Hydraulic circuit system for a vehicle height control device
First Claim
1. A hydraulic circuit system for a vehicle height control device equipped in a vehicle having a plurality of vehicle wheels, comprising:
- a plurality of actuators which are provided corresponding to the vehicle wheels and are adapted to increase and decrease the vehicle heights at locations corresponding to the associated vehicle wheels as respective results of the supply and the discharge of working fluid to and from their working fluid chambers;
a working fluid supply passage means for supplying working fluid to said working fluid chambers;
a working fluid discharge passage means for discharging working fluid from said working fluid chambers;
a bypass valve means for selectively communicating said working fluid supply passage means and said working fluid discharge passage means with each other;
a plurality of control valve means which are provided in said working fluid supply passage means and said working fluid discharge passage means between said bypass valve means and said associated actuators, and which are adapted to control the supply and the discharge of working fluid to and from said working fluid chambers, respectively;
a plurality of cut-off valve means which are provided in said working fluid supply passage means and said working fluid discharge passage means between said bypass valve means and said associated actuators, and which are adapted to remain in their closed position to shut down the fluid communication of said associated supply and discharge passage means at intermediate portions thereof between said bypass valve means and said working fluid chambers so long as the pressure within said supply passage means is not more than a predeterminate value.
1 Assignment
0 Petitions
Accused Products
Abstract
A hydraulic circuit system for a vehicle height control device is provided comprising actuators for increasing and decreasing vehicle heights as respective results of the supply and the discharge of working fluid to and from their working fluid chambers, a supply passage means and a discharge passage means for supplying and discharging working fluid to and from the chambers, respectively, control valve means for controlling the supply and the discharge of working fluid, cut-off valve means provided in the supply and discharge passage means and adapted to remain in their closed position so long as the pressure within the supply passage means is not more than a predetermined value. The system further comprises a bypass valve means for selectively communicating the supply and the discharge passage means with each other so that the pressure within the supply passage means may be controlled. The opening and closing of the cut-off valve means can be performed by solely controlling the bypass valve means, thereby reducing the electric power required to operate the system. Undesired decrease in vehicle height can positively be prevented by the cut-off valve means even in the event where the control valve means is shifted for supplying the working fluid to the chambers under the condition where the pressure within the supply passage means is relatively low.
42 Citations
11 Claims
-
1. A hydraulic circuit system for a vehicle height control device equipped in a vehicle having a plurality of vehicle wheels, comprising:
-
a plurality of actuators which are provided corresponding to the vehicle wheels and are adapted to increase and decrease the vehicle heights at locations corresponding to the associated vehicle wheels as respective results of the supply and the discharge of working fluid to and from their working fluid chambers; a working fluid supply passage means for supplying working fluid to said working fluid chambers; a working fluid discharge passage means for discharging working fluid from said working fluid chambers; a bypass valve means for selectively communicating said working fluid supply passage means and said working fluid discharge passage means with each other; a plurality of control valve means which are provided in said working fluid supply passage means and said working fluid discharge passage means between said bypass valve means and said associated actuators, and which are adapted to control the supply and the discharge of working fluid to and from said working fluid chambers, respectively; a plurality of cut-off valve means which are provided in said working fluid supply passage means and said working fluid discharge passage means between said bypass valve means and said associated actuators, and which are adapted to remain in their closed position to shut down the fluid communication of said associated supply and discharge passage means at intermediate portions thereof between said bypass valve means and said working fluid chambers so long as the pressure within said supply passage means is not more than a predeterminate value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification