On/Off Hydraulic Valve

Abstract

A hydraulic valve includes an on/off seat-type main valve with two ports having a displaceable poppet for opening and closing the main flow channel; an on/off seat-type pilot valve with three ports, with a magnetomotive force producing coil, a magnetic circuit, and an anchor movable with the magnetomotive force produced by the coil; and a frame with required channels and spaces for the poppet and for the anchor. Closing the inlet channel displaces the poppet and opens the main flow channel. Opening the inlet channel forces the poppet to close the main channel. The anchor includes a frame with a first sealing element for closing the low-pressure outlet channel of the pilot valve and with a second sealing element for securing the closing of the high-pressure inlet channel of the pilot valve. The sealing surface of the second sealing element is movable in relation to the frame of the anchor.

Claims

1. A hydraulic valve which comprises: an on/off seat-type main valve with two ports comprising a displaceable poppet for opening and closing a main flow channel, an on/off seat-type pilot valve with three ports, which comprises a magnetomotive force producing coil, a magnetic circuit, and an anchor movable with the magnetomotive force produced by the coil, and a frame with required channels and spaces for the displaceable poppet of the main valve and for the anchor of the pilot valve, wherein closing of a high-pressure inlet channel of the pilot valve allows displacement of the displaceable poppet of the main valve for opening the main flow channel of the main valve, and wherein opening of the high-pressure inlet channel of the pilot valve forces the displaceable poppet of the main valve to close the main channel of the main valve, wherein the anchor of the pilot valve comprises a frame with a first sealing element for closing a low-pressure outlet channel of the pilot valve and with a second sealing element for securing the closing of the high-pressure inlet channel of the pilot valve, and wherein a sealing surface of the second sealing element is movable in relation to the frame of the anchor of the pilot valve.

2. The hydraulic valve according to claim 1, wherein the sealing surface of the second sealing element of the anchor of the pilot valve extends at least partially outwards from the frame of the anchor.

3. The hydraulic valve according to claim 1, wherein the sealing surface of the second sealing element is supported with a spring force in relation to the frame of the anchor of the pilot valve.

4. The hydraulic valve according to claim 1, wherein the frame is at least partially manufactured with an additive manufacturing method, preferably by laminated object manufacturing or by selective laser melting.

5. The hydraulic valve according to claim 1, wherein the valve is a miniature hydraulic valve, having volume under 10 cm.sup.3 and a flow capacity of over 1 I/min with a pressure difference of 5 bar over the main valve.

6. The hydraulic valve according to claim 1, wherein the frame is formed from two or three separate material layers connected together to form one frame entity.

7. The hydraulic valve according to claim 6, wherein the one frame entity comprises required spaces and channels for a plurality of hydraulic valves.

8. The hydraulic valve according to claim 1, wherein the displaceable poppet of the main valve blocks the flow in the main flow channel in both flow directions.

9. A valve system comprising a plurality of hydraulic valves according to claim 1.

Description

[0031] Exemplifying embodiments of the invention and their advantages are explained in greater detail below in the sense of example and with reference to accompanying drawings, where

[0032] FIG. 1 shows schematically an embodiment of a hydraulic valve of the invention as a cross-sectional view,

[0033] FIG. 2 shows schematically an embodiment of an anchor of the pilot valve of the hydraulic valve of the invention as a cross-sectional perspective view.

[0034] FIG. 3 shows schematically an alternative embodiment of a hydraulic valve of the invention as a cross-sectional view,

[0035] FIGS. 4A and 4B show schematically an embodiment of a valve block comprising a plurality of hydraulic valves of the invention.

[0036] FIG. 5 shows schematically an embodiment of a valve system comprising a plurality of hydraulic valves of the invention.

[0037] In FIG. 1 is schematically shown a cross-section of a hydraulic valve 1 of the invention. The hydraulic valve comprises a frame formed from three material layers 2a, 2b and 2c, inside which frame is formed the three main parts of the hydraulic valve: an electromagnetic solenoid actuator, a pilot valve and a main valve.

[0038] The electromagnetic solenoid actuator comprises a coil 3, and the frame parts 2a and 2b together with the frame of anchor 4, which form the magnetic circuit of the solenoid actuator. The parts 2a, 2b and 4 of the magnetic circuit are made from magnetically soft material, wherein the frame parts 2a and 2b surrounds the coil 3 and guides the magnetic flux through the frame 41 of the anchor 4.

[0039] The pilot valve comprises an anchor 4, a high-pressure inlet channel 5, a low-pressure outlet channel 6, and a pilot control channel 7.

[0040] The main valve comprises main flow channels 8 and 9, and a poppet 10.

