CN203228227U - Parallel- series connection industrial robot structure - Google Patents

Abstract

A structure of a parallel-serial industrial robot used in machining, assembly and the like. The industrial robot structure of the utility model is composed of two identical 3-degree-of-freedom parallel structures. Each parallel structure has 3 motion branch chains, and the overall structure includes three platforms and a pneumatic grip. The bottom one is the fixed platform, the middle one is the transition platform, and the upper one is the working platform, and the starting hand is installed on the upper working platform. Each branch chain is connected to the platform in the same way, that is, the lower end is connected to the platform through a rotating joint, the middle of the branch chain is a moving pair, and the upper end is connected to the platform through a ball hinge. The mechanism has the advantages of high precision and small error, and is a structure that converts movement into rotation and movement. Has a strong structure and flexibility.

Description

A structure of parallel-serial industrial robot

technical field

The present invention relates to a and. The structure of serial industrial robots can be used in high-precision occasions such as medicine and bioengineering, and can also be used in fields such as mechanical assembly and movement space. the

Background technique

In the initial stage of industrial robot technology, it is generally composed of a base, a waist (or shoulder), a large arm, a small arm, a wrist and a claw (tool), and the large arm and the small arm are connected in series, which is called a serial robot. At present, most of the research on robots is concentrated in this field, forming a relatively mature theoretical system. People use tandem robots as robot manipulators because it has the advantages of a wide working space like a human arm and flexible maneuverability, but the tandem robot is a cantilever structure, which leads to poor bearing capacity and is easy to bend and deform under heavy loads , It is easy to generate vibration when moving at high speed, and the precise positioning ability in high-precision occasions is not ideal. With the development of robot technology, people are inspired from the perspective of bionics, hoping that parallel robots have better rigidity and positioning capabilities to make up for the shortcomings of serial robots. Just when the series robot was developing vigorously, a new type of robot appeared, that is, the parallel robot. As a powerful supplement to the series robot, it expanded the application range of the entire robot. the

The parallel robot is a kind of parallel machine tool based on the Stewart mechanism with six degrees of freedom. However, six degrees of freedom have inherent defects that cannot be solved, such as strong coupling of position and attitude, and difficulty in position analysis. As it develops, it gradually becomes a mechanism with many degrees of freedom and many structures. Slowly found that some parallel structures with few degrees of freedom are gradually paid attention to because of their simple structure and easy control. For example, the most representative one is the De1ta mechanism invented by C1ave1, which is a three-degree-of-freedom manipulator. Tesar first proposed a spherical three-degree-of-freedom parallel mechanism, which can be used as a shoulder joint or waist joint of a robot, and so on. the

With the continuous development of the parallel structure, we can know that the parallel and series forms a sharp contrast. In terms of advantages and disadvantages, the advantages of series connection are exactly the disadvantages of parallel connection, and the advantages of parallel connection are exactly the disadvantages of series connection. Some scholars have abstracted this situation to a higher level, which is called the "dual" relationship of series and parallel, and further studied the series and parallel mechanisms with this dual view. Due to the dual relationship between series and parallel in terms of structure and performance characteristics, the relationship between series and parallel is not a substitute but a complementary relationship in application, and parallel robots have their special application fields. Parallel robots with many advantages such as strong load-carrying capacity, high rigidity, small self-weight-to-load ratio, and high precision are supplements to serial robots that have been widely used due to their simple design and flexible operation. Therefore, it can be said that the emergence of parallel mechanisms has made up for the shortcomings of series robots and expanded the application range of robots. the

Just because of the influence of parallel mechanisms are structural constraints and singular configurations. In order to expand the working space of the parallel mechanism and to give full play to the advantages of both series and parallel, two parallel mechanisms with three degrees of freedom are used in series to complete some high-precision, high-flexibility, and strong-mechanism work. the

Contents of the invention

The present invention is a serial-parallel hybrid industrial robot structure proposed by combining the advantages of serial and parallel connections, making up for their respective deficiencies as much as possible, and obtaining better work adaptability, and designing a new industrial robot structure. the

A parallel-serial industrial robot designed by the utility model is mainly composed of three platforms, three upper and lower branch chains and a pneumatic hand grip. The lower platform is relatively fixed and is fixed on a base surface. Three branch chains evenly distributed along the circumference are connected to the fixed platform and connected by rotating pairs. The upper ends of the three branch chains are connected with the middle platform by ball hinges, and the middle part of the branch chains is a kind of moving pair, which is completed by the structure of nuts and lead screws. Three branch chains evenly distributed along the circumference are connected to the upper part of the middle platform, which are also connected by rotating pairs. A pneumatic grip is installed on the upper platform, and the lower end of the grip can be rotated. In this way, the whole structure has a total of 7 degrees of freedom, and it can flexibly reach a certain position in a certain space. There are a total of six branch chains connected to the upper and lower sides of the middle platform, the upper three are directly corresponding to the lower three, and there is no rotation angle along the circumferential direction, which is more conducive to the control of its position. the

The structure of this parallel-serial industrial robot has a total of six branch chains. The moving pairs of the six motion branch chains all use screw and nut structures to complete the movement of the moving pair. Since the screw is cantilevered, in order to increase the screw nut. For the motion stiffness, two guide rods are respectively added to each motion branch chain, which also play a guiding role. the

In the structure of the parallel-series industrial robot, the diameters of the lower platform, the middle platform and the upper platform become smaller as they go up, which can increase its stability and facilitate the transmission of force. the

