Scraping device

Abstract

To provide a scraping device in which a scraping tool can be easily changed, and which is suitable for automatic tool change.SOLUTION: A scraping device 1 comprises: a scraping tool 3 at a front end of which a blade tip 31a, which performs scraping, is formed; a gripping unit 42 which grips a gripped part 3211 formed at a rear end of the scraping tool 3 by a collet chuck 421; and a cylinder 43 which performs state change of the gripping unit 42 between a gripping state of gripping the scraping tool 3 and a gripping release state of releasing gripping of the scraping tool 3 on the basis of a command from a controller 5.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a scraping device for performing scraping processing. [Background technology]

[0002] Conventionally, scraping devices that scrape the surface of a workpiece using a scraping tool have been known (see, for example, Patent Document 1). Patent Document 1 proposes a scraping device in which a shaft member to which a scraping tool (scraper) is fixed is rotatably supported by a holder, and the holder is attached to the tip of a robot arm, and scraping is performed by the operation of the robot arm. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-122937 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the scraping device of Patent Document 1, the scraping tool is fixed to the shaft member with a set screw, and because the shaft member is located inside the holder, the set screw that secures the shaft member is inaccessible from outside the holder. Therefore, when replacing the scraping tool, the user must remove the shaft member from the holder, loosen the set screw to remove the scraping tool from the shaft member, insert a new scraping tool into the shaft member, and then install the shaft member inside the holder in the reverse order, a cumbersome process. This creates the problem that replacing scraping tools requires manual labor, which takes time.

[0005] SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a scraping device that allows easy replacement of scraping tools and is suitable for automatic tool replacement. [Means for solving the problem]

[0006] The scraping device of the present invention that solves the above problems is: a scraping tool having a cutting edge formed at its front end for scraping; a gripping device that grips the scraping tool; The device is characterized by including an actuator that is controlled by a control device and changes the state of the gripping device between a gripping state in which the scraping tool is gripped and a gripping release state in which the scraping tool is released.

[0007] According to this scraping device, the state can be changed between the gripped state and the released state by the actuator, so that the scraping tool can be easily replaced and is suitable for automatic tool replacement.

[0008] In this scraping device, The gripping device may have a collet chuck that grips a gripped portion formed on the rear end side of the scraping tool.

[0009] In this embodiment, the state can be changed between the gripped state and the released state with a simple structure, so that the scraping device can be made small and inexpensive.

[0010] Here, the gripped portion may have a cylindrical shape.

[0011] In this scraping device, The scraping tool has a scraper having a cutting edge formed continuously from the cutting edge, and a scraper holder to which a rear end portion of the scraper is fixed, The scraper holder may be formed at a specific angle with respect to the cutting edge, and may have a mounting surface for mounting the scraping tool on a tool changer.

[0012] With this configuration, when the scraping tool is placed on the tool replacement table, it is placed in a position where the cutting edge is at a predetermined angle, so that when the scraping tool is replaced, the scraping tool placed in that position can be held by the gripping device. Then, assuming that the gripping device holds the scraping tool in that position, scraping can be performed with the cutting edge parallel to the surface of the workpiece.

[0013] Here, the blade surface may have a flat shape. The scraper holder may have a parallel surface substantially parallel to the blade surface formed as the mounting surface. The scraper holder may have the scraper fixed thereto in a releasable manner. In addition, the scraper holder may have a front end having a rectangular columnar outer shape. The mounting surface may be one surface constituting the rectangular columnar shape. The mounting surface may be a surface for mounting the scraping tool on the tool changer base when the scraping tool has been removed from the gripping device. The mounting surface may be a surface for mounting the scraping tool on the tool changer base before the scraping tool is gripped by the gripping device. The scraper may be fixed to the scraper holder so that the blade surface is in a predetermined orientation.

[0014] In this scraping device, a support member that supports the gripping device rotatably around a rotation center direction that is the front-rear direction of the scraping tool; The scraping machine may further include a rotation detection device that detects the rotation of the gripping device during execution of the scraping process.

[0015] The rotation detection device can detect if the cutting edge has become inclined relative to the surface to be processed during the scraping process.

[0016] In this scraping device, The gripping device may have a biasing member disposed therein, a continuous hole formed from the front end that grips the scraping tool to the biasing member, and a foreign matter intrusion prevention member that is inserted into the continuous hole to close the continuous hole.

[0017] This makes it possible to prevent chips and the like from reaching the biasing member with a simple structure.

