WO2024071324A1

WO2024071324A1 - Scraping apparatus and scraping method

Info

Publication number: WO2024071324A1
Application number: PCT/JP2023/035484
Authority: WO
Inventors: 港町田; 正三ツ橋; 雅浩佐藤; 健志松本
Original assignee: シチズン時計株式会社
Priority date: 2022-09-30
Filing date: 2023-09-28
Publication date: 2024-04-04

Abstract

A scraping apparatus comprises a processing robot that holds and actuates a scraper having a cutting part 11 and a flexible shaft part 13 to which the cutting part is provided, and a control device that controls the processing robot in accordance with processing instruction data, the shaft part 13 being moved in a processing direction in a state in which the shaft part 13 is flexed to perform scraping on a processing object surface 91, and the control device controlling the processing robot so that the shaft part 13 is caused to move in the direction away from the processing object surface 91 while the shaft part 13 is caused to move a prescribed amount in the processing direction on the basis of the amount that the cutting part 11 moves due to elastic deformation of the shaft part 13 during separation of the cutting part 11 from the processing object surface 91.

Description

Scraping device and scraping method

The present invention relates to technology for automating scraping processes.

Scraping (also called "scraping") is performed on the sliding surfaces of machine tools and other devices with moving parts to increase their flatness and reduce the coefficient of sliding friction. Scraping is a type of metal processing, and traditionally, the surface to be machined of the workpiece is painted with red lead or a pigment, and the worker uses a scraper with a wide, chisel-shaped tip to manually scrape off and remove any protruding parts while checking the difference in color.

The original purpose of scraping is to finish the sliding surface into a highly flat surface, but the minute micron-sized depressions formed on the sliding surface by scraping act as reservoirs for lubricating oil during sliding, improving the lubrication of the sliding surface and preventing ringing during sliding. However, scraping done manually by a worker requires skill and is also very hard work.

In relation to this, an automatic scraping device has also been proposed that scrapes the surface of a workpiece by automatically controlling the operation of a scraper. For example, Patent Document 1 discloses a configuration in which a scraper is moved so that the trajectory of the scraper forms an acute angle with the surface when the cutting edge of the scraper is brought into contact with or separated from the surface.

International Publication No. WO2022/054674

However, in the above-mentioned configuration, the workpiece is machined with the scraper bent, so when the cutting edge is moved away from the surface of the workpiece, the scraper unbends and the cutting edge moves at the same time. Therefore, depending on the trajectory of the scraper, the cutting edge moves in the opposite direction to the machining direction. This can result in the cutting edge not being able to machine the intended length, leaving uncut material, or burrs easily occurring near the end of the machining path.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a technology for scraping devices that perform scraping, which suppresses the occurrence of uncut areas and burrs on the surface to be processed.

(Aspect 1)
In order to solve the above problems, a scraping device according to a first aspect of the present invention comprises a processing robot that holds and operates a scraper having a blade portion and a flexible handle portion on which the blade portion is provided, and a control device that controls the processing robot in accordance with processing instruction data, and by moving the handle portion in a direction approaching the processing surface from a state in which the blade portion is in contact with the processing surface of a workpiece, the handle portion is bent so that the blade portion moves in a processing direction along the processing surface, and in a bent state, the handle portion is moved in the processing direction to perform scraping on the processing surface, and the control device controls the processing robot to move the handle portion in a direction away from the processing surface while moving a predetermined amount in the processing direction based on the amount by which the blade portion moves due to the elastic deformation of the handle portion when the blade portion is moved away from the processing surface.

(Aspect 2)
In the above-mentioned aspect 1, the specified amount may be greater than or equal to the amount by which the blade portion moves in the processing direction when the handle portion bends from a state in which the blade portion begins to come into contact with the surface to be processed, in the scraping process, in a direction approaching the surface to be processed.

(Aspect 3)
In the above-mentioned first or second aspect, the control device may move the handle portion by the predetermined amount in the processing direction before the blade portion separates from the surface to be processed.

(Aspect 4)
In any one of aspects 1 to 3 above, when the amount by which the handle portion moves from a state in which the blade portion is in contact with the surface to be processed toward the surface to be processed in a direction perpendicular to the surface to be processed is defined as a push-in amount, the control device may control the processing robot so that, when the blade portion is moved away from the surface to be processed in the scraping process, the control device controls the processing robot to move the handle portion the predetermined amount in the processing direction before moving the handle portion the push-in amount in the direction away from the surface to be processed in the perpendicular direction.

(Aspect 5)
In any one of the above aspects 1 to 4, the handle portion is approximately strip-shaped, and the blade portion is provided at one end in the longitudinal direction, and the control device may control the orientation of the scraper during the scraping process so that the blade portion is positioned at the tip of the scraper in the processing direction.

(Aspect 6)
In any one of the above aspects 1 to 5, the blade portion may be replaceably attached to the handle portion.

(Aspect 7)
In any one of the above aspects 1 to 6, the processing robot may be configured to be able to adjust a cutting angle between a surface of the blade portion facing the surface to be processed and the surface to be processed.

