Load holding valve

Abstract

Disclosed is a hydraulic valve for an excavator, which can limit hydraulic load loss and valve deformation caused by overpressure. It has a valve block (1) made in one piece, in which a first pipe (13) connects two openings (3, 6), one of the openings (6) being arranged on the side (5) of the valve block, a second pipe (14) connects two other openings (7, 9), one of the openings (7) being arranged on the said side (5), and two other pipes (15, 16), which connect the first pipe (13) to the second pipe (14), wherein the connecting pipe (15) is close to the said side (5), while the other connecting pipe (16) is away from the said side (5) and extends along an inclined longitudinal axis so as to advance from the first pipe (13) to the second pipe (14) and approach the said side (5).

Description

Technical Field

[0001] The present invention relates to a hydraulic valve through which a pressurized fluid passes, in particular a hydraulic valve configured to operate at relatively high fluid flow rates (for example values on the order of up to several hundred liters per minute) and relatively high pressures (for example a fluid pressure of up to 420 bar). Background Art

[0002] Specifically, but not exclusively, the valve in question can be applied to earthmoving machines, in particular in order to support even very large suspended loads, such as for example the articulated arm of an excavator, and to hold the above-mentioned suspended load in a desired position for a set time interval, sometimes even several hours. The valve in question is supplied with a pressurized fluid and the pressurized fluid passes through the valve, which is sent to an actuator, which is typically a double-acting hydraulic cylinder, which in turn is connected to the load to be supported.

[0003] In particular, it refers to the valve according to the preamble of claim 1. Such a valve is shown, for example, by patent publication EP 2 549 124A2 in the name of the applicant.

[0004] Various aspects of the prior art valves are improvable.

[0005] First of all, it is desirable to limit the hydraulic load losses caused, for example, by the movement of the operating fluid within the hydraulic valve during load increase and / or decrease steps.

[0006] Furthermore, it is desirable to limit the deformations that the hydraulic valve may suffer when it is subjected to a sudden and considerable increase in the operating fluid (for example sometimes up to a pressure peak of about 1000 bar). Such overpressure, especially if it is repeated over time, can even lead to structural defects in the valve, such as for example the loosening of the closing elements of the openings arranged outside the valve block.

[0007] Additional disadvantages of the prior art valves include the risk of loss and leakage of the operating fluid. Summary of the Invention

[0008] An object of the present invention is to manufacture a valve capable of avoiding one or more of the disadvantages of the prior art.

[0009] An object of the present invention is to provide an alternative to the prior art hydraulic valves, in particular a type of hydraulic valve that can be used in earthmoving machines.

[0010] An advantage is to limit the hydraulic load losses caused by the movement of the operating fluid within the hydraulic valve.

[0011] An advantage is to limit the deformation of the components of the valve caused by a sudden and considerable increase in the pressure of the operating fluid.

[0012] One advantage is to provide a hydraulic valve that is particularly resilient and resistant to possible overpressure.

[0013] One advantage is to produce a hydraulic valve that can reduce or eliminate the risk of loss or leakage of the operating fluid.

[0014] One advantage is to provide a hydraulic valve with a simple and inexpensive structure.

[0015] The hydraulic valve according to one or more of the claim groups presented below achieves this and other advantages.

[0016] In one embodiment, the valve includes a valve block that is made in one piece, for example, by molding a molten material in a molding cavity, and internally includes a first conduit, a second conduit, and at least two connecting conduits. The first conduit connects two outer openings for transporting the operating fluid, one of which is arranged outside the valve block. The second conduit connects two other outer openings for transporting the operating fluid, one of which is arranged on the aforementioned outside of the valve block. Each of the at least two connecting conduits connects the first conduit to the second conduit. Among the connecting conduits, the proximal connecting conduit is closer to the aforementioned outside of the valve block, while the distal connecting conduit is farther from the aforementioned outside of the valve block. And among the connecting conduits, the distal connecting conduit extends along an axis that is inclined to advance from the first conduit to the second conduit close to the aforementioned outside of the valve block.

[0017] The longitudinal axis of the distal connecting conduit can particularly be in a curved shape, that is, inclined with a variable inclination that can be continuously and progressively changed.

[0018] The first conduit can particularly include a first end that is configured to receive a closing element for closing the valve, and the second conduit can particularly include a second end that is configured to receive a receiving element for receiving the valve. The proximal connecting conduit is particularly configured to communicate the first end and the second end with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention can be better understood and implemented with reference to the accompanying drawings, which illustrate embodiments of the present invention in a non-limiting example, in which:

[0020] Figure 1 is a transparent perspective view of an embodiment of a valve block for a hydraulic valve according to the present invention;

[0021] Figure 2 is Figure 1 a transparent view of the valve block in different perspectives;

[0022] Figure 3 is from Figure 1 a transparent view of the valve block seen from one side;

[0023] Figure 4 is Figure 1 a transparent bottom view of the valve block of

[0024] Figure 5 shows Figure 1 the bottom side view of the valve block of

[0025] Figure 6 and a cross-section along plane A-A according to the foregoing view; a series of cross-sections of the first pipe are shown, which are taken along a cross-section plane close to the first side of the valve block of Figure 1 and parallel to each other and close to the first opening (in the area marked A in the cross-section of Figure 5 );

[0026] Figure 7 a series of cross-sections of the first pipe are shown, which are taken along a cross-section plane close to the third side of the valve block of Figure 1 and parallel to each other in the pipe section between the first opening and the distal pipe (in the area marked B in the cross-section of Figure 5 );

[0027] Figure 8 a series of cross-sections of the distal pipe (in the area marked C in the cross-section of Figure 5 ) are shown, which are taken along a cross-section plane close to the first side of the valve block of Figure 1 and parallel to each other;

[0028] Figure 9 is Figure 1 a perspective transparent view of the valve block of

[0029] Figure 10 which has been further processed by cutting to obtain various pipes and openings; Figure 9 is

[0030] Figure 11 a transparent view of the valve block of Figure 9 in different perspectives; DETAILED DESCRIPTION

[0031] Referring to the foregoing drawings, the valve block of the hydraulic valve is generally designated by 1. The hydraulic valve can particularly include the following hydraulic valves, which can be used, for example, in earthmoving machines such as excavators.

[0032] The valve block 1 can be made integrally, for example, by molding molten material in a molding cavity. The valve block 1 can be manufactured particularly by melting and casting metal in a mold. The metal can particularly include cast iron or other materials that can be used in the casting process.

[0033] The valve block 1 may in particular include cavity devices obtained in the valve block 1 so as to define ducts and openings for conveying a pressurized fluid (liquid, in particular oil).

[0034] The valve block 1 may in particular include at least one first side 2 having at least one first opening 3. The first opening 3 may in particular be arranged to be in fluid connection with a hydraulic actuator. The first side 2 may in particular include a flat outer surface of the valve block 1.

[0035] The valve block 1 may in particular include at least one second side 4 opposite the first side 2. The second side 4 may in particular include a flat outer surface of the valve block 1. The second side 4 may in particular be parallel to the first side 2.

[0036] The valve block 1 may in particular include at least one third side 5 arranged between the first side 2 and the second side 4. The third side 5 may in particular have at least one second opening 6 and at least one third opening 7. The third side 5 may in particular include a flat outer surface of the valve block 1. The third side 5 may in particular be orthogonal to the first side 2. The third side 5 may in particular be orthogonal to the second side 4. The third side 5 may in particular be adjacent to the first side 2. The third side 5 may in particular be adjacent to the second side 4.

[0037] The valve block 1 may in particular include at least one fourth side 8 opposite the third side 5. The fourth side 8 may in particular have at least one fourth opening 9. The fourth side 8 may in particular include a flat outer surface of the valve block 1. The fourth side 8 may in particular be orthogonal and / or adjacent to the second side 4. The fourth side 8 may in particular be parallel to the third side 5.

