Valve and method for controlling a flow medium using the valve

Abstract

The invention relates to a valve (1) comprising at least a valve housing (2) and a piston (3), wherein the piston (3) is seated in the valve housing (2) and is displaceable from a first switching mode of the valve (1) to a second switching mode of the valve (1) and from the second switching mode to a third switching mode of the valve (1). The invention also relates to a method for controlling a flow medium using the valve (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a valve comprising at least a valve housing and a piston, and to a method for controlling a flow medium using the valve. BACKGROUND

[0002] DE 10 2019 108 694 A1 describes a valve of this type. The valve has a housing with an end face opening and an opening radially away from the valve axis (lateral opening). The piston has a two-stage design and is guided in an axially movable manner on the inner wall of the valve housing. The diameter of one piston stage is smaller than the diameter of the other piston stage. Between the piston stages, a connecting portion of the piston is formed, which is almost conical with respect to the valve axis and serves to compensate for the difference in diameter. A compression spring is axially clamped between the piston head and a bearing element. The bearing element is fixed to the valve housing. The valve is operated in two switching modes. The piston has a piston surface on the end face on the piston head, which radially covers the opening cross section of the end face opening in the valve housing from the inside in a first switching mode of the valve. Furthermore, in the first switching mode, another annular piston surface, which is functionally equivalent to a closure edge, rests in sealing contact with a sealing seat of the valve housing. As a result, in the first switching mode, the end face opening of the valve is closed by the piston. In the first switching mode, an annular space is formed between the connecting portion of the piston and the end face portion of the valve housing and the hollow cylindrical portion of the valve housing. The axial extent of the annular space can vary depending on the piston stroke and has the end face opening as an inlet and the lateral opening as an outlet. In a second switching mode, an axial force is exerted on the piston by the flow medium, which acts with pressure on the piston surface, the axial force overcoming the spring force of the compression spring and producing a piston stroke. As a result, the piston is lifted off the end face opening or the valve seat. The flow medium flows from the end face opening through the flow channel formed by the annular space towards the lateral opening. SUMMARY

[0003] It is an object of the invention to provide a valve having improved valve properties.

[0004] The valve according to the invention has at least one valve housing and one piston. The piston is guided in the valve housing in such a way that it can be moved axially along the valve axis.

[0005] The axial directions opposite to each other are thus defined as the longitudinal directions in which the piston is guided in a movable manner in the valve housing. The radial direction is thus transversely aligned with the valve axis.

[0006] Generally, a valve is a component of a device for controlling the pressure, flow velocity and flow direction of a flow medium, and the valve has the following basic structure:

[0007] The valve is seated in a housing. This housing is for example a housing of a vehicle transmission or alternatively a machine part of a vehicle transmission such as a shaft or a hub. A flow channel opens into an end face opening in the valve housing. Alternatively, the end face opening opens into a chamber. At least one lateral opening is formed in the valve housing. The lateral opening also opens into the flow channel or the chamber.

[0008] The valve has the following features:

[0009] The piston is a hollow cylindrical part designed in the shape of a cup and has two stages which are defined by different diameters from one another. The diameter of the first stage is smaller than the diameter of the second stage. The piston is preferably formed from sheet metal, but alternatively can also be firmly pressed or formed from cast material. The piston is guided in an axially movable manner via an outer cylindrical region of the side surface of the second stage on the inside of the inner cylindrical side surface of the valve housing. In this regard, the side surface can cover the entire second piston stage, but alternatively can also be only the outer cylindrical portion of the second piston stage.

[0010] A first piston surface is formed on the end face on the piston top of the first piston stage.

[0011] According to one embodiment of the invention, the second piston surface adjoins the first piston surface radially outwards. The second piston surface is followed in the axial direction by the outer cylindrical first side surface of the first piston stage. According to one embodiment of the invention, a third piston surface is formed radially between the side surface of the first piston stage and the control edge of the piston. The advantage of these embodiments is that the total effective area of the piston under pressure is increased due to the additional second piston surface and the third piston surface, and the response is improved at the same flow medium pressure due to the increased piston force. The geometry of the second piston surface can alternatively correspond to only one edge.

