DE102017127702A1 - Fuse with integrated temperature sensor - Google Patents

Abstract

A safety device (100) for securing an electrical line (880) in a vehicle electrical system (872) of a motor vehicle (870) is described. The securing device (100) comprises a first contact element (102), a second contact element (104), a trigger section (106) electrically connecting the first contact element (102) and the second contact element (104) to a fusible conductor (114) and a measuring point ( 112) electrically and thermally coupled to the fusible conductor (114) and configured such that a metering point temperature of the metering point (112) substantially matches and / or represents a fusible link temperature of the fusible conductor (114). Furthermore, the securing device has a temperature sensor (108) which is designed to detect a temperature value (116) of the measuring point temperature, and an evaluation device (110) which is set up, a state (118) of the securing device (100) using the Temperature value (116) to determine.

Description

Technical area

The present invention relates to a safety device for securing an electrical line in a vehicle electrical system of a motor vehicle, a power distributor for a motor vehicle with a number of corresponding safety devices and a method for securing an electrical line in a vehicle electrical system of a motor vehicle.

State of the art

The present invention will be described below mainly in connection with safety devices for vehicle electrical systems. However, the invention can be used in any application in which supply paths are hedged.

Fuses are used in many electrical and electronic devices to protect the user and components or lines of the device. In modern motor vehicles, for example, there are a large number of fuses to electrically protect individual cable strands or loads. To facilitate the replacement of tripped fuses, these are often designed as plug-in fuse.

For a reliable operation of the motor vehicle or subsystems of the motor vehicle diagnostic functions on the state of the fuses used are useful or necessary. Currently, this is elaborately integrated in ECUs, whereby system-specific no individual security statement can be made.

The status diagnosis of fuses is therefore currently not considered in a standard on-board network. For the topics of automated driving, diagnostic coverage will become more and more important in the future. A first approach is to diagnose at least one triggering of a fuse. Thus, in the post-published DE 10 2017 101 293 A1 a fuse described for use in a motor vehicle. A first contact element, of which a first end section protrudes from a housing on a first housing side, a second contact element, of which a second end section protrudes on the first housing side out of the housing, wherein the first and second contact element by a fusible conductor accommodated in the housing with each other are electrically connected, and a diagnostic contact element, from which a diagnostic end portion protrudes from the first side of the housing and which is electrically connected to a crosspoint of the first contact element with the fusible conductor.

Condition-diagnostic fuses will be important in future systems operating under the premise of automated driving, ie Highly Automated Driving (HAF) with the degree of automation L3 or fully automated driving (VAF) with the degree of automation L4 , The importance arises from the so-called diagnostic coverage (English: Diagnostic Coverage, DC), which plays a role in safety-relevant systems to reduce error rates in components. This diagnostic coverage not only requires that an error be detected, which would be easy if a backup fails, but also that the error is manageable. The controllability can for example be done via redundancy or as described here via a state detection of the fuse can be achieved. Thus, if it is possible to foresee a change of state of a supply path for all "slow errors" and to report a warning, with sufficient distance, before the failure of the supply path, the diagnostic coverage would reduce the failure rate of the fuse and this could be done in systems with ASIL ratings (ASIL = Automotive Safety Integrity Level) according to ISO 26262. Which classifications are possible must be determined in the respective project.

in mission critical applications (e.g., for HAF or VAF) it is advantageous to know the operational readiness of a fuse. This includes the detection of a degradation of the fuse. Today's fuses have no way to do so.

Description of the invention

An object of the invention is therefore to provide a fuse with the use of structurally simple means as possible, whose state development in terms of aging during operation - regardless of normal or fault operation - can be assessed.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention are specified in the dependent claims, the description and the accompanying figures. In particular, the independent claims of a claim category can also be developed analogously to the dependent claims of another claim category.

A securing device according to the invention for use in a motor vehicle comprises two contact elements, which via a electrically conductive trip section are connected together. The triggering section has two components: one of the components is the so-called fusible conductor as a functional component with regard to line protection, the other component comprises a measuring point for determining temperature-time data. In this case, the measuring point is characterized in that it is thermally connected to the fusible conductor and thus defined in conjunction with the fusible conductor, the tripping characteristic. Furthermore, the measuring point is characterized in that a measuring point temperature, that is to say a temperature of the measuring point, corresponds to a melting conductor temperature, that is to say a temperature of the fusion conductor within a tolerance range, that is to say within the specified accuracy, or is determined from the measuring point. Temperature determines the melt conductor temperature. In the first case, the measuring point temperature then represents the melt conductor temperature. In the latter case, the measuring point temperature can be converted to a melting temperature - with corresponding accuracy. Furthermore, the safety device has a temperature sensor for detecting a temperature value of the measuring point temperature and an evaluation device for determining a state of the safety device using the temperature value. By repeatedly recording the temperature value over a time course, a temperature profile or temperature-time data can ultimately be detected and evaluated.