[0038] The valve block 1 may in particular include at least one fifth side 10 opposite the third side 5. The fifth side 10 may in particular be configured such that the distance of the fifth side 10 from the third side 5 is greater than the distance of the fourth side 8 from the third side 5. The fifth side 10 may in particular include a flat outer surface of the valve block 1. The fifth side 10 may in particular be orthogonal and / or adjacent to the first side 2. The fifth side 10 may in particular be parallel to the third side 5.

[0039] The valve block 1 may in particular include at least one sixth side 11 opposite the first side 2. The sixth side 11 may in particular be arranged between the fourth side 8 and the fifth side 10. The sixth side 11 may in particular include a flat outer surface of the valve block 1. The sixth side 11 may in particular be orthogonal and / or adjacent to the fourth side 8. The sixth side 11 may in particular be orthogonal and / or adjacent to the fifth side 10. The sixth side 11 may in particular be parallel to the first side 2. The sixth side 11 may in particular be parallel to the second side 4.

[0040] The valve block 1 may in particular comprise at least two other sides 12 that face each other. Each of the two other sides 12 may in particular comprise a flat outer surface of the valve block 1. The first side 2 and / or the second side 4 and / or the third side 5 and / or the fourth side 8 and / or the fifth side 10 and / or the sixth side 11 may in particular be arranged between the two other sides 12. Each of the two other sides 12 may in particular be orthogonal and / or adjacent to the first side 2 and / or to the second side 4 and / or to the third side 5 and / or to the fourth side 8 and / or to the fifth side 10 and / or to the sixth side 11.

[0041] The valve block 1 may in particular comprise at least one first conduit 13 that connects the first opening 3 and the second opening 6 together. The first conduit 13 may in particular comprise at least one conduit portion (e.g., the conduit portion connected to the second opening 6) that extends along the length of the longitudinal axis of a rectilinear movement. The first conduit 13 may in particular comprise at least one conduit portion (e.g., the conduit portion connected to the first opening 3) that extends along the length of the longitudinal axis and has a variable inclination, which variable inclination in particular has several inclination changes or has a continuous inclination change along a curved longitudinal axis.

[0042] The valve block 1 may in particular comprise at least one second conduit 14 that connects the third opening 7 and the fourth opening 9 together. The second conduit 14 may in particular be provided with a longitudinal axis of rectilinear movement that extends over the entire length of the second conduit 14, such that the third opening 7 and the fourth opening 9 may be coaxial.

[0043] The valve block 1 may in particular comprise at least one connecting proximal conduit 15 for connecting the first conduit 13 and the second conduit 14 together. The proximal conduit 15 may in particular be arranged at a distance from the third side 5 that is less than the distance from the fourth side 8, i.e., the proximal conduit 15 may be closer to the third side 5 than to the fourth side 8.

[0044] The first conduit 13 may in particular comprise a first end 130 that is configured to receive a closing element (not shown) inserted into the second opening 6. The second conduit 14 may in particular comprise a second end 140 that is configured to receive a receiving element (not shown) inserted into the third opening 7. The proximal conduit 15 may in particular be configured to put the first end 130 and the second end 140 into communication with each other.

[0045] The closing element and the receiving element may in particular comprise the same closing element and the same receiving element as disclosed in the patent publication EP2549124A2 incorporated herein by reference (substantially in the same positions to perform substantially the same things). The proximal conduit 15 may in particular perform the same function as the connecting device 58 disclosed in the patent publication EP 2 549124A2 incorporated herein by reference.

[0046] The valve block 1 may in particular include at least one distal pipe 16 that connects the first pipe 13 and the second pipe 14. The distal pipe 16 may in particular be arranged at a distance from the third side 5 that is greater than the distance between the third side 5 and the proximal pipe 15. The proximal pipe 15 may in particular be arranged between the third side 5 and the distal pipe 16.

[0047] The valve block 1 may in particular include at least one intermediate pipe 17 that connects the first pipe 13 and the second pipe 14. The intermediate pipe 17 may in particular be arranged at an intermediate position between the proximal pipe 15 and the distal pipe 16.

