Automatic sand casting valve body cutting device and cutting method thereof
By using the morphological deviation correction mechanism and marking mechanism in the automated cutting device of the sand cast valve body, the problems of low casting accuracy and large cutting trajectory deviation are solved, and high-precision sand cast valve body cutting is achieved.
Patent Information
- Application Number
- CN202411381722.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-01-03
AI Technical Summary
The existing sand cast valve body automatic cutting technology has problems such as low casting accuracy and large deviation in cutting trajectory, which leads to the inability to achieve normal cutting.
An automated cutting device including a cutting robot, identification mechanism and morphological deviation correction mechanism is adopted. The precise position of the corrected body is ensured through the runner positioner and the flange end surface positioner. Combined with the identification mechanism and marking placement point, it can quickly calculate and adjust. Cut the path to reduce the impact of morphological deviation.
It improves the processing accuracy of the sand cast valve body, reduces cutting errors, simplifies equipment structure and maintenance, improves operation convenience, and solves the problems of low casting accuracy and large deviation of cutting trajectory.
Smart Images
Figure CN119238553A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of sand casting valve body production equipment, and in particular to an automatic cutting device for a sand casting valve body and a cutting method thereof. Background Art
[0002] In the automated production of valve bodies, the main cutting is done on the runners, risers, and flange subsidies on the valve bodies. The currently used automated cutting method is mainly to use a camera to identify the spatial position of the feature points on a certain model and specification of the valve body, and calculate the cutting path. The common cutting trajectory is a straight line or a circle of a certain arc, so the number of feature points to determine the cutting path is generally 2-3. The cutting path is calculated using the principle of "three points determine a surface" and "two points determine a line segment", and then the robot and flame cutting torch are controlled to cut the runners, risers, and flange subsidies on the valve body of this model and specification. Due to the large volume of the sand-cast valve body, the slag inclusion at the runner and riser of the valve body is serious, resulting in low casting accuracy and large morphological deviation, and the relative position repeatability of the positioning mark points is low. Even if the relative error of each feature position of the same batch and the same model of the valve body is about 0.5 to 2mm, it leads to a large deviation in the calculated trajectory of different valve bodies in the same batch. Even if the cutting accuracy requirements are reduced, it cannot be applied to normal cutting. Therefore, the large casting error brings great challenges to the automated cutting of the runner and riser of the sand-cast valve body. Summary of the invention
[0003] The technical problem to be solved by the present invention is: in order to solve the problem that the existing sand-cast valve body has low casting precision, and the calculation trajectory deviation of different valve bodies in the same batch in the cutting method is large, and even if the cutting precision requirement is lowered, it cannot be applied to normal cutting, an automatic cutting device and a cutting method for a sand-cast valve body are provided.
[0004] The technical solution adopted by the present invention to solve its technical problems is: an automatic cutting device for a sand-cast valve body, comprising a cutting robot, an identification mechanism and a tooling for fixing the valve body, and also comprising a shape deviation correction mechanism, wherein the shape deviation correction mechanism comprises a correction body, one end of which is provided with a flow channel positioning member and a flange end face positioning member, the flow channel positioning member is used to cooperate with the flow channel hole of the valve body and prevent the correction body from deviating or falling off the valve body, the flange end face positioning member is used to cooperate with the flange end face of the valve body and prevent the correction body from tilting on the valve body, and the other end of the correction body is provided with a marking placement point for the identification mechanism to obtain the relative spatial position of the valve body;
[0005] The other end of the correction body is provided with an identification mechanism for positioning the flow channel positioning part of the correction body relative to the flow channel hole in the circumferential direction. Compared with the prior art, this solution sets a morphology deviation correction mechanism on the valve body, and the identification mechanism obtains the relative spatial position of the valve body through the mark placement point on the correction body, and calculates the relative spatial path of the flange end face and the riser on the valve body. The correction body is quickly assembled at the required position on the valve body through the identification mechanism, and the relative position accuracy between the correction body and the valve body is improved. Therefore, the influence of the valve body surface deviation on the valve body during cutting will be greatly reduced, ensuring the machining accuracy requirements of different valve bodies and improving the machining accuracy of the valve body. At the same time, the morphology deviation correction mechanism has a simple structure, is easy to manufacture and maintain, and is simple and convenient to operate in the later use.
