Convex grinding system, convex grinding method, and method for manufacturing steel product

Abstract

A projection grinding system is provided with: a shape measurement device (3) that measures the three-dimensional shape and orientation of a target; a convex portion detection device (4) that detects a convex portion present on the surface of the object and recognizes the position and shape of the convex portion; a grinding device (7) provided with a grinding tool for grinding the convex part; and a grinding tool control device (5) that calculates a trajectory of movement of the grinding tool on the basis of the measured three-dimensional shape and orientation of the object and the detected position and shape of the convex part, and controls the grinding device so that the grinding tool moves along the trajectory while changing the contact angle of the grinding tool with respect to the convex part.

Description

Technical Field

[0001] The present disclosure relates to a convex portion grinding system, a convex portion grinding method, and a method for manufacturing a steel product. In particular, the present disclosure relates to a convex portion grinding system, a convex portion grinding method, and a method for manufacturing a steel product for removing harmful convex portions existing on the surface of a steel product or the like. Background Art

[0002] In order to suppress the influence of the "runner" that is the passage of the molten metal during casting and the "pores" that are harmful defects generated inside the product, a portion called a "riser" is added to the casting to allow the final cooling process to be performed outside the product. Usually, the above-mentioned unnecessary portions are removed by cutting, shearing, hammering, or breaking by self-weight in the process of removing the casting from the casting mold, but sometimes a part remains and becomes a "convex portion" that is harmful to the surface of the casting.

[0003] Especially in the case of a variety of products, the position and shape of the convex part are various, so the current situation is that the convex part is often removed by manual grinding using a grinder. In the case of such a large convex part, there is a case where the height is several tens of mm, and the load of the grinding operation is high, and it becomes difficult to ensure the safety of the operator. In addition, in the case of a large convex part or in the case of a difficult-to-process material such as high-alloy steel, it is difficult to grind at a high speed.

[0004] Patent Document 1 proposes a method of grinding a steel material by having a robot hold a grinder and applying a constant pressing force along a predetermined machining trajectory. Patent Document 2 proposes a method of grinding a steel material at high speed by machining in a non-oxidizing gas atmosphere.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 3-178766

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 11-267954

[0007] Here, the technology of Patent Document 1 is a system that performs processing along a predetermined trajectory, and cannot automatically cope with a wide variety of products.

[0008] Furthermore, the technology of Patent Document 2 requires sealing and vacuuming of a large-scale production line, and thus equipment cost and running cost become extremely high.

[0009] For the convex parts generated by various products, human operators observe the workpiece with their eyes, press the grinder to the convex part of the workpiece to feel the appropriate pressure, and stop pressing the grinder at the appropriate time. The operator uses his eyes to observe whether there are any convex parts left, and decides whether to perform regrinding or end the repair work. Such operations are required to be automated. Summary of the invention

[0010] The present disclosure has been made in view of the above circumstances and aims to provide a convex portion grinding system, a convex portion grinding method, and a method for manufacturing a steel product that automatically grind convex portions generated on various products.

[0011] The present inventors have carefully studied a method for solving the above-mentioned problems. The operator's work was analyzed, including: (1) measuring the shape and posture of the workpiece based on visual information; (2) the action of pressing the grinding wheel of the grinder; (3) sensing and controlling the grinding reaction force and load after the grinding wheel is pressed based on tactile and force senses; (4) changing the grinding wheel angle during grinding; and (5) checking the remaining condition of the convex part after grinding based on visual information.

[0012] Based on the analysis of the above-mentioned operations, as a method for automating the grinding of the protrusions of the cut workpiece, a system is proposed that performs at least part of the following actions: (1) measuring the shape and posture of the cut workpiece using a three-dimensional shape measuring device; (2) identifying the position of the protrusion; (3) measuring and controlling the grinding reaction force and load; (4) controlling the pressing action toward the protrusion position that can change the contact angle of the grinding wheel during grinding; and (5) checking the residual condition of the protrusion after grinding and judging whether it should be regrinded.

