(22) Because of the high production capacity of the machining center, a large amount of cuttings will be produced and must be collected. This requires some designs that can be used for cutting collection processing, as shown in the figure
As an example, two cutting conveyors are shown at the bottom of the cross-section of a transverse axis machining center. These special machining conveyors are spiral or screw type. They collect cuttings along guide grooves and transport them
To the collection point, another system will use a chain conveyor.
Choice of Tools
(23) Machining centers can have the ability to require effective spending and can be said to carry out effective cost control. They usually have to make at least two moves a day, so they Must be efficient
and can continuously adjust the purchase demand for products in machining centers because of their fixed versatility, but machining centers can be used to manufacture a wide range of special products in a timely manner.
(24) The selection of type and size of machining center depends on the following factors.
a. Product type, size and mold complexity.
b. Types of machining methods and execution methods and the number of times cutting tools are required.
c. The need for precise compensation.
d. production rate requirements.
(25) Although versatility is a key factor in selecting a machining center, we must consider the trade-off between high cost and high precision requirements and the comparison between using traditional machining tools to manufacture the same product
time cost.
Unit5 Industrial Robot
Introduction
Industrial robot is a relatively new electromechanical device that has begun to change the face of modern industry. Industrial robots are not like those in science fiction novels with human-like abilities and the ability to form friendships with other moving objects. Research on robots that can see, hear, touch and hear has been going on for more than 20 years and is now beginning to bear fruit. However, what is commonly referred to as industrial robotics is that most robots only contain one arm rather than the full structure of human anatomy. Normal controls only allow these robots to move from point to point in space to complete relatively simple tasks. The American Robotics Society defines a robot as "a reprogrammable, multi-functional robot hand that completes different tasks through various programmable operations and is used to move raw materials, parts, tools, and special devices. If different types are considered The machining has different functions. Then a CNC machining center can also be considered a robot. Most manufacturing engineers believe that CNC machining centers are not robots, although they have many similarities in the power drive and control of CNC machines. Like CNC mechanisms, robots can be powered by engines, hydraulic systems, and pneumatic systems. Both devices can be controlled by open-loop or closed-loop control. In fact, many technologies used in the development of robots have evolved from the CNC industry and many robot manufacturers have also. Manufacturing CNC machine tools and CNC controllers.
The actual robot consists of a main body with a wrist (or arm) and a tool (usually some support) at the end of the machine. There may be an auxiliary power system. The robot system also includes a controller with some control rings, operating rods, and keys. A typical robot system is shown in Figure 5, 1.
Robot features are usually composed of mechanical systems. The design shows that a robot whose main frame includes three moving axes is called a Cartesian robot. Its name comes from the Cartesian coordinate system that moves along a straight line in a three-dimensional space. Some Cartesian robots are composed of gantry structures so that they can move along each axis. The deviation of each axis is minimal. Figure 5.2 shows the Cartesian robot. The motion control of these robots is generally the most correct gantry robot structure. Usually used in assemblies with tight tolerances and high positioning requirements.
A cylindrical robot consists of two axes of movement and one axis of rotation. The name of this robot comes from the surrounding trajectory (its range of work), which consists of the extreme positions of the axis movement. Figure 5.3 shows a typical cylindrical robot. Cylindrical robots have many applications, the most common being material handling operations.
Program the robot.
In order for a device to qualify as a robot, it must be easily reprogrammable. Mechanisms that are not programmable, no matter how potentially flexible they may be through reassembly or rewiring, do not count as robots. Many of these devices are fixed or variable sequence robots. Many of these robots are powered by air pressure. Instead of controlling its trajectory, the robot is driven to some fixed stops or travel switches using some kind of ladder logic. Although ladder diagram programming can meet the movement requirements of the robot, the travel switches and stops must be moved normally as a whole to change the work tasks that need to be performed. The power starts or the engine turns to "on" or "off" according to the process requirements and conversion status. Robotic operation of such systems is usually limited to fairly simple applications.
Traditional robot programs usually take one of the following three forms: (1) operator programming (2) imported program (3) offline program. Each robot usually has one or more systems of this program type. The advantages and disadvantages of each form vary depending on the application.
Manipulator programming is the most common way of programming a robot. With this type of programming, a pendant usually includes several operating levers that are used to move the robot within its working range. At the end of each process, the robot's position is saved. Like CNC machines, some robots allow programmers the option of defining a route between two points. Additionally, these robots are known as continuous path systems. Systems that do not allow users to specify paths are called point-to-point systems. Many continuous path robots allow the user to define a path connecting two major points. Then, users can define straight lines, arcs, and paths specifying a certain location. In a straight path, the robot moves in Cartesian space with two endpoints of the straight line. As the name suggests, arc motion is motion along a circular arc on a certain main plane. It is not easy to determine the execution path of the robot in order to insert somewhere. In contact interpolation, each joint of the robot moves at a constant speed to ensure that all axes start and stop at the same time. For Cartesian robots, straight line and nodal interpolation schemes produce the same path. This is not true for other types of robotic systems.
Operator programming systems usually provide commands that allow programmers to complete auxiliary operations, such as closing the terminal, waiting, pausing, checking one or several conversion states, returning all conditions to the machine tool, etc. Programmers walk the robot through the necessary steps required to complete a job, saving each intermediate step and supporting information. The operator used to program the fanuc M1 robot is shown in Figure 5.4.
Imported programming is one of the simplest robot programming processes. As the name suggests, the programmer simply moves the robot along the contours of the route. The robot controller feeds back its position and acts like a human programmer to guide the robot through operations. When the programmer is responsible for guiding the robot through necessary actions, power is reduced so that the robot does not harm the operator. Although import programming is the easiest programming language to learn, it also reflects the limitations of some robot applications, such as when the robot is in operation and the operator carries the robot. Gears, motors, and lead screws can introduce erroneous computational readings so that when the weight of the robot, and perhaps the weight of the workpiece, must be borne by the system, the actual position of the end effector may be significantly different from the robot's trained position.
Another problem with this approach is that since the robot's position and speed are recorded to guide it through the desired path, a large amount of data signals are generated. This data does not need to be stored and recalled later. The space and time of storage and recall may cause assembly Perhaps the main problem with the coordination of the imported equations is that the human guiding the robot through the process can do so with limited accuracy which can cause inconsistencies in the process, human error and inaccuracy that undermine the advantages of using robots.
Offline programming is a relatively new technology for robots and offers some of the advantages of import and control board programming. The rules of offline programs are similar to the application of offline languages ??to CNC technology. Several offline languages ??have been developed at major universities and industries in the United States. These languages ??mainly include VAL of unimation, ar-basic of the American Robot Association, microbot, arm-basic of lnc and ami of ibm. Taking ar-basic as an example to explain the offline language, ar-bisic allows users to
Defining the position of the robot
Controlling the movement of the robot
Input and output control data
A refinement of the ar-basis system, which uses many of the same functions The familiar basic programming language is used. In ar-basic, points and tools are defined as initialization data points defined by the following protocol
x, y, z, r, y
X, y, z represent the Cartesian space occupied by the end effector, r p y represents the tool rotation feed and yaw. The definition of each point can be either absolute or relative (also has similar rules to CNC machine tools )
The tool definition command is often used to define the positions of all tools required by the operation. The tool definition specifies the center of the robot panel, including six data with the same definition point
The robot is controlled by motion The command executes the motion. The motion command allows the programmer to define the type of path taken (straight line, arc, node interpolation)
Define the final speed of the tool
Define the reference cabinet
p>Define the type of tool tip
AR-Basic also allows the program compiler to input and output data to the device connected to the robot. The analog digital signal can be sent to the analog-to-digital converter in parallel or serial I/O port. Table 5-1 is an example of point and tool definition. Table 5-2 illustrates the motion control of AR-Basic.
Unit6 Grouping Technology
Grouping Technology is a philosophical concept in manufacturing. It involves the identification and grouping of parts with similar or related attributes, so that we can take advantage of the similarity of products. This characteristic applies this technology to the design, manufacturing and production process of product production. Historically, this novel technology first appeared in the United States in 1920, when Frederick Taylor also agreed that component parts required special processes, followed by Jones and Rumson Machinery Company in the early 1920s. The company uses a rudimentary group machining method to produce machine tools, and they use this principle by dividing departments by product rather than by process or shortened paths. Today, group technologies take advantage of similar components through well-structured classification and coding systems and application support software.
Modern manufacturing technology is competing with many challenges caused by increasing international competition and rapidly changing market demands. The following challenges have been encountered in group technologies.
The first paragraph is omitted.
As a result of the first factor, traditional sales organizations have become very inefficient and wasteful, all because of the extravagant paths that products take between different processing departments (the direct translation is not quite right) .
In order to shorten the preparation time, it is necessary to compact the design and production links, so as to obtain a relatively favorable position in the international market.
