Portable meter for measuring the force generated by magnetic devices

Abstract

A portable meter (1) for measuring the force generated by a magnetic device (2), comprising a mobile probe (3) configured to be coupled to the magnetic device (2), the force of which needs to be measured, and a detection unit (7), the mobile probe (3) comprising at least one active ferromagnetic element (4), the at least one active ferromagnetic element (4) having a configuration corresponding to the configuration of the magnetic poles (N, S) of the magnetic device, the force of which needs to be measured, the probe being equipped with alignment means (5, 6), the alignment means (5, 6) being configured to align the at least one active ferromagnetic element (4) with at least one magnetic pole (N, S) on the magnetic device (2), the at least one active ferromagnetic element (4) having at least one turn (B) of conductive material wound around it, the detection unit (7) being connected to the at least one turn (B) in order to detect the magnetic flux flowing through the coil, at least during transient activation / deactivation of the magnetic device.

Description

Technical Field

[0001] The present invention relates to a portable meter for measuring the force generated by a magnetic table. Background Art

[0002] A magnetic clamping system (or magnetic device) is a device designed to anchor ferromagnetic materials during a mechanical process performed with a machine tool, as part of the movement (handling and / or lifting) of a machined workpiece or for rapid tool clamping.

[0003] Some magnetic devices defined as "electropermanent magnetic" comprise a magnetic section (referred to as an "electropermanent magnetic module") and an electronic activation / deactivation system (referred to as a "control unit").

[0004] The electro-permanent magnetic module comprises a load-bearing structure made of mild steel, designed to house all the internal components, and one or more pole pieces made of mild steel, the load-bearing structure having various shapes and features to allow it to be adapted to different requirements. The pole pieces, also known as poles, are generally arranged to define an anchoring surface.

[0005] Each pole has a permanent magnet coupled to it, and a so-called “reversing” magnet. Each reversing magnet is coupled to a solenoid that can change the polarity of the reversing magnet.

[0006] When the magnetic flux generated by the permanent magnet is added to the magnetic flux of the reversing magnet, the magnetizable surface is activated. When the magnetic fields generated by the permanent magnet and the reversing magnet are removed, the magnetizable surface is deactivated.

[0007] The activation solenoid is controlled by a control unit, the control unit comprising:

[0008] - a controlled bidirectional rectifier that supplies the appropriate power to the solenoids in the electro-permanent magnetic module;

[0009] - one or more control panels to enable an operator to activate and deactivate the electro-permanent magnetic module;

[0010] -System management control logic;

[0011] - an electrical connection system (usually a cable) to connect the control unit and the electro-permanent magnetic module.

[0012] The purpose of the control unit is to activate / deactivate the electropermanent magnetic module by magnetizing, demagnetizing or reversing the polarity of some or all of the reversing magnets contained in the module.

[0013] The control unit may be electrically disconnected from the magnetic module except when two magnetizing operations need to be completed.

[0014] There are other known magnetic devices that operate in different ways.

[0015] For example, magnetic devices formed by electromagnets are known. In this case, in order to magnetize the magnetizable surface, it is necessary to provide a continuous power supply to a coil coupled to a plurality of magnetic poles defining said magnetizable surface (since these devices do not include permanent magnets).

[0016] Other magnetic devices are also known, which are generally referred to as “permanent magnets.” These systems work by utilizing the magnetic field generated by the permanent magnets, and activation of such systems does not require electrical devices and solenoids.

[0017] The magnetic effect can be activated or deactivated using an operating rod that mechanically modifies the combination of iron and magnets located below the magnetizable surface. This is the best known and most common system for simply processing ferrous materials, most importantly because it generally requires no electricity and maintenance.

[0018] However, one feature common to all magnetic devices is the presence of a ferromagnetic surface onto which the part to be anchored is positioned and which performs the anchoring function (by establishing a magnetic flux).

[0019] The anchoring function (ie, the force used to hold a particular part by the magnetic system) is always subject to and may vary significantly depending on the physical properties of the part.

[0020] In particular, the force is governed by the properties of the ferromagnetic material constituting the part to be clamped, by any air gap that may exist between the anchoring surface and the part to be anchored, and by the geometrical characteristics of the part to be clamped.

[0021] Typically, manufacturers of magnetic systems provide graphs showing how the performance (generated force) varies with the parameters mentioned, one at a time.

[0022] Obviously, these graphs do not simplify the way in which the typical operator, for example, needs to determine the force being used to hold the part before commencing work with the machine tool.

