1. MINOR PROJECT ON SIX BAR POWER HAMMER
PRESENTED BY:
Ankit Kr Singh
Divanshi Singh Baghel
Amit Kr Pandey
Shubham Sharma
Akshay Kr Tiwari
Amit kr singh, Sudhir Sharma
2. ACKNOWLEDGEMENT
It is our proud privilege to express deep sense of gratitude, regards and
appreciations to MR Rajneesh sir (HOD DEPARTMENT OF MECHANICAL
ENGINEERING,RKDF BHOPAL) for his exemplary guidance , deep rooted interest ,
inspiration throughout our minor project.
We would like to thank Raja Vishwakarma sir (faculty department of mechanical
engineering) for his continuous efforts and guidance for my project.
I would oblige our institute RKDF Bhopal which provide me such platform of
education.
3. OBJECTIVE:
To design and fabricate a simple mechanical operated
power hammer by applying the principle of kinematic
arrangement and machine design concepts.
4. . INTRODUCTION TO MECHANISMS:
Concept of degrees of freedom: In the design or analysis of a mechanism, one of
the most important concern is the number of degrees of freedom (also called movability) of the
mechanism.
It is defined as the number of input parameters (usually pair variables) which must be
independently controlled in order to bring the mechanism into a useful engineering purpose.
Degrees of Freedom of a Rigid Body in a Plane The degrees of freedom (DOF) of
a rigid body are defined as the number of independent movements it has. Figure 1.2 shows a rigid
body in a plane. To determine the DOF of this body we must consider how many distinct ways the
bar can be moved. In a two dimensional plane such as this computer screen, there are 3 DOF.
The bar can be translated along the x axis, translated along the y axis, and rotated about its
centroid.
5. 1.Degrees of Freedom of a Rigid Body in Space: An unrestrained rigid body in
space has six degrees of freedom: three translating motions along the x, y and z axes and three
rotary motions around the x, y and z axes respectively in the as shown in the fig .
Kutzbach Criterion Equation Consider a plane mechanism with number of links. Since in a
mechanism, one of the links is to be fixed, therefore the number of movable links will be ( -1) and
thus the total number of degrees of freedom will be 3(n-1) before they are connected to any other
link. In general, a mechanism with number of links connected by j number of binary joints or lower
pairs (i.e. single degree of freedom pairs) and h number of higher pairs (i.e. two degree of freedom
pairs), then the number of degrees of freedom of a mechanism is given by
n = 3( -1)-2j-h
This equation is called Kutzbach criterion for the movability of a mechanism having plane motion.
. If there are no two degree of freedom pairs (i.e. higher pairs), then h= 0, substituting h=
0 in equation 1, we have n=3( -1)-2j
Four bar chain mechanism The simplest and the basic kinematic chain is a four bar chain or quadratic cycle chain, as
shown in below fig. It consists of four links p, q, l and s, each of them forms a turning pair. The four links may be of
different lengths. According to Grasshof’s law for a four bar mechanism, the sum of the shortest and longest link lengths
should not be greater than the sum of the remaining two link lengths if there is to be continuous relative motion between
the two links
6. THE 4 BAR MECHANISM
LINK 1
LINK 2
LINK 3
LINK
4
LINK 1
7. 1.According to Grasshof’s law for a four bar mechanism:
The sum of the shortest and longest link lengths should not be greater than the sum of the
remaining two link lengths if there is to be continuous relative motion between the two links. A
very important consideration in designing a mechanism is to ensure that the input crank makes
a complete revolution relative to the other links. The mechanism in which no link makes a
complete revolution will not be useful. In a four bar chain, one of the links, in particular the
shortest link, will make a complete revolution relative to the other three links, if it satisfies the
Grasshof’s law. Such a link is known as crank or driver.
1.6 Single Slider Crank Mechanism A single slider crank chain is a modification of the basic
four bar chain. It consists of one sliding pair and three turning pair. It is, usually, found in
reciprocating steam engine mechanism. This type of mechanism converts rotary motion into
reciprocating motion and vice versa. In single slider crank chain, as shown in below fig the links
1 and 2, links 2 and 3, and links 3 and 4 form three turning pairs while the links 4 and 1 form a
sliding pair.
9. The link 1 corresponds to the crank of the engine. The link 2 corresponds to the ram die; link 3
corresponds to the coupling rod and link 4 corresponds to connecting rod. As the crank rotates
the cross-head reciprocates in the guides and thus the piston reciprocates in the cylinder.
PRINCIPLE of 6 bar power
hammer
10. Construction :
As shown in above diagram it consists of 5 links, and one
fixed link. The five links are crank (link 1), link 3 Connecting
rod (link 4), Crank (link 5) and Ram die (link 2).
Column can be considered as a fixed link. The link 1 rotates
about a turning pair F, it is rotated by a pin joint axis, the
link 3 and link 1 is connected by a turning pair E.
The connecting rod (link 4) and link 3 are connected by a
turning pair D. The crank (link 5) is fixed at a turning pair A
and oscillates about the pin joint axis. Crank (link 5) and
connecting rod (link 4) are connected by a turning pair B.
Ram Die (link 2) and connecting rod (link 4) are connected by
a Pinned joint at C. Ram Die and composite bush are
connected by a turning pair G. CONTINUED…..
11. Crank (link1) is joined at turning pair F to the column and also crank (link 5) is joined at turning pair A. Column
is welded to the base, vice (not shown in above fig) is fitted to the column for holding the work piece. All the
links, Column, Base and Vice are made up of Mild Steel, they are rigid enough to absorb the vibrations and
shocks produced during work.
Composite bush is made up of two materials outer one is of Mild Steel and the liner is made up of Gun Metal to
prevent from wear, tear and corrosion resistance.
A handle is provided at point E, with the help of the handle the crank (link 1) is rotated.
12. WORKING:
The Crank (link 1) rotates at a fixed axis at F it is joined to link 3.
As the link 1 is rotated the motion is transmitted to the link 3 which is connected at point E. The
motion is further transmitted to the connecting rod which is joined with the link 3 at D.
Finally the connecting rod transmits the motion to the Ram Die (link 2) which reciprocates at a
fixed path G. The Connecting rod (link 4) and Ram Die (link 2) are connected at C, Where a slot is
provided for getting a straight line motion of the ram Die. The crank (link 5) is provided for
oscillating the connecting rod at a fixed path.
13. USES OF 6 BAR POWER HAMMER
FORGING PROCESS
PUNCHING
CRUSHING OF ROCK
PRESSING
BLANKING
NOTCHING
VARIOUS TOOL OPERATIONS
14. ADVANTAGES OF 6 BAR POWER HAMMER
OVER TRADITIONAL POWER HAMMER:
MORE FORCE IN
LESS POWER.
CAN WORK IN
BOTH HORIZONTAL
AS WELL AS
VERTICAL
DIRECTIONS
LESS WEAR AND
TEAR DUE TO
ABSENCE OF
SLIDING PAIR
COMPACT IN SIZE
EASY IN
MAINTANANCE AS
THERE IS NO
SLIDING PAIR
