Control valve with radial recesses in the region of a first orifice plate and a second orifice plate

Abstract

This invention relates to a regulating valve with a housing having a first borehole, wherein a control slide is movably accommodated along a longitudinal axis in the first borehole, wherein the control slide defines an adjustable first orifice plate and a second orifice plate. According to the invention, a first reference plane and a second reference plane are respectively oriented perpendicular to the longitudinal axis, wherein the first reference plane is defined by a first control edge, i.e., defined in a position where the first orifice plate is exactly closed; wherein the second reference plane is defined by a second control edge, i.e., defined in a position where the second orifice plate is exactly closed; wherein at least one radial notch, different from the second borehole, is provided at the first borehole along the direction of the longitudinal axis between the first and second reference planes.

Description

Technical Field

[0001] The present invention relates to a regulating valve according to the preamble of claim 1 and a structural assembly having such a regulating valve. Background Technology

[0002] A regulating valve is known from EP 1 409 873 B1 for regulating a hydraulic press. The hydraulic press—for example, implemented as an axial piston machine with a slant-axis configuration—has a single-acting regulating cylinder whose discharge volume can be adjusted. The regulating valve has a first and second orifice plate (Blende) that are reversibly adjustable by a control slide, wherein the first and second orifice plates are connected to the regulating cylinder. Here, the control slide is accommodated about the longitudinal axis in a first borehole in the housing. The control slide has a first control edge and a second control edge, which are respectively annularly arranged around the longitudinal axis, wherein the first and second control edges are spaced apart from each other along the longitudinal axis. The first and second control edges interact with a second borehole—which penetrates the first borehole transversely to the longitudinal axis—to construct the first and second orifice plates. This very simple and inexpensive design of using a slide valve at the two control slides of a known regulating valve allows the invention to be used in both cases.

[0003] The disadvantage of the low-cost design explained above is that the opening characteristics of the first and second orifice plates cannot be influenced by the fine-adjustment grooves at the control slide, as known for example from DE 42 24 469 A1. This is primarily due to the lack of available space. Furthermore, to guarantee the defined opening characteristics in the aforementioned non-rotationally symmetric design, the rotational position of the control slide must be determined about the longitudinal axis. This adversely affects the reliability of the regulating valve. Summary of the Invention

[0004] The advantage of the valve according to the invention is that the opening characteristics of the first orifice plate and the second orifice plate can be finely adjusted with minimal effort. Although the first orifice plate and the second orifice plate are not rotationally symmetrical in general, a torsion stop for the control slide is not required.

[0005] Claim 1 proposes that: a first reference plane and a second reference plane are respectively oriented perpendicular to the longitudinal axis, wherein the first reference plane is defined by the first control edge, i.e., defined in the position where the first orifice plate or the first throttling orifice is exactly closed, wherein the second reference plane is defined by the second control edge, i.e. defined in the position where the second orifice plate or the second throttling orifice is exactly closed, wherein at least one radial notch different from the second borehole is provided at the first borehole along the direction of the longitudinal axis between the first reference plane and the second reference plane.

[0006] Preferably, neither the first reference plane nor the second reference plane touches or intersects with the aforementioned radial notch. A single radial notch is preferably provided. The first control edge and the second control edge are preferably constructed in an annular manner about the longitudinal axis, wherein the first control edge and the second control edge are most preferably completely contained within the first reference plane or the second reference plane. The second borehole is preferably cylindrical. The second borehole is preferably implemented as a blind hole penetrating the first borehole. The control slide is preferably implemented rotationally symmetrically about the longitudinal axis, at least in the regions of the first control edge and the second control edge. The first and second orifice plates preferably have negative overlap. That is, there exists a small position range of the control slide in which not only the first orifice plate but also the second orifice plate is minimally opened. The radial notch according to the invention preferably does not function substantially within the mentioned position range. Preferably, the radial notch according to the invention only functions when either the first orifice plate or the second orifice plate is completely closed.

[0007] Advantageous improvements and modifications of the invention are described in the dependent claims.

