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Explore the World of Soft…e: Engineering & Science
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Explore_the_World_of_Software_Engineering_and_Science_HRS_Software_1998.iso
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programs
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hydrauli
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hc122d.exe
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EXAMPLE.TXT
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1994-02-28
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11KB
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329 lines
Using HydraCyl ver. 1.2
_______________________
E X A M P L E
_____________
1. Run HC.EXE
2. Choose 'OK' on form 'About'
3. Choose 'Analysis'
4. Choose 'Perform Analysis'
You will get a message: 'Cylinder Dimensions must be specified'
5. Choose 'OK'
Let's say you want a heavy duty 2"/1" cylinder
6. Click on '( ) Heavy' in the 'Cylinder's Duty' box
7. Click on Cylinder Bore Diameter 2.00
8. Click on Cylinder Rod Diameter 1.00
9. Click on 'OK'
10. Choose 'Analysis'
11. Choose 'Perform Analysis'
You will get a message: 'Cylinder Operating Parameters must be
specified'
12. Choose 'OK'
Let's say the stroke of your cylinder is 34 inches, firstly you need to
set the correct units.
13. Choose 'Change Units'
14. Click on '( ) inch' in the 'Stroke' box
(this will be the default unit for stroke until you
change it back to 'mm')
15. Click 'OK'
Now you can enter the stroke.
16. Click in '[_ ] inch' under the 'Stroke' heading
17. Type 43 (OOPS my typing mistake, should be 34)
18. Click on 'Clear Values'
19. Click on 'Stroke'
20. Type 34 (correct value)
Let's say the system flow is 25 lit/min
21. Click in '[_ ] lit/min' next to the 'System Flow' heading
22. Type 25
Let's say the Pressure is 60 bar
23. Click in '[_ ] bar' next to 'Pressure'
(if it is required change units to 'bar' in the simmilar maner
as stroke.)
24. Type 60
Let's say the attached mass is 2300 kg
25. Click in '[_ ] kg' next to 'Applied Mass'
26. Type 2300
Let's say the pipeline length between Cylinder's ports and solenoid
valve is 150 inches
27. Click in '[_ ] inch' next to 'Cyl-Valve distance'
28. Type 150
29. Click 'OK'
30. Choose 'Analysis'
31. Choose 'Perform Analysis'
You will get a message: 'Cylinder Mounting Type must be specified'
32. Choose 'OK'
Let's say the cylinder mounting type is 'Intermediate trunnion'
33. Click on 'View Basic Mount Types (a - p)'
34. High resolution picture is shown of all possible mounting
types. Look for Intermediate trunnion. It is marked by 'b'
35. Press any key to get out of diagram.
36. Click on 'b0'
37. Click 'OK'
38. Choose 'Analysis'
39. Choose 'Perform Analysis'
You will get a message: 'Cylinder Mounting Orientation Must be
specified'
40. Choose 'OK'
Let's say a mass of 2300kg is permanently attached (cylinder rod
extending and retracting) to cylinder. Cylinder is mounted under 35
degrees slope, and mass is attached to Piston Rod Stud. Friction
coefficient is 0.15.
41. Click on 'View Orientation Diagrams'
42. High resolution picture is shown of all mounting orientation
types. Look for above description. It is marked as '3'
43. Press any key to get out of diagram.
44. Click on '3'
45. Click in '[_ ]' next to 'Angle between OX and OZ axis'
46. Type 35
47. Click in '[_ ] kg' next to 'Coefficient of friction'
48. Type 0.15
49. Click 'OK'
50. Choose 'Analysis'
51. Choose 'Perform Analysis'
You will get a message: Hydraulic Line Dimensions must be specified
52. Choose 'OK'
Let's say that Hudraulic line between Cylinder port's and Solenoid valve
are 6mm outside diameter and 'L' series.
53. Choose 'Metric'
54. Click on Outside Diameter Size 6
55. Click on Series L
56. Click on 'OK'
57. Choose 'Analysis'
58. Choose 'Perform Analysis'
You will get a message: 'Calculation Complete'
(this means that all relevant data has been entered and now you will see
the results of HydraCyl's analysis)
59. Choose 'OK'
You get a Warning: SUPPPLY PRESSURE Required pressure for Cylinder's
extending is low, consult Page 5.
60. Observe top left corner of the screen. There is title: Cylinder
Data - Page 4 of 5.
61. Choose 'Page Down'
62. Observe Min.Total Pressure Rod Extending = 84.00 bar
Now we will make changes to our specifications to try to
overcome this design problem.
63. Choose 'Cylinder' (on top left hand side of screen)
64. Choose 'Operating Parameters'
65. Change 'Supply pressure to 85 bar.
66. Click 'OK'
67. Choose 'Analysis'
68. Choose 'Perform Analysis'
69. Choose 'OK'
You will get a Warning: ROD BUCKLING Rod is buckling. Select larger
cylinder or use other engineering methods.
Consult pages 2 and 3.
70. Observe top left corner of the screen. There is title: Cylinder
Data - Page 4 of 5.