In the structure of the parallel-series industrial robot, the axes of the three branch chain rotating pairs connected to the lower platform are in the same plane and each pair is at an angle of 60 degrees, and the axes of the three branch chain rotating pairs connected to the middle platform are also on the same plane Inside and every two are at an angle of 60 degrees. the

Among the six branch chains connected up and down between the structure and the middle platform, the three branch chains whose other end is connected to the upper platform and the three branch chains whose other end is connected to the lower platform are corresponding up and down on the middle platform. There is no relative angle, which is more conducive to control. the

Description of drawings

Fig. 1: is a kind of structure principle diagram of parallel-serial industrial robot of the present invention;

Figure 2: is the upper branch of the structure;

Figure 3: is the lower branch of the structure;

Explain the name and working principle of each structure. As shown in the figure, the upper three branched chain structures are the same, and the lower three branched chain structures are the same. the

In the figure, 1 pneumatic hand grip; 2 servo motor; 3 upper platform; 4 ball hinge; 5 nut; 6 guide plate; 7 guide rod; 8 lead screw; 9 bearing; 10 coupling; 11 servo motor; 12 small bolt 13 large bolts; 14 upper bracket; 15 rotating pair; 16 middle platform; 17 nut; 18 guide plate; 19 lead screw; 20 guide rod; 21 bearing; 22 servo motor; 23 lower bracket; ;26 platform

The specific embodiment, the lower platform 26 is to play the supporting role of the whole mechanism, three identical branch chains are connected with the lower platform with the rotating pair 25, the servo motor is installed on the lower bracket 23, and the servo motors 22 respectively are installed in the three branch chains. Under driving, the screw mandrel 19 is driven to rotate through the transmission of the gear 24, thereby making the nut 17 move up and down. Wherein each branch chain has two guide rods 20, and its lower end is fixed on the lower support 23, and the upper end is that guide plate 18 is supported. The guide rod plays a guiding role, so that the nut only moves and does not rotate. The upper end of the nut is connected with the intermediate platform 16 by a ball hinge. The middle platform 16 reaches a certain pose under the movement of the three nuts below. The upper part of the intermediate platform 16 is connected with the upper bracket 14 through the rotating pair 15, and the servo motor 11 is installed on the upper bracket 14. Driven by the servo motor 11, the screw rod 8 is driven to rotate through the shaft coupling 10, and the bearing 9 plays a role of supporting the screw rod. The nut 5 completes the movement under the action of the screw rotation and the two guide rods 7, and acts on the upper platform 3 through the ball hinge 4. In this way, the pose on the platform is obtained under the joint action of the six branch chains. A servo motor 2 is installed on the upper platform to drive the pneumatic hand grip 1 to complete the rotation. the

The moving pairs of the six branch chains can also be completed in other forms, such as pneumatic transmission, hydraulic transmission, etc., which may achieve better results under different occasions and requirements. the

The servo motor is installed on one side of the lower end of the branch chain, and the servo motor provides the power source. Through the gear transmission, the coupling and the lead screw are driven to rotate together, and the whole nut is driven to move up and down along the axis of the lead screw under the rotation of the lead screw. The movement of the nut drives the middle platform to move or rotate. There is a little difference between the upper branch chain and the lower branch chain, that is, in order to save space, reduce the structural size and interference, the axis of the servo motor of the upper branch chain and the axis of the screw nut are on the same straight line, that is, the servo motor directly drives the coupling and screw rotation. the

Claims (5)

1. the structure of a parallel-serial industrial robot, this structure is characterised in that, it is made up of two identical in structure 3DOF parallel institutions simplification, and namely the lower platform of the upper mounting plate of following parallel-connection structure and top parallel-connection structure shares a platform, and halfpace plays over effect; Total just has three platforms and totally six movement branched chain like this, and a pneumatic hand is grabbed composition; Lower platform is fixed platform, plays the supporting role of whole operating mechanism, wherein has three side chain lower ends to link to each other with lower platform by revolute pair, and three side chains evenly distribute; The upper end of these three side chains links to each other with halfpace by spherical hinge, and the centre of side chain is a kind of moving sets, and this moving sets is a kind of active drive; Other three identical side chain lower ends link to each other with halfpace by revolute pair, and the upper end is to link to each other with upper mounting plate by spherical hinge, and workbench top is installed a pneumatic hand and grabbed, and are used for the clamping target object.

2. the structure of a kind of parallel-serial industrial robot according to claim 1 is characterized in that, the moving sets of six movement branched chain all is to adopt leading screw and nut structure to finish the motion of moving sets; Because leading screw is cantilever, for the motion rigidity that increases feed screw nut has added two guide posts.

3. the structure of a kind of parallel-serial industrial robot according to claim 1 is characterized in that, the diameter dimension of lower platform, halfpace and three platforms of upper mounting plate is more up more little.

4. the structure of a kind of parallel-serial industrial robot according to claim 1, it is characterized in that, the axis of three side chain revolute pairs that are connected with lower platform is in same plane and become 60 degree angles in twos respectively, and the axis of the three side chain revolute pairs that are connected with halfpace is also in same plane and become 60 to spend angles in twos respectively.

5. the structure of a kind of parallel-serial industrial robot according to claim 1, it is characterized in that, in totally six side chains that halfpace links to each other up and down, wherein three side chains linking to each other of the other end and upper mounting plate are corresponding about halfpace is with 3 side chains that the other end links to each other with lower platform, do not have relative angle in a circumferential direction.

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