CN100417498C - A palletizing robot - Google Patents

Abstract

A handling and palletizing robot belongs to the field of robots. In order to reduce the torque requirements of existing robots on driving components such as motors, and to reduce the weight by removing counterweights, etc., the invention discloses a handling and palletizing robot, which includes a base, a rotating frame, and consists of a lower arm, a lower arm, The first parallel four-bar linkage mechanism composed of the upper arm and the upper forearm, and the end effector posture holder equipped with the end effector; the connection between the lower arm and the lower forearm is the shoulder joint of the robot; the lower arm and the upper arm The connection of the lower arm is the elbow joint of the robot; the movement of the upper arm and the forearm of the robot is driven by the crank rocker mechanism; the handling and palletizing robot also includes a posture maintaining mechanism, through which the posture of the end effector is maintained The lower surface of the device is always kept level during the working process. The invention reduces the requirements on the driving components, does not need counterweight and spring force reducing balance device, and reduces the weight and cost of the robot body.

Description

A palletizing robot

technical field

The invention relates to a handling and palletizing robot, specifically a robot used in an industrial automation production line, capable of completing various tasks such as loading, unloading, cargo transportation, palletizing, and depalletizing, and belongs to the field of robots.

Background technique

Since the late 1970s, when Japan applied robot technology to the palletizing process, the research on palletizing robots has developed rapidly, and the flexibility, processing speed and grasping weight have been continuously improved. At the same time, the palletizing robot occupies a small area, It is able to handle multiple materials and stack multiple stacks at the same time, which is more and more favored by the majority of users and quickly occupies the market. The use of palletizing robots greatly reduces the labor intensity and improves production efficiency. Modern palletizing robots can complete the transportation, palletizing and depalletizing of bags, boxes and other packaging.

Companies such as ABB Robotics in Sweden, KUKA Roboter in Germany, Fuji Yusoki Kogyo and Okura Yusoki in Japan all produce palletizing robots and have occupied the global market. Take the palletizing robot IRB 660 of ABB Robotics as an example. It has five rotating joints. Starting from the base, it is the waist joint that can rotate around the vertical direction. The rotation direction is perpendicular to the shoulder joint, elbow joint and wrist pitch joint on the paper. , and the end effector rotary joint that can rotate around the vertical direction, it is a typical traditional industrial robot. Figure 1 is a schematic diagram of the overall structure of ABB IRB 660, and Figure 2 is a schematic diagram of the structure above the rotating frame of a traditional palletizing robot represented by ABBIRB 660. As shown in Figures 1 and 2, the rotating frame 3 is installed on the base 1 arranged on the ground through the rotating shaft assembly 2 and can rotate around the vertical direction. This is the waist joint Axis 1 of the robot; the lower arm 5 , the lower arm 7, the upper arm 6 and the upper arm 8 are connected through connecting shafts H, V, B, and C to form a first parallel four-bar linkage mechanism, and the first parallel four-bar linkage mechanism is installed on the connecting shaft H On the rotating frame 3, the connecting shaft H is the shoulder joint Axis 2 of the robot, and the movement of the lower arm 5 is driven by the shoulder joint drive motor 16 through a reducer; the connecting shaft C is the The elbow joint Axis 3 of the robot, the upper forearm 8 relies on the elbow joint driving motor 4 set on the rotating frame 3 to control its motion through the reducer and the first parallel four-bar linkage; the shoulder joint driving motor 16 is coaxially arranged with the elbow joint drive motor 4.

An "L"-shaped connector 10 is installed at the connecting axis C at the intersection of the centerlines of the lower arm 5 and the upper forearm 8, the "L"-shaped connector 10, the first connecting rod 9, the The lower arm 5 is connected with the rotating frame 3 through connecting shafts G, O, H, and C to form a second parallel four-bar linkage mechanism; the "L"-shaped connecting piece 10, the second connecting rod 11, and the upper The forearm 8 is connected with the end effector posture holder 12 through the connecting shafts D, E, P, C to form a third parallel four-bar linkage mechanism, using the second parallel four-bar linkage mechanism and the third parallel four-bar linkage mechanism The mechanism can ensure that the lower surface of the end effector posture holder 12 is always kept horizontal during the working process of the robot. This design has obvious advantages when the goods to be processed or carried are heavy, wherein the connecting axis P is Axis 4 is the wrist pitch joint of the robot. The robot end effector 13 can rotate around the vertical direction under the action of the end effector rotating motor 14 installed on the end effector attitude holder 12, forming the end effector rotating joint Axis 5 of the robot.

