JP2014233773A - Articulated robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an articulated robot which can be positioned into original point positions of respective arm elements simply and precisely without depending on the skill level of an operator.SOLUTION: An articulated robot 1 which can be relatively rotated while a plurality of arm elements 3 to 6 are successively connected by setting a base 2 as a base point includes: a bottomed hole disposed on the connection side of the arm elements 3 to 6 on the base; and through-holes 83 to 86 disposed respectively on the respective arm elements 3 to 6. Therein, the bottomed hole of the base 2 and the through-holes 83 to 86 of the respective arm elements 3 to 6 are arranged on the same straight line in such a state that the respective arm elements 3 to 6 are set as standard positions which assume a prescribed attitude, thereby, the same shaft is inserted into the bottomed hole and through-holes 83 to 86 and, accordingly, the positioning of the base 2 and the respective arm elements 3 to 6 can be performed.

Description

  The present invention relates to an articulated robot used for transporting precision processed products such as semiconductor wafers.

  Conventionally, a workpiece transfer robot has been used to transfer a precision processed product such as a wafer used for semiconductor manufacturing as a workpiece. Many of these are configured as articulated robots having arms that are connected in sequence while three arm elements can be horizontally swiveled with a base configured to be movable up and down as disclosed in Patent Document 1 below. Has been. Specifically, the first arm element is rotatably provided on the base, and the second arm element is rotatably provided at the tip of the first arm. Further, two hands as third arm elements are provided at the tip of the second arm so as to be parallel in the vertical direction, and are configured to be rotatable around the same axis.

  Articulated robots such as those described above are used in many applications other than semiconductor manufacturing, such as transporting glass substrates, but they are often used in situations where precision processed products are handled, so excellent positional accuracy is required. Yes. There is also a great need for higher speeds in order to shorten the transport time. Furthermore, since it is often used in a clean room, it is also necessary not to emit dust.

JP 2012-161858 A

  Meanwhile, in the field of semiconductors and the like, in order to further reduce costs, it is necessary to increase the size of wafers to be processed and shorten the manufacturing time.

  When increasing the size of the wafer, the distance between the port on which the wafer is placed and the processing machine also increase, so it is necessary to increase the length of the arm of the articulated robot used to transfer the wafer. It becomes. Further, since the weight of the wafer increases as the size of the wafer increases, the load acting on the tip of the arm also increases. For this reason, there is a tendency for the arm to bend greatly, and there is also a problem of a decrease in positional accuracy during transfer and interference with a wafer transfer rack or the like. Therefore, it is necessary to ensure the rigidity of the arm more than ever.

  When improving the rigidity of the arm, generally, the weight of each arm element increases, and therefore it is necessary to obtain a larger output in the drive mechanism for operating them. In addition, since the manufacturing time is also required to be shortened as described above, it is necessary to avoid an increase in time required for transporting the wafer even when the wafer is enlarged. This means that the operation speed of the arm is relatively increased because the interval between the port on which the wafer is placed and the processing machine increases. Accordingly, the arm element drive mechanism is required to have higher output and higher speed than ever before.

  Further, in semiconductor manufacturing, higher definition has been demanded, and in addition to the above requirements, higher accuracy is also required for articulated robots that transfer wafers. Therefore, it is necessary to adjust the origin by positioning the relative positions of the arm elements constituting the articulated robot more precisely. Furthermore, even after assembling an articulated robot, it may be necessary to adjust the origin periodically, as positional displacement may occur between arm elements due to deformation and wear of each part due to long-term use. Therefore, it can be said that it is necessary to be able to perform such work more easily and with high accuracy.

  When performing the origin adjustment of such an articulated robot, it is common to reset the origin position of the encoder provided in the motor that drives the arm element after each arm element is set to a specific position using a jig. Has been done. Furthermore, in order to position each arm element, a means for forming a reference surface at a specific position such as a side surface of each arm element and causing the reference surface to contact a jig while rotating the arm element is well known. ing.

  However, when positioning the arm element in this way, a jig having a complicated shape corresponding to the arm element is required, and the origin position is displaced depending on how the arm element is brought into contact with the jig. As a result, variations occur depending on the operator.

  An object of the present invention is to effectively solve such problems. Specifically, it is possible to perform origin adjustment while simply positioning each arm element, and depending on the skill level of the operator. An object of the present invention is to provide an articulated robot that can accurately adjust the origin position without any problem.

  In order to achieve this object, the present invention takes the following measures.

  That is, the articulated robot of the present invention is an articulated robot that is capable of relative rotation while sequentially connecting a plurality of arm elements with a base as a base point, and has a bottomed hole provided on the connection side of the arm elements in the base And a through hole provided in each arm element, so that the bottomed hole of the base and the through hole of each arm element are aligned on the same straight line when each arm element is in a predetermined posture. Thus, the base and each arm element can be positioned by inserting the same shaft into the bottomed hole and the through hole.

  With this configuration, the base and each arm element can be easily aligned by inserting the positioning shaft into the bottomed hole and the through hole while adjusting the position of each arm element with respect to the base. Can be done. Therefore, if such a position is set as a reference position for each arm element and the encoder is reset in this state, the origin adjustment operation can be performed easily and quickly. In addition, since the work content relating to the origin adjustment can be simplified, it is possible to achieve high accuracy of the origin position without depending on the skill level of the operator.

  Furthermore, in order to reduce the manufacturing cost of the shaft that is a positioning jig and to improve the usability of the jig and to make the origin adjustment work more efficient, It is preferable that the hole and the through hole are configured to be circular with the same diameter.

  In addition, it is possible to easily avoid the interference between the drive mechanism provided inside each arm element and the jig through which the through-hole is inserted, thereby reducing the cost of manufacturing and maintenance by reducing the design and assembly / adjustment work. For this purpose, when each arm element is viewed from the direction of the rotation axis, it is preferable that the through hole is arranged at a position spaced a predetermined distance from the center line of the arm element.

  Further, in order to prevent dust due to wear powder generated by the arm element drive mechanism or the like from being released to the outside through the through hole, a cover for covering the through hole is provided at least on the arm element. It is preferable that a part be detachably provided.

  According to the present invention described above, an articulated robot that can perform origin adjustment while easily positioning each arm element and can accurately adjust the origin position without depending on the skill level of the operator is provided. It becomes possible to do.

1 is a perspective view of an articulated robot according to an embodiment of the present invention. The sectional side view of the articulated robot. The sectional side view which expands and shows the base vicinity in the same articulated robot. The sectional side view which expands and shows the connection part vicinity of the 1st arm element and 2nd arm element in the same articulated robot. The sectional side view which expands and shows the drive mechanism of the hand in the same articulated robot. The top view which expands and shows the state which removed the cover from the 2nd arm element in the articulated robot. The bottom view which expands and shows the state which removed the cover from the 2nd arm element in the articulated robot. FIG. 7 is a cross-sectional view taken along the line AA shown in FIG. BB cross-sectional arrow view shown in FIG. The sectional side view which expands and shows the connection part vicinity of the 2nd arm element and hand in the same articulated robot. The expanded perspective view of the principal part which shows the state which partly cut | disconnected the front end side upper cover provided in the 2nd arm element in the same articulated robot. FIG. 11 is a schematic diagram corresponding to the CC cross section shown in FIG. 10. The schematic diagram which shows the state which rotated the lower hand clockwise in planar view from the state of FIG. The schematic diagram which shows the state which rotated the lower hand counterclockwise in planar view from the state of FIG. The top view which expands and shows the state which removed the cover from the upper hand in the articulated robot. The sectional side view which expands and shows the clamp mechanism provided in the hand in the same articulated robot. The top view which shows typically the state which removed the cover of each arm element in the articulated robot. Explanatory drawing which shows typically the state which rotated each arm element in the articulated robot. The top view which shows typically the state which made each arm element in the same articulated robot the reference position. The principal part enlarged side view which shows typically the state which made each arm element in the same articulated robot the reference | standard position.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the articulated robot 1 of this embodiment is configured as a workpiece transfer robot that transfers a wafer W that is a disk-shaped workpiece used for semiconductor manufacturing. This figure shows a state in which the arm 1A of the articulated robot is extended most from the base 2. In the present embodiment, the extending direction of the arm 1A is defined as the front side, and the opposite side is defined as the rear side. To do. Further, the positions of the arm elements 3 to 6 described later when the arm 1A is extended with the base 2 as a base point are referred to as extended positions.

