Equipment and method of pretreatment before painting

Abstract

Equipment of pretreatment before painting for a composite vehicle body comprises a treatment tank, an aluminum chemical conversion unit, and a rinse unit. The treatment tank is filled with a degreasing and chemical conversion solution containing a mixed solution of a polar organic solvent and water, any of sodium ion and lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, and any of nitrate ion and nitrite ion. The mixed solution has a weight ratio of the polar organic solution to the water in a range of 2.8:7.2 to 3.8:6.2. The aluminum chemical conversion unit treats the composite vehicle body with a chemical conversion solution for aluminum. The rinse unit washes the composite vehicle body with a washing solution.

What is claimed is:  
     
         1 . Equipment of pretreatment before painting, comprising: 
 a treatment tank filled with a degreasing and chemical conversion solution containing a mixed solution of a polar organic solvent and water, any of sodium ion and lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, and any of nitrate ion and nitrite ion, the mixed solution having a weight ratio of the polar organic solution to the water in a range of 2.8:7.2 to 3.8:6.2, works being dipped in the treatment tank;    an aluminum chemical conversion unit which treats the works with a chemical conversion solution for aluminum, the aluminum chemical conversion unit being provided at a subsequent stage of the treatment tank; and    a rinse unit which washes the works with a washing solution, the rinse unit being provided at a subsequent stage of the aluminum chemical conversion unit.    
     
     
         2 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein at least part of the works are composite vehicle bodies of iron and aluminum having any of an aluminum and aluminum alloy part for at least part of outer panel portions.    
     
     
         3 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the aluminum chemical conversion unit includes: a chemical conversion solution replenishment tank which accommodates the chemical conversion solution for aluminum being adjusted; and a spray which sprays the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank onto the works.    
     
     
         4 . The equipment of pretreatment before painting according to  claim 3 , 
 wherein the aluminum chemical conversion unit includes: a recovery tank for recovering the chemical conversion solution for aluminum sprayed onto the works; and a first pipe system for returning the chemical conversion solution for aluminum recovered in the recovery tank to the chemical conversion solution replenishment tank.    
     
     
         5 . The equipment of pretreatment before painting according to  claim 4 , 
 wherein the first pipe system has a dust eliminator for removing dust contained in the chemical conversion solution for aluminum being recovered to the recovery tank; a chemical conversion sludge eliminator for removing chemical conversion sludge contained in the chemical conversion solution for aluminum being recovered to the recovery tank; and an oil eliminator for removing oil contained in the chemical conversion solution for aluminum being recovered to the recovery tank.    
     
     
         6 . The equipment of pretreatment before painting according to  claim 5 , further comprising: 
 a second pipe system which introduces the washing solution in the rinse unit to any of the recovery tank and a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         7 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the aluminum chemical conversion unit includes an aluminum chemical conversion tank filled with the chemical conversion solution for aluminum, the works being dipped into the aluminum chemical conversion tank.    
     
     
         8 . The equipment of pretreatment before painting according to  claim 7 , 
 wherein each of the works is fully dipped in the aluminum chemical conversion tank.    
     
     
         9 . The equipment of pretreatment before painting according to  claim 7 , 
 wherein each of the works is half dipped in the aluminum chemical conversion tank.    
     
     
         10 . The equipment of pretreatment before painting according to  claim 7 , 
 wherein the aluminum chemical conversion unit includes: a chemical conversion solution replenishment tank which accommodates the chemical conversion solution for aluminum being adjusted; a third pipe system which supplies the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank to the aluminum chemical conversion tank; and a fourth pipe system which returns the chemical conversion solution for aluminum in the aluminum chemical conversion tank to the chemical conversion solution replenishment tank.    
     
     
         11 . The equipment of pretreatment before painting according to  claim 10 , 
 wherein the fourth pipe system includes a dust eliminator for removing dust contained in the chemical conversion solution for aluminum being recovered to the recovery tank; a chemical conversion sludge eliminator for removing chemical conversion sludge contained in the chemical conversion solution for aluminum being recovered to the recovery tank; and an oil eliminator for removing oil contained in the chemical conversion solution for aluminum being recovered to the recovery tank.    
     
     
         12 . The equipment of pretreatment before painting according to  claim 11 , further comprising: 
 a fifth pipe system which introduces the washing solution of the rinse unit to a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         13 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether.    
     
