DE102012013347B4 - Electronic circuit board and method of installing a sensor on a heater block for an instantaneous water heater - Google Patents

Abstract

Heating block (100) of a heating device for heating a liquid medium with an electronic circuit board (10) attached thereto, wherein- the electronic circuit board (10) has a base plate with a main section (80), a secondary section (82) and at least one secondary section (82) has an elastic web section (84) connecting to the main section (80), - the secondary section (82), the main section (80) and the at least one web section (84) lie in a common main plane in a relaxed state, - the secondary section (82) is equipped with at least one sensor element (11) for recording at least one measured variable of the heating block (100), - the electronic printed circuit board (10) is attached to the heating block (100) in such a way that the at least one sensor element (11) assumes an intended position, - By bending the at least one web section (84) of the secondary section (82) in an area of the at least one sensor element (11) on a Heizblockk body (102) for receiving or guiding the liquid medium, and- the heating block (100) has a first and second counter-contact point (56, 58) which are galvanically connected to one another, for galvanically contacting a first and second contact point (50, 52) a test circuit (40) for checking whether an electrical contact has been established between the at least one sensor element (11) and the heating block (100).

Description

The present invention relates to an electronic circuit board for controlling and/or monitoring a heating device having a heating block for heating a liquid medium. The present invention also relates to such a heating block. Furthermore, the present invention relates to a heating device, in particular a flow heater with such a heating block. The invention also relates to a method of installing a sensor on such a heater block.

Heating devices for heating a liquid medium, in particular flow heaters, are well known. In this context, instantaneous water heaters for heating water are known in particular, which heat the water while it flows through this heater. In principle, other liquid media can also be heated according to this principle, but the following explanations explain the relationships using water as a representative example.

Such a continuous-flow heater includes a heating block with flow channels for guiding the water to be heated. Heating elements, such as, for example, helical heating walls, are arranged in these guide channels. Measurements with appropriate sensors are provided for monitoring and, if necessary, controlling the heating-up or warming-up process resulting therefrom. Parameters such as flow speed and flow rate, temperature and pressure of the water can be recorded and further processed.

The actual physical measurement of the parameter in question or a representative parameter can be carried out using sensors that are arranged indirectly on or in a flow channel. At least such sensors are arranged directly on or in the heating block that has the flow channels. A more extensive recording and evaluation of the measured values and, if necessary, consideration within the framework of a control or regulation can be carried out using an electronic printed circuit board, which carries a corresponding evaluation unit, or the recorded data can be fed to a further evaluation, such as a control chip or process computer .

For example, so-called flow rate measurement systems are installed in electronically controlled or regulated instantaneous water heaters in order to determine the amount of water flowing through the instantaneous water heater and in order to be able to determine how much energy must be added to the water in order to maintain the selected water temperature. Nowadays, most or all well-known manufacturers use a magnetic wheel, which transmits the flow signal to a sensor, a so-called Hall IC, using the magnetic fields on the wheel. Until now, such a Hall IC was either built into a separate housing or plugged into the heating block via a small printed circuit board. In both variants, the Hall IC or the Hall IC assembly must be electrically contacted with a corresponding control or evaluation device via additional connecting elements. Plugs or solder contacts can be used for this.

In EP 1 076 479 A1 shows the possibility of dividing a printed circuit board into two different sections by means of a bend. The first section consists of a sensor component and the second consists of a signal-processing component.

Out of WO 2011/067 181 A1 a flow meter for a beverage preparation machine is known, which is connected to a printed circuit board. There are through-openings on the printed circuit board to accommodate the flow meter.

pamphlet JP 2004 - 119 624 A shows a special circuit board which is designed in such a way that the design is to prevent damage from impact. Depending on the embodiment shown, the sensor element arranged centrally on the printed circuit board is surrounded by notches that absorb impacts.

An adaptation or adjustment of a flow rate detection unit is achieved via separate components with the heating block. The bearing points of the impeller can also be located in such components. A corresponding adapter piece can also be plugged into the heating block. The German utility model DE 20 2008 017 937 U1 shows, for example, a corresponding impeller with magnet.

In other cases, it may be necessary for an evaluation unit of a corresponding sensor to be fixed in a specific spatial position in relation to this and thus to the heating block. During installation, it is often difficult to check whether the evaluation unit or a sensor of the evaluation unit is actually arranged in the desired position, as it is needed.

When using electronic sensors or sensors to be evaluated electronically, there is an electrical connection from the sensors, or from one sensor if only one sensor is used, to the electronic printed circuit board. Such an electronic connection is usually made by means of ent correspondingly prepared plug contacts. For this purpose, for example, an insulated wire can be soldered at one end to the printed circuit board and provided with a plug at its other end, which fits into a corresponding plug on the heating block and is plugged in there after the printed circuit board has been attached to the heating block.

The invention is therefore based on the object of addressing at least one of the above-mentioned problems. In particular, the coupling between sensors in the heating block and evaluation electronics should be improved. If possible, elements should be saved, the arrangement of corresponding printed circuit boards should be made more error-proof and/or costs should be saved. A correct arrangement of a printed circuit board should preferably be created without the use of additional components. At least one alternative solution should be specified.

According to the invention, a heating block of a heating device for heating a liquid medium with an electronic circuit board attached thereto for controlling and/or monitoring a heating device having a heating block according to claim 1 is proposed. Such an electronic circuit board comprises a base plate with a main section, a secondary section and at least one elastic web section connecting the secondary section to the main section. The main section is intended to be mounted on or to the heating block. For example, appropriate bores for screwing the base plate to the heating block can be provided, to name just one example.