[0048] As in the specifically illustrated embodiment, the distal pipe 16 may in particular be shaped and arranged such that, as it extends along the length of the longitudinal axis, the longitudinal axis is inclined so as to advance from the first pipe 13 towards the second pipe 14, approaching the third side 5.

[0049] The distal pipe 16 may in particular have a transition cross-section that decreases from the first pipe 13 to the second pipe 14 in such a way that, considering the passage cross-section taken in a cross-sectional plane parallel to the first side 2 (see in particular Figure 8 ), at least one transition cross-section that is closer to the first pipe 13 or further from the second pipe 14 has a larger area than at least one transition cross-section that is further from the first pipe 13 or closer to the second pipe 14.

[0050] The distal pipe 16 may in particular be shaped and arranged such that it extends along a longitudinal axis with a variable inclination, where the inclination means advancing towards the second pipe 14, approaching the third side 5. In particular, the inclination variability may be set such that at least one inclination near the first pipe 13 is greater than at least one inclination near the second pipe 14, as in the specifically illustrated embodiment. The inclination angle near the first pipe 13 (where the inclination angle means the angle formed by the longitudinal axis of the distal pipe 16 and the orthogonal line between the axes of the first pipe 13 and the second pipe 14) is relatively large (for example equal to or close to 90° or included between 40° and 90°), while the inclination angle near the second pipe 14 is relatively small (for example equal to or close to 0° or included between 30° and 0°).

[0051] The distal pipe 16 may in particular extend along a curved longitudinal axis with a continuous inclination change, as in the specifically illustrated embodiment. In fact, the longitudinal axis of the distal pipe 16 may be shaped as a gradual curve without sharp and / or discontinuous changes in the angle or inclination angle, with a smooth and progressive trend.

[0052] The first conduit 13 may in particular comprise at least one conduit portion 131 which is included between the first opening 3 and the distal conduit 16 and has a transition cross-section which is elliptical. This transition cross-section may in particular be taken in a cross-sectional plane parallel to the third side (see in particular Figure 7 , where in some cross-sections it can be seen that the shape of the transition cross-section of the first conduit 13 is in fact elliptical). In this context, "elliptical" means a dimension which is greater than the other dimensions. This greater dimension may in particular extend in a direction orthogonal to at least one of the two other sides 12 mentioned above.

[0053] As illustrated herein in a particular embodiment, the second side 4 may be completely enclosed by the material of the valve block 1, such that in this embodiment the second side 4 has no opening which communicates with the second conduit 14.

[0054] As illustrated herein in a particular embodiment, the fifth side 10 may be completely enclosed by the material of the valve block 1, such that in this embodiment the fifth side 10 has no opening which communicates with the first conduit 13.

[0055] As illustrated herein in a particular embodiment, the sixth side 11 may be completely enclosed by the material of the valve block 1, such that in this embodiment the sixth side 11 has no opening which communicates with the first conduit 13.

[0056] The second conduit 14 may in particular comprise a recess 18 which is recessed into the second side 4 and is arranged opposite the port of the distal conduit 16 which opens into the second conduit 14.

[0057] The first conduit 13 may in particular comprise at least one connecting portion 132 which is connected to the first opening 3 and extends at least partly along an inclined longitudinal axis, the inclined longitudinal axis in particular having a variable inclination. The longitudinal axis of the connecting portion 132 mentioned above may in particular be curved in the case of a continuous change in inclination.

[0058] The portion of the valve block 1 which is delimited by the sixth side 11, i.e. the projecting portion which projects from the rest of the valve block 1, may in particular be configured to connect the valve block 1 to the machine (such as an excavator) on which the valve operates. In the projecting portion, a plurality of through-holes 22 may be formed, which are adapted to receive mechanical fixing means, such as screws, for connecting the valve block 1 to the machine. The projecting portion projects from the rest of the valve block 1 such that the valve block 1 is substantially "L"-shaped when viewed from the side.