  This multi-joint robot 1 has a base 2 as a base point, and a first arm element 3, a second arm element 4, and hands 5 and 6 as third arm elements that constitute an arm 1 A are sequentially connected to be rotatable. ing. The base 2 includes a fixed base 2A and a movable base 2B supported by the fixed base 2A so as to be movable up and down.

  On the movable base 2B, the 1st arm element 3 is supported in the base end part 3a, and it can be rotated centering on the rotating shaft center ST set to the perpendicular direction. At the distal end 3b of the first arm element 3, the second arm element 4 is supported at the base end portion 4a, and is rotatable about the rotation axis SR set in the vertical direction. Furthermore, at the tip 4b of the second arm element 4, the lower hand 5 and the upper hand 6 as the third arm element are arranged in parallel in the vertical direction and supported so as to be rotatable about the same rotational axis SH. Has been. A lower hand 5 serving as a first hand and an upper hand 6 serving as a second hand are respectively provided with a main body 51, in which mounting plates 52 and 62 for mounting a wafer W are configured as a frame. 61, and the wafers W can be held on the mounting plates 52 and 62 by clamp mechanisms 7A and 7B (see FIG. 2), which will be described later.

  FIG. 2 is a side sectional view of the articulated robot 1. The movable base 2B is connected to the inside of the fixed base 2A via the lifting mechanism 2E. The first arm element 3 is rotatably supported by the movable base 2B, and can be rotated by a drive mechanism 3R provided inside the movable base 2B. In addition, the second arm element 4 is supported on the distal end portion 3 b of the first arm element 3, and a drive mechanism 4 </ b> R for rotating the second arm element 4 is accommodated inside the first arm element 3. Furthermore, the lower hand 5 and the upper hand 6 are supported on the tip end portion 4b of the second arm element 4 so as to be rotatable about the same rotation axis SH, and drive mechanisms 5R and 6R for rotating them. Are accommodated in the second arm element 4, respectively. Each of the hands 5 and 6 includes clamp mechanisms 7A and 7B with the inside of the main body portions 51 and 61 as the center.

  The first arm element 3 has an upper cover 32 and a lower cover 33 detachably attached around the frame 31. When the first arm element 3 is removed, the drive mechanism 4R can be exposed. Yes. The second arm element 4 has an upper cover 42 and a lower cover 43 that are detachably attached around the frame 41. When the second arm element 4 is removed, the drive mechanisms 5R and 6R can be exposed. It is like that. Further, the main body portions 51 and 61 in the lower hand 5 and the upper hand 6 are also provided with detachable covers 51a and 61a. When these are removed, the entire clamp mechanisms 7A and 7B can be exposed. It can be done.

  Hereinafter, each part will be described in detail.

  First, FIG. 3 is an enlarged side sectional view of the base 2 in the articulated robot 1. As described above, the base 2 includes the fixed base 2A and the movable base 2B, and the movable base 2B is supported so as to be movable up and down inside the fixed base 2A.

  Specifically, the fixed base 2A has a front cover 21a on the front side and a back cover 21b on the rear side, with the frame 21 formed in an inverted T shape with the standing wall 212 raised from the bottom wall 211 in a side sectional view. And a side cover (not shown) in the depth direction of the paper is provided to cover the outer periphery, and the inner space 2A1 having an open top is formed into a frame shape.

Similarly, the movable base 2B is also configured in a frame shape having an internal space 2B1 by providing a cover 22a with the frame 22 at the center. The frame 22 includes a side wall 221 disposed in parallel with the standing wall 212 and an upper wall 222 disposed so as to be substantially horizontal and orthogonal to the side wall 221.
It has become.

  The movable base 2B is connected to the fixed base 2A via a guide rail 23b that constitutes the linear guide 23 that extends in the vertical direction and a linear block 23a that meshes with the guide rail 23b, and can move linearly in the vertical direction along the guide rail 23b. It has become. Further, a screw shaft 24a constituting the ball screw 24 is provided on the fixed base 2A side along the vertical direction, and a guide block 24b meshing with the screw shaft 24a is provided on the movable base 2B side, and the screw shaft 24a rotates. By doing so, the movable base 2B can be moved up and down. More specifically, a pulley 25 is integrally provided at the lower end of the screw shaft 24a, and a motor 26 is disposed in parallel with the screw shaft 24a. The pulley 26a provided at the tip of the shaft and the pulley 25 are infinite. It is connected by an endless belt 27 that is a track body. In this way, by driving the motor 26 and rotating the screw shaft 24a, the guide block 24b can be moved and the movable base 2B can be moved up and down along the guide rail 23b.

  As described above, the linear guide 23, the ball screw 24, the motor 26, the pulleys 25 and 26a, and the endless belt 27 constitute an elevating mechanism 2E for elevating the movable base 2B described above.

  Here, since the motor 26 is provided on the opposite side of the frame 22 of the movable base 2B across the linear guide 23 and the ball screw 24, even if the motor 26 is a large-sized one that can obtain high output. The internal space 2B1 can be secured widely without affecting the internal space 2B1 in the movable base 2B.

  Further, a speed reducer 35 is provided on the upper surface of the upper wall 222 of the frame 22 constituting the movable base 2B, and an input shaft 35a projects downward from the upper wall 222, and a pulley 36 is integrally provided. ing. Further, a motor 37 is arranged in parallel with the shaft center of the pulley 36, and the pulley 37a provided at the shaft tip and the pulley 36 are connected by an endless belt 38 which is an endless track body. The output shaft 35b at the upper part of the speed reducer 35 is connected to a rotating shaft 34 formed in a cylindrical shape, and the frame 31 constituting the first arm element 3 is connected to the upper portion of the rotating shaft 34. That is, when the motor 37 rotates, the driving force is transmitted to the input shaft 35a of the speed reducer 35 via the pulley 36, and the output shaft 35b of the speed reducer 35, the rotary shaft 34, and the first arm element 3 are integrated. It comes to rotate.

  In this way, the reduction mechanism 35, the motor 37, the pulleys 36 and 37a, and the endless belt 38 constitute the drive mechanism 3R for rotating the first arm element 3 described above.

  A space below the upper wall 222 forming a part of the internal space 2B1 of the movable base 2B is used as a space for accommodating the motor 37 and a wiring pipe (not shown). Here, the wiring pipe is one of an electric wiring cable for transmitting driving power or a detection signal and a piping tube for supplying or sucking air or oil used for driving a cylinder or the like, Alternatively, both are collectively referred to.

  The space above the upper wall 222 is used as a space for housing the rotation shaft 34 that supports the speed reducer 35 and the first arm element 3. Furthermore, since the motor 46 for driving the second arm element 4 (see FIG. 2) is accommodated in the inner space 34a of the rotating shaft 34, the inner space 2B1 is indirectly indirect through the rotating shaft 34. It is also used as a space for accommodating the motor 46.

