JP4575627B2 - Robot for workpiece transfer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a workpiece transfer robot used for transferring a workpiece such as a substrate or a wafer in a liquid crystal substrate manufacturing apparatus, a semiconductor manufacturing apparatus, or the like.
[0002]
[Prior art]
  In a liquid crystal substrate manufacturing apparatus and a semiconductor manufacturing apparatus, a robot is used when transferring a workpiece such as a substrate or a wafer. As a workpiece transfer robot used for this type of purpose, it is attached to the front and rear arms, which have the same length and are connected to each other so as to rotate with respect to each other, and to the tip of the rear arm. In many cases, an arm robot is provided that includes a workpiece holding hand and is configured to displace the workpiece holding hand in one direction as the front arm and the rear arm rotate.
[0003]
  In this type of arm robot, the rotational displacement of the front-side arm is transmitted to the rear-side arm with the rotation direction reversed and at a gear ratio of 1: 2, so that the rear-side arm is moved to the front-side arm. A transmission mechanism that rotates in the direction opposite to the rotation angle of the front side arm in a direction opposite to the rotation direction, and a workpiece with a two-to-one gear ratio by reversing the rotation direction of the rear side arm rotation displacement. By transmitting to the holding hand, a transmission mechanism for rotating the work holding hand in the direction opposite to the rotation direction of the rear arm by a half of the rotation angle of the rear arm is required.
[0004]
  This type of robot includes a belt drive type in which the front arm and the rear arm are formed hollow and each arm and hand are driven by a belt / pulley mechanism housed in the hollow portion of both arms. It is known that the front-stage arm and the rear-stage arm are constituted by parallel links, and the hand is translated by the action of the parallel links.
[0005]
  The belt-driven arm robot includes a front arm whose rear end is rotatably supported by a support frame, a rear arm whose rear end is rotatably supported at the tip of the front arm, A workpiece holding hand rotatably supported at the tip of the side arm, an arm driving device for rotating the front arm, and a rotational displacement of the front arm accommodated in the hollow portion of the front arm Is reversely rotated and transmitted to the rear-stage side arm at a gear ratio of 1: 2, and accommodated in the rear-stage arm, and the rotational displacement of the rear-stage arm is rotated. It is composed of a rear side belt / pulley mechanism that reverses the direction and transmits it to the hand at a gear ratio of 2: 1.
[0006]
  The link-type arm robot includes, for example, a front-side and rear-side parallel link mechanism that constitutes a front-side arm and a rear-side arm, and a front-side parallel link as disclosed in JP-A-7-205062. A belt / pulley mechanism that transmits the rotation of the mechanism to the parallel link mechanism on the rear stage side by reversing the rotation direction at a gear ratio of 1: 2, and a work holding unit attached to the tip of the parallel link mechanism on the rear stage side And a hand for use.
[0007]
[Problems to be solved by the invention]
  The arm robot using the belt / pulley mechanism has a problem that since the life of the belt is relatively short, the maintenance cycle becomes short and the cost required for the maintenance becomes high.
[0008]
  In addition, since a workpiece transfer robot used in a semiconductor manufacturing apparatus or the like is required to transfer a workpiece toward a narrow entrance of the process chamber, the reproducibility of the hand reaching position when the transfer operation is repeated is high. However, in a belt-driven arm robot using a long belt, when the belt expands and contracts due to heat, a rotational displacement corresponding to the expansion and contraction occurs in the work holding hand, The direction of the hand is deviated, or the belt position expands and contracts due to changes in the tension applied to the belt during operation, so that the position of the hand slightly changes. There was a problem that it was difficult to design to fit.
[0009]
  Further, in the link-type arm robot, the front-stage arm and the rear-stage arm are each constituted by a parallel link, and the reversal of the rotation direction and a pair of pairs are connected to the connecting portion of the front-stage parallel link and the rear-stage parallel link. Since it is necessary to provide a belt / pulley mechanism for performing the second speed change, there is a problem that the structure is complicated and the size is increased.
[0010]
  The object of the present invention is to transmit displacement from the front side arm to the rear side arm without using a belt / pulley mechanism and without using a complicated link mechanism, and to move from the rear side arm to the work holding hand. To avoid the problems that occur when using a belt / pulley mechanism, and to enable stable transport operations with high position reproducibility without making the device large. An object of the present invention is to provide a workpiece transfer robot.
[0011]
[Means for Solving the Problems]
  The workpiece transfer robot according to the present invention is configured to rotate about the first axis.Rear edgeIs positioned at a predetermined distance L from the first axis, and the front arm supported rotatably on the support frameIn theAn internal gear attached to the tip of the front arm with the central axis aligned with a second axis extending parallel to the first axis, and the number of teeth is ½ of the number of teeth of the internal gear A sun gear set concentrically on the inner side of the internal gear, an intermediate rotating member rotatably supported at the tip of the front arm with the center axis of rotation coincident with the second axis, A planetary gear that is rotatably supported by a rotating member and meshed with an internal gear and a sun gear, and a rotation center axis line that coincides with the second axis lineThe rear end isFront armAt the tip ofA rear-side arm that is rotatably supported and fixed to the sun gear and rotated with the rotation of the sun gear, and a position separated from the second axis by a certain distance LInA hand support member rotatably supported at the distal end of the rear arm, with the rotation center axis aligned with a third axis extending parallel to the first axis and the second axis;The rear end isA supported workpiece holding hand;Drive the front arm and move the front arm around the first axisRotateThe arm driving device is supported by the support frame so as to be rotatable relative to the support frame or together with the support frame about the first axis.A link support member;One end is pivotally supported by the link support member via a first pivot shaft that is disposed in parallel with the front arm and extends in parallel with the first axis, and has a constant distance L from the axis of the first pivot shaft. The second axis is arranged in parallel with the front-side link and the rear-side arm, the other end of which is pivotally supported by the intermediate rotation member via a second pivot shaft extending in parallel with the second axis at a separated position. One end is pivotally supported by the intermediate rotation member via a third pivot shaft extending in parallel, and the fourth shaft extends in parallel with the third axis at a distance L from the axis of the third pivot shaft. The other end is pivotally supported by the hand support member via the pivot shaftAnd a link mechanism including a rear stage side link. In the link mechanism, the front-stage side link and the rear-stage side link are relatively rotated while the front-stage arm and the rear-stage arm are relatively rotated.The orientation of the plane including the second axis and the axis of the second pivot axis is kept the same as the plane including the first axis and the axis of the first pivot axis, and the first axis and the second axis 3 is configured to keep the direction of the plane including the third axis in the same direction as the plane including the second axis and the axis of the second pivot shaft, and in the state where the link support member is stopped When the arm is rotated, the front side arm and the rear side arm are relatively rotated while keeping the plane including the first axis and the third axis always in the same direction. The support member is configured to be linearly displaced along a plane including the first axis and the third axis.