     
         14 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein 0.8 to 3.3 parts by weight of any of sodium ion and lithium ion are contained per 100 parts by weight of mixed solution of the polar organic solution and water.    
     
     
         15 . The equipment of pretreatment before painting according to  claim 14 , 
 wherein a molar ratio of the sodium ion to lithium ion is in a range of 50:50 to 2:98.    
     
     
         16 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein 0.2 to 0.5 parts by weight of phosphate ion and 0.5 to 0.7 parts by weight of zinc ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         17 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein 0.09 to 0.23 parts by weight of nickel ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         18 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein 0.03 to 0.16 parts by weight of manganese ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         19 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein 3.5 to 10.8 parts by weight of any of nitrate ion and nitrite ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         20 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the temperature of the degreasing and chemical conversion solution filled in the treatment tank is in a range from 40 to 60° C., and a dipping time of each of the works is in a range from 3 to 10 minutes.    
     
     
         21 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the chemical conversion solution for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate.    
     
     
         22 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the chemical conversion solution for aluminum sprayed on the work has a pH in a range from 2.5 to 10 and a temperature in a range from 20 to 70° C., and a period of spraying the chemical conversion solution for aluminum onto the work is in a range from 20 to 100 seconds.    
     
     
         23 . The equipment of pretreatment before painting according to  claim 1 , further comprising: 
 a second rinse unit which washes the works with a washing solution, the second rinse unit being provided at a subsequent stage of the treatment tank and at a preceding stage of the aluminum chemical conversion unit;    a first circulating system which has the treatment tank and circulates the degreasing and chemical conversion solution;    a dust eliminator which removes dust contained in the degreasing and chemical conversion solution;    a chemical conversion sludge eliminator which removes chemical conversion sludge contained in the degreasing and chemical conversion solution, the chemical conversion sludge eliminator being provided for the first circulating system;    an oil eliminator which removes oil contained in the degreasing and chemical conversion solution; and    a treatment solution replenishment tank which adjusts a solution having passed the dust eliminator, the sludge eliminator, and the oil eliminator and replenishes the treatment tank with the adjusted solution, the treatment solution replenishment tank being provided for the first circulating system.    
     
     
         24 . The equipment of pretreatment before painting according to  claim 1 , 
 wherein the aluminum chemical conversion unit is a rinse-aluminum chemical conversion unit which sprays a washing solution onto the works when the works do not include any of the aluminum and aluminum alloy part and which treats the works with the chemical conversion solution for aluminum when each of the works includes at least any of the aluminum and aluminum alloy part.    
     
     
         25 . The equipment of pretreatment before painting according to  claim 24 , further comprising: 
 a vehicle type detector which detects vehicle specifications, the vehicle type detector allowing materials of components of each of the works to be distinguished; and    a controller which controls the treatment in the rinse-aluminum chemical conversion unit in accordance with material specifications of each of the works being detected by the vehicle type detector.    
     
     
         26 . The equipment of pretreatment before painting according to  claim 24 , further comprising: 
 a washing solution recovery tank which recovers the washing solution used in the rinse-aluminum chemical conversion unit;    a chemical conversion solution recovery tank which recovers a chemical conversion solution for aluminum used in the rinse-aluminum chemical conversion unit;    a washing solution replenishment tank which stores the washing solution used in the rinse-aluminum chemical conversion unit;    a chemical conversion solution replenishment tank which stores the chemical conversion solution for aluminum to be used in the rinse-aluminum chemical conversion unit;    a sixth pipe system which sucks the washing solution recovered by the washing solution recovery tank and supplying the washing solution to the washing solution replenishment tank;    a seventh pipe system which supplies the chemical conversion solution for aluminum recovered by the chemical conversion solution recovery tank to the chemical conversion solution replenishment tank;    a spray which sprays any of the washing solution and the chemical conversion solution for aluminum onto the works; and    an eighth pipe system which sucks any of the washing solution in the washing solution replenishment tank and the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank and supplies the sucked solution to the spray.    
     
     
         27 . The equipment of pretreatment before painting according to  claim 26 , further comprising: 
 a dust eliminator which removes dust contained in the washing solution in the washing solution recovery tank, the dust eliminator being provided for the sixth pipe system;    a chemical conversion sludge eliminator which removes chemical conversion sludge contained in the washing solution, the chemical conversion sludge eliminator being provided for the sixth pipe system; and    an oil eliminator which removes oil contained in the washing solution, the oil eliminator being provided for the sixth pipe system.    
     
