CN101690984B - Method for machining high-precision sealing surface by numerical control gantry mill - Google Patents

Abstract

The invention discloses a method for machining a high-precision sealing surface by a numerical control gantry mill, and relates to the field of a machining method of a numerical control milling machine. The method comprises the following steps: compensating a workpiece regulating inclination included angle alpha by acquiring an error included angle alpha of a cutter plane, and setting the included angle in a numerical control system and enabling a cutter to run along the included angle alpha so as to compensate the error between a ram or a main shaft (namely Z axis) of the gantry mill and the motion direction (namely X axis) of a workbench under the condition of not adding equipment, eliminate jointed tool marks, meet the quality requirement of a product, cancel a bench work process, improve the quality of the product and improve the production efficiency. In the flatness error within 0.02 millimeter on a whole plane of 3,250mm*1,320mm, the method has no obvious jointed tool marks which can pass the examination once in follow-up examination, the contact is complete, the surface roughness is below Ra3.2, the follow-up gantry milling and bench work remaking processes are fully cancelled, and a large amount of time is saved.

Description

A kind of method of machining high-precision sealing surface by numerical control gantry mill

Technical field

The present invention relates to the method in CNC milling machine processing method field, particularly a kind of machining high-precision sealing surface by numerical control gantry mill.

Background technology

Gas-turbine combustion chamber housing horizontal seal face is to prevent that the high-temperature gas leakage has high required precision; The sealing surface of standard-required housing closes down at the moment of torsion handle of standard code; Key area need reach 100% contact requirement with the method inspection of red blue oil, does not more allow to occur the inside and outside gas leakage passage that connects.Because the burning chamber shell size is bigger, the length and width height is generally greater than 3m * 1.3m * 1.5m, and sealing surface is generally greater than 3m * 1.3m; General factory does not possess so large-scale grinding machine, and the method that adopts usually is to use gantry to mill by the conventional method processing plane, because ram is milled at gantry or there is the error of perpendicularity in main shaft with the working table movement direction when mounted; And the gantry of at room temperature working mills that this error amount also can change under different temperatures, and the flatness that therefore processes can not reach standard-required, between adjacent two cuttves, exists to connect tool marks; Had a strong impact on the effect of crudy and red blue oil inspection; Therefore the result who after completion of processing, needs pincers worker to check according to red blue oil carries out careful repairing with oilstone and grinds, and needs repeatedly repeatedly, and labour intensity is big; Inefficiency, product appearance is of poor quality.The perpendicularity of numerical control gantry mill ram or main shaft (being the Z axle) and working table movement direction (being the X axle) or with perpendicularity along the crossbeam direction of motion (being the Y axle) be (there is error in single direction) under any geometric accuracy; Wherein the error of Z axle and Y axle is easy to adjustment, and difficult point is to solve the error of Z axle and the appearance of X axle.

Summary of the invention

Technical problem to be solved by this invention provides a kind of method of machining high-precision sealing surface by numerical control gantry mill, can compensate the error that Z axle and X axle occur, thus eliminate that the processing sealing surface occurs connect tool marks and indent, improve the sealing surface machining accuracy.

For solving the problems of the technologies described above, the technical scheme that the present invention adopted is: a kind of method of machining high-precision sealing surface by numerical control gantry mill comprises the steps:

1) obtain tool plane and ideal plane, i.e. the step of the error angle between the y-x plane °:

At suitable position welding procedure lug, make it to form the plane parallel with sealing surface, draw the step of sealing surface processing line;

The sealing surface of workpiece is downward, at A, B, C and D place adjustable sizing block and sphere parallels is set, be adjusted to etc. high, high step such as between the finish-milling technology lug;

Work piece sealing is towards last, but adorns contour pad iron everywhere on the tooling platform at the position of mounting process lug, and height such as parallels are milled everywhere at gantry, and the technology lug is placed on the parallels, compress thick, half finish-milling sealing surface, made allowance 1mm;

The Y axle feed length L in contour pad iron upper edge is measured between 2 height error h, obtains angle ° through formula α=arc tan (h/L);

Draw angle=α ° of error between tool plane and the ideal plane;

2) the processing plane slanted angle of adjustment workpiece makes it the step parallel with tool plane for α °:

According to the spacing K between the technology lug,, try to achieve the height H that to fill up under the technology lug through formula H=K * sin α;

With the step of pad pad under corresponding technology lug that highly is H;

Can adjust processing plane slanted angle=α ° of workpiece through above-mentioned steps and make it parallel with tool plane;

3) in digital control system, plane to be processed rotation is made it parallel with tool plane for angle=α °, or stipulate the spacing between two cuttves and stipulate that according to angle=α ° of rotation angle next cutter rises or the step of decline level altitude;

Can on workpiece, process the high-precision sealing surface that reaches quality requirement through above-mentioned steps.

