After closing the question it will be completely closed. Don't enable down- or up-voting on that question?
After closing a question, the original poster can still reformulate their question and flag it for reopening. Voting up or down is possible until it's deleted. Once deleted, it requires undelete votes.
I'm not sure whether you were suggesting to disable up/downvotes. If you were, read on:
If upvotes were disabled during that time, why would anyone bother editing their question? they might as well delete it and post another question. Enforcing this behaviour isn't the way to go.
Disabling downvotes after a question has been closed, however, may be a better suggestion. But really bad questions should really be buried imo ;-)
when to vote down
Use your downvotes whenever you encounter an egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect.
so it doesn't mean that closed question should not be downvoted (it that deserve downvote)
so its perfectly right
additionally in my opinion there should be kind of limit(like -3 ) on the down vote for new user who posted question <3 so it would give a chance to improve and new user friendly