  As described above, since the motor 26 used for raising and lowering the movable base 2B is disposed on the opposite side of the frame 22 of the movable base 2B with the linear guide 23 and the ball screw 24 interposed therebetween, the internal space 2B1 in the movable base 2B. Therefore, the motor 37, the speed reducer 35, the rotating shaft 34, the motor 46, and a wiring pipe (not shown) can be arranged with a margin in the internal space 2B1. It has become. Therefore, even when a large motor 37 or 46 is used for the purpose of high output and high speed, it is possible to avoid an increase in the height of the base 2. In this way, even when the wafer W is enlarged, the minimum height of the arm 1A when the movable base 2B is at the lowest position can be lowered, and the wafer W to be transferred is stored. It is possible to prevent an increase in the height of the transport rack such as a hoop.

  Next, a connection structure between the first arm element 3 and the second arm element 4 will be described with reference to FIG. FIG. 4 is an enlarged side sectional view showing the vicinity of the connecting portion between the first arm element 3 and the second arm element 4 in the articulated robot 1. As will be described later, the second arm element 4 can be rotated by applying a driving force from the first arm element 3 side. That is, when attention is paid to the relationship between the first arm element 3 and the second arm element 4, the first arm element 3 does not rotate when the driving force for causing relative rotation only is applied. It is an arm element. The second arm element 4 is a relative rotation-side arm element that performs a rotation operation when only a driving force for causing relative rotation is applied.

  At the distal end portion 3b of the frame 31 constituting the first arm element 3, a cylindrical wall portion 31a formed in a cylindrical shape whose axial direction is matched with the vertical direction, and the vertical direction, that is, the thickness direction of the first arm element 3 And an intermediate wall portion 31b formed substantially horizontally at a position slightly below the center.

  Inside the cylindrical wall portion 31a, an internal space S1 for accommodating a reduction gear 44 as a rotation support for supporting the second arm element 4 is formed, and this internal space S1 is formed by the second arm. An opening is formed toward the element 4 side, that is, an opening is formed. Inside the cylindrical wall portion 31a, a reduction gear 44 is provided on the upper surface of the intermediate wall portion 31b, and the input shaft 44a of the reduction gear 44 is positioned at a position corresponding to the center of the cylindrical wall portion 31a. It protrudes downward through a central hole 31b1 provided in and is connected to the pulley 45. Further, the output shaft 44 b protruding above the speed reducer 44 is connected to the bottom wall 41 a of the frame 41 constituting the second arm element 4, and can rotate integrally with the second arm element 4. In addition, the reduction gear 44 in the figure is only what was typically shown, and is different from an actual cross-sectional structure.

  What gives a driving force to the input shaft 44a of the reduction gear 44 is the motor 46 described above with reference to FIG. The motor 46 is fixed to a part of the frame 31 constituting the first arm element 3, and a pulley 46 a is provided on the rotation shaft thereof. And this pulley 46a and the pulley 45 shown in FIG. 4 are connected by the endless belt 47 which is an endless track body. In this way, by driving the motor 46 (see FIG. 3), the pulleys 46a and 45 are synchronously rotated via the endless belt 47, and the second arm element 4 is rotated together with the output shaft 44b of the speed reducer 44. Is possible.

  As described above, the motor 46, the pulleys 45 and 46a, the endless belt 47, and the speed reducer 44 constitute a drive mechanism 4R for rotating the second arm element 4 described above.

  Since the drive mechanism 4R includes a portion that rolls or slides inside, dust due to wear is generated, and this tendency becomes more prominent as the output increases and the speed increases as long as a general-purpose product is used. The dust caused by the friction between the endless belt 47 and the pulley 45 is such that the endless belt 47 and the pulley 45 are disposed below the intermediate wall portion 31b, and the space in which these are disposed is sealed by the lower cover 33. Since it is stopped, there is little discharge to the outside of the first arm element 3.

  However, the dust generated inside the speed reducer 44 is externally transmitted through a gap X formed between the cylindrical wall portion 31a constituting the internal space S1 and the bottom wall 41a of the frame 41 constituting the second arm element 4. May be released. Although the speed reducer 44 includes an oil seal 44c for holding internal grease as a general configuration, it cannot effectively suppress dust generation from the sliding portion during rotation, and is described above. When dealing with such high output and high speed, and when dealing with high definition of semiconductors, it can be said that it is insufficient as a measure against dust generation. Therefore, in the present embodiment, a ring-shaped seal member 49 is provided on the lower surface of the bottom wall 41a, and the gap X is made small by bringing it close to the inside of the cylindrical wall portion 31a. That is, the seal member 49 functions as a sealing portion that substantially seals the opening of the internal space S1 by reducing the gap X.

  The intermediate wall 31b is provided with a through hole as a suction portion 31b2 at a position near the cylindrical wall portion 31a, and the gas in the internal space S1 is connected through a pipe tube (not shown) connected to the suction portion 31b2. Can be aspirated. This piping tube is routed in the first arm element 3 together with the wiring piping CT drawn into the first arm element 3 from the second arm element 4, and is passed through the base 2 (see FIG. 2). It is pulled out of the joint robot 1. By doing so, the gas sucked from the suction unit 31b2 is discharged to a predetermined discharge destination provided outside the multi-joint robot 1 and processed, and dust is discharged to the surrounding environment where the multi-joint robot 1 exists. It is possible not to release. Further, since the pressure in the internal space S1 is lowered by sucking the gas in the internal space S1, it is possible to further suppress the release of the gas and the dust contained therein through the gap X. It is possible.

  Next, a connection structure between the second arm element 4 and the lower hand 5 and the upper hand 6 serving as the third arm element will be described with reference to FIGS. 5 and 10. FIG. 5 is an enlarged side sectional view showing drive mechanisms 5R and 6R provided in the second arm element 4 for rotating the lower hand 5 and the upper hand 6, and FIG. FIG. 6 is a side sectional view showing, in an enlarged manner, the vicinity of a connection portion between the second arm element 4 and the lower hand 5 and the upper hand 6 in FIG. As will be described later, the lower hand 5 and the upper hand 6 can rotate by applying a driving force from the second arm element 4 side. That is, when attention is paid to the relationship between the second arm element 4 and the lower hand 5 or the upper hand 6, the second arm element 4 rotates when only driving force for causing relative rotation is applied. It is a fixed arm element that is not performed, and the lower hand 5 or the upper hand 6 is a relative rotation arm element that performs a rotating operation when only a driving force for performing relative rotation is applied.

  At the front end portion 4b of the frame 41 constituting the second arm element 4, a cylindrical wall portion 41b formed in a cylindrical shape whose axial direction is aligned with the vertical direction, and the vertical direction, that is, the thickness direction of the second arm element 4 And an intermediate wall portion 41c formed substantially horizontally at a position slightly above the center.

  The main body 51 constituting the lower hand 5 is connected to a rotation shaft 53 as a first rotation shaft formed in a substantially cylindrical shape, and the rotation shaft 53 is located inside the cylindrical wall portion 41b and is connected to the intermediate wall portion 41c. Is supported rotatably through a bearing 54a. And the pulley 54 is connected to the lower end of the rotating shaft 53, and the rotating shaft 53 and the lower hand 5 rotate integrally with rotation of the pulley 54. As shown in FIG.

  A hole 51d is also formed in the main body 51 so as to communicate with a through hole 53a formed in the axis of the rotation shaft 53, and a rotation shaft 63 as a second rotation shaft is inserted through these holes 51d. Are arranged as follows. The lower end of the rotary shaft 63 extends below the pulley 54 and is connected to a pulley 64 disposed in parallel below the pulley 54. The pulley 64 is rotatably supported via a bearing 64a in the vicinity of the lower end of the cylindrical wall portion 41b. Therefore, the rotary shaft 63 and the upper hand 6 rotate integrally with the rotation of the pulley 64. Since the rotation shaft 63 is arranged so that the shaft center is the same as the rotation shaft 53, the upper hand 6 rotates about a rotation shaft center SH (see FIG. 2) common to the lower hand 5. It has become.

