CN116276099A - A dual-robot intelligent collaborative processing system and method for large castings - Google Patents

Abstract

The invention discloses a large-scale cast part double-robot intelligent cooperative machining system and a large-scale cast part double-robot intelligent cooperative machining method, wherein the machining system comprises a horizontal guide rail, a clamping and rotating assembly is arranged on the horizontal guide rail, and a cutting and polishing rough machining robot, a milling and drilling finish machining robot and a scanning measuring instrument are arranged on one side of the horizontal guide rail; the processing method comprises the following steps: importing a theoretical model library; performing point cloud scanning; plane fitting or curved surface reconstruction, and then determining a target surface and machining allowance; judging whether a casting head exists or not, and performing cutting operation; defining a cutter starting surface of the next procedure; judging whether the die line needs rough grinding; carrying out quick rough grinding; determining whether a profile surface exists on the workpiece; carrying out quick rough grinding; grinding; removing burrs; determining whether a mounting surface is present; conveying the workpiece to a finishing station; determining the starting surface of a finishing tool; carrying out finish machining; and judging whether the workpiece processing is finished or not. The invention improves the processing efficiency and the processing precision of the large casting.

Description

A dual-robot intelligent collaborative processing system and method for large castings

technical field

The invention belongs to the technical field of large-scale or large-size workpiece processing, and in particular relates to a dual-robot intelligent collaborative processing system and method for large-scale castings.

Background technique

As one of the most widely used and most typical structural parts for processing, castings play an irreplaceable role in the field of mechanical equipment. At the same time, processing robots play an important role in the processing and manufacturing industry, especially in large-scale equipment and core structural parts, high-performance materials, and high-tech manufacturing processes. Processing robots play a pivotal role.

Castings have the characteristics of multi-scale, multi-type, and multi-material, and affected by the casting process, the surface of the casting blank will shrink and expand in random proportions, and there are large residual features such as sprue risers and parting lines. Casting blanks must undergo a series of mechanical processing such as cutting, grinding, milling, and drilling to meet the needs of practical applications. The extremely high efficiency requirements and cost constraints of each process, as well as the huge structural stress on the surface of the workpiece, all bring great technical challenges to the post-processing of castings.

At present, traditional castings are mainly processed by machine tools, but the processing volume, processing force, processing technology, and processing accuracy requirements of large and small residual features are different, and it is difficult to complete them all on one machine tool. The process of transporting workpieces to multiple machine tool processing stations and installing them is complex and requires workers' experience to complete. The accumulation of time and cost brought about by multiple card loading seriously restricts the development of the foundry industry.

In addition, limited by the processing space of the machine tool, complex surfaces of different types and scales need to be adjusted by clamping or adapted to machine tools of different specifications. The existing equipment has poor flexible processing capabilities.

With the development of major national projects, the large-scale high-end equipment industry has continuously improved the efficiency and quality requirements of its core casting structural parts; The solution for automatic machining systems for quality machining of large castings.

Contents of the invention

The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a dual-robot intelligent collaborative processing system and method for large-scale castings.

The technical solution of the present invention is: a large-scale casting double-robot intelligent collaborative processing system, including a horizontal guide rail, the horizontal guide rail is provided with a clamping and rotating assembly, and the clamping and rotating assembly clamps and fixes the workpiece. One side of the horizontal guide rail is provided with a cutting and grinding rough machining robot for cutting and grinding rough machining operations and a milling drilling finishing robot for milling and drilling finishing. The horizontal guide rail is also provided with a scanning measuring instrument for workpieces. The above-mentioned scanning measuring instrument scans the OEM workpiece.

Further, the horizontal guide rail is provided with a moving unit that moves linearly along it, and the clamping rotary assembly includes a reassembly workbench, the reassembly workbench is arranged on the upper end of the movement unit, and the reassembly workbench A clamping device is arranged on the top, and the clamping device clamps the workpiece.

Furthermore, the scanning measuring instrument corresponds to the initial position of the clamping rotary assembly, and the scanning measuring instrument scans the clamped workpiece.

Furthermore, the rough cutting and grinding robot includes a high-rigidity robot body and a terminal multi-functional processing unit, and the high-rigidity robot body is connected to the multi-functional processing unit through a robot wrist joint flange.

