Member for the combined gripping and detection of the presence of a ferromagnetic part

Abstract

The present invention relates to a member for the combined gripping and detection of the presence of a ferromagnetic part, which member takes the form of a presence or proximity detector (1) comprising, at least, a detection member (2), a circuit (3) at least for processing the signals output thereby, also ensuring the powering or energisation of the member (2), and a protective casing (4) housing the member (2) and the circuit (3) and having a wall (5) defining a sensitive face (6) in relation to the detection member (2), as well as electrical connection means (7) for the circuit (3). This member is characterised in that the detector (1) is of the LC inductive circuit type and in that it further comprises at least one magnet (8), of the permanent or electromagnet type, mounted in the protective casing (4), in the region of the sensitive face (6), the abovementioned member (2) and circuit (3) being selected and / or configured such that the presence or proximity detection function is not disturbed by this magnet (8).

Description

Description Title of the invention: Combined member for gripping and detecting the presence of a ferromagnetic part

[0001] [The present invention relates to the field of industrial devices for detecting and handling metal parts, and has as its objects a combined member for gripping and detecting the presence of a ferromagnetic part in the form of an improved presence or proximity detector, with integrated holding function, and an industrial workstation comprising at least one such combined member.

[0002] Many varieties of detectors of the above-mentioned type are already known, in particular inductive detectors.

[0003] In particular, inductive detectors have been marketed by the applicant for many years and are, for example, described in documents FR 2 827 677, EP 1 580 889, EP 1 580 536, EP 1 965 177 and EP 2 546 614. A specific detector of this type, called “factor 1”, is disclosed by document EP 3 430 443.

[0004] These presence or proximity detectors are often used in association with or integrated into gripping devices for parts (particularly small parts) which must be positioned and held precisely in relation to at least one other part, with which it must be secured, for example by welding, or cooperate, for example by engagement.

[0005] Currently, these parts are taken, moved, manipulated, held, engaged and / or blocked in a position by specific gripping members and blocking means, magnetic, mechanical (pneumatically, hydraulically or electrically actuated grippers), suction or similar, which either integrate the aforementioned detectors or cooperate with them to verify the actual presence and / or the appropriate position of the expected part.

[0006] This results in complex, expensive and cumbersome workstation constructions, especially when the parts concerned are relatively small and have to be placed in a high-risk environment. This is the case for small ferromagnetic metal parts. (typically a few hundred grams) to be brought, placed and held in position temporarily, before being assembled by welding with larger ferromagnetic metal parts.

[0007] The main aim of the present invention is to overcome at least the main drawbacks mentioned above, in particular but not limited to the above-mentioned context, by proposing a simple, economical and compact solution.

[0008] To this end, it relates to a combined member for gripping and detecting the presence of a ferromagnetic part, in the form of a presence or proximity detector comprising at least one detection member, at least one circuit for processing the signals delivered by the latter, also ensuring the power supply or excitation of said member, and a protective housing housing said member and said circuit and having a wall defining a sensitive face in relation to the detection member, as well as electrical connection means for said circuit, combined member characterized in that said detector consists of an inductive detector with a detection member of the LC circuit type and a suitable circuit for excitation and processing of the signals, and in that said detector also comprises at least one magnet, of the permanent or electromagnet type, mounted in the protective housing, in the region of the sensitive face,the aforementioned detection member and circuit being configured in such a way that the presence or proximity detection function is not disturbed by this magnet.,

[0009] The invention will be better understood from the following description, which relates to preferred embodiments, given as non-limiting examples, and explained with reference to the appended schematic drawings, in which:

[0010] [Fig. 1A] is a sectional view along a plane perpendicular to its sensitive face of a combined member according to a first embodiment of the invention;

[0011] [Fig. 1 B] is an exploded perspective view of the combined member shown in Figure 1A;

[0012] [Fig. 1 C] is a perspective view of the functional elements of the combined member of Fig. 1 A, with the housing removed;

[0013] [Fig. 2] is a view similar to that of Fig. 1A, with the combined member installed and cooperating with a reference part;

