DE102016224283A1 - EXPANSION VALVE - Google Patents

Abstract

The invention relates to an expansion valve (100) for reducing a pressure of a fluid flowing through the expansion valve (100) along a fluid flow path, the expansion valve (100) comprising: at least one fluid inlet (101) and at least one fluid outlet (102), a first valve element (10) with at least one first channel structure (11), a second valve element (20a, 20b) with at least one second channel structure (22a, 22b) and a third channel structure (23a, 23b), wherein the first valve element (10) and the second Valve element (20a, 20b) are movable relative to each other, wherein in a first position of the valve elements (10; 20a, 20b) the first channel structure (11) and the second channel structure (22a, 22b) are aligned with each other and a first fluid flow path with a first Forming flow resistance between the fluid inlet (101) and the fluid outlet (102), and wherein in a second position of the valve elements (10; 20a, 20b) the e The first channel structure (11) and the third channel structure (23a, 23b) are aligned with each other and form a second fluid flow path having a second flow resistance different from the first flow resistance between the fluid inlet (101) and the fluid outlet (102).

Description

The invention relates to expansion valves for reducing a pressure of a fluid flowing through the expansion valve along a fluid flow path.

Expansion valves can be used for example in refrigeration circuits. 8th shows such a refrigeration cycle 81, as is known in the art. The refrigeration cycle 81 has a condenser 82 and an evaporator 83. Between the condenser 82 and the evaporator 83 is a local constriction 84a, 84b of the flow cross-section, which leads to a reduction of the fluid pressure and causes an increase in volume or expansion of the fluid flowing through. This local restriction 84a, 84b is functionally referred to as a throttle or expansion valve.

In the simplest case, a piece of tube with a very small inner diameter acts as an uncontrolled, non-adjustable expansion element, which is then typically referred to as throttle capillary 84b. Low-cost throttle capillaries are preferably used in systems with low cooling capacity, such as household fridge-freezers.

More elaborate, variable expansion valves 84a are continuously variable valves that allow adjustment of the fluid flowing through. These are preferably used in systems with greater cooling capacity.

A fundamental problem with expansion valves for small cooling capacities is the continuously metered small mass flow of refrigerant, which places extraordinary demands on the precision of a continuously adjustable valve.

Often, therefore, one manages this by the fact that no continuously adjustable valve but a switching valve is used, which is then temporarily completely open or closed, i. is operated in the sense of a pulse width modulation. However, this procedure is not considered as energetically favorable as well as with regard to the system behavior.

A small refrigeration capacity expansion valve may also be referred to as a microexpansion valve.

In the DE 10 2011 004 109 A1 For example, an expansion valve with a continuously variable pinhole will be described. The flow through the aperture is controlled by means of an eccentric cover, which can vary the opening cross-section of the aperture infinitely. However, very high demands are placed on the precision of the diaphragm and on the precision of the stepless drive, which leads to increased production costs.

As an alternative to the aforementioned orifice, channels are known through which the fluid flows. In the case of the perforated diaphragm, the slowing down and thus the expansion of the fluid is mainly due to eddy currents caused at the diaphragm edge. In the case of channels, on the other hand, as the fluid flows through it, additional frictional losses occur along the walls of the channels, since the channels have a significantly longer extent compared to the diaphragm, so that the fluid can spread over the entire length of the channel and thereby be slowed down due to the friction losses.

An expansion valve with channels, for example, in the DE 31 08 051 A1 proposed. Here, a switchable in discrete switching stages expansion valve will be described. There are several discs stacked, forming between the discs radially extending channels through which the fluid can flow. In the center of the discs, a piston is arranged, which is movable in the axial direction to allow a flow of fluid through the individual channels. Due to the stacked in the axial direction of individual discs in combination with the movable piston in the axial direction, this expansion valve has a complicated structure and a large axial height. For devices with small cooling capacities, where usually only a very small space is available, this expansion valve is therefore less well suited.

It is an object of the present invention to improve expansion valves in that they have a simple structure and small dimensions, while at the same time can precisely regulate the flow rate of a fluid.

This object is achieved by an expansion valve with the features of claim 1.

The expansion valve of the invention is configured to reduce a pressure of a fluid flowing through the expansion valve along a fluid flow path. For this purpose, the expansion valve has, inter alia, at least one fluid inlet, through which the fluid can flow into the expansion valve, and at least one fluid outlet, through which the fluid can flow out of the expansion valve. The expansion valve also has a first valve element with at least one first channel structure. Furthermore, the expansion valve has a second valve element with at least one second channel structure and a third channel structure. According to the invention, the first valve element and the second valve element are movable relative to each other, wherein in a first position of the valve elements, the first channel structure and the second channel structure are aligned with each other and form a first fluid flow path with a first flow resistance between the fluid inlet and the fluid outlet. In a second position of the valve elements, the first channel structure and the third channel structure are aligned with each other and form a second fluid flow path having a second flow resistance between the fluid inlet and the fluid outlet that is different from the first flow resistance.

With the expansion valve according to the invention so at least two different switching positions can be taken. Depending on the switching position, this results in a different fluid flow path. The fluid flow paths have different flow resistances. A flow resistance may be, for example, a length of the channel structure through which flows, not necessarily along the channel length uniform cross section of the flowed through channel structure, a change in the flowed cross section or the channel profile, a geometric cross-sectional shape, a roughness of the surface of the walls of the flow-through channel structure, or from a Combination of these parameters. The different flow resistances throttle the flow of the fluid to different extents. The throttle effect can be adjusted by means of a variation of the aforementioned parameters. The expansion valve according to the invention can cause a complete throttling in a switching position, so that the flow of the fluid from the fluid inlet to the fluid outlet is almost completely blocked. The expansion valve according to the invention can, for example, have no significant throttling in another switching position, so that the fluid can flow from the fluid inlet to the fluid outlet almost unhindered. The expansion valve may be any throttle level, i. between complete blockage and complete flow-through capability. This is possible, as previously mentioned, by means of a variation of the channel structure parameters. When the fluid flows through the expansion valve according to the invention, in addition to the throttling of the flow rate, the pressure drop of the fluid pressure, i. the fluid relaxes. The fluid can evaporate at least partially, while at the same time the temperature of the fluid can drop. The amount of pressure drop, as well as the amount of restriction of the flow rate, by the throttle stages, i. through the flow resistance, which determines individual channel structures. The invention thus provides the integration of different flow resistances together with a switchable distributor within a single expansion valve. This can significantly reduce the space required compared to distribution circuits with separate throttles or capillaries. In addition, compared to known continuously adjustable pinhole much lower demands on the required precision of the drive provided, which in turn significantly reduces manufacturing costs.

Conceivable embodiments are mentioned in the dependent claims.

• 1A eine erste Ausführungsform eines erfindungsgemäßen Expansionsventils in einer Explosionsdarstellung und in einer ersten Schaltstellung,
• 1B das Expansionsventil der ersten Ausführungsform in einem zusammengesetzten Zustand und einer ersten Schaltstellung,
• 1C die erste Ausführungsform des erfindungsgemäßen Expansionsventils in einer Explosionsdarstellung und in einer zweiten Schaltstellung,
• 1D das Expansionsventil der ersten Ausführungsform in einem zusammengesetzten Zustand und einer zweiten Schaltstellung,
• 2A eine zweite Ausführungsform eines erfindungsgemäßen Expansionsventils in einer Explosionsdarstellung und in einer ersten Schaltstellung,
• 2B das Expansionsventil der zweiten Ausführungsform in einem zusammengesetzten Zustand und einer ersten Schaltstellung,
• 3A ein Ausführungsbeispiel eines erfindungsgemäßen Expansionsventils gemäß der ersten Ausführungsform in einer Explosionsdarstellung und in einer ersten Schaltstellung, wobei die Kanalstrukturen des zweiten Ventilelements in Reihe geschaltet sind,
• 3B das Expansionsventil aus 3A in einem zusammengesetzten Zustand,
• 4A ein Ausführungsbeispiel eines erfindungsgemäßen Expansionsventils gemäß der zweiten Ausführungsform in einer Explosionsdarstellung und in einer ersten Schaltstellung, wobei die Kanalstrukturen des zweiten Ventilelements in Reihe geschaltet sind,
• 4B das Expansionsventil aus 4A in einem zusammengesetzten Zustand,
• 5A ein Ausführungsbeispiel eines erfindungsgemäßen Expansionsventils gemäß der ersten Ausführungsform in einer Explosionsdarstellung und in einer ersten Schaltstellung, wobei die Kanalstrukturen des zweiten Ventilelements parallel zueinander schaltbar sind,
• 5B das Expansionsventil aus 5A in einem zusammengesetzten Zustand,
• 6A ein Ausführungsbeispiel eines erfindungsgemäßen Expansionsventils gemäß der zweiten Ausführungsform in einer Explosionsdarstellung und in einer ersten Schaltstellung, wobei die Kanalstrukturen des zweiten Ventilelements parallel zueinander schaltbar sind,
• 6B das Expansionsventil aus 6A in einem zusammengesetzten Zustand,
• 7 ein schematisches Blockschaltbild für eine Art der Verschaltung einzelner Flusswiderstände, und
• 8 einen Kältekreislauf aus dem Stand der Technik mit einer Fluid-Expansionsstelle wie sie im Stand der Technik verwendet wird.

