PDCA applies at crankshaft to produce circularly

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Crankshaft is the airframe part with important engine, to ensure engine movement is smooth, requirement crankshaft has very good dynamic balancing sex. PDCA loop help shortens crankshaft dynamic balancing amends metre, raise manufacturing movement rate. In some project of my company, we use PDCA circulation, through be opposite observation of spot of amendatory of crankshaft dynamic balancing, data is collected, analytic research and countermeasure are carried out wait for measure, be united in wedlock mechanical with geometric principle, to central aperture broach treatment position undertakes adjustment, make the geometrical center of crankshaft approachs quality center, reduced lopsided quantity and number of dynamic balancing amendatory thereby, shortened metre of amendatory of crankshaft dynamic balancing, raised manufacturing movement rate. The working principle crankshaft of crankshaft and dynamic balancing machine is one of airframe parts with the most important engine, its function basically is the aeriform force change that transmits troop of piston connecting rod is outputted external for torque, and the etc of compressed air distribution mechanism of drive engine all sorts of auxiliary unit. When the job, crankshaft high speed rotates, bear aeriform force, force and the torque that its produce and the joint action that bend quadrature, bear at the same time hand in change the concussion of bear, accordingly, crankshaft besides having enough strength and stiffness, still should have very good dynamic balancing property, in order to ensure the movement of engine is smooth. The brace of crankshaft cries again " balance piece " , it is the join part of main shaft neck and abduct neck, cross section is sector. Dynamic balancing is repaired measure the measurement of machine according to dynamic balancing just about data, in each through broach brace piece goes up except redundant lopsided heavy, wait for the centrifugal force of generation and its moment of force in order to achieve neck of big head of balance connecting rod, abduct and brace, in order to make engine movement smooth, achieve the balance of crankshaft force and moment of force through reducing the negative charge of crankshaft bearing. Dynamic balancing problem appears the formal put into production as my company engine plant, output has every months grow considerably, how the problem that through shortening the manufacturing metre of each working procedure raised manufacturing movement rate to become to answer to the key considers and be solved. Review whole crankshaft product line (with BETA1.

6L crankshaft is exemple) , design production metre is 47s (produce per year 300 thousand) , and metre of dynamic balancing amendatory is in on average 73s, exceeded design metre greatly, affected the manufacturing movement of crankshaft product line badly to lead. Accordingly, how to shorten the correction time of dynamic balancing is in into the key to improve productivity. The course is analysed to the observation of the spot, most crankshaft measures prow in dynamic balancing second lopsided amount is too large after measuring (400g.

Cm ～ 550g.

Cm) , exceeded the 30g of lopsided quantity upper limit of requirement place set far.

Cm. Because dynamic balancing machine suffers equipment to design the limitation of parameter of ability and cutting angle, deepness, treatment and cutting tool function, every time can the amendatory is lopsided the amount is limited, cause measure and revise a number overmuch (it is 3 times commonly) , increased manufacturing metre, reduce frequency of dynamic balancing amendatory to make the way that solves a problem so through reducing the lopsided amount of crankshaft. PDCA is circularly in PDCA loop, p points to a plan (Plan) , certain activity plans a target; D points to carry out (Do) , go carrying out the content in the plan on the spot; C points to an examination (Check) , summary carries out the result in the plan, according to the effect, find out a problem; A points to the action (Action) , the result that checks to summary namely undertakes handling, try successful experience to affirm and be popularized appropriately, made standardization; Unsuccessful lesson tries to sum up, avoid to happen again. The problem that did not solve puts next PDCA among the loop. If circulate the job of whole project as a big PDCA, so the settlement of each problems is small PDCA loop, every loop solves one part problem, big clitellum moves annulet, organic ground makes system of a movement is (if pursue,1 is shown) . PDCA loop application is planted with QC7 the statistical processing technique that the tool gives priority to and industrial project (IE) medium working research technique serves as have the job and discovery, tool that solves a problem, these tools apply to the problem in solving us to produce practice. Solve dynamic balancing problem to be informed through further analysis, because machining beginning,lopsided quantity crosses crankshaft is greatly, the treatment position of central aperture is improper, distributinging center of the geometrical center that brings about crankshaft and quality is not on same axes, create crankshaft quality center prejudicial. Accordingly, present problem change becomes the geometrical center that how passes the treatment position that adjusts central aperture to change crankshaft, approach quality center as far as possible, reduce the lopsided amount of crankshaft with this. The crankshaft that the spot collects first the data after dynamic balancing is measured is shown like the watch. the data that records the picture is on the graph (see a picture 2) undertake an analysis, abandon go choosing the several stronghold with further deviate with great majority (the purple dot in the graph) , through significant drop (the blue in the graph is nodded) the distributinging scope that determines a lopsided amount (the red circle in the graph) , applied AutoCAD drew round method to decide the centre of a circle at 3 o'clock, its (the gules dot in the graph) regard lopsided quantity as to center a dot, read in the graph take its lopsided quantity and angle, it is 240g respectively.

Cm, 2 ° (FLANGE side) with 144g.

Cm, 7 ° (PULLEY side) , the picture gives a right-angled triangle (green) , according to trigonometric function the relation has: FLANGE side: =8 of ° of Sin2 of subtense =240 × .

38g.

=239 of ° of Cos2 of × of =240 of Cm adjacent edge.

85g.

CmPULLEY side: =17 of ° of Sin7 of subtense =144 × .

55g.

=142 of ° of Cos7 of × of =144 of Cm adjacent edge.

93g.

Cm combines practical manufacturing experience according to the relation of the density of semifinished product and quality, the initial impact that adjusts lopsided quantity and central aperture the distance is every 80g surely.

Correspondence of Cm lopsided quantity is adjusted 0.

3mm, have from this: FLANGE side should square of axis of X of edge of central opening position to adjust 239.

80 × of 85 ÷ 0.

3=899 μ M, along Y axis negative direction is adjusted 8.

80 × of 38 ÷ 0.

3=31 μ M; PULLEY side should lose axis of X of edge of central opening position direction to adjust 142.

80 × of 93 ÷ 0.

3=536 μ M, square of edge Y axis to adjust 17.

80 × of 55 ÷ 0.

3=66 μ M. To the treatment of central aperture according to this numerical value the position makes after adjusting, discover, it seems that corresponding adjustment is apart from slant small. The method that circulates through applying PDCA undertakes adjust and be correctioned stage by stage, through a few practice reached more accurate correspondence concerns, namely every 80g.

Correspondence of Cm lopsided quantity is adjusted 0.

4257mm, go to the lavatory for computation in be adjusted actually, but approximate correspondence is 0.

45mm. The effect is evaluated after by this correspondence the relation is adjusted, the metre of crankshaft dynamic balancing gets shortening considerably, average now metre is 45s (design metre 47s) , UPH is worth (produce a number hourly) from 49.

3 promotion come 80, amplitude is achieved 62% , manufacturing efficiency rises significantly. In addition, decrease as a result of what dynamic balancing revises a number, to cutting tool use up also reduce greatly, via cursory consideration, can save capital every months to make an appointment with 400 thousand yuan, reduced handlers to change knife time at the same time, reduced labor intensity of the worker. On put together, pass what machine the position to crankshaft center aperture to adjust, improved the treatment efficiency of crankshaft dynamic balancing effectively, improved productivity significantly. CNC Milling CNC Machining