Expansion element, preferably for actuators, preferably for control valves

Abstract

The present invention relates to an expansion element (24), preferably for actuators (2), having a housing (24b) which substantially encloses a receiving space (24c), having an expansion material (24d), preferably a wax (24d), which is arranged in the receiving space (24c), the expansion material (24d) being designed to expand during, preferably electrical, heating, having an elastic sealing element (24e) which essentially tightly closes the receiving space (24c) together with the housing (24b) around the expansion material (24d), the sealing element (24e) having a passage opening (24e1) along the longitudinal axis (X), and having a piston (24a) which runs along the longitudinal axis (X) through the passage opening (24e1) in the sealing element (24e). The expansion element (24) is characterized in that the sealing element (24e) is held in the housing (24b) directly by the flanged edge (24b1) of the housing (24b).

Description

[0001] DESCRIPTION

[0002] Expansion element, preferably for actuators, preferably for control valves

[0003] The present invention relates to several expansion elements, preferably for actuators, preferably for control valves, an actuator, preferably for a control valve, with such an expansion element, and a fluid distributor, preferably a heating circuit distributor, with at least one control valve with such an actuator.

[0004] For various technical applications, it may be necessary to regulate the flow of a fluid through a fluid line. Control valves, also known as regulating valves, can be used for this purpose. A control valve can be continuously adjusted between a fully open and a fully closed position, thus altering the fluid flow through it. Depending on the technical application, this can influence, for example, the pressure, temperature, or flow rate. Such fluids can be gases or liquids. These control valves can be used, for example, in buildings with hot water heating systems and in building automation systems. In other words, these control valves can be used in heating, ventilation, and air conditioning (HVAC) systems.The setting of the control valve can be changed by means of a drive, which is accordingly called an actuator and can be operated, for example, electrically or pneumatically.

[0005] To regulate the temperature of individual rooms in a building, these control valves can be used as the valves of the heating circuit manifold in underfloor heating systems. Individual control valves can also be used as the valves for individual radiators. In both cases, the control valves are typically connected to a fluid circuit in the form of the heating circuit's return line. Depending on the valve position, which is determined by the thermal actuator, a predetermined amount of heating water or a specific flow rate is allowed to flow into the radiator or into the pipes of a section of the underfloor heating system. The position of the control valve can be predetermined by a thermostat via the respective actuator, depending on the detected room temperature, so that a user-defined target room temperature can be reached and maintained.Regarding the operation of such actuators and control valves, it should be noted that the control valve typically has a relatively weak valve spring or return spring. The spring force of this spring moves a plunger of the control valve along the same longitudinal axis, thereby opening the control valve to allow fluid to pass through. Such control valves are thus fully opened by the spring force of their own actuating spring and can therefore allow the fluid to pass through.

[0006] When an actuator is mounted on a control valve, the spring force of the control valve is counteracted by an adjustable force from the actuator, allowing stepless regulation of the degree to which the control valve is open or closed, thus enabling fluid flow. The force transmission and interaction between the actuator and the control valve occur via a plunger of the actuator, which interacts along their common longitudinal axis with a plunger of the control valve, also called a valve stem.

[0007] Thermal actuators are generally divided into two designs or two operating principles:

[0008] 1. NC (normally closed): if the actuator is mounted on the control valve and the actuator is not activated, then the control valve is closed.

[0009] 2. NO (normally open): if the actuator is mounted on the control valve and the actuator is not activated, then the control valve is open.

[0010] In thermal NC actuators, the spring force of the control valve's return spring is counteracted by a comparatively strong compression spring of the NC actuator. This means the spring force of the NC actuator is greater than the spring force of the control valve's return spring, so the control valve is generally closed by the NC actuator under normal conditions. The spring force of the NC actuator's compression spring, also known as the closing force of the NC actuator, is typically around 100 N.

[0011] An NC actuator further comprises an actuating element which, when actuated, exerts an additional force on the actuator's compression spring, thereby assisting the movement of the control valve's return spring. The force of the actuating element is typically greater than the force of the control valve's return spring. Thus, when the actuating element of the NC actuator is actuated, the actuating element and the control valve's return spring together can overcome the comparatively strong spring force of the NC actuator's compression spring and thereby open the control valve. The actuating element of the NC actuator can be implemented, for example, using an electric heating element in combination with a temperature-dependent expansion element, see, for example, DE 3140472 C2. The expansion element can also be referred to as a thermoelectric actuating element.In any case, this also refers to the entire assembly consisting of a PTC element, a Kapton film and the actual expansion element, which can heat up and expand when an electric current is applied.

[0012] The advantage here is the comparatively simple and / or compact implementation of the drive force or actuating force of the NC actuator. This can keep the costs and / or the installation space of the NC actuator low.

[0013] A particular advantage of the fact that the spring force of the compression spring of the NC actuator is greater than the spring force of the return spring of the control valve is that, when the actuator element of the NC actuator is unactuated or de-energized, the control valve is closed in its normal position. Assuming that there is no heat demand during most of the operating time of, for example, a heating system, the fact that the control valve of the NC actuator is closed in its normal state and the heating element of the NC actuator remains de-energized, thus keeping the actuator's energy consumption low.

[0014] In thermal NO actuators, the closing force is transmitted directly from the actuator to the control valve. Unlike NC actuators, which require an additional compression spring whose spring force must be overcome by the actuator, NO actuators do not have this spring force. This can save costs and installation space. Furthermore, this design allows for the creation of an actuator type that keeps the control valve open when the NO actuator is not in operation.

[0015] A disadvantage of NO actuators, however, is that the actuating force, typically around 100 N, and the stroke of the actuator are often much greater than the stroke and closing force required for the valve stem of the control valve. This creates a risk that the valve stem of the control valve will be damaged by the excessively high actuating force of the NO actuator.

