Part machining process Pump housing - heading

Contents

Contents

Introduction

1. General Section

1.1. Brief information about the part. Analyzing Drawing Requirements

1.2. Development of routing technology of "Pump housing" part manufacturing

1.3. Application and purpose of HAAS ST- machine

2. Selection of PTK layout

2.1. RTC Layout Overview

2.2. Selection of PTK layout

3. Algorithm of RTC operation

4. Automated system control system

4.1. Machine Control System

4.2. Industrial Robot Control System

5. Development of device for accumulation and piece-by-piece dispensing of blanks

5.1 Analysis and selection of storage devices

5.2 Device Design Proposals

5.3 Calculation of the device and selection of main components

5.4 Design development of the device

Conclusion

List of used literature

Application

Summary

In this course project, an automated system has been developed that allows you to automatically load blanks into the machine and unload processed blanks from the HAAS ST20 multi-purpose lathe. Workpieces are loaded and unloaded into trays. 

Introduction

The main direction of the development of mechanical engineering is to increase the output of products and increase its quality while reducing labor costs. This is achieved by improving existing and introducing new types of equipment and technological processes, means of their mechanization and automation, as well as improving the organization and management of production.

Work on the creation and improvement of automation tools should develop in two directions: the creation of automation tools for the equipment produced and currently operating in order to increase its efficiency; creation of new automated technological complexes, which link the issues of improvement of productivity, reliability, accuracy of works execution, as well as level of automation of operations with necessary and economically justified flexibility for quick re-adjustment in order to adapt to changing production conditions.

The efficiency of automation due to the use of robotics can be achieved only with a comprehensive approach to the creation and implementation of industrial robots (PR), processing equipment, control tools, auxiliary mechanisms and devices, etc. Only the expanded use of PR in complex robotic systems will be justified technically, economically and socially. Compared to traditional automation tools, the application of PR provides more flexibility of technical and organizational solutions, reduced completion time and start-up of flexible automated systems. According to preliminary data, for example, providing automatic installation and removal of parts on machines with the help of PR allows the worker to service from four to eight metal cutting machines. Thus, industrial robots must be considered as an important factor in ensuring multi-site maintenance, and therefore labor saving. The greatest economic effect can be achieved when the robot maintains several machines, while ensuring two- and three-shift operation of the equipment.

The social aspect of their use is also closely related to economic issues arising in the use of industrial robots. In determining the feasibility of using robots in one case or another (especially if it is necessary to replace a worker for work in areas with dangerous, harmful to health of work), the interests of a person, their safety and convenience of work should come first. It is necessary to take into account the continuous growth in the level of general and special training of workers in our country.

Industrial robots should free a person from performing mechanical mindless work, compensate for the increasing need for low-skilled labor.

The main prerequisites for the use of industrial robots are:

- Facilitating the labour of the worker with the ultimate aim of freeing him from unskilled, monotonous and hard labour;

- increase of labor productivity and quality of manufactured products due to intensification of technological processes and provision of constant operation mode of equipment in two and three shifts;

- creating prerequisites for the next qualitative leap in the organization of production and the transition to fully automated flexible production.

Robotic systems shall meet the following requirements: 

Provide technological flexibility and adaptation to changes in production conditions; 

to connect equipment of different purposes with wide variation of loading and other accessories; 

have high operability and reliability in operation;

Provide for further development and improvement.

General Section

1.1 Part Brief. Analyzing Drawing Requirements

Manufactured part "Pump housing" (drawing C 330B010501) belongs to the group of cylindrical parts.

After analyzing the drawing data of the Pump Housing part, you can draw the following conclusions: 

The working drawing of the part contains all the necessary information that gives a complete view of the part, that is, all projections, sections that clearly and uniquely determine its configuration and possible methods of obtaining workpieces.

The drawing shows all dimensions with required tolerances, precision classes of machined surfaces, allowable deviations from geometric shapes.

The most accurate surface of the part has a 10 quota of accuracy and a roughness parameter Ra1.6.

One of the surfaces of the part has the shape of a hexagon. This surface is not machined.

The part "Pump housing" (drawing C 330B010501) is made of steel 35 GOST 105074. 

