Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed

Field of the invention
[0001] The present disclosure relates to a sensing element assembly for detecting a working state of a valve.
Background of the invention
[0002] In a control valve configured by connecting a plurality of valve blocks, periodic maintenance and inspection are important for stabilizing the operation and extending the service life. Size of the previous sensor puts constraints on space in compact hydraulics domain. The present invention provides solution for avoiding the calibration and mapping of the sensor before using in the valve and also to provide accurate results when compared to inductive sensor or a hall effect sensor.

[0003] A Japanese patent application JP2017219060 discloses a state detection system of a control valve suitable for deterioration diagnosis of the control valve.SOLUTION: A state detection system of a control valve includes: a magnet 25 arranged in a sensor case 31, which is filled with hydraulic oil, of a control valve C, and moving integrally with a spool 16 for each valve block 1; a spool position sensor 3 including a Hall element 32a arranged near the magnet 25, and configured to detect a position of the spool 16 based on output of the Hall element 32a; and at least a radio module (slave machine) 4, as a transmission unit, configured to transmit detection data of the spool position sensor 3 as data for hydraulic oil deterioration state analysis to an analysis and diagnosis device 9 through radio communication

Brief description of the accompanying drawings
[0004] An embodiment of the invention is described with reference to the following accompanying drawings:
[0005] Figure 1 illustrates a sensing element assembly of a valve according to one embodiment of the invention.

 
Detailed description of the drawings

[0006] Figure 1 illustrates a sensing element assembly of a valve according to one embodiment of the invention. The valve 10 comprises a moving element 12, an armature 14, a pole tube 16, a solenoid 18. The armature 14 is positioned inside the pole tube 16 and the solenoid 18 is circled around the pole tube 16 on an exterior surface. The moving element 12 is connected to one end of the armature 14. The sensing element assembly 11 comprises at least one magnetized ring magnet 20 diametrically stacked and coupled to the armature 14 of the valve 10. The sensing element assembly 11 comprises a sensing element 22 positioned above at least one magnetized ring magnet 20 such that an air gap 24 is formed between the sensing element 22 and the at least one ring magnet 20. The sensing element 22 is attached to one end of the armature 14 such that, the sensing element 22 adapted to detect a flux change in the air gap 24 based on a movement of the armature 14 and the moving element 12.

[0007] Further the construction of the sensing element assembly of a valve is explained in detail. According to one embodiment of the invention, the valve 10 is a hydraulic valve. The hydraulic valve 10 comprises an inlet 32 and an outlet 30 for allowing a fluid to flow during at least one operational state. The fluid is a hydraulic fluid. The moving element 12 is connected to one end of the armature 14 and other end of the moving element 12 is positioned in proximity to the inlet 32. The movement of the moving element 12 towards and far from the inlet 32 allows the fluid to flow from the inlet 32 and the outlet 30. The armature 14 is positioned inside the pole tube 16 and the solenoid 18 is circled or enclosed around the pole tube 16. The solenoid 18 is connected to a connector 28 of the valve 10. A predefined amount of voltage is provided to the valve 10 via the connector 28. For instance, the predefined amount of voltage is 24V, DC. Due to the application of the voltage, the armature 14 is energized and pulls the moving element 11 away from the inlet 32.

[0008] The sensing element assembly 11 is connected to one end of the armature 14 (the end that is away from the moving element 12). The sensing element assembly 11 comprises a sealing area 34 formed between the sensing element assembly 11 and the armature 14 for restricting the flow of fluid into the sensing element 22. According to one embodiment of the invention, the sensing element 22 comprises is an AMR (Anisotropic Magneto resistor) sensor. The sensing element assembly 11 comprises multiple magnetized ring magnets 20 diametrically stacked above the sensing element 22 such that, an airgap 24 is formed between the magnets 20 and the sensing element 22 for detecting a change in the flux during the working state of the valve 10.