Further, the multifunctional processing unit includes a riser cutting unit for cutting the riser, a rough grinding unit for rough grinding with a large amount of grinding, and a burr removal unit.

Furthermore, the milling, drilling and finishing robot includes a high-precision robot body and an end milling and drilling head, and the end milling and drilling head is connected to the action output end of the high-precision robot body.

Further, the high-precision robot body includes a three-degree-of-freedom position adjustment module and a two-degree-of-freedom parallel attitude module, the three-degree-of-freedom position adjustment module performs position adjustment, and the two-degree-of-freedom parallel attitude module performs attitude adjustment, so The two-degree-of-freedom parallel attitude module is connected with the end milling and drilling processing head.

A method for a large-scale casting dual-robot intelligent collaborative processing system, comprising the following steps:

A. The system controller imports the theoretical model library of the required casting blank;

B. At the initial position, use the scanning measuring instrument to scan the point cloud of the workpiece to be processed, obtain the scanning result, and determine the type of workpiece according to the scanning result;

C. Carry out plane fitting on the plane casting blank, and then determine the target surface and machining allowance;

D. Reconstruct the surface of the casting blank with curved surface, and then determine the target surface and machining allowance;

E. Based on the target surface, judge whether there is a riser in the workpiece, and perform the cutting operation of the riser;

F. Define the starting surface of the tool for the next process;

G. Determine whether rough grinding is required on the parting line;

H. The cutting and grinding rough machining robot is switched to a rough grinding unit with a large grinding amount to perform fast rough grinding on the mold line;

I. According to the type of workpiece, determine whether the workpiece has an external surface;

J. The cutting and grinding rough machining robot is switched to a processing tool for rapid rough grinding of the outer surface;

K. Increase the speed of the coarse grinding unit with a large grinding amount, and perform grinding after rough grinding;

L. The cutting and grinding rough machining robot is switched to the burr removal unit, and the burr is removed from the outer surface;

M. According to the workpiece type, determine whether the workpiece has an assembly surface;

N. The horizontal guide rail transports the workpiece to the processing station of the knife milling, drilling and finishing robot;

O. Determine the starting surface of the cutter for the cutter milling, drilling and finishing robot;

P. Finish the assembly surface according to the assembly surface parameters and the starting surface of the tool;

Q. The horizontal guide rail sends the finished workpiece to the initial position, and the scanning measuring instrument scans to judge whether the workpiece processing is completed.

Furthermore, in step B, at the initial position, use a scanning measuring instrument to scan the point cloud of the workpiece to be processed to obtain the scanning result, and determine the type of workpiece according to the scanning result. The specific process is as follows:

Firstly, the clamped workpiece is scanned by the scanning measuring instrument at the initial position of the horizontal guide rail, the point cloud file is obtained after scanning, and the point cloud file is saved as the scanning result;

Then, according to the point cloud file, the maximum length and width profile of the workpiece to be processed is obtained;

Then, the plane coordinates of the length and width contours are obtained;

Then, compare the obtained plane coordinates with the theoretical plane coordinates in the theoretical model library of step A;

Finally, determine whether the workpiece is a flat or curved casting.

Furthermore, Step C performs plane fitting on the plane casting blank, and then determines the target surface and machining allowance. The specific process is as follows:

First, extract the sampling points and fit the plane according to the sampling points;

Then, determine the processing area and non-processing area of the workpiece;

Then, the maximum normal height difference between the fitting plane and the point cloud of the non-processing area is obtained;

Then, determine the target plane;

Finally, the maximum distance between the point cloud of the processing area and the target plane is determined to determine the processing allowance.

The beneficial effects of the present invention are as follows:

In the present invention, the cutting and grinding rough machining robot and the milling, drilling and finishing robot respectively complete different machining tasks. During the whole machining process, the workpiece only needs to be clamped on the horizontal guide rail once, eliminating the need to enter the machine tool and The cumbersome steps of clamping improve the efficiency and machining accuracy of large castings.

In the present invention, the collaborative processing of two different precision and performance robots avoids the loss of robot finishing precision caused by the huge processing load of cutting and rough grinding during the rough and finish machining process of the same equipment at the same time; according to the application and detection of castings For the machining allowance, different robots can be used to perform different steps, which increases the flexibility of the system and the scope of grinding; according to the estimation of the residual characteristics after rough machining, it realizes one measurement and multiple machining, which improves the machining efficiency; great It meets the grinding needs of large castings.

