Electrorheological Valve

Abstract

An ER fluid valve includes a housing and a plurality of parallel flow passages through the housing each defined by spaced electrodes at least one of which is controllable independently of other flow passages electrodes. A controller is configured to selectively establish electrical fields for all of the independently controllable electrodes to close all of the flow passages to ER fluid flowing through the housing. By removing the fields from all of the independently controllable electrodes, all the flow passages are open to the ER fluid flowing through the housing. By establishing fields for select independently controllable electrodes to close their associated flow passages and by leaving other flow passages open, restricted flow of the ER fluid through the housing is accomplished to vary the flow rate through the housing.

Claims

1. An electrorheological fluid valve comprising: at least one fluid input port; at least one fluid output port; a housing configured to enable an electrorheological fluid to flow from the at least one fluid input port to at least one fluid output port; a grid of electrodes on at least one substrate of the housing; and a controller configured to selectively establish an electric field for at least one electrode in the grid, wherein the electric field causes a restriction in a flow of the electrorheological fluid.

2. The valve of claim 1, further comprising more than one fluid input port, wherein the controller is further configured to selectively establish an electric field for at least one electrode in the grid in order to control electrorheological fluid flow between the more than one fluid input port and the at least one fluid output port.

3. The valve of claim 1, further comprising more than one fluid output port, wherein the controller is further configured to selectively establish an electric field for at least one electrode in the grid in order to control electrorheological fluid flow between the at least one fluid input port and the more than one fluid output port.

4. The valve of claim 1, further comprising more than one fluid input port and more than one fluid output port, wherein the controller is further configured to selectively establish an electric field for at least one electrode in the grid in order to control electrorheological fluid flow between the more than one fluid input port and the more than one fluid output port.

5. The valve of claim 4 in which the controller is configured to energize electrodes in the grid between select ports.

6. The valve of claim 5, wherein the controller is configured to connect an input port to a respective output port by selectively establishing an electric field for at least one electrode in the grid.

7. The valve of claim 1 in which each grid electrode includes a conductive member surrounded by an insulator.

8. The valve of claim 1 in which the flow passages are in the same plane.

9. The valve of claim 1 in which the flow passages are in different planes.

10. The valve of claim 1 in which the independently controllable electrodes are rectangular, square, or irregularly shaped.

11. The valve of claim 1 in which the controller is configured to selectively apply a voltage to the independently controllable electrodes while the electrode spaced therefrom remain grounded.

12. The valve of claim 1 in which the controller is configured to selectively ground the independently controllable electrodes.

13. A method of operating a valve comprising: providing a housing having at least one fluid input port and at least one fluid output port; restricting flow of electrorheological fluid between a fluid input port of the at least one fluid input port and a fluid output port of the at least one fluid output port by establishing electrical fields between various electrodes of a grid of electrodes.

14. The method of claim 13, further comprising defining multiple flow passages between respective fluid input ports and multiple fluid output ports, wherein the flow passages are defines based on establishing electrical fields between various electrodes of a grid of electrodes.

15. The method of claim 14, wherein the multiple flow passages are reconfigurable.

16. The method of claim 14, further comprising adjusting a flow rate of the electrorheological fluid by adjusting a number of electrodes having an electrical field applied.

17. An electrorheological fluid valve comprising: a housing; a plurality of fluid input ports; a plurality of fluid output ports; a grid of electrodes; and a controller configured to selectively define multiple flow passages between respective fluid input ports and fluid output ports, wherein the flow passages are defines based on establishing electrical fields between various electrodes of a grid of electrodes.

18. The electrorheological fluid valve of claim 17, wherein the controller is further configured to reconfigure the multiple flow passages.

19. The electrorheological fluid valve of claim 17, wherein the controller is further configured to adjust a flow rate of the electrorheological fluid by adjusting a number of electrodes having an electrical field applied.