(Aspect 8)
In order to solve the above problems, a scraping method according to an eighth aspect of the present invention is a scraping method using a scraping device that includes a processing robot that holds and operates a scraper having a blade portion and a flexible handle portion on which the blade portion is provided, and a control device that controls the processing robot in accordance with processing instruction data, and performs scraping on a surface to be processed of a workpiece, wherein in the scraping, the control device controls the processing robot to move the handle portion from a state in which the blade portion is in contact with the surface to be processed in a direction approaching the surface to be processed, thereby bending the handle portion so that the blade portion moves in a processing direction along the surface to be processed, and to move the handle portion in the bending state in the processing direction to move the blade portion away from the surface to be processed, while moving the handle portion a predetermined amount in the processing direction based on the amount by which the blade portion moves due to the elastic deformation of the handle portion.

(Aspect 9)
In the above-mentioned aspect 8, the specified amount may be greater than or equal to the amount by which the blade portion moves in the processing direction when the handle portion bends from a state in which the blade portion begins to come into contact with the surface to be processed, in the scraping process, in a direction approaching the surface to be processed.

(Aspect 10)
In the above-mentioned aspect 8 or 9, the cutting edge of the blade portion has a convex arc shape at the center in the blade width direction, and the method may include a first processing step in which a first abutment portion of the cutting edge is abutted against the surface to be machined while an angle between a center line of the blade portion in the blade width direction and the machining direction is set to a first angle when viewed from a direction perpendicular to the surface to be machined, and a second processing step in which a second abutment portion of the cutting edge, located at a position different from the first abutment portion, is abutted against the surface to be machined while the angle is set to a second angle different from the first angle, to machine the surface to be machined.

The present invention provides a technology for scraping devices that perform scraping processes and that suppresses the occurrence of uncut areas and burrs on the surface to be processed.

FIG. 1 is a diagram showing a schematic configuration of a scraping device according to an embodiment. FIG. 1 is a diagram showing a scraper held by a robot hand in an embodiment. FIG. 2 is a block diagram showing an example of a configuration of a control device according to an embodiment. FIG. 2 is a block diagram illustrating an example of a functional configuration of a control device according to an embodiment. FIG. 13 is a diagram showing a machining path of scraping according to a comparative example. FIG. 13 is a diagram showing the vicinity of the end point of a machining path of scraping in a comparative example. FIG. 4 is a diagram showing a machining path of scraping according to the embodiment. FIG. 13 is a diagram showing the vicinity of the end point of the machining path of the scraping process in the embodiment. FIG. 11 is a diagram showing a trajectory of a robot hand during scraping in the embodiment. FIG. 2 is a schematic top view showing the relationship between a scraper and a processing area according to the embodiment.

Below, with reference to the drawings, a detailed description of the mode for carrying out this invention will be given by way of example. Note that the dimensions, materials, shapes and relative arrangements of the components described in this embodiment should be modified as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, it is not intended to limit the scope of this invention to the following embodiment.

<Example>
(Scrape processing device 100)
First, a schematic configuration of a scraping apparatus 100 according to an embodiment of the present invention will be described. Fig. 1 is a schematic diagram showing a schematic configuration of the scraping apparatus 100 according to the embodiment. The scraping apparatus 100 includes a robot arm 20 that holds and operates a scraper 10, and a control device 30 that controls the robot arm 20 according to processing instruction data.

The scraping device 100 is a device that automatically performs scraping on the processing target surface (machined surface) 91 of the workpiece 90, which is the object to be processed. The workpiece 90 is, for example, a metallic sliding member that constitutes a machine tool, and its sliding surface is processed by scraping as the processing target surface 91. Scraping is a type of metal processing, and uses a scraper 10, which is a scraping tool (cutting tool), to scrape off the convex parts of the processing target surface 91, increasing the flatness of the processing target surface 91, and further reducing the coefficient of sliding friction by forming an oil reservoir.

The surface 91 to be machined in scraping is generally a flat surface with a certain degree of flatness and minute irregularities, which is achieved by cutting, grinding, or other processes on the cast surface. The original purpose of scraping is to finish the sliding surface into a highly accurate flat surface. Furthermore, in order to prevent the wringing phenomenon from occurring when the sliding surface slides, the scraping process forms many minute depressions on the sliding surface, measuring in microns, as reservoirs for lubricating oil, improving the lubricity of the sliding surface.

The scraping device 100 in this embodiment performs a flattening process to cut convex portions of the surface 91 to be machined so that the flatness of the surface 91 meets a predetermined target flatness, and a finishing process to form depressions for oil reservoirs in the surface 91 to be machined after the flattening process. In order to improve precision and processing efficiency, different cutting conditions and scraping tools are generally used for each process.

The scraper 10 has a blade portion 11 and a flexible handle portion 13 that can be attached and detached to the robot arm 20. The blade portion 11 is made of, for example, a cemented carbide alloy, and is capable of cutting the processing surface 91 of, for example, a metal workpiece 90.

The handle 13 is generally strip-shaped and made of a flexible metal material, with the blade 11 replaceably attached to one end in the longitudinal direction. That is, the handle 13 holds the blade 11 in a removable manner. When the blade 11 wears out due to repeated machining, or when a blade 11 with a different cutting edge width or curvature radius is used, a new blade 11 can be attached to the handle 13. Note that when applying the present invention, the scraper configuration is not limited to the one described above, and may be, for example, one in which the blade is inseparable from the handle, or one in which the blade and handle are formed as one unit.

