Gripping device and gripping method

Abstract

To provide a gripping device and a gripping method capable of gripping a workpiece of an arbitrary shape.SOLUTION: A gripping device 10 includes: a base stand 12; a rotation part 14 which is extended along a radial direction of the base stand 12 and is rotatable around an axial line thereof; a guide part 18 which is movable in a radial direction of the base stand 12, on the rotation part 14; a base 22 which is rotatable on the guide part 18; a clamp claw 24 which is arranged on a radial direction inner side of the base stand 12 and is provided with a plurality of pins 24a, on the base 22; and a fine movement mechanism part 26 which is arranged on the base 22 and pressurizes a chamber 60 connected with the plurality of pins 24a. The gripping device is characterized in that the rotation part 14 is rotated around the axial line of the base stand 12, based on workpiece information including shape data of the workpiece W, at the same time, the guide part 18 is moved along a radial direction of the base stand 12, the base 22 and the clamp claw 24 are rotated, and the plurality of pins 24a of the clamp claws 24 are pushed against the workpiece shape formed after the shape of the workpiece W by the fine movement mechanism part 26.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gripping device and a gripping method. [Background technology]

[0002] In order to perform machining automatically, it is necessary to stably attach the workpiece to the machine tool and stably fix it to the machine tool. On the other hand, the shape and size of the workpiece may vary depending on the purpose of machining, and it is not a fixed shape like cargo for delivery, so for example, even if the workpiece is gripped by clamping it from both sides with arms, it may not be possible to stably grip the workpiece. For this reason, Patent Document 1 discloses a chuck for supporting a rotationally symmetric workpiece to be machined using a machine tool, which includes a chuck body, at least three clamp jaws, an electric motor as a driving means, and a control unit. In addition, Patent Document 2 discloses a gripping head for gripping objects of various shapes, which includes a base and a gripping jaw that is linearly guided in the gripping direction on the base and has a frame and a plurality of pins that can be displaced along the gripping direction.

[0003] However, the clamp jaws described in Patent Document 1 and the gripping head described in Patent Document 2 can move along the radial direction of the workpiece, but cannot move along the circumferential direction of the workpiece. For this reason, even if these gripping devices can grip workpieces of similar shapes but different sizes, it may be difficult to grip workpieces with significantly different peripheral shapes. In addition, when the rigidity of the workpiece varies depending on the part, it may be difficult to grip the workpiece while avoiding the parts with low rigidity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6594100 [Patent Document 2] Patent No. 6725808 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a gripping device and a gripping method capable of gripping a workpiece of any shape. [Means for solving the problem]

[0006] According to the present invention, there is provided a gripping device that grips a workpiece of any shape using a plurality of clamping claws, the gripping device comprising: a base; a rotating section arranged on the base, extending along the radial direction of the base and configured to be rotatable around the axis of the base; a guide section arranged on the rotating section and movable along the radial direction of the base; a base rotatably arranged on the guide section; a clamping claw arranged on the base radially inside the base and having a plurality of pins; and a fine movement mechanism section arranged on the base, having a chamber that contains a pressurized fluid and is connected to the plurality of pins, and pressurizing the chamber, wherein, based on workpiece information including shape data of the workpiece, the rotating section is rotated around the axis of the base and the guide section is moved along the radial direction of the base, rotating the base and the clamping claws, and the fine movement mechanism section pressurizes the chamber.

[0007] Further, according to the present invention, there is provided a method for gripping a workpiece of any shape using the gripping device of the present invention in a machine tool having three mutually perpendicular linear feed axes and at least two rotary feed axes, the gripping device having a memory unit that stores workpiece information including shape data of the workpiece, the method including: (i) a spindle head of the machine tool moving the workpiece to the gripping device based on the workpiece information stored in the memory unit; (ii) rotating the rotating part around the axis of the base and positioning the clamping claws in the circumferential direction of the base based on the workpiece information; (iii) moving the guide part along the radial direction of the base and positioning the clamping claws in the radial direction of the base based on the workpiece information; and (iv) pressurizing multiple pins of the clamping claws by a chamber and pressing them against the workpiece in accordance with the shape of the workpiece based on the workpiece information. Effect of the Invention