Embodiments of the invention are illustrated in the drawings and will be explained below. Show it:

• 1A A first embodiment of an expansion valve according to the invention in an exploded view and in a first switching position,
• 1B the expansion valve of the first embodiment in an assembled state and a first switching position,
• 1C the first embodiment of the expansion valve according to the invention in an exploded view and in a second switching position,
• 1D the expansion valve of the first embodiment in an assembled state and a second switching position,
• 2A A second embodiment of an expansion valve according to the invention in an exploded view and in a first switching position,
• 2 B the expansion valve of the second embodiment in an assembled state and a first switching position,
• 3A An embodiment of an expansion valve according to the invention according to the first embodiment in an exploded view and in a first switching position, wherein the channel structures of the second valve element are connected in series,
• 3B the expansion valve off 3A in a composite state,
• 4A An embodiment of an expansion valve according to the invention according to the second embodiment in an exploded view and in a first switching position, wherein the channel structures of the second valve element are connected in series,
• 4B the expansion valve off 4A in a composite state,
• 5A An embodiment of an expansion valve according to the invention according to the first embodiment in an exploded view and in a first switching position, wherein the channel structures of the second valve element are parallel to each other,
• 5B the expansion valve off 5A in a composite state,
• 6A An embodiment of an expansion valve according to the invention according to the second embodiment in an exploded view and in a first switching position, wherein the channel structures of the second valve element are parallel to each other,
• 6B the expansion valve off 6A in a composite state,
• 7 a schematic block diagram for a type of interconnection of individual flow resistances, and
• 8th a prior art refrigeration cycle having a fluid expansion site as used in the art.

Hereinafter, some embodiments of the invention will be described in more detail with reference to the figures, wherein elements with the same or similar function are provided with the same reference numerals. In addition, all that has been mentioned with reference to a particular embodiment, as it applies to all other embodiments. Hereinafter, to simplify the reading of the description, many features will be described with reference to FIGS 1A to 1D be explained. It goes without saying, however, that all these characteristics also apply to those in the rest 2A to 7 Illustrated embodiments apply.

When fluid is referred to hereinafter, it may mean both a liquid and a gas. Mixed forms of partially gaseous and liquid states of the fluid may also be meant here. In general, the fluid, in the sense of the present disclosure, can be present in all occurring states of aggregation. For example, the fluid upstream of the expansion valve may be in a substantially liquid state, while in the flow direction downstream of the expansion valve (possibly with a downstream evaporator) it may be in a substantially gaseous state. The fluid may include a refrigerant such as e.g. R600a or R134a, his.

The 1A and 1B show a first embodiment of an expansion valve according to the invention 100 , The expansion valve 100 has at least one fluid inlet 101 and at least one fluid outlet 102 on.

The expansion valve 100 also has a first valve element 10 with at least a first channel structure 11 on. Furthermore, the expansion valve 100 a second valve element 20 on. The second valve element 20 can, as shown here by way of example, of two parts 20a . 20b consist. Further embodiments provide that the second valve element 20 is formed in one piece. The second valve element 20 has at least one second channel structure 22a . 22b and a third channel structure 23a . 23b on.

Channel structures in general, and the mapped channel structures 11 . 22a . 22b . 23a , 23b in particular, are in the respective valve element 10 . 20 provided structures, for example in the form of recesses, which provide a flow path for a fluid flowing through.

The first valve element 10 and the second valve element 20 are movable relative to each other. As in particular in 1B can be seen, are in a first position of the valve elements 10 . 20 the first channel structure 11 and the second channel structure 22a . 22b aligned with each other and form a first Fluid flow path 110 with a first flow resistance between the fluid inlet 101 and the fluid outlet 102 ,

The 1C and 1D show a second position of the valve elements 10 . 20 , In this second position of the valve elements 10 . 20 are the first channel structure 11 and the third channel structure 23a . 23b aligned with each other and form a second fluid flow path 111 with a second flow resistance between the fluid inlet other than the first flow resistance 101 and the fluid outlet 102 ,

In 1C For example, to see that the third channel structure 23b in a circular circulating channel structure 55 opens, extending to the fluid outlet 102 extends.

Accordingly, the fluid flows through the third channel structure 23b and the circumferential channel structure 55 , in the 1D partially covered by the drawing, up to the fluid outlet 102 ,

Also the second channel structure 22a . 22b flows into the surrounding canal structure 55 , The circumferential channel structure 55 connects, so to speak, in the second valve element 20 trained channel structures 22a . 22b . 23a . 23b with each other and forms a common feed to the fluid outlet 102 , The amount of the total flow resistance for the fluid flowing through can be composed of a) the flow resistance of the first channel structure 11 of the first valve element 10 , b) the flow resistance of the respective channel structure 22a . 22b , 23a, 23b of the second valve element 20 and c) the flow resistance of the circulating channel structure 55 ,

In the 1B and 1D Thus, various switching positions of the expansion valve 100 are shown. By means of the aforementioned relative movement between the first valve element 10 and the second valve element 20 These switch positions can be achieved. The expansion valve 100 So you can switch back and forth between different switching positions or switching stages.

As in particular in the 1A and 1C can be seen, the second valve element 20 may also, in addition to the second and third channel structures 22a . 22b ; 23a . 23b , also other channel structures 24a . 24b ; 25a . 25b exhibit. These will be described in more detail below.

The individual channel structures may have different flow cross sections, not necessarily the same along the channel length, i. a channel structure may have a variable flow area. According to conceivable embodiments of the invention, the flow cross sections of the individual channel structures can be either constant or even variable.

A variable flow cross section can be achieved, for example, in that the geometric cross section of the respective channel structure changes at least once over its channel length. For example, a channel structure with a variable flow cross-section may have a first flow cross-section at a first location and a second flow cross-section different from the first flow cross-section at a second location.

For example, a channel structure may be designed such that the flow cross-section increases or decreases along the fluid flow direction. According to another conceivable example, the channel structure could have a first flow cross-section at the beginning and at the end and a second (smaller or larger) flow cross-section, e.g. in the form of a constriction and the like.

The flow area of a channel structure may affect the flow rate of a fluid passing through that channel structure. This means, for example, that with the same channel length, a smaller volume of a channel structure causes a smaller flow cross section of this channel structure, which opposes the fluid flowing through a greater flow resistance, whereby the flow rate of the fluid can be throttled.

In addition to the flow cross section, the shape of a channel structure can also decisively influence its flow resistance. Thus, channel structures are conceivable according to the invention, which have a round shape. These can be produced for example by drilling. However, it is also conceivable that the channel structures have a rectangular shape. These can be produced for example by means of milling. In principle, other geometric shapes of the channel structures are conceivable, such as triangular, round, semicircular, or polygonal. For example, a triangular-shaped channel structure may have a higher flow resistance than a quadrangular-shaped channel structure.

Regardless of whether the different flow cross sections are now achieved by means of a variation of the geometric cross section and / or by means of a variation of the geometric shape of the channel structures, different flow cross sections provide the fluid with different flow resistances and thus throttle the flow rate of the fluid to different extents. Accordingly, channel structures having different flow cross sections may also be referred to as different throttle stages for throttling the flow rate.

At the same time, the throttling also causes a decrease in the pressure of the fluid flowing through, ie the pressure of the fluid at the fluid outlet 102 is lowered against the pressure of the fluid at the fluid inlet 101 , When flowing through the fluid through the expansion valve 100 the fluid relaxes. It may also evaporate, at least in part.

The flow rate Q is essentially characterized by the volume flow of a fluid flowing through a certain flow cross section, according to the known formula $$Q=\dot{V}=\frac{dV}{dt}$$

mit der Durchflussrate Q zusammen, wobei p die Dichte des Fluids ist.The mass flow ṁ depends on the relationship $$\dot{m}=\frac{dm}{dt}=\rho \cdot \dot{V}$$

with the flow rate Q, where p is the density of the fluid.

As mentioned above, therefore, the individual channel structures can be referred to as throttle stages, by means of which the expansion valve according to the invention 100 the flow rate or the mass flow of the fluid flowing through can throttle.

According to embodiments of the invention, for example, the second channel structure 22a, 22b have a first flow cross-section, and the third channel structure 23a , 23b may have a second flow cross section different from the first flow cross section. Thus, the expansion valve has 100 So at least two different throttle levels.

The throttle stages can according to the invention have throttle rates between almost 100% and almost 0%. The relative value of the throttle rates refers to the throttling of the flow rate of the fluid between the fluid inlet 101 and fluid output 102 with respect to a period Δt.