[0018] Here, the foreign matter intrusion prevention member may be press-fitted into the continuous hole. The continuous hole may be a cylindrical hole, and the foreign matter intrusion prevention member may be a cylindrical member having approximately the same diameter as the continuous hole. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a scraping device that allows easy replacement of scraping tools and is suitable for automatic tool replacement. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is an explanatory diagram showing a scraping device according to the present embodiment. [Figure 2] 1, (a) is a plan view of the scraping tool shown in FIG. 1, (b) is a front view of the scraping tool shown in FIG. 1, (c) is a left side view of the scraping tool shown in FIG. 1, and (d) is a right side view of the scraping tool shown in FIG. 1. [Figure 3] 2 is a cross-sectional view showing the structure of a gripping unit of the scraping device shown in FIG. 1. FIG. [Figure 4] FIG. 4 is a cross-sectional view similar to FIG. 3, showing the gripping device in a released state. [Figure 5] FIG. 4 is a view taken along line AA in FIG. 3. [Figure 6] 3(a) is an enlarged view of part B in FIG. 3 showing the rotary brake mechanism when the rotary brake is not activated, and FIG. 3(b) is an enlarged view similar to FIG. 3(a) showing the rotary brake mechanism when the rotary brake is activated. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is an explanatory diagram showing a scraping device 1 according to this embodiment.

[0023] As shown in Figure 1, the scraping device 1 includes a robot arm 2, a scraping tool 3, a gripping unit 4, and a control device 5. The robot arm 2 is an articulated robot that can move the gripping unit 4 attached to the tip in three axial directions where the axes intersect at right angles, and can also rotate the gripping unit 4 around each axial direction. The scraping process is performed by the robot arm 2 by pressing the cutting edge 31a (see Figure 2) of the scraping tool 3 held by the gripping unit 4 against the surface of the workpiece 9 while moving the scraping tool 3 along the surface.

[0024] A replacement tool table 6 on which replacement scraping tools 3 are placed is located near the scraping device 1. A plurality of replacement scraping tools 3 are placed on the top surface of the replacement tool table 6, aligned in a direction perpendicular to the plane of FIG. 1 . The top surface of the replacement tool table 6 corresponds to an example of a mounting surface on which replacement scraping tools 3 are placed. The scraping device 1 and the replacement tool table 6 of this embodiment form a scraping system that can perform scraping processing continuously for long periods of time while automatically replacing the scraping tools 3. In FIG. 1 , the robot arm 2 is shown by a two-dot chain line shortly before placing the scraping tool 3 used in the tool replacement operation on the replacement tool table 6. Note that the replacement scraping tools 3 placed on the replacement tool table 6 all have the same shape as the scraping tool 3 held by the gripping unit 4. However, a plurality of scraping tools 3 of different types may be placed on the replacement tool table 6.

[0025] The robot arm 2 operates based on an NC program stored in the storage means of the control device 5. In other words, the robot arm 2 operates in response to signals from the control device 5 to perform scraping using the scraping tool 3 and tool replacement. Scraping is a process in which the surface of the workpiece 9, which is the surface of the workpiece 9 fixed on the work table 8, is cut in small increments with the scraping tool 3, creating extremely small depressions in the surface while achieving a flat overall finish. These extremely small depressions act as oil reservoirs (oil pockets) to improve the sliding properties of the machined workpiece, enabling smooth sliding on the surface. The control device 5 also causes the robot arm 2 to perform a tool replacement operation for the scraping tool 3 before the scraping tool 3 wears out and the scraping accuracy falls below the desired level. The timing of the tool change is determined by the control device 5. The control device 5 measures the cutting resistance generated in the robot arm 2 during scraping, and when the average value of the cutting resistance from the most recent multiple times exceeds a predetermined threshold, it determines that it is time to change the tool and causes the robot arm 2 to perform a tool change operation. Note that a load sensor that measures the cutting load in the movement direction during processing may be provided, and the timing for tool change may be determined by measuring the load in the movement direction with the load sensor. Alternatively, the control device 5 may count the number of times scraping is performed and determine that it is time to change the tool when the count exceeds a predetermined number.

[0026] In the tool replacement operation, the scraping tool 3 that has worn out due to repeated scraping operations is placed on the top surface of the replacement tool table 6, and the gripping unit 4 grips the replacement scraping tool 3 that was placed on the replacement tool table 6 instead and lifts it up from the replacement tool table 6. Then, scraping operations are resumed using the new gripped scraping tool 3.

[0027] 2(a) is a plan view of the scraping tool 3 shown in FIG. 1, FIG. 2(b) is a front view of the scraping tool 3 shown in FIG. 1, FIG. 2(c) is a left side view of the scraping tool 3 shown in FIG. 1, and FIG. 2(d) is a right side view of the scraping tool 3 shown in FIG. 1. In the following description of the scraping tool 3, the left side in FIGS. 2(a) and 2(b) may be referred to as the front side, and the right side in FIGS. 2(a) and 2(b) may be referred to as the rear side. Also, in FIG. 2(b), the direction perpendicular to the paper surface may be referred to as the width direction. Furthermore, in the description of the gripping unit 4 described later, the scraping tool 3 may be used as the reference point to refer to the front side, rear side, and width direction.

