JP2001293631A - Handling robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fit a handling robot for enabling alignment work with little labor by reducing space in installation of processing machinery and a storage locker device. SOLUTION: In the handling robot 10, a first arm and a second arm are respectively journalled for bending and extending, and a pulley and a belt rotated relative to the rotation of the first and second arms according to phase difference are disposed within each of the arms for a chuck to be able to move linearly. The handling robot 10 is mounted on the storage locker device 2 in a manner such as to be able to be positioned between the processing machinery 1 and the locker device 2 for a workpiece W on the locker device 2 to be conveyed to the processing machinery 1 in the shortest distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handling robot for transferring a work part between a processing machine such as a machine tool or a dedicated machine and a stocker device.

[0002]

2. Description of the Related Art Conventionally, in a processing machine such as a machining center, an NC machine or a dedicated machine, a plurality of parts are stocked in a stocker device in order to automatically transport and process a large number of parts. The processing parts stocked in the stocker device are held by a handling robot arranged between the processing machine and the stocker device and sequentially transferred to the processing machine, and the processed parts that have been processed are again held by the handling robot. Was transported to the stocker device or the next process device.

A conventional handling robot is provided between a processing machine and a stocker device and supported by a machine base, has an arm configured to be refractible, and drives the arm to swing with respect to the machine base. Was configured to.

[0004]

However, in general, when a new machine or device is installed in a processing plant, it is desired that the installation space for each machine or device be as small as possible with respect to a limited floor area. I have. In particular, machining centers require a large installation space for machines to perform various types of processing, and unmanned processing of a large number of parts, so stocker equipment also stocks up as many parts as possible and enlarges the equipment itself. I tended to.

[0005] The conventional handling robot is installed with a large space between the processing machine having a large space and the stocker device, so that the entire space including the processing machine and the stocker device is further enlarged, and the factory layout is increased. Was inefficient. Furthermore, in order to install the handling robot, the center of the processing machine, the stocker device, and the handling robot must be aligned, and the centering work takes time and effort.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a handling robot which is arranged so as to reduce the installation space of a machine and perform centering adjustment work with each machine or apparatus in a short time. The purpose is to do.

[0007]

In the handling robot according to the present invention, in order to solve the above-mentioned problems,
It is configured as follows. That is, a handling robot disposed between a stocker device in which the processing component is stocked and a processing machine that processes the processing component, wherein the processing component is linearly transferred between the stocker device and the processing machine. A pair of arms that are pivotally supported at least at one end to each other, and a chuck that is pivotally supported at one end of the pair of arms and holds the processed component, and It is mounted on a gantry disposed on the frame of either the stocker device or the processing machine.

[0008] Further, it is sufficient that the gantry is provided with elevating means, and is arranged so as to be able to ascend and descend by the elevating means.

Preferably, the pair of arms have a first arm driven at one end by a first driving means and a second arm driven by a second driving means at the other end of the first arm.
The first drive means has a drive motor supported on the gantry, and a first output shaft connected to the drive motor, the second drive means A first rotation driving member disposed concentrically with the first output shaft at one end in the first arm and rotatable with respect to the first arm; At the other end of the first
A second rotation drive member rotatable with respect to the arm of the first rotation transmission member, and a first drive transmission member for transmitting the rotation of the first rotation drive member to the second rotation drive member, A second arm has a third rotation driving member supported by the first arm concentrically with the second rotation driving member at one end in the second arm, and a second rotation driving member confined in the second arm. The second at the end
A fourth rotation drive member rotatable with respect to the arm of the second rotation transmission member, and a second drive transmission member for transmitting the rotation of the third rotation drive member to the fourth rotation drive member, The rotation ratio between the first rotation driving member and the second rotation driving member is set to 1: 2, and the third rotation driving member and the fourth rotation driving member are connected to each other.
It is sufficient if the rotation ratio of the rotation driving member is 2: 1.

Further, the first arm or the second arm
It is more preferable that the arm provided with an automatic tension device having an urging means for adjusting the first drive transmission member or the second drive transmission member to be stretchable.