20. The electrorheological fluid valve of claim 17, in which the electrodes are rectangular, square, or irregularly shaped.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0017] Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:

[0018] FIG. 1 is a schematic three dimensional end view of a prior art cylinder type ER valve;

[0019] FIG. 2 is a schematic three dimensional end view of a prior art plate type ER valve;

[0020] FIG. 3 is a schematic three dimensional exploded view showing the primary components associated with one embodiment of a new ER valve in accordance with an example of the subject invention;

[0021] FIG. 4A is a schematic end view showing the ER valve of FIG. 3 with a voltage applied to approximately half of the valve electrodes resulting in one flow rate through the valve;

[0022] FIG. 4B is a schematic end view of the valve show in FIG. 3 again with a voltage applied to approximately half of the electrodes but now resulting in a different flow rate than the configuration shown in FIG. 4A;

[0023] FIG. 5 is a graph of flow rate as a function of a number of open flow passages for an example of an ER valve in accordance with the invention;

[0024] FIG. 6 is a schematic three dimensional top view showing a prototype ER valve in accordance with the invention;

[0025] FIG. 7 is a schematic three dimensional end view showing another embodiment of a new ER valve in accordance with the invention;

[0026] FIG. 8A is a schematic top view showing an example of a valve manifold with electrodes in a grid-like pattern in accordance with still another example of the subject invention;

[0027] FIG. 8B is a schematic view showing several different flow paths obtainable for the manifold of FIG. 8A;

[0028] FIG. 9A is a schematic top view showing an example of a manifold with a flow passage therethrough defined by grid electrodes;

[0029] FIG. 9B is a schematic top view of the manifold shown in FIG. 9A except now the flow rate for the flow passage shown in FIG. 9A is reduced;

[0030] FIG. 10 is a schematic top view showing an example of an ER valve/manifold with uniquely shaped electrodes; and

[0031] FIG. 11 is a diagram of an example of the controller shown in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.

[0033] FIG. 1 shows a prior art cylinder type ER valve 10 with inner electrode 12 and outer electrode 14. An electrical field established between electrodes 10 and 12 increases the viscosity of an ER fluid flowing in annular space 16 between the electrodes and stops the flow. Removing the electrical field allows the ER fluid to flow again. FIG. 2 shows a prior art plate type ER valve 20 with electrodes 22a, 22b, and 22c separated by insulators as shown. Plate 22b is connected to ground and plates 22a and 22c are connected together to a common voltage source. When the voltage source is switched on, ER fluid will not flow between the plates. When no voltage is applied to plates 22a and 22c, the ER fluid will flow. As noted in the Background section above, controlling the flow rate through the prior art ER valves can be problematic in some instances.

[0034] FIG. 3 shows an example of a new ER fluid valve 30 with a housing defined by electrode 32, substrate 34 (typically printed circuit board material), and spacers/walls 36a and 36b. A plurality of parallel flow passages through the housing such as passages A, B, C, and D (typically there are 10-20 or more flow passages) are established between the input port and the output port. Each flow passage is defined by spaced electrodes of at least one of which is controllable independently of the other flow passage electrodes. That is, flow passage A is defined by electrode 38a on substrate 34 (e.g., a conductive trace) and electrode 32; flow passage B is defined by electrode 38b on substrate 34 and electrode 32; and flow passage C is defined by electrode 38c on substrate 34 and electrode 32. Each lengthy conductive trace member 38 in this example is spaced from its neighbors and insulated therefrom via the material of printed circuit board 34.

[0035] Controller 40 is configured to selectively establish an electrical field for all of the independently controllable electrodes 38a-38d to close all of the flow passages to ER fluid through the housing defined by substrate 34, continuous top electrode 32, and spacers 36a and 36b. Controller 40 can also selectively remove the electrical field from all of the independently controllable electrodes 38a-38d to open all the flow passages A-D through the housing. Controller 40 is also configured to establish electrical fields for select independently controllable electrodes 38a-38d to close their associated flow passages (A, B, C and/or D) for restricted flow of ER fluid through the housing.

[0036] Thus, if no voltage is applied to any electrode, the valve is fully open and low viscous ER fluid flows along flow passages A-D. If a voltage is applied to all electrodes 38a-38b with electrode 32 grounded, the valve is fully closed since the ER fluid in each flow passage A-D is highly viscous in the presence of the electrical fields. The flow rate of the ER fluid through the valve is controlled by applying a high voltage to only select electrodes as shown in the examples of FIGS. 4A and 4B. In FIG. 4A, all of the electrodes on one side of the valve are energized resulting in one flow rate and in FIG. 4B, again, about one half of the total electrodes are energized by energizing every other electrode but the result is a lower flow rate then was the case with FIG. 4A. In other examples, only electrode 38a, FIG. 3 has a voltage applied thereto and thus flow passage A is blocked by the high viscosity ER fluid in flow passage A but flow passages B and C remain open to low viscosity ER fluid flowing through the housing. This way, flow passages A, B, and C can be selectively opened and closed (e.g., A open, B and C closed; A and B open, C closed; A and C open, B closed; and the like) resulting in variable flow rates through the valve. In FIGS. 4A and 4B, the electrical fields shown may all have approximately the same strength.