[0028] As shown in FIG. 2, the scraping tool 3 includes a scraper 31 and a scraper holder 32. The scraper 31 has a uniform thickness at its rear end, which is the base, and a generally rectangular parallelepiped shape that is elongated in the front-to-rear direction, with the thickness decreasing toward the front except for the front end. Hereinafter, the line connecting the centers (centers of gravity) of the cross section of the scraper 31 will be referred to as the scraper center line L1. The direction of this scraper center line L1 coincides with the front-to-rear direction. A cutting edge 31a is formed at the lower corner of the front end of the scraper 31 in the position shown in FIG. 2(b). This cutting edge 31a cuts the surface of the workpiece 9 (see FIG. 1) in minute increments, thereby performing scraping. A flat cutting edge 31b is formed on the underside of the front end of the scraper 31, continuing from the cutting edge 31a. In scraping, the cutting edge 31a of the scraper 31 is pressed against the surface to be processed by the operation of the robot arm 2 (see Figure 1), causing the scraper 31 to bend and move forward, thereby scraping off the surface of the workpiece 9 in small amounts.

[0029] The scraper holder 32 is composed of a lower block 321, an upper block 322, and a holder screw 323. The lower block 321 and the upper block 322 are connected by the holder screw 323. The scraper 31 is fixed to the scraper holder 32 by sandwiching the rear end portion of the scraper 31 between the lower block 321 and the upper block 322 with the fastening force of the holder screw 323. The scraper 31 can be removed from the scraper holder 32 by loosening the holder screw 323. The scraper 31 can also be fixed to the scraper holder 32 by sandwiching the scraper 31 between the lower block 321 and the upper block 322 and tightening the holder screw 323. This allows the scraper holder 32 to continue being used, for example, if the cutting edge 31a of the scraper 31 is damaged, by replacing it with another scraper 31.

[0030] As shown in Figures 2(b) and 2(c), a recess 321a extending in the front-rear direction is formed in the center of the width of the lower block 321. Furthermore, a protrusion 322a extending in the front-rear direction is formed in the center of the width of the upper block 322. The protrusion 322a of the upper block 322 is formed to be slightly narrower than the recess 321a of the lower block 321 and is inserted into the recess 321a. The scraper 31 is sandwiched between the lower block 321 and the upper block 322, with the lower surface of the rear end portion contacting the bottom surface of the recess 321a and the upper surface of the rear end portion contacting the protruding surface of the protrusion 322a.

[0031] The front portion of the scraper holder 32 has a generally rectangular prism shape that is long in the front-to-rear direction. The holder lower surface 321b, which is one side of the rectangular prism shape, and the bottom surface of the recess 321a are formed parallel to each other. Both the holder lower surface 321b and the bottom surface of the recess 321a are formed by the lower block 321, so they can be formed with a high degree of parallelism. The holder lower surface 321b corresponds to an example of a mounting surface for mounting the scraping tool 3 on the tool replacement stand 6 (see FIG. 1). The cutting edge 31b of the scraper 31 is parallel to the lower surface of the rear end portion of the scraper 31 sandwiched between the lower block 321 and the upper block 322, so the holder lower surface 321b is parallel to the cutting edge 31b of the scraper 31. However, the holder lower surface 321b and the bottom surface of the recess 321a may be formed so that the holder lower surface 321b is at a specific angle different from the cutting edge 31b.

[0032] The scraping tool 3 is placed on the tool replacement table 6 (see FIG. 1) in the position shown in FIG. 2(b). That is, the scraping tool 3 is placed on the tool replacement table 6 with the holder lower surface 321b in contact with the upper surface, which is the mounting surface, of the tool replacement table 6, and thus placed on the tool replacement table 6 with the cutting surface 31b in a horizontal position. In this way, when replacing the scraping tool 3, the scraping tool 3 placed on the tool replacement table 6 can be held by the gripping device 42 with the cutting surface 31b in a horizontal position. The control device 5 (see FIG. 2) controls the robot arm 2 (see FIG. 1) on the assumption that the gripping device 42 has gripped the scraping tool 3 with the cutting surface 31b in a horizontal position, and presses the scraping tool 3 against the workpiece surface so that the cutting edge 31a is parallel to the workpiece surface, thereby performing scraping. If the holder lower surface 321b is formed as an inclined surface so that the holder lower surface 321b is at a specific angle different from the cutting surface 31b, the scraping tool 3 will be placed on the tool exchange table 6 in a position where the cutting surface 31b is at that specific angle. In this case, the control device 5 controls the robot arm 2 based on that specific angle, and the scraping tool 3 is pressed against the surface to be processed so that the cutting edge 31a is parallel to the surface to be processed, thereby performing scraping.

