JPH0323314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an articulated robot.

[Conventional technology]

Conventionally, as shown in FIG. 1, an arm mechanism connected between a main body 1 of an industrial robot and a hand mechanism 2 consisting of a chuck or the like for grasping an object is composed of a crank lever 3 and a crank lever 4. A motor 5 for rotating the crank 3 is installed at the connection point between the main body 1 and the crank 3 of the industrial robot, and a crank lever 4 is installed at the connection point between the crank lever 3 and the crank lever 4. A motor 6 for rotating the crank lever 4 and a motor 7 for rotating the hand mechanism 2 relative to the crank lever 4 are provided at the connection point between the crank lever 4 and the hand mechanism 2.
is provided. Other prior art includes Japanese Patent Application Laid-Open No. 47-7418, "Electric Research Institute News" No. 271, page 7, published August 1972, and U.S. Patent No.
There is a specification and drawings of No. 2861699.

[Problem that the invention seeks to solve]

However, in the former conventional technology, since a motor with considerable weight is mounted on the moving end of the crank lever, the inertial force of the crank lever becomes large, making it impossible to quickly control the posture and position of the hand mechanism. This had the disadvantage of inducing vibration and slippage. In addition, in order to maintain the posture of the hand mechanism tilted in a predetermined direction in the arm mechanism, the motor 7 must be rotated by the amount of change each time the tilt of the crank lever 4 changes. This has the problem of requiring complicated control and slowing down the control operation.

An articulated industrial robot that solves this problem is disclosed in Japanese Patent Application Laid-open No. 7418/1983.

However, in this conventional industrial robot, the driving force for rotating the upper arm member and the intermediate member is obtained from the linear motion output of the piston of each cylinder, so the rotation angle of the upper arm member and the intermediate member and each The linear momentum of the cylinder piston is not proportional. Therefore, when moving the tip of the lower arm member from one position to another, it is not possible to immediately determine the linear momentum of the cylinder, which ultimately complicates the control of the cylinder, and only allows low-speed operation, and the arm drive mechanism The problem was that it became complicated.

In addition, in the manicopilator described in Densoken News, the arm drive motor is attached to the base rather than the shoulder, so when the shoulder rotates, the arm moves and must be compensated, making control complicated. It had the following problems.

In addition, the manicopilator of U.S. Patent No. 2861699 uses a chain to drive the forearm, so its rigidity is low.
This has the problem of not being able to position with high precision.

The purpose of the present invention is to simplify the power transmission mechanism and reduce its weight in order to solve the above-mentioned problems of the conventional technology, and in addition, the shoulder part that supports the arm mechanism of the robot has high rigidity, enabling highly accurate positioning. Furthermore, it is an object of the present invention to provide an articulated robot with a wide range of work.

[Means for solving problems]