Steel 35

Mark: 35

Substitute: 30, 40, 35D

Classification: structural carbon steel of high quality.

Application: low-strength parts with low stresses: axles, cylinders, crankshafts, connecting rods, sprockets, rods, rims, crossarms, shafts, shrouds, discs and other parts.

1.3. Application and purpose of HAAS ST20 machine

Designed for turning and cutting threads on parts of the type of bodies of revolution in the cartridge and centers in automatic mode with contour shaping. The lathe-multipurpose semi-automatic machine is also intended for treatment of non-central holes located parallel or perpendicular to the axis of the article, with a rotating tool and milling of rectilinear and curvilinear surfaces on parts, where turning is predominant in time and accuracy of execution.

The field of application is large-scale, medium-scale and small-scale production.

The machine is equipped with a revolver head with rotating tools installed on the upper or lower support, as well as a polar coordinate drive for orientation and rotation in the next mode of the main spindle when processing the part with rotating tools. Semi-automatic processing can be carried out using an automatic self-centering lunette with programmable longitudinal movement delivered on order. The semiautomatic machine is equipped with automatic tool measurement and correction input devices for linking the newly installed tool to coordinate axes.

Select the PTK layout. 

2.1. Overview of RTC layouts.

In general, RTC includes the following equipment: main and auxiliary PR, main and auxiliary (performing transport functions, functions of accumulation and storage of blanks) process equipment; special equipment such as instrumentation, demagnetization, branding, etc.; RTK automation systems.

Reliability of RTC operation is estimated by finding a complex reliability indicator - RTC technical usage factor, determined taking into account own downtime of its main and auxiliary equipment. For RTC machining, the technical use factor is 0.8 - 0.85.

In RTC it is possible to include equipment operating with full cycle automation and requiring little time for re-adjustment. The equipment shall provide a high level of concentration and alignment of processing transitions. CNC machines satisfy these requirements most fully. To improve the reliability of RTC, it is necessary to provide automation of control during processing, automation of supply of lubricating and cooling media to the cutting zone, automatic tool change. A reliable chip crushing and removal system shall be provided on the machines in an active or passive manner.

The layout and parameters of the working area of the machines, the structures of the devices should provide free access to the PR hand for installation and removal of the workpiece. The machines shall be equipped with auxiliary devices compensating for the low technological capabilities of the existing PR: devices for preliminary basing of the workpiece, for transportation of the workpieces to the technological bases of the devices. All machine units moving during operation associated with the operation of the FP (tailstock pinol, calipers, fences, prebase devices, etc.) shall be equipped with sensors fixing their final position.

The process tooling shall ensure the specified accuracy of the workpieces installation, despite the fact that the PR supplies the workpiece to the installation area, which is not sufficiently oriented. In the design of the process tooling, sensors are provided that ensure that the workpiece is fixed only after a command is received about its correct location in the accessory. When processing asymmetric workpieces, the equipment must ensure that the spindle is stopped in a given position. RTK working area shall be protected from chips and splashes of lubricating cooling liquid. Machines with more than 30 kg of chips during the shift shall be equipped with automatic conveyors for removal. If less than 30 kg of chips are formed during operation, then the machines must be equipped with container for its reception. 

When using cartridge machines, it is necessary to ensure that the workpiece is pressed to the bases of the accessory. This is done by installing the pushers on the movable units of the machine or the corresponding structure of the gripping device. When placing equipment, it is necessary to ensure that the worker can approach the machine to monitor the operation and interfere with the loading or operation of the machine.

For machine tools of drilling and milling groups, parts are loaded and unloaded in a certain table position, which eliminates the possibility of touching a gripping device or a blank with cutting edges of a tool. For RTK, which includes grinding machines, it is necessary to provide the possibility of complete automation of the workpieces attachment and active control of the parameters of the machined part.

Joint operation of PR and process equipment shall be provided by coordination of operation of program control system of PR and electrical automation of the machine. The function of dialogue between the PR and the machine should be added to the function of electric automation of the machine to ensure the working cycle. The dialogue shall be carried out by direct and reverse commands (direct - from the PRE to the machine and to the clamp and expansion of the workpiece, activation of the machine, etc.; reverse - from the machine to the PRE on execution of commands received from the PRE).

