JPH0340554Y2 - - Google Patents

Description

[Detailed description of the invention] -Field of industrial application- This invention relates to an industrial robot equipped with a hydraulic hand at the tip of an arm mechanism extending from the robot body. This invention relates to an improvement in the fluid passage leading to the hand.

-Prior Art- Today, industrial robots equipped with an arm mechanism and a hydraulic hand are widely used mainly in the manufacturing industry. The arm mechanism has one or more arms connected to the robot body, and a wrist member is connected to the tip of the arm mechanism, and this wrist member is operated by a hydraulic hand, that is, by fluid pressure such as hydraulic pressure or air pressure It is normal to hold the hand that is played.

In this type of industrial robot, an auxiliary link is added that forms a parallel link mechanism with the arm in order to keep the wrist member parallel to the reference plane no matter how the arm mechanism rotates in one plane. There is something I did. This is often aimed at, for example, making it easier to control the hand by having the hand perform work while keeping the wrist member in a horizontal state.

Conventionally, in robots equipped with this type of arm mechanism and auxiliary link, in order to guide fluid pressure (for example, hydraulic pressure) from the robot body to the hand, a steel pipe was passed inside the arm for an oil passage, and a flexible pipe was used at the joint. Either hydraulic hoses were used, or all piping from the robot body to the hand was done using hydraulic hoses.

-Problems that the invention attempts to solve- However, in piping that connects steel pipes by passing a steel pipe inside the arm and installing a hydraulic hose at the joint, the space at the joint, that is, the space at the joint (the protrusion of the hydraulic hose) ) becomes considerably large. This is not so much of a problem in the case of large robots, but in the case of small robots, the ratio of the piping space in the joint increases, causing a problem that impairs the balance in appearance. Furthermore, not only is it troublesome to install piping inside the arm, but if the inside of the arm is used as a space for a power transmission path, etc., the piping must be installed in a place where there is not enough room, making piping work difficult. and increase design difficulties.

On the other hand, piping that uses hydraulic hoses for everything from the robot body to the hand has the disadvantage that it is not easy to route the hydraulic hoses, the hydraulic hoses tend to interfere with other parts when working on the robot, and the appearance is poor. It also becomes complicated.

Incidentally, when the hand is operated by pneumatic pressure, the same applies to the piping that guides the compressed air.

-Means for solving the problems- The present invention was developed under these circumstances, and its features include the robot body, arm mechanism, wrist member, hand, and auxiliary robot as described above. In industrial robots including links,
A fluid passage for guiding the fluid pressure for operating the hand from the robot body to the hand is formed inside the auxiliary link, and the fluid passages of each auxiliary link are connected to each other by a rotary pipe joint.

- Actions and Effects - As described above, by using the auxiliary link, even if the inside of the arm is used as a space for other purposes (for example, a power transmission path), there will be no restrictions thereon. Moreover, by using a rotary pipe joint, the appearance of the joint part is simpler than when a hydraulic hose is used as a joint. Moreover,
The joint portion can be configured more compactly than when a fluid passage is formed inside the arm and a rotary pipe joint is provided therein. In other words, arms receive bending moments due to work loads and their own weight, so they need to be thick enough to withstand them, whereas auxiliary links only receive simple tensile or compressive loads, so they are not as thick as arms. It's fine if it's thin. Therefore, if a rotary pipe joint is installed at the joint of a thick arm, that part will become even thicker, but if a rotary joint is installed at the joint of an auxiliary link, the part that is already thin will become thicker. It is also normal for the arm to be thinner than the arm,
Even if it becomes thicker than the arm, the amount is small, and the arm mechanism as a whole can be made smaller.

-Example- Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows the entirety of an industrial robot which is an embodiment of the present invention. This robot is 2
A movable base 4 is provided which is movable in the horizontal direction guided by book guide rails 2 and 3, and a rotating table 6 is held on this movable base 4 so as to be pivotable around a vertical axis. the first arm 10, and this arm 10
The second arms 12 are connected to each other to form an arm mechanism that is relatively rotatable in a vertical plane, and these arms 10 and 12 are two elements that are driven independently of each other. A block-shaped wrist member 14 is connected to the tip of the arm 12 so as to be relatively rotatable in a vertical plane, and two hands 16 in the form of a three-claw chuck are attached to the tip of the wrist member 14 back to back. 14 and is rotatably held about the centerline of wrist member 14 . 2 hands 16
One is for gripping an unprocessed workpiece, and the other is for gripping a machined workpiece. By running this robot along guide rails 2 and 3, the unprocessed workpiece is supplied to the machine tool. , ejecting the machined workpiece from the machine tool,
It transfers unprocessed workpieces and processed workpieces to and from neighboring robots.