[0016] To prevent damage to the valve stem of the control valve caused in this way, the actuator element in NO actuators is therefore spring-mounted. This spring of the NO actuator is dimensioned and pre-tensioned so that, after reaching the intended closing force of typically around 100 N, the remaining travel and actuating force of the actuator element are absorbed by the spring of the NO actuator. This means that the actuator element of the NO actuator moves away from the valve stem of the control valve against its spring.

[0017] In any case, such thermoelectric actuators are known in the form of expansion elements, which can also be referred to as expansion element actuators. An expansion element is an actuator filled with expansion material, which typically consists essentially of a housing, a working piston, and the expansion material itself. The housing, which is fixedly arranged in the actuator, contains the expansion material in a receiving chamber. The expansion material expands when electrically heated. The housing and the working piston are designed and arranged in such a way that the thermally induced expansion of the expansion material results in a translational movement of the working piston, also simply called a piston or plunger, with a comparatively short stroke but a comparatively large force.The return of the working piston at reduced heating and thus at reduced expansion of the expansion material must be achieved externally, which is realized by the spring force of the return spring of the control valve or by the spring force of the compression spring of the NC actuator.

[0018] In such thermoelectric actuators, the sealing of the expansion element must be ensured even under high pressure due to the high temperature of the expansion material, and throughout the service life of the expansion element or the control valve. Therefore, it is currently known for such expansion elements to seal the cylindrical housing, after the expansion material has been filled into the receiving chamber, with a separate sealing element and then with a separate cover element, each of which has a through-hole for the working piston. Alternatively, a separate sealing element with a blind hole for receiving the working piston can also be used. In either case, the cover element holds the sealing element on the expansion material, and a usually inwardly crimped edge of the housing holds the cover element on the sealing element.

[0019] German patent DE 1958563 describes a thermostatic actuating element consisting of a housing containing a substance that expands when heated, and an elastic sleeve into which a piston with a conical end is slidably inserted. The elastic sleeve is held at its upper end by a sealing disc and a support disc, which in turn is held by the crimped edge of the cylindrical rim of the housing.

[0020] Therefore, three components are required – the elastic sleeve, the support disc, and the sealing disc – to seal the material, which expands when the temperature rises, from the environment. Accordingly, three components must be manufactured and assembled.

[0021] US Patent 3,357,252 A describes a temperature-dependent power transmission device comprising a housing with a side and an end wall containing an expansion material; a guide element that is forcibly fitted into one end of the housing and held axially stationary therein by the force fit between the guide and the housing; a drive element that is guided for movement within the housing; and an elastic sleeve made of rubber or a similar material, which is arranged between the expansion material and the guide element. DE 10 2009024263 A describes an expansion element comprising a housing in which expansion material is arranged or can be arranged, a sealing insert for enclosing the expansion material in the housing, and a cover for fixing the sealing insert, in which a piston rod is arranged that is axially displaceable relative to the housing and optionally projects into the expansion material. The cover is made of plastic.During assembly, the expansion element, after being filled with the appropriate expansion material, is closed using common methods such as flanging or rolling the head collar of the housing.

[0022] In both cases, two components are required to seal the expansion material or the expansion element from the environment: the elastic sleeve and the guide element of US 3,357,252 A, and the sealing insert and the cover of the expansion element of DE 10 2009 024263 Al. Accordingly, two components must be manufactured and assembled.

[0023] It should also be noted that in the case of metallic housings for expansion elements, these are usually manufactured by machining, whereby the receiving space for the expansion element is created by drilling. Brass, which contains lead to enable machining, is typically used as the metal.

[0024] The disadvantage in this case is that a lead-containing metal is used to manufacture expansion elements, since lead is toxic and should therefore generally be avoided.

[0025] One object of the present invention is to improve the expansion element of the type of actuators described above. In particular, the manufacturing costs with regard to material usage and / or assembly effort are to be reduced. Additionally or alternatively, only lead-free materials should be usable, especially for the housing of the expansion element. In any case, this should be implemented as simply, cost-effectively, and / or durably as possible. At the very least, an alternative to known expansion elements of such actuators should be created.

[0026] The problem is solved according to the invention by a thermal expansion element according to claim 1, by a thermal expansion element according to claim 6, by an actuator according to claim 14, and by a fluid distributor according to claim 15. Advantageous embodiments are described in the dependent claims.

[0027] Thus, the present invention relates to an expansion element, preferably for actuators, comprising a housing which substantially encloses a receiving space, an expansion material, preferably a wax, which is arranged in the receiving space, wherein the expansion material is designed to expand upon, preferably electrical, heating, an elastic sealing element which, together with the housing, substantially seals the receiving space around the expansion material, wherein the sealing element has a through-opening along the longitudinal axis, and a piston which extends along the longitudinal axis through the through-opening of the sealing element.

[0028] Corresponding expansion elements, preferably for actuators, especially for thermal actuators, are known as described above. However, expansion elements can also be used for other control engineering applications, such as in automotive cooling circuits, in valves, in water flows, and the like.

[0029] The expansion element according to the invention is characterized in that the sealing element is held directly in the housing by the crimped edge of the housing.

[0030] In other words, between the receiving space of the housing or the expansion material contained therein and the environment of the expansion element, there is only the housing itself and the sealing element, which closes off the receiving space along the longitudinal axis and is held away from the receiving space by the edge of the housing, which was flanged, i.e. bent inwards, after the sealing element was inserted there.

[0031] Accordingly, the invention eliminates the need for additional elements such as previously known support discs, guide elements, covers, and the like, thus saving a corresponding assembly step. The manufacturing and acquisition costs of such additional elements can also be saved. Furthermore, such additional elements do not need to be stored, transported, or managed, resulting in further cost savings.

[0032] This can be achieved in particular by ensuring that the sealing element provides a sufficiently good and durable seal. This can be accomplished through various design features and / or an appropriate choice of material for the sealing element, as will be described in more detail below. In every case, the sealing element is designed in such a way as to achieve an effective and long-lasting seal. Furthermore, the crimped edge of the housing is sufficiently robust to reliably and durably hold the sealing element in place.