[0041] The anchor 4 of the pilot valve is formed from a frame part 41, to which frame part is fixedly connected a first sealing element 42 for closing the low-pressure outlet channel 6. In this embodiment the sealing element 42 is a ball bearing. The anchor 4 also comprises a second sealing element 43, which is also in this embodiment in form of a metal or ceramic ball and which is located partially inside the frame part 41 and connected to the first sealing element 42 with a spring 44.

[0042] The anchor 4 of the pilot valve is located in an anchor space 11 formed in the second frame material layer 2b vertically movably (upwards and downwards in the orientation of the FIG. 1). In the position of FIG. 1 the first sealing element 42 of the anchor closes the low-pressure outlet channel 6 and the high-pressure inlet channel 5 is open, which causes the high-pressure liquid in the pilot control channel 7 to force the poppet 10 of the main valve to keep the main flow channel 8 closed.

[0043] For opening the main valve, the coil 3 is energized for creating a magnetomotive force, which pulls the anchor 4 upwards towards and against the surface of the first material layer 2a of the frame. In this position the second sealing element 43 is forced to close the high-pressure inlet channel 5. Proper closing of the opening of the high-pressure channel 5 is guaranteed with the spring force of the spring 44, which allows relative movement of the second sealing element 43 in relation to the frame part 41 of the anchor 4. With the upward movement of the anchor 4, the first sealing element 42 opens the low-pressure outlet channel 6 thus causing the pressure in the pilot control channel 7 to drop. The pressure drop in the pilot control channel 7 allows the hydraulic pressure of the liquid in the main flow channels 8 and 9 to push the poppet 10 upwards thus opening the main valve and connecting the main flow channels 8 and 9, and allowing liquid to flow through the main valve.

[0044] For closing the main valve, the coil 3 is de-energized, which causes the magnetomotive force to drop, anchor 4 of the pilot valve is pushed downwards due to the hydraulic pressure in high-pressure inlet channel 5, the first sealing element 42 closes the low-pressure outlet channel 6, and the hydraulic pressure from the high-pressure inlet channel 5 causes the pressure in the pilot control channel 7 to increase, which causes the poppet 10 of the main valve to close the main flow channel 8.

[0045] In FIG. 2 is schematically shown an embodiment of a structure of an anchor 4 of the pilot valve for the hydraulic valve of the invention. In addition the parts already shown in FIG. 1, the frame part 41, the first sealing element 42, the second sealing element 43 and the spring 44, this figure illustrates channels 45, which helps the hydraulic pressure from the high-pressure inlet channel 5 (FIG. 1) to pass through the anchor 4 to the pilot control channel 7 (FIG. 1), when the pilot valve is open.

[0046] In FIG. 3 is schematically shown an alternative embodiment of a hydraulic valve 1′ of the invention. In this embodiment the valve structure is otherwise substantially same than in FIG. 1, but the frame of the valve is formed from only two frame material layers 2a and 2b, the coil 3 of the solenoid actuator is located below the anchor 4 of the pilot valve, and the structure of the pilot valve is turned to reversed horizontal orientation.

[0047] FIGS. 4A and 4B show schematically an embodiment of a valve block 21 comprising a plurality of, in this embodiment four, hydraulic valves of the invention connected to the channeling 22 of a larger valve unit. FIG. 4A shows the valve block 21 in perspective view, and FIG. 4B shows exploded view of the valve block 21 with a second, unexploded valve block 21 connected to the opposite side of the channeling 22.

[0048] In the valve block 21 there are four valves in a square formation located inside the valve block. The valve block 21 comprises a single frame 2, which is formed from three material layers 2a-2c. Inside the single frame 2 of the valve block 21 are formed rooms and channels for four hydraulic valves of the invention, in order to minimize the outer dimensions of the valve block.

[0049] FIG. 4B shows exploded view of the valve block 21 showing the internal key parts of the separate hydraulic valves of the invention. The hydraulic valves located inside the valve block 21 all have the same structural parts as discussed in relation to the embodiments of FIGS. 1 and 3, for example. In this embodiment, the coils 3 of the solenoid actuators are located around the spaces for anchors 4 within frame layer 2b, instead of being located in frame layer 2a as in the previously presented embodiments.

[0050] FIG. 5 shows schematically an embodiment of a digital valve system 20 comprising a plurality of hydraulic valves of the invention and with four metering edges. The valve system 20 is formed of eight pieces of valve blocks 21, each of the valve blocks comprising four hydraulic valves, such as shown in FIGS. 1 and 3 for example. The valve system 20 thus comprises 32 hydraulic valves of the invention. This valve system embodiment has preferably height of about 13 cm, which emphasizes the compactness of the hydraulic valves of the invention.

[0051] The specific exemplifying embodiments of the invention shown in figures and discussed above should not be construed as limiting. A person skilled in the art can amend and modify the embodiments described in many evident ways within the scope of the attached claims. Thus, the invention is not limited merely to the embodiments described above.