Road finishing machine including heating device and heating method

Abstract

To be able to well monitor via a simple structure the operation of road finishing machines and screed heating devices of the road finishing machines.SOLUTION: The present invention relates to a road finishing machine which has a screed embodied for making road pavement and having a heating device (100) comprising multiple heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n). The road finishing machine further includes at least one generator (17) for supplying power to the heating device (100). The road finishing machine further has a control system (8, 8') embodied to operate the generator (17). The road finishing machine has such a feature that each of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) has at least one temperature sensor (T) used to detect faults occurring in the heating element. In addition, it detects malfunctions of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) installed in the screed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a road finishing machine according to claim 1. The present invention further relates to a method according to claim 16.

Background Art

[0002] A road finishing machine is configured to create a road pavement from a hot bituminous paving material. To compress the paving material (in advance), the road finishing machine has a screed, which is pulled in the paving progress direction and maintained at a desired working temperature by a heating device incorporated therein. The heating device includes a plurality of heating elements, for example heating rods, which are installed in respective screed sections and heat the compression aggregate installed on the heating element and the compression plate facing the ground. The heating device is powered by a generator of the road finishing machine.

[0003] The quality of the paving depends, among other things, on the operating ability of the heating elements installed on the screed body. Therefore, it is desirable to monitor the operation of the heating elements during the paving operation to detect defective heating elements as early as possible and replace them with operable heating elements.

[0004] European Patent No. 3527721A1 discloses a road finishing machine equipped with a power adapter for an electric screed heating device.

[0005] European Patent No. 1295990A2 discloses a closed-loop control device for heating elements installed on the screed of a road finishing machine.

[0006] International Patent Publication No. 2014 / 124545A1 discloses a method of heating a screed of a road finishing machine equipped with a heating device, which changes the heating force of the heating device by changing the voltage supplied to the heating elements of the heating device.

[0007] German Patent No. 102015012298A1 discloses a road finishing machine equipped with a generator that supplies electrical energy to an electric screed heating device for the screed of the road finishing machine. This screed heating device includes multiple sets of heating elements connected to various functional components of the screed, such as a bottom plate and a tamper. Furthermore, a current meter device is provided, which is embodied to measure the output current of the generator and communicates with the machine's control unit via a data bus. Based on the current measurement, error diagnosis can be performed on the screed heating device. However, repair work can be complicated because it is difficult to identify the individual heating elements that are faulty based on this power supply-related error diagnosis, especially their location. This can lead to prolonged downtime for the road finishing machine on site.

[0008] German Patent No. 202015104723U1 discloses an electric heating cartridge incorporating a temperature control device. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a method for better monitoring the operation of a road finishing machine and the screed heating device of a road finishing machine through simple structural technical features.

[0010] This objective is achieved by the road finishing machine described in claim 1 and the method described in claim 16.

[0011] Advantageous developments of the present invention are described in the dependent claims. [Means for solving the problem]

[0012] The road finishing machine according to the present invention has a screed embodied for making road pavement and a heating device comprising a plurality of heating elements. The road finishing machine according to the present invention further has at least one generator for supplying power to the heating device and a control system embodied for operating the generator.

[0013] According to the present invention, each heating element has at least one temperature sensor used to detect malfunctions occurring in the heating element. Malfunctions can be detected individually based on temperature measurements directly performed by each heating element. That is, malfunctions in one or more specific heating elements among the heating elements used in the screed can be detected.

[0014] Each heating element used according to the present invention is designed to detect the temperature directly generated during the operation of the road finishing machine. Therefore, the temperature state of each of these heating elements can be continuously and accurately detected and transmitted to the control system to detect any potential malfunctions. Thus, the function of all heating elements with temperature sensors on the screed can be individually monitored. This has the advantage of allowing for the quick identification and replacement of defective heating elements, thereby significantly contributing to the production of high-quality road pavements. Furthermore, the temperature-based diagnostic device according to the present invention can significantly reduce the downtime of the road finishing machine.

