As shown in the example, there are two cutting belts at the bottom of the cross section of the horizontal axis machining center. These special processing belts are spiral, and they collect chips along the guide grooves.
And transport them to the collection point, and another system will choose the chain conveyor belt.
Selection of cutting tools
(23) The machining center can require effective cost control. They usually move at least twice a day, so they must be effective.
And the purchase demand of products can be constantly adjusted in the machining center, because they have fixed universality, but the machining center can be used to manufacture a wide range of special products in time.
(24) The choice of the type and size of machining center depends on the following factors.
A. product type, size and mold complexity.
B. The types and execution methods of machining methods and the times required for cutting tools.
C. accurate compensation is needed.
D. the demand for productivity.
(25) Although versatility is a key factor in choosing a machining center, we must consider the need to balance high cost and high precision, and compare it with manufacturing using traditional machining tools.
The cost of the product.
Unit 5 Industrial Robots
introduce
Industrial robot is a relatively new mechanical and electrical equipment, which has begun to change the face of modern industry. Industrial robots do not have the ability of people in science fiction, and can establish friendship with other moving objects. The research that robots can see and hear tactile hearing has been carried out for more than 20 years, and now it has begun to bear fruit. However, what is usually called industrial robot technology is that most robots only contain one arm, instead of all human anatomical structures. The usual control only allows these robots to move from one point to another in space to complete relatively simple work. The American Robotics Society defines a robot as a "reprogrammable multifunctional robot hand, which can accomplish different tasks through various programmable operations and be used to move raw materials, parts, tools and special equipment. If we think that different types of processing have different functions. Then the NC machining center can also be considered as a robot. Most manufacturing engineers think that NC machining centers are not robots, although they have many similarities. The power drive and control of NC mechanism and robot are very similar. Like numerical control mechanism, robot can be powered by engine, hydraulic system and pneumatic system. Both devices can be controlled by open loop or closed loop. In fact, many technologies applied to robot development have evolved from the CNC industry, and many robot manufacturers also manufacture CNC machine tools and controllers.
A real robot consists of a body with a wrist (or arm) and tools (usually some supports) at the end of the machine. Robots may also have auxiliary power systems. The robot system also includes a controller with some control loops, joysticks and buttons. A typical robot system is shown in Figure 5, 1.
The characteristics of robots are usually expressed by the design of mechanical systems. A robot whose main frame includes three axes of motion is called a cartesian robot. Cartesian robot, its name comes from the linear motion of Cartesian coordinate system along three-dimensional space. Some Cartesian robots are made of gantry structure to minimize the deviation along each axis. These robots are called gantry robots. Figure 5.2 shows a Cartesian robot whose motion control is similar to the traditional three-coordinate machine tool. Generally speaking, the gantry structure is the most correct actual structure of the robot. Gantry robots are usually used in assembly with small tolerance and high position requirements.
A cylindrical robot consists of two moving shafts and a rotating shaft. The name of this robot comes from the orbit (its working range), which consists of the extreme position of axis movement. Figure 5.3 shows a typical cylindrical robot. Cylindrical robots have many applications, the most common of which is carrying materials.
Program the robot.
In order for a device to qualify as a robot, it must be easy to reprogram. A non-programmable mechanism, no matter how flexible it is through reassembly or rewiring, can't be regarded as a robot. Many of these devices are fixed or variable serial robots. Many such robots are driven by air pressure. This kind of robot drives to some fixed stop switches with the help of some trapezoidal logic diagrams, instead of controlling its trajectory. Although ladder diagram programming can meet the motion requirements of the robot, to change the task to be performed, the travel switch and stop must be moved normally. Power start or engine start to "on" or "off" depends on the requirements of the process and the conversion state. The robotic operation of such a system is usually limit to fairly simple applications.
Traditional robot programs usually take one of the following three forms: (1) operator programming (2) import program (3) offline program. Each robot usually has one or more systems of this program type. The advantages and disadvantages of each form are different according to different applications.
Manipulator programming is the most commonly used robot programming method. In this type of programming, the suspended console usually includes several joysticks for moving the robot within its working range. At the end of each process, the position of the robot is saved. Like CNC machine tools, some robots allow programmers to choose to define a route between two points. In addition, these robots are called continuous path systems. A system that doe not allow users to specify path is called a point-to-point system. Many continuous path robots allow users to define a path connecting two main points. Then, the user can define a straight line, arc path, and specify a location. In a straight path, the robot moves at both ends of a straight line in Cartesian space. As the name implies, circular motion is motion along an arc on the main plane. It is difficult to determine the execution route of robot insertion in a certain place. In joint interpolation, all joints of the robot move at a uniform speed to ensure that all axes start and stop at the same time. For Cartesian robots, straight line and node interpolation schemes produce the same path. This is not true for other types of robot systems.
