JP4800222B2 - Method and apparatus for magnetizing an object - Google Patents

Description

  The present invention relates to a method and apparatus for magnetizing an object, a method and apparatus for calibrating a force and torque detection device, the use of an apparatus for magnetizing an object in a particular technical field, and a specific The invention relates to the use of a device for calibrating force and torque detection devices in the technical field.

  Magnetic transducer technology has been applied to torque and position measurements. It was specifically developed for non-contact measurement of torque on the shaft and any other part that receives torque or follows linear motion. Components that rotate or reciprocate, or that receive axial loads or shear forces, are provided with magnetized regions, ie magnetically encoded regions, and the shaft rotates or reciprocates. Sometimes such magnetically encoded regions generate signals characteristic of a magnetic field detector (such as a magnetic coil) that can determine the torque, force or position of the shaft.

For example, in such a sensor disclosed in Patent Document 1, it is important to have a precisely defined magnetic encoding region that can be manufactured and calibrated at low cost.
International Publication No. 02/063262 Pamphlet

  It is an object of the present invention to provide a detection device having a magnetically encoded region, which can be manufactured and operated at low cost.

  This object is in accordance with the independent claims a method and apparatus for magnetizing an object, a method and apparatus for calibrating a force and torque detection device, and the use of an apparatus for magnetizing an object in a particular technical field. And the use of a device for calibrating force and torque detection devices in a particular technical field.

  According to an embodiment of the present invention, a method for magnetizing a first object or a second object or a first and a second object is provided, wherein the method is such that the first object surrounds the second object. And applying a first electrical signal to the second object, wherein the first electrical signal magnetizes at least a portion of the first object or the second object or the first and second objects. Configured to be

  According to another embodiment of the present invention, an apparatus for magnetizing a first object or a second object or first and second objects is provided. The apparatus includes a first object, a second object, and an electrical signal source. The first object is arranged such that the first object surrounds the second object. The electrical signal source is configured to apply a first electrical signal to the second object, where the first electrical signal magnetizes at least a portion of the first object or the second object or the first and second objects.

  According to yet another embodiment of the present invention, a method for calibrating a force and torque detection device is provided, the method comprising a magnetically encoded region on an object and a force or torque applied to the object. Resulting from the steps of placing a force and torque detector having a magnetic field detector configured to detect a signal resulting from, applying a known force to the object, and the known force applied to the object Detecting a signal and calibrating the force and torque detector based on a correlation between the known force and the detected signal resulting from the known force.

  Furthermore, in accordance with another embodiment of the present invention, an apparatus for calibrating a force and torque detection device is provided, the device comprising a force and torque detection device, a known force generating element and a calibration. Includes units. The force and torque detection device includes a magnetically encoded region on the object and a magnetic field detector configured to detect a signal resulting from the force or torque applied to the object. The element that generates the known force is configured to apply a known force to the object, and the calibration unit is configured to determine the force based on the correlation between the known force and the detection signal resulting from the known force. And calibrating the torque detection device.

  According to another embodiment of the present invention, an apparatus having the above-described features is used to magnetize one in a group consisting of a mining shaft, a concrete processing cylinder, a push-pull rod in a gear box, and an engine shaft. .

  Further, according to another embodiment of the present invention, an apparatus having the above-described features calibrates a group force and torque detection apparatus consisting of a mining shaft, a concrete processing cylinder, a push-pull rod in a gear box, and an engine shaft. Used for.

  In the present specification, the expression “magnetization” refers in particular to a microscopic magnet or elemental magnet, that is, a magnetic moment, magnetic particle or magnetic domain existing in a magnetizable material, at least a part of which is specified. Means that the random magnetic field orientation is processed to be at least partially removed.

  A method for magnetizing a first object, and an apparatus for magnetizing a first object according to the exemplary embodiments described above, includes applying an electrical signal to a second object surrounded by a first object. Has the advantage of being magnetized. For example, a wire, shaft or rod as the second element is surrounded by a hollow cylinder as the first object. Then, by applying an appropriate electrical signal to the second object, a magnetized region can be generated in the first object by a physical effect similar to the physical effect that occurs in the case of a transformer. In other words, a time-dependent electrical signal, such as a current pulse, flowing through the second object generates a magnetic field that affects the magnetizable material of the first object so that the first object is magnetized. The magnetization method of the present invention enables inexpensive and easy magnetization even for a large hollow cylinder, particularly as conceived in the field of mining and drilling equipment. Thus, the magnetically encoded region can be formed in an existing industrial steel hollow cylinder or tube. This allows, for example, magnetically encoded regions in existing magnetizable objects such as drilling shafts to be magnetized with torque, bending forces and axial loads applied to such objects. It can be detected by a simple magnetic field detector such as a coil placed near the object.

  According to the described embodiment, in particular the outer first object is magnetized. However, when the inner second object is made of a magnetizable material, the second object is magnetized at the same time.

  Another advantage associated with a method and apparatus for magnetizing a second object according to an exemplary embodiment of the present invention includes selected locations, such as at the end of the first object and the end of the second object. In some cases, the first object is connected to the second object in a timely manner. With such a configuration, the current flowing through the second object is also injected into the first object there to form a magnetic field in the opposite direction, thereby stabilizing the current distribution in the object. Accordingly, a high quality magnetically encoded region is formed in the second object, resulting in a sensor with better reproducibility and higher reliability.

  According to the described embodiment, in particular the inner second object is magnetized. However, if the outer first object is made of a similarly magnetizable material, the first object is magnetized simultaneously.

  Next, a method and apparatus for calibrating a force and torque detection device will be described. One concept of this calibration method is to simply create one known calibration force, eg, a known mass or weight, by a magnetically encoded region (eg, the method of the present invention for magnetizing an object). Be added to objects with Such weight or gravity applied to the torque and force sensor produces a magnetic signal that is detected by a magnetic field detector located in the vicinity of the magnetically encoded region. Therefore, a data pair having a correlation between the applied force and the detection signal obtained by the magnetic field detector is stored. The magnetically encoded region can be encoded, for example, according to the method described above for magnetizing an object, the technique described in the above-mentioned patent document 1, or the so-called PCME technique described in detail below. .

  The correlation between the axial load thus measured and the detection signal of the magnetic field detector can then be used for sensor calibration. When such a calibrated object is actually used (eg, as a drilling shaft), the measured detection signal corresponds using a calibration data pair estimated using a known mass. It can be related to the force of the axial load. It is also possible during calibration to measure a plurality of calibration data pairs in order to refine the calibration.

  In addition, a known axial load and corresponding data pair of detection signals also serve as calibration information, which is used in conjunction with sensors that receive applied torque during actual use. In other words, the calibration of the axial load calibrates the torque sensor. This aspect is particularly advantageous in applications using very heavy objects, for example in the case of drilling shafts in mining applications, useful for measuring the torque applied to such drilling shafts. In this case, it is very simple to simply place the drilling shaft, for example a tube, on a stable ground and place a known mass element on top of the drilling shaft. In contrast, it is very difficult to apply a calibration torque to such a drilling shaft to calibrate the torque sensor. It is easier to calibrate the torque sensor using the axial force for calibration.

  According to a further aspect of the invention, the method and apparatus described above are implemented with respect to a mining shaft, a concrete processing cylinder, a push-pull rod in a gearbox, and an engine shaft. In all these applications, such torque, force and position sensor magnetization and calibration are very advantageous. This is because force, position and torque sensors calibrated with high accuracy and reliability can be manufactured at low cost. In particular, the system of the present invention is provided in mining and drilling equipment and is used for monitoring the drilling direction and the drilling force. A further application of the present invention is the evaluation and analysis of engine knocking.

  Thus, the present invention enables real-time (real-time) measurement of actual mechanical force that is applied and validated during “operation” of large mining and drilling equipment. While harsh outdoor conditions and handling of abrasive materials are difficult to handle with conventional sensing technology, the system of the present invention can accommodate such conditions without any problems. The mechanical forces measured by the present invention are torque, bending, axial load and potential mining equipment overload.

  The magnetizing method of the present invention employs a unique power shaft encoding process and can take advantage of the magnetic properties of many types of industrial steel, thereby transforming a standard drilling shaft into a high precision force sensor. The actual time required to apply the encoding process is only a moment, and this time does not change. After the desired portion of the drilling shaft is processed in the process of the present invention, that portion of the shaft emits a specific signal related to the mechanical force applied to the shaft. This signal is detected, for example, by passive electrical components placed a few millimeters away from the shaft surface. Since there is no need to attach anything to the shaft and no need to touch the shaft at all, the mean time between failures is therefore very long (ie, the present invention provides a very reliable detection solution). The principle of measuring the non-contact mechanical force depends only on the excavation or the ferromagnetic characteristics of the power transmission shaft. It provides real-time information about all the mechanical forces transmitted through the shaft's encode portion, ie, rotational torque, bending force, shear force, and axial push-pull load. The total signal bandwidth of the force sensing technology is 29 kHz or about 100,000 measurement samples per second, according to an embodiment. Also, the drilling shaft is subject to mechanical overload and fails, generating a clear signal at such times.

  In large devices, the mechanical force is often not transmitted symmetrically or evenly distributed through the power shaft or drilling shaft. Thus, for example, the magnetic field detector “sees” some dangerous spots on the shaft to obtain a wider field of view. However, it is recommended to work with only one magnetic detection device in many cases, particularly in a device that operates in a stationary state (the shaft does not rotate).

  The sensor of the present invention can operate in water, in oil, or even in very dusty environments (such as concrete pumps and concrete mixing stations). The sensor can withstand a very wide temperature range, in particular from -50 ° C to + 210 ° C.

  The sensor signal detection unit is connected to a specially made dedicated electronic circuit several meters away from the magnetic field detector. Only two wires (“twisted pair”) are used to connect the magnetic field detector to the corresponding electronic circuit. The output signal of such an electronic circuit is a buffered analog + 5V signal, where + 2500V is equal to zero torque. In the case of torque, axial load or bending sensors, the total current consumption is less than 5 mA per sensor channel.

  The magnetic field detector can be placed outside or inside the magnetically encoded hollow shaft. Assuming that the mechanical force transmitted through such a shaft does not pass symmetrically through the magnetically encoded part, several high-resolution “force pictures” can be grasped. Magnetic field detectors can be installed in a geometric arrangement around the shaft.

  The encoding process for large drilling shafts has the need to transport heavy shafts to a specific factory site, and to eliminate this, the process can be performed “in the field”. The encoding device is portable / movable and can be used under almost all climatic conditions. In an ideal situation, the drilling shaft can itself be placed on the ground for the encoding process. However, in the right situation, the shaft is encoded while it is still in the drilling or mining equipment. This is particularly possible when the shaft is accessible and the shaft is not obscured. Such a movable, magnetizing and calibration unit can be brought very close to the drilling shaft.

  A feature of the sensing technique according to the invention is the way to calibrate a permanently encoded drilling shaft. In the case of a 1 m diameter drilling shaft capable of handling 1 million Nm of torque, it is usually difficult to apply the “beam and weight” method to calibrate the shaft torque sensor. The measurement performance of a magnetically encoded shaft, when placed straight on a horizontal, structurally stable surface, is compared depending on the behavior of the “permanent” embedded source. Within a short time. This is particularly advantageous when the excavator is inspected and maintained at a remote location and it is difficult to reach that location.

  The mechanical force sensing technique according to the present invention is implemented in a large oil drilling device to detect the direction in which the drilling head is moving and to measure the axial load (forward thrust) of the drilling pipe at the drilling head position. be able to. In this application, the entire sensor system is exposed to pressures exceeding 1,500 bar (150 million Pa) and temperatures exceeding 200 ° C. In another application, the sensing strategy is to measure the mechanical force applied to a large movable or moving crane. Here, the task of the magnetically encoded sensor is to prevent the crane from tipping over (falling down or tilting) when a critical load condition occurs. Other applications of the present invention include wind power generators, large extrusion devices, abrasive pump stations, and large industrial gearbox systems.

  It is stated that a second object (eg, a shaft) surrounded by a first object (eg, a hollow tube) can be magnetized by applying an electrical signal to the first object. This aspect relates to a method for magnetizing a second object, the method comprising positioning the first object such that the first object surrounds the second object, and applying an electrical signal to the first object. Applying, and configured to magnetize at least a portion of the second object by the electrical signal. This method is such that when the end of the second object is shorted outside the first object, for example, two such ends are electrically connected to each other by wires guided outside the first object. In some cases it works exceptionally well.

  Further embodiments of the invention will now be described with reference to the dependent claims.

  In the following, an exemplary embodiment of a method for magnetizing an object is described. However, for these embodiments, there is also an apparatus for magnetizing an object, a method and apparatus for calibrating a force and torque detection device, and the use of an apparatus for magnetizing an object in a particular technical field. As well as the use of a device for calibrating force and torque detection devices in a particular technical field.

  The first electrical signal is a first pulse signal or a series of continuous pulse signals. Such a pulse signal is in particular a signal that differs from zero only during a certain specified period.

  For example, in the time-to-current diagram, the first pulse signal has a fast rising edge that is essentially vertical and a slow falling edge. When such a pulse signal is used, the obtained magnetic encoding region has high quality. Also, a plurality of such pulses can be applied sequentially to form a magnetic encoding region.

  The second electrical signal is applied to the second object after applying the first electrical signal, and the second electrical signal is configured to magnetize at least the first object or the second object or a portion of both objects. . The second electrical signal is different from the first electrical signal with respect to at least one of the group consisting of amplitude, sign, signal waveform, and duration.

  According to this embodiment, two pulses are applied to the second object whose current flow directions are opposite.

  The second electrical signal is a second pulse signal or a series of continuous pulse signals that have an essentially vertical rising edge and a slow falling edge in the time-current diagram.

  According to an embodiment of the method of the invention, the first object is magnetized by applying a first electrical signal and a second electrical signal, but the surface of the first object or the second object or the first object and the second object. A magnetic field structure is generated in a direction essentially perpendicular to the surface of the object, producing a first magnetic flow (electromagnetic flow) in the first direction and a second magnetic flow in the second direction, The first direction is opposite to the second direction. The geometric direction of the magnetization of the two layers is due to two different pulses applied to the magnetizable material, thereby producing a sensor like PCME according to the technique described below.

  The second electrical signal is also a current or voltage.

  An exemplary embodiment of an apparatus for magnetizing an object will now be described. However, these embodiments also provide a method for magnetizing an object, a method and apparatus for calibrating a force and torque detection device, and the use and identification of a device for magnetizing an object in a particular technical field. Applied to the use of a device for calibrating force and torque detection devices in the technical field.