The movable base 4 is provided with rollers 18 and balls 20 that roll on guide rails 2 and 3,
Although not shown, a servo motor for traveling is installed, and a pinion fixed to the motor shaft is engaged with a rack 22 arranged parallel to the guide rail 3. The movable base 4 has a box shape with a circular opening on the lower side, and a table main body 24, which is the upper half of the rotating table 6, is housed inside the movable base 4. A pivot shaft 26 extending upward is fixed to the table body 24, and is rotatably held by the movable base 4, and a pivot motor that is hydraulically operated is attached to the movable base 4 in a position parallel to the pivot shaft 26. 28 are provided. Two plate cams 30 are fixed alternately to the shaft of this motor 28, while a turret 34 holding a plurality of follower rollers 32 in two rows is fixed to the rotation shaft 26, and the combination of these A parallel cam mechanism 36 is constructed. The two plate cams 30 mesh with the follower roller 32 like a kind of gear, and intermittently rotate (swivel) the pivot shaft 26 and the entire pivot table 6, arm mechanism, etc. in 90 degree increments within a 180 degree range. It is. The rotation of the swivel table 6 is guided by a bearing 40 provided between a flange 38 formed on the table body 24 and the lower end opening of the movable base 4, and the index position of the swivel table 6 is movable. It is precisely defined by a positioning cylinder 41 provided on the base 4.

As is clear from FIG. 2, a pair of legs 42 extend downward in parallel from the bottom of the table body 24, and between these legs 42 is the arm 10 having a box-shaped cross section. It is incorporated and supported so as to be rotatable around one axis. Returning to FIG. 1, the tip of this arm 10 is formed into a yoke shape, and the arm 12, which is split into two, is connected to the inside thereof, and the axis is the same as the rotation axis of the connecting portion of both. around the bracket link 4
4 is supported so as to be rotatable relative to both arms 10 and 12. The bracket link 44 as a whole has a substantially right-angled triangular shape, and each right-angled portion thereof is incorporated between the bifurcated arm 12, and each remaining portion and the rotating table leg portion 42 are connected to the rod link 46.
The other parts and the wrist member 14 are connected by a rod link 48. The rod link 46 has both ends rotatable relative to both the bracket link 44 and the swing table leg 42, and is parallel to the arm 10, and is a parallel link with the arm 10, the swing table leg 42, and the bracket link 44. It constitutes a mechanism. The rod link 48 also has both ends rotatable relative to both the bracket link 44 and the wrist member 14 and is parallel to the arm 12, forming a parallel link mechanism together with the arm 12, the bracket link 44, and the wrist member 14. are doing. Therefore, no matter how much the arm 10 rotates, the attitude of the bracket link 44 with respect to the horizontal plane does not change, and no matter how much the arm 12 rotates, the attitude of the wrist member 14 with respect to the bracket link 44 does not change. Further, since the connecting axis of the bracket link 44 to the arms 10 and 12 and the connecting axis to the rod link 48 are located in one horizontal plane, the wrist member 14 is always held horizontally no matter how the arm mechanism rotates. In other words, it is kept parallel to the horizontal plane serving as the reference plane. A bracket link 44 and rod links 46 and 48 added to form two sets of parallel link mechanisms function as auxiliary links.

