Simulation device for screw joint simulation of a nut runner

Abstract

To provide a simulation device for screw-joining simulation of a nut runner.SOLUTION: The simulation device includes a testing connection element and a brake unit. The testing connection element is firmly connected to the brake unit. A nut runner can connect to the testing connection element and can be operated. The nut runner applies torque to the testing connection element and the torque rotates the testing connection element about a rotation axis. The brake unit can be operated and brakes the testing connection element rotating about the rotation axis. The simulation device includes a torque converter for measuring the torque applied and a rotation angle converter for measuring a rotation angle at which the testing connection element rotates about the rotation axis. The simulation device further includes a null mark, and the brake unit can be adjusted with respect to the null mark at null angle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a simulation device for simulating screw joining of a nut runner as described in the preamble of the independent claim. The present invention also relates to a method for performing a screw joining simulation of a nut runner using the simulation device as described in the preamble of the independent claim. Further, the present invention relates to a method for modifying an existing simulation device to form the simulation device as described in the preamble of the independent claim.

Background Art

[0002] According to the guidelines VDI / VDE 2647 of February 2013, a nut runner is a motor-driven screw-turning tool. The nut runner can be operated, and the operated nut runner applies torque to the connecting element by continuously rotating around the rotation axis.

[0003] The connecting element has a thread and is a bolt, nut, etc. The connecting element is used to connect components. The connection is made by the clamping force between the components. Due to the clamping force, the components can be reliably used under the maximum operating force.

[0004] Therefore, the torque applied by the operated nut runner helps to generate the clamping force. For this purpose, the nut runner increases the applied torque over time and / or increases the applied torque via the rotation angle. The applied torque increases until it reaches a specific nominal torque for the clamping force and / or until it reaches a specific nominal rotation angle for the clamping force. The nominal torque and / or the nominal rotation angle can be set on the nut runner. Hereinafter, the nominal torque and / or the nominal rotation angle will be referred to as the nominal value.

[0005] The nut runner is equipped with an indicator system. As soon as the nominal value is reached, the nut runner stops applying torque. The indicator system can operate according to different functional principles. Therefore, when the nominal value is reached, the click-type torque wrench automatically interrupts the application of torque. The acoustic torque wrench automatically induces an acoustic signal or an optical signal when the nominal value is reached. The display nut runner displays the actual applied torque and / or the actual rotation angle on a scale or on an electronic screen.

[0006] Nut runners of the aforementioned type are used in many industrial production processes. The performance of the nut runner is tested at regular intervals to ensure that the nut runner actually reaches the set nominal value.

[0007] For this purpose, the guidelines VDI / VDE 2647 of February 2013 specify what and how should be tested. The nut runner performance test is called a screw joint simulation. The screw joint simulation is carried out using a simulation device comprising a brake unit and a test connection element. The test connection element can rotate around the axis of rotation. The brake unit and the test connection element are firmly connected to each other. The nut runner is connected to the simulation device via the test connection element.

[0008] The nut runner connected to the simulation device is operated to apply torque to the test connection element. Due to the applied torque, the test connection element begins to rotate around the axis of rotation. The brake unit is operated to apply a brake to the test connection element.

[0009] The simulation device further comprises a measuring unit comprising a torque transducer and a rotation angle transducer. The torque transducer measures the rotational torque, and the rotation angle transducer measures the rotation angle by which the test connection element rotates around the axis of rotation. The measuring unit is arranged between the brake unit and the test connection element.

[0010] The time course of the measured torque with respect to the measured rotation angle is represented graphically as the torque rate. To obtain statistical significance, the screw joint simulation is run multiple times. The torque rates obtained from these multiple screw joint simulations are overlaid and represented graphically. For each torque rate, the maximum measured torque and the maximum measured rotation angle corresponding to that maximum measured torque are determined. The arithmetic mean of the maximum measured torques is called the average torque. The arithmetic mean of the maximum measured rotation angles is called the average rotation angle. Further, the screw joint simulation is repeated for different set nominal torques and for different amounts of torque rate.

[0011] According to the guidelines VDI / VDE 2647 of February 2013, the mass moment of inertia of the rotating part of the simulation device should not have a significant impact on the average torque. The rotating part of the simulation device is the rotor of the brake unit, the measuring disk of the measuring unit, the test means, etc. For screw joint simulations with a low torque rate, a difference in the maximum measured rotation angle of ±15% with respect to the average rotation angle is allowed. Further, for screw joint simulations with a high torque rate, a difference in the maximum measured rotation angle of ±5% with respect to the average rotation angle is allowed.

[0012] That is, the requirements regarding the concentricity of the rotating part of the simulation device are very high. More specifically, the rotational imbalance of the rotor of the brake unit and the rotational imbalance of the measuring disk of the measuring unit with respect to the rotation axis must be minimized. These high requirements for concentricity increase the manufacturing cost and acquisition cost of the simulation device.

