JP5136064B2 - robot - Google Patents

Description

  The present invention relates to a robot in which an arm is provided with a telescopic moving body, and more particularly to an interlocking configuration of two moving members constituting the telescopic mobile body.

  For example, the Cartesian coordinate robot has a configuration in which a moving body is provided on the distal arm so as to be movable up and down, and a hand for holding a workpiece is attached to the moving body. In this case, in order to shorten the length of the moving body, the moving body is composed of two moving members, and one moving member is supported on the arm so as to move up and down, and the other moving member is supported by the arm. It is preferable that the two moving members are moved in a telescope shape by supporting the moving member supported by the one moving member so as to be movable up and down.

In Patent Document 1, although not moving in the vertical direction, in the Cartesian coordinate robot, the first and second position determination units are provided on the horizontal arm so as to be movable in the horizontal direction, and the first position determination unit is the vertical support unit. A double speed mechanism is disclosed in which the second position determining unit is moved in the horizontal direction at a speed twice that of the horizontal arm. In the double speed mechanism disclosed in Patent Document 1, a pair of shafts are rotatably provided in a horizontal arm, and two pulleys are fixed to each shaft. The first position determining unit is fixed to one belt, the second position determining unit is fixed to the other belt, and one of the shafts is rotationally driven by a motor. .
Japanese Patent Laid-Open No. 9-1481

In a Cartesian coordinate robot, when a moving body that moves up and down with a hand attached is configured in a telescope shape (expandable type) by two moving members, as a mechanism for moving the two moving members in conjunction with each other, It is conceivable to apply the double speed mechanism described in Patent Document 1.
However, since the double speed mechanism of Patent Document 1 uses two belt transmission mechanisms, the entire moving body tends to be large, and there is a problem that there is a lot of dust generation due to a decrease in positional accuracy due to belt elongation and belt wear. Is produced. Furthermore, in patent document 1, since the double speed mechanism is provided in the inside of one moving member (horizontal arm) with the motor which is the drive source, a moving member becomes heavy and it may have a bad influence on a portable weight.

  However, without using a double speed mechanism as shown in Patent Document 1, for example, a nail is put out from one moving member to the other moving member, and the other moving to the nail while one moving member moves It is conceivable that a member is hooked and the other member is moved by a half distance of one member, but in this case, the moving member is simply moved by hooking with a claw. Therefore, when the two moving members are stopped halfway, the positional relationship between the two moving members inevitably deviates from the normal positional relationship, and a stable support state may not be obtained.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to move the two moving members constituting the telescopic moving body correctly in conjunction with each other and move the two moving members in conjunction with each other. The robot can be realized in a form that can suppress dust generation as much as possible while avoiding an increase in size, and further, it is possible to provide a robot that does not require a drive source for expanding and contracting the moving body inside the moving member. There is to do.

  According to the first aspect of the present invention, the first and second moving members constituting the telescopic movable body are each provided with a rack, and the first pinion on the small diameter side provided on the rotating member is engaged with the rack of the first moving member. Since the second pinion on the large-diameter side is engaged with the rack of the second moving member, the first and second moving members are interlocked and the second moving member is more than the first moving member. It can be configured to move long distances. Further, the first and second moving members can be moved in conjunction with each other by meshing the racks respectively provided on the first and second moving members with the two pinions provided on one rotating member. Therefore, the enlargement of the interlocking mechanism can be avoided, and there is no possibility that the positional relationship between the first and second moving members will be out of order, and the contact between the rack and the pinion is used. Compared with, dust generation can be suppressed. In addition, since the rotational drive source can be provided not on the moving body side but on the arm, an increase in the weight of the moving body can be suppressed.

In claim 2, the support mechanism that supports the first and second moving members so as to be linearly movable includes a rail and a support member that is combined with the rail and moves linearly relative to the rail. Configuration is simplified.
According to the third aspect of the present invention, since a plurality of support members are provided with respect to one rail in a moving direction, the support is stable.
In claim 4, the diameter ratio between the first pinion and the second pinion, and the attachment position of the support mechanism, even when the first and second moving members are most moved in the extending direction, each supporting member Supports the rail in its entirety (full length), so that the support state of the moving member is stabilized.
In the fifth aspect, since the diameter of the first pinion is set to ½ of the diameter of the second pinion, the second moving member is moved twice as much as the first moving member. Become. For this reason, the length of the first and second moving members can be minimized with respect to the moving distance of the second moving member.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows a 4-axis (joint) horizontal articulated robot. In the horizontal articulated robot of FIG. 5, the robot body 1 includes a base 2 fixed to the installation surface of the robot, and a first arm 3 connected to the base 2 so as to be pivotable about a vertical axis J1. And a second arm 4 that is pivotally connected to the tip of the first arm 3 about a vertical axis J2, and a vertical direction indicated by an arrow Z to the second arm 4 that is the tip side arm. The movable body 5 is provided so as to be movable, and a flange 6 is provided at the front lower portion of the movable body 5 so as to be rotatable about the vertical axis J3. The flange 6 is configured to be attached with a hand (not shown) for gripping the workpiece.