[0008] According to the gripping device of the present invention, the gripping device includes a base, a rotating part arranged on the base, extending along the radial direction of the base, and configured to be rotatable around the axis of the base, a guide part arranged on the rotating part and movable along the radial direction of the base, a base arranged rotatably on the guide part, and a clamp claw arranged on the base radially inside the base and having a plurality of pins. Therefore, the clamp claw can be rotated along the circumferential direction of the base by rotating the rotating part around the axis of the base, and the clamp claw can be moved along the radial direction of the base by moving the guide part on the rotating part along the radial direction of the base. Furthermore, by rotating the base and the clamp claw, the orientation of the clamp claw with respect to the workpiece can be adjusted. This allows the position of the clamp claw with respect to the workpiece to be adjusted based on workpiece information including shape data of the workpiece. Furthermore, the clamp claw has a chamber that contains a pressurized fluid and is connected to a plurality of pins, and a fine movement mechanism that pressurizes the chamber is arranged on the clamp claw. Therefore, the insertion and removal of a plurality of pins of the clamp claw can be adjusted in response to the shape and rigidity of the workpiece, and these can be pressed against the workpiece in accordance with the shape of the workpiece. As a result, the gripping device according to the present invention can grip workpieces of any shape.

[0009] According to the gripping method of the present invention, the gripping device includes a storage unit that stores workpiece information including shape data of the workpiece, and the spindle head of the machine tool can move the workpiece to the gripping device based on the workpiece information stored in the storage unit. Furthermore, based on the workpiece information, the rotating unit can be rotated around the axis of the base to match the position of the workpiece moved by the spindle head, thereby positioning the clamping claws in the circumferential direction of the base, and the guide unit can be moved along the radial direction of the base to position the clamping claws in the radial direction of the base. This makes it possible to adjust the position of the clamping claws relative to the workpiece according to the shape of the workpiece. Furthermore, the multiple pins of the clamping claws can be pressurized by the chamber and pressed against the workpiece in accordance with the shape of the workpiece. In this way, the gripping method of the present invention can grip a workpiece of any shape. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 shows a perspective view of a gripping device according to a first embodiment. [Diagram 2] FIG. 2 shows a perspective view of a gripping device that adjusts its position relative to a workpiece. [Diagram 3] FIG. 3 shows a perspective view of the gripping device with the workpiece clamped at a fixed position. [Figure 4] FIG. 4 shows a schematic diagram of the position adjustment of the clamp jaws relative to the workpiece. [Figure 5A] FIG. 5A is a schematic diagram showing the position adjustment of the clamp jaw pin relative to the workpiece. [Figure 5B] FIG. 5B is a schematic diagram showing the position adjustment of the clamp jaw pin relative to the workpiece. [Figure 5C] FIG. 5C is a schematic diagram showing the position adjustment of the clamp jaw pin relative to the workpiece. [Figure 6] FIG. 6 shows a schematic diagram of a modified example of the gripping device. [Figure 7] FIG. 7 shows a perspective view of a gripping device according to the second embodiment. [Figure 8]8(a) to 8(c) are perspective views of a gripping device that changes its posture to perform three-sided machining of a gripped workpiece. [Figure 9] 9(a) to 9(c) are perspective views of a gripping device for changing the setup of a workpiece. [Figure 10] FIG. 10 shows a perspective view of the gripping device from which the workpiece has been removed after side surface machining has been completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a gripping device according to an embodiment will be described with reference to the accompanying drawings. Similar or corresponding elements are given the same reference numerals, and duplicated explanations will be omitted. In order to facilitate understanding, the scale of the drawings may be changed.

[0012] (First embodiment) FIG. 1 shows a perspective view of a gripping device 10 according to a first embodiment. The gripping device 10 is used to grip a workpiece W in a machine tool 32 having three linear feed shafts and at least two rotary feed shafts that are orthogonal to each other (not shown). The gripping device 10 is configured to be able to grip a workpiece W of any shape, that is, a workpiece W whose outer peripheral shape and rigidity vary depending on the part, and includes a base 12, a rotating part 14 arranged on the base 12 and extending along the radial direction of the base 12, and a guide part 18 arranged on the rotating part 14. Here, the three rotating parts 14 and the guide part 18 are arranged on the base 12. The base 12 includes a base guide groove 16 formed along the circumferential direction and a central shaft 28 arranged in the center and configured to be rotatable by a driving device such as a motor (not shown). The rotating part 14 has a radially inner end portion on the base 12 connected to the central shaft 28, and an engagement portion 14a formed on the lower surface side of the rotating part 14 is engaged with the base guide groove 16. For this reason, the rotating part 14 is configured to be rotatable around the axis of the base 12, i.e., around the central axis 28. The gripping device 10 also includes a control unit 48 that is electrically connected to the central axis 28 and controls the rotation of the central axis 28 to adjust the position of the rotating part 14 on the base 12.