[0033] The rear portion of the scraper holder 32 has a cylindrical shape with a constant diameter except for a tapered rear end. This cylindrical portion becomes a gripped portion 3211 that is gripped by the gripping unit 4. The rear portion of the scraper holder 32 is formed integrally with the lower block 321. The center line of the gripped portion 3211 coincides with the scraper center line L1 of the scraper 31.

[0034] Fig. 3 is a cross-sectional view showing the structure of the gripping unit 4 of the scraping device 1 shown in Fig. 1. Note that hatching indicating cross sections is not used in Fig. 3 and Figs. 4 to 6 described later.

[0035] 3, the gripping unit 4 has a support member 41, a gripping device 42, a cylinder 43, an air blowing device 44, a rotation detecting device 45, and a braking device 46. The support member 41 is fixed to the tip of the robot arm 2 (see FIG. 1). The support member 41 is composed of a connecting part 411 connected to the robot arm 2 and a generally cylindrical housing part 412 inside which the gripping device 42 is arranged.

[0036] The gripping device 42 is supported by the housing 412 so as to be rotatable around the front-to-rear direction as the center of rotation. FIG. 3 shows the gripping device 42 in a gripping state. The rotation center line L2 of the gripping device 42 coincides with the scraper center line L1 of the scraper 31. Hereinafter, the direction of rotation around the scraper center line L1 or the rotation center line L2 may be referred to as the rotation direction. The gripping device 42 has a collet chuck 421, a cap 422, a chuck sleeve 423, a chuck biasing spring 424, a sleeve biasing spring 425, a rotating cylinder 426, and a foreign matter intrusion prevention member 427.

[0037] The collet chuck 421 is generally cylindrical, and has a continuous hole 4211 formed inside, into which the gripped portion 3211 of the scraping tool 3 is inserted. The collet chuck 421 is a gripping portion that grips the gripped portion 3211 inserted into the continuous hole 4211. The continuous hole 4211 is formed continuously in the front-rear direction from the front end to the rear end of the collet chuck 421. Furthermore, since the collet chuck 421 has multiple slits formed from the front end to the rear, when an external force is applied toward the inner periphery, the collet chuck 421 elastically deforms, causing the front portion to shrink in diameter. The outer circumferential surface near the front end of the collet chuck 421 is formed with a tapered surface that becomes larger toward the front. The diameter forward of the tapered surface is smaller than the diameter of the front end of the tapered surface, and a step is formed between the tapered surface and the small-diameter portion.

[0038] Cap 422 is bowl-shaped with a circular cap through-hole formed in the center that penetrates in the front-to-rear direction. A stepped portion of collet chuck 421 abuts against the part of cap 422 that corresponds to the bottom of the bowl, thereby preventing collet chuck 421 from moving forward. Cap 422 is fixed to rotatable cylinder 426 by engaging a female screw portion formed on the inside of the edge of the bowl with a male screw portion formed at the front end of rotatable cylinder 426.

[0039] The chuck sleeve 423 is cylindrical and has an inner periphery shaped similarly to the outer periphery of the collet chuck 421, and covers the outer periphery of the collet chuck 421 except for the tip portion. A tapered surface is formed on the inner periphery of the front end portion of the chuck sleeve 423, the diameter of which increases toward the front. The rear end portion of the chuck sleeve 423 is formed with a sleeve small diameter portion 4231 whose inner diameter is smaller than that of the remaining portions.

[0040] The chuck biasing spring 424 is a compression spring arranged between the collet chuck 421 and the chuck sleeve 423, more specifically, between the rear end of the collet chuck 421 and the small diameter sleeve portion 4231. This chuck biasing spring 424 corresponds to an example of a biasing member. The chuck biasing spring 424 biases the collet chuck 421 forward and the chuck sleeve 423 rearward.

[0041] The sleeve biasing spring 425 is a compression spring disposed behind the chuck sleeve 423 and between the chuck sleeve 423 and the rotating cylinder 426. The sleeve biasing spring 425 biases the chuck sleeve 423 forward and the rotating cylinder 426 rearward. The rotating cylinder 426 is supported by the support member 41 so as to be rotatable but immovable in the front-rear direction. The sleeve biasing spring 425 has a stronger elastic force than the chuck biasing spring 424. Therefore, if no external force in the front-rear direction other than that of the chuck biasing spring 424 and the sleeve biasing spring 425 is applied to the chuck sleeve 423, the chuck sleeve 423 will move forward to the position shown in FIG. 3. In this position, the tapered surface formed on the outer periphery near the front end of the collet chuck 421 is pressed against the tapered surface formed on the inner periphery of the front end portion of the chuck sleeve 423, causing the diameter of the front portion of the collet chuck 421 to decrease. As a result, the gripped portion 3211 of the scraping tool 3 is gripped.