Description of drawings

Fig. 1 is the structural representation of processing system among the present invention;

Fig. 2 is the schematic flow sheet of processing method among the present invention;

in:

1 horizontal guide rail 2 scanning measuring instrument

3 Cutting and Grinding Rough Machining Robot 4 Milling Drilling and Finishing Machining Robot

5 workpieces

301 Cutting disc 302 Rough grinding wheel

303 small grinding head

401 milling and drilling processing unit.

Detailed ways

Below, the present invention is described in detail with reference to accompanying drawing and embodiment:

As shown in Figures 1 to 2, a dual-robot intelligent collaborative processing system for large-scale castings includes a horizontal guide rail. The horizontal guide rail 1 is provided with a clamping rotary assembly, and the clamping rotary assembly clamps the workpiece 5. Fixed, one side of the horizontal guide rail 1 is provided with a cutting and grinding rough machining robot 3 for cutting and grinding rough machining operations and a milling and drilling finishing robot 4 for milling and drilling finishing, and one side of the horizontal guide rail 1 is also provided with The workpiece is scanned by a measuring instrument 2 , which scans the workpiece 5 to be processed on behalf of the customer.

The horizontal guide rail 1 is provided with a moving unit that moves linearly along it, and the clamping and rotating assembly includes a reassembly workbench, and the reassembly workbench is arranged on the upper end of the movement unit, and the reassembly workbench is provided with A clamping device, the clamping device clamps the workpiece 5 .

The scanning measuring instrument 2 corresponds to the initial position of the clamping rotary assembly, and the scanning measuring instrument 2 scans the clamped workpiece 5 .

The cutting and grinding rough machining robot 3 includes a high-rigidity robot body and a terminal multi-functional processing unit, and the high-rigidity robot body is connected to the multi-functional processing unit through a robot wrist joint flange.

The multifunctional processing unit includes a riser cutting unit for cutting the riser, a rough grinding unit for rough grinding with a large grinding amount, and a burr removal unit.

The milling, drilling and finishing robot 4 includes a high-precision robot body and an end milling and drilling head, and the end milling and drilling head is connected to the action output end of the high-precision robot body.

The high-precision robot body includes a three-degree-of-freedom position adjustment module and a two-degree-of-freedom parallel attitude module, the three-degree-of-freedom position adjustment module performs position adjustment, the two-degree-of-freedom parallel attitude module performs attitude adjustment, and the two-degree-of-freedom The parallel attitude module is connected with the end milling and drilling processing head.

Specifically, the workpiece 5 is installed on the horizontal guide rail, and the moving slider in the horizontal guide rail 1 drives the workpiece 5 to move in the horizontal direction. The scanning measuring instrument 2 includes a corresponding binocular vision camera or an articulated measuring robot arm.

The scanning measuring instrument 2, the cutting and grinding rough machining robot 3 and the milling and drilling finishing robot 4 are successively arranged on one side of the workpiece 5 from the beginning end of the horizontal guide rail 1; the robot control cabinet and the cutting and grinding rough machining robot 3, the milling drill The hole finishing robot 4 and the scanning measuring instrument 2 are electrically connected, and the robot control cabinet generates robot processing control commands to control the robot to perform processing actions on a specified path. The system control cabinet is connected with the horizontal guide rail and the robot control cabinet to control the start, stop and speed of the servo motor in the horizontal guide rail.

Specifically, the cutting and grinding rough machining robot 3 includes a high-rigidity robot body and a multi-functional processing unit at the end. The cutting and grinding rough machining robot 3 is used to realize the rough grinding of casting blank casting riser cutting, large mold line and casting riser cutting residual features. , Burrs and small parting line removal work.

Specifically, the high-rigidity robot body has at least four degrees of freedom in space.

Specifically, the high-stiffness robot body includes a high-stiffness plane 5R mechanism and a vertical lifting guide rail, and the high-stiffness robot body realizes three-degree-of-freedom position translation in space. The flange of the robot wrist joint is connected to the multi-functional processing unit, and the robot wrist joint is driven by a motor reducer structure, which can realize rotary motion for switching processes.

Specifically, the multifunctional processing unit includes a riser cutting unit, a rough grinding unit with a large grinding amount and a deburring unit.