[0013] [1] A convex portion grinding system according to one embodiment of the present disclosure includes:

[0014] A shape measuring device for measuring the three-dimensional shape and posture of an object;

[0015] a convex portion detection device for detecting a convex portion existing on the surface of the object and identifying the position and shape of the convex portion;

[0016] a grinding device having a grinding tool for grinding the convex portion; and

[0017] A grinding tool control device calculates a trajectory of movement of the grinding tool based on the measured three-dimensional shape and posture of the object part and the detected position and shape of the protrusion, and controls the grinding device in a manner that causes the grinding tool to move along the trajectory while changing a contact angle of the grinding tool relative to the protrusion.

[0018] [2] As an embodiment of the present disclosure, based on [1], it has:

[0019] a grinding reaction force measuring device for measuring the grinding reaction force received by the grinding tool from the object;

[0020] The grinding tool control device corrects the trajectory based on the measured grinding reaction force, and controls the grinding device so that the grinding tool moves along the corrected trajectory.

[0021] [3] As an embodiment of the present disclosure, based on [2],

[0022] The grinding tool control device is configured to include a first grinding tool control device and a second grinding tool control device.

[0023] The first grinding tool control device corrects the trajectory in the height direction based on the measured height component of the grinding reaction force.

[0024] The second grinding tool control device corrects the trajectory in a direction different from the height direction based on the measured component of the grinding reaction force in a direction different from the height direction.

[0025] [4] As an embodiment of the present disclosure, in addition to any one of [1] to [3], it includes:

[0026] The inspection device inspects the surface of the object at the position of the convex portion after the convex portion is ground.

[0027] [5] As one embodiment of the present disclosure, in addition to any one of [1] to [4],

[0028] The above-mentioned grinding tool is a grinding wheel that rotates around a rotation axis.

[0029] The grinding tool control device controls the grinding device so that the rotation axis is tilted according to a position where the grinding wheel contacts the convex portion.

[0030] [6] A method for grinding a convex portion according to an embodiment of the present disclosure includes:

[0031] The shape measurement process measures the three-dimensional shape and posture of the object;

[0032] a convex portion detection step of detecting a convex portion existing on the surface of the object, and detecting the position and shape of the convex portion; and

[0033] The grinding process calculates the trajectory of the grinding tool for grinding the above-mentioned protrusion based on the measured three-dimensional shape and posture of the above-mentioned object part and the detected position and shape of the above-mentioned protrusion, and grinds the above-mentioned protrusion by moving the above-mentioned grinding tool along the trajectory while changing the contact angle of the above-mentioned grinding tool relative to the above-mentioned protrusion.

[0034] [7] As an embodiment of the present disclosure, based on [6],

[0035] The grinding step measures a grinding reaction force received by the grinding tool from the workpiece, corrects the trajectory based on the measured grinding reaction force, and grinds the convex portion by moving the grinding tool along the corrected trajectory.

[0036] [8] As an embodiment of the present disclosure, based on [6] or [7], it includes:

[0037] An inspection step of inspecting the surface of the object at the position of the convex portion after the grinding step.

[0038] [9] A method for manufacturing a steel product according to one embodiment of the present disclosure grinds a convex portion on a surface of a steel product as the target object using the convex portion grinding method according to any one of [6] to [8].

[0039] According to the present disclosure, it is possible to provide a convex portion grinding system, a convex portion grinding method, and a method for manufacturing a steel product that automatically grind convex portions generated on various products. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of a convex portion grinding system according to one embodiment.

[0041] Figure 2 This is a diagram for explaining the reference point of the grinding wheel.

[0042] Figure 3 This is a diagram for explaining the contact angle of the grinding wheel.

[0043] Figure 4 It is a figure which shows an example of shape measurement and convex part extraction.

[0044] Figure 5 It is a diagram showing another example of shape measurement and convex portion extraction.

[0045] Figure 6 This is a diagram illustrating a method of generating a machining trajectory on the xy plane.

