JP6944008B1 - Working robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and energy-saving work robot capable of covering a wide work range with a small number of axes and performing work with a small output motor. SOLUTION: The work robot includes a support frame and one or a plurality of arms supported by the support frame, and each of the arms is a forearm swinging horizontally and a forearm thereof. An elbow that swings horizontally at the tip, a forearm that swings up and down supported by the elbow, and an end effector that rotates horizontally supported by the wrist supported by the tip of the forearm A parallel link consisting of a rear link fixed to the elbow, a front link fixed to the wrist, a connecting link arranged in parallel with the forearm, and a forearm, which are formed between the elbow and the wrist. It is placed between the mechanism and the tip of the rear link and the base of the front link, or between the base of the rear link and the tip of the front link, and the front link is always attached upward with respect to the rear link. It has a spring and a force. [Selection diagram] Fig. 1

Description

The present invention relates to an inexpensive and energy-saving work robot that covers a wide work range with a small number of axes and enables work with a small output motor.

Various types of work robots have been conventionally known. For example, in the work robot described in Non-Patent Document 1, the intermediate portion of the arm is moved horizontally by a shoulder portion that is rotated around the vertical axis by a swivel motor. A parallel link mechanism that supports the robot so that it can be moved and drives it forward and backward with a motor, and has an upper link and a lower link that are parallel to each other, and moves the hand as an end effector up and down in a horizontal position. It is supported as much as possible, and the base of the upper link of the parallel link mechanism is swung around the horizontal axis by a motor provided on the wrist so that the hand can be moved up and down.

Further, in the work robot described in Patent Document 1, the base of the upper arm and the base of the lower link are coaxially arranged around the horizontal axis at the upper end of the body that is rotated around the vertical axis by a swivel motor, and each is rotated by the motor. Move the rear link so that it is positioned parallel to the upper arm, connect the base of the rear link to the tip of the lower link so that it can swing around the horizontal axis, and position the forearm parallel to the lower arm. The forearm is oscillatingly connected to the tip of the upper arm and the tip of the rear link, respectively, around the horizontal axis, and the upper arm and the rear link, and the lower link and the forearm form a parallel link mechanism. The extension from the base of the link is connected to the lower end of the torso via a spring, and the spring urges the rear link downward to compensate for the weight of the hand and wrist applied to the tip of the forearm. ing.

"Measurement and Control", Vol. 7, No. 12, "Artificial Hands Controlled by Logical Machines," published by the Society of Instrument and Control Engineers, December 1968.

Japanese Unexamined Patent Publication No. 07-227791

However, the work robot described in Non-Patent Document 1 has a parallel link mechanism provided on the wrist so that the hand can be moved up and down while keeping the hand horizontal by a simple configuration. The problem is that the shoulder configuration is complicated because it is necessary to move the arm forward and backward while supporting the weight of the hand, and a high-power motor is required to drive the weight of the hand and wrist. There is.

Further, in the work robot described in Patent Document 1, since the spring is arranged between the body and the rear link, even if the rear link maintains a constant angle such as horizontal and the length of the spring is constant. As the upper arm tilts forward, the arm of the moment due to the weight of the hand and wrist extends, and there is a problem that the weight cannot be sufficiently compensated by the spring.

The present invention has been made in view of the above problems, and is inexpensive and includes a parallel link mechanism and a spring to cover a wide working range with a small number of shafts and to perform work with a small output motor. The purpose is to provide energy-saving work robots.