[0012]
  As described above, an intermediate rotating member is provided between the front end of the front side arm and the rear end of the rear side arm, and the internal gear attached to the front end of the front side arm and the rear end of the rear side arm A planetary gear mechanism in which the gear ratio between the internal gear and the sun gear is 1 to 2 is constituted by the sun gear attached to the intermediate portion and the planetary gear attached to the intermediate rotating member, and the planetary gear mechanism When the front-stage arm and the rear-stage arm are connected, when the front-stage arm is rotated with the intermediate rotating member fixed, the rear-stage arm is placed on the opposite side of the rotation direction of the front-stage arm. And the tip of the rear arm moves linearly in one direction.
[0013]
  Accordingly, a link mechanism including a front-side link that connects the link support member supported by the support frame and the intermediate rotation member, and a rear-stage link that connects the intermediate rotation member and the hand support member, is provided. In the process in which the front stage side arm and the rear stage side arm are relatively rotated, the front stage side link and the rear stage side link are relatively rotated.The orientation of the plane including the second axis and the axis of the second pivot axis is kept the same as the plane including the first axis and the axis of the first pivot axis, and the first axis and the second axis The link mechanism so as to keep the orientation of the plane including the third axis in the same direction as the plane including the second axis and the axis of the second pivot shaft.When configured,When the front arm is rotated while the link support member is stopped, the front arm and the rear arm are always oriented with the planes including the first axis and the third axis in the same direction. The hand support member can be linearly displaced along a plane including the first axis and the third axis by rotating the head support member relatively.By attaching a work holding hand to the hand support member, the work can be linearly moved in one direction.
[0014]
  As described above, when the planetary gear mechanism is used as a mechanism for transmitting the rotation of the front arm to the rear arm by reversing the rotation direction, the gear mechanism connects the front arm and the rear arm. Therefore, the robot can be configured more compactly than when a belt / pulley mechanism is used.
[0015]
  Further, as described above, when a planetary gear mechanism is used as a transmission mechanism for transmitting the rotation of the front arm to the rear arm, there is no need to accommodate the belt / pulley mechanism in the two arms. The thickness dimension can be reduced to reduce the size and weight of the robot.
[0016]
  In addition, since the belt does not exist in the displacement transmission mechanism from the front stage side arm to the rear stage side arm when configured as described above, the conventional positional movement of the hand due to the expansion and contraction of the belt has occurred due to the use of the belt. Various problems of the robot can be solved, and a workpiece transfer robot with high position reproducibility during repeated operations can be obtained.
[0017]
  In a preferred aspect of the present invention, a pair of the rear stage side links are provided, and the pair of rear side links are provided.Extending parallel to each other with a plane including the second axis and the third axis in betweenDeploy. One end and the other end of each of the pair of rear links are pivotally supported by the intermediate rotating member and the hand support member via a pair of third pivot shafts and a pair of fourth pivot shafts, respectively.
[0018]
  When configured as described above, the distances between the third pivot shaft of the pair and the fourth pivot shaft of the pair corresponding to the third pivot shaft of the pair are naturally set equal. The
[0019]
  The pair of third pivot shafts are arranged symmetrically with respect to the second axis, and the pair of fourth pivot shafts are arranged symmetrically with respect to the third axis.
[0020]
  As described above, when a pair of the rear-stage side links are provided and the rear-stage side links are arranged in parallel, the hand support member can be smoothly rotated.Also, the rear arm is formed hollow,If the rear link is disposed in the hollow portion of the rear arm, the robot can be configured more compactly than in the case where the rear link is disposed outside the rear arm.
[0021]
  As described above, in the present invention, it is preferable to arrange the rear-stage side link in the rear-stage side arm, but this does not prevent the rear-stage side link from being arranged outside the rear-stage side arm.
[0022]
  Further, it is not always necessary to provide one pair of the rear side links, and only one pair may be provided. When only one rear stage side link is provided, the rear stage side link may be arranged in the hollow portion of the rear stage side arm, or may be arranged outside the rear stage side arm.
[0023]
  In the present invention,If the link drive device is provided, the hand support member is turned around the first axis by rotating the front arm by the arm drive device and simultaneously turning the link support member by the link drive device. Therefore, the hand holding the workpiece can be directed in various directions.
[0024]
(0028)
  The present invention is not limited to the case where the entire robot is turned by rotating the link support member as described above. The link support member is fixed to the support frame and the entire support frame is rotated. The entire robot may be turned by providing a mechanism separately.
[0025]
  As the work holding hand, a known one constituted by a member including a base portion and a pair of finger portions having rear end portions fixed to the base portion can be used. In this case, the work holding hand is supported with the pair of finger portions being fixed to the hand support member in a state where the pair of finger portions are arranged at positions symmetrical with respect to the plane including the first axis and the third axis. Is done.
