CN106625558A - Variable-degree-of-freedom linkage mechanism welding mechanical arm - Google Patents

Abstract

A variable-degree-of-freedom linkage mechanism welding mechanical arm comprises a base 1, a big arm lifting mechanism, a wrist linkage pitching mechanism, a wrist 27, a welding gun 28, a servo driving device, a first locking device 5 and a second locking device 12. The big arm lifting mechanism comprises a big arm 8, a fourth linkage 3 and a fifth linkage 6, the wrist linkage pitching mechanism comprises a driving rod 16, a first linkage 18, a second linkage 21 and a third linkage 11, and the first locking device 5 and the second locking device 12 are installed on an eleventh rotary pair 4 and an eighth rotary pair 7 respectively and can conduct locking at proper time according to different working conditions of the welding mechanical arm. The servo driving device comprises a first servo motor and is connected with the driving rod 16 to drive the driving rod 16 to rotate. The first locking device 5 and the second locking device 12 are locked in an electromagnetic mode. Two-degree-of-freedom welding can be achieved through only one driving rod, the number of motors in use is reduced, and the manufacturing cost of the welding mechanical arm is reduced.

Description

A welding robot arm with variable degree of freedom link mechanism

technical field

The invention relates to the mechanical field, in particular to a welding mechanical arm of a variable-degree-of-freedom link mechanism.

Background technique

In the past few years, due to the shortage of personnel in the labor market, labor costs have increased year by year, which has promoted the wide application of welding manipulators in welding operations. There are two types of welding manipulators: mechanical and hydraulic. At present, most welding manipulators are hydraulically driven. Since hydraulic transmission uses hydraulic oil as the medium for power transmission, there are the following problems: its starting performance is poor, and it is easy to wear due to internal components. Finally, leakage will occur, and the leaked hydraulic oil will pollute the environment; hydraulic oil is greatly affected by temperature, the overall efficiency is low, and sometimes there is noise and vibration. Sometimes there will be overheating, weak work and other phenomena; hydraulic components require high machining accuracy, strict assembly requirements, difficult manufacturing, and high technical and difficult maintenance requirements during use. With the increase of the function of welding manipulator, its hydraulic system becomes more and more complicated, and the failure is more sudden and concealed. The mechanical welding manipulator uses mechanical transmission parts to realize the welding action, which has the advantages of being strong and durable, but the traditional single-degree-of-freedom mechanical welding manipulator cannot complete complex actions, and its application range is very limited. The mechanical controllable mechanism electric welding machine The hydraulic transmission is replaced by a link mechanism. When the active lever is driven by a servo motor, it is easy to realize automation and numerical control, which solves some shortcomings of the hydraulic system, but it needs to be equipped with the same number of degrees of freedom as the link mechanism. Controlling the motor to control the complex structure brings about the problems of mechanism weight, large motion inertia and high cost.

The variable degree of freedom mechanism adapts to the functional requirements of different stages by combining new topological structures. At present, there are very few variable-degree-of-freedom mechanisms that can be applied to practical applications, and no variable-degree-of-freedom mechanisms that have been applied to welding manipulators have been seen.