Each of the riser cutting unit and the coarse grinding unit with a large grinding amount includes a corresponding processing head and a degree-of-freedom rotating and attitude-adjusting joint. The axes of the two rotational posture adjustment joints are perpendicular to the rotational axis of the wrist joint of the high-stiffness robot. The rotating joint of the rough grinding unit with a large grinding amount is linked with the degree of freedom of the high-rigidity robot body to realize the five-axis grinding function.

The rotation attitude adjustment joint of the riser cutting unit does not participate in the five-axis linkage, and is only used to adjust the initial attitude of the riser cutting.

The processing abrasive tools corresponding to the coarse grinding unit can realize large grinding amount grinding at different angles of end faces and sides.

Specifically, the milling, drilling and finishing robot 4 includes a high-precision robot body and an end milling and drilling processing head for milling, drilling and finishing the assembly surface of the casting blank.

The high-precision robot body has a three-degree-of-freedom position adjustment module and a two-degree-of-freedom parallel attitude module.

The three-degree-of-freedom position adjustment module should have a longer beam length, so as to straddle the processed area. The vertical lift of the three-degree-of-freedom position adjustment module is realized by the rotary joint close to the base, which is used to adapt to different heights. Processing casting blanks.

Specifically, the clamping rotary assembly includes a clamping device and a reassembly workbench. The workpiece 5 to be processed is fixed on the reassembly workbench through the clamping device, and the pose of the workpiece to be processed is adjusted through the rotary workbench fixed on the horizontal guide rail. The full circle rotation of the rotary table can realize the replacement of the side wall processing surface.

According to the processing functions of the cutting and grinding rough machining robot 3 and the milling and drilling finishing robot 4, and according to the point cloud files obtained by the scanning measuring instrument 2, the workpiece 5 is divided into several working steps and procedures through the path planning software, and each The working steps and procedures correspond to the corresponding robots and processing heads for processing. Under the control of the system control cabinet, the horizontal guide rail 1 drives the workpiece 5 to move, so that the workpiece 5 is in the corresponding robot processing area.

The robot control cabinet is connected with the cutting and grinding roughing robot 3 and the milling, drilling and finishing robot 4 at the same time to generate robot movement control instructions, and control the robot to drive the processing head to perform processing operations according to the planned path.

The cutting and grinding rough machining robot 3 and the milling, drilling and finishing robot 4 act according to the robot movement instructions output by the robot control cabinet, drive the processing head to process and leave the workpiece after completion.

The system control cabinet communicates with the robot control cabinet. After a processing step is completed and the processing tool is completely out of contact with the workpiece, the robot control cabinet communicates with the system control cabinet, and the system control cabinet controls the horizontal guide rail to drive the workpiece into the next step.

The system control cabinet predicts the residual features. According to the workpiece features identified by the point cloud file, combined with the stiffness matrix of the robot body and the fluctuation of the spindle load, the actual outline after the previous process is estimated, and the initial process of the next process is determined by the offset surface method. pass.

A method for a large-scale casting dual-robot intelligent collaborative processing system, comprising the following steps:

A. The system controller imports the theoretical model library of the required casting blank;

B. At the initial position, use the scanning measuring instrument to scan the point cloud of the workpiece to be processed, obtain the scanning result, and determine the type of workpiece according to the scanning result;

C. Carry out plane fitting on the plane casting blank, and then determine the target surface and machining allowance;

D. Reconstruct the surface of the casting blank with curved surface, and then determine the target surface and machining allowance;

E. Based on the target surface, judge whether there is a riser in the workpiece, and perform the cutting operation of the riser;

F. Define the starting surface of the tool for the next process;

G. Determine whether rough grinding is required on the parting line;

H. The cutting and grinding rough machining robot is switched to a rough grinding unit with a large grinding amount to perform fast rough grinding on the mold line;

I. According to the workpiece type, determine whether the workpiece has an external surface;

J. The cutting and grinding rough machining robot is switched to a processing tool for rapid rough grinding of the outer surface;

K. Increase the speed of the coarse grinding unit with a large grinding amount, and perform grinding after rough grinding;

L. The cutting and grinding rough machining robot is switched to the burr removal unit, and the burr is removed from the outer surface;

M. According to the workpiece type, determine whether the workpiece has an assembly surface;

N. The horizontal guide rail transports the workpiece to the processing station of the knife milling, drilling and finishing robot;

O. Determine the starting surface of the cutter for the cutter milling, drilling and finishing robot;

P. Finish the assembly surface according to the assembly surface parameters and the starting surface of the tool;

Q. The horizontal guide rail sends the finished workpiece to the initial position, and the scanning measuring instrument scans to judge whether the workpiece processing is completed.

