The present disclosure relates to sensors and, more specifically, to temperature sensor assemblies having one or more temperature sensors and the method of manufacturing such temperature sensor assemblies.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Sensors are used in a wide variety of operational environments to monitor operating and environmental characteristics. These sensors can include temperature, pressure, velocity, position, motion, current, voltage, and impedance sensors, by way of example. They are placed in or associated with the operational environment being monitored and are designed for generating an electrical signal or having an electrical characteristic such as an impedance, voltage or current that varies in response to the changes in values as the monitored operating or environment characteristic changes.
Temperature sensing probes include numerous components, such as, for example, a temperature sensing element, various wiring, resistors, diodes, and switches, among others. Generally, the temperature sensing probe is subjected to harsh environments that easily can damage the components of the temperature sensing probe. Furthermore, the temperature sensing probe is subject to mechanical stress due to vibration from surrounding machinery. To reduce the potential for damage to the probe from environmental and mechanical stress, various packaging schemes have been implemented to protect the measuring circuitry of the probe. However, such packaging schemes and the methods that are used for manufacturing often result in premature failure or a reduction in performance of the temperature sensing probe.
The present disclosure generally includes temperature sensor assemblies and methods of manufacturing temperature sensor assemblies that are capable of improved performance in harsh temperature sensing environments and that are cost effective to manufacture.
According to one aspect, a temperature sensor assembly including a temperature probe, a mounting connector, a wire set, a transition component, a housing and a circuit, the temperature probe includes a probe body, a temperature sensor and at least one conductor configured for providing a temperature signal indicative of a temperature over the at least one conductor, the mounting connector is adapted for securing the probe body to a mounting assembly, the wire set having at least one wire corresponding to each of the at least one conductors, each wire having a first end and a second end, the transition component adapted for coupling each of the at least one conductors to a first end of the at least one wire of the wire set, the housing having an input for receiving a second end of the wires of the wire set and an output for coupling to a temperature measurement system and providing a temperature characteristic, and the a circuit enclosed within the housing and configured for receiving the temperature signal from the temperature probe and generating the temperature characteristic in response to the received temperature signal.
According to another aspect, a temperature sensor assembly including a first temperature sensor probe, a second temperature sensor probe, and an adaptor circuit assembly, the first sensor probe having a first temperature sensor and one or more first conductors coupled to the first temperature sensor and configured for providing a first temperature signal indicative of a first temperature; the second sensor probe having a second temperature sensor and one or more second conductors coupled to the second temperature sensor and configured for providing a second temperature signal indicative of a second temperature, and the adaptor circuit assembly fixedly coupled directly to one or more of the conductors of the first temperature sensor probe and one or more of the conductors of the second temperature sensor probe and having a first input for receiving the first temperature signal and a second input for receiving the second temperature signal, and an output for coupling to a temperature measurement system and providing a first temperature characteristic and a second temperature characteristic, and a circuit configured for receiving the first temperature signal and generating the first temperature characteristic in response to the first temperature signal and receiving the second temperature signal and generating the second temperature characteristic in response to the second temperature signal.
According to yet another aspect, a method for manufacturing a thermocouple sensor assembly includes attaching a first wire to a first end of a first conductor, attaching a second wire to a first end of a second conductor, placing a grommet having a first channel over the attachment of the first wire to the first conductor and having a second channel over the attachment of the second wire to the second conductor, placing a transition body over the first and second conductors and about the grommet for securing the grommet and attachments within a cavity of the transition body, joining a first end of the first conductor to a first end of the second conductor to form a thermocouple junction at a second end of the conductors, attaching the transition body to a second end of the probe body, positioning a mounting connector about the outer surface of the probe body between the first end and the second end of the probe body, attaching a collar to an intermediate outer surface of the probe body between the first end of the probe body and the mounting connector, attaching a second end of the first wire to a circuit board, and attaching a second end of the second wire to the circuit board.