Summary of the Invention

Problems to be Solved by the Invention

[0013] The first object of the present invention is to provide a cost-effective simulation device for simulating the screw joint of a nut runner, the simulation device meeting the requirements of the guidelines VDI / VDE 2647 of February 2013 and keeping the allowable deviation of the maximum measured rotation angle with respect to the average rotation angle within the range of the deviation required for the screw joint simulation.

[0014] A further object of the present invention is to propose a method for performing a screw joint simulation of a nut runner using the simulation device, the simulation device meeting the requirements of the guidelines VDI / VDE 2647 of February 2013 and keeping the allowable deviation of the maximum measured rotation angle with respect to the average rotation angle within the range of the deviation required for the screw joint simulation, and the method being able to be executed simply and quickly.

[0015] Furthermore, an additional object of the present invention is to provide a method for modifying an existing simulation device for simulating the screw joint of a nut runner, the modified simulation device meeting the requirements of the guidelines VDI / VDE 2647 of February 2013 and keeping the allowable deviation of the maximum measured rotation angle with respect to the average rotation angle within the range of the deviation required for the screw joint simulation.

Means for Solving the Problems

[0016] At least one of these objects has been achieved by the features of the independent claims.

[0017] The present invention relates to a simulation device for simulating screw joints of a nut runner. The simulation device comprises a test connection element and a brake unit, wherein the test connection element is firmly connected to the brake unit, and the nut runner can be connected to the test connection element, the nut runner can be operated, the operated nut runner applies torque to the connected test connection element, the applied torque rotates the test connection element around the rotation axis, the brake unit can be operated, and the operated brake unit brakes the test connection element rotating around the rotation axis. The simulation device comprises a torque transducer for measuring the applied torque, and a rotation angle transducer for measuring the rotation angle of the test connection element rotating around the rotation axis. The simulation device is provided with a zero mark, and the brake unit can be adjusted to a zero angle with respect to the zero mark.

[0018] Further embodiments of the subject matter of the simulation device according to the independent claims are claimed in the dependent claims.

[0019] The present invention also relates to a method for performing a screw joint simulation of a nut runner using the simulation device according to any one of claims 1 to 10. In a first step of this method, the brake unit is adjusted to a zero angle with respect to the zero mark. In a second step of this method, the nut runner is connected to the test connection element. In a third step of this method, the screw joint simulation is started in an angle-synchronized manner starting from the zero angle.

[0020] The inventors have surprisingly discovered that when the screw joint simulation is consistently started from the zero angle adjusted with respect to the zero mark, the requirements of the February 2013 guideline VDI / VDE 2647 regarding the allowable deviation of the measured rotation angle with respect to the average rotation angle can be met. Thus, the rotating part of the simulation device is always in the same defined starting position of the rotational movement, and thus, any rotational imbalance of the rotating part of the simulation device is angle synchronized. The screw joint simulation is repeated multiple times, and thus, the rotational imbalance occurs in a manner that is angle synchronized with respect to the zero angle. Furthermore, in the overlap in the graph of the subsequent torque rates of the screw joint simulations performed multiple times, the deviation of the maximum measured rotation angle from the average rotation angle caused by this rotational imbalance is also displayed in an angle-synchronized manner. Determining the zero mark and adjusting the brake unit to the zero angle with respect to the zero mark is not very costly and, furthermore, it is possible to execute the process in a simple and rapid manner.

[0021] Furthermore, the present invention relates to a method for retrofitting an existing simulation device to form the simulation device according to any one of claims 1 to 10, wherein the existing simulation device comprises an existing rotation angle converter and an existing measurement disk without a zero mark. In a first step of this method, the existing measurement disk is removed. In a second step of this method, a measurement disk having a zero mark is provided. In a third step of this method, the provided measurement disk is installed in place of the existing measurement disk. In a fourth step of this method, the orientation of the existing rotation angle converter with respect to the zero mark is defined as the zero angle.

[0022] Alternatively, the present invention further relates to a method of modifying an existing simulation device for simulating a screw joint of a nut runner in order to form the simulation device according to any one of claims 1 to 10, wherein the existing simulation device includes an existing rotation angle converter and an existing measurement disk having angle marks but no zero mark. In an alternative first step of this method, one of the angle marks of the existing measurement disk is defined as a zero mark. In a fourth step of this method, the orientation of the existing rotation angle converter with respect to the zero mark is defined as a zero angle.

[0023] Hereinafter, the present invention will be described in more detail by way of examples with reference to the drawings.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a schematic diagram of a simulation device 1 for screw joint simulation of a nut runner 2.

[0026] According to the guidelines VDI / VDE 2647 of February 2013, the nut runner 2 is a motor-driven screw-turning tool. The nut runner can be actuated, and the actuated nut runner continuously rotates around the rotation axis Z and applies torque.