[0023] This is primarily because the “de-rating” parameters all vary simultaneously (rather than one at a time as shown in the graph), and secondly because it is not always possible to size them perfectly.

[0024] For example, if we mention the air gap, determining the size and the average value is always very complicated, considering that said gap can only be observed from the edge of the anchored part, and even if one does have such information available, it is actually impossible to easily determine the anchoring force from the graph.

[0025] Currently, two methods are used to measure the force used to hold ordinary parts by magnetic systems, both of which have the disadvantage of always significantly disturbing the anchoring conditions.

[0026] The first method involves the use of a mechanical force generator (such as a press) and a load cell.

[0027] The mechanical force generator will apply the force to the part anchored to the magnetic surface until the part breaks away, wherein the force value at which separation occurs is recorded using the load cell.

[0028] This technique is primarily used when testing magnetic equipment. During repair / testing, the equipment is transported to a location where a press is available and tested.

[0029] This is not possible in the case of large appliances such as magnetic work tables (for example for clamping workpieces during machining) or in the case of lifts for heavy objects.

[0030] Besides any technical limitations and costs associated with attempting to replicate this strategy in every possible situation, it is clear that obtaining information about the clamping forces necessarily results in significantly perturbing such forces (causing separation).

[0031] The second method involves obtaining an appropriate air cavity or gap between the magnetic table and the workpiece to be anchored. A probe connected to a magnetic induction meter can then be inserted into the cavity or gap. Knowing the magnetic induction intensity, calculations can be performed to estimate the anchoring force.

[0032] This technique is easier to implement since it does not require moving the device being tested, but it essentially modifies the anchoring conditions.

[0033] In particular, the introduction of a gap leads to an exponential decrease in the force, so that the force is known but the anchoring is much worse than in reality.

[0034] Some more advanced electropermanent magnetic systems, such as those described in EP3357075-A1, have integrated devices for measuring force. By measuring the magnetic flux, these systems can provide information about the actual anchoring force. However, as mentioned above, these systems are integrated into the magnetic workbench. Summary of the Invention

[0035] The purpose of the present invention is to overcome the technical defects of the known technology.

[0036] Another object of the present invention is to provide a portable meter that is able to detect the force used by the magnetic system to clamp common workpieces and that is simple, reliable and inexpensive.

[0037] It is another object of the present invention to provide a portable meter that minimizes or eliminates disturbance of anchoring conditions, thereby allowing reliable field testing.

[0038] This and other objects are achieved by a portable meter produced according to the technical teaching of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further features and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of the device, which is illustrated by way of non-limiting example in the accompanying drawings, in which:

[0040] Figure 1 A simplified perspective view of the device according to the invention with a magnetic device and a workpiece to be clamped in a partially exploded configuration;

[0041] Figure 2 for Figure 1 A stereogram of the instrument during the test phase;

[0042] Figure 3 Show Figure 1 Exploded perspective view of an open-loop type probe for an instrument;

[0043] Figure 4 The detection unit of the meter of the present invention is shown, and the detection unit cooperates with the probe during use;

[0044] Figure 5 、 6 and 7 shows Figure 3 A three-dimensional assembly diagram of possible configurations of the probe;

[0045] Figure 6A Shown in detail Figure 3 and 10 The details circled in the

[0046] Figure 8 Shown in a three-dimensional diagram Figure 3 Different configurations of probes in the apparatus (particularly, closed loop types) and different magnetic devices that can be used with the probes;

[0047] Figure 9 for Figure 8 Exploded perspective view of the probe in FIG;

[0048] Figure 10 Schematically shown Figure 4 a detection unit in when coupled to a probe (also shown schematically); and

[0049] Figure 11 and 12 Different configurations of the probe (of the closed loop type) are shown in a three-dimensional assembled view and a three-dimensional exploded view. DETAILED DESCRIPTION

[0050] With reference to the aforementioned figures, reference numeral 1 is generally used to indicate an instrument for measuring the force of a magnetic device 2, 2A.

[0051] The portable meter 1 for measuring the force generated by a magnetic device 2 comprises a mobile probe 3 configured to be coupled to the magnetic device 2 , the force of which is to be measured, and a detection unit 7 connected or connectable to the probe 3 .

[0052] The connection between the detection unit 7 and the probe 3 can be accomplished in a simple manner, for example via a cable 20 equipped with at least one connector 12 (the cable 20 is shortened in the figure for the sake of simplicity).