That is, the present invention includes a shoulder portion rotatably supported by a rotary drive motor mounted on a robot body, and the shoulder portion is provided with a first supporting member and a first supporting member that are arranged parallel to each other and facing each other. The arm mechanism of the robot consists of two supporting members and a connecting member that integrally connects one side of these supporting members on the robot body side. A first rotary actuator is configured of a parallelogram link mechanism rotatably supported by a support member, and has one end connected to an output shaft of a first rotary actuator for driving an arm mechanism of the robot. A horizontal drive shaft of the robot is rotatably supported on a fixed fulcrum of the first support member, and the arm mechanism of the robot is driven so as to be coaxial with the axis of the first horizontal drive shaft. a second horizontal drive shaft, one end of which is connected to the output shaft of the second rotary actuator, is rotatably supported on a fixed fulcrum of the second support member;
The parallelogram link mechanism is composed of a first arm member, a first link member, a second link member, and a second arm member, and the plane of movement thereof is between the first support member and the second support member. The first arm member has one end fixed to the other end of the first horizontal drive shaft, and uses the one end as a fulcrum of rotation to rotate the first arm member. The other end is a swing end point that swings in direct proportion to the rotation of the first rotary actuator, and the first link member has one end fixed to the other end of the second horizontal drive shaft, and the first link member has one end fixed to the other end of the second horizontal drive shaft. The second link member has one end at a swinging end point that swings in direct proportion to the rotation of the second rotary actuator, with the second link member having one end at the swinging end point of the first link member. is supported, converts the rocking motion of the one end into a reciprocating motion in the longitudinal direction and transmits it to the other end as a rocking motion directly proportional to the rotation of the second rotary actuator, The arm member has one end supported by the swinging other end of the second link member, and an intermediate portion supported by the swinging end point of the first arm mechanism, thereby preventing the swinging movement of the one end. The first horizontal drive shaft is supported by a fixed fulcrum of the first support member, and the second horizontal drive shaft is supported by a fixed fulcrum of the second support member. The second horizontal drive shaft is one in which the drive transmission axes are arranged opposite to each other on the same axis, and each horizontal drive shaft is rotatable so that driving force can be transmitted independently. It is supported and
As a result, the rocking motion of the first arm member is directly transmitted from the rotation of the first horizontal drive shaft in a rotating pair, and the rocking motion of the second arm member is transmitted to the rotation of the second horizontal drive shaft. This is an articulated robot characterized in that it is configured such that rotational motion is transmitted in pairs via a first link member.

[Effect]

With the above configuration, the arm member drive mechanism can be simplified and the weight can be significantly reduced.

Furthermore, in the case where the two arm drive motors are supported on the respective fixed fulcrums of the first support member and the second support member of the shoulder, both support members are integrally connected by the connection member. This increases the rigidity of the shoulder and minimizes the torsion that occurs in the shoulder even if the reaction forces of the cantering power of the two arm drive motors that act between the two support members are different or act in opposite directions. It can be suppressed. In this way, it is possible to obtain a shoulder part that supports the arm mechanism of the robot with high rigidity, and as a result, it is possible to highly accurately position the wrist position of the tip of the arm mechanism supported by the shoulder part. It is.

Furthermore, the working range of the arm members of the parallelogram link mechanism is widened by making the side of each support member opposite to the robot body open so as not to impede the swinging movement of the parallelogram link mechanism. Can be done.

〔Example〕

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

FIG. 2 is a perspective view showing the assembled state of parts constituting the arm mechanism of the articulated industrial robot of the present invention;
FIG. 3 is an enlarged view of the working gear mechanism of FIG. 2. That is, 1 is a main body of an industrial robot, and rotatably supports a shaft 9 fixed to an L fitting 8 so that the L fitting 8 rotates in a horizontal plane.When the shaft 9 is rotated, a motor (not shown) is connected. ) is listed. The shoulder portion 10 consists of a first support member 57, a second support member 58, and a connecting member 59 that integrally connects one side of both support members on the robot body side, and rotates in a vertical plane. Axis 1 to get
1 is rotatably supported on an L fitting 8, and this shaft 11 is connected to a motor (not shown) placed on the main body 1 through a ball joint (not shown).
Reference numeral 12 designates a first horizontal drive shaft rotatably supported in the horizontal direction on a fixed fulcrum of the first support member 57 of the shoulder portion 10. The first motor is a motor for driving the mechanism.
The rotary actuator (not shown) is connected to the output shaft of the rotary actuator (not shown). 14 is the first horizontal drive shaft 1
2 and the second support member 5 of the shoulder 10 on the same axis.
A second horizontal drive shaft is rotatably supported in the horizontal direction on a fixed fulcrum of 8, and a second rotary actuator has one end of the first link 15 fixed to it and is a motor for driving the arm mechanism. (not shown).