Operator programming systems usually provide commands that allow programmers to complete auxiliary operations, such as closing the terminal, waiting, pausing, checking the state of one or more switches, returning all conditions to the machine tool, and so on. Programmers let robots go through the necessary steps to complete a job, and save every intermediate step and auxiliary information. Manipulator for programming fanuc M 1 robot, as shown in Figure 5.4.
Import program is one of the simplest robot programming processes. As the name implies, the programmer simply and practically moves the robot along the outline of the route. The robot controller feeds back its position and guides the robot to complete the operation like a programmer. When the programmer is responsible for guiding the robot to complete the necessary actions, the power is reduced so that the robot does not hurt the operator. Although lead-in programming is the easiest programming language to learn, it also reflects the limitations of some robot applications, such as the operator carrying the robot when the robot is operating. Gears, motors and lead screws will introduce wrong operation readings, so when the weight of the robot, perhaps the weight of the workpiece, must be borne by the system, the actual position of the end effector may be very different from the training position of the robot. Another problem in this way is that when the position and speed of the robot are recorded and guided through the expected path, a large number of data signals will be generated, and these data do not need to be stored and then called. The space and time for storing and calling may cause assembly problems. Perhaps the main problem of coordination with the import equation is that the person who guides the robot to complete the process can make limited accuracy, which may lead to disharmony in the process, and human errors and inaccuracies weaken the advantages of using the robot.
Off-line programming is a relatively new technology for robots, which can provide some advantages of import and control panel programming. The law of offline programming is similar to the application of offline language in numerical control technology. Major universities and industries in the United States have developed several offline languages. These languages mainly include VAL of unimation, ar-basic of American Robotics Association, Microbot of LNC, arm-basic and ami of ibm. Take AR-Basic as an example to explain offline language, and ar-bisic allows users.
Define the position of the robot
Control the movement of the robot
Input and output control data
In the improvement of ar-basis system, many of the same functions he used adopted the familiar basic programming language. In ar-basic, points and tools are defined as initialization data points, which are defined by the following protocols.
x，y，z，r，y
X, y and z represent the Cartesian space occupied by the end effector, and r p y represents the rotary feed and yaw of the tool. The definition of each point can be absolute or relative (CNC machine tools have similar rules).
The tool definition command is usually used to define the positions of all tools required for operation. The tool definition specifies the center of the robot panel, including six data with the same definition points.
Robots perform motion through motion control commands, which allow programmers to define path types (straight line, arc, node interpolation).
Defines the final speed of the tool.
Define reference frame
Defines the categories of tooltips.
AR-Basic also allows programmers to input and output data to devices connected to robots, and analog digital signals can be transmitted to parallel or serial I/O ports of analog-to-digital converters. Table 5- 1 is an example of point and tool definition. Table 5-2 illustrates the motion control of AR-Basic.
Unit 6 Group Technology
Grouping technology is a philosophical concept in manufacturing industry, which involves identifying and grouping parts with similar or related attributes, so that we can use the similarity of products to apply this technology to the design, manufacturing and production process of product production. This novel technology first appeared in America in 1920. At that time, frederick taylor also agreed that the group's parts needed special technology, and then Jones and Lamson Machinery Company also agreed. In the early 1920s, this company produced machine tools by a crude grouping processing method. The way they use this principle is to divide departments by products, not by technology or shortening the path. Nowadays, group technology gains advantages through good structural classification and coding system and similar components used in application support software.
Modern manufacturing technology is facing the challenges brought by increasingly fierce international competition and rapidly changing market demand. The following challenges have been encountered in the Group's technology.
The first paragraph was omitted.
Due to the first factor, the traditional sales organization has become very inefficient and wasteful, all because of the extravagance and waste of products between different processing departments.
In order to shorten the preparation time, it is necessary to make the design and production links compact, so as to gain a relatively favorable position in the international market.