[0053] Other more complex forms of connection are conceivable, such as a wireless connection for signal transmission with transceiver systems on both the probe and the detection unit 7 .

[0054] The probe 3 comprises at least one active ferromagnetic element 4 having a configuration substantially corresponding to the configuration of the magnetic poles N, S on the magnetic device whose force is to be measured.

[0055] In this context, the term "active ferromagnetic element 4" means that said element has at least one turn B (or coil) made of electrically conductive material wound around it, said turn being interfaced with or "readable" by the detection unit 7 in order to detect the magnetic flux flowing through said turn during the activation / deactivation transients of the magnetic device.

[0056] exist Figure 1 In the example shown in , the probe 3 has six ferromagnetic elements 4, 4A. Figure 3 In FIG, it can be seen that the turns B surround only three ferromagnetic elements (those marked 4), which are therefore active.

[0057] On the probe 3 , there are also three ferromagnetic elements 4A which, for the sake of simplicity, are without turns B.

[0058] The passive ferromagnetic element 4A and the active ferromagnetic element 4 are separated from each other by a magnetic insulator I. The magnetic insulator may be made of, for example, brass, aluminum, non-magnetic stainless steel, plastic, resin, copper, or the like.

[0059] The ferromagnetic element may be made of, for example, iron having high magnetic permeability and low coercive field, such as pure iron (trade name ARMCO).

[0060] It should be noted that the probe 3 is equipped with alignment means configured to align the at least one active ferromagnetic element 4 with at least one magnetic pole N, S on the magnetic device 2 .

[0061] In this context, the term "alignment device" may be any device capable of allowing at least one ferromagnetic element 4 to be aligned or coupled to at least one magnetic pole N, S of the magnetic device 2 so as to allow the active ferromagnetic element 4 to be effectively and precisely positioned on top of the magnetic poles N, S.

[0062] The alignment means may be of a visual type. For example, the ferromagnetic element 4 may be aligned with the magnetic pole simply by visually centering the ferromagnetic element 4 on top of the magnetic pole, for example using the insulating material I (e.g. epoxy) as a reference, as the insulating material typically has a different color or different physical properties than the magnetic pole on both the magnetic device and the probe.

[0063] It should be emphasized that the at least one active ferromagnetic element 4 has a configuration corresponding to the configuration of the at least one active surface of the magnetic pole.

[0064] “Active surface of the poles N, S” refers to a generally flat surface designed to couple with the workpiece P to be clamped during machining; the active surface of each pole N, S is advantageously surrounded by an insulator I, which makes it easily and unambiguously identifiable.

[0065] As in Figure 1 As can be seen in the figure, it should be noted that the magnetic device 2 can be a magnetic workbench having a plurality of magnetic poles N, S on its supporting surface 2A, which are arranged in a checkerboard pattern and insulated from each other by an insulating material I.

[0066] In the example shown, the magnetic poles N, S have a square configuration, so the active ferromagnetic element 4 of the probe 3 is also square and has the same dimensions as the magnetic poles N, S on the device 2. Obviously, the passive ferromagnetic element 4A also corresponds in shape and arrangement to the magnetic poles N, S on the magnetic device 2 to be tested (is the same as the magnetic poles N, S on the magnetic device 2 to be tested).

[0067] It must be pointed out that the square shape of the poles, and therefore of the magnetic element, is only one of the possibilities. There can be rectangular poles (as will be seen later), circular poles, etc., and therefore the magnetic element 4, 4A will have the same shape as the pole whose force is to be measured.

[0068] Therefore, even though the probe 3 may have fewer ferromagnetic elements 4, 4A than the magnetic poles N, S on the device to be tested, the shape and arrangement of the ferromagnetic elements 4, 4A and the probe 3 (the distance between them and the positioning) are the same as the shape and arrangement of the magnetic poles N, S on the magnetic device 2 to be tested.

[0069] This makes it very simple to visually align the probe with the magnetic device.

[0070] exist Figure 1 As can be seen in , other types of alignment means are conceivable. For example, each ferromagnetic element (or only some of the ferromagnetic elements on the probe) may have a hole 5 for a pin or screw 10 which engages in a corresponding hole 5A (which may be threaded) in the magnetic device 2 (typically in a magnetic plate).

[0071] These alignment devices are very effective because they make positioning errors almost impossible.

[0072] If screws 10 are used, the fastening of the probe 3 to the magnetic device is even more stable.

[0073] In order to obtain an effective alignment (or centering) with the magnetic device, at least two pins or screws 10 (and corresponding holes 5 ) are advantageously envisaged.

[0074] To complete the description, it should be noted that the turn B (or more precisely, each turn B) can be constructed as follows Figure 6A As shown in .

[0075] In this text, the term “turn” is used to denote the basic unit of a winding. Advantageously, instead of a single turn B, an element made of several turns B (ie a coil) can be used, which greatly improves the reading of the magnetic flux.

[0076] Figure 6A A detail of this coil (a set of turns B) is shown, which may be made of a copper track R on a vetronite structure S suitably insulated with a solder mask.

[0077] Obviously, the coil made of turns B can also be made in other more conventional ways (for example, wound directly around a ferromagnetic element).

[0078] It is important to note that the distinction between "positive" and "negative" ferromagnetic elements on the board does not depend on the presence or absence of wire turns connecting these elements. Rather, it is more of a logical distinction.

[0079] In practice, to simplify the construction, all ferromagnetic elements 4, 4A on the probe 3 can be surrounded by at least one turn B. However, during "reading", only one or only half or only some of the ferromagnetic elements present on the probe 3 will be "read" by the detection unit 7. In this case, the ferromagnetic elements that have been "read" can be defined as "active" 4.

[0080] Obviously, it is also possible to configure the detection unit 7 to read the turns B on all ferromagnetic elements 4, 4A. In this case, it will detect a first flux from half of the ferromagnetic elements and a flux with opposite polarity from the other ferromagnetic elements.

[0081] Although not required, the detection unit 7 may use detection of flux in the "opposite" direction for testing.

[0082] Structurally, probe 3 is very simple and Figure 3 It can comprise a frame T, under which a clamp M is fastened (for example, by screws). The ferromagnetic elements 4, 4A are coupled to the clamp M together with the corresponding turns B.

[0083] An arrangement of spacers D made of magnetically insulating material (for example brass) is then created, and the spaces between the magnetic elements are filled with insulating material I, such as resin.

[0084] The spacer D may also be welded (eg brazed) to the ferromagnetic element 4 , 4A.

[0085] Figure 3 It is clearly shown that the turns B are located on alternating ferromagnetic elements. They are also preferably connected in series. Thus, the active ferromagnetic elements are those ferromagnetic elements of the same polarity that read the flux generated by the magnetic device. For example, Figure 2 As shown in FIG, when the coil is placed on top of the table, the active ferromagnetic element is located on the N pole. Obviously, it is also possible to place the active element on the S pole (by moving the probe 3 down one row and then placing it closer to the Figure 2 edge of the work surface in the work area).

[0086] The above description relates to a particular configuration of a hexapole stackable probe 3 on a magnetic apparatus 2 as shown in the figures, and which is suitable for detecting forces acting on a workpiece P as shown in the figures.

[0087] However, precisely because the probe 3 is simple in construction and very low in cost, other types of probes 3 can be envisaged, each suitable for detecting forces on different magnetic devices or simply detecting forces on workpieces P of different shapes.

[0088] Therefore, in general, the probe can include a plurality of active ferromagnetic elements 4 and a plurality of passive ferromagnetic elements 4A arranged in a checkerboard pattern, wherein a magnetic insulator I is positioned between each active ferromagnetic element 4 and each passive ferromagnetic element 4A arranged side by side, and the plurality of active and passive ferromagnetic elements have the same shape and arrangement as the magnetic poles N, S on the magnetic device 2 whose force needs to be measured.

[0089] exist Figures 5 to 7 Some examples of possible alternative or additional configurations of the probe 3 are shown in FIG.

[0090] In these figures, the same reference numerals as previously used are used to denote components that are functionally similar to those already described and therefore will not be described again.

[0091] Generally, in any case, the various types of probes will be represented as 3, and to simplify the description, each type of probe will be identified by a letter following 3.

[0092] Figure 5 The probe 3A in FIG has four ferromagnetic elements 4, 4A instead of six. During operation, two ferromagnetic elements are active and two are negative. The other structural features are the same as those already described.

[0093] Figure 7 The probe 3B in FIG has only two ferromagnetic elements. During use, one is positive and one is negative.

[0094] Obviously, this probe is used for small workpieces P.