[0026]
  In order to make it easy to attach the front side link, the link support member is provided with a first arm portion projecting in the direction from the first axis toward the first pivot shaft, and the intermediate rotation member is provided with the second axis from the second axis. A second arm portion protruding in a direction toward the pivot shaft side is provided, and a first pivot shaft and a second pivot shaft are respectively provided at the distal end portion of the first arm portion and the distal end portion of the second arm portion. It is preferable to support the shaft.
[0027]
  In addition, it is preferable that a planetary gear position adjusting mechanism for finely adjusting the position of the planetary gear along the circumferential direction of the internal gear and the sun gear is provided in the intermediate rotating member. By providing such an adjustment mechanism, it is possible to easily perform adjustment for eliminating the backlash of the planetary gear mechanism.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS.
[0029]
  FIG. 1 is a plan view showing an overall configuration of an embodiment of the present invention, FIGS. 2 to 6 are plan views showing different operation states of a configuration example of a workpiece transfer robot according to the present invention, and FIG. 6 is a bottom view of the robot in the operation state of FIG. 6, FIG. 8 is a longitudinal sectional view showing the internal structure of the robot shown in FIGS. 1 to 7, and FIG. 9 is a diagram of the front and rear arms of the robot. FIG. 10 is an enlarged vertical sectional view showing the structure of the connecting portion between the tip of the rear arm of the robot and the hand support member, and FIG. 11 is a rear link of the robot. FIG. 12 is a bottom view showing the structure of the connecting portion with the hand support member, FIG. 12 is a plan view showing an example of the internal gear provided at the tip of the front arm of the robot, and FIG. 13 is the plan view of the internal gear of FIG. Thick that is concentrically arranged on the inside and is connected to the rear end of the rear arm FIG. 14 is a plan view showing an example of a gear, FIG. 14 is a bottom view showing a planetary gear supported by the intermediate rotating member of the robot and meshed with the internal gear of FIG. 12 and the sun gear of FIG. FIG. 16 is a plan view showing the structure of a planetary gear mechanism composed of 12 internal gears, the sun gear of FIG. 13 and the planetary gear of FIG. 14, and FIG. 16 is a planetary gear for finely adjusting the position of the planetary gear of the planetary gear mechanism. It is an expanded sectional view explaining the structure of a position adjustment mechanism.
[0030]
  First, an overall configuration of a workpiece transfer robot according to the present invention will be described with reference to FIG. 1. In FIG. 1, reference numeral 1 includes a support frame, an arm drive device and a link drive device supported by the support frame. The arm-link driving device 2 has a front arm whose one end is rotatably supported by a support frame so as to rotate about the first axis O1, and 3 is the front end of the front arm from the first axis O1. Position with a certain distance L to the sideInThe internal gear 4 attached to the front end of the front arm 2 with the central axis aligned with the second axis O2 extending in parallel with the first axis O1, 4 is the number of teeth of the internal gear 3 Is a sun gear set concentrically on the inner side of the internal gear 3.
[0031]
  Reference numeral 5 denotes an intermediate rotating member that is rotatably supported at the front end of the front arm 2 with the center axis of rotation coincident with the second axis O2, and 6 is rotatably supported by the intermediate rotating member 5 and the internal gear 3. And a planetary gear meshed with the sun gear 4.
[0032]
  Note that at least one planetary gear is sufficient, but in the illustrated example, four planetary gears are provided.
[0033]
  Reference numeral 7 denotes a rear stage arm rotatably supported at the front end of the front stage side arm 2, and the rear stage side of the rear stage side has its rear end portion aligned with the second central axis O2 in the state where the center axis of rotation is aligned with the second stage O2. The arm 2 is rotatably supported and fixed to the sun gear 4, and is rotated as the sun gear 4 rotates.
[0034]
  Reference numeral 8 denotes a hand support member, which is located at a predetermined distance L from the second axis O2 to the distal end side of the rear arm.InIt is rotatably supported at the distal end of the rear arm 7 in a state in which the center axis of rotation coincides with the third axis O3 extending in parallel with the first axis O1 and the second axis O2.
[0035]
  Reference numeral 9 denotes a link support member, and this link support member is rotatably supported by a support frame provided in the arm / link driving device 1 in a state where the rotation center axis coincides with the first axis O1.
[0036]
  Reference numeral 10 denotes a linear front stage side link arranged in parallel with the front stage side arm 2, and one end of this link is connected via a first pivot shaft 11 having a central axis O1 'extending in parallel with the first axis O1. The link support member 9 is pivotally supported. The other end of the front link 10 is located at a predetermined distance L from the axis O1 'of the first pivot shaft 11 to the front end of the front arm.InThe central axis O2 'is pivotally supported by the intermediate rotating member 5 via a second pivotal shaft 12 extending in parallel with the second axis O2.
[0037]
  Reference numerals 13A and 13B denote linear pairs of rear-stage links arranged in parallel with the rear-stage arm in a hollow portion provided in the rear-stage arm 7. One end of these rear-stage links has a central axis O3A '. And O3B 'are pivotally supported on the intermediate rotating member 5 via a pair of third pivot shafts 14A and 14B extending parallel to the second axis O2. Further, the other ends of the pair of rear-stage links 13A and 13B have center axes O4A 'and O4B' constant from the axis lines O3A 'and O3B' of the pair of third pivot shafts 14A and 14B to the distal end side of the rear-stage arm. Position separated by distance LInThe hand support member 8 is pivotally supported through a pair of fourth pivot shafts 15A and 15B extending in parallel with the third axis O3.
