Hand and industrial robot

Abstract

The utility model relates to a hand and an industrial robot. Even if the action quantities of two pairs of forks are different, the action time can be the same. The hand is a hand of an industrial robot that transports an object to be transported, and is provided with: a pair of first forks that extend in a first direction that is orthogonal to the vertical direction; a pair of second forks extending in the first direction; a first opening / closing mechanism that changes the pitch between the pair of first forks in a second direction orthogonal to the vertical direction and the first direction so as to move the pair of first forks in a direction approaching each other or in a direction away from each other in the second direction; and a second opening / closing mechanism that changes the pitch between the pair of second forks in the second direction so as to move the pair of second forks toward each other or away from each other in the second direction, one of the pair of first forks and the pair of second forks having a greater amount of movement in the second direction than the other one, and one of the pair of first forks and the pair of second forks has a greater amount of movement in the second direction than the other one of the pair of first forks and the pair of second forks. The first opening / closing mechanism or the second opening / closing mechanism corresponding to one is provided with an AC motor as a drive source, and the first opening / closing mechanism or the second opening / closing mechanism corresponding to the other is provided with a DC motor as a drive source.

Description

Technical Field

[0001] The utility model relates to a hand and an industrial robot. Background Art

[0002] A hand of an industrial robot is known, which is provided with a pair of first forks and a pair of second forks extending in the same direction, a first opening and closing mechanism and a second opening and closing mechanism, wherein the first opening and closing mechanism changes the spacing of the pair of first forks in the orthogonal direction orthogonal to the up-down direction and the extending direction of the first forks, and the second opening and closing mechanism changes the spacing of the pair of second forks in the orthogonal direction, and each opening and closing mechanism is provided with: a DC (direct current) motor as a driving source; and a screw component driven to rotate by the driving source, the screw component including two screws having threads in opposite directions formed on the outer peripheral surface and connected via a coupling, each first fork (each second fork) is engaged with the corresponding screw at the base end, so that when the motor is driven, the rotational motion is converted into linear motion, and the pair of first forks (the pair of second forks) move the same distance closer to or farther from each other in the orthogonal direction via the two screws. In this way, when the hand is provided with two opening and closing mechanisms for opening and closing the pair of first forks and the pair of second forks, respectively, each opening and closing mechanism is driven by a DC motor.

[0003] However, when a DC motor is used as the motor, the moving speed of the fork is relatively slow. When the movement amounts of the opening and closing mechanisms are different, if the speeds are the same, the opening and closing time of the one with a larger movement amount is longer, and the movement time becomes the opening and closing time that matches the one with a larger movement amount. Utility Model Content

[0004] The utility model is completed in view of the above-mentioned problems, and aims to provide a hand and an industrial robot, which can make the action time the same even if there are differences in the action amounts of the two pairs of forks.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the utility model provides a hand, which is a hand of an industrial robot for carrying a handling object, and comprises: a pair of first forks extending along a first direction orthogonal to the up-down direction; a pair of second forks extending along the first direction; a first opening and closing mechanism, the first opening and closing mechanism changes the spacing of the pair of first forks in the second direction in a manner that allows the pair of first forks to move toward each other or away from each other in a second direction orthogonal to the up-down direction and the first direction; and a second opening and closing mechanism, the second opening and closing mechanism changes the spacing of the pair of second forks in the second direction in a manner that allows the pair of second forks to move toward each other or away from each other in the second direction, one of the pair of first forks and the pair of second forks moves more in the second direction than the other, and the first opening and closing mechanism or the second opening and closing mechanism corresponding to the one has an AC motor as a driving source, and the first opening and closing mechanism or the second opening and closing mechanism corresponding to the other has a DC motor as a driving source.

[0006] According to the hand of the utility model, a pair of forks with a large amount of movement is controlled by an AC motor with a fast rotation speed, and a pair of forks with a small amount of movement is controlled by a DC motor with a slow rotation speed. Even if there are differences in the movement amounts of the two pairs of forks, the movement times can be made the same.