[0011]

According to the present invention, the handling robot for transporting the workpiece is mounted on either the processing machine or the stocker as described above, and is further configured to move the workpiece linearly. Therefore, the space between the processing machine and the stocker device can be reduced. Therefore, the machine layout in the factory can be set efficiently. Also, when aligning the center with a processing machine or stocker device, the handling robot is positioned on one of the machines or devices, so it is only necessary to adjust the center alignment between the machine and the device. Can be shortened. Further, since the handling robot is mounted on a processing machine or a stocker device, the number of parts can be reduced to reduce costs.

Further, if the handling robot is configured to be able to move up and down on a pedestal provided in either a processing machine or a stocker device, the height position can be adjusted according to various processing parts. And can be moved without interfering with each part of the machine or device during the transportation.

This handling robot has a first shaft rotatably supported at one end in order to convey the workpiece in a straight line.
And a second arm, and each arm is configured to be rotated by a first drive unit and a second drive unit indirectly driven by the first drive unit. That is,
Due to the rotation of the first arm driven by the first drive means, the first rotation drive member is rotated by a phase difference corresponding to the rotation angle and transmitted to the second rotation drive member. Then, by the rotation of the second rotary drive member, the second arm is rotated by the rotation of the second rotary drive member. The second arm has a third rotation driving member supported by the rotation of the first arm and a fourth rotation driving member to which the rotation of the third rotation driving member is transmitted.
And a chuck connected to the fourth rotary driving member grips and transports the processed component at its tip. At this time, if the rotation ratio between the first rotation drive member and the second rotation drive member is 1: 2 and the rotation ratio between the third rotation drive member and the fourth rotation drive member is 2: 1, The workpiece held by the chuck can be moved linearly. In this configuration, since the first arm and the second arm swing at their respective pivot points, if the swing range of both arms is set in the vertical direction or the horizontal direction, the processing machine and the stocker device Can be narrowed, and the space occupied by the processing machine and the stocker device can be narrowed.

Further, by arranging the rotation transmitting member so as to be able to be stretched by an automatic tension device, tension can always be applied to the rotation transmitting member, so that troubles due to loosening of the rotation transmitting member do not occur and the rotation transmitting member can be periodically arranged. There is no need to adjust the tension.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the handling robot 10 of the present embodiment can sequentially transport a plurality of processing parts W stocked in the stocker device 2 to a processing machine 1, for example, a machine tool such as a machining center. In the present embodiment, it is attached to the machine frame 3 of the stocker device 2.

An attachment base 5 is attached to one end (the left end in FIG. 1) of the opposite side of the stocker device 2 on the processing machine 1 side, and the attachment base 5 extends upward from the side surface of the stocker device 2. Long frame 6 to be installed
Are attached via an L-shaped bracket 7.
An elevating guide 8 is arranged on the gantry 6 along the gantry 6,
A handling robot 10 is provided with a movable base 11 that can be moved up and down on an elevating guide 8 by a drive motor 9 mounted on an upper part of the gantry 6. The sliding mechanism between the elevating guide 8 and the moving base 11 is not particularly limited. For example, the elevating guide 8 has a fixed part of a known linear guide, and the moving base 11 has a movable part of the linear guide. And the lifting guide 8 has a ball screw,
The moving table 11 may have a nut portion that engages with a ball screw. Further, a known linear motor including the lifting guide 8, the driving motor 9, and the moving table 11 may be used.

The workpiece W stocked in the stocker device 2 is supported by a plurality of pallets 4 which are moved endlessly on the stocker device 2, and is gripped by a chuck of a handling robot 10 at a take-out position S. And transferred to the processing apparatus 1.

As shown in FIG. 4, the handling robot 10 is mounted on the gantry 6 so as to be movable up and down.
1, a drive motor unit 15 supported by the movable base 11, an arm body 20 connected to the drive motor unit 15 and arranged to be rotatable with respect to the drive motor unit 15, and rotatable by the arm body 20 , And a chuck 40 supported by the chuck.

The moving table 11 has an elevating unit 12 that is guided by the elevating guide 8 to move up and down, and a support unit 13 that supports a drive motor unit 15. The elevating unit 12 and the support unit 13 are fixed to each other by bolts. ing. The support portion 13 has an upper support portion 13a and a lower support portion 13b in the horizontal direction. The upper support portion 13a supports the drive motor portion 15, and the lower support portion 13 is provided in a first arm 21 described later. The arm body 20 is formed so as to be able to swing in the horizontal direction while supporting the first pulley 23 to be arranged.

