JP3187100B2 - Horizontal scalar robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotatable first arm and a base end of a second arm pivotally attached to a protruding end of the first arm. The present invention relates to a horizontal scalar robot that performs multi-point positioning of rotation and lifting and lowering on a work tool such as a suction pad or a robot tool provided at the tip of a second arm without providing a cylinder device.

[0002]

2. Description of the Related Art Conventionally, a horizontal scalar robot has a base end of a second arm pivotally attached to a projecting end of a rotatable first arm.
At the end of the second arm, there are provided a servo motor and an air cylinder device for driving a work tool (work equipment) for performing various works on a work such as a suction pad and a robot tool. By driving the air cylinder device and the air cylinder device, the work tool can perform up and down and rotation in a combined manner including the gripping operation.

[0003] Conventionally, as an industrial robot arm, a base arm attached to a drive shaft is rotated by driving a motor provided on a support member, and a winding transmission means is driven by another motor provided on the support member. There has been proposed an arm-type robot that drives a rotating shaft attached to the distal end of a base arm via a base to rotate a working arm fixed to the rotating shaft (Japanese Patent Laid-Open No. 61-38883). This arm robot is configured as a double arm type robot having two sets of a motor, a drive shaft, a base arm, a rotating shaft and a working arm, arranging both motors coaxially and rotating both base arms in parallel.

[0004] Further, there is also an arm structure of an industrial robot in which a working tool is mounted on the tip of a vertical arm shaft provided at the foremost portion of an articulated horizontal arm to perform various robot operations such as vertical movement and rotation. It has been proposed (JP-A-63-77).
675, JP-A-63-77682). In the arm structure disclosed in Japanese Patent Application Laid-Open No. 63-77675, a hollow vertical arm shaft formed by overlapping a thread groove engaged with a nut and a spline groove engaged with a spline nut is formed at the leading end of a horizontal arm. The vertical arm shaft is rotated or axially moved by driving a nut and a spline nut with a servomotor via a toothed pulley and a belt, respectively. The hollow of the vertical arm shaft is used as a laying space for supplying an electric signal, a working fluid, and the like to avoid interference with a work object or the like. In the arm structure disclosed in Japanese Patent Application Laid-Open No. 63-77682, a thread groove in which a nut engages and a spline groove in which a spline nut engages are separately provided on a hollow vertical arm shaft. Giving rotation or axial movement.

Further, by rotating the base-side rotating shaft by a driving device for the base-side rotating shaft connected to the lower end thereof, the base-side horizontal arm attached to the upper end of the base-side rotating shaft is rotated. The working side transmission shaft arranged inside the side rotation shaft is rotated by the working side transmission shaft driving device connected to the lower end thereof, whereby the work side winding transmission device connected to the upper end of the working side rotation shaft. The working side drive shaft provided at the tip of the horizontal arm on the base side is rotated through to drive the working side horizontal arm, and the handle side transmission shaft disposed inside the working side transmission shaft is connected to the lower end thereof. By rotating by the handle-side transmission shaft, the work is performed via a handle-side wrapping transmission device that is connected to the upper end of the handle-side transmission shaft and extends to the tip of the working-side horizontal arm through the inside of the working-side drive shaft. Speed up the operation by driving the handle provided at the tip of the side horizontal arm. Ri, industrial robot to prevent problems caused by bridging the cable has been proposed (JP-A-1-316184).

[0006]

In the above-mentioned conventional multi-joint type industrial robot, a mechanism for raising and lowering a work tool provided at the tip of an arm on the work side is not provided or is provided. Even if the actuator is provided with an actuator such as a servo motor or air cylinder device at the tip of the working side arm, or a wrapping transmission mechanism provided with the rotation output from the drive source over the base side arm and the working side arm And the work tool is raised and lowered using the action of the feed screw. When an actuator is provided at the tip of the arm on the working side as an elevating mechanism for the working tool, the weight applied to the tip of the arm increases, and the bending moment acting on the arm on the base side and the working side increases. Further, when a winding transmission mechanism for performing a feed screw action is provided on the base side arm and the work side arm for lifting and lowering the work tool,
In addition to the wrapping transmission mechanism for the rotation of the work side arm and the work tool, the internal structure of the base side and work side arms becomes complicated, and the size of the arm increases. As a result, the weight of the arm increases, the operating speed decreases, and a drive source with a high output is required. Therefore, in order to accurately determine the position of the work tool, it is necessary to take measures such as increasing the cross-sectional shape of both arms and using a rigid structure with a large wall thickness, and the necessity of driving with a servomotor with a large torque. There is a problem that it is difficult to perform high-speed operation and reduce the weight of the robot.

