WO2015185705A1

WO2015185705A1 - Centrifugal-force-based testing device

Info

Publication number: WO2015185705A1
Application number: PCT/EP2015/062531
Authority: WO
Inventors: Peter Kunow
Original assignee: Kunow Electronic Gmbh
Priority date: 2014-06-04
Filing date: 2015-06-04
Publication date: 2015-12-10
Also published as: DE102014210656A1

Abstract

The invention relates to a testing device (10; 10'; 10''; 10'''; 10''''; 10''''') for testing a test specimen (21, 21';21'';21''') by means of a centrifugal force acting on the test specimen (21, 21';21'';21''') with a rotational drive (12), a rotational unit (14), an attachment device (16, 16'; 28'; 72), at least one compensation unit (15; 51, 60) and a distance-measuring unit (32; 78). The test specimen has at least one test body (22, 22'; 22''; 22'''). The rotational unit (14) is connected to the rotational drive (12) and is designed to rotate about a rotational axis (18) when the rotational unit (14) is driven by the rotational drive (12). The attachment device (16, 16'; 28'; 72) is connected to the rotational unit (14) or forms part of the rotational unit (14) and is designed to attach a test specimen (21, 21';21'';21'''). The at least one compensation unit (15; 51, 60) is designed to ensure, when the rotational drive (12) drives the rotational unit (14) and a test specimen (21, 21';21''; 21''') is attached to and/or in the attachment device (16, 16'; 28'; 72), that a centre of mass (24) of the masses which are driven in rotation, including the masses of the rotational unit (14), attachment device (16, 16'; 28'; 72) and test specimen (21, 21';21'';21'''), coincides with the rotational axis (18). The distance-measuring unit (32; 70) is designed to measure, during the operation of the testing device (10; 10'; 10''; 10'''; 10''''; 10'''''), a length of the test specimen (21, 21') and/or a position of the test specimen (21, 21') relative to the distance-measuring unit (32; 78) if the test specimen (21, 21') is attached to and/or in the attachment device (16, 16'; 28'; 72).

Description

Centrifugal force based test device

The present invention relates to a test apparatus for testing a specimen, for example, a cable by a centrifugal force. The tester has for this purpose a rotary drive, a rotation unit and a fastening device. Furthermore, the present invention also relates to a method for testing a sample by a centrifugal force. The test device and the test method serve to test material properties, in particular tensile and tensile properties of a respective test object.

Test devices, in particular material testing devices, are typically used in the testing of properties of workpieces and materials. A special embodiment of a testing device is a material testing machine which generates test forces hydraulically via pressure cylinders or electromotively via threaded spindles. These material testing machines must be designed for the maximum test power. Conventional material testing machines typically have a large space requirement, since the generation of tensile forces of, for example, 50 kN requires very large drive units, such as electric motors, driver stages and other large machine elements. These materials testing machines are mostly suitable only for stationary use. In DE 522 425 C tensile testers are shown in which the load of the test specimen is generated by a weight.

DE 1 125 206 B shows a test stand for machine and device parts. In the test stand, if necessary, the test specimen in an evacuated receiver lined with a protective wall can be stressed beyond the breaking point of centrifugally acting forces. The test is applied to rotors of working and power machines, such as e.g. Turbine and compressor rotors, or performed on rotors of electrical machines to check the tensile strength of a given construction.

DE 202 14 292 U1 shows a tensile testing machine with a machine frame. The machine frame consists of a base traverse, a crossbeam and the two trusses connecting guide columns. Between the traverses a test device is arranged. The guide columns are designed as unidirectional pressure cylinder with a cylinder housing and a guided in the cylinder housing cylinder piston. EP 2 570 791 A2 shows a device for determining the biaxial strain characteristics of a sample. The device has a tensile testing machine with four sample holders. The tensile testing machine has a fixed member, a movable member and a force transducer for measuring the force required for the deformation of the sample in response to the path of the movable member. The device makes it possible to determine biaxial strain characteristics of a sample in two mutually perpendicular axes of the sample on the basis of the stress and strain diagram. For example, a sample may be a plastic or a composite material, e.g. be a plastic bound solid fuel.

The aim of the invention is to provide an improved testing device. According to the invention, a test device for testing a test specimen by a centrifugal force acting on the test specimen is proposed which has a rotary drive, a rotation unit, a fastening device, at least one compensation unit and a distance measuring unit. The test specimen has at least one test specimen, for example a cable, a rod, a tube, or a differently shaped specimen. The rotary unit is connected to the rotary drive and is configured to rotate about an axis of rotation when the rotary unit is driven by the rotary drive. The fastening device is compatible with the Rotati Onseinheit connected or forms part of the rotation unit and is designed for fastening a respective test piece. The at least one compensation unit is configured to ensure that a center of mass of the rotationally driven masses, including the masses of rotation unit, fastening device and test specimen, is mounted to the rotation unit and a specimen is attached to and / or in the fastening device Rotation axis coincides. During the operation of the test apparatus, the distance measuring unit is designed to measure a length of the test object and / or a position of the test object relative to the distance measuring unit when the test object is attached to and / or in the fastening device.

The test piece is attached to and / or in the test apparatus and is rotated by the test apparatus about the axis of rotation, whereby a centrifugal force in a plane perpendicular to the axis of rotation on the entire test piece acts or can act.

The compensation unit prevents imbalance and compensates it if necessary. In particular, imbalance occurs due to the mass center of gravity displacement of the test specimen due to the elongation of the specimen. Imbalance can already be caused by attaching the test specimen, for example, if the center of mass does not coincide with the attachment of the test specimens with the axis of rotation. The compensation unit thus serves for balancing the test apparatus and thus also allows high rotational speeds and thus high test loads, which can be achieved with only low driving force and drive power. The compensation unit may have different modes of operation to ensure that the center of mass of the rotationally driven masses, including the masses of rotary unit, fixture and specimen, coincides with the axis of rotation. The compensation unit can, for example, adjust the center of mass during operation with the aid of movable or displaceable masses. However, the compensation unit can also be designed to arrange the test object in such a way that no mass center of gravity displacement of the test object occurs, for example by ensuring that the test object expands to the same extent during operation on both sides of the axis of rotation.

A test specimen may comprise a test specimen, eg a cable, and fasteners attached to the test specimen, eg a shank connected via a crimp connection, an eyelet, a plug, a socket, or the like, around the test specimen on the test apparatus and on any additional tensile masses. for example, two each at the opposite longitudinal ends of the test specimen to be attached Zugmas- sen to secure. For example, a test specimen may be a cable having an inner metallic part and an outer limp insulating sheath. The test specimen can be attached to and / or in the test device and / or traction compounds, for example, by means of a crimp connection. The test object may comprise one or more materials, for example a metallic part and a plastic part, as in the case of an electrically conductive cable. Testing a device under test is to be understood as testing the properties of the device under test, in particular the tensile strength and elongation properties of the device under test and, for example, if necessary, the connection between the connecting element and the test element. In this case, the test piece is formed by the test piece and the connecting member, so that it can be checked, for example, first, if the test piece or the connection of the test piece to the tester tears when the centrifugal force is continuously increased to a demolition of the test piece. It can also be checked, for example, whether the connection between the test specimen and the connecting element or the test specimen breaks first. In one embodiment, a test specimen may be used which has a much greater tensile strength against the connections to the connecting element, so that essentially the connections are tested. Various connections and connecting elements can also form part of the test object. The distance measuring unit can determine the length and / or the position (eg displacement) of the test object relative to the distance measuring unit. The distance measuring unit can therefore be used, for example, to perform a strain measurement. In this case, a length of the test object in a stationary state is measured with the aid of the distance measuring unit, and this length is compared with a length of the test object measured by the distance measuring unit in a rotating state. The distance measuring unit can, for example, have a measuring scale which makes it possible to determine its length both in the stationary state and in the rotating state of the device under test. Furthermore, the distance measuring unit can have, for example, a displacement meter or protractor. In particular, the distance measuring unit can also be designed such that it indirectly determines the (path) length to be determined, for example by tracking holding elements for holding the test object.