[0027] The nut runner 2 increases the applied torque over time and / or increases the applied torque via the rotation angle. The increase in the applied torque is carried out until the nominal torque is reached and / or until the nominal rotation angle is reached. The nominal torque and / or the nominal rotation angle can be adjusted on the nut runner 2. Hereinafter, the nominal torque and / or the nominal rotation angle are also referred to as nominal values.

[0028] The nut runner 2 is equipped with an indicator system. As soon as the nominal value is reached, the nut runner 2 stops applying torque. The indicator system can operate according to different functional principles. The nut runner 2 may be a click-type torque wrench that automatically releases itself when the nominal torque is reached. The nut runner 2 may be an acoustic torque wrench that automatically induces an acoustic signal or an optical signal when the nominal torque is reached. The nut runner 2 may be a display nut runner that displays the applied torque on a scale or on an electronic screen.

[0029] The simulation device 1 comprises a test connection element 13. The nut runner 2 is firmly connected to the simulation device 1 via the test connection element 13. The connection between the nut runner 2 and the simulation device 1 achieved by the test connection element 13 is releasable.

[0030] The simulation device 1 comprises a measurement unit 12. The measurement unit 12 is of a hollow cylindrical shape and is arranged in a measurement unit housing 12.0 made of robust metal. The measurement unit housing 12.0 has a cavity. A measurement disk 12.1 is arranged in the cavity.

[0031] The measurement disk 12.1 is a cylinder made of robust metal. The test connection element 13 is firmly connected to the measurement disk 12.1. The nut runner 2 connected to the test connection element 13 is actuated to apply torque to the test connection element 13. The test connection element 13 and the measurement disk 12.1 firmly connected to the test connection element 13 start to rotate around the rotation axis Z under the applied torque. The measurement disk 12.1 has a measurement surface 12.10, and the measurement surface 12.10 is in a plane whose normal is parallel to the rotation axis Z. The measurement disk 12.1 has an angle mark 12.11, and the angle mark 12.11 is arranged on the measurement surface 12.10.

[0032] In a first embodiment of the measurement disk 12.1 as shown in FIGS. 2 and 3, the angle mark 12.11 is a plurality of light and dark dashes. The plurality of light and dark dashes are arranged in a first area on the measurement surface 12.10, and the first area has a constant radial distance from the rotation axis Z. The plurality of light and dark dashes are arranged at equal intervals from each other when viewed in the rotation direction. The plurality of light and dark dashes are incremental code values. The incremental code values specify the rotation angle during the rotational movement of the measurement disk 12.1 around the rotation axis Z. The specification of the rotation angle by the incremental code values is not clearly defined during the rotation of the measurement disk 12.1 around the rotation axis Z.

[0033] In a second embodiment of the measurement disk 12.1 as shown in FIGS. 4 and 5, the angle mark 12.11 is a gray code. The gray code is substantially arranged over the entire measurement surface 12.10. The gray code includes a plurality of gray-scale code values. When viewed in the rotation direction, the gray-scale code values are arranged side by side with each other. The gray-scale code values are absolute code values. That is, each absolute code value has a clearly defined value. The absolute code values clearly specify the rotation angle during the rotation of the measurement disk around the rotation axis Z.

[0034] The simulation device 1 includes a rotation angle converter 12.2. The rotation angle converter 12.2 is fixedly attached to the measurement unit housing 12.0. The rotation angle converter 12.2 measures the rotation angle of the measurement disk 12.1 rotating around the rotation axis Z. The rotation angle converter 12.2 is disposed above the measurement surface 12.10 of the measurement disk 12.1. The rotation angle converter 12.2 includes a sensor element 12.21. The sensor element 12.21 detects the angle mark 12.11. Preferably, the rotation angle converter 12.2 is an optical rotation angle converter including an optical sensor element, and the optical rotation angle converter emits light onto the angle mark 12.11 and detects the emitted light reflected by the angle mark 12.11 by the optical sensor element. Therefore, when the angle mark 12.11 rotates around the rotation axis Z, the section of the angle mark 12.11 covered by the optical sensor element also changes.

[0035] In the first embodiment of the angle mark 12.11 as shown in FIGS. 2 and 3, after the rotation angle converter 12.2 generates a corresponding rotation angle signal WS as the section of the angle mark 12.11 changes, it counts the number of increment code values detected by the sensor element 12.21.

[0036] In the second embodiment of the angle mark 12.11 as shown in FIGS. 4 and 5, after the rotation angle converter 12.2 generates a corresponding rotation angle signal WS as the section of the angle mark 12.11 changes, it identifies the absolute code value detected by the sensor element 12.21.

[0037] Preferably, the rotation angle converter 12.2 measures the rotation angle of the measurement disk 12.1 rotating around the rotation axis Z with an angular resolution less than or equal to 1° / equal to 1°. The rotation angle converter 12.2 generates a rotation angle signal WS of the measured rotation angle. The rotation angle signal WS is transmitted via the rotation angle signal line 14.2. Preferably, the rotation angle converter 12.2 measures the rotation angle at a measurement frequency exceeding / equal to 2000 Hz.