1. Benefits in product design.
When it comes to product design, the principle benefit of component technology is that it allows product designers to avoid "re-designing the wheel" (i.e., repeated modifications), or to increase the impact of design. In other words, it eliminates the need to design a product that has already been designed. Product possibilities because it makes storage easy and retrieval of engineering designs relatively easy. (Next sentence in the book) If the exact part design is not included in the company's computer archives, a design close enough to what is needed can be retrieved and adjusted to meet the needs. A further advantage of group technology is that it promotes the standardization of design features such as corner radii, chamfers, etc., which leads to the standardization of production tools and production equipment.
2. Standardization of molds and installation. Since parts are grouped into categories, a flexible manufacturing facility can be designed to accommodate various processes within the same category that are machined in the same way, thus reducing the cost of fixtures by reducing the number of fixtures required. Likewise, a machine installation can also fit the entire category rather than individual components.
3. Already
4. Improve the economic system of problem-based production. Typically, batch production involves many non-standard parts. There seems to be no similarity at all. Therefore, the grouping of components into different categories enables economic benefits to be obtained only in large series production.
5. Easier to schedule. Grouping parts makes it easier to schedule tasks so that work can be done on a class of parts rather than on a single part.
6. Reduce work processes and preparation time.
7 Faster and more reasonable process design. Grouping technology paves the way for automated process planning, which can be achieved through appropriate part classification and coding systems, storing codes in detailed process diagrams for each part for easy retrieval.
Unit7
1 CAD/CAM (computer-aided design) is a term for computer-aided design or computer-aided design. It is a technology that uses digital computers to complete specific functions in the design and production process. This technology is moving towards the integration of design and manufacturing, two processes that were once traditionally considered to have independent divisions of labor in the production process. In short, CAD/CAM will provide a technical foundation for the future computer-integrated industry.
2. A computer system composed of hardware and software that will perform special design functions proposed by a specific user. The basic CAP hardware includes: computer. One or more terminal graphics displays, keyboards, and other external devices. CAD software includes computer programs that can run computer graphics within its system and applications that can facilitate the design work of company users. For example: component pressure analysis (program) machine power response (program) heat exchange calculation program, and various control programs, etc. Due to differences in production lines, manufacturing processes and customer markets, various applications will also change with the needs of different users. Therefore, these factories also bring differences in the needs for CAD systems
3 Computer-aided manufacturing ( CAM) can be defined as the use of computer systems to plan, manage and control the operations of a manufacturing plant through direct or indirect computer interfaces possessing shop floor production information. Its definition shows that the application of computer-aided manufacturing can be divided into two major categories: 1
Computer monitoring and management, which is the most direct application of computers to monitor and manage the production process and is directly linked to the production process
2. Applications supported by manufacturing. This is where computers are directly used in factory production operations, but there is no interface between the computer and the manufacturing process.
CAD/CAM system Features a new set of charting fundamentals, any of which can improve charting efficiency. For example: Most systems currently on the market have inherent functions that can implement emerging and practical mapping technologies.
For example, layering technology allows drawings to be drawn according to a logical structure, immediately formed into a whole, and saved separately for identification, but these parts do not demonstrate the entire production process. This process is similar to the anatomical patterns we see in living things. Bones, nerves, internal organs, blood vessels and muscles are each replaced by plastic with different colors. They are viewed as individuals, or they are stacked together to show how the various parts fit together. Layering color through the graphics system uses the same principles, except the overlay is logical rather than non-physical. There are many such applications. Stratification can also be used to distinguish English and numeric dimension information, data information. Text information, electronic needs saw hammer detection, mechanical component paths, etc. The result is clear, unambiguous drawings
Other analysis benefits:
CAD/CAM can also impact a company's engineering systems in other ways by streamlining all physical processes ization and allow for the re-evaluation of modern engineering techniques and processes. CAD/CAM improves quality assurance technology and is a natural fit for maintaining accurate documentation of materials and keeping accurate records of part quantities and bill of materials.
The correct installation of a fully integrated CAD/CAM system facilitates a company's evaluation of design and production methods and creates standards for the suitability of those methods. Often this assessment proves effective, but it can also lead to unexpected harm for those who are unprepared. Managers who consider both issues are very smart. The application of CAD/CAM is always a complicated matter.
What are the disadvantages?
The disadvantages of CAD/CAM may not be obvious, but they are destructive to even the best designs. The biggest drawback comes from the jump necessary to move directly from hand sketches and saved records to a CAD/CAM system. It's like putting a jet engine into a Volkswagen. The car may start going very fast for a short period of time, but if the chassis isn't strong enough to handle the forces, then all the design will vibrate apart.
In other words, CAD/CAM will highlight the incompleteness of the most vulnerable areas of the work, which is cruel to people and rules that cannot be maintained, as one description of it says: "If A company's inability to use drafting bill of materials and partial digital systems will exacerbate the problem."