The security device is set up to protect an electrical line in a motor vehicle electrical system. Under the fusible conductor can be understood at least one melting section. The contact elements may be blade contacts, contact tongues, contact pins, plug contacts or the like. Ultimately, the security device is comparable to a conventional fuse, but extended to a diagnostic capability. Depending on the sensor system used, the measuring point is designed so that, depending on the complexity of the requirements or the required accuracy, an emission factor suitable for the temperature measurement or a suitable heat connection is achieved. The temperature value obtained by the temperature sensor can be provided as an analog voltage signal or as a digital signal of the evaluation device. An analog voltage signal can easily be evaluated by a microcontroller. If it is a digital signal, this can be configured in conformity with a standardized fieldbus. In particular, a LIN bus is suitable here. Both the transmission protocol and the physical properties are in this case adapted to the selected fieldbus. Depending on the application and considering numerical aspects, the selection can be limited.

Failures that are not a hard short can be detected and reported. A hard short circuit, however, not. Here, the line protection is a priority and it still has to be a separate supply. All other longer-lasting processes that lead to a disconnection of the supply can be detected and reported here. Thus, the early loss of redundancy-except in hard Kurzschlussfall- predictable. The time window of the availability of the function plus the data recording rate thus determine the scope of the error cases which become predictable in the context of the present invention. This reduces the number of possible errors i.e. /. unpredictable redundancy loss.

An advantage of the safety device described is that a local temperature at a measuring point in the region of the fusible conductor is determined and not just a gradient over a measuring distance. The measuring point can be arranged at a hotspot of the securing device or the fusible conductor or in the immediate vicinity thereof, whereby an improved, more direct statement about an aging of the fuse can be made.

The trigger section can be integrated in a particular embodiment on a circuit board (= board). In this case, the contact elements can also be arranged in each case at the edge of the circuit board and integrated into it. Advantageously, the triggering device is then mechanically connected to the printed circuit board or arranged on this.

For cost-effective production optional contact elements and the trigger section can be made in one piece from locking plate. For example, the securing plate in the region of the contact elements and additionally or alternatively in the region of the measuring point may be formed in multiple layers to increase the current carrying capacity and also the mechanical strength in this area.

The trigger section can be arranged in an electrically insulating fuse housing. The contact elements are then each partially disposed within the fuse housing and partially outside the fuse box. Thus, in each case an end portion of the contact elements extends away from the fuse housing or, in other words, in each case the end section of the contact elements projects out of the fuse housing. In one embodiment, the fuse housing is substantially cuboid. That's one Density, ie compact arrangement of a variety of plug fuses feasible.

Depending on the embodiment and the type of temperature sensor used, the temperature sensor is located inside or outside the fuse box. If the temperature sensor is arranged inside the fuse housing, and the evaluation device is arranged outside the fuse housing, then in a first variant the fuse device has at least one diagnostic contact element via which the sensor signal representing the temperature value or the temperature profile is available externally to the fuse housing of the evaluation device provides. In a second variant, the sensor signal representing the temperature value is stamped onto the voltage applied to the safety device and read in by the evaluation device at a different location. In an arrangement of the temperature sensor and the evaluation device also within the fuse housing, there is a direct connection between the temperature sensor and the evaluation device, via which the sensor signal is provided.

Also, the temperature sensor can be arranged externally to the fuse housing. In this case, the fuse housing has a recess through which the temperature sensor can sense the measuring point temperature. Under the recess, a shaft can be understood. The recess in the fuse box is designed so that influences with a negative effect on the measurement accuracy are reduced.

The temperature sensor can be designed to detect the measuring point temperature without contact. In this case, the temperature sensor may be an optical temperature sensor. For example, the optical temperature sensor may be an infrared temperature sensor. Such an optical temperature sensor can be arranged both inside and outside a fuse box. In an arrangement outside the fuse housing, the optical temperature sensor may be arranged, for example, on a printed circuit board arranged substantially parallel to the fuse housing and detect the measuring point temperature through a recess in the fuse housing. In this case, the recess may also have a cover, provided that it is permeable to the thermal radiation or the frequency spectrum of the optical temperature sensor. In this case, the recess is a permeable medium in the frequency spectrum of the optical sensor.