The work robot of the present invention that advantageously solves the above problems
In a work robot having a support frame and one or more arms supported by the support frame.
Each of the one or more arms
A box-shaped closed cross-sectional upper arm whose base is supported by the support frame so as to be swingable around the first vertical axis.
An upper arm horizontal drive motor that is housed in the base of the upper arm and swings the upper arm horizontally around the first vertical axis.
An elbow that is supported by the tip of the upper arm so that it can swing around the second vertical axis.
An elbow horizontal drive motor provided at the tip of the upper arm and rotating the elbow horizontally around the second vertical axis.
A box-shaped closed cross-sectional forearm whose base is supported by the elbow so as to swing around the first horizontal axis.
A forearm vertical drive motor mounted on the elbow and swinging the forearm up and down around the first horizontal axis.
A wrist portion that is rotatably supported by the tip of the forearm around the second horizontal axis and rotatably supports the end effector mounting portion around the third vertical axis.
An end effector mounting part horizontal drive motor that rotates the end effector mounting part horizontally around a third vertical axis, and
A rear link whose base is fixed to the elbow and extends in the vertical direction,
A front link whose base is fixed to the wrist and extends in the vertical direction in parallel with the rear link.
The rear end is swingably connected to the rear link and the front end is swingably connected to the front link so as to extend parallel to the forearm, and the rear link, the front link, and the forearm. The connecting links that together form the parallel link mechanism,
The front link is always arranged with respect to the rear link by being arranged between the tip of the rear link and the base end of the front link or between the base end of the rear link and the tip of the front link. A spring that urges upward and
It is characterized by having.

In the working robot of the present invention, a box-shaped closed cross section in which one or a plurality of arms supported by a support frame each has a base supported by a support frame so as to be swingable around a first vertical axis. The shape of the upper arm was oscillated horizontally around the first vertical axis by an upper arm horizontal drive motor housed in the base of the upper arm, and was supported by the tip of the upper arm so as to be swingable around the second vertical axis. By rotating the elbow horizontally around the second vertical axis with an elbow horizontal drive motor provided at the tip of the upper arm, the base can be swung around the first horizontal axis on the elbow. A supported box-shaped closed-section forearm is swung horizontally with respect to the upper arm, and the forearm is swung up and down around the first horizontal axis by a forearm up-and-down drive motor mounted on the elbow. The end effector mounting portion rotatably supported around the third vertical axis on the wrist portion oscillatingly supported around the second horizontal axis at the tip is attached to the end effector mounting portion by the horizontal drive motor. The end effector mounted on the end effector is rotated horizontally around the vertical axis of the above, and the end effector is used to perform work on a work object.

Then, when the forearm is swung up and down by the forearm vertical drive motor, the rear link is fixed to the elbow and extends in the vertical direction, and the base is fixed to the wrist and is parallel to the rear link in the vertical direction. The extending front link and the connecting link that is swingably connected to the rear link at the rear end and swingably connected to the front end and extends parallel to the forearm are the elbow. Since a parallel link mechanism is formed between the wrist and the wrist, the forearm swings up and down while maintaining the parallelism of the front link with respect to the rear link and the parallelism of the connecting link with respect to the forearm, and the base of the front link is fixed. The wrist part and the end effector supported there via the end effector mounting part also move up and down in parallel with the rear link.

Therefore, according to the working robot of the present invention, the upper arm and the forearm are each lightweight with a highly rigid box-shaped closed cross section, and each motor is arranged near the base of the drive target to simplify the drive mechanism. Therefore, the load on each motor can be reduced, and the parallel link mechanism is provided between the elbow and the wrist, so even if you do not have a motor that drives the wrist around the horizontal axis, the forearm The wrist can maintain the horizontal position of the end effector while swinging up and down, and a spring is provided to always urge the front link of the parallel link mechanism upward with respect to the rear link, so that the upper arm The spring can always compensate for the weight of the forearm and wrist and the end effector regardless of the swing position, so it covers a wide working range with a small number of shafts and works with a small output motor. Therefore, it is possible to realize an inexpensive and energy-saving work robot configuration.

Further, the work robot of the present invention is characterized that you have includes a hand mounted as an end effector to the end effector mounting portion. Thus in to Rukoto, it is possible to perform the task of handling the work object with the hand.