[0033] In particular, gap extrusion between the sealing element and the piston can be avoided. Gap extrusion refers to the penetration of the sealing element material into the manufacturing-related gap in the fit between the piston and the housing due to the high internal pressure of the expansion material. The movement of the piston exacerbates the gap extrusion effect, causing the sealing element material to be pulled upwards or even torn off. Preferably, the expansion element is cylindrical and rotationally symmetrical about its longitudinal axis, which can promote a compact design and uniform force generation.

[0034] The crimping of the housing edge can be performed with a suitable tool which, when moved along the longitudinal axis towards the receiving space of the expansion element, progressively bends the housing edge. The tool can simultaneously incorporate a corresponding mandrel or similar feature to maintain an opening in the crimped housing edge during the crimping process, through which the piston can then pass.

[0035] According to one aspect of the invention, the crimped edge of the housing touches the piston perpendicular to the longitudinal axis, wherein the stroke of the piston along the longitudinal axis is sufficiently small such that the section of the piston which is touched by the crimped edge of the housing is always outside the receiving space of the housing.

[0036] This aspect of the present invention is based on the understanding that grooves extending along the longitudinal axis of the piston can form on the piston due to the contact between the inner edge of the crimped rim of the housing and the outer surface of the piston, as the piston is repeatedly extended and retracted during use. If these grooves extend sufficiently far along the longitudinal axis beyond the sealing element, connections can form between the receiving chamber and the surroundings of the expansion element, through which the heated and consequently pressurized expansion material could escape from the receiving chamber of the housing into the surroundings of the expansion element.

[0037] According to the invention, this can be avoided by designing the expansion element such that these grooves on the outside of the piston, should they occur during a full or maximum piston stroke, never reach the receiving space, even when the piston is fully retracted. This is because the full or maximum stroke, which results from the application or installation situation in the actuator, is always less than the distance along the longitudinal axis between the contact point of the crimped edge of the housing and the outside of the piston when the expansion material is cold (no stroke at all) and when the piston is fully or at its maximum stroke. This prevents the grooves on the outside of the piston from affecting the sealing element's tightness.

[0038] According to a further aspect of the invention, the sealing element, in its unassembled state, has a narrowing of the through-opening perpendicular to the longitudinal axis, which, in the assembled state of the sealing element, is pressed in perpendicular to the longitudinal axis by the piston. Thus, the inner side of the through-opening of the sealing element can be sectionarily narrower than in the rest of the area in order to achieve a higher force of the sealing element on the outside of the piston at this point, which can increase the seal between the sealing element and the piston precisely at that location.

[0039] According to another aspect of the invention, the narrowing of the through-opening of the sealing element in the assembled state of the sealing element borders directly on the receiving space of the housing along the longitudinal axis.

[0040] Accordingly, the enhanced sealing effect of the narrowed through-hole of the sealing element occurs directly opposite the receiving chamber or the expansion material located there, thus effectively preventing the ingress of expansion material into the space between the sealing element and the piston when it heats up. This can further improve the seal between the sealing element and the piston.

[0041] According to a further aspect of the invention, the narrowing of the through-opening of the sealing element in the unmounted state of the sealing element is designed to widen in a wedge shape towards the receiving space of the housing, so that the narrowing of the through-opening in the mounted state of the sealing element extends in a curved shape into the receiving space of the housing.

[0042] The wedge-shaped constriction of the sealing element's through-hole is thus greatest, and the through-hole of the sealing element is therefore narrowest, where the sealing element ends along its longitudinal axis towards the receiving chamber of the housing. When the piston is installed from the side opposite the receiving chamber of the housing along its longitudinal axis, this causes the material of the wedge-shaped constriction of the sealing element's through-hole to be bent or pushed outwards in an arc-shaped manner, lying against the outside of the piston and into the receiving chamber of the housing, thereby forming an arc-shaped sealing lip. As the expansion material heats up and expands, it presses against this sealing lip, causing it to fit more tightly against the outside of the piston and thus increasing the seal between the sealing element and the piston.

[0043] The present invention also relates to an expansion element with a housing which substantially encloses a receiving chamber, with an expansion material, preferably a wax, which is arranged in the receiving chamber, wherein the expansion material is designed to expand when heated, preferably electrically, with a sealing element which, together with the housing, completely seals the receiving chamber tightly around the expansion material, wherein the sealing element has a blind hole along the longitudinal axis, and with a piston which is arranged along the longitudinal axis in the blind hole of the sealing element.

[0044] This expansion element according to the invention is also characterized in that the sealing element is held directly in the housing by the crimped edge of the housing.

[0045] Thus, the properties and advantages of the present invention described above can also be applied to a thermal expansion element if the piston is received by a blind hole in the sealing element. Accordingly, the piston can be moved or pushed out of the housing as described above, without the piston coming into contact with the receiving space of the housing or with the thermal expansion material contained therein.

[0046] According to another aspect of the invention, the sealing element in the unassembled state has a projection perpendicular to the longitudinal axis, which is pressed in perpendicular to the longitudinal axis by the housing in the assembled state of the sealing element.

[0047] This allows the corresponding properties and advantages of narrowing the through-hole of the sealing element to be applied comparably to the seal between the outside of the sealing element and the inside of the housing. This can be done regardless of whether the sealing element receives the piston through the through-hole or in the blind hole.

[0048] According to another aspect of the invention, the projection of the sealing element, in the assembled state of the sealing element, borders directly on the receiving space of the housing along the longitudinal axis.

[0049] This allows the corresponding properties and advantages of narrowing the through-hole of the sealing element to be applied comparably to the tightness between the outside of the sealing element and the inside of the housing.

[0050] According to a further aspect of the invention, the projection of the sealing element in the unmounted state of the sealing element is designed to increase in a wedge shape towards the receiving space of the housing, so that the projection in the mounted state of the sealing element extends in a curved shape into the receiving space of the housing.

