grid selType: 'checkboxmodel', 取消没行选中

让grid中选中的行 取消选中 

var sel_Model = me.equipmentGrid.getSelectionModel();
                var sel_records = sel_Model.getSelection();

                for (var i = 0; i < sel_records.length; i++) {
                    var sel_record = sel_records[i];
                    if (sel_record.get("trackername") == component.title) {
                        sel_Model.deselect([sel_record])
                        break;
                    }
                }