[0008] The volume that can be set—the radial notch extending beyond the cylinder defined by the first borehole—is chosen so small that it causes a reduction in flow resistance to either the first or second orifice plate depending on the position of the control slide, the reduction not exceeding 50% of the corresponding flow resistance in any position of the control slide without the radial notch. This results in a particularly compact control valve. The radial notch can be smoothly integrated into the overall control valve.

[0009] It is possible to configure the radial notch to be formed by a third borehole in the housing, the third borehole extending transversely to the longitudinal axis, wherein the diameter of the third borehole is smaller than the diameter of the first borehole. This embodiment can be manufactured particularly simply. Preferably, the third borehole is cylindrical. The third borehole is preferably implemented as a blind hole, and most preferably, the open side of the blind hole is closed with a plug. The second borehole and the third borehole are preferably staggered from each other by an amplitude of 90° about rotation about the longitudinal axis.

[0010] It is possible to configure the radial notch to be formed by a groove in the housing, the groove having a constant cross-sectional shape and surrounding the longitudinal axis in an annular manner. It is conceivable that not only the groove but also the third borehole are configured as radial notches. The cross-sectional shape of the groove can be chosen with considerable freedom, thereby allowing for flexible configuration of the opening characteristics of the first and second borehole plates. Furthermore, the groove requires minimal structural space.

[0011] It is possible to configure the cross-sectional shape to have a first inclined segment and a second inclined segment, the first and second inclined segments being inclined in opposite directions about the longitudinal axis, wherein the first and second inclined segments are arranged adjacent to each other in the region of the maximum depth of the trench. The inclination of the first and second inclined segments can effectively influence the flow direction within the trench. The inclination also subsequently affects the opening characteristics of the first and second orifice plates. The first and / or second inclined segments preferably terminate at the first borehole. The corresponding transitions can be implemented with sharp edges, wherein other transitions are explained below.

[0012] It is possible to configure the first inclined segment and / or the second inclined segment to be constructed in a straight line. They can therefore be manufactured particularly easily.

[0013] It can be set that the inclination of the first inclined section and / or the second inclined section relative to the longitudinal axis is between 5° and 45°. The applicant's experiments have shown that the adjustment characteristics with this design are particularly advantageous. The mentioned inclination angle is, for example, 38°.

[0014] It can be configured such that the transition between the first inclined section or the second inclined section and the first borehole is constructed in a rounded or beveled manner. This avoids bending in the opening characteristics of the first or second borehole plate.

[0015] It can be configured such that the control slide has a third neck section with a reduced diameter relative to the first borehole, wherein the third neck section is arranged between the first control edge and the second control edge. Particularly in the connection with the first and second inclined sections, this allows the helical forces acting on the control slide along the longitudinal axis to be balanced. These helical forces adversely affect the regulating characteristics of the control valve.

[0016] Furthermore, protection is required for structural components with regulating valves according to the invention, wherein the second borehole is permanently connected to the regulating cylinder of the hydraulic press, wherein the discharging volume of the hydraulic press can be set by means of the regulating cylinder, wherein the first orifice plate is permanently connected to a pressure fluid source, and wherein the second orifice plate is permanently connected to a pressure fluid recess. The hydraulic press is preferably a hydraulic pump or a hydraulic motor, wherein alternating operation of the two modes is feasible. The hydraulic press can be implemented as an axial piston machine in the form of a swashplate configuration or a swashplate configuration. The pressure fluid source can be the high pressure of the hydraulic press or a pressure derived therefrom. A separate control oil pump can be configured as the pressure fluid source. The pressure fluid recess preferably consists of a substantially unpressurized tank from which the hydraulic press draws pressure fluid. The pressure fluid is preferably a liquid and most preferably hydraulic oil. The high pressure should be understood as a higher pressure at the two working joints of the hydraulic press. In the case of a 4-quadrant-capacity hydraulic press, the high pressure can be provided by means of a directional valve connected to the two aforementioned working joints. The regulating cylinder is preferably implemented as a single-acting cylinder.