[0015] In particular, the present invention makes it possible to continuously identify malfunctions based on temperature measurements performed directly on the heating elements, regardless of the power supply for each heating element, and this can be done at arbitrary intervals.

[0016] In a favorable modification, the temperature sensor is connected to the control system by a gateway configured for signal processing. This is perfectly suited as a functional module for connecting heating elements to the control system for the purpose of diagnosing errors, and it is also possible to adjust the power distribution to each heating element. The temperature sensor can be connected to a screed distributer designed to receive and transmit the actual temperature values ​​detected by the temperature sensor. While the screed distributer can primarily be used for power distribution, it can also transmit the actual temperature values ​​of each heating element to the control system as a functional coupling unit, so to speak, acting as a transceiver.

[0017] It would be useful to implement the screed distributer to transfer the actual temperature values ​​of each heating element received to a gateway configured for signal processing and connected to a control system. As a central gateway, this gateway can receive all measurement signals detected by the screed, particularly the actual temperature of each heating element, from the screed distributer and transfer them to the control system in an optionally processed format for each open-loop and / or closed-loop control sequence performed, especially for error diagnostic functions.

[0018] According to one embodiment, the screed has multiple screed sections, each screed section having multiple heating elements and a gateway configured for signal processing, the gateway connecting temperature sensors provided on the heating elements to a control system. Alternatively, each screed section has multiple heating elements and each has one screed disperser.

[0019] The gateway and / or screed distributer is designed, in particular, as a hardware and / or software component that establishes a connection between each heating element and the control system. Specifically, the screed distributer is configured as a transceiver that receives the temperature state continuously measured at each heating element during the operation of the road finishing machine and sends it to the gateway. The gateway can provide the control system with the respective temperature data received by the screed, in a manner that allows the control system to check the operational capability of each heating element based on this data.

[0020] The gateway and / or screed distributer is configured to connect the heating elements installed within the screed to the control system, at least for accurate error diagnosis. Individual temperature values ​​measured at each heating element and received by the gateway or screed distributer can be transferred to the control system in a data-processed format by the gateway and / or screed distributer, thereby enabling the control system to perform individual error diagnosis of each heating element based on those temperature values. Thus, the gateway and / or screed distributer acts as a central interface embodied for data processing between the temperature sensors installed in the screed body at each heating element and the control system with respect to temperature-based error diagnosis.

[0021] The gateway and / or screed distributer may further provide the ability to transfer each received temperature measurement signal to a control system in a data format suitable for the open-loop and / or closed-loop processes of the screed's operation, thereby enabling dynamic operation of the screed's compression unit in particular.

[0022] Preferably, the screed has multiple screed sections, each screed section has multiple heating elements, each has a gateway configured for signal processing, and temperature sensors provided on the heating elements are connected to a control system. Alternatively, each screed section has multiple heating elements and a screed disperser that connects temperature sensors connected to the heating elements to a gateway. This screed disperser may precede the gateway as a transceiver.

[0023] A screed can have three or more screed sections, which consist of a central base screed and extensions attached to its sides, the extensions being conceivable to be expandable to change the pavement width across the laying direction of the road finishing machine. In a variation, another screed section can be attached to the screed extension in the form of an extension to create a wider pavement width. Each of the aforementioned screed sections can have a separate gateway or at least a separate screed disperser for the heating elements installed therein, thereby allowing each heating element installed in the screed section to be monitored and / or operated separately based on the respective heating state measured at that heating element.

[0024] In particular, each gateway or each screed distributer can be embodied as an integral part of the screed, especially as each screed section. Each screed section may be equipped with a separate gateway or separate screed distributer. During the operation of the road finishing machine, each screed section acts as a central data receiving unit, receiving values ​​measured by individual sensors, mainly temperature measurement signals of each heating element, and transmitting them to the control system in an optionally further processed format for specific functions, particularly temperature-related error diagnostic functions. Each gateway or screed distributer installed and integrated into the screed thereby forms a data receiver and data transmitter module, which, prior to the control system, transmits the measured temperature values ​​received therein to the control system in an optionally processed format for the aforementioned temperature-related error diagnostic functions.