[0051] This allows the corresponding properties and advantages of the projection of the sealing element's through-hole to be compared to the tightness between the outside of the

[0052] The sealing element is applied to the inside of the housing. According to one aspect of the invention, the housing has a recess perpendicular to the longitudinal axis, preferably inclined, wherein the sealing element has a stop perpendicular to the longitudinal axis, preferably inclined, which is formed corresponding to the recess of the housing.

[0053] This can simplify the positioning of the sealing element during assembly, as the movement of the sealing element being inserted into the interior of the housing along its longitudinal axis can be stopped by the contact of the sealing element's stop against the recess of the housing. For this purpose, the recess of the housing and the stop of the sealing element can be designed as corresponding shoulders, which can be a simple way to implement this.

[0054] Designing the stop of the sealing element and the recess of the housing to correspond to each other at an angle can lead to increased pressure between the sealing element and the housing in the contact area, which can increase the tightness.

[0055] According to another aspect of the invention, the edge of the housing from the recess of the housing is thinner than the housing in the area of ​​the receiving space.

[0056] This allows the sealing element to be inserted into the interior of the housing until it reaches the stop against the recessed edge of the housing. Furthermore, this area of ​​the housing, due to its relatively thin design, can be more easily crimped, which can simplify assembly.

[0057] According to a further aspect of the invention, the through-opening of the sealing element has at least one sealing ring, preferably several sealing rings spaced apart from each other along the longitudinal axis, perpendicular to the longitudinal axis, which is designed to contact the piston perpendicular to the longitudinal axis when the expansion material is heated up in the assembled state of the sealing element.

[0058] This can further improve the tightness there, especially with increasing pressure from the expansion material.

[0059] According to another aspect of the invention, the elastic sealing element consists of a thermoplastic polymer or a fluororubber, which can represent concrete possibilities for implementation in order to achieve the desired properties as previously described by using a suitable material for the sealing element.

[0060] Additionally or alternatively, the elastic sealing element has a Shore A hardness of at least 60 ShA, which allows the required or desired tightness to be achieved by using a suitable sealing element material while maintaining sufficient elongation. Using a material with a higher Shore A hardness can improve the material's resistance, particularly with regard to the previously mentioned gap extrusion. A higher Shore A hardness is therefore generally better in terms of mechanical resistance for preventing or reducing gap extrusion (the material of the sealing element being pulled through the gap, etc.). This can be particularly useful for designing the sealing element as a rod seal with a through-hole.

[0061] On the other hand, using a material with a lower Shore A hardness can improve the ductility of the sealing element, which can benefit its durability. This can also be advantageous in the case of a blind-hole sealing element, allowing the blind hole to be pressed in.

[0062] In any case, the material of the sealing element should not be too hard in terms of Shore A hardness, as this generally reduces the sealing effect because the sealing element no longer conforms as well to the sealing surfaces and does not fill the microscopic surface roughness as effectively. For a sealing element with a blind hole or a blind element, a high Shore hardness can be disadvantageous anyway, since the sealing element requires high material ductility because the blind hole must be able to be compressed, which is made difficult or impossible by excessive stiffness.

[0063] Specifically, when designing the sealing element with a blind hole instead of a through hole, a Shore A hardness in the range of 60 ShA to 70 ShA can be advantageous to ensure sufficient elasticity of the material around the blind hole. At the same time, the material can then exhibit a certain resistance to the previously mentioned gap extrusion, which, however, is less critical in this case than with a through-hole sealing element, since there is no through-hole.

[0064] When the sealing element is designed with a through-hole instead of a blind hole, a Shore A hardness of at least 83 ShA and preferably 95 ShA can be advantageous to more effectively prevent gap extrusion. In particular, it may be especially preferable in this case to provide a Shore A hardness of 95 ShA for a thermoplastic material used for the sealing element and a Shore A hardness between 83 ShA and 90 ShA or between 83 ShA and 95 ShA for a fluororubber, in order to find a suitable compromise for the application between the material properties described above.

[0065] Additionally or alternatively, the housing is made of a lead-free metal, preferably lead-free brass, thus avoiding the use of lead in the housing material. Additionally or alternatively, the housing is deep-drawn. This eliminates the need for machining, as previously known, to manufacture the housing, particularly as a cylindrical sleeve. Using brass as the material for deep-drawing the housing can be achieved, in particular, by using a lead-free brass alloy or lead-free brass, thereby enhancing these properties and advantages.

[0066] The present invention also relates to an actuator, preferably for a control valve, with a wax element as previously described.

[0067] Thus, the properties and advantages of a thermal expansion element according to the invention can be implemented and used in an actuator.

[0068] Preferably, the actuator should be designed by electrically heating the expansion material of the expansion element, which can represent a compact implementation option.

[0069] The present invention further relates to a fluid distributor, preferably a heating circuit distributor, with at least one control valve with an actuator as described above.

[0070] Such a fluid distributor can, in particular, be a heating circuit distributor of an underfloor heating system, a hot water heating system, or a radiator of a hot water heating system. This allows a fluid distributor to be created in order to implement and utilize the aforementioned properties and advantages of an actuator according to the invention. In any case, the fluid distributor or the heating circuit distributor, its control valve, and the actuator according to the invention can be manufactured as separate components or assemblies and then joined together, optionally by means of an adapter. However, the control valve and / or the actuator according to the invention can also be designed as a component of the fluid distributor and thus integrated into the fluid distributor. Alternatively, at least the control valve and the actuator according to the invention can be designed as a common integral assembly and arranged or integrated in the fluid distributor.

[0071] Several exemplary embodiments and further advantages of the invention are shown and explained in more detail below in purely schematic terms in connection with the following figures. These figures show:

[0072] Figure 1 shows a sectional view of a control valve of a fluid distributor according to the prior art;

[0073] Figure 2 shows a sectional view of an actuator according to the invention connected to an adapter of the control valve in a fully closed position;

[0074] Figure 3 shows a perspective exploded view of a thermal expansion element according to a first embodiment of an actuator according to the invention;

[0075] Figure 4 shows a perspective view of a sealing element of the expansion element according to the invention in the first embodiment; Figure 5 shows a sectional view of the sealing element of Figure 4;

[0076] Figure 6 shows a perspective view of the expansion element according to the invention in the first embodiment;

[0077] Figure 7 shows a sectional view along the longitudinal axis of the expansion element according to the invention shown in Figure 6; and

[0078] Figure 8 shows a sectional view along the longitudinal axis of an expansion element according to a second embodiment of the invention.

[0079] The figures above are viewed in cylindrical coordinates. A longitudinal axis X extends along the axis. Perpendicular to the longitudinal axis X, a radial direction R extends away from the longitudinal axis X. Perpendicular to the radial direction R and around the longitudinal axis X, a circumferential direction U extends.

[0080] Figure 1 shows a sectional view of a control valve 12 of a fluid distributor 1 according to the prior art. The fluid distributor 1 is considered using the example of a heating circuit distributor 1 of a heating system. The heating circuit distributor 1 has a wall 10 which encloses an interior space 11 as an internal volume 11. Inside the interior space 11 is a fluid 18 in the form of heating water 18.

[0081] The heating circuit manifold 1 has several control valves 12 arranged side by side, of which only one control valve 12 is shown in Figure 1. The control valve 12 has a pipe connection 13, which, in the illustration of Figure 1, extends downwards through the wall 10 of the heating circuit manifold 1. A fluid line 19 in the form of a pipe 19 is connected to the lower or outer end of the pipe connection 13. The control valve 12 has a valve stem 14 in the form of a cylindrical rod, which is guided through the heating water 18 and widens radially at its lower end, facing the pipe connection 13, into a circular valve disc 15. Facing the pipe connection 13, the valve disc 15 has an annular valve seal 16 made of an elastic material at its edge.

[0082] Outside the wall 10 of the heating circuit manifold 1, the control valve 12 is fixedly mounted on the wall 10 such that the valve stem 14 extends along the longitudinal axis X through the control valve 12 and protrudes upwards from the control valve 12 with its upper edge 14a. Inside the control valve 12, a return spring 17 is arranged as a valve spring 17 and connected to the control valve 12 and the valve stem 14 such that the spring force F of the return spring 17 moves the valve stem 14 away from the line connection 13 along the longitudinal axis X, thus opening the line connection 13 to allow fluid flow. The control valve 12 has a connection thread 17a on its cylindrical outer surface, to which an actuator 2 can be attached. This can also be done using an adapter or adapter system, or a union nut.To actuate the control valve 12, a thermal actuator 2 according to the invention, as shown in Figure 2, can now be used. This is a so-called normally closed actuator 1, or NC actuator 1 for short, which, in its unactuated state, exerts a sufficiently high force on the valve stem 14 of the control valve 12, which is greater than the spring force of the return spring 17 of the control valve 12. Accordingly, in the unactuated state of the actuator 2, the valve stem 14, together with the valve disc 15 and valve seal 16, is pressed along the longitudinal axis X against the upper end of the pipe connection 13, thus closing the pipe 19.

[0083] Figure 2 shows a schematic sectional view of an actuator 2 according to the invention connected to an adapter 12a of the control valve 12 in a fully closed position.

[0084] The actuator 2 has a housing 20 which is essentially cylindrical around the longitudinal axis X and is dome-shaped, facing away from the control valve 12 (see Figure 1), except for a housing opening 20a on the longitudinal axis X, which also functions as a stroke indicator opening 20a.

[0085] Inside the housing 20, a base body 21 is arranged, which can also be referred to as a mounting element 21. Along the longitudinal axis X of the housing opening 20a, the mounting element 21 has a connecting element 22 or a locking element 22 for connecting to the connection thread 17a of the control valve 12 or to a corresponding undercut or shoulder of the aforementioned adapter 12a or adapter ring 12a by engaging from behind. A connecting line (not shown) runs laterally away from the mounting element 21.

[0086] Facing away from the control valve 12 or the adapter 12a, and towards the housing opening 20a, a thermal expansion element 24 is received by the mounting element 21. The thermal expansion element 24 with heating source (not shown) is a thermoelectric actuator that can be electrically powered via the connecting cable to be heated and thereby generate a change in length along the longitudinal axis X pointing away from the control valve 12 or the adapter 12a. By means of this change in length of the heatable thermal expansion element 24, a piston 24a of the thermal expansion element 24 can be moved along the longitudinal axis X away from the control valve 12 or the adapter 12a, and towards the housing opening 20a. Due to the electrically heated thermal expansion element 24 as the actuator, the actuator 2 is a thermal actuator 2.

[0087] As will be described in more detail below, the expansion element 24 according to the invention has a metallic housing 24b, which was manufactured by deep drawing, but could alternatively be machined if the degree of deformation is materially feasible. The housing 24b forms a cylindrical receiving chamber 24c, closed at the bottom along the longitudinal axis X, which is filled to a certain height along the longitudinal axis X with the expansion material 24d as an expansion material filling 24d in the form of wax 24d or a wax filling 24d of the expansion element 24. The expansion material 24d is sealed at the top by a sealing element 24e of the expansion element 24. The sealing element 24e has a through-opening 24el along the longitudinal axis X, through which the piston 24a extends along the longitudinal axis X. The sealing element 24e is held by the crimped edge of the housing 24b.The piston 24a runs through the sealing element 24e and through the crimped edge 24bl of the housing 24b, held in a sealing manner but movable translationally with force.

[0088] The piston 24a of the expansion element 24 is in contact along the longitudinal axis X with a hollow cylindrical control element 25, which can also be referred to as the lower part 25. The control element 25 encloses the expansion element 24. The outer surface of the closed surface forms a stroke indicator 25a of the control element 25, which can project upwards out of the housing 20 along the longitudinal axis X through the housing opening 20a or through the stroke indicator opening 20a of the housing 20. The inner surface of the closed surface of the control element 25 is in contact with the piston 24a of the expansion element 24, so that the control element 25 can be pushed by the expansion element 24 along the longitudinal axis X away from the control valve 12 or the adapter 12a and towards the housing opening 20a.