[0017] The adjustable valve is a component of the regulating circuit, and the regulating value of the regulating circuit is the opening cross-section of the first orifice plate or the second orifice plate. The regulating differential of the regulating circuit is achieved through force balance along the longitudinal axis at the control slide. The regulating circuit can induce a pressure regulation, wherein the high pressure of the hydraulic press loads the control slide in one direction, and a pre-tensioned spring loads the control slide in the opposite direction. The regulating circuit can induce a flow regulation.

[0018] It goes without saying that, without departing from the scope of the invention, the features mentioned above and to be explained below can be used not only in the combinations described, but also in other combinations or individually. Attached Figure Description

[0019] The invention will now be explained in more detail with reference to the accompanying drawings. Wherein:

[0020] Figure 1 A rough schematic cross-sectional view of a structural assembly with a regulating valve according to a first embodiment of the invention is shown;

[0021] Figure 2 A cross-sectional view of a regulating valve according to a second embodiment of the present invention is shown; and

[0022] Figure 3 A cross-sectional view of a regulating valve according to a third embodiment of the present invention is shown.

[0023] List of reference numerals

[0024] x controls the travel of the slider.

[0025] 10 Structural Components

[0026] 11 Hydraulic Press

[0027] 12 Adjusting cylinder

[0028] 13 Pressure Fluid Groove

[0029] 14. Pressure Fluid Source

[0030] 20. Control valve (first embodiment)

[0031] 20' Control valve (second embodiment)

[0032] 20'' Control Valve (Third Embodiment)

[0033] 21 First Hole Plate

[0034] 22 Second Hole Plate

[0035] 23. Longitudinal axis

[0036] 30 Casing

[0037] 31 First Drill Hole

[0038] 32 Second Drill Hole

[0039] 32a Blind hole section of the second borehole

[0040] 33 Third Drill Hole

[0041] 33a Blind hole section of the third borehole

[0042] 34. Plug (at the third borehole)

[0043] 35 Grooves

[0044] 40 Control slider

[0045] 41 First Control Edge

[0046] 42 Second Control Edge

[0047] 51 First neck section

[0048] 52 Second neck section

[0049] 53 Third neck section

[0050] 60 Radial notch

[0051] 61 First inclined section

[0052] 62 The second inclined section

[0053] 63. Cylindrical section

[0054] 64 Rounded part

[0055] 71 First Reference Plane

[0056] 72 Second reference plane. Detailed Implementation

[0057] Figure 1 A rough schematic cross-sectional view of a structural assembly 10 with a regulating valve 20 according to a first embodiment of the invention is shown. The structural assembly 10 includes, for example, a hydraulic press 11 implemented as an axial piston machine in a swashplate configuration. The hydraulic press 11 has a continuously adjustable discharge volume, which can be adjusted using a regulating cylinder 12. The regulating cylinder 12 is currently configured as a single-acting cylinder. The regulating pressure provided by the regulating valve 20, for example, causes a decrease in the discharge volume, while the hydraulic force within the hydraulic press 11 causes an increase in the discharge volume. The hydraulic press 11 draws pressurized fluid from a pressurized fluid reservoir 13 in the form of a tank and delivers the pressurized fluid to at least one hydraulic actuator (not shown). The pressurized fluid is preferably a liquid and most preferably hydraulic oil. Figure 1 All tank markings indicate the same tank.

[0058] The regulating valve 20 has a housing 30 in which a control slide 40 is linearly movably accommodated along a longitudinal axis 23. For this purpose, the control slide 40 is accommodated in a first borehole 31, which is cylindrical about the longitudinal axis 23 and fluid-tightly fitted to the control slide 40. The control slide 40 can be constituted by at least one of the two valve pistons in EP 1 409 873 B1, wherein it is preferably constituted by a valve piston directly connected to the regulating cylinder. The entire contents of EP 1 409 873 B1 are incorporated herein by reference.