On the base plate, which has the main section, secondary section and web section, in particular consists of these three sections, has at least one connecting conductor track, which runs from the main section via the web section to the secondary section. The secondary section can thus be electrically connected to the main section via the web section by means of this at least one connecting strip conductor.

In a relaxed state, the minor section, the main section and the web section lie in a common plane, referred to herein as the main plane. The electronic printed circuit board thus has a basically flat base plate. The secondary section is designed with at least one sensor element for recording at least one measured variable of the heating block. It is therefore proposed to arrange such a sensor element on the secondary section. In this respect, it is proposed at all to arrange such a sensor element on the electronic printed circuit board, namely the base plate, instead of arranging it on a separate printed circuit board or otherwise separately from the electronic printed circuit board.

The secondary section is so elastically connected to the main section via the at least one web section that the secondary section can be bent out of the main plane by bending the web section. In this respect, a bend is addressed in which the at least one connecting conductor track is not damaged, so that even in the case of this bend, electric current can continue to flow via this conductor track. In particular, the sensor element can be connected and functionally coupled to other elements on the main section via this conductor track. This connection or coupling remains in place despite the bending of the base plate in the area of the web section. The fact that one or more such conductor tracks are not damaged when the web section is bent can be achieved, for example, by the material of the relevant conductor track having a corresponding elasticity. If an electronic printed circuit board is used which has a plurality of layers in the web area, the layer on which the at least one conductor track is arranged can be provided as particularly inelastic. Bending of the web section then leads to less compression or stretching of this layer than of the other layers. The effect of a bend on the at least one conductor track is correspondingly small. A further possibility of preventing damage to the at least one conductor track consists in artificially lengthening the conductor track on the web section, for example by arranging it obliquely or in a meandering, zigzag or similar manner.

In addition or as an alternative, the web section can also be designed in such a way that the bending out of the secondary section from the main plane only leads to weak bending in the area of the at least one web section. For this purpose, the web section can be made very long, for example, by a corresponding course, such as, for example, by a labyrinthine course.

The bending of the secondary section from the main section is intended for the purpose of adapting the at least one sensor element in its position and/or orientation to the heating block. As a result, the sensor element can be brought closer to the heating block or, if necessary, the secondary section of the heating block can also be pushed away when the electronic printed circuit board is fastened to the heating block. In particular, the distance between the sensor element and the heating block, in particular at a position where the sensor element or the electronic circuit board touches the heating block in this area, designates the position of the sensor element to the heating block.

In addition, the sensor element or a relevant area of the secondary section on which the sensor element is arranged can have a certain two-dimensional extent that is not negligible, so that a punctiform sensor element cannot be assumed. In this case, a plane-parallelism of such a surface of the sensor element or of the corresponding area of the secondary section to a corresponding surface, in particular a contact surface, of the heating block denotes an alignment. However, a plane-parallel alignment of such two surfaces is only one possible alignment. In particular, it is provided that the elastic web section first enables a plane-parallel alignment between the sensor element and the heating block. In other words, there can initially be a non-plane-parallel alignment and when the electronic printed circuit board is attached to the heating block, the secondary section comes into contact with the heating block in such a way that plane-parallelism results there. This orientation or change in orientation is only made possible by the elasticity of the web section.

The sensor element can therefore be provided on the base plate of the electronic printed circuit board and, due to the elasticity of the web section, can be adapted to the heating element in terms of position and alignment. As a result, electrical connections can also be achieved at a corresponding point of contact by means of corresponding electrical contacts, as a result of which electrical plug connections can be avoided. The structure of the electronic printed circuit board and the attachment of the same to the heating block for the purpose of coupling to sensor elements of the heating block can thus be designed in a simple manner.

The secondary section can preferably be bent by the web section by at least one, preferably at least three, average thicknesses of the electronic printed circuit board from the main plane, so that the secondary section in the area of the at least one electronic sensor element mounted on the secondary section is bent by at least one of these average thicknesses, in particular by at least three of these mean thicknesses, can be bent out of the main plane in a direction perpendicular to the main plane. Thus, the electronic circuit board, particularly in the area of its main portion, can be mounted on a body such as the heating block and the sensor element mounted on the electronic circuit board can still be changed in position by at least one or at least three thicknesses. It is thus possible to create a certain degree of positioning flexibility without an additional element for the sensor element. Arrangement and connection of the electrical sensor element on the circuit board can be done in a simple manner before mounting the circuit boards.

A controller electrically connected to the sensor element is preferably provided on the main section for evaluating signals, in particular measured values of the sensor element. An electrical connection takes place in particular via the at least one conductor track which is provided between the secondary section and the main section via the web section. It is thus possible to provide the sensor element and also a controller on the same circuit board, in particular to equip the circuit board with all these elements and the components required for them and still achieve flexibility when arranging the sensor element.

The at least one sensor element is preferably soldered onto the electronic circuit board as an SMD component. An SMD component is one that is soldered directly onto a circuit board without using wires. The abbreviation SMD originated in English and stands for "Surface Mounted Device". In this way, the arrangement of a corresponding sensor element can be simplified even further in that it is arranged and soldered as an SMD component on the secondary section and can be connected to a controller via the web section.

The secondary section can preferably be tilted in at least two directions, in particular in two orthogonal directions, relative to the main plane via the at least one web section. This ability to tilt in several directions is intended in particular to achieve a flexible possibility of aligning the secondary section, in particular a sensor element installed there.