As shown in FIG. 4, the drive motor unit 15
A reduction gear 18 is attached via a coupling 17 to a drive shaft 16a of a servo motor 16 for rotatingly driving the arm body 20 to reduce the rotation of the motor 16, and the output shaft 18a of the reduction gear 18 It is attached to one end of the arm 21. The drive motor unit 15 is supported by the movable base 11 by being attached to the upper support part 13a of the movable base 11 at the end face of the reduction gear 18 on the output shaft 18a side.

The arm body 20 has a first arm 21 connected to and driven by the drive motor unit 15 and a second arm 31 pivotally supported at the other end of the first arm 21. . The first arm 21 and the second arm 31 have cases 22 and 32 formed in a hollow shape, respectively, and a hollow portion of each of the cases 22 and 32 has a pulley as a rotation driving member and a rotation transmission member. And a belt as a member.

The first arm 21 is formed so that one end thereof is sandwiched between the upper support portion 13a and the lower support portion 13 of the movable base 11, and the other end extends horizontally. The other end can be swung in the horizontal direction about the axis of the output shaft 18a of the speed reducer 18.

The one end of the first arm 21 is provided with the speed reducer 1
A first pulley 23 having one end fixed to the lower support portion 13b concentrically with the output shaft 18a of the motor 8 is rotatably supported by the case 22 so that the pulley portion 23a is arranged in the case 22. The other end of the first arm 21 has the second
The second pulley 24 having one end fixed to the case 32 of the arm 31 of the first arm 21 is arranged such that the pulley portion 24 a is disposed within the case 22 of the first arm 21.
Is rotatably supported. The pulley portion 23a of the first pulley 23 and the pulley portion 24a of the second pulley 24
It is connected by a first belt 25, for which the rotation of the first pulley 23 is transmitted to a second pulley 24. Since the outer diameters of the pulley portions 23a and 24a of the first pulley 23 and the second pulley 24 are formed to be 2: 1, the pulley portion 23a of the first pulley 23 and the The rotation ratio of the pulley 24 to the pulley portion 24a is 1: 2.
Becomes

Further, the second pulley 24 is formed in a hollow shape, and the hollow portion of the second pulley 24 is
A third pulley 33 fixed to the case 22 of the first arm 21 concentrically with the fourth pulley 33 is arranged. Third pulley 3
3 is inserted through the second pulley 24 and the second arm 31
The case 32 is formed so that the pulley portion 33a is disposed therein. Then, the pulley portion 33 of the third pulley 33
At the other end of the second arm 31, a pulley portion 34 a of a fourth pulley 34 is disposed in the case 32 so as to face the second arm 31. The pulley portion 34a of the fourth pulley 34
Is fixed to the case 32 of the second arm 31 and is rotatably supported by a shaft portion 36 that passes through the hollow portion of the fourth pulley 34. The pulley portion 33 a of the third pulley 33 and the fourth pulley 34 The second belt 35 is connected to the pulley portion 34a.

The axial distance between the third pulley 33 and the fourth pulley 34 is set to be the same as the axial distance between the first pulley 23 and the second pulley 24.
The third pulley 33a and the fourth pulley 34
It is formed so that the outer diameter with a is 1: 2. Therefore, the rotation ratio between the pulley portion 33a of the third pulley 33 and the pulley portion 34a of the fourth pulley 34 is 1: 2,
The center position of the fourth pulley 34 moves on a straight line connecting to the center position of the first pulley 23.

The shape of the belt is not particularly limited, and may be, for example, a known flat belt, a V-belt, a timing belt, or the like, and the shape of the pulley can be engaged with each belt. Any flat pulley, V pulley, or timing pulley may be used. Further, a chain and a sprocket may be used instead of the belt and the pulley.

Further, one end of the fourth pulley 34 is provided with a chuck 4 for holding a workpiece W as shown in FIGS.
0 is attached, and the workpiece W can be conveyed on a straight line. Chuck 40 used in this embodiment
A main body case 41 forming a cylinder chamber 42 and a cylinder chamber 4 for transferring a relatively heavy processed part processed by a machine tool or the like with a strong gripping force.
The piston 43 is movably inserted into the piston 2 and has a sliding surface sealed with a packing 44, and a claw supporting portion 50 mounted on the piston 43. The cylinder chamber 42 is formed by arranging a lid 47 whose outer peripheral surface is sealed with a packing 46 on the entrance side of an opening 45 formed from the end face of the main body case 41 on the second arm 31 side. The insertion of the disk-shaped piston 43 divides the upper chamber 42a and the lower chamber 42b into two chambers. The upper chamber 42a and the lower chamber 42b are supplied with a fluid piped from the outside, and supply the fluid to one of the chambers, thereby moving the piston 43 in the vertical direction.