The robot arm 20 is, for example, a six-axis articulated robot arm, and is a processing robot controlled by the control device 30. The robot arm 20 has a robot hand 21 at its tip. The robot hand 21 can detachably hold (grasp) the scraper 10 and a hand chuck (not shown). That is, the robot arm 20 can selectively attach and remove the scraper 10 and the hand chuck to the robot hand 21. The robot arm 20 can move the robot hand 21 to any position in the XYZ three-dimensional orthogonal coordinate system by driving each joint (for example, the first axis to the sixth axis) with a servo motor or the like. The robot arm 20 can also bring the scraper 10 held by the robot hand 21 into contact with the surface 91 to be processed in any direction or angle.

The robot arm 20 also includes a force sensor (not shown). The force sensor is a sensor that detects the load (resistance) acting on the scraper 10 during scraping. The control device 30 of the scraping device 100 monitors the load state during scraping output by the force sensor, and can perform feedback control based on the strength of the load as necessary. Note that the above-mentioned robot arm 20 is an example of a scraping robot according to the present invention, and scraping robots are not limited to the robot arm 20. The scraping robot according to the present invention is not particularly limited as long as it is configured to automatically scrape the surface 91 to be processed of the workpiece 90 by operating the scraper 10 held by it.

The scraping process for the workpiece surface 91 of the workpiece 90 is performed, for example, by fixing the workpiece 90 to the processing stand 80 and controlling the robot arm 20 with the control device 30 controlling the robot arm 20 while the scraper 10 is held by the robot hand 21. The surface of the processing stand 80 is formed into a horizontal plane, and the workpiece surface 91 may or may not be parallel to this surface.

In addition, in scraping, three-dimensional shape data (convex and concave shape data) of the surface 91 to be processed is acquired in advance by a three-dimensional shape measuring device. The three-dimensional shape measuring device may be of either a contact or non-contact type, but since measurement accuracy has a large effect on the finished surface accuracy, it is preferable that the three-dimensional shape data be measured with high accuracy.

(Scraper 10)
Next, a detailed configuration and movement of the scraper 10 according to this embodiment will be described. Fig. 2(a) is a schematic diagram showing a state in which the blade portion 11 of the scraper 10 held by the robot hand 21 is in contact with the processing target surface 91 of the workpiece 90. Fig. 2(b) is a schematic diagram showing a state in which the handle portion 13 has moved in a direction approaching the processing target surface 91 from the state shown in Fig. 2(a) and has been deflected. Fig. 2(c) is an enlarged view of part A in Fig. 2(b).

In the following, among the directions along the surface 91 to be processed (directions roughly parallel to the surface 91 to be processed), the processing direction during scraping will be described as the first direction X1, and the direction opposite to the first direction X1 will be described as the second direction X2. Furthermore, among the directions roughly perpendicular to the surface 91 to be processed, the direction away from the surface 91 to be processed will be described as the moving away direction Y1, and the direction approaching the surface 91 to be processed will be described as the approaching direction Y2.

The scraper 10 shown in Figure 2(b) is in the state when scraping is being performed. Figure 2(b) shows the scraper 10 and robot hand 21 in the same state as Figure 2(a), with the blade portion 11 beginning to come into contact with the surface 91 to be processed, in dotted lines. Furthermore, in Figure 2(b), the general direction of movement of the robot hand 21 and handle portion 13 after the blade portion 11 begins to come into contact with the surface 91 to be processed is shown by black arrows, and the general direction of movement of the blade portion 11 is shown by white arrows.

When the blade 11 comes into contact with the work surface 91 and the handle 13 is in a generally straight position, the robot hand 21 moves in the approach direction Y2 to approach the work surface 91, causing the handle 13 to bend as it approaches the work surface 91. At this time, as shown by the white arrow in Figure 2(b), the elastic deformation of the handle 13 causes the blade 11 to move in the first direction X1 while biting into the work surface 91. Below, the amount of movement of the robot hand 21 and handle 13 in the approach direction Y2 at this time will be described as the push-in amount YA, and the amount of movement of the blade 11 in the first direction X1 will be described as the movement amount PA.

The reference height of the push-in amount YA is set to the height of a reference point on the surface 91 to be machined, measured by a three-dimensional shape measuring device, with the height set as the zero point. For example, a corner of the surface 91 to be machined may be set as the reference point, and the surface height may be set as the reference height.

The scraping process is performed by moving the robot hand 21 and scraper 10 together in a direction along the surface 91 to be processed, with the blade 11 biting into the surface 91 to be processed and the handle 13 bent. At this time, the orientation of the scraper 10 is controlled so that the blade 11 is positioned at the tip of the scraper 10 in the processing direction. That is, in FIG. 2(b), the first direction X1 (the right direction in the figure) is the processing direction.

Figure 2(c) shows details of the blade portion 11 of the scraper 10 in contact with the surface 91 to be machined. The blade portion 11 has a scooping surface 11a located at the tip of the scraper 10, a clearance surface 11b adjacent to the scooping surface 11a that faces the surface 91 to be machined during scraping, and a cutting edge 11c formed on the ridge portion that is the boundary between the scooping surface 11a and the clearance surface 11b. In this embodiment, the cutting edge 11c has a convex arc (rounded) shape at the center in the blade width direction, but when applying the present invention, the shape of the cutting edge 11c is not limited to this and may be a straight line.