[0007] In addition, in the present invention, the first opening and closing mechanism may include: a first threaded member; and a first driving source, wherein the first threaded member is driven and rotated by the first driving source to move the pair of first forks in the second direction, and the second opening and closing mechanism may include: a second threaded member; and a second driving source, wherein the second threaded member is driven and rotated by the second driving source to move the pair of second forks in the second direction. Thus, the pair of first forks and the pair of second forks can be opened and closed with a relatively simple structure.

[0008] In addition, in the present invention, the first threaded component may include a first external threaded component forming a right-handed external thread, a second external threaded component forming a left-handed external thread, and a first coupling connecting the first external threaded component and the second external threaded component, one of the pair of first forks has a first internal threaded portion engaged with the first external threaded component at the base end side, the other of the pair of first forks has a second internal threaded portion engaged with the second external threaded component at the base end side, the second threaded component includes a third external threaded component forming a right-handed external thread, a fourth external threaded component forming a left-handed external thread, and a second coupling connecting the third external threaded component and the fourth external threaded component, one of the pair of second forks has a third internal threaded portion engaged with the third external threaded component at the base end side, and the other of the pair of second forks has a fourth internal threaded portion engaged with the fourth external threaded component at the base end side. According to the above structure, the reduction of the straightness of the external threaded component can be suppressed.

[0009] Furthermore, in the present invention, the AC motor may be a three-phase AC servo motor.

[0010] A second aspect of the present invention provides an industrial robot having any of the above-mentioned hands.

[0011] According to the industrial robot of the present invention, even if there are differences in the movement amounts of the two pairs of forks on the same hand, the movement times can be made to be of the same level.

[0012] In addition, in the industrial robot of the present invention, it is also possible that the industrial robot further includes: a base capable of linear movement; a turntable rotatably arranged above the base; a lifting mechanism arranged in an upright manner relative to the turntable; an arm that moves the hand forward and backward relative to the lifting mechanism; a wrist axis, and the hand is rotatably connected to the front end side of the arm via the wrist axis; and a control unit, which controls the movement of at least one of the base, the turntable, the lifting mechanism, the arm and the hand.

[0013] Furthermore, in the industrial robot of the present invention, the AC motor may include a power cable and a signal cable, and the power cable and the signal cable may pass through the inside of the wrist shaft and be connected to the control unit.

[0014] Furthermore, the industrial robot of the present invention may include two hands. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a top view showing an industrial robot according to an embodiment of the present invention.

[0016] Figure 2 This is a side view showing an industrial robot according to an embodiment of the present invention.

[0017] Figure 3 This is a diagram for explaining the structure of a hand in an industrial robot according to an embodiment of the present invention.

[0018] Figure 4 yes Figure 3 A partial enlarged view of .

[0019] Figure 5 yes Figure 3 A partial enlarged view of .

[0020] Figure 6 yes Figure 3 A partial enlarged view of .

[0021] (Explanation of symbols)

[0022] 1 lot

[0023] 4 arms

[0024] 9 abutments

[0025] 10 Rotating table

[0026] 12 First Fork

[0027] 13 The Second Fork

[0028] 21First opening and closing mechanism

[0029] 22 Second opening and closing mechanism

[0030] 100 Robots

[0031] 121 first internal thread portion

[0032] 122 second internal thread portion

[0033] 131 third internal thread portion

[0034] 132 fourth internal thread portion

[0035] 211 first threaded component

[0036] 211a First external thread component

[0037] 211b Second external thread component

[0038] 211c first coupling

[0039] 212 first driving source

[0040] 221 second threaded component

[0041] 221a Third external thread component

[0042] 221b Fourth external thread component

[0043] 221c second coupling

[0044] 222 Second driving source

[0045] A1 wrist axis

[0046] WTransportation Object DETAILED DESCRIPTION

[0047] Hereinafter, the technical scheme of the embodiment and the modified example of the utility model will be described with reference to the accompanying drawings. In addition, the scope of the utility model is not limited to the following embodiment and the modified example, and can be arbitrarily changed within the scope of the technical idea of ​​the utility model. In addition, in the following drawings, in order to facilitate the understanding of each structure, the actual structure is sometimes different from the scale, quantity, etc. in each structure.