  As the bearings 54a and 64a, cross roller bearings in which the outer ring side is fixed to the frame 41 and the inner ring side is rotatable are used. Although it is supported, it is possible to receive a moment effectively, and it is possible to suppress the phenomenon that the center of rotation is inclined such that the tips of the hands 5 and 6 hang down. It is also possible to adopt a similar configuration using a four-point contact ball bearing instead of the cross roller bearing.

  A mechanism for applying a driving force to the pulleys 54 and 64 integrated with the rotary shafts 53 and 63 in order to rotate the hands 5 and 6 is configured as follows.

  That is, the first motor 56 that applies a driving force to the rotation shaft 53 is provided at a position from the base end portion 4 a inside the second arm element 4. The driving force of the motor 56 is transmitted to the rotary shaft 53 via the first intermediate transmission shaft 55. Similarly, the second motor 66 that applies a driving force to the rotating shaft 63 is provided in the second arm element 4 at a position slightly closer to the distal end portion 4 b than the first motor 56. Then, the driving force of the second motor 66 is transmitted to the rotary shaft 63 via the second intermediate transmission shaft 65 disposed between the second motor 66 and the first intermediate transmission shaft 55. It is like that.

  The motors 56 and 66 and the intermediate transmission shafts 55 and 65 are arranged in a straight line toward the rotation shafts 53 and 63 along the extending direction of the second arm element 4 in which these are provided in plan view. (See FIGS. 6 and 7).

  The motors 56 and 66 have the same specifications, and are fixed to the frame 41 of the second arm element 4 using brackets 56c and 66c, respectively. At this time, both the motor shafts 56 a and 66 a are oriented in the upward direction, but the first motor 56 is positioned slightly above the second motor 66. The motor shafts 56a and 66a are provided with pulleys 56b and 66b having the same diameter.

  The intermediate transmission shafts 55 and 65 have shaft bodies 55s and 65s fixed to the frame 41 using bearing units 55c and 65c, and large-diameter pulleys 55a and 65a are provided at positions projecting upward from the bearing units 55s and 65s. The pulleys 55b and 65b having small diameters are provided at positions projecting downward from the bearing units 55s and 65s. The pulleys 54 and 64 provided on the rotary shafts 53 and 63 have the same diameter as the large-diameter pulleys 55a and 65a described above. The bearing units 55c and 65c are each provided with a bearing so that the shaft body can be rotatably supported by the shaft body 55s and 65s.

  Specifically, the first intermediate transmission shaft 55 is attached to the frame 41 in the form shown in FIG. FIG. 8 shows an AA cross-sectional arrow view shown in FIG. As described above, the frame 41 has a substantially H-shaped cross section when cut by a plane orthogonal to the direction in which the second arm element extends, and an opening 41d is formed at the center of the intermediate wall portion 41c. The first intermediate transmission shaft 55 is provided so that the opening 41d is inserted vertically. That is, the shaft main body 55s is inserted into the intermediate wall 41c by screwing the bearing unit 55c that rotatably supports the shaft main body 55s in the first intermediate transmission shaft 55 to the intermediate wall 41c from below. Stand up. Then, by providing the above-described pulleys 55a and 55b at the upper and lower ends of the shaft body 55s, the pulley 55a is disposed above the intermediate wall portion 41c, and the pulley 55b is disposed below.

  Similarly, the second intermediate transmission shaft 65 is attached to the frame 41 in the form shown in FIG. FIG. 9 shows a cross-sectional view taken along the line B-B shown in FIG. An opening 41d is formed at the center of the intermediate wall portion 41c of the frame 41 having a substantially H-shaped cross-sectional shape, and the second intermediate transmission shaft 65 is provided so that the opening 41d is inserted vertically. That is, the shaft main body 65s is inserted in the form of inserting the intermediate wall portion 41c by screwing the bearing unit 65c that rotatably supports the shaft main body 65s in the second intermediate transmission shaft 65 to the intermediate wall portion 41c from below. Stand up. Then, by providing the above-described pulleys 65a and 65b at the upper and lower ends of the shaft body 65s, the pulley 65a is disposed above the intermediate wall portion 41c, and the pulley 65b is disposed below.

  Returning to FIGS. 5 and 10, the first intermediate transmission shaft 55 is arranged slightly shifted upward with respect to the second intermediate transmission shaft 65, and is provided on the first intermediate transmission shaft 55. The large-diameter pulley 55a is located at a position corresponding to the vertical direction of the pulley 56b provided in the first motor 56, and the two are connected by an endless belt 57 as a first endless track body. Similarly, the large-diameter pulley 65a provided on the second intermediate transmission shaft 65 is in a position corresponding to the up-down direction between the pulley 66b provided on the second motor 66, and the second is between the second and second pulleys 66b. Are connected by an endless belt 67 as an endless track body.

  Further, a small-diameter pulley 55b provided on the opposite side of the large-diameter pulley 55a across the bearing unit 55c in the first intermediate transmission shaft 55 is located at a position corresponding to the up-down direction of the pulley 54 provided on the rotary shaft 53. The two are connected by an endless belt 58 as a third endless track. Similarly, the small-diameter pulley 65b provided on the opposite side of the large-diameter pulley 65a across the bearing unit 65c in the second intermediate transmission shaft 65 corresponds to the pulley 64 provided on the rotary shaft 63 in the vertical direction. The two are connected to each other by an endless belt 68 as a fourth endless track.

  In this way, the four endless belts 57, 58, 67, 68 are arranged at different positions in the axial direction of the rotary shafts 53, 63, so that they do not interfere with each other. Yes.

  FIGS. 6 and 7 are enlarged views of a portion where the upper cover 42 and the lower cover 43 (see FIG. 2) are removed from the second arm element 4, respectively, as a plan view and a bottom view.

  As can be seen from these, among the four endless belts 57, 58, 67, 68, the endless belts 57, 67 are arranged above the intermediate wall 41c in the frame 41, and the endless belts 58, 68 are arranged in the intermediate wall 41c. It is arranged on the lower side. That is, at the time of assembly, it is only necessary to attach and adjust the two endless belts 57 and 67 from above the frame 41 and to attach and adjust the two endless belts 58 and 68 from below the frame 41. Workability is good, and it is possible to reduce assembly man-hours.

  More specifically, as can be seen from FIG. 6, the pulleys 66b and 65a are disposed between the pulleys 56b and 55a, and are set at positions lower than these. Therefore, by attaching and adjusting the lower endless belt 67 and then attaching and adjusting the upper endless belt 57, it is possible to work easily and prevent mutual interference between the endless belts 57 and 67. It is also possible to do.

  Similarly to the above, as can be seen from FIG. 7, the pulley 55 b is disposed between the pulleys 65 b and 64, and is set at a higher position, that is, a position closer to the intermediate wall portion 41 c of the frame 41. Therefore, by attaching and adjusting the upper endless belt 58 and then attaching and adjusting the lower endless belt 68, the work can be easily performed and the mutual interference between the endless belts 58 and 68 can be prevented. It is also possible to do.

  As described above, the first motor 56 shown in FIG. 5 is connected by the first intermediate transmission shaft 55 and the endless belt 57, and the first intermediate transmission shaft 55 is endless via the rotating shaft 53 and the pulley 54. Since it is connected by the belt 58, the rotating shaft 53 and the lower hand 5 can be rotated by the driving force of the first motor 56. That is, the first motor 56 and the pulley 56b, the first intermediate transmission shaft 55, the pulley 54, and the endless belts 57 and 58 constitute a drive mechanism 5R for rotating the lower hand 5.