  The first object is a hollow tube. For example, a hollow cylinder or the like can be used for the first object surrounding the second object. This structure provides a very symmetric geometric structure and is easy to manufacture. However, the first object arranged as a hollow tube need not necessarily have a circular cross section, but can have a polygonal (eg, triangular or square) geometric cross section. Such a more asymmetrical arrangement can be used to improve the sensing characteristics.

  The second object is a wire or shaft or a hollow tube. Such a shaft or wire is arranged along the axis of symmetry of the first object, in particular along the axis of symmetry of the first object embodied as a hollow tube. In an embodiment in which the second object is a hollow tube, the radius of the hollow tube as the second object is smaller than the radius of the hollow tube as the first object, so that the second object is surrounded by the first object. . The second object arranged as a hollow tube does not necessarily have a circular cross section and can have a polygonal (eg, triangular or square) geometric cross section. Such a more asymmetrical arrangement can be used to improve the sensing characteristics.

  The second object is arranged at the center of the first object. In this configuration, a very symmetrical current and magnetic field distribution is achieved.

  The electrical signal source includes a capacitor bank. Such a capacitor bank comprises a plurality of capacitors (capacitors), which can generate a pulse signal with a very large current amplitude and a small time width as a whole, especially in the field of mining and drilling rigs. Generated to magnetize large objects that are recalled. Such a capacitor bank has a capacity of 0.5 F, for example. As another option for the capacitor bank, the electrical signal source or power source may comprise a normal power supply or power pack.

  The first object may have a first connection and may have a second connection, or the second object may have a first electrical connection and a second electrical connection. The second electrical connection of the first object is coupled to the first electrical connection of the second object. According to this embodiment, two objects are connected such that a portion of the first object (eg, one end) is coupled to a portion of the second object (eg, one end). With this arrangement, current flowing through the second object is injected into the first object, and a “feedback” of the magnetic field generating the current is achieved. With this feedback, a magnetic field in the opposite direction is generated in the first object, giving a very symmetrical arrangement with the current flowing through the second object, and an advantageous current distribution inside the object. Torque and force sensors with this type of magnetic encoding have very high signal-to-noise (S / N) ratios and small hysteresis.

  With respect to the previous embodiment, the electrical signal source is connected such that a first electrical signal can be applied between the first electrical connection of the first object and the second electrical connection of the second object. According to this circuit arrangement, the current is transferred from the first electrical connection of the first object to the second electrical connection of the first object, from there to the first electrical connection of the second object, and from there to the second object. To the second electrical connection.

  The first object can also have a third electrical connection, and the second object can have a third electrical connection.

  For this embodiment, the electrical signal source is connected such that a first electrical signal can be applied between the first electrical connection of the first object and the second electrical connection of the second object, and the second electrical signal A signal is connected such that it can be applied between the third electrical connection of the first object and the third electrical connection of the second object. With this configuration, a magnetizing current can flow from both ends of the first and second objects, and the first and second objects are electrically coupled to each other at their center.

  The apparatus may further comprise a conductive coupling element arranged to couple the second electrical connection of the first object to the first electrical connection of the second object. Such a conductive coupling element is a conductive plate, such as a metal plate, which is coupled to one end of a shaft as a second object and is coupled to one end face of a hollow tube as a first object. . However, the conductive coupling element may also be realized with a simple wire or the like. The conductive coupling element may also be realized with a conductive liquid, for example based on mercury.

  In addition to the first object, the second object can be configured to be magnetized when a first electrical signal is applied. In other words, according to the arrangement described above in which the first object is surrounded by the second object, both objects are magnetized and they can be used as magnetized objects of the torque or force sensor.

  The second object can include a first connection and a second connection, and the electrical signal source is connected between the first connection and the second connection of the second object. According to this circuit configuration, the electrical signal source is disconnected from the first object. In other words, this configuration can be thought of as a transformer-like arrangement, in which the first object surrounding the second object is magnetized without a direct ohmic contact between the two objects. In this connection, the magnetization of the first object is caused by an electrical signal propagating to the second object and is caused by aligning the element magnets in the material of the first object.

  According to one exemplary embodiment, a part of the second object is not surrounded by the first object, and further the device can include a shielding element. The shielding element is arranged and configured to electromagnetically shield a portion of the second object not surrounded by the first object from the first object. In this embodiment, the wiring of the second object to the electrical signal source also generates a magnetic field, i.e. weakens the magnetization generated by the part of the second object surrounded or surrounded by the first object, Considering the generation of a magnetic field that affects the first object. In order to avoid such undesired weakening and to achieve uniform and reproducible magnetization in the first object, the shielding element is a magnetic field generated by the wiring portion of the second object that is not covered by the first object Shield.

  Such a shielding element may be, for example, an object such as a tube, which is formed of a magnetizable material disposed between a first object and a portion of a second object that is not surrounded by the first object. There are also options. In this configuration, the shielding element creates some kind of magnetic “shadow” and magnetically decouples the first object from a portion of the second object not covered by the first object.

  The shielding element may also be a single tube (optionally formed of magnetizable material), which is arranged to surround a portion of the second object that is not surrounded by the first object. According to this embodiment, the shielding tube surrounds at least a portion of the portion of the second object that is not surrounded by the first object.

  As another option, the shielding element may be a plurality of tubes (optionally formed of magnetizable material) so that they surround at least a portion of the portion of the second object that is not surrounded by the first object. Be placed. Such a shielding tube may be arranged symmetrically around the part of the second object to be shielded.

  Next, an embodiment of an apparatus for calibrating a force and torque detection apparatus will be described. However, these embodiments also provide a method and apparatus for magnetizing an object, a method for calibrating a force and torque detector, and the use and identification of an apparatus for magnetizing an object in a particular technical field. Applies to the use of devices for calibrating force and torque detection devices in the technical field.

  In the calibration apparatus, a known weight can be used as an element that generates a known force. The known weight is, for example, 1000 kg, which is in the form of a hollow cylinder to be calibrated, just placed on top of the force and torque detection device and applied to the detection device in a constant and known axial direction. A load is formed, which enables high-precision calibration.

  Also, the element that generates the known force is configured to apply a known shear stress. By applying a shear stress, a pair of data values (force and magnetic signal resulting from it) can be obtained as a basis for calibration.

  Alternatively, the element generating the known force is configured to be a known torque, in particular a known reaction torque.

  The above and other features, objects, features and advantages of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings, in which like parts or elements are designated with like reference numerals.

First, a sensor having a sensor element such as a shaft is disclosed. The sensor element is manufactured according to the following manufacturing process. That is,
When applying the first current pulse to the sensor element
The first current pulse is applied so that the first current flows in a first direction along the longitudinal axis of the sensor element;
The first current pulse creates a magnetically encoded region in the sensor element by applying the current pulse.

  It is disclosed that yet another second current pulse may be applied to the sensor element. The second current pulse is applied so that the second current flows in a direction along the longitudinal axis of the sensor element.

  It is also disclosed that the directions of the first and second current pulses may be opposite to each other. Also, each of the first and second current pulses may have a rising edge and a falling edge. For example, the rising edge is steeper than the falling edge.

  Applying a current pulse results in a magnetic field structure in the sensor element, the structure having a first annular magnetic current having a first direction and a second magnetic field having a second direction in the cross-sectional view of the sensor element. Current is assumed to exist. The radius of the first magnetic flow may be larger than the radius of the second magnetic flow. In a shaft with a non-circular cross-section, the magnetic flow is not necessarily circular and basically has a shape that corresponds to and conforms to the cross-section of the respective sensor element.

  If no torque is applied to the sensor element, it is considered that there is no magnetic field that can be detected externally or that there is essentially no magnetic field. When torque or force is applied to the sensor element, a magnetic field is generated from the sensor element that can be detected by a suitable coil. This will now be described in more detail.

  The torque sensor has a circumferential surface that surrounds the core region of the sensor element. The first current pulse is introduced into the sensor element at a first position on the circumferential surface such that the first current flows in a first direction within the core region of the sensor element. The first current pulse is emitted from the sensor element at a second position on the circumferential surface. The second position is separated from the first position in the first direction. The second current pulse is introduced into the sensor element at or near the second position on the circumferential surface so that the second current flows in the second direction in or near the core area of the sensor element. May be. The second current pulse is emitted from the sensor element at or near the first position on the circumferential surface.

  As already mentioned, the sensor element may be a shaft. With respect to the core region of such a shaft, it may extend in the longitudinal direction and extend inside the shaft so that the core region surrounds the center of the shaft. The circumferential surface of the shaft is the outer surface of the shaft. The first and second positions are each in a circumferential region outside the shaft. There may be a limited number of contact portions that make up those regions. By way of example, the actual contact area is given, for example, by providing an electrode area made of a brass ring as an electrode. The conductor core may also be looped around the shaft to provide good electrical contact between the shaft and the conductor, such as an uninsulated cable.

  The first current pulse and the second current pulse are not applied to the sensor element at one end surface of the sensor element. The first current pulse can have a maximum value between 40 and 1400 amps, or 60 to 800 amps, or 75 to 600 amps, or 80 to 500 amps. The current pulse may have a maximum value so that proper encoding is made to the sensor element. However, because of the various materials used, the various shapes of the sensor elements and the various sizes of the sensor elements, the maximum value of the current pulse is adjusted according to these parameters. The second current pulse may have a similar maximum value, or may have a maximum value that is about 10, 20, 30, 40, or 50% less than the first maximum value. However, the second current pulse may also have a higher maximum value that is 10, 20, 40, 50, 60, or 80% higher than the first maximum value.

  The duration of these pulses may be the same. However, it is possible that the first pulse has a sufficiently longer duration than the second pulse. Alternatively, it is also possible that the second pulse has a longer duration than the first pulse.

  The first and / or second current pulse has a first duration from the start of the pulse to a maximum value and a second duration from the maximum value to essentially the end of the pulse. The first duration may be sufficiently longer than the second duration. For example, the first duration may be shorter than 300 ms and the second duration may be longer than 300 ms. It is also possible that the first duration is shorter than 200 ms and the second duration is longer than 400 ms. Also, the first duration may be between 20 ms and 150 ms, in which case the second duration may be between 180 ms and 700 ms.

  As described above, it is possible to add not only a plurality of first current pulses but also a plurality of second current pulses. The sensor element may be made of steel and the steel may contain nickel. The primary sensor, i.e. the sensor material used for the sensor element, is DIN 1.2721, or 1.4313, or 1.4542, or 1.2787, or 1.4034, or 1.4021, or 1.5752, or It may be 50NiCr13, or X4CrNi13-4, or X5CrNiCuNb16-4, or X20CrNi17-4, or X46Cr13, or X20Cr13, or 14NiCr14, or S155, as described in 1.6928.

  The first current pulse is applied by an electrode system having at least a first electrode and a second electrode. The first electrode is located at or near the first position, and the second electrode is located at or near the second position.

  Each of the first and second electrodes may have a plurality of electrode pins. In each of the first and second electrodes, a plurality of electrode pins are arranged circumferentially around the sensor element, wherein the sensor element is at a plurality of contact points on the outer circumferential surface of the shaft at the first and second positions. Contacted by the electrode pins of the first and second electrodes.

  As described above, a layered or two-dimensional electrode surface may be used instead of the electrode pin. For example, the electrode surface is applied to the surface of the shaft to ensure good contact between the electrode and the shaft material.

  At least one of the first current pulses and at least one of the second current pulses may be applied to the sensor element so that the sensor element has a magnetically encoded region and is fundamental to the surface of the sensor element. In the direction perpendicular to the magnetic field, the magnetically encoded region of the sensor element has a magnetic field structure such that the first magnetic current is in the first direction and the second magnetic current is in the second direction. The first direction is opposite to the second direction.

  In a cross-sectional view of the sensor element, a first circular magnetic flow having a first direction and a first radius is generated, and a second circular magnetic flow having a second direction and a second radius is generated. The first radius may be larger than the second radius.

  Further, the sensor element may have a first pinned zone near the first position and a second pinned zone near the second position.

  The pinned zone can be formed according to the following method. According to this method, in order to form the first pinned zone at or near the first position, the third current pulse is applied to the circumferential surface of the sensor element so that the third current flows in the second direction. Add to. This third current is emitted from the sensor element at a third position away from the first position in the second direction.

  Also, in order to form the second pinned zone at or near the second position, a fourth current pulse is applied to the sensor element at the circumferential surface so that the fourth current flows in the first direction. Also good. The fourth current is discharged at a fourth position away from the second position in the first direction.

  The torque sensor is provided including a first sensor element having a magnetically encoded region, the first sensor element having one surface. In a direction essentially perpendicular to the surface of the first sensor element, the magnetically encoded region of the first sensor element has a first magnetic current in the first direction and a second magnetic current in the second direction. It can have a magnetic field structure to be oriented. The first and second directions are opposite to each other.

  The torque sensor may further include a second sensor element using one or more magnetic field detectors. The second sensor element is configured to detect variations (variations) in the magnetically encoded region. More precisely, the second sensor element is configured to detect a change in the magnetic field emanating from the magnetically encoded region of the first sensor element.

  The magnetically encoded region extends longitudinally along a portion of the first sensor element, but does not extend from one end surface of the first sensor element to the other end surface of the first sensor element. In other words, the magnetically encoded region does not extend along all of the first sensor element, but extends only along a portion thereof.

  The first sensor element has a change in the material of the first sensor element, which changes the magnetically encoded region or generates the magnetically encoded region. Caused by at least one current pulse or surge current. Such material changes may be caused, for example, by different contact resistances between the electrode system applying the current pulse and the surface of each sensor element. Such a change is, for example, a burn mark, a color difference, or an annealing mark.

  The above change is on the outer surface of the sensor element and not on the end face of the first sensor element, because the current pulse is applied to the outer surface of the sensor element and not on its end face.

  The shaft for the magnetic sensor can have at least two circular magnetic loops running in opposite directions in its cross section. Such a shaft is manufactured according to the manufacturing method described above.

  Furthermore, the shaft is provided with at least two circular magnetic loops arranged concentrically.

  A shaft for the torque sensor is manufactured and provided according to the following manufacturing steps, first a first current pulse is applied to the shaft. The first current pulse is applied to the shaft such that the first current flows in a first direction along the longitudinal axis of the shaft. The first current pulse is applied such that applying the current pulse creates a magnetically encoded region in the shaft. This is done by using the electrode system described above and by applying the current pulse described above.

  An electrode system may be provided for applying a current surge to the sensor element for the torque sensor, the electrode system having at least a first electrode and a second electrode, the first electrode being a first on the outer surface of the sensor element. Installed in position. The second electrode is installed at a second position on the outer surface of the sensor element. The first and second electrodes are configured to apply and emit at least one current pulse at the first and second positions, whereby current flows in the core region of the sensor element. At least one current pulse creates a magnetically encoded region in a portion of the sensor element.