[0046] Figure 7 This is a diagram illustrating the calculation of the z-coordinate position of the machining trajectory.

[0047] Figure 8 This is a diagram showing a configuration example of a convex portion grinding system that performs control in accordance with the grinding reaction force.

[0048] Fig. 9 This is a diagram showing another configuration example of a convex portion grinding system that performs control according to the grinding reaction force. DETAILED DESCRIPTION

[0049] Hereinafter, a convex portion grinding system, a convex portion grinding method, and a method for manufacturing a steel product according to an embodiment of the present disclosure will be described with reference to the drawings.

[0050] Figure 1 An example of a schematic diagram of a convex portion grinding system according to the present embodiment is shown. A convex portion 2 exists on the surface of a workpiece 1 as an example of an object. A three-dimensional shape measuring device 3 as an example of a shape measuring device measures the three-dimensional shape and posture of the workpiece 1. As the three-dimensional shape measuring device 3, for example, a camera that performs three-dimensional scanning of the workpiece 1, a shape laser sensor, etc. can be used. An image processing device 4 as an example of a convex portion detection device detects the convex portion 2 existing on the surface of the workpiece 1 based on the measurement result of the three-dimensional shape measuring device 3, and recognizes the position and shape of the convex portion 2. A robot motion control device 5 as an example of a grinding tool control device performs inverse kinematics calculation based on the measured three-dimensional shape and posture of the workpiece 1 and the detected position and shape of the convex portion 2, and calculates the trajectory of movement in a manner such that the grinding wheel 8 is pressed against the position of the convex portion 2. Here, the grinding wheel 8 is a grinding tool for grinding the convex portion 2, and is equipped in a grinder 7 as an example of a grinding device. The grinder 7 is moved by a robot 6 having multiple joints. The robot 6 is controlled by the robot motion control device 5. That is, the robot motion control device 5 can control the grinder 7 via the robot 6 so that the grinding wheel 8 moves along the calculated trajectory. In addition, the calculated trajectory of movement of the grinding wheel 8 also corresponds to the motion trajectory of the robot 6.

[0051] The robot 6 moves based on the generated motion trajectory, and the grinding wheel 8 contacts the workpiece 1 and the convex portion 2 to grind the convex portion 2. At this time, the grinding reaction force measuring device 9 measures the grinding reaction force received by the grinding wheel 8 from the workpiece 1. The robot motion control device 5 controls the motion of the robot 6 in such a way that the measured grinding reaction force becomes the target grinding reaction force, and presses the grinding wheel 8 against the workpiece 1 and the convex portion 2, or separates the grinding wheel 8 from the workpiece 1 and the convex portion 2. After grinding the convex portion 2 to a constant time or a predetermined grinding amount, the robot motion control device 5 measures the shape of the workpiece 1 after grinding through the three-dimensional shape measuring device 3. The robot motion control device 5 determines whether the remaining convex portion 2 is detected by the image processing device 4, and if the convex portion 2 remains, grinding is performed again. If no convex portion 2 remains, the robot motion control device 5 ends grinding. The convex portion grinding system may include an inspection device that inspects the surface of the workpiece 1 at the position of the convex portion 2 after the convex portion 2 is ground. At this time, the robot motion control device 5 can perform grinding again or end grinding based on the inspection result from the inspection device. The inspection device may be configured to include a three-dimensional shape measuring device 3 and an image processing device 4.

[0052] Here, one of the features of the convex portion grinding system according to the present embodiment is that the robot motion control device 5 controls the grinder 7 in such a manner that the grinding wheel 8 moves along the calculated trajectory while changing the contact angle of the grinding wheel 8 relative to the convex portion 2. The grinding performed by the convex portion grinding system according to the present embodiment while changing the contact angle of the grinding wheel 8 is sometimes referred to as "contact angle change grinding".

