Design of luggage production machinery. Conceiving, analyzing and calculating the working principle, structure, movement mode, transmission mode of force and energy, material, shape and size of each part, lubrication method, etc. of luggage production machinery according to the requirements of use, and translate them into specific description for the working process of manufacturing basis.

The design of luggage production machinery is an important part of luggage production machinery engineering, the first step of luggage production machinery production, and the most important factor to determine the performance of luggage production machinery. The goal of suitcase manufacturing machinery design is to design the best suitcase manufacturing machinery under a variety of limited conditions (such as materials, processing capacity, theoretical knowledge and calculation means, etc.), that is, to make an optimal design. Optimum design requires a comprehensive consideration of many requirements, generally the best performance, the lowest manufacturing cost, the smallest size and weight, the most reliable in use, the lowest consumption and the least environmental pollution. These requirements are often contradictory, and their relative importance varies depending on the type and purpose of the suitcase manufacturing machinery. The task of the designer is to weigh the weight according to the specific circumstances and give overall consideration so that the design of the luggage production machinery has the best comprehensive technical and economic effect. In the past, design optimization mainly depended on the knowledge, experience and vision of the designer. With the development of basic mechanical engineering theory and value engineering, system analysis and other new disciplines of luggage production, the accumulation of technical and economic data in manufacturing and use, and the popularization and application of computers, optimization gradually abandons subjective judgment and relies on scientific calculation.

Design classification
The design of luggage manufacturing machinery can be divided into three types: new design, inheritance design and variant design.

1. New design

Using the mature science and technology or the new technology proved by the experiment to be feasible, the design of the new luggage production machinery has never been before.

2. Inherit the design

Design and update the existing luggage manufacturing machinery based on experience and technical development to improve its performance, reduce its manufacturing cost or reduce its operating cost.

3. Variant design

In order to adapt to the new needs of the existing luggage production machinery to make partial modifications or additions or deletions to develop products different from the standard type.


The main process
1. Design tasks according to customer orders, market needs and new scientific research results.

2. Preliminary design. This includes determining the working principle and basic structural form of the luggage production machinery, conducting motion design, structural design and preliminary general drawing and preliminary review.

3. Technical design. This includes the modification of the design (based on the initial review), the drawing of all parts and new general drawings and a second review.

4. Working drawing design. Including final revision (according to the opinion of second instance), drawing all working drawings (such as parts drawing, parts assembly drawing and general assembly drawing, etc.), making all technical documents (such as parts list, wearing parts list, use instructions, etc.).

5. Finalize the design. luggage production machinery for batch or mass production. For some of the design tasks are relatively simple (such as the new design of simple luggage production machinery, general luggage production machinery inheritance design or variant design, etc.) the design of luggage production machinery can be eliminated the preliminary design procedures.

Stage description
(I) The planning stage

The planning stage is only a preparatory stage after the introduction of a new machine to be designed according to the needs of production or life. At this point, there is only a vague idea of the machine to be designed.

(2) The stage of scheme design

This stage plays a key role in the success or failure of the design. In this stage, the design work is characterized by multiple solutions.

The functional analysis of the machine is to comprehensively analyze the requirements, minimum requirements and desired requirements that must be met in the machine functions proposed in the design specification, namely, whether these functions can be realized, whether there are contradictions between multiple functions, and whether they can be replaced by each other. Finally, the function parameters are determined as the basis for further design. In this step, the contradictions that may arise between need and possibility, ideal and reality, development goals and current goals should be properly handled.

After the functional parameters are determined, possible solutions, i.e., possible solutions, can be proposed. When looking for a solution, it can be discussed according to the original moving part, driving part and executing part respectively. A more common approach is to start with the operative part.

When discussing the working part of a machine, the first question is about how it works. For example, when designing a machine for manufacturing screws, its working principle can be used in cylindrical blank with a turning tool to turn threads, but also can be used in cylindrical blank with a rolling die to roll threads. This suggests two different ways of working. Different working principles, of course, the design of the machine will be fundamentally different. Particular emphasis should be placed on the need for constant research and development of new working principles. This is an important way for the development of design technology.






The constraint
There are many constraints in the design of machinery parts for luggage production, and the design criteria are the constraints that should be satisfied in the design.