One aspect of the invention is that the test force for testing the specimen by centrifugal acceleration of the mass of the specimen, ie generated as a centrifugal force becomes. The invention includes the insight that testing a sample with a centrifugal force as a test force allows a relatively small device size with a comparatively high test force, for example 50 kN. Another aspect of the invention is that the test load can be maintained permanently without significant energy losses, since the drive must overcome only air and bearing friction after an acceleration phase, which can be reduced by means of suitable, for example, known from the prior art measures. Furthermore, the test load is over a speed, for example 1200 U / min. precisely adjustable, with an energy input to the tester increases the speed and thus the test load. During a test cycle, apart from the energy necessary to overcome the low friction, essentially only the kinetic energy required to accelerate the rotationally driven masses must be supplied. Thus, it is possible to generate very large test loads, for example of 50 kN or even, for example, up to 100 kN with low driving force. Advantageously, the test forces arise in the form of centrifugal inertial forces directly on each atom of the test specimen. There is no complex Prüflingsspannvorrichtung necessary from the outside, for example, by a cable insulation, with a coefficient of static friction of about 1, must generate a corresponding test force clamping force.

In one embodiment of the test device, the fastening device has two holding elements, which are connected to at least one adjusting element. It can also be connected to an adjustment of each of the two holding elements. The at least one adjustment element is connected to the rotation unit or forms part of the rotation unit. The at least one adjusting element is arranged and formed such that it forms at least part of the compensation unit. Each of the holding elements is arranged and designed to hold the test body at or near a respective longitudinal end of the test body and the at least one adjusting element is adapted to move the respective holding element at least along a Prüflingslängsachse. The holding elements are preferably displaced by the adjusting element in opposite directions, so that the holding elements are moved either towards or away from each other. The holding elements can also be moved to different heights, in particular, only one of the holding elements can be moved, for example, to take into account an asymmetric mass distribution inherent in the test specimen.

The compensation unit of the embodiment of the test device described above functions according to the principle of arranging the test item in such a way that no mass is present. center of gravity displacement of the test specimen during operation of the test device, ie rotation of the specimen occurs. The holding elements hold the test specimen at or near the longitudinal ends of the test specimen. The test object may have connecting elements at the respective longitudinal ends of the test body, for example a cable, for example a shaft, eyelets, plugs, sockets or the like which are connected via a crimp connection and have a larger outside diameter than the test body. In this case, the holding elements can be moved to the transition from the test specimen to the connecting element and during further displacement caused by the rotation of the rotation unit tensile force then acts on the connections of fasteners and test specimen. Characterized in that the test device rotates during operation, a tensile force on the components of the test device, in particular the adjusting elements and holding elements, so that a displacement of the holding elements away from each other, ie in the direction of the tensile force acting substantially without effort is possible. By moving the holding elements away from each other, tensile force is introduced into the test specimen. Preferably, also tensile masses can be arranged at the respective longitudinal ends of the test piece in order to increase the tensile force acting on the test piece and to facilitate a displacement of the holding elements along the longitudinal axis of the test piece.

The above-described embodiment of the test device makes it possible to arrange the specimen symmetrically about the axis of rotation due to the holding elements and adjusting elements, so that the center of gravity coincides with the axis of rotation at all times. Furthermore, the design of the test device allows to examine the specimen with a tensile force by the holding elements can be moved away from each other substantially without any effort to introduce the tensile force generated by the rotation in the specimen. The test device can be installed in a housing to intercept parts of the test object flying around during the demolition of the test object through a housing wall. In the demolition of the test specimen, the tensile force is transferred back to the holding elements and adjusting elements.

In a preferred embodiment of the test device, the compensation unit has at least one parallel to a Prüflingslängsachse arranged guide which is fixedly connected to the rotation unit or forms part of the rotation unit, the fastening device has two operatively connected to the guide displaceable holding elements, each adapted thereto The specimen shall be held at or near a respective longitudinal end of the specimen. The holding elements are displaceable along the guide. The preferred embodiment of the test device described above functions according to the principle of arranging the test object such that no mass center of gravity displacement of the test object during operation of the test device, ie rotation of the test object, occurs. For this purpose, the holding elements hold the test specimen at or near a respective longitudinal end of the test specimen. The holding elements can firmly enclose the test piece so that it is held firmly in all directions, or the test piece can be loosely held in the holding element, so that the test piece has mechanical play and the test piece or the holding elements can be moved by a certain distance, without to introduce a tensile force into the test object. The test specimen can be connected at its respective longitudinal ends with connecting elements which have a larger outer diameter than the test specimen. The holding elements can be moved in this case, preferably only up to the connecting elements, without introducing a tensile force in the specimen. Further displacement of the retaining elements generates a tensile force acting on the test specimen through the retaining elements. Actively connected is to be understood here such that the holding elements are connected directly to the guide slidably or even more elements between the holding elements and the guide are arranged, for example, a connecting element, for example, a solid metal block and a setting element, such as a rotatable in the connecting element, however non-displaceable nut with an internal thread or the like. The test device in its preferred embodiment described above may comprise adjusting elements for adjusting the position of the respective holding element along the guide. By means of the adjusting elements, the holding elements along the guide or along the Prüflingslängsachse be moved.

In its preferred embodiment described above, the test device preferably has two traction masses which are displaceable along the guide and are each connected to one of the holding elements. As a result, the tensile force acting on the test specimen can be increased. The tensile compositions may, for example, in each case have a weight of more than 1 kg, for example more than 5 kg, for example more than 10 kg, for example more than 15 kg, for example 18 kg or for example more than 20 kg. Each of the Zugmassen is preferably connected via one of the holding elements with the test specimen. The tensile mass may form part of a holding element. For example, the Zugmasse have a thread which engages in a mating thread of a setting member which is connected to the guide. About the thread, the train mass can be moved. This is for example via a driven by a drive Drive wheel possible, which drive the adjusting element rotating and so can move the traction mass and retaining element on the thread.

In operation of the preferred embodiment of the test device described above, ie when rotating the test specimen at a certain speed, the holding elements can be moved along the guide without a significant effort is required because the tensile force generated by the rotation already on the components of Testing device acts. The adjusting elements for adjusting the position of the respective holding element along the guide serve to move the holding elements. If the holding elements were arranged close to each other along the specimen longitudinal axis on the specimen and would not hold the specimen firmly, the specimen could slip along the specimen axis, which could cause an imbalance. In this case, the center of mass of the rotationally driven masses would not coincide with the axis of rotation. The compensation unit is intended to prevent such a situation. The holding elements can be moved by the adjustment elements move the holding elements away from each other. By moving the holding elements to the respective longitudinal end or in the vicinity of the respective longitudinal end of the specimen, the specimen can be arranged symmetrically about the axis of rotation so that the center of gravity of the rotating masses lies on the axis of rotation. If the holding elements are moved even further away from each other, ie in the direction of the centrifugal force generated by the rotation, the centrifugal force acting on the Zugmassen acts as a tensile force increasingly on the test object. Previously, ie as long as the retaining elements are not readjusted, the centrifugal force acting on the train mass acts on the guide, the adjusting elements and the retaining elements. The adjusting elements can thereby displace the holding elements substantially without any effort until the tensile force introduced into the guide is minimized and the tensile force introduced into the test object is maximized. As the rotational speed of the testing device is further increased, the centrifugal force increases and is partially absorbed by the guide. By a further displacement of the holding elements, the tensile force introduced into the guide can be minimized again, so that finally the entire acting centrifugal force is introduced as tensile force (and test force) into the test object. By means of the rotation speed defined by the rotational speed, the known masses of the components of the device and of the test object and their position, the tensile force acting on the test specimen can be determined, and by the path traveled by the retaining elements, expansion and tensile properties of the test specimen can then be determined , Preferably, in the case of the preferred embodiment of the test device described above, the distance measuring unit has a displacement meter or protractor which detects the movement of the adjusting elements and thus indirectly the displacement of the holding elements along the longitudinal axis of the test piece. Alternatively, the detection of the path can be done directly via a odometer. Preferably, the distance measuring unit is designed to detect the angle change caused by the rotation of a driving wheel connected to the respective adjusting element by means of the protractor.

Furthermore, in the case of the preferred embodiment of the test apparatus described above, each of the tensile masses may comprise at least one wheel which rolls on the guide. The guide may, for example, have one, two, four, six, eight or more guide rails or guide rods arranged parallel to the test piece axis. The guide rails or guide rods are preferably arranged symmetrically around the fastening device for the test object, so that when a test object is fastened in the fastening device, the guide rails or guide rods have an identical spacing from the test object. The guide is preferably designed so that it expands very little under tensile force or has a negligible in relation to the specimen elongation. Preferably, a force sensor, such as a strain gauge or the like is connected to the guide to detect the centrifugal force acting on the guide. Preferably, each of the Zugmassen on at least one wheel for each of the guide rails or guide rods of the guide. The wheel is preferably arranged between the traction mass and the guide and guided along the guide. The respective wheel has the effect of reducing the friction between the traction mass and the guide when moving the traction mass along the guide. One aspect of the embodiment of the test device described above is that the tensile masses can not move freely outwardly during the demolition of the test specimens and can thereby assume a high radial velocity, since these are held by the adjusting elements and thus instead acts on the tensile force on the thread. In this way, very large forces that might otherwise occur when braking the demolished train mass can be avoided.