[0048] <First embodiment>

[0049] (Overall structure of industrial robot)

[0050] The industrial robot (hereinafter sometimes referred to as "robot") 100 of the present embodiment is a horizontal multi-joint robot for carrying a predetermined carrying object W. The carrying object W is, for example, a glass substrate for a liquid crystal display, which can be formed into a rectangular flat plate. The robot 100 of the present embodiment can carry a variety of carrying objects W of different sizes.

[0051] The robot 100 includes two hands (end effectors) 1 for carrying a transport object W, two arms 4 connected to the two hands 1 at the front end, a main body 5 supporting the two arms, and a base 6 supporting the main body 5 movably in the horizontal direction. The main body 5 includes an arm bracket 7 supporting the base end side of the arm 4 and being able to move up and down, a support frame 8 supporting the arm bracket 7 movably up and down, a base 9 constituting the lower end portion of the main body 5 and being able to move linearly in the horizontal direction relative to the base 6, and a rotating table 10 to which the lower end of the supporting frame 8 is fixed and which is rotatably provided above the base 9 (rotatable relative to the base about a rotation axis extending in the vertical direction Z). In other words, the robot 100 includes a base 9 capable of linear movement and a rotating table 10 rotatably provided above the base 9.

[0052] The robot 100 has two arms 4 that move the hand 1 forward and backward (extend and retract) relative to the lifting mechanism described below. The base end side of the arm 4 is rotatably connected to the main body 5 (rotatable around a rotation axis extending in the vertical direction Z). The arm is composed of two arm parts, a first arm part 41 and a second arm part 42. The base end side of the first arm part 41 is rotatably connected to the arm support 7. The base end side of the second arm part 42 is rotatably connected to the front end side of the first arm part 41 (rotatable around a rotation axis extending in the vertical direction Z). The hand 1 is rotatably connected to the front end side of the second arm part 42 (the hand 1 is rotatably connected to the front end side of the arm). In more detail, the robot 100 has a wrist axis A1, and the hand 1 is rotatably connected to the front end side of the arm 4 via the wrist axis A1. The second arm part 42 is rotatably connected to the front end side of the first arm part 41 via the second arm shaft A42. The first arm 41 is rotatably connected to the arm support 7 via a first arm shaft A41. The robot 100 also includes two arm driving mechanisms for extending and retracting the two arms 4, respectively.

[0053] The support frame 8 holds the hand 1 and the arm 4 via the arm support 7 so that they can be raised and lowered. The support frame 8 includes a first support frame 81 in the shape of a column that holds the arm support 7 in the shape of a column and a second support frame 82 in the shape of a column that holds the first support frame 81 in the shape of a column. The robot 100 includes a lifting mechanism that is arranged in an upright manner relative to the rotating table 10. The lifting mechanism includes: a first lifting mechanism that lifts the arm support 7 relative to the first support frame 81; and a second lifting mechanism that lifts the first support frame 81 relative to the second support frame 82. A guide mechanism that guides the first support frame 81 in the up-down direction Z and a guide mechanism that guides the arm support 7 in the up-down direction Z may also be provided. The lower end of the second support frame 82 is fixed to the rotating table 10. As described above, the rotating table 10 is rotatable relative to the base 9. The robot 100 includes a rotating mechanism that rotates the rotating table 10 relative to the base 9. The base is horizontally movable relative to the base 6. The robot 100 includes a horizontal moving mechanism that moves the base 9 horizontally relative to the base 6.

[0054] The robot 100 also has a control unit (not shown). The control unit is connected to the main body 5 of the robot 100, for example. The control unit controls the movement of at least one of the base 9, the rotating table 10, the lifting mechanism, the arm 4, and the hand 1. In the present embodiment, the control unit controls the movement of the base 9, the rotating table 10, the lifting mechanism, the arm 4, and the hand 1. The control unit controls the AC servo motors of each axis. In the robot 100 of the present embodiment, in addition to the AC servo motor 222 described below, the following five servo motors are also provided on the robot body: a servo motor built into the base 9 to move the base 9 relative to the base 6; a servo motor built into the base 9 to realize the rotation of the rotating table 10; a servo motor provided in the lifting mechanism for lifting; a servo motor provided in the arm support 7 to move the hand 1 forward and backward; and a servo motor provided in the arm support 7 to move the other hand 1 forward and backward.

[0055] (Hand structure)

[0056] Figure 3 It is a diagram for explaining the structure of the hand 1 in the industrial robot 100 according to the present embodiment. Figure 4 yes Figure 3 A partially enlarged view showing the vicinity of the center portion in the second direction Y of the opening and closing mechanism. Figure 5 yes Figure 3 A partially enlarged view showing the opening and closing mechanism near the second direction Y side. Figure 6 yes Figure 3 A partial enlarged view showing the opening and closing mechanism near the other side of the second direction Y.

[0057] The hand 1 includes: a base 11 rotatably connected to the front end side of the second arm; and a plurality of forks 12, 13 on which the transport object W is placed on the upper surface side. In the present embodiment, the hand 1 includes a pair of first forks 12 and a pair of second forks 13, which are a total of four forks 12, 13. In addition, the hand 1 may include a plurality of loading members (not shown) fixed to the upper surface side of the forks 12, 13 and on which the transport object W is placed, and a plurality of suction mechanisms (not shown) that vacuum suction the lower surface of the transport object W placed on the loading members.

[0058] The base 11 is, for example, hollow and flat and generally rectangular with a thin thickness in the vertical direction Z. The forks 12 and 13 may be formed of resin. The forks 12 and 13 extend in a first direction X perpendicular to the vertical direction Z. In the present embodiment, the forks 12 and 13 are linear, and the four forks 12 and 13 are arranged parallel to each other. The four forks 12 and 13 protrude from the base 11 in the same direction in the horizontal direction. Figure 3In the embodiment, four forks 12 and 13 protrude from the base 11 to the X1 side (the first direction side). A pair of first forks 12 are arranged on the inner side of a second direction Y that is orthogonal to the up-down direction Z and the first direction X, and a pair of second forks 13 are arranged on the outer side of the second direction Y. In the present embodiment, the second direction Y is a direction orthogonal to the extension direction (length direction) of the forks 12 and 13 and the up-down direction Z.

[0059] In addition, the forks 12 and 13 may be formed into a hollow shape, for example, into an elongated substantially rectangular parallelepiped shape. For example, the upper and lower surfaces of the forks 12 and 13 form planes. In addition, the side surfaces of the forks 12 and 13 in the second direction Y form planes orthogonal to the second direction Y. The thickness of the forks 12 and 13 in the vertical direction Z may gradually become thinner from the base end of the forks 12 and 13 toward the front end.

[0060] The base ends of the forks 12 and 13 are arranged inside the base 11 formed in a hollow shape. The hand 1 further includes: a first opening and closing mechanism 21 for changing the distance between the pair of first forks 12 in the second direction Y by moving the pair of first forks 12 in the second direction Y toward each other or away from each other, respectively; and a second opening and closing mechanism 22 for changing the distance between the pair of second forks 13 in the second direction Y by moving the pair of second forks 13 in the second direction Y toward each other or away from each other, respectively. In this embodiment, the first opening and closing mechanism 21 for changing the distance between the pair of first forks 12 in the second direction Y and the second opening and closing mechanism 22 for changing the distance between the pair of second forks 13 in the second direction Y are arranged inside the base 11. In the first opening and closing mechanism 21, one of the pair of first forks 12 and the other first fork 12 are moved in the opposite directions in the second direction Y by the same amount, thereby changing the distance between the pair of first forks 12 in the second direction Y. Similarly, in the second opening and closing mechanism 22 , one second fork 13 and the other second fork 13 of the pair of second forks 13 move in opposite directions in the second direction Y by the same amount, thereby changing the pitch of the pair of second forks 13 in the second direction Y.