Specifically, in step A, the system controller imports the theoretical model library of the required casting blank, and the specific process is as follows:

First, the system controller imports and stores theoretical models of various blanks, and the theoretical models of blanks are combined to form a theoretical model library;

Then, the theoretical model library also includes the processing information of the theoretical model;

Finally, the processing information includes the processing accuracy, external surface, assembly surface, three-dimensional model, mass, and volume of the theoretical model.

Specifically, in step B, at the initial position, use a scanning measuring instrument to scan the point cloud of the workpiece to be processed to obtain the scanning result, and determine the type of the workpiece according to the scanning result. The specific process is as follows:

Firstly, the clamped workpiece is scanned by the scanning measuring instrument at the initial position of the horizontal guide rail, the point cloud file is obtained after scanning, and the point cloud file is saved as the scanning result;

Then, according to the point cloud file, the maximum length and width profile of the workpiece to be processed is obtained;

Then, the plane coordinates of the length and width contours are obtained;

Then, compare the obtained plane coordinates with the theoretical plane coordinates in the theoretical model library in step A; determine which theoretical model the workpiece to be processed belongs to, determine whether the workpiece is a plane casting or a curved surface casting, and whether it contains assembly noodle.

Specifically, step C performs plane fitting on the plane type casting blank, and then determines the target surface and machining allowance. The specific process is as follows:

First, extract the sampling points and fit the plane according to the sampling points;

Then, determine the processing area and non-processing area of the workpiece;

Then, the maximum normal height difference between the fitting plane and the point cloud of the non-processing area is obtained;

Then, determine the target plane;

Finally, the maximum distance between the point cloud of the processing area and the target plane is determined to determine the processing allowance.

More specifically, sampling points are extracted, and the plane is fitted according to the sampling points. The specific process is as follows:

First of all, for planar casting blanks, there is no need to perform surface reconstruction, and the planar cuboid coordinates of the point cloud are discretized;

Then, according to the plane area, it is divided into 20 equal-area plane areas, and at least one sampling point is randomly selected in each area;

Afterwards, the sampling points whose normal height difference from the lowest sampling point is greater than 5 mm are eliminated;

Finally, according to the retained sampling points, fit the plane.

More specifically, to determine the processing area and non-processing area of the workpiece, the specific process is as follows:

First, according to the normal height, the residual feature contour of the point cloud file is identified;

Then, define the area where residual features exist as the processing area;

Finally, the area outside the processed area is defined as the non-processed area.

Among them, the gate riser in the residual feature profile is generally cylindrical, the parting line is generally elongated in the plane, and the normal height is irregular tooth shape.

More specifically, calculate the maximum normal height difference between the fitting plane and the point cloud of the non-processing area, offset the fitting plane according to the highest point of the point cloud of the non-processing area, and define this plane as the target surface. The machining allowance is determined by the maximum distance between the point cloud of the machining area and the target surface.

Specifically, step C performs plane fitting on the plane type casting blank, and then determines the target surface and machining allowance. The specific process is as follows:

First of all, for surface-type casting blanks, reconstruct the point cloud file into a real surface;

Then, calculate the shape-to-volume ratio of the real surface and the theoretical model;

Then, the ratio of the volume ratio is defined as the expansion coefficient;

Then, the blank castings whose shrinkage coefficient is smaller than the machining accuracy requirements are directly processed according to the theoretical model;

Then, for the blank casting whose contraction and expansion coefficient is greater than the machining accuracy requirement, the real surface and the theoretical surface are registered according to the ICP algorithm, and the registration surface is set as the target surface to determine the machining allowance.

Specifically, step E is based on the target surface, judges whether there is a riser in the workpiece, and performs the cutting operation of the riser. The specific process is as follows:

First, calculate the maximum local distance between the contour surface and the target surface,

Then, according to the set riser margin threshold, which is generally more than 60 mm, it is judged whether there is a riser in the workpiece 5 to be processed.