[0012] The control edge of the piston, which radially outwards encloses the third piston surface, is a body edge which is guided in a sliding manner along the inner side surface of the valve housing to form a seal. The outer cylindrical second side surface of the second piston stage adjoins the control edge axially.

[0013] The valve seat is either formed separately from the valve housing and supported on the valve housing or attached to the valve housing, or is formed directly on the material of the valve housing. The valve housing is preferably a shaped part made from sheet steel.

[0014] The valve housing is generally a hollow cylindrical part, the hollow cylindrical part of the valve housing being provided with a bottom on one end. The bottom has an end face opening. At least one second opening (lateral opening) is formed in the hollow cylindrical part. The hollow cylindrical part can also have a plurality of second openings which are circumferentially spaced apart and / or axially offset.

[0015] The piston is loaded with at least one spring, preferably a compression spring. The advantage of using at least one compression spring is that compression springs are available in large quantities at low cost in a variety of designs and the operating range of the valve can thus be individually adapted to different requirements, for example by selecting one or more springs with a suitable spring force (closing force or control force). Such an adjustment and change of the spring is possible even without a change in the design of the valve.

[0016] The function of the valve is as follows:

[0017] Three switching modes of the valve or device according to the application are provided. In a first switching mode, the valve is closed. The piston rests in sealing contact with the valve seat. There is no passage for the flow medium between the end face opening and the lateral opening. In a second switching mode, the end face opening of the valve is released by the piston and the flow medium can flow into the interior of the valve. The control edge of the piston still rests in sealing contact with the valve housing between the closing edge of the second opening of the valve housing and the valve seat, so that even in the second switching mode there is still no passage between the first opening and the second opening. According to the application, the control edge of the piston rests in axial sealing contact with a part of the valve housing extending between the valve seat and the closing edge, between the closing edge of the second opening of the valve housing and the valve seat. In the second switching mode, no passage for the flow medium is formed between the end face opening and the lateral opening either. In a third switching mode, the piston is retracted axially to the extent that the control edge releases a part of the lateral opening. In this device, the flow medium can flow from one flow channel through the end face opening and a flow chamber formed in the valve and from the flow chamber through the second opening into the other flow channel or back to the first opening and from the first opening into the other flow channel.

[0018] In the first switching mode, as already mentioned, the valve is closed, i.e. the first opening is closed by the piston. For this purpose, the first piston surface of the piston covers the first opening from the inside, viewed from the flow channel in the valve housing, and at the same time the second piston surface rests against the valve seat under the action of the closing force. In the first switching mode, the pressure of the flow medium acting on the first piston surface through the end face opening is either equal to zero or so small that the axial actuating force acting on the piston surface is smaller than the closing force with which the piston is preloaded in a sealing manner against the valve seat, for example by means of a spring.

[0019] As soon as the piston lifts off the valve seat, the closing force of the spring is cancelled and the control force acts on the piston. The control force acting on the piston can also be generated by the flow medium or, preferably, as provided in the preferred embodiment of the application, by means of the spring characteristics of one or more compression springs inserted in the valve.

[0020] In the first switching mode of the device, the second opening (transversal opening) is completely closed by the outer lateral surface (second lateral surface) of the second piston stage. Inside the valve, an annular space or closed annular chamber is defined by a portion of the inner lateral surface of the valve housing, the first lateral surface of the first piston stage and the third piston surface. The control edge of the piston is axially positioned between the end face of the valve and the second opening. More specifically, the control edge of the piston is axially positioned between the closing edge formed at the first opening of the valve housing and the end face of the valve housing, where the control edge of the piston rests in radial sealing contact with a portion of the valve housing.

[0021] In the sense of the present invention, alternatively, a radial seal is defined as a pressure seal or as a partial permeation through a leakage gap.

[0022] The outer cylindrical lateral portion of the axially adjoining control edge of the second piston stage is guided in a radially sealed manner on the inner cylindrical lateral portion of the valve housing. The inner cylindrical lateral portion of the valve housing extends axially between the portion of the inner lateral surface of the valve housing that defines the annular chamber and the closing edge formed at the second opening. The closing edge is formed on the border of the second opening or is part of the border and defines the second opening in the direction of the end face of the valve that is in radial contact with the piston.

[0023] Thus, in the second switching mode, the passage through the valve has not yet been opened. The actuating force caused by the pressure of the flow medium on the first piston surface at the end face opening generates an opening force. The opening force of the piston is greater than the closing force. This leads to the piston being lifted axially from the valve seat. In contrast to the prior art, this opening force leads to an axial travel of the piston, but not to the final opening of the valve. The piston is initially only lifted axially from the valve seat. The pressure of the flow medium "fills" the annular chamber and also acts on the third piston surface. The total piston surface on which the pressure of the flow medium acts increases. Because the control edge of the piston is still axially positioned between the closing edge and the end face of the valve and thus the second opening is not yet released by the piston, this inevitably leads to an increase in the actuating force on the piston. A control force is generated which causes a piston travel and ultimately leads to the third switching mode of the valve.

[0024] In the third switching mode, the control edge of the piston is pushed axially beyond the closing edge of the second opening (transverse opening) under the action of the control force, so that a second opening cross section defined by the control edge and the closing edge is formed at the second opening. The free passage from the flow channel via the end face first opening and from the first opening into the now formed annular chamber as flow chamber and from the annular chamber through the second opening is released. The flow medium can continue to flow between the flow channels until the pressure drop of the pressure medium causes the stroke to reverse and thus the piston to be displaced in the direction of the valve seat, and the control edge moves beyond the closing edge again. In the case of a slight pressure drop, the pressure of the pressure medium initially acts again on the piston surface consisting of three piston surfaces, and the resulting counterforce inhibits the movement of the piston in the direction of the valve seat.

[0025] The difference between the valve according to the present application and the prior art valve described in the "Invention Background" section of DE 10 2019 108 694 A1 is in particular that the design of the valve according to the present application allows three switching modes instead of two switching modes. Thus, compared to the prior art, the valve has an improved control characteristic and control behavior for the following reasons:

[0026] In the valve disclosed in DE 10 2019 108 694 A1, in the first switching mode there is an outward connection between the annular space and the outside environment of the valve, which can permeate the flow medium via the second opening, i.e. in the first switching mode the second opening is not completely closed by the piston. Thus, in the second switching mode, after the closing force is overcome and the piston is lifted off the valve seat, the flow medium immediately flows back from the end face opening via the annular chamber inside the valve through the transverse opening to the environment. The advantage of this arrangement is that the valve responds quickly, i.e. the valve opens quickly. However, in the second switching mode, the piston stroke of the axial movement of the piston away from the valve seat is relatively short. Furthermore, due to the short spring stroke, the "sensitivity" of the spring is limited. The control force on the piston is always close in size to the closing force of the spring. After opening the valve in the second switching mode, due to pressure compensation, the actuating force on the piston surface decreases relatively quickly to a level below the preloading force (closing force) of the spring, so that the piston is guided back by the force of the spring against the valve seat and the valve closes again for a short time. However, shortly thereafter, the pressure on the piston surface becomes so high again that the piston is lifted slightly off the valve seat again. Due to the short piston stroke, this change from the first switching mode to the second switching mode occurs at a high frequency, so that the piston of the valve known from the prior art starts to "flutter" back and forth between the two positions in an undesirable and harmful manner. This not only causes undesirable noise, but can also have a negative impact on the function of the device operated or controlled by the flow medium.

[0027] Due to the special design of the valve according to the invention, in particular due to the axial sealing contact of the control edge of the piston between the closing edge of the second opening and the first opening on the end face of the valve housing or the inner cylindrical portion of the valve housing, in the second switching mode the passage of the pressure or flow medium through the valve is prevented, since in the second switching mode the second opening is still closed by the skirt of the piston. Overall, the piston stroke is increased, since the distance of the second opening or the closing edge of the second opening from the valve seat is increased by the inner cylindrical portion. The reaction time of the piston between the first mode and the third mode is increased, which also prevents "chattering". In the second switching mode, the effective piston surface is first increased, so that a higher actuating force on the piston is generated. It can be said that the second switching mode is an intermediate switching mode, with which the reaction of the piston to the compensation of the actuating force and the control force is suppressed and calmed by the increased control force. The third piston surface, which is radially located between the control edge and the outer side surface of the first piston stage, changes the response of the piston, since the opening force on the piston is converted into a greater control force by the pressure of the flow medium acting on the enlarged piston surface (actuating force = product of the total piston surface area and the pressure of the flow medium acting on the piston surface). In the second switching mode, the total piston surface is the sum of the first piston surface and the third piston surface and the approximate contour of the second piston surface in any imaginary radial plane, wherein the third piston surface, which is formed as an annular surface, and the first piston surface, which is formed as a circular surface, can also be reproduced. The movement of the piston under the influence of the higher control force is suppressed, and an undesired high-frequency oscillation of the piston between the first switching mode and the second switching mode is avoided. The position of the piston in the valve according to the invention away from the valve seat is maintained even at low pressures, since the larger piston surface generates an increased actuating force, under the influence of which the piston on previously known prior art valves would again hit against the valve seat. The reaction sensitivity of the valve is higher. In the additional third switching mode, the valve does not open the passage for the flow medium until the control edge of the piston releases the slot of the second opening, which is defined by the closing edge of the second opening and the control edge of the piston. Only now does the pressure on the piston decrease quickly, and the piston moves axially back in the direction of the valve seat. The control edge moves axially beyond the closing edge, so that the second opening is closed again. However, the piston cannot hit the valve seat, since the pressure of the flow medium now acts immediately on the three piston surfaces, and the actuating force on the piston has already approached the closing force of the spring under a slight pressure build-up. The movement of the piston back to the valve seat is suppressed.

[0028] In one embodiment of the invention, at least one annular surface of the first piston surface and the third piston surface is a flat surface located in a parallel radial plane and thus aligned parallel to each other; that is, the first piston surface is preferably a circular surface and the third piston surface is preferably an annular surface. However, it is also conceivable that one or both piston surfaces are axially convex or concave in one or the other direction. The design of the piston surfaces can be used to regulate the responsive behavior of the piston, and thus the responsive behavior of the valve, but can also positively influence the self-cleaning of the valve based on residues / deposits of the flowing medium.

[0029] According to another embodiment of the invention, the third piston surface has two portions. One portion, radially adjacent to the first side surface of the first piston stage, is an annular surface. When viewed in any longitudinal section along the valve axis, the other portion, extending radially outward from the annular surface to the control edge, has a curved or straight path inclined toward the valve axis. The geometry of the second portion is preferably described by a truncated conical side surface. This measure prepares for a sharp transition to the control edge, which also maintains the contact between the inner side surface of the valve housing and the piston free of deposits during piston movement. Attached Figure Description

[0030] The invention will now be explained in more detail with reference to exemplary embodiments. In the accompanying drawings:

[0031] Figure 1 —Valve 1 is shown in a longitudinal section along its valve axis 5.

[0032] Figure 2 —shown Figure 1 The cross-section of valve 1 is shown, wherein the position of piston 3 is in the first switching mode of valve 1.

[0033] Figure 3 —shown Figure 2 The cross-section shown is such that, however, the position of piston 3 is in the second switching mode of valve 1, and

[0034] Figure 4 —shown Figure 3 The cross-section shown is such that piston 3 is in the third switching mode of valve 1. Detailed Implementation

[0035] Figure 1The valve 1 comprises a valve housing 2, a piston 3, a spring 4, a sealing element 31 and a support element 27. The piston 3 is guided radially in the valve housing 2 and is pressed axially against a valve seat 14 by the spring 4. For this purpose, the spring 4 is axially immersed into the piston 3 and rests against the bottom of the piston 3. The sealing element 31 is seated on a neck 32 of the valve housing 2, which surrounds the first opening 6. The sealing element 31 is provided with a reinforcement 33, which supports and reinforces a sealing lip 34.

[0036] The valve housing 2 has a two-stage design and is provided with a first housing stage 25 and a second housing stage 26. The housing stages 25 and 26 are designed to be substantially hollow-cylindrical. The diameter of the first housing stage 25 is smaller than the diameter of the second housing stage 26. The first housing stage 25 has the first opening 6 at the end face 21. The first opening 6 is surrounded by a neck 32 of the valve housing 2. The first housing stage 25 is further provided with at least two second openings 7, which are formed as lateral openings in the valve housing 2 radially spaced apart from the valve axis 5. The illustrated valve housing 2 is a thin-walled shaped part made of sheet metal and is provided at the end facing away from the end face 21 with a flanged step at which the wall thickness of the valve housing 2 is reduced and flanged. Due to the flanged step, the rear boundary of the valve housing 2 is slightly radially curved in the direction of the valve axis 5 on the circumferential side, thereby forming a circumferential groove 29. The support element 27 is firmly supported in the circumferential groove 29. The spring 4 is a coil spring which is axially clamped between the bottom of the piston 3 and the support element 27. The first opening 6 is followed within the valve housing 2 by the valve seat 14, which is stamped into the material of the valve housing 2.

[0037] The second openings 7 are delimited circumferentially by a boundary 28 and are provided at the boundary 28 with a closed edge 16 axially facing the end face 21, which is formed on site by a part of the boundary 28, but can also be provided separately.

[0038] The piston 3 is a thin-walled and cup-shaped shaped part made of sheet metal and has a first piston stage 8 and a second piston stage 9. The bottom of the piston 3 is provided with a flat first piston surface 10 on the side of the first opening 6, which is formed as a radially circular surface.

[0039] Figure 1 and Figure 2- The first piston surface 10 is followed in the radial direction by the second piston surface 11. The first piston surface 10 is a circular surface which lies flat in an imaginary radial plane which adjoins perpendicularly to the valve axis 5. The second piston surface 11 extends in a curved manner, but can alternatively be formed by one or more surface portions provided with a curved profile and / or a frustoconical surface profile. On the outer circumference of the first piston stage 8 there is formed an outer cylindrical first side surface 15. The first piston surface 10 ends at the second piston surface 11, and the second piston surface 11 merges radially into the first side surface 15 of the first piston stage 8. The first side surface 15 is followed by the third piston surface 12. The third piston surface 12 merges at the control edge 13 of the piston 3 into an outer cylindrical second side surface 24 of the second piston stage 9. One portion of the third piston surface 12 is a flat annular surface 19 which lies in an imaginary radial plane which is passed through perpendicularly by the valve axis 5. Another portion 20 of the third piston surface 12 is formed as a frustoconical side surface. Together, the portion of the inner side surface 22 of the valve housing 2, the first side surface 15 and the third piston surface 12 define an annular chamber 23.

[0040] The valve 1 is in the first switching mode. The piston 3 is in the closed position. The piston 3 is axially preloaded by the closing force of the spring 4, and the second piston surface 11 of the piston rests in sealing contact with the valve seat 14.

[0041] Figure 2 - First switching mode of the valve 1 - The first piston surface 10 radially covers the first opening cross section 17 of the first opening 6 formed as a circular surface on the inside of the valve housing 2, thereby completely closing the first opening. A portion of the second side surface 24 of the second piston stage 9 rests in sealing contact with the inner side surface 22 of the valve housing 2. The control edge 13 of the piston 3 is axially positioned between the end face 21 of the valve 1 or the valve seat 14 and the closure edge 16. The second side surface 24 completely covers the second opening 7 of the valve housing 2 in the axial direction and thus closes the second opening, wherein the piston 3 rests in the first switching mode radially sealingly on the inner cylindrical portion of the inner side surface 22 formed between the annular chamber 23 and the closure edge 16 by the outer cylindrical portion of the second side surface 24 and is guided at this inner cylindrical portion.

[0042] Figure 3 - Second switching mode of the valve 1 - The piston 3 has been displaced to the right by the opening pressure of the flow medium, not shown, on the first piston surface 10 against the resistance of the spring 4 in the figure. The opening force lifts the second piston surface 11 off the valve seat 14. In the second switching mode, the piston 3 is in the open position. Figure 1 and Figure 2The volume of the annular chamber 23 increases axially due to the stroke of the piston 3 compared to the position in the first switching mode (see Figure 1 and Figure 2 ) The control edge 13 of the piston 3 has moved axially away from the valve seat 14 and is approximately at the level of the closing edge 16, but has not yet released the second opening 7. The second side surface 24 still completely covers the second opening 7.

[0043] Figure 4 Third switching mode of the valve 1 - As in the second switching mode (see Figure 3 ) the piston 3 is in a position in which the second piston surface 11 is lifted off the valve seat 14. The control edge 13 of the piston 3 moves axially over the border 28 of the second opening 7 and thus moves beyond the closing edge 16 and the second opening 7 is thereby partially released by the piston 3. This results in a free second opening cross section 18 of the second opening 7 which is defined by the control edge 13 and the closing edge 16. A flow chamber 30 is formed which connects the first opening cross section 17 of the first opening 6 and the second opening 7 in a permeable manner and is defined by the valve housing 2 and the piston surfaces 10, 11, 12. This means that in the third switching mode the annular chamber 23 forms a flow chamber 30 which is open in a permeable manner for the flow medium from the first opening 6 via the annular chamber 23 towards the second opening 7.

[0044] Legend of the figures

[0045]

[0046]

Claims

1. A valve (1), said valve comprising at least a valve body (2) and a piston (3), wherein, - The piston (3) is seated in the valve housing (2) and is capable of shifting along the valve axis (5) of the valve (1) from the first switching mode of the valve (1) to the second switching mode of the valve (1) and from the second switching mode to the third switching mode of the valve (1). - The valve housing (2) has a first opening (6) with a first open cross-section (17) on the end face (21), and at least one second opening (7) with a closing edge (16), wherein the closing edge (16) is formed on the boundary (28) defining the second opening (7). - The piston (3) has a first piston stage (8), the first piston stage having a first piston surface (10) pointing toward the end face (21) and having a first side surface (15). - The piston (3) has a second piston stage (9) having a control edge (13) pointing toward the end face (21) and a second side surface (24). - In the first switching mode, the first piston surface (10) covers the opening cross section (17) of the first opening (6). - In the first switching mode, the piston (3) is positioned in a sealing contact with the valve seat (14) of the valve housing (2). - The second opening (7) is closed via the second side surface (24) of the second piston stage (9) in both the first and second switching modes, wherein the control edge (13) is positioned axially movable between the closed edge (16) and the valve seat (14) in the valve housing (2) in both the first and second switching modes. - The free second opening cross section (18) of the second opening (7), defined by the control edge (13) and the closing edge (16), is released in the third switching mode to form a flow chamber (30) that connects the first opening cross section (17) of the first opening (6) and the second opening (7) in a permeable manner, and is defined here by the valve housing (2) and the piston surface (10, 11, 12).

2. The valve according to claim 1, wherein, In the first switching mode and the second switching mode, at least a portion of the second side surface (24) of the second piston stage (9) is placed in sealing contact with the valve housing (2).

3. The valve according to claim 1, wherein, The piston (3) is provided with a second piston surface (11) pointing towards the end face (21) at the first piston stage (8), wherein the piston (3) is placed in the first switching mode to seal contact with the valve seat (14) through the second piston surface (11), and wherein the second piston surface (11) is lifted away from the valve seat (14) in the second switching mode and the third switching mode, and wherein the second piston stage is provided with a third piston surface (12) pointing towards the end face (21), wherein the third piston surface (12) is radially formed between the first side surface (15) and the control edge (13).

4. The valve according to claim 3, wherein, At least one annular surface (19) of the first piston surface (10) and the third piston surface (12) are parallel to each other and coaxially aligned.

5. The valve (1) according to claim 3, wherein, The third piston surface (12) has an annular portion (20) which, when viewed in any longitudinal section along the valve axis (5), is either curved and extends obliquely relative to the valve axis (5), or is described by a truncated conical side surface.

6. The valve (1) according to claim 3, wherein, The third piston surface (12) has an annular portion (20) with a truncated conical profile, and wherein the control edge (13) is formed by a body edge that radially defines the third piston surface (12) and the portion (20) and extends around the valve axis (5).

7. The valve (1) according to claim 3, having an annular chamber (23) extending about the valve axis (5) and defined by at least a portion of the third piston surface (12) and the inner side surface (22) of the valve housing (2) and the first side surface (15) of the first piston stage (8).

8. The valve (1) according to claim 3, having an annular chamber (23) extending about the valve axis (5) and defined by at least a portion of the third piston surface (12) and the inner side surface (22) of the valve housing (2) and the first side surface (15) of the first piston stage (8), wherein, The annular chamber (23) is closed in the first switching mode of the valve (1) and open in the second switching mode and the third switching mode, wherein the annular chamber (23) is opened toward the first opening (6) in the second switching mode and the annular chamber (23) is formed as a flow chamber (30) in the third switching mode, the flow chamber being opened from the first opening (6) toward the second opening (7) in a passable manner via the annular chamber (23).

9. The valve (1) according to claim 3, having an annular chamber (23) extending about the valve axis (5) and defined by at least a portion of the third piston surface (12) and the inner side surface (22) of the valve housing (2) and the first side surface (15) of the first piston stage (8), wherein, In the first switching mode, the piston (3) is radially sealed by the outer cylindrical portion of the second side surface (24) at the inner cylindrical portion of the inner side surface (22) formed between the annular chamber (23) and the closed edge (16).

10. The valve (1) according to any one of the preceding claims, having a valve housing (2), the valve housing having at least a first housing stage (25) and a second housing stage (26), wherein, The housing stages (25, 26) are different from each other in terms of their outer diameters, and wherein the piston (3) is guided axially along the valve axis (5) on the inner side surface (22) of the first housing stage (25), and wherein the first housing stage (25) is provided with the first opening (6) and at least one second opening (7), and wherein the spring (4) is axially supported in the second housing stage (26) and elastically held between the piston (3) and the support element (27).

11. A method for controlling a flowing medium using a valve (1) according to any one of the preceding claims, wherein, In the first switching mode, the valve (1) is closed by the piston (3). In the second switching mode, the annular chamber (23) inside the valve (1) is opened toward the first opening (6) by the axial movement of the piston (5) under the pressure of the flowing medium. In the third switching mode, the valve (1) is opened by the piston (5) to the flow chamber (30), and the flowing medium can pass through the flow chamber from the first opening (6) toward the second opening (7) and in the opposite direction through the flow chamber.

Images