Friday, February 19, 2021

Drilling - Process and Machine - Evolution

Rotary cutting tool having PCD cutting tip

Abstract
A rotary cutting tool with an elongate body disposed about a longitudinal axis, the elongate body including a helical flute and a polycrystalline-diamond cutting tip. The cutting tip comprises an inner portion having an inner point angle and an outer portion having an outer point angle different from the inner point angle.
2019-06-25
Publication of US10328536B2
Inventor: L Karthik Sampath,  Armin Zimmerman, Steve George; Current Assignee: Kennametal Inc
https://patents.google.com/patent/US10328536B2/en

Deep hole drilling methods as well as tools for deep hole drilling machines

Abstract
The present invention relates to a deep hole drilling method for manufacturing a pipe having an inner profile having at least one recess spirally extending along the inside of the pipe, the deep hole drilling machine comprising: a basic body extending along a longitudinal axis And at least one cutting edge arranged on the outer periphery of the base body, wherein the tool is pulled through the interior of the pipe while the cutting edge is rotated around the longitudinal axis such that the cutting edge completes the cut along the spiral curry line on the inside of the pipe; Pushed.
2019-08-06
Publication of KR20190091438A
https://patents.google.com/patent/KR20190091438A/en


Drill head for a deep hole drilling tool for bta deep hole drilling, and deep hole drilling tool


A drill head (100) for a deep hole drilling tool for BTA / STS or ejector hole drilling, comprising a main body (101) of a drill head, a cutting edge (109), and guide pads (110, 111) (101) is rotatable about an axis of rotation (113) and has a hollow conduit (107) with a chip collection orifice (106) on the perforated side (160) and the perforated side (160) 109 are arranged on the upper side and have a ridge 114 of the main cutting edge and a ridge 115 of the minor cutting edge and the minor cutting edge is arranged on the outer side in the radial direction of the cutting edge,
2018-02-13
Publication of KR101829079B1
https://patents.google.com/patent/KR101829079B1/en


Drills: Science and Technology of Advanced Operations
Viktor P. Astakhov
CRC Press, 08-Apr-2014 - Science - 888 pages

In a presentation that balances theory and practice, Drills: Science and Technology of Advanced Operations details the basic concepts, terminology, and essentials of drilling. The book addresses important issues in drilling operations, and provides help with the design of such operations. It debunks many old notions and beliefs while introducing scientifically and technically sound concepts with detailed explanations.

The book presents a nine-step drilling tool failure analysis methodology that includes part autopsy and tool reconstruction procedure. A special feature of the book is the presentation of special mechanisms of carbide (e.g. cobalt leaching) and polycrystalline (PCD) tool wear and failure presented and correlated with the tool design, manufacturing, and implementation practice. The author also introduces the system approach to the design of the drilling system formulating the coherency law. Using this law as the guideline, he shows how to formulate the requirement to the components of such a system, pointing out that the drilling tool is the key component to be improved.

Teaching how to achieve this improvement, the book provides the comprehensive scientific and engineering foundations for drilling tool design, manufacturing, and applications of high-performance tools. It includes detailed explanations of the design features, tool manufacturing and implementation practices, metrology of drilling and drilling tools, and the tool failure analysis. It gives you the information needed for proper manufacturing and selection of a tool material for any given application.
https://books.google.co.in/books?id=3wwNAwAAQBAJ

Drills - Materials
https://books.google.co.in/books?id=3wwNAwAAQBAJ&pg=PA228#v=onepage&q&f=false



The invention also relates to a method of drilling composites by means of a ceramic drill bit of the type described above, in which method the drill bit has a peripheral cutting speed of between 600 and 1000 m/min.

Advantageously, the drill bit is advanced at between 0.05 and 0.20 mm/revolution.

Ceramic drill bit for high-speed drilling of composites


The ceramic drill bit has a particular geometry and is very advantageously applicable to the very high-speed drilling of parts made of a composite, especially a carbon-fiber composite having an epoxy resin matrix. The invention also relates to a method for the high-speed drilling of composites.

2009-01-29 Publication of US20090028654A1
2012-06-26 Application granted
2012-06-26 Publication of US8206067B2
Status Active
2031-04-26 Adjusted expiration
InventorL Claude Turrini; Current Assignee:  Safran Aircraft Engines SAS


6/15/1998 

The Fast Track To High Speed Drilling
Drill more productively by making a few strategic changes to the process. Those same changes may also let you drill dry.

Peter Zelinski, Editor-in-Chief, Modern Machine Shop


The Morse Twist Drill and Machine Co ...
[Catalogue]

Corporate Author: Morse Twist Drill & Machine Co., New Bedford, Mass.
Language(s): English
Published: New Bedford, 1912.
https://catalog.hathitrust.org/Record/100493266?type%5B%5D=title&lookfor%5B%5D=drilling%20machine&ft=

Modern drilling practice

A treatise on the use of various type of single- and multiple-spindle drilling machines, including their application to standard and special operations, the relation of speeds and feeds to intensive production, and the different types of tools and fixtures utilized in progressive machine shops for increasing the range and efficiency of machines of this class [by] Edward K. Hammond
Main Author: Hammond, Edward K., b. 1885.
Published: New York, The Industrial Press; [etc., etc.] 1919.
Edition: 1st ed.
https://babel.hathitrust.org/cgi/pt?id=uc2.ark:/13960/t06w97384&view=1up&seq=7


Suggested unit course in drill press work for beginners in machine shop practice ...
Corporate Author: New York (State).
Related Names: Witzel, Ewald L.
Language(s): English
Published: [Albany] : The University of the state of New York, the State education dept., Bureau of industrial and technical education, 1940.

https://catalog.hathitrust.org/Record/009211727?type%5B%5D=title&lookfor%5B%5D=drilling%20machine&ft=

Modern drilling practice, Hammond, Edward K

Published: New York, The Industrial Press; 1919.
Edition: 1st ed.
https://babel.hathitrust.org/cgi/pt?id=uc2.ark:/13960/t06w97384&view=1up&seq=7

Drilling machines which find the most general application in American manufacturing plants may be roughly divided into three general classes, as follows:
1. Vertical drilling machines. 2. Radial drilling machines. 3. Multiple-spindle drilling machines.

Each of these general classes is capable of further subdivision, so that drilling machines are finally classified under the following headings:

1. Vertical or " upright " drilling machines. 2. Vertical sensitive drilling machines. 3. Vertical high-duty drilling machines. 4. Radial drilling machines. 5. Multiple-spindle drilling machines of straight-line type. 6. Multiple-spindle drilling machines of cluster type. 7. Automatic drilling machines. 8. Turret-type drilling machines.

In addition to the eight preceding types of machines, a great deal of useful work is done by special machines built to meet the requirements of individual cases. Such machines are generally of the multiple-spindle type, but they are especially designed for specific classes of work.


Vertical or Upright Drilling Machines.


The vertical or up-right machine is the most commonly used type of " drill press " employed in the machine shop. It is usually equipped with power feed, and a tapping attachment is often provided, which may be engaged to provide for handling work in which holes have to be tapped. The term " sensitive " is applied to those types of light drilling machines which are equipped with hand feed, so that the opera tor is able to judge the amount of feed pressure with which the drill is being driven into the work. These machines are usually adapted for drills from the smallest sizes up to from f to J inch in diameter. They are used on a great variety of work, and for handling small parts in quick-acting jigs or fixtures they are capable of giving very satisfactory results. One advantage of the hand feed is that an experienced operator may use his judgment in releasing the feed pressure, if he finds that the drill has struck a hard spot in the work. This is the means of saving the breaking of drills. Machines of this type are now being built for operation at speeds which were unheard of a few years ago. For instance, some types of sensitive drilling machines are built for operation at speeds ranging from 10,000 to 15,000 revolutions per minute.

Vertical High-duty Drilling Machines.


As their name implies, high-duty drilling machines are adapted for the performance of heavy work, and they are commonly employed for using a range of drill sizes running from the maximum capacity of sensitive drilling machines up to the largest sizes in which drills are made. In addition to the performance of drilling operations, high-duty drilling machines are used for a great variety of other classes of work, including such operations as hollow-milling, spot-facing, facing, counterboring, threading, tapping, etc. In general, machines of this character may be employed to advantage wherever it is desired to use a rotating tool on stationary work under conditions where heavy cuts are to be taken. To meet the requirements of such severe service, the high-duty drilling machine is equipped with power-driven feed, and the rates of feed are commonly much greater than that employed on sensitive drilling machines, while the speed at which the drill is operated is correspondingly reduced, owing to the greater diameter of the drill. There are various forms of mechanisms used on these machines, but in all cases provision is made for obtaining any of a range of speed and feed changes suitable for the work on which the machine is engaged.