Further, in the working robot of the present invention, the hand opens and closes by supporting the two gripping members so as to be separated from each other and moving close to each other, and driving the gripping members to move away from each other and moving close to each other. It is characterized by that. Thus in to Rukoto, the workpiece it is possible to easily perform the task of releasing gripped in the hand after moving to the predetermined position. The working robot of the present invention, the two gripping members, one by one respectively two gripping plates, characterized by hanging support only pivotable same direction to each other from beneath. Thus in to Rukoto can work object placed horizontally to grip in an inclined position.

In the working robot of the present invention, the one or a plurality of arms may be two arms supported by the support frame, and in this way, the two arms may be used. To improve work efficiency by performing the same work on two work objects in parallel, or to perform complicated work by jointly working on a common work object with two arms. be able to.

It is a perspective view which shows the working robot which concerns on one Embodiment of this invention in the state which was seen from the diagonally above on the front side. It is a schematic diagram which shows the operation of the parallel link mechanism of the work robot which concerns on the said embodiment. FIGS. (A) to (D) are explanatory views showing a procedure in which one arm of the work robot according to the above embodiment performs a work of moving a work object. (A) to (c) are explanatory views following FIG. 3 showing a procedure in which one arm of the work robot according to the above embodiment performs a work of moving a work object.

Hereinafter, an embodiment of the working robot of the present invention will be described in detail with reference to the drawings. Here, FIG. 1 is a perspective view showing a working robot according to an embodiment of the present invention as viewed from diagonally above on the front side, and FIG. 2 shows an operation of a parallel link mechanism of the working robot according to the above embodiment. It is a schematic diagram.

The working robot 1 of this embodiment is shown in FIGS. 3 and 4, which will be described later, for example, according to a program given in advance to the robot control device by a control signal from a normal robot control device including a computer or the like (not shown). As described above, the work object W such as a small box of sweets is picked up from the work table T and stored in the case C. As shown in FIG. 1, for example, a columnar support frame 2 and a columnar support frame 2 are used. A dual-arm robot is configured by including a right arm portion 3 and a left arm portion 4 as two arm portions supported on both sides of the support frame 2. Since the right arm portion 3 and the left arm portion 4 have the same configuration as each other except that they are symmetrical to each other, the right arm portion 3 will be described as a representative below.

The right arm portion 3 has an upper arm 5 whose base is supported by a support frame 2 so as to be swingable around the first vertical axis V1 and an upper arm 5 housed in the base of the upper arm 5 so that the upper arm 5 is around the first vertical axis V1. The upper arm horizontal drive motor 6 that swings horizontally, the elbow 7 that is supported by the tip of the upper arm 5 so that it can swing around the second vertical axis V2, and the elbow that is provided on the tip of the upper arm 5. An elbow horizontal drive motor 8 that rotates the portion 7 horizontally around the second vertical axis V2, a forearm 9 whose base is supported by the elbow 7 so as to be swingable around the first horizontal axis H1, and an elbow. The forearm up and down drive motor 10 mounted on the portion 7 and swings the forearm 9 up and down around the first horizontal axis H1 and is supported by the tip of the forearm 9 so as to swing around the second horizontal axis H2. It also includes a wrist portion 11 that rotatably supports the end effector mounting portion 11a around the third vertical axis V3.

The upper arm 5 and the forearm 9 may each have a box-shaped closed cross-sectional shape to ensure rigidity, and may accommodate wiring, a motor drive circuit board, or the like inside.

The right arm portion 3 also has a plate-shaped rear link 12 having a base fixed to the elbow portion 7 and extending in the vertical direction, and a plate-shaped rear link 12 having a base fixed to the wrist portion 11 and extending in the vertical direction in parallel with the rear link 12. The plate-shaped front link 13 and the rear link 12 are swingably connected to the rear end portion, and the front end portion is swingably connected to the front link 13 to swingably connect the forearm 9 and the rear link as shown in FIG. The rod-shaped connecting link 14 forming the parallel link mechanism 15 together with the front link 13 and the tension of the rod-shaped connecting link 14 stretched between the tip of the rear link 12 and the base end of the front link 13 in the illustrated example. The front link 13 is always urged upward with respect to the rear link 12, for example, a spring 16 made of a coil spring is provided.