[0038] Instead of using an optical rotation angle converter equipped with an optical sensor element, those skilled in the art who know the present invention can also use a magnetic rotation angle converter equipped with a magnetic sensor element, a capacitance-type rotation angle converter equipped with a capacitance-type sensor element, or other rotation angle converters that operate according to different functional principles.

[0039] The simulation device 1 includes a torque converter 12.3. The torque converter 12.3 is attached to the measurement disk 12.1. The torque converter 12.3 measures the force at a perpendicular distance from the rotation axis Z along the lines of force to obtain the torque. Preferably, the torque converter 12.3 includes several strain gauges. The strain gauges are attached to the measurement disk 12.1 with respect to the lines of force so as to expand and contract under the influence of the force. Due to this expansion and contraction, a change occurs in the electrical resistance of the strain gauges. The strain gauges are electrically connected to a bridge circuit. Due to the change in electrical resistance, a voltage signal is generated in the bridge circuit of the strain gauges, and the voltage signal is proportional to the magnitude of the torque. Therefore, the voltage signal generated by the torque converter 12.3 is transmitted as a torque signal MS via the torque signal line 14.3. Preferably, the torque converter 12.3 measures the torque in various measurement ranges such as 0.4 - 2 Nm, 2 - 10 Nm, 10 - 50 Nm, 50 - 250 Nm, 100 - 500 Nm, 400 - 2000 Nm, 1200 - 6000 Nm. Preferably, the torque converter 12.3 measures the torque at a measurement frequency of 2000 Hz or more.

[0040] The simulation device 1 includes a brake unit 10. The brake unit 10 is arranged inside a hollow cylindrical brake unit housing 10.0 made of a tough metal. The brake unit housing 10.0 has a cavity. The brake element 10.1 and the rotor 10.2 are arranged in the cavity.

[0041] The simulation device 1 includes a connecting element 11. When viewed along the rotation axis Z, the connecting element 11 is disposed between the rotor 10.1 and the measuring unit 12. The connecting element 11 is firmly connected to both the rotor 10.1 and the measuring disk 12.1. The connecting element 11 connects the rotor 10.1 to the measuring disk 12.1.

[0042] The brake element 10.1 preferably operates in a hydraulic or electric manner. The brake element 10.1 can be actuated, and the actuated brake element 10.1 converts hydraulic energy or electrical energy into force. The rotor 10.2 is a cylindrical body made of metal and is firmly connected to the brake element 10.1. The force generated by the brake element 10.1 acts on the rotor 10.2 and rotates the rotor 10.2 around the rotation axis Z. The rotation direction of the rotor 10.2 around the rotation axis Z is opposite to the rotation direction of the test connection element 13 around the rotation axis Z. As a result, the actuated brake element 10.1 applies a brake to the test connection element 13.

[0043] The brake unit 10 further includes a control and regulation unit 10.3. The control and regulation unit 10.3 actuates and stops the brake element 10.1. However, the control and regulation unit 10.3 also regulates and controls the magnitude and duration of the generated force, as well as the speed, acceleration, and duration of the rotational movement of the rotor 10.2. Preferably, the rotor 10.2 rotates at a rotational speed within a rotational speed range of 10 to 3000 rpm.

[0044] The measuring disk 12.1 includes a zero mark 12.12. Preferably, the zero mark 12.12 is disposed on the measuring surface 12.10.

[0045] In the first embodiment of the measurement disk 12.1 as shown in FIGS. 2 and 3, the zero mark 12.12 is a black line. The black line is arranged in different areas of the measurement surface 12.10, and the black line has a radial distance shorter from the rotation axis Z than the first area where the angle mark 12.11 is arranged. Therefore, the zero mark 12.12 is not part of the angle mark 12.11. The zero mark 12.12 and the angle mark 12.11 are spatially separated from each other on the measurement surface 12.10. This type of measurement disk 12.1 having the zero mark 12.12 and the angle mark 12.11 in spaced-apart areas from each other is not very costly. The sensor element 12.21 detects the zero mark 12.12 arranged in a different area independent of the angle mark 12.11 arranged in the first area. Regarding the zero mark 12.12 detected by the sensor element 12.21, the rotation angle converter 12.2 generates a zero mark signal NS. The zero mark signal NS is transmitted via the rotation angle signal line 14.2.

[0046] In the second embodiment of the measurement disk 12.1 as shown in FIGS. 4 and 5, the zero mark 12.12 is the defined absolute code value of the gray code of the angle mark 12.11. Therefore, the zero mark 12.12 is an integral part of the angle mark 12.11. The zero mark 12.12 and the angle mark 12.11 are not spatially separated from each other on the measurement surface 12.10. The sensor element 12.21 detects the zero mark 12.12 together with the angle mark 12.11. Regarding the zero mark 12.12 detected by the sensor element 12.21, the rotation angle converter 12.2 generates a zero mark signal NS. The zero mark signal NS is transmitted via the rotation angle signal line 14.2.