Contents of the invention

The object of the present invention is to provide a welding manipulator with variable degree of freedom link mechanism, which overcomes the shortcomings of high precision requirements, complex structure, easy oil leakage and other shortcomings of the hydraulic system components of the hydraulic welding manipulator, and overcomes the need for drive motors with open chain structures. The disadvantage of being installed at the joint position, and making the number of controllable driving motors less than the degree of freedom of the welding manipulator linkage mechanism, overcomes the need for the existing mechanical electric welding manipulator to be equipped with the same number of control motors as the degree of freedom of the linkage mechanism. Control the shortcomings, simplify the complexity of the structure, reduce the weight, inertia, volume and cost of the mechanism. In order to achieve the above object, the present invention provides a welding mechanical arm with a variable degree of freedom link mechanism, including a base 1, a boom lifting mechanism, a wrist link pitching mechanism, a wrist 27, a welding torch 28, a servo drive device, a first lock The locking device 5 and the second locking device 12; the base 1 is installed on a movable slewing platform; the boom lifting mechanism includes a boom 8, a fourth connecting rod 3 and a fifth connecting rod 6, and the boom 8. One end is connected to the base 1 through the sixth rotating pair 14, and the other end is connected to the wrist link 10 through the ninth rotating pair 9; one end of the fourth connecting rod 3 is connected to the base 1 through the tenth rotating pair 2, and the other end is connected through the The eleventh rotating pair 4 is connected to one end of the fifth connecting rod 6, and the other end of the fifth connecting rod 6 is connected to the boom 8 through the seventh rotating pair 13; the wrist connecting rod pitch mechanism includes an active rod 16, a first connecting rod 18. The second connecting rod 21 and the third connecting rod 11, the sixth connecting rod 23 and the seventh connecting rod 25. One end of the active rod 16 is connected to the base 1 through the first rotating pair 15, and the other end is connected to the base 1 through the second rotating pair. 17 is connected with one end of the first connecting rod 18, and the other end of the first connecting rod 18 is connected with one end of the second connecting rod 21 through the third rotating pair 19, and the other end of the second connecting rod 21 is connected with the wrist connecting rod 10 through the fifth rotating pair 22. One end of the sixth connecting rod 23 is connected to one end of the seventh connecting rod 25 through the twelfth rotating pair 24, the other end of the sixth connecting rod 23 is connected to the middle of the first connecting rod 18 through the thirteenth rotating pair 26, and the seventh connecting rod The other end of the rod 25 is connected to the base 1 through the first rotating pair 15; one end of the third connecting rod 11 is connected to the boom 8 through the eighth rotating pair 7, and the other end is connected to the second connecting rod 21 through the fourth rotating pair 20; The first locking device 5 and the second locking device 12 are installed on the eleventh rotating pair 4 and the eighth rotating pair 7 respectively, and can be locked in time according to different working conditions of the welding mechanical arm structure; the servo drive device includes the first A servo motor is connected with the active rod 16 to drive its rotation; the first locking device 5 and the second locking device 12 are locked by electromagnetic means.

The invention adopts a controllable multi-rod closed-chain mechanism, which overcomes the disadvantage that the driving motors of the open-chain structure need to be installed at joint positions, improves the stability and reliability of the arm operation, has no cumulative error, and has high precision; the structure is compact, High rigidity, large bearing capacity, low inertia, good dynamic performance, flexible and diversified arm movement trajectory. A locking device is added to the linkage mechanism, and it is allowed to lock and release a specific rotating pair according to the different working conditions of the mechanism, which reduces the degree of freedom of the mechanism in a timely manner, and realizes the possibility of being used under the condition of fulfilling the expected requirements. The number of control drive motors is less than the degree of freedom of the linkage mechanism of the welding manipulator, and the two-degree-of-freedom welding operation can be realized by using one active rod, which overcomes the need for the existing welding manipulator to be equipped with the same number of control motors as the degree of freedom of the linkage mechanism. Control the shortcomings, simplify the complexity of the structure, reduce the weight, inertia, volume and cost of the mechanism, increase the controllability and stability of the mechanism, and improve work efficiency. At the same time, it also overcomes the shortcomings of high precision requirements for components in the hydraulic system of the hydraulic welding manipulator, complex structure, easy oil leakage, poor reliability, and low transmission efficiency.

Description of drawings

Fig. 1 is a schematic diagram of a welding robot arm of a variable-degree-of-freedom link mechanism according to the present invention.

detailed description

A welding mechanical arm with a variable degree of freedom link mechanism, including a base 1, a boom lifting mechanism, a wrist link pitching mechanism, a wrist 27, a welding torch 28, a servo drive device, a first locking device 5 and a second locking device 12; the base 1 is installed on a movable slewing platform; the boom lifting mechanism includes a boom 8, a fourth connecting rod 3 and a fifth connecting rod 6, and one end of the boom 8 connects with the sixth rotating pair 14 The base 1 is connected, and the other end is connected to the wrist link 10 through the ninth rotating pair 9; one end of the fourth connecting rod 3 is connected to the base 1 through the tenth rotating pair 2, and the other end is connected to the fifth connecting rod through the eleventh rotating pair 4. One end of the connecting rod 6 is connected, and the other end of the fifth connecting rod 6 is connected with the boom 8 through the seventh rotating pair 13; Three connecting rods 11, the sixth connecting rod 23 and the seventh connecting rod 25, one end of the active rod 16 is connected to the base 1 through the first rotating pair 15, and the other end is connected to one end of the first connecting rod 18 through the second rotating pair 17 , the other end of the first connecting rod 18 is connected to one end of the second connecting rod 21 through the third rotating pair 19, the other end of the second connecting rod 21 is connected to the wrist connecting rod 10 through the fifth rotating pair 22, and one end of the sixth connecting rod 23 is passed through The twelfth rotating pair 24 is connected to one end of the seventh connecting rod 25, the other end of the sixth connecting rod 23 is connected to the middle of the first connecting rod 18 through the thirteenth rotating pair 26, and the other end of the seventh connecting rod 25 is connected through the first rotating pair 15 is connected to the base 1; one end of the third connecting rod 11 is connected to the boom 8 through the eighth rotating pair 7, and the other end is connected to the second connecting rod 21 through the fourth rotating pair 20; the first locking device 5 and the second The locking device 12 is installed on the eleventh rotating pair 4 and the eighth rotating pair 7 respectively, and can be locked in time according to the different working conditions of the welding mechanical arm structure; the servo drive device includes a first servo motor, which is connected with the active rod 16 to drive it to rotate; the first locking device 5 and the second locking device 12 are locked electromagnetically.

