Development of part manufacturing process Side lever

Part Design Analysis for Processability

The enlarged process analysis of the part is performed by decoding the design and process code. A further process analysis of a part is to define the processing methods for each of the part surfaces used in the process at the base plant. The result of the analysis should be entered in the right column of Table 1.4.

Based on the study of the part and its analysis, a qualitative assessment of the processability of the part design can be carried out. Part 7453001001 is a side lever, weighing 9.8 kg., With overall dimensions of 285x125x100 mm, it is a body, load-bearing and basic part.

The part is subject to significant dynamic loads.

Part fabrication specification:

Surfaces 1, 3, 13 to 7, surfaces 2, 4, 5, 6, 7, 8, 12, 15, 16 to 14, surfaces 9 and 14 to 13;

The hardness of the surface is 143... 229 HV;

The perpendicular tolerance of hole B with respect to the end surface is 0.1 mm;

Tolerance of perpendicular of hole D relative to end surface is 0.1 mm;

Tolerance of parallelism of holes D and B relative to each other is 0.1 mm;

The roughness of surfaces 1, 3 is Ra 0.8, Ra 3.2 at surfaces 15, 16, Ra 2.5 at surfaces 9, 14, and the remaining surfaces with roughness Ra 12.5;

Analysis of Part Fabrication Specifications

Analysis of technical requirements (TT) is performed based on determination of service purpose of the product. The composition of the TT, their quantitative and qualitative indicators depend on the service purpose of the part and the conditions of its work in the assembly unit. The TT of almost all working drawings of parts are the accuracy of dimensions (their qualitas), the accuracy of the shape and arrangement of the surfaces of the part, and surface roughness. In addition, the requirements for hardness, heat treatment, electroplating and paint protective and decorative coatings, non-destructive testing methods and much more are presented in many working drawings. The purpose of the TT analysis is, first, a full understanding of the technological tasks of manufacturing the part in accordance with the requirements of the working drawing and, second, checking the correctness of their purpose.

1. Hardness of material 143... 229 HB. This specification shows the extent to which the true hardness of the material may fluctuate.

2. Unspecified limit deviations as per OST 37.001.24682. The specified industry standard regulates the values ​ ​ of unspecified dimensional deviations.

3. Casting slopes as per GOST 321279.

4. Other TTs as per GOST 2664588.

5. Material-substitute - SCh20. Means that if you do not have the necessary material, you can replace it with the specified one.

Process Part

2.1 Substantiation of the procurement selection and its design.

The correct selection of the initial workpiece directly affects the construction of the manufacturing process of the part, contributes to a decrease in material capacity, manufacturing costs, and therefore a decrease in the cost of manufacturing the part.

2.4 Development and justification of the designed process

The design of machining processes begins with a thorough study of the initial design data: assembly and working drawings of the product with the corresponding specifications for the manufacture of the part, the drawing of the initial workpiece and the dimensions of the program task. Additional design conditions are also studied: the presence or absence of equipment on which it is planned to manufacture the designed product; equipment upgrades; the possibility of using advanced types of raw materials, progressive tools and devices, etc.

In the absence of the possibility of using the unified technological processes existing at the enterprise, after carrying out the specified preparatory work, the technologist begins to directly design the technological processes.

At the beginning of the design, the technologist pre-establishes the types of processing of individual surfaces of the workpiece and methods for achieving their accuracy, which meet the requirements of the drawing and serial production and existing equipment in the enterprise.

At the same time, a sequence of operations is being developed, that is, a procurement process route. With low accuracy of initial blanks, the process begins with rough treatment of surfaces with the highest allowances.

Development of technological operations

The operational technology is developed taking into account the location of each operation in the route technology. By the time each operation is designed, it is known which surfaces and with what accuracy have been machined in previous operations, which surfaces and with what accuracy the operation needs to be machined in.