The claw support portion 50 includes a rod portion 51 which is attached to the distal end portion of the piston 43 (the lower end portion of the piston 43 in FIG. 5) and moves up and down, and a movable support portion 53 which is engaged with the rod portion 51. Have. , The rod portion 51 has a plurality of (three equally divided in this embodiment) inclined sliding portions 52 at the bottom.
The movable supporting portion 53 has an inclined sliding portion 54 that engages with each inclined sliding portion 52 and an engagement guide portion 55 that engages the inclined sliding portion 52 of the rod portion 51 on both sides. It is formed. And, at the lower end of the movable support portion 53,
A claw mounting portion 56 protruding from the lower end of the main body case 51 is formed. Accordingly, when the rod portion 51 moves in the vertical direction by the movement of the piston 43, the movable support portion 53 causes the inclined sliding portion 54 to slide on the inclined sliding portion 52 of the rod portion 51 in the inclined direction, and the chuck 40 Is moved in the horizontal direction in a direction approaching and separating from the axis of the lens.

The claw mounting portion 56 of each movable support portion 53
, Various chuck claws that are different depending on the shape of the workpiece W to be conveyed are attached.

Further, the first arm 21 and the second arm 3
Each of the belts arranged at 1 is always tensioned by the automatic tensioning devices 60 and 70. As shown in FIGS. 8 and 9, the first automatic tensioning device 60 that applies tension to the first belt 25 disposed in the first arm 21 presses the first belt 25 to perform the first A tension roller 61 for applying tension to the belt 25, a swing lever 63 formed to be able to swing by supporting the tension roller 61 at one end, and a first belt 25 at the other end of the swing lever 63. A rod 65 for winding a coil spring 66 biasing in the tension direction of
And a supporting member 68 that supports the supporting member 5.

The swing lever 63 is formed in a bell crank shape having two arms 63a and 63b, and has a case 22 at the center.
It is pivoted on. At the distal ends of the arms 63a and 63b, shafts 62 and 64 are vertically projected, respectively, and the tension roller 61 is rotatably supported on one shaft 62 and one end of a rod 65 is pivoted on the other shaft 64. I'm wearing it. The rod 65, one end of which is pivotally supported by one arm 63b of the swing lever 63, has a threaded portion 65a formed at the other end, and is supported by a support member 68 at the center. Two nuts 69, 69 are screwed to the tip of the screw portion 65a and arranged in a locked state as a double nut. And nut 6
A coil spring 66 is wound between the support member 9 and the support member 68 to urge the rod 65 to move to the nut 69 side.

The support member 68 is rotatably disposed in the case 22 so that the rotation of the swing lever 63 can adjust the escape of the positional deviation from the axis of the rod 65.

The second automatic tensioning device 70 mounted in the second arm 31 is also the first automatic tensioning device 6.
As shown in FIG. 10, a tension roller 71 for pressing the second belt 35 to apply tension to the second belt 35, and supporting the tension roller 71 at one end to swing it. Swing lever 73 movably formed
And a rod 75 that winds a coil spring 76 that urges the other end of the swing lever 73 in the tension direction of the second belt 35.
And a support member 78 for supporting the rod 75. The coil spring 76 is disposed between the nut 79 screwed to the end of the rod and the support member 78, and urges the rod 75 to move to the nut 79 side. The support member 78 is rotatably supported so that the escape of the positional deviation from the axis of the rod 75 can be adjusted by the rotation of.

Next, the operation of the handling robot 10 configured as described above will be described mainly with reference to FIG.

As shown in FIG. 11, the handling robot 10 decelerates when the servomotor 16 is driven at a position P1 (indicated by a two-dot chain line) where the first arm 21 and the second arm 31 overlap. Output shaft 18a of device 18
, The first arm 21 rotates counterclockwise in FIG. Since the first pulley 23 disposed in the first arm 21 is supported by the lower support portion 11b of the movable base 11, the first pulley 23 is rotated by the first arm 21 with a phase difference corresponding to the rotation angle thereof. It rotates with respect to one arm 21.
The rotation of the first pulley 23 is transmitted to the first belt 25 to rotate the second pulley 24.

