PRESSURE LOSS COMPENSATING DEVICE FOR FLUID PRESSURE CIRCUIT AND CAM DEVICE EQUIPPED WITH SUCH DEVICE

Japanese Patent JP3787397

B2

PROBLEM TO BE SOLVED: To secure required fluid pressure at all times by automatically compensating a fluid pressure circuit for the working fluid pressure loss as required or periodically. SOLUTION: A cylinder device 70 for compensating oil pressure loss is provided in the midway of a piping 18 on the fluid pressure circuit 12. The cylinder device 70 is equipped with a working fluid introduction room 76 into where air pressure is introduced and a fluid pressure generating room 80 making communication through a branch piping 78 having a check valve provided on the piping 18. A piston 74 is provided with a return spring 84 and the fluid pressure generating room 80 is connected with a fluid introduction piping 88 communicating with an oil pan 86. When the piston 74 moves to the fluid pressure generating room 80 side, an excess pressure introduction port 72b communicating with a drain port 72a is provided and connected to the piping 18 through an escape pipe 92. A gap presenting an orifice function is provided between the excess pressure introduction port 72b and the drain port 72a and the gap is blocked at the lower position of the piston 74.