The design of operations is associated with the development of their structure, with the compilation of adjustment diagrams, calculation of tuning sizes and expected processing accuracy, with the assignment of processing modes, the determination of the time norm and its comparison with the cycle of work (in-line production). Accuracy calculations and performance checks may require some changes in routing technology, equipment selection, operation content, or conditions.

Operating technology allows you to issue a task for the design of special equipment, mechanization and automation tools, for the development of technological equipment and metrological support for the process.

Operation design - multivariable task; The options are evaluated on the basis of productivity and cost, guided by the technical and economic principles of design, bearing in mind the maximum time saving and high productivity.

3.1 Selection of process equipment and accessories.

In accordance with the previously established list of operations required to carry out the workpiece processing process, we will select a specific type of machine.

In 010 operations, we use the 6P13F3 milling semi-machine.

6P13F3 NC cantilever-cutting vertical machine. Purpose and Scope

Vertical milling machine 6P13F3 is intended for processing of various parts of complex profile made of steel, cast iron, hard-to-process non-ferrous metals, mainly end and end cutters, drills in medium-scale and small-scale production.

The milling machine of the 6P13F337 model is equipped with an NC NZZ2M device, which allows you to process products in program control mode simultaneously according to three coordinates: longitudinal and transverse (moving a table and sled with a machined part) and vertical (moving a slider with a tool).

Programmable vertical movement (Z coordinate) is carried out by the movement of the slider. The NC milling machine console 6P13F3 has only a locating movement that eliminates positioning and servo operation of the console having significant weight. Processing accuracy is improved as the console is always clamped during cutting.

The machine is equipped with tracking controlled feed drives with high-torque DC motors.

The use of servo adjustable drives with DC motors provides a speed of quick movement of the table up to 4.8 m/min and eliminates part scrap during contouring in case of failure of the feed drive by one of the coordinates.

Centralized lubrication of guides is introduced.

The machine uses an electromechanical tool clamping device that provides a stable clamping force of 2000 kg.

For remote equipment there is a finished wiring with plug connectors.

Roughness of the treated surface Rz = 20 μm.

Machine accuracy class - H as per GOST 8 - 82.

The developer is the Gorky Machine Tool Production Association.

The quality category is the highest.

3.2 Determination of rational cutting modes.

When assigning cutting modes, we focus on the recommendations given in the catalogs of the manufacturer of the Sandvik Coromant tool.

Cutting modes for processing holes are calculated using the online calculator from Sandvik Coromant. At the same time, at these cutting modes, the necessary parameters of roughness and power of the machine engine are achieved enough for processing. Modes are assigned to other types of processing according to general machine-building standards of time and cutting modes.

Workplace Safety

Operators of numerical control machines (CNC) are subject to general safety rules when working on metal cutting machines.

Each newly accepted employee must undergo induction training and individual training at the workplace.

During individual instruction, the instructor introduces the employee to the rules for handling equipment and vehicles, the rules for maintaining the workplace and wearing special and working clothes, shoes, personal protective equipment at this workplace and other workplaces included in the technology of machining and preparation of production

The employee can be admitted to work only after comprehensive familiarization with the safety rules.

The results of the briefing are recorded in a special journal, which is signed: the person who conducted the briefing and the employee who received this briefing.

4.1 Safety Requirements Prior to NC Machine Operation

Put in order working clothes and shoes:

- fasten or strap with rubber of sleeves covering, fill clothes so that there are no fluttering ends;

- work in a headgear that fits the head tightly, the hair must be securely covered;

- the shoes must protect the legs reliably from chips, dirt and dust. (It is not allowed to work on machines in light shoes - slippers, sandals or barefoot shoes.)

Make sure the machine and workplace are in good condition, get everything out of the way that can cause a fall.

Ensure sufficient lubrication of the machine, check the level of oil in the tanks intended for it.

Check presence, serviceability and strength of attachment:

- enclosures of gears, drive belts, rollers, drives, spindle, etc., as well as current-carrying parts of electrical equipment (starters, choppers, transformers);

- safety devices for protection against chips and devices for supply of cooling oils and lubricating-cooling liquids (LFR).

If necessary, adjust the local lighting of the machine so that the working area is sufficiently illuminated and the light does not fall directly into the eyes. (Do not use local lighting with voltage more than 36 V.)

Check the presence of individual lifting devices attached to the machine and snap-in devices according to special instructions.

Check serviceability of the machine at idle, in manual and automatic modes, at that make sure that:

- controls - electric push-button devices of brakes, lifting and feeding devices;

- lubrication and cooling systems ensuring normal and uninterrupted lubrication and supply of LPG;

- fixation of actuation and switching levers ensuring impossibility of spontaneous switching from idle to working;

- clamping pneumopatrons, mechanized clamping devices.

Make sure that there is no jamming or excessive weakness in the moving parts of the machine (especially in the spindle, in the front head, with longitudinal, transverse or vertical moves of the caliper or table).

In case of failure of the machine and equipment immediately inform the responsible person and do not start work until the failure is eliminated. (It is forbidden to operate on defective machines and on machines that do not have the necessary protective barriers.)

Prepare a chip removal hook, brushtag, wrenches and other necessary tools.

Lay stably on liners or racks the parts submitted for processing, without cluttering the work place and passages. The height of stacks for small parts should not exceed 0.5 m, for medium ones - 1.0 m, and for large ones - 1.5 m.

Before processing metals with flying chips, if there are no special protective devices, put on glasses or a safety shield made of transparent material.

The wooden grille under the feet must always be serviceable.

Check reliability of actuation of limit switch interlocks, which protect machine units from impacts and breakdowns.

Before each activation of the machine, make sure that the launch of the machine is not a danger to anyone.

4.2 CNC Machine Safety Requirements

Constantly monitor the operation of the CNC machine during operation:

- by alarm on control panel of electronic device;

- by program control points (return of machine working elements "to initial state," "constancy of tool change point" in the same position, etc.);

- by the nature and magnitude of linear movements and rotational movements of the machine tools and other equipment;

- deviations in the nature and noise level of different mechanisms;

- in terms of accuracy of NC equipment units execution of various process commands.

Do not work on a CNC machine using worn or deformed software media (perforated tape, magnetic tape, PZM, etc.).

Monitor the purity and serviceability of tape drive devices for entering software media.

When changing over one name from the part processing to another, pay attention to the correct arrangement of stops, which determine the points of "initial state" of working bodies to start work on the program. Remember that improperly installed stops can lead to impacts of movable elements of equipment against stationary and rotating ones.

To prevent impacts of tools and working elements of equipment on other elements in case of failures and failure, limit the amount of movement of movable elements from possible impacts by setting such position of limit switches, which automatically eliminates the emergency situation.

Keep a close eye on the state of the cutting tool. Keep in mind that untimely stopping the machine during tool breakdowns can lead to serious consequences.

When replacing worn out software medium or using a new one, it is mandatory to check its correctness when the machine is idle without a part, and check the correctness of the program itself in the "program development without movement" mode.

Be particularly attentive and careful when processing the first part after resetting or changing the software medium. Do not enter the maximum movement values from the correction switch to the part in the control system.

Trust the dimensions and shape of the blanks. If the dimensions and shape of the workpiece deviate from the workpiece drawing (included in the part processing program), inform the parcel manager immediately.

Always remember that a significant excess of the processing allowance relative to the design, when machined on an NC machine, can lead to unacceptably large overloads, part departure, tool and machine breakdowns.

Report any flaws in the processing programs immediately to the site manager.

Do not allow LPG to hit terminals, connectors, sensors and other electrical equipment and automation elements. If these deficiencies exist, take measures to eliminate them.

In case of any malfunctions in the process of operation, or deviations from normal operation, immediately notify the head of the site and the relevant service by the nature of the alleged cause of the malfunction.