  Similarly, the second motor 66 is connected to the second intermediate transmission shaft 65 by an endless belt 67, and the second intermediate transmission shaft 65 is connected to the rotation shaft 63 and the pulley 64 by an endless belt 68. Therefore, the rotating shaft 63 and the upper hand 6 can be rotated by the driving force of the second motor 66. That is, the second motor 66 and the pulley 66b, the second intermediate transmission shaft 65, the pulley 64, and the endless belts 67 and 68 constitute a drive mechanism 6R for rotating the upper hand 6.

  Thus, when the hands 5 and 6 are rotated, the rotations of the motors 56 and 66 are greatly decelerated in two stages and transmitted, so there is no need to use a special device such as a speed reducer. It is possible to reduce the cost by using parts and to obtain high positioning accuracy while obtaining high output.

  Here, since the hands 5 and 6 are provided with the clamp mechanisms 7A and 7B for holding the wafer W described above, the wiring piping CT for operating them is routed inside the main body portions 51 and 61. It has come to be. The wiring pipe CT passes through the inside of the second arm element 4 and is routed to the base 2 via the inside of the first arm element 3 (see FIG. 2).

  The wiring piping CT in the main body 61 of the upper hand 6 is drawn downward through a through hole 63 a provided in the center of the rotating shaft 63 and reaches the inside of the second arm element 4. By arranging the wiring pipe CT at the center of rotation of the upper hand 6 in this way, the relative position between the wiring pipe CT and the second arm element 4 does not change even when the upper hand 6 rotates. Accordingly, the wiring piping CT can be easily routed, and it is possible to prevent damage by suppressing catching on other components and entanglement of the wiring piping CT.

  On the other hand, since the wiring piping CT in the main body 51 of the lower hand 5 cannot pass through the center of the axis, it is configured as follows. That is, the housing case 48 is provided integrally with the second arm element 4 on the outer periphery of the rotating shaft 53. The storage case 48 is provided inside the upper cover 42 and has a bottomed cylindrical shape with the upper side opened. The inner peripheral wall 48 a faces the outer periphery of the rotating shaft 53, and forms a ring-shaped wiring piping space S 3 with the rotating shaft 53. The housing case 48 may have any shape as long as it can be accommodated in the second arm element 4 regardless of the shape of the outer peripheral side as long as the inner peripheral wall 48a is configured to form a circumferential surface. Even if it is the structure which carried out, it does not interfere.

  The wiring piping space S3 is substantially sealed by a sealing member 53c as a sealing portion provided so as to form a bowl shape toward the outer periphery of the rotating shaft 53. By doing so, the bottom surface and the outer peripheral surface for closing the wiring pipe space S3 are constituted by the housing case 48, so that they are fixed to the second arm element 4 side, while the inner peripheral surface and the upper surface are respectively the rotary shaft 53. By being constituted by the seal member 53c, it is fixed to the lower hand 5 side.

  Further, an insertion hole 53b as an insertion passage is formed in the upper part of the rotating shaft 53 at a position on the center side of the wiring piping space S3, and the wiring piping space S3 from the main body 51 of the hand 5 through the insertion hole 53b. The wiring piping CT is drawn in to the inside.

  Here, a CC cross section in FIG. 10 is schematically shown in FIG. On the outer peripheral side of the wiring pipe space S3, a part of the inner peripheral wall 48a is opened to form an insertion hole 48b as an insertion passage, and the second arm is formed from the wiring pipe space S3 through the insertion hole 48b. The wiring piping is drawn out inside the element 4.

  In the wiring piping space S3, the wiring piping CT drawn from the insertion hole 53b provided on the center side is arranged in a spiral shape like a spring for about one and a half around the rotation shaft 53, and is provided on the outer peripheral side. It is pulled out from the inserted insertion hole 48b. Further, the wiring pipe CT is fixed to the insertion holes 53b and 48b.

  As a result, as shown in FIG. 13, when the position of the insertion hole 53b on the center side relatively changes due to the lower hand 5 rotating clockwise in plan view, the relative position of the wiring pipe CT is also changed. The number of turns of the wiring pipe CT around the rotation shaft 53 in the wiring pipe space S3 decreases, but the wiring pipe CT arranged in a spiral shape changes its position toward the inner peripheral wall 48a of the housing case 48. Therefore, it is possible to absorb the influence due to the change in position of the wiring pipe CT.

  On the contrary, as shown in FIG. 14, when the position of the insertion hole 53 b on the center side relatively changes due to the lower hand 5 rotating counterclockwise in plan view, The position also changes, and the number of turns of the wiring pipe CT around the rotary shaft 53 in the wiring pipe space S3 increases, but the wiring pipe CT arranged in a spiral shape is wound inward so as to be wound around the rotary shaft 53. Since the position is changed, the influence due to the position change of the wiring pipe CT can be absorbed.

  In this way, the wiring piping CT is arranged in a spiral shape in the housing case 48, and the wiring piping caused by a change in the position of the insertion hole 53b accompanying the rotation of the lower hand 5 by being deformed like a mainspring. It is possible to absorb the influence of the CT position change. At this time, since the wiring pipe CT is fixed to the insertion holes 53 b and 48 b, the position of the wiring pipe CT is within the lower hand 5 and the second arm element 4 before and after the housing case 48. Is not changed, and it is possible to suppress rubbing and catching of the wiring piping CT in these portions.

  In addition, the wiring pipe CT used in the present embodiment uses a so-called flat tube, flat cable, or the like in which a plurality of wiring pipes are integrated in parallel to form a strip shape. For this reason, it is possible to further stabilize the form when it is formed in a spiral shape and to suppress damage due to friction between wiring pipes. Moreover, since the plurality of wiring pipes are integrated, the rigidity is higher than that of a single wiring pipe, so that the deformation like the spring spring can be performed more smoothly.

  Returning to FIG. 10, the connecting portion between the hands 5 and 6 and the second arm element 4 also includes a structure for suppressing the release of dust from the inside of the second arm element 4 to the outside. .

  The upper cover 42 in the second arm element 4 is composed of a base end side upper cover 42a and a distal end side upper cover 42b, and since the distal end side upper cover 42b is provided on the outer periphery of the rotary shaft 53, these A gap Y extending from the inside of the second arm element 4 to the outside is formed between the distal end side upper cover 42 b and the rotary shaft 53. The seal member 53c provided on the rotary shaft 53 described above seals the wiring piping space S3 in the housing case 48, and on the inner peripheral side thereof, is provided close to the distal end side upper cover 42b, thereby providing a gap. Y is narrowed.

  That is, paying attention to these relationships, a bearing as a rotation support portion that supports the lower hand 5 that is the arm element on the relative rotation side in the internal space S2 of the second arm element 4 as the arm element on the relatively fixed side. 54a and the rotation shaft 53 supported thereby are provided, and the seal member 53c narrows the gap Y formed between the rotation shaft 53 and the front end side upper cover 42b, so that the outer periphery of the rotation shaft 53 is provided. 1 functions as a sealing portion that substantially seals the opening provided in the internal space S2.

  Furthermore, on the outer peripheral side of the seal member 53c, another thin plate-like seal member 42c is attached to the lower surface of the distal end side upper cover 42b. The sealing member 42c is provided with a bottom surface close to the sealing member 53c, so that the gap Y is further narrowed. That is, this sealing member 42c also functions as a sealing portion for substantially sealing the opening provided in the internal space S2.