[0038]
  The pair of third pivot shafts 14A and 14B are arranged symmetrically with respect to the second axis O2, and the pair of fourth pivot shafts 15A and 15B are arranged symmetrically with respect to the third axis O3. Yes.
[0039]
  Reference numeral 16 denotes a work holding hand for holding a work W (see FIGS. 2 to 6) such as a semiconductor wafer or a liquid crystal substrate, and is attached to the hand support member 8. The illustrated work holding hand is composed of a member including a base portion 16a and a pair of finger portions 16b1 and 16b2 having rear end portions fixed to the base portion, and the pair of finger portions 16b1 and 16b2 are connected to the second axis. The base portion 16a is fixed to the hand support member 8 in a state where the base portion 16a is disposed symmetrically with respect to a plane including O1 and the third axis O3.
[0040]
  The arm driving device provided in the arm / link driving device 1 drives the front-side arm 2 using a motor as a driving source, and rotates the arm 2 around the first axis O1.
[0041]
  The link drive device provided in the arm / link drive device 1 drives the link support member 9 using a motor provided separately from the motor of the arm drive device as a drive source, and the link support member 9 is used as the first drive. Rotate around axis O1.
[0042]
  In the present invention, the distance between the first axis O1 and the second axis O2, the distance between the second axis O2 and the third axis O3, and the axis of the first pivot shaft 11 The distance between O1 'and the axis O2' of the second pivot shaft 12, the axes O3A 'and O3B' of the third pivot shafts 14A and 14B, and the axis O4A of the fourth pivot shafts 15A and 15B. In the process in which the distances between 'and O4B' are set equal and the front arm 2 and the rear arm 7 rotate relatively, the axis O1 'of the first pivot shaft 11 and the fourth pivot The axial axes O4A 'and O4B', the first axial line O1, and the third axial line O3 are maintained on the common first plane A1-A1, and the axial line O2 'of the second pivot shaft 12 is maintained. And the third pivot shafts 14A and 14B so that the axes O3A 'and O3B' are located on the second plane A2 -A2 parallel to the first plane A1 -A1. Pivot shaft is provided of.
[0043]
  In the example shown in FIG. 4, when the front arm 2 and the rear arm 7 overlap each other and the first axis O1 and the third axis O3 coincide with each other, the first axis O1 is shown. And the first axis A1 -A1 including the first pivot axis O1 'is perpendicular to the plane A3 -A3 including the second axis O2 and the third axis O3, and the second axis O2 And the second pivot axis A2 -A2 including the second pivot axis O2 'is orthogonal to the plane A3 -A3 including the second axis O2 and the third axis O3. Is provided.
[0044]
  By providing the pivot shaft in this way, the direction of the intermediate rotation member 5 is kept in the same direction as the link support member 9 in the process of relatively rotating the front stage side arm 2 and the rear stage side arm 7, and the hand support member Since the direction of 8 can be maintained in the same direction as the intermediate rotating member 5, the hand 16 can be linearly moved in one direction by rotating the front arm 2.
[0045]
  In the present embodiment, the front-stage side link 10 that connects the link support member 9 and the intermediate rotation member 5 and the rear-stage side links 13A and 13B that connect the intermediate rotation member 5 and the hand support member 8 are used. A link mechanism is configured to keep the orientation of the link support member 9, the intermediate rotation member 5, and the hand support member 8 constant while the arm 2 and the rear arm 7 rotate.
[0046]
  In the robot according to the present invention, when the front arm 2 is rotated by the angle θ while the link support member 9 is stopped in a certain direction, the rotation of the front arm is the internal gear. 3, the sun gear 4, and the planetary gear 6 are transmitted to the rear arm 7 at a transmission ratio of 1: 2 via a planetary gear mechanism composed of the sun gear 4 and the planetary gear 6. It rotates by 2θ.
[0047]
  Therefore, as shown in FIGS. 2 to 6, the front arm 2 and the rear arm 7 always have the first plane A1 -A1 including the first axis O1 and the third axis O3 in a fixed orientation. The hand support member 8 is relatively rotated while maintaining the state (determined by the direction of the link support member 9), and the hand support member 8 is linearly displaced along the first plane A1-A1 with this rotation.
[0048]
  Further, due to the action of the front stage side link 10, the direction of the intermediate rotation member 5 is held in the same direction as the direction of the link support member 9 in the process of turning the front stage side arm 2 and the rear stage side arm 7. Since the hand support member 8 is held in the same direction as the direction of the intermediate rotation member 5 by the action of 13B, the hand support member 8 holding the workpiece W is, as shown in FIGS. As the rear arm 7 is rotated, it is linearly displaced along the first plane A1 -A1 with its direction always kept constant.
[0049]
  In the illustrated example, the position where the rear-stage links 13A and 13B arranged in parallel are in contact with each other is the limit position of the rotation range of the front-stage arm 2 and the rear-stage arm 7, and the front-stage arm and the rear-stage arm The hand displacement amount (stroke) is determined by the rotation angle of the hand, but in order to obtain a practical hand displacement amount, the rotation angle of the rear arm 7 with respect to the front arc 2 is set to 90 ° to 120 °, for example. It is enough if it can be secured about °.
[0050]
  In the illustrated example, the arm drive device provided in the arm / link drive device 1 rotates the front arm 2, and the link support member 9 can be rotated by the link drive device. As described above, when the link driving device is provided, the arm driving device and the link driving device are operated simultaneously, and the front arm 2 and the link support member 9 are rotated in the same direction, thereby the hand support member 8. Can be turned around the first axis O1 to freely change the direction of the hand 16.
[0051]
  Next, the structure of each part of the present embodiment will be described in detail with reference to FIGS. In the present embodiment, the first to third axes O1 to O3 are made to coincide with each other in the vertical direction.
