How to make the lens aperture in a steady state process?
First, the reference aperture unstable
1, processing conditions:
1) Abrasive powder particle diameter size, and concentration ratio of the size of the impact on the iris; abrasive powder particle diameter is too large and too much concentration, the radius of curvature of the grinding pan change the greater (convex radius of curvature larger pan; concave radius of curvature smaller dish) as compared with the water, the higher the aperture will change direction; likely to cause side vertical.
2) the speed of the impact speed of local irregular aperture, the linear velocity of the grinding pan edge and the center line speed is not the same. Lenses put more edge grinding dish, lens aperture, the more negative the aperture to change; can cause the lens center and edge wear is not balanced, low and high, the tone and tune into the lens is the truth.
Size 3) Pressure> lens 10 has a direct impact on the central web and D / T, (when using the rod string processing is particularly evident) affecting stress across the entire lens-shaped main surface uneven stress cause.
4) Processing time change also affects the surface accuracy, because the abrasive follow cosine grinding, grinding dish radius of curvature * sand after hanging goods in time correction. (Always keep the mill due to the curvature radius of the dish, dish fast grinding center wear is inevitable).
5) adjust the size of the swing: swing is too large, low aperture lens aperture to change, accompanied by low occurred; swing is too small, high-aperture lens aperture to change, accompanied by high-appear.
6) Adjustment of quasi-spherical core: core adjustment quasi ball good and bad, is the influence of pressure is uniform pressure.
7) to adjust the concentricity: coaxial spindle means, a relay jig grinding dish center uniform requirement. Fails to reach the center of uniform requirement, beating the lens in the job, does not run smooth impact surface accuracy. zI &).
8) rod string height adjustment: press and hold the jig rod string; it will be easy to scratch the skin jig grinding pan drive the rotation of the lens, the rod string of high-pressure transmission can not be guaranteed, the rod string is low.
9) various parts firm, confirm the locking portion.
10) on the lens grinding dish offset.
11) put multiple lenses, the lens is easy to produce the impression, faces of the low number of volatile, easy to move when Alice swung to the edge. Put a small amount of wear small, easy side vertical.
12) parallel to the arm lever: the lever arm is not parallel to the centerline of the lens affect the centerline and grinding dish can not be overlaps.
2, the device
1) machine spindle runout is offset center shaft, causing the lens is not running smoothly during processing.
2) clearance machine activity joints too much, and put into force the lens when put on suddenly suddenly small, lens discontinuity.
3) not flexible telescopic cylinders, machines of different sound and vibration.
Solid point 4) rod string is not strong, rod and string distance between the grinding pan is too large, in the processing, string rod tip shaking change on the surface accuracy.
3, governance tools
1) matching the outer diameter of governance tools is accurate, that is combined with drilling and workover dish dish size ratio, the ratio of the size of the repair drilling and grinding dish pan, pan size ratio and grinding lenses.
2) drilling and repairing local dish error is equal to the local error of the lens.
3) precision jig grinding dish surface curvature, lens processing is to determine the surface, an important part of the force and face fixture fully consistent subject.
4) end jig hole, a high degree of design.
5) face is level with the height of the relay fixture.
6) the shape of polished rod string: polished rod string is the key to the smooth operation of the jig table No, the rod string is too blunt, affecting the smooth functioning; string stick too sharp, easy to wear darker terminal hole.
7) co-grinding dish repair: by hand is difficult to grind the surface of the dish combined average repair due to hand control of the grinding pan swing amount, and the rotational speed of the grinding pan is not balanced, it does not advocate hands together to repair.
Paste and check tightness 8) fixture housing: This can cause the most lens surface shape deformation (dispersion, saddle).
9) pad of paper, skin smoothing treatment pad: pad of paper, mat skin elasticity selection pad of paper, leather pad outer diameter size and thickness dimensions, smooth and clean.
10) the depth of the impact terminals: Terminal deep; and the terminal rod string interfere in operation swing. Terminal light; the rod string and the terminal is in operation swing easily thrown out.
11) surface accuracy when adjusted for changes in the timing: when the surface accuracy of the change on the adjustment, do not super-size form when the surface again until commissioning. By that time, surface accuracy is not easy to control.
12) surface inspection frequency: high frequency surface inspection, surface accuracy understand variation, trends, easy to control.
Second, the prerequisite for a stable aperture
1) When the aperture diaphragm changes to high, medium high and difficult to debug, while large vertical surface accuracy difficult to process, the concentration ratio should not be too thick, you can control the concentration of slurry is not greater than 1.020; abrasive powder particle diameter smaller selection. For example, when the iris aperture changes to low, and vice versa when the low difficult to debug.
2) speed too fast will increase the amount of vertical edges, such as with coaxial beating too, dangling lens, the contact center is difficult to be polished. Surface of the lens is not worn in equilibrium. Large outer diameter with a low speed (<1500 rev / min), the outer diameter of the small high-speed (> 2500 rev / min) processing. Pressure, local large force; pressure is small, the lens surface force more evenly. Centre for thin and D / T> 1.0 lens, the pressure should be light not heavy. So, in difficult to machine the parts they want to stabilize the surface accuracy, processing conditions set to be considered light concentration, pressure, light, slow speed, time is short and so on.
3) illustrates: gg parts by considering the above settings, not only did not increase the operating time; but low operating time can be reduced, reducing the investment in equipment, personnel, and to take action to overcome the lens to take more of the drawbacks.
4) must be calculated according to the formula of the fixture ideal size and good production control error. Local error correction in drilling and workover dish within 0.0005mm.
5) "no face" does not mean outflow face instability, just across from the quality control evaluation. Usually the outer diameter of the lens is set to 1/4 to 1/5 for the swing size. (The value of different types of machine set is different).
6) Adjustment of quasi-spherical core is again determined to turn up the swing. Small swing is difficult to distinguish the accuracy of the ball core.
7) to adjust the specific practices are coaxial, grinding dish mounted on the fixture in the trunk, corrected with the ball core instrument calibration. Beating deviation within 0.03mm, height adjustment of the grinding rod string dish better in 0.1mm lens grinding dish put on about 1/5 of the diameter of the lens, and then swing the lever to debug parallel operation, the rod string polished should shape the shape of the terminal hole coincide, conical. Dish grinding machine with a combined repair, do not put more than overcome * Low surface, such as surface drilling and workover repair low direct dish, not so hard to believe that every time, will face some stability.
8) When the clamp shell paste glue to prevent overflow into the curvature of the surface of the jig table.