[0095] Obviously, other types of probes can be envisaged, such as having 8 ferromagnetic elements, 10 ferromagnetic elements, etc. Preferably, but not necessarily, there is an even number of ferromagnetic elements on the probe.

[0096] The probes described so far are all of the open loop type. In practice, in the presence of a workpiece P (which may be a normal workpiece to be clamped) on the probe 3, the magnetic circuit is closed outside the probe through the workpiece.

[0097] However, some other types of (also open-circle) probes can be envisaged, e.g. Figure 6 As shown in FIG, the probe is denoted as 3C.

[0098] The probe 3C has only one active ferromagnetic element 4 .

[0099] During use, the one active ferromagnetic element 4 must be coupled to another passive ferromagnetic element 4B, separate from (not integrated into) the probe. The passive element 4B serves only to close the magnetic circuit and can have any dimensions in plan view.

[0100] However, the thickness must be similar or equal to the thickness of the magnetic element 4 on the probe.

[0101] Figure 8 Another different embodiment of the probe is shown, in this case in closed loop form.This 3D probe is optimized for measuring the forces of a very popular portable manual system known as the "Permanent Magnet" system 2A.

[0102] Because the 3D probe is a closed loop type, it has a single element 140 made of ferromagnetic material, wherein the ferromagnetic elements 4 and 4A are made using the shape formed on the magnetic element. In fact, the ferromagnetic elements 4 and 4A have the same configuration as the magnetic poles on the manual device 2A and are magnetically short-circuited.

[0103] In this case, the magnetic poles on the device are rectangular and extremely elongated, and so are the ferromagnetic elements 4, 4A on the 3D probe (see Figure 9 ).

[0104] In the above-described embodiment, the ferromagnetic elements 4 and 4A and the element 140 are made as a single piece, but different configurations are possible, for example, one in which the ferromagnetic elements are simply mechanically fixed to an element that magnetically short-circuits them.

[0105] The alignment system of the 3D probe comprises a simple frame 6 that centers the perimeter of the magnetic device 2A relative to the ferromagnetic elements 4, 4A on the probe, thereby ensuring that the ferromagnetic elements 4, 4A perfectly match the poles on the device 2A.

[0106] Obviously, the turns B which must surround at least the active pole 4 also have an elongated configuration, as in Figure 9 Can be seen in.

[0107] Advantageously, the 3D probe also has a handle R1 for easy portability.

[0108] Figure 11 and 12 A further possible configuration of a closed-loop probe is shown.

[0109] Also in this case, the ferromagnetic elements 4 and 4A and the element 140 are made in a single piece and are therefore magnetically short-circuited.

[0110] Obviously, also in this case, the element 140 can be formed as a single part (as shown in the figures) or as several assembled parts.

[0111] In some variants, the system described pursues the goal of not disturbing the magnetic flux generated by the magnetic device 2 , 2A, or disturbing said magnetic flux only minimally by means of thin elements made of ferromagnetic material.

[0112] In practice, the thickness H of the ferromagnetic element 4 , 4A may be comprised between 1 mm and 10 mm, preferably between 2 mm and 5 mm, even more preferably 2 mm.

[0113] In particular, the thickness H of the ferromagnetic element or elements can be calculated to ensure the maximum magnetic permeability under the expected conditions of use. This is possible because the magnetic permeability curve of the material used is precisely known.

[0114] In particular, it is assumed that the flux through the anchoring surface is equal to , and assuming that the flux is uniform, the magnetic induction effect of the flux can be calculated using the following formula:

[0115] R1:

[0116] in, is the magnetic induction intensity and is the surface through which the magnetic flux passes. Once it is known , we can use the known The simple relationship associated with calculating the surface force density ,for example:

[0117] R2:

[0118] Whatever magnetic system is considered (permanent or electropermanent), activation of said magnetic system generates a variation of the magnetic flux ranging from zero to a certain value.

[0119] This flux variation can be intercepted and processed by turns S (or coils) situated on the periphery of a ferromagnetic element 4 , 4A interposed between the magnetic surface and the workpiece P to be anchored.

[0120] The probe 3 may be constructed to be magnetically permeable, completely free of air gaps, and to have exactly the same contour as the magnetic surface (or at least the magnetic poles) on which it is placed or integral with.

[0121] During the activation phase of the magnet below the pole, the wire turn B integrated into these probes will generate at its end a voltage proportional to the change in the magnetic flux flowing through said wire turn (and therefore through the pole). In the literature, this relationship is known as Faraday Neumann Lenz's law:

[0122] R3:

[0123] in, is the generated voltage, is the number of turns that make up the sensing coil, and is the time derivative of the magnetic flux passing through the surface of the sensing coil.

