1、 MIL-D-7724 39 W 7777706 0244010 O W 18 August.1961 MILEARY SPECIFICATION 1.1 Scope,- This specification covers two shes of boac colum drilling machines, The machines shall be electric motor drivan, floor mounted, with equipnent and accessories as described here- in, 1.2 Classification,- The drillin
2、g machines covered by this specification shall be of the follawing sizes (see 6.2): Size I Size II (Capacity; 1-l/2“ diameter hole in cast iron) (Capacity; 3“ diamster hole in cast iron) 2, AFF!LICABIZDOCUMENTS 2.1 The foliowing documents, ofthe issue in effect on date of invitation for bid, form a
3、part of this specification to the extent specified herein: Si33CIFICAT IONS I Federal CM436 Ebtors, Fractional Horseper, cwr-iu Motors, Alternating-Current , FF-B-111 Bearings, Ball FF-B-186 Bearings, Roller Alternating Current Integral Horsepwe- Military mp-4574 Preparation for Storage an Shippaent
4、 of Government Owned (Um) Inustrial Reserve Equipnt and Miiitary support It- STA- Licensed by Information Handling ServicesMIL-D-9924 34 = 999790b 0244OLl 2 -3.29 Marking for Shipnent MIEsTD-130 Identification Marking of U. S. Military Property (CoNes of specifications, standards, drawings, and pubi
5、hations required by contractors n connection with specific procureSient functions should be obtained *om the activity or as directed ocurhg the contracting officerPf 2.2 Other PubUcati0ns.- The follmdng documents form a part of tus specification to the extent specified herein. Un- less otherwise ind
6、icated, the issue h effeot on date of invitation for bids shall apply. National Bureau of Standards Handbodr H28 Screw-Thread Standards for Federal Semrices (Application for copies should be addressed to the Superintendent of Documents, Governmen$ Printing Office, Waahlngton 25, D. C.). Nationsl Ele
7、cteical Manufacturers Assodation Standsrda Wl1959 Motors and Generators (Apucation for copies should be addressed to National Electrical Manufacturers Association, 159 E. 44th Street, New York 17, New York). brican Sbars Association 4 I 35.1 5.10 %,6 Gear Tolerance and Inspection TSlots - Tbeir Bolt
8、s, Nuts, Tongues and Cutters Machine Tapers, Self-Holding and Steep Taper Serges 36.1 Spr Gear Tooth Form (Application for maes should be addressed to American kdards Asclodation, 10 East 4th Street, Neu York 16, Ney,), National Machins Tool Builderrs Association Standards Hacbine Tool Electrical St
9、andaraS 2 Licensed by Information Handling Services(Copies of NMPU Electrical Standards may be obtained from the National Machine Tool Builders Association, 2l.39 Wisconsin Avenue, N.W., Washington 7, D. C.). 3. m2-m 3.1 Preproduction saniple.- The contractor shaU furnish a complete drilling machine
10、 for preproduction inspection and test in accordance with paragraph 4.3. The sample may be a preproduction item or if the contractor has a production item which meets the requirements of this specification a sample may be taken from stock. shall be identical with the proposed items and shall be made
11、 or shall have been made and assembled by the sme method8 that are to be used or were used in production of items to fulfill the terms of the contract. Che preproduction saiilple shall be furnished and the approved sample shall be used as the production standard. Approval of a preproduction samaple
12、shall not relieve the contractor of the responsibility to furnish ecpipnent in accordance with the requirements of this specification. 3.2 Design.- The rilling nachines covered by this speci- cation shall be of the upright, baoc column, slicking spLncile bracket desis. Power from the motor shay be d
13、elivered to the spindle by belt and gear or all gear drive, The changing of speeds and feeds shaU. be accomplished by sliding gears or variable speed pulleys. Step cone pulleys shaU not be used as a means for changing speeds. Pick-off gears shall not be acceptable as a mans for changing feed rates.