[0006] In order to prevent the correction body from shifting or falling off on the valve body, in some preferred embodiments, the flow channel positioning member includes at least two first positioning pins arranged in parallel, the first positioning pins are arranged along the circumferential direction, and the first positioning pins and the flow channel hole are mutually inscribed. By means of at least two first positioning pins arranged in parallel, the radial displacement of the correction body along the flow channel hole is limited, that is, the correction body can be axially displaced and rotated in the flow channel hole, which facilitates the assembly of the correction body on the valve body, ensures that the correction body is placed correctly on the valve body, and does not shift or fall off the correction body, thereby ensuring that the subsequent valve body processing is stable and reliable.
[0007] In order to prevent the correction body from being skewed on the valve body by the flange end face positioning member, in some preferred embodiments, the flange end face positioning member includes at least two second positioning pins arranged in parallel, and the second positioning pins are located at the outer periphery of the flow channel positioning member along the flow channel aperture. At least three second positioning pins arranged in parallel are in contact with the flange end face, and the three second positioning pins limit the distance between the correction body and the flange end face, ensuring that the correction body and the flange end face are parallel to each other, ensuring that the correction body is placed straight on the valve body, and that the correction body and the flange end face are not skewed to each other.
[0008] In order to better ensure the installation accuracy of the correction body and the valve body, in some preferred embodiments, the identification mechanism includes a positioning mark set on the correction body and a specific mark on the valve body, and the positioning mark corresponds to the specific mark on the valve body. The positions of the two are corrected by the specific mark of the valve body and the positioning mark of the correction body, thereby improving the installation accuracy of the two.
[0009] In order to realize the correction of the positioning mark on the main body and the specific mark on the valve body, in some preferred embodiments, the positioning mark is a positioning point, and there are two positioning points;
[0010] The specific marking point is the closing line, and the two positioning points correspond to the closing lines on the valve body on both sides of the flow channel hole. By setting the positioning points on the correction body, the positioning points correspond to the closing lines on the valve body, and the correction body is quickly installed at the required position on the valve body. Positioning points are set on both sides of the correction body, and the two positioning points correspond to the closing lines respectively, so as to improve the position accuracy of the correction body as a whole and the valve body when installing.
[0011] Preferably in some implementation modes, the positioning point is an arrow pointing to the box closing line.
[0012] In order to facilitate the operation of the correction body, in some preferred embodiments, a handle is provided on the other end of the correction body. By providing a handle on the correction body, the handle is convenient for the staff to hold, and it is convenient for the staff to place the correction body on the valve body, thereby improving the installation efficiency.
[0013] In order to better identify the marking points on the correction body, some preferred embodiments have three marking points, which are respectively distributed at any three vertices of the rectangle. Three marking points are set on the correction body, and the three marking points are respectively at any three vertices of the rectangle. The correction body is quickly determined through the three points to improve recognition efficiency.
[0014] A cutting method using the above-mentioned sand casting valve body automatic cutting device, the specific operation steps are as follows:
[0015] S1. Define the coordinate system of the shape deviation correction mechanism through the identification mechanism, and use the defined shape deviation correction mechanism coordinate system to control the motion of the cutting robot in this coordinate system;
[0016] S2. Fix the valve body to be processed on the tooling;
[0017] S3. Place the flow channel positioning member on the shape deviation correction mechanism into the flow channel hole of the valve body, and then place the flange end face positioning member against the flange end face of the valve body.
