DESC:Field of the invention:

The present invention relates to oil filling and more particularly, to an oil filling system for a shock absorber and a method thereof.

Background of the invention:

Oil is a main contributor for suspension functioning in terms of viscosity and volume control to be filled to obtain the required damping effect. Conventionally, an oil filling process is done in two ways:
a) Syringe method: by sucking the oil from a reservoir to a defined chamber and dispensing with a non-returnable valve mechanism to required tube/ container.
b) Oil is pumped through a Wane mechanism which rotates with a set time/ number of rotations to the set oil quantity to be dispensed.
However, in both the methods there are concerns of varied oil quantity dispensing requirement, consistency and air traps while dispensing that in turn affects the capability of the filling process. Hence, there is a need to work on an accurate and quick response filling method for a variety of quantity without compromising on the filling capability.

Figure 1 shows an oil filing system (100a) of the prior art. The oil filing system (100a) comprises an oil dispenser (10a), a shut off valve (30a), an oil tank (40a), a filter (50a), a nozzle (80a) and a component (90a). However, the system (100a) and a working method thereof have drawback of filling oil to varying volume requirements and obtaining the accuracies.

Accordingly, there exists a need to provide an oil filling system for a shock absorber and a method thereof that overcomes the above mentioned drawbacks in the prior art.

Objects of the invention:

An object of the present invention is to provide an automatic adjustment of oil filling with respect to change in pressure and flow of oil.

Another object of the present invention is to provide pressure sensitive automatic flow controlled oil filling method.

Summary of the invention:

Accordingly, the present invention provides an oil filling system for a shock absorber. The oil filling system comprises a pair of pumps, a flow meter, a shut-off valve, an oil tank, a pair of filters, a pair of seated valves, a programmable logic control (hereinafter, “PLC”), a pair of pressure relief valves and a nozzle.

The pair of pumps is connected to the oil tank for drawing oil therefrom. The pair of pumps is driven by a motor. The pair of filters is connected to the pair of pumps. The oil drawn by the pair of pumps is transferred to the pair of filters through a pair of non-return valves. The flow meter receives oil from the pair of filters through the pair of seated valves.

The PLC is operably connected to the flow meter for receiving a data in the form of pulses to calculate quantity of oil running there through. The PLC is programmed to consider the difference in pressure and flow while dispensing the oil. The pair of pressure relief valves is operably connected to the pair of pumps. The pair of pressure relief valves being mechanical control relief valves is adapted to release the excess pressure passing to the oil filling system. The shut-off valve is connected to the flow meter. The shut-off valve is capable of opening and closing in response to a signal received from the PLC. The nozzle is connected to the shut-off valve for dispensing oil to the shock absorber.

In another aspect, the present invention provides an oil filling method for a shock absorber. Specifically, the method is a pressure sensitive automatic flow controlled oil filling method.

Brief description of the drawings:

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a schematic diagram of an oil filling system, in accordance with a prior art; and

Figure 2 shows a schematic diagram of an oil filling system for a shock absorber, in accordance with the present invention.

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 embodiments.

The present invention provides an oil filling system for a shock absorber. The oil filling system provides an automatic adjustment of oil filling with respect to change in pressure and flow of oil. The present invention also provides a pressure sensitive automatic flow controlled oil filling method.

The 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.

Referring to figure 2, an oil filing system (100) (hereinafter referred as, “the system (100)”) for a shock absorber (110) in accordance with the present invention is shown. The system (100) comprises a pair of pumps (10), a flow meter (20), a shut-off valve (30), an oil tank (40), a pair of filters (50), a pair of seated valves (60), a programmable logic control (not shown), a pair of pressure relief valves (70) and a nozzle (80).

The pair of pumps (10) is connected to the oil tank (40). The pair of pumps (10) draws the oil from the oil tank (40). The pair of pumps (10) is driven by a motor (5). The pair of filters (50) is connected to the pair of pumps (10). The oil drawn by the pair of pumps (10) is transferred to the pair of filters (50) through a pair of non-return valves (45). The pair of non-return valves (45) ensures that the consistent pressure of oil flow in one direction is maintained and a required accuracy of oil dispensing is achieved. The oil from the pair of filters (50) is transferred to the flow meter (20) through the pair of seated valves (60). The programmable logic control (hereinafter, “PLC”) is operably connected to the flow meter (20). The flow meter (20) continuously gives a data to the PLC in the form of pulses to calculate quantity of oil running there through. The PLC adjusts the shut-off valve (30) as soon as the required quantity is dispensed in the shock absorber (110).