Require the maintenance personnel to carry out timely and high-quality scheduled preventive, preventive or ongoing (TR) repairs.

Check the CNC machine assemblies on your own periodically to determine deviations from normal operation at an earlier stage.

Pay special attention to the technical condition of the clamping elements of pneumopatrons, monitor their serviceable operation and require systematic cleaning. Remember that fuzzy operation of the clamping elements can cause the part to fly out during processing.

If wear occurs on the clamping elements, restore their operability. In this case, strictly observe the parameters of the recesses (diameter, depth, height, width) in accordance with the processing program (technology) of a particular part. Failure to comply with these conditions can also lead to the departure of the part, or to cutting into the clamping elements.

Do not leave the NC equipment on or running unattended. In case of short-term excommunication, completely turn off all equipment.

Avoid dangerous techniques and methods of working on CNC machines.

All preparatory works on CNC machines shall be performed in their de-energized state or in "Adjustment" mode:

- installation and replacement of tools, accessories, cartridges, blanks and parts, etc.;

- for installation of stops of "initial state" and limit switches;

- for adjustment of mechanical units and lubrication systems.

Do not work without guarding the rotating parts in the working area of the machine.

Do not interfere with the automatic operation cycle of the machine using switches, buttons, other elements on the control panels of the machine, electronic device and other equipment except for "Termination of the general cycle."

For multistage servicing of CNC machines, ensure safe operating conditions:

- Ensure that the service area of the machines is not cluttered with blanks, machined parts, tools, accessories, racks and bedside tables, other objects;

- monitor the provision of reliable protection against chips and scale coming down and flying off the cutting tool, as well as spattering and leaking under the LPG legs;

- remove the service area from chips in a timely manner, prevent it from being under its feet, periodically wipe the fittings and lamps of local lighting, monitor cleanliness and order at the workplace.

In case of insufficient process of part processing on CNC machines (frequent tool breakdowns, workpiece allowance fluctuations, difficulties in setting up, adjusting and adjusting the machine and equipment, holding during processing of operational dimensions, etc.), inform the site manager about impossibility of multistage maintenance.

Carefully treat the signals supplied from lifting devices and moving vehicles without being under the lifted and moving load.

4.3 Emergency Safety Requirements for CNC Machine Operation

Take measures to call to the accident site the head of the site and services by belonging (fire, ambulance, gas, technical, etc.).

In the event of a hurricane, earthquake and other natural disasters, stop all work, turn off equipment, leave the workplace and take measures to save yourself.

If you are injured during an accident, see a doctor or ask for an ambulance at 03.

4.4 NC Machine Completion Safety Requirements

Completely turn off the machines and equipment.

Put the work center in order:

- remove the CNC machine from chips, scale and dirt;

- wipe out the machine and other equipment.

Lubricate all moving parts and mechanical units of the machine with oil. Pay special attention to the condition of guides, running screws, tool change units, constantly keep them clean.

Warn the changer (in multi-shift mode of operation) about all, even the slightest and insignificant, malfunctions of the machine and equipment.

Take off your workwear and shoes, put them in a special place, change clothes and change into clean clothes and shoes.

Meet individual requirements for personal body hygiene.

Control over the implementation of this instruction shall be entrusted to the site manager and to the persons responsible for ensuring safety at this site of the enterprise.

Conclusion

During the course work, options for constructing a technological process were studied taking into account the production program, the nature of the products, as well as the technical and economic conditions for the implementation of the production process. The developed technological process is mainly differentiated, i.e. divided into separate operations, which are assigned to individual machines. When using machines, universal devices, a universal cutting tool, a measuring tool were used to ensure the interchangeability of processed parts.

Content and sequence of process transitions, cutting modes are determined. Process Improvement

The use of CNC machines significantly reduces the auxiliary time for processing the part by reducing the auxiliary time for changing the tool, numerous reinstallations of the part and reducing the main time due to the possibility of increasing cutting modes.