[0124] By inverting this relationship, the average magnetic flux can be calculated , and then - using the relation R1 - calculate the induction intensity .

[0125] Then, since the induction intensity is known And using known relations from the literature (such as R2), the surface force density can be calculated , once the magnetic pole The surface generates the surface force density , the surface force density The values ​​of the forces generated by the respective magnetic poles N and S are provided.

[0126] The detection unit 7 will process the signal from the probe 3 and then invert equation R3 in order to calculate the magnetic induction intensity as in R1.

[0127] Once the induction strength is known And also knowing the surface of the active ferromagnetic element 4 on the probe, the unit is able to calculate the pressure as R2, and the anchoring force of one or more surfaces.

[0128] It must be emphasized that the magnetic permeability of the material used for the ferromagnetic element, as well as its thickness, is very important in order to ensure that the probe does not significantly affect the force used by the anchoring system to clamp the ferromagnetic material to it, because the magnetic reluctance (i.e. the measure of the probe's resistance to the passage of magnetic flux) is inversely proportional to the magnetic permeability of the material. And it is proportional to the probe thickness.

[0129] Therefore, it is advantageous to have a ferromagnetic element 4, 4A made of pure iron, ARMCO or the like.

[0130] Obviously, the lower the ratio between the probe thickness and the total magnetic path length, the less important the geometrical properties of the ferromagnetic element 4, 4A are in the calculation of the total flux.

[0131] The detection unit 7 will be configured to accept a plurality of probes 3, 3A, 3B, 3C, 3D, and so on.

[0132] In addition to performing the calculations seen above, the unit 7 will also be able to perform said calculations parametrically, accepting a plurality of input probes, identifying said plurality of input probes and adapting the calculation procedure to the physical, magnetic and mechanical characteristics of the probes in question.

[0133] For example, each probe 3 may include an identifier 300 ( Figure 10 ), said identifier 300 can be read by the unit 7 to identify the type of probe coupled to the unit 7 , and calculations can then be parameterized based on the physical properties of said probe 3 .

[0134] Using the unit 7 with an appropriate probe 3 means that one can always measure the relative anchoring force performance in any location and for any magnetic device, without significantly changing the performance of the magnetic circuit in question.

[0135] As it is known that a permanent or electropermanent magnetic system remains in the same state unless acted upon mechanically or electrically, it can clearly be concluded that the detection unit can only be activated during the magnetization phase of the magnetic device.

[0136] A suitable control panel 7C will allow operation of the unit 7 and display of the measured forces.

[0137] Figure 10 A possible schematic diagram illustrating the principle on which the device is based is shown.

[0138] Note how the probe 3 may contain an indicator 300 enabling the unit to identify the connected probe in addition to the sensing coil S. The identifier 300 may simply be a resistor, a chip or any other system allowing the probe to be uniquely marked.

[0139] A low noise, low offset preamplification block 7A amplifies the signal from coil S. This signal is then processed by a processing unit 7B in order to solve the above equations.

[0140] The implementation of the R3 equation deserves special mention. Since the inversion of this equation requires the calculation of integrals, special care must be taken in managing the associated calculation procedures. Let us consider the ordinary signal, the ordinary Signals can be written as:

[0141] R4

[0142] in, is the acquired signal, is the true value of the quantity obtained, and The noise still exists.

[0143] Noise can play a significant role in the integration process. For example, if the noise is an offset originating from the preamplifier circuitry or has a non-zero mean value, integrating this offset will produce a drift in the integrated signal that can completely invalidate the calculation being performed.

[0144] Therefore, the noise is almost completely eliminated is preferred.

[0145] The button unit 7C allows the calculation program to be activated only in the vicinity of a flux change, ie when the magnet is activated.

[0146] The obtained values ​​are then shown on the display unit 7D in the form of force and found magnetic induction intensity values.

[0147] Finally, the digital-to-analog converter allows one to display the time course of the result of equation R3 on the 7D display and / or any external display via a viewer.

[0148] This feature ensures that expert technicians can better interpret the magnetic properties of the system to be anchored during the transition processing phase.

[0149] As already partially described, there are basically two types of probes used for magnetic flux detection:

[0150] Closed-loop probe

[0151] Open loop probe.