[0018] S4, assembling the shape deviation correction mechanism to the required position on the valve body through the marking mechanism, thereby completing the assembly of the shape deviation correction mechanism on the valve body;
[0019] S5. Identify the marking placement point on the shape deviation correction mechanism through the recognition mechanism, and obtain the relative spatial position of the valve body;
[0020] S6. When cutting the valve body, run the ignition program of the cutting robot, control the opening and closing of the solenoid valve, turn on the cutting oxygen switch of the cutting gun on the cutting robot, determine the position of the valve body and calculate the cutting trajectory through the single-chip microcomputer, perform arc or linear motion at a preset speed and riser end face distance, run through the riser cutting midpoint until the riser cutting end position, after the riser is cut off and falls off, turn off the cutting oxygen switch, and then move the cutting robot to the next cutting point, the same as the above cutting process, start cutting another riser;
[0021] S7. When cutting the next valve body, repeat steps S2-S6.
[0022] The beneficial effects of the present invention are as follows: when the sand-cast valve body automatic cutting device and cutting method of the present invention are in use, a morphology deviation correction mechanism is arranged on the valve body, and the identification mechanism obtains the relative spatial position of the valve body by correcting the mark placement points on the main body, and calculates the relative spatial path of the flange end face compensation and the riser on the valve body, thereby greatly reducing the influence of the valve body surface deviation, improving the processing accuracy, and ensuring the processing accuracy requirements of different valve bodies. At the same time, the morphology deviation correction mechanism has a simple structure, is easy to manufacture and maintain, and is simple and convenient to operate in the later use, thereby avoiding the problem that the existing sand-cast valve body has low casting accuracy, and the cutting method has large deviation in the calculated trajectory of different valve bodies in the same batch, and cannot be applied to normal cutting even if the cutting accuracy requirements are lowered. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.
[0024] Figure 1 is a schematic diagram of the three-dimensional structure of Example 1 of the present invention;
[0025] Figure 2 is a schematic diagram of the three-dimensional structure of the valve body and the shape deviation correction mechanism when they are installed in Example 1 of the present invention;
[0026] Figure 3 This is a front view of the valve body and the shape deviation correction mechanism when they are installed in Example 1 of the present invention;
[0027] Figure 4 is a top view of the valve body and the shape deviation correction mechanism when they are installed in Example 1 of the present invention;
[0028] Figure 5 yes Figure 3 Middle AA section view;
[0029] Figure 6 is a front view of the shape deviation correction mechanism in Example 1 of the present invention;
[0030] Figure 7 is a rear view of the shape deviation correction mechanism in Example 1 of the present invention;
[0031] Figure 8 is a top view of the shape deviation correction mechanism in Example 1 of the present invention;
[0032] Fig. 9 It is a schematic diagram of the three-dimensional structure of the morphology deviation correction mechanism in Example 1 of the present invention.
[0033] In the figure: 1. Cutting robot, 2. Identification mechanism, 3. Tooling, 4. Correction body, 5. Flow channel positioning member, 501. First positioning pin, 6. Flange end face positioning member, 601. Second positioning pin, 7. Identification mechanism, 8. Positioning point, 9. Handle, 10. Marking placement point, 11. Valve body, 12. Flow channel hole, 13. Flange, 14. Assembly line, 15. Handle. DETAILED DESCRIPTION
[0034] The present invention is further described in detail below in conjunction with embodiments:
[0035] The present invention is not limited to the following specific embodiments. A person skilled in the art can implement the present invention in various other specific embodiments according to the contents disclosed in the present invention, or any simple changes or modifications made to the design structure and ideas of the present invention fall within the protection scope of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.
[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.
[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.
[0038] Example 1
[0039] like Figure 1-9 As shown, an automatic cutting device for a sand-cast valve body comprises a cutting robot 1, an identification mechanism 2, a tool 3 for fixing a valve body 11 and a shape deviation correction mechanism, wherein the shape deviation correction mechanism comprises a correction body 4, one end of which is provided with a flow channel positioning member 5 and a flange end face positioning member 6, the flow channel positioning member 5 is used to cooperate with the flow channel hole 12 of the valve body 11 and prevent the correction body 4 from deviating from or falling off the valve body 11, the flange end face positioning member 6 is used to cooperate with the end face of the flange 13 of the valve body 11 and prevent the correction body 4 from tilting on the valve body 11, and the other end of the correction body 4 is provided with a mark placement point 10 for the identification mechanism 2 to obtain the relative spatial position of the valve body 11, the mark placement point 10 provides a precise positioning reference for the valve body 11 of the same series, and in this embodiment, the identification mechanism 2 is a recognition camera;
[0040] The other end of the correction body 4 is provided with a marking mechanism 7 for positioning the flow channel positioning member 5 of the correction body 4 relative to the flow channel hole 12 in the circumferential direction and improving the relative accuracy between the correction body 4 and the valve body 11 .