[0059] The control slide 40 has first, second, and third neck sections 51, 52, and 53, each having a reduced diameter relative to the first borehole 31 to allow pressurized fluid to flow in the resulting free space. An optional third neck section 53 is arranged along the longitudinal axis 23 between the first neck section and the second neck sections 51 and 52. The first neck section 51 forms a first control edge 41 at the control slide 40, the first control edge annularly surrounding the longitudinal axis 23. Figure 1 In the position shown—in which not only the first orifice plate but also the second orifice plate 21; 22 are exactly closed—the first control edge 41 is fully arranged in the first reference plane 71, which is oriented perpendicularly to the longitudinal axis 23. It should be noted here that, for clarity, Figure 1 A regulating valve 20 is shown that has neither positive nor negative zero overlap, such that the first orifice plate and the second orifice plate 21; 22 are exactly closed in the same position of the control slide 40. However, negative zero overlap is preferred, in which the first orifice plate and the second orifice plate 21; 22 are simultaneously and minimally opened within a small adjustment range of the control slide 40. The first reference plane or the second reference plane 71; 72, as defined in the claims, thus describes two minimally different positions of the control slide 40. The stroke x of the control slide is preferably in Figure 1 The origin of the travel is shown in the position shown or in the following positions: in which the first orifice plate and the second orifice plate 21; 22 are opened to the same extent.

[0060] The second neck section 52 defines a second control edge 42 at the control slider 40, the second control edge being annularly arranged around the longitudinal axis 23. When the second orifice plate 22 is just closed, the second control edge 42 is fully positioned within the second reference plane. Further reference below... Figure 3 To explain the optional third neck segment 53 and its function.

[0061] The housing 30 has a second borehole 32, which is currently oriented exactly perpendicular to the longitudinal axis 23, wherein the central axes of the first borehole and the second borehole 31; 32 intersect. In principle, it is sufficient that the second borehole 32 extends into the first borehole 31 such that the corresponding shear edge (Verschneidungskante) together with the first control edge or the second control edge 41; 42 forms the first or second orifice plate 21; 22. The second borehole 32 currently penetrates the first borehole 31 such that the second borehole forms a blind hole segment 32a. Correspondingly, there are two shear edges among the aforementioned shear edges, wherein the two shear edges work together with the first control edge or the second control edge 41; 42 to form the first orifice plate 21; 22. The diameter of the second borehole 32 is preferably implemented to be smaller than the diameter of the first borehole 31.

[0062] The first neck section 51 is preferably connected to a pressure fluid source 14, which can be, for example, a control oil pump. Therefore, the first orifice plate 21 influences the pressure fluid flowing to the regulating cylinder 12. The second neck section 52 is preferably connected to a pressure fluid recess 13, which can be, for example, a storage tank as mentioned above. Therefore, the second orifice plate 22 influences the pressure fluid flowing back from the regulating cylinder 12.

[0063] In a first embodiment of the invention, the radial notch 60 is formed by a groove 35 that surrounds the longitudinal axis 23 in an annular manner at the inner circumferential surface of the first borehole 31. The groove 35 is completely arranged between the first reference plane and the second reference planes 71; 72, wherein the groove preferably has a small spacing relative to the two reference planes 71; 72. This means that the groove 35 is interrupted in the circumferential direction by two shear edges mentioned above. Accordingly, the groove affects the opening characteristics of the first and second orifice plates 21; 22. The opening characteristics should be understood as the relationship between the stroke x of the control slide 40 and the flow resistance or open cross-sectional area of ​​the first orifice plate or the second orifice plate 21; 22.

[0064] The cross-sectional shape of the groove 35 is preferably constructed consistently over the entire periphery of the groove. The cross-sectional shape has a first inclined section and a second inclined section 61; 62, respectively implemented in a straight line, wherein it is adjacent to the first reference plane or the second reference plane 71; 72 with a sharp edge and a rounded portion (see reference). Figure 3Alternatively, a chamfer can be used to transition into the first borehole 31. In the first embodiment, the first inclined section and the second inclined section 61; 62 have relatively small inclinations, such that the first inclined section and the second inclined section form a common edge in the middle of the groove 35, the common edge circumferentially surrounding the longitudinal axis 23. When the first inclined section and the second inclined section are more sharply inclined (see...), Figure 3 The groove can have a cylindrical section in the middle (in Figure 3 (China No. 63).

[0065] The precise cross-sectional shape of the groove 35—especially the inclination of the first inclined section and the second inclined sections 61; 62, as well as the open cross-sectional area of ​​the groove 35—is preferably obtained by experiment or simulation to determine the desired regulating characteristics of the regulating valve 20.

[0066] Figure 2 A cross-sectional view of a regulating valve 20' according to a second embodiment of the invention is shown. The second embodiment is implemented identically to the first embodiment, except for the differences described below, so that reference in this regard is made to the following description of... Figure 1 The implementation plan. Figure 1 and Figure 2 Identical or corresponding parts are indicated by the same reference numerals.

[0067] In the second embodiment, the radial notch 60 is formed not by a surrounding groove but by a third borehole 33. Figure 2 The cross-sectional plane is oriented perpendicularly to the longitudinal axis 23, wherein the cross-sectional plane includes the central axes of the second borehole and the third boreholes 32, 33. Accordingly, the two central axes are arranged in the same plane. The two central axes are preferably staggered from each other by an angle of 90° with respect to the longitudinal axis 23. The third borehole 33 penetrates the first borehole 31, i.e., similar to the second borehole 32. The third borehole 33 is implemented as a blind hole, wherein the third borehole forms a blind hole section 33a that extends beyond the first borehole 31. The diameter of the third borehole 33 is implemented to be smaller than the diameter of the first borehole 31, i.e., particularly in the range where the first borehole and the third borehole 31; 33 intersect. The third borehole 33 is sealed outwardly with a plug 34, wherein the plug 34 is constructed, for example, as a countersunk bolt.

[0068] Similar to the second drill hole 32, the third drill hole 33 forms two shear edges with the first drill hole 31. These shear edges also coincide with the first and second control edges at the control slide 40 (in... Figure 1 The numbers 41 and 42 in the diagram interact to affect the opening characteristics of the first and second orifice plates, such that their opening cross-sections are increased relative to the state without the third borehole 33, i.e., increased at each position of the control slide 40.

[0069] The second embodiment can be combined with the first or third embodiment.

[0070] Figure 3 A cross-sectional view of a regulating valve 20'' according to a third embodiment of the invention is shown. This third embodiment is implemented identically to the first embodiment, except for the differences described below, and thus, for this purpose, reference is made to... Figure 1 The implementation plan. Figure 1 and Figure 3 Identical or corresponding parts are indicated by the same reference numerals.

[0071] First, the inclination of the first inclined section and the second inclined sections 61 and 62 relative to the longitudinal axis 23 is greater than that implemented in the first embodiment. These two inclinations are preferably implemented in equal numbers. To prevent the volume of the recess 60 from becoming excessively large, a cylindrical section 63 is provided between the first inclined section and the second inclined sections 61 and 62.

[0072] The increased inclination of the first inclined section or the second inclined sections 61; 62 particularly causes a portion of the pressurized fluid flowing through the first orifice plate or the second orifice plate to be diverted into the third neck section 53. There, the pressurized fluid generates a force acting on the control slide 40 along the longitudinal axis 23. Preferably, the inclination is designed such that all the hemodynamic forces acting on the control slide 40 along the longitudinal axis 23 are canceled out as completely as possible. For this purpose, the inclination, as well as the depth and width of the third neck section, can also be varied.

[0073] Furthermore, in the third embodiment, the transition from the first borehole 31 to the first inclined section or the second inclined section 61; 62 is implemented as a rounded portion 64. It goes without saying that this measure can also be applied to the first embodiment.

Claims

1. A regulating valve (20; 20'; 20”) with a housing (30), said housing having a first bore (31), wherein, A control slide (40) is movably accommodated in the first borehole (31) along a longitudinal axis (23), wherein the control slide (40) has a first neck section and a second neck section (51; 52), the first neck section and the second neck section having a reduced diameter relative to the first borehole (31), wherein the control slide (40) abuts against the first borehole (31) in a sealing manner between the first neck section and the second neck section (51; 52), wherein it defines a first control edge and a second control edge (41; 42) therein, the first control edge and the second control edge being spaced apart from each other along the longitudinal axis (23) and the first control edge and the second control edge being circumferentially surrounding the longitudinal axis (23), wherein the housing (30) has a second borehole (32) extending transversely to the longitudinal axis (23) into the first borehole (31) such that the second borehole (32) is adjacent to the first control edge. Together with the second control edge (41; 42), a first orifice plate and a second orifice plate (21; 22) are defined, the first orifice plate and the second orifice plate being adjustable by movement of the control slide (40), characterized in that a first reference plane and a second reference plane (71; 72) are respectively oriented perpendicular to the longitudinal axis (23), wherein the first reference plane (71) is defined by the first control edge (41), i.e., defined in the position of the control slide (40) in which the first orifice plate (21) is closed; wherein the second reference plane (72) is defined by the second control edge (42), i.e. defined in the position of the control slide (40) in which the second orifice plate (22) is closed; wherein at least one radial notch (60) different from the second borehole (32) is provided at the first borehole (31) along the direction of the longitudinal axis (23) between the first reference plane and the second reference plane (71; 72).

2. The regulating valve (20; 20'; 20") according to claim 1, characterized in that, The following volume—the radial notch (60) extending beyond the cylinder defined by the first borehole (31)—is chosen to be so small that it causes a reduction in the flow resistance to the first orifice plate or the second orifice plate (21; 22) depending on the position of the control slide (40), such reduction not exceeding 50% of the corresponding flow resistance in the absence of the radial notch (60) in any position of the control slide (40).

3. The regulating valve (20') according to claim 1 or 2, wherein, The radial notch (60) is formed by a third borehole (33) in the housing (30), the third borehole extending transversely to the longitudinal axis (23), wherein the diameter of the third borehole (33) is smaller than the diameter of the second borehole (32).

4. The regulating valve (20; 20”) according to claim 1 or 2, wherein, The radial notch (60) is formed by a groove (35) in the housing (30) surrounding the longitudinal axis (23) in an annular manner with a constant cross-sectional shape.

5. The regulating valve (20; 20”) according to claim 4, wherein, The mentioned cross-sectional shape has a first inclined section and a second inclined section (61; 62), the first inclined section and the second inclined section are inclined in opposite directions about the longitudinal axis (23), wherein the first inclined section and the second inclined section are arranged adjacent to each other in the region of the maximum depth of the trench (35).

6. The regulating valve (20; 20”) according to claim 5, wherein, Construct the first inclined segment and / or the second inclined segment (61; 62) in a straight line.

7. The regulating valve (20; 20”) according to claim 6, wherein, The inclination of the first inclined section and / or the second inclined section (61; 62) relative to the longitudinal axis (23) is between 5° and 45°.

8. The regulating valve (20”) according to any one of claims 5 to 7, wherein, The transition between the first inclined section or the second inclined section (61; 62) and the first borehole (31) is constructed in a rounded (64) or oblique cut manner.

9. The regulating valve (20; 20”) according to claim 1 or 2, wherein, The control slide (40) has a third neck section (53) with a reduced diameter relative to the first borehole (31), wherein the third neck section (53) is arranged between the first control edge and the second control edge (41; 42).

10. A structural component (10) having a regulating valve (20; 20'; 20") according to any one of the preceding claims, wherein, The second borehole (32) is permanently connected to the regulating cylinder (12) of the hydraulic press (11), wherein the discharging volume of the hydraulic press (11) can be adjusted by means of the regulating cylinder (12), wherein the first orifice plate (21) is permanently connected to the pressure fluid source (14), and wherein the second orifice plate (22) is permanently connected to the pressure fluid groove (13).

11. The structural component (10) according to claim 10, wherein, The regulating valve (20; 20'; 20”) is a component of the adjustment circuit, the adjustment value of which is the open cross section of the first orifice plate or the second orifice plate (21; 22), wherein the adjustment difference of the adjustment circuit is formed by force balance along the longitudinal axis (23) at the control slider (40).

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