  Further, as shown in FIG. 11, the seal member 42c has a concave portion 42d formed by lowering a part of the inner side in a step shape, so that a slight space is formed between the seal member 42c and the front end side upper cover 42b. It has become. Furthermore, a through-hole is provided as a suction portion 42d1 at the end of the recess 42d, and the above-described suction is performed by sucking the gas in the internal space S2 through a piping tube (not shown) connected to the suction portion 42d1. It is possible to discharge to the same predetermined discharge destination as the part 31b2 (see FIG. 4). Further, similarly to the internal space S1, it is possible to reduce the pressure in the internal space S2 and suppress the release of gas and dust contained therein through the gap Y.

  Further, since the housing case 48 as the housing portion of the wiring pipe ST that forms the wiring pipe space S3 described above is provided between the bearing 54a and the seal members 42c, 53c, Even if dust is generated due to sliding of the wiring pipe CT, it is possible to effectively prevent the dust from being released to the outside. In addition, since the bearing 54a is located relatively below and is disposed at a position far away from the seal members 42c and 53c, it is possible to further suppress the release of dust. Furthermore, since the pulley 54 is provided at a position opposite to the seal members 42c and 53c across the bearing 54a, the discharge of dust accompanying sliding between the pulley 54 and the endless belt 58 is also possible. It can be effectively suppressed.

  Further, when attention is paid to the rotating shaft 63 that supports the upper hand 6 and the bearing 64a that rotatably supports this via the pulley 64, the dust generated from these is between the rotating shaft 53 and the tip-side upper cover 42b. In addition to the gap Y that is formed, it can also be released from the gap Z that is formed between the upper hand 6 and the lower hand 5. However, in the present embodiment, the distance between the pulleys 54 and 64 is narrowed, and the space between the through hole 53a provided at the center of the rotation shaft 53 and the outer periphery of the rotation shaft 63 is narrowed. The continuous gap Z is made smaller and the small range of the gap is made wider. Furthermore, by forming the gap Z in a bent shape, it is possible to further suppress the release of dust from the inside.

  Next, the clamp mechanisms 7A and 7B (see FIG. 2) provided in the lower hand 5 and the upper hand 6 will be described. In principle, the clamp mechanisms 7A and 7B differ only in the setting of the relative position of each component in the height direction, and the positional relationship between the components is substantially the same when viewed in plan. Therefore, each part will be described by taking the clamp mechanism 7B in the upper hand 6 as an example.

  FIG. 15 is an enlarged plan view showing a state in which the cover 61a (see FIG. 2) included in the upper hand 6 is removed. The upper hand 6 has a mounting plate 62 attached to the main body 61 as described above. The main body 61 is configured such that the clamp mechanism 7 </ b> B for holding the wafer W on the mounting plate 62 is exposed when the cover 61 a is removed.

  The mounting plate 62 is provided with a fixed block 71 as a work mounting table, two in total at the front end side divided into two forks and two at the base end side, and these are arranged in a rectangular shape. Thus, one wafer W can be placed. Each fixed block 71 is formed in a substantially rectangular shape in plan view, and is arranged so that the longitudinal direction thereof coincides with the direction toward the center of the wafer W to be placed. Further, each fixed block 71 is provided with an upward tapered surface 71a inclined downward toward the center direction of the wafer W, and a stepped portion 71b having a slightly larger height than other portions at an outer position. Is provided.

  The clamp mechanism 7 </ b> B holds the wafer W placed on the fixed block 71 in cooperation with the fixed block 71.

  The clamp mechanism 7B includes a movable block 72 arranged inside an opening 62a provided on the base end side of the mounting plate 62. The movable block 72 is arranged at the center of the wafer W, that is, each fixed block 71 is provided with the movable block 72. It is configured to advance and retreat toward the center of the rectangle formed by the arrangement. The movable block 72 includes a downward tapered surface 72a (see FIG. 16) that is inclined upward toward the center direction of the wafer W. By moving the movable block 72 forward, two fixed blocks 71, The edge of the wafer W is brought into contact with the stepped portion 71b of the 71 to perform precise alignment, and the wafer W can be held while being pressed downward by the downward tapered surface 72a (see FIG. 16). It has become.

  The movable block 72 is supported at an appropriate height position by a support member 73B formed in a block shape. And inside the main body 61 formed in a frame shape, there is provided a slide guide 76 which is movable freely along the extending direction of the hand 6 and a connecting member 75B supported by the slide guide 76. The connecting member 75B and the support member 73B are arranged in parallel to the linear movement direction of the slide guide 76 and spaced apart in the horizontal direction, and are inserted through the opening 61d provided on the wall surface of the main body 61. They are connected by a pair of shafts 74, 74 arranged to do so. The opening 61d is provided with a seal member 78 that closes the gap with the shaft 74, so that even if dust due to wear or the like is generated inside the main body 61, it is not released to the outside.

  Further, the slide guide 76 is connected to a cylinder shaft 77a of a cylinder 77 installed inside the main body 61, so that the operation center line 77b of the cylinder 77 and the linear movement direction of the slide guide 76 are parallel to each other. Is arranged. As the cylinder 77, a single-acting type that is operated by compressed air as a pressure medium is used. By supplying compressed air from a supply source (not shown), the cylinder shaft 77a is drawn and the compressed air is discharged. The cylinder shaft 77 is projected by a spring provided inside.

  Therefore, the movable block 72 is moved together with the slide guide 76, the connecting member 75B, the shafts 74 and 74, and the support member 73B by shifting from the state in which compressed air is supplied to the cylinder 77 to the discharge state and causing the cylinder shaft 77a to protrude. The wafer W can be held by moving toward the center of the wafer W. Further, by supplying compressed air to the cylinder 77 and drawing the cylinder shaft 77a, the movable block 72 is moved to the opposite side of the center of the wafer W together with the slide guide 76, the connecting member 75B, the shafts 74 and 74, and the support member 73B. The wafer W can be released by operating.

  As described above, since the wafer W is set to be held when no compressed air is supplied, the wafer W is held unexpectedly even when the supply of compressed air is unexpectedly stopped. There is no danger of being released.

  Here, FIG. 16 shows a side sectional view of each clamp mechanism 7A, 7B in each hand 5,6. In the upper hand 6, the lower surface 61 b of the main body portion 61 and the lower surface 62 b of the placement plate 62 are set to be substantially flush with each other, but the lower hand 5 is configured to be lower than the lower surface 51 b of the main body portion 51. The lower surface 52b of the mounting plate 52 is offset upward and is positioned above the center of the main body 51 in the thickness direction. Therefore, the placement plate 52 in the lower hand 5 and the placement plate 62 in the upper hand 6 are close to each other in the height direction so long as they do not interfere with each other even when the hands 5 and 6 are relatively rotated. Has been placed.

  Further, although the constituent elements of the clamp mechanisms 7A and 7B in the lower hand 5 and the upper hand 6 are the same, the shapes of the support members 73A and 73B and the connecting members 75A and 75B are different, so It is possible to cope with the difference in the height positions of the mounting plates 52 and 62.

  Specifically, first, the cylinders 77 and 77 in the hands 5 and 6 are provided at substantially the same positions on the inner upper surfaces 51c and 61c of the main body portions 51 and 61, respectively. Similarly, the slide guides 76 and 76 connected to the cylinders 77 and 77 are also provided at substantially the same positions on the inner upper surfaces 51c and 61c, and the connecting members 75A and 75B are provided on the slide guides 76 and 76, respectively. It has been.

  Here, the connecting member 75A constituting the clamp mechanism 7A of the lower hand 5 is connected to the shaft 74 at a position above the operation center line 77b of the cylinder 77. Further, the mounting position of the support member 73 </ b> A that determines the position of the movable block 72 while being connected to the shaft 74 is set so that the center of gravity of the movable block 72 is above the shaft 74. Therefore, in the lower hand 5, the center of gravity of the movable block 72 can be set higher than the operation center line 77 b of the cylinder 77. By doing so, it is possible to configure the clamp mechanism 7 </ b> A corresponding to the position where the mounting plate 52 is offset upward with respect to the main body 51.

