3 / 2-ROAD ENTRY

Description

Field of the invention

[0001] The invention relates to a 3 / 2-way valve for controlling and / or regulating a control pressure of a pressurized fluid, e.g. compressed air, by means of an electrical signal.

[0002] The position control of pneumatically actuated control valves, especially those with "smart" positioners, is typically achieved by IP converters (current-to-pressure converters) with very low power consumption (a few mW at most) and downstream pneumatic amplifiers. The reasons for this are primarily the input signal (4-20 mA) standardized in process control technology, which also provides the power for the IP converters (so-called two-wire technology), but also explosion protection requirements.

[0003] However, modern developments in process control technology mean that such low power consumption will no longer be a requirement in the future. So-called 4-wire technology and bus systems allow for higher electrical power consumption of control and regulation components. Due to the increased use of modern communication interfaces (e.g., APL, Bluetooth), such systems that provide higher electrical power will become increasingly widespread.

[0004] The increased available electrical power allows new approaches to position control of pneumatically driven control valves. State of the art

[0005] From the publication DE 10 2015 122 229 A1, an electromagnetically actuated valve is known that can be used to operate a pressure-operated actuator of a process control valve. Since this is a simple valve and not a 3 / 2-way valve, a connection of at least two such valves is required to control or regulate the drive of a process valve. This entails greater complexity, particularly in terms of the space required for the valves themselves and the lines for their connection, but also with regard to the logic and pulses for controlling or regulating these valves.

[0006] Electromagnetically driven 3 / 2-way valves are known, for example, from publications DE 10 2015 005 369 A1 or DE 10 2018 124 310 A1. These 3 / 2-way valves utilize a drive, which, however, is not suitable for continuous, proportional control of the valve. This drive consists of a stationary permanent magnet between two coils. This drive moves a control armature, which alternately closes one of the two valve seats. The two valve seats are therefore always either fully open or fully closed. Publication US 9 915 360 B2 describes a 3 / 2-way valve according to the preamble of claim 1. Task

[0007] The object of the invention is to provide a 3 / 2-way valve which is suitable for the direct control of a fluidic drive of a control valve, which in particular can proportionally control and / or regulate a fluid with an inlet pressure of up to 8 bar depending on an electrical input signal, does not require any downstream fluid pressure amplifiers and has the lowest possible electrical power consumption. Solution

[0008] This problem is solved by the subject matter of the independent claim. Advantageous developments of the subject matter of the independent claim are characterized in the subclaims. The wording of all claims is hereby incorporated by reference into this description.

[0009] The use of the singular shall not exclude the plural, and this shall also apply in the reverse sense unless otherwise disclosed.

[0010] To achieve this objective, a 3 / 2-way valve is proposed for controlling and / or regulating the control pressure of a pressurised fluid using an electrical signal. The 3 / 2-way valve has three fluid connections: an inlet for the fluid subject to an inlet pressure, a control outlet for the fluid subject to the control pressure, and a relief outlet for the fluid against a base pressure that is lower than the inlet pressure. If the fluid is compressed air, the base pressure is generally ambient pressure, i.e. the relief outlet vents to the atmosphere. The 3 / 2-way valve can establish a fluid connection between the inlet and the control outlet, as well as between the control outlet and the relief outlet. An inlet valve seat with an inlet valve element is connected downstream of the inlet, while an relief valve seat with an relief valve element is connected upstream of the relief outlet.Both the input valve element and the relief valve element each have a closed position. The 3 / 2-way valve also has an armature that actuates both the input valve element and the relief valve element. To do this, the armature moves linearly along an axis. The armature is a permanent magnet magnetized along the axis. The 3 / 2-way valve also has an electromagnetic drive that drives the armature so that it assumes a desired position depending on the electrical signal. The electromagnetic drive has at least one coil. The coil is arranged radially outside the armature with respect to the axis. In this 3 / 2-way valve, the armature is decoupled from the input valve element and the relief valve element in such a way that the input valve element and the relief valve element only follow a movement of the armature up to the respective closed position.