[0053] Figure 2 1 is a diagram for explaining the reference point 12 of the grinding wheel 8. The reference point 12 is the point where the convex portion 2 contacts the grinding wheel 8 when the grinding wheel 8 is in the reference posture. However, when the contact portion is not a point, it refers to the center of the contact portion. In this embodiment, the grinding wheel 8 rotates around the rotation axis 10. When viewed from a viewpoint perpendicular to the rotation axis 10 and the paper surface ( Figure 2 The point where the convex portion 2 contacts the grinding wheel 8 is the reference point 12. When the rotation axis 10 is parallel to the paper surface ( Figure 2 ), the thickness of the grinding wheel 8 is set to t, and the point where the convex portion 2 contacts the grinding wheel 8 at a position t / 2 from the grinding wheel surface 11 which is the front end surface of the grinding wheel 8 becomes the reference point 12 (reference point 12 in the thickness direction of the grinding wheel 8). The thickness of the grinding wheel 8, i.e., t, is, as an example, 10 to 50 mm.

[0054] Figure 3 It is a diagram for explaining the contact angle θ of the grinding wheel 8 . Figure 3 The processing trajectory 13 and the rotation axis 10 are shown in an imaginary cross-sectional view on the paper surface (on the same plane). The processing trajectory 13 is the trajectory of the grinding wheel 8 calculated by the robot motion control device 5. Figure 3 In FIG. 1 , an auxiliary line 14 perpendicular to the machining trajectory 13 is drawn, and the contact angle θ is the angle between the auxiliary line 14 and the grinding wheel surface 11. Figure 3 In the example, the point where the grinding wheel 8 starts moving, the point where it advances to the midpoint of the processing trajectory 13, and the point where it ends moving are represented as trajectory starting point 15, trajectory midpoint 16, and trajectory ending point 17, respectively. The contact angle θ at the trajectory starting point 15 is θmax. The contact angle θ at the trajectory midpoint 16 is 0. The contact angle θ at the trajectory ending point 17 is θmin, which is equal to –θmax. θmax is 5° as an example. The grinding wheel 8 is tilted by the robot motion control device 5 in a manner having a contact angle θ corresponding to a displacement from the reference point 12 in one direction (the x direction in the example described later). In other words, the robot motion control device 5 controls the grinder 7 in a manner in which the rotating shaft 10 is tilted according to the position at which the grinding wheel 8 contacts the protrusion 2. The robot motion control device 5 performs contact angle change grinding in a manner in which θ continuously changes at each position of the processing trajectory 13. In Figure 3In the example of FIG. 1 , the grinding wheel 8 at the midpoint 16 of the trajectory takes the reference posture, and the midpoint 16 of the trajectory corresponds to the reference point 12 in the thickness direction of the grinding wheel 8. Figure 3 In the example of FIG. 1 , the grinding wheel 8 is tilted symmetrically around the reference point 12 like a pendulum, but may be asymmetrical (θmin is not equal to −θmax).

[0055] In the contact angle changing grinding, the contact angle between the grinding wheel 8 and the convex portion 2 is changed in various ways to promote the shedding of abrasive grains, so that clogging does not occur and new abrasive grains are always used for cutting, thereby achieving high-speed grinding. The change pattern of θ is not limited to Figure 3 For example, various adjustments can be made according to the characteristics of the workpiece 1 and the grinding wheel 8, the rotation speed, the feed speed, the pressing pressure and other grinding conditions. For example, by selecting an appropriate change pattern of θ according to the type of the workpiece 1, higher-speed processing can be achieved. Figure 3 In the example shown in FIG. 1 , the machining trajectory 13 is shown as a straight line for simplification. The actual machining trajectory 13 is often a complex curve that matches the shape of the convex portion 2. However, by making the tangent of the curved trajectory Figure 3 The contact angle-changing grinding can be performed in accordance with the linear machining trajectory 13 as in the example of FIG.