In one embodiment, the temperature sensor may be a contact-based thermal sensor, such as a thermistor or preferably a thermistor. In this case, the temperature sensor may be part of, or even essentially form, the measuring point. A NTC thermistor can be understood as being a thermistor, and a PTC thermistor can be understood as a PTC thermistor. A trained as a thermistor or PTC thermistor temperature sensor could be located outside of the fuse housing, which is then passed through a recess in the fuse housing during assembly of the securing device through this recess into an interior of the fuse housing into and then usually in direct contact ( thermally, which usually also requires a mechanical contact) to the measuring point. The sensors can be electrically insulated from the supply path.

In one embodiment, it may be a temperature sensor, which determines the temperature of the measuring point via heat flow and heat capacity. Due to the necessary temperature range and the necessary accuracy of the application, the selection of available measuring sensors may be limited.
Also, a contact-based temperature sensor could be inserted into the fuse housing during assembly from outside through a present recess. Ensuring the thermal contact between sensor and measuring point is to be ensured with this method.

The measuring point can be arranged in one embodiment between one of the two contact elements and the fusible conductor. In an alternative embodiment, the measuring point is arranged within the extension of the fusible conductor and thus divides this into a first fusible conductor section and a second fusible conductor section. In a particular embodiment, the measuring point is arranged centrally in the fusible conductor, so that the two resulting fusible conductor sections are approximately the same length. There may be a direct relationship between the symmetry and the accuracy of the state determination. The closer the hotspot is displayed in the measuring point, the easier it is to monitor the security status with regard to aging progress.

In the triggering section, a plurality of measuring points can be distributed and arranged correspondingly over the fusible conductor. The fusible conductor is then subdivided into more than two fusible conductor sections. In this case, the safety device has a number of temperature sensors corresponding to the number of measuring points, each of which has a measuring point number. Detect the temperature of the associated measuring point and provide as a temperature value of the evaluation available. In this case, the evaluation device is designed to determine the state of the safety device using the plurality of temperature values. As a result, uneven heating of individual melt conductor sections can be detected. In this case, an integral over the detected temperature values Tdt or the temperature profile can be determined and compared with a threshold value or monitored for an exceeding of a threshold value. There may be a correlation between the result value of the integral over the detected temperature values and the aging of the security device. In this case, furthermore, a variance of the detected temperature values in the evaluation device can be determined and the state of the safety device can be determined by a comparison with one or more variance threshold values. An alternative evaluation determines the maximum temperature value of the detected measuring point temperatures of the plurality of measuring points and determines the state of the safety device using the maximum temperature value. Of course, the different methods can be linked together or used to validate an alternative method.

The measuring point may have a melting point which differs in the development of the melting temperature of the melt conductor.

The evaluation device can be set up to compare the temperature value with at least one threshold value and provide a warning about a state of the security device when this threshold value is exceeded. In this case, a plurality of threshold values can be determined, which each represent a different state of the security device. In this case, when a first threshold value is exceeded, a first warning, which represents a first warning level or a first state, and when a second threshold value is exceeded, a second warning, which represents a second warning level or a second state, is output. This can be continued as desired with further threshold values or warning levels or states of the security device. The respective application determines the complexity of the following system. From a first threshold, the integral Tdt is created and the life of the fuse is reduced accordingly. For example, a first warning may be issued from the first threshold or possibly a smaller threshold. The integral Tdt ultimately determines how the further procedure is determined in the context of the definition of the application (for example, from a reduction of the lifetime to a certain residual value, the process can be initiated "safe shutdown" or the HAF function can be neutralized Only the information is provided by the safety device described, the procedure is determined in the respective application For the integral, it makes sense to increase the recording rate 1 / dt accordingly from a further threshold value for a more exact one Monitoring, but this is also the responsibility of the application.

In one embodiment, the second threshold may be determined in response to a determined aging condition. Thus, the second threshold can be slowly lowered in correlation to the state of the security device. Thus, a change in the tripping characteristic associated with increasing aging of the security device can be accommodated.

The evaluation device may be configured to determine a time period in which the temperature value is above a certain threshold value, and then to determine the state of the safety device using this time duration. Thus, a first period of time may be determined in which the temperature value is above the first threshold value and a second period of time in which the temperature value is above the second threshold value, etc. Such a determined period of time can be stored in an internal memory, so that a Total time can be determined in which the temperature value was above the relevant threshold. Thus, different time intervals, which are associated with a specific threshold, can be calculated according to a mathematical combination and the result used to determine the condition or the aging of the security device. In a simplified version, different time intervals associated with a particular threshold can be added.

A power distributor according to the invention has a number of variants of the safety device described above. In this way, the functions of distributing, safeguarding and monitoring can be integrated in a power distributor to save space. In this way, an overriding control level can be informed in good time about possible failures of safety devices or a state of the safety devices which makes a failure within a defined time interval probable, and thus the overall safety of the motor vehicle system can be increased.

Optionally, the power distributor has a field bus, such as a LIN bus, to receive and process the digital signal of the number of security devices. An optional fieldbus interface to the outside makes it possible to provide a result signal to a higher-level control device. In addition, a processing, evaluation and storage of the digital signal over time in a processing device, for example in the form of an ASIC or microcontroller is possible.

A vehicle according to the invention comprises at least one power distributor according to the invention.

The idea according to the invention can also be implemented in a method for securing an electrical line in a vehicle electrical system of a motor vehicle. In this case, the method comprises at least the steps of capturing, reading and evaluating. If a measuring point temperature of a measuring point of a safety device is detected by means of a temperature sensor, the measuring point being electrically and thermally connected to a fuse element of the safety device connecting a first contact element and a second contact element. The measuring point temperature represents or substantially corresponds to a fusible conductor temperature of the fusible conductor. In the reading-in step, a temperature value representing the measuring point temperature is read into an evaluation device. In the step of the evaluation, the read-in temperature value in conjunction with the connected time intervals in which the respective temperatures were present is evaluated in order to determine a state or an aging state of the safety device.

list of figures

• 1 bis 6 vereinfachte Darstellungen von Sicherungsvorrichtungen gemäß Ausführungsbeispielen der vorliegenden Erfindung;
• 7 einen Temperaturverlauf einer Messstelle einer Variante einer beispielsweise in 1 bis 6 gezeigten Sicherungsvorrichtung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 8 ein Kraftfahrzeug mit einem Stromverteiler gemäß einem Ausführungsbeispiel der vorliegenden Erfindung; und
• 9 einen Ablaufplan eines Verfahrens zum absichern einer elektrischen Leitung in einem Bordnetz eines Kraftfahrzeugs gemäß einem Ausführungsbeispiel der vorliegenden Erfindung.

Hereinafter, an advantageous embodiment of the invention will be explained with reference to the accompanying figures. Show it:

• 1 to 6 simplified representations of securing devices according to embodiments of the present invention;
• 7 a temperature profile of a measuring point of a variant of an example in 1 to 6 shown securing device according to an embodiment of the present invention;
• 8th a motor vehicle with a power distributor according to an embodiment of the present invention; and
• 9 a flowchart of a method for securing an electrical line in an electrical system of a motor vehicle according to an embodiment of the present invention.

The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently provided with the same reference numerals.

Detailed description

1 shows a safety device in a plan view 100 for securing an electrical line in a vehicle electrical system of a motor vehicle. The safety device 100 comprises a first contact element 102 , a second contact element 104 , a the first contact element 102 and the second contact element 104 connecting trigger section 106 , a temperature sensor 108 as well as an evaluation device 110 , Of course, the temperature sensor 108 , as also described in other embodiments, depending on the choice of the temperature sensor 108 , for example, when choosing an optical temperature sensor 108 , also not integrated. The trigger section 106 has a measuring point 112 and a fuse wire 114 on. The measuring point 112 is with the fusible link 114 electrically and thermally connected. One measuring point temperature of the measuring point 112 essentially corresponds to a fusible conductor temperature of the fusible conductor 114 or offers the possibility of a statement about the temperature in the fusible conductor 114 hold true. The temperature sensor 108 is designed to detect the measuring point temperature and as a temperature value 116 provide. The evaluation device 110 is trained, a state 118 (ie, aging state) of the security device 100 using the temperature value 116 and to determine associated time intervals.