Since the second pulley 24 is fixed to the case 33 of the second arm 31, the rotation of the second pulley 24 causes the second arm 31 to rotate in FIG.
Will be rotated clockwise with respect to the center of. Third
The pulley 33 is concentric with the second pulley 24 and rotates with respect to the second arm 31 with a phase difference corresponding to the rotation angle due to the rotation of the second arm 31. Then, the rotation of the third pulley 33 is transmitted to the second belt 35 to rotate the fourth pulley 34.

The rotation ratio between the first pulley 23 and the second pulley 24 is set to 1: 2, and the rotation ratio between the third pulley 33 and the fourth pulley 34 is set to 2: 1. , The distance between the axes of the first pulley 23 and the second pulley 24,
Since the distance between the axes of the third pulley 33 and the fourth pulley 34 is set to the same dimension, the position of the axis of the fourth pulley 34 is shifted from the movement start position P1 in FIG. 2 on a straight line toward the take-out position S.

Further, a chuck 40 is attached to one end of the fourth pulley 34, and the fourth pulley 34 and the chuck 4
Since the 0 axis is on the same line, the center of the chuck 40 reaches the removal position S of the stocker device 2.

During this time, the first belt 25 is adjusted by the tension roller 61 urged by the coil spring 66 of the automatic tensioning device 60 so that the first belt 25 is always stretched. The belt 35 is constantly adjusted by the tension roller 71 urged by the coil spring 76 of the automatic tensioning device 70 so that the second belt 35 is stretched. Nothing.

In order for the chuck 40 to grip the workpiece W at the unloading position S, the lifting unit 12 of the handling robot 10 is lowered by the drive motor 9, and the workpiece W,
For example, when the piston 43 of the chuck 40 reaches the upper part of a cylindrical or cylindrical part W such as a can, the piston 43 of the chuck 40 moves up in the cylinder chamber 42, and the predetermined chuck claws mounted on the three movable support parts 53 are moved to the center. The workpiece W is moved to grip the workpiece W. The movement of the movable supporting portion 53 is performed by the sliding of the inclined sliding portion 54 of the movable supporting portion 53 with respect to the inclined sliding portion 52 of the rod portion 51 as the rod portion 51 rises.

When the chuck 40 grips the workpiece W,
The handling robot 10 moves up and separates from the pallet 3. When the handling robot 10 moves up to a predetermined position, the handling robot 10 again rotates the first arm 21 and the second arm 31 by driving the servo motor 16 to thereby hold the chuck 4 holding the workpiece W.
0 is moved linearly toward the position P2 of the component mounting table of the processing machine 1. As a result, the workpiece W is transported. Then, the handling robot 10 that has transported the processing component W, while processing the processing component W with the processing machine 1,
It will return to its original position and wait.

When the processing of the workpiece W by the processing machine 1 is completed, the handling robot 10 is operated again to grasp the workpiece W and transport it to the stocker device 2 or extend the arm body 20 further. , And transported to the next process equipment installed separately.

As described above, the handling robot 10
Is attached to the machine frame of the stocker device 2 (or the processing machine 1), and works by transporting the processing component W linearly between the processing machine 1 and the stocker device 2 at the shortest distance. The space between the processing machine 1 and the stocker device 2 can be reduced, and many machines installed in a factory can be laid out efficiently. In addition, since the handling robot 10 is mounted on the stocker device 2 in advance, it is not necessary to adjust the center alignment of the handling robot 10 when the processing machine 1 and the stocker device 2 are installed, and the centering work is shortened. Can be done in time.

Further, since the handling robot 10 is mounted on the gantry 6 so as to be able to move up and down, it is possible to carry the workpiece W without interfering with the machining machine 1 or the stocker device 2.

Further, since the first belt 25 and the second belt 35 are always tensioned by the automatic tensioning devices 60 and 70, there is no trouble caused by the loosening of the belt, so that the first Periodic maintenance performed by releasing the case 22 of the arm 21 and the case 32 of the second arm 31 can be omitted, and the labor and time for maintenance work can be reduced.