[0152] An open-loop probe is a probe that connects n north magnetic poles and n south magnetic poles on the magnetic device 2 , 2A through a ferromagnetic path generated by a specific workpiece P to be anchored.

[0153] In these probes (e.g. Figure 3 In the probe (in the example), preferably, in the present case of north magnetic polarity, only the output flux is monitored, that is, all poles with the same magnetic polarity. The reason is that, since the magnetic field is a closed line field, the flux of the magnetic induction intensity vector entering the south pole is the same as the flux leaving the north pole. In practice, there is nothing to prevent one from adding three more coils and measuring the north pole flux and the south pole flux. In addition, it should be noted that the coils can be connected in series, so equation R3 becomes:

[0154] R5:

[0155] in

[0156] R6:

[0157] The three fluxes can then be calculated by inverting equation R5 and considering the following:

[0158] R7:

[0159] It will be possible to calculate 、 , and therefore .

[0160] Unlike previous probes, the open-loop probe ( Figure 6 ) is inserted between the magnetic system and any workpiece to be magnetically anchored.

[0161] The probe 3C can be positioned on top of one or more magnetic poles, and the magnetic ring is closed by the workpiece to be anchored.

[0162] Essentially, a parallelepiped 4B made of ferromagnetic material 1 is positioned on the magnetic system and is integrated with it by means of screws placed in clamping holes.

[0163] Probe 3C will be used to acquire changes in flux.

[0164] Various embodiments of the present invention have been described, but other embodiments can be conceived using the same innovative concepts.

Claims

1. A portable meter (1) for measuring the force generated by a magnetic device (2), the portable meter (1) comprising a mobile probe (3) configured to be coupled to the magnetic device (2) whose force is to be detected, and a detection unit (7), the mobile probe (3) comprising at least one active ferromagnetic element (4), the at least one active ferromagnetic element (4) having a configuration corresponding to the configuration of the magnetic poles (N, S) of the magnetic device (2), the mobile probe being equipped with an alignment device configured to align the at least one active ferromagnetic element (4) to at least one magnetic pole (N, S) of the magnetic device (2), the at least one active ferromagnetic element (4) being surrounded by at least one wire turn (B) made of an electrically conductive material, the detection unit (7) being docked with the at least one wire turn (B) in order to detect the magnetic flux flowing through the wire turn at least during a transient activation / deactivation of the magnetic device.

2. The portable meter according to claim 1, wherein: The turns (B) are the portion of the coil associated with the active ferromagnetic element.

3. The portable meter (1) according to claim 1, characterized in that The mobile probe (3) comprises at least one active ferromagnetic element (4) and at least one passive ferromagnetic element (4A) separated from each other by a magnetic insulator (I), or comprises the active ferromagnetic element (4) and the passive ferromagnetic element (4A) in a magnetic short circuit.

4. The portable meter (1) according to claim 2, characterized in that The mobile probe comprises a plurality of active ferromagnetic elements (4) and a plurality of passive ferromagnetic elements (4A) arranged in a checkerboard pattern, a magnetic insulator (I) being positioned between each active ferromagnetic element (4) and each passive ferromagnetic element (4A) positioned side by side with each other, and / or the plurality of active ferromagnetic elements and the plurality of passive ferromagnetic elements having a shape and arrangement corresponding to the shape and arrangement of the magnetic poles (N, S) of the magnetic device (2).

5. The portable meter according to claim 1, wherein: The alignment means are of visual type.

6. The portable meter according to claim 3 or 4, characterized in that: The alignment means are of mechanical type and comprise at least one pin or screw (10) and / or a frame (6) for centering the hole (5) of the active ferromagnetic element (4) or the passive ferromagnetic element (4A).

7. The portable meter according to claim 1, wherein: The detection unit (7) is docked with the mobile probe (3) via at least one removable electrical connector (12).

8. The portable meter according to claim 1, wherein: The detection unit (7) comprises a processing unit (7B) configured to read the magnetic flux detected by the turns (B) during the magnetization transient process of the magnetic device (2) and convert the magnetic flux into a force value.

9. The portable meter according to claim 8, characterized in that The mobile probe (3) comprises an identifier which can be read by the detection unit in order to associate the mobile probe (3) with its own physical parameters in order to convert the magnetic flux into a force value.

10. The portable meter according to claim 8, characterized in that The detection unit (7) comprises a screen (7D) on which the force value and / or the force curve graph are displayed.

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