| 摘要 |
The valve has a piston valve (3) mounted within a piston valve cylinder (4) by two spaced apart bearing regions (13, 14) so that the piston valve (3), can rotate and/or move axially relative to the piston valve cylinder (4) under the control of an air quantity measuring device. Fuel under pressure is introduced in the cylinder space between the bearing regions (13, 14) and low pressure prevails outside the bearing regions. The bearing regions (13, 14) of piston valve (3) are provided with circumferentially disposed grooves (27). The pressurised fuel migrates into those grooves (27) and tend to equalise the pressure on the circumferential surfaces of the bearing regions (13, 14) so that the piston (3) does not tend to adopt an eccentric attitude and bear against the side wall of the cylinder (4). <IMAGE> |