Metal cutting equipment must be equipped with devices that block its operation with open protective devices of the cutting zone and a loose or incorrectly fixed blank.

The machines shall be locked to allow movement of the elements in the absence of rotation of the workpiece and in the initial position of the tool.

On the basis of the same machine models, RTK of different layouts can be created, equipped with PR, which have different technological and technical capabilities.

The following RTK layout solutions were most widely used: single-station - from a single machine serviced by the PR located above the machine, next to the machine or built into the machine; multi-stage circular arrangement using PR.

Linear arrangements of RTK using PR are characterized by the following features:

- occupy a smaller production area than the circular arrangement complexes;

- provide re-installation and repair of equipment without shutdown of the whole complex, possibility of visual observation of equipment operation;

- provide safe working conditions of maintenance personnel and maintenance of three machines or more by one PR.

The peculiarity of circular arrangements is determined by the distinctive features of the applied floor-mounted PR, including lower material capacity and simple preventive work and repair of the PR.

RTK with built-in PR occupy a minimum area.

2.2 Selection of RTC layout

The layout consists of one lathe multi-purpose CNC machine model HAAS ST20 and an industrial robot Kuka KR16.

 

     Turning machining center with NC HAAS ST20 is designed for turning parts of the type of bodies of revolution with a rectilinear and curvilinear profile, including for cutting threads in an automatic cycle. It is equipped with a drive tool and a controlled coordinate "C," which allows for milling, drilling and threaded work on the cylindrical surface of the part and the end face. The field of application of the processing center is the processing of parts of various complexity in conditions from small-scale to large-scale production in the mechanical workshops of machine-building enterprises. The center allows you to work in an automatic cycle when equipped with an automatic loading tool .

Application and purpose of Kuka KR16 industrial robot 

The new KR 16 arc robot complements the KUKA product range in the light duty segment. With a lifting capacity of 5 kg, it is excellent for performing standard arc welding tasks. Thanks to its attractive price and compact size, it is also suitable for your system. Regardless of the type of installation (on the floor or on the ceiling), the KR 16 arc robot always reliably performs its tasks.

Principle of operation

Blank from tray - accumulator 3 is set by robot 2. The robot rotates 90 ° and feeds the workpiece into a self-centering cartridge of the HAAS ST20 lathe, where the workpiece is fully machined. After performing the operations, the robot picks up the workpiece and takes it to the unloading position 4.

Advantages:

Using a lathe multipurpose machine

Using an Electromechanical Robot

Great flexibility

Small occupied area

Small material costs

No machine downtime

 Disadvantages:

Relative cost of an industrial robot

Robot Programming Complexity

 4 Automated system control system

The automated RTC control system should include a machine control system, a robot control system and a clock table control system. These systems must communicate with each other via an interface that supports the highest data rate and is less sensitive to the length of the data lines.

Industrial Robot Control System

 The industrial robot of the KR16 model is equipped with the numerical software control system KR C2 Fig. 6.

A class PCNC management system based on the Windows 2000 operating system with a built-in real-time VxWin system. This control system is capable of controlling eight coordinates. AC servo motors are used as drive mechanisms. Signals from photopulse sensors that control turns of links of an industrial robot are transmitted from an industrial robot to the drive control system. For communication with other devices, the TCP/IP controller provides Ethernet connection and RS 485 and RS422 interfaces are used. 

Systems RobotControl, MotionControl, LogicControl, ProcessControl and SafetyControl combined in a single management system 

Real-time communication and communication between specialized management systems 

Maximize data integrity and consistency with central core network services 

Seamlessly integrated safety for completely new applications 

Integrated software firewall to improve network security 

Innovative software features for optimized energy efficiency 

Tomorrow's Compliant Technology Platform without Patented Hardware 

Multi-core processor support for scalable power 

Fast Gigabit Ethernet Communication 

Integrated memory cards for storing important system data 

Designed for 400-480 V AC voltage 

New Fan Concept for Maximum Energy Efficiency 

Maintenance-free cooling system without filter mats 

Maximum power in minimum space 

Maximum availability

Development of device for accumulation and piece-by-piece dispensing of blanks

5.1. Analysis and selection of storage devices.

Automation of loading and unloading in a general set of tasks for automation of technological processes is one of the most complex, which is caused by a variety of processes, as well as the shapes and sizes of blanks (parts). Sometimes the design of the workpieces (parts) is such that it is impossible to automate loading at all.