The trigger section 106 is inside an electrically insulating fuse housing 120 arranged. The first contact element 102 and the second contact element 104 are formed in the illustrated embodiment as blade contacts, wherein the first contact element 102 a recess 122 has, through which the first contact element, for example, with a bus bar, not shown, can be screwed. The second contact element 104 is for example inserted into a spring contact, not shown, bar, or, for example, alternatively with a busbar by means of clinching (also known as Toxen) connectable.

The measuring point 112 is centered in the fusible link 114 arranged and divides this into a first fuse section 124 and a second fuse section 126 , Due to the central arrangement of the measuring point 112 in the fusible link 114 are the two fusible conductor sections 124 . 126 the same length, whereby the statement on the Temperature in the fusible link 114 simplified. In the illustrated embodiment, the temperature sensor 108 as a PTC thermistor 128 educated. The temperature sensor 108 is in the measuring point 112 integrated. In this case, the measuring point 112 SnCu has a higher melting point than the fusible link 114 ,
The operation of the external in this embodiment, the fuse box 120 arranged evaluation 110 is based on the diagram in 7 explained in more detail.

2 shows an alternative arrangement of the measuring point 112 , As already shown, the triggering section comprises 106 the measuring point 112 as well as the fusible link 114 , In the in 2 illustrated embodiment is the measuring point 112 between the second contact element 104 and the fusible conductor 114 arranged.

3 shows in a sectional view a securing device 100 in which a contactless measuring temperature sensor 108 external to the fuse box 120 is arranged. The temperature sensor 108 is as an optical temperature sensor 330 such as an infrared temperature sensor formed. The fuse box 120 has a recess 332 through which the optical temperature sensor 330 the measuring point temperature of the measuring point 112 certainly. The recess 332 can also be referred to as a measuring shaft. The optical temperature sensor 330 is on a circuit board 334 positioned, for example, part of a power distribution, in which the securing device 100 is integrated. Instead of the circuit board 334 In an alternative embodiment, the temperature sensor 108 . 330 positioned on another substrate. When mounting the safety device 100 on the circuit board 334 becomes the security device 100 positioned so that the recess 332 is placed such that the optical temperature sensor 330 can detect the measuring point temperature. The shaft could also be made laterally. The optical temperature sensor 330 does not necessarily have to be connected to a printed circuit board. He could also laterally substantially parallel to one of the contact elements 102 . 104 be arranged. In this case, the fuse element 114 have a stepped portion, so that the optical temperature sensor 330 at a measuring angle between 50 ° and 130 ° to the fusible conductor 114 is arranged.

4 and 5 show safety devices molded as plug-in fuses 100 , At the in 4 illustrated embodiment, the securing device 100 an additional diagnostic contact 440 on. If the evaluation device 110 inside the fuse box 120 is arranged so is via the diagnostic contact 440 a state such as the aging state of the safety device 100 representing signal provided. When the selected device 110 outside the fuse box 120 is arranged so is via the diagnostic contact 440 a the temperature value 116 representing signal provided. In the in 4 embodiment shown is the temperature sensor 108 as NTC thermistor 442 trained and in the measuring point 112 integrated. That the temperature value 116 representing signal is sent to the evaluation 110 passed, which the the state of the security device 100 representing signal via the diagnostic contact 440 provides. In the in 5 illustrated embodiment, the fuse housing 120 a recess formed as a measuring shaft 332 on, through which an external to the fuse box 120 arranged temperature sensor 108 the temperature value 116 detected. This is a PTC thermistor 128 or an NTC thermistor 442 , The temperature sensor 108 is on a circuit board 334 arranged. As soon as the fuse designed as a plug-in fuse is plugged into the respective spring contacts, a thermal and mechanical contact arises between the temperature sensor 108 and the measuring point 112 ,

6 shows a further embodiment of a securing device 100 , wherein the triggering section 106 a plurality of measuring points 112 having. One measuring point each 112 is between the contact elements 102 . 104 and the fusible conductor 114 arranged. Another measuring point 112 is centered in the fusible link 114 arranged. The two remaining fusible conductor sections are repeated by a measuring point 112 divided. The in the measuring points 112 arranged temperature sensors 108 are with one in the fuse box 120 arranged evaluation 110 connected. To provide the state information 650 the embodiment shows an evaluation 110 , which is integrated in the fuse box. As both the evaluation device 110 as well as the temperature sensor 108 or the five temperature sensors 108 in the fuse box 120 are integrated, so you can also do this as a backup device 100 denote with integrated measurement data module. The processing of the measured values takes place in the safety device and is used inter alia for load reduction or signaling. In addition to the temperature sensor 108 contains the safety device 100 a block for comparing the measured data with the set and stored there temperature values of the safety device 100 and one possibility the measurement data in a time reference (see also 7 ) to set, store and deliver signals to the outside. The signals can be transmitted via a connector interface, wirelessly or as an impressed signal via the Load connections of the safety device 100 be issued.