[0056] (Example)

[0057] Figure 4 and Figure 5 An example in which the convex portion 2 is identified by shape measurement is shown. Figure 4 Represents the recognition logic of the protrusion 2 based on the height. First, the image processing device 4 sets the measurement coordinate system 18 when the three-dimensional shape measuring device 3 measures the shape of the workpiece 1. The three-dimensional shape measuring device 3 is a camera. The measurement coordinate system 18 is set to use the height direction as the z coordinate. The workpiece shape data 19 obtained by the measurement performed by the three-dimensional shape measuring device 3 is ordinary three-dimensional point cloud data. The point cloud with a z coordinate value above a certain value in the three-dimensional point cloud data is used as the protrusion shape data 20 (point cloud data of the protrusion 2). The recognition logic of this method is very simple and can perform calculations at a high speed. However, in the case where the height dimension of the workpiece 1 changes frequently, and in the case where the deviations in posture and size are large, there is a concern that the protrusion shape data 20 contains inaccurate data.

[0058] Figure 5A method for obtaining convex shape data 20 as a portion not existing in the comparative CAD data 21 by performing three-dimensional pattern matching between the measured workpiece shape data 19 and the comparative CAD data 21 is shown. The comparative CAD data 21 is CAD data of the workpiece 1. The image processing device 4 obtains the comparative CAD data 21 from a computer or the like that has previously designed the workpiece 1. This method is not easily affected by the posture and dimensional deviation, shape change, etc. of the workpiece 1. For example, when the workpiece 1 is tilted during measurement, the convex shape data 20 can be accurately obtained by making the comparative CAD data 21 tilted in the same manner in the image processing device 4 for comparison.

[0059] Here, you can select and apply according to the situation. Figure 4 Ways and Figure 5 For example, when it is determined that the workpiece 1 is tilted during measurement, or when multiple types of workpieces 1 with frequently changing height dimensions are taken as the object, the image processing device 4 can Figure 4 Switch to Figure 5 By selecting the method according to the situation, the image processing device 4 can improve the recognition accuracy of the convex portion 2, can also handle a variety of workpieces 1, and can also suppress the calculation load as much as possible.

[0060] Figure 6 and Figure 7 An example of generating the machining trajectory 13 is shown. Figure 6 The method of generating the processing trajectory 13 on the xy plane is shown. The xy plane is a plane perpendicular to the z direction which is the height direction. Figure 6 In the example of FIG. 8 , the x direction corresponds to the thickness direction of the grinding wheel 8 .

[0061] The robot motion control device 5 acquires the convex shape data 20 from the image processing device 4 and generates a processing trajectory 13 for grinding the convex portion 2. The robot motion control device 5 generates the processing trajectory 13 on the xy plane as follows. Figure 6 As shown in 1), the robot motion control device 5 determines the y coordinate position with the smallest y coordinate position in the convex shape data 20. min The trajectory reference line A0 is parallel to the x-axis and passes through the y-axis with the maximum y-coordinate position. max And the trajectory reference line A1 is parallel to the x-axis.

[0062] like Figure 6 As shown in 2), the robot motion control device 5 determines the trajectory interval lines B drawn from the trajectory reference line A0 at equal intervals of Δp and parallel to the x-coordinate axis. i (i=0~N). Here, N is determined by “((y max –ymin ) / Δp)-2” is given.

[0063] The pitch Δp is set according to the shape of the grinding wheel 8. When the diameter of the grinding wheel 8 is D and the assumed cutting depth is ta, the assumed cutting depth ba is given by (D-2ta)tan(cos -1 (1-2ta / D)). At this time, the pitch Δp satisfies 0.1ba≤Δp≤ba. Here, it is assumed that the cutting depth ta is determined by a grinding experiment in advance, and is preferably in the range of about 0.1 to 8.0 mm.

[0064] Track interval line B i The intersection point B with the outer periphery of the convex portion 2 is is and B ie Here, B is is the intersection point with the smaller x coordinate value, B ie It is the intersection point with the larger x coordinate value.

[0065] like Figure 6 As shown in 3), the robot motion control device 5 will move from B in the x direction is The point with large Δx is set as C is In addition, the robot motion control device 5 will move from B in the x direction ie The point with small Δx is set as C ie Δx is the width of the blank portion which is set not to be exposed from the outer periphery of the protrusion 2 when the grinding wheel 8 moves along the machining trajectory 13. Δx can be determined based on the thickness of the grinding wheel 8. For example, assuming that the thickness of the grinding wheel 8 is t, Δx can be determined as t / 2.

[0066] like Figure 6 As shown in 4), if i is an even number, the robot motion control device 5 determines from C ie By C (i+1)s Grinding path p i In addition, if i is an odd number, the robot motion control device 5 determines from C is By C (i+1)e Grinding path p i .

[0067] Figure 7 The figure is a diagram illustrating the calculation of the z coordinate position of the machining trajectory 13. The robot motion control device 5 calculates the z coordinate position of the machining trajectory 13 in each grinding path p. i The processing path is divided into two parts according to the number of divisions Np, and each division point is set as the processing trajectory control point pg ij (j=0 to Np) The number of divisions Np between machining paths can be determined based on machining accuracy and the measurement density of the convex portion shape data 20 as point cloud data.

[0068] As an example, when the x-direction dimension LB of the convex portion 2 is i =√(B ie -B is ) 2 When the maximum size (maximum value) in (i=0-N) is set to LBmax, the number of divisions Np between machining paths is preferably in the range of LBmax / t≤Np. However, although the machining accuracy is improved as the number of divisions Np between machining paths is larger, the load of the robot motion control device 5 is higher, and thus it can also be set to LBmax / t>Np according to the memory resources of the robot motion control device 5 and the size of the convex portion 2.

[0069] The robot motion control device 5 obtains the processing trajectory control point pg based on the four points (four point cloud data) closest to the measured point i,j For example, Figure 7 As shown, the four closest measurement points are Pm k =(x k ,y k , z k ), Pm k+1 =(x k+1 ,y k+1 , z k+1 ), Pm k+2 =(x k+2 ,y k+2 , z k+2 ) and Pm k+3 =(x k+3 ,y k+3 , z k+3 ) In the case of pg i,j The z coordinate value zg i,j It is expressed by the following formula.

[0070] [Formula 1]

[0071]

[0072] l=0~3

[0073]

[0074] z coordinate value zg i,j The z coordinate values ​​of the four measurement points are weighted according to the deviation from the xy plane. i,j Here, it is used to calculate the z coordinate value zg i,j The number of measurement points is not limited to 4. In addition, as another example, the z coordinate value zg i,j It can also be obtained by averaging the z-coordinate values ​​of a plurality of closest measurement points.

[0075] Figure 8 and Fig. 9 An example of the structure of a convex grinding system that performs control corresponding to the grinding reaction force is shown. The processing trajectory 13 is determined as described above, and the grinding wheel 8 moves on the processing trajectory 13 to perform contact angle change grinding in which the contact angle θ changes according to the moving position in the x-axis direction. Here, in actual grinding, there are cases where the trajectory needs to be corrected due to the wear of the grinding wheel 8, the change of the contact angle θ of the grinding wheel 8, etc. The convex grinding system involved in this embodiment measures the load of the reaction force during grinding, etc., by the grinding reaction force measuring device 9, and changes the trajectory in a manner that becomes a preset target load to perform feedback control. For example, the robot motion control device 5 can correct the trajectory based on the measured grinding reaction force, and control the grinder 7 in a manner that the grinding wheel 8 moves along the corrected trajectory. Here, the range of the target load can be determined, for example, by extracting an appropriate load during grinding from past grinding performance data.

[0076] For example Figure 8 As shown, the processing trajectory 13 calculated as described above, that is, the predetermined trajectory 24, is fed back to the robot motion control device 5 based on the load and other measurement data of the grinding reaction force measuring device 9. The robot motion control device 5 controls the robot 6 in real time through the trajectory control operation 26, and adjusts the actual trajectory of the grinding wheel 8 to the control trajectory 25.