     
         28 . The equipment of pretreatment before painting according to  claim 26 , further comprising: 
 a vehicle type detector which detects vehicle specifications, the vehicle type detector allowing materials of components of each of the works to be distinguished; and    a controller which controls the treatment in the rinse-aluminum chemical conversion unit in accordance with material specifications of each of the works detected by the vehicle type detector,    wherein the eighth pipe system includes a first pump which sucks the washing solution in the washing solution replenishment tank, a second pump which sucks the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank, and a first switch valve which switches a supply path for the spray, and    wherein the controller transmits operation signals to the first pump, the second pump, and the first switch valve in accordance with the material specifications of each of the works being detected by the vehicle type detector.    
     
     
         29 . The equipment of pretreatment before painting according to  claim 28 , further comprising: 
 a ninth pipe system which introduces the washing solution used in the rinse-aluminum chemical conversion unit to the washing solution recovery tank and introduces the chemical conversion solution for aluminum used in the rinse-aluminum chemical conversion unit to the chemical conversion solution recovery tank; and    a second switch valve which switches paths of the used washing solution and the used chemical conversion solution for aluminum, the second switch valve being provided for the ninth pipe system,    wherein the controller transmits an operation signal to the second switch valve in accordance with the material specifications of each of the works being detected by the vehicle type detector.    
     
     
         30 . The equipment of pretreatment before painting according to  claim 27 , further comprising: 
 a tenth pipe system which introduces the washing solution in the rinse unit to any of the washing solution recovery tank and a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         31 . The equipment of pretreatment before painting according to  claim 24 , further comprising: 
 a first circulating system which has the treatment tank and circulates the degreasing and chemical conversion solution;    a dust eliminator which removes dust contained in the degreasing and chemical conversion solution;    a chemical conversion sludge eliminator which removes chemical conversion sludge contained in the degreasing and chemical conversion solution, the chemical conversion sludge eliminator being provided for the first circulating system;    an oil eliminator which removes oil contained in the degreasing and chemical conversion solution; and    a treatment solution replenishment tank which adjusts a solution having passed the dust eliminator, the sludge eliminator, and the oil eliminator and replenishes the treatment tank with the adjusted solution, the treatment solution replenishment tank being provided for the first circulating system.    
     
     
         32 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the dust eliminator and the oil eliminator are provided for the first circulating system.    
     
     
         33 . The equipment of pretreatment before painting according to  claim 32 , further comprising: 
 a water-polar organic solvent separator which separates water and a polar organic solvent of the solution having passed the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator and supplies the polar organic solvent to the treatment solution replenishment tank.    
     
     
         34 . The equipment of pretreatment before painting according to  claim 33 , further comprising: 
 a second circulating system which supplies the water separated by the waterpolar organic solvent separator to the second rinse unit.    
     
     
         35 . The equipment of pretreatment before painting according to  claim 34 , further comprising: 
 an ion eliminator which removes ion components from the water separated by the water-polar organic solvent separator and supplies the residual water to the second rinse unit, the ion eliminator being provided for the second circulating system.    
     
     
         36 . The equipment of pretreatment before painting according to  claim 35 , 
 wherein at least part of the water obtained by the ion eliminator is supplied to the treatment solution replenishment tank.    
     
     
         37 . The equipment of pretreatment before painting according to  claim 23 , further comprising: 
 a third circulating system which sucks the used washing solution in the second rinse unit and introduces the sucked solution to a most upstream eliminator among the dust eliminator, the chemical conversion sludge, and the oil eliminator.    
     
     
         38 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the dust eliminator includes any of a settling tank, a centrifugal separator, a magnetic separator and a combination thereof.    
     
     
         39 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the chemical conversion sludge eliminator includes a dead-end filter capable of suppressing a concentration of sludge of the degreasing and chemical conversion solution in the treatment tank to 150 ppm or less.    
     
     
         40 . The equipment of pretreatment before painting according to one of  claim 23 , 
 wherein the oil eliminator includes a heating type oil eliminator, a coalescer type oil eliminator, an ultrafiltration type oil eliminator and combination thereof.    
     
     
         41 . The equipment of pretreatment before painting according to  claim 33 , 
 wherein the water-polar organic solvent separator separates water and the polar organic solvent by pervaporation.    
     
