Tubular cable shielding for an exhaust gas temperature sensor assembly and exhaust gas temperature sensor assembly

Abstract

Tubular cable shielding (9) for an exhaust gas temperature sensor arrangement (1), wherein the tubular cable shielding (9) comprises a first shielding tube (13), wherein the first shielding tube (13) has one or more through-channels for receiving one or more cables (6a, 6b, 8a, 8b, 11a, 11b) and / or for receiving one or more temperature measuring sensors (7), wherein the tubular cable shielding (9) further comprises a second shielding tube (14) that radially surrounds the first shielding tube (13), wherein the tubular cable shielding (9) comprises a first tube adhesive layer (15) that is arranged between the first shielding tube (13) and the second shielding tube (14), wherein the first tube adhesive layer (15) fixes the first shielding tube (13) to the second shielding tube (14), characterized in that the tubular conductor shielding (9) has a third shielding tube (19),radially surrounds the second shielding tube (14), wherein the tubular conductor shielding (9) has a second tube adhesive layer (20) arranged between the second shielding tube (14) and the third shielding tube (19), the second tube adhesive layer (20) fixing the second shielding tube (14) to the third shielding tube (19).

Description

[0001] The present invention relates to a tubular conductor shield for an exhaust gas temperature sensor arrangement with the features of the preamble of claim 1.

[0002] Furthermore, the present invention relates to an exhaust gas temperature sensor arrangement.

[0003] Such an exhaust gas temperature sensor can comprise one or more temperature measuring sensors, a connecting cable and a conductor arrangement for electrically connecting the one or more temperature measuring sensors via the connecting cable, wherein the conductor arrangement comprises one or more pairs of conductors that are conductors of the connecting cable, and one or more tubular conductor shields, preferably one or more tubular conductor shields according to the invention, wherein each tubular conductor shield radially surrounds at least one conductor of the conductor arrangement by providing a through-channel that accommodates the at least one conductor.

[0004] Also known is a method for assembling an exhaust gas temperature sensor arrangement which has a tubular line shield which radially surrounds one or more lines of a line arrangement, wherein the line arrangement has one or more pairs of conductors for electrically connecting a temperature measuring sensor via a connecting cable of the exhaust gas temperature sensor arrangement.

[0005] WO 2014 / 125078 A1 discloses a thermoelectric high-temperature sensor. The thermoelectric high-temperature sensor comprises a thermocouple and a sheath that shields the thermocouple leads. This document further discloses two weld points that connect the pair of thermocouple leads to a connecting cable of the thermoelectric high-temperature sensor outside the sheath. The sheath also includes two segments with different outer diameters.

[0006] US 2012 / 0039362 A1 discloses a temperature sensor unit. Two temperature sensors are connected to conductors of a cable connection via two wires each. Each of the four connections to the cable is located inside a tubular cable shield. The temperature sensors are positioned closer to the radial wall of the cable shield than the conductors. The temperature sensors are further arranged in a linear extension along their respective wires.

[0007] WO 92 / 02794 A1 describes a thermocouple assembly comprising an axially elongated ceramic insulator provided with a pair of axially extending passages for receiving a pair of thermocouples. The thermocouple assembly further comprises an axially elongated uniform ceramic sheath provided with a chamber, the chamber having a closed end for receiving the elongated ceramic insulator. This thermocouple assembly can be housed cartridge-like in an existing protective tube, or inserted into a stainless steel tube which is then screwed into the wall of a chamber to be monitored, or provided with a spark plug-like external thread for installation in an exhaust system or the like.

[0008] US 5,999,081 A describes a temperature measurement system with a thin-film thermometer and a wired RTD element. The housing materials of the temperature measurement system are matched to those of the material being measured, thus minimizing the use of interface potting materials that would otherwise cause a thermal gradient. A screw connection stabilizes the connection between the housing and the material being measured. Double- and triple-shielded thermal elements filter RFI and RMI. The incorporation of a thermal mass within a thermocouple housing provides improved surface measurements at high temperatures.

[0009] CN 2 042 589 U describes a thermoelectric element whose outer layer consists of recrystallized silicon carbide and serves as a protective tube. Several electrode components of an inner layer are fitted with a round sealing cap and reinforced with high-temperature adhesive.

[0010] The object of the invention is to provide a tubular cable shield and an exhaust gas temperature sensor arrangement that offer good mechanical stability.

[0011] In one aspect, the problem is solved by a tubular cable shield with the features of claim 1.

[0012] The tubular cable shielding includes, among other things, a first tube adhesive layer that is arranged between the first shielding tube and the second shielding tube, the first tube adhesive layer fixing the first shielding tube to the second shielding tube.

[0013] Such a shielding design can be described as a "sandwich design." Exhaust gas temperature sensors are often exposed to high temperatures and strong vibrations. Therefore, there is a risk that the temperature sensors will fail due to mechanical stress. For example, elements of the exhaust gas temperature sensor assembly can break, leading to a failure of the entire assembly.

