I expect much more commitment from my PhD-supervisor. How do I communicate this to him?
Realise your own commitment first. As a PhD candidate, you are training to become an independent researcher. Ideally, you aim to reach the stage when you are able to tell good results from bad, proofread and edit your own writing, prepare the PhD thesis for publication and defence. Many PhD candidates struggle because their advisers are over-protective and micromanage every step, leaving them little chance for self-reflection and self-improvement. Embrace the freedom to do your research your way and to learn from your own mistakes in the process. Own your work and own responsibility for making it better.
Use others. Many questions can be answered by people other than your PhD supervisor. Use online resources, such as Stack Exchange, use other peers and colleagues, use support systems in your department. Ask questions, try to understand answers, find and use the relevant literature. Do not sit and passively wait  for your adviser to come back to you with suggestions - use this time to find the answer yourself.
Do not wait for your supervisor's approval of your work. Assume that silence  is a sign of approval and move on. If in doubt, show your work to someone else and ask for their advice. Politely cc your supervisor in the email.  It may work wonders.
Understand the process of submission and clearly distinguish the points when your supervisor is essential to move forward, from those when their advice is only desirable. Politely ask your supervisor to give you feedback by a particular date, but be prepared to move forward regardless of whether or not you receive the response. Depending on your University structure, you may even be able to submit your thesis without your PhD supervisor's approval. Know the people who are in charge of the PG education in your University - such as Research Office of Head of Department - and cc them in all really important emails (but only in really important ones). They may help to encourage your supervisor to find time to give you feedback or approval when it's critical.