[0052]
  As shown in FIG. 8, the arm / link driving apparatus 1 includes a casing 100 formed in a cylindrical shape, and a support frame 101 is fixed to an upper portion of the casing. In the support frame 101, the arm driving rotation member 102 and the link driving rotation member 103 arranged in a state where the rotation center axes coincide with each other, the respective rotation center axes coincide with the first axis O1. It is supported by.
[0053]
  In the illustrated example, the link driving rotary member 103 is formed of a substantially cylindrical member, and the rotary member 103 is supported by the support frame 101 via a bearing 104. The arm driving rotating member 102 is a shaft member disposed inside the link driving rotating member 103 and is supported to the link driving rotating member 103 via bearings 105 and 106.
[0054]
  In the illustrated example, a large gear 107 is attached to the outer periphery of the lower end of the arm driving rotating member 102, and a small gear 109 attached to the rotating shaft of the arm driving motor 108 fixed in the casing 100 meshes with the large gear 107. Has been. Therefore, the arm driving rotary member 102 is driven to rotate about the first axis O1-O1 as the motor 108 rotates.
[0055]
  A large gear 110 is attached to the outer periphery of the lower end of the link driving rotating member 103, and a small gear 112 attached to the rotating shaft of the link driving motor 111 fixed in the casing 100 is engaged with the large gear 110. Accordingly, the link driving rotary member 103 is driven to rotate about the first axis O 1 -O 1 as the motor 111 rotates.
[0056]
  In this example, the motor 108 and the gears 107 and 109 constitute an arm driving device, and the motor 111 and the gears 110 and 112 constitute a link driving device.
[0057]
  As already described, when the hand 16 holding the workpiece is transported in one direction, the link support member 9 is held in a stopped state, and only the front arm 2 is driven by the motor 108. When the hand 16 is turned about the first axis O1 in order to change the direction of the hand 16, both the motors 108 and 111 are driven to connect the front arm 2 and the link support member 9 together. Turn in the same direction.
[0058]
  A cylindrical arm mounting portion 102a is formed at the upper end of the arm driving rotary member 102, and the arm mounting portion 102a is disposed in a state where the longitudinal direction is along a plane orthogonal to the first axis O1. The rear end of the front arm 2 is fixed. In the example shown in the drawing, a concave portion 2a having a circular cross section opened to the bottom surface side of the arm is formed at the rear end portion of the front stage side arm 2, and an arm mounting portion 102a is inserted into the concave portion 2a. The arm 2 is disposed in a state in which the central axis of the recess 2a coincides with the central axis (first axis) of the arm driving rotary member 102, and the rear end of the arm 2 and the arm of the arm driving rotary member 102 are arranged. The mounting portion 102 a is fastened by the bolt 21, and the rear end portion of the arm 2 is fixed to the arm driving rotary member 102.
[0059]
  The link support member 9 is fixed to a cylindrical attachment portion 103a formed at the upper end of the link driving rotary member 103. The link support member 9 has a rear end of the front stage side arm 2 in a state where the plate surface is along a plane orthogonal to the first axis O1 and can rotate with respect to the front stage side arm 2 and the support frame 101. A disc portion 9a disposed between the support portion 101 and the support frame 101, and an arm portion 9b projecting radially outward from the outer peripheral portion of the disc portion 9a, and provided at the center of the disc portion 9a. The link supporting member 9 is positioned by fitting the mounting portion 103a of the link driving rotary member 103 into the mounting hole. The disk portion 9 a and the attachment portion 103 a are fastened by bolts, and the link support member 9 is fixed to the rotating member 103.
[0060]
  A first pivot shaft 11 extending in parallel with the first axis O1 is attached to the distal end of the arm portion 9b of the link support member 9 with the distal end directed upward. This first pivot shaft One end of the front stage side link 10 is connected to the other through a bearing 10a.
[0061]
  The front arm 2 is formed in a hollow shape, and an inspection window is formed on the bottom surface thereof, and this window is closed by a cover plate 22 (see FIG. 7).
[0062]
  A gear mounting portion 2b formed in a ring shape is formed at the distal end portion of the front arm 2. The gear mounting portion 2b is provided with its center axis aligned with the second axis O2, and an annular member 3a is provided on the inner periphery of the lower end of the gear mounting portion 2b as shown in FIG. An internal gear 3 in which a large number of teeth 3b are engraved on the inner circumference is fitted in a state where its center axis coincides with the second axis O2. As shown in FIG. 9, the internal gear 3 is fixed to the gear mounting portion 2 b by a bolt 23.
[0063]
  The gear mounting portion 2b also supports an intermediate rotating member 5 disposed in a state where the center axis of rotation coincides with the second axis O2 via a bearing 25. A gear support member 27 is rotatably supported via bearings 28 and 29.
[0064]
  As schematically shown in FIG. 14, the intermediate rotating member 5 has a substantially disc-shaped main body portion 5a disposed concentrically with the ring-shaped gear mounting portion 2b, and a diameter from the outer peripheral portion of the main body portion 5a. The arm portion 5b protrudes outward in the direction, and is supported by the gear mounting portion 2b via the bearing 25 in a state where the central axis of the main body portion 5a is aligned with the second axis O2.
[0065]
  A second pivot shaft 12 having an axis O2 'extending in parallel with the second axis O2 is attached to the tip of the arm portion 5b with the tip facing downward. The other end of the front-side link 10 is connected to the tip of this through a bearing 10b.