[0089] The control element 25 is furthermore in contact along the longitudinal axis X with a plunger 28, so that the plunger 28 of the actuator 2 is movable along the longitudinal axis X. The plunger 28 is in contact along the opposite longitudinal axis X with the valve plunger 14 of the control valve 12. Furthermore, the control element 25 is in contact along the longitudinal axis X, by means of its radially outwardly curved edge (not labelled), with a spring element 26, which is designed as a compression spring 26 in the form of a coil spring 26. The coil spring 26 is supported along the longitudinal axis X at its opposite end against the radially inwardly curved edge (not labelled) of an upper part 27, which is fixedly connected to the mounting element 21.

[0090] The control element 25 is thus movable along the longitudinal axis X by the interplay of the forces of the coil spring 26, which pushes the control element 25 towards the control valve 12 or the adapter 12a and away from the housing opening 20a, and the expansion element 24, which can push the control element 25 away from the control valve 12 or the adapter 12a and towards the housing opening 20a by means of its piston 24a. The movement of the control element 25 along the longitudinal axis X is transmitted to the plunger 28 of the actuator 2 by means of the contact between the plunger 28 and the control element 25. At the same time, in the mounted state of the actuator 2 on the control valve 12, its return spring 17 or valve spring 17 also acts along the longitudinal axis X on the plunger 28 of the actuator 2, so that pressure forces can be transmitted in both directions along the longitudinal axis X by means of the plunger 28 of the actuator 2.If the expansion element 24 is not energized and therefore not heated, it exerts no pressure force along the longitudinal axis X on the control element 25 by means of its piston 24a. The control element 25 is thus pushed completely towards the control valve 12 or away from the housing opening 20a by the spring force of the coil spring 26. The pressure force of the coil spring 26 is transmitted from the control element 25 to the plunger 28, which then presses on the valve stem 14 of the control valve 12. Although the spring force of the valve spring 17 of the control valve 12 opposes the pressure exerted by the plunger 28 of the actuator 2, this force is overcome by the greater spring force of the coil spring 26 of the actuator 2.Thus, when the expansion element 24 is not energized, the spring force of the coil spring 26 of the actuator 2 presses the valve stem 14, together with the valve disc 15 and valve seal 16 of the control valve 12, along the longitudinal axis X against the upper end of the pipe connection 13, thereby closing the pipe 19. This can be described as the closed position of the control valve 12, see Figure 1. Since the closed position of the control valve 12 exists when the expansion element 25 of the actuator 2 is not energized, the actuator 2 is a normally closed actuator 2.

[0091] When the expansion element 24 is energized and thus heated, it exerts a pressure force, proportional to the energization and heating, along its longitudinal axis X by means of its piston 24a on the control element 25. This force opposes and overcomes the spring force of the coil spring 26, pushing the control element 25 away from the control valve 12 or towards the housing opening 20a, and possibly through the housing opening 20a. The stroke can then be detected visually and haptically from the outside by means of the stroke indicator 25a of the control element 25. This also reduces the pressure force of the coil spring 26 on the plunger 28, so that the spring force of the valve spring 17 of the control valve 12 can now lift the valve plunger 14, together with the valve disc 15 and valve seal 16 of the control valve 12, along the longitudinal axis X from the upper end of the line connection 13, thereby opening the pipe 19. The extent of opening the pipe 19 orThe degree of opening of the upper end of the line connection 13 of the control valve 12 depends on the degree of current energization or heating of the expansion element 24 of the actuator 2, so that the degree of opening of the pipe 19 or of the upper end of the line connection 13 of the control valve 12 can be continuously specified.

[0092] Figure 3 shows a perspective exploded view of a thermal expansion element 24 according to a first embodiment of an actuator 2 according to the invention. Figure 4 shows a perspective view of a sealing element 24e of the thermal expansion element 24 according to the first embodiment. Figure 5 shows a sectional view of the sealing element 24e of Figure 4. Figure 6 shows a perspective view of the thermal expansion element 24 according to the first embodiment. Figure 7 shows a sectional view along the longitudinal axis X of the thermal expansion element 24 according to Figure 6. The housing 24b of the thermal expansion element 24, mentioned previously, is manufactured in one piece, i.e., integrally, from lead-free brass by deep drawing or machining as a cylindrical brass sleeve.The lower, closed area of ​​the housing 24b along the longitudinal axis X is thicker-walled than the upper, open area of ​​the housing 24b, see for example Figure 3. The thus thinner-walled upper, open area of ​​the housing 24b can be flanged more easily.

[0093] The lower, closed area of ​​the housing 24b forms the aforementioned receiving space 24c for the expansion element 24, in which the expansion material 24d is located. The transition from the lower, closed area of ​​the housing 24b to the upper, open area of ​​the housing 24b is formed by an inclined recess 24b2 of the housing 24b, against which, in the assembled state, a corresponding stop 24e3 of the sealing element 24e abuts, which can increase the seal and simplify assembly due to a defined positioning of the sealing element 24e in the housing 24b.

[0094] The previously mentioned sealing element 24e consists of a thermoplastic polymer or a fluororubber. In any case, the material of the sealing element 24e has a Shore A hardness in the range between 83 ShA and 95 ShA in order to, firstly, press radially against the piston 24a in a spring-like manner and close a gap or space between the inside of the through-hole 24el of the sealing element 24e and the outside of the piston 24a, and secondly, to allow relative movement of the piston 24a along the longitudinal axis X out of the housing 24b of the expansion element 24.

[0095] Accordingly, additional elements for holding or supporting the sealing element 24e along the longitudinal axis X on the side of the sealing element 24e facing away from the receiving space 24c can be omitted. This can reduce manufacturing costs and simultaneously ensure the desired seal against the expansion material 24d with a long service life for the expansion element 24.

[0096] In particular, this prevents gap extrusion between the sealing element 24e and the piston 24a.