     
         42 . The equipment of pretreatment before painting according to  claim 35 , 
 wherein the ion eliminator includes: a cation exchange tower filled with first cation exchange resin; an anion exchange tower filled with anion exchange resin; an ion exchange tower filled with second cation exchange resin; and a decarbonator tower.    
     
     
         43 . The equipment of pretreatment before painting according to  claim 42 , 
 wherein the first cation exchange resin is chelate type cation exchange resin, the anion exchange resin is styrene type strong base anion exchange resin, and the third cation exchange resin is strong acid cation exchange resin in H form.    
     
     
         44  The equipment of pretreatment before painting according to  claim 1 , further comprising: 
 a second rinse unit which washes-the works with a washing solution, the second rinse unit being provided at a subsequent stage of the treatment tank and at a proceeding stage of the aluminum chemical conversion unit;  
 a treatment solution replenishment tank which replenishes the treatment tank with the degreasing and chemical conversion solution; and  
 a vacuum distillation unit which separates the solutions in the treatment tank and the second rinse unit into the polar organic solvent, water, and residual sludge by use of vacuum distillation, supplies the separated polar organic solvent to the treatment replenishment tank, and supplies the separated water to the treatment solution replenishment tank and the second rinse unit.  
 
     
     
         45 . The equipment of pretreatment before painting according to  claim 44 , 
 wherein waste heat of a paint drying oven is used for a heat source of the vacuum distillation unit.    
     
     
         46 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the second rinse unit includes a dipping tank filled with the washing solution, the works being dipped in the dipping tank.    
     
     
         47 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the second rinse unit includes a spray which sprays the washing solution onto the works.    
     
     
         48 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein at least part of the works are composite vehicle bodies of iron and aluminum having any of an aluminum and aluminum alloy part for at least part of outer panel portions.    
     
     
         49 . The equipment of pretreatment before painting according to  claim 48 , 
 wherein the works include: an iron vehicle body with all components made of iron; an aluminum vehicle body with all components made of any of aluminum and aluminum alloys; and a composite body of iron and any of aluminum and alloy with at least part of components made of any of aluminum and aluminum alloy.    
     
     
         50 . The equipment of pretreatment before painting according to one of  claim 23 , 
 wherein the aluminum chemical conversion unit includes: a chemical conversion solution replenishment tank which accommodates the adjusted chemical conversion solution for aluminum; and a spray which sprays the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank onto the works.    
     
     
         51 . The equipment of pretreatment before painting according to  claim 50 , 
 wherein the aluminum chemical conversion unit includes: a recovery tank which recovers the chemical conversion solution for aluminum sprayed onto the works; and a eleventh pipe system which returns the chemical conversion solution for aluminum recovered to the recovery tank to the chemical conversion solution replenishment tank.    
     
     
         52 . The equipment of pretreatment before painting according to  claim 51 , 
 wherein the eleventh pipe system has a dust eliminator for removing dust contained in the chemical conversion solution for aluminum being recovered to the recovery tank; a chemical conversion sludge eliminator for removing chemical conversion sludge contained in the chemical conversion solution for aluminum being recovered to the recovery tank; and an oil eliminator for removing oil contained in the chemical conversion solution for aluminum being recovered to the recovery tank.    
     
     
         53 . The equipment of pretreatment before painting according to  claim 51 , further comprising: 
 a twelfth pipe system which introduces the washing solution in the rinse unit to any of the recovery tank and a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         54 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the aluminum chemical conversion unit includes a aluminum chemical conversion tank filled with the chemical conversion solution for aluminum, the works being dipped in the aluminum chemical conversion tank.    
     
     
         55 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether.    
     
     
         56 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein 0.8 to 3.3 parts by weight of any of sodium ion and lithium ion are contained per 100 parts by weight of mixed solution of the polar organic solution and water.    
     
     
         57 . The equipment of pretreatment before painting according to  claim 56 , 
 wherein a molar ratio of the sodium ion to lithium ion is in a range of 50:50 to 2:98.    
     