Technical performance criterion
Technical performance refers to all performance, including product function, manufacturing and health, both static and dynamic performance. For example, the power, efficiency, service life, strength, stiffness, friction resistance, wear performance, vibration stability, thermal characteristics of the product can be transferred. Technical performance criteria means that the relevant technical performance must meet the specified requirements. For example, the vibration will generate extra dynamic load and variable stress, especially when its frequency is close to the natural frequency of the mechanical system or parts of the luggage production, the phenomenon of resonance will occur. At this time, the amplitude will increase sharply, which may lead to the rapid damage of the parts or even the whole system. The criterion of vibration stability is to limit the vibration parameters of the mechanical system or parts of the suitcase production, such as natural frequency, amplitude, noise and so on, within the allowed range. Another example is the heat generated when the machine is working, which may lead to thermal stress, thermal strain and even thermal damage. The thermal characteristics criterion is to limit various related thermal parameters (such as thermal stress, thermal strain, temperature rise, etc.) within the specified range.

Standardization criterion
The main standards related to the product design of luggage manufacturing machinery are as follows:

Concept standardization: the terms, symbols and units of measurement involved in the design process shall meet the standards;

Physical form standardization: parts, raw materials, equipment and energy, such as structural form, size, performance, etc., should be selected in accordance with the unified provisions.

Standardization of methods: The operation method, measurement method and test method shall be implemented according to the corresponding provisions.

Standardization criterion means that all behaviors in the whole process of design should meet the requirements of standardization mentioned above. The standards related to the design of spare parts for the production of luggage, which have been released, can be divided into three grades: national standard, industrial standard and enterprise standard in terms of application scope. From the use of mandatory, can be divided into mandatory and recommended use of the two.

Reliability criterion
Reliability: The probability that a product or component can fulfill its specified function within its expected life under specified service conditions. Reliability criterion means that the designed product, component or part should be able to meet the specified reliability requirements.

steps
Before the design begins, the design task must be set. When the design task is complex, three-stage design is generally adopted, that is, preliminary design, technical design and working drawing design. When the task is relatively simple, such as the new design of the simple suitcase production machinery, the general suitcase production machinery design or variant design, the design at the beginning of the technical design depth, after review, modification and approval of the working drawing design, and become a two-stage design. In the preliminary design stage of the three-stage design, the main steps of the design are: to determine the working principle and basic structure type, motion design, design the main components, draw a preliminary general drawing, preliminary design review. In the technical design stage, the main steps are as follows: revise the design according to the review opinions, design all parts, draw a new general drawing, and review the technical design. At the design stage of the working drawing, revise the design according to the review opinions, draw all the working drawing and prepare all the technical documents. For batch or mass - produced products, but also to carry out the stereotyped design.

At each step of the design process, you may find that some of the decisions in the previous step were unreasonable, which requires you to go back to the previous step, modify the unreasonable decisions, and redo the subsequent design work.

1. Develop design tasks this is the preliminary work of the design. Design tasks are based on customer orders, market needs and new research results. The design department uses various technologies and market intelligence to draw up possible schemes, compare their advantages and disadvantages, and negotiate with the business department and users to formulate reasonable design tasks and objectives. This is particularly important for new designs. The failure of mission target will cause serious loss in economy and even suffer a total failure.

2, determine the working principle and basic structure type if the design task is not clearly specified, the first step of the design is to determine the overall scheme, that is, to determine the working principle to be applied and the corresponding structure type. For example, in designing a high-power Marine diesel engine, it is necessary to determine whether to use a two-stroke, double-acting, crosshead, low-speed diesel or a four-stroke, single-acting, medium-speed diesel. For example, the design for the rough rock crushing luggage production machinery, the first to determine is to crush and bend as the main crushing function of jaw or cycle crusher, or the use of impact as the main role of single rotor or double rotor impact crusher.

3. After the overall scheme of motion design is determined, it is necessary to use the knowledge of mechanism learning and select the appropriate mechanism to get the required motion scheme. The jaw crusher mentioned above relies on the swing of its movable jaw plate to crush, bend and split the rock into the crushing chamber, and the swing of movable jaw plate can be used for the simple swing of double-elbow plate mechanism, or the complex swing of single-elbow plate mechanism. In the new design, it may be necessary to synthesize a new mechanism to obtain the required motion scheme, which is often a difficult work. Therefore, designers generally try their best to apply the motion scheme proposed by the existing and mature mechanism.