[0013] A rotating part guide groove 20 is formed on the upper surface of the rotating part 14 in the longitudinal direction, i.e., along the radial direction of the base 12. The guide part 18 is configured so that a fitting part 18a formed on the lower surface thereof is fitted into the rotating part guide groove 20 and is movable along the longitudinal direction of the rotating part 14, i.e., along the radial direction of the base 12. The guide part 18 is also electrically connected to the control part 48, and the control part 48 can adjust the position of the guide part 18 with respect to the rotating part 14 by controlling the movement of the guide part 18.

[0014] A base 22 is disposed above the guide unit 18 so as to be rotatable relative to the guide unit 18. The base 22 is electrically connected to a control unit 48, and the control unit 48 can adjust the orientation of the base 22 with respect to the workpiece W disposed on the central axis 28 side of the base 12 by controlling the rotation of the base 22.

[0015] A clamp claw 24 is disposed on the front side of the base 22, i.e., on the radial inside of the base 12. The clamp claw 24 includes a plurality of pins 24a extending toward the central axis 28. The base 22 also includes a chamber 60 (see FIG. 6) that contains a pressure fluid and is connected to the plurality of pins 24a, and includes a fine movement mechanism 26 for moving the pins 24a in and out by pressurizing or depressurizing the chamber 60. The fine movement mechanism 26 is electrically connected to the control unit 48, and the control unit 48 can adjust the movement of the pins 24a in and out of the base 22 by controlling the pressurization or depressurization of the chamber 60. This allows the pins 24a to be pressed against the workpiece W in accordance with the shape of the workpiece W moved onto the base 12.

[0016] A force sensor 56 (see FIG. 6) is disposed between the base 22 and the guide portion 18. The force sensor 56 can detect the repulsive force of the workpiece W against the pin 24a pressed against the workpiece W in accordance with the shape of the workpiece W. The force sensor 56 is electrically connected to the control portion 48, and the control portion 48 can detect the repulsive force detected by the force sensor 56 and control the pressurization or depressurization of the chamber 60 based on this. This makes it possible to adjust the clamping force applied to the workpiece W by the pin 24a of the clamp claw 24.

[0017] The fine movement mechanism 26 has a pressure screw 26a for adjusting the pressure in the chamber 60. The force that applies pressure to the inside of the chamber 60 is configured to be proportional to the torque for rotating the pressure screw 26a. For this reason, as shown in FIG. 3, the pressure in the chamber 60 can be increased or decreased by inserting a tool such as a wrench from above the pressure screw 26a and turning the pressure screw 26a. This allows fine adjustment of the clamping force of the pin 24a of the clamp claw 24 on the workpiece W.

[0018] 1, the base 22 is configured to be movable up and down from the guide unit 18, and the height position of the base 22 can be adjusted by the control unit 48. Therefore, the height position of the pin 24a of the clamp claw 24 that is pressed against the workpiece W can be adjusted.

[0019] A central support part 30 having a plurality of pins 30a extending upward is formed above the central shaft 28. Therefore, the workpiece W moved onto the base 12 can be supported from below by the central support part 30. The central support part 30 is electrically connected to the control part 48, which can adjust the movement of the pins 30a in and out of the central shaft 28. This allows the pins 30a to be pressed against the workpiece W moved onto the base 12 in accordance with its shape.

[0020] A chuck 38 can be attached to the spindle 36 attached to the spindle head 34 of the machine tool 32. The chuck 38 includes an arm 40 configured to be slidable along its longitudinal direction, and a movable claw 42 having a pin 42a configured to be retractable from the arm 40. Therefore, a workpiece W taken out from a work shelf or the like can be stably gripped by the arm 40 and the movable claw 42, and moved to above the base 12 of the gripping device 10.

[0021] 2, a gripper 44 can be attached to the spindle 36 in place of the chuck 38. The gripper 44 is formed so as to be able to clamp the base 22 from above, and can rotate the base 22 relative to the guide part 18. This makes it possible to adjust the orientation of the base 22 with respect to the workpiece W arranged on the central axis 28 side of the base 12.