According to still another aspect, a method for manufacturing a thermocouple sensor assembly includes stripping a first end of a mineral insulated cable to expose a first conductor and a second conductor, forming a thermocouple junction at a second end of the mineral insulated cable, attaching a collar about an intermediate portion of the probe body, enclosing the second end of the probe body, positioning a mounting connector about an outer surface of the probe body between the first end of the probe body and the collar, placing a transition body over the first end of the probe body, attaching a first wire to the exposed first conductor and the second wire to the exposed second conductor, placing a grommet having a first channel over the attachment of the first wire to the first conductor and having a second channel over the attachment of the second wire to the second conductor, attaching the transition body in a position proximate to the first end of the probe body with the transition body substantially covering the grommet, attaching a second end of the first wire to a circuit board, and attaching a second end of the second wire to the circuit board.
Further aspects of the present disclosure will be in part apparent and in part pointed out below. It should be understood that various aspects of the disclosure may be implemented individually or in combination with one another. It should also be understood that the detailed description and drawings, while indicating certain exemplary embodiments, are intended for purposes of illustration only and should not be construed as limiting the scope of the disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
The following description is merely exemplary in nature and is not intended to limit the present disclosure or the disclosure's applications or uses.
Referring to
A housing 28 receives the lead wires 26 and includes an output portion 30 for coupling to a temperature measurement system and providing a temperature characteristic. A circuit assembly (not shown) is enclosed within the housing 28 and is configured for receiving the temperature signal from the temperature probe 12 and generating a temperature characteristic in response to the received temperature signal.
The temperature probe 12 can include a mineral insulated (MI) cable 16 having one or more conductors contained therein or can be a conductor surrounded by a conductor such as a compressed powder. The MI cable can include one or two resistance heating elements or conductors embedded in highly compressed magnesium oxide covered by a copper or an Alloy 825 stainless steel sheath, by way of example. The specification of the MI cable 16 is based, at least in part, on the application requirements and associated conductivity, resistance and sheath material.
The mounting connector 18 is adapted for securing the temperature probe 12 to a mounting assembly in an operating environment. Such an arrangement can be as simple as a hanger or can include a nut, flange, rotatable connector, or other device. For example, in some embodiments, the mounting connector 18 includes a sealing ring or collar 20 for placing the temperature sensor within a temperature sensing environment that is then sealed by the mounting connector 18. In one embodiment, the mounting connector 18 can be a powder metal high strength nut (in the form of a hex nut or other geometry). In such embodiments, the power metal nut can provide for cost effectively securing the temperature probe 12 in a hostile or enclosed environment, such as within an engine, power plant, fluid flow, or chemical process, by way of example.
The lead wires 24 include one or more wires that correspond to one or more of the conductors within the temperature probe 12. Each lead wire 24 includes a first end 32 and a second end 34 and can be stranded or solid wires, among others. The transition component 22 is adapted for coupling or aiding in the coupling each of the conductors to an end of lead wire 24, as described in greater detail below.
The housing 38 also includes an input portion 32 for receiving an end of the lead wires 24, and the output portion 30 couples to a temperature measurement system and provides one or more temperature characteristics. A circuit assembly (not shown) is enclosed within the housing 38 and is configured for receiving the temperature signal from one or more temperature probes 12 (and/or temperature sensors) and generating temperature characteristics in response to the received temperature signals.
The temperature sensor can be any type of sensor including a thermocouple, a thermistor, or resistance temperature detector. In one example, the sensor is a thermocouple that can be formed by coupling the conductors (ungrounded thermocouple) or coupling to the probe body (grounded thermocouple). The temperature signal typically can include a voltage level generated by the thermocouple. In such an example embodiment, a cold junction compensation circuit can be implemented within the probe assembly or within the circuit or housing 28. The generated temperature characteristic can be any characteristic desired and practical for providing information as a function of the temperature signal and as required or desired by the application. For instance, this can include a resistance value, a frequency, a digital pulse stream, a current, an impedance, or a voltage.
The circuit assembly receives the one or more temperature signals from one or more sensors and/or temperature probes 12 and can generate an output signal or characteristic in response to the signals. These output characteristics can include a ratiometric analog voltage signal (RAVS), a pulse width modulated signal, a variable frequency signal, a variable output impedance, a variable voltage signal, and a variable current signal, by way of example.