[0061] For example, when the size of the object W to be transported by the robot 100 is determined, before the robot 100 carries out the transport operation of carrying the object W, the first opening and closing mechanism 21 changes the spacing between the pair of first forks 12 in the second direction Y as needed (according to the size of the object W to be transported by the robot 100), and the second opening and closing mechanism 22 changes the spacing between the pair of second forks 13 in the second direction Y as needed. The opening and closing mechanisms 21 and 22 may be configured not to change the spacing between the forks 12 and 13 in the second direction Y during the transport operation of the robot 100 carrying the object W.

[0062] In addition, a detection mechanism (sensor, etc., not shown) for detecting the position of the first fork 12, a detection mechanism (sensor, etc., not shown) for detecting the position of the second fork 13, a detection mechanism (sensor, etc., not shown) for detecting the proximity of the first fork 12 and the second fork 13 adjacent to each other in the second direction Y, or a detection mechanism (sensor, etc., not shown) for avoiding interference between the first fork 12 and the second fork 13 adjacent to each other in the second direction Y may be arranged inside the base 11.

[0063] (Structure of opening and closing mechanism)

[0064] The first opening and closing mechanism 21 is located adjacent to the second opening and closing mechanism 22 on the X2 side (the other side in the first direction). The first opening and closing mechanism 21 includes: a first screw member 211; and a first drive source 212, and the first screw member 211 is driven and rotated by the first drive source 212 to move the pair of first forks 12 in the second direction Y. The pair of first forks 12 are located at the same distance on the Y1 side (one side in the second direction) and the Y2 side (the other side in the second direction) relative to the center line of the first screw member 211 in the second direction Y. In addition, the first opening and closing mechanism 21 may include an encoder that detects the rotation amount of the first screw member 211.

[0065] The first threaded component 211 includes a first externally threaded component 211a forming a right-handed external thread, a second externally threaded component 211b forming a left-handed external thread, and a first coupling 211c connecting the first externally threaded component 211a and the second externally threaded component 211b. The first externally threaded component 211a and the second externally threaded component 211b are formed, for example, in the shape of an elongated rod. The first externally threaded component 211a and the second externally threaded component 211b are formed separately. In this way, the first externally threaded component 211a and the second externally threaded component 211b formed separately are connected by the first coupling 211c, and the length of the integrally formed part of the externally threaded component (screw) can be shortened compared to the case where the first externally threaded component 211a and the second externally threaded component 211b are integrally formed. As a result, the reduction in the straightness of the externally threaded component can be suppressed.

[0066] The first external thread component 211a is coaxially arranged with the second external thread component 211b at a position closer to the Y1 side than the second external thread component 211b. The first external thread component 211a and the second external thread component 211b are respectively formed with threads such as trapezoidal threads or square threads on the outer peripheral surfaces. The first external thread component 211a and the second external thread component 211b are arranged so that their respective axial directions are consistent with the second direction Y, and rotate with the second direction Y as the axial direction of rotation.

[0067] One of the pair of first forks 12 has a first internal thread portion 121 engaged with the first external thread component 211a on the base end side. The other of the pair of first forks 12 has a second internal thread portion 122 engaged with the second external thread component 211b on the base end side. The first internal thread portion 121 and the second internal thread portion 122 can be provided on a component that is separate from the first fork 12 and fixed to the base end side of the first fork 12. For example, one of the pair of first forks 12 has an internal thread hole extending in the second direction and through which a screw rod serving as the first external thread component 211a passes on the base end side, and the first internal thread portion 121 is provided on the inner circumferential surface of the internal thread hole; the other of the pair of first forks 12 has another internal thread hole extending in the second direction and through which a screw rod serving as the second external thread component 211b passes on the base end side, and the second internal thread portion 122 is provided on the inner circumferential surface of the other internal thread hole.

[0068] In this embodiment, the first drive source 212 adopts a DC (direct current) motor. The Y2 side end of the first threaded member 211 is connected to the output shaft of the DC motor 212, for example, via a coupling. In one example, the maximum speed of the DC motor 212 is 132 rpm / min. The DC motor 212 can be operated with less power, and less conductor wiring is required for power. For example, the action of the DC motor 212 can be controlled by a remote I / O (not shown) provided on the base 11, and the remote I / O can communicate with the control unit of the robot.

