Fast-Switching 2/2-Way Cartridge Valve

Abstract

In a fast-switching 2/2-way cartridge valve, which can serve as a check valve, a closing movement of the closing body thereof is damped by contact portions which lie on one another and are movable in relation to one another during the closing movement. The contact portions are formed on the closing body and on the valve bore in which the closing body is guided.

Claims

1. A fast-switching 2/2-way cartridge valve of poppet valve design comprising: a control spool; a valve housing in which the control spool is guided, the valve housing including a first seat ring for the control spool; and a damping arrangement for a closing movement of the control spool, the damping arrangement including an outer casing portion of the control spool and an inner casing portion of the valve housing.

2. The cartridge valve according to claim 1, wherein said cartridge valve is a check valve.

3. The cartridge valve according to claim 1, wherein: the valve housing is configured as a sleeve, is tubular, or is a sleeve or a tube at least in sections; and the inner casing portion is formed at an end portion of the valve housing, said end portion lying opposite a seat region of the cartridge valve.

4. The cartridge valve according to claim 1, wherein the inner and outer casing portions of the damping arrangement are conical.

5. The cartridge valve according to claim 1, wherein the inner and outer casing portions of the damping arrangement are circular-cylindrical.

6. The cartridge valve according to claim 1, further comprising: a high pressure port; and a low pressure port, wherein an overlap between the valve housing and the control spool is configured to close or shut-off a connection between the high pressure port and the low pressure port.

7. The cartridge valve according to claim 6, wherein: the control spool includes a second seat ring; the first and second seat rings are conical; and the overlap is formed by a control-spool-side overlapping portion adjacent to the second seat ring of the control spool and by a valve-housing-side overlapping portion adjacent to the first seat ring of the valve housing.

8. The cartridge valve according to claim 7, wherein: the high pressure port is formed by radial bores defined in the valve housing; and the valve-housing-side overlapping portion is arranged between the first seat ring of the valve housing and the radial bores.

9. The cartridge valve according to claim 1, wherein the control spool defines a through recess via which two mutually opposite end sides of the control spool are connected to each other.

10. The cartridge valve according to claim 9, wherein the through recess has a radius at a narrowest point of the through recess that is at least 45% of a second radius of the control spool.

11. The cartridge valve according to claim 10, wherein the narrowest point of the through recess is formed by an inner radial shoulder which extends inwardly, and the cartridge valve further comprises a spring, which acts, via the radial shoulder, on the control spool with a closing force.

12. The cartridge valve according to claim 11, wherein: the control spool includes a second seat ring; and a portion of the through recess is defined between the inner radial shoulder and the second seat ring, the portion having a third radius that is at least 60% of the second radius of the control spool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] An exemplary embodiment of the fast-switching 2/2-way cartridge valve according to the disclosure is illustrated in the figures, in which:

[0024] FIG. 1 shows, in a longitudinal section, the first exemplary embodiment of the fast-switching 2/2-way cartridge valve according to the disclosure,

[0025] FIG. 2 shows a detail from FIG. 1 with an overlap, and

[0026] FIG. 3 shows a detail from FIG. 1 with a damping means.

DETAILED DESCRIPTION

[0027] FIG. 1 shows, in a longitudinal section, a fast-switching 2/2-way cartridge valve with a damping means 1 according to the disclosure for a closing movement (directed downwards in FIG. 1) of the control spool 2 of said cartridge valve. The control spool 2 is substantially rotationally symmetrical with respect to a longitudinal axis 4 and is shown here in its closed position (at the bottom in FIG. 1).

[0028] The control spool 2 is designed in the manner of a sleeve and is guided here in a valve bore of a valve housing 6. The valve housing 6 is inserted at its end portion 22 (at the top in FIG. 1) into a valve block 8 in which a control pressure line 10 is formed. Furthermore, the valve block 8 also forms a part (at the top in FIG. 1) of the valve bore in which the control spool 2 is guided.

[0029] The cartridge valve has, at its end portion (at the bottom in FIG. 1) opposite the valve block 8, a seat region 12 which blocks off a high pressure port HD in relation to a low pressure port ND in the closed position of the control spool 2. The high pressure port HD is in the form of a radial bore star with a plurality of radial bores 14 in the valve housing 6, with only two radial bores 14 being illustrated in FIG. 1. The low pressure port ND is formed as an end-side opening (at the bottom in FIG. 1) of the sleeve-like valve housing 6.

[0030] FIG. 2 shows the seat region 12 in an enlarged illustration A. It can be seen that a control-spool-side seat ring 12a and a valve-housing-side seat ring 12b are arranged in the seat region 12, said seat rings being pressed onto each other in the closed position shown in FIGS. 1 and 2. The two seat rings 12a, 12b are in the shape of truncated cones.

[0031] It is illustrated in FIG. 1 that a spring 16 is arranged largely in the interior of the control spool 2 and of the valve block 8. In more precise terms, a spring chamber 18 is provided for the spring 16, a larger part of said spring chamber being bounded by the control spool 2 and a smaller part by the valve block 8. The spring 16 is supported on a cover (not shown in FIG. 1) and pretensions the control spool 2 via an inner radial shoulder 20 of the control spool 2 into the closed position.

[0032] FIG. 3 shows an enlargement B of a detail of the end portion 22 of the valve housing 6, the outer diameter of which is reduced and which is inserted with a centering effect into the valve block 8 and is sealed here by a seal 24. The valve block 8 and the sleeve-like valve housing 6 thus together form the valve bore, already discussed, for the control spool 2.

[0033] The damping means 1 according to the disclosure is formed at the end portion 22 of reduced outside diameter. For this purpose, an inner casing portion 26 of the end portion 22 in the shape of a truncated cone interacts with an outer casing portion 28 of the control spool 2 that is likewise in the shape of a truncated cone.

[0034] The two casing portions 26, 28 that are in the form of truncated cones have an identical (small) inclination or steepness with respect to the longitudinal axis 4. The inclination or steepness is, for example, <7 degrees. The casing portions 26, 28 are arranged here in such a manner that their respective smaller diameter faces the seat region 12 while the respective larger diameter faces the valve block 8.

[0035] The two casing portions 26, 28 (as shown in FIG. 3) preferably extend from a control pressure chamber, which is formed on the outer circumference of the control spool 2, as far as an end surface 32 of the end portion 22 of the valve housing 6, on which end surface the control pressure chamber 30 is also arranged.

[0036] If the control spool 2 is pushed from the closed position (shown in FIG. 3), in which the two casing portions 26, 28 form only a minimal gap in the shape of a truncated cone, into the opening position (upwards in FIG. 3), the gap between the two casing portions 26, 28 is increased and the control pressure chamber 43 is filled with pressure medium from the control pressure chamber 30. During the closing operation, first of all the control pressure chambers 43 and 30 are connected to each other, and therefore the fluid can flow off unobstructed from the control pressure chamber 43 via control pressure chamber 30 and via the control pressure line 10. After approx. 60%-70% of the stroke, the conical portion of the control spool 2 retracts into the conical portion of the valve housing 6 and a damping gap arises which becomes continuously narrower and longer during the further closing operation. The damping gap is therefore at the narrowest shortly before the impact of the control spool 2 and an ever greater counterpressure is built up in the control pressure chamber 43, the counterpressure damping the impact of the control spool 2. It is advantageous to design the damping in such a manner that it is at its most effective when the control spool 2 retracts into the overlapping portion 34. The closing speed (and therefore the impact energy) of the control spool 2 is therefore reduced only when the high pressure region HD is substantially separated from the low pressure region ND by the overlap 34/36.

[0037] Depending on the desired damping action, the length of the two casing portions 26, 28 along the longitudinal axis 4 (shown in FIG. 1) of the cartridge valve, the discussed angle of the two casing portions 26, 28 in the shape of truncated cones and the gap which remains in the closed position, shown in FIG. 3, of the control spool 2 can be designed differently.

[0038] According to a differing exemplary embodiment, the two casing portions 26, 28 forming the damping 1 can also be designed to be circular-cylindrical.

[0039] FIG. 2 shows an overlap in the seat region 12, said overlap being realized by a cylindrical socket for the end portion of the control spool 2. The cylindrical socket may also be referred to as a valve-housing-side overlapping portion 34 which interacts with a corresponding control-spool-side overlapping portion 36 and therefore forms the overlap. The effect therefore achieved is that, in the event of a possibly remaining brief lifting of the control spool 2 from the valve-housing-side seat ring 12b upon rapid closing of the cartridge valve, minimal leakage, if any at all, occurs between the two ports HD, ND.

[0040] FIG. 1 shows a through recess 38 which is enlarged in comparison to the prior art and, in the exemplary embodiment shown, extends concentrically with respect to the longitudinal axis 4 and which completely passes through the control spool 2. The spring chamber 18 is connected to the low pressure port ND via the through recess 38. The through recess 38 has a narrowest point which is defined by the radial shoulder 20 and the radius of which is at least 50% of the radius of the control spool 2 (at the same point). The radial shoulder 20 separates the spring chamber 18 from a portion 40 of the through recess 38 that extends from the narrowest point 38 as far as the seat region 12.

[0041] A cross section of the portion 40 of the through recess 38 (perpendicular to the longitudinal axis 4) is significantly enlarged in comparison to the cross section of the prior art in this region. The mass of the control spool 2 is therefore reduced, as a result of which the rapid and secure closing of the control spool 2 is significantly aided.

[0042] Furthermore, a circular-ring-shaped contact surface 42 is formed on the end side of that end portion of the control spool 2 which faces away from the seat region 12, said contact surface in the open position (not shown in FIG. 1) of the control spool 2 lying against the cover (likewise not shown in FIG. 1) of the cartridge valve and facilitating detaching of the control spool 2 from the cover during the rapid closing movement.

[0043] A fast-switching 2/2-way cartridge valve which can serve as a check valve is disclosed. A closing movement of the closing body of said cartridge valve is damped by contact portions lying on one another and being movable in relation to one another during the closing movement. The contact portions are formed on the closing body and on the valve bore in which the closing body is guided.