Specifically, step E also includes the following process:

First, offset the target surface of the sprue and riser area by 3 to 5 mm along the direction of the sprue and riser. Calculate the diameter of the riser according to the outline of the riser identified by the point cloud file, and judge whether the radius of the cutting piece is greater than the diameter of the riser.

Then, if the radius of the cutting piece is larger than the diameter of the sprue riser, it will be cut off in one piece, and the path is the horizontal plane where the maximum point of the target surface after offset is located.

Afterwards, if the radius of the cutting piece is smaller than the radius of the pouring riser, cut off with two cuts along both sides. The cutting direction and path planning of the cutting riser are cut by the cutting blade for the rough machining robot, which is obtained according to the shortest moving distance of the robot.

Then, the path planning algorithm uses inclusion calculation to check the minimum distance between the cylindrical contour of the cutting piece and the surface of the non-machined area to avoid interference.

Finally, according to the planned path, the multifunctional processing unit of the cutting and grinding rough machining robot 3 is switched to the riser cutting unit to cut the pouring riser.

The riser cutting unit is a cutting piece 301 .

Specifically, step F defines the starting surface of the tool for the next process, and the specific process is as follows:

First, according to the common cutting force empirical formula of the corresponding material, the real-time power of the cutting spindle is estimated, and the tangential cutting force in the cutting process is estimated.

Then, according to the stiffness matrix of the cutting and grinding rough machining robot 3 , the maximum machining offset Δx=f/K of the cutting piece along the riser direction during machining is predicted.

The expression of the stiffness matrix is as follows,

K＝∑S _w,i (S _w,i ^T C _i S _w,i ) ^-1 S _w,i ^T ,

In the formula, S _w,i is the instantaneous force spiral of the i-th branch chain of the robot, which is affected by the pose of the robot,

C is the flexibility matrix corresponding to the branch chain, which is pre-obtained by finite element software combined with actual measurement and set in the control system.

Finally, the maximum offset point is used to offset the target surface, which is defined as the starting surface of the tool in the next process.

Specifically, step G determines whether rough grinding is required on the parting line, and the specific process is as follows:

For blanks that do not need to cut the riser, judge whether rough grinding is required on the parting line according to the distance calculated in step E and the set rough grinding threshold. If rough grinding is required, perform sequential execution. If rough grinding is not required, Skip directly to the deburring procedure.

Among them, the coarse grinding threshold is generally greater than 5 mm.

Sequential execution is performed for casting blanks with cut risers.

Specifically, in step H, the cutting and grinding rough machining robot is switched to a rough grinding unit with a large grinding amount to perform rapid rough grinding on the parting line. The specific process is as follows:

First, the multifunctional processing unit of the cutting and grinding rough machining robot 3 is switched to the rough grinding unit;

Then, the maximum distance between the starting surface of the tool and the target curve is defined as the rough grinding allowance, and the unloaded path and the loaded path of the rough grinding of the mold line are determined according to the rectangular bounding box of the local mold line feature, that is, in the long stroke path, there is a machining The area of the feature is the loaded path, and the area without the machining feature is the unloaded path.

Then, according to the size of the side wall, top wall, and margin, the corresponding end face or side grinding process is used for grinding.

Specifically, the side wall and the top wall with a large allowance are side-ground, and the top wall with a small allowance is ground. The size of the allowance is determined based on the threshold value input in advance. The threshold value is related to the casting material and the area. The threshold value is generally determined by prior experiments. A definite empirical formula is obtained. The goal of the path planning is to optimize the stiffness of the robot and the shortest running distance. Among them, the feed speed of the intermittent unloaded path robot is correspondingly increased.

Concretely, step 1 determines whether there is a shape surface in the workpiece according to the workpiece type, and the specific process is as follows:

According to the workpiece type judged in step B, determine whether there is a contour surface. If there is an outer surface, then execute step J, if there is no outer surface, then execute step K.

Specifically, step K increases the rotational speed of the rough grinding unit with a large grinding amount, and performs grinding after the rough grinding process. The specific process is as follows:

The cutting and grinding rough machining robot 3 uses the rough grinding unit to increase the speed of grinding according to the target path of the last knife in the previous process.

Specifically, in step L, the cutting, grinding and roughing robot is switched to the burr removal unit, and the burrs are removed from the outer surface. The specific process is as follows:

The multi-functional processing unit of the cutting and grinding rough machining robot 3 is switched to a burr removal unit, and the burr is ground on the outer surface according to the target surface and the target path of the last cut in the previous process.