[0069] For example, a DC motor having the parameters shown in Table 1 below may be used.

[0070] [Table 1]

[0071]

[0072] In the first opening and closing mechanism 21 , when the DC motor 212 rotates and the first screw member 211 rotates, as described above, one first fork 12 and the other first fork 12 move in opposite directions in the second direction Y by the same amount, thereby changing the pitch of the pair of first forks 12 in the second direction Y.

[0073] The second opening and closing mechanism 22 includes: a second threaded member 221; and a second drive source 222, and the second threaded member 221 is driven to rotate by the second drive source 222 to move the pair of second forks 13 in the second direction Y. The pair of second forks 13 are located at the same distance on the Y1 side and the Y2 side relative to the center line of the second direction Y of the second threaded member 221. In addition, the second opening and closing mechanism 22 (the second drive source 222) may include an encoder. By detecting the rotation amount of the second threaded member 221 by the encoder, the position of the pair of second forks 13 can be accurately grasped. The second opening and closing mechanism 22 and the first opening and closing mechanism 21 can be constructed in the same manner except that the first drive source 212 and the second drive source 222 are different.

[0074] The second threaded member 221 includes a third externally threaded member 221a forming a right-handed external thread, a fourth externally threaded member 221b forming a left-handed external thread, and a second coupling 221c connecting the third externally threaded member 221a and the fourth externally threaded member 221b. The first coupling 211c and the second coupling 221c may be at least partially connected to each other.

[0075] The third external thread component 221a and the fourth external thread component 221b are formed into elongated rod shapes, for example. The third external thread component 221a and the fourth external thread component 221b are formed separately. The third external thread component 221a is coaxially arranged with the fourth external thread component 221b at a position closer to the Y1 side than the fourth external thread component 221b. The third external thread component 221a and the fourth external thread component 221b are respectively formed with threads such as trapezoidal threads or square threads on the outer peripheral surfaces. The third external thread component 221a and the fourth external thread component 221b are arranged so that their respective axial directions are consistent with the second direction Y, and rotate with the second direction Y as the axial direction of rotation.

[0076] One of the pair of second forks 13 has a third internal thread portion 131 engaged with the third external thread component 221a on the base end side. The other of the pair of second forks 13 has a fourth internal thread portion 132 engaged with the fourth external thread component 221b on the base end side. The third internal thread portion 131 and the fourth internal thread portion 132 can be provided on a component that is separate from the second fork 13 and fixed to the base end side of the second fork 13. For example, one of the pair of second forks 13 has an internal thread hole extending in the second direction and through which a screw rod serving as the third external thread component 221a passes on the base end side, and the third internal thread portion 131 is provided on the inner circumferential surface of the internal thread hole; the other of the pair of second forks 13 has another internal thread hole extending in the second direction and through which a screw rod serving as the fourth external thread component 221b passes on the base end side, and the fourth internal thread portion 132 is provided on the inner circumferential surface of the other internal thread hole.

[0077] The first threaded member 211 (the first externally threaded member 211a and the second externally threaded member 211b) and the second threaded member 221 (the third externally threaded member 221a and the fourth externally threaded member 221b) are arranged at a predetermined interval in the first direction X. Both ends of the first externally threaded member 211a and the third externally threaded member 221a and both ends of the second externally threaded member 211b and the fourth externally threaded member 221b are rotatably supported by bearings mounted on the base 11. In addition, the first externally threaded member 211a and the third externally threaded member 221a and the second externally threaded member 211b and the fourth externally threaded member 221b are formed into rolled threads by, for example, rolling.

