Laravel-excel: Supprimer les citations de csv

Salut tout le monde, je reçois le fichier CSV exporté, mais toutes les données de cellule ont des guillemets. Pouvez-vous m'aider à supprimer les guillemets lors de l'exportation au format CSV ? ici un exemple :
"20150521","62549","2492","","16.52","1.98","0","0","0","","922330816001","","","P ","","2492"
"20150521","71343","2493","","8.26","0.99","0","0","0","","922330816001","","","P ","","2493"
Je veux ceci..
20150521,62549,2492,,16.52,1.98,0,0,0,,922330816001,,,P,,2492
20150521 71343,2493,,8.26,0.99,0,0,0,,922330816001,,,P,,2493
Merci

voici mon code :

//generating .csv
$csv = Excel::create($conciliacion->nombre, function($excel){
            $excel->sheet('Lista', function($sheet) {
                $empresa = Empresa::find(1);
                $conciliacion = Session::get('conciliacion');
                Session::forget('conciliacion');
                $fecha_conciliacion = $conciliacion->fecha;

                $i = 1;
                $ordenes = Orden::whereBetween('fecha_emision', array($fecha_conciliacion.' 00:00', $fecha_conciliacion.' 23:59'))->get();
                var_dump($ordenes);
                foreach($ordenes as $o){
                    $sheet->row($i, array(
                        (int)date("Ymd", strtotime($o->fecha_emision)),
                        (int)date("His", strtotime($o->fecha_emision)),
                        (int)$o->numero_orden,
                        (int)$o->tipo_tarjeta,
                        (float)number_format(($o->subtotal_12+$o->subtotal_0), 2),
                        (float)number_format($o->iva, 2),
                        (float)'0.00',
                        (float)number_format($o->intereses/100, 2),
                        (float)number_format($o->total_intereses/100, 2),
                        (int)$o->numero_autorizacion,
                        (int)$empresa->ruc,
                        (int)$o->tipo_credito,
                        (int)$o->meses_credito,
                        'P',
                        '',
                        (int)$o->numero_orden,
                    ));
                    $i++;
                }
            });
        })->export('csv');