[0059] The hydraulic valve may in particular comprise various elements (not shown) which may be associated with the valve block 1. The hydraulic valve may for example comprise a receiving element which is in particular identical to the receiving element 16 disclosed in EP 2 549 124 A2. The hydraulic valve may for example comprise a closing element which is in particular identical to the closing element 14 disclosed in EP 2 549 124 A2.

[0060] The hydraulic valve may for example include a sealing device, in particular the same as the sealing device 64 disclosed in EP 2 549 124 A2, which is received in the outer side wall of the receiving element.

[0061] The hydraulic valve may for example include other sealing devices, in particular the same as the other sealing devices 66 disclosed in EP 2 549 124 A2, which are received in the outer side wall of the closing element.

[0062] The hydraulic valve may for example include a guiding piston, in particular the same as the guiding piston 37 disclosed in EP 2 549 124 A2, which is received in the second conduit 14.

[0063] In Figures 9 to 11 it shows the valve block 1 in the foregoing figures, which is made by melting and casting metal in a forming cavity of a mold and can be further processed by cutting to obtain various conduits and openings, which can be obtained in the body of the valve block 1 to become part of the hydraulic valve.

[0064] The hydraulic valve may for example include at least one feeding opening 19 arranged on at least one of the two other sides 12. The feeding opening 19 may in particular be the same as the feeding opening disclosed in EP 2 549 124 A2 and marked with the reference numeral 3.

[0065] The hydraulic valve may for example include at least one guiding opening 20 arranged on at least one of the two other sides 12. The guiding opening 20 may in particular be the same as the guiding opening 4 disclosed in EP 2 549 124 A2.

[0066] The hydraulic valve may for example include at least one discharge opening 21 arranged on at least one of the two other sides 12. The discharge opening 21 may in particular be the same as the discharge opening 5 disclosed in EP 2 549 124 A2.

[0067] The hydraulic valve may for example include a through hole 22, which is configured to receive a fixing device of, for example, screw type to fix the hydraulic valve to a machine. The through hole 22 may in particular be the same as the through hole 7 disclosed in EP 2 549 124 A2.

[0068] The hydraulic valve may further include other auxiliary through holes or blind holes, which are not numbered for simplicity.

[0069] The patent publication EP 2 549 124 A2 is incorporated herein by reference.

[0070] In one use configuration of the valve under discussion, the first opening 3 can be connected to a hydraulic actuator, the injection port 19 can be connected to a hydraulic supply (such as a hydraulic pump, especially via a hydraulic distributor), the guiding opening 20 can be connected to a guiding line, and the discharge port 21 can be connected to a drain pipe. The hydraulic control circuit of the hydraulic actuator can in particular be the same as that disclosed in Figure 5 reference EP 2 549124A2.

[0071] The valve block 1 is capable of manufacturing a hydraulic valve, especially a type of hydraulic valve that can be used, for example, in earthmoving machines, in which the hydraulic load losses caused by the movement of the liquid flowing in the valve are significantly limited.

[0072] It has also been determined that, due to the joining of the valve block 1 to form the hydraulic valve under discussion, the deformation of the components of the valve that may be caused by a sudden and considerable increase in the operating fluid pressure is also limited.

[0073] In addition to being able to reduce or eliminate the risk of operating liquid losses or leaks, the valve block 1 can also make the hydraulic valve to be manufactured particularly tough and resistant to possible overpressure.