After the motion design, the designer starts to carry out the structural design, calculates the force, strength, shape, size and weight of each main part of the luggage production machine, and makes sketches of the main parts and components. At this time, if the original structure is found to be unworkable, it must be adjusted or modified. The possibility of overheating, excessive wear or vibration should also be considered.

In this step, the designer will discover the shape, size, proportion and other contradictions of the parts by sketching. In order to strengthen or improve one aspect, one may weaken or deteriorate the other. At this time must weigh the weight, carry on the coordination, in order to achieve the best comprehensive effect. After repeatedly revising the sketch and finding it satisfactory, the preliminary general drawing and the cost estimate can be made. The preliminary general diagram is drawn strictly to scale and sufficient views and sections are selected.

5. Preliminary Review After the preliminary general drawing is drawn, a preliminary review shall be conducted on experienced designers, manufacturers and users of this kind of suitcase manufacturing machinery as well as on behalf of the user or the entrusted design company. If the results of the examination indicate that the design is not applicable (such as weight, volume is too large, cost is too high, the reliability of the structure is in doubt, etc.), then the motion design shall be redone, or even other working principles and basic structural types shall be used. In most cases, some improvement is made to the design.

6. Modify the technical design according to the preliminary review opinions, and draw all the parts and components. Perform accurate stress analysis on major parts and components, modify details such as shape, size, etc., and specify material and heat treatment. Determine the machining accuracy of parts and assembly conditions of components and final assembly. Complete lubrication design, electrical design (drive and control). Redrawing the general drawings, some important and mass-produced luggage production machines are sometimes modeled. Submit the finished technical design for a second review.

After the final modification according to the opinions of the second review, formal part drawing, component assembly drawing and general assembly drawing can be drawn, and technical documents such as part list, vulnerable part list and use guide can be prepared. The designer should pay attention to coordinate the dimensions between parts, check the tolerance fit between coupling parts, and check the strength and stiffness of some parts. It is very important to start drawing checking after the part drawing is finished. Carefully proofread drawings ensure smooth assembly after processing. The most reliable method of proofreading is to redraw a general assembly drawing from the already drawn parts drawing, and all the contradictions will show up. At the same time the drawing of the parts also need to carry out two work: one is the process review, make the parts easy to process and reduce the manufacturing cost; The second is the review of the standards, so that the structural elements, dimensions, tolerances, matching, heat treatment technical conditions and standards and general parts in line with the standards.

8. Trial production and Finalizing Design For a single piece or a small batch of luggage production machinery, the design drawings completed by the above steps can be put into formal production. For bulk or mass production of luggage production machinery, before the formal production should be a trial prototype, functional test and identification, after passing, then according to the batch production process for batch trial production. The problems in the batch trial production may also need to modify the design accordingly, so that it can be used for formal production.




Design methodology

The purpose of design methodology is to upgrade design thinking into a rational process, so that design can follow a certain logic, so that more designers can make good design. It generally includes the following contents:

1. Separate the design stages in detail so that each stage becomes a thinking activity with rules to follow and justifications to be based on.

2. Store successful or good designs and establish a design database for future reference or adoption.

3. Introduce the concept and method of value engineering in the design work, balance the function and cost of the contradiction in the design, so as to obtain good use effect.

4. In the design, knowledge of new disciplines such as tribology, vibration, fracture mechanics, finite element method, reliability design, optimization design, systems engineering and human engineering should be adopted to improve the scientific nature of the design and reduce blindness.

5. Expand the scope of design work, extending forward to market forecast and backward to after-sales service.

6. Use computer-aided design to reduce design labor and improve design speed and quality.


Looking forward to
In the future, the design of suitcase manufacturing machinery will be permeated into semiconductor manufacturing, biological engineering, nanotechnology and robotics and other industries. While making contributions to social development, it will constantly improve itself and make further theoretical innovation.

(1) Further realize systematicness. That is, from the system point of view, the luggage production machinery products as a system or a whole, relying on computer technology, to achieve human, machine, environment and mutual coordination. To be specific, the system is decomposed into several subsystems, and various modern design theories and methods are adopted to coordinate the design and matching of each subsystem in pursuit of system optimization.