71. Choose 'Page Up'
72. Browse pages until you get page 2 on the screen.
73. Play between pages 2 and 3 and observe values of:
(page 2) Extending Force = 1723 daN
(page 3) Column Strength = 585 daN
Obviously that actual extending (static) force is almost 3 times higher
than Piston Column strength. Now we will make some changes to our
specifications to try to overcome this design problem.
74. Choose 'Cylinder' (on top left hand side of screen)
75. Choose 'Dimensions'
76. Click on Cylinder Rod diameter 1.375".
(we have just changed cylinder rod diameter from 1" to 1.375" to
try to eliminate buckling effects)
77. Click 'OK'
78. Choose 'Analysis'
79. Choose 'Perform Analysis'
80. Wait until you get a message 'Calculation complete'
81. Choose 'OK'
At last NO Warnings. That means all parameters are acceptable and properly
entered. You have selected a suitable cylinder.
Let's look at the analysis results. Use 'Page Up' and 'Page Down' to browse
the inputs and results on the 'Cylinder Data' form, they are as follows:
Dimensions:
Bore Diameter 2.00 inch (This is the cylinder
Rod Diameter 1.375 inch size you have now selected
Stroke 34.00 inch for your application)
Hydr.Line Dimensions:
Pipe (Tube) Diameter 6 L
Cyl-Valve Distance 150.00 inch
Mounting:
Duty Heavy
Type b0 Intermediate trunnion
Orientation 3 Fixed Cylinder Body. Piston Rod retracting and
extending. Load attached to Piston Rod Stud.
Cylinder's Slope 35.00 deg
Friction Coefficient 0.15
Operating Parameters:
System Flow 25.00 lit/min
Extending Speed 205.58 mm/sec
Extending Time 4.20 sec
Retracting Speed 389.83 mm/sec
Retracting Time 2.22 sec
Supply Pressure 85.00 bar
Max Pressure Rating 138.00 bar
Extending Force 1723.00 daN
Retracting Force 909.00 daN
Column Strength 2091.00 daN
Applied Mass 2300.00 kg
Other Analysis Results:
Stop Tube 50.00 mm
Extending Return Flow 13.18 lit/min
Retracting Return Flow 47.41 lit/min
System Power 3.54 KW
Bore Area 3.14 sq.inch
Rod Area 1.48 sq.inch
Annulus Area 1.66 sq.inch
Displacement Volume:
Cylinder Head 0.9230 litre
Cylinder Cap 1.7504 litre
Total 0.8273 litre
Deceleration Device: ┌────────────────────────────────┐
│ Braking Diagram │
└────────────────────────────────┘
Warnings:
No Warnings.
Undamped Natural Frequency, Minimum Acceleration/Deceleration Time,
Distance and Pressure.
Natural Frequency Rod Extending 9.9 Hz
Natural Frequency Rod Retracting 9.9 Hz
Minimum Ramp Time Rod Extending 0.38 sec
Minimum Ramp Time Rod Retracting 0.38 sec
Min.Travel Distance Rod Extending 3.1 inch
Min.Travel Distance Rod Retracting 5.9 inch
Min.Total Pressure Rod Extending 84.00 bar
Min.Total Pressure Rod Retracting -42.00 bar
Conclusions:
============
Stop tube of 50 mm must be mounted in your cylinder.
Although pump (System) delivered flow is only 25 lit/min, command
hydraulics block (solenoid valve and other components) should be
dimensioned on nominal value of flow 47.41 lit/min. If you neglect this
data you could not expect to get all speeds in your application.
When Cylinder's rod is retracted on that side you need 0.923 litre of
oil. When Cylinder's rod is extended on that side you need 1.7504 litre
of oil. For proper work of cylinder you need only 0.8273 litre of oil in
your power unit (reservoir). That is total value of oil that is required
by cylinder for proper 'breathing'.
If you are in need to implement proportional device, you should consider
ramp time longer than 0.38 sec. Under those conditions, the attached
load requires at least 3.1 (respecively 5.9) inch travel distance for
its acceleration/deceleration from zero to maximal (maximal to zero)
corresponding speed.
On the page 5, you could read up:
Min.Total Pressure Rod Retracting = -42.00 bar
Due to fact that negative apsolute pressure is nonexistent one (in the
nature), the sign '-' is only pointing to absolute pressure of 42 bar at
the cylinder cap end port generated by attached mass and friction forces
only. In other words, you should have the relief valve in that line
during acceleration ind deceleration and adjust its value to 42 bar. In
such way you will be able to control acceleration and deceleration of
attached mass during rod retracting.
Stroke-Braking Pressure Chart
By observing this chart you are able to rapidly determine correlation
between generated braking pressure and accompanied braking stroke.
Due to fact that braking pressure at Cylinder's Head End is under 138
bar (maximal pressure rating for choosen cylinder), that side of
Cylinder should be supplied with standard cushion. On the other side,
Cap End should be supplied with standard cushion only if its length is
over 3/4 inch. For that length, the maximal pressure rating (red line)
and generated braking pressure (green line) are at the same value.
You can easily obtain information on standard cushion length (braking
stroke) and maximal pressure rating from your favourite supplier of
cylinders. Just enter those data on the chart and you will get
information on what would happen in the cylinder. Generally, for any
value of braking stroke between 1/2 inch and 2 inch you are able to
determine actual braking pressure.
--- end of file ---