The first arm 3 is turned by a first shaft motor (not shown) provided in the base 2, and the second arm 4 is a second arm provided on the second arm 4 itself. It is turned by a shaft motor (not shown). The flange 6 is rotated by a third shaft motor 7 attached to the moving body 5 via a speed reducer 8.
The movable body 5 is configured as a telescopic movable body that expands and contracts in the vertical direction, and by the expansion and contraction, a hand (not shown) attached to the flange 6 can be moved to a desired height position. . That is, the moving body 5 includes a first moving member 9 and a second moving member 10, and the first moving member 9 is placed on the tip of the second arm 4 as shown in FIG. A movable mechanism (support mechanism) 11 is supported so as to be movable in the vertical direction, and the second movable member 10 is supported by the first movable member 9 in the vertical direction via a second linear motion mechanism (support mechanism) 12. By being supported so as to be linearly movable, it is configured to expand and contract like a telescope.

  The first linear motion mechanism 11 and the second linear motion mechanism 12 basically include a rail and a support member coupled to the rail so as to be linearly movable. In the present embodiment, the first linear motion mechanism 11 and the second linear motion mechanism 12 The linear motion mechanism 11 includes a pair of first rails 13 and two first support members 15 coupled to each of the first rails 13. Similarly, the second linear motion mechanism 12 includes It comprises a pair of second rails 14 and a second support member 16 coupled to each second rail 14 by two. In this case, the coupling between the first rail 13 and the first support member 15 and the coupling between the second rail 14 and the second support member 16 are performed by the balls 17 as shown in FIG. That is, as shown in FIG. 4, the first support member 15 and the second support member 16 are substantially U-shaped, and the first rail 13 and the second rail 14 are fitted inside with a small gap. It is.

  V-grooves 13a, 14a and V-grooves 15a, 16a are formed on the outer surfaces of the first rail 13, the second rail 14, and the inner surfaces of the first support member 15 and the second support member 16, respectively. In the tunnel constituted by the V grooves 13a, 14a and 15a, 16a, a large number of balls 17 are accommodated so as to straddle both the V grooves 13a, 14a and 15a, 16a. As a result, the first rail 13 and the second rail 14 are coupled to the first support member 15 and the second support member 16 via the balls 17, and the first rail 13 and the second rail 14 are connected to each other. The first support member 15 and the second support member 16 are coupled to each other so as to be relatively linearly movable. Although not shown, on the first support member 15 and the second support member 16 side, a ball 17 that rolls along with the linear movement is taken out from the V grooves 13a, 14a and 15a, 16a, and again the V groove. Circulation paths for returning to 13a, 14a and 15a, 16a are formed.

  Then, the pair of first rails 13 is fixed to the rear surface of the first moving member 9 (the rear surface when viewed from the flange 6 side), and is coupled to each first rail 13. The two first support members 15 are fixed to the distal end surface of the second arm 4 at a predetermined distance in the vertical direction, which is the moving direction. Of the two first support members 15 coupled to each first rail 13, the lower first support member 15 is positioned at the lower end of the front end surface of the second arm 4, The upper first support member 15 is located a predetermined distance above the first support member 15.

  Further, the pair of second rails 14 is fixed to the rear surface of the second moving member 10 in a lateral direction, and the two second support members 16 coupled to the second rails 14 are moved. It is fixed to the front surface of the first moving member 10 at a predetermined distance in the vertical direction. Of the two second support members 16 coupled to each second rail 14, the lower second support member 16 is positioned at the lower end of the front surface of the first support member 15, The upper second support member 16 is positioned a predetermined distance above it.

  As a rotational drive source for moving the first moving member 9 and the second moving member 10 constituting the telescopic movable body 5 up and down, an elevating motor 18 is used. A rack and pinion mechanism is used as a rotation-linear motion conversion mechanism for converting the rotation of the lifting motor 18 into the vertical movement of the first moving member 9 and the second moving member 10. .