The method of a kind of machining high-precision sealing surface by numerical control gantry mill provided by the present invention, the error angle through obtaining tool plane ° is adjusted slanted angle α ° compensation with workpiece; And in digital control system, set, make cutter also along ° operation of this angle, thus can be in the situation of not adding equipment following; The error of ram or main shaft (being the Z axle) and working table movement direction (being the X axle) is milled at compensation gantry; Elimination connects tool marks, satisfies the quality requirement of product, cancellation pincers worker operation; Improve the quality of products, enhance productivity.Adopt the flatness error of the inventive method on the whole plane of 3250mm * 1320mm in 0.02mm; Do not have and obviously connect tool marks; Can single pass check all that in subsequent examination contact reaches 100%, surface roughness Ra is below 3.2; Fully phase out follow-up dragon and milled and the pincers worker operation of doing over again, practiced thrift great amount of time.

Through adopting welding procedure lug and the method that adopts contour pad iron; Can not be used on the workpiece test, clamping; Thereby obtain the error angle ° of tool plane, improved the security of processing, reduced the risk of scrapping of workpiece; And need not use too complicated measuring instrument, reduced production cost.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is described further.

Fig. 1 is the sketch map that process tool of the present invention and workpiece compensate through processing;

Fig. 2 measures error angle ° sketch map among the present invention;

Fig. 3 is that mill and the reference axis sketch map at gantry among the present invention;

Fig. 4 is that the present invention compensates preceding process tool and workpiece sketch map on the z-x plane;

Fig. 5 is that the present invention compensates preceding process tool and workpiece sketch map on the y-z plane;

Fig. 6 is the sketch map that parallels is set among the present invention;

Fig. 7 is the feed sketch map in the time of can't in program, doing the out-of-plane rotation among the present invention.

The specific embodiment

Like Fig. 3, Fig. 4 and shown in Figure 5, certain model burning chamber shell, sealing face length * wide is: 3250mm * 1320mm; Key area requires red blue oil inspection 100% contact; Use the usual way processing plane, can't meet the demands, need repeatedly do over again; Average every imperial miller time～8-10 hour/platform reprocessing, pincers worker are repaiied man-hour～160 of grinding hour/platform.Find that on inspection gantry mills the Z axle direction of motion and X-direction out of plumb; Be tool plane 4 and ideal plane 5 has an error angle °; Connect tool marks seeing on the z-x plane to add to produce on the processing plane 6 in man-hour like this, connect tool marks and indent seeing on the y-z plane to add to produce on the processing plane 6 man-hour.

At workpiece 2 suitable position welding procedure lugs, make it to form the plane parallel with the horizontal flange sealing surface.Draw the sealing surface processing line.

Last gantry is milled and is done roughing, and concrete clamping step is following:

As shown in Figure 6, workpiece 2 sealing surfaces are downward, and clamping method is following: fill up with adjustable sizing block (adding ball ring) everywhere earlier and be placed on A, B, C, D place; Transfer A, B two place's lines flat, placement dependence one adjustable sizing block at diagram E place (apart from rear flange 970mm place), with E place parallels with workpiece jack-up; Take out C, D place parallels, adjust E place parallels then, E place line is adjusted to and A, height such as B place line grade; Press dial gauge at C, D place, make zero, add adjustable sizing block and sphere parallels respectively at C, D place then; Careful adjustment C, D place parallels are adjusted to C, the dial gauge variation＜0.01mm of D place, loosen E place parallels then; The observation indicator changes, as changes, and then will changing one jiao of place, to be adjusted to the dial gauge reading be zero.Compress (should notice when compressing that respectively the place's of compressing meter reading does not have big variation), finish-milling is height such as technology lug everywhere, and the pine pressing plate guarantees that workpiece is in free state during finish-milling.

Workpiece 2 stands up, but adorns contour pad iron everywhere on the tooling platform at the position of mounting process lug, and height such as parallels are milled everywhere at gantry, and the technology lug is placed on the parallels, compress thick, half finish-milling sealing surface, made allowance 1mm, connecting hole on the processing sealing surface.

Change other operation and do roughing, eliminate most of allowance.

Natrual ageing 1～2 day.

Last numerical control gantry mill fine finishining sealing surface, step is following:

As shown in Figure 2, but adorn 4 place's contour pad iron at the position of mounting process lug on the tooling platform, at first on contour pad iron, do processing experiment; Confirm that gantry mills geometric error,, go out a plane at contour pad iron glazing along crossbeam (Y is axial) feed; On main shaft or ram, place an amesdial; Lathe moves a length L accurately along workbench direction (X axis), measures between 2 just error h with amesdial 3, through formula: tan α=h/L α=arc tan (h/L); Draw the error angle ° between tool plane 4 and the ideal plane 5, the ideal plane 5 here is meant the y-x plane.