The connecting link 14 is adjusted so that the rear link 12 and the front link 13 are parallel to each other by providing, for example, a female screw portion and a male screw portion screwed therein and adjusting the length like a turnbuckle. You may. Further, the spring 16 is stretched between the base end of the rear link 12 and the tip of the front link 13 instead of between the tip of the rear link 12 and the base end of the front link 13. May be good. Further, the spring 16 may be made of a gas spring.

The parallel link mechanism 15 shows the state of the forearm 9 before the descent / swing with a solid line and the state of the forearm 9 after the descent / swing with a alternate long and short dash line as shown by the arrow of the forearm 9. Regardless of the swing, the posture of the wrist portion 11 is maintained so as to keep the third vertical axis V3 in a vertical state. Then, the tension of the spring 16 stretched by the downward swing of the forearm 9 constantly urges the front link 13 upward with respect to the rear link 12, and at least the weights of the forearm 9, the wrist portion 11 and the hand 17 described later are compensated. , The load on the forearm vertical drive motor 10 due to their weight is reduced.

The right arm portion 3 further includes a hand 17 as an end effector mounted on the end effector mounting portion 11a of the wrist portion 11 that can rotate around the third vertical axis V3, and an end housed in the wrist portion 11. A hand horizontal drive motor 18 for horizontally rotating the hand 17 around the third vertical axis V3 is provided together with the effector mounting portion 11a, and the hand 17 includes two gripping members 19 as a plurality of gripping members. The grip member guide mechanism 20 that guides the separation and approach movement of the two grip members 19 in the predetermined horizontal axis direction, and the grip member guide mechanism 20 that drives the two grip members 19 in the horizontal axis direction to separate and approach each other. It has a hand opening / closing drive motor 21 that opens / closes the hand 17 by causing the hand 17 to open / close.

As shown in FIG. 1, each of the two gripping members 19 has an L-shaped bracket, a grip plate having a rectangular lower portion and a trapezoidal upper portion, and a grip plate penetrating the upper portion of the grip plate. The vertical arm portion of the L-shaped bracket has a hanging screw that swingably suspends and supports around a third horizontal axis H3 parallel to the predetermined horizontal axis direction, and each grip plate has a hanging screw. Is provided with a notch along its upper end. A non-slip pad may be provided on the surface of each grip plate.

Further, the gripping member guide mechanism 20 is a guide member (not shown) extending in the predetermined horizontal axis direction, and separately guides the movement of each of the two sliders (not shown) in the horizontal axis direction, and guides the movement of the two sliders in the horizontal axis direction. The slider fixes the horizontal arms of the L-shaped brackets of the two gripping members 19, respectively, and suspends and supports the two gripping plates of the two gripping members 19 so as to face each other.

The lateral arm portion of the L-shaped bracket of each of the gripping members 19 comes into contact with one end of the notch of the gripping plate in a state where each gripping plate is suspended directly below, and each gripping plate has a third horizontal axis. In a state where it swings around H3 at a predetermined angle and hangs, it abuts on the other end of the notch of the grip plate, and the two grip plates swing in the same direction with each other and hang directly below in one direction. It is regulated not to go beyond the state where it is swayed, and it is regulated not to go beyond the state where it swings by the same predetermined angle from directly below in other directions. Therefore, the lateral arm portion of the L-shaped bracket of each gripping member 19 functions as a swing stopper.

Further, the hand opening / closing drive motor 21 rotates and drives a cam member (not shown) around the fourth vertical axis V4 orthogonal to the extending direction of the guide member, and the cam member engages with each of the two sliders. The rotation drives the two sliders and moves the two sliders in directions of separation and approach from each other along the guide member. As a result, the two sliders move closer to each other and apart from each other by being driven by the hand horizontal drive motor 18, so that the work object is gripped between the grip members 19, and the work object is gripped between the grip members 19. Can be released.

3 (a) to 3 (d) are explanatory views showing a procedure in which one arm of the work robot according to the above embodiment performs a work of moving a work object, and FIGS. 4 (a) to 3 (d). 4 (c) is an explanatory view showing a procedure in which one arm of the work robot according to the above embodiment performs a work of moving a work object, following FIG.

When the work robot 1 of the above embodiment shown in FIG. 1 picks up the work object W from the work table T and stores it in the destination case C, first, as shown in FIG. 3 (a). In addition, the wrist portion 11 moves above the work object W due to the horizontal swing of the upper arm 5 and the horizontal swing of the forearm 9, and the two grip plates work by the horizontal rotation of the hand 17 by the wrist portion 11. It is located above both sides of the work object W so that the object W can be gripped.

Next, as shown in FIG. 3B, the wrist portion 11 moves closer to the work object W due to the downward swing of the forearm 9, and the two grip plates of the hand 17 are positioned on both sides of the work object W. Subsequently, two grip plates driven by the hand opening / closing drive motor 21 and moving close to each other grip the work object W from both sides thereof. At this time, the two grip plates grip the work object W at a position offset from the position of the center of gravity in the longitudinal direction (width direction) of the grip plates.

Next, as shown in FIG. 3C, the wrist portion 11 moves up and down while maintaining the swing axis of the hand 17 at the third vertical axis V3 due to the ascending and swinging of the forearm 9, and the hand 17 moves up and down while the hand 17 is the work object. Lift W from the table T. At this time, the work object W lifted by the hand 17 tilts around the third horizontal axis H3 due to the offset in the longitudinal direction of the grip plate from the position of the center of gravity of the work object W, and serves as the swing stopper. The posture is tilted at a predetermined angle regulated by the lateral arm of the L-shaped bracket.

Next, as shown in FIG. 3D, the wrist portion 11 moves the work object W above a predetermined position in the case C by the horizontal swing of the upper arm 5 and the horizontal swing of the forearm 9, and the wrist portion 11 The horizontal swing of the hand 17 is directed so that the work object W is aligned with the insertion space in the case C in a predetermined direction.

Next, as shown in FIG. 4A, the wrist portion 11 moves the work object W downward by the downward swing of the forearm 9, and the lower end of the work object W in the inclined posture is the case C. Place in the insertion space inside.

Next, as shown in FIG. 4B, the wrist portion 11 further moves the work object W downward due to the further downward swing of the forearm 9. At this time, even if there is not enough insertion space in the case C to which the work object W is moved, such as when the last one of the work objects W is inserted into the case C, the work object W is inserted. Is inclined so that an insertion space is secured from the work object W by applying a descending force in a wedge shape around the work object W, whereby the work object W is arranged horizontally without a gap in the insertion space in the case C. be able to.

After that, as shown in FIG. 4C, the two grip plates driven by the hand opening / closing drive motor 21 of the hand 17 and moved apart from each other release the work object W, and subsequently, the forearm 9 rises and swings. The wrist portion 11 moves upward due to the movement, and the work robot 1 returns to the state shown in FIG. 3A for the work on the next work object W.

Although FIGS. 3 and 4 have described the operation of the right arm portion 3, since the left arm portion 4 also has the same configuration as the right arm portion 3, the work object W is moved on the work table T by the same operation as the right arm portion 3. It is possible to carry out the work of picking up from the above and storing it in the insertion space in the case C.

Therefore, according to the work robot 1 of this embodiment, the same work can be performed on the two work objects W in parallel by the operation of the right arm portion 3 and the left arm portion 4, and the work efficiency can be improved. Instead, the right arm portion 3 and the left arm portion 4 can be co-operated to jointly work on a common work object W to carry out a complicated work.