  That is, the first rack 19 and the second rack 20 are fixed to the rear surfaces of the first moving member 9 and the second moving member 10. On the other hand, the elevating motor 18 is disposed in the second arm 4 so as to be in a horizontal axis shape toward the lower end in the extending direction of the telescopic movable body 5. A rotating shaft (rotating member) 18 a of the lifting motor 18 protrudes forward through the distal end surface of the second arm 4 so that the first moving member 9 is positioned between the pair of first rails 13. It protrudes to the 2nd moving member 10 side through the elongate hole 9a formed in the up-down direction.

  As described above, the rotary shaft 18 a is arranged so as to extend from the lifting motor 18 to the second rack 20 through the first rack 19, and meshes with the first rack 19 at an intermediate portion thereof. The first pinion 21 is fixed, and the second pinion 22 that meshes with the second rack 20 is fixed to the tip.

  In this embodiment, when the 1st moving member 9 and the 2nd moving member 10 expand and contract, the 2nd moving member 10 is comprised so that it may move the double distance of the 1st moving member 9. For this purpose, the diameter of the second pinion 22 is set to twice the diameter of the first pinion 21. Here, the diameters of the first pinion 21 and the second pinion 22 are the diameters of the pitch circles. Thereby, when the rotating shaft 18a rotates, the first moving member 9 and the second moving member 10 move in conjunction with each other, and the second moving member 10 is twice the distance of the first moving member 9. To move.

  In the state where the first moving member 9 and the second moving member 10 have moved in the extending direction to the lowest (most extended) position, the upper end of the first rail 13 of the first moving member 9 is on the upper side ( The upper end portion of the second rail 13 of the second moving member 10 is located at the same height as the upper end portion of the first support member 15 on the anti-extension direction side or on the upper side (the anti-extension direction side). Is configured to be located at the same height as the upper end portion of the second support member 16 on the upper side (anti-extension direction side) or on the upper side (anti-extension direction side).

  Next, the operation of the above configuration will be described. When the robot is stopped, the first moving member 9 and the second moving member 10 are at the most elevated position (original position; most contracted position) shown in FIG. From this state, when the robot starts operation and grips a workpiece with a hand (not shown) attached to the flange 6, first, the first arm 3 and the second arm 4 are turned and attached to the flange 6. The hand (not shown) is moved directly above the work. Next, in order to hold the workpiece by the hand, the telescopic movable body 5 is extended and the flange 6 is lowered. When the elevating motor 18 rotates in the forward direction for lowering the telescopic movable body 5, the rotation of the first pinion 21 and the second pinion 22 is below the first rack 19 and the second rack 20. The first moving member 9 and the second moving member 10 move downward (elongate) in conjunction with each other, and lower the flange 6 (hand). At the time of this lowering, the second moving member 10 moves twice as much as the first moving member 9 at twice the speed.

  When the second moving member 10 is lowered to a certain position, the elevating motor 18 is stopped, and the hand holds the workpiece here. FIG. 2 shows a state where the flange 6 is lowered to the lowest position. Thereafter, the elevating motor 18 rotates in the reverse direction to return the hand to the original position. Then, the rotation of the first pinion 21 and the second pinion 22 is converted into a linear movement upward of the first rack 19 and the second rack 20, and the first moving member 9 and the second moving member 10. Rise (shrink) in conjunction with each other. Also at this time, the second moving member 10 moves twice as much as the first moving member 9 at twice the speed. And if the 1st moving member 9 and the 2nd moving member 9 return to an original position, the raising / lowering motor 18 will stop.

  As described above, according to the present embodiment, the first pinion 21 and the second pinion 22 having different diameters are fixed to the single rotating shaft 18a, and the first pinion 21 and the second pinion 22 are connected to the first pinion 21. Since the first moving member 9 and the second moving member 10 are engaged with the first rack 19 and the second rack 20, the first moving member 9 and the second moving member 10 move up and down in conjunction with each other. At the same time, the second moving member 10 moves a longer distance (twice in this embodiment) than the first moving member 9.

  Since the interlocking relationship between the first moving member 9 and the second moving member 10 is achieved by the rack and pinion mechanism, an increase in size can be avoided and dust generation can be suppressed. . In addition, since the lifting motor 18 is disposed in the second arm 4, an increase in the weight of the entire moving body 5 can be suppressed.

