Hardness testing device for carrying out a hardness test on a test specimen

Abstract

The invention relates to a hardness testing device (10) for carrying out a hardness test on a test specimen, comprising a turret head (11) rotatably mounted about a rotational axis (11a) in a support body (12) with a plurality of receiving locations (1, 2, 3, 4, 5, 6, 7, 8) for the releasable fastening of at least one indenter holder (20, 21, 22, 23) for an indenter (26, 27, 28, 29) and / or at least one measuring objective (24, 25), wherein at least two receiving locations (1, 2, 3, 4, 5, 6, 7, 8) each have at least one electrical connection (41, 42) for an electrical accessory part (30) that can be electrically connected to the turret head (11), and wherein the at least one electrical connection (41, 42) of the turret head (11) is or can be electrically connected to the support body (11) via an interface (S).In order to enable an electrical connection of the receiving locations (1, 2, 3, 4, 5, 6, 7, 8) to the support body (12) in the simplest possible manner, it is provided that the turret head (11) has at least one switching board (40) with an electronic switching function in order to switch between the electrical connections (41, 42) of the receiving locations (1, 2, 3, 4, 5, 6, 7, 8), wherein preferably at least one electrical connection (41, 42) is arranged on the switching board (40).

Description

The invention relates to a hardness testing device for carrying out a hardness test on a test body, having a turret head which is mounted rotatably about an axis of rotation in the supporting body and has a plurality of receiving locations for the releasable fastening of at least one indenter holder for an indenter and / or at least one measurement objective, wherein at least two receiving locations each have at least one electrical connection for an electrical accessory part which can be electrically connected to the turret head, and wherein the at least one electrical connection of the turret head is electrically connected or can be electrically connected to the supporting body via an interface.Hardness testing devices often use rotatable turrets which are provided with a plurality of receiving sites for fitting measuring objects and penetration bodies. A turret head is a rotary body of a hardness testing device, which is rotatably mounted in a stationary supporting body and to which a plurality of measuring object and / or penetration bodies can be fastened, which can be changed between an active turret position and an inactive rest position by rotating the turret head. For adjusting the height of the turret head and for generating measurement impressions and for carrying out measurements, the supporting body has a height adjustment device for adjusting the turret head in the vertical direction and for carrying out hardness tests and measurements on the test body.For the precise generation of measurement impressions, indenter holders with integrated, DMS-based force sensors are frequently used at these positions. Measurement objects with an active LED light and / or positioning lasers for positioning the test parts are also used and must be supplied with energy in the respective active turret position.Slip ring transmitters are often used for transmitting the signal or power lines so that they can be guided from the rotating turret part to the static carrier part and subsequently evaluated and further processed in a machine-side control module. For a larger usable measurement range, two or more force sensors are often also installed and evaluated in series in the indenter holder. For each force sensor, for example, four signal lines must be routed via a plurality of poles of the slip ring transmitter to a separate evaluation module. In applications with four indenter holders, for example, two integrated force sensors are used on the measuring turret, wherein 32 signal lines (4 times 8 signal lines) must be routed via the slip ring to eight evaluation modules. The large number of evaluation modules and poles required for the slip ring transmitter has a very disadvantageous effect on the costs and the space requirement.A further possibility for signal transmission in the case of measuring turrets is shown, for example, in the document U.S. Pat. No. 11,435,270 B2. The signal or power supply of the turret positions is realized via coupled-in spring contacts. After the pivoting process and the positioning, the active turret position to be supplied is electrically supplied with the aid of spring-mounted supply contacts and via corresponding counter contacts. However, a disadvantage of this solution is the mechanical wear, which can quickly lead to contact problems, particularly in fully automated installations and a correspondingly high number of pivots.It is the object of the invention to enable an electrical connection of the receiving spaces to the supporting body in the simplest possible mannerAccording to the invention, this is achieved in a hardness testing device of the type mentioned at the beginning in that