[0066]
  The sun gear support member 27 includes a bottomed cylindrical portion 27a disposed with its central axis aligned with the second axis O2, and an outer flange portion 27b formed at the open end (upper end) of the cylindrical portion 27a. The outer flange portion 27b is rotatably supported by the main body portion 5a of the intermediate rotating member 5 via the bearing 28, and the cylindrical portion 27a is attached to the main body portion 5a of the intermediate rotating member 5. Further, it is supported via a bearing 29 on the inner periphery of a gear support member 31 described later. At the bottom of the cylindrical portion 27a of the sun gear support member, the sun gear 4 disposed concentrically inside the internal gear 3 has a bolt 30 (see FIG. 5) with its central axis aligned with the second axis. 9)). As shown in FIG. 13, the sun gear 4 is composed of a gear in which teeth 4 a are engraved on the outer periphery of the disk, and the number of teeth of the sun gear 4 is ½ of the number of teeth of the internal gear 3. Is set to
[0067]
  As shown in FIGS. 14 to 16, four arc-shaped gear support members 31 are attached to the surface on the internal gear side of the main body portion 5 a of the intermediate rotation member 5 by lock bolts 32. Four planetary gears 6 disposed at 90 ° intervals on these gear support members 31 are rotatably supported via shafts 33, and these planetary gears 6 are connected to the internal gear 3 as shown in FIG. And the sun gear 4. The internal gear 3, the sun gear 4, and the planetary gear 6 constitute a planetary gear mechanism.
[0068]
  In addition, the diagonal line attached | subjected to each part of FIG. 15 is for distinguishing a member, and is not hatching which shows a cross section.
[0069]
  As shown in the developed cross-sectional view of FIG. 16, tapered surfaces 31a are formed at both ends of the arc-shaped gear support member 31, and the gap formed between the tapered surfaces 31a and 31a of adjacent gear support members is formed. A wedge-shaped position adjusting tool 34 is engaged. The bolt insertion holes provided in each gear support member 31 for allowing the lock bolt 32 to pass therethrough are loosely formed. When the bolt 32 is loosened, each gear support member 31 is moved in the circumferential direction of the internal gear 3. It can be displaced by a minute amount. An adjustment screw 35 is provided in a state where each gear support member 31 is penetrated, and each adjustment screw 35 is screwed into a screw hole provided in the main body portion 5 a of the intermediate rotation member 5. In this example, a planetary gear position adjustment mechanism that adjusts the position of the planetary gear is configured by the gear support member 31, the position adjustment tool 34, the adjustment screw 35, and the bolt 32.
[0070]
  When adjusting the position of each planetary gear, the adjustment screw 35 is rotated while the lock bolt 32 is loosened to adjust the amount of engagement of the position adjusting tool 34, whereby each gear support member 31 is moved to the internal gear. 3 to slightly adjust the position of each planetary gear 6 with respect to the circumferential direction of the internal gear and the sun gear. Thereby, after adjusting the meshing state of the planetary gear 6, the internal gear 3 and the sun gear 4, the lock bolt 32 is tightened to fix the gear support member 31.
[0071]
  If a position adjusting mechanism for finely adjusting the position of the planetary gear 6 is provided in this way, after the planetary gear 6 is meshed with the internal gear 3 and the sun gear 4, the planetary gear 6, the sun gear 4 and the internal gear are engaged. 3 can be adjusted to a state where there is no play, and therefore, adjustment for eliminating backlash of the planetary gear mechanism can be easily performed.
[0072]
  As shown in FIG. 9 and FIGS. 2 to 6, the outer flange portion 27b of the sun gear support member 27 includes two arc-shaped long holes 27cA arranged symmetrically with respect to the second axis O2. 27cB is formed, and the third pivot shafts 14A and 14B fixed to the main body portion 5a of the intermediate rotating member 5 are slidably fitted into the long holes 27cA and 27cB. The third pivot shafts 14A and 14B are arranged at positions symmetrical with respect to the second axis O2, with their respective axes O3A 'and O3B' oriented in a direction parallel to the second axis O2. Yes. By fitting the third pivot shafts 14A and 14B and the long holes 27cA and 27cB, the rotation range of the sun gear 4 (the rotation range of the rear arm 7) is restricted to approximately 120 °.
[0073]
  The opening at the lower end of the gear mounting portion 2b at the tip of the front arm 2 is closed by a detachable lid plate 37.
[0074]
  As described above, since the intermediate rotation member 5 is connected to the link support member 9 via the front link 10, the intermediate rotation member 5 is always held in the same direction as the link support member 9. Therefore, when the front arm 2 is rotated with the link support member 9 fixed to the support frame, the rotation of the internal gear 3 is transmitted to the sun gear 4, and the sun gear 4 is opposite to the internal gear 3. Rotate to. Since the number of teeth of the internal gear 3 and the number of teeth of the sun gear 4 are set to 2 to 1, the sun gear 4 rotates in the direction opposite to the rotation direction of the internal gear 3 and the rotation angle θ of the internal gear. Is rotated by an angle 2θ that is twice as large as.
[0075]
  As shown in FIG. 9, a concave portion 7a having a circular cross section opened downward is formed at the rear end portion of the rear stage side arm 7, and a concave portion 7b having a smaller diameter than the concave portion 7a is formed at the center of the bottom of the concave portion 7a. Is formed. Third pivot shafts 14A and 14B that are fitted with the outer flange portion 27b of the sun gear support member 27 in the recess 7a of the rear arm 7 and penetrate the long holes 27cA and 27cB of the outer gear portion 27b of the sun gear support member. Is inserted into the recess 27b. The rear end portion of the rear-stage side arm 7 is fastened to the outer flange portion 27 b of the sun gear support member 27 by the bolt 40, whereby the rear end portion of the rear-stage side arm 7 is coupled to the sun gear 4. Accordingly, the rear arm 7 is rotated around the second axis O2 as the sun gear 4 rotates.
[0076]
  As described above, when the front arm 2 is rotated, the sun gear 4 is rotated in the direction opposite to the rotation direction of the internal gear 3 by twice the rotation angle of the internal gear 3. The rear stage side arm 7 rotates twice as much as the rotation angle of the front stage side arm in the direction opposite to the rotational direction of the front stage side arm as the front stage side arm 2 rotates.