[0078] In this embodiment, the second drive source 222 adopts an AC (alternating current) motor. The Y2 side end of the second threaded member 221 is connected to the output shaft of the AC motor 222, for example, via a coupling. For example, the AC motor 222 uses a three-phase AC servo motor. The wiring of the AC motor 222 includes: a power cable (not shown) for a three-phase power supply for driving the motor; and a signal cable (not shown) for monitoring the output of the encoder. That is, the AC motor 222 has a power cable and a signal cable. In one example, the maximum speed of the AC motor 222 is above 3000rpm / min. The power cable and signal cable of the AC motor 222 are connected to the control unit through the action parts such as the arm of the robot (including the inside of the above-mentioned wrist axis). In other words, these two cables are pulled around the controller (control unit) in the robot. The AC motor 222 is a motor capacity with a degree of wiring that is directly electrically connected to the control unit through the action parts such as the arm (the wiring of the AC motor uses other shaft parts).

[0079] For example, an AC motor having the parameters shown in Table 2 below may be used.

[0080] [Table 2]

[0081]

[0082] In the second opening and closing mechanism 22, when the AC motor 222 rotates and the second threaded member 221 rotates, as described above, one second fork 13 and the other second fork 13 move by the same amount in opposite directions in the second direction Y, thereby changing the interval between the pair of second forks 13 in the second direction Y. The DC motor 212 and the AC motor 222 may be disposed on the same side in the second direction Y of the base 11.

[0083] One of the pair of first forks 12 and the pair of second forks 13 moves more in the second direction Y than the other. In the present embodiment, the pair of second forks 13 moves more in the second direction Y than the pair of first forks 12. As an example, each of the pair of first forks 12 moves from a position 45 mm from the center line of the second direction Y of the first threaded component 211 on the Y1 side and a position 45 mm from the center line of the second direction Y on the Y2 side to a position 200 mm from the center line of the second direction Y on the Y1 side and a position 200 mm from the center line of the second direction Y on the Y2 side; each of the pair of second forks 13 moves from a position 360 mm from the center line of the second direction Y of the second threaded component 221 on the Y1 side and a position 360 mm from the center line of the second direction Y on the Y2 side to a position 540 mm from the center line of the second direction Y on the Y1 side and a position 540 mm from the center line of the second direction Y on the Y2 side. The center line of the second direction Y of the first threaded member 211 and the center line of the second direction Y of the second threaded member 221 are located at the same position 360 mm in the second direction Y. The second opening and closing mechanism 22 corresponding to the one with a larger amount of movement of the pair of first forks 12 and the pair of second forks 13 is equipped with an AC motor as a driving source, thereby increasing the moving speed. The distance traveled by the first fork or the second fork when the first threaded member 211 and the second threaded member 221 rotate one circle is determined by the rotation speed and the pitch of the first threaded member 211 (the first external threaded member 211a, the second external threaded member 211b) and the second threaded member 221 (the third external threaded member 221a, the fourth external threaded member 221b). In this embodiment, it is assumed that the pitch of the first threaded member 211 (the first external threaded member 211a, the second external threaded member 211b) and the second threaded member 221 (the third external threaded member 221a, the fourth external threaded member 221b) is the same. The first opening and closing mechanism 21 corresponding to the other party with a smaller amount of movement is equipped with a DC motor as a driving source. Thus, even if there is a difference in the operation amount of each of the two pairs of forks, the operation time can be made similar.

[0084] Consider the case where AC servo motors are used for both a pair of first forks 12 and a pair of second forks 13 provided on the same hand 1. However, since the hand 1 is installed at the front end of the arm, the conductor wiring to the hand 1 needs to pass through the arm and other moving parts, making it difficult to pass a large number of conductor wiring used to drive the servo motors of the two pairs of forks. On the other hand, since other axis mechanisms are also driven by servo motors (for example, in a control unit that can only control up to eight axes), it is difficult to use servo motors to operate a total of four opening and closing mechanisms of the two hands.

[0085] Furthermore, since the first opening and closing mechanism 21 corresponding to the other side with a smaller movement amount includes a DC motor as a driving source, the number of conductor wires arranged through the wrist axis can be reduced.

[0086] In addition, the pair of first forks 12 and the pair of second forks 13 can be guided in the second direction Y by a pair of common guide rails 30. The guide rails 30 are fixed to the base 11, and the length direction of the guide rails 30 is consistent with the second direction Y. The pair of guide rails 30 are arranged at intervals on the outside of the first threaded member 211 and the second threaded member 221 in the first direction X. For example, the pair of first forks 12 and the pair of second forks 13 can each have an engaging portion (not shown) engaged with the pair of guide rails 30.

