2. ABSTRACT
โข My project is to design and construct a
bending machine. This machine is used to
bend steel into curve or other curvature
shape. The size of the machine is very
convenient for portable work. It is fully made
by steel. Moreover it is easy to be carried and
used at any time and any place.
3. INTRODUCTION
โข To build this machine many equipment or
machine is used. By using all this equipment,
process for making the project is faster and
easier. I had also learned a proper method for
operating all this machine and equipment.
Choosing component material is very important,
because it will affect the overall cost of the
machine and the product quality. With this
consideration, I had design this machine with the
maximum quality and low in cost.
5. TYPE OF BENDING MACHINES
โข TUBE BENDING
โข CIRCLE BENDING
โข BAR BENDING
โข CHENNEL BENDING
โข SQUARE BENDING
6. TUBE BENDING:
The Forming Roller trod of tube bending is recommended for
all large bends. where the centerline radius is at least 4 times
the outside diameter of the tube. It can also be successfully
employed for bending pipe or heavy wall tubing to smaller
radii and is the most practical method of bending very small
diameter tubing. The Forming Roller and Radius Collar must
be grooved to exactly fit the tube and the tube must not be
allowed to slip during the bending operation as even a slight
amount of slippage will cause distortion.
7.
8. CIRCLE BENDING:
This operation is somewhat involved by the fact
that most materials โspring backโ after they have
been formed. To compensate for this, it is often
necessary to use a Radius Collar having a smaller
diameter than that of the circle required. Actual
size can best be determined by experiment, as the
โspring backโ varies in different materials.
Material should be precut to exact length before
forming.
9.
10. โข CHANNEL BENDING:
The same general bending rules which cover the forming of
channel with
โflanges outโ also apply when it is formed with โflanges in.โ
Since it is necessary to compress the flanges as they are bent
inward, the operation shown below requires considerably more
bending pressure than when forming with the โflanges outโ, and
it is recommended that the largest possible radius be used to
allow for compression of the material. if a sharp 90ยฐ bend is
desired, it can be obtained by cutting a notch out of the channel
flanges before forming around a special Zero
Radius Block as illustrated . It is sometimes possible to make a
circle in channel by using a segment of a Radius Collar similar .
By following the procedure outlined on, the circle can be formed
in three operations. To form channel with the flanges facing
upward it is necessary to first fill it with Cerro bend or some
other commercial filler as it is not possible to support the flanges
in this position with a radius Collar.
11.
12. โข SQUARE BENDING:
Forming zero radius bends around square, rectangular,
or other multisided blocks employs the same principle
used in scroll bending. Forming Nose โleadsโ material
between corners of the block. Any number of zero
radius bends can be obtained in one operation by this
method in all types of solid materials. Both centered
and off-center square eye can also be formed by
following the same procedure outlined on. This method
of bending is limited by the size of the square block and
the ductility of the material. In general, when squares
larger than 1โ are needed, they should be formed in
progressive operations using the zero radius block.
15. WORKING
The rod to be bent is placed in between the
two Jigs mounted on the circular plate. The motor
is attached with the circular plate. The power from
the motor is transfered which rotates the circular
plate in anticlockwise direction.one Jig is connected
to the motor and the other Jig is rotated due to the
rotation of circular plate. The rod will be fixed since
the fixed rod lies on the other side . since the rod is
kept in between the two Jigs, the rod would bent.
16. CALCULATION
Given motor speed is 40 rpm and power is equal to 0.5 hp.
Speed (N) = 40rpm
Power =0.5hp=0.37285kw
=0.3728*103 w
Power is transmitted by the motor is known as
P = 2๐๐๐ รท 60
0.3728*10^3 = 2๐ โ 40 โ ๐ รท 60
T = 89*103 Nm
WKT, T = (ฯรท16)ร๐๐3
89ร103 = (ฯรท16)ร๐d3
Here d = 10mm (where diameter of rod to be bend
ฯ = 458 N/mm2
17. calculated shear stress ฯ = 458 N/mm2
wkt , (ฯbรทy) = (MtรทI)
y = (dรท2) = (10รท2) = 5mm
moment of inertia I = (ฯรท64)รd4
I = (ฯรท64)ร104 = 490.87 mm4
ฯb= 89ร103ร5/490.87
bending stress ฯb = 906.66 N/mm2
substitute all the values in the above relation.
18. 906.66/10 = M/490.87
M = 44500 N mm
WL/4= 44500
W = 44500ร4/100
L = length of the rod = 200 mm
W = 1780 N =182 kg
Polar moment of Twist
J = (ฯรท32)d4
= (ฯรท32) ร104
J = 981.74 mm4
Common angle of Twist
ฮ = (TรLรทCsรJ)
Cs = modulus of rigidity
= 8.4ร104 N/mm2
ฮ = (90ร103ร100/8.4ร104ร981.74)
ฮ = 0.109 rad
ฮ = 0.109ร(180รทฯ)
ฮ = 6.25ยฐ