[0041] The flow channel positioning member 5 includes four first positioning pins 501 arranged in parallel. In order to prevent the first positioning pins 501 from being over-positioned, the number of the first positioning pins 501 in this embodiment is controlled and should not be too many. There are four first positioning pins 501. In addition to the four first positioning pins 501, there can also be two or three. The four first positioning pins 501 are evenly arranged along the circumferential direction with the central axis of the flow channel hole 12 as the center point. The four first positioning pins 501 are all inscribed with the flow channel hole 12. In this embodiment, the flow channel positioning member 5 is the first positioning pin 501. The positioning pin is a standard part with high positioning accuracy. In addition to being a positioning pin, it can also be a plurality of positioning blocks arranged along the circumferential direction, or the flow channel positioning member 5 can also be a first positioning ring matching the flow channel hole 12.
[0042] The flange end face positioning member 6 includes four second positioning pins 601 arranged in parallel. In this embodiment, there are four second positioning pins 601. In addition to the four second positioning pins 601, there may also be three or five. The four second positioning pins 601 are evenly arranged along the circumferential direction with the central axis of the flow channel hole 12 as the center point. The four second positioning pins 601 are of equal length. The four second positioning pins 601 are located at the outer periphery of the four first positioning pins 501 on the flow channel positioning member 5 along the radial direction of the flow channel hole 12. In this embodiment, the flange end face positioning member 6 is the second positioning pin 601. The positioning pin is a standard part with high positioning accuracy. In addition to the positioning pin, it can also be a plurality of positioning blocks arranged along the circumferential direction, or the flange end face positioning member 6 can also be a second positioning ring in contact with the end face of the flange 13.
[0043] The identification mechanism 7 includes a positioning mark set on the correction body 4 and a specific mark on the valve body 11. The positioning mark corresponds to the specific mark on the valve body 11. The positioning mark includes a positioning point 8. The specific mark point is the closing line 14. The positioning point 8 is used to correspond to the closing line 14. There are two positioning points 8 respectively set on both sides of the correction body 4. The two positioning points 8 are distributed at the end points on both sides of the center line of the flow channel hole 12 respectively. The positioning point 8 is an arrow pointing to the closing line 14. The arrow can be colored to improve the contrast of the positioning point 8 and facilitate observation by the staff.
[0044] A handle 9 is provided on the other end of the correction body 4 .
[0045] There are three marking points 10, which are respectively distributed at any three vertices on the rectangle. The three points form a surface, and since the three points are three vertices on the rectangle, the positions between the three points are determined, and the distances between the three points are also determined, forming a coordinate system on the surface, thereby improving the recognition efficiency and accuracy of the correction body 4.