Benefits of product design. When it comes to product design, the main advantage of combinatorial technology is that it can help product designers avoid "re-designing wheels" (that is, repeatedly transforming) or increase the influence of design. In other words, it excludes the possibility of designing a designed product, because it makes storage easier and retrieval of engineering design relatively easier. If there is no design of precision parts in the company's computer files, the design will be close enough to the content that needs to be retrieved and adjusted to meet the demand. The further advantage of group technology is that it promotes the standardization of design features, such as fillet radius and chamfering, which leads to the standardization of production tools and production equipment.
2. Standardization of molds and installation. Because the parts are classified, the design of flexible production equipment can make it adapt to all kinds of processing in the same category processed in the same way, thus reducing the cost by reducing the number of fixtures. Similarly, the installation of a machine can also adapt to the whole category rather than independent components.
3. Existing
4. Improve the problem-based production economic system. Usually, mass production involves many non-standard parts. There seems to be nothing in common. Therefore, different types of grouping components make economic benefits only exist in mass production.
5. It's easier to arrange. Grouping parts helps to schedule tasks, so as to complete a process, rather than just processing a single part.
6. Reduce workflow and preparation time.
7 Faster and more reasonable process design. Group technology paves the way for automatic process planning, which can be realized by a suitable part classification and coding system. The code is stored in the detailed process drawing of each part for easy retrieval.
Unit 7
1 CAD/CAM (computer aided design) is a term of computer aided design or computer aided design. It is a technology that uses digital computers to complete specific functions in the process of design and production. This technology is developing in the direction of design and manufacturing. Traditionally, design and manufacturing are the combination of two independent processes in the production process. In a word, CAD/CAM will provide a technical basis for the future computer integration industry.
2. The computer system composed of hardware and software will perform the special design functions put forward by specific users. CAP hardware includes: computer. One or more terminals display images, keyboards and other external devices. CAD software includes computer programs that can run computer charts in its system and application programs that can provide convenience for the design work of company users. For example: component pressure analysis (program), machine dynamic response (program), heat exchange calculation program, and various control programs. Due to the differences in production lines, manufacturing processes and customer markets, various applications will change with the needs of different users, so these factories also bring about differences in the demand for CAD systems.
Computer-aided manufacturing (CAM) can be defined as planning, managing and controlling the operation of manufacturing plants by using computer systems and workshop production information through direct or indirect computer interfaces. Its definition shows that the application of computer-aided manufacturing can be divided into two categories: one category
Computer monitoring management is the most direct application of computer to monitor and manage the production process, which is directly related to the production process.
The second is the application supported by manufacturing industry, which means that computers are directly used in the production and operation of factories, but there is no interface between computers and manufacturing processes.
CAD/CAM system has a brand-new basic principle of drawing, any one of which can improve drawing efficiency. For example, most systems on the market at present have the inherent function of braking the emerging practical drawing technology. For example, layered technology enables drawings to be made according to logical structure, and immediately form a whole and be saved separately for identification, but these components cannot demonstrate the whole production process. This process is similar to the anatomical pattern we see in biology. Bones, nerves, internal organs, blood vessels and muscles are all replaced by plastics of different colors. They are treated as individuals or stacked together to show how the parts match. Layering and coloring through an image system use the same principle, unless the overlay is logical rather than physical. There are many such applications. Layering can also be used to distinguish English and digital dimension information from data information. Text information, electronic needs saw hammer detection, mechanical parts path, etc. The result is a clear pattern.
Advantages of other analysis:
CAD/CAM can also affect the company's engineering system in other ways, which can simplify all physical processes and allow re-evaluation of modern engineering methods and processes. CAD/CAM improves the quality assurance technology, and is naturally suitable for maintaining accuracy, improving documents and materials, and accurately recording parts quantity and bill of materials.
The correct installation of fully integrated CAD/CAM system promotes the company's evaluation of design and production methods, and creates standards suitable for these methods. Usually this kind of evaluation is proved to be effective, but it will also bring unexpected harm to those who are not prepared. Considering that the managers in these two aspects are very smart, the application of CAD/CAM is always a complicated matter.
What are the disadvantages?
The shortcomings of CAD/CAM may not be obvious, but even for the best design, it is destructive. Among them, the biggest disadvantage comes from the necessary jump from drawing sketches by hand and saving records to linear motion of CAD/CAM system. It's like installing a jet engine on a Volkswagen. At first, the car may travel very fast in a short time, but if the chassis is not strong enough to bear, all the designs will be out of vibration.
In other words, CAD/CAM will highlight the incompleteness of the most vulnerable areas in the work, which is cruel to people and cannot be maintained, just like a description of it: "If a company can't make good use of the bill of drawings and materials and some digital systems, the CAD/CAM system will make the problem worse."