The arm 10 is driven by a first motor 50, which is a servo motor, and the arm 12 is similarly driven by a second motor 52. These motors 50, 52
is incorporated inside the table body 24.
The table body 24 is in the form of a box-shaped structure, and has a space for incorporating both motors 50 and 52, and a motor mounting portion. As is clear from FIG. 3, the motors 50 and 52 are
The motors 50 and 52 are mounted in parallel across the rotation axis O of the rotation table 6, that is, so that the motor axes of the motors 50 and 52 are parallel to each other with a certain distance apart, and these motor axes are mounted in a plane perpendicular to the rotation axis O. (in this case in the horizontal plane) and are arranged alternately. That is, the output shafts of the motors 50 and 52 are arranged opposite to each other, and a timing pulley 56 or 58 is fixed to each motor.
Both motor axes, which are the rotational axes of each timing pulley 56, 58, are not only parallel to each other, but also
It is perpendicular to the rotation plane of the arm mechanism.

The distance between the motors 50 and 52 is made as small as possible, and the motors 50 and 52 are arranged side by side with almost no separation between them. Therefore, the dimensions of each motor 50 and 52 from the farthest part from the rotation axis O are minimized, and even when these motors 50 and 52 are rotated together with the rotation table 6, the space required for the rotation is small. Become. This space is secured within the box-shaped wall of the movable base 4, that is, between this box-shaped wall and the table body 24, and the motors 50 and 52 are not visible from the outside. Although not shown, the cables for supplying power to these cables are routed inside from the top or wall of the movable base 4, and disappear from the vicinity of the arm mechanism.

As is clear from FIG. 4, a cyclo reducer 60 is attached to one leg 42 of the rotating table 6 from the outside concentrically with the rotation axis of the arm 10, and a timing pulley 64 is attached to the input shaft 62 of the cyclo reducer 60.
is fixed, and the arm 10 is fixed to the output shaft 66. As shown in FIG. 2, between the timing pulley 64 of this cyclo reducer 60 and the timing pulley 56 of the motor 50, there is a table main body
A timing belt 70 is passed through an opening 68 formed at the bottom of the arm 10, and the arm 10 is rotated upward or downward by driving the motor 50.

Further, a cyclo reducer 72 is attached to the other leg 42 of the turning table 6, facing the cyclo reducer 60, and as shown in FIG. A shaft 80 is fixed to each shaft 78 .
The shaft 80 is provided concentrically with the rotational axis of the arm 10 and is freely rotatable relative to the arm 10, and a lever link 82 is fixed to the shaft 80 by serrations. The lever link 82 has a torque link 8 as shown in FIG.
One end of the torque link 84 is connected to the arm 12 for relative rotation by a pin 86, and the other end of the torque link 84 is similarly connected to the arm 12 by a pin 88. Lever link 82 is parallel to arm 12, torque link 84 is parallel to arm 10, and these constitute a parallel link mechanism. And the timing pulley 76 of the cyclo reducer 72 shown in FIG.
A timing belt 92 is passed through an opening 90 formed in the bottom of the table body 24 and is stretched between the timing pulley 58 of the motor 52 (see FIG. 3). Therefore, by driving the motor 52, the arm 12 is rotated in the left-right direction via the timing belt 92, the cyclo reducer 72, the shaft 80, the lever link 82, and the torque link 84, and the arm 10 is rotated in the vertical direction. The position of the hand 16 is appropriately set by the combination of the above.

A rotor 94 for rotating the hand that rotates the entire hand 16 with respect to the wrist member 14 is attached to the arm 10.
It is provided at the rear end of the. This motor 94 is an electric motor with a built-in reduction gear train, and a sprocket 96 is fixed to its output shaft, and a chain 98 is wound around this. chain 9
8 passes through the inside of the arm 10 which has a box-shaped cross section, but since a reinforcing plate portion 100 (see FIG. 4) is provided inside the arm 10 at right angles to the longitudinal direction or at an angle, the chain 98 passes through a notch 102 formed therein and is wrapped around a sprocket 104 located at the other end of the arm 10. A chain guide 10 is installed in the middle of the arm 10.
6 is fixed to prevent the chain 98 from hanging down. The sprocket 104 is fixed to a shaft 108 that is concentric with the rotation axes of the arms 10 and 12. This shaft 108 is rotatably supported by the arm 12 and also serves as the rotation axis of the bracket link 44. A sprocket 110 is also fixed on the opposite side of the sprocket 104 with the sprocket 44 in between. A chain 114 is stretched through the inside of the arm 12 between this sprocket 110 and a sprocket 112 (see FIG. 1) provided at a lower portion of the arm 12, and a chain 114 is stretched between the sprocket 110 and a sprocket 112 (see FIG. 1) provided at a lower portion of the arm 12. is chain 11
Idle sprocket 116 that adjusts the tension of 4
and 118 are provided. Sprocket 1
On the back side of arm 12, another sprocket 120 is provided concentrically as shown in FIG.
2 and the wrist member 14.
22 is provided to be rotatable relative to both shafts 122, and a sprocket 124 is also fixed to this shaft 122. Both sprockets 120 and 12
A chain 126 is stretched between the shaft 122 and the shaft 122, and the rotational driving force of the motor 94 is guided to the shaft 122.

As shown in FIG. 5, the wrist member 14 has a horizontal axis 128 that intersects this axis 122 at right angles.
is held rotatably, and the hand 16 is attached to the shaft 1.
The hand main body 132 is fixed to a flange 130 formed at the tip of the hand 28 . and,
A cam 134 having a plurality of spiral ribs is fixed to the shaft 122, while a turret 138 having a plurality of rollers 136 radially implanted on the outer peripheral surface thereof is fixed to the shaft 128, and these actuate the roller gear cam mechanism 140. 90 by driving the motor 94.
The hand 16 is intermittently rotated at an index angle of 50 degrees.

As shown in FIG. 1, three guide grooves 142 are formed radially on one side of the hand body 132.
Claw members 144 are each held movably in that direction. Although not shown in this figure, the following
As disclosed in FIGS. 6 and 7 of Japanese Unexamined Patent Publication No. 60-117039, on the back side there are cam portions (for example, A rotating body with a cam groove (cam groove) is provided concentrically, and each cam portion is formed so that the distance from the center of rotation gradually increases as the rotating body rotates in one direction.
44 opens and closes by rotating in the opposite direction, that is, hand 1
6 opens and closes. The claw member 144 grips the outer peripheral surface of the workpiece when it is closed, but it is also possible to hold the workpiece from the inside when it is opened. The rotating body has teeth on its outer circumferential surface and also serves as a pinion, and the rack piston of the rack cylinder engages with this pinion. Both ends of the rack pin are fitted into the cylinder bores, and hydraulic pressure is supplied to one end to close the hand 16. A hydraulic chamber is formed at the other end to which hydraulic pressure for opening the hand 16 is supplied. By selectively supplying pressurized oil to one of these hydraulic chambers, the rack piston is moved to rotate the rotating body by a predetermined angle, and the above-mentioned cam action causes the hand 16 to perform opening and closing operations. Since there are two hands 16 in such a rack cylinder, two corresponding to the number of hands 16 are provided, and thus a total of four hydraulic circuits, two systems each, are required.

Four systems of mutually independent hydraulic pressure for operating these two rack cylinders are supplied from a manifold 146 provided on the movable base 4 to the swivel table 6, the rod link 46, the bracket link 44, the rod link 48, and the wrist member 14.
The liquid is guided to each hand 16 via the same route, and is discharged along a similar route.

First, four oil passages (not shown) extend from a manifold 146 equipped with an appropriate number of electromagnetic switching valves 146 toward the upper end of the pivot shaft 26, and are formed in the pivot shaft 26 via a rotary pipe joint 150. The four longitudinal oil passages communicate with each other. These oil passages extend downward within the pivot shaft 26, and when they reach the upper part of the table body 24, they are split into two parts, each running along two opposing vertical walls of the table body 24, and further rotate. two extending inside each of the table legs 42;
and a connecting portion with the rod link 46.

As shown in FIG. 7, on the inner surface of each leg 42 in this connecting portion, there are boss portions 15 facing each other.
2 are formed and the oil passages 1 are divided into two.
54 are guided to respective boss portions 152.
Hereinafter, in order to make it easier to understand, the four systems will be distinguished by adding the symbols a, b, c, and d after the numbers representing the oil passages, and the oil passages marked with a or c will be Hydraulic pressure for closing the hand 16 is introduced, and oil passages marked with b or d are for introducing oil pressure for opening the hand 16. The rod link 46, whose one end is rotatably supported by the two bosses 152, is shown as a single piece in FIGS. 8, 9, and 10.