According to one embodiment, it is proposed that the secondary section is surrounded by the main section, that in addition or instead, cutouts are provided between the secondary section and the main section and that several of the web sections are formed between the cutouts. In this respect, a basically conventional, for example rectangular, circuit board or circuit board plate can be used. This is then provided with free cuts, i.e. cutouts are made that separate the secondary section from the remaining main section. However, there remain web sections that connect the secondary section to the main section. The provision of these free cuts, as a result of which only the connection via the web sections remains, creates the flexibility that is required to bend the minor section out of the main plane of the board.

The free cuts, and thus the resulting or remaining web sections, can now be designed in such a way that a corresponding flexibility results. In particular, it is proposed that the web sections represent a direct or shortest connection between the secondary section and the main section, in order in particular to make the respective connection path created by a web section as long as possible, in order to thereby increase the flexibility of the connection between the secondary and main sections . For example, the cutouts can also be provided in such a way that labyrinthine web sections result. Such a labyrinthine configuration also leads to long connecting sections between the secondary section and the main section, namely connecting sections which are significantly longer than the actual distance to be bridged between the secondary section and the main section.

The at least one web section and/or corresponding cutouts are preferably designed in the manner of a labyrinth, at least in sections. According to a further embodiment, it is proposed that the at least one of the web sections and/or the cut-outs be designed in a spiral shape, either entirely or in sections. As described above, flexibility in the connection between the secondary section and the main section can also be achieved by means of a spiral configuration.

In addition or as an alternative, it is proposed that the at least one web section and/or the cutouts run around the at least one sensor element by at least 90° from the main section to the secondary section. In addition or as an alternative, the at least one conductor runs from the main section to the secondary section by at least 90° around the at least one sensor element. This also creates a path of mechanical or electrical connection between the main and secondary sections, which is significantly longer than the actual distance between the secondary and main sections. The flexibility can be increased accordingly. A bend that leads to a positional deviation of the secondary section compared to the main section by only a few thicknesses of the board leads to small or even hardly noticeable bends in such extended web sections. This also makes it possible to ensure that the connecting conductor track or connecting conductor tracks are not damaged in the intended bend.

What all embodiments basically have in common is that the bending of the web section can result in a restoring force being produced, which is directed in the opposite direction to the bending, starting from the circuit board, in particular the web section. This restoring force can also be used as the pressing force or pressing force of the slave portion against the heater block when the electronic circuit board is properly installed on the heater block. Preferably, an electronic circuit board is used, which has a commonly used board material. A known electronic printed circuit board of this type is essentially or exclusively adapted in terms of its shape in that the secondary section and web section are created, in particular in that the cutouts described are made. Such an electronic circuit board is usually made of an elastic material, so that bending leads to a permanent counterforce.

According to a further embodiment it is proposed that the secondary section forms with the web section a finger section extending from the main section in a finger-like direction. Such a finger section can, for example, have a fifth or less of the width of the main section and have a length that is at least 3 times, in particular at least 5 times, the width of the web section or finger section. An electronic printed circuit board can thus be provided which, in a known manner, contains control units, evaluation units and/or other desired elements or assemblies on a main section. For the provision of at least one sensor element, this is provided on a slender, finger-like extending finger section basically at the end and is connected to corresponding elements on the main section via corresponding conductor tracks on the finger section.

The at least one sensor element can preferably be a Hall IC for picking up magnetic signals, in particular magnetic signals of a magnet wheel for detecting a flow rate. Here, a corresponding magnet wheel can be installed in the heater block and the electronic circuit board is installed on the heater block so that the subsidiary section with the sensor element thereon, namely the Hall IC, is placed immediately adjacent to the magnet wheel. the sensor element can pick up the signals from the magnetic wheel there and forward them to the main section for evaluation.

According to one embodiment, it is proposed that the sensor element is a temperature sensor for detecting a temperature in the heating block. Through the electronic circuit board, such at a desired position on the heater be arranged in blocks. There, the sensor element can either record and measure a temperature directly or record corresponding signals from an electrical component, such as a sensor that is permanently installed on or in the heating block. For example, resistance values of a temperature-dependent resistor arranged in the heating block can be evaluated by the sensor on the electronic printed circuit board.

A further embodiment proposes that a pressure sensor is provided for detecting a pressure, which thus forms the electrical sensor element. Such a pressure sensor can also detect a pressure directly or indirectly, as was explained in connection with the temperature sensor.

According to a further embodiment, it is proposed that a test circuit be provided for checking whether an electrical contact has been established between the sensor element on the secondary section and the heating block. This test circuit includes a first and second contact. For establishing a galvanic connection with a first or second mating contact arranged on the heating block. In this case, the test circuit is prepared to detect whether an electric current flows from the first contact point to the second contact point.

Thus, two contact points are provided on the subsidiary portion of the electronic circuit board. These should be connected to corresponding mating contact points of the heating block, namely in such a way that the first contact point is connected to the first mating contact point and the second contact point is connected to the second mating contact point. It is assumed here that the first and second counter-contact points are galvanically connected to one another. If the above contact is now made between the first and second contact point and the first or second counter-contact point, there is a galvanic connection between the first and second contact point via the galvanic connection between the two counter-contact points. The test circuit checks whether an electric current flows from the first contact point to the second contact point and thereby checks in particular whether there is contact between the first contact point and the first counter-contact point and/or whether there is contact between the second contact point and the second counter-contact point, because only then can an electrical Current flow from the first contact point to the second contact point, which also flows through the heating block.

The first contact point is preferably prepared with an evaluation unit, in particular the sensor element for evaluating a sensor or sensor part connected to the first mating contact. The first contact point and its contact with the first counter-contact point is therefore important for the functionality of the evaluation by the sensor element, because information, in particular in the form of electrical signals, about this contact between the first contact point and the first counter-contact point to the sensor element or evaluation unit on the electronic Circuit board can be routed. If this contact does not exist between the first contact point and the first counter-contact point, this information cannot be transmitted. Thus, by checking whether current is flowing between the first and second contact point, it can be checked whether this contact exists and, if not, an error message can be output.

The second contact point can preferably have a spring element in order to improve galvanic contact between the second contact point and the second counter-contact point. It can thus be assumed that a relatively secure contact between the second contact point and the second counter-contact point can be achieved by means of this spring element. If it is now detected that no current is flowing between the first and second contact points, it can be concluded that there is no contact between the first contact point and the first counter-contact point, assuming contact between the second contact point and the second counter-contact point.

The first contact point is preferably an electrical positive pole and the second electrical contact point is an electrical negative pole. In this respect, at least the test circuit uses a direct current to test the contact.

It is thus provided in particular that the test circuit is designed such that the electric current can only flow between the first and second contact point via the first and second counter-contact point if the first and second counter-contact point are electrically connected to one another.

Furthermore, a heating block of a heater, in particular a heating block of a flow heater, is proposed, the electronic circuit board having a base plate with a main section, a secondary section and at least one elastic web section connecting the secondary section to the main section, the secondary section, the main section and the web section in a relaxed state State lie in a common main plane, the secondary section with at least one sensor element for recording at least one measured variable of the heating blocks is fitted, the electronic printed circuit board is attached to the heating block in such a way that the sensor element assumes a specified position and, by bending the web section, the secondary section in one area, in particular in the area of the at least one sensor element, on a heating block body for receiving or guiding the liquid medium.

In particular, an electronic circuit board according to at least one of the embodiments described above is used. This is attached to the heating block with its main section in such a way that the sensor element assumes a predetermined position on the secondary section. In this way, the secondary section for the sensor element or the area of the secondary section carrying the sensor element achieves the flexibility or freedom to adapt to the heating block. In particular, it is achieved that the sensor element can assume a position outside the main plane of the circuit board and/or that the sensor element or the corresponding section on the secondary section can be tilted relative to the main plane of the circuit board. A deviating position and deviating orientation is thus achieved in a simple manner, which namely enables an adaptation to the heating block.

To compensate for heights and/or bearing tolerances, the secondary section is preferably pressed out of the main plane by the heating element. On the one hand, this can occur when the electronic printed circuit board is attached to the heating block, but it is also a static state in particular when the electronic printed circuit board is attached to the heating block or heating block body.

Additionally or alternatively, the minor portion may be pressed against the heater block body from the main plane by a fastener. In this case, the secondary section is pressed in particular out of the main plane of the circuit board towards the heating block, in particular the heating block body.

Preferably, the heater block has first and second galvanically interconnected mating contact points which are prepared for galvanically contacting the first and second contact points, respectively, of the electronic circuit board when the latter is attached to the heater block and heater block body, respectively. Thus, when the circuit board is fastened to the heating block and there is no fault, there is a galvanic contact between the first contact point and the first counter-contact point and a galvanic contact between the second contact point and the second counter-contact point. The first and second contact points are then also galvanically connected to one another via the galvanic connection between the first and second counter-contact points. If this connection is broken, no current can flow and it can be assumed that at least one of the contacts is broken.

It is proposed that a heating device, in particular a continuous-flow heater with a heating block, be designed according to one of the described embodiments. The advantages described, in particular the cost-effective construction and the avoidance of errors, benefit the heating device accordingly, which can thereby itself become more cost-effective and can have a lower susceptibility to errors.

• - Positionieren einer mit wenigstens einem Sensorelement bestückten elektronischen Leiterplatine an einem Heizblock,
• - Messen einer elektrischen Leitfähigkeit zwischen der elektronischen Leiterplatine oder dem Sensorelement und einem an dem Heizblock angeordneten Referenzelement,
• - Vergleichen der gemessenen elektrischen Leitfähigkeit mit einem Referenzwert oder Prüfen, ob überhaupt ein elektrischer Kontakt besteht und
• - Wiederholen des Positionierens, wenn die gemessene elektrische Leitfähigkeit dem Betrag nach um mehr als einen vorbestimmten Wert von dem Referenzwert abweicht bzw. etwa Null beträgt und/oder
• - Verwenden einer Prüfschaltung zum Überprüfen, ob zwischen dem Sensorelement auf dem Nebenabschnitt und dem Heizblock ein elektrischer Kontakt hergestellt wurde.

To install a sensor on a heater block to measure a physical quantity in the heater block, a method including the following steps is proposed:

• - Positioning an electronic circuit board equipped with at least one sensor element on a heating block,
• - Measuring an electrical conductivity between the electronic printed circuit board or the sensor element and a reference element arranged on the heating block,
• - Compare the measured electrical conductivity with a reference value or check whether there is any electrical contact at all and
• - Repeat positioning if the measured electrical conductivity deviates from the reference value by more than a predetermined value or is approximately zero and/or
• - Using a test circuit to verify that electrical contact has been made between the sensor element on the slave section and the heater block.

Accordingly, an electronic printed circuit board is positioned on the heating block and, in particular, also fastened, and electrical conductivity is then measured between the electronic printed circuit board or between the sensor element and a reference element arranged on the heating block. In this way, in particular by comparing the measured electrical conductivity with a reference value, it is possible to check whether there is a desired electrical contact. The comparison with the reference value does not necessarily have to be very precise. It can be sufficient to check whether a current is flowing at all if a corresponding electrical test voltage is applied.