[0014] [Fig. 3A] is a perspective and partially sectional view of a combined member according to a second embodiment of the invention;

[0015] [Fig. 3B] is a sectional view along a plane perpendicular to its sensitive face of the combined member of Figure 3A;

[0016] [Fig. 4A] is a perspective view of a combined member according to a third embodiment of the invention;

[0017] [Fig. 4B] is a sectional view along a plane perpendicular to its sensitive face of the combined member of Figure 4A;

[0018] [Fig. 5A] is a perspective view of a combined member according to a fourth embodiment of the invention;

[0019] [Fig. 5B] is a sectional view along a plane perpendicular to its sensitive face of the combined member of Figure 5A.

[0020] Figures 1 to 5 illustrate different constructive variants of a combined member for gripping and detecting the presence of a ferromagnetic part, in the form of a presence or proximity detector (1) comprising, at least, a detection member (2), at least one circuit (3) for processing the signals delivered by the latter, also ensuring the power supply or excitation of said member (2), and a protective casing (4) housing said member (2) and said circuit (3) and having a wall (5) defining a sensitive face (6) in relation to the detection member (2), as well as means (7) of electrical connection for said circuit (3). This latter circuit may or may not also ensure the excitation of the detection member (2), depending on the case and the nature of said member. This circuit (3) can be mounted on a single support (figures 1, 2 and 4) or be distributed over at least two supports (figures 3 and 5), see include an additional part (3').The wall (5) may for example be part of a cap and be extended by a side skirt, said cap closing the front end of the main body of the housing (4) in the form of a tube.

[0021] According to the invention, this detector (1) consists of an inductive detector (1) with a detection member (2) of the LC circuit type and a circuit (3) adapted excitation and signal processing, and also comprises at least one magnet (8), of the permanent or electromagnet type, mounted in the protective housing (4), in the region of the sensitive face (6), the aforementioned detection member (2) and circuit (3) being configured in such a way that the presence or proximity detection function is not disturbed by this magnet (8).

[0022] Thanks to these provisions, the invention provides a combined member in the form of an improved proximity or presence detector, namely having an additional functionality of holding and maintaining in position one or more metal parts, having a mass compatible with the magnetic attraction force (FAM) generated by the magnet (8). It is thus possible to do without, depending on the contexts and applications of use of this improved detector (1), specific holding devices or grippers.

[0023] Furthermore, by integrating this additional functionality in its entirety into the housing of the detector (1) to form the combined member of the invention, the size, fixing and connection of said detector (1) are not modified compared to the same detector without said additional functionality. For this purpose, the shape of the magnet (8) at least present is adapted to the interior volume available in the housing (4), in particular in the region of said volume located at the rear of the sensitive face (6). Although several magnets can be integrated to achieve the functionality (combination of several similar or different magnets for reasons of standardization or obtaining a sufficient magnetic attraction force (MAF), optimal use of the space available in the housing, etc.), the implementation of a single magnet (8) is favored.It can be noted that given the independence of the two functionalities and in particular the fact that the detection function is not influenced by the presence and action of the magnet (8), the latter can be chosen solely according to the characteristics desired for the second functionality of the combined member (magnetic attraction / holding), in other words the desired FAM.

[0024] If necessary, it may also be considered to modify the configuration or arrangement of the detection member (2) and / or the circuit (3) to accommodate the magnet (8). The attached figures illustrate different forms of detectors (with cylindrical housings with or without external thread, with cylindrical housings with or without constant diameter, with cubic or parallelepiped housing with a fixing screw (9) through) according to the invention, housing a magnet (8) for the purpose of holding part(s).

[0025] The latter, in one piece or composed of several parts forming a block, can consist of a permanent magnet (8) making the additional functionality totally autonomous (neodymium or AlniCo magnet, or even ferrite). However, the magnet (8) can also be an electromagnet powered and possibly controlled via the connection means (7) of the detector (1), and thus allowing, if necessary, the additional functionality provided to be activated and deactivated at will, or even the intensity of its action to be controlled.