  The electrode system may include at least two groups of electrodes, each including a plurality of electrode pins. The electrode pin of each electrode is arranged on one circle, and the sensor element contacts the electrode pin of the electrode at a plurality of contact points on the outer surface of the sensor element.

  The outer surface of the sensor element does not include the end face of the sensor element.

  FIG. 1 shows one exemplary embodiment of a torque sensor according to the present invention. The torque sensor includes a first sensor element, i.e. shaft 2, having a rectangular cross section. The first sensor element 2 basically extends along the direction indicated by X. An encoded region 4 exists in the center of the first sensor element 2. The first position is indicated by reference numeral 10 and indicates one end of the encoded area, and the second position is indicated by reference numeral 12 and the other end of the encoding area, ie the area 4 to be magnetically encoded. Indicates. Arrows 14 and 16 indicate applying a current pulse. As shown in FIG. 1, the first current pulse is applied to the first sensor element 2 in the external region next to or near the first position 10. For example, as will be described in detail later, the current is applied to the first sensor element 2 at a plurality of points or regions near the first position and surrounding the outer surface of the first sensor element 2, for example, along the first position 10. To be introduced. As indicated by the arrow 16, the current pulse is emitted from the first sensor element 2, for example at a plurality of locations along the edge of the region 4 to be encoded, near or next to the second position 12 or in situ. . As described above, a plurality of current pulses may be sequentially applied with a direction alternately changing from the position 10 to the position 12 or from the position 12 to the position 10.

  Reference numeral 6 denotes a second sensor element, which is, for example, a coil connected to the control circuit 8. The control circuit 8 is configured to process the signal output by the second sensor element 6, and the output signal is output from the control circuit in response to the torque applied to the first sensor element 2. The control circuit 8 may be an analog or digital circuit. The second sensor element 6 is configured to detect a magnetic field emanating from the encoded region 4 of the first sensor element 2.

  As already mentioned, there is essentially no magnetic field detected by the second sensor element 6 if there is no stress or force applied to the first sensor element 2. However, when a stress or force is applied to the first sensor element 2, there is a change in the magnetic field emanating from the encoded region so that an increase in the magnetic field from a state where there is almost no magnetic field is detected by the second sensor element 6. become.

  According to another exemplary embodiment of the present invention, there is a magnetic field that can be detected outside or near the encoded region 4 of the first sensor element 2 even if there is no stress applied to the first sensor element. Note that it can. However, it should be noted that the stress applied to the first sensor element 2 causes a change in the magnetic field emanating from the encoded region 4.

  2a, 2b, 3a, 3b, and 4, a method for manufacturing a torque sensor according to one exemplary embodiment of the present invention will now be described. In particular, the method relates to the magnetization of the magnetically encoded region 4 of the first sensor element 2.

  As can be seen from FIG. 2a, a current I is applied to one end of the region 4 that is magnetically encoded. This end portion already described is indicated by reference numeral 10 and may be a circumferential portion of the outer surface of the first sensor element 2. The current I is emitted from the first sensor element 2 at the other end of the magnetically encoded region (ie the region to be magnetically encoded), which is indicated by reference numeral 12 Is called the second position. Current is drawn from the first sensor element on its outer surface, preferably in the circumferential direction in the region near or near position 12. As indicated by the dashed line between positions 10 and 12, the current I introduced to the first sensor element at or along position 10 flows to position 12 through or parallel to the core region. In other words, the current I flows through the region 4 to be encoded in the first sensor element 2.

  FIG. 2b shows a cross-sectional view along AA '. As a schematic representation of FIG. 2b, the current is shown in the plane of FIG. Here, the current is shown at the center of the cross section of the first sensor element 2. With the introduction of a current pulse having the shape described above or below and having the maximum value described above or below, it has a magnetic flow direction in one direction in the cross-sectional view, here in the clockwise direction. A magnetic flow structure 20 results. The magnetic flow structure 20 shown in FIG. 2b is basically drawn in a circle. However, the magnetic flow structure 20 matches the actual cross section of the first sensor element 2 and may be, for example, more elliptical.

  FIGS. 3a and 3b show the steps of the method according to one exemplary embodiment of the invention, which can be applied after the steps shown in FIGS. 2a and 2b. FIG. 3a shows a first sensor element according to one exemplary embodiment of the invention applying a second current pulse, and FIG. 3b shows a cross-sectional view along BB ′ of the first sensor element 2. .

  As can be seen from FIG. 3a, in comparison to FIG. 2a, the current I, indicated by the arrow 16 in FIG. 3a, is introduced into the sensor element 2 at or near position 12 and the sensor element at or near position 10 2 is released, i.e. removed. In other words, the current is released in FIG. 3a at the location introduced in FIG. 2a, and vice versa. Thus, the introduction and discharge of the current I to the first sensor element 2 in FIG. 3a produces a current through the region 4 to be magnetically encoded, as opposed to each current in FIG. 2a.

  The current is shown in the core region of the sensor element 2 in FIG. As can be seen from a comparison between FIG. 2b and FIG. 3b, the magnetic flow structure 22 has the opposite direction to the magnetic flow structure 20 in FIG. 2b.

  As previously indicated, the steps depicted in FIGS. 2a, 2b, 3a, and 3b may be applied individually or continuously with each other. When the steps depicted in FIGS. 2a and 2b are first performed and then the steps depicted in FIGS. 3a and 3b are performed, the magnetism depicted in the cross-sectional view through the encoded region 4 depicted in FIG. A flow structure is created. As can be seen from FIG. 4, the two magnetic flow structures 20 and 22 are both encoded in the encoding region. Accordingly, the first magnetic current has a first direction in a direction essentially perpendicular to the surface of the first sensor element 2 in the direction toward the core of the sensor element 2, and the second magnetic current is below it. Will have a second direction. As shown in FIG. 4, the directions of magnetic flow are opposite to each other.

  Therefore, when no torque is applied to the first torque sensor element 2, the two magnetic flow structures 20 and 22 cancel each other, and basically no magnetic field exists outside the encoded region. However, when stress or force is applied to the first sensor element 2, the magnetic flow structures 20 and 22 stop canceling and a magnetic field is generated outside the encoded region, which is detected by the second sensor element 6. This will be described in detail below.

  FIG. 5 shows another typical example of the first sensor element 2 according to one exemplary embodiment of the present invention, which is manufactured by a manufacturing method according to one exemplary embodiment of the present invention. May be used in a torque sensor according to one exemplary embodiment. As can be seen from FIG. 5, the first sensor element 2 has an encoding region 4 which is encoded, for example, according to the steps and arrangements depicted in FIGS. 2a, 2b, 3a, 3b and 4.

  In the vicinity of positions 10 and 12, pinning zones 42 and 44 are arranged. These zones 42 and 44 are provided in order to avoid instability of the encoding region 4. In other words, the start position and the end position of the encoding area 4 become clearer by the pinning zones 42 and 44.

  In short, the first pinned zone 42 is formed, for example, by introducing a current 38 into the first sensor element 2 near or near the first position 10 in the same manner as described with reference to FIG. Is done. However, the current I is emitted from the first sensor element 2 at a first position 30 near the position 10, i.e. away from the end of the region encoded there. This additional location is indicated by reference numeral 30. The introduction of this additional current pulse I is indicated by arrow 38 and its emission is indicated by arrow 40. The current pulse has the same shape as described above and has a maximum value.

  In order to form the second pinned zone 44, current is introduced into the first sensor element 2 at a location 32 near the location 12, ie, away from the end of the region 4 encoded in the vicinity thereof. Current is then emitted from the first sensor element 2 at or near position 12. The introduction of current pulse I is indicated by arrows 34 and 36.

  Preferably for the pinned zones 42 and 44, the magnetic flow structures of these pinned zones 42 and 44 are in opposite directions to the adjacent magnetic flow structures in the adjacent encoding region 4, respectively. As can be seen from FIG. 5, the pinned zone is encoded into the first sensor element 2 after coding of the encoding region 4 or complete coding.

  FIG. 6 shows another exemplary embodiment of the present invention, where there is no encoding region 4. In other words, according to one exemplary embodiment of the present invention, the pinned zone is encoded in the first sensor element 2 before actually encoding the magnetically encoded region 4.

  FIG. 7 shows a simplified flowchart for a method of manufacturing a first sensor element 2 for a torque sensor according to one exemplary embodiment of the present invention.

  After the start in step S1, the method continues to step S2 and a first pulse is applied as described with reference to FIGS. 2a and 2b. Then, after step S2, the method continues to step S3 and a second pulse is applied as described with reference to FIGS. 3a and 3b.

  The method then continues to step S4, where it is determined whether the pinned zone is to be encoded on the first sensor element 2. If it is determined in step S4 that there is no pinned zone, the method continues to step S7, where it ends.

  If it is determined in step S4 that the pinning zone is encoded on the first sensor element 2, the method continues to step S5, where the third pulse is pinned zone 42 in the direction indicated by arrows 38 and 40. And is added to the pinning zone 44 in the direction indicated by arrows 34 and 36. The method then continues to step S6 where a fourth pulse is applied to each pinned zone 42 and 44. For the pinned zone 42, the fourth pulse is applied in the opposite direction to that indicated by arrows 38 and 40. Also, with respect to the pinning zone 44, a fourth pulse is applied to the pinning zone having the opposite direction of the arrows 34 and 36. The method then continues to step S7 where it ends.

  In other words, two pulses are applied to encode the magnetically encoded region 4. These current pulses have, for example, opposite directions. In addition, two pulses, each with a corresponding direction, are applied to the pinned zone 42 and applied to the pinned zone 44.

  FIG. 8 shows the current versus time diagram of the pulses applied to the magnetically encoded region 4 and the pinned zone. The positive direction of the y axis in FIG. 8 indicates the current in the x direction, and the negative direction of the y axis in FIG. 8 indicates the current in the y direction.

  As can be seen from FIG. 8, a current pulse in the x direction is first applied for the coding of the magnetically encoded region 4. As can be seen from FIG. 8, the rising edge of the pulse is very sharp, while its falling edge tends to be relatively long compared to the tendency of the rising edge. As shown in FIG. 8, the pulse may have a maximum value of about 75 amps. In other applications, the pulse may not be as sharp as shown in FIG. However, the rising edge should be steeper or have a shorter duration than the falling edge.

  The second pulse is then applied to the encoding region 4 in the opposite direction. The pulse may have the same shape as the first pulse. However, the maximum value of the second pulse may also be different from the maximum value of the first pulse. The peripheral shape of the pulse may be different.

  Then, for pinning zone coding, pulses similar to the first and second pulses are applied to the pinning zone as described in connection with FIGS. Such pulses may be applied simultaneously to the pinned zones or may be applied sequentially to each pinned zone. As depicted in FIG. 8, the pulses may have essentially the same shape as the first and second pulses. However, the maximum value may be smaller.

  FIG. 9 shows another exemplary embodiment for the first sensor element of the torque sensor according to one exemplary embodiment of the present invention, for encoding the magnetically encoded region 4. The electrode arrangement for applying a current pulse is shown. As can be seen from FIG. 9, the non-insulated conductors may be looped around the first sensor element 2, in which case this first sensor element 2 has a circular shape as can be seen from FIG. It is a circular shaft with a cross section. In order to ensure that the conducting wire is in close contact with the outer surface of the first sensor element 2, the conducting wire may be clamped as indicated by arrow 64.

  FIG. 10a shows another exemplary embodiment of the first sensor element according to one exemplary embodiment of the present invention. In addition, FIG. 10a shows another exemplary embodiment of an electrode system according to one exemplary embodiment of the present invention. The electrode systems 80 and 82 depicted in FIG. 10a contact the first sensor element 2, which has a triangular cross section with two contact points. These contact points are attached to each side of the triangular first sensor element at each side of the region 4, ie, the region to be encoded as a magnetic encoding region. Therefore, as a whole, there are six contact points on the side surface of the region 4. Individual contact points are connected to each other and then to one individual contact point.

  If there is only a limited number of contact points between the electrode system and the first sensor element 2 and the applied current pulse is very high, the contact between the electrode system contacts and the first sensor element 2 Different contact resistances may cause burn marks on the first sensor element 2 at the contact points of the electrode system. These burn marks 90 are discolored, weld spots, annealed spots, or simply burn marks. In one exemplary embodiment of the present invention, a contact surface is provided that increases the number of contact points or avoids such burn marks 90.

  FIG. 11 shows another exemplary embodiment of the first sensor element 2 which is a shaft with a circular cross section according to one exemplary embodiment of the present invention. As can be seen from FIG. 11, the magnetically encoded region 4 is in a region near one end of the first sensor element 2. According to one exemplary embodiment of the invention, the magnetically encoded region 4 does not extend over the entire length of the first sensor element 2. As can be seen from FIG. 11, it may be installed at one end thereof. However, it should be noted that, according to one exemplary embodiment of the present invention, the current pulse is applied from the outer circumferential surface of the first sensor element 2 but is not applied from the end face 100 of the first sensor element 2.

  Next, a so-called PCME ("Pulse-Current-Modulated-Encoding" pulse current modulation encoding) sensing technique will be described in detail. It can be provided according to one exemplary embodiment of the present invention to magnetize a magnetizable object that is partially demagnetized by the present invention. PCME technology is then described in part in the context of torque detection. However, this concept is provided in the context of position detection as well.

  This description uses many acronyms, otherwise many explanations and descriptions are difficult to read. While the acronyms “ASIC”, “IC”, and “PCB” are already market standard definitions, there are many terms that relate specifically to NCT sensing technology based on magnetostriction. Note that in this description, where there is a reference to NCT technology, or PCME, it is referred to an exemplary embodiment of the present invention.

Table 1 shows a list of abbreviations used in the following description of PCME technology.

  Designing a wide range of "physical parameter sensors" (such as force sensing, torque sensing, and material diagnostic analysis) that can be applied when ferromagnetic materials are used by magnetic stress sensing technology based on the laws of magnetism Can be produced. The most common techniques used to build a “magnetic law-based” sensor are inductive differential displacement measurements (which require a torsional shaft), material permeability change measurements, and magnetostrictive effect measurements. is there.

  Over the past 20 years, many different companies have developed their own and very specific solutions on how to design and produce torque sensors based on magnetic principles. (Ie ABB, FAST, Frauenhofer Institute, FT, Kubota, MDI, NCTE, RM, Siemens, etc.). Each of these technologies is in the development stage and differs in "how it works", performance achievable, system reliability, and manufacturing and system prices.