If it is determined here that there is no or insufficient electrical contact, the electronic printed circuit board is repositioned and the check is repeated. A test circuit is preferably used for this purpose, as has been described above in some embodiments.

Preferably, an electronic circuit board according to at least one of the above embodiments is used and/or a heating block according to one of the above embodiments is used.

• 1 zeigt einen Heizblock mit einem aus zwei Teilschalen zusammengesetzten Heizblockkörper.
• 2 zeigt einen Ausschnitt eines Heizblocks ähnlich der 1 in einer perspektivischen Ansicht.
• 3 zeigt den Ausschnitt der 2 in einer Draufsicht.
• 4 zeigt den Ausschnitt der 2 in einer Seitenansicht.
• 5 zeigt den Ausschnitt der 2 in einer weiteren Seitenansicht.
• 6 zeigt den Ausschnitt der 2 in einer Schnittansicht.
• 7 zeigt den Ausschnitt der 2 in einer weiteren Schnittansicht.
• 8 zeigt einen Ausschnitt einer elektronischen Leiterplatine gemäß einer Ausführungsform mit einem sich fingerartig erstreckenden Fingerabschnitt.
• 9 zeigt eine weitere Ausführungsform einer elektronischen Leiterplatine mit einem spiralförmigen Stegabschnitt.
• 10 zeigt eine weitere Ausführungsform einer elektronischen Leiterplatine mit einem labyrinthförmigen Stegabschnitt.
• 11 zeigt schematisch einen Ausschnitt eines Nebenabschnitts mit einer Prüfschaltung.
• 12 zeigt schematisch den Nebenabschnitt der 11 in einer Frontansicht schematisch.

The invention will now be explained below by way of example using exemplary embodiments.

• 1 shows a heating block with a heating block body composed of two partial shells.
• 2 shows a section of a heating block similar to 1 in a perspective view.
• 3 shows the section of the 2 in a top view.
• 4 shows the section of the 2 in a side view.
• 5 shows the section of the 2 in another side view.
• 6 shows the section of the 2 in a sectional view.
• 7 shows the section of the 2 in another sectional view.
• 8th shows a section of an electronic printed circuit board according to an embodiment with a finger section extending like a finger.
• 9 FIG. 12 shows another embodiment of an electronic circuit board with a spiral-shaped web section.
• 10 FIG. 12 shows another embodiment of an electronic circuit board with a labyrinth-shaped land section.
• 11 shows schematically a section of a secondary section with a test circuit.
• 12 shows schematically the subsidiary section of FIG 11 in a schematic front view.

The figures contain partially simplified, schematic representations. In some cases, identical reference symbols are used for the same but possibly not identical elements. Different views of the same elements can be scaled differently.

1 shows a perspective view of a heating block 100 with a heating block body 102, which is composed essentially of a first partial shell 1' and a second partial shell 2'. The second partial shell 2 'is arranged substantially below the first partial shell 1', wherein in the 1 in the lower left area, the second partial shell 2' protrudes from under the first partial shell 1'. Flow channels 104 are formed between the two partial shells 1' and 2', which carry water as intended, which flows through them and can be heated in some of the flow channels 104 in the process. The heating can take place, for example, by means of heating coils, which can be controlled electrically via what are known as triacs 106 . The water to be heated or the heated water can flow in or out through one of the water connections 108 .

For measuring a flow speed of the water, a receiving bulge 13' is shown, which can basically receive a magnet wheel, which is moved by the flowing water. The rotational speed of such a magnetic wheel thus provides information about the flow rate of the water and thus about the flow rate.

For evaluation, the movement of the magnet wheel must be recorded using an appropriate sensor. This can be done by a Hall sensor or Hall IC, which detects the magnetic field or changed magnetic field that is changed or generated by the movement of the magnet wheel or by individual magnet wings or magnet pins of the magnet wheel. A measurement recording 110 is provided for arranging such a Hall sensor. Such a Hall sensor is therefore arranged there for measuring and is connected to an evaluation circuit or control.

The following 2 until 7 show in detail the arrangement of a sensor 11 for detecting such a magnetic wheel, which can also be generally referred to as a rotating body. The embodiments of 2 until 7 differ in some details from that of 1 . the 1 therefore uses primed reference numerals 1', 2' and 13' for the first sub-shell, the second sub-shell and the bulge to clarify the context of the similar but not identical embodiments.

2 shows a section of a first partial shell 1, which is assembled with a second partial shell 2, in a perspective view. The first partial shell 1 has a first inner side 4 with a first partial cavity 8 and a first outer side 6 . The second partial shell 2 has a second inner side 5 with a second partial cavity 9 and a second outside 7 on. In addition, a bulge 13 can be seen, which accommodates a rotating body of a flow rate detection device. The first partial shell 1 and the second partial shell 2 are connected to one another via a joining area 12, so that they form a cavity 3 between them from the two partial cavities 8 and 9, which can also be referred to as a hollow space. The cavity 3 in turn forms a water flow path.