In one embodiment, the compensation unit has at least one first compensation mass displaceable by means of the compensation unit. The rotationally driven masses include the first compensation mass. The compensation unit is preferably designed to move the first compensation mass, whereby the center of gravity of the rotationally driven masses is moved.

The first compensation mass can be arranged on a line of action with the mass of the test object. The compensation unit can be designed to shift the first compensation mass radially along the line of action with the mass of the test object. The radial displacement of the first compensation mass corresponds with increasing centrifugal force of the elongation of the specimen and thus a shift of the center of mass of the specimen. By way of example, the arrangement can be realized with the aid of a retaining element arranged below the plane of the test object such that the first compensation mass can be displaced in the plane of the test object. Alternatively or additionally, the compensation unit may have a conveying device which is designed to displace the compensation mass along the line of action.

In one embodiment, the rotationally driven masses have at least one second compensating mass displaceable by means of the compensation unit. The second compensation mass is arranged around a displaceable by means of the compensation unit angle to the line of action between the first compensation mass and the mass of the test specimen.

In one embodiment, the test apparatus has at least two second compensation masses. The second compensation masses can be arranged at a respective angle to the line of action of the first compensation mass with the mass of the test object, about the axis of rotation and for simultaneous rotation with the test object about the axis of rotation. Arranged and trained second compensation masses are used to compensate for an imbalance generated by a mismatch of the first compensation mass to a strain change of the specimen. In an alternative embodiment of the testing device, the rotationally driven masses have at least one first compensating mass displaceable by means of the compensating unit and at least one second compensating mass displaceable by means of the compensating unit. The second compensation mass is arranged around a displaceable by means of the compensation unit angle to the line of action between the first compensation mass and the mass of the test specimen.

In one embodiment, the test device has two tensile masses. Each of the tensile masses is preferably formed at a longitudinal end or near a longitudinal end of the To be attached to test items. Each of the tow masses may include a mass coupling device or be connected to a mass coupling device. The mass coupling device is preferably designed to connect the traction mass with one of the ends of the specimen. The mass coupling device can be designed, for example, in the form of a crimp connection, a crimped connection, or in the form of another connection or another connection which is or is designed to connect the test object to the traction mass. The mass coupling device and / or the respective train mass can also form part of the test object, so that in the case of testing the test object, the properties of the train mass and / or the mass coupling device are also tested.

Additionally or alternatively, the test apparatus may have a central mass. The central mass can be arranged on, in or around the longitudinal axis of the rotation unit to keep a center of gravity of the test device as far as possible in the vicinity of the axis of rotation during operation of the test device and so allow only a small imbalance, ignoring the compensation unit. For this purpose, the central mass can be significantly larger than the other rotationally driven masses, for example the mass of the test specimen. Significantly larger is the central mass, for example, if it corresponds to twenty times the mass of the specimen. With the help of the compensation unit, the remaining small imbalance can therefore be more easily balanced and / or compensated so that the center of mass can be brought into conformity with the axis of rotation.

In one embodiment, the fastening device has two displaceable adjusting elements. The adjustment elements are preferably arranged and designed to enclose the test object between them, for example, by arranging the two adjustment elements opposite one another with the test object between them. Also, each adjusting member may be connected to a holding member configured to enclose the sample so as to be held or only movable along an axis. In this case, the holding elements may be arranged, for example, at or near the respective longitudinal ends of the specimen of the test specimen. If the specimen is movable along an axis, this is preferably the longitudinal axis of the specimen, wherein preferably a movement only along the specimen is possible and the movement is limited by the connecting elements. Each of the two adjustment elements can be displaceable at least along an axis passing through the two adjustment elements. In the event that the two adjustment elements enclose the test object between them, the test object can thus be fastened by adjusting the adjustment elements are pushed towards each other. In the case that each of the two adjusting elements is connected to a holding element, by pushing apart of the holding elements by the adjusting elements, the force acting on the test piece force can be increased. Adjustment elements may be in the form of rods, rods, rollers, wheels, blocks, combinations of these or the like, for example. Adjustment elements connected to holding elements can have, for example, threads, mating threads or the like, in particular the holding element can have a thread and the setting element a corresponding mating thread or vice versa.

Each of the adjusting elements may be rotatably mounted and have a Einstelldrehsachse or fixedly connected to the rotary drive, i. without rotatable mounting, but suitable for moving a retaining element. The Einstelldrehachsen run parallel to the axis of rotation. The rotatably mounted adjustment elements may be, for example, two opposing rods, rods, rollers, wheels, blocks, combinations of these or the like. The adjusting elements are preferably arranged and configured such that they form at least part of the compensation unit. In the rotatably mounted configuration of the adjusting elements, the adjusting elements are preferably arranged and configured such that a rotation of the adjusting elements about their respective adjusting rotational axis shifts the test object along a longitudinal axis of the test piece. By moving the test specimen along its longitudinal axis, the center of gravity of the specimen is displaced relative to the axis of rotation. This makes it possible to move the center of gravity in the axis of rotation when an imbalance has occurred in the tester. For example, one of the adjustment elements, e.g. a wheel, while a second opposing adjustment member, e.g. another wheel, freely rotatable. In the embodiment with the non-rotatably mounted adjusting elements, which are connected to holding elements, the adjusting elements are preferably arranged and designed such that a displacement of the holding elements by the adjusting elements along the Prüflingslängsachse to the test specimen applied to a tensile force.

In one embodiment, the rotation unit has at least one shaft which is designed to rotate about the axis of rotation. The rotation unit can also have several waves, for example two waves. For example, the rotation unit may have two shafts mounted on a platform, which are displaceable along at least one axis by an adjusting element. For example, these shafts can serve as adjustment elements by being able to rotate about their own axis in order to move the specimen along the specimen axis and thus the center of gravity of the system. At the same time, these adjustment elements can be held together by holding a test object. Such a setting element has a double function as a holding element and an adjusting or displacing element. In one embodiment, the rotation unit is connected to the rotary drive smoothly or at least approximately frictionless connected. As a result, friction losses are largely reduced and the tester can be operated with a lower energy consumption.

The test apparatus may comprise a housing. The housing preferably includes an evacuated cavity. Preferably, at least the rotary unit, the fastening device and the compensation unit are arranged in the evacuated cavity. In this case, the test apparatus is preferably designed to test the test object in the evacuated cavity. As a result, the test object in the evacuated cavity can be checked in such a way that virtually no air friction between the test object and the remaining gas particles in the cavity occurs during operation of the test device. The cavity can be evacuated, for example, after the test specimen has been introduced into it. Alternatively or additionally, the test apparatus may also include a Prüflingseinführungssystem, which is designed to transfer the DUT from the atmospheric environment in the evacuated cavity so that contamination with gas particles of the evacuated cavity is largely avoided.

In a preferred embodiment, the test device has a housing which encloses an evacuated cavity. In this embodiment, at least the rotation unit, the fastening device and the compensation unit are arranged in the evacuated cavity and the testing device is designed to check the test object in the evacuated cavity.

In one embodiment, the test apparatus is designed to examine a test object in the form of a cable with a cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm. In this case, the test piece is preferably a cable. The cable may, for example, have a flexible insulating plastic around the manure and an electrically conductive metallic core. The cable may have a cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm. Zugmassen can, but need not be provided. For example, it can be provided to dispose of traction masses if the transverse cable is greater than 20 mm ² and the volume of the cable is greater than, for example, 3000 mm ³ or the weight is greater than, for example, 25 g. If the cable has a smaller volume than, for example, 3000 mm ³ , preferably tensile masses are arranged at the ends of the cable to be tested and fastened to the cable ends by means of connecting elements or mass coupling devices, for example crimp connections. The test apparatus can therefore also be designed to test a test object in the form of a cable with a cross section of less than 20 mm ² . In one embodiment of the test apparatus, the evacuated cavity is designed such that it can accommodate a maximum of a test specimen with a cross section of 400 mm ² and a maximum length of 150 mm.

