Автор работы: Пользователь скрыл имя, 15 Сентября 2013 в 02:30, курсовая работа
So in this course project the production line that produces vertical sleeve hole with gloss on one side have been designed. During designing we’ve calculated technical and economic parameters of the production line, built graphics that present the synchronization of operations and load of equipment, also the time limit graph have been made.
The production line, we’ve got include 10 operations, use 18 machines and refer to the unsynchronized production lines.
Introduction
Mass production is the production of large amounts of standardized products, including and especially on production lines. The concepts of mass production are applied to various kinds of products, from fluids and particulates handled in bulk (such as food, fuel, chemicals, and mined minerals) to discrete solid parts (such as fasteners) to assemblies of such parts (such as household appliances andautomobiles).
Nowadays the main problems of mass production are:
The object of the work is to design a production line that produces vertical sleeve hole with gloss on one side. So, the main tasks of the project are:
According to the objective the production line should produce vertical sleeve hole and gloss on one side.
Table 1.1 - List of manufacturing operations and characterization of the equipment
№ of operation |
Operation name |
Equipment | ||||
Equipment sign |
Wholesale Price, UAH |
Engine power, kW |
Dimensions mm |
Occupied area, m2 | ||
1. |
Handling of enterance |
2Н135 |
28675 |
4 |
2535×825 |
4,25 |
2. |
Broach hole |
7Б55У |
149110 |
18,5 |
4070×1600 |
26,05 |
3 |
Turning |
1И611П |
166315 |
3 |
1790×670 |
8,83 |
4. |
Mechanical milling cutter |
6Р80 |
57350 |
3 |
1600×1875 |
14,3 |
5. |
Boring holes Ø20 |
2Н125 |
22940 |
2,5 |
2350×785 |
3,59 |
6. |
Locksmith treatment |
Locksmith treatment |
11470 |
- |
1000×800 |
4,1 |
7. |
Washing |
Washing |
17205 |
0,5 |
950×750 |
3,6 |
8. |
Heat treatment |
Heat treatment |
34410 |
4 |
1020×950 |
6,2 |
9. |
Internal grinding |
3К227А |
206460 |
4 |
2815×1900 |
24,07 |
10. |
External grinding |
3А-110В |
177785 |
1.5 |
1600×1670 |
17,03 |
The minimum wage for the current period is 1147 UAH.
Table 1.2 - Duration of process operations
Indicators |
# of operation |
Category of work |
Value | ||
The annual output (Nр), units./year. |
57000 | ||||
The complexity of operations (tшт i), min./unit |
1 |
3 |
7,13 | ||
2 |
5 |
2,26 | |||
3 |
5 |
10,81 | |||
4 |
6 |
5,77 | |||
5 |
3 |
3,88 | |||
6 |
2 |
2,89 | |||
7 |
1 |
2,06 | |||
8 |
4 |
5,85 | |||
9 |
6 |
9,52 | |||
10 |
6 |
4,84 | |||
Net weight of item, kg/unit. |
6,66 | ||||
Consumption rate of metal, kg/unit. (НВМ) |
5,661 | ||||
Complexity of manufacturing the product norm – kg/unit |
|
55,01 |
During determination of the rate of metal consumption we’ve used the coefficient 0,85. The complexity of manufacturing the product was got by summarizing of the values of the complexity of manufacturing operations.
2 Designing of a production line in machining
2.1 Features and benefits of the mass production
As it was said in the Introduction: mass production is the production of large amounts of standardized products, including and especially on production lines.
Mass production have several advantages before traditional production.
The economies of mass production come from several sources. The primary cause is a reduction of nonproductive effort of all types. In mass production, each worker repeats one or a few related tasks that use the same tool to perform identical or near-identical operations on a stream of products. The exact tool and parts are always at hand, having been moved down the assembly line consecutively. The worker spends little or no time retrieving and/or preparing materials and tools, and so the time taken to manufacture a product using mass production is shorter than when using traditional methods.
The probability of human error and variation is also reduced, as tasks are predominantly carried out by machinery. A reduction in labour costs, as well as an increased rate of production, enables a company to produce a larger quantity of one product at a lower cost than using traditional, non-linear methods.