[0026] The attractive force of the magnet is of course advantageously sufficient to keep the part(s) concerned in the detection field of the member (2), in particular against the face (5) or another support surface, when the detector (1) is mounted in a recess for example.

[0027] The electrical connection means (7) can either be integrated into a rear part (7') of the housing (4), or be offset from the latter (presence of a connection cord - figures 4).

[0028] The improved inductive detector (1) forming a combined member comprises a coil L forming part of an oscillating circuit LC (detection member 2), crossed by a variable current, in order to generate / exploit an electromagnetic induction phenomenon, used to detect ferromagnetic parts located in the vicinity. This coil L can be obtained by winding (conductive wire windings) or via a printed circuit (windings materialized by conductive tracks - PCB). In practice, no ferrite is associated with this coil L, in order not to be saturated and / or influenced by the magnetic field produced by the permanent magnet or the electromagnet (8) which for its part ensures the function of attracting / holding a ferromagnetic part.

[0029] Furthermore, the proximity of the magnet or electromagnet (8) located just behind or around the coil L (devoid of ferrite) is not a problem, because its influence is (in the same way as that of a possible metal box 4) erased or compensated, during the range adjustment phase (detection threshold) of the detector (1) which takes place during the manufacture of said detector.

[0030] Thus, the function of detecting a ferromagnetic part, on the one hand, and the function of attracting / holding this ferromagnetic part, on the other hand, are independent of each other, and in particular the permanent magnetic field generated by the magnet or magnets (8) does not disturb the alternating magnetic field used for detection, whatever its power.

[0031] The detector (1) may optionally be an inductive detector of the “factor 1” type. In a detector of this type, for example known from the applicant’s aforementioned document EP 3430443, the magnet may be arranged around or at the rear of the PCB coil L.

[0032] In all the variant embodiments of the invention, the shape of the magnet or magnets (8) present will be advantageously adapted to the space available in the housing (4), the nature, positioning and dimensions determining the magnetic attraction force (MAF) produced.

[0033] Preferably, said at least one magnet (8) is arranged in the protective housing (4), preferably in the immediate vicinity or in the vicinity of the sensitive detection face (6), so as to generate a magnetic attraction force (FAM) in a direction (D) substantially perpendicular to the plane of said sensitive face (6). The force of the magnetic attraction field produced by the magnet (8) is typically sized to ensure that the part(s) to be held (typically a few hundred grams) is held at a distance less than the range or detection distance of the detector (1). This holding of the part(s) can be achieved by pressing it(them) under the effect of the attraction force against the face of the wall (5) of the housing (4) forming the sensitive face (6).The detection and attraction ranges are of course adjusted (sizing of the two functionalities) in an absolute manner, but can also be adjusted in a relative manner to each other. The absence of influence on the detection function makes it possible in particular to choose one or more magnets (8) with a high FAM.

[0034] Alternatively, the attraction function may be dependent on the detection function (e.g. selective powering of the electromagnet 8 only in the event of positive detection).

[0035] As shown in Figures 1A, 2, 3B and 4B, at least a part (in particular the coil L of the LC circuit) of the detection member (2) is arranged on the internal side of the wall (5) defining the sensitive face (6) and the detector (1) comprises a magnet (8) mounted around or at the rear of said part of the detection member (2), said magnet (8) having a shape adapted to the latter and to the shape of the housing (4) in the region of said sensitive face (6). The magnet (8) can be mounted immediately at the rear of the relevant part of the detection member (2), or at a distance from the latter when a temperature compensation circuit for the coil L is present (allowing precise and reliable operation of said detection member over the entire required temperature range).

[0036] In the context of the design and development of the combined member according to the invention, it may advantageously be provided that the magnet (8) is configured and has a sufficient magnetic field strength to ensure that at least one reference ferromagnetic part (PR) is held in position in a region of a determined plane (PD) perpendicular to the direction (D) of said magnetic attraction force (FAM) generated by said magnet (8) and located outside the housing (4), beyond the sensitive face (6).

[0037] In relation to embodiments of the invention illustrated in Figures 1, 2, 4 and 5, it may be provided that the protective housing (4) has a cylindrical tubular shape, preferably with an external thread and where appropriate with definition of a detection head (4') of larger diameter housing the detection member (2) and the magnet (8), said magnet (8) having a discoidal or annular shape and the longitudinal axis of the housing (4) being coincident with the direction (D) of said magnetic attraction force (FAM) generated by the magnet (8).

[0038] In relation to another embodiment illustrated by way of example in figures 3, the protective housing (4) may have a parallelepiped shape, for example substantially cubic, with a sensitive face (6) of square or rectangular shape, a fixing screw (9) advantageously passing through said housing (4) to ensure its attachment and its orientation.

[0039] The invention also relates, in connection with an advantageous application of the combined member in the form of an improved detector (1), to an industrial workstation (not shown), in particular a welding station, automated or semi-automated. automated, comprising at least one robotic device for picking up, moving and holding, at least temporarily, for example in an indexed position, a ferromagnetic part.

[0040] This workstation is characterized in that the robotic device is provided with at least one combined member for gripping and detecting the presence of the ferromagnetic part, as described above.

[0041] Of course, the invention is not limited to the embodiments described and shown in the attached drawings. Modifications remain possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Combined member for gripping and detecting the presence of a ferromagnetic part, in the form of a presence or proximity detector (1) comprising at least one detection member (2), at least one circuit (3) for processing the signals delivered by the latter, also ensuring the power supply or excitation of said member (2), and a protective housing (4) housing said member (2) and said circuit (3) and having a wall (5) defining a sensitive face (6) in relation to the detection member (2), as well as means (7) of electrical connection for said circuit (3), combined member characterized in that said detector (1) consists of an inductive detector (1) with a detection member (2) of the LC circuit type and a circuit (3) adapted for excitation and processing of the signals, and in that said detector (1) also comprises at least one magnet (8), of the permanent or electromagnet type, mounted in the protective housing (4). protection (4),in the region of the sensitive face (6), the aforementioned detection member (2) and circuit (3) being configured in such a way that the presence or proximity detection function is not disturbed by this magnet (8).,

2. Combined member according to claim 1, characterized in that said at least one magnet (8) is arranged in the protective housing (4) so ​​as to generate a magnetic attraction force (FAM) in a direction (D) substantially perpendicular to the plane of said sensitive face (6).

3. Combined member according to any one of claims 1 and 2, characterized in that at least a part of the detection member (2) is arranged on the internal side of the wall (5) defining the sensitive face (6) and in that said detector (1) comprises a magnet (8) mounted around or at the rear of said part of the detection member (2), said magnet (8) having a shape adapted to the latter and to the shape of the housing (4) in the region of said sensitive face (6).

4. Combined member according to any one of claims 1 to 3, characterized in that the magnet (8) is configured and has a magnetic field strength sufficient to ensure the maintenance in position of at least one ferromagnetic reference part (PR) in a region of a determined plane (PD) perpendicular to the direction (D) of said magnetic attraction force (FAM) generated by said magnet (8) and located outside the housing (4), beyond the sensitive face (6).

5. Combined member according to any one of claims 1 to 4, characterized in that the protective housing (4) has a cylindrical tubular shape, preferably with an external thread and where appropriate with definition of a detection head (4') of larger diameter housing the detection member (2) and the magnet (8), said magnet (8) having a discoidal or annular shape and the longitudinal axis of the housing (4) being coincident with the direction (D) of said magnetic attraction force (FAM) generated by the magnet (8).

6. Combined member according to any one of claims 1 to 4, characterized in that the protective housing (4) has a parallelepiped shape, for example substantially cubic, with a sensitive face (6) of square or rectangular shape, a fixing screw (9) advantageously passing through said housing (4) to ensure its attachment and its orientation.

7. Industrial workstation, in particular welding station, automated or semi-automated, comprising at least one robotic device for picking up, moving and holding, at least temporarily, for example in an indexed position, a ferromagnetic part, workstation characterized in that the robotic device is provided with a combined member for gripping and detecting the presence of the ferromagnetic part according to any one of claims 1 to 6.

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