This configuration method is adopted by most of the existing articulated palletizing robots, but this configuration method has the following problems. In order to reduce the requirements for the drive motor, it is often used to add a counterweight to the palletizing robot, or a spring force reduction balance device Or a hydraulic and pneumatic force reduction balance device to reduce the driving torque required during the robot's working process. For example: ABB Robotics' IRB 660 uses a spring force reduction balance device 15, and K in Figure 2 is a spring; ABB Robotics' IRB 6400 also uses Counter Weight and spring force reduction balance device, however, this kind of mechanical structure still has high requirements for the drive components, and the drive components used are usually motors. In addition, adding a counterweight or spring force reduction balance device increases the robot The weight of the body increases the consumption of energy and the wear and tear of the machine.

Therefore, it is necessary to transform and innovate the mechanical structure of the palletizing robot in this configuration, which can not only reduce the requirements of the robot for the driving components (usually the motor), but also remove the counterweight to reduce the weight of the robot body and reduce the load on the robot. The consumption of energy and the wear and tear of the machine in the working process can keep the cost low while having good stability and durability.

Contents of the invention

The purpose of the present invention is to provide a palletizing robot, which can reduce the robot's drive torque requirements for motors and other driving components, thereby reducing the cost of the robot, and can remove the counterweight and spring force reduction balance device to reduce The body weight and wear of the robot improve the stability and durability of the robot.

Technical scheme of the present invention is as follows:

The invention provides a handling and palletizing robot, comprising a base, a rotating frame mounted on the base and capable of rotating around the vertical direction, consisting of a lower arm, a lower arm, an upper arm and an upper arm A first four-bar linkage mechanism, and an end effector posture holder; the first four-bar linkage mechanism is installed on the rotating frame through a first connecting shaft at the intersection of the centerlines of the lower arm and the lower forearm, form the shoulder joint of the robot; the lower arm is connected with the upper forearm through the second connecting shaft to form the elbow joint of the robot; the outwardly protruding side end of the upper forearm is connected with the The end effector attitude holders are connected to form the wrist pitch joint of the robot, and the end effector attitude holder is also equipped with an end effector that can rotate around the vertical direction; it is characterized in that:

The first four-bar linkage mechanism is a parallel four-bar linkage mechanism;

The handling and palletizing robot also includes a shoulder joint driving element, and the shoulder joint driving element drives the lower arm to move around the shoulder joint through the first crank rocker mechanism arranged on the rotating frame;

The handling and palletizing robot also includes an elbow joint driving element, and the elbow joint driving element drives the upper small arm around the elbow through the second crank rocker mechanism and the first four-bar linkage mechanism arranged on the rotating frame. joint movement;

The handling and palletizing robot also includes a posture maintaining mechanism, through which the lower surface of the posture holder of the end effector is always kept horizontal during the working process.

As an embodiment of the present invention, the posture maintaining mechanism is composed of a motor assembly arranged at the wrist pitch joint, and the posture maintaining mechanism adjusts the end effector in real time according to the posture of the first four-bar linkage mechanism. The included angle between the attitude holder of the end effector and the upper forearm makes the lower surface of the attitude holder of the end effector always keep horizontal during the working process.

As another embodiment of the present invention, an "L"-shaped connecting piece can also be installed on the first four-bar linkage mechanism, and one end of the "L"-shaped connecting piece is connected to the rotating shaft through the first connecting rod. The frame is connected to form a second four-bar linkage mechanism together with the lower arm; the other end of the "L"-shaped connecting piece is connected to the attitude holder of the end effector through a second link, and is connected to the upper arm. The small arms together form the third four-bar linkage mechanism, the second four-bar linkage mechanism and the third four-bar linkage mechanism are both parallel four-bar linkage mechanisms, and both form the posture maintaining mechanism. This design method has obvious advantages when the goods to be handled or carried are heavy.

The present invention has a simple and compact structure, and drives the arm of the robot to move through the crank rocker mechanism composed of the motor-screw nut assembly, which greatly reduces the requirements for the driving motor during the working process of the palletizing robot, thus eliminating the need for counterweights and springs The force-reducing balance device effectively reduces the weight of the robot body, which has low cost and energy consumption, light weight and small wear, and good stability and durability.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of ABB IRB 660.