Workpieces (parts) that are shaped and dimensioned to automatically capture, orient, and feed into a machining or assembly position, if necessary, are workpieces (parts).

An automatic unloading device is a set of mechanisms that automatically move the workpiece from a given storage place to the working zone of the machine and, after the completion of the processing operation, remove the processed part (semi-finished product) to a given storage place. Loading and unloading devices for piece blanks are made in the form of independent machine units, units organically connected to the machine, or units of machine tools. Despite the extremely important role in automatics, loading and unloading devices are classified as a group of auxiliary mechanisms, since they themselves do not participate in the actual processing (assembly) process, that is, in the process of changing the state of the object of work. The devices consist of a tank (magazine, hopper), in which the stock of blanks is concentrated, and of functional mechanisms: an orientation mechanism, a storage device, a shutoff device, a feeder, a push-rod, an agitator, an ejector, an unloader, a receiving tray and a drive. The design and operation of loading and unloading devices are determined by the type of workpieces, the type of processing and the features of the working space of the machine (automatic line) on which this device is installed. Loading devices according to the method of concentrating the stock of piece blanks in them are: magazine, bunker and bunker.

Magazine loading devices are characterized by the fact that the stock of blanks in the container is concentrated in one row and each blank is manually given a certain orientation in space. The transfer of blanks to the working area of the machine (appliance) is carried out using a feeder, and sometimes directly from the magazine.

Hopper-and-store loading devices are characterized in that stock of blanks is concentrated in several rows in the container and each blank is given a certain orientation by hand or by a special mechanism that is not part of the loading device. Receiver is made in the form of tray, and width of tray is limited by length (height) of blank. The workpieces are transferred to the working area of the machine by the feeder.

Hopper loading devices are characterized in that stock of blanks is concentrated in tank (hopper) randomly (in bulk). The necessary orientation of the blanks before transferring them to the storage is carried out by a special mechanism. The billets are transferred from the accumulator to the working area of the machine by the feeder.

Magazine loading devices should be used for workpieces whose orientation is difficult due to the peculiarities of geometric shape, size, or when it is inappropriate to manufacture complex loading devices in terms of scale of production. Hopper-and-store devices should be used to load simple geometrical workpieces that require a short processing time or when the manufacture of orientation mechanisms is difficult (impossible) or economically impractical. Hopper loaders should be used for workpieces of simple and medium geometrical complexity, of small dimensions, the processing of which takes little time.

Regardless of the type, boot devices can still be divided into universal, universal and special. The first two types can be used for a group of blanks other than each other in size and sometimes shape as a result of re-setting or re-laying and replacement of some parts of the device; devices of the third type are only suitable for workpieces of a certain type.

Distinguish between loading and unloading devices. The first ones carry out loading of blanks, and removal (unloading) of processed parts is performed by machine pushers or part is supplied to receiving tray under action of gravity forces. The second performs not only loading, but also unloading. Loading and unloading devices are commonly called auto operators.

From all of the above, magazine loading devices will be used to load process equipment.

Magazine Boot Devices

Depending on the method of movement of blanks, magazines are divided into gravity, forced and semi-gravity. In gravity stores (gravitational) billets move under the influence of gravity; these magazines are used to supply blanks closely, and blanks of a special shape - discharge, that is, with an interval, for which each blank is placed in a separate seat or between grips of the transporting element.

In gravity stores, blanks are moved by rolling or sliding, and in stores-conveyors - under the influence of applied force or forces of gravity and applied force. Blanks in stores-conveyors are transported closely and separately, piece by piece or in portions. In semi-machine magazines, the blanks slide along a plane located at an angle significantly lower than the friction angle. Billets move due to artificial reduction of friction force between sliding surfaces at transverse oscillation or uniform movement of bearing surface or as a result of formation of air cushion between sliding surfaces.

There are: tubular gravity magazines, tubular (shaft) magazines, rod magazines, trays.

