Machining center is the machine tool of numerical control treatment with bigger range of a kind of craft, can undertake milling, boring, auger cut and the multinomial job such as thread machining. Machining center is special agree with casing kind spare parts and the treatment that aperture fastens. Treatment craft limits pursues like graph 1- 4.
Graph 1 milling treatment
Graph 2 auger cut treatment
Graph 3 thread machining
Graph 4 boring treatment
1. analysis for technological efficiency
Basically consider the following aspects commonly:
(1) the choice machines content
Machining center suits to process form most complex, working procedure more, demand is higher, need to use the general purpose machine tool of a variety of types, cutting tool and clamping apparatus, be placed via be being installed for many times and adjust ability to complete the part of treatment.
(2) examination hardware design
Part drawing appearance should be conveyed correct, tag all ready. Want special attention at the same time, unified design should be used as far as possible on the design fiducial, simplify thereby process designing, make sure the precision of the spare parts asks.
Graph what 5 spare partses machine is fiducial and unified
Pursue for example 5 in what show part drawing pattern. In graph 5a, two sides of A, B all is machined in working procedure of advanced already face end, undertake on machining center place poriferous is machined only. When locating with two sides of A, B, the design that did not unite as a result of high direction is standard, ф 48H7 aperture and upper part the dimension of aperture of two ф 25H7 and B face assures secondhand, be about to assure 32.5 ± 0.1 with 52.5 ± 0.04 dimension, must going up in working procedure to 105 ± 0.1 dimension public errand undertakes compression. If place of instead graph 5b is shown,tag dimension, dimension of each opening position is with A face fiducial, fiducial and unified, and craft is fiducial as fiducial as the design coincide, each dimension assures easily.
(3) the technical requirement that analyses a spare parts
Be in according to the spare parts the function in the product, analyse each geometry precision and technical requirement reasonable; Consider to be machined in machining center, whether make sure its precision and technology ask; Choose which kind of machining center most reasonable.
(4) the structural craft sex that examines a part
The structural stiffness that analyses a spare parts is enough, the structural craft sex that machines place each is reasonable wait.
Process designs 2.
When craft is designed, main consideration precision and efficiency two respects, abide by commonly first the aperture after the face, first fiducial hind other, first thick hind the principle of essence of life. Machining center is in in outfit clip, complete all treatment that can machine the surface as far as possible. Contrapuntal buy precision asks taller aperture fastens treatment, the treatment that wants special attention to plan opening is ordinal, arrangement is undeserved, possible drive deputy backlash is taken, affect positional precision directly. For example, when the aperture department that arranges graph 6a place to show a part processes order, if press the course treatment of graph 6b, as a result of 5. 6 aperture are in with 184.108.40.206 aperture Y to orientation way is opposite, y can make to backlash the error increases, affect the positional precision of 5.6 aperture and other aperture thereby. Place of the 6c that press a plan shows a line, can avoid backlash introduce.
Graph 6 bore hole treatment course
In machining a process, change knife time to decrease, can use cutting tool to center working procedure, use namely same machine cutting tool the corresponding place on the spare parts, change have a smattering of a subject to provide again continue to machine. But, ask to precision very tall aperture is fastened, when if the spare parts is,determining corresponding treatment position through workbench circumgyrate, because existence repeats fixed position error, cannot adopt this kind of method.
The outfit of 3. spare parts is placed
(1) the choice with standard fixed position
When machining center is machined, the fixed position of the spare parts still should be abided by located at 6 o’clock principle. In the meantime, still answer special attention the following:
1) undertake multitask when treatment, lv can finish the choice take an examination with standard fixed position to machine content more as far as possible, the orientation way that even if can be machined at each surfaces. For example, to casing spare parts, use one side as far as possible kind of two sold assorted fixed position.
2) the fixed position when the spare parts is standard as fiducial as the design hard when coincide, answer to analyse assembly drawing sample seriously, make clear this spare parts to design fiducial design function, pass the computation of dimension catenary, strict regulation fixed position is standard as fiducial as the design the requirement of dimension position precision between, ensure treatment precision.
3) process designing origin and spare parts fixed position are standard need not coincide, but both between must want to have affirmatory geometrical concern. The choice of process designing origin basically considers to facilitate process designing is mixed measure. For example, graph 7 medium spare partses machine aperture of 25H7 of Φ of 4- of Φ 80H7 Kong He on machining center, among them 4- ф 25H7 is with ф 80H7 aperture fiducial, process designing origin should choose to be on the central line of ф 80H7 aperture. Locate when the spare parts fiducial when be two sides of A, B, fixed position is standard with process designing origin not coincide, but can assure to machine precision likewise.
Graph origin of 7 process designing and fixed position are standard
(2) the clamp of the spare parts
When considering clamp plan, should make sure clamp is reliable, reduce clamp to be out of shape as far as possible.
(3) of clamping apparatus choose
On machining center, the task of clamping apparatus is the spare parts that hold clip not only, and want in order to locate fiducial for reference fiducial, decide the treatment origin of the spare parts. Accordingly, fixed position is standard want accurate and reliable.
The choice of 4. cutting tool
Machining center is to the main demand of cutting tool:
1) good cutting performance: Can bear high speed cutting and puissant cutting and performance is steady;
2) taller precision: The appearance precision that the precision of cutting tool points to cutting tool and cutting tool and outfit block the positional precision of device;
3) provide perfect tool system: Satisfy the requirement that much knife machines continuously.
The knife head part of use cutting tool of machining center place and the cutting tool that numerical control milling machine uses are basic and identical, about cutting tool of numerical control milling choose. The knife handle part of use cutting tool of machining center place and milling machine of ordinary numerical control use knife handle part to differ, machining center contains clip to hold groove for manipulator clip with knife handle.