     
         58 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein 0.2 to 0.5 parts by weight of phosphate ion and 0.5 to 0.7 parts by weight of zinc ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         59 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein 0.09 to 0.23 parts by weight of nickel ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         60 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein 0.03 to 0.16 parts by weight of manganese ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         61 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein 3.5 to 10.8 parts by weight of any of nitrate ion and nitrite ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         62 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the temperature of the degreasing and chemical conversion solution filled in the treatment tank is in a range from 40 to 60° C., and a dipping time of each of the works is in a range from 3 to 10 minutes.    
     
     
         63 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the chemical conversion solution for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate.    
     
     
         64 . The equipment of pretreatment before painting according to  claim 23 , 
 wherein the chemical conversion solution for aluminum sprayed on the work has a pH in a range from 2.5 to 10 and a temperature in a range from 20 to 70° C., and a period of spraying the chemical conversion solution for aluminum onto the work is in a range from 20 to 100 seconds.    
     
     
         65 . The equipment of pretreatment before painting according to  claim 1 , further comprising: 
 a vehicle type detector which detects vehicle specifications, the vehicle type detector allowing materials of components of each of the works to be distinguished; and    a controller which controls a treatment condition in the aluminum chemical conversion unit in accordance with material specifications of each of the works being detected by the vehicle type detector.    
     
     
         66 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein the works include: an iron vehicle body with all components made of iron; an aluminum vehicle body with all components made of any of aluminum and aluminum alloys; and a composite body of iron and any of aluminum and alloy with at least part of components made of any of aluminum and aluminum alloy.    
     
     
         67 . The equipment of pretreatment before painting according to  claim 66 , 
 wherein the aluminum chemical conversion unit includes: a chemical conversion solution replenishment tank which accommodates the adjusted chemical conversion solution for aluminum; and a spray which sprays the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank onto the works.    
     
     
         68 . The equipment of pretreatment before painting according to  claim 67 , 
 wherein the controller controls a spraying condition of the chemical conversion solution for aluminum by the spray in accordance with material specifications of each of the works detected by the vehicle type detector.    
     
     
         69 . The equipment of pretreatment before painting according to  claim 68 , 
 wherein the controller carries out control to stop spraying of the chemical conversion solution for aluminum by the spray when each of the works is the iron vehicle body, and the controller carries out control to spray the chemical conversion solution for aluminum by the spray when each of the works is any of the aluminum vehicle body and the composite vehicle body.    
     
     
         70 . The equipment of pretreatment before painting according to  claim 69 , 
 wherein the controller carries out control to spray the chemical conversion solution for aluminum onto the whole of the vehicle body by the spray when each of the works is the aluminum vehicle body, and the controller carries out control to spray the chemical conversion solution for aluminum mainly onto aluminum parts of the vehicle body by the spray when each of the works is the composite vehicle body.    
     
     
         71 . The equipment of pretreatment before painting according to  claim 67 , 
 wherein the aluminum chemical conversion unit includes: a recovery tank which recovers the chemical conversion solution for aluminum sprayed onto the works; and a thirteenth pipe system which returns the chemical conversion solution for aluminum recovered to the recovery tank to the chemical conversion solution replenishment tank.    
     
     
         72 . The equipment of pretreatment before painting according to  claim 71 , 
 wherein the thirteenth pipe system has a dust eliminator for removing dust contained in the chemical conversion solution for aluminum being recovered to the recovery tank; a chemical conversion sludge eliminator for removing chemical conversion sludge contained in the chemical conversion solution for aluminum being recovered to the recovery tank; and an oil eliminator for removing oil contained in the chemical conversion solution for aluminum being recovered to the recovery tank.    
     
     
         73 . The equipment of pretreatment before painting according to  claim 72 , further comprising: 
 a fourteenth pipe system which introduces the washing solution in the rinse unit to any of the recovery tank and a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         74 . The equipment of pretreatment before painting according to  claim 67 , further comprising: 
 a bypass line which bypasses the aluminum chemical conversion unit, the bypass line being provided in parallel to the aluminum chemical conversion unit,    wherein the controller selects any one of the aluminum chemical conversion unit and the bypass line as a destination of each of the works in accordance with the material specifications of each of the works being detected by the vehicle type detector.    
     
     
         75 . The equipment of pretreatment before painting according to  claim 74 , 
 wherein the controller carries out control to convey the works to the bypass line when each of the work is the iron vehicle body, and the controller carries out control to convey the works to the aluminum chemical conversion unit when each of the works is any of the iron vehicle body or the composite vehicle body.    
     
