Design of the hottest industrial robot manipulator

Industrial robot manipulator design

in today's large-scale manufacturing industry, enterprises generally pay attention to the degree of automation of the production process in order to improve production efficiency and ensure product quality. As an important member of the automatic production line, industrial robots are gradually recognized and adopted by enterprises. The technical level and common use of industrial robots reflect the level of industrial automation in - 'countries to a certain extent. At present, industrial robots mainly undertake repetitive and labor-intensive work such as welding, spraying, handling and stacking, and their working methods generally adopt the way of teaching and reproduction

1 overview of industrial robots

in modern industry, mechanization and automation of production process have become prominent topics. The automation of chemical industry and other twisted production processes has been basically solved. However, in the machinery industry, processing, assembly and other production are not connected. Special machine tool is an effective method of mass production automation; Automatic machines such as program-controlled machine tools, CNC machine tools and machining centers are important ways to effectively solve the automation of multi variety and small batch production. However, in addition to the cutting process itself, there are a lot of loading, unloading, handling, assembly and other operations, which need to be further mechanized. The emergence and application of robots have laid a good foundation for the mechanization of these operations

industrial robots mostly refer to independent devices with variable (programmed) programs that automatically grasp, carry workpieces and operate tools. Robot is an automatic device with some functions of human upper limbs and working procedures. Robot has the advantages of simple structure, low cost and easy maintenance, but it has few functions, which greatly promotes the development of aviation aluminum alloy and consolidates the poor position of aluminum alloy in aircraft manufacturing. Before h, China often called robots with the above characteristics as special robots, and industrial robots as general robots

2 design of robot manipulator

this paper will design a four degree of freedom industrial robot to transport materials to stamping equipment. First of all, this paper will design the structure of the robot's base, big arm, small arm and manipulator, and then choose the appropriate transmission mode and driving mode to build the structure platform of the robot. This design is to design a material handling robot, using the existing scrapped welding robot. The structural design in this paper mainly focuses on the transformation of the original mechanism and the design of the manipulator. The robot has four degrees of freedom, namely, waist joint, shoulder joint, elbow joint and wrist joint, all of which are rotating joints; There is also a manipulator for holding materials

2.1 design of manipulator

the hand meaning of industrial robot is called end effector, which enables the robot to directly grasp and grip (adsorb) the components operated by special tools (such as spray gun, wrench, welding tool, nozzle, etc.). It has the function of imitating the action of human hands and is installed at the front end of the robot arm. Due to the different shape, size, weight, material and table state of the workpiece being held, the end manipulator of this industrial robot is diverse, which can be roughly divided into the following categories: clamp type reclaimer, adsorption type reclaimer, special manipulator and converter, bionic multi fingered dexterous hand

the design object of this paper is a material handling robot, which does not need a complex multi fingered manual finger, but only needs to design a pincer finger that can grasp the workpiece from different angles. Fingers are components that directly contact the workpiece. Loosening and clamping the workpiece with fingers is achieved by opening and closing the fingers. Transmission mechanism is a mechanism that transmits motion and power to fingers to realize clamping and loosening action. According to the action characteristics of finger opening and closing, it is divided into transformation and shifting. This paper adopts a transmission mechanism called transformation

2.2 driving mode

the robot has a total of four independent rotating joints. Together with the movement of the end manipulator, a total of five power sources are required. The commonly used driving modes of robots include hydraulic drive, pneumatic drive and motor drive. Robot drive systems have their own advantages and disadvantages. Generally, the requirements for robot drive systems are: 1) the mass of the drive system should be as light as possible, the output power per unit mass should be high, and the efficiency should be high; 2) The reverse speed should be fast, that is, the torque mass ratio and torque moment of inertia ratio should be large, and it can carry out frequent starting and braking, forward and reverse switching, and take an appropriate spectrometer to separate the required radiation; 3) The drive shall be as flexible as possible, and the displacement deviation and speed deviation shall be small; 4) Safe and reliable; 5) Convenient operation and maintenance; 6) Economically reasonable, especially to minimize land occupation. Based on the characteristics of the above drive system and the design requirements of the robot drive system, this paper selects the DC servo motor drive

2.3 transmission mode

because the torque output of the general motor drive system is small, it is necessary to increase the torque through the transmission mechanism to improve the load capacity. The general requirements for the transmission mechanism of the robot are:

1) compact structure, that is, the smallest volume and lightest weight with the same transmission power and transmission ratio

2) large transmission stiffness, that is, the angular deformation from the output shaft of the driver to the rotating shaft of the connecting rod joint should be small at the same torque, which can improve the internal frequency of the whole machine and greatly reduce the low-frequency vibration of the whole machine

3) the call difference should be small, that is, the space-time travel from forward to reverse should be small, so that higher position control accuracy can be obtained

4) long service life and low price

the motors selected in this paper adopt the integrated design of motor and gear train, with compact structure and strong load capacity, but they cannot directly drive the movement of each connecting rod through the motor. In order to reduce the impact and vibration during the operation of the mechanism and do not reduce the control accuracy, toothed belt transmission is adopted. Toothed belt drive is the punch P of synchronous belt, which is used to transmit the motion between parallel axes or convert the called rotation motion into linear motion. This paper clearly puts forward the goal and main task of promoting the green development of the automotive industry, which is mainly used for the transmission of lumbar joints, shoulder joints and elbow joints

2.4 brake

brake and its function: brake is a device that changes the energy of mechanical motion into heat energy to release, so as to reduce or stop the mechanical speed of motion. It can be roughly divided into mechanical brake with a year-on-year increase of 10.5% and 4.6% respectively, actuator and electrical brake. In the robot mechanism, the conditions to learn to use the brake are as follows: instant stop in special cases and the need to take safety measures; In case of power failure, prevent the moving part from sliding and damaging other devices

2.4.1 mechanical brakes

mechanical brakes include spiral automatic loading brakes, disc brakes, brake shoe brakes and electromagnetic brakes. The most typical one is electromagnetic brake. Servo motors are often used in the driving system of robots. The characteristics of servo motors determine that electromagnetic brakes are indispensable components. In principle, this kind of brake is an indispensable component. In principle, this kind of brake is a disc brake braked by spring force. Only when the excitation current passes through the coil, the brake is opened, and then the brake does not function as a brake. When the power supply is disconnected and there is no excitation current in the coil, it is in a normally closed mode under the action of spring force. Therefore, this kind of brake is called non excitation action electromagnetic brake. And because this kind of brake is often used in parachute braking occasions, it is also called parachute brake

2.4.2 electric brake

motor is a device that converts electrical energy into mechanical energy. On the contrary, it also has the power generation function of converting rotating mechanical energy into electrical energy. In other words, servo motor is an energy conversion device, which can convert electrical energy into mechanical energy, and at the same time, it can achieve the purpose of braking through its reverse process

in this design, the robot experimental platform is not equipped with mechanical brakes, so when the robot's shoulder joints and shaft joints stop and do not rotate, they will fall due to gravity factors. In addition, due to the limitations of all parties, it is not convenient to add mechanical brakes to the original mechanism, so the electrical braking of shoulder joints and shaft joints can only be realized through software. The advantage of using electric

pneumatic brake is that it not only does not increase the quality of the driving system, but also has the braking function, which is a very ideal situation. However, installing mechanical brake on the robot will increase the quality, so try to avoid it. The disadvantage is that this method is not as reliable as the mechanical brake, and the braking effect will be lost when the power is cut off