In one embodiment, the test device is designed for a cable with a cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm, a tensile force in the form of a centrifugal force of at least 15 kN, for example at least 20 kN, at least 25 kN, at least 30 kN, at least 35 kN, at least 40 kN, at least 45 kN, for example at least 50 kN, for example at least 60 kN, for example at least 75 kg or for example at least 100 kN. The centrifugal force depends on the test specimen, in the present case on the cable, since the mass of the cable as a test mass flows into the acting as a test force centrifugal force. The producible centrifugal force further depends on the size, shape, and components, such as the drive, of the tester. The smallest possible size of the test device is aimed at high test force generated in the form of centrifugal force.

The testing device may be designed for use as a testing device for tensile and / or strain measurement in materials testing. The test apparatus can then be used to determine properties of specimens, i. Check the test specimen and the connecting elements, as well as the connections between the test specimen and connecting elements or connecting elements and testing device and determine measured values for the properties of the specimens. For example, a strain measurement can be determined by means of a change in length between stationary specimen and rotating specimen depending on the acting centrifugal force. For example, a tensile strength measurement is possible by determining the centrifugal force at which the specimen or part of the specimen breaks off.

The invention further relates to a method for testing a device under test. The method includes a step of determining a length along a longitudinal axis of a DUT. Furthermore, the method comprises a step of attaching the test specimen to and / or in a test apparatus. The method further includes the step of rotating the specimen about an axis of rotation to a predetermined speed. During rotation, a continuous adjustment of the mass center of gravity of the rotating system ensures that the center of gravity of the rotating system coincides with the axis of rotation. On the one hand, the method comprises a step of determining a measured tensile strength value when the test specimen breaks off before reaching the predetermined rotational speed. On the other hand, the method comprises the step of determining a strain measurement value via a change in the length of the specimen along the longitudinal axis of the specimen when the specimen has reached the predetermined rotational speed. By rotating the test specimen, a centrifugal force acting on the entire specimen is generated, which acts as a test force.

The invention further relates to a method for testing a test specimen having at least one specimen by a centrifugal force acting on the specimen in a Prüfvor- direction. The testing device has two holding elements for holding the test body, at least one adjusting element connected to a guide for displacing the holding elements, and a distance measuring unit for detecting a distance covered by the holding elements. The method comprises the following steps:

Holding a specimen at or near a respective longitudinal end of the specimen through the holding elements.

Rotate the test object around a rotation axis. During rotation of the test object about an axis of rotation, the adjusting element connected to the guide is driven and displaces the holding elements until the tensile force introduced into the guide becomes minimal and the tensile force introduced into the test object becomes maximum.

Determining a strain and / or tensile strength measured value by the distance measuring unit, which determines the distance traveled by the driving with the adjusting element of the holding element.

The invention further relates to a use of the test apparatus in one of the methods according to the invention for testing a test object. Furthermore, the invention relates to the use of the test device for testing a test specimen by acting on the specimen centrifugal force.

In one embodiment, the connection between the rotary drive and the rotary unit is designed such that the rotary unit is suspended in a movable manner and the suspension has an at least 10 mm wide circumferential free space.

In one embodiment, the drive is designed to be operated as a generator in order to convert a kinetic energy stored in a rotating mass into an electrical energy. The drive may include a braking resistor that may be configured to brake the rotation of the rotating mass and release the energy in the form of heat to the environment. The energy can also be supplied to an energy store, for example an electrical or kinetic energy store. The energy can be supplied in this case, if necessary, the test device, whereby a total of testing at very low energy consumption is possible.

An independent aspect of the invention is further that a test device is provided in which a compensation of the center of gravity displacement is superfluous, since the test device arranges the test object such that the test object is kept symmetrical. In this case, the center of gravity always falls at least approximately in the axis of rotation. In such a test device, the compensation of the center of gravity displacement is thus already effected by the arrangement of the test specimen, without that the compensation unit would have to actively move the center of gravity during rotation. Such a testing device for testing a test specimen having at least one specimen by a centrifugal force acting on the specimen comprises a rotary drive, a rotation unit, a fastening device and a distance measuring unit. The rotation unit is connected to the rotation drive and is designed to rotate about an axis of rotation when the rotation unit is driven by the rotation drive. The fastening device is connected to the rotation unit or forms part of the rotation unit. The fastening device is designed to fasten a test object in such a way that the center of mass coincides with the axis of rotation when rotating about the axis of rotation. In this case, the test object is held symmetrically around the axis of rotation, so that the center of gravity remains in the axis of rotation during the rotation and does not shift. During the operation of the test device, the distance measuring unit is designed to measure a length of the test object and / or a position of the test object relative to the distance measuring unit when the test object is on and / or in the test piece Fastening device is attached. In this case, the position of the test piece relative to the distance measuring unit means, in particular, the greatest distance between them, for example, because the test piece expands due to the centrifugal force acting on it. The other aspects of the invention, as will be apparent to those skilled in the art, may be combined with this independent aspect.

The invention will now be explained in more detail with reference to embodiments schematically illustrated in the figures. From the figures show:

Figure 1 is a schematic representation of a first embodiment of a test device with a tensioned between two tensile masses cable in a plan view.

Figure 2 is a schematic representation of the first embodiment of a test apparatus in a housing with a tensioned between two tensile masses cable in a plan view and a side view.

3 is a schematic representation of a second embodiment of a testing device in a plan view;

4 is a schematic representation of the second exemplary embodiment of a test device in a plan view with a demolished test object;

5 is a schematic representation of a third exemplary embodiment of a test apparatus in a plan view in a first position of two compensation masses arranged at an angle to the test specimen;

6 is a schematic representation of the third exemplary embodiment of a test device in a plan view in a second position of two compensation masses arranged at an angle to the test object;

7 is a schematic representation of the third exemplary embodiment of a test device in a plan view in a third position of two compensation masses arranged at an angle to the test object, in which a part of the test object has fallen off;

8 shows a schematic illustration of the third exemplary embodiment of a test apparatus in a plan view in a fourth position of two compensation masses arranged at an angle to the test object; 9 is a schematic representation of a fourth embodiment of a test device with a test specimen arranged between two tensile masses in the form of a cable in a plan view;

10 is a schematic representation of the fourth embodiment of a Prüfvor- direction in a side view;

Fig. 1 1 is a schematic representation of a fifth embodiment of a test apparatus in a plan view;

12 shows a schematic illustration of a sixth exemplary embodiment of a testing device in a plan view; 13 is a block diagram representation of a first embodiment of a method for testing a device under test;

14 is a block diagram representation of a second embodiment of a method for testing a device under test.

FIG. 1 shows a first exemplary embodiment of a testing device 10 in a plan view. The test apparatus 10 includes a rotary drive 12, a shaft 14 and a compensation unit 15 (see side view of Fig. 2), which includes in the test apparatus 10, two adjusting rollers 16 and 16 '. The rotary drive 12 is connected to the shaft 14 and drives it by rotating the shaft 14 about an axis of rotation 18 (see Fig. 1). The shaft 14 is connected to the adjustment rollers 16 and 16 ', which can be displaced along an axis 20 extending therebetween to secure a specimen 21. The test piece 21 has a test piece 22. To attach the test piece 22, this is clamped between the adjusting rollers 16 and 16 '. In the embodiment, the adjustment rollers 16 and 16 'are manually, i. pushed by hand or with a tool on each other to attach the test piece 22. The adjusting rollers 16 and 16 'may also be connected to a drive which can push them together (not shown). During operation of the test apparatus, the test object 21 is rotated in the test apparatus 10 with the aid of the rotary drive 12.

The test apparatus 10 can be used as a tensile tester for tensile and elongation measurement for use in materials testing. For this purpose, the test apparatus 10 generates a test force by means of the rotary drive 12 through the centrifugal acceleration of the mass of the specimen 21. The drive power in rotating systems depends in the balanced state, ie when the axis of rotation 18 coincides with a center of gravity 24 of the system, only from the remaining bearing and air friction. In the present case, the rotationally driven masses on a streamlined construction, whereby the bearing and air friction is largely reduced and can be almost neglected compared to conventional testing machines. The parameters which determine the centrifugal force are the rotationally driven mass, an angular velocity 26 squared and a trajectory radius, ie, F _z = m - co ² - r. The friction losses go to 0; If this is set equal to 0, a rotating system can maintain the generated test force in the form of a centrifugal force indefinitely without further energy input. Each additional energy supply or removal in the form of speed changes Αω ² increases or decreases the test load. Since the test apparatus 10 is in the form of a centrifuge, it is an accumulating system and has an integral behavior. The test apparatus 10 must therefore be supplied during a whole test cycle ', which takes for example about 30 s, only the kinetic energy of the rotationally driven masses and a very low energy to overcome the remaining low friction.