     
         76 . The equipment of pretreatment before painting according to  claim 75 , 
 wherein the aluminum chemical conversion unit includes a chemical conversion solution replenishment tank which accommodates the adjusted chemical conversion solution for aluminum, and a spray which sprays the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank onto the works,    wherein the controller carries out control to spray the chemical conversion solution for aluminum onto the whole of the vehicle body by the spray when each of the works is the aluminum vehicle body, and the controller carries out control to spray the chemical conversion solution for aluminum onto mainly aluminum components of the vehicle body by the spray when each of the works is the composite vehicle body.    
     
     
         77 . The equipment of pretreatment before painting according to  claim 75 , 
 wherein the aluminum chemical conversion unit includes a aluminum chemical conversion tank filled with the chemical conversion solution for aluminum, the works being dipped in the aluminum chemical conversion tank.    
     
     
         78 . The equipment of pretreatment before painting according to  claim 77 , 
 wherein the aluminum chemical conversion unit includes: a chemical conversion solution replenishment tank which accommodates the chemical conversion solution for aluminum being adjusted; a fifteenth pipe system which supplies the chemical conversion solution for aluminum in the chemical conversion solution replenishment tank to the aluminum chemical conversion tank; and a sixteenth pipe system which returns the chemical conversion solution for aluminum in the aluminum chemical conversion tank to the chemical conversion solution replenishment tank.    
     
     
         79 . The equipment of pretreatment before painting according to  claim 78 , 
 wherein the thirteenth pipe system has a dust eliminator for removing dust contained in the chemical conversion solution for aluminum being recovered to the recovery tank; a chemical conversion sludge eliminator for removing chemical conversion sludge contained in the chemical conversion solution for aluminum being recovered to the recovery tank; and an oil eliminator for removing oil contained in the chemical conversion solution for aluminum being recovered to the recovery tank.    
     
     
         80 . The equipment of pretreatment before painting according to  claim 79 , further comprising: 
 a seventeenth pipe system which introduces the washing solution in the rinse unit to a most upstream eliminator among the dust eliminator, the chemical conversion sludge eliminator, and the oil eliminator.    
     
     
         81 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether.    
     
     
         82 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein 0.8 to 3.3 parts by weight of any of sodium ion and lithium ion are contained per 100 parts by weight of mixed solution of the polar organic solution and water.    
     
     
         83 . The equipment of pretreatment before painting according to  claim 82 , 
 wherein a molar ratio of the sodium ion to lithium ion is in a range of 50:50 to 2:98.    
     
     
         84 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein 0.2 to 0.5 parts by weight of phosphate ion and 0.5 to 0.7 parts by weight of zinc ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         85 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein 0.09 to 0.23 parts by weight of nickel ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         86 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein 0.03 to 0.16 parts by weight of manganese ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         87 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein 3.5 to 10.8 parts by weight of any of nitrate ion and nitrite ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         88 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein the temperature of the degreasing and chemical conversion solution filled in the treatment tank is in a range from 40 to 60° C., and a dipping time of each of the works is in a range from 3 to 10 minutes.    
     
     
         89 . The equipment of pretreatment before painting according to  claim 65 , 
 wherein the chemical conversion solution for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate.    
     
     
         90  The equipment of pretreatment before painting according to  claim 65 , 
 wherein the chemical conversion solution for aluminum sprayed on the work has a pH in a range from 2.5 to 10 and a temperature in a range from 20 to 70° C., and a period of spraying the chemical conversion solution for aluminum onto the work is in a range from 20 to 100 seconds.  
 
     
     
         91 . A method of pretreatment before painting, comprising: 
 dipping a composite vehicle body, which has any of an aluminum and aluminum alloy part for at least part of outer panel portions, into a degreasing and chemical conversion solution containing at least a mixed solution of a polar organic solvent and water, any of sodium ion and lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, and any of nitrate ion and nitrite ion, the mixed solution having a weight ratio of the polar organic solution to the water in a range of 2.8:7.2 to 3.8:6.2;    treating the vehicle body in a chemical conversion solution for aluminum; and washing the vehicle body with a washing solution.    
     
     
         92 . The method of pretreatment before painting according to  claim 91 , 
 wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether.    
     
     
         93 . The method of pretreatment before painting according to claims  91 , 
 wherein 0.8 to 3.3 parts by weight of any of sodium ion and lithium ion are contained per 100 parts by weight of mixed solution of the polar organic solution and water.    
     