Figure 2(c) shows the amount QA of penetration of the blade portion 11 into the workpiece surface 91, and the amount PA of movement of the cutting edge 11c of the blade portion 11 in the first direction X1 due to bending of the handle portion 13. The amount QA of penetration of the blade portion 11, which corresponds to the cutting depth, is a dimension on the order of microns or submicrons. Meanwhile, the amount YA of the robot hand 21 pushing in during processing can be set as a displacement on the order of millimeters. In this way, when the robot hand 21 moves in a direction along the workpiece surface 91 with the blade portion 11 penetrated, the workpiece surface 91 is cut by a thickness on the order of microns or submicrons.

As described above, when the handle 13 moves in the approach direction Y2 by the pushing amount YA, the cutting edge 11c of the blade 11 moves in the first direction X1 by the moving amount PA while biting into the work surface 91 by the biting amount QA. In other words, from the time the blade 11 starts to come into contact with the work surface 91 until the handle 13 is completely bent, the blade 11 behaves differently from the handle 13 and the robot hand 21. Specifically, as the handle 13 moves in the approach direction Y2 and bends, the blade 11 moves in the first direction X1, which is the processing direction.

The cutting angle, which is the angle between the workpiece surface 91 and the clearance surface 11b of the blade portion 11, changes before and after the handle portion 13 is deflected. Specifically, as shown in FIG. 2(c), the cutting angle θA1 before the handle portion 13 is deflected changes to a smaller cutting angle θA2 as the handle portion 13 is deflected. These angles and the amount of depression YA can be adjusted as desired by the operation of the robot arm 20.

The above-mentioned push-in amount YA and cutting angle θA1 are typically used as control parameters for scraping. The controller 37 operates the robot arm 20 in accordance with each control parameter to perform scraping.

(Control device 30)
Next, the control device 30 of the scraping device 100 will be described. The control device 30 controls the robot arm 20 according to the processing instruction data, and as a result, scraping processing is performed on the processing target surface 91 of the workpiece 90 according to the processing instruction data. The control device 30 also generates processing instruction data for controlling the robot arm 20. That is, the control device 30 functions as a device for controlling the robot arm 20 and also functions as an information processing device (processing instruction data generating device) for generating processing instruction data used when controlling the robot arm 20. However, the processing instruction data for controlling the robot arm 20 may be generated by an information processing device (processing instruction data generating device) other than the control device 30. In this case, the control device 30 acquires the processing instruction data generated by the information processing device (processing instruction data generating device), and the control device 30 controls the robot arm 20 according to the acquired processing instruction data. The processing instruction data may be transmitted from the information processing device (processing instruction data generating device) to the control device 30 by either wired communication or wireless communication.

FIG. 3 is a block diagram showing an example of the configuration of the control device 30. The control device 30 is, for example, a general computer. The computer constituting the control device 30 includes a communication interface (communication I/F) 31, a storage device 32, an input/output device 33, and a processor 34, which are connected via a communication bus 35.

The communication I/F 31 may be, for example, a network card or a communication module, and communicates with other computers, devices, etc. based on a specific protocol. For example, the control device 30 receives three-dimensional shape information of the machining surface 91 of the workpiece 90 from a three-dimensional shape measuring device via the communication I/F 31.

The storage device 32 includes, for example, a main storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and an auxiliary storage device (secondary storage device) such as a HDD (Hard-Disk Drive), an SSD (Solid State Drive), or a flash memory. The main storage device temporarily stores the programs read by the processor 34 and information sent and received between other computers, and secures a working area for the processor 34. The auxiliary storage device stores the programs executed by the processor 34 and information sent and received between other computers. The auxiliary storage device may also include a removable medium (portable recording medium). The removable medium is, for example, a USB memory, an SD card, or a disc recording medium such as a CD-ROM, a DVD disk, or a Blu-ray disk. The storage device 32 (for example, the auxiliary storage device) stores an operating system (OS), various programs, and various information tables.

The input/output device 33 is a user interface, such as an input device such as a keyboard or a mouse, an output device such as a monitor, or an input/output device such as a touch panel. Through the input/output device 33, the worker can input control parameters for setting the machining path for scraping.

The processor 34 is an arithmetic processing device such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and performs each process related to this embodiment by executing a program. For example, the processor 34 loads a program stored in the auxiliary storage device of the storage device 32 into the main storage device and executes it, thereby realizing various processes such as a processing instruction data generation process for generating processing instruction data as described below.

The control device 30 does not necessarily have to be realized by a single physical configuration, but may be configured by multiple computers that work together.

Next, the functional configuration of the control device 30 will be described with reference to FIG. 4. FIG. 4 is a block diagram showing an example of the functional configuration of the control device 30. The control device 30 has a processing instruction data generation unit 36 and a control unit 37 as functional units. The processor 34 of the control device 30 loads a program stored in the auxiliary storage device of the storage device 32 into the main storage device and executes it, thereby realizing each of the above-mentioned functional units. The processing instruction data generation unit 36 executes a processing instruction data generation process that generates processing instruction data. The control unit 37 acquires the processing instruction data generated by the processing instruction data generation unit 36, and controls the robot arm 20 in accordance with the processing instruction data.

As described above, the scraper 10 is operated by the robot arm 20 controlled by the control device 30. However, because the handle 13 of the scraper 10 bends, when the blade 11 is brought into contact with or separated from the workpiece surface 91, the blade 11 of the scraper 10 behaves differently from the robot hand 21 moving along the workpiece path. In other words, if the workpiece path is set without taking into account the bending of the handle 13, the intended workpiece may not be processed. Next, the workpiece path during scraping will be described for a comparative example that does not take into account the bending of the handle 13, and this embodiment that takes into account the bending of the handle 13. The present invention can be applied to both a finishing process that forms a recess for an oil reservoir on the workpiece surface 91, and a flattening process.