During work, when the boom 8 is raised and lowered, the first locking device 5 is opened, the eleventh turning pair 4 recovers the degree of freedom, the second locking device 12 is closed, and the eighth turning pair 7 loses the degree of freedom. At this time, the boom 8 lifts under the action of active lever 16. When the wrist link 10 is pitched alone, the second locking device 12 is opened, the eighth rotation joint 7 restores the degree of freedom, the first locking device 5 locks, the eleventh rotation joint 4 loses the degree of freedom, and the big arm 8 is relative to the base 1 The degree of freedom is lost, and now the wrist link is driven by the active rod 16 to pitch. During the whole welding process, the first locking device 5 and the second locking device 12 can be selected to lock or open respectively according to different working conditions, and jointly complete the lifting and telescoping of the boom, and the locking and closing of the wrist link 10 and the wrist 27. Motions such as pitching realize the welding operation of the welding torch 28. The first locking device 5 and the second locking device 12 can be locked by electromagnetic means, and the control is easy to realize.

Claims (1)

1. A variable-degree-of-freedom link mechanism welding mechanical arm, characterized in that it comprises: a base 1, a boom elevating mechanism, a wrist link pitching mechanism, a wrist 27, a welding torch 28, a servo drive device, and a first locking device 5 and the second locking device 12; the base 1 is mounted on a movable slewing platform; the boom lifting mechanism includes a boom 8, a fourth connecting rod 3 and a fifth connecting rod 6, and one end of the boom 8 passes through The sixth rotating pair 14 is connected to the base 1, and the other end is connected to the wrist link 10 through the ninth rotating pair 9; one end of the fourth connecting rod 3 is connected to the base 1 through the tenth rotating pair 2, and the other end is connected through the eleventh rotating pair. The rotating pair 4 is connected to one end of the fifth connecting rod 6, and the other end of the fifth connecting rod 6 is connected to the boom 8 through the seventh rotating pair 13; the wrist link pitch mechanism includes an active rod 16, a first connecting rod 18, a second Two connecting rods 21, the third connecting rod 11, the sixth connecting rod 23 and the seventh connecting rod 25, one end of the active rod 16 is connected to the base 1 through the first rotating pair 15, and the other end is connected to the second rotating pair 17 through the second connecting rod. One end of a connecting rod 18 is connected, the other end of the first connecting rod 18 is connected with one end of the second connecting rod 21 through the third rotating pair 19, the other end of the second connecting rod 21 is connected with the wrist connecting rod 10 through the fifth rotating pair 22, the second One end of the six connecting rod 23 is connected to one end of the seventh connecting rod 25 through the twelfth rotating pair 24, the other end of the sixth connecting rod 23 is connected to the middle of the first connecting rod 18 through the thirteenth rotating pair 26, and the seventh connecting rod 25 is connected to the middle of the first connecting rod 18 through the thirteenth rotating pair 26 One end is connected to the base 1 through the first rotating pair 15; one end of the third connecting rod 11 is connected to the boom 8 through the eighth rotating pair 7, and the other end is connected to the second connecting rod 21 through the fourth rotating pair 20; the first lock The tightening device 5 and the second locking device 12 are installed on the eleventh rotating pair 4 and the eighth rotating pair 7 respectively, and can be locked in time according to different working conditions of the welding mechanical arm structure; the servo drive device includes a first servo motor It is connected with the active rod 16 to drive it to rotate; the first locking device 5 and the second locking device 12 are locked by electromagnetic means.