1.1 Introduction
Hammer drills are used in commercial construction to drill holes in concrete. An example of this would be to place anchors. The hammer drill is manually guided by a human, which results in a strong interaction of the two subsystems (Anton et al., 2010; Blache et al., 2015). Hammer drills are used in commercial construction to drill holes in concrete. The hammer drill is manually guided by a human, which results in a strong interaction of the two subsystems. Drilling plays a vital role in open-pit operations prior to blasting. The cost of drilling is a significant element. Given lowering commodity prices and resource degradation, a reduction in drilling costs will help mine management to sustain operations. Thus, drilling equipment monitoring and optimization of the drilling parameters are crucial for mining operation (Dhillon 2008).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Drilling operation is affected by many factors which are related to mechanical parameters of drilling machine, and rock mass properties (Zang & Huang 2013). Geology has also influenced on drilling operation directly. There is a negative exponential relation between rock compressive strength – density – quartz content and drilling rate (Zang & Huang 2013). In other words, it is accepted that geological properties affect drill ability inversely proportional (Hoseinie et al. 2009). The relationship between texture properties of the rock and rock drillability is defined that there is a statistically high correlation, which is demonstrated by analysis of rock’s texture, between rock strength and drillability (Bilgin et al. 2000).
A drilling machine, called a drill press, is used to cut holes into or through metal, wood, or other materials. Drilling machines use a drilling tool that has cutting edges at its point. This cutting tool is held in the drill press by a chuck or Morse taper and is rotated and fed into the work at variable speeds. Drilling machines may be used to perform other operations. They can perform countersinking, boring, counter boring, spot facing, reaming, and tapping.
Drill rate also depends upon the rock type. In softer rock which has low strength, drill rate will be high, and in hard rock which has high strength, drill rate will be low (Zang & Huang, 2013). Therefore, the strength is the key parameter to measure the performance of drilling operation. In other words, In other words, drilling rate would be stable if drilling parameters of the machine and the type of drill bit were the same. However, in practice, due to the sys- tem degradation and bit wear, drilling rate cannot be stable. Mechanical performance must be considered to understand drilling operation. Hence, the analysis of equipment reliability and availability using historical data is a key to evaluate equipment performance for a drilling activity.
Reliability analysis mostly depends on system fail- ure data (Wang & Coit 2005). There is generally a non-renewal process for drilling mechanism. In most of real life situations, mining systems have degradation trends due to system ages. Hence, successive time between failures is decreasing. A Non- Homogenous Poisson Process (NHPP) can be modeled by this situation. It is widely used for repairable systems (Wang & Coit 2005).
To maximize drilling operation performance, optimal values of controllable variables should be determined. In this context, experimental design which is used to evaluate the effects of several different independent factors on a response variable is the second step for drilling optimization. Multiple input factors are considered and controlled simultaneously to ensure that the effects on the output responses are statistically significant (Ryan 2007).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to construct the Arm Mounted Hammer Drilling Machine.
1.3 Statement of Problems
Investigation revealed that there is difficulty at a higher height it becomes difficult to make holes manually or by using equipment. And in such case accuracy is an important phenomenon. Also, many fatal accidents can occur while drilling holes manually at a higher height with the help of a ladder.
Balancing the self-weight of worker on ladder with maintaining stability of ladder and working with heavy drilling machine made a very tricky situation for the worker, which engaged another worker for balancing of ladder.
1.4 Aim and Objectives of Study
The aim of the study is to design and construct of Arm Mounted Hammer Drilling Machine. In achieving this aim, the following specific objectives were laid out as follows to construct an Arm Mounted Hammer Drilling Machine that will:
- Ensure all holes will be accurate and of same depth as set by user;
- Provide increased drilling operation speed;
- Make fabrication more efficient and fast during work operation; and
- Allow hammer drill machine for fast and easy drilling using smartly designed mechanisms to improve work efficiency.
1.5 Significance of Study
This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The scope of the research is focused on the design and construction of Arm Mounted Hammer Drilling Machine.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