The deburring unit may be a small grinding head 303 .

Specifically, step M determines whether the workpiece has an assembly surface according to the type of the workpiece, and the specific process is as follows:

According to step B, the type of casting blank is judged, and it is determined whether there is an assembly surface in the workpiece. If there is an assembly surface, the assembly surface finishing process is performed, and if there is no assembly surface, the finishing process is skipped.

Specifically, step O determines the starting surface of the cutter of the cutter milling, drilling and finishing robot, and the specific process is as follows:

预测切割过程的切向切削力，其中，P为主轴功率可直接读取，D、n分别为末端执行器直径，α为有效功率系数。According to the last cutting path of the rough grinding process, according to the empirical formula of the real-time power and grinding force of the rough grinding spindle

Predict the tangential cutting force of the cutting process, where P is the spindle power which can be read directly, D and n are the diameters of the end effector respectively, and α is the effective power coefficient.

According to the stiffness matrix of the cutting and grinding rough machining robot 3, calculate the maximum normal offset deformation during the rough grinding process, and determine the new starting surface of the tool.

According to the starting surface of the tool, the path planning for machining with milling and drilling tools is carried out. The path is planned according to the regular shape of the assembly surface, etc.

Specifically, in step Q, the horizontal guide rail sends the finished workpiece to the initial position, and the scanning measuring instrument scans to determine whether the processing of the workpiece is completed. The specific process is as follows:

The horizontal guide rail transports the workpiece back to the starting point of the production line to scan and detect the processed workpiece, and sequentially identify the possible assembly surface, riser area, parting line area, and external surface, and judge whether the height difference of the point cloud of the corresponding surface is within the corresponding processing accuracy .

According to the test results, it is judged whether the processing is up to standard, if it is up to the standard, the workpiece processing is completed, otherwise return to the previous step and repeat processing.

In the present invention, the cutting and grinding rough machining robot and the milling, drilling and finishing robot respectively complete different machining tasks. During the whole machining process, the workpiece only needs to be clamped on the horizontal guide rail once, eliminating the need to enter the machine tool and The cumbersome steps of clamping improve the efficiency and machining accuracy of large castings.

In the present invention, the collaborative processing of two different precision and performance robots avoids the loss of robot finishing precision caused by the huge processing load of cutting and rough grinding during the rough and finish machining process of the same equipment at the same time; according to the application and detection of castings For the machining allowance, different robots can be used to perform different steps, which increases the flexibility of the system and the scope of grinding; according to the estimation of the residual characteristics after rough machining, it realizes one measurement and multiple machining, which improves the machining efficiency; great It meets the grinding needs of large castings.

Claims (10)

1. The utility model provides a large-scale casting double robot intelligence collaborative processing system, includes horizontal guide rail (1), its characterized in that: the automatic cutting and polishing device is characterized in that a clamping rotary assembly is arranged on the horizontal guide rail (1), the workpiece (5) is clamped and fixed by the clamping rotary assembly, a cutting and polishing rough machining robot (3) for performing cutting and polishing rough machining operation and a milling and drilling finish machining robot (4) for performing milling and drilling finish machining are arranged on one side of the horizontal guide rail (1), a scanning measuring instrument (2) is further arranged on one side of the horizontal guide rail (1), and the scanning measuring instrument (2) scans the workpiece (5) instead of machining.

2. The large cast part double-robot intelligent cooperative machining system according to claim 1, wherein: the horizontal guide rail (1) is provided with a moving unit which linearly moves along the horizontal guide rail, the clamping rotary assembly comprises a reloading workbench, the reloading workbench is arranged at the upper end of the moving unit, the reloading workbench is provided with a clamping device, and the clamping device clamps a workpiece (5).

3. The large cast part double-robot intelligent cooperative machining system according to claim 2, wherein: the scanning measuring instrument (2) corresponds to the initial position of the clamping rotary assembly, and the scanning measuring instrument (2) scans the clamped workpiece (5).

4. The large cast part double-robot intelligent cooperative machining system according to claim 1, wherein: the cutting and polishing rough machining robot (3) comprises a high-rigidity robot body and a tail end multifunctional machining unit, and the high-rigidity robot body is connected with the multifunctional machining unit through a robot wrist joint flange.