[0097] In addition to the previously described material properties of the sealing element 24e and the secure retention of the sealing element 24e in the housing 24b by means of the crimped edge 24bl of the housing 24b, further design features are present to improve or achieve the tightness of the receiving space 24c to the environment.

[0098] The circumstance of crimping the edge 24b2 of the housing 24b results in the crimped edge 24bl of the housing 24b touching the piston 24a perpendicular to the longitudinal axis X, i.e. radially, which can create grooves on the outside of the piston 24a during movements, which can then connect the receiving space 24c with the environment of the expansion element 24, if these grooves are sufficiently long along the longitudinal axis X and the piston 24a is positioned accordingly.

[0099] To avoid this, the design of the expansion element 24 is such that these grooves on the outside of the piston 24a, if they occur during a full or maximum stroke of the piston 24a, never reach the receiving chamber 24c, even when the piston 24a is fully retracted. This is because the full or maximum stroke, which results from the application or installation situation in the actuator 2, is always less than the distance along the longitudinal axis X between the contact point of the crimped edge 24bl of the housing 24b and the outside of the piston 24a when the expansion material is cold (no stroke) and when the piston is fully or at its maximum stroke. This prevents the grooves on the outside of the piston 24a from affecting the sealing of the sealing element 24.Accordingly, the stroke of the piston 24a along the longitudinal axis X is sufficiently small so that the section of the piston 24a which is touched by the crimped edge 24bl of the housing 24b is always outside the receiving space 24c of the housing 24b.

[0100] Furthermore, in its unassembled state, the sealing element 24e has a radial and circumferential constriction 24e4 of the through-opening 24el perpendicular to the longitudinal axis X, which is pressed in by the piston 24a perpendicular to the longitudinal axis X when the sealing element 24e is assembled. In its assembled state, the constriction 24e4 of the through-opening 24el of the sealing element 24e abuts the receiving chamber 24c of the housing 24 along the longitudinal axis X; that is, the sealing element 24e seals against the receiving chamber 24c along the longitudinal axis X with the constriction 24e4 of the through-opening 24el.The constriction 24e4 of the through-opening 24el of the sealing element 24e is designed in the unmounted state of the sealing element 24e to widen in a wedge shape towards the receiving space 24c of the housing 24, so that the constriction 24e4 of the through-opening 24el extends in a curved shape into the receiving space 24c of the housing 24 when the sealing element 24e is mounted, see for example Figure 5.

[0101] In this way, the wedge-shaped constriction 24e4 of the through-hole 24el of the sealing element 24e forms an arc-shaped sealing lip in the assembled state, which extends along the longitudinal axis X and radially away from the longitudinal axis X or from the outer surface of the piston 24a, resting against the outside of the piston 24a. If the expansion material 24d now heats up and expands as a result, it presses against this sealing lip, which thus fits more tightly against the outside of the piston 24a and thereby increases the seal between the sealing element 24e and the piston 24a.

[0102] Likewise, the sealing element 24e has a projection 24e5 perpendicular to the in the unmounted state.

[0103] Longitudinal axis X, which, in the assembled state of the sealing element 24e, is pressed into the housing 24b perpendicular to the longitudinal axis X. In the assembled state of the sealing element 24e, the projection 24e5 of the sealing element 24e abuts the receiving space 24c of the housing 24 directly along the longitudinal axis X. In the unassembled state of the sealing element 24e, the projection 24e5 of the sealing element 24ee is wedge-shaped, widening towards the receiving space 24c of the housing 24, so that in the assembled state of the sealing element 24e, the projection 24e5 extends in a curved shape into the receiving space 24c of the housing 24. Thus, a sealing lip can also be formed against the inside of the housing 24b, as described above.

[0104] Additionally, the through-opening 24el of the sealing element 24e has two sealing rings 24e6 spaced apart from each other along the longitudinal axis X, which are designed to contact the piston 24a perpendicular to the longitudinal axis X when the sealing element 24e is installed and the expansion material 24d is heated. This can further improve the seal with increasing pressure from the expansion material 24d.

[0105] Figure 8 shows a sectional view along the longitudinal axis X of an expansion element 24 according to a second embodiment of the invention.

[0106] In this case, the sealing element 24e, together with the housing 24b, completely seals the receiving chamber 24c around the expansion material 24d. The sealing element 24e has a blind hole 24e2 along its longitudinal axis X, in which the piston 24a is positioned along the longitudinal axis X. This ensures a complete seal between the piston 24a and the receiving chamber 24c of the housing. In this case, the material of the sealing element 24e has a Shore A hardness in the range of 60 ShA to 70 ShA to allow the blind hole 24e2 to be pressed in while maintaining a sufficient seal.

[0107] The remaining features of the expansion element 24 according to the invention, as described in the second embodiment, correspond to those of the first embodiment.

[0108] REFERENCE MARK LIST (Part of the description)

[0109] R radial direction

[0110] U circumferential direction

[0111] X Longitudinal axis

[0112] 1 fluid distributor; heating circuit distributor

[0113] 10 wall

[0114] 11 Interior; Interior volume

[0115] 12 Control valve

[0116] 12a Adapter or adapter ring of the control valve 12

[0117] 13 Line connection of the control valve 12

[0118] 14 valve tappets

[0119] 14a Top edge of the valve tappet 14

[0120] 15 valve plates

[0121] 16 Valve seal

[0122] 17 Return spring; valve spring

[0123] 17a Connection thread of the control valve 12

[0124] 18 Fluid; Heating water

[0125] 19 Fluid line; pipe

[0126] 2 (thermal) (NC) actuators

[0127] 20 cases

[0128] 20a Housing opening or stroke indicator opening of the housing 20

[0129] 21 Base body; mounting element

[0130] 22 Connecting element; locking element

[0131] 24 Expansion element

[0132] 24a Piston of the expansion element 24

[0133] 24b Housing of the expansion element 24

[0134] 24bl (rolled) edge of the casing 24b

[0135] 24b2 Recoil of the casing 24b

[0136] 24c Receiving space of the expansion element 24

[0137] 24d Expansion material, expansion material filling, wax or wax filling of the expansion element 24