[0025] Preferably, the temperature sensors are embodied to be integrated with their respective heating elements. Thus, each heating element and temperature sensor structurally form one unit, and the heating element can be easily installed and removed as a small unit together with the temperature sensor. This has great advantages mainly in repair and / or inspection work. Thus, each heating element has an inlet for power supply and an outlet for temperature detection performed by the heating element.

[0026] Each heating element can include, for example, high-temperature, low-temperature and / or semiconductor temperature sensors. Each heating element can be embodied as a heating rod. The temperature sensor can extend according to the shape of the heating rod along the heating coil provided in the temperature sensor.

[0027] In particular, all the heating elements of the heating device include at least one temperature sensor integrally formed in the heating element. Thus, it is possible to perform extremely accurate temperature measurement with all the heating elements installed in the screed. Based on this, the functions of each heating element can be accurately diagnosed and each heating element can be accurately operated.

[0028] It is advantageous to connect each of the temperature sensors to the gateway or screed distributor by a plug connection. In particular, this plug connection can be configured to be installed and removed without tools so that each heating element can be easily connected and individually removed.

[0029] It can be envisioned to connect each temperature sensor to the gateway via a common bus system or to a screed distributor. This network can be connected to the gateway or screed distributor by a single plug connection. Thus, the amount of cables in the screed can be reduced.

[0030] According to one embodiment of the present invention, the gateway or the screed distributer for each screed section is directly embodied as a PLC gateway. In the case of screeds, improved possible applications provide themselves in terms of both structure and function. In particular, despite the increasing number of sensor mechanisms, the structural design of the screeds can be made smaller and / or the operating behavior of the screeds can be better observed and controlled.

[0031] As a PLC gateway, the gateway or screed distributer embodied as a PLC gateway can modulate the temperature measurement signals received from each heating element over the connected power lines and transmit the modulated temperature measurement data to the control system via those power lines. The power lines used for this data transfer can be conceived to be formed by at least one section of the power lines used to supply power to each heating element and / or each PLC gateway.

[0032] In a modified version of the present invention, each PLC gateway is connected to the control system by a PLC line (power line communication supply line). For example, in at least one section, a power supply line from a generator to a screed can be used as the PLC line. In particular, a power supply line supplying power to each heating element can be used as the PLC line. Since the PLC gateway can be directly connected to such a PLC line, it functions as a power distributer toward the heating element and modulates the temperature measurement data from the PLC line toward the control system as the PLC gateway.

[0033] As an alternative to or supplement to PLC lines, the gateway can be connected to the control system by a separate data bus system. This data bus system can be implemented, for example, as a CAN bus or an Ethernet connection.

[0034] The (PLC) gateway is configured as an internet gateway and performs, at least temporarily during the road finishing machine's paving work, the function of supplementally transferring temperature measurement data to at least one external receiver connected via the Internet, in addition to transmitting temperature measurement data to the road finishing machine's control system, which can be conceived as transferring temperature measurement data to, for example, a central construction site management facility, a service center, and / or another construction vehicle working with the road finishing machine.

[0035] The (PLC) gateway can be implemented as a VPN gateway, thereby enabling queries regarding heating element malfunctions and / or operation in a data-protected manner, particularly from external construction sites, such as a service center. This service center may be operated by the machine manufacturer, and based on the VPN connection on which the screeds are installed, the service center can transmit service information for each screed section to operators at the construction site. Thus, downtime for the machines at the construction site can be reduced.

[0036] The (PLC) gateway can be conceived as a media gateway. When configured in this way, the gateway can further process the temperature state of each received heating element, in particular the critical temperature state measured therein, into a corresponding audio output signal, which is transmitted audibly to the operator of the road finishing machine, and in particular to the operator of the screed's external control platform during paving work.