[0042] The rotating barrel 426 is also generally cylindrical. As described above, the rotating barrel 426 is supported by the housing 412 via two bearings arranged on the support member 41 so as to be rotatable but immovable in the front-rear direction. These two bearings are bearings arranged between the rotating barrel 426 and the housing 412 and spaced apart from each other in the front-rear direction. The chuck sleeve 423 is arranged inside the front portion of the rotating barrel 426 and rotates together with the rotating barrel 426. The chuck sleeve 423 is supported by the rotating barrel 426 so as to be movable in the front-rear direction.

[0043] The foreign matter intrusion prevention member 427 is inserted into the continuous hole 4211 of the collet chuck 421. The foreign matter intrusion prevention member 427 is cylindrical and has an outer diameter that is the same as the diameter of the continuous hole 4211. Foreign matter such as chips may enter the continuous hole 4211 from the front end. A sleeve biasing spring 425 is disposed immediately behind the rear end of the continuous hole 4211, and a grip release rod 432 is disposed inside the sleeve biasing spring 425. If a foreign matter enters the continuous hole 4211 and reaches the sleeve biasing spring 425 or the grip release rod 432, the elastic function of the sleeve biasing spring 425 may be impaired, or the grip release rod 432 may not operate normally. By inserting the foreign matter entry prevention member 427 into the continuous hole 4211 and blocking the continuous hole 4211 with the foreign matter entry prevention member 427, foreign matter can be prevented from reaching the sleeve biasing spring 425 and the grip release rod 432 with a simple and inexpensive configuration.

[0044] The cylinder 43 has a cylinder body 430, a piston 431, and a grip release rod 432. The cylinder 43 moves the piston 431 back and forth by the pressure of air supplied and exhausted in response to a signal from the control device 5 (see FIG. 1). In other words, the operation of the cylinder 43 is controlled by the control device 5. This cylinder 43 corresponds to an example of an actuator. Note that the cylinder 43 may also be a cylinder that moves the piston 431 by the pressure of a fluid other than air, such as a hydraulic cylinder. Furthermore, the piston 431 may be driven by a motor instead of the cylinder 43. In that case, the motor corresponds to an example of an actuator. FIG. 3 shows the piston 431 positioned at the frontmost position.

[0045] The cylinder body 430 is fixed to a cylinder base 439 attached to the rear end of the housing part 412 of the support member 41. The piston 431 has a base portion on the rear side disposed within the cylinder body 430, and a front portion protruding forward from the cylinder body 430. The piston 431 and the release rod 432 both have a cylindrical shape extending in the front-to-rear direction. The release rod 432 is fixed to the front end portion of the piston 431. A rod large diameter portion 4321 having a diameter larger than that of the other portions is formed at the front end of the release rod 432. In the gripped state shown in FIG. 3 , the rod large diameter portion 4321 is spaced apart from and positioned forward of a sleeve small diameter portion 4231 formed at the rear end of the chuck sleeve 423.

[0046] The air blow device 44 blows out air from an outlet formed at the front end to blow away chips and the like adhering to the vicinity of the cutting edge 31a of the scraping tool 3 and the vicinity of the processed portion of the workpiece 9 (see Figure 1).

[0047] The rotation detection device 45 has a light shielding plate 451 and two rotation detection sensors 452. One of the rotation detection sensors 452 is shown in FIG. 3. The light shielding plate 451 is attached to a rotating flange 4261 fixed to the rear end of the rotating barrel 426 and rotates together with the rotating barrel 426. The rotation detection sensor 452 is a transmission type photosensor that detects the rotation of the light shielding plate 451. The rotation detection sensor 452 is fixed to a cylinder base 439. The rotation detection device 45 and the cylinder main body 430 are covered by a cover 49 except for a supply pipe that supplies air to the cylinder main body 430 for driving the piston 431. The configurations of the rotation detection device 45 and the brake device 46 will be described in detail later.

[0048] FIG. 4 is a cross-sectional view similar to FIG. 3, showing the gripping device 42 in the released state.