The adjusting roller 16 is further driven in the embodiment shown in Figures 1 and 2 by a drive (not shown) and can be rotated about a Einstelldrehachse 27. The adjustment axis of rotation 27 extends parallel to the axis of rotation 18. The adjusting roller 16 'is the adjusting roller 16 disposed opposite and freely rotatably mounted, so that when the adjusting roller 16 is rotated, the test piece 21 can be moved along its longitudinal axis. As a result, the center of mass 24 of the rotationally driven masses can be displaced or balanced such that it coincides with the axis of rotation 18. It can also be both adjusting rollers 16 and 16 'driven by a drive. Instead of adjusting rollers 16 and 16 'may alternatively be used other adjustment elements, such as dials, adjusting shafts or the like.

In the exemplary embodiment of the test apparatus 10 shown in FIGS. 1 and 2, the test body 22 is connected to a pull mass 30 via a respective crimp connection 28 at the respective end of the test body 22. In this case, the test specimen 21 thus comprises the test body 22, the crimp connections 28 and the traction masses 30 and the connections between the components of the specimen 21 and the connection to the test apparatus 10. The tensile masses 30 in the present case serve for rotation Centrifugal acceleration of the mass of the specimen 21 to reinforce. If the test specimen 22, for example a cable with a cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm, has sufficient intrinsic mass, then only the test specimen 22, ie in this case only one test specimen 22 in the form a cable. In this case, no Zugmassen 30 and no crimp 28 are needed and therefore not tested. The use of traction compounds 30 is provided in the present case if the mass of the test specimen 22 has a low weight, for example below 25 g, so that the generation of a sufficient test load (F _z = m - co ² - r) without additional traction mass 30 would require a very high angular velocity 26. The actuating forces of the adjusting rollers 16 and 16 'must, when traction masses 30 are used, correspond substantially to the centrifugal differential force of the traction masses 30. The traction masses 30 have a distance measuring unit 32 in order to determine a change in length of the specimen 21. Alternatively, other distance measurement units (not shown), in particular those that are not connected to the train mass 30 or are included, can be used, which allow a change in length of the specimen 21 in the idle state and in a rotating operation of the test apparatus 10 determine. The alternative distance measuring units may, for example, contain displaceable light barriers whose position is displaceable on a length measuring element in order to determine the length of the test piece 21 (not shown). In order to carry out a strain measurement, for example, a first measurement is carried out at rest and a resting length of the test piece 21 is determined. Further length measurements can then be determined, for example, at predetermined rotational speeds of the test object 21 driven in rotation by the rotary drive 12. In the exemplary embodiment shown in FIG. 2, the test apparatus 10 has a housing 34. The housing 34 may also be arranged in a cavity of a larger outer housing in an exemplary embodiment that is not shown. The housing 34 has a cavity 36 which is hermetically, ie gas-tight closed. In the cavity 36 of the rotary drive 12 and a test chamber 38 is arranged, which contains the shaft 14 and the adjusting rollers 16, and attached between the adjusting rollers 16 test body 22 connected via crimp 28 Zugmassen 30. The shaft 14 connects the test chamber 38 with the rotary drive 12. The test chamber 38 is closed with a Prüfkammerdeckel 40 and contains at their sides in each case a rubber element 42 which is provided in the event that a test piece 21 breaks off the tearing parts catch without in that the test apparatus 10 or a user of the test apparatus 10 is damaged. The cavity 36 is evacuated by means of vacuum pumps (not shown) before the rotary drive 12 rotates the specimen 21 in the test chamber 38 to reduce air friction between the test chamber 38 and gas particles during testing of the specimen 21. Alternatively, the test piece 21 can also be tested without test chamber 38 and thus the test specimen 21 exposed to air friction (not shown).

If the test apparatus 10 is already disposed in an evacuated outer housing, the need for post-evacuation of the evacuated cavity 36 prior to testing a new test object 21 can be reduced. This is possible when a sample insertion system, not shown, introduces the test piece 21 into the test apparatus 10 without the vacuum generated in the evacuated cavity 36, i. In this case, compared to the normal atmosphere greatly reduced particle density in the gas phase, is impaired. This is possible, for example, via a lock system having intermediate cavities which have different gas phase particle densities (not shown).

In the present case of the test apparatus 10, not only the test body 22, but also the crimped connections 28 and the tensile masses 30 are tested. Depending on the materials of which the test specimen 22, the crimps 28 and the tensile compositions 30 are made and their shape, each of these may be the component with the least tensile strength and tear. The connection of the individual components and the connection to the test apparatus 10 are also tested. For example, two different crimp connections 28 can also be used, so that two different crimp connections 28 and their connection to the test body 22 can be tested simultaneously in the test apparatus 10. It can also alone a test piece 22, for example, a test piece 22 are tested in the form of a cable; ie without crimped connections 28 and tensile masses 30. FIG. 3 shows a second exemplary embodiment of a test apparatus 10 'in a plan view. In the test apparatus 10 ', in contrast to the test apparatus 10, no tensile masses 30 are provided. The test force is generated in the test apparatus 10 'solely by the centrifugal acceleration of the mass of the test piece 21. For this purpose, the test piece 22 is, for example, a cable with a cable cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm. The test piece 22 is connected to the shaft 14 by a crimped connection 28 '. In this case, the test specimen 21 thus contains the test body 22 and the crimped connection 28 ', but no additional traction mass 30. The mass of the shaft 14 serves in this case as a central mass 44 whose center of mass 46 coincides with the axis of rotation 18. The test apparatus 10 'furthermore has a first compensation mass 48, which is arranged displaceably on the line of action 50 of the centrifugal force acting on the test object 21, so that a change in the center of mass 24 due to a change in the center of gravity 52 of the test object 21 can be compensated. For displacing the first compensation mass 48, for example, a conveying device 51 is arranged along the line of action 50, which can displace the first compensation mass 48 along the line of action 50.

Due to the balanced arrangement of the center of gravity 52 of the test piece 21 and a center of mass 54 of the first compensation mass 48, the center of mass 24 coincides with the axis of rotation 18 in a stationary state. In a rotated state, the test piece 21 'expands and its center of gravity 52' is thereby displaced outwardly from the axis of rotation 18. This would push the center of mass 24 away from the axis of rotation 18 in the direction of the center of gravity 52 'without compensation. To prevent this, the first compensation mass 48 'in the rotating state of the test device 10 along the line of action on the opposite side of the sample 21 is displaced outwards, so that the shifted center of mass 54' of the first compensation mass 48 'the shifted center of gravity 52' of the Test specimens compensated and the center of gravity 24 of the rotationally driven masses with the axis of rotation 18 coincides.

The test apparatus 10 may comprise piezoelectric elements on a main bearing of the rotary drive 12 which are adapted to detect a displacement of the center of gravity 24 of the rotationally driven masses by measuring a diagonal voltage value in the manner of a Wheatstone bridge circuit (not shown). The shift of the center of mass 54 'of the first compensation mass 48' in the Wheatstone bridge circuit leads to a decreasing diagonal voltage value, the closer the center of gravity 24 of the axis of rotation 18 comes because the piezoelectric elements are compressed less strongly and therefore a low voltage occurs. When the diagonal voltage of the Wheatstone bridge circuit has dropped to 0 V, the axis of rotation 18 coincides with the center of gravity 24 of the rotationally driven masses. With the help of the Wheatstone bridge circuit and the displacement of the test object 21, it is also possible to determine an elongation of the test object 21. In order to displace the first compensation mass 48 such that the center of gravity 24 coincides with the axis of rotation 18, the test apparatus may comprise sensor units, for example a distance measuring unit and / or other sensors and a control circuit connected to them, which ensures that the conveying apparatus 51 first compensation mass 48 shifts according to the change in length of the specimen 21. In operation, therefore, serving as a centrifuge test apparatus 10 'by means of the first compensation mass 48, for example, by moving r _k to r _k ' on the common line of action 50 with the mass of the specimen 21, balanced. The radial displacement of the center of gravity 54 to 54 '(m _ks - m _ks ') of the first compensation mass 48 and 48' with increasing test force, corresponds to the Prüflingsdehnung and thus the shift of the center of gravity 52 to 52 '(m _ps - nrip _S ') of the test piece 21 or 21 '. In the exemplary embodiment shown here, essentially the length of the test body 22 or 22 'changes.