An electronic printed circuit board 10 with a sensor 11 shown schematically is arranged on the first partial shell 1 . The sensor 11 detects the revolutions of a magnetic disc arranged in the cavity and attached to the rotating body, in order to determine the flow rate of the water.

the 1a until 1c show the assembled partial shells 1 and 2 in a plan view and side view. In the 1c two rows of pins 21 arranged parallel to one another can be seen in the cavity 3, which are fastened to a rotary body. When water flows through the cavity 3 , the rotary body with the pins 21 is set in rotary motion.

the 1d shows the sectional view AA of the assembled partial shells 1 and 2 of FIG 1 . The second partial shell 2 forms a receiving space 25 in the area of the bulge 13 for receiving the rotating body 20 of a flow rate measuring device. The receiving space 25 is formed solely by the second partial shell 2 . No additional individual part is required as a housing for the rotary body 20. The first partial cavity 8 and the second partial cavity 9 each have a narrowing 30 or 31 of the cross section in the direction of flow 32 in front of the rotating body 20 . The tapers 30 and 31 are arranged mirror-symmetrically to one another. As a result, a nozzle is formed in which the water is accelerated and can be directed onto the rotating body 20 in a targeted manner.

The rotating body 20 is arranged in the receiving space 25 or in the partial shells 1 and 2 . The sensor 11 is arranged on the first outside 6 above the rotating body 20 . The rotary body 20 has a ring 21 on which ten pins 21 are arranged radially to the axis of rotation 23 . The pins 21 form a small contact surface for the water flowing through, through which the rotating body is moved. In addition, a magnetic disc 23 is arranged on the rotary body 20 . The magnetic disc 23 is preferably made of a magnetized plastic, in particular a plastic that contains magnetic material and/or has permanent magnetic properties. The magnetic disc 23 rotates with the rotating body 20 and thereby generates a signal in the sensor 11 which is representative of the flow rate.

1 e shows the sectional view BB of the assembled partial shells 1 and 2 of 1 . The first partial shell 1 has two support arms 14 arranged parallel to one another, each of which has a pin-shaped element 15 pointing towards the rotary body 20 in the direction of the axis of rotation 24 . The support arms 14 extend into the receiving space 25 and rest at least partially on the second partial shell 2 with one side 17 .

The body of revolution 20 has two central receptacles in the form of bores 16 which have central axes approximately coinciding with the axis of rotation 24 . In addition, the rotating body has two rings 22 which are arranged parallel to one another in the direction of the axis of rotation 24 . Two rows of pins 21 are mounted on the rings 22 and are also arranged parallel to one another in the direction of the axis of rotation 24 . In addition, a magnetic disc 23 can be seen, which is arranged on the rotary body 20 in a rotationally fixed manner. The pin-like elements 15 of the first partial shell 1 engage in the receptacles 16 . The rotating body 20 is thus rotatably fixed between the two support arms 14 . The two support arms 14 are designed to be elastic so that they can be bent apart in order to insert the rotating body 20 as long as they are not inserted into the second partial shell 2 . in the in 1e shown, inserted into the second partial shell position, the support arms 14 are prevented by the second partial shell 2 from being bent apart again, as a result of which the rotary body 20, ie the wheel 20 shown, is fixed in a rotatably movable manner.

The electronic circuit board 10 is divided into a main section 80 , a secondary section 82 and a web section 84 connecting the secondary section 82 to the main section 80 . This division of the electronic circuit board 10 is particularly in the 2 and 3 clearly visible. The secondary section 82 accommodates the sensor 11 in this case. The sensor 11 is connected with two conductor tracks from the secondary section 82 via the web section 84 to the main section 80 with a control or evaluation device to be provided there. The traces and the evaluation or control device is simplified in the 2 until 7 not marked.

For fastening purposes, the printed circuit board 10 has fastening openings 86 in the area of its main section 80, with which the electronic printed circuit board 10 can be fastened to a heating block, such as the heating block 100, in particular there to the heating block body 102 can be attached. Here, the secondary section 82 together with its web section 84 forms a finger section which extends from the main section 80 . This finger section and thus the secondary section 82 is inserted with the sensor 11 into the measuring receptacle 110′ in order to record signals from the magnet wheel or rotary body 20 with the magnetic disc 23 and forward them via the web section 84 to the main section 80 for further evaluation. The finger section, namely the secondary section 82 and web section 84, allows the sensor 11 to be preassembled or preloaded directly on the circuit board 10 and can be arranged directly in the desired position, namely in the measuring receptacle 110', when the circuit board is fastened. An elasticity of the finger section, in particular of the web section 84, can help to compensate for any inaccuracies.

The embodiment of 8th FIG. 8 shows an electronic circuit board 810 having a main portion 880 with one end shown open. Furthermore, a secondary section 882 is provided, which is connected to the main section 880 via a web section 884 . Two conductor tracks 888 are indicated on the secondary section 882 , which connect the sensor 811 to the main section 880 . In the drawing, the conductor tracks 888 run out on the main section 880, since the specific design of a control or evaluation unit or the like to be connected thereto is not important here.

The secondary section 882 together with the web section 884 forms a finger section extending like a finger. This finger section was created in that two cutouts 890 are formed in the electronic circuit board 810 . This increases the flexibility of the web section 884, which otherwise only arises as a result, and the secondary section 882 and thus the sensor 811 can thus be moved in its position according to the movement arrows 892 relative to the main section 880. Correspondingly, the main section 880 also forms a main plane from which the sensor 811 can be moved, as indicated by the movement arrows 892 .

The embodiment of 9 shows an electronic circuit board 910 schematically. A secondary section 982 is provided there, which is completely surrounded by a main section 980 . A connection between the secondary section 982 and the main section 980 is via two spiral web sections 984. From the sensor 911, two conductor tracks 988 lead via one of the web section 984 to the main section 980. For reasons of clarity, the two conductor tracks 988 are on the web section 984 as one line drawn.

