EP3227592A1

EP3227592A1 - Valve having a metal-bellows/piston unit

Info

Publication number: EP3227592A1
Application number: EP15787483.5A
Authority: EP
Inventors: Tadeusz Glazewski
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-12-05
Filing date: 2015-10-08
Publication date: 2017-10-11
Also published as: US10295068B2; US20170370481A1; WO2016087097A1; DE102014224979A1

Abstract

The invention relates to a valve (1), comprising a valve housing (4) and a closing body (3) arranged in the valve housing (4) in such a way that the closing body can be moved longitudinally, wherein at least one inlet channel (5) and at least one outlet channel (6) are arranged in the valve housing (4). The closing body (3) interacts with a valve seat (8) formed on the valve housing (4) by means of the longitudinal motion of the closing body and thereby opens and closes at least one hydraulic connection between the at least one inlet channel (5) and the at least one outlet channel (6). The closing body (3) can be driven by means of a metal-bellows/piston unit (2), wherein the metal-bellows/piston unit (2) has a variable-length metal bellows (20) and a variable-volume working chamber (23) and wherein the metal bellows (20) bounds the working chamber (23) in a sealing manner.

Description

title

VALVE WITH METAL BALE PISTON UNIT

description

The invention relates to a valve with a metal bellows-cylinder unit, wherein the valve is driven by the metal bellows-cylinder unit. The

Valve according to the invention can for example in a

Waste heat recovery system of an internal combustion engine can be used.

Prior Art Valves are known in various designs from the prior art.

A known valve comprises a valve housing and a longitudinally movably arranged in the valve housing closing body. At least one inlet channel and at least one outlet channel are arranged in the valve housing. The closing body cooperates by its longitudinal movement with a valve seat formed on the valve housing and thereby opens and closes at least one hydraulic connection between the at least one inlet channel and the at least one outlet channel. Such a valve is, for example, as a control valve for a fuel injector from the published patent application

DE102011004640 AI known.

Furthermore, it is known from the published patent application DE102013114769 AI that such valves in a waste heat recovery system for a

Internal combustion engine as intake or exhaust valves for a in Abwärm recovery system arranged expander can be used.

From the publication DE112012004058 AI is also a

Electromagnetically controllable valve known, which is arranged as a bypass valve in a waste heat recovery system.

Due to the effects of the known valves open and closed positions are quickly and robust controlled, intermediate positions such as throttle positions, however, are no longer fast and robust controllable.

Disclosure of the invention

The valve according to the invention, which is drivable with a metal bellows-cylinder unit, has the advantage that all valve positions can be controlled quickly and robustly. As a result, the flow rates through the valve can be very well controlled quantitatively and also any

Throttle functions of the valve are very well realized and used.

For this purpose, the valve comprises a valve housing and a longitudinally movably arranged in the valve housing closing body. At least one inlet channel and at least one outlet channel are arranged in the valve housing. The closing body cooperates by its longitudinal movement with a valve seat formed in the valve housing and thereby opens and closes at least one hydraulic connection between the at least one inlet channel and the at least one outlet channel. The closing body can be driven by a metal bellows-cylinder unit. The metal bellows-cylinder unit has a length-adjustable metal bellows, wherein the metal bellows a

volume changeable working space sealingly limited. This is the result

Metal bellows on the one hand part of the drive of the valve, on the other hand, it also seals the working space to the environment.

Advantageously, the closing body of the metal bellows-cylinder unit against the spring force of a valve spring is driven. The valve spring can thereby simply pushing the closing body back to its starting position.

Due to the control by the metal bellows-cylinder unit valve according to the invention is very robust in all possible valve positions can be controlled. Due to the pressure in the working space of the metal bellows-cylinder unit, the closing body is displaced and thus reaches a certain valve position. Advantageously, the closing body is clamped between the metal bellows cylinder unit and a valve spring.

In an advantageous development, the metal bellows-cylinder unit comprises a first cylinder, wherein the first cylinder is arranged to be displaceable relative to the valve housing. As a result, the metal bellows-cylinder unit can be stretched or

be compressed by the metal bellows is stretched or compressed; There then occurs a relative displacement between the first cylinder and the valve housing. The closing body of the valve is thus in a simple and reliable manner by the expanding or upsetting metal bellows cylinder unit

driven. The first cylinder does not necessarily have to be cylindrically shaped, but may for example also be tapered.

Advantageously, the metal bellows-cylinder unit comprises a second cylinder, wherein the second cylinder is fixedly connected to the valve housing, in particular screwed. As a result, the second cylinder is fixed to the valve housing and only the first cylinder must be guided displaceably. The second cylinder need not be cylindrically shaped as a whole, only his part connected to the metal bellows advantageously has a cylindrical or conical shape.

In one embodiment of the valve according to the invention, the first cylinder interacts with the closing body. This results in a direct power transmission from the first cylinder to the closing body. Any assembly tolerances between the first cylinder and closing body can be compensated by the contact between the first cylinder and closing body is frictionally engaged. In another embodiment of the valve according to the invention, the first cylinder and the closing body are made in one piece. This will be the

Component number of the valve is reduced, and the valve can be made correspondingly cheaper.

In an advantageous development of the valve, a cylinder bore is formed in the second cylinder. Inside the metal bellows is a volume changeable between the first cylinder and the second cylinder

Additional volume formed, which forms the working space together with the cylinder bore. As a result, the working space can be filled or emptied in a simple manner through the cylinder bore.

In an alternative embodiment, a blind hole is formed in the first cylinder and a cylinder bore in the second cylinder. In the interior of the metal bellows, a volume-variable additional volume is formed between the first cylinder and the second cylinder. The blind hole forms together with the cylinder bore and the additional volume the working space. As a result, on the one hand, the working space is increased, so that the pressure increase within the metal bellows-cylinder unit can be better controlled. On the other hand, by the blind hole, the moving mass of the first

Cylinder reduces and thus its inertia; All valve positions can thus be controlled reliably and quickly without ringing.

In a further development of the valve, the working space of a control unit with a working fluid can be filled, the cylinder bore by a

Connecting cable is connected to the control unit. The working fluid can be easily promoted through the cylinder bore in the working space or emptied from this. Preferably, the control unit fills or deflates the working space as a function of different physical variables, for example a pressure and / or a temperature in

Inlet channel. As a working fluid can be used both a liquid and gas.

In an advantageous development of the valve, the closing body comprises a first lock cylinder and a second lock cylinder. The first Lock cylinder cooperates with the valve seat, and the second

Lock cylinder cooperates with a valve housing formed in the further valve seat. The additional valve seat expands the functionality of the valve.

Advantageously, a further outlet channel is arranged in the valve housing, wherein the second lock cylinder cooperates with the further valve seat and thereby opens and closes a further hydraulic connection between the inlet channel and the further outlet channel. As a result, the valve has three ports and at least two valve positions. For example, by this design, a 3/2-way valve can be displayed.

In an advantageous embodiment, in a first valve position of the valve, the first hydraulic connection is opened and the second hydraulic connection is closed and in a second valve position of the valve the first hydraulic connection is closed and the second hydraulic connection is opened. This ensures that in the two end positions of the valve, the first hydraulic connection and the second hydraulic

Connection is closed while the other hydraulic

Connection is open. Thus, the valve, for example, very well

Bypass valve can be used.

In an advantageous development, the first hydraulic connection and the second hydraulic connection are opened in a third valve position of the valve. As a result, for example, a 3/3-way valve can be displayed.

The reliable and fast control of valve positions is particularly well suited to valves that have a variety of valve positions. The mass flow of a fluid from the inlet channel to the outlet channel or to the further outlet channel can thereby be arbitrarily divided.

In another advantageous development, the first hydraulic connection and the second hydraulic connection are closed in a third valve position of the valve. As a result, both the outlet channel and the further outlet channel can be closed. The valve fulfills the function of two check valves in this valve position. In an advantageous embodiment, the valve according to the invention is arranged in a waste heat recovery system of an internal combustion engine. The waste heat recovery system comprises a working medium carrying circuit, wherein the circuit in the flow direction of the working medium comprises a collecting container, a pump, an evaporator, a bypass valve, an expansion machine and a condenser. Parallel to

Expansion machine is arranged a bypass line, wherein the bypass valve controls the mass flow of the working medium to the expansion machine and the bypass line. The bypass valve is the valve according to the invention. As a result, the mass flow of the working medium can be divided as desired between the expansion machine and the bypass line. This can be done, for example, depending on the degree of evaporation of the working medium or the temperature of the working medium.

In another advantageous embodiment, the valve according to the invention is arranged in a further waste heat recovery system of an internal combustion engine. The further waste heat recovery system has a working medium leading circuit, wherein the circuit in the direction of flow of the working fluid a sump, a pump, a distribution valve, two evaporators in parallel, an expansion machine and a

Capacitor includes. The distribution valve controls the mass flows of the working medium to the two evaporators. The distribution valve is the valve according to the invention. As a result, depending on the performance of the two evaporators, the mass flow of the working medium can be optimally divided between the two evaporators. Even with fast changing

Operating situations of the internal combustion engine thus almost any valve positions of the valve can be controlled quickly.

drawings

Fig.l shows a longitudinal section of an embodiment of the

Valve according to the invention, wherein only the essential areas are shown. 2 shows a longitudinal section of a further embodiment of the valve according to the invention, wherein only the essential areas are shown.

3 shows a longitudinal section of a further embodiment of the valve according to the invention, wherein only the essential areas are shown.

4 shows a longitudinal section of a development of the valve according to the invention, wherein only the essential areas are shown.

Figure 5 shows a similar embodiment of the valve as Figure 4, but in addition to a control of the metal bellows-cylinder unit, the control is shown only schematically.

6 shows schematically the valve according to the invention within a

Waste heat recovery system.

7 shows schematically the valve according to the invention within a further waste heat recovery system.

description

Fig.l shows a longitudinal section of an embodiment of the

Valve 1 according to the invention, wherein only the essential areas are shown. The valve 1 comprises a metal bellows-cylinder unit 2 and a

Valve housing 4, wherein in the valve housing 4, an inlet channel 5 and an outlet channel 6 are formed. Furthermore, in the valve housing 4 a

Housing bore 7 is formed, in which the inlet channel 5 and the outlet channel 6 open. In the embodiment of Fig.l the valve housing 4 is made in two parts, with a first housing part 4a and a second housing part 4b, which are bolted together. The bellows-cylinder unit 2 comprises a first cylinder 22, a second cylinder 21 and a metal bellows 20. The first cylinder 22 and the second cylinder 21 are arranged displaceable in the axial direction relative to each other and mechanically connected to each other and through the metal bellows 20 sealed on the outside. The first cylinder 22 is arranged longitudinally movable in the housing bore 7. The second cylinder 21 is rigid to

Valve housing 4 is arranged.

In the second cylinder 21, a cylinder bore 21 a is formed and in the first cylinder 22 a blind hole 22 a. In addition to the blind hole 22a 22 further holes may be formed in the first cylinder, for example, to connect more valves 1 in series. The metal bellows 20 is at least partially surrounding the first cylinder 22 and the second cylinder 21, so that the interior of the metal bellows 20 hydraulically with the

Cylinder bore 21a and blind hole 22a is connected and thereby forms a working space 23. The working space 23 thus includes the

Cylinder bore 21 a, the blind hole 22 a and inside the

Metal bellows 20 formed additional volume 20 a, which is variable due to the extensibility of the metal bellows 20. Preferably, the metal bellows 20 is made of a good deformable thin metal.

In an alternative to Fig.l embodiment, the metal bellows 20 may also be partially disposed within the blind hole 22a, so that a pressure increase in the working space 23, the sealing effect between the metal bellows 20 and first cylinder 22 supported by the surface pressure between the metal bellows 20 and first cylinder 22 increases becomes.

On the first cylinder 22, a closing body 3 is arranged, for example screwed or pressed. The closing body 3 acts through the

Longitudinal movement of the first cylinder 22 together with a valve seat 8 formed on the valve housing 4 and thereby opens and closes a hydraulic connection from the inlet channel 5 to the outlet channel 6. Der

Closing body 3 is arranged by a in the housing bore 7

Valve spring 9 pressed against the valve seat 8. When filling the working space 23, the metal bellows cylinder unit 2 expands against the spring force of Valve spring 9 and the closing body 3 is lifted from the valve seat 8. When emptying the working space 23, the metal bellows-cylinder unit 2 is compressed by the spring force of the valve spring 9 and the closing body 3 is pressed against the valve seat 8. In the embodiment of Fig.l the interaction of closing body 3 and valve seat 8 is designed as a poppet valve.

In alternative embodiments, the first cylinder 22 has no

Blind hole 22a, so that the working space 23 includes only the cylinder bore 21a and the additional volume 20a. Although this reduces the volume of the

Working space 23, at the same time, however, the manufacturing cost of the first cylinder 22 are lowered. The exemplary embodiments described below can each alternatively be carried out without blind hole 22a. 2 shows a longitudinal section of a further embodiment of the valve 1 according to the invention, wherein only the essential areas are shown. In the following, only the differences from the exemplary embodiment of FIG. 1 will be discussed. In the embodiment of Figure 2, the second cylinder 21 with the

Screwed valve housing 4. The first cylinder 22 and the needle-shaped closing body 3 are made in one piece. The valve seat 8 is arranged surrounding the inlet channel 5 annular. The valve spring 9 is clamped between the first cylinder 22 and the valve housing 4 and, unlike the exemplary embodiment of FIG. 1, acts on the closing body 3.

3 shows a longitudinal section of a further embodiment of the valve 1 according to the invention, wherein only the essential areas are shown. Here too, only the differences to the

Embodiment of Fig.l received.

In this embodiment, the closing body 3 is made with the first cylinder 22 in one piece. For this purpose, the first cylinder 22 is arranged longitudinally movable in the housing bore 7, wherein the housing bore 7 and the

Valve seat 8 represents. The valve 1 is thus designed as a slide valve. The Valve spring 9 is clamped between the first cylinder 22 and the valve housing 4 and has an opening effect on the hydraulic connection between the inlet channel 5 and the outlet channel 6. In alternative embodiments, the valve spring 9 can also act as a closing device.

4 shows a longitudinal section of a development of the valve 1 according to the invention, wherein only the essential areas are shown. The valve 1 of Figure 4 is designed as a slide valve with two outlet channels 6, 6b. For this purpose, the outlet channel 6 and a further outlet channel 6b open into the

Housing bore 7. The closing body 3 comprises a first lock cylinder 3a, a second lock cylinder 3b and a connecting bolt 3c for connecting the two lock cylinders 3a, 3b. It can be the first

Lock cylinder 3a, the second lock cylinder 3b and the connecting pin 3c be made in one piece but also in several parts.

The first lock cylinder 3a cooperates with the first cylinder 22 of the metal bellows cylinder unit 2. Alternatively, the first lock cylinder 3a and the first cylinder 22 may be made in one piece. The second cylinder 21 is bolted to the valve housing 4.

On the valve housing 4, the valve seat 8 and another valve seat 8b

formed, wherein the valve seat 8 surrounds the outlet channel 6 and the further valve seat 8b, the further outlet channel 6b. In the exemplary embodiment of FIG. 4, the valve seat 8 and the further valve seat 8b are part of the regions

Housing bore 7 is formed. The first lock cylinder 3a cooperates with the valve seat 8 and the second lock cylinder 3b with the further valve seat 8b.

The Figure 5 shows a similar embodiment of the valve 1 as in Figure 4, but in addition to a control of the metal bellows-cylinder unit 2, wherein the control is shown only schematically. The control of the valve 1 is effected by a control unit 50. The control unit 50 comprises a control valve 53, two electrical connections 61, 62, a low-pressure accumulator 51, a pressure supply 52 and a connection line 54. The connecting line 54 leads from the control valve 53 to the cylinder bore 21 a of the metal bellows-cylinder unit 2. About the control valve 53 is the

Connecting line 54 switchable either with the low-pressure accumulator 51 or with the pressure supply 52 hydraulically or pneumatically coupled. The low pressure accumulator 51 and the pressure supply 52 can thereby

for example, be filled with a hydraulic oil or with air; Accordingly, the control of the metal bellows cylinder unit 2 is carried out either hydraulically or pneumatically. The control of the control valve 53 is carried out electrically by the two electrical connections 61, 62 and is preferably carried out by a control unit, not shown.

Fig.6 shows the valve 1 according to the invention within a

Waste heat recovery system 100 as a bypass valve. The

Waste heat recovery system 100 has a working medium leading circuit 100 a, in the flow direction of the working medium a

Sump 101, a pump 102, an evaporator 103, the valve 1 as a bypass valve, an expansion machine 104 and a condenser 105 includes. Liquid working fluid is removed by the pump 102 from the

Collective container 101 is conveyed into the evaporator 103 and evaporated there by the heat energy of an exhaust gas of an internal combustion engine. The vaporized working medium is then in the expansion machine under release of mechanical energy, for example, to a generator, not shown, or to a non-illustrated transmission relaxed. Subsequently, the working medium in the condenser 105 is liquefied again and in the

Sump 101 returned.

According to the invention, the valve 1 as a bypass valve for the

Expander 104 used. For this purpose, a bypass line 106 is arranged parallel to the expansion machine 104. Depending on the operating condition of the

Internal combustion engine and resulting variables, for example

Temperatures of the working medium, the working medium of

Expander 104 supplied or passed by the bypass line 106 on the expander. By way of example, a temperature sensor 107 is arranged in front of the condenser 105. The temperature sensor 107 detects the temperature of the working medium in front of the condenser 105 and transmits corresponding signal to a control unit 108. The control unit 108 controls depending on various data, such as the temperature of the working medium in front of the condenser 105, via the two electrical

Ports 61, 62, the control unit 50 at. The control unit 50 is connected via the connecting line 54 to the valve 1. The valve 1 is switched so that the working medium is guided either by the expansion machine 104, or by the bypass line 106. If the valve 1 is designed as a 3/3-way valve, then the mass flow of the working medium can also be divided, so that a part the working medium of the expansion machine 104 is supplied and another part of the bypass line 106th

7 shows the valve 1 according to the invention within an alternative further waste heat recovery system 100 'as distributor valve 1. In contrast to the embodiment of FIG. 6, the circuit 100a' of this further waste heat recovery system 100 'comprises a first evaporator 103a and a second evaporator 103b connected in parallel; For example, the first evaporator 103a may be connected to an exhaust pipe of the internal combustion engine and the second evaporator 103b may be connected to an exhaust gas recirculation line of the internal combustion engine.

The valve 1 according to the invention is designed as a 3/3-way valve and arranged in front of the two evaporators 103a, 103b, so that it divides the mass flow of the working medium to the two evaporators 103a, 103b. By way of example, a first pressure sensor 111 after the first evaporator 103a and a second pressure sensor 112 after the second evaporator 103b are arranged, which can be used as control variables within the waste heat recovery system 100 '. The signals of the two pressure sensors 111, 112 are supplied to the control unit 108 ', which from these data a

Control determined for the control unit 50 and controls the control unit 50 accordingly, so that the valve 1, the mass flow of the

Working medium optimally divided on the two evaporators 103 a, 103 b.

The operation of the valve 1 according to the invention is as follows: The valve 1 is driven by the control unit 50. That is: that

Control valve 53 connects the cylinder bore 21a of the metal bellows cylinder unit 2 either with the low-pressure accumulator 51 or with the pressure supply 52. The low-pressure accumulator 51 is at atmospheric pressure

Working fluid - for example, hydraulic oil or air - filled. The pressure supply 52, however, has under working pressure - for example, 1.5 bar to 15 bar - standing working fluid.

If the cylinder bore 21a connected to the low-pressure accumulator 51, so is the working space 23 of the metal bellows-cylinder unit 2 under the

Pressure level of the low-pressure accumulator 51, and the closing body 3 is pressed by the valve spring 9 in a first valve position in the direction of the metal bellows-cylinder unit 2, so that the metal bellows 20 is compressed.

If the cylinder bore 21 a connected to the pressure supply 52, so is the working space 23 of the metal bellows-cylinder unit 2 under the

Pressure level of the pressure supply 52. The closing body 3 is thus pressed by the pressure of the working fluid to the first cylinder 22 against the spring force of the valve spring 9 in a second valve position of the metal bellows-cylinder unit 2, so that the metal bellows 20 is stretched.

Depending on the embodiment of the valve 1, the first and the second

Valve position different functions:

Embodiment of FIG.

o First valve position: The closing body 3 is pressed by the valve spring 9 against the valve seat 8 and thereby closes the hydraulic

Connection from the inlet channel 5 to the outlet channel 6.

Second valve position: The closing body 3 is pushed away by the metal bellows cylinder unit 2 from the valve seat 8 and thereby opens the hydraulic connection from the inlet channel 5 to the outlet channel 6.

Embodiments of FIGS. 2 and 3:

o First valve position: The closing body 3 is pushed away or pushed away from the valve seat 8 by the valve spring 9 and thereby opens the hydraulic connection from the inlet channel 5 to the outlet channel 6. o Second valve position: The closing body 3 is pressed by the metal bellows cylinder unit 2 against the valve seat 8 or over the valve seat

8 and thereby closes the hydraulic connection from the inlet channel 5 to the outlet channel 6.

Embodiments of Figure 4 and Figure 5 as a 3/2-way valve:

o First valve position: The first lock cylinder 3a is pushed by the valve spring

9 pushed away from the valve seat 8 and at the same time the second

Lock cylinder 3b pushed over the other valve seat 8b. This opens the hydraulic connection from the inlet channel 5 to the outlet channel 6 and closes a further hydraulic connection from the inlet channel 5 to the further outlet channel 6b.

o Second valve position: The second lock cylinder 3b is through the

Metal bellows cylinder unit 2 pushed over the valve seat 8 and at the same time the second lock cylinder 3b pushed away from the other valve seat 8b. This will make the hydraulic connection from

Inlet duct 5 to the outlet channel 6 is closed and opened the other hydraulic connection from the inlet channel 5 to the further outlet channel 6b.

Embodiments of Figure 4 and Figure 5 as 3/3-way valve: This

Embodiments have in addition to those described above

Embodiments a third valve position on:

o First valve position: as above with the 3/2-way valve.

o Second valve position: as above with the 3/2-way valve.

o Third valve position: The third valve position is an intermediate position between the first and second valve position, that is, the working space 23 of the metal bellows-cylinder unit is under a pressure level which is between the pressure level of the low-pressure accumulator 51 and the

Pressure level of the pressure supply 52 is located; This can for example be achieved by the working space 23 only briefly pressurized working fluid from the pressure supply 52 is supplied, or by the control valve 53 has a further connection to a

Has intermediate pressure accumulator. In the third valve position, both the hydraulic connection from the inlet channel 5 to the outlet channel 6 and the further hydraulic connection from the inlet channel 5 to the further outlet channel 6b are opened. In all embodiments of the valve 1 shown, the metal bellows cylinder unit 2 shifts when filling the working space 23, the closing body 3 against the spring force of the valve spring 9. Alternatively to the valve spring 9, but also with a membrane or a

Compression volume can be used, which push back the closing body 3 when emptying the working space 23, so that the metal bellows cylinder unit 2 is compressed.

The embodiments of the valve 1 according to the invention of FIGS. 4 and 5 as a 3/3-way valve are very well suited for use within a waste heat recovery system 100, 100 'of an internal combustion engine, as shown in FIGS. 6 and 7. In this case, the third valve position can be designed so that both the hydraulic connection from the inlet channel 5 to

Outlet channel 6 and the other hydraulic connection from the inlet channel 5 to the further outlet channel 6b are either open or closed.

Claims

claims

1. Valve (1) with a valve housing (4) and a longitudinally movable in the valve housing (4) arranged closing body (3), wherein in the valve housing (4) at least one inlet channel (5) and at least one outlet channel (6) are arranged, wherein the closing body (3) by its longitudinal movement cooperates with a valve seat (8) formed in the valve housing (4) and thereby opens and closes at least one hydraulic connection between the at least one inlet channel (5) and the at least one outlet channel (6),

characterized in that

the closing body (3) can be driven by a metal bellows-cylinder unit (2), the metal bellows-cylinder unit (2) having a length-adjustable metal bellows (20), wherein the metal bellows (20) has a variable volume

Working space (23) limited sealing.