[0022] 3, a wrench driver 46 can be attached to the spindle 36 instead of the chuck 38. Therefore, the wrench driver 46 attached to the spindle 36 can be inserted into the pressure screw 26a and rotated by torque control rather than speed control. This makes it possible to increase or decrease the pressure in the chamber 60 and finely adjust the clamping force of the pin 24a of the clamp jaw 24 on the workpiece W.

[0023] The control unit 48 has a storage unit 48a in which work information including data such as three-dimensional shape data of the work W, the material of the work W, and the rigidity of each part of the work W is stored. The work information stored in the storage unit 48a also includes information such as the tool (not shown) used to process the work W, the part of the work W to be processed, and the processing conditions of the work W performed using the tool. The control unit 48 can comprehensively determine which part of the work W is to be gripped when gripping the work W with the gripping device 10 and the chuck 38, based on the work information. Specifically, the control unit 48 calculates the position of the center of gravity of the work W from the shape data and material data of the work W included in the work information before gripping the work W using the chuck 38 attached to the spindle 36 as shown in FIG. 1. Next, the control unit 48 calculates the cutting resistance of the work W, i.e., the force acting on the work W when cutting and the direction in which the cutting resistance acts on the work W, from the tool, the part of the work W to be processed, and the processing conditions of the work W included in the work information. Here, when there are multiple machining processes for the workpiece W, the magnitude and direction of the cutting resistance are calculated for each machining process. Based on the magnitude and direction of the cutting resistance thus calculated, the control unit 48 determines a gripping position that can securely grip the workpiece W and minimize the clamping force for gripping, i.e., the position of the pin 24a of the clamp jaws 24 relative to the workpiece W.

[0024] 1, the control unit 48 operates the chuck 38 to grip the workpiece W based on the calculated position of the center of gravity of the workpiece W and the determined gripping position of the workpiece W. When the chuck 38 grips the workpiece W, the control unit 48 moves the spindle 36 and the chuck 38 to the central support part 30 of the base 12 and places the workpiece W on the central support part 30. At this time, the position of the clamping jaws 24 with respect to the workpiece W may be adjusted by rotating the spindle 36 while the chuck 38 is gripping the workpiece W, or may be adjusted by rotating the rotating unit 14 after the workpiece W is placed on the central support part 30.

[0025] FIG. 4 is a schematic plan view of the workpiece W and the base 12 placed on the central support 30 as an example of positioning of the clamping claws 24 relative to the workpiece W. Also shown in the figure are the X-axis and the Y-axis, which are orthogonal axes with the center of the base 12 as the origin. In the example shown here, as a result of calculating the cutting resistance of the workpiece W, it is found that the cutting resistance acting in the positive direction along the X-axis and the cutting resistance acting in the negative direction along the Y-axis are dominant. For this reason, the control unit 48 rotates and positions two (a, c in FIG. 4) of the three bases 22 (a, b, c in FIG. 4) so ​​that the clamping force acts in the negative direction along the X-axis and the positive direction along the Y-axis, which are opposite to the cutting resistance, that is, the clamping claws 24 can be pressed against the workpiece W (P1, P3 in FIG. 4). Furthermore, the remaining base 22 (b in FIG. 4) is rotated and positioned (P2 in FIG. 4) so ​​as to balance the clamping forces from P1 and P3. This allows the clamp jaws 24 to be pressed against the workpiece W so as to counteract the cutting resistance, making it possible to stably grip the workpiece W of any shape.