[0047] The rotational angle transducer 12.2 is arranged in a defined manner at the zero angle 12.22 with respect to the zero mark 12.12. The rotational angle transducer 12.2 is fixedly attached to the simulation device 1. Advantageously, the rotational angle transducer 12.2 is fixedly attached to the measurement unit housing 12.0.

[0048] In an embodiment of the rotational angle transducer 12.2 as shown in FIGS. 2 to 5, the zero angle 12.22 designates the maximum radial extension of the rotational angle transducer 12.2 along the radial direction, and that radial direction is perpendicular to the rotation axis Z. Advantageously, the position of the zero angle 12.22 coincides with the position of the sensor element 12.21.

[0049] The zero angle 12.22 is the defined starting position of the rotational movement around the rotation axis Z for performing the screw joint simulation. This is because the zero mark 12.12 and the zero angle 12.22 enable the angularly synchronized positioning of the rotating parts of the simulation device 1. The rotating parts of the simulation device 1 include the brake element 10.1, the rotor 10.2, the connecting element 11, the measurement disk 12.1, the torque transducer 12.3, and the test connection element 13. Since the rotating parts are firmly connected to each other, adjusting the zero mark 12.12 of the measurement disk 12.1 to the zero angle 12.22 of the installed rotational angle transducer 12.2 is sufficient to obtain the angularly synchronized positioning of all the rotating parts of the simulation device 1. FIGS. 2 and 4 show the zero mark 12.12 and the zero angle 12.22 positioned without angular synchronization. FIGS. 3 and 5 show the zero mark 12.12 and the zero angle 12.22 adjusted to the angular synchronization position.

[0050] The simulation device 1 includes an evaluation unit 14. The evaluation unit 14 includes a processor, a data memory, a rotation angle signal line 14.2, a torque signal line 14.3, and an output device. An evaluation program 14.1 can be loaded from the data memory into the processor. The evaluation program 14.1 loaded into the processor is designed to import a rotation angle signal WS from the rotation angle signal line 14.2 via an interface. The evaluation program 14.1 loaded into the processor is designed to import a torque signal MS from the torque signal line 14.3 via an interface.

[0051] As shown in FIG. 6, the method of performing a screw joint simulation using the simulation device 1 is carried out in a plurality of steps IS to VIIIS.

[0052] In the first step IS of this method, the brake unit 10 is adjusted in such a way that it is angularly synchronized with the zero mark 12.12 at the zero angle 12.22. This is shown in FIGS. 2 to 5. In FIGS. 2 and 4, the zero mark 12.12 and the zero angle 12.22 are angularly offset from each other, while in FIGS. 3 and 5, the zero mark 12.12 and the zero angle 12.22 are positioned in an angularly synchronized manner. The adjustment of the zero mark 12.12 and the zero angle 12.22 is achieved by the brake element 10.1. The brake element 10.1 is actuated by the control and regulation unit 10.3. The actuated brake element 10.1 drives the rotor 10.2 and thus also drives the measuring disk 12.1 which is firmly connected to the rotor 10.2 via the connecting element 11 in order to rotate around the rotation axis Z. As soon as the sensor element 12.21 detects the zero mark 12.12 of the rotating measuring disk 12.1, the rotation angle converter 12.2 generates a zero mark signal NS, and the zero mark signal NS is transmitted to the control and regulation unit 10.3 via the rotation angle signal line 14.2. The control and regulation unit 10.3 imports the zero mark signal NS from the rotation angle signal line 14.2 via the interface. The control and regulation unit 10.3 stops the operation of the brake element 10.1 for the imported zero mark signal NS. Here, the zero mark 12.12 is angularly synchronized with the zero angle 12.2.

[0053] In the second step IIS of this method, the nominal torque is set on the nut runner 2. The nut runner 2 is connected to the test connection element 13.

[0054] In the third step IIIS of this method, the screw joint simulation starts from the zero angle 12.22. For this purpose, the nut runner 2 is actuated.

[0055] The nut runner 2 connected to the test connection element 13 applies torque to the test connection element 13 and the measurement disk 12.1 firmly connected to the test connection element 13, and the torque increases with time via the rotation angle. As a result, the test connection element 13 and the measurement disk 12.1 rotate in one direction around the rotation axis Z.

[0056] The brake unit 10 is actuated to apply a brake to the test connection element 13. For this purpose, the brake element 10.1 is actuated by the control and adjustment unit 10.3. The actuated brake element 10.1 rotates the rotor 10.2 around the rotation axis Z in a rotational direction opposite to the rotational direction of the test connection element 13. Since the rotor 10.2 is firmly connected to the measurement disk 12.1 via the connecting element 11, and since the measurement disk 12.1 is firmly connected to the test connection element 13, the rotational movement of the test connection element 13 around the rotation axis Z is thus decelerated.

[0057] In the fourth step IVS of this method, torque measurement is started. For this purpose, the torque transducer 12.3 starts measuring the torque starting from a pre-defined threshold torque. Preferably, the threshold torque is 10% of the nominal torque. The torque transducer 12.3 generates a torque signal MS for the measured torque. The torque signal MS is transmitted via the torque signal line 14.3 to the evaluation unit 14 and imported by the evaluation program 14.1.

[0058] In the fifth step VS of this method, measurement of the rotation angle is started. The rotation angle is measured by a rotation angle transducer 12.2 starting from a pre-defined angular starting torque. Preferably, the angular starting torque is 50% of the nominal torque. The rotation angle transducer 12.2 generates a rotation angle signal WS for the measured rotation angle. The rotation angle signal WS is transmitted via the rotation angle signal line 14.2 to the evaluation unit 14 and imported by the evaluation program 14.1.

[0059] The sixth step VIS of this method includes determining whether the set nominal torque has been achieved. As soon as the nominal torque is achieved, there is a reaction by the nut runner 2. The reaction varies according to the functional principle, and according to that functional principle, the nut runner 2 moves. A click-type torque wrench stops applying torque when the nominal torque is achieved. An acoustic torque wrench automatically induces an acoustic signal or an optical signal when the nominal torque is applied. The display nut runner displays the applied nominal torque. The reaction of the nut runner 2 is detected, and the brake element 10.1 is stopped from operating by the control and regulation unit 10.3. Further, the measurement of torque by the torque transducer 12.3 and the measurement of the rotation angle by the rotation angle transducer 12.2 are terminated.

[0060] In the seventh step VIIS of this method, the time course of the measured torque signal MS with respect to the measured rotation angle signal WS is graphically represented as torque ratios R1, R2, R3. For this purpose, the imported torque signal MS and the imported rotation angle signal WS by the evaluation program 14.1 are graphically displayed on the screen of the evaluation unit 14 as the torque ratios R1, R2, R3. To obtain statistical significance, the screw joint simulation is executed multiple times. The repeatedly measured torque signal MS and rotation angle signal WS are imported by the evaluation program 14.1 and graphically displayed as the superimposed torque ratios R1, R2, R3.

[0061] This is illustrated in FIGS. 7 and 8. FIG. 7 shows the superimposed torque ratios R1, R2, R3 of the screw joint simulation using the simulation device 1 without angular synchronization. Further, FIG. 8 shows the superimposed torque ratios R1, R2, R3 of the screw joint simulation using the simulation device 1 with angular synchronization. In the graphs shown, the torque M is plotted on the vertical axis and the rotation angle W is plotted on the horizontal axis. The torque signal MS and the rotation angle signal WS are measured from the starting torque. For each torque ratio R1, R2, R3, the measured starting torque signals Ms1, Ms2, Ms3 and the measured starting rotation angle signals Ws1, Ws2, Ws3 are represented by dashed lines. In the example, three torque ratios R1, R2, R3 are shown superimposed, but according to the guidelines VDI / VDE 2647 of February 2013, 25 torque ratios are superimposed for each screw joint simulation.

[0062] For each torque ratio R1, R2, R3, the evaluation program 14.1 determines the maximum measured torque signals Me1, Me2, Me3 and the maximum measured rotation angle signals We1, We2, We3 corresponding to the maximum measured torque signals Me1, Me2, Me3. In FIGS. 7 and 8, the maximum measured torque signals Me1, Me2, Me3 are represented by dashed lines. The maximum measured rotation angle signals We1, We2, We3 are also represented by dashed lines in FIGS. 7 and 8.

[0063] The evaluation program 14.1 calculates the arithmetic mean of the maximum measured torque signals Me1, Me2, Me3, and this arithmetic mean is called the average torque Mm. In FIGS. 7 and 8, the average torque Mm is represented by a dotted line.

[0064] The evaluation program 14.1 calculates the arithmetic mean of the maximum measured rotation angle signals We1, We2, We3, and the said arithmetic mean is called the average rotation angle Wm. In FIGS. 7 and 8, the average rotation angle Wm is represented by a dotted line.

[0065] In the screw joint simulation shown in Fig. 8 performed with angular synchronization, the starting rotation angle signals Ws1, Ws2, and Ws3 are much closer to each other than in the screw joint simulation shown in Fig. 7 performed without angular synchronization. Furthermore, the maximum measured rotation angle signals We1, We2, and We3 are also much closer to each other in the angular synchronization screw joint simulation shown in Fig. 8 than in the screw joint simulation shown in Fig. 7 without angular synchronization. The closer spacing between the starting rotation angle signals Ws1, Ws2, and Ws3 and the closer spacing between the maximum measured rotation angle signals We1, We2, and We3 are the result of the rotational imbalance of the rotating part of the simulation device 1. In the case of the screw joint simulation performed without angular synchronization, the rotational imbalance occurs in an angularly offset manner, while in the case of the screw joint simulation performed with angular synchronization, the rotational imbalance is angularly synchronized.

[0066] As a result, the deviations Δ1, Δ2, and Δ3 of the maximum measured rotation angle signals We1, We2, and We3 from the average rotation angle Wm are also smaller in the screw joint simulation shown in Fig. 8 performed with angular synchronization than in the screw joint simulation shown in Fig. 7 without angular synchronization. More specifically, the angular synchronization screw joint simulation meets the requirements of the February 2013 guideline VDI / VDE 2647 regarding the allowable deviation of the maximum measured rotation angle with respect to the average rotation angle.

[0067] Fig. 9 shows a schematic diagram of a series of steps IN, IN’ to VIIIN for a method of modifying an existing simulation device 1’. The existing simulation device 1’ includes an existing rotation angle converter 12.2’ and an existing measurement disk 12.1’ without a zero mark 12.12.

[0068] In the first step IN of this method, the existing measurement disk 12.1' is removed. In the second step IIN of this method, a measurement disk 12.1 having a zero mark 12.12 is provided. In the third step IIIN of this method, the provided measurement disk 12.1 is installed in place of the existing measurement disk 12.1'. In the fourth step IVN of this method, the orientation of the existing rotation angle converter 12.2' with respect to the zero mark 12.12 is defined as the zero angle 12.22. When the angle mark 12.11 is not a clearly defined increment code value, and thus none of the increment code values can be defined to be the zero mark 12.12, the replacement of the existing measurement disk 12.1' described in the first to fourth steps IN to IVN is useful.

[0069] In an alternative first step IN' of this method, one of the angle marks 12.11 of the existing measurement disk 12.1' is defined to be the zero mark 12.12. Then, the fourth step IVN of this method is executed, and the orientation of the existing rotation angle converter 12.2' with respect to the zero mark 12.12 is defined as the zero angle 12.22. The alternative first step IN' is appropriate when the angle mark 12.11 is an absolute code value so that one of the absolute code values can be uniquely defined as the zero mark 12.12.

[0070] If the existing rotary angle transducer 12.2' is not designed to measure the zero mark 12.12, the existing rotary angle transducer 12.2' is removed in the fifth step VN of this method. In the sixth step VIN of this method, a rotary angle transducer 12.2 configured to measure the zero mark 12.12 is provided. Further, in the seventh step VIIN of this method, the provided rotary angle transducer 12.2 is installed in place of the existing rotary angle transducer 12.2'. When the existing rotary angle transducer 12.2' is not designed to measure the zero mark 12.12, for example, since the zero mark 12.12 and the angle mark 12.11 are arranged apart from each other on the measurement surface 12.10, the replacement of the existing rotary angle transducer 12.2' after steps VN to VIIN is useful.

Description of Signs

[0071] 1 Simulation device 1' Existing simulation device 2 Nut runner 10 Brake unit 10.0 Brake unit housing 10.1 Brake element 10.2 Rotor 10.3 Control and adjustment unit 11 Connecting element 12 Measuring unit 12.0 Measuring unit housing 12.1 Measuring disk 12.1' Existing measuring disk 12.10 Measurement surface 12.11 Angle mark 12.12 Zero mark 12.2 Rotary angle transducer 12.2' Existing rotary angle transducer 12.21 Sensor element 12.22 Zero angle 12.3 Torque transducer 13 Test connection element 14 Evaluation unit 14.1 Evaluation Program 14.2 Rotation Angle Signal Line 14.3 Torque Signal Line Δ1, Δ2, Δ3 Deviation Steps of the Method for Modifying an Existing Simulation Device IN~VIIN Steps of the Method for Executing Thread Joint Simulation IS~VIIS M Torque Me1, Me2, Me3 Maximum Torque Mm Average Torque Ms1, Ms2, Ms3 Starting Torque Signal MS Torque Signal NS Zero-Mark Signal R1, R2, R3 Torque Ratio W Rotation Angle We1, We2, We3 Maximum Rotation Angle Ws1, Ws2, Ws3 Starting Rotation Angle Signal Wm Average Rotation Angle Z Rotation Axis