[0077]
  As shown in FIGS. 10 and 11, a mounting hole 7c having a circular cross section is formed at the distal end portion of the rear arm 7, and a central axis is set at the third axis O3 on the inner periphery of the mounting hole 7c. A hand support member 8 having a circular cross section, which is arranged in a state of being aligned with each other, is rotatably supported via a bearing 41.
[0078]
  In the illustrated example, the hand support member 8 is composed of a large-diameter first member 8A and a small-diameter second member 8B arranged so as to overlap the first member 8A. The bolt 42 is fastened and integrated. As shown in FIG. 10, an annular shaft support member 43 is fixed to the lower end of the rotating member 8 with a bolt 44, and the shaft support member 43 has a pair of fourth pivot shafts 15 </ b> A and 15B is supported with each tip directed downward. As described above, the fourth pivot shafts 15A and 15B are oriented symmetrically with respect to the third axis O3 so that the axes O4A 'and O4B' are oriented in a direction parallel to the third axis O3. Arranged in a state.
[0079]
  A hollow portion 7d that opens downward is formed in the rear-stage side arm 7, and a pair of rear-stage side links 13A and 13B extending in parallel with the rear-stage side arm are provided in the hollow portion 7d. It is accommodated in a state of being positioned on both sides of a plane including the axis O2 and the third axis O3. One ends of the pair of links 13A and 13B are connected to third pivot shafts 14A and 14B supported by the intermediate rotating member 5 via a bearing 13a. The other ends of the pair of rear-stage links 13A and 13B are connected to a pair of fourth pivot shafts 15A and 15B supported by the hand support member 8 via a bearing 13b. The opening of the hollow portion of the rear end side arm 7 is closed by a removable cover plate 45.
[0080]
  As described above, since the intermediate rotation member 5 and the hand support member 8 are connected by the rear link 13A and 13B, the hand support member is in the process of rotating the front end arm 2 and the rear arm 7. 8 is always held in the same direction as the intermediate rotating member 5.
[0081]
  In order to smoothly rotate the hand support member 8 with the rotation of the intermediate rotation member 5, it is preferable to provide two rear side links and arrange them in parallel as in the above embodiment. Is not limited to the case where two rear-stage links are provided as described above, and only one rear-stage link may be provided.
[0082]
  In order to make the robot compact, it is preferable that the rear side link be accommodated in the hollow part of the rear side arm as in the above embodiment, but as shown in FIG. May be arranged outside the rear arm 7. In the example shown in FIG. 17, the intermediate rotating member 5 is further provided with an arm portion 5 c for pivotally supporting one end of the rear-stage side link 13 in addition to the arm portion 5 b. An arm portion 8a for pivotally supporting the end is provided. The rear stage side link 13 is arranged in parallel with the rear stage side arm 7, and one end of the rear stage side link 13 is pivotally supported by the arm portion 5c via a third pivot shaft 14 having an axis O3 'extending in parallel with the second axis O2. ing. The other end of the rear link 13 is pivotally supported by the arm portion 8a of the hand support member via a fourth pivot shaft 15 having an axis O4 'extending in parallel with the third axis O3. Other configurations are the same as those of the embodiment shown in FIGS.
[0083]
【The invention's effect】
  As described above, according to the present invention, as a mechanism for transmitting the rotation of the front arm to the rear arm by reversing the rotation direction, the planetary gear mechanism that can be easily accommodated in the joint portion connecting both arms. Since it is used, there is an advantage that the robot can be configured more compactly than in the case of using a belt / pulley mechanism.
[0084]
  Further, since it is not necessary to accommodate the belt pulley mechanism in the arm, the thickness of the arm can be reduced, and the robot can be reduced in size and weight.
[0085]
  Further, according to the present invention, since there is no belt in the displacement transmission mechanism from the front side arm to the back side arm, a conventional robot that has occurred due to the use of the belt, such as positional displacement of the hand due to expansion and contraction of the belt Thus, it is possible to obtain a workpiece transfer robot having high position reproducibility during repeated operations.
[Brief description of the drawings]
FIG. 1 is a plan view showing an overall configuration of an embodiment of a workpiece transfer robot according to the present invention.
FIG. 2 is a plan view showing an operation state of the embodiment.
FIG. 3 is a plan view showing another operation state of the same embodiment;
FIG. 4 is a plan view showing still another operation state of the same embodiment.
FIG. 5 is a plan view showing still another operation state of the same embodiment.
FIG. 6 is a plan view showing still another operation state of the same embodiment.
7 is a bottom view of the embodiment in the operating state shown in FIG. 6;
FIG. 8 is a longitudinal sectional view showing the internal structure of the embodiment.
FIG. 9 is an enlarged longitudinal sectional view showing a structure of a connecting portion between the front stage side arm and the rear stage side arm of the same embodiment;
FIG. 10 is an enlarged longitudinal sectional view showing a structure of a joint portion between the distal end of the rear arm of the embodiment and the hand support member.
FIG. 11 is a bottom view showing the structure of the connecting portion between the rear link and the hand support member of the same embodiment.
FIG. 12 is a plan view showing an example of an internal gear provided at the tip of the front arm of the embodiment.
13 is a plan view showing an example of a sun gear that is concentrically arranged on the inner side of the internal gear of FIG. 12 and is coupled to the rear end portion of the rear arm.
14 is a bottom view showing a planetary gear supported by an intermediate rotation member and meshed with the internal gear of FIG. 12 and the sun gear of FIG. 13 in the present embodiment.