5. The large-scale cast member double-robot intelligent cooperative machining system according to claim 4, wherein: the multifunctional processing unit comprises a riser cutting unit for cutting a riser, a large grinding amount rough grinding unit for rough grinding and a burr removing unit.

6. The large cast part double-robot intelligent cooperative machining system according to claim 1, wherein: the milling and drilling finish machining robot (4) comprises a high-precision robot body and a tail end milling and drilling machining head, and the tail end milling and drilling machining head is connected with an action output end of the high-precision robot body.

7. The large-scale cast member double-robot intelligent cooperative machining system according to claim 6, wherein: the high-precision robot body comprises a three-degree-of-freedom position adjusting module and a two-degree-of-freedom parallel gesture module, wherein the three-degree-of-freedom position adjusting module adjusts the position, the two-degree-of-freedom parallel gesture module adjusts the gesture, and the two-degree-of-freedom parallel gesture module is connected with the tail end milling and drilling processing head.

8. The method of the large-scale cast part double-robot intelligent cooperative machining system according to claim 1, wherein the method comprises the following steps: the method comprises the following steps:

A. the system controller imports a theoretical model library of the required casting blank;

B. in the initial position, performing point cloud scanning on a workpiece to be processed by using a scanning measuring instrument to obtain a scanning result, and determining the type of the workpiece according to the scanning result;

C. performing plane fitting on the plane-like casting blank, and determining a target surface and machining allowance;

D. performing curved surface reconstruction on the curved surface casting blank, and determining a target surface and machining allowance;

E. judging whether a casting head exists on the workpiece based on the target surface, and performing casting head cutting operation;

F. defining a cutter starting surface of the next procedure;

G. judging whether rough grinding processing is needed to be carried out on the involution mold line or not;

H. the cutting and polishing rough machining robot is switched to a large grinding amount rough grinding unit to perform quick rough grinding machining on the die line;

I. determining whether an appearance surface exists on the workpiece according to the type of the workpiece;

J. the cutting and polishing rough machining robot is switched into a machining cutter to perform quick rough grinding machining on the appearance surface;

K. the rotating speed of the rough grinding unit with large grinding quantity is increased, and the rough grinding is performed;

l, switching the cutting and polishing rough machining robot into a burr removing unit, and removing burrs on the external surface;

m, determining whether an assembly surface exists on the workpiece according to the type of the workpiece;

n, conveying the workpiece to a machining station of a cutter milling, drilling and finishing robot by a horizontal guide rail;

o, determining a cutter starting surface of a cutter milling drilling finishing robot;

p, carrying out finish machining on the assembly surface according to the assembly surface parameters and the cutter starting surface;

and Q, conveying the finished workpiece to an initial position by the horizontal guide rail, and scanning by the scanning measuring instrument to judge whether the workpiece is machined or not.

9. The method of the large-scale cast part double-robot intelligent cooperative machining system according to claim 8, wherein the method comprises the following steps: and B, performing point cloud scanning on the workpiece to be processed by using a scanning measuring instrument at the initial position to obtain a scanning result, and determining the type of the workpiece according to the scanning result, wherein the specific process is as follows:

firstly, scanning a clamped workpiece through a scanning measuring instrument at the initial position of a horizontal guide rail, scanning to obtain a point cloud file, and storing the point cloud file as a scanning result;

then, obtaining the maximum width profile of the workpiece to be processed according to the point cloud file;

then, obtaining the plane coordinates of the long and wide profile;

and then, comparing the obtained plane coordinates with theoretical plane coordinates in the theoretical model library in the step A; determining a theoretical model corresponding to the workpiece, and knowing whether the workpiece is a plane casting or a curved casting according to a theoretical model library, wherein the package does not comprise an assembly surface.

10. The method of the large-scale cast part double-robot intelligent cooperative machining system according to claim 8, wherein the method comprises the following steps: and C, performing plane fitting on the plane-type casting blank, and determining a target surface and machining allowance, wherein the specific process is as follows:

firstly, sampling points are extracted, and a plane is fitted according to the sampling points;

then, determining a machining area and a non-machining area of the workpiece;

then, obtaining the maximum normal height difference of the fitting plane and the point cloud of the non-processing area;

then, determining a target plane;

and finally, determining the maximum distance between the point cloud of the processing area and the target plane, and determining the processing allowance.

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