The shut-off valve (30) is connected to the flow meter (20). The shut-off valve (30) is capable of opening and closing in response to a signal received from the PLC. The nozzle (80) is connected to the shut-off valve (30). The nozzle (80) dispenses the oil to the shock absorber (110). Specifically, the oil from the oil tank (40) is dispensed to the shock absorber (110) via the pair of filters (50), the pair of seated valves (60) and the nozzle (80). The pair of pressure relief valves (70) is operably connected to the pair of pumps (10). The pair of pressure relief valves (70) being mechanical control relief valves are adapted to release the excess pressure passing to the system (100). The pair of pressure release valves (70) also ensures as a safety circuit when the motor (5) is on and the shut-off valve (30) is closed.

In accordance with the present invention, the PLC is programmed to consider the difference in pressure and flow while dispensing the oil and accordingly pulses are tuned to fill the oil to required quantity. This is a continuous process of monitoring the flow and pressure, and the system (100) automatically adjusts to compensate the variance and correct to the designed value.

In another aspect, the present invention provides an oil filling method (hereinafter, “the method”) for a shock absorber (110). Specifically, the method is a pressure sensitive automatic flow controlled oil filling method. The method is described herein below in conjunction with the system (100) of figure 2.

In the oil filing method, the pair of pumps (10) continuously drives oil through the flow meter (20). The flow meter (20) simultaneously gives data to the PLC in the form of pulses to calculate the quantity of oil dispensed. The PLC closes the shut-off valve (30) after confirmation of required quantity of oil is dispensed. The PLC adjusts the shut-off valve (30) with a response time and also considers any changes in pressure and/or flow in the pair of pumps (10) without disturbing oil quantity dispensed. Here, the oil from the oil tank (40) is dispensed to the shock absorber (110) via the pair of filters (50), the pair of seated valves (60) and the nozzle (80).

If pressure or flow changes, the PLC monitors quantity of oil and calculate whether there is any excess or shortfall of oil has happened in last filling cycle and accordingly in next cycle the PLC corrects filling quantity set value to maintain output oil quantity. The method is self- calibrated for a specific oil viscosity.

In accordance with the present invention, irrespective of the oil quantity requirement the system (100) facilitates achievement of process capability. The system (100) and the method provide flexibility of filling varied volumes of oil requirement and still achieve the accuracies on filled quantity.

Advantages of the invention:

1. The system (100) does not require manual interventions to set up.
2. The system (100) and the method have capability of Cpk > 2.0.
3. The system (100) and the method provide quick response and dispensing, for example cycle time 10 seconds for 1000 cc.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.
,CLAIMS:We claim:
1. An oil filling system (100) for a shock absorber (110), the system (100) comprising:
a pair of pumps (10) connected to an oil tank (40) for drawing oil therefrom, the pair of pumps (10) being driven by a motor (5);
a pair of filters (50) connected to the pair of pumps (10);
a flow meter (20) connected to the pair of filters (50) for receiving oil therefrom through a pair of seated valves (60),
a programmable logic control operably connected to the flow meter (20) for receiving a data in the form of pulses to calculate quantity of oil running there through, the programmable logic control being programmed to consider the difference in pressure and flow while dispensing the oil;
a pair of pressure relief valves (70) operably connected to the pair of pumps (10);
a shut-off valve (30) connected to the flow meter (20), the shut-off valve (30) capable of opening and closing in response to a signal received from the programmable logic control; and
a nozzle (80) connected to the shut-off valve (30) for dispensing oil to the shock absorber (110).

2. The system (100) as claimed in claim 1, wherein the oil drawn by the pair of pumps (10) is transferred to the pair of filters (50) through a pair of non-return valves (45).

3. The system (100) as claimed in claim 1, wherein the pair of pressure relief valves (70) being mechanical control relief valves are adapted to release the excess pressure passing to the system (100).