In some embodiments, the circuit assembly can be configured for generating a digital signal including the temperature characteristic, wherein the circuit and the housing are each adapted for coupling to an connected component, network, instrument or controller, such as an engine control module. For example, they can be adapted for communication over any well known digital or analog communication facility including a wired or wireless connection. Additionally, by way of example but not intended to be limited thereto, this can include communication protocols such as a controller area network (CAN). CAN is just one example of a well known and widely used communication protocol that can be implemented by the circuit and the housing. Additionally, proprietary interfaces and communications protocols can also be implemented. The circuit assembly and further details of the housing are described in greater detail in copending application titled “Sensor Adaptor Circuit Housing Assembly and Method of Manufacturing Thereof,” filed concurrently herewith on Jun. 22, 2007, which is commonly assigned with the present application and the contents of which are incorporated herein by reference in their entirety.
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i illustrates the assembly of
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In other embodiments, the method can include attaching a cover to the transition body and enclosing a portion of the first and second wires within the cover between the transition body to the housing. In yet other embodiments, the method can include bending an intermediate portion of the probe body between the transition body and the mounting connector to form about an angle such as a 90 degree angle.
The method can also include connecting the first wire and the second wire to a circuit enclosed within a housing assembly having an input for receiving a second end of the wires, said circuit configured for receiving a temperature signal from the thermocouple and generating the temperature characteristic in response to the received temperature signal; and connecting an output of the circuit to an output pin of the housing assembly configured for providing the generated temperature characteristic to a temperature measurement system coupled to the output pin.
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The wires can also be directly attached to the exposed conductors. In some embodiments, connectors can be mechanically (such as by crimping) and, in some embodiments, welded to the ends of the conductors and then again to the ends of the lead wires as shown in
A grommet having one or more channels is placed over the attachments of the wires to the conductors as in
Additionally, as described in the example above with regard to
As known to those skilled in the art, each of the processes described herein can be repeated to produce one or more probes. After such probes are manufactured, one or more, for example, two probes can be connected to a common circuit for receiving a plurality of temperature signals. In such embodiments, the sensor adaptor circuit can be configured for generating and providing one or more temperature characteristics at the output. Each temperature characteristic can be based on one or more of the temperature signals depending on the desired application and operational environment for the temperature sensor assembly.
Various benefits are provided by one or more embodiments of the temperature sensor assemblies and methods of manufacturing such temperature sensor assemblies as generally described in this disclosure. One or more of these embodiments can provide for a high compaction construction, an assembly that is high vibration and shock resistance and therefore provides a longer useful life. The temperature sensor assemblies described herein are capable of use in a wide variety of temperature applications including temperature of flames and temperatures of greater than 900 degree Celsius and have been shown to perform well up to temperatures of 1200 degree Celsius through the use of Alloy 600 in the construction. The design and method of construction provides for utilizing either a moderate duty lead wire or up to an extra heavy duty lead wire which is the source of many faults and failures for temperature sensor assemblies. Similarly, the assemblies of the present disclosure can be utilized in a wide variety of temperature sensing applications including low temperature applications such as coolant, brake fluid, inlet air, sea water, and oil temperature.
In some embodiments more than one temperature probe 12 can be included in the temperature sensor assembly 10 or more than one temperature sensor can be included in one or more temperature probes 12. In such cases, one or more of the temperature probes 12 or sensors can provide separate temperature signals to the circuit associated with one or more measured or sensed temperatures. In one such embodiment, the assembly includes a second wire set having at least one wire corresponding to each of the at least one second conductors, and a second transition component for coupling each of the at least one second conductors to at least one of the wires of the second wire set. In these cases, the housing 28 will include a second input for receiving the second wire set. The circuit is adapted to receive the second temperature signals and generating a second temperature characteristic indicative of the temperature about the exterior of the second temperature probe.
In one embodiment, the temperature probe 12 is assembled from a mineral insulated cable having conductors, a metal body, and insulating material. In other embodiments, the temperature probe 12 can be manufactured to include the conductors and the body. In some embodiments, a collar is positioned about an exterior surface of the probe body and adapted for engaging the fitting to secure the temperature probe to the mounting assembly. The collar is attached, such as by welding, to the exterior surface of the probe body. The collar can be attached to the exterior surface of the probe body by an known or future method including laser welding, spin welding, electronic beam welding, resistance welding, and ultrasonic welding, by way of example.
In some embodiments, the transition component 22 includes a grommet and a transition body. The grommet can include one or more internal cavities each dimensioned for receiving an end of one of the at least one conductors and for receiving an end of at least one of the at least one wire of the wire set, and the transition body having a cavity substantially enclosing the grommet and being welded to the probe body. Each of the internal cavities of the grommet can also be configured to include a first portion and a second portion coupled and positioned in series with the first portion. The second portion can have a cavity width greater than or less than a cavity width of the first portion.
In some embodiments, the conductors are directly connected to the wires by welding or soldering or other known forms of directly connecting conductors. In other embodiments, an electrical connector is utilized to couple the conductors to the wires. For example, one electrical connector can include a first end compressively engaging the one conductor and/or a second end compressively engaging the one wire. This can be a crimp compression engagement or similar coupling. In such cases, the electrical connector can be positioned within one of the internal cavities of the grommet, when provided. In some embodiment, the compressive engagement can be supplemented with a welding or soldering. In such cases, the electrical connector is preferably composed of a weldable material, such as an alloy 42 material, by way of example.
In some embodiments, the probe body is formed from a metal tube. This can aid in the manufacturing process and help reduce costs. In such embodiments, one end of the metal tube can be closed about the temperature sensor by crimping, welding, roll forming and/or swaging an end of the metal tube. In other embodiments, a tip cap or disc can be positioned proximate the end of the metal tube including the temperature sensor, and can be welded, brazed, or otherwise bonded to the end of the metal tube to close the end of the metal tube and to seal it for temperature sensing applications.
As noted above, the probe body can be formed, bent or otherwise arranged for mounting on the desired temperature sensing application. For example, the probe body can be bent or formed to have any required angle, and as shown in the examples of some of the figures, has an intermediate portion having an angled portion positioning the first end of the probe body at about 90 degrees from the second end of the probe body.
In some embodiments, a cover covering all or a portion of the wire set from the transition portion or probe to the housing input can be provided to provide an aesthetic or practical benefit to the temperature sensor assembly. For example, in some cases the temperature sensor assembly may be placed in a high heat environment where it may be desirable for the cover to be adapted with heat shielding or deflecting material. In other embodiments, it may be desired to protect the leads due to moving parts or a likelihood that the leads may be snagged or pulled in the operating environment.
Each of the sensor probes can include a wire set having one or more wires and a transition component coupled to an end of the probe body. A grommet having one or more channels adapted for receiving one or more of the conductors and one or more of the wires provides, at least in part, a transition between the probe assembly and the wire set. The grommet can also be configured to enclose the coupling of each wire to each conductors.
In some embodiments, each sensor probe can include a collar attached to the exterior of the probe body and a connector rotatably coupled to the probe body that is configured to engage the first collar and to secure the temperature probe to a first mounting assembly within the operating environment.
In some embodiments, the leads from the sensor probes are directly connected to the adaptor circuit assembly such that the assembly is an integrated unit, e.g., the probes are not unpluggable. In such embodiments, the first lead is fixedly coupled to the circuit and the second lead is fixedly coupled to the circuit. Such fixedly coupling preferably includes a coupling mechanism that does not enable the unplugging or otherwise detachment of the wire from the adaptor circuit or adaptor circuit housing.
The adaptor circuit assembly includes a housing that can be assembled from two or more portions, can be integrated portions, or can be an integrated or unitary body. In some cases, the wire leads can be retained by the housing itself such as an integral portion of the molded assembly.
When describing elements or features and/or embodiments thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements or features. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements or features beyond those specifically described.
Those skilled in the art will recognize that various changes can be made to the exemplary embodiments and implementations described above without departing from the scope of the disclosure. Accordingly, all matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.
It is further to be understood that the processes or steps described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated. It is also to be understood that each process or step can be repeated more than once and that additional or alternative processes or steps may be employed and still be within the scope of the present disclosure.
This application claims the benefit of U.S. Provisional Application No. 60/815,620, filed on Jun. 22, 2006. The disclosure of the above provisional application is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60815620 | Jun 2006 | US |