(Comparative Example Machining Path)
First, the processing path of the scraping method of the comparative example will be described with reference to Fig. 5 (a) to (d) and Fig. 6. Fig. 5 (a) to (d) are diagrams showing the movement of the scraper 10 and the robot hand 21 in a series of processing paths of the comparative example, showing how the blade portion 11 abuts against, processes, and separates from the processing target surface 91. In these diagrams, the scraper 10 and other components in the original position before the movement are shown by dotted lines, the general movement direction of the handle portion 13 and the robot hand 21 is shown by a black arrow, and the general movement direction of the blade portion 11 is shown by a white arrow. In the comparative example, when the blade portion 11 is separated from the processing target surface 91, the control device 30 moves the robot hand 21 in a separation direction Y1 that is approximately perpendicular to the processing target surface 91.

FIG. 5(a) is a side view showing the blade 11 abutting against the surface 91 to be machined with the handle 13 in a substantially unbent state. At this time, the handle 13 is in a substantially straight state, although there is a small amount of bending due to gravity and the like that can be ignored.

Figure 5(b) is a side view showing the state when the handle 13 and the robot hand 21 move in the approach direction Y2 by the pushing amount YA from the state in Figure 5(a). At this time, the handle 13 moves in the approach direction Y2, but the cutting edge 11c of the blade 11 moves in the first direction X1 by the moving amount PA while biting into the workpiece surface 91.

Figure 5(c) is a side view showing how the scraper 10 and robot hand 21 move in the first direction X1 from the state shown in Figure 5(b), and the surface to be machined 91 is machined by the blade portion 11. At this time, the scraper 10 moves in the first direction X1 together with the robot hand 21 with the handle portion 13 remaining in a bent state. The surface to be machined 91 is machined to a thickness QA that is the amount of penetration of the blade portion 11 into the surface to be machined.

FIG. 5(d) is a side view showing the state when the handle 13 and the robot hand 21 have moved an amount YB in the separation direction Y1 from the state shown in FIG. 5(c). The amount YB is approximately the same as the pushing amount YA. At this time, the deflection of the handle 13 is released, and the blade 11 moves away from the processing surface 91.

When the blade 11 is moved away from the machining surface 91, the cutting edge 11c moves in the second direction X2 by a return amount PB1 as the handle 13 is unbent. Because the return amount PB1 is the amount of movement caused by the handle 13 being unbent, the return amount PB1 is approximately the same as the movement amount PA. That is, in the machining path of the comparative example, the cutting edge 11c moves in the first direction X1 as the handle 13 bends, and moves in the second direction X2 as the handle 13 is unbent.

Figure 6 is an enlarged view of part B in Figure 5 (d). Near the end point of the machining path, the cutting edge 11c moves in the second direction X2, making it easy for burrs 92 to occur on the workpiece 90. If burrs 92 remain on the sliding surface, they will not only significantly affect the sliding properties, but will also damage the surface of the other object against which they slide. Also, adding a new process to remove large burrs 92 will increase manufacturing costs, so it is desirable to suppress the occurrence of burrs 92.

In the comparative example, the machining path in which the robot hand 21 moves in a direction perpendicular to the machining surface 91 to move the blade portion 11 away from the machining surface 91 has been described, but the occurrence of burrs is not limited to the above-mentioned machining path. For example, a similar problem may occur in a machining path in which the robot hand 21 moves in the first direction X1 while also moving in the separation direction Y1 to move the blade portion 11 away from the machining surface 91. Specifically, when moving the blade portion 11 away from the machining surface 91, if the movement amount of the robot hand 21 in the first direction X1 is smaller than the return amount PB1 described above, the cutting edge 11c moves in the second direction X2, which may cause burrs. Furthermore, if the cutting edge 11c moves in the second direction X2 opposite to the machining direction, the intended length of machining may not be achieved, and the machining surface 91 may be left uncut near the end point of the machining path. Therefore, the inventors came up with a technology to prevent burrs and uncut areas by controlling the robot arm 20 based on the amount of movement of the blade 11 caused by the elastic deformation of the handle 13.

(Processing path in this embodiment)
Next, the machining paths according to the scraping method of this embodiment will be described with reference to Figures 7(a) to 7(d) and 8. Figures 7(a) to 7(d) are diagrams showing the movement of the scraper 10 and the robot hand 21 in a series of machining paths in this embodiment, showing the state from when the blade 11 comes into contact with the surface 91 to when it is about to separate from the surface 91. In these diagrams, the scraper 10 and other components in their original positions before movement are shown by dotted lines, the general movement directions of the handle 13 and the robot hand 21 are shown by black arrows, and the general movement direction of the blade 11 is shown by white arrows.

FIG. 7(a) is a side view showing the blade portion 11 abutting against the surface to be machined 91 with the handle portion 13 not substantially bent. FIG. 7(b) is a side view showing the state when the handle portion 13 and the robot hand 21 move in the approach direction Y2 by the pushing amount YA from the state of FIG. 7(a). FIG. 7(c) is a side view showing the state when the scraper 10 and the robot hand 21 move in the first direction X1 from the state of FIG. 7(b) and the surface to be machined 91 is machined by the blade portion 11. That is, in this embodiment, as in the comparative example, the scraper 10 and the robot hand 21 move with the handle portion 13 in a bent state, and the surface to be machined 91 is machined by the blade portion 11.