[0087] <Other Modifications>

[0088] In the above embodiment, an example is given in which the pair of second forks 13 moves more in the second direction Y than the pair of first forks 12. However, the present invention is not limited thereto, and the pair of first forks may move more in the second direction than the pair of second forks. In this case, the first opening and closing mechanism corresponding to the pair of first forks includes an AC motor as a driving source, and the first opening and closing mechanism corresponding to the pair of second forks includes a DC motor as a driving source.

[0089] The above specific embodiments of the utility model are described in detail in conjunction with the accompanying drawings. However, it can be understood that the above description does not limit the utility model in any form, and the technical features in each embodiment can be combined with each other in any way to form a new embodiment. In addition, after understanding the above specific embodiments, those skilled in the art can make various other modifications and changes to the utility model as needed. These do not deviate from the essential content of the utility model.

Claims

1. A hand, the hand being a hand of an industrial robot for carrying a transport object, It is characterized in that have: a pair of first forks extending in a first direction orthogonal to the up-down direction; a pair of second forks extending along the first direction; a first opening and closing mechanism, wherein the first opening and closing mechanism changes the spacing between the pair of first forks in a second direction so that the pair of first forks are moved toward each other or away from each other in a second direction orthogonal to the up-down direction and the first direction; as well as a second opening and closing mechanism, wherein the second opening and closing mechanism changes the distance between the pair of second forks in the second direction in such a manner that the pair of second forks are moved toward each other or away from each other in the second direction, respectively; One of the pair of first forks and the pair of second forks moves more in the second direction than the other one. The first opening and closing mechanism or the second opening and closing mechanism corresponding to the one has an AC motor as a driving source, The first opening and closing mechanism or the second opening and closing mechanism corresponding to the other one includes a DC motor as a driving source.

2. The hand according to claim 1, It is characterized in that The first opening and closing mechanism includes: a first screw member; and a first driving source, wherein the first screw member is driven to rotate by the first driving source to move the pair of first forks in the second direction. The second opening and closing mechanism comprises: a second threaded member; and a second driving source, wherein the second screw member is driven to rotate by the second driving source to move the pair of second forks in a second direction.

3. The hand according to claim 2, It is characterized in that The first threaded component includes a first externally threaded component forming a right-handed external thread, a second externally threaded component forming a left-handed external thread, and a first coupling connecting the first externally threaded component and the second externally threaded component. One of the pair of first forks has a first internal thread portion engaged with the first external thread member at a base end side. The other first fork of the pair of first forks has a second internal thread portion engaged with the second external thread member at a base end side. The second threaded component includes a third externally threaded component forming a right-handed external thread, a fourth externally threaded component forming a left-handed external thread, and a second coupling connecting the third externally threaded component and the fourth externally threaded component. One of the pair of second forks has a third internal thread portion on the base end side that engages with the third external thread member. The other second fork of the pair of second forks has a fourth internal thread portion on a base end side that engages with the fourth external thread member.

4. The hand according to claim 1, It is characterized in that The AC motor is a three-phase AC servo motor.

5. An industrial robot, It is characterized in that A hand according to any one of claims 1 to 4 is provided.

6. The industrial robot according to claim 5, It is characterized in that Also available: A base capable of linear movement; A rotating table rotatably disposed above the base; a lifting mechanism disposed in an upright manner relative to the rotating table; an arm for advancing and retracting the hand relative to the lifting mechanism; a wrist axis, through which the hand is rotatably connected to the front end side of the arm; as well as A control unit controls the movement of at least one of the base, the rotating table, the lifting mechanism, the arm, and the hand.

7. The industrial robot according to claim 6, It is characterized in that The AC motor includes a power cable and a signal cable, and the power cable and the signal cable are connected to the control unit through the inside of the wrist axis.

8. The industrial robot according to claim 5, It is characterized in that There are two said hands.

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