[0049] 4, when the cylinder 43 retracts the piston 431 rearward, the release rod 432 fixed to the front end of the piston 431 moves rearward. Then, the large-diameter rod portion 4321 of the release rod 432 that has moved rearward comes into contact with the small-diameter sleeve portion 4231 of the chuck sleeve 423, moving the chuck sleeve 423 rearward, thereby changing the state of the gripping device 42 from the gripping state to the release state. In this release state, the tapered surface of the inner periphery of the chuck sleeve 423 no longer presses against the tapered surface of the outer periphery of the collet chuck 421, and the diameter of the front portion of the collet chuck 421 increases. In other words, the force of the cylinder 43 retracting the release rod 432 rearward cancels out the forward pressing force of the sleeve biasing spring 425. As a result, the tapered surface of the inner circumference of the chuck sleeve 423 no longer presses the tapered surface of the outer circumference of the collet chuck 421 while the collet chuck 421 remains pressed against the front cap by the chuck biasing spring 424, and the diameter of the front portion of the collet chuck 421 expands. Then, as the diameter of the front portion of the collet chuck 421 expands, the grip of the scraping tool 3 by the gripping device 42 is released. Conversely, as the cylinder 43 moves the piston 431 forward, the state of the gripping device 42 changes from the released state shown in FIG. 4 to the gripping state shown in FIG. 3.

[0050] FIG. 5 is a view taken along line AA in FIG.

[0051] As shown in Fig. 5, light blocking plate 451 of rotation detection device 45 is disk-shaped, and detection protrusions 4511 are formed around the entire periphery of the periphery, protruding radially at uniform angular intervals. Each of two rotation detection sensors 452 has a detection point 452a between the protruding end of detection protrusion 4511 and the base of detection protrusion 4511, and detects whether detection protrusion 4511 is present at detection point 452a. Fig. 5 shows a state in which light blocking plate 451 is stopped at an angle where detection protrusion 4511 is not present at either of two detection points 452a.

[0052] For example, when the light shielding plate 451 starts to rotate clockwise in FIG. 5 from the angle shown in FIG. 5, the rotation detection sensor 452 on the left side in FIG. 5 detects the light shielding plate 451 first, and a little later, the rotation detection sensor 452 on the right side in FIG. 5 detects the light shielding plate 451. Conversely, when the light shielding plate 451 starts to rotate counterclockwise in FIG. 5 from the angle shown in FIG. 5, the rotation detection sensor 452 on the right side in FIG. 5 detects the light shielding plate 451 first, and a little later, the rotation detection sensor 452 on the left side detects the light shielding plate 451. In this way, the rotation detection device 45 can detect whether or not the light shielding plate 451 is rotating and the direction of rotation. Furthermore, since the light shielding plate 451 is fixed to the rotating tube 426 (see FIG. 3) and rotates together with the gripping device 42 (see FIG. 3), detecting the rotation of the light shielding plate 451 can detect whether or not the gripping device 42 and the scraping tool 3 (see FIG. 3) are rotating and the direction of rotation. That is, the rotation detection device 45 functions as an incremental encoder that detects the rotation of the gripping device 42 and the scraping tool 3 gripped by the gripping device 42. Note that the rotation detection device 45 may be configured so that the angle origin is known, and may function as an absolute encoder.

[0053] If a load exceeding the braking force of the brake device 46 (see FIG. 3) is applied to the scraping tool 3 (see FIG. 3) during scraping due to the presence of large irregularities on the workpiece surface, there is a risk that the scraping tool 3 will rotate with the front-to-rear direction as the center of rotation. If scraping is continued with the scraping tool 3 rotating and the cutting edge 31a (see FIG. 2) tilted, the workpiece surface may be cut more than necessary or may be damaged by the scraping tool 3. By detecting the rotation of the scraping tool 3 with the rotation detection device 45, it is possible to detect that the cutting edge 31a has tilted relative to the workpiece surface.

[0054] Figure 6(a) is an enlarged view of part B in Figure 3 showing the rotary brake mechanism when the rotary brake is not activated, and Figure 6(b) is an enlarged view similar to Figure 6(a) showing the rotary brake mechanism when the rotary brake is activated.

[0055] As shown in Fig. 6, the brake device 46 is an electromagnetic brake having a stator 461 and an armature 462. The stator 461 is a magnetic body fixed to the housing 412 of the support member 41. The stator 461 has a hollow cylindrical shape with a bottom, and a coil 4611 is disposed in the middle between the inner diameter and the outer diameter. A magnetic force is generated in the stator 461 by passing a current through the coil 4611 in response to a command from the control device 5 (see Fig. 1).

[0056] The armature 462 is attached to a rotating flange 4261 fixed to the rear end of the rotating barrel 426, and rotates together with the rotating barrel 426. The armature 462 is a slightly thick, disk-shaped magnetic body arranged opposite the stator 461. A leaf spring 4262 is arranged between the armature 462 and the rotating flange 4261. The leaf spring 4262 is screwed to both the armature 462 and the rotating flange 4261. The leaf spring 4262 biases the armature 462 toward the rotating flange 4261 on the rear side, and is configured to rotate together with the rotating barrel 426 (rotating flange 4261). 6(a) in which the rotary brake is not activated, the armature 462 is positioned on the rotary flange 4261 side by the leaf spring 4262, and faces the stator 461 with a minute gap of about 0.2 mm in the front-to-rear direction between the armature 462 and the rear end face of the stator 461. In this state, the armature 462 and the gripping device 42 are rotatable.