As shown in Figures 7(a) to (c), in this embodiment, the movement of the robot hand 21 and scraper 10 from when the blade portion 11 comes into contact with the surface to be machined 91 until the robot hand 21 moves parallel to the surface to be machined 91 is the same as in the comparative example. On the other hand, as shown in Figure 7(d), in this embodiment, in order to suppress the occurrence of machining residues and burrs, when the blade portion 11 is moved away from the surface to be machined 91, the control device 30 moves the robot hand 21 in the moving away direction Y1 while moving it a predetermined amount in the first direction X1. That is, in this embodiment, the angle formed between the trajectory of the robot hand 21 when the blade portion 11 is moved away from the surface to be machined 91 and the surface to be machined 91 is an acute angle.

FIG. 7(d) is a side view showing the state immediately before the blade 11 leaves the processing surface 91 from the state shown in FIG. 7(c). In this embodiment, when the blade 11 is moved away from the processing surface 91, the handle 13 and the robot hand 21 move obliquely relative to the processing surface 91. The movement amount of the handle 13 and the robot hand 21 at this time is a movement amount XB in the first direction X1 and a movement amount YB in the moving away direction Y1. The movement amount YB is approximately the same as the pushing amount YA, as in the comparative example. In other words, the handle 13 moves by the movement amount XB in the first direction X1 while the blade 11 remains in contact with the processing surface 91 until the handle 13 moves by the movement amount YB in the moving away direction Y1. Then, from the state shown in FIG. 7(d), the robot hand 21 moves further in the same direction, and the blade 11 is completely moved away from the processing surface 91.

The movement amount XB of the handle 13 in the first direction X1 is set to be larger than the movement amount PA of the blade 11 in the first direction X1 when the handle 13 is bent. Since the movement amount PA is approximately the same as the return amount PB1 of the blade 11 in the second direction X2, it can be said that the movement amount XB is set to be larger than the return amount PB1. By setting the machining path in this manner, the robot hand 21 moves in the first direction X1 by more than the amount by which the blade 11 moves in the second direction X2 as the handle 13 is released from the bending. Therefore, according to this embodiment, when the handle 13 moves in the separation direction Y1, the cutting edge 11c also moves in the first direction X1. If the movement amount of the cutting edge 11c in the first direction X1 at this time is set to the movement amount PB2, the movement amount PB2 is approximately the same as the difference between the movement amount XB of the handle 13 and the return amount PB1 of the cutting edge 11c.

Figure 8 is an enlarged view of part C in Figure 7(d). According to this embodiment, near the end point of the machining path, the cutting edge 11c moves in the first direction X1 while moving away from the machining target surface 91, so that the occurrence of uncut parts and burrs can be suppressed.

Next, the trajectory of the robot hand 21 during scraping in this embodiment will be described in more detail with reference to FIG. 9. FIG. 9 is a schematic diagram showing the trajectory of the robot hand 21 during scraping. In FIG. 9, the trajectory of the robot hand 21 is shown by a dotted line with an arrow, and representative positions of the robot hand 21 are shown as points D1 to D4. As described above, the movement of the robot hand 21 is controlled by the control device 30, and it moves while holding the scraper 10.

When the robot hand 21 is located at point D1, the handle 13 is not bent at all, and the blade 11 is in contact with the work surface 91 without digging into it. The robot hand 21 then moves in the approach direction Y2 by the push amount YA from point D1 to point D2. At this time, the handle 13 bends, and the blade 11 moves in the first direction X1 while digging into the work surface 91.

With the handle 13 in a bent state, the robot hand 21 moves from point D2 to point D3 in the first direction X1. The amount of machining of the surface 91 to be machined is determined by the amount of movement and the amount of depression YA at this time. The machining path up to this point can be determined by setting the coordinate position of point D1, the amount of depression YA, and the amount of movement in the first direction X1.

Then, the robot hand 21 moves from point D3 to point D4. At this time, the robot hand 21 moves in the first direction X1 by a movement amount XB while moving in the separating direction Y1 by a movement amount YB. That is, the trajectory of the robot hand 21 is inclined at an acute angle RB with respect to the processing target surface 91. As described above, the movement amount YB in the separating direction Y1 is approximately the same as the pushing amount YA, and the movement amount XB in the first direction X1 is greater than the movement amount PA and the return amount PB1. Then, by moving further from point D4 in a direction away from the processing target surface 91, the blade portion 11 moves completely away from the processing target surface 91, and the series of processing passes ends. Processing along such processing passes is repeated to perform flattening processing and finishing processing.

When setting the machining path from point D3 to point D4, the operator may input the movement amount XB and angle RB in advance, or the operator may input the movement amount PA and return amount PB1 and the control device 30 may automatically determine the movement amount XB, etc. For example, an information table in which the movement amount PA and the movement amount XB are associated may be stored in the control device 30, and the operator may input the movement amount PA and the control device 30 may set the movement amount XB.