For ease of understanding, reference numerals will be used in the following description 1-6 retained as a reference.

7 shows a temperature profile 760 over time t. In a Cartesian coordinate system the time on the abscissa is t and on the ordinate the temperature T shown. Here are a first threshold T ₁ and a second threshold T ₂ located. The temperature profile 760 exceeds at the time t ₁ the first threshold T ₁ at the time t ₂ again below the first threshold T ₁ to sink. At the time t ₃ exceeds the temperature profile 760 the first threshold T ₁ , at time t4, the temperature profile exceeds 760 the second threshold T ₂ , At the time t ₅ the temperature gradient decreases 760 below the second threshold T ₂ , at the time t ₆ the temperature gradient decreases 760 below the first threshold T ₁ , The following is the time interval between t ₁ and t ₂ when Δt ₁ , the time interval between t ₃ and t ₆ when Δt ₂ as well as the time interval between t ₄ and t ₅ when Δt ₃ designated.

The evaluation device 110 is formed, the state of the securing device 100 using the temperature history 760 and in particular the information about exceeding and falling below the various thresholds T ₁ . T ₂ to determine. So can the condition of the security device 100 using the number of times the threshold is exceeded T ₁ . T ₂ , the duration of the crossing of the individual thresholds T ₁ . T ₂ , or an integral over the temperature profile 760 as long as the temperature course 760 above a corresponding threshold T _1; T ₂ is to be determined.

For the thus determined number of transgressions, duration of the crossing or a correspondingly formed integral, certain limits can be defined which on reaching or exceeding an indication of a state such as an aging state of the safety device 100 are. In this case, a plurality of limits (threshold values) can be defined, each of which defines a different state. thresholds T2 or other thresholds, above which the application is to cause a reaction, are functions depending on the integrals of the temperature profile.

In other words, the temperature in the area of the fusible conductor 114 with the for the security device 100 specified temperature values T ₁ . T ₂ compared and thereby the operability / operational readiness of the security device 100 rated. Where the functionality / operational readiness can be assessed qualitatively by the determination of several temperatures. In addition, a time factor can be the temperature values 116 be assigned. The residence time above the threshold T ₁ . T ₂ Defined temperature values can be measured along the operating time of the security devices 100 for an additional assessment of the operability / operational readiness of the security device 100 recorded and evaluated. Except the temperature in the area of the fusible conductor 114 and, if necessary, the time Δt ₁ . Δt ₂ no further measured variable is detected. The processing of the measured values t ₁ . t ₂ . t ₃ . t ₄ . t ₅ . t ₆ . Δt ₁ . Δt ₂ takes place outside the safety device 100 and is used for example for load reduction or signaling.

8th shows a vehicle 870 with a wiring system 872 in which at least one power distributor 874 and a number of loads 876 are arranged. The power distributor 874 has at least one securing device 100 according to one of the embodiments, as this example in the figures 1 to 6 is shown on, about which at least one 876 was powered .. The power distributor 874 is with a power supply system 878 connected and distributes the energy from there to the over lines 880 connected loads 876 ,

9 shows a flowchart of a method for securing an electrical line in a vehicle electrical system of a motor vehicle. The motor vehicle may be a vehicle 870 according to the in 8th shown embodiment act. The method has one step S1 of grasping, one step S2 reading in and a step S3 of the evaluation. In step S1 the acquisition becomes a measuring point temperature of a measuring point 112 a security device 100 by means of a temperature sensor 108 recorded, and then in the step S2 reading in as a temperature representing the measuring point temperature 116 read. In step S3 becomes the temperature value 116 evaluated to a state 118 the security device 100 to investigate.