As is clear from these figures, the rod link 46 includes a longitudinal link body 156 having a rectangular cross-sectional shape, and a protruding portion having a circular cross-section extending from one end (left end) of the link body 156 in a direction perpendicular to the longitudinal direction. are symmetrically and integrally formed into a T-shape. Of this protruding part, the inner part adjacent to the link body 156 is the bearing part 158, and the part protruding outward from this part is the rotary pipe joint part 160, and these are located symmetrically. . The opposite end of the link body 156 has exactly the same structure. Inside this rod link 46, there are four mutually independent oil passages 162a, 16.
2b, 162c, and 162d are formed. The oil passages 162a and 162c are connected to each rotary pipe joint part 16.
0 in the radial direction from the outer circumferential surface, and extend parallel to the axis of the pair, passing through the bearing portion 158 and reaching one end of the link body 156. Turn at a right angle here,
The two are lined up and extend to the other end of the link body 156, then split into two, and each opens into the outer circumferential surface of the rotary pipe joint part 160 through each of the bearing parts 158 on the other end side. On the other hand, inside the link body 156, the oil passages 162b and 162d are similar to the previous two and extend parallel to them.
are perforated not from the outer circumferential surface but from the end surface, extend back-to-back in a U-shape, and open into the end surface of each rotary pipe joint section 160 on the other end side. In addition,
Another rod link 48 also has the same structure as above.

One end of such a rod link 46 is connected to the seventh
As shown in the figure, the boss portion 1 of the rotating table leg portion 42
52 and is rotatably held in each of the bearing parts 158 by bearings 164 provided between the inner peripheral surface of each boss part 152. Further, each of the rotary pipe joint parts 160 is rotatably fitted into each boss part 152, leaving a space in the axial direction at a deeper part, and the space is used as an oil chamber 166b, 166d, respectively. , these oil chambers 166b, 166d constantly communicate the oil passages 154b, 154d of the rotating table leg 42 with the oil passages 162b, 162d of the rod link 46, respectively. Further, annular oil grooves 168a and 168c are formed on the inner circumferential surface of the boss portion 152 that fits into each rotary pipe joint portion 160, and these oil grooves 168a and 168
c is oil passage 154a, 154c and oil passage 162
a and 162c are in constant communication with each other.
That is, the rotary pipe joint 170 is configured here.

The other end of the rod link 46 is connected to the bracket link 44, and within the bracket link 44 there are four oil passages 172a, 172 which are independent of each other as shown in FIGS. 11 and 12.
b, 172c, and 172d are formed so as to linearly connect the ends of the rod links 46 and 48. A rotary pipe joint 174 is provided at the connecting portion between the bracket link 44 and the rod link 46, and its configuration is the same as described above.
That is, as shown in FIG.
6 bearing part 158 and rotary pipe joint part 160
is incorporated into the bracket link 44 having a two-part structure, and is rotatably held by a bearing 176, and is connected to the oil passages 162a, 162c of the rod link 46 via oil grooves 178a, 178c.
and the oil passages 172a, 17 of the bracket link 44.
2c are communicated with each other, and the oil chambers 180b, 1
Similarly, oil passages 162b and 162d are connected via 80d.
and the oil passages 172b and 172d are communicated with each other.

The same rotary joint 182 is also provided at the connection between the bracket link 44 and the link rod 48, and the four oil passages 172 of the bracket link 44
The four oil passages 184a to 184d formed in the link rod 48 are communicated with each other. Further, as shown in FIG. 13, a rotary pipe joint 186 is also provided at the connection portion between the link rod 48 and the wrist member 14, and an oil groove 188a,
Oil passages 190a and 190c are connected to oil passages 190a and 190c from 188c, and oil passage 1 is connected to oil chambers 192b and 192d thereof.
90b and 190d each extend toward the rotationally fitting portion between the shaft 128 of the hand 16 and the wrist member 14.