As another method for setting the machining path when the blade portion 11 is separated, the control device 30 may set the angle RB. The angle RB is expressed by tan(RB)=YB/XB, and the movement amount YB is approximately equal to the push-in amount YA. Therefore, in order to make XB>PA when the angle RB is in the acute angle range, it is sufficient to satisfy RB<tan ^-1 (YA/PA). Therefore, the control device 30 may be configured to calculate the angle RB by inputting the push-in amount YA and the movement amount PA by the operator using the calculation function of the control device 30. By setting the machining path in this manner, the blade portion 11 moves in the first direction X1 while moving away from the machining target surface 91.

The movement amount PA used to set the machining path may be calculated from the shape and physical properties of the handle 13, or may be measured and obtained for each machining condition. For example, when the robot hand 21 is moved in the approach direction Y2 with the blade 11 in contact with the machining surface 91 and then moved in the separation direction Y1, a machining mark is left on the workpiece 90 by the amount of movement of the blade 11 due to the deflection of the handle 13. By performing such measurement machining under various machining conditions and measuring the length of the machining mark, the movement amount PA of the blade 11 corresponding to each machining condition is obtained. Therefore, the movement amount PA for each machining condition obtained by measurement may be stored in the scraping device 100, and the control device 30 may automatically obtain the movement amount PA from the machining conditions and determine the movement amount XB.

As described above, according to this embodiment, it is possible to set a machining path that takes into account the amount of movement of the blade 11, which moves due to the elastic deformation of the handle 13. Furthermore, near the end point of the machining path, it is possible to prevent the cutting edge 11c from moving in the opposite direction (second direction X2) to the machining direction (first direction X1) as the deflection of the handle 13 is eliminated, thereby suppressing the occurrence of uncut parts and burrs.

Next, a scraping method for extending the life of the blade portion 11 of the scraper 10 will be described with reference to Figures 10(a) and (b). When scraping is performed repeatedly and the cutting edge 11c of the blade portion 11 wears, the cutting edge becomes rounded and loses its sharpness, resulting in shallower cuts. However, frequent replacement of the blade portion 11 or the scraper 10 leads to increased processing costs due to increased replacement time and tool costs.

On the other hand, as described above, the cutting edge 11c of the blade portion 11 has a convex arc shape at the center in the blade width direction, and has a predetermined blade width. During scraping, for example, if the push-in amount YA is small, only a part of the cutting edge 11c abuts against the surface 91 to be machined, and the cutting edge 11c will have parts that have been used in machining and worn away, and parts that have not been used in machining and have not worn away. Therefore, the inventors of the present application came up with a technology to extend the tool life by devising a machining method that shifts the position at which the cutting edge abuts, dividing a single cutting edge into multiple parts that can be used individually for machining.

10(a) and (b) are schematic top views showing the relationship between the scraper 10 and the machining area 91a of the surface 91 to be machined when viewed from a direction perpendicular to the surface 91 to be machined. In each of Figs. 10(a) and (b), the machining area 91a, which is the area of the surface 91 to be machined, is shaded with diagonal lines, and the direction of movement of the handle 13 is indicated by a solid black arrow.

First, the first machining performed in the state shown in FIG. 10(a) will be described. In the first machining, the handle 13 moves to machine the machining area 91a while the center line 11d of the blade 11 in the blade width direction is parallel to the machining direction. If the angle between the center line 11d and the machining direction at this time is a first angle, the first angle is 0°. Since the center line 91b in the width direction of the machining area 91a is parallel to the machining direction, in the first machining, the robot arm 20 is driven so that the center line 11d and the center line 91b overlap. Therefore, the first abutment portion 11e of the cutting edge 11c that abuts against the machining area 91a is located at the center in the blade width direction. In other words, both ends of the cutting edge 11c in the blade width direction do not abut against the machining target surface 91 during machining, and therefore do not wear out.

Next, the second processing performed in the state shown in FIG. 10(b) will be described. In the second processing, the center line 11d of the blade 11 is inclined with respect to the processing direction, and the handle 13 moves to process the processing area 91a. That is, in the second processing, the angle between the center line 11d and the processing direction changes compared to the first processing. If the angle between the center line 11d and the processing direction at this time is the second angle, the second angle is an acute angle that is different from the first angle. In addition, the center line 11d of the blade 11 and the center line 91b of the processing area 91a are inclined. At this time, the second abutment portion 11f of the cutting edge 11c that abuts against the processing area 91a is located on the end side of the cutting edge 11c in the blade width direction with respect to the first abutment portion 11e. That is, in the second processing, the robot arm 20 is driven so that a different position of the cutting edge 11c abuts against the processing area 91a compared to the first processing, and processing is performed.

In this embodiment, when the first machining is repeated and the first contact portion 11e of the cutting edge 11c becomes worn, the machining can be switched to the second machining, and the machining can be continued using the unworn second contact portion 11f without the need for tool replacement. Furthermore, when the second contact portion 11f becomes worn, the machining can be continued using a portion of the cutting edge 11c located on the opposite end side of the second contact portion 11f from the first contact portion 11e. That is, in this embodiment, the cutting edge 11c is used in three separate regions, and the robot arm 20 is controlled so that different regions are used for machining as the wear of each region progresses.