[0026] 5A to 5C are schematic diagrams showing the pin 24a of the clamp claw 24 pressed against the workpiece W to grip the workpiece W. As shown in FIG. 5A, the workpiece W is gripped by the pin 24a pressed against the workpiece W. A force acting on the workpiece W, such as a cutting resistance, is transmitted to the base 22 through a force transmission path LP formed by the workpiece W and the pin 24a pressed against it, and can be detected by the force sensor 56. The pin 24a is configured to be lockable at any position relative to the base 22, and when gripping the workpiece W with the clamp claw 24, two modes, locking and unlocking of the pin 24a, can be switched for each pin 24a. Therefore, the control unit 48 can switch between locking and unlocking of the pin 24a according to the magnitude of the force detected by the force sensor 56, and can also switch the pin 24a pressed against the workpiece W. This allows the position of the pin 24a to be optimized so that the workpiece W can be gripped stably. FIG. 5B shows a state in which the pin 24a is locked. By increasing or decreasing the pressure in the chamber 60 by rotating the pressure screw 26a, the force of the pins 24a pressing against the workpiece W can be increased or decreased. In addition, as the pressure in the chamber 60 is increased, the pins 24a are brought into close contact with each other in the vertical direction, generating a frictional force between the pins 24a. The movement of the pins 24a is suppressed by this frictional force, so that the position of the pins 24a can be stabilized. Furthermore, by pressing some of the pins 24a against the surface of the workpiece W and locking the remaining pins 24a in a state in which they are separated from the surface of the workpiece W, the workpiece W can be gripped while avoiding, for example, a portion with low rigidity against which the pin 24a is not desired to be pressed, or a portion against which the pin 24a cannot be pressed because an opening is formed. FIG. 5C shows a state in which the pins 24a are unlocked. In the unlocked state, the binding force of the pins 24a themselves is weak, so that the pins 24a can press the pins 24a against the surface of the workpiece W to grip the workpiece W with the entire pins 24a, and the clamping force can be distributed to the multiple pins 24a.

[0027] (Modification) Furthermore, a modified example of the gripping device 10 according to this embodiment will be described. Elements similar to or corresponding to those in this embodiment will be given the same reference numerals, and duplicated explanations will be omitted.

[0028] 6 shows a schematic diagram of a main part of a gripping device 50 according to a modified example. As shown in the figure, the rotating part may be constituted by a guide rail 52. Also, the guide part may be constituted by a rodless cylinder 54 arranged across the guide rail 52, or the like. Furthermore, the force sensor 56 may be arranged between the base 58 and the rodless cylinder 54, rather than inside the base 58. Also, depending on the shape of the workpiece W, a plurality of bases 58 having clamp claws 24 may be arranged on one guide rail 52.

[0029] Next, the operation and effects of the gripping device 10 and gripping method according to this embodiment will be described.

[0030] The gripping device 10 according to the present embodiment includes a base 12, a rotating part 14 arranged on the base 12, extending along the radial direction of the base 12, and configured to be rotatable around a central axis 28 of the base 12, a guide part 18 arranged on the rotating part 14 and movable along the radial direction of the base 12, a base 22 rotatably arranged on the guide part 18, and a clamp claw 24 arranged on the base 22 on the radial inside of the base 12 and having a plurality of pins 24a. Therefore, by rotating the rotating part 14 around the central axis 28 of the base 12, the clamp claw 24 can be rotated along the circumferential direction of the base 12, and by moving the guide part 18 on the rotating part 14 along the radial direction of the base 12, the clamp claw 24 can be moved along the radial direction of the base 12. Furthermore, by rotating the base 22 and the clamp claw 24, the orientation of the clamp claw 24 with respect to the workpiece W can be adjusted. This allows the position of the clamp claw 24 with respect to the workpiece W to be adjusted according to the shape of the workpiece W. Furthermore, the clamping jaws 24 have a chamber 60 that contains a pressurized fluid and is connected to the multiple pins 24a, and a fine movement mechanism 26 is disposed to pressurize the chamber 60. Therefore, the multiple pins 24a of the clamping jaws 24 can be adjusted to move in and out in response to the shape and rigidity of the workpiece W, and pressed against the workpiece W in accordance with the shape of the workpiece W. As a result, the gripping device 10 can grip a workpiece W of any shape.

[0031] Furthermore, according to the gripping device 10 of this embodiment, a force sensor 56 is provided between the base 22 and the guide portion 18. Therefore, the force sensor 56 can detect the repulsive force of the workpiece W against the pins 24a pressed against the workpiece W in accordance with the shape of the workpiece W. This allows the control portion 48 to detect the repulsive force detected by the force sensor 56 and control the pressurization or depressurization of the chamber 60, thereby adjusting the clamping force of the pins 24a of the clamp claws 24 on the workpiece W.

[0032] Furthermore, according to the gripping device 10 of this embodiment, the fine movement mechanism 26 has a pressure screw 26a for adjusting the pressure in the chamber 60. Therefore, the wrench driver 46 attached to the spindle 36 can be inserted into the pressure screw 26a and rotated. This makes it possible to increase or decrease the pressure in the chamber 60, and finely adjust the clamping force of the pin 24a of the clamp claw 24 on the workpiece W.