As is clear from FIG. 5, a circular shaft accommodating hole 194 is formed in the wrist member 14 from the hand 16 side, and a sleeve 195 is oil-tightly fitted and fixed in this shaft accommodating hole 194. 128 is fitted in this sleeve 195 in an oil-tight manner and is rotatable by bearings 196 and 198 on both sides. Four annular oil grooves 200a, 200b, 200 are provided on the outer peripheral surface of the sleeve 195.
c, 200d are formed, and a rotary shaft joint 1 is attached to these.
The four oil passages 190a to 190d extending from 86 are in communication with each other. The inner peripheral surface of the sleeve 195 has annular oil grooves 202a, 202b, 202c, and 202d at positions corresponding to those oil grooves.
are formed, and corresponding inner and outer oil grooves are communicated with each other through communication holes (not shown). Additionally, within the shaft 128, there are four oil passages 204a, 204b, 204c, and 204 each consisting of an axial hole parallel to the axial direction and a radial hole perpendicular to the axial hole.
d are formed, and these radial holes communicate with the oil grooves 202a to 202d, respectively, thereby forming a rotary pipe joint 206, while the axial holes communicate with the rack cylinder of the hand 16. There is. That is, the oil passages 204a and 204b communicate with each hydraulic chamber of one rack cylinder, and the oil passages 204c and 204d communicate with each hydraulic chamber of the other rack cylinder. Hydraulic oil for opening and closing the hand is supplied to each rack cylinder from 146.

In this way, the four hydraulic paths are linked to the four
Rotary pipe joints 160, 17 are formed inside the bracket links 44, 6, 48, etc., and are provided at the joints.
Since 0,174,182, etc. are used, hydraulic hoses for piping and joints are not required. In addition, these rotary joints protrude laterally, but since they are incorporated into the thin rod links 46, 48 and the bracket link 44, which are auxiliary links, as is clear from FIG. is also smaller than the width of the arms 10 and 12.

In addition, in the embodiment described above, the hand 16 is 2
However, if there is one, two hydraulic circuits may be formed, and if air pressure is used, the oil passage may be replaced with an air passage.

On the other hand, as for the two motors 50 and 52, they may be arranged to be slightly shifted in the axial direction.
It may be located not in a plane perpendicular to the axis of rotation, but in a plane slightly inclined. Although arranging the motors 50 and 52 in parallel contributes to space savings, it is not essential and they can also be arranged in series.

Although specific explanations are omitted, it goes without saying that there are various other embodiments based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing the entirety of an industrial robot which is an embodiment of the present invention. FIG. 2 is a left side view (partially sectional) thereof, and FIG. 3 is a plan view showing an enlarged part thereof. FIG. 4 is a cross-sectional view taken from FIG. 1, and FIG. 5 is an enlarged cross-sectional view showing a part of FIG. 1. FIG. 6 is a rear view of FIG. 5, and FIG. 7 is a cross-sectional view taken from FIG. 8 is a front view of the rod link shown in FIG. 1, FIG. 9 is a plan view thereof, and FIG. 10 is a left side view thereof. FIG. 11 is an enlarged view showing the vicinity of the bracket link in FIG. 1, and FIG. 12 is a sectional view thereof. FIG. 13 is a cross-sectional view of FIG. 5. 6... Turning table, 10... First arm,
12...Second arm, 14...Wrist member, 16
... Hand, 26 ... Rotating axis, 36 ... Parallel cam mechanism, 44 ... Bracket link, 46,4
8... Rod link, 50... First motor, 5
2... Second motor, 70, 92... Timing belt, 82... Lever link, 84... Torque link, 140... Roller gear cam mechanism, 15
0,170,174,182,186,206...
...Rotary pipe joint, 158...Beared part, 160...
Rotary pipe joint part, 154, 162, 172, 18
4,190,204...Oil passage, 166,18
0,192...Oil chamber, 168,178,188,
200, 202...oil groove.

Claims (1)

[Claims for Utility Model Registration] An arm mechanism that includes one or more arms and is connected to a robot body; a wrist member that holds a hand operated by fluid pressure and is connected to the tip of the arm mechanism; an auxiliary link that forms a parallel link mechanism together with the arm and keeps the wrist member parallel to a reference plane no matter how the arm mechanism rotates in one plane; An industrial robot, characterized in that a fluid passage for guiding fluid pressure from the robot body to the hand is formed inside the auxiliary link, and the fluid passages of each auxiliary link are connected to each other by a rotary pipe joint. .