In this way, by using a scraping method including a first process and a second process in which different positions of the cutting edge 11c are used for processing, the life of the blade portion 11 can be extended compared to a scraping method in which only the same part of the cutting edge 11c is used continuously. In the above embodiment, the first abutment portion 11e is located at the center of the cutting edge 11c in the blade width direction in the first process, but this configuration is not limited to extending the life of the blade portion 11. For example, it is also possible to divide the cutting edge 11c into two regions so that the first abutment portion 11e is located at one end side of the cutting edge 11c and the second abutment portion 11f is located at the other end side opposite to the one end side of the cutting edge 11c in the blade width direction of the cutting edge 11c. In addition, although the first angle is set to 0° in the above embodiment, it is also possible to set both the first angle and the second angle to be acute angles.

<Other Examples>
The above-mentioned embodiment is merely an example, and the present disclosure may be modified as appropriate without departing from the spirit and scope of the present disclosure. Furthermore, the processes and means described in the present disclosure may be freely combined and implemented as long as no technical contradiction occurs.

For example, in the above embodiment, the machining path is configured as a straight line, but the machining path when the robot hand 21 is moved away from the surface 91 to be machined may be configured to include a curve. In other words, if the machining path is such that the robot hand 21 moves in the first direction X1 by more than the movement amount PA until the cutting edge 11c moves away from the surface 91 to be machined (until the robot hand 21 moves by the movement amount YB in the moving away direction Y1), the occurrence of uncut areas and burrs can be suppressed.

Furthermore, a process that has been described as being performed by one device may be shared and executed by multiple devices. Or, a process that has been described as being performed by different devices may be executed by a single device. In a computer system, the hardware configuration that realizes each function can be flexibly changed.

10... scraper, 11... blade, 13... handle, 20... robot arm (machining robot), 30... control device, 90... workpiece (workpiece), 91... surface to be machined, 100... scraping device

Claims

A processing robot that holds and operates a scraper having a blade portion and a flexible handle portion on which the blade portion is provided;
A control device that controls the processing robot in accordance with processing instruction data;
Equipped with
a scraping device for scraping the surface to be processed by moving the handle in a direction approaching the surface to be processed from a state in which the blade is in contact with the surface to be processed, thereby bending the handle so that the blade moves in a processing direction along the surface to be processed, and moving the handle in the bent state in the processing direction,
The scraping device is characterized in that the control device controls the processing robot to move the handle portion in a direction away from the surface to be processed while moving the handle portion a predetermined amount in the processing direction based on the amount by which the blade portion moves due to elastic deformation of the handle portion when the blade portion is moved away from the surface to be processed.
The scraping device according to claim 1, characterized in that the predetermined amount is equal to or greater than the amount by which the blade moves in the processing direction when the handle bends and moves in a direction approaching the processing surface from a state in which the blade begins to come into contact with the processing surface during the scraping process.
The scraping device according to claim 1, characterized in that the control device moves the handle portion in the processing direction by the predetermined amount before the blade portion separates from the surface to be processed.
When the amount of movement of the handle portion toward the surface to be processed from the state where the blade portion is in contact with the surface to be processed in a direction perpendicular to the surface to be processed is defined as a pressing amount,
The scraping device according to claim 1, characterized in that the control device controls the processing robot so that, when the blade portion is moved away from the workpiece surface during the scraping process, the handle portion is moved the predetermined amount in the processing direction before the handle portion is moved the amount of the push-in in the direction away from the workpiece surface in the perpendicular direction.
The handle portion has a generally band-like shape, and the blade portion is provided at one end in a longitudinal direction.
The scraping device according to claim 1 , wherein the control device controls the orientation of the scraper during the scraping process so that the blade portion is positioned at a tip of the scraper in the processing direction.
The scraping device according to claim 1, characterized in that the blade portion is replaceably attached to the handle portion.
The scraping device according to claim 1, characterized in that the processing robot is configured to be able to adjust the cutting angle between the surface of the blade portion that faces the surface to be processed and the surface to be processed.
A processing robot that holds and operates a scraper having a blade portion and a flexible handle portion on which the blade portion is provided;
A control device that controls the processing robot in accordance with processing instruction data;
A scraping method using a scraping device that performs scraping on a surface to be processed of a workpiece, comprising:
In the scraping process, the control device
From a state in which the blade portion is in contact with the surface to be processed, the handle portion is moved in a direction approaching the surface to be processed, thereby bending the handle portion so that the blade portion moves in a processing direction along the surface to be processed;
The handle portion is moved in the processing direction while the handle portion is bent.
A scraping method in which, when the blade portion is moved away from the surface to be processed, the processing robot is controlled so as to move the handle portion in a direction away from the surface to be processed while moving the handle portion a predetermined amount in the processing direction based on an amount by which the blade portion moves due to elastic deformation of the handle portion.
The scraping method according to claim 8, characterized in that the predetermined amount is equal to or greater than the amount by which the blade moves in the processing direction when the handle bends after the blade starts to come into contact with the processing surface and the handle moves in a direction approaching the processing surface.
The cutting edge of the blade portion has a convex arc shape at the center in the blade width direction,
a first processing step in which a first contact portion of the cutting edge is brought into contact with the surface to be processed while a center line of the blade portion in the blade width direction and the processing direction form a first angle when viewed from a direction perpendicular to the surface to be processed;
a second processing step of processing the surface to be processed by bringing a second contact portion of the cutting edge, which is located at a position different from the first contact portion, into contact with the surface to be processed while the angle is set to a second angle different from the first angle;
The scraping method according to claim 8, further comprising the steps of: