably grip coated sand mold shells of different shapes. It also avoids the problem that existing clamps are prone to cracking brittle coated sand mold shells due to stress concentration when gripping coated sand mold shells, as well as the problem of some points being left empty by hard clamps. In addition, there is no need to add force sensors, saving costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the connection structure between the two robotic arms in the diagram;

[0022] Figure 3 for Figure 2 The front view;

[0023] Figure 4 for Figure 2A schematic diagram of the structure of one of the robotic arms;

[0024] Figure 5 for Figure 4 A schematic diagram of the middle section structure;

[0025] Figure 6 for Figure 4 The right view;

[0026] Figure 7 for Figure 5 A magnified schematic diagram of the structure at point A;

[0027] Figure 8 for Figure 5 A magnified schematic diagram of the structure at point B;

[0028] Figure 9 for Figure 6 A magnified schematic diagram of the structure at point C.

[0029] In the diagram: 1. Robotic arm; 2. Positioning frame; 3. Gripper assembly; 301. Arc-shaped shell; 302. Sliding block; 303. Passive plate; 304. Lower rotating block; 305. Upper rotating block; 306. Gripping belt; 307. Limiting shaft; 308. Positioning cylinder; 309. Piston; 310. T-connector; 311. Air guide pipe; 312. One-way air outlet valve; 313. Sealing plug; 314. Sealing ring; 315. Tension spring; 4. Servo cylinder; 5. First camera; 6. Second camera. Detailed Implementation

[0030] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Examples, such as Figures 1-4A fully automatic shell-grinding robot for coated sand mold shell lines includes a robotic arm 1. A positioning frame 2 is rotatably connected to the end of the robotic arm 1. Two gripper assemblies 3 are movably mounted on the positioning frame 2, and servo cylinders 4 are fixedly installed on the positioning frame 2 to drive the movement of the two gripper assemblies 3. Each gripper assembly 3 includes an arc-shaped shell 301. Sliding blocks 302 are fixedly mounted at both ends of the top of the arc-shaped shell 301. The outer sides of the two sliding blocks 302 have protrusions, and these protrusions are movably connected to a slide rail opened inside the positioning frame 2. A passive plate 303 located on one side of the sliding blocks 302 is fixedly mounted on the top of the arc-shaped shell 301. The passive plate 303 is fixedly connected to one end of the piston shaft of the servo cylinder 4. The servo cylinder 4 drives the piston shaft to move the passive plate 303. Combined with the sliding block 302's movement within the slide rail inside the positioning frame 2, the two arc-shaped shells 301 can be controlled to move towards or away from each other.

[0032] like Figures 4-8 The top and bottom ends of the arc-shaped shell 301 are respectively movably fitted with a number of equidistantly arranged lower rotating blocks 304 and upper rotating blocks 305. The lower rotating blocks 304 are located directly below the upper rotating blocks 305, and there are at least two lower rotating blocks 304 and upper rotating blocks 305. The lower rotating blocks 304 and upper rotating blocks 305 are movably fitted to the arc-shaped shell 301 through bearings, which facilitates the rotation of the lower rotating blocks 304 and upper rotating blocks 305 relative to the arc-shaped shell 301. The moving block 305 has a through groove of the same size in the middle, and the groove openings are all designed with smooth chamfers. The lower rotating block 304 and the upper rotating block 305 are fitted with a clamping strap 306 in the through groove. The bottom end of the clamping strap 306 is fixedly connected to a limiting shaft 307 located below the lower rotating block 304. The outer diameter of the limiting shaft 307 is greater than the width of the through groove of the lower rotating block 304. The lower rotating block 304 limits the clamping strap 306 above the limiting shaft 307, so that the bottom end of the clamping strap 306 will not separate from the lower rotating block 304.

[0033] A positioning cylinder 308 is fixedly installed on the top of the upper rotating block 305. A piston 309 is movably fitted inside the positioning cylinder 308. The top of the clamp 306 extends into the interior of the positioning cylinder 308 and is fixedly connected to the bottom of the piston 309. A three-way pipe 310 is connected to the top of the positioning cylinder 308, and two adjacent three-way pipes 310 are connected to each other through a guide pipe 311. One end of one of the outermost three-way pipes 310 is connected to a one-way air valve 312, and a sealing plug 313 is fixedly fitted to one end of the other outermost three-way pipe 310. A negative pressure is drawn into the cavity of the positioning cylinder 308 at one end of the one-way air valve 312. The cavity of each positioning cylinder 308 is connected through the guide pipe 311. The negative pressure causes the piston 309 to move upward and approach the top of the positioning cylinder 308, thereby clamping the clamp. When 306 is in a straightened state, and the two arc-shaped shells 301 move towards each other to grasp the coated sand mold shell, the negative pressure suction of the negative pressure chamber in the positioning cylinder 308 on the piston 309 causes the clamping band 306 to adhere to the surface of the coated sand mold shell, thereby achieving the effect of grasping the coated sand mold shell. By using multiple clamping bands 306 to adhere to the surface of the coated sand mold shell in a soft grasping manner, it can adapt to coated sand mold shells of different shapes (such as arc, inclined, and irregular shapes). This avoids the stress concentration problem that existing clamps cause when grasping coated sand mold shells, which can easily crack brittle coated sand mold shells, as well as the problem of some points being left empty by hard clamps. Furthermore, when grasping the coated sand mold shell, the negative pressure suction of the piston 309 in the inner cavity of each positioning cylinder 308 can effectively buffer the impact during grasping, preventing damage to the coated sand mold shell.