Moreover, according to the work robot 1 of this embodiment, the posture of the wrist portion 11 and thus the hand 17 is maintained during the vertical swing of the forearm 9 without having a motor for driving the wrist portion 11 around the horizontal axis. Therefore, the configuration is simplified, and since the parallel link mechanism 15 is provided between the elbow portion 7 and the wrist portion 11, the forearm 9 is always provided by the spring 16 regardless of the swing position of the upper arm 5. And the weight of the wrist portion 11 and the hand 17 can be compensated.

Although the above description has been made based on the illustrated embodiment, the present invention is not limited to this, and can be appropriately changed within the scope of the claims, for example, the arm portion is as in the embodiment. Instead of having two on both sides of the support frame 2, two may be provided on the front side of the support frame 2 in two upper and lower stages, or one or three or more arms may be provided. ..

Thus, according to the working robot of the present invention, since the parallel link mechanism is provided between the elbow and the wrist, the forearm is swinging up and down without having a motor for driving the wrist around the horizontal axis. In addition, the wrist can maintain the horizontal position of the end effector, and a spring is provided to urge the front link of the parallel link mechanism upward with respect to the rear link, so that the upper arm can be swung. Regardless, the spring can always compensate for the weight of the forearm and wrist and the end effector, and therefore it can cover a wide working range with a small number of shafts and work with a small output motor. , It is possible to realize an inexpensive and energy-saving work robot configuration.

1 Work robot 2 Support frame 3 Right arm 4 Left arm 5 Upper arm 6 Upper arm horizontal drive motor 7 Elbow 8 Elbow horizontal drive motor 9 Forearm 10 Forearm vertical drive motor 11 Wrist 11a End effector mounting part 12 Rear link 13 Front link 14 Connecting link 15 Parallel link mechanism 16 Spring 17 Hand 18 Hand horizontal drive motor 19 Gripping member 20 Gripping member guide mechanism 21 Hand opening / closing drive motor H1 First horizontal axis H2 Second horizontal axis H3 Third horizontal axis V1 First Vertical Axis V2 Second Vertical Axis V3 Third Vertical Axis V4 Fourth Vertical Axis C Case T Table W Work Object

Claims (2)

In a work robot having a support frame and one or more arms supported by the support frame.
Each of the one or more arms
A box-shaped closed cross-sectional upper arm whose base is supported by the support frame so as to be swingable around the first vertical axis.
An upper arm horizontal drive motor that is housed in the base of the upper arm and swings the upper arm horizontally around the first vertical axis.
An elbow that is supported by the tip of the upper arm so that it can swing around the second vertical axis.
An elbow horizontal drive motor provided at the tip of the upper arm and rotating the elbow horizontally around the second vertical axis.
A box-shaped closed cross-sectional forearm whose base is supported by the elbow so as to swing around the first horizontal axis.
A forearm vertical drive motor mounted on the elbow and swinging the forearm up and down around the first horizontal axis.
A wrist portion that is rotatably supported by the tip of the forearm around the second horizontal axis and rotatably supports the end effector mounting portion around the third vertical axis.
An end effector mounting unit horizontal drive motor that rotates the end effector mounting unit horizontally around the third vertical axis.
A rear link whose base is fixed to the elbow and extends in the vertical direction,
A front link whose base is fixed to the wrist and extends in the vertical direction in parallel with the rear link.
The rear end is swingably connected to the rear link and the front end is swingably connected to the front link so as to extend parallel to the forearm, and the rear link, the front link, and the forearm. The connecting links that together form the parallel link mechanism,
It is arranged between the tip of the rear link and the proximal end of the anterior link or between the proximal end of the posterior link and the distal end of the anterior link so that the anterior link is always above the posterior link. With a spring that urges
With a hand mounted as an end effector on the end effector mounting portion ,
The hand opens and closes by supporting the two gripping members so as to be separated from each other and moving close to each other, and driving the gripping members to move apart and close to each other.
The two gripping members one by one respectively two gripping plates, suspended only pivotable same direction to each other from beneath the support to the work robot according to claim Rukoto. Arm of the one or more books, and said a two arm portions supported by the support frame, according to claim 1 working robot according.

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