When this unsatisfactory result appears, it is usually best to point the finger at the CAD/CAM system-although this is almost beyond reproach, it is usually better than pointing the finger at people or organizations. Any computer will only work when inputting data, which is the most basic data processing rule: waste in and waste out. If a company is using an incomplete directory control system, it is only because it is automatic. This system will not be improved. In fact, automation will make this incompleteness more obvious. And it may be more confusing. Therefore, when implementing CAD/CAM system, we should not only evaluate the technical requirements, but also improve the existing rules.
If managers are unwilling to evaluate the existing operating conditions, standards and technological processes, the use of CAD/CAM is likely to fail for a series of reasons. One of the reasons is that the management policy will not be well organized due to the separation of CAD/CAM system and standard operating process. Low-level managers will have a feeling that this system will never be effectively used by people. Another reason is that the information channels between different departments have not been established, which also leads to the feeling that CAD/CAM system can not be used for a long time. Another reason is that the operator did not input the aspects of system implementation, which led to the shortcomings of drawing standards, the lack of system management and the ignorance of system users. This cycle is unforgivable. In particular, the evaluation of standard operating conditions will directly provide suggestions for improving these processes, although CAD/CAM systems have never been used.
Application of CAD/CAM
CAD/CAM technology has gone through a long process from sketchpad to now, and is widely used in various industrial production, from space shuttle control to weapon research. From drawing to dynamic diagnosis, from circuit analysis to structural steel analysis. CAD/CAM is widely used in all aspects of drawing and manufacturing, from sketching video and audio equipment to controlling a large number of robot assembly lines, and its application is constantly developing.
CAD/CAM was first used in electronic manufacturing. This is because CAD/CAM is not a recognized technology outside the computer industry. People have realized the market demand of CAD/CAM in aviation and civil industry. With the help of drawing manual, manual drawing can no longer meet the new and complicated design. CAD/CAM has become an inevitable solution. Now this technology has a strong technical and financial foundation. Therefore, the potential users of CAD/CAM can meet the key requirements of final adoption, and they no longer need to buy inferior or useless equipment.
Today's CAD/CAM market;
At present, there are four kinds of CAD/CAM providers in the market. The first is the subsidiary or department of a large company. The CAD/CAM department of IBM is an example. These branches do a lot of business with his head office. They not only sell key systems, but also call the after-sales service office. Because these companies have strong backing, they operate well. However, they are also influenced by the binding style, which makes them unable to respond to market changes quickly and apply advanced technology to the production line to improve the performance of equipment.
The second is a specialized turnkey system supplier. These companies provide various CAD/CAM systems for different industrial environments. These companies have been engaged in CAD/CAM industry for several years or decades. They have established a good reputation in the continuous technological development. Such companies include. . . . Because of their small specifications, these enterprises sometimes can't provide good after-sales service, but they are very sensitive to the market, can meet customers' requirements well, and can provide various available CAD/CAM systems.
The first is a new CAD/CAM sales enterprise. These companies are small, young and innovative, but their market share is only 5%, but each company is good at providing unique high-quality systems for some markets. Usually, the micro monitoring systems sold by these enterprises are very useful for customers who need miniaturized and specialized CAD/CAM systems. In fact, these customers are well thought out before buying equipment.
The second is the service organization, which specializes in CAD/CAM services. Meet small or coordinated needs. Service organizations are becoming more and more common and become the first choice for companies that cannot afford to buy CAD/CAM systems or do not have the purchasing conditions. These institutions not only participate in commercial activities related to CAD/CAM, but also hold relevant training and seminars for enterprises that will consider purchasing their equipment.
Doing business with any type of supplier has advantages and disadvantages. Large companies are hard to bargain and slow in technological innovation, but most of them can provide good services and reliable products. Specialized sales enterprises are more flexible in customer demand and the product upgrade cycle is shorter.
1, CAD/CAM is a term for computer-aided design or manufacturing. It is a technology that uses digital computer to complete specific functions in the process of design and production, and this technology is developing to the process of combining design and manufacturing, which has always been regarded as independent and clearly divided in the production process. In a word, CAD/CAM will provide a technical basis for the future computer fusion industry.
2. The computer system is composed of hardware and software, and performs special design functions provided by specific users. Basic CAD hardware includes computers, one or more terminal mode displays, keyboards and other external devices. CAD software includes icons and programs that can run inside a computer system. Such as component pressure analysis program, dynamic response program, heat transfer calculation program and various control programs. Due to the differences in production line, manufacturing process and customer market, the application will change with the different needs of users. This also leads to the different requirements of CAD system.
