Heating device with plastic connectors

Abstract

Heating device for space heating and / or hot water preparation, equipped with a mounting plate 50 for connecting the heating device to stationary domestic circuits, a hydraulic module comprising a plastic structural body with connecting channels for directing a heat transfer fluid between the hydraulic module and the stationary domestic circuits, each channel being equipped with a connecting connector 10.

Description

[0001] The invention relates to heating devices for space heating and / or hot water preparation with hydraulic modules made of plastic and to the design of the plastic connecting pieces for connecting the channels of the hydraulic modules to the stationary housing lines.

[0002] In recent years, the development of heating systems, particularly boilers for space heating and domestic hot water production, has focused, among other things, on equipping heating systems with compact hydraulic modules whose components are designed in a lightweight construction.

[0003] The inexpensive lightweight construction is particularly important for wall-mounted boilers, which have now become the standard.

[0004] The hydraulic module usually consists of several separately manufactured structural connecting parts, which are preferably made of plastic composite materials instead of the metal alloys previously used (usually brass), which are expensive and have a significantly higher weight.

[0005] The frequently used composite materials include, in particular, polyamide (PA), polypropylene (PP) or polyphthalamide (PPA) modified with glass fibers (GF) in various compositions, which are designated, for example, by the following designations: PA66+30%GF, PA66+35%GF, PA66+40%GF, PP+40%GF or PPA+40%GF, although this list of the composite materials used is not exhaustive.

[0006] A similarly constructed hydraulic module is described in detail in document WO2018 / 202436 A1. In this document, the structural unit of the hydraulic module is formed from three separate parts. When assembled, the hydraulic module contains, in addition to the circulation pump and the secondary plate heat exchanger, all other hydraulic components, in particular valves and sensors for the physical parameters of the heating system. The four connecting channels for the heat transfer fluid between the hydraulic module and the stationary house circuits for space heating and hot water preparation are circular in cross-section and directed downwards. During installation, they are routed to the circular holes in the mounting plate. The installation of a boiler with such a hydraulic unit proceeds as follows: The hydraulic module is mounted on the mounting plate with the four channels pointing towards the prepared holes, or the module is fixed close to the holes on the mounting plate by a suitable detachable connection (e.g.fastening screws), a brass coupling nipple provided with a hexagonal flange is inserted from the underside of the mounting plate into each connection channel to create a hydraulically tight connection between the two pipes, the coupling nipple must be provided with an external seal (O-ring) on ​​the hydraulic unit side and a groove for clipping in the hydraulic module, the nipple is provided with an external thread on the stationary line side for screwing the line by means of a threaded nut, the hexagonal flange is engaged with the tool (wrench) used to apply the torque to create a tight screw connection during boiler installation.

[0007] It is up to the installer to determine whether the stationary lines have been secured with sufficient torque. Insufficient tightening torque, and thus inadequate fastening, poses a risk of heat transfer fluid leakage. Therefore, when installing heaters on stationary lines, high torque is usually required to ensure a reliable connection between the heaters and the casing circuits.

[0008] Because brass nipples are expensive, the natural tendency is to replace them with plastic ones. However, in many cases, installers don't use the correct equipment (torque wrenches) and may achieve a higher than required torque during installation, which can lead to damage to the thread and other plastic parts.

[0009] The task is to provide a suitable solution for connecting the heater to the stationary lines using plastic connectors, whereby this connection is secured against possible damage due to excessive torque.

[0010] This problem is solved as follows. The connector for the connection between the heater's hydraulic module and the stationary lines is made of a suitable plastic. On the hydraulic module side, the connecting piece is provided with an external seal (O-ring) and a groove for the hydraulic module's clamp connection. On the stationary line side, the connecting piece is provided with an external thread for screwing the pipe with a threaded nut. The connecting piece is provided with a shaped flange with lugs. To fasten the connector, a counterpart with grooves is used. This counterpart is made of the same plastic or a different material, e.g., metal. The shape of the grooves corresponds to the shape of the lugs, and the lugs can be inserted into the grooves.The connector and the counterpart are connected to each other in a form-fitting manner before they form a hydraulically tight connection with the stationary line.

[0011] If a torque greater than the limit torque is applied to the thread, the connector begins to rotate around its own axis, informing the installer that the required torque has been reached and the connection is sufficient. The value of the limit torque depends on the shape of the lugs on the plastic connectors and the corresponding design of the notches. The counterpart does not have to be a separate component, but can advantageously be designed as a hole in a mounting plate that is part of the heating device.

[0012] The stress-strain analysis tested components that can be subjected to static or dynamic loads or other environmental stresses such as tension, torque, compression, vibration, or temperature. The proposed connector was tested, and it was found that, when made of PA66+30%GF composite material, the connector begins to rotate at a torque between 6.4 Nm and 10.8 Nm (depending on the specific design of the lugs and grooves). Thus, the further applied higher torque has no deforming effect on the connector. Depending on the coefficient of friction between the components, a torque of 57 Nm to 160 Nm is required to destroy or damage the plastic connector. The designed plastic connector is resistant to damage even at higher torques due to its low-friction construction.

