Reduce grinding work of crock aperture top gem effectively to abandon the technical measure of rate

95% , exceed 0.

The labour of 9% abandons target. We undertook permutation graph statistic to the unqualified problem of cylinder body product line, the scale that discovers crock aperture honing occupies total reject to count is 39.

3% , arrange the first. So our make choice of " reduce crock of Kong Hang grinding work useless rate " those who regard QC as the group tackle key problem task. The labour of crock aperture honing abandons a type to basically out of tolerance of the mark that retreat a knife, horizontal grain, diameter waits. In Feburary 2012 - during April, the useless ratio of average worker worker of crock aperture honing is amounted to 0.

027% , and the scale of the among them mark that retreat a knife is as high as 69.

6% . So we conclude: If was solved,decline knife mark the problem can reduce crock of Kong Hang to grind industry useless ratio considerably. Surface of aperture of the crock after honing has upend state inside sunken stripe (see a picture 2) , the result that detects with surface roughness appearance is: Surface roughness value cannot satisfy craft requirement, especially the measured value of Mr1 and Mr2 (Mr1: Outline bearing length is led, its numerical value reacted directly the treatment level of crock aperture and service life; Mr2: Outline bearing length is led, its numerical value decided the lay aside oil of surface of crock aperture job and lubricant ability) . Graph the mark retreating a knife of honing of 2 crocks of aperture we are final be versed in crock aperture honing the quality objective setting of useless rate is 0.

09% . Nextpage passes brains storm law, we undertook discussion to the mark retreating a knife of crock aperture honing, scale the fish bone that cause and effect analyses pursues (see a picture 3) , list in all 8 extreme element. Graph graph of fish bone of analysis of 3 cause and effect is aimed at afore-mentioned extreme elements, we were made because affirm schedule,want, affirm the process is as follows: Extreme element one (oilstone face sticks have scrap) know a process really: Our microscope all oilstone on honing head: Oilstone surface builds up without scrap. Because of,conclusion dispute wants. Extreme element 2 (contractive bedspring invalidation) know a process really: We changed with new spring old bedspring (see a picture 4) , process 1100 work continuously, labour of 3 mark that retreat a knife is abandoned, industry useless ratio is 0.

27% . Because of,conclusion dispute wants. Graph 4 change bedspring extreme element 3 (go up core and oilstone have dirt) know a process really: Ravel our discovery goes up after honing head core and oilstone the surface adhered to bilge of shape of a few grain (see a picture 5) , after clean and be being assembled, process 1100 work continuously, appear only labour of a mark that retreat a knife is useless, industry useless ratio is 0.

09% . Conclusion is to because of,want. Graph 5 detect element of honing head extreme 4 (oilstone answers shrink the capacity is insufficient) know a process really: We oilstone time shrink the position by - 100um is adjusted - after 500um, process 1100 work continuously, labour of 2 mark that retreat a knife is abandoned, industry useless ratio is 0.

18% . Because of,conclusion dispute wants. Extreme element 5 (filter precision is poor) know a process really: We checked what the spot uses to cross filter paper leave factory norms: Filter precision is 24um. Accord with craft to ask (cross filter paper precision: 18-25um) . Because of,conclusion dispute wants. Nextpage extreme element 6 (honing fluid function exceeds bid) know a process really: We checked a month " dynamical assembly chemical analyses a report " , the chroma of the honing fluid of OP110 of cylinder body line and acid-base value all accord with craft to ask (chroma is: 6%-8% ; PH value is: 8.

3-9.

8) . Because of,conclusion dispute wants. Extreme element 7 (honing pressure is great) know a process really: We examined the pressure monitoring watch of the machine tool: The cutting pressure of platform top gem and smooth whole pressure are mixed for 9bar respectively 3.

4bar. All satisfy craft to ask (cutting pressure: 9 ± 0.

5bar; Light does pressure: 3.

5 ± 0.

5bar) . Conclusion is to because of,want. Extreme element 8 (feed oil pressure dismantles lag) know a process really: We adjust the smooth full time of platform top gem by 1 second for 0 seconds, theoretic ahead of schedule 1 second dismantles feed oil pressure. We process 1100 work continuously, industry useless ratio is 0. Conclusion is to because of,want. All member affirms finally: Go up core and oilstone oil pressure of bilge, feed dismantles lag is two when bring about crock aperture honing to decline knife mark main reasons. Because of,want in the light of these, we made corresponding countermeasure list through research. We adopted two kinds of countermeasure to drop grinding work of crock aperture top gem useless rate: Countermeasure carries out one: Line of NSE cylinder body already put into production 3 years, the oilstone that long-term use brings about honing head and go up the surface of core adhered to the bilge of shape of a few grain, these bilge raised oilstone and go up the coefficient of friction between core, the accretion of attrition force causes oilstone easily shrinking the card sluggish in knife process. We undertake all top gem wheelhead decomposing, clean and assemble afresh, achieved cleared oilstone and go up the purpose of the exterior bilge of core. Countermeasure carries out 2: What platform top gem uses is hydraulic pressure goes up the feed means of the knife (see a picture 5) , control process is as follows (see a picture 6) : Graph 6 hydraulic pressure go up knife machine composition of a picture pursues 7 hydraulic pressure go up after the process that shrink controls graph honing head to enter crock hole, oilstone goes up Dao Zhikong wall (STZ) . We can be installed in cutting phase many go up knife pressure (KR1, KR2, KR3) , grading machines crock aperture technology measure. To get taller treatment precision, honing head still can be inside formulary time (ABZ) with going up inferiorly knife pressure (ABK) to the crock Kong Jin makes treatment solely all right. Final oilstone shrinks quickly knife (ZZU) , complete whole treatment process. We make light level (ABZ phase) setting time repairs instead by 1 second 0 seconds, 1 second shifts to an earlier date after making the oilstone on honing head is machining technology measure retractile, achieve dismantle ahead of schedule the purpose of feed oil pressure. For light of test and verify full treatment is opposite the influence of precision of crock aperture treatment, after cancelling to make treatment solely, we dogged continuously 50 workpiece, undertook to value of their circularity, Mr1, Mr2 SPC is analysed (see a picture 8) , CPK value is respectively 1.

81, 1.

69 with 1.

46, all be more than 1.

The craft of 33 asks. Graph 8 SPC analyses what the report passes these countermeasure to carry out, we obtained right result: Above all, the circumstance that is exterior treatment quality adopts afore-mentioned measure carry out, quality of crock aperture surface is improved apparently, the mark that retreat a knife the phenomenon disappears basically (see a picture 9) . Graph 9 comparative effects pursue next, our statistic industry useless ratio, 0 before discovering crock aperture honing is versed in useless rate is carried out by measure.

27% (the average of 2-4 month) 0 after falling to be carried out to measure.

07% (the average of 6-8 month) . Achieved the quality target cost that expects set. To consolidate further these achievement, spot engineer was written " honing head cleans exercise instructor " , made clear honing head clean flow and clean cycle (1 / 6 months) ; Craft engineer was revised " parameter of craft of treatment of crock aperture honing " , the smooth full time platform top gem repairs instead 0 seconds. The last word passes collective effort, we not only lowered useless rate of grinding work of crock aperture top gem substantially, the cost that reduced is used up, also improved the labor productivity that the product machines at the same time. More commendable is the QC activity that we succeed through this, accumulated the experience of rich quality management and processing technique, laid firm foundation for in the future job. CNC Milling CNC Machining