Figure 2 is a schematic diagram of the structure above the rotating frame of a traditional palletizing robot represented by ABB IRB 660.

Fig. 3 is a schematic structural diagram of the above part of the rotating frame in the present invention.

Fig. 4 is a three-dimensional schematic diagram of the overall structure of a typical embodiment of the present invention.

Fig. 5 is a schematic front view of the overall structure of a typical embodiment of the present invention.

Fig. 6 is a schematic diagram of a crank rocker mechanism in a typical embodiment of the present invention.

Fig. 7 is a schematic diagram of an arrangement of a typical embodiment of the present invention in an industrial production line.

1 of them: base. 2: Rotary shaft assembly. 3: Rotate the rack. 4: Elbow drive motor. 5: lower arm. 6: upper arm. 7: Lower forearm. 8: Upper forearm. 9: The first connecting rod. 10: "L" type connector. 11: Second connecting rod. 12: End effector posture holder. 13: End effector. 14: End effector rotation motor. 15: spring force reduction balance device. 16: Shoulder joint driving motor.

H: connecting shaft. V: connecting shaft. B: connecting shaft. C: connecting shaft. D: connecting shaft. G: connecting shaft. E: connecting shaft. P: connecting shaft. O: Connect the axis. U: connecting shaft. M: connecting shaft. N: connecting shaft.

201: Base. 202: Rotary shaft assembly. 203: rotating frame. 204: the connecting part of the lower arm. 205: lower arm. 206: upper arm. 207: Lower forearm. 208: Upper forearm. 209: First link. 210: "L" type connector. 211: Second connecting rod. 212: End effector attitude maintainer. 213: End effector. 214: connecting rod connecting piece. 301: a rotating frame driving motor. 302: the driving motor of the shoulder joint. 241: the first motor support member. 251: First nut. 261: First nut. 271: the first leading screw. 303: Elbow joint driving motor. 242: the second motor support member. 252: Second nut. 262: Second nut. 272: the second leading screw. 304: End effector rotation motor. 231: the first telescopic mechanism. 232: the second telescopic mechanism. 20: Handling and palletizing robot. 21: Conveyor line for items to be transported. 22: Items to be moved. 23: pallet transport line. 24: Item tray.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and typical embodiments.

The present invention is formed on the basis of existing articulated palletizing robot (similar to the IRB 660 of ABB Robotics). The palletizing robot disclosed in the present invention does not drive the robot arm through a motor-reducer like IRB 660, but uses a crank rocker mechanism to drive. As shown in Figure 3, along with the expansion and contraction of the first telescopic mechanism 231 (using a motor-screw nut assembly or a hydraulic drive mechanism that can realize corresponding functions, etc.), the lower arm 205 of the robot will revolve around the rotating frame 203 The connecting shaft H on the top is the rotation of the shoulder joint of the robot. Similarly, with the expansion and contraction of the second telescopic mechanism 232 (using a motor-screw nut assembly or a hydraulic drive mechanism that can realize corresponding functions, etc.), the robot's The lower forearm 207 rotates around the connecting axis H, and the upper forearm 208 of the robot is driven to rotate around the elbow joint at the connecting axis C through the first parallel four-bar linkage mechanism. Electric drive is the most widely used drive mode at present. It is characterized by convenient power supply, fast response, large drive force, convenient signal detection, transmission and processing, and can adopt a variety of flexible control methods. Therefore, the present invention preferably adopts motor- —The driving mechanism of screw nut assembly, which is a force-increasing driving mechanism, is used together with the crank rocker mechanism described above to drive the robot arm. Using this scheme, the requirements for the driving motor in the working process of the stacking robot can be greatly improved , so there is no need for counterweight and spring force reduction balance device, which effectively reduces the weight of the robot body. It has low cost and energy consumption, light weight and small wear, good stability and durability.

A typical embodiment of the present invention is disclosed below with reference to FIG. 3 to FIG. 6 .