     
         94 . The method of pretreatment before painting according to  claim 93 , 
 wherein a molar ratio of the sodium ion to lithium ion is in a range of 50:50 to 2:98.    
     
     
         95 . The method of pretreatment before painting according to  claim 91 , 
 wherein 0.2 to 0.5 parts by weight of phosphate ion and 0.5 to 0.7 parts by weight of zinc ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         96 . The method of pretreatment before painting according to  claim 91 , 
 wherein 0.09 to 0.23 parts by weight of nickel ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         97 . The method of pretreatment before painting according to  claim 91 , 
 wherein 0.03 to 0.16 parts by weight of manganese ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         98 . The method of pretreatment before painting according to  claim 91 , 
 wherein 3.5 to 10.8 parts by weight of any of nitrate ion and nitrite ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         99 . The method of pretreatment before painting according to  claim 91 , 
 wherein the temperature of the degreasing and chemical conversion solution filled in the treatment tank is in a range from 40 to 60° C., and a dipping time of each of the works is in a range from 3 to 10 minutes.    
     
     
         100 . The method of pretreatment before painting according to  claim 91 , 
 wherein the chemical conversion solution for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate.    
     
     
         101 . The method of pretreatment before painting according to  claim 91 , 
 wherein the chemical conversion solution for aluminum sprayed on the work has a pH in a range from 2.5 to 10 and a temperature in a range from 20 to 70° C., and a period of spraying the chemical conversion solution for aluminum onto the work is in a range from 20 to 100 seconds.    
     
     
         102 . The method of pretreatment before painting according to  claim 91 , further comprising: 
 washing the vehicle body with a washing solution after the dipping.    
     
     
         103 . The method of pretreatment before painting according to  claim 102 , 
 wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether.    
     
     
         104 . The method of pretreatment before painting according to claims  102 , 
 wherein 0.8 to 3.3 parts by weight of any of sodium ion and lithium ion are contained per 100 parts by weight of mixed solution of the polar organic solution and water.    
     
     
         105 . The method of pretreatment before painting according to  claim 104 , 
 wherein a molar ratio of the sodium ion to lithium ion is in a range of 50:50 to 2:98.    
     
     
         106 . The method of pretreatment before painting according to  claim 102 , 
 wherein 0.2 to 0.5 parts by weight of phosphate ion and 0.5 to 0.7 parts by weight of zinc ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         107 . The method of pretreatment before painting according to  claim 102 , 
 wherein 0.09 to 0.23 parts by weight of nickel ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         108 . The method of pretreatment before painting according to  claim 102 , 
 wherein 0.03 to 0.16 parts by weight of manganese ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         109 . The method of pretreatment before painting according to  claim 102 , 
 wherein 3.5 to 10.8 parts by weight of any of nitrate ion and nitrite ion are contained per 100 parts by weight of the mixed solution of the polar organic solution and water.    
     
     
         110 . The method of pretreatment before painting according to  claim 102 , 
 wherein the temperature of the degreasing and chemical conversion solution filled in the treatment tank is in a range from 40 to 60° C., and a dipping time of each of the works is in a range from 3 to 10 minutes.    
     
     
         111 . The method of pretreatment before painting according to  claim 102 , 
 wherein the chemical conversion solution for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate.    
     
     
         112 . The method of pretreatment before painting according to  claim 102 , 
 wherein the chemical conversion solution for aluminum sprayed on the work has a pH in a range from 2.5 to 10 and a temperature in a range from 20 to 70° C., and a period of spraying the chemical conversion solution for aluminum onto the work is in a range from 20 to 100 seconds.    
     
     
         113 . Equipment of pretreatment before painting, comprising: 
 a treatment tank filled with a degreasing and chemical conversion solution containing a mixed solution of a polar organic solvent and water, any of sodium ion and lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, and any of nitrate ion and nitrite ion, the mixed solution having a weight ratio of the polar organic solution to the water in a range of 2.8:7.2 to 3.8:6.2, works being dipped in the treatment tank;    aluminum chemical conversion means for treating the works with a chemical conversion solution for aluminum, the aluminum chemical conversion means being provided at a subsequent stage of the treatment tank; and    rinse means for washing the works with a washing solution, the rinse means being provided at a subsequent stage of the aluminum chemical conversion means.