As the devices and methods described in detail above are exemplary embodiments, they may be readily modified by one skilled in the art to a wide extent without departing from the scope of the invention. In particular, the mechanical arrangements and the size ratios of the individual elements to each other are merely exemplary

LIST OF REFERENCE NUMBERS

100

safety device

102

first contact element

104

second contact element

106

trigger portion

108

temperature sensor

110

evaluation

112

measuring point

114

fuse element

116

temperature value

118

State

120

fuse box

122

recess

124

first melt conductor section

126

second fusible conductor section

128

PTC thermistor

330

optical temperature sensor

332

Recess, measuring shaft

334

circuit board

440

diagnostics contact

442

NTC thermistor

650

state information

760

temperature curve

T ₁ , T ₂

threshold

t ₁ , t ₂ , t ₃ , t ₄ , t ₅ , t ₆

time

Δt ₁ , Δt ₂

Time interval, time duration

870

Vehicle, motor vehicle

872

board network

874

power distribution

876

load

878

Power system

880

cables

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102017101293 A1 [0005]

Claims (15)

Securing device (100) for securing an electrical line (880) in a vehicle electrical system (872) of a motor vehicle (870), comprising: a. a first contact element (102), b. a second contact element (104), c. a triggering section (106) electrically connecting the first contact element (102) and the second contact element (104) a fusible conductor (114) and - A measuring point (112) which is electrically and thermally connected to the fusible conductor (114) and is formed so that a measuring point temperature of the measuring point (112) of a fusible conductor temperature of the fusible conductor (114) substantially corresponds and / or these represents d. a temperature sensor (108) adapted to detect a temperature value (116) of the measuring point temperature, and e. an evaluation device configured to determine a state of the security device using the temperature value. Safety device (100) after Claim 1 in that the trigger section (106) is received in an electrically insulating fuse housing (120). Safety device (100) according to the preceding claim, wherein the temperature sensor (108) in the fuse housing (120) is arranged. Safety device (100) according to the preceding claim, wherein the evaluation device (110) in the fuse housing (120) is arranged. Securing device (100) according to Claim 2 in which the evaluation device (110) and / or the temperature sensor (108) are arranged outside the fuse housing (120). Securing device (100) according to one of the preceding claims, in which the temperature sensor (108) is designed to contactlessly detect the measuring point temperature, in particular wherein the temperature sensor (108) is designed as an optical temperature sensor (330), in particular wherein the temperature sensor (108) is designed as an infrared temperature sensor. Securing device (100) according to one of Claims 1 to 5 in which the temperature sensor (108) is designed as a PTC thermistor (PTC) thermistor (128) and / or thermistor NTC thermistor (442). Safety device (100) according to one of the preceding claims, in which the measuring point (112) is arranged in the fusible conductor (114) and subdivides it into a first fusible conductor section (124) and a second fusible conductor section (126), in particular the measuring point (112) substantially is arranged centrally in the fusible conductor (114). A fuse device (100) according to any one of the preceding claims, wherein the measurement site (112) has a melting point that differs in melting temperature evolution from that of the fusible conductor (114). Safety device (100) according to one of the preceding claims, in which the evaluation device (110) is set up to compare the temperature value (116) with at least one first threshold value (T ₁ ) and if the first threshold value (T ₁ ) is exceeded, a first warning, which represents a first warning level, via the state (118) of the security device (100) and / or when a second threshold value (T ₂ ) is exceeded, a second warning, which represents a second warning level, about the state (118) of the security device (100) issue. Safety device (100) according to the preceding claim, wherein the evaluation device (110) is arranged to determine a first time duration (Δt ₁ ) in which the temperature value (116) is above the first threshold value (T ₁ ), and / or a second one Time duration (At ₂ ), in which the temperature value (116) is above the second threshold (T ₂ ), and the state (118) of the securing device (100) using the first time period (At ₁ ) and / or second time duration (Δt ₂ ) to determine. Securing device (100) according to one of Claims 10 or 11 in which the evaluation device (110) is set up to determine the second threshold value (T ₂ ) using the state (118). A security device (100) according to any one of the preceding claims, wherein the state (118) represents an aging condition of the security device (100). A power distributor (874) for a motor vehicle (870) having a plurality of fuse devices (100) according to any one of the preceding claims. Method for securing an electrical line in a vehicle electrical system of a motor vehicle with the following steps: a. Detecting (S1) a measuring point temperature of a measuring point (112) of a safety device (100) by means of a temperature sensor (108), wherein the measuring point (112) electrically and thermally with a a fuse element (100) connecting a first contact element (102) and a second contact element (104) is connected, the measurement point temperature substantially corresponding to and / or representing a fuse temperature of the fuse conductor (114), b , Reading in (S2) a temperature value (116) representing the measuring point temperature, c. Evaluating (S3) the temperature value (116) to determine a state (118) of the security device (100).

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