2. Valve (1) according to claim 1, characterized in that the metal bellows cylinder unit (2) comprises a first cylinder (22), wherein the first cylinder (22) is arranged displaceably to the valve housing (4).

3. Valve (1) according to claim 2, characterized in that the metal bellows cylinder unit (2) comprises a second cylinder (21), wherein the second cylinder (21) fixedly connected to the valve housing (4), in particular screwed ,

4. Valve (1) according to claim 2 or 3, characterized in that the first cylinder (22) cooperates with the closing body (3).

5. Valve (1) according to claim 2 or 3, characterized in that the first cylinder (22) and the closing body (3) are made in one piece.

6. Valve (1) according to one of claims 2 to 5, characterized in that in the second cylinder (21) has a cylinder bore (21 a) is formed and that in the interior of the metal bellows (20) between the first cylinder (22) and the second Cylinder (21) a variable volume additional volume (20 a) is formed, which together with the cylinder bore (21 a) the

Working space (23) forms.

7. Valve (1) according to one of claims 2 to 5, characterized in that in the first cylinder (22) has a blind hole (22a) is formed, that in the second cylinder (21) has a cylinder bore (21a) is formed and that in the interior the metal bellows (20) between the first cylinder (22) and the second cylinder (21) a volume variable additional volume (20a) is formed, wherein the blind hole (22a) together with the cylinder bore (21a) and the additional volume (20a) the working space ( 23).

8. Valve (1) according to claim 6 or 7, characterized in that the working space (23) of a control unit (50) can be filled with a working fluid, wherein the cylinder bore (21 a) by a connecting line (54) with the control unit (50 ) connected is.

9. Valve (1) according to one of the preceding claims, characterized

characterized in that the closing body (3) comprises a first lock cylinder (3a) and a second lock cylinder (3b), the first lock cylinder (3a) cooperating with the valve seat (8), and the second lock cylinder (3b) having one in the valve housing (4) formed further valve seat (8b) cooperates.

10. Valve (1) according to claim 9, characterized in that in the valve housing (4), a further outlet channel (6b) is arranged, wherein the second

Lock cylinder (3b) cooperates with the further valve seat (8b) and thereby opens and closes a further hydraulic connection between the inlet channel (5) and the further outlet channel (6b).

11. Valve (1) according to claim 10, characterized in that in a first valve position of the valve (1) opens the first hydraulic connection and the second hydraulic connection is closed and that in a second valve position of the valve (1), the first hydraulic connection closed and the second hydraulic connection is open.

12. Valve (1) according to claim 11, characterized in that in a third valve position of the valve (1) the first hydraulic connection and the second hydraulic connection are opened.

13. Valve (1) according to claim 11, characterized in that in a third valve position of the valve (1) the first hydraulic connection and the second hydraulic connection are closed.

14. waste heat recovery system (100) with a working medium leading circuit (100 a), wherein the circuit (100 a) in the direction of flow of the working medium a collecting container (101), a pump (102), a

Evaporator (103), a bypass valve (1), an expansion machine (104) and a condenser (105), wherein parallel to the expansion machine (104), a bypass line (106) is arranged and wherein the bypass valve (1) Mass flow of the working medium to the expansion machine (104) and to the bypass line (106) controls, characterized in that the bypass valve (1) is a valve (1) according to one of claims 10 to 13.

15. waste heat recovery system (100 ') with a working medium leading circuit (100a'), wherein the circuit (100a ') in the flow direction of the working medium a collecting container (101'), a pump (102 '), a

Distributor valve (1), two evaporators (103a, 103b) in parallel, an expansion machine (104 ') and a condenser (105'), wherein the distribution valve (1) the mass flows of the working medium to the two

Evaporators (103a, 103b) controls, characterized in that the

Distributor valve (1) is a valve (1) according to one of claims 10 to 13.