4 shows the second exemplary embodiment of the test apparatus 10 'in a plan view with a torn-off test body 22 "If a test object tears off in a balanced test apparatus 10', for example a tearing off of the test body 22" or a dissolution of the connection between test body 22 "and crimp connection As a result of the design, the position of the remaining rotationally driven masses, ie essentially the position of the central mass 44 and the first compensation mass 48, is removed from the rotating system, depending on the location of the break , does not change anything, a new equilibrium must be established, with the new center of gravity 24 and the new axis of rotation 18 are on the line of action between the center of mass 46 of the central mass 44 and the center of mass 54 of the first compensation mass 48. In the illustrated embodiment, the Prüfvorric 10 'a movable suspension, ie, the test apparatus 10' is floating, so that the test apparatus 10 'after a demolition of the test piece 22 "rotates about its center of mass 24 and thus the axis of rotation 18 moves accordingly when a new equilibrium occurs , This balance leads to a rotation axis 18, which does not coincide with the longitudinal axis of the shaft 14, so that in this case the shaft 14 rotates about the rotation axis 18. In an embodiment not shown, the suspension is rigid; In this case, the center of gravity 24 does not coincide with the axis of rotation 18.

The entire rotational energy is distributed in equal parts on the remaining central mass 44 and the first compensation mass 48. In the exemplary embodiment shown, play the test apparatus 10 ', the central mass 44 has approximately 20 times the mass of the specimen 21, for example, about 12 kg. The central mass 44 also has about 20 times the first compensation mass 48, which is provided with a mass similar to the mass of the test piece 21 mass. This ensures that the center of mass 24 remains as close as possible to the longitudinal axis of the shaft 14 when the test specimen 22 "is torn off.

The centrifugal force of the two rotating masses acting in the axis of rotation 18, ie the centrifugal force of the central mass 44 ( _m.sub.z ) and the first compensating mass 48 ( _m.sub.k ), must be equal. Therefore, results for example in the case that the central mass 44 is exactly 20 times as large as the first compensation mass 48, the following equation for the web radii: m _z - co ² - r _z = m _k - co ² - r _k II m _z = 20 · m _k ; l-

Y

20m _k - r _z = m _k -r _k ^ r _z = -

With a path radius r _{k of} the first compensation mass 48 of 100 mm, the path radius r _{z of} the central mass 44 is only 5 mm. The movable suspension of the centrifuge serving test device 10 'may have an approximately 10 mm wide circumferential free space. Therefore, no acceleration forces are transmitted to the housing 34 in this case. In order to deliver the energy stored in the rotatingly driven masses, the rotary drive 12 can be switched as a generator. Here, the rotary drive 12 converts the kinetic energy into electrical energy. The kinetic energy can either be released as heat to the environment with the aid of a braking resistor or stored with the aid of electrical and / or kinetic energy stores, for example capacitors. If the energy is delivered to electrical and / or kinetic energy stores, eg a flywheel or the like, it can be reused for testing a new test object 21.

5 shows a third exemplary embodiment of a testing device 10 "in a plan view in a first position of two second compensating masses 56 and 56 '. The balancing masses 56 and 56' are arranged at an angle to the line of action 50 and thus to the test piece 21 5, the angle between Wirkungsli- never 50 and the Balanciermassen 56 and 56 'each 90 °. During operation of the test apparatus 10 ", ie when the test object 21 is checked by rotation, the balancing masses 56 and 56 'rotate about the axis of rotation 18.

The test device 10 "serving as a centrifuge makes it possible to compensate for an imbalance resulting from a mismatch of the first compensating mass 48. For this purpose, the center of gravity 58 of the balancing masses 56 and 56 'can be displaced by a balancing mass compensation unit 56, 56', a so-called balancing unit 60 For this purpose, the balancing unit 60 displaces the balancing masses 56 and 56 'along the radius' r _b by a respective angle in order to bring the center of gravity 24 into conformity with the axis of rotation 18 (see FIGS. 6 to 8) first compensation mass 48 (m _k ) is arranged such that it accurately compensates the mass of the test object 21. Therefore, the balancing masses 56 and 56 '(m _b1 , m _b2 ) are arranged at 90 ° to the line of action 50, so that they have no influence on the Test force, since the centrifugal forces of the balancing masses 56 and 56 'mutually compensate each other, the force application point of the balancing masses 56 and 56 '(m _b1 , m _b2 ) is located on the axis of rotation 18 and does not generate a load moment for the Balancierantrieb. The balancing unit 60 must only overcome the bearing friction of the balancing masses 56 and 56 'in the center of the testing device 10 "when operating at a constant rotational speed since the radius of rotation r _{b of} the balancing masses 56 and 56' remains constant and thus the kinetic energy of the balancing masses 56 and 56 'remains constant.

E _red = (m _bl + m _b2 ) - r _b ² - ω ² II r _b = constant; ω = constant.

FIG. 6 shows the third exemplary embodiment of the test apparatus 10 "with the balancing masses 56 and 56 '(m _b1, m _b2 ) in an angular position which displaces the center of gravity 58 of the balancing masses 56 and 56' onto the side of the first compensating mass 48 Adjustment of the angular position leads to a symmetrically balanced system and is, for example, a consequence of a mismatch of the first compensation mass 48 (m _k ) and / or because the test specimen 21, in particular the test specimen 22, has expanded under the influence of the test load and thus the center of mass 52 of the test piece 21 has shifted on the line of action 50 to the center of mass 52 'of the test piece 21' (m _ps - nrip _S ').

Figure 7 shows the third embodiment of the test apparatus 10 "with the Balanciermassen 56 and 56 '(m _b1, m _b2 ) in an angular position, which moves the center of mass 58 of the Balanciermassen 56 and 56' on the side of the specimen 21"'. Im shown In the exemplary embodiment, a cable sheath or cable insulation has slid off a test body 22 '' in the form of a cable, as a result of which the center of mass 52 '' of the test piece 21 '' has moved closer to the axis of rotation 18. The balancing masses 56 and 56 'compensate for this reduced mass of the specimen 21 "'compared to the first compensation mass 48th

FIG. 8 shows the third exemplary embodiment of the test device 10 "with the balancing masses 56 and 56 '(m _b1, m _b2 ) in a different angular position which shifts the center of gravity 58 of the balancing masses 56 and 56' to the side of the first compensation mass 48 Angular position of Balanciermassen 56 and 56 'is not symmetrical to the line of action 50, so that the center of mass 58 of Balanciermassen 56 and 56' in this case does not fall on the line of action 50. The asymmetric adjustment of Balanciermassen 56 and 56 'also allows acceleration forces, with compensate for any direction pointing away from the center of rotation.

9 and 10 show a fourth embodiment of a testing device 10 "'in a plan view (Figure 9) and in a schematic side view with partial transparencies (Figure 10)." The testing device 10 "' has a rotary drive 12, a shaft 14 and a compensation unit 15.

The rotary drive 12 is connected via the shaft 14 to a rotary shaft platform 61 and drives it by rotating the rotary shaft platform 61 about a rotation axis 18. The rotary drive 12 can provide a speed of up to 1200 revolutions per minute (RPM). The rotary drive 12 can provide a predetermined speed or the speed can be increased continuously, for example, until the test piece 21 breaks. Alternatively, the rotary drive 12 can also be designed with a speed of up to 800 rpm, up to 1000 rpm, up to 1250 rpm, up to 1300 rpm, up to 1500 rpm. or up to 2000 rpm. to deliver.

Compensation unit 15 includes a guide 62, dynamometers 63, wheels 64, traction masses 30, connecting elements 66, adjusting elements 68, retaining elements 72, drive wheels 74, drive shaft 76, drive motor 78 and protractor 79.

The Zugmassen 30 is assigned in each case an adjustment 68. The traction masses 30 have an external thread 70 into which a respective internal thread of a respective adjusting element 68 engages. The threads are self-locking. The adjusting members 68 are rotatable about a respective connecting member 66, but immovable with the Guide 62 connected. The tensile masses 30 can be displaced along the guide 62 by rotation of the respective adjusting element 68. The external thread 70 of the left traction mass 30 is a left-hand thread and the external thread 70 of the right traction mass 30 is a right-hand thread, so that upon rotation of the respective adjustment element 68, the traction masses 30 are displaced in opposite directions, ie towards or away from each other.

To rotate the adjustment members 68, the drive motor 78 is used. The drive motor 78 is connected to the drive wheels 74 via the drive shaft 76. The drive wheels 74 may rotate the adjustment members 68 in two directions of rotation so that the adjustment members 68 may push the tow masses 30 toward or away from each other. The protractor 79 can detect the revolutions of the drive shaft 76 and determine a distance of the traction masses 30 from this. The drive wheels 74 have in this embodiment, a spur toothing which engages in a spur toothing of the respective adjusting member 68. The connection between drive wheels 74 and adjustment elements 68 may also have any other shape known to those skilled in the art, which allows the adjustment elements 68 to be driven via the drive wheels 74. The drive shaft 76 is a continuous shaft in this embodiment. Alternatively, it can also be designed split (not shown) so that each of the drive wheels 74 can be controlled individually in order to displace the traction masses 30 and the holding elements 72 connected thereto. For this purpose, two drive motors 78 may be provided. Alternatively, the drive wheels 74 may be configured to be moved up and down on the adjustment member 68 or to be coupled in and out to selectively drive or rotate one of the adjustment members 68 and to displace only one of the tow masses 30 (not shown) ). The aforementioned alternative embodiments are particularly useful when the test piece 22 has an asymmetric mass distribution, for example, because at the longitudinal ends different shafts connected to crimps 28, e.g. differently sized eyelets 80 or other connecting elements are arranged.

The guide 62 in this embodiment includes four guide rods forming a frame. The guide 62 may also include only one guide bar, or two, six, eight, or any number of guide bars. The guide 62 guides the two traction masses 30, which each have wheels 64, which roll on the guide rods of the guide 62, so that no or only slight frictional forces act between the guide 62 and the traction mass 30. Each train mass 30 has a mass of 18 kg in this embodiment. Alternatively, each train mass 30 may also have a mass of, for example, 1 kg, 2 kg, 5 kg, 10 kg, 15 kg, 20 kg or 25 kg. The outer threads 70 are designed so that each of the Zugmassen 30 can be moved by 50 mm. The external threads 70 may alternatively be designed to displace each of the traction masses 30 by up to 20 mm, 25 mm, 30 mm, 40 mm, 60 mm, 70 mm, 80 mm, 90 mm or 100 mm.

The traction masses 30 are each connected to a holding element 72, which serves to hold the specimen 22 of a specimen 21. The holding elements 72 hold the test piece 21 at or near the two longitudinal ends of the test piece 22. In this embodiment, the test piece 22 is held loosely in the holding element 72, so that the test piece 22 has a mechanical clearance and the test piece 21 or the holding elements 72 around a certain distance can be moved without introducing a tensile force in the test piece 21. The holding elements 72 can also firmly enclose the test body 22, so that it is held firmly in all directions. The holding elements 72 abut respectively on a shaft of an eyelet 80 forming a crimp connection 28. The test piece 22 has in this embodiment, an insulation and a conductor 82, for example in the form of an electrical conductor, optical conductor or the like. The outer diameter of the test piece 22, in particular of the conductor 82, is less than the outer diameter of the shank forming the crimp connection 28, so that the holding elements 72 can only be displaced as far as the crimp connection 28 without exerting a tensile force on the test piece 21. Since the holding members 72 are fixed to the Zugmassen 30, they move when the Zugmassen 30 are moved. The protractor 79, since the holding elements 72 are attached to the traction masses 30, also determine the distance covered by the holding elements 72. The dynamometer 63 is mounted on the guide 62 and may, for example, have a strain gauge or the like connected to the guide 62 which, via the extension of the guide 62, allows the centrifugal force on the guide 62 to be determined during rotation of the test apparatus 10 "' In order to detect whether the centrifugal force acting on the guide 62 is minimal, it may alternatively be detected whether an outer end flank 81 of the respective adjusting element 68 bears against a respective counter flank of the connecting element 66. As long as this is the case for both adjusting elements 68, At least a part of the centrifugal force can still act on the guide 62. As soon as an outer end flank 81 of one of the adjusting elements 68 no longer bears against the corresponding counter flank of the connecting element 66, no centrifugal force is introduced into the guide 62 the full centrifugal force acts on the test piece 21 and the adjusting elements 68 do not need to be tracked further. This condition can be sensed. The adjusting member 68 acts in this case as part of the train mass 30th

The functioning of the test apparatus 10 "'differs from the test apparatuses working with compensation masses, since the test apparatus 10" "according to the exemplary embodiment of FIGS. 9 and 10 arranges the test piece 21 in such a way that a center of mass displacement occurs during rotation about the axis of rotation 18 does not occur, ie the specimen 21 is stretched symmetrically about the rotation axis 18. The compensation of the shift of the center of gravity 24 is therefore inherent to the exemplary embodiment of the test device 10 "'of FIGS. 9 and 10 and is effected automatically on the basis of the arrangement of the test object 21.

Hereinafter, the operation of the test apparatus 10 "'in detail in the operation of the test apparatus 10"', i. explained during rotation about the rotation axis 18.

The centrifugal force acts on the components of the test apparatus 10 "'as a result of the rotation about the axis of rotation 18. As a result, the traction masses 30 and thus the holding elements 72 can be displaced along the guide 62 without a significant expenditure of force being required, since the force required by the Rotation generated tensile force already on the components, the test device 10 "'acts. By moving the holding elements 72 to the respective longitudinal end or in the vicinity of the respective longitudinal end of the Prüfkör- pers 22, the sample 21 can be arranged symmetrically about the axis of rotation so that the center of gravity 24 of the rotating masses of the test apparatus 10 "'is located on the axis of rotation 18 When the holding members 72 are further displaced away from each other, ie, in the direction of the centrifugal force generated by the rotation, the centrifugal force acting on the pulling masses 30 increasingly acts as a pulling force on the test piece 21. Previously, ie, as long as the holding members 72 are not adjusted The force acting on the train mass 30 centrifugal force on the guide 62, the adjusting elements 68, the Zugmasse 30 and the holding elements 72. The adjusting 68 can thereby move the holding elements 72 substantially without effort until the introduced into the guide 62 tensile force is minimized and the tensile force introduced into the test piece 21 max The tensile force introduced into the guide 62 can be detected by the force gauge 63. In this embodiment, the drive motor 78 is designed so that the force generated by the drive motor 78 is insufficient to cause an (additional) elongation of the test piece 21 or exert a significant force on the test piece 21. This means that the adjusting elements 68 through the Drive motor 78 can only be moved as long as the introduced into the specimen 21 part of the centrifugal force is less than the total centrifugal force. In this case, can be dispensed with a separate force sensor or force gauge for detecting the introduced into the guide 62 (partial) centrifugal force. Alternatively, the drive motor 78 may also be designed to continue to drive the adjusting elements 68. As the rotational speed of the test apparatus 10 "'is further increased, the centrifugal force increases and is partially recovered by the guide 62. This can be detected by the dynamometer 63. By retracting the retainer members 72, the spring can be inserted into the guide 62 Tensile force are again minimized, so that finally the total acting centrifugal force as tensile force (and test force) is introduced into the test piece 21. By the rotational speed defined by the rotational speed, the known masses of the components of the test device 10 "'and the test piece 21 and their Position, the tensile force acting on the test piece 21 can be determined, and by the distance traveled by the holding elements 72 then the tensile and tensile properties of the specimen 21 can be determined. The covered distance is detected by the protractor 79 in this embodiment. Alternatively, the covered distance can also be detected by another distance measuring unit, for example a displacement meter, for example in the form of an optical displacement meter or the like. As soon as the test piece 21 breaks off, a measured tensile strength value can be determined. In contrast to the test devices described in the previous figures, the tensile masses 30 are not thrown outwards in this case, since they are held by the self-locking threads. 9 and 10 thus makes it possible to prevent the drawers 30 from being thrown outwards, for example, against a stop (cf., the exemplary embodiment of FIGS 1 1).