When such unsatisfactory results occur, the blame is usually pointed at them. CAD/CAM systems are almost impossible to blame, but it is usually better to point the finger at people or organizations. Any computer will only work when data is fed in. This is the most basic rule of data processing: garbage in, garbage out. If a company is using an incomplete directory control system, it is simply because it is automatic. The system will not improve. In fact, automation will make this imperfection even more obvious. And probably more confusing. Therefore when implementing a CAD/CAM system it is important not only to assess the technical needs, but also the existing regulations that are expected to improve.
If managers are unwilling to evaluate existing operating conditions, standards, and processes, the use of CAD/CAM will likely fail—for a variety of reasons. One reason is that management policies will not be well organized due to the separation of CAD/CAM systems from standard operating procedures. There will be a feeling among low-level managers that the system will never be used effectively. Another reason is that the information channels between different departments have not yet been established, which also leads to the feeling that the CAD/CAM system cannot be used for a long time. Another reason is that operators have no input into aspects of system implementation, which leads to shortcomings in drawing standards, poor system management, and ignorance of system users. This cycle is inexcusable. In particular, the evaluation of standard operating conditions will provide direct input into improving these processes, even if the CAD/CAM system has never been used.
Application of CAD/CAM
CAD/CAM technology has gone through a long process from the drawing board to the present. It has been widely used in various industrial productions, involving These range from space shuttle controls to weapons research. From drawing to dynamic diagnostics, from circuit analysis to structural steel analysis. CAD/CAM is widely used in all aspects of drawing and manufacturing, from sketching film and television audio-visual equipment to controlling a large number of robot assembly lines. Its uses are constantly developing.
CAD/CAM was first used in the electronic manufacturing industry. This is because CAD/CAM is not a recognized technology beyond the computer industry. Only then did people realize the market demand for CAD/CAM in the aviation and civil industry. New and complex designs can no longer be satisfied by manual drawing with the aid of a reference manual. CAD/CAM has become the inevitable solution. Today this technology already has a strong technical and financial foundation. As a result, potential CAD/CAM users can meet the demanding requirements of their eventual adoption, and they no longer have to purchase inferior or inoperable equipment.
Today's CAD/CAM market:
Currently, there are 4 CAD/CAM providers on the market. The first is an affiliate or division of a larger company. IBM's CAD/CAM division is one example. These branches and their head office handle a large number of commercial transactions. They not only sell key systems, but are also called after-sales service offices. Because these companies have strong backing, they work well. However, they are also affected by a restrictive style, which prevents them from responding quickly to market changes, nor can they apply advanced technology to the production line to improve the performance of the equipment.
The second type is dedicated turnkey system sellers. These companies offer a variety of CAD/CAM systems for use in different industrial environments. These companies have been in the CAD/CAM industry for several years or decades. They have built a solid reputation on constant technological developments that this type of company has. . . . , these companies sometimes cannot provide good after-sales service due to their small size, but they are responsive to the market, can well meet customer requirements, and can provide a variety of CAD/CAM systems that can be used.
The first is an emerging CAD/CAM sales company. These companies are relatively small, young, and innovative, but their market share is only 5%, but each company specializes in unique high-quality systems for a single market segment. Usually, the micro-monitoring systems sold by these companies are very useful to customers who need small and specialized CAD/CAM systems. In fact, these customers have thought carefully before purchasing the equipment.
The second type is service agencies. These companies specialize in CAD/CAM services. to meet small or coordinated needs. Service bureaus are increasingly common and have become the first choice for companies that cannot afford to purchase a CAD/CAM system or are not qualified to purchase one. These institutions not only participate in CAD/CAM-related business activities, they can also conduct relevant training and seminars for companies that will consider purchasing their equipment.
There are advantages and disadvantages to doing business with any kind of seller. It is not easy for large companies to bargain, and their technological innovation is slow, but most of them can provide good services and reliable products. Specialized sales companies Customer needs are more flexible, and the product upgrade cycle is shorter.
1. CAD/CAM refers to a term that uses computer-aided design or computer-aided manufacturing. It is a technology that uses digital computers to complete specific functions in the design and production process. This technology is moving towards design and manufacturing, two processes that have always been considered to be independent and with clear division of labor in the production process. combined process development. In short, CAD/CAM will provide a technical foundation for the future computer integration industry.
2. This computer system consists of two parts: hardware and software, and performs special design functions provided by specific users.