[0138] 24e Sealing element or rod sealing element of the expansion element 24

[0139] 24el Through opening of the sealing element 24e

[0140] 24e2 Blind hole of the sealing element 24e 24e3 Stop of the sealing element 24e

[0141] 24e4 Narrowing of the passage opening 24el of the sealing element 24e

[0142] 24e5 Projection of the sealing element 24e

[0143] 24e6 Sealing rings of the sealing element 24e 25 Control element; lower part

[0144] 25a Stroke indicator of the control element 25

[0145] 26 Spring element; compression spring; coil spring I upper part

[0146] 28 pestles

Claims

PATENT CLAIMS 1. Expansion element (24), preferably for actuators (2), comprising a housing (24b) which substantially encloses a receiving chamber (24c), comprising an expansion material (24d), preferably a wax (24d) which is arranged in the receiving chamber (24c), wherein the expansion material (24d) is designed to expand upon, preferably electrical, heating, comprising an elastic sealing element (24e) which, together with the housing (24b), substantially seals the receiving chamber (24c) around the expansion material (24d), wherein the sealing element (24e) has a through-opening (24el) along a longitudinal axis (X), and comprising a piston (24a) which extends along the longitudinal axis (X) through the through-opening (24el) of the sealing element (24e), characterized in that the sealing element (24e) extends directly from the crimped edge (24bl) of the housing (24b) into the housing. (24b) is held.

2. Expansion element (24) according to claim 1, wherein the crimped edge (24bl) of the housing (24b) contacts the piston (24a) perpendicular to the longitudinal axis (X), wherein the stroke of the piston (24a) along the longitudinal axis (X) is sufficiently small such that the section of the piston (24a) which is contacted by the crimped edge (24bl) of the housing (24b) is always outside the receiving space (24c) of the housing (24b).

3. Expansion element (24) according to claim 1 or 2, wherein the sealing element (24e) in the unassembled state has a constriction (24e4) of the through-opening (24el) perpendicular to the longitudinal axis (X), which in the assembled state of the sealing element (24e) is pressed in perpendicular to the longitudinal axis (X) by the piston (24a).

4. Expansion element (24) according to claim 3, wherein the narrowing (24e4) of the through-opening (24el) of the sealing element (24e) in the assembled state of the sealing element (24e) directly adjoins the receiving space (24c) of the housing (24b) along the longitudinal axis (X).

5. Expansion element (24) according to claim 3 or 4, wherein the constriction (24e4) of the through-opening (24el) of the sealing element (24e) in the unassembled state of the sealing element (24e) is formed in a wedge shape increasing towards the receiving space (24c) of the housing (24b), so that the constriction (24e4) of the through-opening (24el) in the assembled state of the sealing element (24e) extends in a bent manner into the receiving space (24c) of the housing (24b).

6. Expansion element (24) with a housing (24b) which substantially encloses a receiving chamber (24c), with an expansion material (24d), preferably a wax (24d) which is arranged in the receiving chamber (24c), wherein the expansion material (24d) is designed to expand when heated, preferably electrically, with an elastic sealing element (24e) which, together with the housing (24b), completely seals the receiving chamber (24c) around the expansion material (24d), wherein the sealing element (24e) has a blind hole (24e2) along a longitudinal axis (X), and with a piston (24a) which is arranged along the longitudinal axis (X) in the blind hole (24e2) of the sealing element (24e), characterized in that the sealing element (24e) is held directly in the housing (24b) by the crimped edge (24bl) of the housing (24b).

7. Expansion element (24) according to one of the preceding claims, wherein the sealing element (24e) in the unassembled state has a projection (24e5) perpendicular to the longitudinal axis (X), which in the assembled state of the sealing element (24e) is perpendicular to the The longitudinal axis (X) is pressed in by the housing (24b).

8. Expansion element (24) according to claim 7, wherein the projection (24e5) of the sealing element (24e) in the assembled state of the sealing element (24e) directly adjoins the receiving space (24c) of the housing (24b) along the longitudinal axis (X).

9. Expansion element (24) according to claim 7 or 8, wherein the projection (24e5) of the sealing element (24e) in the unassembled state of the sealing element (24e) is designed to increase in a wedge shape towards the receiving space (24c) of the housing (24b), so that the projection (24e5) in the assembled state of the sealing element (24e) extends in a bent manner into the receiving space (24c) of the housing (24b).

10. Expansion element (24) according to one of the preceding claims, wherein the housing (24b) has a, preferably inclined, recess (24b2) perpendicular to the longitudinal axis (X), wherein the sealing element (24e) has a, preferably inclined, stop (24b2) perpendicular to the longitudinal axis (X), which is formed corresponding to the recess (24b2) of the housing (24b).

11. Expansion element (24) according to claim 10, wherein the edge (24bl) of the housing (24b) is thinner from the recess (24b2) of the housing (24b) than the housing (24b) in the area of ​​the receiving space (24c).

12. Expansion element (24) according to one of the preceding claims, wherein the through-opening (24el) of the sealing element (24e) has at least one sealing ring (24e6), preferably several sealing rings (24e6) spaced apart from each other along the longitudinal axis (X), perpendicular to the longitudinal axis (X), which is designed to contact the piston (24a) perpendicular to the longitudinal axis (X) when the expansion material (24d) is heated.

13. Expansion element (24) according to one of the preceding claims, wherein the elastic sealing element (24e) is made of a thermoplastic polymer or of a fluororubber and / or has a Shore A hardness of at least 60 ShA and / or wherein the housing (24b) is made of a lead-free metal, preferably lead-free brass and / or is deep-drawn.

14. Actuator (2), preferably for a control valve (12), with a thermal expansion element (24) according to one of the preceding claims, wherein the actuator (2) is preferably configured to electrically heat the thermal expansion material (24d) of the thermal expansion element (24).

15. Fluid distributor (1), preferably a heating circuit distributor (1), with at least one control valve (12) with an actuator (2) according to claim 14.

Images