  Some of these techniques depend on whether a mechanical change is applied to the shaft whose torque is to be measured (chevron) or a mechanical twisting effect (requires a long shaft to be twisted by torque). Or require something to adhere to the shaft itself (pressing a ring with certain properties on the shaft surface) or to coat the shaft surface with a special material. To date, no one has achieved stringent performance tolerances, can be applied to (almost) any shaft size, and has not achieved mass production processes that are not based on existing technology patents.

  Next, non-contact torque (NCT) sensing technology based on the magnetostriction principle will be described. This provides the user with a vast number of new features and improved performance that were previously unavailable. This technology allows for fully integrated (small space), real-time (high signal bandwidth) torque measurements that are reliable and affordable regardless of what is desired. Can be produced at a reasonable price. This technique is called PCME (Pulse-Current-Modulated-Encoding) or magnetostrictive lateral torque sensor.

  PCME technology can be applied to the shaft without mechanical changes to the shaft or without attaching anything to the shaft. Most importantly, PCME technology can be applied to any shaft diameter (almost all other technologies have limitations in this regard) and there is no need to rotate or spin the shaft during the encoding process (very Simple and low cost manufacturing process), which makes this technology highly applicable in mass production applications.

  Next, the magnetic field structure (sensor principle) will be described.

  The lifetime of the sensor depends on the “closed loop” magnetic field design. PCME technology is based on two magnetic field structures stored on top of each other and running in opposite directions. When no torque or kinetic stress is applied to the shaft (aka sensor host, or SH), SH behaves magnetically neutral (no magnetic field is detected outside SH).

  FIG. 12 shows that two magnetic fields are generated in the shaft and run in a closed circle. The outer magnetic field runs in one direction, while the inner magnetic field runs in the opposite direction.

  FIG. 13 illustrates that the PCME sensing technique uses two reverse circular magnetic field loops that are created close to each other (piggyback mode).

  When mechanical stress (such as reciprocation or torque) is applied across the PCME magnetized SH (sensor host or shaft), the flux lines (ie loops) of both magnetic structures were applied. Tilt in proportion to torque.

  As shown in FIG. 14, when no mechanical stress is applied to SH, the flux lines run in their initial path. When mechanical stress is applied, the magnetic flux lines tilt in proportion to the applied stress (such as linear motion or torque).

  Depending on the direction of applied torque (clockwise or counterclockwise with respect to SH), the magnetic flux lines tilt to the right or to the left. When the magnetic flux lines reach the boundary of the magnetically encoded region, the magnetic flux lines from the upper layer are connected to the magnetic flux lines from the lower layer, and vice versa. This then forms a fully controlled toroidal shape.

The advantages of such a magnetic structure are as follows.
Reduced (almost eliminated) parasitic magnetic field structure when mechanical stress is applied to SH (this results in good RSU performance).
-Higher sensor output signal slope. This is because there are two “active” layers that complement each other when generating signals related to mechanical stress.
Explanation: When using a single layer sensor design, the “tilted” magnetic flux lines that exist at the encoding domain boundary must create a “return” from one boundary side to the other. This effort affects how much signal can be sensed and used to be measured outside the SH with the secondary sensor unit.
-When PCME technology is applied, there is almost no limit on the size of SH (shaft). The two-layer magnetic structure can be applied to any solid or hollow shaft size.
• The physical dimensions and sensor performance can be programmed very broadly and therefore tailored to the target application.
This sensor design allows the measurement of mechanical stresses arising from all three dimensional axes, including linear forces applied to the shaft (applicable as load cells).
Explanation: Early magnetostrictive sensor designs (eg, those from FAST technology) were limited to being sensitive only to the two-dimensional axis and could not measure linear forces.

  Referring to FIG. 15, when torque is applied to SH, the magnetic flux lines of two opposite circular magnetic loops are connected to each other at the sensor region boundary.

  When mechanical torque stress is applied to SH, the magnetic field no longer turns in a circle and tilts somewhat in proportion to the applied torque stress. This connects the magnetic field lines of one layer to the magnetic field lines of the other layer and thereby forms a toroidal shape.

  Referring to FIG. 16, this is an exaggerated representation of how the magnetic flux lines form an angled toroidal structure when a high level of torque is applied to the SH.

  Next, features and advantages of the PCM encoding (PCME) process will be described.

The magnetostrictive NCT sensing technology from NCTE according to the present invention provides the following high performance sensing characteristics.
-The sensor host does not require any mechanical changes (the existing shaft can be used as it is).
No need to attach anything to the sensor host (thus, nothing will fall off or change during the life of the shaft, i.e. high MTBF).
During measurement, the SH can rotate at any desired speed, can reciprocate, or move (no limit to rpm).
Very good RSU (Rotational Signal Uniformity Rotation Signal Uniformity) performance.
• Excellent measurement linearity (up to 0.01% of FS).
・ High measurement reproducibility.
Very high signal resolution (better than 14 bits)
• Very high signal bandwidth (better than 10 kHz).

  Depending on the type of magnetostriction sensing technology selected and the physical sensor design selected, the mechanical power transmission shaft (also known as “sensor host” or “SH” for short) has no mechanical modification to it. It can be used "as is" without adding anything to the shaft and without attaching anything to the shaft. This is called the “true” non-contact torque measurement principle, which allows the shaft to freely rotate in both directions with any desired speed.

The PCM encoding (PCME) manufacturing process described herein according to one exemplary embodiment of the present invention provides an additional feature that cannot provide any other magnetostrictive technology (uniqueness of the technology).
Signal strength greater than 3 times compared to other alternative magnetostrictive encoding processes (such as the FAST “RS” process).
• Easy and simple shaft loading process (high production throughput).
-No moving parts during the magnetic encoding process (uncomplicated manufacturing equipment, ie high MTBF and low cost).
Enabling the NCT sensor to “fine-tune” to achieve a target accuracy of 1 percent or less.
A manufacturing process (high manufacturing throughput) that allows shaft “pre-processing” and “post-processing” in the same process cycle.
・ Sensing technology and manufacturing process are ratiometric and therefore applicable to all shaft diameters and tube diameters.
The PCM encoding process can be applied while the SH is already assembled (depending on accessibility) (easy to maintain).
A final sensor that is not sensitive to the movement of the shaft (actually allowed shaft movement depends on the physical “length” of the magnetically encoded area).
The magnetically encoded SH remains neutral and is almost free of magnetic fields when no force (such as torque) is applied to the SH.
• Sensitive to mechanical forces on all three-dimensional axes.

  Next, the magnetic flux distribution in SH will be described.

  PCME processing technology is based on using current flowing through SH (sensor host or shaft) to achieve the desired permanent magnetic encoding of ferromagnetic materials. In order to obtain the desired sensor performance and characteristics, a very special and well controlled current is required. Early experiments using DC current failed due to a lack of understanding of how small amounts of DC current and large amounts of DC current flow through the conductor (in this case, the “conductor” is the mechanical power The transmission shaft, also known as the sensor host, or “SH” for short.)

  FIG. 17 shows the assumed current density in the conductor.

  The current density in the conductor is generally assumed to be uniformly distributed across the entire cross section of the conductor as current (DC) flows through the conductor.

  FIG. 18 shows a small current that forms a magnetic field that bundles current paths in the conductor.

  Our experience is that when a small amount of current (DC) flows through a conductor, the current density is highest at the center of the conductor. Two main causes for this are that the current flowing through the conductor generates a magnetic field that bundles the current path together at the center of the conductor and that the impedance is lowest at the center of the conductor.

  FIG. 19 illustrates one typical flow of small currents in the conductor.

  In practice, however, current does not have to flow in a “straight” line from one connecting pole to the other (like the shape of a lightning bolt in the sky).

  At some level of current, the generated magnetic field is large enough to cause permanent magnetization of the ferromagnetic shaft material. When the current flows near or through the center of the SH, a permanently generated magnetic field is present at the same location, ie near or at the center of the SH. Now, when applying mechanical torque or linear force to the shaft for vibration or reciprocation, the shaft with the magnetic field inside responds by tilting its flux path according to the applied mechanical force. When the permanently generated magnetic field is deep below the shaft surface, the measurable effect is very small and not uniform and is therefore not sufficient to make a reliable NCT sensor system.

  FIG. 20 shows the uniform current density in the conductor at the saturation level.

  Only at the saturation level, the current density (when using DC) is uniformly distributed across the cross-section of the entire conductor. The amount of current that achieves this saturation level is very large and is mainly influenced by the cross-section and conductivity (impedance) of the conductors used.

  FIG. 21 shows a current flowing under or on the surface of the conductor (skin effect).

  It is generally widely assumed that when alternating current (such as a radio frequency signal) flows through a conductor, the signal flows through the skin layer of the conductor, i.e. called the skin effect. The selected frequency of the alternating current defines the “location / position” and “depth” of the skin effect. At high frequencies, current flows at or near the surface of the conductor (A), while at low frequencies (in the region of 5-10 Hz for 20 mm diameter SH), alternating current is more centered on the shaft cross-section ( Go through E). Also, the relative current density is higher in the portion occupied by the current at a higher AC frequency compared to the relative current density near the center of the shaft at a very low AC frequency (which is higher at the lower AC frequency). , Due to the larger area available for current to flow).

  FIG. 22 shows the current density (90-degree cross section with respect to the current) of the conductor when alternating current is passed through the conductor with different frequencies.

  The preferred magnetic field design for PCME sensor technology is two circular magnetic field structures, brought into two layers close to each other ("piggyback") and running in opposite directions (Counter-Circular: This is an inverted ring structure.

  Referring again to FIG. 13, this shows a desirable magnetic field sensor structure, i.e., two closed magnetic loops located in close proximity to each other and running in opposite directions, i.e., an anti-annular "piggyback" magnetic field. Designed.

  In order to make the magnetic field design highly sensitive to mechanical stress applied to the SH (shaft) and to allow the largest sensor signal, the desired magnetic field structure should be placed closest to the shaft surface. I must. Placing a circular magnetic field close to the center of the SH reduces the gradient of the sensor output signal available to the user (many of the sensor signal travels through the ferromagnetic shaft material, which is compared to the air. And higher sensor signal non-uniformity (with respect to shaft rotation and shaft axial movement associated with the secondary sensor).

  FIG. 23 shows a magnetic field structure formed near the shaft surface and a magnetic field structure formed near the center of the shaft.

  When using AC (alternating current), it is difficult to achieve the desired permanent magnetic encoding of SH, because the polarity of the magnetic field produced is constantly changing and hence rather acts as a degaussing system. .

  PCME technology requires that a strong current ("unipolar" or DC to prevent loss of the desired magnetic field structure) flows directly under the shaft surface (sensor signal is uniform and measurable outside the shaft) To ensure that). Further, it is necessary to form an inverted annular piggyback magnetic field structure.

  Placing two inverted annular magnetic field structures on the shaft is possible by providing them alternately on the shaft. First, the inner layer is brought into SH and then the outer layer is caused by using a weaker magnetic force (preventing the inner layer from being neutralized and erased accidentally). To achieve this, known “permanent” magnet encoding techniques can be applied, as described in the FAST Technology patent, or a combination of current and “permanent” magnet encoding can be used. Is done by doing.

  A simpler and faster encoding process is to use the current alone to achieve the desired anti-annular “piggyback” magnetic field structure. The most challenging part here is to create an inverted annular magnetic field.

  The uniform current generates a uniform magnetic field that runs around the conductor at an angle of 90 degrees with respect to the current direction (A). When two conductors are placed side by side (B), the magnetic field between the two conductors cancels each other's effect (C). Note that there is no detectable (or measurable) magnetic field between two closely spaced conductors, although present. When multiple conductors are placed side by side (D), a “measurable” magnetic field will circulate outside the “flat” shaped conductor surface.

  FIG. 24 shows the magnetic effect when a conductor through which a uniform current flows is viewed in cross section.

  The above “flat” or rectangular shaped conductor shall be bent into a “U” shape. When a current is passed through the “U” -shaped conductor, the current along the “U” -shaped outline then cancels the measurable effect in the inner half of the “U” -shape.

  Referring to FIG. 25, the area within the “U” shaped conductor appears magnetically “neutral” when current is flowing through the conductor.

  When no mechanical stress is applied to the cross section of the “U” shaped conductor, it appears that no magnetic field is present inside the “U” shape (F). However, when the “U” shaped conductor is bent or twisted, the magnetic field no longer follows its initial path (90 degree angle to the current). Depending on the applied mechanical force, the magnetic field will begin to change its path somewhat. At that point, the magnetic field vector caused by the mechanical stress is sensed and measured at the surface of the conductor, inside and outside the “U” shape. Note that this phenomenon only applies at very specific current levels.

  The same applies to the design of “O” type conductors. When a uniform current is passed through the “O” -type conductor (tube), the magnetic field effects that can be measured inside the “O” -type conductor (tube) cancel each other (G).

  Referring to FIG. 26, the area inside the “O” conductor appears magnetically “neutral” when current flows through the conductor.

  However, when mechanical stress is applied to the “O” type conductor (tube), it becomes apparent that there was a magnetic field present inside the “O” type conductor. The internal reverse magnetic field (as well as the external magnetic field) begins to tilt in relation to the applied torque stress. This gradient magnetic field is clearly sensed and can be measured.

  Next, encoding pulse design will be described.

  In order to achieve the desired magnetic field structure (inverse annular piggyback magnetic field design) inside the SH, according to one exemplary embodiment of the method of the present invention, a unipolar current pulse passes through the shaft (or SH). To do. By using “pulses”, the desired “skin effect” is obtained. By using a “unipolar” current direction (the direction of the current does not change), the resulting magnetic field effect is not accidentally counteracted.

  The shape of the current pulse used is most important to achieve the desired PCME sensor design. Each parameter must be accurately and reproducibly controlled, including current rise time, constant current on time, maximum current amplitude, and current fall time. It is also very important that the current enters and exits very uniformly across the entire shaft surface.

  Next, a rectangular current pulse shape will be described.

  FIG. 27 illustrates a rectangular current pulse.

  A rectangular current pulse has a fast rising positive edge and a fast falling current edge. When flowing a rectangular current pulse through SH, the rising edge is responsible for the formation of the target magnetic field structure of the PCME sensor, whereas the flat “on” time and falling edge of the rectangular current pulse are counterproductive. Arise.

  FIG. 28 shows the relationship between the rectangular current encoding pulse width (constant current on-time) and the sensor output signal slope.