[0011] This 3 / 2-way valve is cost-effective to manufacture and robust. An electrical control signal, e.g., a current of up to 600 mW, is converted directly into proportionally controllable output pressure or mass flow, whereby all pressures between the inlet pressure and the base pressure can be achieved. This makes the 3 / 2-way valve ideally suited, for example, for directly controlling a pneumatic actuator of a process control valve, provided that the electrical power consumption of the 3 / 2-way valve can be met. In this case, the otherwise sensitive IP converters and many additional components such as pneumatic pre-pressure reducers, air power or volume flow amplifiers, pneumatic flow controllers and additional sealing and filter elements, etc., can be dispensed with, which significantly simplifies the control of such process control valves and, above all, makes it more cost-effective.

[0012] According to the invention, the inlet valve seat of the 3 / 2-way valve is arranged along the axis of the armature, with the inlet valve seat and input valve member being oriented such that the inlet valve member is lifted out of the inlet valve seat in the direction away from the armature to open. For this purpose, the 3 / 2-way valve has an inlet valve actuating element which, starting from the armature, reaches around the inlet valve seat and actuates the inlet valve member from the side facing away from the armature. The inlet valve seat does not have to lie exactly on the axis, but merely parallel to it. Thus, a slightly offset arrangement is easily possible. A ball preferably serves as the inlet valve member.

[0013] The input valve actuator allows the input valve member to be actuated by the movement of the armature, even though the input valve member and input valve seat are oriented as described. This arrangement is particularly advantageous at high inlet pressures of up to 8 bar. It also ensures the required decoupling of the movement of the armature and the input valve actuator or input valve member.

[0014] The actuation of the input valve member is facilitated if the 3 / 2-way valve has a first actuating cap which transmits movements of the armature to the input valve actuating element.

[0015] A particularly preferred development of the 3 / 2-way valve is one in which the input valve actuating element has a plurality of, preferably three, connecting rods. The connecting rods are arranged parallel to the axis past the input valve seat and are actuated by the actuating cap. This allows the movement of the armature to be transmitted particularly evenly to the input valve member. In particular, tilting of the input valve actuating element is avoided.

[0016] Particularly good guidance of the input valve actuating element is achieved if the 3 / 2-way valve has a guide sleeve arranged parallel to the axis and if the input valve actuating element has a pin which is guided in the guide sleeve.

[0017] Viewed in the direction of fluid flow, the inlet pressure is present before the fluid passes the inlet valve seat. The inlet valve element throttles this pressure to the control pressure. The 3 / 2-way valve has a housing with holes for the connecting rods of the inlet valve actuating element. The holes have a larger diameter than the connecting rods. Through these holes, the fluid with the control pressure flows into the armature chamber and thus toward the relief outlet. Additional fluid connection channels are then not required, but can be provided.

[0018] Easier mobility and a saving in mass of the inlet valve actuating element can be achieved by providing the inlet valve actuating element with through-holes through which the fluid can flow.

[0019] The tightness of the corresponding closing state as well as the controllability are improved if the input valve actuating element is preloaded by a spring in such a way that, in the unactuated state, it presses the input valve member into the input valve seat.

[0020] A particularly preferred embodiment of the 3 / 2-way valve is one in which at least one inlet pressure relief channel is provided, providing a fluid connection from the inlet to the side of the guide sleeve or the pin of the inlet valve actuating element facing away from the armature. In this way, the actuation of the inlet valve member by means of the inlet valve actuating element is pressure-relieved.

[0021] Preferably, the relief valve seat is arranged along the axis behind the armature, as seen from the inlet valve seat. Along the axis does not necessarily mean on the axis, but rather merely parallel to it. Lateral offset is readily possible. This arrangement allows the relief valve element to be operated by the armature.

[0022] The actuation of the relief valve member is facilitated if the 3 / 2-way valve has a second actuating cap that transmits the armature's movements to the relief valve member. The second actuating cap has a sieve-like perforation. This improves the flow characteristics of the fluid through the valve past the armature toward the relief outlet.

[0023] The tightness of the corresponding closing state as well as the controllability are improved if the expansion valve member is preloaded by a spring in such a way that it is pressed into the expansion valve seat in the unactuated state.

[0024] The low power consumption is further contributed to by the presence of at least one outlet pressure relief channel, which provides a fluid connection from the area where the armature is located to the side of the relief valve member facing away from the armature. The relief valve member can be guided, for example, in a guide cylinder. In this way, the actuation of the relief valve member is completely pressure-relieved.

[0025] The pressure relief on both sides ensures that the required magnetic force, and thus the control current, is virtually independent of the fluid supply pressure and the pressure in the area where the armature is located. In particular, pressure differences do not need to be overcome for adjustment, significantly reducing the force required by the actuator and thus power consumption.

[0026] In a further embodiment of the 3 / 2-way valve, the cross section of the side of the relief valve member facing away from the armature and / or the side of the pin of the input valve actuating element facing away from the armature, on which the respective pressure relief acts, is larger than the effective cross section of the respective associated valve seat.

[0027] This variant of the 3 / 2-way valve does not require springs on the relief valve element or the input valve actuating element. In this case, secure closure of the respective valve seats is achieved by the described slight "tuning" of the pressure relief geometry. For example, the effective diameter of the relief valve element on the side facing away from the armature, on which the pressure relief acts, can be designed slightly larger than the diameter of the relief valve seat. This creates an excess force that presses the relief valve element into the relief valve seat. The input valve seat and the pin of the input valve actuating element can be designed accordingly. However, this design makes the characteristic current values ​​for opening and closing the valve elements slightly pressure-dependent. This can be used to reduce the pressure in certain circumstances.can be used for diagnostic purposes: From the current values ​​at the respective switching points (beginning of the pressure increase or decrease) conclusions can then be drawn about the pressure of the fluid at the inlet and the control pressure.

[0028] A further preferred development of the 3 / 2-way valve is one in which the input valve seat and the relief valve seat are arranged at a distance such that between a first position of the armature, in which the actuation of the input valve member begins, and a second position of the armature, in which the actuation of the relief valve member begins, there is an idle travel that is at least large enough to prevent the actuation of the input valve member and the actuation of the relief valve member from overlapping. This creates a position of the armature in which both the input valve member and the relief valve member are closed, thereby maintaining the control pressure in the fluid.

[0029] The 3 / 2-way valve is particularly suitable for applications with increased safety requirements if it has a spring connected to the armature that is preloaded so that the 3 / 2-way valve assumes a safety position when no electrical signal is present. Typically, the safety position is achieved when the relief valve element is fully open and the input valve element is closed, so that the control pressure drops to the base pressure. The spring connected to the armature must be significantly stronger than any spring present on the relief valve element.

[0030] The fluid can flow particularly easily through the 3 / 2-way valve if the armature is designed as a cylindrical magnet with at least one bore arranged parallel to the axis. Preferably, it is a hollow cylinder with a central bore.

[0031] To position the armature more efficiently and precisely, the electromagnetic actuator has two coils. These are arranged radially outside the armature relative to the axis, i.e., spaced apart from each other around the control chamber. The two coils are either connected in series and wound in opposite directions, or wound in the same direction and connected in opposite directions. Both arrangements have the same effect, but the second variant is preferred because manufacturing costs are generally lower.

[0032] Unwanted external stray fields can be minimized and the efficiency of the drive increased if the electromagnetic drive has a cylindrical return sleeve made of magnetically conductive material. This is arranged radially outside the coils relative to the axis.

[0033] Further details and features will become apparent from the following description of a preferred embodiment in conjunction with the figures. The respective features can be implemented individually or in combination with one another. The possibilities for achieving the object are not limited to the embodiment.

[0034] An exemplary embodiment is shown schematically in the figures. Identical reference numerals in the individual figures denote identical or functionally equivalent elements, or elements that correspond to one another in terms of their functions. In detail: Fig. 1 is a schematic sectional view of the 3 / 2-way valve, showing the control output; Fig. 2 is a schematic sectional view of the 3 / 2-way valve in a relief position; Fig. 3 is a schematic sectional view of the 3 / 2-way valve in the holding position; Fig. 4 is a schematic sectional view of the 3 / 2-way valve in a pressure build-up position; and Fig. 5 is a schematic oblique view of the input valve actuating element of the 3 / 2-way valve.

[0035] Fig. 1 shows a 3 / 2-way valve 100 with a housing 104, an inlet 108 for a pressurized fluid, a control outlet 112 for the fluid, and a relief outlet 116. There may also be multiple relief outlets to increase the fluid throughput. The inlet is located at the back in this illustration. Compressed air with a pressure of up to 8 bar is typically used as the fluid. Inside the housing 104 there is an interior space or control chamber 120, which can be essentially cylindrical and in which the fluid already has the set control pressure. The control outlet 112 is openly connected to the control chamber. At this point, for example, a pneumatic actuator for a process control valve or similar can be directly connected.

[0036] Located in the control chamber is an armature 124, which is designed as a ring or cylindrical magnet with a central bore 128. The armature 124 is axially magnetized, e.g., north pole at the top, south pole at the bottom, and can move smoothly up and down in the control chamber 120.

[0037] Two coils 132, 136 are arranged in a ring around the control chamber 120, spaced apart from each other, to drive the armature 124 and adjust its position depending on an electrical input signal (typically a predetermined current). The two coils 132, 136 of the electromagnetic drive are either electrically connected in series and wound in opposite directions, or wound in the same direction but connected in opposite directions, meaning that the current flows through the two coils in opposite directions.

[0038] When energized, a magnetic field is created, depending on the current direction, which interacts with the armature magnet 124 and exerts a force on it in the axial direction. This force depends on the strength of the coils' magnetic field and thus on the current strength. Consequently, the position of the armature 124 can be adjusted as desired by varying the current strength, since there is a balance between the magnetic force and the sum of all spring forces occurring.

[0039] The drive also includes a tubular magnetic return sleeve 140 made of magnetically conductive material, which surrounds the coils 132, 136 and optimizes the magnetic field shape. The return sleeve 140 also helps prevent unwanted stray fields. The armature 124 is connected to a spring 144 that pushes it into the upper position when the drive is de-energized. This represents a safety feature.

[0040] At the lower end of the armature 124 is a first actuating cap 148, which can transmit the movement of the armature 124 to the input valve actuating element 152, whereby the input valve actuating element 152 actuates the input valve member 156. A smooth ball made of, for example, steel or ceramic is preferably used as the input valve member 156.

[0041] The input valve actuator 152 has a plurality of arms or connecting rods 160. Preferably, there are three such connecting rods, of which Fig. 1 but not all are shown; they are in Fig. 5 These engage around the input valve seat 164 so that the input valve member 156 can be actuated from the side facing away from the armature 124.

[0042] The input valve actuating element 152 further has a pin 168, which is guided in a guide sleeve 172. A spring 176 engages this pin and is preloaded such that it presses the input valve member 156 into the input valve seat 164 via the input valve actuating element 152 when the input valve actuating element is not actuated.

[0043] At the upper end of the armature 124 is a second actuating cap 180, with the aid of which the armature 124 can actuate the relief valve member 184. This can be guided in a guide cylinder 186. The relief valve member 184 is also pressed into the relief valve seat 192 by a correspondingly preloaded spring 188 when not actuated. An output pressure relief channel 196 establishes a fluid connection between the rear of the relief valve member 184, possibly in the guide cylinder 186, and the control chamber 120, thereby relieving pressure on the relief valve member 184 and thus making it largely force-free. The relief valve member 184 "floats," so to speak, in the control pressure. The actuation of the relief valve member 184 thus requires only minimal force, thus requiring low power consumption from the electromagnetic drive.Spring 188 can be designed accordingly weaker, since it does not have to overcome the pressure difference between the control pressure and the base pressure. Accordingly, spring 144, which must push armature 124 against spring 188 into the maximum opening position of the relief valve member 184 when de-energized, can also be dimensioned weaker.

[0044] A pressure relief channel is also provided on the inlet valve member 156; this is located in Fig. 1 However, from the viewer's perspective it is at the back and is therefore not shown.

[0045] By appropriately controlling the position of the armature, the pressure in the control chamber 120 can be adjusted anywhere between the maximum fluid pressure (e.g., 8 bar) and the base pressure (e.g., 1 bar). A correspondingly sensitive position adjustment even allows the rate of the pressure change to be adjusted by opening the inlet valve member 156 and / or the relief valve member 184 more or less, thereby allowing the release of cross-sections of varying sizes.

[0046] In Fig. 2 The 3 / 2-way valve 100 is shown rotated 120° around a vertical axis. In this case, the control output points to the rear and is therefore not visible in this illustration. However, the inlet 108 for the fluid under inlet pressure and the associated pressure relief channel are fully visible. Otherwise, the design is identical to that of the 3 / 2-way valve. Fig. 1 .

[0047] The armature 124 is in an upper position, and the safety spring 144 is largely relaxed. The second actuating cap 180 presses the relief valve member 184 against the spring 188 out of the relief valve seat 192, thereby opening the relief outlet 116 and equalizing the control pressure in the control chamber 120 and at the control outlet with the base pressure at the relief outlet (typically atmospheric pressure). This is facilitated by allowing the fluid (preferably compressed air) to flow through the central bore 128 and the sieve-like openings 282 of the second actuating cap 180.

[0048] Since the armature 124 is in an upper position, it is decoupled from the input valve actuator 152 and thus from the input valve member 156. The spring 176 pushes the input valve actuator 152 upward, thereby pressing the input valve member 156 into the input valve seat 164 and thus closing the inlet 108.

[0049] The other balls 257, 258, and 259 visible at inlet 108 are permanently attached, non-removable locking elements that simply allow for a convenient assembly of the lines. Other designs of these lines without these balls are readily possible.

[0050] In Fig. 2 The pressure relief of the input valve member 156 can be seen. For this purpose, there is an input pressure relief channel 262, which establishes a fluid connection from the inlet 108 to the side of the guide sleeve 172 facing away from the armature 124. The input pressure thus acts not only on the input valve member 156, but also on the pin 168 of the input valve actuating element 152, whereby the actuation of the input valve member 156 requires only a small force from the electromagnetic drive, since no pressure difference needs to be overcome.

[0051] Fig. 3 shows the 3 / 2-way valve 100 in the holding position. Due to the electrical signal, a suitable current flows through the coils 132, 136, exerting a suitable force on the armature 124, which pushes it slightly downward against the spring 144. In this example, the force is sufficient for the relief valve member 184 to be pressed into the relief valve seat 192 by the spring 188. This closes the relief outlet 116, and the pressure in the control chamber 120 or at the control outlet does not drop. Upon further downward movement, the relief valve member 184 is decoupled from the movement of the armature 124.

[0052] In this position, the input valve actuating element 152 is not yet driven by the armature 124. The input valve member 156 is therefore still pressed into the input valve seat 164 by the spring 176 and the input valve actuating element 152, thus closing the inlet 108. The pressure in the control chamber 120 or at the control output therefore does not increase, but remains constant.

[0053] In this state, apart from minor leaks, there is no fluid consumption.

[0054] In Fig. 4 The armature 124 of the 3 / 2-way valve 100 is in a lower position. This is achieved by a suitable higher current flowing through the coils 132, 136 due to another electrical signal, thereby exerting a greater force on the armature 124, which pushes it further downward against the spring 144. The relief valve member 184 is now decoupled from the movement of the armature 124, and the relief outlet 116 remains closed, so that the control pressure does not drop.

[0055] In this position, the armature 124 presses the connecting rods 160 of the input valve actuating element 152 downward by means of the first actuating cap 148. The input valve actuating element 152 lowers against the spring 176 and thus actuates the input valve member 156, which can lower itself from the input valve seat 164. The inlet 108 for the pressurized fluid is thus opened. Since the bores 406 in the housing for the connecting rods 160 of the input valve actuating element 152 have a sufficiently larger diameter than the connecting rods 160, the fluid flows under pressure through these bores 406 into the control chamber 120, whereby the pressure there and at the control output increases accordingly. Preferably, further bores are provided which connect the area located behind the input valve seat in the flow direction with the control chamber. However, these are not shown.

[0056] Fig. 5shows an input valve actuating element 152 that can be used in 3 / 2-way valves according to the invention. The - preferably three - connecting rods 160 engage around the input valve seat in such a way that the movement of the armature toward the input valve seat enables a backward actuation of the input valve member in order to open it. Since the bores in the valve housing, in which the connecting rods preferably run, can be larger than the diameter of the connecting rods 160, the input valve actuating element 152 is preferably guided in a guide sleeve by means of the pin 168. This design also allows the pin 168 to be used as a pressure relief piston. To achieve good mobility of the input valve actuating element 152, it preferably has through bores 530.These allow the fluid to flow through the inlet valve actuating element 152, thereby significantly reducing the flow resistance during movements of this element.

[0057] A variant of the 3 / 2-way valve without a fail-safe position is also possible. In this case, spring 144 can be omitted. In the de-energized state, no force acts on the armature, so neither the relief nor the input valve elements are actuated. The control pressure then remains unchanged. By applying an appropriate electrical signal, e.g., a suitably directed control current through the coils, the armature can be moved both up and down, for example, increasing or decreasing the control pressure as described. This variant requires less electrical power because the offset current for canceling the spring preload is eliminated.

[0058] In the event that absolutely no fluid may be lost, a variant of the 3 / 2-way valve is possible in which the pressure relief at the inlet valve element or inlet valve actuating element and / or at the relief valve element is realized by diaphragms instead of pistons running in guide sleeves or guide cylinders. glossary 3 / 2-way valve

[0059] Directional control valves are used in fluid technology to open or close the flow path for the working medium (e.g., compressed air or hydraulic fluid), or to change the flow direction. Directional control valves are described by the number of ports and the number of switching positions. A 3 / 2-way control valve, for example, has three ports and two switching positions. anchor

[0060] In electrical engineering, the armature, in the narrower sense, refers to the rotor (rotor) of DC motors and single-phase series-wound motors, or the electrically active part of the rotor—where "rotor" does not necessarily mean that the part rotates. The armature is also the moving iron core of electrical relays, contactors, and electromagnets (according to https: / / de.wikipedia.org / wiki / Anker_(Elektrotechnik)). Base pressure

[0061] Base pressure refers to the minimum pressure that a fluid contained in a system, facility, or component can assume. In many cases, this is ambient or atmospheric pressure, typically approximately 1 bar. Inlet valve element, expansion valve element

[0062] A valve member is the element that closes a valve's flow opening when pressed against the valve seat. The inlet valve member closes or releases the inlet valve seat behind the inlet of the 3 / 2-way valve, while the relief valve member closes or releases the relief valve seat upstream of the relief outlet of the 3 / 2-way valve. Inlet valve seat, relief valve seat

[0063] A valve seat typically surrounds a valve's flow opening. The valve seat usually forms the counterpart to the valve element and is shaped to match it. This ensures that the valve closes tightly, while also allowing the flow cross-section to be dependent on the valve element's position, if desired. The inlet valve seat surrounds the flow opening behind the inlet of the 3 / 2-way valve, while the relief valve seat surrounds the flow opening before the relief outlet of the 3 / 2-way valve. electrical (input) signal

[0064] An electrical input signal can be an electrical voltage from a voltage source or an electrical current from a current source. Input signals can also be generated by resistors, switches, or binary contacts. They can be either analog or digital in nature. Fluid

[0065] Fluid is a common term for gases and liquids. Reference symbol

[0066] 100 3 / 2-way valve 104 Housing 108 Inlet 112 Control outlet 116 Relief outlet 120 Control chamber 124 Armature 128 Central bore 132 Coil 136 Coil 140 Return sleeve 144 Spring for safety function 148 First actuating cap 152 Inlet valve actuating element 156 Inlet valve member 160 Connecting rod 164 Inlet valve seat 168 Pin 172 Guide sleeve 176 Spring 180 Second actuating cap 184 Relief valve member 186 Guide cylinder 188 Spring 192 Relief valve seat 196 Outlet pressure relief channel 257, 258, 259 Closing ball 262 Inlet pressure relief channel 282 Sieve-like Opening 406Bore for connecting rod 530Through-bore of the inlet valve actuator cited literature cited patent literature

[0067] DE 10 2015 122229 A1 DE 10 2015 005369 A1 DE 10 2018 124310 A1

Claims

1. A 3 / 2-way valve (100) for controlling and / or regulating a control pressure of a pressurized fluid by means of an electrical signal: 1.1 with three fluid connections: - an inlet (108) for the fluid under an inlet pressure; - a control outlet (112) for the fluid under the control pressure; - an expansion outlet (116) for the fluid against a base pressure which is lower than the inlet pressure; 1.1.1 wherein, using the 3 / 2-way valve, a fluid connection can be produced between - the inlet (108) and the control outlet (112), as well as between - the control outlet (112) and the expansion outlet (116); 1.1.2 wherein an inlet valve seat (164) with an inlet valve member (156) is connected downstream of the inlet (108); 1.1.3 wherein an expansion valve seat (192) with an expansion valve member (184) is connected upstream of the expansion outlet (116); 1.1.4 wherein both the inlet valve member and the expansion valve member each have a closed position; 1.2 with an armature (124); 1.2.1 wherein the armature (124) actuates both the inlet valve member (156) and the expansion valve member (184); 1.2.2 wherein the armature (124) moves linearly along an axis for actuation; 1.2.3 wherein the armature (124) is a permanent magnet magnetized along the axis; 1.3 with an electromagnetic drive which drives the armature (124) in such a way that it assumes a desired position depending on the electrical signal; 1.3.1 wherein the electromagnetic drive comprises at least one coil (132, 136); 1.3.1.1 wherein the coil (132, 136) is arranged radially outside the armature (124) with respect to the axis; 1.4 wherein the armature (124) is decoupled from the inlet valve member (156) and the expansion valve member (184) such that the inlet valve member (156) and the expansion valve member (184) follow a movement of the armature (124) only up to the closed position of each; 1.5 wherein the inlet valve seat (164) is arranged along the axis of the armature (124); 1.6 wherein the inlet valve seat (164) and the inlet valve member (156) are oriented such that the inlet valve member (156), for opening, is lifted out of the inlet valve seat (164) in the direction away from the armature (124); characterized in that 1.7 the 3 / 2-way valve (100) has an inlet valve actuating element (152) 1.7.1 wherein the inlet valve actuating element (152), going out from the armature (124), engages around the inlet valve seat (164) and actuates the inlet valve member (156) from the side facing away from the armature (124).