Claims

1. A simulation device (1) for simulating a screw connection of a nut runner (2), comprising a test connection element (13) and a brake unit (10), wherein the brake unit (10) includes a brake element (10.1) and a rotor (10.2) firmly connected to the brake element (10.1), the test connection element (13) is firmly connected to the rotor (10.2), the nut runner (2) can be connected to the test connection element (13), the nut runner (2) can be actuated, the actuated nut runner (2) applies torque to the connected test connection element (13), the applied torque rotates the test connection element (13) around a rotation axis (Z), the brake unit (10) can be actuated, the actuated brake unit (10) brakes the test connection element (13) rotating around the rotation axis (Z), the simulation device (1) comprises a torque transducer (12.3) for measuring the applied torque, the test connection element (13) comprises a rotation angle transducer (12.2) for measuring a rotation angle of the test connection element (13) rotating around the rotation axis (Z), in a simulation device (1), the simulation device (1) comprises a measurement disk (12.1), the measurement disk (12.1) comprises a zero mark (12.12), the rotation angle transducer (12.2) comprises a sensor element (12.21), the measurement disk (12.1) is firmly connected to the rotor (10.2), when the brake element (10.1) is actuated to drive the rotor (10.2) and the measurement disk (12.1), and as soon as the sensor element (12.21) detects the zero mark (12.12) of the measurement disk (12.1), the brake element (10.1) stops operating, and the brake unit (10) can be oriented at a zero angle (12.22) with respect to the zero mark (12.12), and the screw connection simulation starts from the zero angle (12.22), and at the start, the zero mark (12.12) is angle-synchronized with the zero angle (12.22), characterized in a simulation device (1).

2. The simulation device (1) according to claim 1, wherein the measurement disk (12.1) is arranged in the direction of the rotation axis (Z) between the brake unit (10) and the test connection element (13), and the zero mark (12.12) is arranged on the measurement surface (12.10) of the measurement disk (12.1).

3. The simulation device (1) according to claim 2, wherein the measurement disk (12.1) comprises an angle mark (12.11), the angle mark (12.11) is arranged on the measurement surface (12.10), and the zero mark (12.12) and the angle mark (12.11) are spatially separated from each other on the measurement surface (12.10).

4. The simulation device (1) according to claim 3, wherein the angle mark (12.11) is an incremental code value.

5. The simulation device (1) according to claim 2, wherein the measurement disk (12.1) comprises an angle mark (12.11), the angle mark (12.11) is arranged on the measurement surface (12.10), and the zero mark (12.12) and the angle mark (12.11) are not spatially separated from each other on the measurement surface (12.10).

6. The simulation device (1) according to claim 5, wherein the angle mark (12.11) is an absolute code value.

7. The simulation device (1) according to any one of claims 1 to 6, wherein the rotation angle converter (12.2) is arranged in a prescribed manner at a zero angle (12.22) with respect to the zero mark (12.12).

8. The simulation device (1) according to any one of claims 1 to 7, wherein the rotation angle converter (12.2) is attached to a fixed position on the simulation device (1).

9. The simulation device (1) according to any one of claims 1 to 8, wherein the sensor element (12.21) detects the zero mark (12.12) adjusted to the zero angle (12.22), and the rotation angle converter (12.2) generates a zero mark signal (NS) for the zero mark (12.12) detected by the sensor element (12.21).

10. A method for performing the screw joint simulation of a nut runner (2) using the simulation device (1) according to any one of claims 1 to 9, wherein in a first step (IS) of the method, the brake unit (10) is adjusted to a zero angle (12.22) with respect to the zero mark (12.12), and in a second step (IIS) of the method, the nut runner (2) is connected to the test connection element (13), and in a third step (IIIS) of the method, the screw joint simulation is started from the zero angle (12.22).

11. A method for modifying an existing simulation device (1') for the screw joint simulation of a nut runner (2) to form the simulation device (1) according to any one of claims 1 to 9, wherein the existing simulation device (1') comprises an existing rotation angle converter (12.2') and an existing measurement disk (12.1') without a zero mark (12.12). In a first step (IN) of the method, the existing measurement disk (12.1') is removed. In a second step (IIN) of the method, a measurement disk (12.1) having a zero mark (12.12) is provided. In a third step (IIIN) of the method, the provided measurement disk (12.1) is installed in place of the existing measurement disk (12.1'). In a fourth step (IVN) of the method, the orientation of the existing rotation angle converter (12.2') with respect to the zero mark (12.12) is defined as the zero angle (12.22).

12. The existing rotation angle converter (12.2') is not designed to measure the zero mark (12.12), and is removed in a fifth step (VN) of the method. In a sixth step (VIN) of the method, a rotation angle converter (12.2) designed to measure the zero mark (12.12) is provided. In a seventh step (VIIN) of the method, the provided rotation angle converter (12.2) is installed in place of the existing rotation angle converter (12.2'). The method according to claim 11, characterized in that

13. A method for modifying an existing simulation device (1') for simulating the screw connection of a nut runner (2) in order to form the simulation device (1) according to any one of claims 1 to 9, wherein the existing simulation device (1') comprises an existing rotation angle converter (12.2') and an existing measurement disk (12.1') having angle marks (12.11) but no zero mark (12.12). In an alternative first step (IN') of the method, one of the angle marks (12.11) of the existing measurement disk (12.1') is defined as the zero mark (12.12). In a fourth step (IVN) of the method, the orientation of the existing rotation angle converter (12.2') with respect to the zero mark (12.12) is defined as the zero angle (12.22).

Images