[0034] The bottom of the arc-shaped shell 301 is fixedly fitted with a sealing ring 314 located above the lower rotating block 304. The inner side of the sealing ring 314 is in contact with the outer side of the lower rotating block 304. The sealing ring 314 seals the gap between the lower rotating block 304 and the arc-shaped shell 301, preventing impurities from falling into the bearing in the gap and affecting the rotation of the lower rotating block 304 relative to the arc-shaped shell 301.

[0035] like Figure 6 and Figure 9 The lower rotating block 304 and the upper rotating block 305 are respectively connected to tension springs 315 on both sides. The end of the tension spring 315 away from the upper rotating block 305 is fixedly connected to the arc-shaped shell 301. By connecting tension springs 315 on both sides of the lower rotating block 304 and the upper rotating block 305, the various clamping bands 306 are kept in a flush state on the same plane under normal conditions. When controlling the two arc-shaped shells 301 to move towards each other to grab the coated sand mold shell, it is beneficial for the surface of the clamping band 306 to adhere to the outer side of the coated sand mold shell.

[0036] Please continue reading. Figures 1-4A first camera 5 is fixedly installed in the middle of the bottom of the positioning frame 2, and a second camera 6 is fixedly installed at both ends of the bottom of the arc shell 301. The vision detection component composed of the first camera 5 and the second camera 6 is connected to the robot arm 1 and the servo cylinder 4. The first camera 5 and the second camera 6 are used to collect images of the coated sand mold shell, identify and locate the position and posture of the coated sand mold shell. According to the positioning results, each robot arm 1 drives the gripper assembly 3 to move to the gripping position, so that the two gripper assemblies 3 surround the coated sand mold shell, ensuring that the gripper 306 is located on the outside of the coated sand mold shell. Then, the servo cylinder 4 is controlled to drive the two gripper assemblies 3 to move towards each other to grip the coated sand mold shell, thereby achieving precise gripping of the coated sand mold shell.

[0037] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fully automated shell-gripping robot for coated sand mold shell lines, characterized in that, include: A robotic arm, and a positioning frame installed at the end of the robotic arm, wherein two gripper assemblies are movably mounted on the positioning frame, and servo cylinders that drive the two gripper assemblies to move are fixedly mounted on the positioning frame. The visual inspection component includes a first camera fixedly installed at the bottom center of the positioning frame, and a second camera installed on both sides of the bottom of the two gripper assemblies; The control unit is communicatively connected to the robotic arm, servo cylinder, and vision inspection component. The vision inspection component identifies and locates the position of the coated sand mold shell. The control unit controls the robotic arm to drive the two gripper assemblies to move to the outside of the coated sand mold shell, and then controls the servo cylinder to drive the two gripper assemblies to move towards each other to grasp the coated sand mold shell.

2. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 1, characterized in that, The gripper assembly includes an arc-shaped shell. Several equidistantly arranged lower rotating blocks and upper rotating blocks are movably sleeved at the top and bottom ends of the arc-shaped shell, respectively. The lower rotating blocks are located directly below the upper rotating blocks, and the middle of the lower and upper rotating blocks is provided with through slots of the same size. A clamping strap is movably sleeved between the through slots of the lower and upper rotating blocks. A positioning cylinder is fixedly installed at the top of the upper rotating block. A piston is movably sleeved inside the positioning cylinder. The top of the clamping strap extends into the interior of the positioning cylinder and is fixedly connected to the bottom of the piston. The second camera is fixedly installed at both ends of the bottom of the arc-shaped shell.

3. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The openings of the through slots are all designed with smooth chamfers.

4. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The clamp is made of high-temperature resistant silicone material.

5. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The bottom end of the clamp is fixedly connected to a limiting shaft located below the lower rotating block, and the outer diameter of the limiting shaft is greater than the width of the through groove of the lower rotating block.

6. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The bottom of the arc-shaped shell is fixedly fitted with a sealing ring located above the lower rotating block, and the inner side of the sealing ring is movably fitted with the outer side of the lower rotating block.

7. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The top of the positioning cylinder is connected to a three-way pipe, and two adjacent three-way pipes are connected to each other through an air guide pipe. One end of one of the outermost three-way pipes is connected to a one-way air valve, and one end of the other outermost three-way pipe is fixedly fitted with a sealing plug. Negative pressure is drawn into the inner cavity of the positioning cylinder by one end of the one-way air valve.

8. The fully automated shell-gripping robot for coated sand mold shell lines according to claim 2, characterized in that, The lower rotating block and the upper rotating block are respectively connected to two sides of a tension spring, and the end of the tension spring away from the upper rotating block is fixedly connected to the arc-shaped shell.

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