(2) Deepen intelligent design. With the progress and development of science and technology, more and more factors of intelligence should be considered in design. A large number of design contents can be described through the establishment of models to describe the various working conditions of the luggage production machinery products, and to solve the model to predict the performance of the products, design rationality and optimality. For example, various types of vehicle performance evaluation of the intelligent decision system, gearbox design expert system, fault diagnosis system has been applied in the development and design of new cars.

(3) Pay more attention to green ideas. Green design technology is a technology designed in accordance with the requirements of environmental protection, the highest resource utilization and the lowest energy consumption during the life cycle of a product. The designer is required to consider the environmental attributes and basic attributes of the product from the full cycle, and always focus on human physical and mental health and environmental protection in the design. Meanwhile, the designed product is required to be recyclable and cause minimal damage to the environment.




Modern design method
Professional modern
Produced by luggage mechanical design and computer professionals to develop computer software, can reflect and describe the suitcase production under the actual working condition of mechanical products of all kinds of damage, failure and failure mechanism of quantitative analysis and calculation can boot in the production of machinery parts and luggage production dynamic behavior, and formed a fixed design program, which is a professional modern design method, such as vibration analysis and design of tribology design, thermodynamic heat transfer design, design strength, stiffness, temperature field analysis and so on. These software are based on the traditional design method, the application of computer technology developed. For example, Pro/M software is used to analyze the dynamic characteristics of the luggage manufacturing machinery, and ANSYS software is used to analyze the stress, which lays a foundation for accurately judging the reliability of the device and selecting design parameters.

General modern
In order to meet the high requirements of the performance of luggage production machinery, computer technology is widely used in the design of luggage production machinery for auxiliary design and system analysis, which is the general modern design method. Common methods include optimization, finite element, reliability, simulation, expert system, CAD, etc. These methods are not only aimed at manufacturing mechanical products of luggage to study, but also their own scientific theories and methods.

1. Optimized design

luggage optimization technology in the production of mechanical optimization design is luggage production transplantation and application in the field of mechanical design, the basic idea is according to the luggage in the production of mechanical design theory, methods and standards, such as establishing a reflect engineering design problems and meet the requirements of the mathematical programming mathematical model, then using mathematical programming method and computer technology automatically find out the optimal design problem solution. It is a modern design method which combines the design theory of luggage manufacturing machinery with optimization mathematics and electronic computer.

Simulation and virtual design

Computer simulation technology is a comprehensive technology to 'establish actual or associative system model' with computer as a tool and to carry out dynamic operation experiments on the model under different conditions. And the essence of the virtual technology with the simulation technology of computer support as the premise, in the product design phase, real-time parallel to simulate the whole product development process and its influence on product design, to predict product performance, the manufacturing cost of products, product manufacturability and maintainability of the product and removable, thus improve a success rate of product design. This approach not only shortens the product development cycle, but also shortens the distance between product development and users.

3 Finite element Design

This method uses mathematical approximation to simulate the real physical system (geometry and load conditions). In addition, simple and interacting elements, namely elements, can be used to approximate the real system of infinite unknowns with a finite number of unknowns. It can not only be used for solving complex non-linear and non-steady problems in engineering, but also for static and dynamic analysis of complex structures in engineering design, and can accurately calculate the stress distribution and deformation of complex parts with complex shapes, becoming a powerful analytical tool for strength and stiffness calculation of complex parts.

4 fuzzy Design

It is a design method that applies fuzzy mathematics knowledge to the design of luggage manufacturing machinery. There is a lot of fuzzy information in the design of machinery for manufacturing luggage. For example, in the design of spare parts for luggage production machinery, the safety coefficient of spare parts is usually conservative and relatively large but not economical, but there is a large fuzzy range within its allowable range. Various fuzzy problems are often encountered in the development of suitcase manufacturing machinery products. Although the characteristics, nature and policy requirements of these problems are not the same, the fuzzy analysis method adopted is similar. Its biggest characteristic is that the influence of each factor on the design result can be analyzed comprehensively and quantitatively, and the comprehensive quantitative index can be obtained, which can be used as the basis for decision making.