[0013] The technical solution is explained in more detail using the figures, but is not limited to them: Figure 1 shows a connector for connecting a hydraulic module to stationary lines, Figure 2 shows the counterpart to the connector from Figure 1 , Figures 3 and 4 show two views of the molded connection of the connector and the counterpart, Figure 5 shows a mounting plate in a heater with integrated projections, Figure 6 shows part of a heater, namely the bottom view of the mounting plate.

[0014] The heater comprises a hydraulic module with a plastic component with four connection channels for guiding the heat transfer fluid circulating between the hydraulic module and the stationary house circuits for space heating and hot water preparation. The channels can be arranged differently within the hydraulic module, therefore, a suitable mounting plate 50 with holes on the heater is required to establish the connections to the environment.

[0015] The heater is provided with a mounting plate 50 for connecting the heater to the stationary housing lines, wherein the mounting plate 50 is arranged on the underside of the heater.

[0016] In a further embodiment, the mounting plate 50 can be arranged on the rear side of the heater, wherein the hydraulic module has connection channels running perpendicular to the underside of the heater.

[0017] In Figure 6a bottom view of a part of the heater with the mounting plate 50 is shown, indicated as an example are a connection piece that can be connected to the domestic water circuit 60 (return flow) and a connection piece that can be connected to the heating water circuit 70 (return flow).

[0018] The mounting plate 50 is provided with integrated counterparts 20 in the form of holes 5 provided with notches 41 on the circumference of the hole. A notch 41 consists of a recess 43 with protrusions 42 arranged downstream of it, as seen in the direction of rotation. Figure 2 .

[0019] The connection channels for guiding the heat transfer fluid on the hydraulic module are provided with connection pieces 10.

[0020] Each connection piece 10 has a clamp connection 1 for hydraulically tight connection to the connection channel of the hydraulic module, a threaded connection 3 for connection to the stationary line and a shaped flange 2 with lugs 40.

[0021] The hydraulic module is connected to the mounting plate 50 in such a way that, in the pre-assembled state, the lugs 40 of each connector 10 engage in the recesses 43 of the notches 41 in the bores 5 of the corresponding counterpart 20 and form a formed connection 30. The body of the connector 10 can be rotated about its axis. The hydraulic module is firmly attached to the mounting plate 50 with fastening screws (not shown). The lugs 40 and the corresponding notches 41, in particular the recesses 42 with the adjacent elevations 43, interact during rotation in such a way that the lugs 40 overcome the elevations 42 when the thread is tightened and the limit torque is exceeded. The noticeable and audible disengagement signals to the installer that the limit torque has been reached. On the other hand, overcoming the notches causes the torque to collapse, thus protecting the components from overload.

[0022] The plastic connectors 10 are designed so that they cannot be damaged and / or destroyed by the torque applied to the threaded connection 3 when connecting the heating device to the stationary lines. If a torque above the limit is applied, the connector 10 rotates around its axis, creating a hydraulically tight connection between the respective channel of the hydraulic module and the stationary line.

[0023] The torque limit value is between 6.4 Nm and 10.8 Nm, depending on the material of the connector and the design of the lugs 40 on the molded flange 2 of the connector 10 made of plastic and the notches 41 on the bores 5 of the counterpart 20.

[0024] The heater for space heating and / or domestic hot water preparation with a hydraulic module with a component made of plastic has molded connections according to the invention for connecting the inlets and outlets of the hydraulic modules to stationary housing lines, which are not damaged even in the event of improper installation if the installer applies too little torque to the screw connection. List of reference symbols

[0025] 1 Clamp connection 2 Formed flange 3 Threaded connection 5 Bore 10 Connector 20 Counterpiece 30 Formed connection 40 Nose 41 Notch 42 Raised section 43 Recess 50 Mounting plate 60 Domestic hot water circuit (return) 70 Heating water circuit (return)

Claims

1. A heating device for installation in a dwelling with stationary dwelling pipes for a heat transfer fluid heated by the heating device, with a mounting plate (50) for connecting the heating device to the stationary dwelling pipes, with a hydraulic module comprising a plastic structure with connecting channels for the conduction of the heat transfer fluid between the hydraulic module and the stationary dwelling pipes, each channel being provided with a connector (10), characterized by that the connector (10) has a clamp connection (1) for hydraulically tight connection to the connection channel of the hydraulic module, a threaded connection (3) for connection to the stationary line and a shaped flange (2) with lugs (40), that the mounting plate (50) is provided with integrated counterparts (20) in the form of holes (5) provided with notches (41) with elevations (42) and depressions (43), and thatthe hydraulic module is designed to be fastened to the mounting plate (50) in such a way that the lugs (40) of each connector (10) engage in the recesses (43) of the catches (41) on the holes (5) of the corresponding integrated bore in the counterpart (20) and form a shaped connection (30).

2. Heating device according to claim 1, characterized in that the connector (10) is pivotally connected in the hydraulic module by means of a clamp connection (1) and to the mounting plate (50) by means of a molded connection (30) in order to enable rotation of the nozzle (10) upon application of a torque limit value.

3. Heating device according to claim 2, characterized in that the lugs (40) and notches (41) are designed in such a way that during assembly, when the connector (10) is rotated relative to the counterpart (20), if the specified torque limit value is exceeded, the lugs (4) overcome the resistance of the elevations (42) of the notches (41).

4. Heating device according to one of claims 2 or 3, characterized in that the specified torque limit is in the range of 6.4 Nm to 10.8 Nm.

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