Radial Drilling Machines.


On the familiar type of radial drilling machine the spindle head is carried on an arm, which may be swung around the column of the machine, and the spindle head may also be moved back and forth along the arm. This combination of movements makes it possible to locate the spindle of a radial drilling machine at any desired point over work which comes within this range of movement. Radial drilling machines are commonly classified according to the length of arm, i.e., a 6-foot radial drill has an arm 6 feet in length. Sizes in which these machines are generally built run from about 2 to 6 feet. Obviously, the size of the work which can be handled with a machine of this type is governed by the length of arm and vertical adjustment of the arm on the machine column. Radial drilling machines are generally employed for handling those classes of work where there are a number of holes to be drilled and where the work is either too heavy or too large to be conveniently set up on multiple-spindle drilling machines.


Multiple-spindle Drilling Machines.


A great many parts that have to be drilled require holes of different diameters, and other operations, such as counterboring, reaming, or counter- sinking, are frequently necessary. When work of this class is done in a machine having one spindle, considerable time is wasted in removing one drill and replacing it with a different size or with some other kind of tool. For this reason, drilling machines having several spindles are often used when the work requires a number of successive operations. The advantage of the multiple spindle or " gang " type as applied to work of the class mentioned is that all the different tools necessary can be inserted in the various spindles, and the drilling is done by passing the work from one spindle to the next. Drilling machines of the multiple-spindle type are also commonly used for drilling a number of holes simultaneously. The arrangement of these machines is varied considerably to suit different kinds of work, but they may be divided into two general classes; namely, those having spindles which remain in the same plane but can be adjusted for varying the center-to- center distance, and those having spindles which can be grouped in a circular, square, or irregular formation. The first class referred to is used for drilling rows of bolt or rivet holes in steel plates, etc., and the second type is adapted to the drilling of cylinder flanges, valve flanges, or similar work.

CHAPTER IV

SPEEDS AND FEEDS FOR DRILLING


The proper speed at which a drilling operation should be performed is that speed at which the most desirable balance is obtained between cutting down of production through lowering the drilling speed and loss of time through the necessity of more frequently stopping the drilling machine to grind drills, where higher drilling speeds are employed. The following recommendations made by different authorities should prove of interest and practical value.

H. 'M. Norris, chief engineer of the Cindnnati-Bickf ord Tool Co.: occasionally a drill is found which is capable of standing up satisfactorily at a cutting speed of 150 feet per minute in either cast iron or steel, but it is seldom desirable to drive anything but very small drills at speeds in excess of 100 feet per minute. Under average conditions of operation, the best results will be obtained with a cutting speed of 80 feet per minute in cast iron, while, for steel, a speed of "7+76 feet per minute will give satisfactory results. Where this rule is used, the cutting speed will be decreased from 100 feet per minute for a |-inch drill to 80 feet per minute for a 3-inch drill. In explaining the rule, attention is called to the fact that, while cast iron is cut dry, a lubricant is required for drilling steel and a volume of lubricant sufficient to keep a J-inch drill cool at 100 feet per minute will only be sufficient to cool a 3-inch drill at 80 feet per minute.

Cleveland Twist Drill Co.:  It is well to start carbon steel twist drills under the following conditions of speed and feed until more definite data are available as to the maximum speed and feed which can properly be employed for the operation under consideration.

When drilling machine steel, use a peripheral speed of 30 feet per minute; for cast iron, use a speed of 35 feet per minute; and for brass, use a speed of 60 feet per minute. In each case, a feed of from 0.004 to 0.007 inch per revolution should be employed for drills up to i inch in diameter, while for larger sizes the feed should be from 0.005 ^^ ^-^^ 5 ^^^ P^^ revolution. In the case of high-speed steel drills, the preceding rates of speed should be increased from 100 to 125 per cent, while the same rates of feed are employed.

The Standard Tool Co. recommends starting high-speed steel drills at a peripheral speed of from 50 to 70 feet per minute for wrought iron or steel, and from 60 to 80 feet per minute for cast iron, or at 140 feet per minute for brass. The feeds recommended are 0.004 i^ch per revolution for a y^5-inch drill in wrought iron or steel, 0.005 inch per revolution for a J-inch drill, 0.008 inch per revolution for a ^-inch drill, o.oio inch per revolution for a i-inch drill, and 0.015 i^ch per revolution for a i^-inch drill.