Claims

1. A hydraulic valve, comprising a valve block (1), the valve block being integrally formed and provided with cavities to define conduits and openings for the passage of liquid under pressure, the valve block comprising: - a first side (2), the first side having a first opening (3); - a second side (4), the second side being opposite to the first side (2); - a third side (5), the third side being disposed between the first side (2) and the second side (4) and having a second opening (6) and a third opening (7); - a fourth side (8), the fourth side being opposite to the third side (5) and having a fourth opening (9); - a fifth side (10), the fifth side being opposite to the third side (5) and being configured such that the distance of the fifth side (10) from the third side (5) is greater than the distance of the fourth side (8) from the third side (5); - a sixth side (11), the sixth side being opposite to the first side (2) and being disposed between the fourth side (8) and the fifth side (10); - two other sides (12), the two other sides being opposite to each other and the first side, the second side, the third side, the fourth side, the fifth side and the sixth side being disposed between the two other sides; - a first conduit (13), the first conduit connecting the first opening (3) and the second opening (6) to each other; - a second conduit (14), the second conduit connecting the third opening (7) and the fourth opening (9) to each other; - a proximal conduit (15), the proximal conduit connecting the first conduit (13) and the second conduit (14) to each other and being disposed at a distance from the third side (5) less than the distance from the fourth side (8); - a distal conduit (16), the distal conduit connecting the first conduit (13) and the second conduit (14) to each other and being disposed at a distance from the third side (5) greater than the distance between the third side (5) and the proximal conduit (15); characterized in that the distal conduit (16) extends along a longitudinal axis, the longitudinal axis being inclined so as to advance from the first conduit (13) to the second conduit (14), approaching the third side (5), wherein the distal conduit (16) has a passage cross-section that decreases from the first conduit (13) to the second conduit (14), whereby, considering the passage cross-section taken in a cross-sectional plane parallel to the first side (2), at least one passage cross-section closer to the first conduit (13) or further from the second conduit (14) has a larger area than at least one passage cross-section further from the first conduit (13) or closer to the second conduit (14).

2. The valve according to claim 1, wherein the distal conduit (16) extends along a longitudinal axis with a variable inclination, where "inclination" means approaching the third side (5) such that at least one inclination closer to the first conduit (13) is greater than at least one inclination closer to the second conduit (14).

3. The valve according to claim 2, wherein the distal pipe (16) extends with a curved longitudinal axis having a continuous inclination change.

4. The valve according to any one of claims 1-3, wherein the first pipe (13) includes at least one pipe portion (131) that is included between the first opening (3) and the distal pipe (16) and has an elongated passage cross-section that is intercepted in a cross-sectional plane parallel to the third side (5), where "elongated" means having a dimension that is greater than the other dimensions in the passage cross-section, and the largest of the dimensions of the passage cross-section extends in a direction orthogonal to at least one of the two other sides (12).

5. The valve according to any one of claims 1-3, wherein the second side (4) is closed by the material of the valve block (1) such that the second side (4) has no opening communicating with the second pipe (14).

6. The valve according to any one of claims 1-3, wherein the fifth side (10) is closed by the material of the valve block (1) such that the fifth side (10) has no opening communicating with the first pipe (13).

7. The valve according to any one of claims 1-3, wherein the sixth side (11) is closed by the material of the valve block (1) such that the sixth side (11) has no opening communicating with the first pipe (13).

8. The valve according to any one of claims 1-3, wherein the second pipe (14) includes a recess (18) that is recessed toward the second side (4) and is disposed before the port where the distal pipe (16) flows into the second pipe (14).

9. The valve according to any one of claims 1-3, wherein the first pipe (13) includes at least one connecting portion (132) that terminates at the first opening (3) and extends with an inclined longitudinal axis.

10. The valve according to claim 9, wherein the at least one connecting portion (132) extends with an inclined longitudinal axis having a variable inclination.

11. The valve according to claim 10, wherein the longitudinal axis of the connecting portion (132) bends with a continuously changing inclination.

12. The valve according to any one of claims 1-3, wherein the valve block (1) includes an intermediate pipe (17) that connects the first pipe (13) and the second pipe (14) to each other and is disposed between the proximal pipe (15) and the distal pipe (16).

13. The valve according to any one of claims 1-3, wherein the first pipe (13) includes a first end (130) that is configured to receive a closure element inserted into the second opening (6).

14. The valve according to claim 13, wherein the second conduit (14) includes a second end (140) configured to receive a receiving element inserted into the third opening (7), and the proximal conduit (15) is configured to communicate the first end (130) and the second end (140) with each other.

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