Tubular gravity magazines [16, 17, 19] are used for balls and cylindrical blanks belonging to a group of bodies of revolution moved along the axis of rotation, as well as small flat blanks.

Tubular (shaft) magazines [17] are used for flat blanks in the form of disks, squares, rectangles.

Rod (pin) magazines [17, 19] are used mainly for blanks of disk class or flat square and rectangular blanks.

Trays [16, 17, 18, 19] are designed for accumulation and gravity or forced movement of blanks in loading devices and in devices of inter-machine transportation. There are lotscats, clips and roller. Stingrays and slides are rectilinear ordinary, rectilinear roller, curved, concave and convex, helical (spiral), zigzag, spiral-oval and special (snake, cascade, etc.), open and closed.

Closed trays are used at their location in vertical position, inclination at angle above 10, at long length of blanks and for blanks of cap type. In the closed trays in the walls, inspection slots 3  8 mm wide are made to monitor the movement of the blanks and push the stuck blanks; in addition, one of the walls (usually the top) must be made openable. Slots are made on the side walls of the trays if there are protrusions at the ends of the supplied blanks.

Trays are made solid, prefabricated and adjustable. In machine transport devices and less often in loading devices used in mass production when loading blanks of the same shape, it is advisable to use adjustable trays, that is, those in which the side walls and grates are expanded and shifted. Required width between walls and chute bars is set by means of spacers or set of washers.

If the workpieces are to change orientation during transportation, the articulated trays are used. The blanks are first moved by rolling in one tray until stop, and then the blank is moved in the other tray by sliding. In order to reduce the final speed, it is recommended that the trays be inclined so that the blanks touch the side wall of the tray with one end; bottom of braking tray is made with small ledges, and spring-loaded levers, flags, etc. are installed in direction of billets movement. Hydraulic retarders are used to slow down large mass billets.

From all of the above, for the accumulation and by-piece dispensing of blanks, we will use a gravity open tray assembly with the possibility of adjusting the width of the tray.

Processing items in trays and stores are moved by a total mass. They contact each other, can mate along the contour elements or to some extent engage with each other. 

The unit-by-unit output mechanism is designed to cut off the common flow of single processing items [16, 17]. 

Piece-by-piece dispensing of processing items can be replaced by a piece-by-piece technique. In the first case, the piece-by-piece dispenser mechanism is an integral part of the lottery store, in the second - the feeder. But in all cases, the operation of the piece-by-piece dispensing mechanism must be synchronized with the process machine. 

The cut-off process can take place under mechanical action, using compressed air, magnetic or electromagnetic forces. The most numerous and diverse group of mechanical mechanisms is piece-by-piece dispensing. The breaker of the unit-by-unit output mechanism can perform the following movements: return, oscillating (reciprocating), rotary, complex (combined).

Mechanism of unit-by-unit delivery with reciprocating and reciprocating-and-rotating movements is implemented at connection of cutoff device with actuator of process machine. The rotary motion of the cutoff is conveniently obtained by coupling it to a camshaft which synchronizes the operation of all mechanisms of the machine. Complex (combined) motion is given to the cutoff device when it is given additional functions, for example, reorientation of the treatment object, cut off from the total mass .

There are mechanisms for piece-by-piece issuance of simple and double action. The simple action mechanism provides unit output in one reception, and double output in two receptacles: separation of the treatment object from the common flow and its delivery to the feeder .

The principle of operation of the unit-by-unit output mechanism of a simple action is that the cutoff device or other element of the device performing its functions is able to capture and move only one item of processing. In the process of gripping, the mechanism makes it possible to advance the object of treatment in the tray by a step, and during cutting off and transportation it limits the movement of the object of treatment in the tray, blocking its channel (transportation channel). 

The operation of the double-action unit-by-unit output mechanism is reduced to alternating movement of two pins (slats, cams) covering the channel for transportation of processing objects. The distance between the pins is selected depending on the configuration of the treatment object and its size. If the object of treatment is rounded or otherwise shaped to be cut off by a rigid stop, the distance between the pins should be such as to ensure that a single object of treatment is located between them. In the case where the object of treatment is mated with its contour so that the rigid stop cannot be wedged between them, the pins are placed at a slightly greater distance and the upper one is spring-loaded. The cut-off pin then does not become in the way of movement of the treatment object, but presses the second treatment object against the lot wall and keeps it and the subsequent ones from moving, while the lower pin opens the transportation channel to dispense the first cut-off treatment object in the direction of movement. 