the turret head has at least one changeover board with an electronic changeover function in order to switch between the electrical connections of the receiving locations, wherein preferably at least one electrical connection is arranged on the changeover board.Because a circuit board with an electronic changeover function is used in the rotating turret head, only the electrical connection of the receiving space, which is in each case located in the active turret position, for a indenter holder and / or for an electrical accessory part connected to the electrical connection is electronically activated.The active turret position is that position of a receiving location of the turret head in which hardness testing, measurement or examination can be carried out on the test body by means of the indenter or measuring objective or electrical accessory part of the receiving location.At least one electrical accessory part is fastened or fastenable detachably at at least two receiving locations and is connected or can be connected in an electrically conductive manner to at least one electrical connection of the changeover circuit board.The electrical accessories are preferably selected from the group consisting of a DMS force sensor, an LED light, a tactile sensor or a positioning laser.The electrical connection advantageously has at least one group of electrical contacts, wherein the electrical contacts are preferably integrated into the changeover board.In one embodiment variant of the invention, it is provided that the changeover board has at least one first electrical connection-preferably a plurality of first electrical connections-and at least one second electrical connection-preferably a plurality of second electrical connections-wherein the at least one electrical connection and the at least one second electrical connection have a different number of electrical contacts. The first terminals can have, for example, a smaller number of electrical contacts than the second electrical terminals. This is possible since not all electrical accessories require a maximum number of electrical connections. This makes it possible to save on signal lines within the turret head.In particular, the first electrical connections can be designed, for example, to connect two DMS force sensors. Additionally or alternatively, an LED luminaire, a tactile sensor and / or a positioning laser can also be connected to the first electrical connection. In order to make this possible, the first electrical connections have, for example, a maximum number of fourteen electrical contacts. The second electrical connections can be designed, for example, to connect an LED luminaire, a tactile sensor and / or a positioning laser, for which a minimum number of, for example, six electrical contacts is sufficient.The changeover board is electrically connected or connectable to the supporting body via the interface. The interface is advantageously formed by a slip ring transmitter having a plurality of poles or tracks, wherein the slip ring transmitter preferably has a plurality of poles. The poles advantageously have at least one switching pole that can be connected to the electrical contacts by the switching function, at least one address pole and supply poles for the energy supply of the DMS force sensor, and in particular a shielding pole. The changeover circuit board has at least one power supply which is connected to at least two supply poles of the slip ring transmitter. Furthermore, the changeover circuit board has at least one shielding potential which is connected to at least one shielding pole of the slip ring transmitter.Due to the switching function of the switching circuit board, the slip ring transmitter can be designed with fewer poles than in the prior art.An advantageous embodiment variant of the invention provides that the electronic changeover function is formed by a multiplexer and / or a demultiplexer. A multiplexer is a selection circuit in analog and digital electronics, with which, for example, one or a few of a large number of input signals can be selected and switched through to an output. Multiplexers are comparable in function to rotary switches that are not manually set but with electronic signals. The difference from a relay is that the connections are not made mechanically, but by semiconductor integrated circuits.A demultiplexer is the counterpart to a multiplexer. The demultiplexer switches an input signal to one of a plurality of outputs. For control purposes, the demultiplexer has control inputs which are connected to address lines and are necessary for switching over its switches.The multiplexer and / or the demultiplexer can be controlled by at least one address line, preferably by three address lines, wherein each address line is connected to an address pole of the slip ring transmitter.According to one embodiment of the invention, the multiplexer has a plurality of inputs and a plurality of outputs, wherein the number of outputs is smaller than the number of inputs. Each input of the multiplexer is advantageously assigned to an electrical contact. Each output of the multiplexer is preferably assigned to one pole of the slip ring transmitter.According to a further embodiment of the invention, the demultiplexer likewise has a plurality of inputs and a plurality of outputs, wherein the number of outputs is greater than the number of inputs. Each input of the demultiplexer is assigned to an address pole of the slip ring transmitter connected to an address line. Each output of the demultiplexer is assigned to an electrical contact of the receiving location of the active turret position.The number of poles of the slip ring transmitter can be limited to a minimum by the multiplexer, since the switching poles of the slip ring transmitter can be used for a plurality of DMS force sensors and / or electrical accessories.Within the scope of the invention, it is provided that a first group of electrical contacts is designed to be connected to sensor lines of a DMS force sensor. A second set of electrical contacts may be configured to connect to sensor lines of a tactile sensor. A third group of electrical contacts may be configured to be connected to supply lines of an LED luminaire and / or a positioning laser.An embodiment according to the invention provides that at least one first terminal has at least one first group, preferably two first groups, of electrical contacts. Thus, for example, two DMS force sensors can be connected to the first connection.In addition, at least one first electrical connection can have at least one second group and / or at least one third group of electrical contacts. Thus, in addition or as an alternative to the two DMS force sensors, a tactile sensor, an LED light, and / or a positioning laser can be connected to the first electrical connection.According to one embodiment of the invention, at least one second electrical connection has at least one second group and / or at least one third group of electrical contacts. Thus, a tactile sensor, an LED light, and / or a positioning laser can be connected to the second electrical connection.For example, the turret head has a plurality-preferably four-first receiving spaces with first electrical connections and a plurality-preferably four-receiving spaces with second electrical connections.An embodiment of the invention provides that the LED lamps and the tactile sensors are controlled via transistors. The signals of the DMS force sensors are advantageously controlled via analog multiplexers in CMOS technology. CMOS technology (CMOS=complementary metal-oxide-semiconductor) is understood to mean the semiconductor process used for the realization of integrated digital as well as analog circuits.The supply voltage for the DMS force sensors is also controlled by means of transistors. For this purpose, the changeover board has at least one power supply which is connected to at least two corresponding supply poles of the slip ring transmitter.In order to control the switching function of the multiplexer and / or de-multiplexer, the switching board has at least one address line, preferably three address lines, wherein each address line is connected to a corresponding separate address pole of the slip ring transmitter. The control can thus be effected, for example, by means of a three-bit addressing.Via the address lines controlled by a central control of the hardness testing device, the contacts of the receiving location of the currently pivoted-in active turret position of the turret head are activated on the changeover board, for example, via a CMOS line decoder de-multiplexer.In order to avoid disturbing influences on the measurement signals, it is favorable if the changeover circuit board has at least one shielding potential which is connected to at least one corresponding shielding pole of the slip ring transmitter.The invention makes it possible to save a plurality of, for example six, complex measuring bridge evaluation circuits, since only the signals of the currently used sensors-for example tactile sensors and DMS sensors-and actuators-for example LED lamps-are always forwarded to the evaluation electronics via the multiplexer.By using a changeover board with changeover function in the rotating turret part, which board electronically activates only the indenter holder located in each case in the active turret position or alternatively the LED luminaire to be supplied or a tactile sensor, it is possible to simplify the system and to save costs.Particularly in the case of indenter holders with integrated DMS force sensors, not only can the required number of signal lines routed via the slip ring transmitter be greatly reduced, but also the number of downstream required evaluation modules.In addition, the changeover board can be equipped with a function for changeover of power and control circuits at the active turret position pivoted in in each case, so that LED lamps or tactile sensors, for example, can also be activated accordingly instead of the force sensors.The invention is explained in more detail below with reference to the non-limiting exemplary embodiment which is shown in the figures. Shown therein are: FIG. 1 shows a turret head of a hardness testing device according to the invention in an axonometric representation; FIG. 2 shows a detail of the turret head in an axonometric representation; FIG. 3 shows a switching plate of the turret head in a plan view; FIG. 4 shows the switching circuit board in an axonometric representation; and FIG. 5 is an electric circuit diagram of the switch board.FIG. 1 schematically shows a turret 11 of a hardness testing device 10, which serves for carrying out a hardness test on a test body, not shown. The turret 11 is rotatably mounted about an axis of rotation 11a on a supporting body 12 of the hardness testing device 10. The support body 12 has a height adjustment device, not shown in detail, for adjusting the turret head 11 in the vertical direction and for carrying out hardness tests and measurements on the test body.The turret head 11 is equipped with a plurality of recording sites 1, 2, 3, 4, 5, 6, 7, 8, which are each designed to receive, selectively or in combination, at least one indenter holder 20, 21, 22, 23 and / or at least one measurement objective 24, 25 and / or at least one electrical accessory part 30 in a detachably attached manner. The indenter holders 20, 21, 22, 23 are configured to receive an indenter 26, 27, 28, 29, respectively. The turret head 11 is thus equipped with different indenter holders 20, 21, 22, 23 and indenters 26, 27, 28, 29 which are suitable for different hardness testing methods and different test specimens.Electrical accessories 30 are, for example, DMS force sensors 31, tactile sensors 32, LED lamps 33 or positioning lasers.The receiving spaces 1, 2, 3, 4, 5, 6, 7, 8 each have at least one electrical connection 41, 42 for electrical connection to at least one of these electrical accessories 30. The at least one electrical connection 41, 42 of the turret head 11 is electrically connected or connectable to the supporting body 12 via an interface S, which is designed, for example, as a slip ring transmitter 14.The turret 20 has at least one changeover board 40 with an electronic changeover function. The switching function-for example by means of a multiplexer 44 and / or a demultiplexer 45-is designed to switch between the electrical connections 41, 42 of the receiving spaces 1, 2, 3, 4, 5, 6, 7, 8. The electrical connections 41, 42 are arranged on the switching board 40 or formed by it, for example, in particular integrated into the switching board 40. A multiplexer 44 is a combinational logic circuit that switches one of a plurality of input lines 44 ato at least one common output line 44 bby applying a control signal. Multiplexers 44 operate like very fast acting rotary switches which connect or control several input lines, so-called "channels", individually to the output.Each electrical terminal 41, 42 has at least one group A, B, C of electrical contacts 43.The electrical connections 41, 42 of the changeover board 40 can be configured differently and have different numbers of contacts 43, as can be seen from FIGS. 3 and 4. For example, first electrical connections 41 can have a greater number of electrical contacts 43 than second electrical connections 42. In the exemplary embodiment shown in FIGS. 1 to 5, turret 11 has four first receiving spaces 1, 3, 5, 7 with first electrical connections 41 and four second receiving spaces 2, 4, 6, 8 with second electrical connections 42.The electrical connection between the turret head 11 and the supporting body 12 takes place via an interface S formed by a slip ring transmitter 14. The slip ring transmitter 14 has a plurality of and different poles, namely switching poles a, b, c, d, e, which are interconnected by the multiplexer 44 with electrical contacts 43, address poles f for controlling the multiplexer 44, supply poles g for supplying power to the DMS force sensor 31 and at least one shielding pole h.FIG. 5 shows a simplified schematic diagram of the switching circuit board 40.The multiplexer 44 of the changeover board 40 has a plurality of inputs 44 aand a plurality of outputs 44 b, wherein the number of outputs 44 bis smaller than the number of inputs 44 a. Each input 44a of the multiplexer 44 is associated with an electrical contact 43 and each output 44b of the multiplexer 44 is associated with one of the switching poles a, b, c, d, e of the slip ring transmitter 14.The demultiplexer 45 likewise has a plurality of inputs 45a and a plurality of outputs 45b, but the number of outputs 45b is greater than the number of inputs 45a. Each input 45a of the demultiplexer 45 is assigned to an address pole f of the slip ring transmitter 14 connected to an address line. Each output 45 bof the demultiplexer 45 is assigned to an electrical contact 43 of the receiving location 1, 2, 3, 4, 5, 6, 7, 8 of the respective active turret position of the turret 11.The electrical terminals 41, 42 have different groups A, B, C of electrical contacts 43. A first group A of, for example, four electrical contacts 43 is used for connection to sensor lines of a DMS force sensor 31. a second group B of, for example, two electrical contacts 43 is used for connection to the sensor lines of a tactile sensor 32. a third group C of, for example, two electrical contacts 43 is used for connection to the supply lines of an LED luminaire 33 and / or for connection to the supply lines of a positioning laser.Each first terminal 41 has two first groups A, a second group B and two third groups C of electrical contacts 43. This enables the electrical connection to two DMS force sensors 31, a tactile sensor 32, an LED light fixture 33, and a positioning laser or a further LED light fixture 33.Each second terminal 42 comprises a second group B and two third groups C of electrical contacts 43. This enables electrical connection to a tactile sensor 32, an LED light fixture 33, and a positioning laser or a further LED light fixture 33.The multiplexer 44 can be controlled by three address lines via a demultiplexer 45 of the switching board 40-for example a CMOS line decoder demultiplexer 44. Each address line is connected to an address pole f of the slip ring transmitter 14.The changeover circuit board 40 has at least one power supply which is connected to at least two supply poles g of the slip ring transmitter 14. Furthermore, the changeover circuit board 40 has at least one shielding potential which is connected to at least one shielding pole h of the slip ring transmitter 14.The changeover board 40 on the turret 11 with the multiplexer 44 and the de-multiplexer 45 enables a structurally simple and cost-effective solution.Only the electrical connection 41, 42 respectively located in the active turret position and the electrical accessory part 30 respectively connected thereto are electronically activated by the multiplexer 44.For this purpose, the outputs or inputs of the electrical connection 41, 42 of the currently pivoted-in measuring turret position are activated on the changeover board 40 via the CMOS line decoder De multiplexer 45 with the three address lines, which are controlled by a central control unit, not shown in detail, of the hardness testing device 10. The control is effected by three-bit addressing of the address poles f. The LED lamps 33 and the tactile sensors 32 are controlled via transistors. The signals of the DMS force sensors 31 are controlled via analog multiplexers 44 in CMOS technology. The DMS supply voltage across the supply poles g is controlled by transistors. The described arrangement according to the invention makes it possible to save a number of complex measuring bridge evaluation circuits, since only the signals of the currently used sensors, actuators and DMS force sensors 31 are always forwarded via the multiplexer 44 to the evaluation electronics of the hardness testing device 10, which are not shown in detail.Particularly in the case of indenter holders 20, 21, 22, 23 with integrated DMS force sensors 31, not only the required number of signal lines to be carried out via the slip ring transmitter 14 can be greatly reduced, but also the number of downstream required evaluation modules.In addition, the switching board 40 may be provided with a function for switching power and control circuits at the respective pivoted-in position, so that instead of the DMS force sensors 31, for example, LED lamps 33 or tactile sensors 32 may also be activated accordingly.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 11,435,270 B2

[0005]

Claims

Hardness testing device (10) for carrying out a hardness test on a test body, having a turret head (11) which is mounted rotatably about a rotation axis (11a) in a supporting body (12) and has a plurality of receiving locations (1, 2, 3, 4, 5, 6, 7, 8) for the releasable fastening of at least one indenter holder (20, 21, 22, 23) for an indenter (26, 27, 28, 29) and / or at least one measurement objective (24, 25), wherein at least two receiving locations (1, 2, 3, 4, 5, 6, 7, 8) each have at least one electrical connection (41, 42) for an electrical accessory (30) which can be electrically connected to the turret head (11), and wherein the at least one electrical connection (41, 42) of the turret head (11) is electrically connected or can be electrically connected to the supporting body (11) via an interface (S), characterized in that the turret head (11) has at least one changeover board (40) with an electronic changeover function, in order to switch between the electrical connections (41, 42) of the receiving spaces (1, 2, 3, 4, 5, 6, 7, 8), wherein preferably at least one electrical connection (41, 42) is arranged on the switching board (40).Hardness testing device (10) according to claim 1, characterised in that at least one electrical accessory (30) and / or a indenter holder (26, 27, 28, 29) with an electrical accessory (30) and / or a measuring objective (24, 25) with an electrical accessory (30) is detachably attachable or attached at at least two recording sites (1, 2, 3, 4, 5, 6, 7, 8) and is electrically connectable or connected with at least one electrical