  On the other hand, the connecting member 75B constituting the clamp mechanism 7B of the upper hand 6 is connected to the shaft 74 at a position below the operation center line 77b of the cylinder 77. Further, the mounting position of the support member 73 </ b> B that determines the position of the movable block 72 while being connected to the shaft 74 is set so that the center of gravity of the movable block 72 is located below the shaft 74. Therefore, in the upper hand 6, the center of gravity position of the movable block 72 can be set below the operation center line 77 b of the cylinder 77. By doing so, even when the mounting plate 62 is at substantially the same height as the lower surface 61b of the main body 61, the clamp mechanism 7B can be configured correspondingly.

  As described above, in each of the clamp mechanisms 7A and 7B, the operation center line 77b of the cylinder 77 and the position of the center of gravity of the movable block 72 are made different in the height direction so as to contact the side surface of the wafer W in the vicinity of the position of the center of gravity. In this case, a moment acts upon holding the wafer W. Since such a moment can be absorbed by the slide guide 76, it is possible to improve positioning accuracy without causing a burden on each portion connected between the cylinder 77 and the movable block 72. Yes.

  Since the clamp mechanisms 7A and 7B are configured in this manner, even when the cylinder 77 is increased in size in response to an increase in the weight of the wafer W, the clamp mechanism including the cylinder 77 inside the main body portions 51 and 61 is provided. A suitable holding force for the wafer W can be obtained while accommodating the main parts of 7A and 7B, and the mounting plates 52 and 62 can be arranged close to each other in the vertical direction. Therefore, the interval between the wafers W held using the mounting plates 52 and 62 can be reduced, and the time required for transporting and exchanging the wafers W can be shortened. Further, when it is allowed to reduce the pitch of the wafers W accommodated in the transfer rack as the interval between the wafers W held by the mounting plates 52 and 62 is reduced, the same transfer rack is used. If so, the number of wafers W can be increased. Furthermore, in order to maintain the same accommodation number, the vertical dimension of the entire transport rack is reduced, and the lifting stroke of the entire articulated robot 1 is reduced correspondingly, thereby reducing the time required to move the wafer W. In addition to shortening, it is possible to reduce the installation space by downsizing the entire apparatus.

  The articulated robot 1 (see FIG. 2) according to the present embodiment configured as described above includes the first arm element 3, the second arm element 4, and the hands (third arm elements) 5, 6 with the base 2 as a base point. In order to control the position precisely, these origin positions can be set accurately.

  17 and 18 schematically show a state in which the frames 31, 41, 51 and 61 are exposed by removing the covers 32, 42a, 51a and 61a (see FIGS. 2 and 10) from the arm elements 3 to 6, respectively. FIG.

  First, as shown in FIG. 17, when the extension position is obtained by extending the arm 1 </ b> A with the base 2 as a base point, the frame 31 constituting the first arm element 3 extends more than the rotation axis ST. A through hole 83 having a circular cross section formed along the vertical direction is provided at a position whose phase is shifted counterclockwise by about 30 ° with respect to the existing direction.

  For the base 2 positioned below the first arm element 3, a bottomed hole 82 is provided on the upper side, which is the connection side of the arm elements 3 to 6, as shown in FIG. Specifically, the bottomed hole 82 is provided on the upper surface of the block 28 that supports the frame 22 that constitutes the movable base 2B with respect to the frame 21 that constitutes the fixed base 2A. In the extended position, it is provided at a position that overlaps with the through hole 83. The bottomed hole 82 has a circular shape with the same diameter as the through hole 83.

  Returning to FIG. 17, the second arm element 4 also has a through hole 84 in the frame 41. The through-hole 84 has a circular shape with the same diameter as the through-hole 83 and is formed at a position 180 ° opposite to the through-hole 83 with the rotation axis SR as the center in plan view.

  Similarly, a through hole 86 is formed in the main body 61 of the upper hand 6. The through-hole 86 has a circular shape with the same diameter as the through-hole 84 and is formed at a position 180 ° opposite to the through-hole 84 around the rotation axis SH in plan view.

  Further, as shown in FIG. 18A, a through hole 85 is also formed in the main body 51 of the lower hand 5 at a position corresponding to the through hole 86 in the upper hand 6. The shape of the through hole 85 is the same as that of the through hole 86.

  The above-mentioned bottomed hole 82 and through-holes 83 to 86 have their respective rotation axes ST to when viewed in a plan view with the arm elements 3 to 6 as extended positions, that is, when viewed from the direction of the rotation axis of the arm elements 3 to 6. It is formed at a position shifted by a predetermined distance from the center line of each of the arm elements 3 to 6 passing through the SH. On this center line, the drive mechanisms 4R to 6R for rotating the arm elements 3 to 6 and the clamp mechanisms 7A and 7B for holding the wafer W are arranged, so By setting the bottomed hole 82 and the through holes 83 to 86 at a position shifted from the center line by a predetermined distance, it is possible to easily avoid overlapping with each component. The predetermined distance is set so as to be substantially the same as the radius of the largest pulleys 55 and 65 among the components of the drive mechanisms 4R to 6R provided in the arm elements 3 to 6. This makes it easier to avoid overlapping.

  FIG. 19 shows a state in which the arm 1A is folded and contracted. The first arm element 3 is located at the same position as the extended position with respect to the base 2, but the tip of the second arm element 4 rotates in the opposite direction by 180 °, and the lower hand 5 and the lower hand 6 have tips. The first arm element 3 is directed in the same upward direction as the paper surface. By doing so, the through holes 86 in the upper hand 6, the through holes 83 to 85, and the bottomed holes 82 are aligned on the same straight line so as to overlap in the vertical direction.

  FIG. 20 is a partially cutaway side view when the arm elements 3 to 6 are set to the reference position. Thus, since the bottomed hole 82 and the through holes 83 to 86 set as the same diameter are arranged in the same position in the vertical direction, the positioning jig 81 formed as a shaft having a circular cross section is inserted from above. Thus, the positions of the arm elements 3 to 6 can be strictly aligned at the same time. As described above, since the bottomed hole 82 and the through holes 83 to 86 are provided at positions shifted from the center lines of the arm elements 3 to 6, each of the drive mechanisms 4R to 6R and the clamp mechanisms 7A and 7B is provided. Interference between the component and the jig 81 can be avoided. In order to easily insert the jig 81, it is also preferable to provide chamfers at the opening edges of the bottomed hole 82 and the through holes 83 to 86.

  Specifically, when the above operation is performed, the power supply to the motors 37, 46, 56, and 66 (see FIGS. 3 and 5) used to control the positions of the arm elements 3 to 6 is stopped to maintain the position. Is released, and the jig 81 is inserted from above into the bottomed hole 82 and the through holes 83 to 86 in a state where the arm elements 3 to 6 are manually rotatable. The origin can be adjusted by resetting the origin of an encoder (not shown) for detecting the rotation angle corresponding to each motor 37, 46, 56, 66.

  When the jig 81 is used, the arm elements 3 to 6 can be easily aligned by simply inserting the jig 81 until it comes into contact with the bottomed hole 82, and the position adjustment work for all the arm elements 3 to 6 can be performed. Since it can be performed at the same time, the work can be easily performed. In addition, compared to a jig that has been used in the past, the arm element is rotated and the side surface of the arm element is brought into contact with each other to perform alignment, less affected by the skill level of the operator, It is also possible to improve the position accuracy when adjusting the origin. Furthermore, since the jig 81 can have a simple circular cross-sectional shape, it is possible to reduce manufacturing costs, and since there is no directionality in use, the usability can be further improved. It has become.

