ConvertTo-Csv or Export-Csv always add double quote to all columns

ConvertTo-Csv or Export-Csv always add double quote to all columns.

• Get-Help Export-Csv -Full shows samples of CSV with no double quotes, but it seems there are no options to suppress double quote.
• This behavior doesn’t depend on system locales. chcp 437 and chcp 932 have no effect to this behavior.