[0057] When a current is supplied to the coil 4611 of the stator 461 to generate a magnetic force in the coil 4611, the armature 462 is pulled forward and comes into contact with the rear end of the stator 461, as shown in FIG. 6(b), and the armature 462 becomes unable to rotate. This makes the gripping device 42 unable to rotate. That is, the brake device 46 changes from a state in which the rotation brake is not activated shown in FIG. 6(a) to a state in which the rotation brake is activated shown in FIG. 6(b). Conversely, by stopping the supply of current to the coil 4611, the brake device 46 changes state from a state in which the rotation brake is activated shown in FIG. 6(b) to a state in which the rotation brake is not activated shown in FIG. 6(a).

[0058] Next, the operation of the scraping device 1 of this embodiment, which is executed under the control of the control device 5, will be described.

[0059] At the start of scraping, the control device 5 tilts the scraper 31 so that its front end is closer to the workpiece surface and its rear end is farther from it, tilting the scraper center line L1 by several degrees relative to the workpiece surface. Then, while maintaining this orientation, the control device 5 deactivates the rotation brake and presses the cutting edge 31a against the workpiece surface. If the cutting edge 31b is tilted in the rotational direction relative to the workpiece surface, causing one end of the cutting edge 31a to contact the workpiece surface first, the other end may contact the workpiece surface first. This pressing force causes the gripping device 42 to rotate around the rotation center line L2, causing the cutting edge 31a to become parallel to the workpiece surface. Pressing the cutting edge 31a against the workpiece surface also deflects the scraper 31, causing the cutting edge 31b to become substantially parallel to the workpiece surface. Here, the rotation of the gripping device 42 may be detected by the rotation detection device 45 when the cutting edge 31a is pressed against the workpiece surface, thereby determining whether the cutting edge 31a has become parallel to the workpiece surface. When making this determination, the gripping unit 4 may be rotated by the robot arm 2 so that the cutting edge 31a is slightly tilted in the direction of rotation relative to the surface to be processed, and then the cutting edge 31a may be pressed against the surface to be processed.

[0060] When the cutting edge 31a is pressed against the workpiece surface, if the cutting edge 31a is inclined at an angle close to 45 degrees relative to the workpiece surface in the rotational direction, the corners at the widthwise ends of the cutting edge 31a may be pressed against the workpiece surface and scratch the workpiece surface. Furthermore, if the cutting edge 31a is inclined at an angle greater than 45 degrees relative to the workpiece surface in the rotational direction, edges other than the cutting edge 31a, such as the boundary between the side and front surfaces of the scraper 31, will be positioned parallel to the workpiece surface. Therefore, when pressing the cutting edge 31a against the workpiece surface, it is necessary to position the cutting edge 31a so that it is approximately parallel to the workpiece surface. This also applies after replacing the scraping tool 3. In this embodiment, the replacement scraping tool 3 is placed on the replacement tool stand 6 so that the cutting edge 31b is positioned in a predetermined orientation. Therefore, when replacing the scraping tool 3, the control device 5 controls the robot arm 2 on the premise that the gripping device 42 grips the scraping tool 3 in that position, so that the cutting edge 31a can be pressed against the surface to be processed in a position where it is approximately parallel to the surface to be processed. This prevents the tip corner of the scraper 31 from scratching the surface to be processed, and prevents edges other than the cutting edge 31a from becoming parallel to the surface to be processed.

[0061] Next, the control device 5 supplies current to the coil 4611 while keeping the scraper 31 bent, activating the rotation brake. Then, the scraper 31 is moved forward a predetermined distance while adjusting the load pressing the cutting edge 31a against the workpiece surface, and then the cutting edge 31a is separated from the workpiece surface, moved to the next processing position, and then the cutting edge 31a is pressed against the workpiece surface again while moving forward a predetermined distance, repeating these operations. In this way, scraping is performed, scraping away the workpiece surface little by little.

[0062] During this scraping operation, the rotation detection device 45 detects the rotation of the gripping device 42. If a rotational load exceeding the braking force of the brake device 46 is applied to the scraping tool 3, the scraping tool 3 may rotate together with the gripping device 42, causing the cutting edge 31a to tilt relative to the workpiece surface. If the rotation detection device 45 detects the rotation of the gripping device 42 while scraping is being performed with the rotation brake activated, there is a risk that the cutting edge 31a may no longer be parallel to the workpiece surface. For this reason, the control device 5 deactivates the rotation brake, as before processing, and then presses the cutting edge 31a against the workpiece surface to return the cutting edge 31a to a parallel position before resuming scraping. Note that when the rotation detection device 45 detects the rotation of the gripping device 42, the scraping device 1 may be stopped due to an error. However, to increase productivity, it is preferable to not stop due to an error and instead resume scraping by returning the cutting edge 31a to a parallel position relative to the workpiece surface.