[0037] FIG. 5 depicts how the flow rate through the valve is a function of the number of open flow passages (i.e., flow passages whose spaced electrodes do not have an electric field applied to them). As noted above in respect to FIGS. 4A and 4B, the flow rate is a function not only of how many flow passages are open but also how close the open flow passages are to each other.

[0038] FIG. 6 depicts a prototype ER valve with 19 flow passages. Substrate 34 is shown as are spacers/walls 36a and 36b. Conductive traces 38 can also be seen. The cover of the valve would typically be a conductive electrode as shown in FIG. 3. Various technologies can be used to fabricate this valve including printed circuit board methodologies, MEMS technology (see U.S. Pat. No. 5,640,995 incorporated herein by this reference), and the like. The new ER valves can be used to control an actuator as shown in U.S. Pat. No. 5,099,884 incorporated herein by this reference, to control spool valves, to provide mechanical forces, and the like.

[0039] So far, the independently controllable electrodes 38 all lie in the plane of substrate 34. But, they may lie in different planes in a fashion similar to prior art plate type electrodes. In FIG. 7, the flow passages are stacked radially. Flow passage A is defined by electrodes 50a and 50b, parallel flow passage B is defined by electrodes 50b and 50c, and parallel flow passage C is defined by electrodes 50c and 50d. Electrodes 50a and 50c may be connected to ground and controller 52 is configured to selectively apply a high voltage to electrodes 50b and/or 50d. If, for example, a high voltage is applied to both electrodes 50b and 50d, no flow occurs and the valve is closed. If a high voltage is applied to neither electrode 50b nor 50d, then flow is not restricted by any electrical field and the valve is fully open. If a high voltage is applied to electrode 50b but not electrode 50d, or vice versa, then the flow through the valve is only partially restricted. That is, for a high voltage applied only to electrode 50d, then flow passages A and B are open but flow passage C is closed.

[0040] FIGS. 8A-8B depict a manifold design wherein both the flow rate and flow direction can be selected. Here, substrate 60 includes grid electrodes 62 each, for example, comprising a square conductive land on a printed circuit board closely spaced to its neighboring electrodes. This manifold defines ports 64a-64k when a top electrode is closely spaced from substrate 60 (and using peripheral spacer/wall structures, not shown). The flow paths between the ports can be varied by selectively applying a voltage (or ground) to groups of grid electrodes. In FIG. 8A, electrode groups A, B, C, D, and E have a voltage applied to them which defines parallel flow passages connecting port 64k with ports 64b, 64e, and 64h; connecting port 64c to port 64d; and connecting port 64f to port 64g.

[0041] In FIG. 8B, different grid electrodes are energized resulting in different flow passage configurations. Thus, one of the two electrodes in the system is divided into a grid-like pattern and each grid electrode is independently controllable or, alternatively, groups of grid electrodes can be independently controlled. Such a valve can have multiple inputs and outputs rendering it a manifold. The pattern of activation of the grid electrodes can form variable width passages between the inputs and outputs and connect different inputs and outputs at different times. In essence, the valve becomes an on the fly programmable reconfigurable manifold. Such a valve will perform adequately with either the ground side or the high voltage side patterned as shown in the figures although patterning the ground electrode to include the grid electrodes appears to be preferable. In one example, the legs of a mobile walking robot can be controlled by such a manifold. The result is independently controllable electrodes defining multiple flow paths between a plurality of ports which can be selectively opened and closed.

[0042] The flow rate can be varied as between two ports by controlling how many grid electrodes in the flow path are left deenergized. For example, in FIG. 9A, the flow passages between ports 66a and 66b are two grid electrodes wide (all the other grid electrodes on substrate 60 having a high voltage applied to them) while in FIG. 9B flow path A is only one grid electrode wide.

[0043] FIG. 10 shows how substrate 70 can include irregularly shaped electrodes to meet the requirements of a valve or manifold as desired.

[0044] FIG. 11 depicts an example of the primary circuitry for controller 40, FIG. 3. Microprocessor 90 controls switches A, B, C, and D (relays or high voltage transistors) which selectively connect electrodes 38a-38d (see FIG. 3) to ground. Voltage source 92 is connected to continuous plate electrode 32 (in this example).

[0045] Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words including, comprising, having, and with as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments.

[0046] In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended.

[0047] Other embodiments will occur to those skilled in the art and are within the following claims.