[0009] The control unit 36 receives an output from the sensing element 22, wherein the output will be the displacement of the moving element 12 from an initial position to a next /final position, when the armature 14 is energized. The control unit 36 is chosen from a group of control units comprising a microprocessor, a microcontroller, a digital circuit, an integrated chip and the like. The control unit 36 comprises an operational amplifier (not shown) and a comparator (not shown) for amplifying the detected output and for comparing the detected output with a predefined value respectively. With the use of the logic gates present in the operational amplifier and the comparator, the control unit 36 defines an initial position and a final /next position that is sensed during the valve 10 actuation.

[0010] The sensing element assembly 11 comprises a heat sink 26 for detecting an operational temperature of the sensing element 22 during the operational/working state of the valve 10. The heat from the assembly 11 is dissipated via the heat sink 26 and the control unit 36 generates an alarm /warning if there is any kind of malfunction detected inside the sensing element 22. The malfunction chosen from a group of malfunctions comprising when no output is sensed due to non-displacement of the armature 14 and the moving element 12, when the heat is not effectively dissipated from the heatsink 26, when no flux is detected in the airgap 24 and the like.

[0011] Figure 2 illustrates a flow chart of a method of working of a sensing element assembly 11 of a valve 10 according to present invention. The valve 10 comprises a moving element 12, an armature 14, a pole tube 16, a solenoid 18, wherein the armature 14 is positioned inside the pole tube 16 and the solenoid 18 is circled around the pole tube 14 on an exterior surface. The moving element 12 is connected to one end of the armature 14. In step S1, at least one magnetized ring magnet 20 diametrically stacked is coupled to the armature 14 of the valve 10. In step S2, a movement of the armature 14 is detected by a sensing element 22 positioned above the at least one magnetized ring magnet 20. In step S3, a change in flux in an air gap 24 formed between said sensing element 22 and said ring magnet 20 is detected, based on a movement of the armature 14. In step S4, an output to the control unit 36 is transmitted upon detecting the change in flux and a displacement by the armature 14 and the moving element 12.

[0012] The method is explained in detail. The fluid flows from the inlet 32 and outlet 30 and vice versa, based on the movement of the moving element 12. During a closed position, the moving element 12 will be in contact with the inlet 32 and the position of the moving element 12 closes the outlet 30. In this scenario, the moving element 12 and the armature 14 will be in their initial position. When the voltage is provided to the connector 28 of the valve 10, wherein the connector 28 is connected to the solenoid 18 of the valve 10, the solenoid 18 will be activated, energizing the armature 14. When the armature 14 is energized, the moving element 12 is pulled from one direction to other i.e., from a left direction to a right direction, thus opening the inlet 32 for the flow of the fluid. The fluid will be flown until the other end of the armature 14 (where the sensing element assembly 11 is connected). And from the inlet 32 the fluid will be flown out via the outlet 30. During this process, the moving element 12 along with the armature 14 is displaced from the initial position. The displacement of the moving element along with the armature 14 is sensed by the sensing element 22.

[0013] The at least one ring magnet 20 (which is in the form of wheat stone bridge setup) present in the sensing element assembly 11 is applied with a positive voltage at one end and a negative voltage is applied at the negative end. From a neutral point in the sensing element assembly 11, a potential divider is formed to take a predefined voltage. The predefined voltage is used for defining the regions of detection. The output from the sensing element 22 is transmitted to an operational amplifier of the control unit 36 for amplification to a range of 0 – 5 V. The amplified signal is then sent to comparators of the control unit to compare against the predefined voltage.

[0014] Based on the comparison result, the valve 10 actuation is detected. For instance, if the moving element 12 is moved for a distance of “x”, then that displacement is converted to a voltage value and is compared to a predefined voltage. If the sensed voltage value is more than the predefined voltage, then the control unit 36 identifies the valve 10 actuation. I.e., the valve is in the ON state. If the sensed voltage value is less than or zero when compared to the predefined voltage value, then the control unit 36 identifies the OFF state of the valve 10.