A throttling rate of 100% means, for example, that the flow rate of the fluid from the fluid inlet 101 to fluid outlet 102 within this time period Δt is close to zero or equal to zero. The expansion valve 100 thus blocks the flow of fluid. The expansion valve 100 Thus, it can thus provide a "stop function" in which a flow of the fluid is stopped. Because of leaks in valves that are frequently known to the person skilled in the art, the flow rate can only be close to 0%, ie, slightly above 0%. By way of example, a flow rate here can be between 0% and 5% in the event of any leakages occurring.

On the other hand, a throttle rate of almost 0% means that the flow of the fluid is almost not throttled, that is, the flow rate of the fluid from the fluid inlet 101 to fluid outlet 102 in the period Δt is almost 100%. Due to flow and friction losses within the flow-through channel structures, which are known to the person skilled in the art, the flow rate here will normally only be nearly 100%, ie always slightly below 100%. For example, a flow rate here can be between 95% and 100%.

The expansion valve 100 Thus, it is thus possible to provide an "open-function" or "free-flow function" in which a flow of the fluid is possible almost unhindered. In this case, therefore, no significant throttling takes place within the expansion valve 100.

As mentioned above, the expansion valve according to the invention 100 at least two throttle stages, ie, the flow resistance of the first flow path in the first switching position differs from the flow resistance of the second flow path in the second switching position. At least one of the two flow resistances may in this case be designed such that the expansion valve 100 has no significant throttling in the respective switching position. That is, at least one of the two flow paths (first switching position or second switching position) forms an aforementioned "open-function" or "free-flow function".

Such an "open function" can be realized, for example, in that the first and second channel structures forming the first fluid flow path 11 ; 22a . 22b or the first and third channel structures forming the second fluid flow path 11 ; 23a , 23b as one through the first and second valve members 10 ; 20 through hole, such as a hole of the same diameter, are formed, this opening has no significant throttling. That means the expansion valve 100 has a throttle rate of almost 0%, or may have a throttle rate between 0% and a maximum of 5%.

A previously mentioned "stop function" can be realized, for example, by virtue of the fact that the first channel structure 11 in the first valve element 10 with none of the channel structures 22a , 22b, 23a, 23b of the second valve element 20 is aligned. This can be realized, for example, in that the first valve element 10 in a (not explicitly shown) third switching position is moved, for example, between the first switching position ( 1B ) and the second switching position ( 1D ). The first channel structure 11 of the first valve element 10 thus no longer discharges into a further channel structure in the second valve element 20 but directly on the surface 28 ( 1A . 1D ) of the second valve element 20 , The fluid thus no longer becomes the fluid outlet 102 directed, ie the flow of the fluid is thereby blocked or interrupted.

For the purposes of the present disclosure, it is meant that a fluid flow between the fluid inlet 101 and the fluid outlet 102 is interrupted, this means that the fluid flow by means of the position of the valve elements 10 . 20 intentionally to interrupt each other, regardless of whether an unwanted or parasitic flow of the fluid due to possible leakage to valves and the like is present. The flow of fluid that is to be interrupted is the direct flow through the channel structures.

The first valve element 10 can relative to the second valve element 20 be moved for example by means of a stepper motor. This is one of the two valve elements 10 , 20 driven by the stepping motor and with respect to the other of the two valve elements 10 . 20 emotional.

In addition, a transmission may be provided that the drive of the stepper motor accordingly reduced or translated.

If the stop function in the third switching position, as mentioned above, lies between the first and the second switching position, this has particular advantages in terms of a possible energy saving. Imagine an initial position of the valve element connected to the stepper motor 10 . 20 be the third switch position. Then the stepper motor would need the valve element 10 . 20 not over the entire path from the first switching position to the second switching position (or back) proceed, but it is sufficient in this case, the valve element 10 . 20 only to move from the third switching position to the first and second switching position. Since the third shift position is between the first and the second shift position, the stepper motor therefore only has to travel halfway.

In the in the 1A to 1D embodiment shown, the first valve element 10 be driven by the stepper motor. An alternative embodiment in which the second valve element 20 can be driven, with reference to the following 2A and 2 B described.

First, however, the first embodiment will be further described. As in particular in the 1A and 1C is shown clearly, is the second valve element 20 formed in this embodiment, two parts, that is, the second valve element has a first part 20b and a second part 20a on.

The first part 20b of the second valve element 20 here has at least a portion 22b, 23b of the second and third channel structures 22a . 22b ; 23a . 23b on. That is, these sections 22b . 23b the channel structures are in the first part 20b of the second valve element 20 educated.

The first part 20b of the second valve element 20 can also have at least one fluid outlet 102 exhibit. The sections 22b . 23b the second and third channel structures are within the first part 20b of the second valve element 20 each with the fluid outlet 102 connected, for example by means of the circumferential channel structure 55. But it is also conceivable that a plurality of fluid outlets in the second valve element 20 and in the first part 20b of the second valve element 20 are arranged.

Advantageously, is between the first part 20b of the second valve element 20 and the second part 20a of the second valve element 20 a seal arranged in the first part 20b of the second valve element 20 formed second and third channel structures 22b . 23b fluidly sealed against each other. This may in particular be a Teflon seal, since this is particularly temperature-resistant, pressure-resistant and age-resistant.

A seal of the two parts 20a . 20b of the valve element 20 but can also be achieved, for example, that the two parts 20a . 20b glued together, screwed or welded together, for example by means of friction or laser welding.

The valve elements 10 . 20 can in principle have various geometric shapes, ie the valve elements 10 . 20 For example, they may be in the form of a cylinder, a cube, a sphere, a hemisphere, a pyramid, a prism and the like.

The in the respective valve elements 10 . 20 trained channel structures 11 . 22a . 22b , 23a, 23b may extend at least in sections in a radial direction and / or at least in sections in an axial direction. When the two valve elements 10 . 20 For example, along an axis of rotation are rotatable relative to each other, then an axial direction and a radial direction can refer to this axis of rotation.

Some embodiments of the invention provide that the first valve element 10 and the second valve element 20 are each cylindrical valve elements, wherein the first channel structure 11 in the first valve element 10 extends at least in sections in the axial and / or radial direction and / or wherein the second and third channel structure 22a . 22b ; 23a . 23b in the second valve element 20 extend at least in sections 22b, 23b in the radial and / or axial direction.

Further embodiments of the invention provide that the first valve element 10 and the second valve element 20 each circular cylindrical valve elements and the first valve element 10 in the axial direction concentric with the second valve element 20 is aligned.

This will be explained below with reference to the 1A to 1D be explained in more detail. As can be seen in these figures, the first valve element 10 and the second valve element 20 here each exemplified as cylindrical valve elements.

It should be noted that, by definition, a cylinder is characterized in that a plane curve in a plane along a straight line which is not contained in this plane is shifted by a fixed distance. Each two corresponding points of the curves and the shifted curve are connected by a route. The totality of these parallel sections forms the associated cylinder surface. The curve or the resulting lateral surface can have any desired shapes.

In the illustrated embodiment, it is a special form of a cylinder, namely a circular cylinder, ie, the first valve element 10 and the second valve element 20 are each formed circular cylindrical, wherein the first valve element 10 in the axial direction 33 ( 1A ) concentric with the second valve element 20 is aligned.

In the illustrated embodiment, the first channel structure extends 11 in the first cylindrical valve element 10 at least in sections in the axial direction 33 ( 1A ). The first channel structure 11 extends completely through the first valve element 10 therethrough. This can be realized by manufacturing technology, for example, that a bore in the axial direction 33 through the first valve element 10 is introduced into the same.

In another conceivable embodiment, the first channel structure could 11 in the radial direction 34 in the first valve element 10 extend. This is in 1A by way of example with the first channel structure shown in dashed lines 11 ' indicated. This can be realized by manufacturing technology, for example, that a bore in the radial direction 34 through the first valve element 10 is introduced into the same. It would also be conceivable that the radially extending first channel structure shown in dashed lines 11 ' from the bottom 12 of the first valve element 10 milled, sawed, lasered or cut into the same by means of a separating process and / or embossed by means of forming processes, molded and / or produced directly by primary shaping methods such as injection molding.

It would also be conceivable that the first channel structure 11 both sections in the radial direction 34 as well as sections in the axial direction 33 extends.

Alternatively or additionally, the second and third channel structure extend 22a . 22b . 23a . 23b in the second valve element 20 at least in sections in the radial direction 34 ( 1A ). More specifically, those in the first part extend 20b of the second valve element 20 arranged sections 22b . 23b the channel structures 22a . 22b . 23a , 23b at least in sections in the radial direction 34 , This can be realized by manufacturing technology, for example, that these sections 22b . 23b from the top into the second valve element 20 Milled, sawn, laser cut or cut by means of separating processes and / or embossed with shaping processes, molded and / or produced directly by primary shaping processes such as injection molding. These are relatively simple process steps that facilitate the production and thus can significantly reduce the unit cost.

Likewise, it would be conceivable that the second channel structure 22a . 22b and / or the third channel structure 23a . 23b at least in sections in the axial direction 33 through the second valve element 20 or the first part 20b of the second valve element 20 extends through. This could be the second channel structure 22a . 22b one from the third channel structure 23a . 23b have different flow cross-section.

The first valve element 10 has a second valve element 20 facing surface 12 on ( 1A and 1C ). The first valve element 10 and the second valve element 20 are movable relative to each other, in the illustrated and parallel to this surface 12 extending level E ₁ . The two valve elements 10 . 20 For example, in this plane E _{1, they can be} translationally moved relative to one another and thus shifted relative to one another.

The first valve element 10 and the second valve element 20 are rotationally movable relative to each other in the illustrated embodiments, so that a movement of the first position of the valve elements 10 . 20 ( 1B ) to the second position of the valve elements 10 . 20 ( 1D ) by means of a rotation of the first valve element 10 relative to the second valve element 20 is executable. In this case, for example by means of a stepping motor, either the first valve element 10 opposite the second valve element 20 be rotated, or the second valve element 20 opposite the first valve element 10 to be turned around.

As in the 1A to 1D can be seen, the expansion valve 100 a cover 30 exhibit. The cover 30 has a recess 31 on. The cover 30 is immovable with the second valve element 20 connected. The first valve element 10 is inside this cover 30 , or within the recess 31 , relative to the second valve element 20 , and thus relative to the cover 30 movably arranged. In this case, therefore, the first valve element 10 in the expansion valve 100 movable, in particular rotationally movable, be arranged.

For this purpose, the expansion valve 100 an axis 41 on, for example, rotationally fixed to the second valve element 20 and / or on the cover 30 can be arranged. The first valve element 10 is by means of a corresponding recording 42 movable, in particular rotatable, on this axis 41 stored.

As in 1A can be seen is the axis 41 in the middle, ie in the center of the second valve element 20 arranged. Also the recording 42 of the first valve element 10 is centered in the first valve element 10 arranged. That is, the first valve element 10 and the second valve element 20 are concentric around this axis 41 arranged. Thus, the first valve element 10 and the second valve element 20 arranged concentrically with each other.

But it is also conceivable that the axis 41 off-center, ie not in the center of the second valve element 20 , is arranged. Then, although the first valve element would be 10 still concentric to the axis 41 arranged. The first valve element 10 and the second valve element 20 But then they would no longer be concentric but eccentric to each other.

It would also be possible for the recording 42 in the first valve element 10 off-center, ie not in the center of the first valve element 10 , is arranged. Then the first valve element would be 10 not concentric but eccentric to the axis 41 arranged.

In the in 1A illustrated embodiment is a second valve element 20 facing lower surface 27 the cover 30 with a surface 28 of the second valve element 20 coupled, eg glued. In this case, so is the cover 30 on the second valve element 20 arranged. The second valve element 20 can, so to speak, together with the cover 30 a housing, in particular a fluid-tight housing form.

It would be equally conceivable that an inner wall 26 the cover 30 with a lateral circumferential outer wall 29a . 29b of the second valve element 20 is coupled. In this case, the second valve element would 20 inside the recess 31 the cover 30 Find a place. The second valve element 20 can also in this case along with the cover 30 a housing, in particular a fluid-tight housing form. Preferably then would be an additional (not pictured here) lid with the bottom surface 27 the cover 30 coupled.

In the cover 30 For example, the fluid inlet 101 be arranged. Alternatively or in addition to the fluid inlet 101 in the cover 30 can in the second valve element 20 , and / or in the cover, not shown, a fluid inlet 101 ' be provided. In 1A is this optional fluid inlet 101 ' indicated by dashed lines. The fluid inlet 101 Can also be side in the cover 30 be arranged. However, there should be at least one fluid inlet that allows the fluid into the recess 31 the cover 30 to introduce the fluid to the channel structures of the two valve elements 10 . 20 to lead.

If the cover 30 with the second valve element 20 is connected, forms the recess 31 the cover 30 a fluid chamber 32 ( 1B ) out. Thus, the fluid can thus through the fluid inlet 101 in through the recess of the cover 30 formed fluid chamber 32 flow. By means of this cover 30 can thus be ensured that the fluid in the channel structures 11 . 22a . 22b . 23a . 23b is directed.

In this embodiment, it can also be seen that the first valve element 10 in front of the second valve element 20 is arranged, based on the flow direction of the fluid from the fluid inlet 101 to the fluid outlet 102 , Thus, the fluid first flows into those in the first valve element 10 trained first channel structure 11 and from there then, depending on the switching position of the expansion valve 100 in at least one of the second valve element 20 arranged channel structures 22a . 22b . 23a . 23b ,

In the 2A and 2 B is another embodiment of an expansion valve according to the invention 100 displayed.

Here is the expansion valve 100 also a cover 30 on, but with the difference that the cover 30 here immovable with the first valve element 10 is connected and the second valve element 20 inside the cover 30 relative to the first valve element 10 is movably arranged.

There is an axis for this 41 rotationally fixed to the first valve element 10 and / or the housing 30 arranged. The second valve element 20 is also formed in two parts, the first part 20b and the second part 20a each by means of a corresponding recording 42 movable, in particular rotatable, on this axis 41 are stored.

As in 2A can be seen is the axis 41 centrally, ie in the center of the first valve element 10 arranged. Also the recording 42 of the second valve element 20 is centered in the second valve element 20 arranged. That is, the first valve element 10 and the second valve element 20 are concentric around this axis 41 arranged. Thus, the first valve element 10 and the second valve element 20 arranged concentrically with each other.

But it is also conceivable that the axis 41 off-center, ie not in the center of the first valve element 10 , is arranged. Then, although the second valve element would be 20 still concentric to the axis 41 arranged. The first valve element 10 and the second valve element 20 But then they would no longer be concentric but eccentric to each other.

It would also be possible for the recording 42 in the second valve element 20 off-center, ie not in the center of the second valve element 20 , is arranged. Then the second valve element would be 20 not concentric but eccentric to the axis 41 arranged.

In contrast to the first embodiment ( 1A to 1D ) is the second valve element 20 here in front of the first valve element 10 arranged with respect to the flow direction of the fluid from the fluid inlet 101 to the fluid outlet 102 ,

As previously mentioned, the second valve element is 20 formed in two parts, with a first part 20b the second Veritilelements 20 the second and third channel structure 22a . 22b ; 23a , 23b, and a second part 20a of the second valve element 20 a closed cover of the second and third channel structures 22a . 22b ; 23a . 23b forms.

Furthermore, in this embodiment, the first channel structure forms 11 at the same time the fluid outlet 102 of the expansion valve 100 ,

2 B shows a composite expansion valve 100 and passing through the expansion valve 100 through the resulting fluid flow path 112 , The fluid passes through the fluid inlet 101 in the expansion valve 100 a, then flows through the in the second valve element 20 trained channel structures 22a . 22b . 23a . 23b and then passes through the fluid outlet 101 that of the in the first valve element 10 trained first channel structure 11 is formed, again from the expansion valve 100 out.

In the in 2 B illustrated embodiment, the expansion valve is located 100 in a first switching position. More precisely, the two valve elements are located 10 . 20 in a first position relative to each other, wherein in this first position, the first channel structure 11 and the second channel structure 22a . 22b aligned with each other and a first fluid flow path 112 with a first flow resistance between the fluid inlet 101 and the fluid outlet 102 form.

In a second switching position, which is not explicitly shown here, the second valve element would be 20 unlike in 2 B pictured first switching position, for example, rotated by 180 °. In this case, the first channel structure would be 11 and the third channel structure 23a . 23b be aligned with each other and a second fluid flow path having a second flow resistance different from the first flow resistance between the fluid inlet 101 and the fluid outlet 102 form.

With the exception of just described structural differences in the 2A and 2 B In the embodiment shown, the same applies to this embodiment as for the previously described with respect to the 1A to 1D described embodiments.

Therefore, below for all in the 1A to 2 B illustrated embodiments, the joint operation will be explained in more detail. Both at the expansion valve 100 according to the first embodiment ( 1A to 1D ) as well as the expansion valve 100 according to the second embodiment ( 2A . 2 B ) is an interconnection of the channel structures, which can also be referred to below as individual switching.

This individual circuit is characterized inter alia by the fact that in the first and second position of the valve elements 10 . 20 exactly one of the second and third channel structures 22a . 22b ; 23a . 23b of the second valve element 20 with the fluid outlet 102 is fluidically coupled to a single fluid flow path 111 . 112 between the fluid inlet 101 and the fluid outlet 102 to build.

That is, it is always exactly one of the second and third channel structures 22a . 22b ; 23a . 23b of the second valve element 20 to that in the first valve element 10 trained first channel structure 11 aligned.

For a more detailed explanation should this again on 1A to get expelled. As mentioned above, the second valve element 20 next to the second and third channel structure 22a . 22b . 23a . 23b also other channel structures 24a . 24b . 25a . 25b exhibit. The first valve element 10 on the other hand, it has only one channel structure, namely the first channel structure 11 , on.