  Further, after the origin adjustment operation is completed, it is possible to immediately restore the usable state by simply attaching the covers 32, 33, 42, 43, 51a, 61a to the arm elements 3-6. By attaching the covers 32, 33, 42, 43, 51 a, 61 a, it is possible to cover the through holes 83 to 86 and to prevent dust and the like due to wear from being released from the inside, thereby preventing contamination of the wafer W being transferred. It is also possible.

  The articulated robot 1 of the present embodiment configured as described above uses a control device (not shown) to hold the position and orientation of the lower hand 5 and the upper hand 6 with respect to the base 2 and the holding and holding of the wafer W. It is possible to cancel.

  That is, as shown in FIGS. 2 to 4, by controlling the motor 26 that constitutes the lifting mechanism 2E, the ball screw 24 can be driven and the movable base 2B can be lifted and lowered with respect to the fixed base 2A. ing. Further, by controlling the motor 37 constituting the drive mechanism 3R, the first arm element 3 is rotated with respect to the movable base 2B, and the motor 46 constituting the drive mechanism 4R is controlled, whereby the first The second arm element 4 can be rotated with respect to the arm element 3. Furthermore, by controlling the motor 56 constituting the drive mechanism 5R and the motor 66 constituting the drive mechanism 6R, the lower hand 5 and the upper hand 6 as the third arm element are moved to the second arm element 4. It can be rotated. In addition, the compressed air is not supplied to the cylinders 77 and 77 constituting the clamp mechanisms 7A and 7B included in the lower hand 5 and the upper hand 6, that is, the compressed air is removed, thereby holding the wafer W. And holding the wafer W can be released by supplying compressed air.

  By performing such an operation, the wafer W held by the hands 5 and 6 can be transferred from a predetermined position to another position, or the wafer W at a predetermined position can be exchanged. .

  As described above, the articulated robot 1 according to the present embodiment is an articulated robot 1 in which a plurality of arm elements 3 to 6 are sequentially connected with a base 2 as a base point, and can be relatively rotated. 3 to 6 are provided with bottomed holes 82 provided on the connection side and through holes 83 to 86 provided in the respective arm elements 3 to 6, and each arm element 3 to 6 is in a predetermined posture. When the bottomed hole 82 of the base 2 and the through holes 83 to 86 of the arm elements 3 to 6 are aligned on the same straight line in the position, the bottomed hole 82 and the through holes 83 to 86 are formed. The base 2 and the arm elements 3 to 6 can be positioned by inserting the same shaft 81.

  With this configuration, the shaft 81 as a positioning jig is inserted into the bottomed hole 82 and the through holes 83 to 86 while adjusting the positions of the arm elements 3 to 6 with respect to the base 2. By doing so, it is possible to easily align the base 2 and the arm elements 3 to 6. Therefore, if such a position is set as a reference position for each of the arm elements 3 to 6 and the encoder for detecting the rotation angle of each of the arm elements 3 to 6 is reset in this state, the origin adjustment operation is performed easily and quickly. be able to. In addition, since the work content related to the origin adjustment can be simplified, it is possible to perform the origin adjustment with higher accuracy without depending on the skill level of the operator.

  In addition, since the bottomed hole 82 and the through holes 83 to 86 are configured to have a circular shape with the same diameter, the shaft 81 that is a positioning jig may have a simple circular cross section. Therefore, the manufacturing cost of the jig can be reduced, and the orientation of the shaft 81 is not questioned at the time of work, so the insertion into and removal from the through holes 83 to 86 and the bottomed hole 82 becomes easy. The origin adjustment work can be made more efficient.

  Further, when each of the arm elements 3 to 6 is viewed from the rotation axis direction, a through hole is formed at a position separated from the center line of the arm elements 3 to 6 by a predetermined distance, that is, a distance that is substantially the same as the radius of the pulleys 55 and 65. Since 83 to 86 are arranged, it is possible to easily suppress interference between the drive mechanisms 4R to 6R provided inside the arm elements 3 to 6 and the shaft 81 through which the through holes 83 to 86 are inserted. Therefore, it is possible to reduce manufacturing and maintenance costs by reducing the design and assembly / adjustment work related to the arrangement of the drive mechanisms 4R to 6R and the layout of the wiring piping CT.

  Further, since the covers 32, 33, 42, 43, 51a, 61a for covering the through holes 83-86 are detachably provided on at least a part of the arm elements 3-6, the arm elements It is possible to suppress dust due to wear powder generated from the 3 to 6 drive mechanisms 3R to 6R and the like from being released to the outside through the through holes 83 to 86.

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, in the above embodiment, the first arm element 3, the second arm element 4, the third arm element 5, 6 are sequentially connected upward from the base 2, but the base 2 is connected to the ceiling. It is also possible to adopt a configuration in which the arm elements 3 to 6 are sequentially connected downwardly by hanging.

  Further, in the above embodiment, the state in which the arm 1A is completely folded is set as the reference position in each of the arm elements 3 to 6, but the bottomed hole 82 and the through holes 83 to 86 are arranged on the same straight line. It is also possible to set the case where the arm 1A is in a different posture as a reference position as long as it can be set.

  Furthermore, the shapes of the covers 32, 33, 42, 43, 51a, 61a provided on the arm elements 3 to 6 can be changed as appropriate, and only avoid the discharge of dust from the through holes 83 to 86. For the purpose, it can be made smaller than that used in the above embodiment.

  Further, the through holes 83 to 86 are formed at positions sufficiently separated from the drive mechanisms 3R to 6R of the arm elements 3 to 6, and communicate with the spaces in the arm elements 3 to 6 in which the drive mechanisms 3R to 6R are accommodated. If it can be configured so as not to occur, there is little risk of dust being discharged from the inside through the through holes 83 to 86, and therefore it is not always necessary to cover the through holes 83 to 86 with a cover. In that case, it is possible to further reduce the manufacturing cost by making the covers provided on the arm elements 3 to 6 small enough to cover the drive mechanisms 3R to 6R, respectively. In addition, since it is not necessary to remove the cover for the origin adjustment work, the work efficiency can be further improved.

  In addition, the articulated robot 1 in the present embodiment is configured to be used for transporting the wafer W used for semiconductor manufacture. However, the articulated robot 1 is applied to various articulated robots that handle general workpieces other than the wafer W. It is possible.

  Other configurations can be variously modified without departing from the spirit of the present invention.

1 ... Articulated robot (work transfer robot)
DESCRIPTION OF SYMBOLS 1A ... Arm 2 ... Base 3 ... 1st arm element 3R-6R ... Drive mechanism 4 ... 2nd arm element 5 ... Lower hand (3rd arm element)
6 ... Upper hand (third arm element)
32, 33, 42, 43, 51a, 61a ... cover 55 ... pulley 65 ... pulley 81 ... shaft (jig)
82: Bottomed hole 83-86 ... Through hole CT ... Wiring piping W ... Wafer (workpiece)

Claims (4)

An articulated robot that can rotate relative to a base while sequentially connecting a plurality of arm elements,
A bottomed hole provided on the connection side of the arm element in the base;
Each arm element is provided with a through hole,
By making the bottom hole of the base and the through hole of each arm element line up on the same straight line in a state where each arm element is in a predetermined posture, the same shaft is inserted into the bottom hole and the through hole. A multi-joint robot characterized in that the base and each arm element can be positioned.   The articulated robot according to claim 1, wherein the bottomed hole and the through hole are circular with the same diameter.   3. The articulated robot according to claim 1, wherein, when each arm element is viewed from the direction of the rotation axis, the through-hole is disposed at a position spaced a predetermined distance from the center line of the arm element.   The articulated robot according to any one of claims 1 to 3, wherein a cover for covering the through hole is detachably provided on at least a part of the arm element.

Images