14、shall have accurateiy scraped or nachined ways on which the spindle head and working table travel. In either case, the sample The colunm 3.2.1 Safety devices.- The safety of the operator shall be an important consideration in the design of the machine, machine shall be fitted with safety devices for
15、 cavering all parts that present safety hazards, guards for belts, Weys, chains, gears, sprockets, etc. AU guards shall be of the removable or adjustable type to provide for access to the machine part. They shall be mountedto eluninate the possibiity of working free or shifting to undesir- able posi
16、tions. AU electrical equipnt shall be grounded to eliminate the possibility of electrical shock uuer narmal operation. The The devices shall include ,d ,. * - 3 Licensed by Information Handling ServicesMIL-D-7724 34 E 7777706 0244033 6 E - 3.2.2 Lubrication.- AU bearings (accept sealed-for-life type
17、), bearing surfaces and rotating parts shall have means for lubrication. All oil holes and grease fittings shall be accessible and shall be protected against the entry of dirt and foreign natter. 3.2.3 Interchangeability.- All replaceable parts shsll be constructed to definite stmdars, tolerances, a
18、nd clearances in order that any such part of a particular manufacturers type or model may be replaced or adjusted without requiring modification. 3.3 Construction.- Constru, Licensed by Information Handling Servicesbe Fovided with counterbalances or a gear rack, pinion, and crank to facilitate verti
19、cal travel. The vertical travel of the bracket on column ways shall be as specified in table I, Unclamphg or clamping of the bracket shall not affect the accuracy requirements specified in section 4, 3Jlrimately 1 inch *om spindle nose (location A), 8nd set dial to zero. . b. Rotate spindle 360 degr
20、ees, Maxhw deviation shaU not exceed 000005 inch. C. Remount indicator so that contact point is at fpee end of test arbor (location B), and set dial to Bero. d. Rotate spindle 360 degrees, maximum deviation shall not exceed 0.001 inch. 4.3.3.2 Spindle square w5th vertical table travel (see figure 2)
21、. a. Mount indicator on table wL%h contac$ point1 on center3lne of test mbor at spindie nose (location A), and set, dial to zero. b. With column gibs adjusted to a snug running fit, laver table until inicator contact point reaches location B. Xndicator rea- shall not exceed plus 0.001inch per foot.
22、Licensed by Information Handling Services NIL-D-7724 34 W 777770b 0244020 3 W WD- 9924(USAF) Repeat operations a and b with indicator contact indicator C. point at 90 degrees fran initial test position. reading shall not exceed 0,002 inch per foot. 1+.3.3.3 Spindie square with fixed table (see figur
23、e 31.- less than half the table width. A), and set dial to zero. not exceed 0,002 inch per foot. 4.3.3.4 Column deflection test (see figure 4).- a. lbunt indicator on spindle at a radius of 1 inch Place indicator contact point on table surface (location b. C. Rotate spinle 360 degrees. &xbuin deviat
24、ion shall a, Adjust sliding head to highest position and table to Advance spindle to develop the follaWing thrust: (1) For size I - 500 pounds (2) FQr size II - 650 pounds C. I%xi.mum deflection shall not exceed the follmhg: lmest position, and arrange test apparatus as shown, b, (1) For size I - 0,
25、006 inch per i2 inches throat depth . (2) For size II - 0,008 inch per 12 inches throat depth 4.3.4 Capacity test.- Bolt a drill vise to the table and place a piece of gray cast iron not less than 1 inch thick in the vise. “he machine shall drill 3 holes In the test specimen ushg the drill size, spi
26、ndie speed and feed as listed below: mm SE6 SPINDLE SPEED SPmm FEED _o (Not less thd Size I 1-1/2* Size U: 3n The use of a combination center ckil9bmy be used for pilot purposes. stalling or excessive belt slippage shall be cause for rejedian. Failure of the machine to perform this test without Lice
27、nsed by Information Handling ServicesI I TABLE TOP VIEW 12 Licensed by Information Handling Services1 DfREC,TI ON OF FORCE- r / U *SPI AI DL E DIAL NlCATOR PLATE -., BALL. 1C JACK 1 f i - - * TABLE .LOCKED+ U I I) + HEAD LOCKED H VDRA 1. t DEFLECTION TEST FIGURE - 4 13 Licensed by Information Handling ServicesLicensed by Information Handling ServicesPreparing Actirity - W4i Licensed by Information Handling Services