The two valve elements 10 . 20 be moved, for example by means of a previously mentioned stepping motor relative to each other, in such a way that the first channel structure 11 of the first valve element 10 always only to a single channel structure 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b of the second valve element 20 is aligned.

The individual channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b of the second valve element 20 have different flow cross sections. In addition, all channel structures open 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b , or at least their radially extending portions 22b . 23b . 24b . 25b into a common channel structure 55 ,

Thus, the throttling of the flow rate on the one hand results from the individual length and the individual, not necessarily constant over the channel length or geometrically variable flow cross-section of each channel structure 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b , and on the other by the length and the flow cross-section of the common channel structure 55 , Thus channel-specific fluid flow paths with individual throttle rates are formed.

The longer the fluid flow path traveled by the fluid, the more another criterion plays a crucial role in determining the individual throttle rate. The fluid flowing through a channel structure undergoes friction on the surface of the walls of the respective channel structure, which additionally slows down the fluid. The individual channel structures can therefore be provided according to the invention with a certain surface roughness. Experiments have shown that with the adjustment of the surface roughness differences in the throttling rate of up to 10% were recognizable, in comparison to fluidically smooth surface characteristics of the channel structures.

In addition to this individual circuit just described, further exemplary embodiments provide for a series connection and / or a parallel connection of the channel structures. A series connection of the channel structures of the first embodiment ( 1A to 1D ) is below with reference to the 3A and 3B to be discribed.

The series circuit is characterized, inter alia, by the fact that the second channel structure 22a . 22b and the third channel structure 23a . 23b within the second valve element 20 at least in sections 22b, 23b are connected to each other, wherein in the second position of the valve elements 10 . 20 the second fluid flow path of the second and associated third channel structure is composed of 22b, 23b, and the second fluid flow path has a total flow resistance resulting from the flow resistance of the second channel structure 22b and the flow resistance of the associated third channel structure 23b composed.

Again, the second valve element 20 again formed in two parts. In the first part 20b are several, here by way of example a total of five, different channel structures 22b . 23b , 24b, 25b, 26b formed. The individual channel structures 22b . 23b . 24b . 25b . 26b are all fluidly interconnected so that they form a long chain or a series connection of multiple channel structures.

The expansion valve 100 however, it only has one common fluid outlet 102 on, with the first or last channel structure 22b is connected from the series circuit. Depending on which channel structure 22b . 23b . 24b . 25b . 26b the fluid ultimately enters, the fluid has different lengths of travel to the fluid outlet 102 run through.

The total flow resistance is in this case composed of the individual flow resistances of the respectively traversed channel structures. Here, the individual channel structures 22b . 23b . 24b . 25b . 26b also have different, not necessarily consistent over the channel length or geometrically variable, flow cross-sections.

In the second part 20a of the second valve element 20 are correspondingly many, here also five, channel structures 22a . 23a . 24a . 25a . 26a trained to those in the first part 20b of the second valve element 20 trained channel structures 22b . 23b . 24b . 25b . 26b are aligned.

The first valve element 10 is rotatable relative to the second valve element 20 and has the first channel structure 11 on. The first channel structure 11 can now in different switching stages optionally to one of the second valve element 20 trained channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b be aligned. Depending on the selected switching stage, a different length of fluid flow path is formed, which the fluid flowing through has to cover in order to reach the fluid outlet 102 to get.

One of these several possible switching positions is exemplary in 3B to see. Here is the first valve element 10 opposite the second valve element 20 aligned such that the first channel structure 11 to the sixth channel structure 26a . 26b is aligned.

The resulting fluid flow path is indicated by the dashed arrow 121 located. The fluid thus passes through the fluid inlet 101 in the expansion valve 100 a, then flows through the first channel structure 11 leading to the sixth channel structure 26a . 26b aligned, through all other channel structures 25b . 24b . 23b then, after flowing through the first channel structure 22b in the fluid outlet 102 to flow into.

The fluid, as it were, meanders through the entire series of channel structures and is throttled accordingly.

A series connection of the second embodiment ( 2A and 2 B ) is below with reference to the 4A and 4B to be discribed.

This series circuit is also characterized by the fact that the second channel structure 22a . 22b and the third channel structure 23a . 23b within the second valve element 20 at least in sections 22b, 23b are connected to each other, wherein in the second position of the valve elements 10 . 20 the second fluid flow path from the second and the third channel structure connected thereto 22b . 23b and the second fluid flow path has a total flow resistance resulting from the flow resistance of the second channel structure 22b and the flow resistance of the associated third channel structure 23b composed.

Again, the second valve element 20 again formed in two parts. In the first part 20b are several, here by way of example a total of five, different channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b educated. The individual channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b , or sections 22b . 23b . 24b . 25b . 26b Of these, all are fluidly interconnected, so that they form a long chain or a series connection of several channel structures.

However, in contrast to the series connection described above, it should be noted here that each channel structure has a radial section 22b . 23b . 24b . 25b . 26b and an axial section 22a . 23a . 24a . 25a . 26a having. In the in 4A The sectional view shown are merely the axial sections 22a and 26a to recognize the second and sixth channel structure. The axial sections 23a . 24a . 25a the remaining channel structures are concealed in this sectional view and therefore only indicated by dashed lines.

The expansion valve 100 again has only one common fluid outlet 102 at the same time the first channel structure 11 of the first valve element 10 forms.

The second valve element 20 is rotatable relative to the first valve element 10 and can now optionally be rotated in different switching stages, wherein in each switching stage, another of the channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b of the second valve element 20 to the first channel structure 11 of the first valve element 10 is aligned. More specifically, depending on the switching stage, an axial section 22a . 23a . 24a . 25a . 26a the respective channel structure of the second valve element 20 to the first channel structure 11 of the first valve element 10 aligned.

The fluid always passes through the radial section 22b the second channel structure 22 in the second valve element 20 one. Depending on which switching position is selected, the fluid must have the corresponding further channel structures 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b in addition to the second channel structure 22a . 22b run through. So the fluid has different lengths to the fluid outlet 102 run through. Thus, depending on the selected switching stage, a fluid flow path of different length is formed, which the fluid flowing through has to cover in order to reach the fluid outlet 102 to get.

The total flow resistance is in this case composed of the individual flow resistances of the respectively traversed channel structures. Here, the individual channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b also have different, not necessarily consistent over the channel length or geometrically variable, flow cross-sections.

One of these several possible switching positions is exemplary in 4B to see. Here is the second valve element 11 opposite the first valve element 10 arranged such that the second channel structure 22a . 22b to the first channel structure 11 is aligned.

The resulting fluid flow path is indicated by the dashed arrow 122 located. At this time, the fluid flows through the radial portion 22b the second channel structure in the second valve element 20 and flows through the axial section 22a the second channel structure 20 to the first channel structure 11 , which at the same time the fluid outlet 102 is.

In one, not explicitly shown, further switching position would be the second valve element 20 for example, by 180 ° compared to in 4B shown switching position turned. In this case, the axial section would 26a the sixth channel structure to the first channel structure 11 (= Fluid outlet 102 ) be aligned. The fluid would then pass through the radial section 22b the second channel structure in the second valve element 20 enter and then along all other in-line channel structures 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b flow to finally through the axial section 26a the sixth channel structure into the first channel structure 11 (= Fluid outlet 102 ).

The fluid, as it were, meanders through the entire series of channel structures and is throttled accordingly.

Alternatively or additionally, with the expansion valve according to the invention 100 a parallel connection of the channel structures can be realized, as shown in the 5A to 6B is shown as an example.

The parallel circuit is characterized among other things by the fact that the first valve element 10 at least a fourth channel structure 14 and wherein in the first position of the valve elements 10 . 20 in addition, the third channel structure 23a . 23b of the second valve element 20 and the fourth channel structure 14 of the first valve element 10 aligned with each other and a third fluid flow path having a third flow resistance between the fluid inlet 101 and the fluid outlet 102 form.

The amount of the third flow resistance may differ from the amount of the first and / or second flow resistance. That is, the third fluid flow path may provide a third throttle level.

That is, in the first switching position so are the first channel structure 11 of the first valve element 10 and the second channel structure 22a . 22b of the second valve element 20 aligned with each other, and at the same time are the second channel structure 14 of the first valve element 10 and the third channel structure 23a . 23b of the second valve element 20 aligned with each other.

A parallel connection of the first embodiment ( 1A to 1D ) is below with reference to the 5A and 5B to be discribed.

In the embodiment shown here, the first valve element 10 at least one more channel structure 14 on. The first valve element 10 here even has three more channel structures, namely a seventh channel structure 14 , an eighth channel structure 14 ' and a ninth channel structure 14 " on.