[0077] In the present embodiment, it is considered that the trajectory control action 26 is mostly an adjustment action in the height direction (z direction). However, the manipulator motion control device 5 controls the manipulator 6 that can move in three-dimensional directions, so even if the adjustment action is only in the height direction, all three-dimensional directions are calculated. Therefore, there is a situation where the calculation load of the manipulator motion control device 5 becomes larger. Therefore, the grinding tool control device can be configured to include a first grinding tool control device and a second grinding tool control device. The first grinding tool control device corrects the trajectory in the height direction based on the component in the height direction of the measured grinding reaction force. The second grinding tool control device corrects the trajectory in a direction different from the height direction based on the component in the direction different from the height direction of the measured grinding reaction force.

[0078] Fig. 9The grinding tool control device is configured to include a first grinding tool control device and a second grinding tool control device. The grinding wheel 8 is adjusted in the height direction by a uniaxial actuator 27. The actuator control device 29 that controls the uniaxial actuator 27 adjusts the height of the grinding wheel 8 in real time through a trajectory control action 30 based on the measured data such as the load measured by the grinding reaction force measuring device 9 that is fed back. The actuator control device 29 corresponds to the first grinding tool control device. In addition, the robot motion control device 5 corresponds to the second grinding tool control device. Fig. 9 The convex grinding system of the structure corrects the trajectory in the height direction and the trajectory in the direction different from the height direction by different grinding tool control devices. Therefore, the calculation processing is dispersed, which can avoid applying a large calculation load to one grinding tool control device and can correct the trajectory at a high speed.

[0079] As described above, the convex portion grinding system according to the present embodiment can automatically grind the convex portions 2 generated on various products by the above-mentioned configuration. Therefore, the labor of the operator who conventionally performed the grinder operation can be allocated to other operations, and the work efficiency of product manufacturing can be improved.

[0080] Although the embodiments of the present disclosure are described based on the drawings and embodiments, it should be noted that it is easy for those skilled in the art to make various deformations or modifications based on the present disclosure. Therefore, it should be noted that these deformations or modifications are included in the scope of the present disclosure. For example, the functions contained in each structural part or each step can be reconfigured in a logically non-contradictory manner, and multiple structural parts or steps can be combined into one or divided. The embodiments of the present disclosure are described with the device as the center, but the embodiments of the present disclosure can also be implemented as a method including steps performed by each structural part of the device. The embodiments of the present disclosure can also be implemented as a method executed by a processor possessed by the device, a program, or a storage medium having a program recorded thereon. It should be understood that they are also included in the scope of the present disclosure.

[0081] For example, a convex grinding method including the following processing can be performed by a convex grinding system. The convex grinding method may include a shape measuring step in which a three-dimensional shape measuring device 3 measures the three-dimensional shape and posture of a workpiece 1. The convex grinding method may include a convex detection step in which an image processing device 4 detects a convex portion 2 existing on the surface of the workpiece 1 and detects the position and shape of the convex portion 2. The convex grinding method may include a grinding step in which a robot motion control device 5 calculates a trajectory of movement of a grinding wheel 8 for grinding the convex portion 2 based on the measured three-dimensional shape and posture of the workpiece 1 and the detected position and shape of the convex portion 2, and moves the grinding wheel 8 along the trajectory while changing the contact angle θ of the grinding wheel 8 relative to the convex portion 2 to grind the convex portion 2. The convex grinding method may include an inspection step in which an inspection device inspects the surface of the workpiece 1 at the position of the convex portion 2. In the inspection step, the inspection device may perform a three-dimensional scan on the surface of the workpiece 1, and compare the measurement data with the comparison CAD data 21, and judge as qualified if the difference in the height direction is within the allowable range.

[0082] A method for manufacturing a steel product is provided in which a convex portion grinding method is implemented, for example, by a convex portion grinding system to grind a convex portion on the surface of a steel product as a target. This method for manufacturing a steel product can automate the grinding machine operation that was conventionally performed by a human operator, thereby improving the productivity of the steel product.