The axis of the first horizontal drive shaft connected to the output shaft of the first rotary actuator for driving the arm mechanism is the same as the axis of the first horizontal drive shaft connected to the output shaft of the second rotary actuator for driving the arm mechanism. The horizontal drive shafts 12 of
and 14 are also supported on the same axis. In this way, the two arm drive motors, which require a larger driving force than the wrist vibration motor, are supported on the respective fixed fulcrums of the first and second support members on the shoulder. In order to support the two horizontal drive shafts so that their axes are always on the same axis due to the configuration, it goes without saying that both fixed fulcrums on which they are supported must also be held on the same axis. Therefore, both supporting members having respective fixed fulcrums need to be integrally connected by a connecting member and have high rigidity. In other words, this makes it possible to minimize the twisting of the shoulder that occurs when the reaction forces of the driving forces of the two arm drive motors that act between the two support members are different or act in opposite directions. . Therefore, in a robot in which two arm mechanism drive motors are placed in the shoulders, it is possible to obtain a support mechanism for the arm mechanisms that has high rigidity, and enables highly accurate positioning of the robot's wrist tip. It is something. This is an effect that cannot be expected from a type of robot in which a wrist motor, which is driven by a relatively small force, is placed in the shoulder.
17 is a second arm member having the same length as the first arm member 13;
, and one end thereof is rotatably connected to the swinging end of the first link 15 by a second horizontal shaft 16. Reference numeral 19 denotes a second arm member, which is rotatably coupled to the other end of the second link 17 and the third horizontal shaft 18, and is attached to the swinging end of the first arm member 13.
The length from the third horizontal axis 18 to the first horizontal axis 20 is equal to the length of the first link 15. Therefore, the first arm equipment 13, the first link 1
5, the second link 17 and the second arm member 19 form a parallelogram link mechanism. 21
The rod has a hand mechanism, such as a chuck for holding an object, attached to its tip, and supports bevel gears 22 and 23 rotatably opposite to its rear end. 2
Reference numeral 4 denotes a horizontal shaft rotatably supported at the lower right end of the second arm member 19, with one end attached to the bevel gear 22.
A bevel gear 25 that meshes with and 23 is fixed. 2
Reference numeral 6 denotes a horizontal shaft rotatably supported at the lower left end of the second arm member 19, with one end attached to the bevel gear 22.
A bevel gear 27 meshing with and 23 is fixed. Therefore, the bevel gears 22, 23, 25, and 27 form a differential gear mechanism 28. A lever 29 has one end fixed to the horizontal shaft 24 and the other end rotatably connected to one end of a link 31 via a pin 30. 32 is rotatably supported by the first horizontal shaft 20, is a triangular joint plate, one end is rotatably connected to the other end of the link 31 by a pin 33, and the other end is connected to the link by a pin 34. It is rotatably connected to one end of 35.
36 is rotatably supported by the first horizontal drive shaft 12, and is a triangular joint plate. One end is rotatably connected to the other end of the link 35 via a pin 37, and the other end is connected to the pin 38. It is rotatably connected to one end of the link 39 via. 42
A third horizontal drive shaft is connected to the output shaft of a third rotary actuator, which is a motor, and rotatably supported at the lower right end of the support member 10, and one end of the crank 41 is fixed to the third horizontal drive shaft. This crank 41
The other end is rotatably connected to the other end of the link 39 by a pin 40. In other words, the important point is link 3
The length of the link 35 and the joint plate 5 are made equal to the distance between the first horizontal drive shaft 12 and the first horizontal shaft 20, and the swing radii of the joint plate 36 and the joint plate 32 are made equal. 3
2 and 36 to form a parallel linkage. Similarly, the length of the link 31 is made equal to the distance between the horizontal axis 24 and the first horizontal axis 20, and
The swing radius of the joint plate 32 and the lever 29 are made equal, and the link 31, the joint plate 32, and the lever 29 form a parallel link mechanism. A lever 43 has one end fixed to the horizontal shaft 26 and the other end rotatably connected to one end of a link 45 via a pin 44. 46
is rotatably supported by the first horizontal shaft 20, is a joint plate having a triangular shape, one end is rotatably connected to the other end of the link 45 by a pin 47, and the other end is connected to the link 49 by a pin 48. It is rotatably connected to one end of the . Reference numeral 50 is rotatably supported by the second horizontal drive shaft 14, is a triangular joint plate, one end is rotatably connected to the other end of the link 49 via a pin 51, and the other end is a triangular joint plate. It is rotatably coupled to one end of a link 53 via a pin 52. A fourth horizontal drive shaft 56 is connected to the output shaft of a fourth actuator, which is a motor, and rotatably supported at the lower left end of the support member 10, and one end of the crank 55 is fixed thereto. The other end of this crank 55 is link 5
It is rotatably connected to the other end of 3 by a pin 54. A parallel link mechanism is formed between the lever 43, the link 45, and the joint plate 46, and between the joint plate 46 and the 50 link 49.