[0015] With the above-mentioned sensing element assembly 11, cost is drastically reduced due to the usage of lesser and simple components. Any kind of malfunction can be easily troubleshooted and rectified due to simple and novel solution provided in the present invention. The above disclosed method can be used for even smaller movement detection up to range of 0.5 mm. And also, the above disclosed sensing element 22 can be used to any kind of valve that is known in the state of the art. The above disclosed method uses a simple processing component instead of digital processors which reduces an additional cost, complexity and regulations. In addition to that, the above concept doesn’t require any controller, memory or calibration and uses only analog components to directly produce the output required. The above disclosed method effectively determines whether any spool has got stuck in intermediate position due to contamination or other factors. Same sensing element assembly 11 disclosed above can be used for NO & NC valves accurately.

[0016] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
, Claims:We Claim:
1. A sensing element assembly (11) for detecting a working state of a valve (10), said valve (10) comprising a moving element (12), an armature (14) , a pole tube (16), a solenoid (18), wherein said armature (14) is positioned inside said pole tube (16) and said solenoid (18) is circled around said pole tube (16) on an exterior surface, said moving element (12) is connected to one end of said armature (14);
said sensing element assembly (11) comprising:
- at least one magnetized ring magnet (20) diametrically stacked and coupled to said armature (14) of said valve (10);
- a sensing element (22) positioned above said at least one magnetized ring magnet (20) such that an air gap (24) is formed between said sensing element (22) and said at least one ring magnet (20);
said sensing element (22) is attached to one end of said armature (14) such that, said sensing element (22) adapted to detect a flux change in said air (24) gap based on a movement of said moving element (12) and said armature (14) when energized.

2. The sensing element assembly (11) of said valve (10) as claimed in claim 1, comprises a heat sink (26) is positioned around said sensing element (22) for detecting an operational temperature.

3. The sensing element assembly (11) of said valve (10) as claimed in claim 1, wherein said working state of said valve (11) is based on an output from said sensing element (22).

4. The sensing element assembly (11) of said valve (10) as claimed in claim 1, wherein during an open state of said valve (10), said armature (14) when energized pulls said moving element (12) such that, a fluid is flown from an inlet (32) to outlet (30) of said valve (10).
5. The sensing element assembly (11) of said valve (10) as claimed in claim 4, wherein said movement of said armature (14) and said moving element (12) is detected by said sensing element (22).

6. The sensing element assembly (11) of said valve (10) as claimed in claim 1, comprises a control unit (36) for controlling at least one operation of said sensing element (22), wherein said at least one operation is receiving said detected output of said sensing element (22).

7. The sensing element assembly (11) of said valve (10) as claimed in claim 1, wherein said sensing element (22) comprises anisotropic magneto resistors arranged in a Wheatstone bridge setup and said valve (10) is a hydraulic solenoid valve.

8. The sensing element assembly (11) of said valve (10) as claimed in claim 1, wherein said output of said sensing element (22) is a voltage value.

9. A method of working of a sensing element assembly (11) of a valve (10), said valve (10) comprising a moving element (12), an armature (14) , a pole tube (16) , a solenoid (18), wherein said armature (14) is positioned inside said pole tube (16) and said solenoid (18) is circled around said pole tube (16) on an exterior surface, said moving element (12) is connected to one end of said armature (14);
said method comprising the steps of:
- coupling at least one magnetized ring magnet (20) diametrically stacked to said armature (14) of said valve (10);
- detecting a movement of said armature (14) by a sensing element (22) positioned above said at least one magnetized ring magnet (20);
- detecting a change in flux in an air gap (24) formed between said sensing element (22) and said ring magnet (20) based on a movement of said armature (14);
- transmitting an output to a control unit (36) upon detecting said change in flux and a displacement by said armature (14) and said moving element (12).