[0063] By inputting the position of the workpiece surface into the NC program, scraping can be automatically performed on multiple workpiece surfaces or multiple workpieces 9 using the scraping device 1. When scraping the next workpiece surface or workpiece 9, the rotary brake is deactivated before scraping, as before the previous process. Then, the cutting edge 31a is pressed against the next workpiece surface, aligning the cutting edge 31a parallel to the workpiece surface, and scraping begins. The cutting edge 31a of the scraping tool 3 gradually wears during the scraping process. When the control device 5 determines that it is time for the aforementioned tool change, it executes a tool change operation. In the tool change operation, the worn scraping tool 3 is placed on the tool change table 6 by the robot arm 2 with the rotary brake activated, with the cutting edge 31a aligned parallel to the workpiece surface. The replacement scraping tool 3 placed on the tool change table 6 is then gripped by the gripping device 42.

[0064] Thereafter, the scraping tool 3 is moved to the vicinity of the workpiece 9, and then, after the rotary brake is deactivated as before the processing, the cutting edge 31a is pressed against the surface to be processed, and the cutting edge 31a is positioned parallel to the surface to be processed, and scraping processing is resumed.

[0065] According to the scraping device 1 of this embodiment described above, the cylinder 43 can change the state of the gripping device 42 between the gripping state and the released gripping state, which makes it easy to replace the scraping tool 3 and enables automatic tool replacement. By repeating scraping and tool replacement, scraping can be performed automatically for long periods of time, day or night.

[0066] Furthermore, by using a gripping structure that uses collet chuck 421, the gripping device 42 has a simpler structure than a tool gripping structure that grips the tool while retracting it, and as a result, it is possible to configure a small and inexpensive scraping device 1. This is because, in scraping processing, the amount of cutting is extremely small and not a large load is applied to the scraping tool 3, and therefore a gripping structure that uses collet chuck 421 with a relatively simple structure is sufficient, which is a circumstance specific to scraping processing.

[0067] The present invention is not limited to the above-described embodiment and various modifications can be made within the scope of the claims. For example, in the description of this embodiment, the gripping unit 4 is moved using the robot arm 2. However, instead of the robot arm 2, a movable body such as a tool post that can move in multiple axial directions may be used. The rotation detection device 45 may also be omitted. Furthermore, the foreign object intrusion prevention member 427 may also be omitted. Alternatively, an air purge device that blows foreign objects from the gripping device 42 to the outside or a fluid supply device that ejects fluid to flush foreign objects from the gripping device 42 to the outside may be provided instead of the foreign object intrusion prevention member 427. In addition, in this embodiment, the gripping device 42 is freely rotatable about the rotation center line L2 when the rotation brake is not activated. However, the gripping device 42 may be constantly non-rotatable. In this case, the brake device 46 may also be omitted.

[0068] It should be noted that even if a constituent element is included only in the description of each of the modified examples described above, that constituent element may be applied to other modified examples. [Explanation of symbols]

[0069] 1 scraping device 3 Scraping tool 5. Control device 31a cutting edge 42 Gripping device 43 Cylinder (actuator) 421 Collet Chuck 3211 Grasped part

Claims

1. a scraping tool having a cutting edge formed at its front end for scraping; a gripping device that grips the scraping tool; a scraping device characterized by comprising an actuator controlled by a control device for changing the state of the gripping device between a gripping state in which the scraping tool is gripped and a released state in which the gripping of the scraping tool is released.

2. 2. The scraping device according to claim 1, wherein the gripping device has a collet chuck for gripping a gripped portion formed on the rear end side of the scraping tool.

3. The scraping tool has a scraper having a cutting edge formed continuously from the cutting edge, and a scraper holder to which a rear end portion of the scraper is fixed, 3. The scraping device according to claim 1, wherein the scraper holder is formed at a specific angle with respect to the cutting edge and has a mounting surface for mounting the scraping tool on a tool changer table.

4. a support member that supports the gripping device rotatably around a rotation center direction that is the front-rear direction of the scraping tool; 3. The scraping device according to claim 1, further comprising a rotation detection device for detecting rotation of said gripping device during execution of said scraping process.

5. 3. The scraping device according to claim 1, wherein the gripping device has an internal biasing member, a continuous hole extending from the front end that grips the scraping tool to the biasing member, and a foreign object intrusion prevention member that is inserted into the continuous hole to close the continuous hole.

Images