A handling and palletizing robot, including a base 201, a rotating frame 203, a first four-bar linkage mechanism composed of a lower arm 205, a lower arm 207, an upper arm 206, and an upper arm 208, and an end effector attitude The holder 212; the rotating frame 203 is installed on the base 201 on the ground through the rotating shaft assembly 202 and can rotate around the vertical direction. This is the waist joint of the robot. The rotation of the waist joint is driven by the rotating frame drive motor 301 to drive; the lower arm 205, the lower arm 207, the upper arm 206 and the upper arm 208 are connected by connecting shafts H, V, B, and C to form a first parallel four-bar linkage mechanism, wherein, VH//BC , VB//HC, and VH=BC, VB=HC; the first parallel four-bar linkage mechanism is installed on the rotating frame 203 by means of the connection axis H, where the connection axis H is the shoulder joint of the robot ;

The lower arm 205 is fixedly connected with the lower arm connecting piece 204 to form an "L"-shaped bar that can rotate around the H axis;

The shoulder joint driving motor 302 is installed on the first motor support 241 on the rotating frame 203 that can rotate around the connecting axis M, and the first nut 251 is installed on the lower arm connecting member 204 through the connecting axis N. , and can rotate around the connecting axis N, the first nut 261 is fixedly installed on the first nut 251, the first lead screw 271 is fixedly connected with the shoulder joint drive motor 302 through a coupling, and the above components are composed The first crank rocker mechanism, the "L"-shaped rod can be used as the rocker in the first crank rocker mechanism in the first telescopic mechanism 231 (by the motor-lead screw nut assembly, that is, the shoulder joint drive motor 302, The first lead screw 271 and the first nut 261) rotate around the connecting axis H, that is, the rotation of the large arm of the articulated robot around the shoulder joint is realized.

Similarly, the elbow joint drive motor 303 is installed on the second motor support 242 on the rotating frame 203 that can rotate around the connection axis U, and the second nut 252 is installed on the lower arm through the connection axis V. 207, and can rotate around the connection axis V, the second nut 262 is fixedly installed on the second nut 252, the second lead screw 272 is fixedly connected with the elbow joint drive motor 303 through a coupling, and the above components are then Form the second crank rocker mechanism, like this, described lower arm 207 just can be used as the rocker in the second crank rocker mechanism in the second telescoping mechanism 232 (by motor---leading screw nut assembly is the elbow joint drive motor 303 , the second lead screw 272 and the second nut 262) to rotate around the connecting axis H, the upper arm 208 can realize the rotation around the connecting axis C through the first parallel four-bar linkage mechanism, and the The connection axis C can be regarded as the elbow joint of the robot, so that the rotation of the forearm of the robot around the elbow joint is realized.

Because the present invention uses the crank rocker mechanism and the force booster such as the lead screw nut, the torque requirement for the drive motor is greatly reduced, which is beneficial to reduce the cost of the robot.

If it is necessary to improve and lower the requirements for the shoulder joint drive motor 302 and the elbow joint drive motor 303, a reducer or other components that can achieve similar functions can be installed at the connection between the shoulder joint drive motor 302 and the elbow joint drive motor 303 and the lead screw respectively. .

The end of one side protruding outward of the upper arm 208 is connected with the end effector attitude holder 212 through the connection axis P, where the connection axis P is the wrist pitch joint of the robot, and the handling and palletizing robot also A posture maintaining mechanism is included, through which the lower surface of the end effector posture holder 212 is always kept horizontal during the working process.

In one embodiment, the posture maintaining mechanism is composed of a motor assembly arranged at the wrist pitch joint, and the posture maintaining mechanism adjusts the posture of the end effector in real time according to the posture of the first four-bar linkage mechanism The included angle between the holder and the upper forearm makes the lower surface of the end effector attitude holder 212 always keep horizontal during the working process.

In another embodiment, the posture maintaining mechanism is composed of two parallel four-bar linkages, the specific form of which is shown in Fig. 3 and Fig. An "L"-shaped connecting piece 210 is installed at the connecting axis C, the "L"-shaped connecting piece 210, the first connecting rod 209, the lower arm 205 and the connecting rod installed on the rotating frame 203 The connecting piece 214 is connected to form a second parallel four-bar linkage mechanism through connecting axes G, O, H, and C, wherein, HO//CG, HC//OG, and HO=CG, HC=OG, that is, the quadrilateral HCGO is A parallelogram; the "L"-shaped connecting piece 210, the second connecting rod 211, the upper arm 208 and the end effector posture holder 212 are connected by connecting axes D, E, P, and C to form a third parallelogram In the link mechanism, DC//EP, DE//CP, and DC=EP, DE=CP, that is, the quadrilateral CDEP is a parallelogram.