[0014] Forming two or more shielding tubes into a single unit by applying an adhesive between adjacent shielding tubes provides good stability. If vibrations occur, they would have to break three or more layers of the tubular line shielding before the tubular line shielding would fail—at least the first shielding tube, the second shielding tube, and the first layer of tube adhesive that fixes the first shielding tube to the second shielding tube.

[0015] A pipe adhesive layer according to the present invention can have a tubular shape. In some embodiments, the pipe adhesive layer can completely fill the space between two shielding tubes, with one of the shielding tubes radially surrounding the other. In other embodiments, however, the pipe adhesive layer can be formed, for example, by one or more adhesive dots arranged separately from one another in this space, fixing the shielding tubes adjacent to each other. In some embodiments, the pipe adhesive layer has a network structure. Thus, it should be clear that the pipe adhesive layer is only preferably a closed and / or tubular layer between the adjacent shielding tubes.

[0016] Preferably, the first pipe adhesive layer comprises a ceramic adhesive. Ceramic adhesives can be very stable under mechanical stress. The ceramic adhesive can provide a strong, permanent bond between the first shielding tube and the second shielding tube. In some embodiments, the first pipe adhesive layer comprises magnesium oxide, preferably magnesium oxide powder. Furthermore, in some embodiments of the invention, the pipe adhesive layer comprises sand. In some embodiments, the first pipe adhesive layer comprises a hardener for curing the adhesive. This can help to cure the first pipe adhesive layer more quickly.

[0017] According to the invention, the tubular cable shield comprises a third shielding tube that radially surrounds the second shielding tube. The tubular cable shield has a second tube adhesive layer arranged between the second and third shielding tubes, the second tube adhesive layer fixing the second shielding tube to the third shielding tube. This embodiment can be even more resistant to mechanical stresses, preferably vibrations. The vibrations would have to break five layers, i.e., three shielding tubes and two tube adhesive layers, before the tubular cable shield would fail. Therefore, the tubular cable shield is very stable when using this sandwich design. Five or more layers are preferred when an RTD element is to be accommodated by the tubular cable shield.

[0018] It is preferred that the second and / or third shielding tubes are steel tubes, while the first shielding tube is a ceramic tube. Preferably, the first shielding tube is a ceramic tube. It is further preferred that the first shielding tube has a round, cylindrical shape. It is preferred that the first shielding tube has at least one through-channel for accommodating one or more conductors. The diameter of each through-channel can be adapted to accommodate two or more conductors that are electrically insulated from each other. Preferably, the first shielding tube comprises two or more through-channels, in some embodiments four through-channels. Preferably, each through-channel is adapted to accommodate exactly one conductor. The one or more through-channels preferably extend longitudinally through the first shielding tube. A preferred second shielding tube is a steel tube.Preferably, the second shielding tube is round and cylindrical. The second shielding tube has a through-channel for receiving the first shielding tube. Preferably, the through-channel of the second shielding tube extends longitudinally through the second shielding tube. A preferred third shielding tube is a steel tube. Preferably, the third shielding tube is round and cylindrical. The third shielding tube has a through-channel for receiving the second shielding tube. The through-channel of the third shielding tube preferably extends longitudinally through the third shielding tube. A ceramic tube is useful for electrically insulating conductors from each other. Furthermore, it can be reasonably stable with regard to mechanical stresses, such as vibrations. A steel tube provides good reinforcement of the tubular conductor shielding.Since the first shielding tube can electrically isolate the cables from each other and from the environment, a steel tube surrounding the first shielding tube is not a disadvantage.

[0019] Preferably, the second pipe adhesive layer differs from the first pipe adhesive layer with respect to its material composition. In some embodiments, the first and second pipe adhesive layers are identical with respect to their material composition. However, it can be advantageous for the material composition of the first and second pipe adhesive layers to differ. For example, the first pipe adhesive layer may contain sand, or the second pipe adhesive layer may contain sand. In some embodiments, the first pipe adhesive layer is thicker in a radial extent than the second pipe adhesive layer, or vice versa. In such a case, the radially thinner of the two adhesive layers may preferably contain sand and / or magnesium oxide.

[0020] It is preferred that the tubular cable shielding includes a tubular segment with a cavity for accommodating one or more temperature sensors, preferably a resistance temperature detector (RTD). This tubular segment can thus help to protect such a temperature sensor. Instead of or in addition to one, two, or more through-channels, each designed to accommodate one or more cables, the tubular segment can have a single cavity, preferably within the first shielding tube. It is preferred that the cavity is arranged longitudinally along the one or more through-channels for the cable. Thus, through-channels adapted for accommodating the cable preferably extend only longitudinally from the cavity. It is preferred that the cavity is designed as a through-channel.This allows for easy adjustment of the temperature sensor.

[0021] Preferably, the second shielding tube surrounds the first shielding tube concentrically. Preferably, the third shielding tube surrounds the second shielding tube concentrically. It is preferred that the tubular segments of the tubular line shield have the same longitudinal extent. The tubular line shield can consist of exactly one tubular segment. However, it is preferred to have two or more tubular segments forming the tubular line shield. This can allow for easier assembly of the exhaust gas temperature sensor arrangement, since the tubular line shield can be formed from a plurality of tubular segments instead of requiring a single individual tubular segment for each line length.

[0022] In another aspect, the object of the invention is solved by an exhaust gas temperature sensor arrangement according to claim 6 or claim 7, wherein the (at least) has a tubular line shield according to the invention.

[0023] The tubular conduit shielding with its sandwich design results in good mechanical stability when installed in an exhaust gas temperature sensor assembly.

[0024] According to one aspect, the exhaust gas temperature arrangement can be designed in such a way that that the at least one temperature measuring sensor is the RTD element, wherein at least one conductor of the conductor arrangement contacting the RTD element is electrically connected to the RTD element outside the passage channel formed by the tubular conductor shielding, and accommodates the conductor and / or the RTD element, and / or that the at least one temperature measuring sensor is an electrical transition, wherein the electrical connection from the electrical transition to the pair of conductors has fewer than two welded joints.

[0025] Welded joints are prone to breakage due to vibrations. Therefore, from this perspective of the invention, welded joints are ideally located outside the tubular conduit shielding, which is often subject to vibrations, or even better, omitted entirely or replaced by other types of connectors that are less susceptible to failure due to vibration. This results in very good mechanical stability.

[0026] In some embodiments, the wiring arrangement consists of the pair of conductors of the connecting cable, preferably when the temperature sensor is an electrical junction, wherein the pair of conductors are preferably thermocouple leads welded together in a stripped section forming the electrical junction. In some embodiments, the wiring arrangement includes two or more additional pairs of conductors, for example, pairs of conductors extending from the RTD element, in addition to the pair of conductors of the connecting cable, wherein a further pair of conductors connects a corresponding temperature sensor to pairs of conductors of the connecting cable. In these embodiments, the additional pair of conductors may be thermocouple leads, preferably when the temperature sensor is an electrical junction for measuring the temperature.Other cable arrangement configurations are possible, as will be described in detail later.

[0027] It is preferred that the temperature sensor be electrically connected to at least one of the conductors by a screw connection located outside the through-channel. Thus, preferably at least one conductor of the other pair of conductors is electrically connected to a corresponding conductor of the cable by a detachable connection. A detachable connection can be advantageous for replacing individual conductors or the entire conductor assembly, if necessary. Furthermore, it can be more reliable to use a detachable but secure connection instead of a welded connection, which may break under vibration. In some embodiments, a detachable connection can be a clamp connection, a hook connection, or a bayonet connection. However, a screw connection is preferred because it can be very stable in situations where vibrations occur.Furthermore, maintenance of the cable assembly can be facilitated by using a detachable screw connection. Since the detachable connection can be located outside the passageway of the tubular cable shield, vibrations of the tubular cable shield will have less of an impact on the connection between the temperature sensor and the one or more conductors of the connecting cable. Preferably, the screw connection is located outside one end of the tubular cable shield and at a distance from the temperature sensor. Thus, the opposite end of the tubular cable shield is preferably located adjacent to the temperature sensor, and particularly preferably radially surrounding it. Preferably, to achieve this, this end of the tubular cable shield has a cavity for accommodating the temperature sensor.In the alternative, however, the screw connection is located outside one end of the tubular cable shield and adjacent to the temperature sensor.

[0028] It is preferred that the exhaust gas temperature sensor assembly has a terminal housing, wherein the terminal housing has at least one screw terminal that electrically connects the temperature sensor to a conductor of the connecting cable. Preferably, the terminal housing is arranged adjacent to the end of the tubular cable shield furthest from the temperature sensor. A preferred terminal housing is a B-type connector. The screw terminal is preferably a terminal block. Thus, the screw terminal can have a socket for the additional wire and a socket for the corresponding conductor of the connecting cable, the screw connection allowing the additional wire to be electrically connected to the corresponding conductor.This setting allows the connection between at least one additional conductor and the corresponding conductor of the cable to be protected without having to place the connection point inside the tubular cable shield. Within the terminal housing, the connection point can be well protected against vibrations.

[0029] It is preferred that the at least one conductor of the conductor assembly is supported on a surface located within the terminal housing. This can stabilize the conductor when vibrations occur. Preferably, the conductor is supported on a side wall of the screw terminal. Alternatively, or additionally, it can be supported on a base plate of the screw terminal. The base plate is located within the terminal housing. Both options allow for good mechanical stability, especially compared to floating wires within the terminal housing. It is preferred that the base plate is fixed to the terminal housing by a screw connection, preferably by two fixing screws. This ensures secure fixation.

[0030] Preferably, at least one temperature sensor is the RTD element, and the RTD element is arranged between conductors of the cable assembly, which electrically connect the RTD element via the connecting cable. A preferred RTD element is selected from the group consisting of a PT element, an NTC element, a PTC element, and a KTY element. Preferred RTD elements are PT100, PT200, PT500, and PT1000 elements. Inserting the RTD element between the pair of conductors, so that it is arranged in an inverted position between the conductors, allows the RTD element to be protected in a cavity of a single segment of the tubular cable shield, thus preventing the shielding of the RTD element from splitting into two segments. Preferably, additional conductors connecting the RTD element to the corresponding conductors of the cable are nickel-plated.If the temperature sensor is an electrical junction instead of an RTD element, the additional leads can be thermocouple leads. The pair of additional leads connecting the electrical junction to the corresponding conductors of the cable preferably consists of a nickel lead and a chromium-nickel alloy lead (R-type). Alternatively, the pair of leads in this case consists of a copper lead and a constantan lead (T-type) or a Nicrosil alloy lead and a Nisil alloy lead (N-type). The two thermocouple leads are welded together, preferably at the ends of the pair of leads, to form the electrical junction that constitutes the temperature sensor. As mentioned previously, the pair of conductors of the connecting cable can be stripped to allow direct connection to the temperature sensor or welded together to form the electrical junction.Then no further pair of wires is required.

[0031] It is preferred that the tubular conductor shield comprises two or more tubular segments with the same outer diameter, each tubular segment radially surrounding a different section of the at least one conductor of the conductor assembly. Several segments can be arranged sequentially on one or more conductors to allow flexibility in the conductor length. Preferably, the length of the tubular conductor segments is the same for all tubular conductor shield segments of the tubular conductor shield. It is preferred that a front tubular conductor shield segment, preferably arranged adjacent to the ends of the pair of conductors furthest from the corresponding conductors of the cable, may have a cavity for the temperature sensor.Due to their reduced length compared to prior art designs, the tubular shielding segments are also less susceptible to breakage under vibration. The conductor pair can be the pair of conductors in the connecting cable or another conductor pair connected to the corresponding conductors.

[0032] Preferably, the tubular line shielding of the exhaust gas temperature sensor arrangement is designed as the tubular line shielding described with regard to the first aspect of the invention.

[0033] Another aspect of the disclosure, to which no separate claim is directed, relates to a method of the type described at the outset, which further comprises the step of fixing a first shielding tube of the tubular cable shielding to a second tubular shielding tube of the tubular cable shielding, wherein the second shielding tube radially surrounds the first shielding tube, by applying a first tube adhesive between the first shielding tube and the second shielding tube; and / or providing an RTD element as the temperature measuring sensor and electrically connecting at least one conductor of the cable arrangement that contacts the RTD element and the RTD element to each other in order to electrically connect the RTD element via the connecting cable and arranging the electrical connection with the RTD element outside a through-channel formed in the tubular cable shielding;and / or providing an electrical junction as a temperature measuring sensor by welding a pair of thermocouples together, connecting the electrical junction electrically via the connecting cable by forming fewer than two further welded connections.;

[0034] With regard to the aspects of the present invention, as described above, it becomes clear that the process steps lead to a mechanically stable exhaust gas temperature sensor that is particularly resistant to vibrations.

[0035] It is preferred that the method includes the step of providing two or more tubular segments of the tubular cable shield in succession for the same cable of the cable arrangement, wherein at least two of the tubular segments have the same outer diameter. Therefore, the tubular cable shield can be composed of different segments having the same outer diameter, so that it is not necessary to provide different types of segments with different outer diameters.

[0036] Preferably, the method comprises the step of providing a temperature sensor, preferably an RTD element. Preferably, one or more, more preferably two or more tubular shielding segments are successively mounted on leads extending from the temperature sensor. One or both of the leads can be welded to corresponding conductors of the cable. However, it is preferred that one or both of the leads are connected to the corresponding connecting conductors using a screw connection instead of a weld. Preferably, one or both of the leads are connected to the corresponding conductors of the cable outside the passage of the tubular shielding segments. Alternatively, one or both of the leads can be stripped conductors of the connecting cable. The shielding segments are thus mounted one after the other on the conductors of the cable.Preferably, a sensor housing is provided, and the temperature sensor, the cable assembly, and the tubular cable shield are inserted into the sensor housing. The sensor housing preferably has a reduced tip. Furthermore, a ring can be provided, and the temperature sensor housing can be wrapped around the cable, with the ring being welded to the outer surface of the temperature sensor housing. Testing and packaging can then be carried out. The process steps can be performed in the sequence specified above. However, it should be clear that the process steps can be performed in any order, as long as the selected sequence leads to the desired result.

[0037] The process allows for a very fast two-day lead time. Furthermore, the process allows the same production line to be used for both RTD elements and solutions with electrical junctions. Therefore, assembly lines can be simplified, and the assembly process can be easily switched from assembling exhaust gas temperature sensors with RTD elements to assembling exhaust gas temperature sensor assemblies with electrical junctions as the temperature measurement sensor.

[0038] The procedure may include tempering a steel tube if a steel tube is intended to be used in the tubular duct shield. This helps to avoid sensor accuracy drift due to sensor aging at high temperatures. However, the tempering process may be omitted for exhaust gas temperature sensor assemblies that are expected to operate continuously below 400°C.

[0039] Providing one or more steel tubes in each segment of the tubular conduit shield is preferred when the temperature measuring sensor is the RTD element.

[0040] Exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which: Fig. 1 shows a perspective view of a temperature sensor arrangement according to a first embodiment; Fig. Figure 2 shows a detailed view of a conductor arrangement and a tubular conductor shield of the first embodiment; Fig. 3 shows a detail of a second embodiment in which the temperature measuring sensor is an RTD element; Fig. 4 shows an embodiment having a first shielding tube attached to a second shielding tube; Fig. 5 shows another embodiment, similar to the one in Fig. The embodiment shown in section 4 is; Fig. Figure 6 shows an embodiment of the invention in which the tubular cable shielding has a first, a second and a third shielding tube; Fig. Figure 7 shows an embodiment in which the tubular cable shielding has a single shielding tube; Fig. Figure 8 shows a perspective cross-sectional view of a detail of an embodiment of the invention; Fig. 9 shows an embodiment of the invention in which a connection housing is implemented; Fig. Figure 10 shows another view of the connector housing; and Fig. Figure 11 shows a perspective cross-sectional view of the embodiment, which includes the connection housing.

[0041] Reference numerals have been included in the following detailed description and the accompanying claims to improve readability. These reference numerals are in no way intended to be limiting. Furthermore, the exemplary embodiments shown below are not intended to be limiting. It should be clear that features shown in one embodiment of the invention may be freely combined with features shown in other embodiments of the invention and with any feature described above.

[0042] Fig. Figure 1 shows a perspective view of an exhaust gas temperature sensor arrangement 1. The exhaust gas temperature sensor arrangement 1 is intended to be used for measuring the exhaust gas temperature of vehicles, more precisely of vehicles based on diesel engines, such as cars or ships.

[0043] The exhaust gas temperature sensor assembly 1 has a sensor head 2. The sensor head 2 has a sensor housing 3 and a ring 4, which is welded to the sensor housing 2 and connected by a connecting element.

[0044] The exhaust gas temperature sensor assembly 1 also includes a connecting cable 5. The connecting cable 5 has two conductors 6a and 6b. The conductors 6a and 6b each have an open end, which allows the temperature sensor assembly 1 to be connected to an analysis device, such as a computer (not shown).

[0045] The conductors 6a, 6b each have a connected end that is equipped with a temperature measuring sensor 7 (in Fig. 1 (not shown) is electrically connected, which is housed within the sensor housing 3. Therefore, the conductors 6a, 6b form part of a conductor arrangement for electrically connecting the temperature measuring sensor via the connecting cable 5. Furthermore, as can be understood, in embodiments the conductor arrangement can include further pairs of conductors 8a, 8b (in Fig. (2 not shown) which are connected to the pair of conductors 6a, 6b and arranged between the pair of conductors 6a, 6b and the temperature sensor 7, as described in more detail below. Thus, an elongated exhaust gas temperature sensor arrangement 1 is provided.

[0046] Fig. Figure 2 shows that the conductors 6a and 6b provide a temperature sensor 7, which in this embodiment is an electrical junction. Therefore, the conductors 6a and 6b are thermocouples. One of the conductors, 6a, is a nickel conductor, and the conductor 6b is a chromium-nickel alloy conductor. Therefore, the thermocouple is a type K thermocouple.

[0047] The pair of conductors 6a, 6b is accommodated in two through-channels formed in each of seven segments 9b to 9g of a tubular conductor shield 9. Thus, the tubular conductor shield 9 radially surrounds both conductors 6a, 6b of the conductor arrangement. Another segment 9a of the tubular conductor shield 9 has a single cavity 10 for accommodating the temperature sensor 7. In this embodiment, each segment 9a to 9g of the tubular conductor shield 9 can consist of just a ceramic tube having the two through-channels, one for each of the conductors 6a, 6b. However, other embodiments feature tubular conductor shields 9 with more sophisticated designs, as explained below.

[0048] The tubular segments 9a to 9g are arranged one after the other on the pair of conductors 6a, 6b and on the temperature sensor in an assembled state. The conductor shielding segments 9a to 9g all have the same outer diameter. The conductor shielding segments 9b to 9g have the same length. The remaining segment 9a is shorter than each of the segments 9b to 9g. However, all segments 9a to 9g are of the same length in all embodiments, or all of them are of different lengths in other embodiments. Each segment 9a to 9g radially surrounds a different section of the two conductors 6a, 6b.

[0049] Two or more tubular shielding segments 9a to 9g ensure good stability when the sensor housing 3 vibrates at a measurement location, for example, an exhaust pipe. Furthermore, since conductors 6a and 6b form the electrical connection, no additional welds are required to electrically connect the temperature sensor 7 via the cable.

[0050] In some embodiments, the additional conductors 8a, 8b of the further conductor pair can be connected to the corresponding conductor 6a, 6b of the connecting cable via a terminal block. Each terminal block can then be located inside the sensor head 3, but outside the tubular conductor shield 9. This also has a positive effect on stability when vibrations occur.

[0051] Fig. Figure 3 shows a detail of another embodiment. Here, the temperature measuring sensor 7 is an RTD element, in particular a PT 1000 platinum sensor according to DIN EN 60751.

[0052] The temperature sensor also includes conductors, specifically a pair of conductors 11a, 11b, each of which is connected to a corresponding conductor 6a, 6b. Since no thermocouple is required in this embodiment, only two nickel conductors 6a and 6b are provided and arranged within the two through-channels of segments 9b and 9c. Crimped sections 12a, 12b are provided in a connection zone between the conductor pair 6a, 6b and the conductor pair 11a, 11b. In these sections, each of the conductors 11a, 11b of the conductor pair is crimped to the corresponding conductors 6a, 6b to ensure a secure fit that remains stable even under vibration or during assembly. The RTD element is positioned between the conductor pair 6a, 6b. Furthermore, the RTD is inserted between the conductor pair 11a, 11b. In embodiments, the RTD element is arranged completely between the pair of conductors 6a, 6b.When the RTD element is positioned between the pair of conductors 6a, 6b, as shown, this can be referred to as the inverted position. In this embodiment, the additional segment 9a, which has the cavity, can be arranged to radially surround the RTD element. Again, the conductor pair can be the pair of conductors 6a, 6b, as shown, or an additional conductor pair 8a, 8b connected to the corresponding conductors 6a, 6b. Furthermore, the conductors 11a, 11b can extend completely through the tubular conductor shield 9 and be connected to the conductors 6a, 6b outside the tubular conductor shield 9.

[0053] It should be clear that in some embodiments the RTD element does not have the conductors 11a, 11b, but the RTD element is directly connected to the corresponding conductors 6a, 6b of the connecting cable 5.

[0054] Fig. Figure 4 shows an embodiment of a tubular cable shield 9 with details. The tubular cable shield 9 is arranged on an exhaust gas temperature sensor assembly 1. The given front view along the longitudinal axis of the tubular cable shield 9 shows that the tubular cable shield 9 has a first shielding tube 13 that radially surrounds the temperature measuring sensor 7, in this embodiment the RTD element. A second shielding tube 14 is arranged such that it radially surrounds the first shielding tube 13. A first tube adhesive layer 15 is arranged between the first shielding tube 13 and the second shielding tube 14 in order to radially fix the first shielding tube 13 to the second shielding tube 14.

[0055] The first in Fig. The shielding tube 13 shown in Figure 4 is a ceramic tube. The second shielding tube 14 is a steel tube. The first tube adhesive layer 15 is a ceramic adhesive layer. A channel adhesive 16, in this embodiment a ceramic adhesive, is arranged within the passage channel of the first shielding tube 13. The ceramic adhesive is essentially made of the same material as the first adhesive layer 15. However, it additionally contains sand. The channel adhesive 16 fixes the elements arranged in the passage channel of the first shielding tube 13 to the first shielding tube 13.

[0056] How to in Fig. As can be seen in Figure 4, a radial air gap 17 is provided between a radial sensor housing wall 18, which surrounds the tubular cable shield 9, and the second shielding tube 14. Thus, in this embodiment, the tubular cable shield 9 consists of four layers, i.e., two shielding tubes 13, 14 and two adhesives 15, 16. Therefore, vibration would have to break all four layers before the temperature sensor 7 would fail. The tubular cable shield 9 and the exhaust gas temperature sensor assembly 1 are therefore of good mechanical stability.

[0057] Fig. Figure 5 shows another embodiment of the tubular line shielding 9 and the exhaust gas temperature sensor arrangement 1.

[0058] Here, the first shielding tube 13 has only one through-channel, and two further conductors 8a, 8b are electrically insulated from each other within this channel. The channel adhesive 16 inside the through-channel fixes the two conductors 8a, 8b to the first shielding tube 13. This helps to understand that regardless of whether an RTD or a thermocouple is to be installed in the exhaust gas temperature sensor assembly 1, the same mounting procedure can be used. Of course, conductors 6a, 6b can be used instead of the further conductors 8a, 8b within the through-channel.

[0059] Even the same segments of the tubular conductor shield 9 can be used, regardless of whether an RTD element or a thermocouple is used, as long as the through-channel of the first shield tube 13 has a diameter large enough to accommodate either the RTD and / or the two conductors of the conductor arrangement.

[0060] Fig. Figure 6 shows an embodiment of the invention. Here, as in Fig. 4 and Fig. Figure 5 shows a view along the longitudinal extent of the tubular cable shield 9. A difference between this embodiment and the previous embodiments is that the tubular cable shield 9 now has three shielding tubes 13, 14, and 19. A third shielding tube 19 is arranged such that it radially surrounds the second shielding tube 14. The third shielding tube 19 is a steel tube. A second tube adhesive layer 20 is arranged between the second shielding tube 14 and the third shielding tube 19. The second tube adhesive layer 20 has a ceramic adhesive and, in this embodiment, also contains sand. In contrast, the first tube adhesive layer 15 is a ceramic adhesive that does not contain sand. Therefore, the second tube adhesive layer 20 differs from the first tube adhesive layer 15 with respect to its material composition.In the given embodiment, the first pipe adhesive layer 15 and the second pipe adhesive layer 20 both have magnesium oxide grains.

[0061] Fig. Figure 7 shows another embodiment of the tubular cable shield 9, which now has the single shielding tube, which is a ceramic tube. This tubular cable shield is applied to the embodiment according to the following Fig. 8 applied.

[0062] Fig. Figure 8 shows a perspective sectional view through one embodiment. As can be seen, a sensor housing 3 is shown. The temperature measuring sensor 7, in this embodiment an electrical junction, is provided by connecting a further pair of conductors 8a, 8b to each other at their respective end sections. Here, the connection was made by spot welding. The further pair of conductors 8a, 8b consists of a constantan conductor 8a and a copper conductor 8b. Tube segments 9b to 9g of the tubular conductor shield 9, each tube segment having two passageways that accommodate one of the conductors 8a, 8b of the further pair of conductors, are part of the tubular conductor shield 9. The further pair of conductors 8a, 8b is electrically connected to the conductor pair 6a, 6b of the connecting cable 5 outside the tubular conductor shield 9.

[0063] The further segment 9a has a cavity 10 that accommodates the temperature measuring sensor 7. The remaining interior of the round cylindrical sensor housing 3 is filled with a ceramic adhesive. In some embodiments, as shown above, the tube segments 9a to 9g can be of the sandwich type, thus having two or more shielding tubes arranged coaxially to each other and fixed to one another by means of an adhesive layer on adjacent shielding tubes.

[0064] Fig. Figure 9 now shows a preferred way of connecting the further conductors 8a, 8b to the corresponding conductors 6a, 6b of the connecting cable 5. Fig. Figure 9 describes a B-type connection head unit. The connection head unit comprises a unit body 21 and a unit cover 22, which together form a terminal housing. The unit cover 22 is designed to be screwed onto the unit body 21 to enclose the interior of the terminal housing. The terminal housing has two screw terminals 23a and 23b, which electrically connect the two conductors of the additional conductor pair to the corresponding conductors 6a and 6b of the connecting cable 5.

[0065] As in Fig. As shown in more detail in Figure 10, each screw terminal 23a, 23b has two screw sockets 24a, 24b and 25a, 25b, respectively. A further conductor 8a, 8b of the conductor arrangement is arranged in one of the screw sockets, while a corresponding conductor 6a, 6b of the connecting cable 5 is arranged in the other screw socket (not shown in Figure 10). Fig. (9 shown). Tightening the corresponding screws of the screw terminals 23a, 23b creates the respective electrical connection between the wires 8a, 8b and the conductors 6a and 6b. This allows for easy replacement of the other wires 8a, 8b of the wiring assembly or the connecting cable 5, since the screw terminals 23a, 23b provide detachable connections. Furthermore, the screw connection is less likely to break due to vibration, unlike, for example, permanent connections such as spot welding.

[0066] To further improve stability, each conductor 8a, 8b is supported on a surface within the terminal housing. More precisely, each additional conductor 8a, 8b is supported on a corresponding side wall surface 26a, 26b of the corresponding screw terminal 23, 23b. The terminal housing also includes a terminal base plate 27. The terminal base plate supports the two screw terminals 23a, 23b. The terminal base plate 27 can also support the conductors 8a, 8b on a surface of the base plate 27. Since the additional conductors 8a, 8b are well supported on one or more surfaces within the terminal housing, vibrations are less likely to interrupt the additional conductors 8a, 8b. Two fastening screws 28a, 28b are provided to fix the terminal base plate 27 to the unit body 21.This can provide a more stable fastening in the event of vibrations than, for example, an adhesive fixing, which can break. Furthermore, this is a comparatively cost-effective solution for fixing the terminal base plate 27 to the unit housing 21. The terminal housing also has a cable guide 29 for mechanically fastening the connecting cable 5 to the terminal housing. Additionally or alternatively, for supporting the other conductors 8a, 8b within the terminal housing, the conductors 6a, 6b can be supported within the terminal housing in the same manner.

[0067] Finally, it shows Fig.Figure 11 shows a different perspective sectional view of the sensor head 2 of the type B connection head unit, which includes the connection housing. As can be clearly seen, the additional lines 8a, 8b are electrically connected to the corresponding conductors 6a, 6b of the connection cable 5 outside the tubular cable shield 9. The screw terminals 23a, 23b replace welded connections for connecting the additional lines 8a, 8b to the corresponding conductors 6a, 6b of the connection cable 5.

[0068] As can be seen from the above, the assembly method, as claimed, results in an exhaust gas temperature sensor 1 with good structural stability.

[0069] Good stability is achieved by using thermocouple leads as conductors 6a, 6b in some embodiments. Thus, there are no transitions or welds for establishing the electrical connection, except for the electrical junction itself. The connecting cable is stripped, and conductors 6a, 6b are used up to the temperature sensor 7, passing through the tubular shield 9. Only the tips of conductors 6a, 6b are welded to form the electrical junction, also known as the hot junction or measuring point. In other embodiments, particularly where an RTD element is used, additional leads 8a, 8b, 11a, 11b pass through the tubular shield 9 and are connected to conductors 6a, 6b outside the shield 9.Alternatively, conductors 6a, 6b are routed through the tubular shielding 9 and connected to the other conductors 8a, 8b, 11a, 11b of the RTD element outside the tubular shielding 9. Since these connections are located outside the unfavorable environment of the tubular shielding 9, the stability of the connections is good. The stability is further improved by using two or more coaxially arranged shielding tubes bonded together, instead of a single shielding tube.

[0070] Thus, the present invention provides a tubular conductor shield 9 and an exhaust gas temperature sensor arrangement 1 with good stability, particularly in situations where vibrations occur that could cause the temperature measuring arrangement to fail over time. Therefore, reliable temperature measurements up to 1000°C are possible, preferably temperature measurements in the range between 650°C and 750°C. This can be useful in vehicles, preferably ships or cars, especially diesel-powered vehicles.

Claims

[1] Tubular cable shield (9) for an exhaust gas temperature sensor arrangement (1), wherein the tubular cable shield (9) comprises a first shielding tube (13), the first shielding tube (13) having one or more through-channels for receiving one or more cables (6a, 6b, 8a, 8b, 11a, 11b) and / or for receiving one or more temperature measuring sensors (7), the tubular cable shield (9) further comprising a second shielding tube (14) radially surrounding the first shielding tube (13), the tubular cable shield (9) comprising a first tube adhesive layer (15) arranged between the first shielding tube (13) and the second shielding tube (14), the first tube adhesive layer (15) fixing the first shielding tube (13) to the second shielding tube (14), characterized by, that the tubular conductor shield (9) has a third shielding tube (19) radially surrounding the second shielding tube (14), wherein the tubular conductor shield (9) has a second tube adhesive layer (20) arranged between the second shielding tube (14) and the third shielding tube (19), wherein the second tube adhesive layer (20) fixes the second shielding tube (14) to the third shielding tube (19). [2] Tubular cable shielding (9) according to claim 1, characterized by , that the first pipe adhesive layer (15) has a ceramic adhesive. [3] Tubular cable shielding (9) according to claim 1, characterized by , that the second shielding tube (14) and / or the third shielding tube (19) is a steel tube, wherein the first shielding tube (13) is a ceramic tube. [4] Tubular conductor shielding (9) according to claim 1 or claim 3, characterized by, that the second pipe adhesive layer (20) differs from the first pipe adhesive layer (15) with regard to the material composition. [5] Tubular cable shielding (9) according to one of claims 1 to 4, characterized by , that the tubular conductor shield (9) has a tube segment (9a-9h) which has a cavity (10) for receiving one or more temperature measuring sensors (7), preferably an RTD element. [6] Exhaust gas temperature sensor arrangement (1) with a tubular line shield (9) according to one of claims 1 to 5. [7] Exhaust gas temperature sensor arrangement (1), wherein the exhaust gas temperature sensor arrangement (1) comprises one or more temperature measuring sensors (7), a connecting cable (5), a conductor arrangement arranged to electrically connect the one or more temperature measuring sensors (7) via the connecting cable (5), the conductor arrangement comprising one or more conductor pairs including a conductor pair (6a, 6b) of the connecting cable (5), and one or more tubular conductor shields (9) according to any one of claims 1 to 5, wherein each tubular conductor shield (9) radially surrounds at least one conductor (8a, 8b) of the conductor arrangement by providing a passage channel that accommodates the at least one conductor (6a, 6b, 8a, 8b, 11a, 11b), wherein at least one temperature measuring sensor (7) is an RTD element, at least one conductor (6a, 6b, 8a, 8b, 11a, 11b) of the conductor arrangement contacting the RTD element is electrically connected to the RTD element outside the through-channel formed by the tubular conductor shield (9) and accommodating the conductor (6a, 6b, 8a, 8b, 11a, 11b) and / or accommodating the RTD element; and / or wherein at least one temperature sensor (7) is an electrical junction, wherein the electrical connection from the electrical junction to the conductor pair (6a, 6b) has fewer than two welded joints. [8] Exhaust gas temperature sensor arrangement (1) according to claim 7, characterized by , that the temperature measuring sensor (7) is electrically connected to at least one of the conductors (6a, 6b) by a screw connection which is located outside the passage channel. [9] Exhaust gas temperature sensor arrangement (1) according to claim 8, characterized by, that the exhaust gas temperature sensor arrangement (1) has a connection housing, wherein the connection housing has at least one screw connection (23a, 23b) which electrically connects the temperature measuring sensor (7) to a corresponding conductor (6a, 6b) of the connecting cable (5). [10] Exhaust gas temperature sensor arrangement (1) according to claim 9, characterized by , that at least one conductor (6a, 6b, 8a, 8b, 11a, 11b) of the conductor arrangement is supported on a surface (26a, 26b) which is located inside the terminal housing. [11] Exhaust gas temperature sensor arrangement (1) according to any one of claims 6 to 10, characterized by , that at least one temperature measuring sensor (7) is an RTD element and the RTD element is arranged between conductors of the conductor arrangement which electrically connect the RTD element via the connecting cable (5). [12] Exhaust gas temperature sensor arrangement (1) according to one of claims 6 to 11, characterized by, that the tubular conduit shield (9) has two or more tubular segments (9a-9g) of the same outer diameter, each of the tubular segments (9a-9g) radially surrounding a different section of the at least one conduit (6a, 6b, 8a, 8b, 11a, 11b) of the conduit arrangement.

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