I don't know that there's any hard-and-fast answer to that question. Bing and Google both will generally crawl a site based at least in part on how often the site's content has changed in the past. So if you have a news site or a blog that's being updated regularly, they will visit more often than if you have a brochure site that has existed pretty much unchanged for several years.
Submitting doesn't necessarily get them to come back any faster. To my understanding, sitemaps are more to make sure the spiders know about and can (at some point) visit pages that may be difficult to reach through standard navigation, not about making the spiders visit earlier or more often than they otherwise would.
Patience is difficult, but often a necessary part of SEO...