[0046] Example 2
[0047] Example 2 is an application of Example 1, specifically: a cutting method using the above-mentioned sand casting valve body automatic cutting device, the specific operating steps are as follows:
[0048] S1. Define the coordinate system of the morphology deviation correction mechanism through the identification mechanism 2, and use the defined morphology deviation correction mechanism coordinate system to call the ignition program of the cutting robot 1, and after the cutting gun of the cutting robot 1 is ignited, control the cutting robot 1 to move to the point to be cut, and control the cutting robot 1 to move from the point to be cut to the starting point of the riser cutting. After reaching the predetermined distance, stay for 30 seconds, and preheat the cutting position of the valve body 11, so as to realize the motion control of the cutting robot 1 in this coordinate system;
[0049] S2, fix the valve body 11 to be processed on the tooling 3, and the central axis of the flow channel hole 12 of the valve body 11 is set horizontally, so as to fix the position of the valve body 11 to be processed;
[0050] S3, then place the four first positioning pins 501 at one end of the correction body 4 in the flow channel hole 12 on the valve body 11, so that the flow channel positioning member 5 on the morphology deviation correction mechanism is placed in the flow channel hole 12 of the valve body 11, and the correction body 4 cannot be displaced radially along the flow channel hole 12, and the flow channel positioning member 5 prevents the correction body 4 from being offset or falling off the valve body 11, and then four second positioning pins 601 are set against the end face of the flange 13 of the valve body 11, so that the correction body 4 and the end face of the flange 13 are equidistant and parallel to each other, so that the flange end face positioning member 6 is set against the end face of the flange 13 of the valve body 11;
[0051] S4, align the positioning points 8 on both sides of the correction body 4 with the corresponding closing lines 14 on the valve body 11, so that the marking mechanism 7 corresponds to the closing line 14 on the valve body 11, and the shape deviation correction mechanism is assembled to the required position on the valve body 11, completing the assembly of the shape deviation correction mechanism on the valve body 11;
[0052] S5, using the recognition camera of the recognition mechanism 2 to correct the three mark placement points 10 at one end of the body 4, and determine the position of the correction body 4, and thus obtain the position of the valve body 11, so as to obtain the relative spatial position of the valve body 11 through the mark placement points 10 on the morphology deviation correction mechanism;
[0053] S6. When cutting the valve body 11, the ignition program of the cutting robot 1 is run to control the opening and closing of the solenoid valve, and the cutting oxygen switch of the cutting gun on the cutting robot 1 is turned on. After determining the position of the valve body 11 and calculating the cutting trajectory through the single-chip microcomputer, the robot 1 performs arc or linear motion at a preset speed and the distance from the end face of the riser, and runs through the midpoint of the riser cutting until the end position of the riser cutting. After the riser is cut off and falls off, the cutting oxygen switch is turned off, and the cutting robot 1 is moved to the next point to be cut, and the cutting of another riser is started according to the cutting steps in step S6;
[0054] S7. When cutting the next valve body 11, repeat steps S2-S6.
[0055] In step S1, the cutting robot 1 takes the Kawasaki robot as an example to define the coordinate system of the morphology deviation correction mechanism. The cutting compensation of the cutting robot 1 can be completed by repositioning the far point of the cutting program coordinate system of the cutting robot 1 by using the FRAME framework program. The three mark placement points 10 of the correction body 4 are used as reference points. The three mark placement points 10 are b, c and d respectively. A user reference coordinate system is established. For the three reference points, the line between bc is required to be at right angles to the line between dc. The cutting robot 1 takes the line between dc as the X-axis, the line between bc as the Y-axis, and point c as the origin to form a relative coordinate. The cutting robot 1 The motion trajectory feature points are recorded and saved in a positional relationship relative to the coordinate origin. After correcting the posture change of the body 4, it is only necessary to re-teach the new positions of the three points b', c' and d' to redefine the reference coordinate system. The relative position of the motion trajectory of the cutting robot 1 remains unchanged. By analogy, it is applied to the valve body 11 cutting program. The trajectory shown in the figure can be replaced by the cutting program. It is only necessary to find the three feature points b, c and d on the valve body 11 to redefine the user reference coordinate system, thereby realizing rapid positioning of the cutting robot 11 and cutting path planning, ensuring that during the cutting process of the same type of valve body 11, the existing program can be directly used for cutting operations.
[0056] When in use, the above-mentioned sand-cast valve body automatic cutting device and cutting method obtain the position of the valve body 11 and calculate the cutting path by identifying the mark placement point 10 on the correction body 4 through the recognition camera, and automatically cut the runner and riser of the valve body 11 through the cutting robot 1. Compared with the existing cutting method, this method has high cutting accuracy for the valve body 11 and is not affected by the runner and riser position and morphological deviation of the valve body 11 or the casting accuracy of different batches of valve bodies 11.