  Moreover, since the 1st moving member 9 and the 2nd moving member 10 are supported by the 1st linear motion mechanism 11 and the 2nd linear motion mechanism 12, the structure supported so that it can move linearly becomes simple. In addition, since the first rail 13 and the second rail 14 are supported by the two first support members 15 and the second support member 16, respectively, a stable support state can be obtained. Further, even when the first moving member 9 and the second moving member 10 are moved to the lowest position, each of the first rail 13 and the second rail 14 has two first support members 15, Since the second support member 16 is supported by the entire length, a more stable support state can be obtained.

  Furthermore, in this embodiment, since the diameter of the second pinion 22 is set to be twice the diameter of the first pinion 21, the second moving member 10 is twice as long as the first moving member 9. Will only move. Therefore, the lengths of the first moving member 9 and the second moving member 10 are made the same, and the vertical length of the entire moving body 5 when contracted is minimized, in other words, the first moving member 9 and the second moving member 10 have the same length. Since the lengths of the moving member 9 and the second moving member 10 are different from each other, it is possible to eliminate a problem that the length of the moving body 5 in the vertical direction when it contracts becomes long.

The present invention is not limited to the embodiment described above and shown in the drawings, and can be expanded or changed as follows.
The diameter ratio between the first pinion 21 and the second pinion 22 is not limited to 1: 2. It is sufficient that the diameter of the first pinion 21 is smaller than the diameter of the second pinion 22.
The rotating member need not be the rotating shaft 18a of the motor 18 itself. A rotating shaft coupled to the motor 18a by a coupling may be used.
The moving body 5 is not limited to one that expands and contracts in the vertical direction.
The present invention is not limited to a moving body of an orthogonal coordinate robot, and can be widely applied to a telescopic moving body of a robot.

The longitudinal side view of the principal part which shows one Embodiment of this invention Longitudinal side view of essential parts shown in a different state from FIG. Cross section plan of the main part Transverse plan view of linear motion mechanism Side view of horizontal articulated robot

Explanation of symbols

  In the drawings, 4 is a second arm, 5 is a telescopic movable body, 9 is a first moving member, 10 is a second moving member, 11 is a first linear motion mechanism (supporting mechanism), and 12 is a second moving member. Linear movement mechanism (support mechanism), 13 is a first rail, 14 is a second rail, 15 is a first support member, 16 is a second support member, 18 is a motor (rotation drive source), 18a is A rotating shaft (rotating member), 19 is a first rack, 20 is a second rack, 21 is a first pinion, and 22 is a second pinion.

Claims (5)

Arm,
A first moving member provided on the arm so as to be linearly movable , and a second moving member provided so as to be linearly movable in the same direction as the first moving member while being supported by the first moving member so as to be relatively movable . A telescopic movable body composed of a moving member of
Racks respectively provided on the first moving member and the second moving member;
A rotational drive source provided on the arm and biased to an end portion on the extension direction side of the telescopic movable body;
A rotating member provided so as to extend from the rotational drive source through the rack of the first moving member to the rack of the second moving member;
A first pinion provided on the rotating member and meshing with the rack of the first moving member; and a second pinion meshing with the rack of the second moving member, and the first pinion Is set smaller than the diameter of the second pinion, and the rotation of the rotating member causes the first and second moving members to move together, and the second moving member is moved to the first pinion. A robot configured to move a distance longer than that of the moving member.   The support mechanism for supporting the first moving member and the second moving member so as to be linearly movable includes a rail extending in the moving direction and a support member that is combined with the rail and moves linearly relative to the rail. The robot according to claim 1, wherein the robot is configured.   The robot according to claim 2, wherein a plurality of the supporting members are provided with respect to one of the rails so as to be separated in a moving direction.   The diameter ratio of the first pinion and the second pinion and the mounting position of the support mechanism are the first moving member and the second moving member in the state where the first moving member and the second moving member are moved in the most extending direction. The support mechanism for supporting the movable member on the arm and the end of the support mechanism for supporting the second movable member on the first movable member on the anti-extension direction side of the rail are respectively provided. It is set so that it may be located in the anti-extension direction side rather than the end part in the most anti-extension direction side, or the end part in the most anti-extension direction side of each support member. Item 4. The robot according to Item 2 or 3. 5. The robot according to claim 1, wherein a diameter of the first pinion is set to ½ of a diameter of the second pinion.

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