  In the following example, an inverted annular “piggyback” field was created and stored in a 15 mm diameter 14CrNi14 shaft using rectangular current pulses. The pulse current has a maximum at about 270 amperes. Also, the “on time” of the pulse was controlled by an electronic circuit. Due to the high frequency components at the rising and falling edges of the encoding pulse, this experiment cannot accurately show the effect of true DC encoding SH. Accordingly, when a constant current on-time pulse of 1000 ms is applied, the sensor output signal gradient curve finally becomes flat above 20 mV / Nm.

  Without using fast rising current pulse edges (so as to use a controlled constant ramp slope), the sensor output signal slope becomes very worse (less than 10 mV / Nm). In this experiment (using 14CrNi14), the hysteresis of the signal was about 0.95% of the FS signal (FS = 75 Nm torque).

  FIG. 29 shows the increase in sensor output signal slope by using several rectangular current pulses in succession.

  The sensor output signal slope can be improved when several rectangular current encoding pulses are used in succession. Compared to other encoding pulse shapes, the fast falling current pulse signal slope in a rectangular current pulse prevents the sensor output signal slope from reaching an optimal performance level. This means that after a small number (2 to 10) of current pulses are applied to SH (or shaft), the sensor output signal slope does not increase any more.

  Next, the discharge current pulse shape will be described.

  The discharge current pulse does not have a constant current on-time and does not have a fast falling edge. Therefore, the main and decisive action in SH magnetic encoding is the fast rising edge of this current pulse type.

  As shown in FIG. 30, steep rising current edges and typical discharge curves give the best results when making a PCME sensor.

  FIG. 31 shows the optimization of the PCME sensor output signal gradient by specifying the proper pulse current.

  At the very low end of the pulse current scale (15 mm diameter shaft, 0-75 amps for 14CrNi14 shaft material), the discharge current pulse type is required to create a persistent magnetic field within the ferromagnetic shaft. Not strong enough to exceed the threshold of the magnetic field. As the pulse current amplitude is increased, a double circular magnetic field structure begins to form below the shaft surface. Increasing the pulse current amplitude also increases the torque sensor output signal amplitude achievable by the secondary sensor system. Optimal PCME sensor design was achieved at about 400A-425A (two oppositely oriented magnetic field regions reached each other's optimal distance and correct magnetic flux density for best sensor performance).

  FIG. 32 shows a cross section of a sensor host (SH) with optimal PCME current density and position during the encoding pulse.

  As the pulse current amplitude is further increased, the absolute value of the sensor signal amplitude with respect to torque force further increases for some time (curve 2 in FIG. 31), while the overall sensor performance of a typical PCME decreases. (Curve 1). Beyond 900 A pulse current amplitude (for a 15 mm diameter shaft), the absolute value of the sensor signal amplitude with respect to torque force also drops (curve 2) and the PCME sensor performance is then very poor (curve). 1).

  FIG. 33 shows the cross section and electrical pulse current density of the sensor host (SH) for various increasing pulse current levels.

  As the current occupies a larger cross section in SH, the spacing between the inner circular portion and the outer (near the shaft surface) circular portion becomes larger.

  Referring to FIG. 34, better PCME sensor performance is achieved when the spacing is narrow (A) with an inverted annular “piggyback” field design.

  The desired dual and reversed annular magnetic field structure makes it difficult to create a closed loop structure under torque forces that result in the signal amplitude of the secondary sensor.

  Referring to FIG. 35, flattening the discharge curve also increases the signal slope of the sensor output.

  Increasing the current pulse discharge time (widening the current pulse) (B) increases the sensor output signal gradient. However, the amount of current required to reduce the falling edge of the current pulse is very large. In order to achieve the highest achievable sensor output signal slope, it is more practical to use a combination of a large current amplitude (at the optimum value) and the slowest possible discharge time.

  Next, an electrical connection device related to primary side sensor processing will be described.

  PCME technology (the term “PCME” technology should be noted that it is used with respect to exemplary embodiments of the present invention) is a very large amount of pulse modulation through the shaft where the primary sensor is produced. Depends on current flow. If the shaft surface is very clean and highly conductive, a multi-point copper or gold connection is sufficient to achieve the desired sensor signal uniformity. What is important is that the impedance is the same at each connection point to the shaft surface. This can best be achieved if the cable length (L) can be guaranteed to be the same before the cable is connected to the main current connection point (I).

  FIG. 36 shows a simple electrical multipoint connection to the shaft surface.

  However, in many cases, a reliable and reproducible multipoint electrical connection can only be achieved by ensuring that the impedance is the same and constant at each connection point. Using a pressed spring, a sharp connector penetrates a possible oxidation or insulation layer (possibly made by a fingerprint) on the surface of the shaft.

  FIG. 37 illustrates a multi-channel electrical connector with spring-loaded contact points.

  When processing the shaft, it is most important to inject and remove current from the shaft in as uniform a manner as possible. The above figure shows several connectors that are insulated from each other that are secured around the shaft by a fixture. This tool is called the shaft processing holding clamp (or SPHC). The number of electrical connectors required for SPHC depends on the outer diameter of the shaft. The larger the outer diameter, the more connectors are required. The spacing between conductors must be the same from one connection point to the next. This method is called symmetric “spot” contact.

  FIG. 38 illustrates supporting the approach of entering and exiting the pulse modulated current by increasing the number of electrical connection points. It also increases the complexity of the required electronic circuit control system.

  FIG. 39 shows one example of how to open the SPHC for easy shaft attachment.

  Next, an outline of encoding related to primary side sensor processing will be described.

  The main shaft encoding is done by using a permanent magnet applied to the rotating shaft or by using a current flowing through the desired part of the shaft. When using permanent magnets, a very complex and continuous process is required to create two layers of closed-loop magnetic fields that are close together in the shaft. When using the PCME procedure, the current must enter and exit the shaft in the most symmetrical way possible to achieve the desired performance.

  Referring to FIG. 40, two SPHCs (Shaft Processing Holding Clumps) are located at the boundaries of the planned sensing encoding area. Pulse current (I) enters the shaft through one SPHC, while pulse current (I) exits the shaft at the second SPHC. The area between the two SPHCs then changes to the primary sensor.

  This special sensor process creates a single magnetic field (SF) encoding region. One advantage of this design (compared to that described below) is that it is not sensitive to any axial shaft movement with respect to the location of the secondary detector. A disadvantage of this design is that it becomes sensitive to stray magnetic fields (such as the Earth's magnetic field) when using MFS coils placed in the axis (ie in a row).

  Referring to FIG. 41, using a MFS coil placed on the axis (ie on a line) by a double magnetic field (DF) encoding region (meaning two independently functioning sensor regions with opposite polarities side by side) In this case, the effect of the uniform stray magnetic field can be eliminated. However, this primary sensor design also narrows the shaft motion tolerance in the axial direction (relative to the location of the MFS coil). There are two ways to create a double magnetic field (DF) encoding region with PCME technology. They are a continuous process in which magnetic encode portions are created from one to the next and a parallel process in which magnetic encode portions are created simultaneously.

  The first process step in a continuous dual field design is to magnetically encode one sensor part (same as a single field process), so that the distance between the two SPHCs is the primary sensor region. Must be half the desired final length. To simplify the description of this process, the SPHC placed in the center of the final primary sensor area is called the central SPHC (C-SPHC), and the SPHC placed on the left side of the central SPHC is called the L-SPHC. To.

  Referring to FIG. 42, the second process stage of continuous dual magnetic field encoding consists of SPHC placed in the middle of the primary sensor area (referred to as C-SPHC) and on the other side (right side) of the central SPHC. Use the second SPHC placed, called R-SPHC. What is important is that the current direction in the central SPHC (C-SPHC) is the same in both process steps.

  Referring to FIG. 43, the performance of the final primary sensor area depends on how close the two encoding areas can be placed in relation to each other. And this depends on the design of the central SPHC used. The narrower the contact width in the axial direction of the C-SPHC, the better the performance of the double magnetic field PCME sensor.

  FIG. 44 illustrates how pulses are applied according to another exemplary embodiment of the present invention. As can be seen from the above figure, the pulses are applied at three points on the shaft. Due to the current distribution on both sides of the central electrode where the current I enters the shaft, the current leaving the shaft with the lateral electrode is only half of the current entering the central electrode, i.e. I / 2. The electrode is drawn with a ring and its size is adapted to the size of the outer surface of the shaft. However, it should be noted that other electrodes may be used, such as an electrode including a plurality of pin electrodes described later in this text.

  FIG. 45 shows the magnetic flux directions of the two sensor portions in a dual field PCME sensor design when no torque or linear motion stress is applied to the shaft. Magnetic flux loops in opposite directions do not interact with each other.

  Referring to FIG. 46, when a torque force or linear stress is applied in one special direction, the flux loop begins to run at an increasing tilt angle within the shaft. When the tilted magnetic flux reaches the boundary of the PCME portion, the magnetic flux lines interact with the magnetic flux lines in the reverse flow direction as shown.

  Referring to FIG. 47, when the direction of applied torque is changing (eg, from clockwise to counterclockwise), the tilt angle for the backflow magnetic flux structure within the PCM encode shaft also changes.

  Next, a multi-channel current driver for shaft processing will be described.

  If the exact same impedance for the current path to the shaft surface cannot be guaranteed, a current controlled drive stage is used to overcome this problem.

  FIG. 48 shows a 6-channel synchronous pulse current drive system for a small diameter sensor host (SH). As the shaft diameter increases, the number of current drive channels increases.

  Next, brass ring contacts and symmetrical “spot” contacts are described.

  If the shaft diameter is relatively small, the shaft surface is clean in the desired detection area and there is no oxidation, the simple “brass” ring (or copper ring) contact method is selected for processing the primary sensor. be able to.

  In FIG. 49, a brass ring (or copper ring) securely attached to the shaft surface is used with a solder connection of the wires. The area between the two brass rings (copper rings) is the area to be encoded.

  However, the achievable RSU performance is much lower than when using a symmetric “spot” contact method.

  Next, the concept of hot spots will be described.

  Standard single magnetic field (SF) PCME sensors are very poor in hot spot performance. The external magnetic flux profile (when torque is applied) of the SF PCME sensor part is very sensitive to possible changes in the surrounding environment (with respect to ferromagnetic materials). Since the magnetic boundaries of the SF encode sensor parts are not clear (not “pinned down”), they can “extend” toward the direction in which the ferromagnetic material is placed near the PCME detection region. .

  Referring to FIG. 50, the magnetized detection region of the PCME process is very sensitive to ferromagnetic material approaching the detection region boundary.

  In order to reduce hot spot sensor sensitivity, the boundaries of the PCME sensor parts need to be clearly defined by pinning them (they can no longer move).

  FIG. 51 shows a PCME process detection region with two pinned magnetic field regions, one of which is on each side of the detection region.

  By placing the pinned area near both sides of the detection area, the boundary of the detection area is constrained to a very specific location. As the ferromagnetic material approaches the detection region, it affects the outer boundary of the pinned region, but it has a very limited effect at the detection region boundary.

  According to an exemplary embodiment of the present invention, how SH (sensor host) obtains a single magnetic field (SF) detection region and two pinned regions, one on each side of the detection region. There are a number of different ways that can be handled. Each region is processed after each other (sequential processing), or two or three regions are processed simultaneously (parallel processing). In parallel processing, providing a more uniform sensor (reduced parasitic field) requires even higher levels of current to reach the target sensor signal gradient.

  FIG. 52 illustrates parallel processing for a single magnetic field (SF) PCME sensor with a pinned region on each side of the main detection region to reduce (or even eliminate) hot spots.

  Dual field PCME sensors are less sensitive to the effects of hot spots because the central region of the sensor is already pinned. However, the remaining hot spot sensitivity can be further reduced by placing pinned areas on either side of the dual sensor area.

  FIG. 53 shows a dual magnetic field (DF) PCME sensor with pinned regions on both sides.

  When the pinned area is unacceptable or not possible (for example, when only limited axial spacing is available), the sensing area needs to be magnetically shielded from the effects of external ferromagnetic materials.

  Next, rotation signal uniformity (RSU) will be described.

  According to the current understanding, RSU sensor performance mainly depends on how the current enters and exits the SH surface uniformly at the periphery and the physical distance between the point where the current enters and exits. Dependent. The larger the distance between the point where the current enters and the point where it exits, the better the RSU performance.

  Referring to FIG. 54, when the distance between the current inflow points placed on the individual circumferential surfaces is relatively large with respect to the shaft diameter (and between the current exit points placed on the circumference). RSU performance will be very inferior). In such a case, the length of the PCM encoding part must be as large as possible. Otherwise, the generated magnetic field will not be uniform on the circumference.

  Referring to FIG. 55, by expanding the PCM encoding portion, the magnetic field distribution on the circumference becomes more uniform at half the distance between the point where the current enters and the point where the current exits (and someday Is almost completely). Therefore, the RSU performance of the PCME sensor is best at a halfway point between the current entry point and the current exit point.

  Next, basic design problems of the NCT sensor system will be described.

  Without going into the details of the PCM encoding technology, the end user of this sensing technology needs to know some design details to be able to utilize and use the sensing concept in its application. is there. In the following pages, the basic elements of an NCT sensor based on magnetostriction (such as primary side sensor, secondary side sensor, and SCSP electronics) and what the individual components are and Describe what choices should be made when integrating technology into an existing product.

  In principle, PCME sensing technology can be used to produce stand-alone sensor products. However, little or no use is available for “stand-alone” products in existing industrial applications. PCME technology can be applied to existing products without the need to redesign the final product.

  When a stand-alone torque detector or position detector is applied to a motor transmission system, the entire system is required to undergo significant design changes.

  Next, FIG. 56 illustrates possible locations of the PCME sensor on the engine shaft.

  FIG. 56 illustrates possible locations for a torque sensor, for example, in a motor car gearbox, according to one exemplary embodiment of the present invention. The upper portion of FIG. 56 shows the placement of a PCME torque sensor according to one exemplary embodiment of the present invention. Also, the lower portion of FIG. 56 shows the arrangement of a stand-alone detection device that is not integrated with the input shaft of the gearbox, as in the exemplary embodiment of the present invention.

  As can be seen from the top of FIG. 56, the torque sensor according to one exemplary embodiment of the present invention can be integrated into the input shaft of the gearbox. In other words, the primary sensor is part of the input shaft. That is, the input shaft may be magnetically encoded to be the primary sensor or sensor element itself. The secondary sensor, i.e., the coil, may be housed in a bearing portion near the encoding area of the input shaft, for example. Thus, when the torque sensor is arranged between the power source and the gear box, there is no need to disturb the input shaft, and as shown in the lower part of FIG. 56, the shaft connected to the motor and another shaft connected to the gear box It is not necessary to arrange another torque sensor between them.