The shown spiral-shaped design of the web sections 984 results from corresponding free cuts 990, which are hatched for the sake of better clarity. The hatching should not show a cut surface here.

It can be seen that the design of 9 provides a flexible design for the minor portion 982. In particular, this can be moved vertically to a plane of the main section 980 . Furthermore, a tilting of the secondary section 982 is also possible.

Another embodiment is in 10 1 is shown showing a labyrinthine land portion 784. FIG. This labyrinthine web section 784 connects the secondary section 782 to the main section 780. Two conductor tracks lead from the sensor 711 via a web section 784 to the main section 780. Here, too, the conductor tracks 788 on the web section 784 are represented by only one line. The labyrinth-like design of the web sections 784 is achieved by cutouts 790, which are shown hatched here for the sake of better clarity.

11 FIG. 12 shows schematically a test circuit 40 on a finger portion 42, which may be composed of a minor portion and a land portion. Instead of a finger section 82, a secondary section with a different web section can also be considered, in particular in a manner as is shown in FIGS 9 and 10 is shown. The finger section 42 can also consist of a side section 82 and a web section 84 as per FIG 2 be composed, or of a secondary section 882 and a web section 884, as in 8th is shown.

In any case, the finger section 42 has a sensor 44, for example, the sensor 11 of 2 can match. Another sensor can also be provided which, for example, carries out a temperature evaluation or a pressure evaluation. To activate the sensor 44, a first control line 46 is provided, which can, for example, feed a positive direct current to the sensor 44 for evaluation. A second control line 48 is provided as a return line, but is not connected directly to the sensor 44 . Rather, it is connected to a second contact point 52 which can be provided with a spring 54 . In order to be able to carry out an evaluation using the first and second control line 46, 48, a current flows via the control line 46 to the sensor 44 and from there back via a first contact point 50, which is arranged below the sensor 44 net is and only in the 12 is shown. The current then flows from the first contact point 50 via the first counter-contact point 56 to a heating block 60 or the like to the second counter-contact point 58 and from there on to the second contact point 52 and finally to the second control line 48. A corresponding control circuit can thereby be closed. However, if a contact, in particular between the first contact point 50 and the first contact point 56, is not closed, no current can flow and this can be recognized as an error.

For illustration is in 12 a first and second control current 62 and 64 are drawn in, which are intended to flow in the first control line 46 and second control line 48, respectively. A previous second control current 66 is also marked with an arrow, but it is crossed out to explain that there is no longer a corresponding return line directly from the sensor 44 and instead the second control line 48 is used as shown, in which the second control current 64 flows. The first and second control currents 62, 64 can only flow when the contacts between the first and second contact points or counter-contact points 50, 52 and 56, 58 are established. In particular, any incorrect positioning can be detected in this way, because then namely at least one of the contact pairs does not touch and accordingly the contact is not present and no current can flow.

Thus, a solution is now created in which a clever combination of the position of a parameter recording point in the heating block, such as the measurement recording 110 'in the area of a magnetic wheel, and the sensor on the control unit or on the electronic circuit board, an arrangement without additional Components such as wires, plugs or additional board is created. For this purpose, these two elements are spatially arranged in such a way that the sensor on the electronic printed circuit board makes electrical or mechanical contact directly at the said parameter acceptance point, in particular a acceptance point of the parameter provided there. Connection elements such as stranded wires and plugs can therefore be omitted. In principle, the proposed solution can be used in all devices in which a control device is not arranged at such parameter acceptance points or parameter acceptance points, but can now be arranged.

In this way, in particular, a flow rate detection, ie a detection of the flow rate or flow rate, can be created on a control unit without additional components, such as connecting elements such as strands, plugs, casting compound and/or interfaces.

By using an SMD Hall IC, it can be soldered directly to the electronic circuit board, eliminating the need for connecting elements such as connectors and stranded wires. So that the Hall IC can determine the magnetic field changes of the corresponding rotating magnet wheel, there must be an exact spatial proximity between the two components, namely between the magnet wheel and the Hall IC. This arrangement can be created without additional components by appropriately arranging the magnet wheel in the heating block body and the Hall IC on the electronic printed circuit board, in particular the control device. Thus, compared to the prior art, the position of the Hall IC was moved to the immediate vicinity of the magnetic wheel by one or more elastic webs on the electronic printed circuit board. In particular, cost savings can also be achieved as a result.

Claims (15)