Therefore, the horizontal axis 2 which becomes the base of the hand mechanism, that is, the wrist
Position information (X,
Y) is given by the following equation (1).

X= lcosα+mcos(π-β) Y= lsinα+msin(π-β)...(1) However, l is the first arm member 13 as shown in FIG.
The total length, m, of the first horizontal axis 20 is as shown in FIG.
α is the angle between the first arm member 13 and the X-axis as shown in FIG. 4, and β is the length between the first link 15 and the X-axis as shown in FIG. A corner. Therefore, when the positional information of a point t (X, Y) on the wrist is given, the angles α and β are determined from equation (1), and the first rotary actuator (motor) is adjusted so that this angle α is achieved. The first horizontal drive shaft 12 is rotated to rotate the first arm member 13 by a predetermined angle, and the second rotary actuator (motor) is rotationally driven so that the angle β is obtained. The second horizontal drive shaft 14 is rotated to rotate the first link 15 by a predetermined angle. At this time, the third
The horizontal drive shaft 42 and the fourth horizontal drive shaft 56 are stopped, and the joints 36 and 50 are stopped, so the joint plates 32 and 46 remain parallel to the joint plates 36 and 50. Further, the levers 29 and 43 are also held parallel to the joint plates 32 and 46, and the posture of the rod 21 supporting the hand mechanism is always maintained constant as shown in FIG. That is, as shown in FIG. 4, for example, even if the first arm member 13 rotates by a predetermined amount, the rod 21 supporting the hand mechanism can always be held in a parallel state, that is, in a fixed direction, and the hand mechanism In order to rotate the rod 21 while maintaining the posture of the rod 21 that supports the
The horizontal drive shaft 42 and the fourth horizontal drive shaft 42 are rotated by the same predetermined amount in opposite directions, and the bevel gears 25 and 27 of the differential gear mechanism 28 are rotated by the same angle in opposite directions. You can get it by twisting it. Furthermore, if it is desired to change only the posture of the rod 21 supporting the hand mechanism without rotating it around the axis, the third horizontal drive shaft 42 and the fourth horizontal drive shaft 56 may be rotated by the same predetermined amount in the same direction. This can be achieved by rotating the bevel gears 25 and 27 of the differential gear mechanism 28 by an equal predetermined amount in the same direction.

The rod 21 supporting the hand mechanism can move freely within the same plane as described above, but horizontal movement can be achieved by rotating the vertical shaft 9 with a motor, and Rotation about an axis in a horizontal plane can be achieved by means of a motor on the axis 11 to which the support member 10 is fixed.

〔Effect of the invention〕

As explained above, according to the present invention, the arm mechanism of the robot is configured with a parallelogram link mechanism, and the drive motor is concentrated on the shoulder closest to the main body of the industrial robot, and the arm drive is directly rotated. The mechanism was made lighter and simpler.

In addition, by integrally constructing the shoulder portion consisting of the first support member, the second support member, and the connecting member that connects these two support members to increase the rigidity of the shoulder portion, the two support members are different from each other. Even if a certain force is applied, the shoulder part is less likely to be twisted, and there is no misalignment of the axis of the fixed fulcrum on each support member of the shoulder part that supports the parallelogram linkage mechanism. The movement surface is accurately secured, and the positioning accuracy of the robot's wrist tip can be improved.

Furthermore, the side of each shoulder support member opposite the robot body is open so as not to interfere with the swinging movement of the parallelogram link mechanism.
It also has the effect that the movable surface of the parallelogram linkage, that is, the working range of the robot can be maintained wide.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of an example of a conventional arm mechanism of an industrial robot, FIG. 2 is a perspective view of a part assembly showing an example of an arm mechanism of an industrial robot according to the present invention, and FIG. FIG. 2 is an enlarged view of the differential gear mechanism shown in FIG. 2, and FIG. 4 is a view showing the operating principle of an embodiment of the arm mechanism of the industrial robot shown in FIG. DESCRIPTION OF SYMBOLS 1... Main body of industrial robot, 10... Support member (shoulder part), 12... First horizontal drive shaft, 13... First arm member, 15... First link, 17... Second link, 19... Second arm member, 14... Second horizontal drive shaft, 21... Rod, 24, 26... Horizontal shaft, 28...
Differential gear mechanism, 29, 43...Lever, 31, 3
5, 39, 45, 49, 53...link, 32, 3
6,46,50...joint plate, 41,5
5... Crank, 42... Third horizontal drive shaft, 56...
Fourth horizontal drive axis.

Claims (1)

[Scope of Claims] 1. A robot body includes a shoulder portion rotatably supported by a rotary drive motor mounted on the robot body, and each shoulder portion is provided with a first support member disposed parallel to each other and facing each other. and a second support member, and a connecting member that integrally connects one side of these support members on the robot body side, and the arm mechanism of the robot includes the first support member of the shoulder portion and the first support member. The parallelogram link mechanism is rotatably supported by the second support member, and one end is connected to the output shaft of the first rotary actuator for driving the arm mechanism of the robot. A first horizontal drive shaft is rotatably supported on a fixed fulcrum of the first support member, and the arm mechanism of the robot is driven so as to be coaxial with the axis of the first horizontal drive shaft. the second of
A second horizontal drive shaft, one end of which is connected to the output shaft of the rotary actuator, is rotatably supported on a fixed fulcrum of the second support member, and the parallelogram link mechanism has a first arm. Element,
It consists of a first link member, a second link member, and a second arm member, and its plane of motion is parallel to each plane of the first support member and the second support member. The first arm member has one end fixed to the other end of the first horizontal drive shaft, and swings in direct proportion to the rotation of the first rotary actuator, using the one end as a rotational fulcrum. The first link member has one end connected to the second end, and the first link member has one end connected to the second end.
The second link member is fixed to the other end of the horizontal drive shaft of the rotary actuator, and has a swing end point that swings in direct proportion to the rotation of the second rotary actuator using the one end as a fulcrum of rotation. , one end supported by a swinging end point of the first link member, converting the swinging motion of the one end into a reciprocating motion in the longitudinal direction, and swinging in direct proportion to the rotation of the second rotary actuator. The second arm member has one end supported by the other swinging end of the second link member, and an intermediate part of the second arm member that is supported by the swinging motion of the first arm member. a first horizontal drive shaft supported at an end point, thereby transmitting a rocking motion directly proportional to the rocking motion of one end to the other end; , the second horizontal drive shafts supported by the fixed fulcrum of the second support member are disposed opposite to each other on the same axis of drive transmission, and the respective horizontal drive shafts are arranged opposite to each other on the same axis. The first arm member is rotatably supported so that the driving force can be transmitted independently.
The rotation of the horizontal drive shaft is directly transmitted in a rotating pair, and the swinging motion of the second arm member is transmitted in a rotating pair from the rotational movement of the second horizontal drive shaft via the first link member. An articulated robot characterized by being configured as follows.