DESC:Field of the invention

The present invention relates generally to a hydraulic suspension system of automobiles and more particularly, to a pressure compensated damper system.

Background of the invention

All automobile hydraulic suspension systems, functions with a combination of dampers and springs to provide a desired ride comfort while riding a vehicle. Dampening effect or in other words resistance to road impact force is designed specifically to the vehicle based on the road conditions and purpose of usage. This dampening effect or damping force is derived through
a) The external requirement which decides size of a shock absorber with the structural mounting requirement, and
b) The internal design is a combination of suitable piston, plate-valve configuration and oil quantity.

Dampening effect consistency depends on the sustenance of plate deflection durability, contamination levels and wear pattern which cause functional failure and lowers the life of the suspension system.

Accordingly and in order to overcome the above mentioned drawbacks, there is a need to measure pressure on either side of the piston and dynamically control oil flow to maintain the required resistance to a piston rod movement.

Object of the invention

An object of the present invention is to provide a superior ride comfort through dynamically controlled precise damping by pressure compensated flow control mechanism.

Summary of the invention

Accordingly, the present invention provides a system for controlled variable damping mechanism for a vehicle. The system comprises a servo motor, a flow control valve, an actuator, a non-return-valve, a pressure gauge and a control unit.

The flow control valve is operated by the servo motor. The non-return-valve is mounted in one end of flow control valve for restricting the oil flow on a reverse direction. The actuator is connected to the servo motor at one thereof and to the flow control valve at another end thereof. The actuator includes a plurality of miniature holes arranged at different planes to control an oil flow. The pressure gauge is connected to an oil chamber of a hydraulic damper of the vehicle for measuring a pressure value of the oil. The control unit is operably connected to the servo motor. The control unit is adapted to measure oil pressure precisely and to provide input to the servo motor that causes any one of an opening and closing of the flow control valve. Specifically, the pressure gauge sends the measured pressure value in the form of a digital signal to the control unit and the control unit as per the digital signal received provides a signal to the servo motor to cause actuation of the actuator in anyone of an upward and a downward direction to control the flow control valve. The control unit is a proportional–integral–derivative controller. The system measures pressure and controls the oil flow on either side of a piston for both tension and compression strokes of the hydraulic damper.

Brief description of the drawings

The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
Figure 1 shows a system for a controlled variable damping mechanism for a vehicle, in accordance with the present invention; and

Figures 2-3 show a sectional view of a flow control valve of the system of figure 1.

Detailed description of the invention

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a system for controlled variable damping mechanism. The system of the present invention provides a superior ride comfort through dynamically controlled precise damping by pressure compensated flow control mechanism. The system measures pressure and controls the oil flow on either side of a piston for both tension and compression strokes of the hydraulic damper.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description and in the table given below.

Table:
Part No. Part Name Part No. Part Name
10 Servo motor 60 Hydraulic damper
20 Flow control valve 65 Oil Chamber
30 Actuator 70 Piston
40 Pressure gauge 80 Piston rod
50 System 90 Plate valve

Referring to figures 1-3, a system (50) for controlled variable damping mechanism for a vehicle in accordance with the present invention is shown. The vehicle includes a hydraulic damper (60), a piston (70), a piston rod (80) and a plate valve (90).

In accordance with the present invention, whenever there is up-down movement of the piston rod (80) in the hydraulic damper (60) due to road conditions, oil flows from one chamber to other through piston holes and the plate valve (90) depending on the direction of the movement of the piston (70). The system (50) for controlled variable damping mechanism restricts the oil flow i.e. damping force is generated to counter the impact of humps and potholes on road, in-turn pressure is released through a controlled path by allowing oil flow to other chamber.

As shown in figures 1-3, the system (50) comprises a servo motor (10), a flow control valve (20), an actuator (30), a non return valve (not shown), a pressure gauge (40) and a control unit (not shown). In an embodiment, the system (50) is designed to work in a simple mono-tube construction without any holes on piston/ base valve and the plate valve (90). However, it is understood here that the system (50) can be modified in other alternative embodiments of the present invention as per the intended application.

The flow control valve (20) is operated by the servo motor (10). The non-return-valve is mounted at one end of the flow control valve (20). The system (50) is protected with the non-return-valve to restrict the oil flow on a reverse (un-desired) direction.
The actuator (30) is connected to the servo motor (10) at one thereof and to the flow control valve (20) at another end thereof. The flow of oil is controlled precisely through the actuator (30) attached to the servo motor (10). The actuator (30) includes a plurality miniature holes (not shown) arranged at different planes and with a unique pattern to control the oil flow.

The pressure gauge (40) is connected to an oil chamber (65) of the hydraulic damper (60) for measuring a pressure value of the oil. Considering the actual intent of the hydraulic damper (60), the system (50) measures pressure on either side of the piston (70) to dynamically control oil flow and maintain the required resistance to the movement of the piston rod (80).

The control unit is operably connected to the servo motor (10). The control unit measures oil pressure precisely and provide input to the servo motor (10) that causes any one of an opening and closing of the flow control valve (20). In an embodiment, the control unit is a proportional–integral–derivative controller (PID). The control unit is independent of vehicle control configuration and performs the function with external sensors on the vehicle for road conditions and passenger loading. However it is understood here that the control unit can also be integrated with the vehicle controls in other alternative embodiments of the present invention.

Referring again to figures 1-3, in an operation, the pressure gauge (40) measures the pressure value and sends the measured pressure value in the form of a digital signal to the control unit. The control unit as per the digital signal received provides a signal to the servo motor (10). The servo motor thereafter causes actuation of the actuator (30) in anyone of an upward and a downward direction to control the flow control valve (20). The pressure compensated damper system (50) is designed to tap and measure pressure and to control oil flow on either side of the piston (70) for both tension and compression strokes of the hydraulic damper (60).
Advantages of the invention

1. The system (50) eliminates need of all precision plate valves and high contamination controls.
2. The system (50) facilitates auto controlled variable damping mechanism instead of a fixed plate valve construction for a particular damper.
3. The system (50) provides an improved ride comfort through dynamically controlled precise damping by pressure compensated flow control mechanism.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the scope of the invention.
,CLAIMS:We claim:

1. A system (50) for controlled variable damping mechanism for a vehicle, the system (50) comprising:
a flow control valve (20) operated by a servo motor (10);
an actuator (30) connected to the servo motor (10) at one thereof and to the flow control valve (20) at another end thereof, the actuator (30) having a plurality of miniature holes arranged at different planes to control an oil flow;
a pressure gauge (40) connected to an oil chamber (65) of a hydraulic damper (60) of the vehicle for measuring a pressure value of the oil;
a control unit operably connected to the servo motor (10), the control unit adapted to measure oil pressure precisely and to provide input to the servo motor (10) that causes any one of an opening and closing of the flow control valve (20); and
a non-return-valve mounted in one end of flow control valve (20) for restricting the oil flow on a reverse direction,
wherein, the pressure gauge (40) sends the measured pressure value in the form of a digital signal to the control unit and the control unit as per the digital signal received provides a signal to the servo motor (10) to cause actuation of the actuator (30) in anyone of an upward and a downward direction to control the flow control valve (20).

2. The system (50) as claimed in claim 1, wherein the control unit is a proportional–integral–derivative controller.

3. The system (50) as claimed in claim 1 measures pressure and controls the oil flow on either side of a piston (70) for both tension and compression strokes of the hydraulic damper (60).