However, mass production is inflexible because it is difficult to alter a design or production process after a production line is implemented.
So in a nutshell, the advantages of mass production over traditional are following:
2.2 Calculation of the tact (τ) of the production line
The tact is the indicator of work of production line.
Tact is the time between release of two products on the production line.
The tact of the streaming line is defined by the formula:
τ = , (2.1)
Where:
Fdob - Day Fund-time (8h2) · 60 = 960 min., with 8-hour working day in two shifts;
BP - regulated time spent on maintenance of machine, take Bp = 60 min.;
Ndob - daily release program, units.
τ = (960 - 60) /227= 3,96 min. / unit.
The daily release program is calculated by the formula:
, (2.2)
Where:
Np - given year program production, units.;
nrd - the number of working days in a year (365-104-10)= 251 days
Ndob = 57000/251 = 227 units.
2.3 Calculation of equipment, loading and degree of synchronization of operations
Calculation of the amount of equipment for each operation conducted by the formula:
, (2.3)
Where:
nri - estimated number of machines on and one-operations units.;
tшт - an artificial time and th operation, min.;
τ - tact of streaming line, min. / units.
nр1= 7,13 / 3,96 = 1,8 units. nпр1 =2 units
nр2= 2,26 / 3,96 = 0,57 units. nпр2 =1 unit.
nр3 = 10,81 / 3,96 = 2,73 units. nпр3 =3 units
nр4 = 5,77/ 3,96 = 1,46 units. nпр4 =2 units
nр5 = 3,88/ 3,96 = 0,98 units. nпр5 =1 unit
nр6= 2,89 / 3,96 = 0,73 units. nпр6 =1 unit
nр7 = 2,06 / 3,96 = 0,52 units. nпр7 =1 unit
nр8 = 5,85/ 3,96 = 1,48 units. nпр8=2 units.
nр9= 9,52/ 3,96 = 2,4 units. nпр9=3 units.
nр10 = 4,84/ 3,96 = 1,22 units nпр10=2 units.
Nri is rounded to the first or next higher integer - get adopted npri number of machines.
Loading equipment ηзi also define for each i-th operation by the formula:
, (2.4)
ηз1 =( 1,8/2) * 100% = 89,95 %
ηз2 =( 0,57/1) * 100% = 57%
ηз3 =( 2,73/3) * 100% = 90,9%
ηз4 =(1,46/2) * 100% =72,8%
ηз5 = (0,98/1) * 100% = 98 %
ηз6 = (0,73/1) * 100% = 73%
ηз7 = (0,52/1) * 100% = 52%
ηз8 = (1,48/2) * 100% = 73,8%
ηз9 = (2,4/3 )* 100% = 80%
ηз10 = (1,22/2) * 100% = 61%
Loading of equipment for specific operations should not exceed 85 - 90% for creating of the reserve of the equipment to ensure the smooth operation of the production line. If the calculations would be higher than 85 - 90%, we should increase the number of machines.
For effective work of the equipment at the production line the level of loading of the machine should exceed 60-70%
Table 2.1 - Calculation of equipment on the production line (A):
№ |
|
Operation name |
tштi, хв. |
nрi,шт. |
nпрi, шт. |
ηзі, % |
tштi/nпрi |
Degree of sinhronization Сі |
1 |
|
Handling ofentrance |
7,13 |
1,8 |
2 |
89,95 |
3,565 |
0,202 |
2 |
|
Broach entrance |
2,26 |
0,57 |
1 |
57 |
2,26 |
-0,238 |
3 |
Turning |
10,81 |
2,73 |
3 |
90,9 |
3,603 |
0,215 | |
4 |
|
Boring entrance Ø20 |
5,77 |
1,46 |
2 |
72,8 |
2,885 |
-0,027 |
5 |
|
Locksmith treatment |
3,88 |
0,98 |
1 |
98 |
3,88 |
0,308 |
6 |
Washing |
2,89 |
0,73 |
1 |
73 |
2,89 |
-0,026 | |
7 |
|
Heat treatment |
2,06 |
0,52 |
1 |
52 |
2,06 |
-0,306 |
8 |
|
Internal grinding |
5,85 |
1,48 |
2 |
73,8 |
2,925 |
-0,014 |
9 |
|
External grinding |
9,52 |
2,40 |
3 |
80 |
3,173 |
0,07 |
10 |
|
Handling ofenterance |
4,84 |
1,22 |
2 |
61 |
2,42 |
-0,184 |
Total |
55,01 |
13,88 |
18 |
74,84 |
29,662 |
Average loading of equipment is calculated by the formula:
, (2.5)
where m - number of operations.
= 13,88/18 = 0,77
Degree of non synchronization of operations is calculated by the formula:
, (2.6)
where - working tact on i operation;
- Average working tact of streaming line.
Average tact of the production line is found according to the formula:
= 29,66/10 = 2,966
С1 = (3,565– 2,966)/ 2,966=0,202
С2 = (2,26- 2,966)/ 2,966= -0,238
С3а =(3,603- 2,966)/ 2,966=0,215
С4 =(2,885- 2,966)/ 2,966= -0,027
С5 =(3,88- 2,966)/ 2,966= 0,308
С6 =(2,89- 2,966)/ 2,966= -0,026
С7 =(2,06- 2,966)/ 2,966= -0,306
С8 =(2,925-2,966)/ 2,966 = -0,014
С9 =(3,173- 2,966)/ 2,966 = 0,07
С10 =(2,42- 2,966)/ 2,966 = -0,184
On the basis of the results we’ve got, we can plot the following graphics:
Figure 2.1 - Graph of synchronization of the operations
Figure 2.2 - Graph of loading of equipment for the operations
According to the level of synchronization the type of production line is determined. Organization of work and choose of transport means depends from the type of the line.
If at all operations the degree of desynchronization does not exceed 10%, then this line is synchronized continuous-flow. If at least one of operations exceeds the specified value, then this line should be called unsynchronized
2.4 Equipment Selection
Selection of equipment in practice carried out simultaneously with the design process. This often guided by existing warehouse equipment. When selecting equipment in the project consider the following:
. 1) the ability to install and machining parts on a machine. For this the size of the details and macine are compared. For drilling machine, such as the basic size is diameter - maximum diameter drilling. For lathe - the height of the centers and the distance between the centers. The radius of details may not exceed the height of the centers and the length of detail - the distance between the centers;
2) the cost of the machine, we must use equipment with less price.
Choosing of the tools usually have to hold pricelist wholesale prices for machine tools.
Table 2.2 - Statement of equipment on the production line:
Operation Name |
|
Model of machine |
Overall dimensions of machine, mm |
Quantity of machines |
Price, UAH. |
Engine power, kW |
||||||||
One item |
Total |
One machine |
Total |
| ||||||||||
1 |
2Н135 |
2535×835 |
2 |
28675 |
57350 |
4 |
8 |
|||||||
2 |
7Б55У |
4070×1600 |
1 |
149110 |
149110 |
18,5 |
18,5 |
|||||||
3 |
1И611П |
1790×670 |
3 |
166315 |
498945 |
3 |
9 |
|||||||
4 |
6Р80 |
1600×1875 |
2 |
57350 |
114700 |
3 |
6 |
|||||||
5 |
2Н125 |
2350×785 |
1 |
22940 |
22940 |
2,2 |
2,2 |
|||||||
6 |
Bench press |
1000×800 |
1 |
11470 |
11470 |
|||||||||
7 |
Washing |
950×750 |
1 |
17205 |
17205 |
0,5 |
0,5 |
|||||||
8 |
Heatequip |
1020×950 |
2 |
34410 |
68820 |
4 |
8 |
|||||||
9 |
3К227А |
2815×1900 |
3 |
206460 |
619380 |
4 |
12 |
|||||||
10 |
3А110В |
1600×1670 |
2 |
177785 |
355570 |
1,5 |
3 |
|||||||
Total |
18 |
1915490 |
67,2 |