The present invention relates to a PTC heating register, as described in the preamble of Claim 1.
It is known, see e.g. US-A-4963716, to use a technique for detecting the air exit temperature of a heat exchanger or the air entry temperature of a PTC heating register with at least one temperature sensor, which is arranged in the space between the heat exchanger and the PTC heating register.
The intervening space between the heat exchanger and the PTC heating register should be kept as small as possible, in order to achieve the smallest possible overall structural dimensions for the arrangement. This requirement for a small intervening space carries a disadvantage in that, in these circumstances, the temperature sensor has to be positioned very close to the PTC heating elements or strips. In the light of the fact that the temperature of the PTC heating register can reach as much as 160°C, it is therefore unavoidable that the radiant heat also influences the temperature sensor, such that the air temperature measurement from the sensor can be distorted to an undesirable extent. What is more, it has to be seen as a disadvantage that, with the known arrangement, additional openings and fastening devices have to be provided for the sensor in a housing of the heating/air conditioning installation, which represents a not inconsiderable additional manufacturing outlay.
The object of the present invention is therefore to provide a PTC heating register, which makes it possible, without distortion, to detect the air exit temperature from a heat exchanger or the air entry temperature of a PTC heating register with at least one temperature sensor, and which can be produced and used in a simple and economical way.
This object is achieved via the characterising features of the independent Claim 1, expedient embodiments being described via the features of the dependent claims.
A PTC heating register is provided with at least one strip as well as a frame, in which, according to the provisions of the invention, at least one temperature sensor which detects the air entry temperature at the PTC heating register or the air exit temperature at the heat exchanger, is integrated into the PTC heating register in a gap between the strip and the frame. The connector for the temperature sensor in this case is arranged at the same level as the connector of the PTC heating register, such that integration is made possible.
The striking advantage of the arrangement according to the provisions of the present invention can be seen in that distortion of the measurement value detected with the help of the temperature sensor due to radiant heat from the PTC heating register can be avoided, in that the temperature sensor takes up a specific position in the air stream, in that no undesirable piercings and/or fastenings are required on the heating/air conditioning installation, because the sensor, together with its housing, is fastened to the frame of the PTC heating register, and in that in the case of two or more temperature sensors, by appropriate arrangement of said sensors, the leads required can be laid in the frame of the PTC heating register, which markedly reduces the manufacturing cost as compared with traditional arrangements.
With the PTC heating register according to the provisions of the present invention, combined connectors for supplying the PTC heating register as well as for the signal from the temperature sensors 12 can be provided, in which case screening can be provided between the connector region for the temperature sensors and that for the supply in order to avoid electromagnetic interference effects.
What is more, electronic control of the PTC heating register can be provided integrated into the register, this preferably being provided in the area of the electrical connections.
Finally, a combined connector for the low-power control currents and the power electronics for driving the radiator elements can be provided, the electronic control installation for the radiator elements preferably containing low-power electronics and/or a microcontroller. The fact that the low currents are in the same connector as the power electronics poses no problem as regards electromagnetic compatibility. In fact, the wiring harness can be routed jointly over a certain distance. The microcontroller locally processes information from the temperature sensors. The processing may serve for preparation for transmission on a network, correcting of information or even more complicated tasks, such as the correcting of the electrical control of the register. As regards its environment, the register module behaves as an autonomous element, which is self-regulating, so as to deliver a particular thermal power.
Further properties, features and advantages of the present invention emerge from the following description of a preferred embodiment, in connection with the attached drawings, in which:
An embodiment of a PTC heating register with an integrated air temperature sensor is depicted in Fig. 1. A frame 2 can be recognised, in which radiator elements, here in the shape of metal strips 4, are accommodated between which PTC elements 6 are arranged, which extend parallel to the radiator elements 4. On the right-hand side of the frame 2 can be seen the connector housing 8, which is configured and arranged in such a way that a lower region on the frame is left free, that is to say not covered by the connector housing 8. In this free region the frame 2 exhibits an opening 10, through which a temperature sensor 12, which detects the air temperature and is built into a sensor housing 18, can be inserted and arranged in a gap 14 between the end of the strips 4 and the frame 2. Besides the embodiment shown in Fig. 1, a number of temperature sensors can be provided in the gaps between the ends of the strips 4 and the frame 2; in the embodiment depicted, for example, in the region 16 opposite the temperature sensor 12. For a heating/air-conditioning installation with water-side temperature adjustment right and left, the temperature detection is advantageously by a second temperature sensor in the part of the frame located opposite; the lead is advantageously led in the long side of the frame 2 to the first temperature sensor 12 onto a combined connector 22.
Fig. 2 shows a side view of the embodiment according to Fig. 1, similar elements being designated with the same reference number. The opening 10 in the frame 2 should particularly be noted; through it the temperature sensor 12 can be inserted into the gap 14 between the end of the strips 4 and the frame 2.
Finally, the temperature sensor 12, together with the housing 18 surrounding it, is depicted in an enlarged view in Fig. 3. The temperature sensor 12 is surrounded by a single- or multi-layer radiant heat and convection shielding 20, which serves the purpose of reducing or even completely eliminating even the slightest remaining heating. The temperature sensor 12 is in this case provided with a preferably annular or rectangular radiant heat and convection shielding 20. On the side of the sensor housing 18 lying opposite the sensor 12 itself a connector 22 is provided on the housing, with which the temperature sensor 12 can be connected to a corresponding measurement device (not depicted) or control electronics. The sensor is fixed in the frame 2, on the connector side of the PTC heating register, preferably by means of a plug connection in such a way that, for servicing, it can easily be fitted and removed. Furthermore it is advantageous for the temperature sensor 12, as depicted, to be placed as close as possible to the air inlet.
Fig. 4 shows a partial top view of the embodiment of the PTC heating register according to Fig. 1. The regions of the frame 2, of the strips 4 as well as of the PTC elements 6 are depicted in which the temperature sensor 12 together with its housing 18, the radiant heat and convection shielding 20 as well as the connector 22 is arranged. In Fig. 4 can clearly be seen, in particular, the gap 14 formed between the end of the strips 4 and the frame 2, which makes use of the arrangement according to the provisions of the present invention, so as to arrange the temperature sensor 12 in a suitable position requiring a particularly small space.
Finally, Fig. 5 shows the region depicted in Fig. 4 in a side view, with the frame 2, the connector housing 8 as well as the opening 10 for accommodating the temperature sensor housing 18.