The functions of the pins can be performed by cams having rotational or reciprocating motion. Action of cams is similar to action of rigid stops. 

The dual-action piece-by-piece dispensing mechanism is used in cases where the processing objects in the tray have a tendency to stick with each other or when the feeder design eliminates the supply of a group of processing objects to it, it is possible to deliver processing objects isolated from each other .

The unit-by-unit dispensing mechanisms, the cutoff of which is made in the form of a sprocket or a toothed drum, may have intermittent or continuous rotation of the working member. They provide high performance under low dynamic loads. 

Screw (screw) devices are also referred to the unit-by-unit dispensing mechanism with rotary movement of the cutoff device. With a single-turn screw for turning one turn, the mechanism cuts off one item of treatment from the total mass, if the two-turn screw is two items of treatment. The unit-by-unit dispensing mechanism is productive, characterized by smooth operation. 

Action of mechanical mechanisms of piece-by-piece output is accompanied by application of contact forces to the object of processing. In cases where this is not acceptable, other cutoff methods may be used to ensure the non-contact separation of the single processing items from their total mass in the apparatus tray. In addition, the mechanisms for piece-by-piece dispensing of contactless action are versatile .

Electrodynamic studies have shown that a traveling magnetic field inductor in the form of a system of coils connected to a three-phase current source can be used for non-contact unit-by-unit dispensing of ferromagnetic processing objects or processing objects with ferromagnetic elements. At the end of the inductor, the magnetic field is purely pulsating. This causes a longitudinal edge effect, as a result of which the force of the opposite sign is applied to the treatment object, inhibiting its movement. Therefore, each new treatment item will move to the end of the inductor, outputting the previous treatment item from the device tray.

Contactless cut-off and fixation of ferromagnetic, non-ferromagnetic current conducting and dielectric objects of treatment in trays can be performed by creating non-uniform magnetic, variable magnetic and electrostatic fields in their sections.

Pneumatic unit-by-unit dispensing mechanisms are effective when loading processing objects with a small density of materials with significant streamlining surfaces. They are useful for treatment objects with low strength characteristics or with a easily damaged surface layer. Counter air jets, which provide unstressed shutdown of processing objects during their braking and cutting off, allow for high-performance loading of brittle processing objects. 

Cut-off of the treated items in the tray by pneumatic methods consists in creation of a balanced pressure difference in the mechanism of unit output at jet cut-off of the single treated item at the end of the tray and its violation at output of the treated item from the tray by the feeder, which leads to jet cut-off of the next single treated item. 

The choice of the specific version of the unit output mechanism and the method of its calculation are determined by the design of the feeder of the process machine and the machine as a whole.

To separate the workpiece from the common flow, we will use the mechanism of piece-by-piece output of the reciprocal principle of simple operation.

5.2. Suggestions for the design of the device .

According to the presented design of the tray (Figure 11), it is necessary to calculate its main characteristics: the length of the tray, the angle of inclination, the distance between the side walls of the tray, the height of the side walls of the tray. It is also necessary to determine the section of the tray supports and the section of studs from the strength conditions. It is also necessary to select the actuator of the tray, which will drive the cutoff. Pneumatic cylinder of reciprocating principle of action will be used as working member. It is not necessary to calculate the tray for both parts, it will be sufficient to calculate its basic parameters for the Spindle part because it exceeds the Shaft part in weight and size, as well as in machining time.

Conclusion

The HAAS ST20 machine-based RTK reduces the time of auxiliary operations, thereby increasing productivity and production efficiency. Increasing labor productivity, there is a decrease in the cost of the part, and, therefore, a decrease in the price of the part. Thus, using RTK for all machines according to the manufacturing process of the part, they achieve maximum productivity and minimum cost of manufacturing the part. In addition, using such automated systems, the heavy manual labor of a person is replaced by the function of monitoring the work of the RTC itself, that is, there is also an improvement in human working conditions.