In order to rotate the work tool provided at the tip of the work side, a wrapping transmission mechanism is provided in the base side and in the arm on the work side. The problem to be solved in that a mechanism that contributes to further simplification and weight reduction of the internal structure of the base side and the working side arm without adopting the wrapping transmission mechanism arranged in the working side arm. There is. The present invention has been devised in view of the above points, and an object of the present invention is to perform multi-point positioning of rotation and elevation on a work tool such as a suction pad or a robot tool provided at the tip of a work-side arm. An object of the present invention is to provide a horizontal scalar robot capable of reducing the cross-sectional shape and thickness of the first arm and the second arm, reducing the weight of the arm, and enabling high-speed operation with a servomotor having a small torque.

[0008]

According to the present invention, there is provided a hollow first shaft pivotally supported by a gantry, a first drive source connected to a lower end of the first shaft, and a first drive source passed through the first shaft. A second axis forming a longitudinal axis together with the first axis, a second drive source connected to a lower end of the second axis, a base end fixed to an upper end of the first axis and driven by the first drive source A horizontally rotatable first arm, a base end of which is pivotally attached to a projecting end of the first arm, and via a second winding mechanism provided on the first arm and the second shaft. A horizontally rotatable second arm driven by the second drive source, a hollow ball spline shaft inserted and supported in a vertically slidable manner on a ball spline nut pivotally attached to the extended end of the second arm, Via a second winding mechanism provided over the first arm and the second arm A third drive source for rotationally driving the ball spline nut together with a ball spline shaft, a flexible tube extending from a proximal end pivotally attached to the gantry and having a distal end pivotally attached to the second arm; Is wound around a reel provided on the gantry, extends in the flexible tube, and has a leading end linked to the ball spline shaft, and the ball spline shaft is moved up and down to move the ball spline. The present invention relates to a horizontal scalar robot including a fourth drive source for rotating and driving the reel to move the core wire in the flexible tube in order to raise and lower a work tool mounted on a lower end of a shaft.

In this horizontal scalar robot, the third drive source is passed through a servomotor provided on the first arm or the second axis, and is a vertical axis together with the first axis and the second axis. Is a servomotor connected to the lower end of the third shaft.

In this horizontal scalar robot, the working tool has a base end connected to a negative pressure generator provided on the gantry via a control valve, and extends from the base end and has a front end. The suction pad is connected to a hose connected to the upper end of the ball spline shaft and is capable of sucking the work through the ball spline shaft. Alternatively, the work tool extends from the base end of the ball spline shaft, which extends from a base end pivotally attached to the gantry and has a distal end connected to the upper end of the ball spline shaft. A robot tool pivotally connected to a distal end of a tool core wire extending therethrough, wherein a base end of the tool core wire is provided on the gantry for moving the tool core wire in the tool flexible tube; and It is wound around a tool reel that is rotated and driven by a tool drive source.

[0011]

According to the present invention, the first arm can be horizontally rotated through the first shaft by the driving of the first driving source. The second arm is driven around the base end pivotally attached to the projecting end of the first arm via the second winding mechanism provided on the second shaft and the first arm by the driving of the second drive source. It can be rotated horizontally. The ball spline shaft provided at the tip of the second arm is rotatable by rotating the ball spline nut via the second winding mechanism by driving of the third drive source, and at the same time, the The reel can be moved up and down by rotating the reel by driving to take up or unwind the core wire and move it in the flexible tube.
The work tool for work handling mounted on the lower end of the ball spline shaft rotates around a first arm that rotates around the first axis and a pivot shaft provided at the projecting end of the first arm. The second arm is brought to a predetermined position in the work plane area, and by rotating the ball spline shaft together with the ball spline nut, a posture of a predetermined rotation or a predetermined angle around the ball spline axis is controlled. Since the output from a drive source such as a servomotor provided on the gantry is controlled via a transmission mechanism by the amount of rotation of each arm or work tool, the plane of the work tool provided at the projecting end of the second arm The position and rotation posture are determined accurately, and accurate robot work is possible. The work tool is moved up and down and its vertical position by a core wire that moves in a flexible tube instead of through a transmission wrapping mechanism that causes the weight of the arm to increase, although not as much as a servomotor or air cylinder device. Is performed, the structure of the arm can be further simplified and the weight can be reduced.

In the horizontal scalar robot, when the third drive source is a servomotor provided on the first arm, the output of the servomotor is output from the servomotor provided on the first arm and the second arm. The ball spline shaft is rotationally driven together with the ball spline nut via the double winding mechanism, and the rotation of the work tool around the ball spline shaft and the attitude of the angle are controlled. Further, when the third drive source is a servomotor that is passed through the second shaft and is connected to the lower end of the third shaft that forms a vertical axis together with the first shaft and the second shaft,
The output of the servomotor is transmitted to the ball spline nut via the third shaft and the second winding mechanism, and the rotation of the work tool around the ball spline axis and the attitude of the angle are controlled.

In this horizontal scalar robot, when the work tool is a suction pad, when the control valve is opened, the negative pressure of the negative pressure generator provided on the gantry causes the ball spline shaft to pass through the hose. The suction pad provided at the lower end of the ball spline shaft acts on the inside from the upper end to be able to suck and hold the work. When the work tool is a robot tool, when the tool reel provided on the mount is rotationally driven by the tool drive source, the tool core wire whose tip is wound around the tool reel is used for the tool. The reel is wound or fed, and moves in a flexible tube for tool connected between the gantry and the ball spline shaft to drive a robot tool pivotally connected to the tip. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a horizontal scalar robot according to the present invention will be described below with reference to the drawings. FIGS. 1 and 2 are longitudinal sectional views of a main part of a horizontal scalar robot according to a first embodiment of the present invention. In this horizontal scalar robot, the hollow first shaft 10 and the hollow second shaft 20 passed through the first shaft 10 are pivotally supported by the housing portion 30a on the top of the gantry 30 so as to be the vertical axis. I have. The first arm 11 whose base end is fixed to the upper end of the first shaft 10 has a first shaft 10
It is rotated by a first servomotor 12 as a first drive source provided to be connected to a lower end of the motor through a timing belt type third winding mechanism 13. The second arm 21 whose base end is pivotally attached to the protruding end of the first arm 11
Servomotor 2 as a second drive source connected to the lower end of the motor through a timing belt type fourth winding mechanism 24
2 is rotated. The first arm 11 connects the upper and lower plates 11a and 11b to a housing 11c with a flange,
The second shaft 20 is connected to the second arm 21 via the first winding mechanism 23. The intermediate shaft 11d and the pivot shaft 11e are connected to each other. The first wrapping mechanism 23 includes a wrapping wheel 23a concentrically integrated with the rotation center of the second arm 21 and a wrapping wheel 23b having the same diameter as the wrapping wheel 23a and fixed to the upper end of the second shaft 20. And timing belt 23
c so as not to be affected by the horizontal rotation of the first arm 11. A ball spline nut 40 is rotatably held at the projecting end of the second arm 21, and a hollow ball spline shaft 41 is inserted through the ball spline nut 40. The output rotation of a third servomotor 42 as a third drive source provided on the first arm 11 is transmitted to the ball spline nut 40 via a second winding mechanism 43. The second winding mechanism 43 includes:
Wrap wheel 4 fixed to the output shaft end of third servo motor 42
A timing belt 43c is wound around the wheel 3b and the wheel 43b fixed to the intermediate shaft 11d, and a wheel 43d and a pivot shaft 11e fixed to the intermediate shaft 11d coaxially and integrally with the wheel 43b. A timing belt 43f is wound around a winding wheel 43e fixedly mounted on the vehicle, and a winding wheel 43e is further wound around the pivot 11e.
The timing belt 43j is wound around a winding wheel 43g fixedly provided coaxially with the winding wheel 43h fitted and fixed to the ball spline nut 40. Since the winding wheels 43g and 43h have the same diameter, they are not affected by the horizontal rotation of the second arm 21. The second arm 21 has a rod 55 fitted in a bush 59 provided at a position close to the ball spline shaft 41.
Are supported so that they can move up and down.
The upper and lower portions of 1 are pivotally supported by a pair of holding plates 54, 54 fixed to the upper and lower ends of a rod 55. A flexible tube 50 extends from the inside of the gantry 30 to the second arm 21 in an arch shape through the inside of the second shaft 20. The flexible tube 50 is pivotally attached to the gantry 30 by a tube holder 57 attached to the base end thereof, and is also pivotally attached to the second arm 21 by a tube holder 56 attached to the distal end. The core wire 51 movably passed through the flexible tube 50 has a reel 5 whose base end is attached to the gantry 30.
2 and a pivotal attachment 58 attached to the tip thereof is pivotally attached to the lower holding plate 54. A fourth servomotor 53 as a fourth drive source is provided to rotationally drive the reel 52. Ball spline shaft 4
A rotating pipe joint 62 is attached to an upper end of the hose 1, and a tip of a hose 61 is connected to the rotating pipe joint 62. The base end of the hose 61 is connected to a negative pressure generator (for example, a suction side of a blower) outside via a control valve 60 provided in the gantry 30, and is provided at a lower end of the ball spline shaft 41. A suction pad (not shown) as a working tool is attached to the flange 44. In order to prevent foreign matter such as dust from entering, the projecting ends of the first arm 11 and the second arm 21
0,82. A reinforcement bracket 81 that holds the second arm 21 is provided at the projecting portion of the first arm 11.

Next, the operation of the first embodiment of the present invention will be described. The first arm 11 is horizontally rotatable around the first shaft 10 by the output rotation of the first servomotor 12.
The second arm 21 is driven by the second servo motor 22, through the second shaft 20 and the first winding mechanism 23 in order,
A pivot shaft 11e provided at the projecting end of the first arm 11
Can be horizontally rotated around the center of rotation. Second arm 21
The ball spline shaft 41 provided at the projecting end of
Rotational force is transmitted from the third servomotor 42 to the ball spline nut 40 via the second winding mechanism 43, whereby the ball spline nut 40 turns around its own axis. The ball spline shaft 41 is moved by a fourth servo motor 53 to a reel 52.
To take up or unwind the core 51,
Is moved in the flexible tube 50 so that the holding plate 5
It moves up and down together with 4. Flexible tube 50 and core wire 51
Are arranged inside the second shaft 20, the diameter of the vertical axis can be made as small as possible. When the control valve 60 at the base end of the hose 61 is opened, the negative pressure of a negative pressure generator (not shown) is transmitted into the ball spline shaft 41 through the hose 61 and the flange 4 provided at the lower end of the ball spline shaft 41
The work can be sucked and held by sucking air from the suction pad attached to the work 4. The proximal end and the distal end of the flexible tube 50 are pivotally attached to the gantry 30 or the second arm 21, respectively, the distal end of the core wire 51 is pivotally attached to the holding plate 54, and the distal end of the hose 61 is connected to the ball spline shaft 41. The first arm 11 and the second arm 21
Even when any one or both of them rotate, the flexible tube 50, the core wire 51, and the hose 61 are not twisted.

FIGS. 3 and 4 are longitudinal sectional views of a main part of a second embodiment of the horizontal scalar robot according to the present invention.
In this horizontal scalar robot, only the differences from the horizontal scalar robot of the first embodiment will be described, and the description of the common components will be omitted by attaching the same reference numerals. A rotating sleeve 74 is attached to the upper end of the ball spline shaft 41. The rotating sleeve 74 is connected to the tip of a flexible tube for tool 70 that extends in an arch from the gantry 30 through the second shaft 20. I have. A tool core wire 71 is movably provided in the tool flexible tube 70, and the base end of the tool core wire 71 is wound around a tool reel 72 attached to the gantry 30. Is connected to a robot tool (not shown) mounted on the lower end of the ball spline shaft 41 through the inside of the rotary sleeve 74. A tube holder 75 attached to the proximal end of the flexible tube for tool 70 is pivotally attached to the gantry 30. In the gantry 30, a fifth servomotor 73 is provided as a tool driving source for rotating and driving the tool reel 72.
By rotating the tool reel 72 by the fifth servomotor 73 and winding or unwinding the tool core wire 71, the tool core wire 71 is turned into the tool flexible tube 7.
Then, the robot tool is moved inside 0 and the robot tool mounted on the lower end of the ball spline shaft 41 is operated to grasp or release the workpiece.