  By integrating the encoding area with the input shaft, for example, in the case of a car, a torque sensor can be provided without any changes to the input shaft. This is very important, for example, in aircraft parts because each part must be subjected to multiple inspections before it is allowed to be used on an aircraft. Such a torque sensor according to the present invention can even eliminate the need for numerous tests performed on shafts in aircraft and turbines, perhaps because the shaft in the meantime is not changed. Also, no serious effect is caused on the shaft material.

  Further, as can be seen from FIG. 56, a torque sensor according to one exemplary embodiment of the present invention can reduce the distance between the gearbox and the power source. This is due to the obvious provision of a separate stand-alone torque sensor between the shaft exiting the power source and the input shaft to the gearbox.

  Next, the sensor component will be described.

  As shown in FIG. 57, a non-contact magnetostrictive sensor (NCT sensor), according to one exemplary embodiment of the present invention, has three main functional elements: a primary side sensor, a secondary side sensor, and It consists of signal conditioning and signal processing (SCSP) electronics.

  Depending on the type of application (quantity and quality requirements, target manufacturing costs, manufacturing process flow), the customer can choose to purchase individual components to manufacture the sensor system under his own control, or The production of individual modules can be subcontracted to subcontractors.

  FIG. 58 schematically shows components of a non-contact torque detector. However, these components can also be used in non-contact position detection devices.

  It is more efficient to integrate the “primary sensor magnetic encoding process” into the customer manufacturing process when the annual production target is thousands of units. In such a case, the customer needs to purchase a “magnetic encoding device” for a specific application.

In mass production applications, the cost and integration of the manufacturing process is important and typically the NCTE supplies only the individual basic components and equipment needed to create a non-contact sensor.
・ IC (surface mount package, electronic circuit for specific applications)
・ MFS coil (as part of secondary sensor)
-Sensor host encoding device (for applying magnetic encoding to the shaft (= primary sensor))

  Depending on the demand, the MFS coil can be provided already assembled on the frame and, if necessary, provided electrically connected to a wire harness with connectors. Similarly, SCSP (signal conditioning and signal processing) electronics can be provided with sufficient functionality in printed circuit board configurations with or without MFS coils built into the printed circuit board.

  FIG. 59 shows the components of the detection device.

  As can be seen from FIG. 60, the number of MFS coils required depends on the expected sensor performance and mechanical tolerances on the physical sensor design. In a properly designed sensor system with a complete sensor host (SH or magnetically encoded shaft) and minimal interference from unwanted parasitic fields, only two MFS coils are required. is there. However, to achieve the desired sensor performance when the SH is moving more than a fraction of a millimeter in the radial or axial direction relative to the position of the secondary sensor, then the MFS coil's It is necessary to increase the number.

  Next, a control and / or evaluation circuit configuration will be described.

  According to one exemplary embodiment of the present invention, the SCSP electronics consists of an NCTE dedicated IC, a number of external passive and active electronic circuits, a printed circuit board (PCB), and an SCSP housing or case. Note that the case needs to be properly sealed according to the environment in which the SCSP unit is used.

Depending on the application requirements, NCTE (according to one exemplary embodiment of the invention) provides a number of different application specific circuits.
・ Basic circuit.
A basic circuit with an integrated voltage regulator.
• High signal bandwidth circuit.
-Optional high voltage and short protection device.
-Optional failure detection circuit.

  FIG. 61 shows the solution for a low cost sensor electronics that is single channel.

  As can be seen from FIG. 61, for example, a secondary sensor unit including a coil is provided. These coils are arranged, for example, as shown in FIG. 60, and detect changes in the magnetic field generated when torque is applied to the primary side sensor unit, ie, the sensor shaft or sensor element. The secondary side sensor unit is connected to the basic IC in the SCST. The basic IC is connected to the positive power supply voltage via a voltage regulator. The basic IC is also grounded. The basic IC is configured to provide an analog output external to the SCST, the output corresponding to magnetic field variations caused by stress applied to the sensor element.

  FIG. 62 shows a two-channel, short protection system design with integrated fault detection. The design consists of five ASIC devices and provides a high degree of system safety. The failure detection IC identifies a failure of the MFS coil or a failure of the electronic drive stage of the “basic IC” when a wire break occurs somewhere in the sensor system.

  Next, the secondary sensor unit will be described.

  According to one embodiment shown in FIG. 63, the secondary sensor comprises the following elements: 1 to 8 MFS (magnetic field sensor) coils, positioning and connecting plates, a wire harness with connectors, and Consists of a secondary sensor housing.

  The MFS coil may be attached to the positioning plate. By using a positioning plate, the two connection wires of each MFS coil can usually be soldered and connected in an appropriate manner. The wire harness is connected to the positioning plate. The plate is fully assembled with the MFS coil and wire harness and then incorporated or held by the secondary sensor housing.

  The main element of the MFS coil is a core wire that needs to be formed of a material such as amorphous.

  Depending on the environment where the secondary sensor unit is used, it is necessary to cover the assembled positioning plate with a protective material. The material should not cause mechanical stress or pressure on the MFS coil when the ambient temperature changes.

  For applications where the operating temperature does not exceed + 110 ° C., the customer has the option of placing SCSP electronics (ASIC) inside the secondary sensor unit (SSU). When ASIC devices operate at temperatures above + 125 ° C., it becomes more difficult to compensate for temperature-related signal offset and signal gain changes.

  The recommended maximum cable length between the MFS coil and the SCSP electronics is 2 meters. With suitable connection cables, distances up to 10 meters can be achieved. In multi-channel applications (two independent SSUs operating at the same primary sensor location = redundant sensor function), to avoid signal crosstalk, there is a special need between the SSU and the SCSP electronics. The shielded cable should be considered.

  When planning the production of a secondary sensor unit (SSU), the producer should decide which part or parts of the SSU should be purchased from the subcontract and what manufacturing steps will be performed in-house. There must be.

  Next, options for manufacturing the secondary sensor unit will be described.

When integrating an NCT sensor into a custom-made tool or standard transmission system, the system producer has several options to choose from:
-Custom-made SSU (including wire harness and connector).
Selected modules or components; final SSU assembly and system testing may be done at the customer's control.
-Only critical components (MFS coils or MFS cores, application specific ICs) and SSUs are produced in-house.

  FIG. 64 shows one exemplary embodiment of secondary sensor unit assembly.

  Next, the primary sensor design will be described.

  The SSU (secondary sensor unit) can be placed outside the magnetically encoded SH (sensor host), or inside the SH if the SH is hollow. When the SSU is placed inside the hollow shaft, the achievable sensor signal amplitude is the same strength, but with better signal-to-noise performance.

  FIG. 65 shows two configurations for the geometric arrangement of the primary and secondary sensors.

  Improved sensor performance is achieved when the magnetic encoding process is applied to straight and parallel parts of the SH (shaft). For shafts with a diameter between 15 mm and 25 mm, the optimal minimum length of the magnetically encoded region is 25 mm. Sensor performance is further improved if the area can be created with a length of 45 mm (plus a guard area). In complex and highly integrated transmission (gearbox) systems, it is difficult to find such spacing. In a more ideal situation, the magnetically encoded area can be shortened to 14 mm, but this may not achieve all of the desired sensor performance.

  As shown in FIG. 66, for the spacing between the SSU (secondary sensor unit) and the sensor host surface, according to one exemplary embodiment of the present invention, to achieve the best signal quality that can be achieved. Should be kept as small as possible.

  Next, the primary sensor encoding apparatus will be described.

  FIG. 67 shows an example.

  Depending on which magnetostrictive sensing technology is selected, the sensor host (SH) needs to be processed and processed accordingly. The techniques are very diverse with each other (ABB, FAST, FT, Kubota, MDI, NCTE, RM, Siemens, etc.) and the required processing equipment is also the same. Some of the magnetostriction sensing techniques that can be used do not require any physical changes to be made to SH and rely solely on magnetic processing (MDI, FAST, NCTE).

  The MDI technique is a two-stage process, while the FAST technique is a three-stage process, and the NCTE technique is a one-stage process, called PCM encoding.

  Note that after magnetic processing, the sensor host (SH or shaft) becomes a “precision measurement” device and should be handled accordingly. Magnetic processing should be the very last step before the processed SH is carefully placed in its final location.

Magnetic processing should be an integral part of the customer's manufacturing process (in-house magnetic processing) under the following circumstances.
• High production volume (like thousands).
-Heavy SH or SH that is difficult to handle (eg, high shipping costs).
• Very special quality and inspection requirements (eg defense applications).

  In all other cases, obtaining SH magnetically processed by a qualified subcontractor such as NCTE is more cost effective. This is because a dedicated manufacturing apparatus is required for “in-house” magnetic processing. Such a device can be fully manually operated, semi-automatic, or fully automated. Depending on the complexity and level of automation, the device is priced above EUR 20k to EUR 500k.

  FIG. 68A shows a magnetizer 140 that magnetizes the shaft 150 to form a magnetically encoded region on the shaft 150. The magnetizing device 140 does not include a shaft surrounded by other objects. When current is applied between different ends of the shaft 150, the shaft 150 is magnetized.

  FIG. 68B shows a magnetizing device 160 of the present invention that includes a hollow tube 121 that surrounds a shaft 150 (not shown in FIG. 68B) to be magnetized. One end of the shaft 150 is coupled to one end of a hollow tube 121 that surrounds the shaft 150. When a current signal is applied to the shaft 150, current is injected into the hollow tube 121. The magnetic field created by the current flowing in the hollow tube 121 stabilizes the current distribution in the shaft 150. As such, the shaft 150 is magnetized in a very uniform manner.

  FIG. 68C is a conceptual diagram of a torque and force detection device 170 having a magnetically encoded region 122, which is formed according to a magnetization generating process performed using the magnetizing device 160. The length of this magnetically encoded region 122 is defined by the length along the current that flows during the magnetization procedure (ie, it depends on the contact shape for injecting the magnetizing current).

  FIG. 68C shows a torque sensor 170 having a shaft 150 that rotates at a predetermined torque value, wherein a portion of the shaft 150 is magnetized to form a magnetically encoded region 122. When the shaft 150 rotates, the magnetically encoded region 122 causes the magnetic field detection coil 123 to generate a magnetic signal.

  68D is a signal versus torque diagram 100 for torque and force detectors magnetized by magnetizer 140 shown in FIG. 68A (experimentally measured curves and schematic curves highlighting the characteristics of the measured curves). ).

  68E shows the signal versus torque diagram 110 of the torque and force detector 170 magnetized by the magnetizer 160 shown in FIG. 68B (a schematic highlighting the experimentally measured curves and the characteristics of the measured curves. Curve).

  Figures 100D and 110E of FIGS. 68D and 68E each have an abscissa 101, along which the torque applied to the shaft having a magnetically encoded region is shown. 68D and 68E show the signal detected by the coil 123 along the ordinate 102 when one particular value in torque plotted along the abscissa 101 is applied.

  68D and 68E show the hysteresis loop 103 and the best-fit straight line 104 for each case. As can be seen, the slope of the best fit straight line 104 is greater in FIG. 68E than in FIG. 68D, and the hysteresis characteristic is much better suppressed in FIG. 68E than in FIG. 68D.

  One of the major challenges of the magnetic field encoding process according to the present invention is to achieve a uniform current distribution around the “to be encoded” shaft 150, ie to have a properly magnetized region 122. It is. Failure to do so results in poor performance of rotational signal uniformity and poor signal linearity.

  FIG. 68D shows the sensor torque signal when the shaft 150 is processed according to FIG. 68A. The sensor characteristic shown in FIG. 68D shows a certain non-linearity, which has a negative effect on the hysteresis performance of the sensor signal.

  Processing the shaft 150 to form the magnetically encoded region 122 by the method shown in FIGS. 68B, 69, and 70 significantly improves the linearity of the sensor signal and affirms the hysteresis of the sensor signal. The hysteresis is further reduced (see FIG. 68E).

  The magnetically encoded sensor corresponding to FIG. 68A has a best fit line 104 slope of 13.8 mV / Nm with a hysteresis of 3.72%. In contrast, the torque sensor magnetized according to FIG. 68B has a slope of 15.1 mV / Nm and a hysteresis of only 2.59%, as shown in FIG. 68E.

  Thus, the signal to noise ratio is significantly improved when the magnetically encoded region 122 is generated in accordance with the present invention.

  The basic principle of the method for magnetizing an object according to the invention is also shown as a self-adjusting process, but it is to generate a reverse magnetic field during the actual magnetization process, this reverse magnetic field being an electrical signal Ensures that it passes through the shaft 150 very uniformly through the detection area 122 to be “encoded”.

  Through the conductive hollow tube 121 surrounding the shaft 150, the electrical signal for magnetizing a portion of the shaft 150 is sent back inside the hollow tube 121 to form a magnetically encoded region 122. The developed magnetic field can work in conjunction with a magnetic field that is created outside the shaft 150. The shaft 150 is centrally located inside the hollow tube 121 and is not allowed to contact the hollow tube 121 except where desired.

  FIG. 69 shows a diagram useful for a better understanding of the present invention. The arrangement shown in FIG. 69 shows the solid shaft 150 and the hollow tube 121. The current I is injected into the solid shaft 150 to form a magnetic field around the solid shaft 150, as shown in FIG. As this current I flows through the hollow tube 121, a further magnetic field is created in the material of the hollow tube 121 as well. Accordingly, FIG. 69 is a schematic diagram illustrating one principle in a method for magnetizing an object according to the present invention.

  70A and 70B are schematic diagrams showing an apparatus for magnetizing an object according to the present invention.

  In order to magnetize the shaft 150, the hollow tube 121 is arranged so as to surround the solid shaft 150. In addition, an electrical signal I is applied to the solid shaft 150. As shown in the diagram 310 of FIG. 70D with the time abscissa 301 and the current ordinate 302, the pulse current signal 300 basically has a vertical fast rising edge and a slow falling edge.

  Further, as can be seen from FIG. 70A, the solid shaft 150 is disposed at the center of the hollow tube 121. The hollow tube 121 has a first electrical connection portion 201 and a second electrical connection portion 202, and the second electrical connection portion 202 of the hollow tube 121 is coupled to the first electrical connection portion 203 of the solid shaft 150. . In addition, the solid shaft has a second electrical connection 204. An electrical signal source (not shown) is connected so that the current signal I is applied between the first connection 201 of the hollow tube 121 and the second connection 204 of the solid shaft 150.

  FIG. 70B shows a view of the shape of FIG. 70A from another angle.

  Since the magnetic flux direction inside the hollow tube 121 (due to the feedback current direction) has the same rotational direction as the magnetic field that circulates around the solid shaft 150 (because of the forward current direction), the magnetic flux density is the hollow tube 121. Itself in the space between the shaft 150 and the shaft 150. As a result, the current flowing in the solid shaft 150 and the hollow tube 121 is uniformly distributed in both objects.

  The resulting solution provides a significant performance improvement for the rotational signal uniformity of the sensor signal (see FIG. 68E), and this improves (lessens) the signal nonlinearity and signal hysteresis, and further The slope increases (larger signal at one applied torque).

  The results are very interesting, especially in the electrical connection between the feed cable and the shaft 150 to be “encoded”. A slight difference in impedance at the location where the cable connects to the shaft (or tube surface) causes the current to not be evenly distributed around the shaft 150 at this particular location.

  As current flows further through the shaft 150, the current density becomes increasingly uniform around the shaft 150. If the current enters uniformly around the shaft 150 at the location where the wire is connected, the effective detection area becomes larger (the region moves closer to the point where the wire connects to the shaft 150). .

  The method of magnetizing a shaft according to the present invention is just about to force the current to flow most uniformly (for the case where the current density is monitored at 360 degrees around the shaft).

  Thus, the present invention has the advantage of simplifying the method of electrical connection that needs to be made to the shaft 150. Furthermore, the present invention significantly improves some sensor performance. Furthermore, the encoding device is simplified and this reduces the cost of the manufacturing device.

  FIG. 70C shows another arrangement for the apparatus for magnetizing the shaft 150. In addition to the first and second connections 201, 202, the hollow tube 121 further has a third electrical connection 351 and the solid shaft 150 has a third electrical connection 352. In the case of FIG. 70C, two different pulses I1 and I2 are applied in an arrangement as shown in FIG. 70C. The first electrical signal I1 is applied between the first electrical connection 201 of the hollow tube 121 and the second electrical connection 204 of the solid shaft 150. Further, the second electric signal I2 is applied between the third electric connection portion 351 of the hollow tube 121 and the third electric connection portion 352 of the solid shaft 150.

  In addition, a conductive coupling element 350 is provided for coupling the second electrical connection 202 of the hollow tube 121 to the first electrical connection 203 of the solid shaft 150. The current distribution shown in FIG. 70C achieves a magnetic field distribution that results in a uniform current distribution in elements 121, 150, thereby having a well-defined magnetization, ie, a well-defined magnetic encoding region 122. Realize the sensor.

  71A and 71B show another embodiment of an apparatus for magnetizing a shaft 150 according to the present invention.

  FIG. 71A shows a configuration in which the connection between the connection part 202 of the hollow tube 121 and the connection part 203 of the conductive solid shaft 150 is realized by the conductive base plate 400 as a connection element. .

  FIG. 71B shows the device of FIG. 71A with an applied current. Current flows through the plate 400 through the shaft 150 and from there through the hollow tube 121 in a direction opposite to that flowing through the shaft 150. As can be seen from FIG. 71B, the current is applied via a plurality of electrical connection cables, which are arranged circumferentially along the periphery of the upper circular surface of the hollow tube 121. For example, such an arrangement with 6 or 8 cables provides a very uniform current distribution.

  Instead of providing a conductive plate 400 for coupling the hollow tube 121 to the shaft 150, the hollow tube 121 can be left disconnected from the shaft 150 (ie, the plate 400 can be omitted) and 2 Two opposite direction current signals can be passed through the shaft 150 and through the hollow tube 121. In that case, the current of the shaft 150 serves to magnetize the shaft 150, and the current of the hollow tube 121 serves to provide a reverse magnetic field to increase the uniformity of magnetization of the shaft 150. It will be. Thus, the two signals are applied simultaneously, one to the hollow tube 121 and the other to the shaft 150.

  Referring now to FIG. 72, an apparatus 500 for magnetizing a magnetizable tube 501 according to another embodiment of the present invention will be described.

  The apparatus 500 includes a magnetizable tube 501, a hollow cylinder, and a wire 502 having a first portion 502 a, a second portion 502 b, and a third portion 502 c, with current flowing through the wire 502. The power supply 503 is provided to inject current into the wire 502 in the operating state in which the switch 504 is closed. Thus, by closing switch 504, pulsed current 505 is injected into wire 502. However, instead of the pulse current 505, for example, a pulse as shown in FIG. Although a pulse as shown in FIG. 70D is desirable, any appropriate pulse having a shape as shown in FIG. 72 may be injected into the wire 502.

  The magnetizable tube 501 is made of industrial steel and has a wall thickness of 4 cm, a diameter of 88 cm, and a length of several meters. The tube 501 to be magnetized is arranged so that the tube 501 surrounds the first portion 502 a of the wire 502. The power source 503 is configured to apply a current pulse 505 to the wire 502, and the magnetizable tube 501 is magnetized by the pulse current 505. When such a current pulse 505 is applied to the first portion 502a of the wire 502, a magnetic field is generated near and around the first portion 502a of the wire 502, which is similar to that of the transformer inside the magnetizable tube 501. Affects the element magnet. As a result, the tube 501 is magnetized by the pulse 505.

  As can be seen from FIG. 72, the first portion 502 a of the wire 502 is disposed at the center of the hollow tube 501. In contrast to the configuration shown in FIGS. 70A-70D, power source 503 is connected to wire 502, but it is disconnected from magnetizable tube 501. In addition, a hollow shielding cylinder 506 is provided, which is manufactured in the same manner as the magnetizable tube 501. As can be further seen, in particular, the third portion 502 c of the wire 502 is free from being surrounded by the magnetizable tube 501, ie not surrounded by the magnetizable tube 501. The shielding cylinder 506 is arranged and configured to electromagnetically shield (ie, decouple) the third portion 502 c of the wire 502 not surrounded by the magnetizable tube 501 from the magnetizable tube 501. A shielding tube 506 made of a magnetizable material is then disposed between the magnetizable tube 501 and the third portion 502 c of the wire 502. Thus, the current pulse 505 flowing through all portions of the wire 502, 502a, 502b, 502c, acts on the magnetizable tube 501 essentially only in the first portion 502a surrounded by the magnetizable tube 501, and the first portion 502a. A negative current on the magnetization generated in the magnetizable tube 501 by the current flowing through the third portion 502c in the opposite direction, especially weakening the magnetization.

  Further, the second portion 502 b of the wire 502 can be shielded from the magnetizable tube 501 by a shielding element similar to the shielding cylinder 506.

  FIG. 73A shows a schematic top view of the device 500. As can be seen, the shielding cylinder 506 efficiently shields the third portion 502 c of the wire 502 from the tube 501.

  73B-73D further illustrate embodiments of shielding elements.

  FIG. 73B shows a configuration in which four shielding cylinders 600 to 603 are arranged around the third portion 502 c of the wire 502. Thus, the shielding cylinders 600 to 603 made of a magnetizable material are arranged to surround the portion 502 c of the wire 502, that is, the portion not surrounded by the magnetizable tube 501.

  FIG. 73C shows a plurality of cylindrical shafts 610-617 that are disposed around the third portion 502 c of the wire 502, thereby being surrounded by the third portion, ie, the magnetizable tube 501. The portion that is not covered is shielded from the magnetizable tube 501.

  FIG. 73D shows six tubes 620-625 arranged to surround the third portion 502c.

  74, an apparatus 700 for magnetizing a magnetizable tube 501 according to another exemplary embodiment of the present invention will now be described.

  According to the embodiment of FIG. 74, the shielding cylinder 506 is arranged to surround the third portion 502 c of the wire 502. Furthermore, the electrical signal source 503 is implemented by a (charged) capacitor bank 701 and is discharged by closing the switch 504 to generate a pulse as shown in FIG. 70D. The magnetizer 700 is “movable” and is illustrated by a transport vehicle 702 that passes the capacitor bank 701 where the magnetizable tube 501 is magnetized (ie, a drilling device at the mining site). ).

  In this manner, the movable processing unit of FIG. 74 can be transported to the nearest to the excavation or large machinery shaft.

  Next, an apparatus 800 for calibrating the force and torque detection apparatus 810 will be described with reference to FIGS. 75A and 75B.

  The apparatus 800 comprises a force and torque detection device 810, a known mass 811 having a weight of 1000 kg, and a calibration unit 818.

  The force and torque detection device 810 includes a magnetically encoded region 812 in the hollow tube 813 and four magnetic field detection coils 814 to 817.

  A known weight 811 is placed at the upper end of the force and torque detector 810 to apply a known axial force to the magnetized hollow tube 813. The calibration unit 818 connected to the magnetic field detection coils 814 to 817 includes a force and torque detection device 810 based on a correlation between the known mass unit 811 and a detection signal generated from the known force of the mass unit 811. Is supposed to be calibrated.

  Thus, a known mass 811 is added to the upper end of a horizontally placed hollow tube 813 standing on a horizontal and stable base 819. As a result of the mass 811 being added to the upper end of the force and torque detection device 810 (which can be magnetized as shown in FIG. 74), the magnetic field generated by the magnetic encoding region 812 changes and the magnetic field A signal is generated in the detection coils 814 to 817. Thus, the signal processed by the calibration unit 818 has a correlation with the known axial force applied to the magnetized tube 813 by the known mass 811. The pair of data sets, that is, the known axial force and the signal detected at that time are stored in the calibration unit 818.

  The upper end surface of the hollow tube 813 (on which the mass portion 811 is placed) is, for example, disposed horizontally, and therefore the force vector generated by the mass portion 811 at the upper end of the tube 813 is basically the hollow tube. Oriented perpendicular to the surface of 813 (ie, directed to the center of the Earth). If the top surface of the tube 813 and / or the base 819 is not horizontal, an angle correction calculation is necessary or desirable.

  When the drilling shaft 813 is returned to the ground and used for drilling, the axial forces and torques applied to the drilling shaft 813 are measured by the magnetic field detection coils 814-817 and compared with the calibration signal. Is done. In this way, absolute measurement of torque and force is performed based on calibration using the axial load 811.

  In calibration, the coils 814 to 817 need to be arranged so that axial force can be measured. In the case of torque detection operation, the coils 814 to 817 need to be arranged so that torque can be measured. Therefore, the axes of coils 814-817 must change direction accordingly when changing from calibration mode to measurement mode.

  FIGS. 76A and 76B show two possible configurations when the magnetic field detection coils 814 to 817 are arranged.

  FIG. 77 shows three possible configurations of a drilling shaft 1000 with magnetically encoded regions 1001, 1002, or 1003.

  The signs 1001 to 1003 indicate where the excavation shaft 1000 (that is, the rotary power transmission shaft 1000) has a magnetic encoding region. In reality, encodings 1001-1003 are not optically visible and do not change or interfere with any of the mechanical properties of shaft 1000. The drilling shaft 1000 is encoded in one special position 1001, or encoded in one part 1002, or encoded in its entirety 1003. In many cases, encoding at one special location 1001 is reasonable for static system operation. Encoding options 1002, 1003 are used exclusively when the drilling shaft 1000 is rotating or moving in some way.

  FIG. 78 shows two configurations for how the magnetic field detection coils 1100-1103 are arranged around the excavation shaft 1000.

  Next, an apparatus 6800 for magnetizing an object will be described with reference to FIG.

  As shown in FIG. 79, the shaft 150 surrounded by the hollow tube 121 is magnetized by applying an electric signal generated by the power source 503 to the hollow tube 121. The device 6800 can magnetize the shaft 150 by placing the hollow tube 121 so that the hollow tube 121 surrounds the shaft 150 and via a plurality of contact points arranged along the circumference. This can be achieved by applying an electrical signal to the hollow tube 121. The electrical signal generated by the power source 503 is, for example, a pulse signal such that at least a portion of the shaft 150 is magnetized. As shown in FIG. 79, two ends of the shaft 150 are short-circuited by wires 6801 arranged outside the hollow tube 121 outside the hollow tube 121.

  FIG. 80 shows yet another apparatus 6900 for magnetizing an object according to one embodiment of the invention.

  The function of the device 6900 is very similar to the function of the device shown in FIGS. 72A and 72B, except that the conductive plate 400 makes the shaft 150 electrically contact the hollow tube 121. It is replaced with a conductive fluid 6902 having a function (for example, mercury).

  Next, how the device 6900 operates will be described. One (eg, electrically insulating) spacer element 6901 in the form of a hollow cylinder having an inner diameter that is essentially equal to the diameter of the shaft 150 and an outer diameter that is basically equal to the inner diameter of the hollow tube 121 includes: The gap between the empty tube 121 and the shaft 150 placed in the hollow tube is sealed, and the hollow tube 121 is disposed so as to have a volume between them. Next, a conductive fluid 6902 is injected into the device 6900 to fill the space defined by the hollow tube 121 and the shaft 150, the spacer element 6901, so that the hollow tube 121 and the The shaft 150 is electrically coupled.

  Next, an apparatus 7000 for calibrating the force and torque detection apparatus according to the present invention will be described with reference to FIG.

  Device 7000 includes a base 7001 that receives the shaft of the torque sensing device. The torque detection device further includes two magnetic field detection coils 7004 and a magnetically encoded region 7003, which region is formed, for example, by the PCME technique described above. The base 7001 receives the shaft 7002 so that it does not move or rotate due to the force applied to the shaft. The motor 7005 is configured to drive a rotatable element 7006 (eg, flywheel). This rotatable element 7006 can be rotated in a controllable manner and is coupled to the shaft 7002, the mechanical shock of the rotatable element 7006 is transmitted to the shaft 7002, and a (reactive) torque is applied to the shaft 7002. Join. In response to such a calibration torque having a known value, a signal is detected by coil 7004, which serves for calibration of the torque detector. Thus, the device 7000 has a rotatable element 7006 that is driven as a known torque generating element. In particular, a sudden change in the rotational state of the rotatable element 7006 (eg, a sudden brake signal) is useful as a (reactive) torque source that is applied to the torque detector as a calibration signal.

The term “comprising” does not exclude other elements or steps, and “a” or “an” does not exclude a plurality. Also, elements described in connection with different embodiments may be combined.
The attached drawings are included for further understanding of the present invention and constitute a part of the specification, and illustrate an embodiment of the present invention.

