Inclined hole getting cuts the improvement of craft and twist drill structure

3µm. Ply of the workpiece when bore is machined is more than nominal dimension 3mm(to leave) of surplus of dig of essence of life. Standard twist drill should be used to be opposite on Z3550 versatile radial drilling machine calm board when undertaking convention getting cuts treatment, produced issue of the following technology: When with standard twist drill head getting cuts 30 ° inclined hole, because the included angle between broach and workpiece is lesser, to assure to machine length, need lengthen drill pipe and bit, make broach tigidity is reduced thereby. In addition, the broach when drilling scarfing hole is in interrupted cutting condition in quite long period of time and radial fights force very big, to avoid collapse blade, assure to machine on the rails, must reduce cutting dosage, this affected treatment efficiency and manufacturing schedule directly. Get when cutting straight hole, use craft of the enlarge that get → to be able to be stabilized achieve Ra6.

The exterior surface roughness of 3µm asks. But get when cutting 30 ° inclined hole, because suffer interrupted cutting and radial to resist the influence of force, broach is being gotten vibration exists from beginning to end in cutting a course, although use,get set oriented can reduce radial to fight force partly, but vibration still can quicken broach to wear away, bring about blade of collapse of the blade outside broach, serious effect gets the on the rails that cuts treatment and bore quality. To solve afore-mentioned problems, we cut craft and the structure of standard twist drill that are used at treatment to undertake improvement to inclined hole getting. 2 get those who cut craft to improve the reaming after cutting inclined hole getting craft to be gotten by direct bore instead, get in Ø24mm namely set inside increase a Ø21mm to get again set, use Ø21mm broach drill first, next reaming of reoccupy Ø24mm broach. To assure to decide board the dimension precision of pitch and raise broach getting to cut the stability that begins phase, designed jig of special inclined hole. The radial that just getting the instantaneous place generation that shows work to eliminate broach side needle fights force, get the technology that an A3 material installs below workpiece when cutting board. The improvement of 3 broach structure gets model choice: To raise the tigidity of broach and bore precision, choose the long knife twist drill that gets core to add chamfer of blade of thick, parabola cutting first, undertake to broach getting needle machine grind, in order to make sure angle of two sharp edge blade is symmetrical, cutting blade gets power even. The blade of broach angle grinds: If graph 1a place is shown,bore uses the form getting a tip of Ø21mm broach. Level broach begins to be in interrupted cutting condition in what drill scarfing hole, cutting area by small arrive big till enter successive cutting state, this phase machines length to be 48mm. In interrupted cutting phase, broach falls in the radial action that fight force, its arris edge and the attrition power that get a wall are greater, to reduce attrition force, the geometrical angle blade that gets Ø21mm bit the tip is ground for group auger model. As a result of broach sharp angle (tool cutting edge angle) the change will make Py of radial cutting force and axial cutting force (force taking a knife) the size scale of Px produces change, py of radial cutting force increases those who follow sharp angle and reduce namely, because this blade is ground,need to increase two sharp angle when broach. In the meantime, the horizontal stroke that get a tip blade is ground narrow in order to reduce axial cutting force; Grind circular arc blade low, arc bottom stands by broach side edge, outside making narrow of straight blade width, reduce the axial height between A, B (1b) seeing a picture, add tall annular muscle thereby, enhance the centering action of broach side needle, raise the goal of cutting stability in order to achieve. Such, should get after cutting length to exceed A, B, get the radial cutting near the needle force and outside the way of radial component of force of straight blade is opposite and straight blade is radial outside be less than component of force (1c) seeing a picture. (A)(b)(c) pursues the blade of angle of the 1 geometry that get a tip is ground 1.

Platform 2.

Pressing plate 3.

Dial gauge 4.

Search core axis 5.

Jig board 6.

Fender pursues 2 workpiece search the 4 treatment effects after improving are in sketch map after broach geometry angle is affirmatory, through cutting the experiment chooses reasonable cutting dosage (rotate speed N=160r/min, feed F=0.

08 ～ 0.

10mm/r) . Calm board the inclined hole that go up is gotten cut after ending, need to undertake be repairinged by hand grinding with emery wheel (repair the aperture after grinding to be Ø24 ～ 24.

5mm) , make light with emery cloth next, make the exterior surface roughness of each aperture achieves Ra6 basically.

3µm. After treatment, the generatrix of hole wall of the office that get a mouth that discovers individual hole is not straight, classics analysis, because,this is angle of main shaft of machine tool slideway, machine tool and get pattern plate mutual between search to forbidding to cause broach feed direction and those who get pattern plate to go up auger set inside aperture axes is abhorrent be caused by. To solve this one problem, one is deployed to search on every treatment machine tool core axis (2) seeing a picture, after every drill a hole, position of mobile the head of a bed, be in installation inside aperture of machine tool main shaft search core axis inserts those who get pattern plate to get set inside, through adjusting position of machine tool main shaft, make core axis can be being gotten set inside free roll, take out broach of core axis, mount to be able to undertake getting cutting machining next. Via producing test and verify, with after improving auger cut craft and twist drill treatment to decide board when the 30 ° inclined hole of the spare parts, treatment result is favorable, bore quality and treatment efficiency rise significantly, every but bore 30 ～ 35. CNC Milling