[0037] A simple but highly practical variation provides that the gateway and / or screed disperser of each screed section has a separate lamp embodied to optically indicate the operating capability of each heating element to all the heating elements installed in that screed section.

[0038] In an advantageous embodiment, the control system identifies the type of heating element based on the temperature gradient detected by temperature sensors formed on the heating element, that is, considering the temperature progression within a predetermined period detected by the heating element, calculates a desired temperature value for each identified type of heating element, and implements a temperature-based error diagnosis function based on that value.

[0039] For example, the control system is implemented to perform an error diagnosis function by comparing each desired temperature value calculated for a heating element with the actual temperature value detected by the heating element. If the detected actual temperature of the heating element reaches or exceeds the desired temperature calculated for that element, the heating element is functioning normally. However, if the control system detects that the detected actual temperature of the heating element is below the desired temperature calculated for that element by a predetermined amount, the heating element may be defective. Such malfunctions can be displayed to the operator on a display located on the external control platform of the road finishing machine.

[0040] It is convenient to implement the control system to identify the screed section containing at least one calculated heating element. For example, the type of enlarged section attached for paving can be calculated from the identified heating element. In particular, the control system is implemented to calculate the screed pavement width based on the calculated heating element type and, primarily, on each type of enlarged section that has been identified and attached. The control system can use the calculated screed pavement width for the various open-loop and closed-loop control processes performed by the road finishing machine, as described above.

[0041] In one preferred embodiment, the gateway and / or screed disperser is configured to supplement the actual temperature values ​​of the heating elements detected by each respective temperature sensor with at least one piece of information regarding their measurement locations, and transmit this as actual temperature and location data to the control system. Thus, it is possible to clearly identify and quickly replace defective heating elements in relation to their installation location, thereby allowing the paving work of the road finishing machine to be carried out without significant interruption.

[0042] Preferably, the operating capability of each heating element is displayed to the screed operator and / or road finishing machine operator by a display device connected to the control system. This can be achieved particularly visually and / or audibly. It is conceivable that the operating capability of each heating element can be displayed on a portable display and / or computer unit, such as a portable operating unit of an external control platform.

[0043] In one advantageous embodiment, the screed includes at least one screed plate, and the control system is configured to calculate a desired temperature value for the screed plate based on the detected actual temperature value of the laying material supplied and used by the road finishing machine to create the road pavement, compare it to the detected actual temperature of the screed plate, and thereby activate the power supply for the heating element associated with the screed plate. To detect the actual temperature of the screed plate, the screed plate may have at least one temperature sensor directly connected to a screed diffuser or gateway. The desired temperature value of the screed plate can be conceived to be manually adjustable by the road finishing machine.

[0044] In one advantageous embodiment, the control system is configured to calculate, based on a provided detected ambient temperature, the remaining heating time for one or more heating elements used to heat the screed plate to reach a desired temperature value of the screed plate, and this heating time is predetermined by the temperature gradient. Based on this, the optimal start time for the pavement drive can be calculated.

[0045] The control system can be configured to check the operating capability of each heating element using a predetermined power supply for each heating element, and the actual temperature value detected therein will reach or exceed the ambient temperature provided to the control system by a predetermined amount within a predetermined period, for example, within 1 minute.

[0046] It is advantageous to implement a control system that calculates the type of heating element and / or the type of associated screed section, such as the type of enlarged portion, based on the time detected as necessary to heat the heating element to a predetermined temperature level. Thus, the structural design of the screed, in particular the type of each screed section used therein, can be indirectly calculated via the heating time of at least one heating element that can be detected individually.

[0047] According to one embodiment, a control system can be implemented to calculate the type of heating element and / or the type of associated screed section, such as the type of enlarged portion, based on the detected operating temperature of the heating element that appears during a predetermined heating period.

[0048] Preferably, the control system is configured to calculate a screed width adjustable during paving work, based on the calculation of the type of heating element and / or the type of screed section described above. According to one embodiment of the present invention, the screed width calculated by the control system based on temperature measurements performed on the heating element can be stored as an input to at least one open-loop and / or closed-loop control function of the screed of the road finishing machine. For example, this can be used to dynamically adjust controlled variables and / or control parameters for operating the device that distributes the material laterally across the screed. Thus, the screed structure derived from the temperature measurements can serve to parameterize the control system to control, for example, the distribution of material forward across the screed.

[0049] In one variation, the control system is designed to calculate the minimum temperature of the paving material stored in the paving machine's material storage based on the heating elements and / or screed section typical derived from the heating time. The minimum temperature can, according to a preferred embodiment, be displayed directly to the operator of the paving machine and / or transmitted from the paving machine's control system to a mixer to prepare the paving material for the paving machine.

[0050] In a favorable modification, information regarding the operation of each heating element, such as the operating temperature and / or installation location of each heating element, can be displayed on a display device located on the road finishing machine. The display device can be implemented as part of the control system, for example, as a display on the driver control platform and / or a display on the screed external control platform. It is also conceivable to display the operating temperature and / or diagnostic results of the heating elements on a smart device. Such a display device can show instructions for installation and removal corresponding to any defective heating elements detected.

[0051] The present invention further relates to a method for detecting a malfunction in at least one heating element installed in the screed of a road finishing machine. According to the present invention, the detection of the malfunction is performed based on the actual temperature value directly detected by the heating element. For this diagnostic function, the actual temperature value of the heating element can be detected by a temperature sensor incorporated in the heating element and transmitted to a control system, which can then determine with great accuracy whether there is a malfunction in the heating element.

[0052] During the operation of a road finishing machine, it is conceivable to continuously or at least temporarily check for malfunctions in all heating elements installed within a single screed, based on the actual temperature value of each heating element detected by that element. To this end, the actual temperature value of each heating element is detected using temperature sensors built into the heating elements.

[0053] In one variation, the type of heating element is identified based on the temperature gradient detected by the heating element, i.e., the heating rate of the heating element. A desired temperature value suitable for the purpose of fault diagnosis is calculated for the identified heating element type, and fault detection is achieved by comparing the desired temperature value with the actual temperature value directly detected by the heating element. If the actual temperature of the heating element detected here reaches or exceeds the desired temperature calculated for that heating element, the heating element is functioning normally. However, if the control system detects that the actual temperature of the heating element detected is below the desired temperature calculated for that heating element by a predetermined amount, the heating element may be defective. Such faults can be displayed to the operator on a display located on the external control platform of the road finishing machine.

[0054] Preferably, the actual temperature values ​​of one or more heating elements are transmitted to the road finishing machine's control system by a screed disperser and / or gateway connected to a temperature sensor. The screed disperser and / or gateway then receives the heating status of each heating element and transmits it to the control system in an optionally processed data format, primarily for diagnostic purposes. These temperature measurements, performed directly on the heating elements, allow for a more accurate diagnosis of their function.

[0055] The screed disperser and / or gateway can supplement the actual temperature value of a heating element detected by a temperature sensor with information about its measurement location, and transmit this as an actual temperature and location value to the control system. This makes it possible to clearly identify any defective heating elements in relation to their location within the screed.

[0056] By switching on the heating device, each heating element can rise to a remaining actual (final) temperature higher than the temperature of the laid material. The control system appropriately and continuously compares the actual temperature of each heating element with the desired temperature calculated for that heating element during the operation of its screed. As long as the actual temperature of each heating element is above its respective desired temperature, the heating element operates normally. However, as soon as the actual temperature of a heating element drops by a predetermined temperature value below the relevant desired temperature value after a predetermined temperature rise stage has elapsed, that heating element may become defective. This defect can be displayed to the operator by a display device. As an alternative or supplement to displaying defective heating elements on a display device, it is appropriate to configure the control system to switch off the heating element detected as defective, i.e., cut off the power supply to that heating element, in order to prevent damage to the heating device.

[0057] Furthermore, it is conceivable to display the location of any heating element detected as defective. This can be done by having the screed disperser and / or gateway transmit the actual temperature value of the faulty element along with the sender's address to the control system. This allows the control system to accurately identify the defective heating element. In one variation, the defective heating element is indicated by a status LED formed on the screed disperser and / or gateway.

[0058] The control system performs type calculations based on the temperature rise rate of the heating element measured by the heating element, and optionally performs type calculations of the screed section based on that, and accordingly the control system calculates the screed paving width of the adjustable screed and / or the screed paving width adjusted at that time during paving work. The calculated screed paving width allows for further processing in the road finishing machine, in particular the distribution of material laterally in front of the screed, to be controlled by open-loop or closed-loop control.

[0059] The present invention will be described in more detail with reference to the following drawings. [Brief explanation of the drawing]

[0060] [Figure 1] This is a diagram showing a road finishing machine according to the present invention. [Figure 2] This is a schematic diagram of a heating device according to an embodiment of the road finishing machine according to the present invention. [Figure 3] This is a schematic diagram of a heating device according to an embodiment of the road finishing machine according to the present invention. [Modes for carrying out the invention]

[0061] In drawings, the same component is always given the same reference numeral.

[0062] Figure 1 shows a road finishing machine 1 that uses a screed 5 to create road pavement 3 on the subsoil from laying material 4 in the laying direction R. The road pavement 3 has a screed pavement width B that crosses the laying direction R, and this pavement width is created according to the configuration of the screed. The screed 5 is realized to compress the laying material 4 that spreads out in front of the screed. The screed 5 has a screed plate 6, as well as a tamper 7 positioned in front of the screed plate 6 in the laying direction R.

[0063] The road finishing machine 1 in Figure 1 has a driver control platform F for the driver. The driver control platform F is equipped with a control system 8. The control system 8 is configured to control and / or monitor the processes being performed on the road finishing machine 1. In particular, the control system 8 can control and monitor the operation of the screed 5.

[0064] Figure 1 further shows that an external control platform A, into which control system 8' is incorporated, is implemented on the screed 5. Control system 8' allows the screed operator to control and / or monitor the operation of the screed 5 from the external control platform A. Control system 8 installed on the driver control platform F and / or control system 8' installed on the screed 5 of the external control platform A can be implemented as display devices D, D' for displaying the respective process states of the road finishing machine 1 to the driver and / or the screed operator.

[0065] Figure 2 shows a schematic diagram of the heating device 100 of the road finishing machine shown in Figure 1. The heating device 100 is implemented to heat the screed 5. Figure 2 shows that the heating device 100 has multiple screed sections 10, 20, and 30. Screed section 10 is the basic screed section. The two screed sections 20 and 30 can be extension screed sections fixed next to screed section 10. The structure of the illustrated heating device 100 may have other screed sections not shown in Figure 2, such as screed extension sections, which may optionally differ in width and / or number and are mounted next to the extension screed sections.

[0066] Scred section 10 has multiple heating elements 11, 12, and 1n, each heating element having an integrally installed temperature sensor T. The temperature state of each heating element 11, 12, and 1n detected by the temperature sensor T can be transmitted to the gateway 15 of the screed section 10 via a signal line 14. The gateway 15 is configured to process the temperature state of each heating element 11, 12, and 1n into a data format for diagnostic purposes. This data is transmitted from the gateway 15 to control systems 8, 8' via a data line 16, for example, a CAN bus system, for diagnostic purposes and optionally for other control functions.

[0067] Control systems 8, 8' are functionally connected to the generator 17 and can activate the generator's operation based on data received from the gateway 15. The generator 17 is connected to the gateway 15 of the screed section 10 via a feed line 18. The power produced by the generator 17 can be distributed via the gateway 15 to each of the heating elements 11, 12, and 1n of the screed section 10 to individually heat the heating elements.