[0033] Furthermore, according to the gripping device 10 of this embodiment, the base 22 is configured to be movable up and down. Therefore, the height position of the base 22 can be adjusted by the electrically connected control unit 48, and the height position of the pins 24a of the clamp claws 24 that press against the workpiece W can be adjusted according to the shape of the workpiece W.

[0034] Furthermore, the gripping device 10 according to this embodiment includes a storage unit 48a that stores work information including information such as the three-dimensional shape data of the work W, the material of the work W, and the rigidity data of each part of the work W, as well as information on the tool used to process the work W, the part of the work W to be processed, and the processing conditions of the work W performed using the tool. Therefore, the gripping device 10 can comprehensively determine which part of the work W to grip when gripping the work W based on the work information. As a result, for example, the clamp claws 24 can be pressed against the work W so as to cancel the cutting resistance, so that the work W of any shape can be stably gripped. In addition, the control unit 48 can switch between locking and unlocking the pin 24a configured to be lockable at any position according to the magnitude of the force detected by the force sensor 56, and can switch the pin 24a pressed against the work W. As a result, the position of the pin 24a can be optimized so that the work W can be stably gripped.

[0035] As described above, the gripping device 10 and gripping method according to this embodiment can stably grip a workpiece W of any shape.

[0036] Second embodiment A gripping device 70 and a gripping method according to the second embodiment will be described below with reference to Figures 7 to 10. Elements similar to or corresponding to those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted.

[0037] As shown in Fig. 7, the gripping device 70 according to this embodiment is disposed on an inclined swivel table 62 as a base provided on a machine tool (not shown). The inclined swivel table 62 is configured to be linearly movable and rotatable by three linear feed shafts and two rotary feed shafts (not shown) that are orthogonal to each other and that are disposed on the machine tool. Therefore, the workpiece W and the machining tool (not shown) gripped by the gripping device 70 can be moved relatively along the three linear feed shafts that are orthogonal to each other, and can be rotated relatively around the two rotary feed shafts.

[0038] The gripping device 70 is provided with a rotating part 64 that is disposed on the inclined swivel table 62, extends along the radial direction of the inclined swivel table 62, and is configured to be rotatable around the axis of the inclined swivel table 62, and a base 66 that is disposed on the rotating part 64 and rotatably disposed on a guide part (not shown) that is movable along the radial direction of the inclined swivel table 62. The gripping device 70 also includes a clamp claw 24 that is disposed on the base 66 radially inside the inclined swivel table 62 and has a plurality of pins.

[0039] As shown in Figures 8(a) to 8(c), the workpiece W on the inclined swivel table 62 gripped by the clamping jaws 24 can be turned upward by rotating the rotary feed shaft, so that the three surfaces against which the clamping jaws 24 are not pressed can be faced upward. This allows machining of the top surface of the workpiece W shown in Figure 8(a) and the long side surfaces of the workpiece W shown in Figures 8(b) and 8(c).

[0040] As shown in FIG. 9(a), in order to change the setup of the workpiece W whose upper surface and long side surfaces have been machined, the workpiece W is released by moving the clamping claws 24 and the base 66 away from the workpiece W. The released workpiece W is lifted while being gripped by the chuck 38 attached to the spindle 36. As shown in FIG. 9(b), the lifted workpiece W (indicated by a dashed line in the figure) changes its orientation together with the chuck 38 which rotates by rotating the spindle 36. The workpiece W whose orientation has been changed is placed again on the rotating part 64 and gripped by the clamping claws 24. Therefore, as shown in FIG. 9(c), the short side surface (surface indicated by the arrow in the figure) of the workpiece W which was initially gripped by the clamping claws 24 can be machined.

[0041] 10, the workpiece W whose short side surface has been machined is released from the clamp jaws 24 again and lifted by the chuck 38. By attaching a machining tool (not shown) to the rotating part 64 side of the lifted workpiece W, the bottom surface of the workpiece W can also be machined.