The second valve element 20 is essentially the same with respect to the 1A to 1D described embodiment. The in the second valve element 20 formed channel structures, namely a second channel structure 22a . 22b , a third channel structure 23a . 23b , a fourth channel structure 24a . 24b and a fifth channel structure 25a . 25b , flow into a common channel structure 55 leading to the common fluid outlet 102 leads.

The individual channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 can to the channel structures, and in particular to the axial sections 22a . 23a . 24a . 25a , the channel structures in the second valve element 20 be aligned. Thus, different switching positions are possible, depending on the switching position, a different number of four channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 to the four channel structures 22a . 23a . 24a . 25a of the second valve element 20 are aligned.

5B shows by way of example a switching position in which all four channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 to the four channel structures 22a . 23a . 24a . 25a of the second valve element 20 are aligned. The resulting fluid flow is indicated by the arrow 123 located.

The fluid thus flows through all four channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 , as well as all four channel structures aligned to it 22a . 23a . 24a . 25a of the second valve element 20 , This is, so to speak, the largest switching stage, in which all channel structures are active at the same time. Accordingly, the flow rate of the fluid may be greatest at this switching position because the fluid can flow through all the channel structures simultaneously.

However, the total flow resistance is in this case also composed of the individual flow resistances of the respectively passed through channel structures. Here, the individual channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b also have different, not necessarily consistent over the channel length or geometrically variable, flow cross-sections.

A stop function could here for example by rotation of the first valve element 10 by 180 ° compared to the in 5B shown switching position can be achieved. There would be none of the channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 to any of the channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b of the second valve element 20 be aligned.

All the embodiments described so far in common is that the expansion valve 100 exactly one fluid outlet 102 and the second and third channel structure 22a , 22b; 23a, 23b of the second valve element 20 with this one fluid outlet 102 can be coupled fluidically. Although not explicitly shown in the figures, it would also be possible for the expansion valves according to the invention 100 not exactly one, but at least one fluid outlet 102 have, ie the expansion valves 100 can also have a second, third, or any number of fluid outlets 102 exhibit.

Such a case is exemplary in the in 6A and 6B illustrated parallel circuit of the second embodiment ( 2A and 2 B ), wherein the first valve element 10 at least a fourth channel structure 14 and the first and the fourth channel structure 11 . 14 one fluid outlet each 102 . 102 ' . 102 ' . 102 '' of the expansion valve 100 form.

In the embodiment shown here, the first valve element 10 at least one more channel structure 14 on. The first valve element 10 here even has three more channel structures, namely a seventh channel structure 14 , an eighth channel structure 14 ' and a ninth channel structure 14 " on.

The second valve element 20 is essentially the same with respect to the 2A and 2 B described embodiment. The in the second valve element 20 formed channel structures, namely a second channel structure 22a . 22b , a third channel structure 23a . 23b , a fourth channel structure 24a . 24b and a fifth channel structure 25a . 25b , have a radially extending portion 22b . 23b . 24b . 25 on, through which the fluid in the second valve element 20 can flow in, as well as an axial section 22a . 23a . 24a . 25a that is to at least one of the in the first valve element 10 arranged channel structures 11 . 14 . 14 ' . 14 " can be aligned.

Thus, different switching positions are possible, depending on the switching position, a different number of four channel structures 22a . 23a . 24a . 25a of the second valve element 20 to the four channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 are aligned.

6B shows the expansion valve 100 exemplary in the in 6A better visible switch position, in all four channel structures 22a . 23a . 24a . 25a of the second valve element 20 to the four channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 are aligned. The resulting fluid flow is with the arrows 124 . 124 ' . 124 ' . 124 "' located. The fluid leaves the expansion valve 100 through all activated fluid outlets 11 . 14 . 14 ' . 14 " which, in turn, with the arrows indicating the fluid flow 124 ' . 124 ' . 124 '" is shown.

More specifically, the fluid first flows through the fluid inlet 101 in the expansion valve 100 into it. It then distributes to all four channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b in the second valve element 20 , what with the arrows 124 . 124 ' . 124 ' . 124 ' 'is shown. That is, a first part 124 the fluid flow occurs at the first channel structure 22a . 22b a, a second part 124 ' the fluid flow occurs at the second channel structure 23a . 23b a, a third part 124 ' the fluid flow occurs in the third channel structure 24a . 24b a, and a fourth part 124 '" the fluid flow occurs in the fourth channel structure 25a . 25b one.

The fluid thus flows through all four radial sections 22b . 23b . 24b . 25b the four channel structures of the second valve element 20 in the second valve element 20 into it. Then the fluid flows in the axial sections 22a . 23a . 24a . 25a the channel structures of the second valve element 20 , which in the switching position shown, all to one channel structure 11 . 14 . 14 ' . 14 " of the first valve element 10 are aligned. The fluid leaves the expansion valve 100 through the respective channel structures 11 . 14 . 14 ' . 14 " of the first valve element 10 because these are the same number of fluid outlets 102 . 102 ' . 102 ' . 102 ' Form 'of the expansion valve.

At the in 6B The illustrated switching stage is, so to speak, the largest switching stage, in which all channel structures are active at the same time. Accordingly, the flow rate of the fluid may be greatest at this switching position because the fluid can flow through all the channel structures simultaneously.

The total flow resistance is in this case also composed of the individual flow resistances of the respectively flowed through channel structures. Here, the individual channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b also have different, not necessarily consistent over the channel length or geometrically variable, flow cross-sections.

A stop function could here, for example, by rotation of the second valve element 20 by 180 ° compared to the in 6A shown switching position can be achieved. There would be none of the channel structures 22a . 22b . 23a . 23b . 24a . 24b . 25a . 25b . 26a . 26b of the second valve element 20 to any of the channel structures 11 . 14 . 14 ' , 14 "of the first valve element 10 be aligned.

According to the invention, the expansion valve proposed here 100 the individual positions of the valve elements 10 . 20 switchable to each other in discrete stages.

The expansion valve 100 could in principle also have a combination of a parallel connection with a series circuit. Such a case is exemplified in the form of a schematic block diagram in FIG 7 shown.

The through the expansion valve 100 running fluid flow initially passes through a channel structure 22 with a first flow resistance 71 and then into a parallel circuit of channel structures 23 . 24 . 25 with a second flow resistance 72 , a third flow resistance 73 and a fourth flow resistance 74 , The flow resistance 71 . 72 . 73 . 74 can be the same size or different. The channel structure 22 is with the parallel connection of the channel structures 23 . 24 . 25 connected in series. The total flow resistance is in this case again made up of the individual flow resistances of the respectively flowed through channel structures 22 . 23 . 24 . 25 together.

The expansion valve 100 can be made of different materials, ie the expansion valve 100 may, for example, metal, plastic, glass or ceramic.

The individual parts, ie the first valve element 10 , the second valve element 20 and the cover 30 can be bolted, jammed, glued or welded together.

The channel structures, and in particular the radially extending channel structures 22b . 23b . 24b . 25b . 26b may be microchannel structures. These microchannel structures may have flow areas in the range of square millimeters or square microns. The microchannel structures can, for example, by means of precision milling in the respective valve element 10 . 20 be introduced or produced by injection molding or embossing. It is also conceivable for the microchannel structures to be in the respective valve element using etching processes 10 . 20 are introduced, for example, when the respective valve element 10 . 20 Contains silicon or other etchant-reactive materials.

The expansion valve according to the invention 100 may also include moisture-binding agents. For example, zeolite may be used as such a moisture-binding agent. Preferably, the zeolite is used in the form of bulk material or as a sintered material.

For example, the means for binding moisture may be in the fluid flow direction in front of the fluid inlet 101 to be ordered. Preferably, the means for binding moisture is between the fluid inlet 101 and the first and second valve elements 10 . 20 arranged. For example, the means for binding moisture may be in the recess 31 the cover 30 be arranged.

However, the means for binding moisture may also be in one or more of the channel structures 11 . 14 . 22 . 23 . 24 . 25 . 26 the first and / or second valve element 10 , 20 are arranged, in particular, when the means for binding moisture in the form of loose bulk material.

The means for binding moisture are advantageous for binding any existing moisture in the refrigerant and thus prevent unwanted ice formation elsewhere in the refrigeration cycle.

Furthermore, the expansion valve according to the invention 100 have at least one particle filter. The particle filter is advantageously arranged in the flow direction downstream of the means for binding moisture. Preferably, the particulate filter filters particles originating from the moisture-binding agent, eg, zeolite particles.

The expansion valve according to the invention 100 For example, it can be arranged in a refrigeration cycle between two heat exchangers. Such heat exchangers can be, for example, so-called evaporators or condensers. The expansion valve may for example be arranged between such an evaporator and a condenser. The expansion valve 100 but can also be arranged between at least two evaporators, which at least one condenser is connected downstream.

In addition, a household refrigerator, in particular a refrigerator and / or freezer, with an expansion valve according to the invention 100 conceivable. In this case, preferably refrigerators and / or freezers are meant with a cooling capacity of less than 1000 watts. For example, these may be refrigerators, freezers, or fridge-freezers.