2. The 3 / 2-way valve (100) according to the immediately preceding claim, characterized in that 2.1 the 3 / 2-way valve has a first actuating cap (148) which transmits movements of the armature (124) to the inlet valve actuating element (152); and 2.2 in that the inlet valve actuating element (152) has a plurality of preferably 3 connecting rods (160); 2.2.1 wherein the connecting rods are arranged parallel to the axis, passing by the inlet valve seat (164); and 2.2.2 wherein the connecting rods are actuated by the first actuating cap (148).

3. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that 3.1 the 3 / 2-way valve has a guide sleeve (172) arranged parallel to the axis; and 3.2 in that the inlet valve actuating element (152) has a pin (168) which is guided in the guide sleeve.

4. The 3 / 2-way valve (100) according to claim 2, 4.1 wherein the 3 / 2-way valve has a housing (104), characterized in that 4.2 the housing has bores (406) for the connecting rods (160) of the inlet valve actuating element (152); 4.2.1 wherein the bores have a larger diameter than the connecting rods; and / or 4.3 in that the inlet valve actuating element (152) has through-bores (530) through which the fluid can flow.

5. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the inlet valve actuating element (152) is pretensioned by a spring (176) such that, in the unactuated state, it presses the inlet valve member (156) into the inlet valve seat (164).

6. The 3 / 2-way valve (100) according to claim 3, characterized in that at least one inlet pressure expansion channel (262) is provided which provides a fluid connection from the inlet (108) to the side of the guide sleeve (172) and / or of the pin (168) of the inlet valve actuating element (152) facing away from the armature (124).

7. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the expansion valve seat (192) is arranged along the axis behind the armature (124), as seen from the inlet valve seat (164).

8. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that 8.1 the 3 / 2-way valve has a second actuating cap (180) which transmits movements of the armature (124) to the expansion valve member (184); 8.2 wherein the second actuating cap is perforated in a sieve-like manner.

9. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the expansion valve member (184) is pretensioned by a spring (188) such that in the unactuated state it is pressed into the expansion valve seat (192).

10. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that at least one outlet pressure expansion channel (196) is provided which provides a fluid connection from a region (120) in which the armature (124) is located to the side of the expansion valve member (184) facing away from the armature.

11. The 3 / 2-way valve according to claims 6 and 10, characterized in that the cross section of the side of the expansion valve member facing away from the armature and / or of the side of the pin of the inlet valve actuating element facing away from the armature, on which the pressure expansion acts in each case, is larger than the effective cross section of the associated valve seat.

12. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the inlet valve seat (164) and the expansion valve seat (192) are arranged at a distance from each other such that, between a first position of the armature (124) in which the actuation of the inlet valve member (156) begins and a second position of the armature in which the actuation of the expansion valve member (184) begins, there is an idle travel path which is at least large enough that the actuation of the inlet valve member and the actuation of the expansion valve member cannot overlap.

13. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the 3 / 2-way valve has a spring (144) connected to the armature (124) which is pretensioned such that the 3 / 2-way valve assumes a safety position when no electrical signal is present.

14. The 3 / 2-way valve (100) according to any of the preceding claims, characterized in that the armature (124) is designed as a cylindrical magnet with at least one bore (128) arranged parallel to the axis.

15. The 3 / 2-way valve according to any of the preceding claims, characterized in that 15.1 the electromagnetic drive has two coils (132, 136); 15.2 wherein the coils (132, 136) are arranged radially outside the armature (124) with respect to the axis; and 15.3 wherein the two coils (132, 136) are either 15.3.1 connected in series and wound in opposite directions, or 15.3.2 are wound in the same direction and connected in opposite directions.

16. The 3 / 2-way valve according to any of the preceding claims, characterized in that 16.1 the electromagnetic drive has a cylindrical magnetic return sleeve (140) made of magnetically conductive material; 16.2 wherein the magnetic return sleeve (140) is arranged radially outside the coils (132, 136) with respect to the axis.