Access to Android phone's SD card from PC, without USB
I personally use FTP to achieve this...

You can try it too. All you'll just need is an understanding of how ftp works which is very basic by the way.

Download any app that provides an ftp server on your android devices, they are always pretty easy to use. I currently use use ES File explorer's functionality to do this.

As shown here

 

Selecting Remote Manager is all you need.

After the ftp services has started on your android device and is on the same network as your computer, you should then spring up windows explorer [win-key + E] or even a web browser and enter ftp://phones_ip_address:ftp_listening_port into the address bar

Note: the column separating address and port.
Lemme know if you get this