In principle, the expansion valve according to the invention 100 be used in any type of chiller, in particular in compression refrigeration machines. Preferably, the expansion valve 100 but can be used in chillers with mass flows of less than 3 kg / h.

Below is the expansion valve according to the invention 100 as well as the concept of the present invention are described again in other words:

An object of the invention is a valve 100 , which can throttle a fluid flow of nearly 100% maximum flow to almost 0% flow in discrete stages. The primary application is called micro expansion valve 100 Seen in refrigeration circuits in the lower cooling capacity, since it solves the above-mentioned problem of refrigerant metering at low mass flows.

Two implementation forms A and B will be described in more detail with reference to the figures. A possible drive for operation is not shown in the figures. To turn the turntable (first valve element 10 or second valve element 20 ), for example, a stepper motor can be used.

Implementation form A

In implementation form A ( 1A to 1D ) are located in the here two-part valve seat (second valve element 20 with first part 20a and second part 20b ) N inlets (axial sections 22a . 23a . 24a . 25a ) to individual microfluidic channel structures (radial sections 22b . 23b . 24b . 25b ), whose respective outlets in turn to a single common main outlet (fluid outlet 102 ) are summarized.

On the valve seat 20 there is a rotatable disc (first valve element 10 ). By rotational positioning of the distributor (first channel structure 11 ) in the turntable 10 On the one hand, the flow through the valve 100 completely prevented or on the other hand in each case one of the microfluidic channel structures 22b . 23b . 24b . 25b be unlocked. As the channel structures 22b . 23b . 24b . 25b differ geometrically and thus have different flow resistance, represents each channel structure 22b . 23b . 24b . 25b a specific throttle stage. A structure in the valve seat 20 can also be designed so that no significant throttling takes place (passage).

Implementation form B

In implementation form B ( 2A and 2 B ) are located in the here two-part turntable (second valve element 20 with first part 20a and second part 20b ) N inlets (radial sections 22b . 23b . 24b . 25b ) to individual microfluidic channel structures (radial sections 22b . 23b . 24b . 25b ), whose respective outlets (axial sections 22a . 23a . 24a . 25a ) on the sliding surface 12 between turntable 20 and Valve seat (first valve element 10 ), ie the microfluidic channel structures 22b . 23b . 24b . 25b are completely in the disk 20 ,

The valve seat 10 itself contains the main outlet 11 . 102 , By rotational positioning of the disc 20 on the valve seat 10 On the one hand, the flow through the valve 100 completely prevented or on the other hand in each case one of the microfluidic channel structures 22b . 23b . 24b . 25b be unlocked. A channel structure / rotational position can also be designed so that no significant throttling takes place (passage).

Functional demarcation

Fluidics in general

If one differentiates functionally

• • Directional Control Valves (Control Valves): Valves with multiple switch positions that completely block, release, or interconnect fluid between different ports.
• • Flow valves: valves that reduce or shut off the flow area. In the simplest case, the flow changes depending on the pressure difference:
  • ○ Shutter valve (short iris) ■ Rigid ■ Adjustable
  • o Throttle valve (longer throttle section) ■ Rigid ■ Adjustable

Thus, the present invention can be considered as a directional valve with integrated, differently designed, rigid chokes.

While adjustable flow control valves typically only locally limit the effective cross section at one point (see needle valve), in the present case microfluidic channel structures are "switched", ie depending on the switching stage, different fluid paths may also be flowed through. Comparing the present invention, for example, with a needle valve, the differences shown in Table 1 result. Table 1: Comparison needle valve of the present invention. needle valve Present invention Continuous switching process N discrete switching stages Mechanical precision and positioning accuracy of the actuator determine the achievable flow accuracy. Only the precision of the microfluidic channel structures determines the achievable flow accuracy. Limited dynamic range: It is not practical to map very small and larger flows in a valve: Unlimited dynamic range: The actuator can - regardless of the flow to be realized - the switching positions always start the same, since the change of the flow is completely realized by the respective microfluidic channel. Small flow requires precise mechanics since smallest valve gap, but this precise mechanism is too slow for larger flow rates.

In other words - with a relatively coarse Ventilaktorik even small mass flows can be precisely throttled.

refrigeration technology

• • Wegeventile basierend auf drehbaren Scheiben (nur an/aus)
• • Wegeventile allgemein (nur an/aus bzw. Pulsweitenmodulation)
• • Nadelventile (stetige Verstellbarkeit)
• • Stromventile basierend auf drehbaren Scheiben (zumindest als Patent)

In refrigeration, the following valve types are preferably used as "small" (expansion) valves:

• • directional valves based on rotatable discs (only on / off)
• • Directional valves in general (only on / off or pulse width modulation)
• • Needle valves (continuous adjustability)
• • Flow valves based on rotatable discs (at least as a patent)

Further technical embodiments

Underlying directional valve

Implementation forms A and B can be understood as a combination of a (macroscopic) directional valve based on a turntable and (microscopic) microfluidic channels for throttling.

Alternatively, it would also be possible to use any other (translational, rotary, ...) directional control valve as a basis, as long as the necessary number of switching stages is provided.

drive

It is proposed a stepper motor for driving the turntable 10 . 20 to use. In principle, other types of drive could also be used here.

Interconnection of the channel structures

1. a) Individuell (siehe 1A bis 1D sowie 2A und 2B)
2. b) Seriell (siehe 3A, 3B, 4A, 4B)
3. c) Parallel (siehe 5A, 5B, 6A, 6B)
4. d) sowie Kombinationen aus a)-c) (siehe 7)

In principle, the microfluidic channel structures, similar to an electrical resistance network, can be interconnected in different ways:

1. a) Individual (see 1A to 1D and 2A and 2B)
2. b) Serial (see 3A . 3B . 4A . 4B )
3. c) Parallel (see 5A . 5B . 6A . 6B )
4. d) and combinations of a) -c) (see 7 )

In both implementation forms A and B, the channel structures are interconnected according to a) individually.

Arrangements of the channel structures with respect to the turntable

• • Geschlossene Kanalstruktur unterhalb der Drehscheibe (Umsetzungsform A)
• • Geschlossene Kanalstruktur in der Drehscheibe (Umsetzungsform B)

The implementation forms A and B differ with regard to the arrangement of the channel structures:

• • Closed channel structure below the turntable (implementation form A)
• • Closed channel structure in the turntable (implementation form B)

• • Offene Kanalstruktur auf der Unterseite der Drehscheibe (rotierend auf dem Ventilsitz)
• • Offene Kanalstruktur an der Oberseite des Ventilsitzes (Drehscheibe gleitet darüber)

In principle, the microfluidic channel structures can also be arranged as follows:

• • Open channel structure on the underside of the turntable (rotating on the valve seat)
• • Open channel structure at the top of the valve seat (turntable slides over)

Possible additional functionalities / especially refrigeration technology

• • Control / regulation by device electronics
• • Valve contains "Bypass", which is opened during production vacuum drawing (better / faster production of vacuum in the refrigeration circuit, avoidance of long vacuuming times or double-sided vacuum drawing on the high and low pressure side.
• • Integration of the dryer: Valve contains substances such as zeolite, which can absorb moisture in sintered form or bulk material and thus take over the function of the dryer:
  • o Substances can fulfill a filter function for particles.
  • o Substances can be placed in the valve or in the pipe connection.
  • o Substances may be designed to be interchangeable without replacing the valve.
• • upstream or downstream partial or basic throttling:
  • ○ Valve contains eg sintered body (if necessary as part of the dryer). The sintered body can take over a partial or basic throttling, so that the channels can be designed larger and to avoid the problem of contamination.
  • ○ The same could of course be achieved, for example, by the inlet or outlet of the valve is already narrowed or a filter, sintered body, Vorkapillare, etc. is added.
• • Valve contains particulate filter
  • ○ Particulate filter can be interchangeable, so the valve does not need to be replaced.
• • Welded valve body
• • Positioning of the valve in the refrigeration circuit
  • ○ Type of attachment
• • fluid
  • ○ Refrigerant can be gas / liquid or vapor

• • Drosselventil 100 für Fluide, das einen Fluidstrom blockiert oder drosselt,
• • wobei das Drosselventil 100 mikrostrukturierte Elemente 22a, 22b, 23a, 23b, 24a, 24b, 25a, 25b, 26a, 26b enthält,
• • wobei die Drosselung in diskreten Abstufungen erfolgt,
• • wobei der einströmende Fluidstrom durch ein Stellglied blockiert oder auf einen oder mehrere Mikrokanäle verschaltet wird,
• • wobei die Mikrokanäle innerhalb des Ventils wieder in einen einzigen ausströmenden Fluidstrom münden,
• • wobei die Drosselfunktion hauptsächlich durch den Strömungswiderstand des Mikrokanals erzeugt wird,
• • wobei zusätzlich zur Drosselung der verschaltbaren Mikrokanäle ein Teil der Drosselung (Grunddrosselung) durch einen bei Durchfluss immer durchströmte vor- oder nachgeschaltete Komponente (Widerstand) erzeugt wird,
• • wobei jeweils kein oder nur ein Mikrokanal aktiv ist (Individualschaltung),
• • wobei es sich bei dem Ventil um ein Drehventil handelt,
• • wobei die Mikrokanäle in die Drehscheibe integriert sind:
  • ￮ Scheibe mit Kanälen ist drehbar, oder
• • wobei die Mikrokanäle unterhalb der Drehscheibe liegen:
  • ￮ Kanäle sind nicht drehbar.