FIG. 2 shows a torque sensor with a sensor element according to one exemplary embodiment of the present invention to illustrate a method of manufacturing a torque sensor according to one exemplary embodiment of the present invention. In order to further illustrate one exemplary embodiment of the principles of the present invention and the manufacturing method of the present invention, FIG. 1 shows one exemplary embodiment of a sensor element of a torque sensor according to the present invention. Figure 2b shows a cross-sectional view along the line AA 'of Figure 2a. FIG. 4 shows another exemplary embodiment of a sensor element of a torque sensor according to the present invention to further illustrate one exemplary embodiment of the principles of the present invention and the method of manufacturing a torque sensor according to the present invention. FIG. 3b is a cross-sectional view taken along the line BB 'of FIG. 3a. FIG. 3 shows a cross-section of a sensor element in the torque sensor of FIGS. 2a and 3a manufactured according to a method according to one exemplary embodiment of the invention. FIG. 5 shows another exemplary embodiment of the sensor element of the torque sensor according to the present invention in order to further describe the exemplary embodiment of the manufacturing method for manufacturing the torque sensor according to the present invention. FIG. 4 is a diagram illustrating another exemplary embodiment of the sensor element of the torque sensor according to the present invention in order to further describe an exemplary embodiment of the method of manufacturing a torque sensor according to the present invention. FIG. 3 is a flow chart for further illustrating certain exemplary embodiments of a method for manufacturing a torque sensor according to the present invention. FIG. 6 is a graph illustrating current versus time for further illustrating a method according to one exemplary embodiment of the present invention. FIG. 3 shows another exemplary embodiment of the sensor element of a torque sensor according to the present invention with an electrode system according to one exemplary embodiment of the present invention. FIG. 3 shows another exemplary embodiment of a torque sensor according to the present invention with an electrode system according to one exemplary embodiment of the present invention. FIG. 10b shows the sensor element of FIG. 10a after applying a current surge by the electrode of FIG. 10a. FIG. 6 shows another exemplary embodiment of a torque sensor element for a torque sensor according to the present invention. FIG. 4 shows a situation where two magnetic fields are generated in a shaft and are running in a closed circle, showing a schematic diagram of a sensor element of a torque sensor according to another exemplary embodiment of the present invention. Fig. 4 shows another schematic diagram for illustrating a PCME sensing technique using two reverse cycles, i.e. magnetic field loops, made according to the manufacturing method according to the invention. FIG. 6 shows another schematic diagram for illustrating that the magnetic flux lines run in their initial path when no mechanical stress is applied to the sensor element according to one exemplary embodiment of the present invention. FIG. 4 shows another schematic diagram for further illustrating the principles of one exemplary embodiment of the invention. FIG. 4 shows another schematic diagram for further illustrating the principles of one exemplary embodiment of the invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 2 is a schematic diagram for further explaining the principle of one exemplary embodiment of the present invention. FIG. 4 shows another schematic diagram for further illustrating the principles of one exemplary embodiment of the invention. FIG. 2 shows a schematic diagram for further explaining the principle of one exemplary embodiment of the invention. FIG. 2 shows a schematic diagram for further explaining the principle of one exemplary embodiment of the invention. FIG. 2 shows a schematic diagram for further explaining the principle of one exemplary embodiment of the invention. FIG. 4 is a current versus time diagram for illustrating current pulses applied to a sensor element according to the manufacturing method of one exemplary embodiment of the present invention. FIG. 6 illustrates output signal versus current pulse length according to one exemplary embodiment of the present invention. FIG. 3 shows current versus time with current pulses applied to a sensor element according to the method of the invention according to one exemplary embodiment of the invention. FIG. 4 is another current versus time diagram illustrating one exemplary embodiment for a current pulse applied to a sensor element, such as a shaft, according to the method of one exemplary embodiment of the present invention. FIG. 3 is a signal and signal efficiency versus current diagram in accordance with one exemplary embodiment of the present invention. FIG. 3 shows a cross-sectional view of a sensor element with a desired PCME current density according to one exemplary embodiment of the present invention. FIG. 4 shows a cross-sectional view of sensor elements and pulse current density at various increasing pulse current levels, according to one exemplary embodiment of the present invention. FIG. 6 shows the distance achieved by the magnetic current of different current pulses in the sensor element according to the invention. FIG. 3 shows a current versus time diagram of a current pulse applied to a sensor element according to one exemplary embodiment of the present invention. FIG. 4 illustrates an electrical multipoint connection to a sensor element according to one exemplary embodiment of the present invention. FIG. 4 shows a multi-channel electrical connection having spring loaded contact points for applying current pulses to a sensor element according to one exemplary embodiment of the present invention. FIG. 3 shows an electrode system with an increased number of electrical connection points according to one exemplary embodiment of the present invention. FIG. 38 illustrates one exemplary embodiment of the electrode system of FIG. FIG. 3 shows a shaft processing retention clamp for use in a method according to one exemplary embodiment of the present invention. It is a figure which shows the encoding area | region of the double magnetic field of the sensor element by this invention. FIG. 3 shows sequential dual field encoding process steps according to one exemplary embodiment of the present invention. FIG. 6 illustrates another process step of dual field encoding according to another exemplary embodiment of the present invention. FIG. 6 shows another exemplary embodiment of a sensor element, including a description of application of current pulses, in accordance with another exemplary embodiment of the present invention. Fig. 3 shows a schematic diagram showing the direction of magnetic flux in a sensor element according to the present invention when no stress is applied. It is a figure which shows the magnetic flux direction in the sensor element of FIG. 45 when stress is applied. FIG. 46 illustrates the magnetic flux inside the PCM encoded shaft of FIG. 45 when the direction of applied torque is changing. FIG. 2 illustrates a 6 channel synchronous pulse current drive system according to one exemplary embodiment of the present invention. FIG. 6 is a simplified illustration of an electrode system according to another exemplary embodiment of the present invention. FIG. 3 illustrates a sensor element according to one exemplary embodiment of the present invention. FIG. 4 shows another exemplary embodiment of a sensor element according to the present invention having a PCME processing detection region with two pinned magnetic field regions. FIG. 6 is a schematic diagram illustrating a manufacturing method according to one exemplary embodiment of the present invention for manufacturing a sensor element having one encoded region and a pinned region. FIG. 6 is another schematic diagram illustrating a sensor element according to one exemplary embodiment of the present invention in accordance with a manufacturing method according to one exemplary embodiment of the present invention. FIG. 2 is a simplified schematic diagram for further illustrating one exemplary embodiment of the present invention. FIG. 6 is another simplified schematic diagram for further illustrating one exemplary embodiment of the present invention. FIG. 6 shows the application of a torque sensor according to one exemplary embodiment of the invention in a motor gearbox. FIG. 2 illustrates a torque sensor according to one exemplary embodiment of the present invention. 1 is a schematic diagram of components in a non-contact torque detection device according to one exemplary embodiment of the present invention. FIG. FIG. 2 shows components of a detection device according to one exemplary embodiment of the present invention. FIG. 3 shows a coil arrangement of a sensor element according to one exemplary embodiment of the present invention. FIG. 2 illustrates a single channel sensor device according to one exemplary embodiment of the present invention. FIG. 2 illustrates a two-channel short circuit protection system according to one exemplary embodiment of the present invention. FIG. 6 illustrates a sensor according to another exemplary embodiment of the present invention. FIG. 6 illustrates one exemplary embodiment for secondary sensor unit assembly according to one exemplary embodiment of the present invention. FIG. 4 shows two forms of primary sensor and secondary sensor geometrical arrangements according to one exemplary embodiment of the present invention. It is the schematic for demonstrating that it is desirable for the space | interval between a secondary side sensor and a sensor host to be as small as possible. It is a figure which shows embodiment about the encoding apparatus of a primary side sensor. It is a figure which shows the magnetization apparatus which does not contain the object surrounding other objects. FIG. 2 shows a magnetizing device according to the invention including an object surrounding another object. 1 shows a schematic diagram of a torque and force detection device with a magnetic encoding region formed in accordance with the present invention. FIG. FIG. 68B is a signal versus torque diagram of the torque and force detector magnetized by the magnetizer shown in FIG. 68A. FIG. 69B is a signal versus torque diagram of the torque and force detector magnetized by the magnetizer shown in FIG. 68B. 1 is a schematic diagram illustrating the principle of a method for magnetizing an object according to the invention. 1 is a schematic diagram showing an apparatus for magnetizing an object according to the present invention. FIG. 70B is a schematic diagram showing an apparatus for magnetizing an object according to the present invention in conjunction with FIG. 70A. FIG. 6 is a schematic diagram illustrating another apparatus for magnetizing an object according to the present invention. FIG. 71 is a diagram showing a pulse signal for magnetizing an object by the apparatus shown in FIGS. 70A to 70C. FIG. 3 shows another embodiment of an apparatus for magnetizing an object according to the present invention. FIG. 71B illustrates another embodiment of an apparatus for magnetizing an object according to the present invention in conjunction with FIG. 71A. FIG. 6 shows yet another apparatus for magnetizing an object according to one embodiment of the invention. FIG. 2 shows a top view of an apparatus for magnetizing an object according to an embodiment of the invention. FIG. 2 shows a top view of various devices for magnetizing an object according to an embodiment of the invention. FIG. 2 shows a top view of various devices for magnetizing an object according to an embodiment of the invention. FIG. 2 shows a top view of various devices for magnetizing an object according to an embodiment of the invention. FIG. 3 shows another device for magnetizing an object according to the invention. FIG. 2 shows a device for calibrating a force and torque detection device according to the invention. Fig. 3 shows a view from different directions of a device for calibrating a force and torque detection device according to the invention. 1 shows a schematic view of a force and torque detection device according to the invention. 1 shows a schematic view of a force and torque detection device according to the invention. FIG. 3 shows a view of a magnetically encoded hollow cylinder from different directions. It is a figure which shows the detection apparatus by this invention. FIG. 5 shows yet another apparatus for magnetizing an object. FIG. 6 shows yet another apparatus for magnetizing an object according to one embodiment of the invention. FIG. 5 shows another device for calibrating a force and torque detection device according to the invention.

Claims (25)

In the first product body及 beauty / or methods for magnetizing the second object,
A step of the first object is to place the first object so as to surround the second object,
The first electrical signal comprises the steps of applying to said second object,
The first object is a hollow tube;
It said first electrical signal, at least a portion of the first material body及 beauty / or the second object is added to be magnetized,
After applying the first electrical signal, a second electrical signal is applied to the second object, and the second electrical signal is applied such that at least a portion of the first object and / or the second object is magnetized. The second electrical signal differs from the first electrical signal with respect to at least one of the group consisting of amplitude, sign, signal shape, and duration;
The first object and / or the second object is magnetized by applying the first electrical signal and the second electrical signal and is perpendicular to the surface of the first object and / or the second object The magnetic field structure is generated such that the first magnetic flow is in the first direction, the second magnetic flow is in the second direction, and the first direction is opposite to the second direction. A method characterized by that. The method of claim 1, wherein the first electrical signal is a first pulse signal or a series of continuous pulse signals. A method according to claim 2, in which the time-current diagram, the first pulse signal has a vertical of fast rising edge, characterized in that and have slow falling edge. 4. A method as claimed in any preceding claim, wherein the first electrical signal is a current or a voltage. The method of claim 1 , wherein
The method of claim 2, wherein the second electrical signal is a second pulse signal or a series of continuous pulse signals. The method of claim 5 , wherein
In time versus current diagram, wherein the having the second pulse signal has a vertical of fast rising edge, and a slow falling edge. The method according to claim 5 or 6 , wherein
The method wherein the second electrical signal is a current or a voltage. An apparatus for magnetizing a first material body及 beauty / or the second object,
A first object that is a hollow tube ;
A second object,
An electrical signal source,
The first object is arranged such that the first object surrounds the second object;
The electric signal source is constituted of the first electrical signal to apply to said second object, such that the first electrical signal is at least a portion of the first material body及 beauty / or the second object is magnetized Added,
After applying the first electrical signal, a second electrical signal is applied to the second object, and the second electrical signal is applied such that at least a portion of the first object and / or the second object is magnetized. And the second electrical signal differs from the first electrical signal with respect to at least one of the group consisting of amplitude, sign, signal shape, and duration;
The first object and / or the second object is magnetized by applying the first electrical signal and the second electrical signal and is perpendicular to the surface of the first object and / or the second object The magnetic field structure is generated such that the first magnetic flow is in the first direction, the second magnetic flow is in the second direction, and the first direction is opposite to the second direction. A device characterized by that. The apparatus according to claim 8 .
The apparatus wherein the second object is one of a group consisting of a shaft, a wire, and a hollow tube. The apparatus according to claim 8 or 9 ,
The apparatus, wherein the second object is arranged at the center of the first object. The apparatus according to any one of claims 8 to 10 ,
The apparatus of claim 1, wherein the electrical signal source comprises a capacitor bank. 12. The device according to any one of claims 8 to 11 ,
The first object has a first electrical connection and a second electrical connection, the second object has a first electrical connection and a second electrical connection, and a second of the first object An apparatus, wherein an electrical connection is coupled to the first electrical connection of the second object. The apparatus of claim 12 , wherein
The electrical signal source is connected such that a first electrical signal can be applied between a first electrical connection of the first object and a second electrical connection of the second object. The apparatus of claim 12 , wherein
Wherein the first object has a third electrical connection, device said second object and having a third electrical connection. The apparatus of claim 14 .
The electrical signal source, together with connected thereto so as to be applied between the second electrical connection portion of said first electrical signal and the first electrical connection portion of said first object second object, the second electrical signal Is connected so that it can be applied between the third electrical connection of the first object and the third electrical connection of the second object. The device according to any one of claims 12 to 15 ,
The apparatus further comprising a conductive coupling element arranged to couple the second electrical connection of the first object to the first electrical connection of the second object. The apparatus of claim 16 .
A device characterized in that the coupling element is a conductive plate or a conductive liquid. The apparatus according to any one of claims 8 to 17 ,
In addition to the first object, the second object is adapted to be magnetized when a first electrical signal is applied. 12. The device according to any one of claims 8 to 11 ,
The second object includes a first connection part and a second connection part, and the electrical signal source is connected between the first connection part and the second connection part of the second object. The apparatus according to any one of claims 8 to 11 or 19 ,
The apparatus wherein the electrical signal source is disconnected from the first object. The device according to claim 19 or 20 ,
A portion of the second object is not surrounded by the first object, and is further arranged to electromagnetically shield a portion of the second object not surrounded by the first object from the first object. And a configured shielding element. The apparatus of claim 21 .
The apparatus according to claim 1 , wherein the shielding element is arranged between the first object and a part of the second object not surrounded by the first object. The apparatus of claim 21 .
The device characterized in that the shielding element is a tube and is arranged to surround a part of the second object not surrounded by the first object. The apparatus of claim 21 .
A device wherein the shielding element comprises a plurality of sub-elements, the elements being arranged to surround a portion of the second object not surrounded by the first object. 25. A method of using an apparatus according to any one of claims 8 to 24 to magnetize one of the group consisting of a mining shaft, a concrete processing cylinder, a push-pull rod in a gearbox, and an engine shaft.

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