I was having the same problem with my Lumia 1520. I tried removing all of the Bing apps, it would still reboot. It quit rebooting when I turned off WIFI. I had read somewhere to turn off blutooth and WIFI and the problem would go away. I had originally turned off blutooth and noticed that the phone would still reboot but not three times a day. So I turned off WIFI and the phone is now working without a problem. If I turn on WIFI, it will reboot within 24 hours if you leave it turned on.
So, what I do is to turn on WIFI when I'm at home and want to update APPS, SEARCH then net, or anything that requires WIFI, and then I turn it off when I leave home.
I will "assume" that Nokia or Microsoft will resolve this issue un the next phone update. Then again, we all no the real meaning of assume...