3. Computer-aided manufacturing CAM can be defined as planning, managing and controlling the operation of manufacturing workshop by using computer system, direct or indirect computer interface and workshop production information. Its definition shows that the application of computer-aided manufacturing can be divided into two categories:
Improve drawing efficiency
1、
2、
Its potential is indeed unlimited, and the improvement of productivity is only limited by management principles. For example, the drawing center can be regarded as a builder who specializes in designing warehouses. Most of their work is repetitive and can be reused in one job.
For example, standard floors or stairs; Or a standard door or door frame, the system can complete this work in a few seconds, and the draftsman does not have to redesign the part that must be inserted into the drawing every time.
In addition, there are many macro programs used. When a group of buttons are combined together, the specifications of the drawing can be automatically converted into English numerical units, or the whole drawing can be automatically adjusted and rotated to an ideal orientation, or a bill of materials about complex engineering drawings can be generated.
5. Besides, the whole design process can be stored in the system. When a draftsman receives an assignment with similar drawing specifications, he only needs to call it again, introduce it into the work library, and then modify the specifications of the part of the new assignment that does not match the original drawing. In this way, the efficiency is improved, the original process is improved, and the next process is also improved, which shows that there is a perfect and well-divided database to be maintained and convenient for users to operate.
Unit 8 Flexible Manufacturing System
Flexible manufacturing system has many different definitions. In most cases, how to define it depends on the personal views of its users on its components and usage.
However, the following description is a summary of the definition of FMS, that is, active search and passive search resources.
U.S. government: A series of automatic machine tools and production and processing equipment projects are linked to the automatic material handling system. General level data is pre-programmed and controlled by the computer, which is ready for any part or combination produced and processed to be included in a given part group.
Kvearney and Tvrecker:FMS is a part of CNC machine tools. Under the control of the central computer, it can assemble parts at will, automatically handle materials and dynamically balance the utilization of resources. Therefore, the system can automatically adapt to the changes of parts production, product variety composition and output.
FMS is an automatic system that can assign tasks at will. This system is based on leasing manufacturing technology, combined with computer integrated control and a set of machine tools that can process parts continuously and automatically.
FMS combines microelectronics technology and mechanical engineering to make mass production more economical. Machine tools and other workstations controlled by the central online computer can complete the transmission and processing of parts. Computers can also improve monitoring and information control, which combines flexibility with global control, making small batch and large-scale production possible.
Carry out diversified production of controlled parts and products within the existing production capacity and the predetermined planned scope.
The technology to help excellent factories get faster processing time is to achieve lower unit cost and higher quality production under a higher level of management and central control.
Basically, FMS consists of software and hardware. The hardware part is visible and touchable. For example: CNC machine tools, rotating trays, material conveying equipment (robots, automatic guided cars), focusing on chip removal system, tool magazine, coordinate measuring machine, workpiece cleaning table, computer hardware equipment. The software part is invisible and intangible, such as numerical control program, traffic management software, tool information, working sequence file of coordinate measuring instrument, complex FMS software and so on. Figure 8. 1 is a typical FMS layout and its main dynamic components and identifiable components.
Ninth unit
In order to understand the limiting factors of improving the comprehensive productivity of automation, the following analogy is made. Assuming that all kinds of auxiliary systems of a car have been automated, the driver's work will become easier, and he will automatically accelerate, decelerate, turn and brake.
Will be more effective than manual operation. However, think about what will happen. If these automatic auxiliary systems are not connected to a certain extent, that is, they cannot communicate and share accurate and up-to-date information immediately and continuously, and one system tries to speed up and the other system tries to brake. Automated manufacturing equipment also has the same constraints, which leads to another stage of manufacturing technology development: integration.
Unit 15
Using air shaft to realize the translation movement of sliding ruler. In order to minimize friction and reduce the consequences caused by slide defects, a suitable air source is needed.
The movement of the base shaft depends entirely on the cheap manual three-coordinate measuring instrument. Most manual machines are equipped with an accurate handwheel device, although many users prefer to move the slider directly by hand.
More expensive machines use motor-driven shaft drives, DC servo motors run through special mechanisms, and each shaft has an instant switch to control and allow manual control movement.
Introduce yourself 1
My name is xx, and I am a lively, cheerful, enterprising and strong girl. I have my own