[0057] The above-mentioned ideal embodiments of the present invention are for inspiration. Through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. An automated sand casting valve body cutting device, comprising a cutting robot (1), an identification mechanism (2) and a tool (3) for fixing a valve body (11), characterized in that: It also includes a shape deviation correction mechanism, the shape deviation correction mechanism includes a correction body (4), one end of the correction body (4) is provided with a flow channel positioning member (5) and a flange end face positioning member (6), the flow channel positioning member (5) is used to cooperate with the flow channel hole (12) of the valve body (11) and prevent the correction body (4) from deviating or falling off the valve body (11), the flange end face positioning member (6) is used to cooperate with the end face of the flange (13) of the valve body (11) and prevent the correction body (4) from tilting on the valve body (11), and the other end of the correction body (4) is provided with a marking placement point (10) for the identification mechanism (2) to obtain the relative spatial position of the valve body (11); The other end of the correction body (4) is provided with a marking mechanism (7) for positioning the flow channel positioning member (5) of the correction body (4) relative to the flow channel hole (12) in the circumferential direction.
2. The automatic cutting device for sand casting valve body according to claim 1, characterized in that: The flow channel positioning member (5) comprises at least two first positioning pins (501) arranged in parallel, the first positioning pins (501) being arranged along the circumferential direction, and the first positioning pins (501) and the flow channel hole (12) being inscribed with each other.
3. The automatic cutting device for sand casting valve body according to claim 1, characterized in that: The flange end surface positioning member (6) comprises at least three second positioning pins (601) arranged in parallel, and the second positioning pins (601) are radially located outside the flow channel positioning member (5) along the flow channel hole (12).
4. The automatic cutting device for sand casting valve body according to claim 1, characterized in that: The identification mechanism (7) comprises a positioning mark arranged on the correction body (4) and a specific mark on the valve body (11), and the positioning mark corresponds to the specific mark on the valve body (11).
5. The automatic cutting device for sand casting valve body according to claim 4, characterized in that: The positioning mark is a positioning point (8), and there are two positioning points (8); The specific marking point is a closing line (14), and the two positioning points (8) respectively correspond to the closing lines (14) on the valve body (11) at both sides of the flow channel hole (12).
6. The automatic cutting device for sand casting valve body according to claim 1, characterized in that: A handle (9) is provided on the other end of the correction body (4).
7. The automatic cutting device for sand casting valve body according to claim 1, characterized in that: There are three marking placement points (10), and the three marking placement points (10) are respectively distributed at any three vertices on the rectangle.
8. A cutting method using the automatic cutting device for sand casting valve body according to any one of claims 1 to 7, characterized in that: The specific steps are as follows: S1, defining the coordinate system of the shape deviation correction mechanism through the identification mechanism (2), and using the defined shape deviation correction mechanism coordinate system to control the motion of the cutting robot (1) in this coordinate system; S2, fixing the valve body (11) to be processed on the tooling (3); S3, placing the flow channel positioning member (5) on the shape deviation correction mechanism in the flow channel hole (12) of the valve body (11), and then placing the flange end face positioning member (6) against the end face of the flange (13) of the valve body (11); S4, assembling the shape deviation correction mechanism to a desired position on the valve body (11) through the marking mechanism (7), thereby completing the assembly of the shape deviation correction mechanism on the valve body (11); S5, identifying the marking placement point (10) on the shape deviation correction mechanism through the identification mechanism (2), and obtaining the relative spatial position of the valve body (11); S6. When cutting the valve body (11), the ignition program of the cutting robot (1) is run to control the opening and closing of the electromagnetic valve, and the cutting oxygen switch of the cutting gun on the cutting robot (1) is turned on. After determining the position of the valve body (11) and calculating the cutting trajectory, the robot performs arc or linear motion at a preset speed and distance from the end face of the riser, passes through the midpoint of the riser cutting, and reaches the end position of the riser cutting. After the riser is cut off and falls off, the cutting oxygen switch is turned off, and the cutting robot is moved to the next point to be cut. The same as the above cutting process is used to start cutting another riser. S7. When cutting the next valve body (11), repeat steps S2-S6.