Starting with any of the preceding speeds and feeds which have been recommended by different authorities, the operator carefully notes the condition of the drill after it has been working for some time. If the drill shows a tendency to wear away on the outside, it is running too fast, while if it breaks or chips on the cutting edges, the feed is probably too heavy for the work required. A little careful experimenting in this way, making changes gradually according to indications which are shown after working for some time, will usually result in securing a combination of speed and feed which will be the means of obtaining something approaching the maximum possible production.  It will, of course, be obvious that, to obtain a given peripheral cutting speed, the number of revolutions per minute must differ according to the size of the drill which is being used. This is the reason for running very small drills at extremely high speeds in order to have them working under conditions which approximate the required cutting speed for the material that is being machined. For the convenience of users of twist drills and other rotary cutting tools, tables are available which show the number of revolutions per minute at which a given size of drill should be run in order to obtain the required cutting speed. In Tables 1 and 2 the diameters of drills are given in the left-hand column, while peripheral cutting speeds in feet per minute are noted at the top of the table. By finding the intersection of horizontal and vertical lines through the given drill diameter and the required cutting speed, the number of revolutions per minute at which the drill must be run in order to obtain this speed will be found. Table 3 gives the decimal equivalents of nominal sizes of drills, and will be found useful when calculating the peripheral cutting speed of drills of various sizes; this table also shows the relation of the different sizes of drills, which are designated by letters and numbers, as compared to the fractional sized drills.

Critical Drilling Speeds. — In experimenting to determine the number of revolutions per minute at which a drill will have the greatest productive capacity, some interesting results are secured. Researches which were made at the plant of Baker Bros., with the view of securing data required in connection  with the design of their drilling machines, showed that there are certain critical speeds at which a twist drill will have a satisfactory rate of production, while there are other speeds — often lying between two rates of speed where the production is satisfactory — at which the drill will fail to give anything approaching satisfactory results. This condition is clearly shown by Fig. 3, which is plotted with data taken from original tests. These investigations were made several years ago, so that, while the condition shown by this set of curves is an established fact, the rates of speed and feed are lower than would be used in conducting similar tests at the present time. The point brought out by this diagram is the remarkable increase in production which can be secured by increasing the speed. The curves are plotted for the maximum feed at which the stock was successfully drilled without destroying the drill; at the next higher feed the drill would be destroyed. Curve No. 2 shows that the drill would give a far greater production without failing at 2CX) revolutions per minute than it would at 250 revolutions per minute, and also that it would give a much greater production if the speed were still further increased to 4cx) revolutions per minute.

Recently a well-known manufacturing establishment had an investigating committee working for over two years on the development of a table of speeds and feeds for use in connection with different sizes of drills working in various materials. The result of this investigation is presented in Tables 4 and 5, and although it is not claimed that the data presented can be followed without modification, it is claimed that the thousands of tests which were made during the period over which these data were secured have led to results which may safely be regarded as an average maximum of the rate of speed and feed under which a drilling machine may be operated. These tables are copyrighted by the Henry & Wright Mfg. Co., and the tests were made on a special drilling machine built by this company.


In starting to work on a new job the operator of the drilling machine will use the speed and feed shown in these tables, but should he find that the drill shows a tendency to wear around its periphery or that there is a considerable amount of chipping along the cutting edges of the drill, it indicates that the speed or feed is too heavy, and so the required adjustment of operating conditions must be made. In the plant where these data were obtained, the investigating committee reported that the installation of machines capable of operating under these conditions of speed and feed would represent a saving of $30,000 a year. The speeds recommended are rather high, and if twist drills are unable to stand them, the drill manufacturers should be notified, as it is claimed that any responsible maker can furnish suitable drills for use under these conditions if he is required to do so. The speeds are also too high for machines equipped with plain bearings, but properly constructed machines with ball bearings will easily stand up under such conditions of operations.

The best advice which can be given to the man who is trying to improve conditions in his drilling department is to adopt the method of experimenting with trial speeds and feeds — adopting those trial speeds and feeds recommended in the preceding discussion — until he has found the conditions
of speed and feed which give the most satisfactory results on his work.