15 is a plan view showing a structure of a planetary gear mechanism constituted by the internal gear of FIG. 12, the sun gear of FIG. 13, and the planetary gear of FIG. 14;
16 is a developed cross-sectional view for explaining the structure of the planetary gear position adjusting mechanism that finely adjusts the position of the planetary gear of the planetary gear mechanism shown in FIG. 15;
FIG. 17 is a plan view showing the configuration of another embodiment of the present invention.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 ... Arm link drive device, 2 ... Previous stage side arm, 3 ... Internal gear, 4 ... Sun gear,5 ... Intermediate rotating member,6 ... Planetary gear, 7 ... Rear stage side arm, 8 ... Hand support member, 9 ... Link support member, 10 ... Front stage side link, 11 ... First pivot shaft, 12 ... Second pivot shaft, 13A, 13B ... latter stage side link, 14A, 14B ... third pivot shaft, 15A, 15B ... fourth pivot shaft, 16 ... work holding hand, O1 ... first axis, O2 ... second axis, O3 ... Third axis.

Claims (9)

A front arm whose rear end is rotatably supported by a support frame so as to rotate about a first axis;
It said first internal gear which is mounted at a position spaced a predetermined distance L from the axis to the tip portion of the front side arm in a state of being matched a central axis to a second axis extending parallel to the said first axis Gears,
A sun gear whose number of teeth is set to ½ of the number of teeth of the internal gear and is arranged concentrically inside the internal gear;
An intermediate rotation member rotatably supported at the front end of the front-side arm so that the rotation center axis coincides with the second axis;
A planetary gear rotatably supported by the intermediate rotation member and meshed with the internal gear and the sun gear;
With the rear end with a rotation center axis is aligned with the second axis is rotatably supported by the distal end portion of the front side arm is fixed to the sun gear rotating with the rotation of the sun gear A rear arm that is moved,
Rotatably to the tip portion of the rear stage side arm to match the rotation center axis to the third axis extending parallel to the first axis and the second axis at a position spaced a predetermined distance L from the second axis A hand support member supported by
A hand for holding a work whose rear end is supported by the hand support member;
An arm driving device for driving the front-side arm to rotate the front-side arm about the first axis;
A link support member supported by the support frame so as to be rotatable relative to the support frame or around the first axis together with the support frame ;
One end is pivotally supported by the link support member via a first pivot shaft that is arranged in parallel with the front arm and extends in parallel with the first axis, and from the axis of the first pivot shaft. Parallel to the front-stage side link and the rear-stage side arm, the other end of which is pivotally supported by the intermediate rotation member via a second pivot shaft extending in parallel to the second axis at a position spaced apart from the predetermined distance L. One end is pivotally supported by the intermediate rotation member via a third pivot shaft that is arranged and extends in parallel with the second axis, and is separated from the axis of the third pivot shaft by the predetermined distance L. A link mechanism comprising a rear stage side link whose other end is pivotally supported by the hand support member via a fourth pivot shaft extending in parallel with the third axis at a position ;
Comprising
The front-stage side link and the rear-stage-side link relatively rotate in the process of relatively rotating the front-stage arm and the rear-stage arm, and include the second axis and the axis of the second pivot shaft. The orientation of the plane is maintained in the same orientation as the plane including the first axis and the axis of the first pivot axis, and the orientation of the plane including the first axis and the third axis is the second. The link mechanism is configured to maintain the same orientation as a plane including the axis of the second pivot axis and the axis of the second pivot shaft,
When the front arm is rotated while the link support member is stopped, the front arm and the rear arm always have a plane including the first axis and the third axis in the same direction. A workpiece transfer robot configured to rotate relative to each other while maintaining a directing state so that the hand support member linearly displaces along a plane including the first axis and the third axis . The link support member is rotatably supported by the support frame in a state in which a rotation center axis coincides with the first axis.
  The workpiece transfer robot according to claim 1, further comprising a link driving device that drives the link support member to rotate the link support member about the first axis. The workpiece transport robot according to claim 1, wherein the link support member is fixed to the support frame, and a mechanism for rotating the support frame around the first axis is provided. The rear stage side link is provided a pair of rear stage side link of the pair is sandwiched between a plane including the second axis and the third axis are arranged so as to extend parallel to each other,
A pair of third pivot shafts pivoting one end of each of the rear-stage side links of the pair to the intermediate rotation member are disposed at positions symmetrical with respect to the second axis,
2. The fourth pivot shaft of a pair that pivotally supports the other end of each of the rear-stage side links of the pair on a hand support rotating member is disposed at a position symmetrical to the third axis. , 2 or 3, the workpiece transfer robot. 4. The workpiece transfer robot according to claim 1, wherein only one rear stage side link is provided and is disposed on a side of the rear stage side arm. The rear stage side arm is formed hollow,
The second-stage link workpiece conveying robot according to any one of the four claims 1 is disposed in the hollow portion of the second-stage arm. The work holding hand is composed of a member including a base portion and a pair of finger portions whose rear end portions are fixed to the base portion, and the pair of finger portions includes the first axis and the third axis. The workpiece transfer robot according to claim 1, wherein the base portion is fixed and supported by the hand support member in a state of being arranged at a position symmetrical to a plane including The link support member has a first arm portion that protrudes in a direction from the first axis toward the first pivot shaft, and the intermediate rotation member extends from the second axis to the second pivot shaft. A second arm portion projecting in a direction toward the shaft side, and the first pivot shaft and the second arm portion at the distal end portion of the first arm portion and the distal end portion of the second arm portion, respectively. The robot for workpiece transfer according to any one of claims 1 to 7, wherein a pivot shaft is supported. 9. The planetary gear position adjustment mechanism for finely adjusting the position of the planetary gear along the circumferential direction of the internal gear and the sun gear is provided in the intermediate rotation member. Robot for workpiece transfer.

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