As shown in Figure 1; Then according to the spacing K between the technology lug,, can calculate the height H that to fill up below the technology lug according to computing formula: H=K * sin α; Gantry is milled everywhere, and parallels makes it to wait high; This moment, workpiece processing plane 6 was just parallel with the tool plane 4 of cutter after the bed hedgehopping degree is the pad of H below corresponding lug, and the plane that will process then is used as a plane that is α ° of angle with the X axle and is processed.Simple way is in program, to utilize order " ROT " or " AROT " that whole face to be processed is carried out programmable rotation angle ° in the numerical control dragon of Siemens system is milled; At this moment cutterhead 1 will be processed along the plane that is parallel to actual tool plane 4, and the processing plane that processes can be eliminated and connect tool marks.Mill at common gantry or the comparatively simple numerical control dragon of system also can clearly be stipulated the spacing L between two cuttves can't in program, do the out-of-plane rotation in milling the time; After covering a cutter; Calculate the height h that adjacent cutter Z axle needs rise or descend according to angle; Computing formula: h=L * cos α, thus reach the effect that cutterhead 1 is processed along the plane that is parallel to actual tool plane 4.

Certain type burning chamber shell, sealing face length * wide is: 3250mm * 1320mm, do processing experiment on contour pad iron; Confirm that gantry mills geometric error, adopt thick smart composite milling cutterhead 6CKK315, use the fine finishining blade; Along crossbeam (Y is axial) feed; Go out a plane at contour pad iron glazing, on ram, place an amesdial, in the plane that processes, move a length L=200mm accurately along workbench direction (X axis); Can measure between 2 height error h=0.037mm this moment, through formula calculation error angle α:

tanα＝h/L＝0.037/200＝0.000185

α＝arc?tan(h/L)＝arc?tan0.000185＝0.0105997°

The strong point spacing of known contour pad iron supporting workpiece is 2800mm, calculate at 2 between difference of height should be:

2800×sin0.0105997＝0.51799mm≈0.52mm

At the strong point underlay copper sheet 0.52mm of correspondence,, process sealing surface by following procedure then with workpiece 2 side alignments:

R1=-0.02 confirms variable

G54G91G17；

G0 X0 Y0 Z100; The program starting point

G0 Z5.; Safe altitude

ROT Y0.0105997; The plane is along 0.0105997 ° of Y axle rotation

S250 M03; Main shaft starts

G1Z=R1 F200; Z axially descends feed 0.02mm

G1Y1750 F400; Along the feed of Y axle

G0X-400; Fall back on X fast

Y-1750; Fall back on Y fast

G0 X265; Starting point to another cutter

G1 Y1750 F400; Along the feed of Y axle

G0?X1550；

Y-1550；

X1550；

G1?Y1750?F400；

G0?X400；

Y-1750；

X-265；

G1?Y1750；

G0?Z100；

M05；

M09；

M30；

In process, should produce than involuntary conversion blade before the galling at blade according to the durability of blade, the regulation cutter is every on this workpiece walks 2 cuttves along the Y axle, i.e. feed length reaches 3.5m and changes a finishing tool sheet.

Beat table look-up behind the copper sheet that fill up on the plane of processing by this method below removing; Flatness on whole plane is in 0.02mm, and nothing obviously connects tool marks, in subsequent examination, all can single pass check; Contact reaches 100%; Surface roughness Ra is below 3.2, fully phased out follow-up dragon and milled and the pincers worker operation of doing over again, and practiced thrift great amount of time.

Claims (1)

1. the method for a machining high-precision sealing surface by numerical control gantry mill is characterized in that comprising the steps:

1) obtain tool plane (4) and ideal plane (5), i.e. the step of the error angle between the y-x plane °:

At suitable position welding procedure lug, make it to form the plane parallel with sealing surface, draw the step of sealing surface processing line; The sealing surface of workpiece (2) is downward, at A, B, C and D place adjustable sizing block and sphere parallels is set, be adjusted to etc. high, high step such as between the finish-milling technology lug;

Workpiece (2) sealing surface upwards, but adorn contour pad iron everywhere on the tooling platform at the position of mounting process lug, height such as parallels are milled everywhere at gantry, and the technology lug is placed on the parallels, compress thick, half finish-milling sealing surface, made allowance 1mm;

The Y axle feed length L in contour pad iron upper edge is measured between 2 height error h, obtains angle ° through formula α=arc tan (h/L);

Draw angle=α ° of error between tool plane (4) and ideal plane (5);

2) processing plane (6) of adjustment workpiece (2) makes it and the parallel step of tool plane (4) for slanted angle α °:

According to the spacing K between the technology lug,, try to achieve the height H that to fill up under the technology lug through formula H=K * sin α;

With the step of pad pad under corresponding technology lug that highly is H;

The processing plane (6) that can adjust workpiece (2) through above-mentioned steps makes it parallel with tool plane (4) for slanted angle=α °;

3) in digital control system, plane to be processed rotation is made it parallel with tool plane (4) for angle=α °, or stipulate the spacing between two cuttves and stipulate the step of next cutter rising or decline level altitude according to angle=α ° of rotation;

Can on workpiece, process the high-precision sealing surface that reaches quality requirement through above-mentioned steps.

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