Heating block (100) of a heating device for heating a liquid medium with an electronic printed circuit board (10) attached thereto, wherein - the electronic circuit board (10) has a base plate with a main section (80), a secondary section (82) and at least one elastic web section (84) connecting the secondary section (82) to the main section (80), - the secondary section (82), the main section (80) and the at least one web section (84) lie in a common main plane in a relaxed state, - the secondary section (82) is equipped with at least one sensor element (11) for recording at least one measured variable of the heating block (100), - the electronic printed circuit board (10) is attached to the heating block (100) in such a way that the at least one sensor element (11) assumes an intended position, - by bending the at least one web section (84), the secondary section (82) rests in a region of the at least one sensor element (11) on a heating block body (102) for receiving or guiding the liquid medium and - the heating block (100) has a first and second counter-contact point (56, 58) galvanically connected to one another, for galvanically contacting a first and second contact point (50, 52) of a test circuit (40), for checking whether between the at least one Sensor element (11) and the heating block (100) an electrical contact was made. Heating block (100) of a heater claim 1 , characterized in that to compensate for height and / or positional tolerances - the minor portion (82) is pushed out of the main plane by the heater block body (102), or - the minor portion (82) is pushed out of the main plane against the heater block body (102) by a fastener. Heating block (100) of a heater claim 1 or 2 , wherein the heating device is a flow heater. Electronic printed circuit board (10) for controlling and/or monitoring a heating device having a heating block (100) according to one of Claims 1 until 3 , for heating a liquid medium, comprising a base plate with a main section (80), a secondary section (82) and at least one elastic web section (84) connecting the secondary section (82) to the main section (80), wherein - the main section (80) for attachment to or on the heating block (100), - on the base plate at least one connecting strip conductor runs from the main section (80) via the at least one web section (84) to the secondary section (82), - the secondary section (82), which The main section (80) and the at least one web section (84) lie in a common main plane in a relaxed state, - the secondary section (82) is equipped with at least one sensor element (11) for recording at least one measured variable of the heating block (100), - the Secondary section (82) via the at least one web section (84) is so elastically connected to the main section (80) that the secondary section (82) via a bending of the at least one en web section (84) can be bent out of the main plane without damaging the at least one connecting conductor track, in order to thereby adapt the at least one sensor element (11) in its position and/or alignment to the heating block (100). Electronic circuit board (10) after claim 4 , characterized in that the electronic circuit board (10) has an average thickness and that the secondary section (82) can be bent over the at least one web section (84) by at least one, preferably at least three, average thicknesses from the main plane, so that the secondary section (82) in the area of the at least one sensor element (11) mounted on the secondary section (82) can be bent out of the main plane by at least one thickness, in particular by at least three thicknesses, in a direction perpendicular to the main plane. Electronic circuit board (10) after claim 4 or 5 , characterized in that for evaluating signals, in particular measured values of the at least one sensor element (11), a controller electronically connected to the at least one sensor element (11) is provided on the main section (80), the electrical connection being established in particular via the at least one connecting trace takes place. Electronic printed circuit board (10) according to one of Claims 4 until 6 , characterized in that the at least one sensor element (11) is soldered as an SMD component on the electronic circuit board (10). Electronic printed circuit board (10) according to one of Claims 4 until 7 , characterized in that the secondary section (82) can be tilted in at least two directions, in particular in two orthogonal directions, relative to the main plane via the at least one web section (84). Electronic printed circuit board (10) according to one of Claims 4 until 8th , characterized in that the secondary section (82) is surrounded by the main section (80) and/or cutouts are provided between the secondary section (82) and the main section (80) and a plurality of the web sections (84) are formed between the cutouts. Electronic circuit board (10) after claim 9 , characterized in that the at least one web section (84) and/or the cutouts are in the form of a labyrinth and/or spiral, either entirely or in sections, and/or from the main section (80) to the secondary section (82) by at least 90° around the at least one sensor element (11) and/or that the at least one connecting strip conductor runs from the main section (80) to the secondary section (82) by at least 90° around the at least one sensor element (11). Electronic printed circuit board (10) according to one of Claims 4 until 10 , characterized in that the secondary section (82) with the at least one web section (84) forms a finger section extending finger-like from the main section (80) in one direction. Electronic printed circuit board (10) according to one of Claims 4 until 11 , characterized in that the at least one sensor element (11) is - a Hall IC for recording magnetic signals, in particular magnetic signals of a magnetic wheel for detecting a flow rate, - is a temperature sensor for detecting a temperature in the heating block (100) and/or - a pressure sensor for detecting a pressure in the heating block (100). Electronic printed circuit board (10) according to one of Claims 4 until 12 , characterized in that a test circuit (40) is provided for checking whether an electrical contact has been established between the at least one sensor element (11) on the auxiliary section (82) and the heating block (100), and that the test circuit (40) has a first and second contact point (50, 52) on the auxiliary section (82) for establishing a galvanic connection with a first and second mating contact point (56, 58) arranged on the heating block (100), and in that the test circuit (40) prepares this is to recognize whether an electric current flows from the first contact point (50) to the second contact point (52). Electronic circuit board (10) after Claim 13 , characterized in that - the first contact point (50) is prepared with an evaluation unit and/or the at least one sensor element (11) for evaluating a sensor or sensor part connected to the first counter-contact point (56), - the second contact point (52) a spring element (54) to improve the galvanic contact between the second contact point (52) and the second counter-contact point (58), - the first contact point (50) forms an electrical positive pole and the second electrical contact point (52) forms an electrical negative pole and/ or - the test circuit (40) is designed in such a way that the electric current can only flow between the first and second contact point (50, 52) via the first and second counter-contact point (56, 58) if the first and second counter-contact point (56, 58 ) are galvanically connected to each other. Method for installing at least one sensor element (11) on a heating block (100) for measuring a physical quantity, wherein an electronic circuit board (10) according to one of Claims 4 until 14 is used, and / or wherein a heating block (100) according to one of Claims 1 until 3 is used, comprising the steps: - positioning an electronic printed circuit board (10) equipped with at least one sensor element (11) on a heating block (100), - measuring an electrical conductivity between the electronic printed circuit board (10) or the at least one sensor element (11) and a reference element arranged on the heating block (100), - comparing the measured electrical conductivity with a reference value or checking whether there is any electrical contact at all and - repeating the positioning if the measured electrical conductivity has increased by more than a predetermined value of deviates from the reference value or is approximately zero and/or - using a test circuit (40) as in FIGS claims 13 and 14 described, for checking whether an electrical contact has been established between the at least one sensor element (11) on the secondary section (82) and the heating block (100).

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