[0083] In addition, in the above-mentioned embodiment, the image processing device 4, the robot motion control device 5, and the actuator control device 29 are illustrated as notebook computers, but they may be other types of computers. In addition, the image processing device 4, the robot motion control device 5, and the actuator control device 29 may be implemented by other computing devices other than computers as long as they are structures capable of communicating with each other.

[0084] Description of Reference Numerals

[0085] 1…workpiece (an example of an object part); 2…convex part; 3…three-dimensional shape measuring device (an example of a shape measuring device); 4…image processing device (an example of a convex part detecting device); 5…robot motion control device (an example of a grinding tool control device); 6…robot; 7…grinder (an example of a grinding device); 8…grinding wheel (an example of a grinding tool); 9…grinding reaction force measuring device; 10…rotation axis; 11…grinding wheel surface; 12…reference point; 13…processing trajectory; 14…auxiliary line; 15…trajectory starting point; 16…trajectory midpoint; 17…trajectory ending point; 18…measurement coordinate system; 19…workpiece shape data; 20…convex part shape data; 21…comparison CAD data; 24…predetermined trajectory; 25…control trajectory; 26…trajectory control action; 27…single-axis actuator; 29…actuator control device; 30…trajectory control action.

Claims

1. A convex part grinding system, characterized in that: have: A shape measuring device for measuring the three-dimensional shape and posture of an object; a convex portion detection device for detecting a convex portion existing on the surface of the object and identifying the position and shape of the convex portion; a grinding device having a grinding tool for grinding the convex portion; as well as A grinding tool control device calculates a trajectory of movement of the grinding tool based on the measured three-dimensional shape and posture of the object part and the detected position and shape of the protrusion, and controls the grinding device in a manner that causes the grinding tool to move along the trajectory while changing the contact angle of the grinding tool relative to the protrusion.

2. The convex portion grinding system according to claim 1, characterized in that: have: a grinding reaction force measuring device for measuring the grinding reaction force received by the grinding tool from the object; The grinding tool control device corrects the trajectory based on the measured grinding reaction force, and controls the grinding device so that the grinding tool moves along the corrected trajectory.

3. The convex portion grinding system according to claim 2, characterized in that: The grinding tool control device is configured to include a first grinding tool control device and a second grinding tool control device. The first grinding tool control device corrects the trajectory in the height direction based on the measured height component of the grinding reaction force, The second grinding tool control device corrects the trajectory in a direction different from the height direction based on the measured component of the grinding reaction force in a direction different from the height direction.

4. The convex portion grinding system according to any one of claims 1 to 3, characterized in that: have: The inspection device inspects the surface of the object at the position of the convex portion after the convex portion is ground.

5. The convex portion grinding system according to any one of claims 1 to 4, characterized in that: The grinding tool is a grinding wheel that rotates around a rotation axis. The grinding tool control device controls the grinding device so that the rotation axis is tilted according to the position where the grinding wheel contacts the convex portion.

6. A method for grinding a convex portion, characterized in that: include: The shape measurement process measures the three-dimensional shape and posture of the object; a convex portion detection step of detecting a convex portion existing on the surface of the object, and detecting a position and a shape of the convex portion; as well as The grinding process calculates the trajectory of the grinding tool for grinding the convex portion based on the measured three-dimensional shape and posture of the object part and the detected position and shape of the convex portion, and grinds the convex portion by moving the grinding tool along the trajectory while changing the contact angle of the grinding tool relative to the convex portion.

7. The convex portion grinding method according to claim 6, characterized in that: The grinding step measures a grinding reaction force received by the grinding tool from the workpiece, corrects the trajectory based on the measured grinding reaction force, and grinds the convex portion by moving the grinding tool along the corrected trajectory.

8. The method for grinding a convex portion according to claim 6 or 7, characterized in that: include: An inspection step of inspecting the surface of the target material at the position of the convex portion after the grinding step.

9. A method for manufacturing a steel product, characterized in that: The convex portion on the surface of the steel product as the target object is ground by the convex portion grinding method according to any one of claims 6 to 8.

Images