High Speeds of Modem Drilling Machines. — Machine tool builders are now making drilling machines fully equipped with ball bearings so that they are adapted for operation at speeds which would have been utterly impossible of attainment a few years ago. For instance, the Leland-Gifford Co. builds a ma-
chine which is adapted for operation at speeds of from 11,000 to 15,000 revolutions per minute, and the same speeds are recommended for use on a bench drilling machine recently brought out by the Fenn Mfg. Co. Other machinery builders are making high-speed drilling machines. Driving twist drills at such
speeds means that the drilling operation is practically instantaneous; in fact, the speed at which holes may be drilled is often equal, if not in excess, of the speed at which the same work could be done on a power press. It is this constant increase in the speed of drilling, with the constant reduction of the ratio between " drilling time " and " setting-up time," which has emphasized the fact that, in order to approach the maximum rate of production, the user of high-speed drilling machines must design his work-holding fixtures in such a way that work may either be set up in indexing fixtures while the drilling operation is being performed, or, if this is not feasible, the clamping devices on fixtures must be so made that a minimum amount of time is consumed in securing the work in place ready to be drilled.

Several important advantages are secured through drilling at high speed, and this is particularly the case with small sized drills, which are likely to break, and also with high-speed steel drills. The reasons for this are as follows: In the case of small drills operated in sensitive drilling machines equipped with hand feed, running the drill at high speed makes it improbable that the operator will impose an excessive feed on the drill, because, in the case of a drill which is running at from 10,000 to 15,000 revolutions per minute, it would be necessary to pull the feed-lever down extremely fast in order that the feed for any one revolution of the drill would be sufficient to impose a stress in the steel which would be in excess of the maximum that the strength of the drill is capable of withstanding. A further explanation for the increased strength of a drill when running at high speed is that where an excessive amount of feed pressure tends to bend the drill slightly when running at high speed, the length of time that any set of fibers in the drill is subjected to stress is so short that the danger of breaking may be less than if the load remains on such fibers for a greater length of time. This is, of course, an unsettled question and is advanced in the form of a hypothesis rather than a statement of fact; in V any case, the question is an interesting one.

A series of tests was conducted on this machine by Paul Bedell Starr and John Millard Marsh to secure data for a thesis presented at the time these men took the degree of Bachelor of Science in mechanical engineering at the Case School of Applied Science. The object of this investigation was principally to determine the feed pressure required to drive different sizes of drills under various conditions of speed and feed. That very little reliable data were available on this subject was shown by the fact that, when the special drilling machine was first built by a firm of wide experience in the design and construction of equipment of this type, a pressure gage reading up to 3000 pounds was provided. At the first test, using a i-inch drill at a normal rate of feed, the range of this gage was shown to be entirely inadequate; therefore, a gage reading up to 15 tons was substituted, which proved suitable for the service required of it, this difference in gages showing conclusively that the knowledge concerning the magnitude of feed pressures was not at all definite.

Coolants and Lubricants used for Drilling. — For drilling operations, satisfactory results can usually be obtained through the use of one of the soluble oil coolants, for all classes of work where the length of chips produced is not very great; but in cases where long chips are formed, there is a rubbing action produced by the chips sliding over the lips of the drill, which produces a condition analogous to that of a machine bearing, thus making it necessary to apply a fluid which serves the combined purpose of lubricant and coolant. The following is an outline of lubricants and coolants recommended for drilling operations in various classes of material, and the lubricants used are recommended in the order in which they are named. In this list " cutting compound '' refers to any satisfactory brand of soluble oil mixed with water, in accordance with the manufacturer's instructions; and " mineral lard oil " is a mixture of lard oil and light petroleum oil. The proportions of this mixture vary according to the work, but one part of lard oil to two parts of petroleum gives a mixture that is well suited to the requirements of many average drilling operations. For drilling high-carbon or alloy steel, use mineral lard oil or turpentine; low-carbon steel, mineral lard oil or cutting compound; cast iron, dry or compressed air; wrought iron, cutting compound or mineral lard oil; malleable iron, cutting compound; brass, dry; bronze, cutting compound or dry; copper, mineral lard oil; aluminum, kerosene, beeswax, or tallow; monel metal, cutting compound; and glass, solution of camphor in turpentine.


Updated  19 Feb 2021
Published on 27 April 2020






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