In the following are conceivable embodiments of the expansion valve according to the invention 100 summarized in a nutshell:

• • throttle valve 100 for fluids that block or restrict fluid flow,
• • where the throttle valve 100 microstructured elements 22a . 22b . 23a . 23b . 24a , 24b, 25a, 25b, 26a, 26b,
• • where the throttling takes place in discrete steps,
• Wherein the inflowing fluid flow is blocked by an actuator or connected to one or more microchannels,
• • wherein the microchannels within the valve re-open into a single outflowing fluid stream,
• Wherein the throttling function is mainly generated by the flow resistance of the microchannel,
• Wherein, in addition to the throttling of the interconnectable microchannels, part of the throttling (basic throttling) is generated by a forward or downstream component (resistance), which is always flowed through in the course of flow,
• • where no or only one micro-channel is active (individual switching),
• • where the valve is a rotary valve,
• • where the microchannels are integrated in the turntable:
  • ○ Disc with channels is rotatable, or
• • where the microchannels are below the turntable:
  • ○ Channels are not rotatable.

The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims and not by the specific details presented in the description and explanation of the embodiments herein.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011004109 A1 [0008]
• DE 3108051 A1 [0010]

Claims (26)

An expansion valve (100) for reducing a pressure of a fluid flowing through the expansion valve (100) along a fluid flow path (110, 111, 112, 121, 122, 123), the expansion valve (100) comprising: at least one fluid inlet (101) and at least one fluid outlet (102), a first valve element (10) with at least one first channel structure (11), a second valve element (20) having at least one second channel structure (22a, 22b) and a third channel structure (23a, 23b), wherein the first valve element (10) and the second valve element (20) are movable relative to one another, wherein in a first position of the valve elements (10, 20) the first channel structure (11) and the second channel structure (22a, 22b) are aligned with each other and a first fluid flow path having a first flow resistance between the fluid inlet (101) and the fluid outlet (102). form, and wherein in a second position of the valve elements (10, 20) the first channel structure (11) and the third channel structure (23a, 23b) are aligned with each other and a second fluid flow path having a second flow resistance different from the first flow resistance between the fluid inlet (101) and form the fluid outlet (102). Expansion valve (100) after Claim 1 wherein the second channel structure (22a, 22b) has a first variable or constant flow cross section, and wherein the third channel structure (23a, 23b) has a second variable or constant flow cross section different from the first flow cross section. Expansion valve (100) after Claim 1 or 2 in which, in a third position of the valve elements (10, 20), the first channel structure (11) provided in the first valve element (10) is not aligned with one of the channel structures (22a, 22b, 23a, 23b) provided in the second valve element (20) is, and a fluid flow between the fluid inlet (101) and the fluid outlet (102) is interrupted thereby. The expansion valve (100) according to any one of the preceding claims, wherein the first and second channel structures (11; 22a, 22b) forming the first fluid flow path or the first and third channel structures (11; 23a, 23b) forming the second fluid flow path are one through the first and second channel structures the second valve element (10, 20) through opening are formed without significant throttling. Expansion valve (100) according to one of the preceding claims, wherein the first channel structure (11) in the first valve element (10) extends at least partially in the axial direction (33) and / or in the radial direction (34), and / or wherein the second and third channel structure (22a, 22b, 23a, 23b) extend in the second valve element (20) at least in sections (22b, 23b) in the radial direction (34) and / or in the axial direction (33). Expansion valve (100) according to one of the preceding claims, wherein the first valve element (10) in the axial direction (33) concentrically aligned with the second valve element (20). Expansion valve (100) according to one of the preceding claims, wherein the first valve element (10) has a surface (12) facing the second valve element (20), and the second valve element (20) is arranged relative to the first valve element (10) in a plane (E ₁ ) is movable parallel to this surface (12). An expansion valve (100) according to any one of the preceding claims, wherein the first valve element (10) and the second valve element (20) are rotationally movable relative to each other such that movement from the first position of the valve elements (10, 20) to the second position of the valve elements (10, 20) is executable by means of a rotation of the first valve element (10) relative to the second valve element (20). Expansion valve (100) according to one of the preceding claims, wherein the individual positions of the valve elements (10, 20) to each other in discrete stages are switchable. An expansion valve (100) according to any one of the preceding claims, wherein the expansion valve (100) comprises a cover (30), the cover (30) being immovably connected to the second valve element (20) and the first valve element (10) within the cover (10). 30) is arranged movable relative to the second valve element (20). An expansion valve (100) according to any one of the preceding claims, wherein the first valve member (10) is disposed in front of the second valve member (20) with respect to the flow direction of the fluid from the fluid inlet (101) to the fluid outlet (102). Expansion valve (100) according to one of the preceding claims, wherein the second valve element (20) is formed in two parts (20a, 20b), wherein a first part (20b) of the second valve element at least a portion (22b, 23b) of the second and third channel structures ( 22a, 22b, 23a, 23b) and the fluid outlet (102), wherein these portions (22b, 23b) of the second and third channel structures within the first part (20b) of the second valve element are each connected to the fluid outlet (102). Expansion valve (100) after Claim 12 in that between the first part (20b) of the second valve element (20) and the second part (20a) of the second valve element (20) is arranged a seal which forms the second part formed in the first part (20b) of the second valve element (20) and third channel structures (22a, 22b, 23a, 23b) fluidly against each other. Expansion valve (100) after one of the Claims 1 to 9 wherein the expansion valve (100) comprises a cover (30), wherein the cover (30) is immovably connected to the first valve element (10) and the second valve element (20) within the cover (30) relative to the first valve element (10 ) is arranged movable. An expansion valve (100) according to any one of the preceding claims, wherein the second valve member (20) is disposed in front of the first valve member (10) with respect to the flow direction of the fluid from the fluid inlet (101) to the fluid outlet (102). Expansion valve (100) after Claim 15 wherein the second valve element (20) is formed in two parts (20a, 20b), wherein a first part (20b) of the second valve element (20) has the second and third channel structure (22a, 22b; 23a, 23b), and a second part (20a) of the second valve element (20) forms a closed cover of the second and third channel structures (22a, 22b; 23a, 23b). Expansion valve (100) after one of the Claims 14 to 16 wherein the first channel structure (11) forms the fluid outlet (102) of the expansion valve (100). Expansion valve (100) according to one of the preceding claims, wherein in the first and second positions of the valve elements (10, 20) each exactly one of the second and third channel structures (22a, 22b, 23a, 23b) of the second valve element (20) with the fluid outlet (102) is fluidically coupled to form a single fluid flow path between the fluid inlet (101) and the fluid outlet (102). Expansion valve (100) after one of the Claims 1 to 17 wherein the second channel structure (22a, 22b) and the third channel structure (23a, 23b) are connected to one another within the second valve element (20) at least in sections (22b, 23b), wherein in the second position the valve elements (10, 20) the second fluid flow path is composed of the second and the associated third channel structure (22b, 23b), and the second fluid flow path has a total flow resistance composed of the flow resistance of the second channel structure (22b) and the flow resistance of the third channel structure (23b) connected thereto , Expansion valve (100) after one of the Claims 1 to 17 wherein the first valve element (10) has at least one fourth channel structure (14), and wherein in the first position of the valve elements (10, 20) additionally the third channel structure (23a, 23b) and the fourth channel structure (14) are aligned with each other and forming a third fluid flow path having a third flow resistance between the fluid inlet (101) and the fluid outlet (102). An expansion valve (100) according to any one of the preceding claims, wherein the expansion valve (100) has precisely one fluid outlet (102) and the second and third channel structures (22a, 22b, 23a, 23b) of the second valve element (20) have a fluid outlet (102 ) are fluidically coupled. Expansion valve (100) after one of the Claims 1 to 20 wherein the first valve element (10) has at least one fourth channel structure (14) and the first and fourth channel structures (11, 14) each form a fluid outlet (102, 102 ') of the expansion valve (100). Expansion valve (100) according to one of the preceding claims, wherein the expansion valve (100) can be arranged in a refrigeration cycle between two heat exchangers. An expansion valve (100) according to any one of the preceding claims, wherein the expansion valve (100) comprises means for binding moisture. An expansion valve (100) according to any one of the preceding claims, wherein the expansion valve (100) comprises at least one particulate filter. Domestic refrigerating appliance, in particular refrigerator and / or freezer, with an expansion valve (100) according to one of the preceding claims.

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