The following will prove that according to the above-mentioned setting method, that is, using the posture holding mechanism composed of the second parallel four-bar linkage mechanism and the third parallel four-bar linkage mechanism can ensure that the lower surface of the end effector posture holder 212 Always keep level while the robot is working. As shown in Figure 3, first, the centerline HO of the connecting shaft H and the connecting shaft O remains stationary relative to the rotating frame 203, according to the geometric position relationship CG//HO, CD//PE, and CG and CD are "L The center line on both sides of the "type connector, so CG is stationary relative to CD, so relative to the rotating frame 203, PE will maintain translational motion, so that the lower end surface of the end effector position holder 212 will remain horizontal during the operation of the robot . This design has obvious advantages when the goods to be handled or carried are heavy.

The robot end effector 213 can rotate around the vertical direction under the action of the end effector rotation motor 304 installed on the end effector attitude holder 212 to form an end effector rotary joint of the robot.

Fig. 7 is an arrangement of a handling and palletizing robot 20 disclosed in this invention in an industrial production line. The handling and palletizing robot 20 transports the article 22 to be transported from the source point on the article conveying line 21 to the destination point above the article pallet 24 on the pallet conveying line 23 along the direction indicated by the arrow in FIG. On the 24th, the article 22 to be transported is put neatly in yards, and after the shipment is completed, the production line goes down along the direction of the arrow among Fig. 7 .

Combined with different robot end effectors, the handling and palletizing robot disclosed in the present invention can transfer the goods to be processed from the source point to the target point, and complete the corresponding loading, unloading, cargo transportation, palletizing, depalletizing, etc. Various jobs.

Claims (5)

1. A handling and palletizing robot, comprising a base, a rotating frame that is installed on the base and can rotate around the vertical direction, the first arm composed of the lower arm, the lower arm, the upper arm and the upper arm Four-bar linkage mechanism, and end effector attitude maintainer; The first four-bar linkage mechanism is installed on the rotating frame through the first connecting shaft at the intersection of the lower arm and the center line of the lower arm to form the shoulder joint of the robot; the lower arm is connected through the second The axis is connected with the upper forearm to form the elbow joint of the robot; the end of one side protruding outward of the upper forearm is connected with the attitude holder of the end effector through the third connecting shaft to form the wrist of the robot. In the pitch joint, an end effector that can rotate around the vertical direction is also installed on the attitude holder of the end effector; it is characterized in that: The first four-bar linkage mechanism is a parallel four-bar linkage mechanism; The handling and palletizing robot also includes a shoulder joint driving element, and the shoulder joint driving element drives the lower arm to move around the shoulder joint through the first crank rocker mechanism arranged on the rotating frame; The handling and palletizing robot also includes an elbow joint driving element, and the elbow joint driving element drives the upper small arm around the elbow through the second crank rocker mechanism and the first four-bar linkage mechanism arranged on the rotating frame. joint movement; The handling and palletizing robot also includes a posture maintaining mechanism, through which the lower surface of the posture holder of the end effector is always kept horizontal during the working process; The posture maintaining mechanism is composed of a motor assembly arranged at the wrist pitch joint, and the posture maintaining mechanism adjusts the position of the end effector and the upper small arm in real time according to the posture of the first four-bar linkage mechanism. an angle between the arms, so that the lower surface of the end effector attitude holder is always kept horizontal during operation; or An "L"-shaped connecting piece is installed on the first four-bar linkage mechanism, and one end of the "L"-shaped connecting piece is connected with the rotating frame through the first connecting rod, together with the lower arm A second four-bar linkage mechanism is formed; the other end of the "L"-shaped connecting piece is connected to the end effector posture holder through a second link, and forms a third four-bar linkage mechanism together with the upper arm; Both the second four-bar linkage mechanism and the third four-bar linkage mechanism are parallel four-bar linkage mechanisms, and they form the posture maintaining mechanism. 2. The handling and palletizing robot according to claim 1, characterized in that: the shoulder joint driving element is a motor-screw nut assembly. 3. The handling and palletizing robot according to claim 1, characterized in that: the shoulder joint drive element is a hydraulic drive mechanism. 4. The handling and palletizing robot according to claim 1, characterized in that: the elbow joint driving element is a motor-screw nut assembly. 5. The handling and palletizing robot according to claim 1, characterized in that: the elbow joint drive element is a hydraulic drive mechanism.

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