Claims
1. A quick release valve (100) for an air suspension system (250) with a lift axle (260)
of a vehicle (200a), in particular a utility vehicle (200b), wherein the quick release
valve (100) comprises:
a supply port (110), a delivery port (120) and an exhaust port (130), an inlet valve (140) with an inlet valve seat (141), an exhaust valve (150) with anexhaustvalveseat(151), and a diaphragm (160) being movably and/or deformably arranged between the inlet valve seat (141) and the exhaust valve seat (151) and configured to tran¬sition between an application state (AS) in which the supply port (110) and the delivery port (120) are in fluid communication and a release state (RS) in which the delivery port (120) and the exhaust port (130) are in fluid communi¬cation, wherein
the inlet valve seat (141) comprises a double-angled profile(142) and/or the diaphragm (160) is pre-loaded.
2. The quick release valve (100) as claimed in claim 1, wherein the inlet valve seat (141) comprises a first seat portion (143) and a second seat portion (144), wherein each of the first seat portion (143) and the second seat portion (144) comprises a seat width (W) that varies linearly along a longitudinal axis (A).
3. The quick release valve (100) as claimed in claim 2, wherein the first seat portion (143) is arranged radially outwardly from the second seat portion (144) and the width (W) of the second seat portion (144) varies more strongly along the longitudinal axis (A) than the width (W) of the first seat portion (143).
4.The quick release valve (100) as claimed in claim 2 or 3, wherein the diaphragm (160) is adapted and arranged to sealingly contact,in the release state (RS),the first seat portion (143) and the second seat portion (144).
5. The quick release valve (100) as claimed in any one of the preceding claims, wherein the exhaust valve seat (151) and the diaphragm (160) are adapted to pre-load the diaphragm (160) in the application state (AS).

6. The quick release valve (100) as claimed in any one of the preceding claims, whe-reinthe quick release valve (100) is adapted to.in the release state (RS), holda deli¬very pressure (DP) of a fluid in the delivery port (120) constant and to decrease a supply pressure (SP) of a fluid in the supply port (110) by less than a threshold pres-sure (PT).
7. The quick release valve (100) as claimed in any one of the preceding claims, wherein the quick release valve (100) is adapted to.in the application state (AS), hold a supply pressure (SP) of a fluid in the supply port (110) constant in case a delivery pressure (DP) of a fluid in the delivery port (120) increases by less than a threshold pressure (PT).
8. The quick release valve as (100) claimed in 6 or 7, wherein the threshold pressure (PT) is in the range of 1 bar to 2 bar.
9. The quick release valve (100) as claimed in any one of the preceding claims, wherein the diaphragm (160) is pre-loaded by deflecting a center portion (161) of the diaphragm (160) by at least 0.5 mm and by up to 1.8 mm.
10. The quick release valve (100) as claimed in claim 9, wherein the center portion
(161) is deflected by pressing the exhaust valve seat (151) against the diaphragm
(160).
11: An air suspension system (250) for a vehicle (200a), in particular a utility vehicle (200b), wherein the air suspension system (250) comprises a lift axle (260), a main bellow (265), a lift axle control valve (270) and a quick release valve (100) as claimed in any one of the preceding claims connecting the main bellow (265) and the lift axle control valve (270).
12. A vehicle (200a), in particular a utility vehicle (200b), comprising an air suspen-sion system (250) as claimed in claim 11.