connection (41, 42) of the changeover board (40), wherein preferably at least one electrical accessory (30) is selected from the group consisting of a DMS force sensor (31), an LED luminaire (33), a tactile sensor (32) or a positioning laser.Hardness testing device (10) according to claim 1 or 2, characterised in that the electrical connection (41, 42) has at least one group (A, B, C) of electrical contacts (43), wherein preferably the electrical contacts (43) are integrated into the switching circuit board (40).Hardness testing device (10) according to claim 3, characterised in that the changeover board (40) has at least one first electrical connection (41) - preferably a plurality of first electrical connections (41) - and at least one second electrical connection (42) - preferably a plurality of second electrical connections (42) - wherein the at least one electrical connection (42) and the at least one second electrical connection (42) have a different number of electrical contacts (43).Hardness testing device (10) according to claim 4, characterised in that the turret head (11) has a plurality - preferably four - first receiving positions (1, 3, 5, 7) with first electrical connections (41) and a plurality - preferably four - receiving positions (2, 4, 6, 8) with second electrical connections (42).Hardness testing device (10) according to one of claims 1 to 5, characterised in that the interface (S) is formed by a slip ring transmitter (14), wherein preferably the slip ring transmitter (14) has a plurality of poles (a, b, c, d, e, f, g, h), wherein particularly preferably the poles have at least one switching pole (a, b, c, d, e) and at least one address pole (f), supply poles (g) and in particular a shielding pole (h).Hardness testing device (10) according to one of Claims 1 to 6, characterized in that the electronic switching function is formed by a multiplexer (44) and / or a demultiplexer (45).Hardness testing device (10) according to claim 7, characterised in that the multiplexer (44) has a plurality of inputs (44a) and a plurality of outputs (44b), wherein the number of outputs (44b) is smaller than the number of inputs (44a).Hardness testing device (10) according to claim 7 or 8, characterised in that each input (44a) of the multiplexer (44) is associated with an electrical contact (43).Hardness testing device (10) according to claim 8 or 9, characterised in that each output (44b) of the multiplexer (44) is associated with a switching pole (a, b, c, d, e) of the slip ring transmitter (14).Hardness testing device (10) according to one of Claims 7 to 10, characterized in that each input (45a) of the demultiplexer (45) is assigned to an address pole (f) of the slip ring transmitter (14).Hardness testing device (10) according to one of claims 7 to 11, characterised in that each output (45b) of the de-multiplexer (45) is assigned to an electrical contact (43) of the receiving location (1, 2, 3, 4, 5, 6, 7, 8) of an active turret position.Hardness testing device (10) according to one of claims 3 to 12, characterised in that a first group (A) of electrical contacts (43) is configured to be connected to sensor lines of a DMS force sensor (31).Hardness testing device (10) according to any one of claims 3 to 13, characterized in that a second group (B) of electrical contacts (43) is configured to be connected to sensor lines of a tactile sensor (32).Hardness testing device (10) according to one of claims 3 to 14, characterised in that a third group (C) of electrical contacts (43) is configured to be connected to supply lines of an LED luminaire (33) or a positioning laser.Hardness testing device (10) according to one of claims 1 to 15, characterised in that at least one first electrical connection (41) has at least one first group (A) - preferably two first groups (A) - of electrical contacts (43).Hardness testing device (10) according to one of claims 1 to 16, characterised in that at least one first electrical connection (41) has at least one second group (B) of electrical contacts (43).Hardness testing device (10) according to one of claims 1 to 17, characterised in that at least one first electrical connection (41) has at least one third group (C) - preferably two third groups (C) - of electrical contacts (43).Hardness testing device (10) according to one of claims 1 to 18, characterised in that at least one second electrical connection (42) has at least one second group (B) of electrical contacts (43).Hardness testing device (10) according to one of claims 1 to 19, characterised in that at least one second electrical connection (42) has at least one third group (C) - preferably two third groups (C) - of electrical contacts (43).Hardness testing device (10) according to one of claims 7 to 20, characterised in that the multiplexer (44) and / or the demultiplexer (45) can be controlled by at least one address line, preferably by three address lines, wherein each address line is connected to an address pole (f) of the slip ring transmitter (14).

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