Basic CAD hardware includes a computer, one or more terminal graphic displays, a keyboard and some other external devices. CAD software includes icons and programs that can run within a computer system. For example, component pressure analysis program, dynamic response program, heat exchange calculation program and various control programs, etc. Due to differences in production lines, manufacturing processes and customer markets, applications will change with the different needs of users. This also leads to differences in CAD system requirements.
3. Computer-aided manufacturing CAM can be defined as the use of computer systems to plan, manage and control the operations of a manufacturing workshop through a direct or indirect computer interface that possesses workshop production information. Its definition shows that the application of computer-aided manufacturing is divided into two major categories: lt; 1gt; Computer monitoring and management, which is the purpose of computers to monitor and manage
Improving drawing efficiency
1.
2.
3. Its potential is indeed unlimited, and the improvement of productivity is only limited by management principles. For example, think of a drafting center as a construction company that specializes in designing warehouses. Most of their work is repetitive and can be used repeatedly in one job.
For example, a standard floor or staircase; or a standard door or door frame. The system can complete the work in a few seconds, and the drafter does not have to redesign it every time. part in the picture.
4. In addition, there are many macro programs used. A group of buttons put together can automatically convert drawing specifications in English into numerical units, or automatically adjust and rotate an entire drawing to a desired orientation, or generate a bill of materials for a complex engineering drawing.
5. Furthermore, the entire design process can be stored in the system. When the draftsman receives a job that is similar to the stored drawing specifications, he can simply recall it, bring it into the job repository, and re-modify the specifications of the parts of the new job that do not match the original drawing. In this way, the efficiency is improved. The original process is improved in efficiency, and in turn, the next process is also improved in efficiency. This shows that a complete and advanced database needs to be maintained and easy for users to operate.
Unit8 Flexible Manufacturing System
There are many different definitions of flexible manufacturing systems. In most cases, how they are defined depends on the user's understanding of its components and usage. Personal opinion.
However, the following description is a summary of the definition of FMS, which is source-findable and unsource-findable resources.
U.S. Government: A series of automatic machine tools and production processing equipment projects associated with automatic material handling systems. General-level data pre-programmed computer control, pre-specified for any production-processed part or combination. Prepare the parts set.
Kvearney and Tvrecker: FMS is the component of CNC machine tools. It can arbitrarily execute parts groups, automate material handling and central computer control to dynamically balance resource utilization. Therefore, the system can automatically adapt to changes in part production, product variety composition and output.
FMS is an automated system that can assign tasks at will. This system is based on rental manufacturing technology and combines computer integrated control with a set of machine tools that can continuously process and process parts.
FMS combines microelectronics technology and mechanical engineering to make mass production more economical. Central online computer-controlled machine tools and other workstations can complete the transmission and processing of parts. Computers can also improve monitoring and information control. This combination of flexibility and global control makes it possible to produce a wide range of products in small batches.
Execute diverse production of parts and products under control within existing capabilities and pre-defined planning.
One technology that will help sophisticated factories achieve faster processing times is to achieve lower unit costs and higher quality production under a higher level of management and central control.
Basically, FMS is composed of software and hardware. Hardware parts are visible and touchable.
For example: computer numerically controlled machine tools, rotating pallets, material transfer equipment (robots and automatic guided vehicles), mainly chip removal systems, tool magazines, coordinate measuring machines, workpiece cleaning stations and computer hardware equipment. The software part is invisible and intangible, such as: CNC programs, traffic management software, tool information, coordinate measuring machine work sequence files and complex FMS software. Figure 8.1 is a typical FMS layout and its main dynamic components and identifiable components.
Unit9
In order to understand the limiting factors in improving the comprehensive productivity of automation, the following analogy is made. Assume that various auxiliary systems of a car have been automated, and the driver's work will become More easily, automatic acceleration, deceleration, steering, and braking
will be more effective than manual operation. However, consider what would happen if these automated assistance systems were not linked together to the extent that they could not continuously communicate and share accurate and up-to-date information in real time. One system was trying to speed up while the other was trying to speed up. brake. The same constraints exist on automated manufacturing equipment, and these constraints have led to another stage in the development of manufacturing technology today: integration.
Unit15
The translational movement of the slide ruler is achieved by using an air shaft. In order to minimize friction and reduce the consequences caused by defects in the slide, a suitable air source is Required.
The movement of the base axis relies entirely on a cheap manual coordinate measuring machine. Most manual machines are equipped with a precision handwheel device, although many users prefer to move the slide ruler directly by hand.
More expensive machines have motor-driven axis drives using DC servo motors operating through a special mechanism, with each axis controlled by a snap-off switch and allowing manual control of movement.