FIG. 5 is a vertical sectional view showing a main part of a third embodiment of the horizontal scalar robot according to the present invention. In this horizontal scalar robot, only the differences from the horizontal scalar robot of the first embodiment will be described, and the description of the common components will be omitted by attaching the same reference numerals.
In the third embodiment, as compared with the first embodiment, a third servomotor 42 for rotating and driving the ball spline nut 40 together with the ball spline shaft 41 is disposed on the gantry 30, and the rotation of the third servomotor 42 is performed. The difference is that a third axis is used as the vertical axis for transmitting the drive via the second winding mechanism 43. That is, the hollow first shaft 10
And a hollow second shaft 20 passed through the first shaft 10 and a hollow third shaft 44 passed through the second shaft 20 in the housing portion 30a on the upper part of the gantry 30 such that the vertical axis is obtained. It is pivoted. The lower end of the third shaft 44 is connected to a third servomotor 42 as a third drive source.
Reference numeral 1 denotes a ball spline nut 40 via a third shaft 44 and a second winding mechanism 43 by a third servomotor 42.
Is driven to rotate. Second winding mechanism 43
Is a winding wheel fixed to the upper end of the third shaft 44 and the pivot shaft 11
e, the timing belt is wound around the winding wheel fitted to e, and is fitted and fixed to another winding wheel integral with the winding wheel fitted to the pivot 11e and the ball spline nut 40. The timing belt is wound around the vehicle. The flexible tube 50 has its proximal end pivotally attached to the gantry 30, passes through the third shaft 44 from inside the gantry 30, extends in an arch shape, and has its distal end pivotally attached to the second arm 21. The air suction hose 61 passes through the third shaft 44 from the gantry 30 and then extends in an arch shape. The handling action is the same as that of the first embodiment.

FIG. 6 is a vertical sectional view showing a main part of a horizontal scalar robot according to a fourth embodiment of the present invention. In this horizontal scalar robot, only the differences from the horizontal scalar robot of the third embodiment will be described, and the description of the common components will be omitted by attaching the same reference numerals. The flexible tube for tool 70 has its base end pivotally attached to the gantry 30 and passes through the third shaft 44 from inside the gantry 30 and then extends in an arch shape, and its tip is attached to the upper end of the ball spline shaft 41. Connected to the rotating sleeve 74.
A tool core wire 71 movable in the tool flexible tube 70 has a base end wound around a tool reel 72 attached to the gantry 30, and a tip end provided with a rotating sleeve 7.
4 and is pivotally connected to a robot tool (not shown) mounted on the lower end of the ball spline shaft 41. The tool reel 72 is driven by a fifth servomotor 73 as a tool driving source. Accordingly, the robot tool rotates the tool reel 72 by driving the fifth servo motor 73 to perform the winding movement or the feeding movement of the tool core wire 71 to move the tool core wire 71 into the tool flexible tube 70. By moving, the workpiece can be disturbed and released. The handling action is the same as in the second embodiment.

[0019]

According to the horizontal scalar robot of the present invention, since the servomotor and the air cylinder device are not provided at the tip of the second arm, the weight of the second arm can be extremely reduced, and the first arm and The second arms can each be driven at high speed by a servomotor having a small torque. In particular, since the ball spline shaft can be moved up and down and positioned at multiple points vertically with a lightweight and simple configuration consisting of a flexible tube and a core wire, the work tool can be adapted to works located at various heights. As a result, the height positioning function is improved, and the manufacturing cost can be reduced. Also,
Since the output from a drive source such as a servomotor provided on the gantry is controlled through the wrapping mechanism, the amount of rotation of each arm and the work tool is controlled. The plane position and the rotation posture are accurately determined, and accurate robot work can be performed on the position of the work. The control of the lifting position of the work tool does not use a drive source such as a servomotor or air cylinder, but also a wrapping mechanism that causes an increase in the weight of the arm. Instead, a flexible tube and a core wire that moves inside the tube are used. Thus, the structure can be made simple and lightweight, so that the cross-sectional shape and wall thickness of each arm can be reduced to further simplify the structure and reduce the weight of the horizontal scalar robot.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a horizontal scalar robot according to a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of a distal end of a second arm in FIG. 1;

FIG. 3 is a vertical sectional view of a main part of a horizontal scalar robot according to a second embodiment of the present invention.

FIG. 4 is an enlarged vertical sectional view of an essential part of a distal end portion of a second arm in FIG. 3;

FIG. 5 is a longitudinal sectional view of a main part of a horizontal scalar robot according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a main part of a horizontal scalar robot according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 1st axis 11 1st arm 12 1st servomotor 20 1st axis 21 2nd arm 22 2nd servomotor 23 1st winding mechanism 30 mount 40 ball spline nut 41 ball spline shaft 42 3rd servomotor 43 2nd Wrapping mechanism 50 Flexible tube 51 Core wire 52 Reel 53 Fourth servo motor 54 Holding plate 60 Control valve 61 Hose 70 Flexible tube for tool 71 Core wire for tool 72 Reel for tool 73 Fifth servo motor (drive source for tool) ) 74 rotating sleeve

Continuation of front page (56) References JP-A-61-38883 (JP, A) JP-A-1-316184 (JP, A) JP-A-63-77682 (JP, A) JP-A-63-77675 (JP) , A) JP-A-63-272490 (JP, A) JP-A-1-228792 (JP, A) JP-A-58-881 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B25J 9/06 B25J 17/02

Claims (4)

(57) [Claims] 1. A hollow first shaft pivotally supported by a gantry, a first drive source connected to a lower end of the first shaft, and a longitudinal axis formed with the first shaft through the first shaft. A second shaft, a second drive source connected to the lower end of the second shaft, a horizontally rotatable first base fixed to the upper end of the first shaft, and driven by the first drive source. An arm, a base end of which is pivotally attached to a projecting end of the first arm, and driven by the second drive source via the second shaft and a first winding mechanism provided on the first arm. Horizontally rotatable second arm,
A hollow ball spline shaft vertically slidably inserted and supported by a ball spline nut pivotally attached to a projecting end of the second arm; a second winding provided between the first arm and the second arm; A third drive source for rotatingly driving the ball spline nut together with the ball spline shaft via a hook mechanism, extending from a base end pivotally attached to the gantry, and having a distal end pivotally attached to the second arm; A flexible tube, a core wire whose base end is wound around a reel provided on the gantry, extends inside the flexible tube, and has a distal end linked to the ball spline shaft; The reel is rotated to move the work tool attached to the lower end of the ball spline shaft up and down by moving the core wire to the flexible tube. Horizontal scalar robot consisting of fourth driving source for moving the inner. 2. The third drive source is a servomotor provided on the first arm, or a third drive source that is passed through the second axis and forms a vertical axis together with the first axis and the second axis. The horizontal scalar robot according to claim 1, wherein the horizontal scalar robot is a servomotor connected to lower ends of three axes. 3. The work tool has a base end connected to a negative pressure generator provided on the pedestal via a control valve, extends from the base end, and has a front end at an upper end of the ball spline shaft. 3. A suction pad which is connected to a hose which is connected in communication and is capable of sucking the work through the ball spline shaft.
The horizontal scalar robot according to 1. 4. The inside of the ball spline shaft and a flexible tube for a tool extending from a base end pivotally attached to the gantry and having a tip connected to an upper end of the ball spline shaft. Is a robot tool pivotally connected to the tip of a tool core wire extending continuously.In order to move the tool core wire in the tool flexible tube, the base end of the tool core wire is connected to the mount. 3. The horizontal scalar robot according to claim 1, wherein the horizontal scalar robot is provided and wound around a tool reel that is rotationally driven by a tool drive source.