The handling robot of the present invention
The configuration is not limited to the above. For example, the same effect can be obtained by mounting the handling robot not on the machine frame of the stocker device but on the processing machine side.

In order to move the chuck linearly, the arm of the handling robot may be driven by a parallel four-bar linkage instead of a pulley and a belt.

Further, the arrangement of the handling robot is as follows.
As long as it is between the processing machine and the stocker device, the method of attachment is not limited, and two handling robots are mounted on both sides of the processing machine, and the processed parts conveyed by the two handling units May be assembled.

Further, instead of swinging the arm body in the horizontal direction as in the above embodiment, a handling robot may be mounted so as to swing in the vertical direction.

[Brief description of the drawings]

FIG. 1 is a plan view showing a mounted state of a handling robot according to an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a sectional view showing an embodiment of an arm of the handling robot in FIG. 1;

FIG. 5 is a sectional view showing one embodiment of a chuck of the handling robot in FIG. 1;

FIG. 6 is a view taken in the direction of arrow A in FIG. 5;

FIG. 7 is a view taken in the direction of arrow B in FIG. 6;

FIG. 8 is a plan view showing a first automatic tension device.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a plan view showing a second automatic tension device.

FIG. 11 is a plan view showing the operation of the handling robot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Processing machine 2 ... Stocker apparatus 3 ... Machine frame 6 ... Stand 8 ... Elevating guide (elevating means) 9 ... Driving motor (elevating means) 10 ... Handling robot 11 ... Moving table 12 ... Elevating part 16 ... Servo motor (first) 18a ... output shaft (first driving means) 20 ... arm body 21 ... first arm 23 ... first pulley (second driving means) 24 ... second pulley (second driving means) 25 ... first belt (second drive means) 31 ... second arm 33 ... third pulley (third rotation drive member) 34 ... fourth pulley (fourth rotation drive member) 35 ... Second belt (second rotation transmitting member) 40 ... Chuck 42 ... Cylinder chamber 43 ... Piston 50 ... Claw support part 51 ... Rod part 53 ... Movable support part 60 ... First automatic tension device 61, 71 ... Tension roller 63, 73 ... Swinging levers 65,75 ... Rods 66,76 ... Coil springs (biasing means) 70 ... Second automatic tension device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C033 BB00 HH12 HH16 HH22 MM04 3F022 AA05 JJ20 KK11 KK20 MM01 3F060 AA01 BA00 DA09 EB12 EC12 FA02 GB02 GB06 GB07 GB31

Claims (4)

[Claims] 1. A handling robot arranged between a stocker device in which a processing component is stocked and a processing machine for processing the processing component, wherein the processing component is moved straight between the stocker device and the processing machine. A pair of arms that are pivotally supported at least at one end to each other, and a chuck that is pivotally supported at one end of one of the pair of arms and holds the workpiece. And a handling robot mounted on a gantry disposed on a frame of one of the stocker device and the processing machine. 2. The handling robot according to claim 1, wherein the pedestal is provided with elevating means, and is arranged so as to be able to elevate by the elevating means. 3. A pair of arms, one end of which is driven by a first drive means at one end, and the other of which is driven by a second drive means at the other end of the first arm. And wherein the first driving means has a driving motor supported by the gantry, and a first output shaft connected to the driving motor, and wherein the second driving means has A first rotation driving member disposed concentrically with the first output shaft at one end in the first arm and rotatable with respect to the first arm; A second rotation drive member rotatable with respect to the first arm at an end, a first drive transmission member for transmitting rotation of the first rotation drive member to the second rotation drive member, The second arm has one end in the second arm and the first arm concentrically with the second rotation drive member. A third rotation driving member supported by a second arm, a fourth rotation driving member rotatable with respect to the second arm at the other end in the second arm, and a third rotation driving member. And a second drive transmission member for transmitting the rotation of the first rotation drive member to the fourth rotation drive member, wherein the rotation ratio between the first rotation drive member and the second rotation drive member is 1: 2. 3. The handling robot according to claim 1, wherein a rotation ratio of the third rotation driving member to the fourth rotation driving member is set to 2: 1. 4. An automatic tensioner having a biasing means on the first arm or the second arm to adjust the first drive transmission member or the second drive transmission member to be stretchable. 4. The handling robot according to claim 3, wherein a device is provided.