[0068] As shown in Figure 2, the screed section 10 further has a temperature sensor 19 that detects the actual temperature of the screed plate 6 of the screed 5. The temperature sensor 19 is connected to the gateway 15. Based on a comparison of the detected actual temperature of the screed plate 6 with a desired temperature value for the screed plate, which is calculated based on the temperature of the laying material, for example, or manually adjusted by the screed operator, the control systems 8, 8' can dynamically control the power supply to each of the heating elements 11, 12, 1n installed in the screed section 10.

[0069] In Figure 2, the data line 16 and the power supply line 18 are represented by separate lines. The data line 16 may exist as a CAN bus system. Alternatively, the power supply line 18 is implemented as a PLC line, and the gateway 15 is configured to modulate the actual temperature values ​​of the heating elements 11, 12, and 1n, received from the temperature sensor T of the screed section 10, with respect to the power supply line 18, and transmit these values ​​to the control systems 8, 8'.

[0070] The design of the other screed sections 20 and 30 of the heating device 100 is almost the same as the design of screed section 10.

[0071] Scred section 20 includes at least three heating elements 21, 22, and 2n, temperature sensors T installed on the heating elements, and a gateway 25 that receives the temperature state of each heating element 21, 22, and 2n and transmits that temperature state to control systems 8 and 8' for functional diagnosis of the heating elements.

[0072] Scred section 30 includes three heating elements 31, 32, and 3n, temperature sensors T installed on the heating elements, and a gateway 35 that receives the temperature state of each heating element 31, 32, and 3n and transmits that temperature state to control systems 8 and 8' for functional diagnosis of the heating elements.

[0073] As shown in Figure 2, each screed section 10, 20, 30, and especially each heating element 11, 12, 1n, 21, 22, 2n, 31, 32, 3n installed in that screed section, can be individually inspected for function. This is because the temperature state is detected by all heating elements 11, 12, 1n, 21, 22, 2n, 31, 32, 3n and transmitted by their respective gateways 15, 25, 35 to the control systems 8, 8' for function control, and transmitted in a format that can be processed as desired. Defective heating elements 11, 12, 1n, 21, 22, 2n, 31, 32, 3n can be displayed on the display devices D, D', along with their installation location.

[0074] Figure 2 further shows an ambient temperature sensor 40, which is implemented to detect the ambient temperature in the area of ​​the screed 5. The ambient temperature sensor 40 is connected to control systems 8 and 8'. Based on the ambient temperature detected by the ambient temperature sensor 40, the control systems 8 and 8' can calculate the heating time required for the screed plate 6 to reach the desired temperature and optionally display this to the operator.

[0075] Figure 2 further shows the desired temperature value S, which is calculated by the control systems 8 and 8' for all heating elements 11, 12, 1n, 21, 22, 2n, 31, 32, and 3n based on the measured heating rate, and is used for functional diagnosis of the heating elements 11, 12, 1n, 21, 22, 2n, 31, 32, and 3n.

[0076] Figure 3 shows a slightly modified embodiment compared to Figure 2. In Figure 3, it is shown that screed section 10 has a screed distributer 15', screed section 20 has a screed distributer 25', and screed section 30 has a screed distributer 35', and that the respective screed distributers 15', 25', and 35' are connected to control systems 8, 8' via a shared gateway 50.

Claims

1. 1. A road finishing machine (1) comprising a screed (5) embodied for making a road pavement (3) and having a heating device (100) comprising a plurality of heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n), at least one generator (17) for supplying power to said heating device (100), and a control system (8, 8') embodied for operating said generator (17), characterized in that said heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) each have at least one temperature sensor (T) used to detect a malfunction occurring in said heating element.

2. 2. A road finishing machine according to claim 1, characterized in that the temperature sensor (T) is connected to the control system (8, 8') via a gateway (15, 25, 35) configured for signal processing or to a screed distributor (15', 25', 35') designed to receive and transfer the actual temperature values ​​sensed by said temperature sensor (T).