[0042] In a known gripping device, when the setup of the workpiece W is changed during processing, that is, when the workpiece W is changed over, the processing position may be shifted due to the changeover. In this regard, according to the gripping device 70 of this embodiment, based on the workpiece information including the shape data of the workpiece W, the rotating part 64 is rotated around the axis of the inclined swivel table 62 and the base 66 and the clamping claws 24 are rotated, and the clamping claws 24 can be pressed against the shape of the workpiece W. Therefore, even if the setup of the workpiece W is changed during processing, the gripping device 70 can be precisely aligned based on the workpiece information including the shape data of the workpiece W, and the setup of the workpiece W can be changed at an appropriate gripping position. This can improve the processing accuracy of the workpiece W.

[0043] As described above, the gripping device 70 and gripping method according to this embodiment can stably grip a workpiece W of any shape while ensuring processing accuracy.

[0044] Although the embodiments of the gripping devices 10, 50, and 70 have been described above, the present invention is not limited to the above-mentioned embodiments. Various modifications of the above-mentioned embodiments are included in the embodiments of the present invention within the scope of those skilled in the art. [Explanation of symbols]

[0045] 10 Gripping device 12 Foundation 14 Rotating part 18 Information Department 22 Base 24 Clamp jaws 24a pin 26 Fine movement mechanism section 32 Machine tools 34 Spindle head 48a Storage section 50 Gripping device 52 Guide rail (rotating part) 54 Rodless cylinder (guide part) 56 Force Sensor 58 Base 60 Chamber 62 Tilt rotating table (base) 64 Rotating part 66 Base 70 Gripping device

Claims

1. A gripping device that grips a workpiece of any shape using multiple clamp jaws, The base and A rotating part that is disposed on the base, extends along a radial direction of the base, and is configured to be rotatable around an axis of the base; A guide portion disposed on the rotating portion and movable along a radial direction of the base; A base is disposed on the guide portion and configured to be rotatable with respect to the guide portion about an axis parallel to an axis of the base; The clamp claw is disposed radially inside the base of the base and has a plurality of pins; a fine movement mechanism disposed on the base, the fine movement mechanism having a chamber for containing a pressure fluid and connected to a plurality of the pins, and for pressurizing the chamber; A gripping device characterized in that, based on work information including shape data of the work, the rotating part is rotated around the axis of the base and the guide part is moved along the radial direction of the base, the base and the clamping claws are rotated, and the fine motion mechanism part presses the multiple pins of the clamping claws in accordance with the shape of the work.

2. The gripping device according to claim 1 , wherein the clamping jaws are provided with a force sensor capable of changing a clamping force for the workpiece.

3. The gripping device according to claim 2 , wherein the fine movement mechanism includes a screw for adjusting the pressure in the chamber.

4. The gripping device according to claim 3 , wherein the base is configured to be movable up and down.

5. The gripping device according to claim 4 , wherein the workpiece information includes information on the material of the workpiece, a tool used to machine the workpiece, and conditions for machining the workpiece using the tool.

6. A gripping method for gripping a workpiece of any shape using the gripping device according to any one of claims 1 to 5 in a machine tool having three linear feed axes and at least two rotary feed axes perpendicular to each other, comprising: The gripping device includes a storage unit that stores workpiece information including shape data of the workpiece, (i) a spindle head of the machine tool moves the workpiece to the gripping device based on the workpiece information stored in the memory unit; and (ii) rotating the rotating part around the axis of the base based on the work information, and positioning the clamp claws in the circumferential direction of the base; (iii) moving the guide portion along the radial direction of the base based on the work information, and positioning the clamp claws in the radial direction of the base; (iv) applying pressure to the pins of the clamp jaws by the chamber based on the workpiece information, and pressing the pins against the workpiece in accordance with the shape of the workpiece; A gripping method for gripping a workpiece of any shape, comprising:

7. 7. The method for gripping a workpiece of any shape according to claim 6, further comprising positioning the clamp claws in the circumferential direction of the base based on the workpiece information stored in the memory unit.

8. 8. The method for gripping a workpiece of any shape according to claim 7, further comprising positioning the clamp claws in a radial direction of the base based on the workpiece information stored in the memory unit.

9. 9. A method for gripping a workpiece of any shape as described in claim 8, further comprising the steps of: moving the clamping jaws to a position where the pins are adjacent to the workpiece; and then pressurizing the chamber to pressurize the pins in accordance with the shape of the workpiece.

10. 10. The method for gripping a workpiece of any shape as described in claim 9, further comprising adjusting a position of the workpiece relative to the clamp jaws by moving the workpiece in the radial and circumferential directions of the base using the spindle head of the machine tool.

Images