3. 3. A road finishing machine according to claim 2, characterized in that the screed distributors (15', 25', 35') are embodied to forward the received actual temperature values ​​of each of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) to a gateway (50) configured for signal processing and connected to the control system (8, 8').

4. 4. A road finishing machine according to claim 3, characterized in that the screed (5) comprises a number of screed sections (10, 20, 30), each of which comprises a number of heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) and a gateway (15, 25, 35) configured for signal processing and connecting the temperature sensors (T) provided on the heating elements to the control system (8, 8'), or each of which comprises a number of heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) and one screed distributor (15', 25', 35').

5. 2. A road finishing machine according to claim 1, characterized in that all of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) of the heating device (100) comprise at least one temperature sensor (T) integrally embodied in said heating element.

6. 2. Road finishing machine according to claim 1, characterized in that the temperature sensors (T) are each connected to the gateway (15, 25, 35) or to the screed distributor (15', 25', 35') by a plug connection.

7. 2. Road finishing machine according to claim 1, characterized in that the gateway (15, 25, 35) or the screed spreader (15', 25', 35') is embodied as a PLC gateway.

8. 2. Road finishing machine according to claim 1, characterized in that each said gateway (15, 25, 35) or said screed distributor (15', 25', 35') is connected to said control system (8, 8') via a PLC line (18) or via a separate data bus system (16).

9. 2. A road finishing machine according to claim 1, characterized in that the control system (8, 8') is implemented to identify the heating element type of each of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) based on the respective temperature gradients sensed by the temperature sensors (T) embodied in the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) and to calculate, based on said identification, respective desired temperature values ​​(S) used to diagnose errors in the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n).

10. 10. A road finishing machine according to claim 9, characterized in that the control system is embodied to compare the respective desired temperature value (S) calculated for the respective heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) with the actual temperature value sensed at said heating element in order to perform a diagnosis of errors of said heating element.

11. 11. A road finishing machine according to claim 9 or 10, characterized in that the control system (8, 8') is embodied to identify, based on the calculated type of at least one heating element, the screed portion which comprises said heating element type.

12. 10. Road finishing machine according to claim 9, characterized in that the control system (8, 8') is embodied to determine a screed paving width (B) based on the calculated type of at least one heating element.

13. 2. A road finishing machine according to claim 1, characterized in that the gateway (15, 25, 35) or the screed distributor (15', 25', 35') is configured to supplement the actual temperature values ​​of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) sensed by the respective temperature sensors (T) with a piece of information relating to their measurement location and to forward said information to the control system (8, 8') as actual temperature and location data for diagnostic purposes.

14. 2. A road finishing machine according to claim 1, characterized in that the screed (5) has at least one screed plate (6), and the control system (8, 8') is configured to calculate a desired temperature value of the screed plate (6) based on a sensed actual temperature value of a supplied laying material (4) used by the road finishing machine (1), compare it with the sensed actual temperature of the screed plate (6) and to activate a power supply of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) associated with the screed plate (6) based on the comparison.

15. 15. A road finishing machine according to claim 14, characterized in that the control system (8, 8') is configured to calculate, based on the provided sensed ambient temperature, the heating time of the heating elements (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) used to heat the screed plate (6) remaining to reach the desired temperature value of the screed plate (6).

16. 1. A method for detecting a malfunction of at least one heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) installed in a screed (5) of a road finishing machine (1), characterized in that said detection of said malfunction is realized on the basis of actual temperature values ​​sensed directly at said heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n).

17. 17. The method according to claim 16, characterized in that a heating element type of the heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) is determined by the temperature gradient detected at the heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n), a desired temperature value (S) for the heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n) is calculated taking into account the heating element type, and the detection of the malfunction is performed by comparing the desired temperature value (S) with the actual temperature value detected directly at the heating element (11, 12, 1n, 21, 22, 2n, 31, 32, 3n).

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