Fig. 1 1 shows a fifth embodiment of a test apparatus 10 "". The operation of this test apparatus is similar to that of FIG. 9 and FIG. 10. Also, the test apparatus 10 "" arranges the test piece 21 such that a center of gravity displacement does not occur during rotation about the rotation axis 18, ie, the test piece 21 is around the Rotation axis 18 symmetrically stretched around. The compensation of the shift of the center of gravity 24 is therefore also the embodiment of the test apparatus 10 "" of Figure 1 1 inherent. In contrast to the embodiment of FIGS. 9 and 10, however, the test apparatus 10 "" does not have a guide 62.

The testing device 10 "" has adjusting elements 68 and displaceable holders 84. The adjusting elements 68 are arranged in the rotation shaft platform 61 in this exemplary embodiment. The slidable holders 84 are slidably connected at one longitudinal end to the adjusting elements 68 and can be displaced therefrom. At the other longitudinal end of the holder 84, the test piece 21 can be held by holding elements 72. The holding members 72 hold the specimen 22 of the specimen 21 at a respective longitudinal end or near a respective longitudinal end of the specimen 22. The support members 72 may for example consist of two U-shaped sections. The test piece 22 is then inserted into an upwardly open U-shaped portion and another downwardly open U-shaped portion of the support member 72 is mounted from above the test piece 22 and attached to the other U-shaped portion, so that the test specimen 22 can only slip along the Prüflingsachse. The retaining elements 72 can also hold the test specimen 22 so tightly that no slippage along the specimen axis is possible.

When the test apparatus 10 "" is rotated about the axis of rotation 18, the holders 84 can be moved outwardly along the rotation shaft platform 61 with almost no force. be shifted in the direction of the acting centrifugal force, so that a tensile force can be introduced into the specimen 21 via the holding elements 72.

The details of the operation are similar to the embodiment of the test apparatus described in FIGS. 9 and 10. Some components of the test apparatus 10 "" were therefore not shown in the schematic representation. However, these will be readily apparent to those skilled in the art in connection with FIG. In this exemplary embodiment, the traction masses 30 can be braked by the housing wall surrounding the test apparatus 10 "", which serves as a stop in this case.

Fig. 12 shows a sixth embodiment of a test apparatus 10 ""'. In this embodiment, the two traction masses 30 are connected by means of a connecting device 86, so that in the case of the demolition of a specimen 21 (not shown, in perspective behind the connecting device 86 and disposed between the holding elements 72), the distance, the traction masses 30 after can move outside, is limited by the length of the connecting device 86. This exemplary embodiment also uses the functional principle of the arrangement of the test object 21 around the rotator. onsachse, so that the center of gravity 24 coincides with the axis of rotation 18 and the specimen 21 expands symmetrically about the axis of rotation 18. Additional compensation masses are superfluous even in this case.

Fig. 13 shows a first embodiment of a method for testing a device under test. The method comprises the steps:

200 determining a length along a longitudinal axis of a test piece.

210 attaching the test specimen and / or in a tester.

220 Rotate the test specimen about an axis of rotation up to a predetermined speed. During rotation, continuously adjusting the center of gravity of the rotating system ensures that the center of mass of the rotating system coincides with the axis of rotation.

230 determining a tensile strength measurement value if the candidate demolishes before reaching the predetermined speed.

240 determining a strain measurement value over a change in the length of the specimen along the longitudinal axis of the specimen when the specimen has reached the predetermined speed.

14 shows a second embodiment of a method for testing a specimen having at least one specimen by a centrifugal force acting on the specimen in a test apparatus. The test apparatus has two holding elements for holding the test specimen, at least one adjusting element connected to a guide for displacing the holding elements, and a distance measuring unit for detecting a traversed distance of the holding elements. The method comprises the steps:

300 holding a test specimen at or near a respective longitudinal end of the test specimen by the holding elements.

310 Rotating the test specimen about an axis of rotation. During rotation of the test object about the axis of rotation, the adjusting element connected to the guide is driven for so long and shifts the holding elements until reaching the position in the guide. The tensile force introduced is minimal and the tensile force introduced into the test specimen becomes maximum.

LIST OF REFERENCES

10 tester

12 rotary drive

14 wave

15 compensation unit

16 adjusting rollers

18 rotation axis

20 axis through the adjustment rollers

21 test object

22 specimens

24 Mass center of the rotationally driven masses

26 angular velocity

27 adjusting rotary axis

28 crimp connection

30 train mass

32 distance measurement unit

34 housing

36 cavity

38 test chamber

40 test chamber lid

42 rubber element

44, mz central mass (m _z ) 46, mzs center of gravity of the central mass (m _zs )

48, mk first compensation mass

50 line of action

51 conveying device

52, mps Mass center of the specimen (m _ps )

54, mks center of mass of the first compensation mass (m _ks ) 56, mb1 second compensating mass 1 or balancing mass 1 (m _b1 ) 56 ', mb2 second compensating mass 2 or balancing mass 2 (m _b2 ) 58, mbs center of mass of the balancing masses (m _bs )

60 compensation unit for Balanciermassen, Balanciereinheit mp mass of the test piece (m _p)

rp rotation radius of the mass of the test piece (r _p )

rk rotation radius of the first compensation mass (r _k )

rz rotation radius of the central mass (r _z )

rb rotation radius of the balancing masses (r _b )

61 Rotary shaft platform

62 leadership

63 dynamometer

64 wheels

66 connecting element

68 adjustment element

70 external thread 72 holding elements

74 drive wheels

76 drive shaft

78 Drive motor 80 eyelet

81 outer front edge

82 conductors

84 holders

86 connection device

Claims

claims

Testing device (10; 10 '; 10 "; 10"'; 10 ""; 10 "" ') for testing a specimen (21, 21', 21 ", 21" ') with at least one specimen (22, 22'; 22 "') by a centrifugal force acting on the test piece (21, 21'; 21"; 21 "'), with a rotary drive (12), a rotation unit (14) connected to the rotary drive (12) is to rotate about a rotation axis (18) when the rotation unit (14) is driven by the rotary drive (12), a fastening device (16, 16 ', 28') connected to the rotation unit (14) or forming part of the rotation unit (14) 72) for fastening a test piece (21, 21 ', 21 ", 21"'), at least one compensation unit (15, 51, 60), which is formed when the rotary drive (12) drives the rotary unit (14) and a test piece (21, 21 ', 21 ", 21"') is attached to and / or in the fastening device (16, 16 ', 28', 72) to ensure that a center of mass (24) of the r otierend driven masses including the masses of rotation unit (14), fastening device (16, 16 '; 28 '; 72) and the test piece (21, 21 ', 21 ", 21"') coincides with the axis of rotation (18) and a distance measuring unit (32, 78) which is formed during operation of the testing device (10, 10 ', 10 "). measuring a length of the test piece (21, 21 ') and / or a position of the test piece (21, 21') relative to the distance measuring unit (32, 78) when the test piece (21, 21 ') and / or in the fastening device (16, 16 ', 28', 72) is attached.

The testing apparatus (10 "") according to claim 1, wherein said fixing device (72) comprises two holding members (72) connected to at least one adjusting member (68), said at least one adjusting member (68) being connected to said rotating unit (61) or forms part of the rotation unit (61), wherein the at least one adjustment member (68) is arranged and configured to form at least part of the compensation unit (15), and wherein each of the support members (72) is arranged and formed at the test body (22) at or near a respective longitudinal end of the To hold test specimen (22) and the at least one adjusting element (68) is adapted to move the respective holding element (72) at least along a Prüflingslängsachse.

The test apparatus (10 "') according to claim 1, wherein the compensation unit (15) has at least one guide (62) arranged parallel to a longitudinal axis of the test piece, fixedly connected to the rotation unit (61) or forming part of the rotation unit (61) the fastening device (72) has two displaceable holding elements (72) which are operatively connected to the guide (62) and which are each designed to hold the test body (22) at or near a respective longitudinal end of the test body (22) and wherein the holding elements (72) along the guide (62) are displaceable.

The test apparatus (10 "') according to claim 3, wherein the test apparatus (10"') has at least one adjustment member (68) for adjusting the position of the respective support member (72) along the guide (62).

A test device (10 "') according to claim 4, wherein the test device (10"') has two traction masses (30) displaceable along the guide (62) and each connected to one of the retaining elements (72).

Test device (10, 10 ', 10 ") according to claim 1, wherein the rotationally driven masses at least a first by the compensation unit (51) displaceable compensation mass (48, 48') and at least one second by means of the compensation unit (60) displaceable compensation mass ( 56, 56 '), which is arranged around an offset by means of the compensation unit (60) angle to the line of action (50) between the first compensation mass (48, 48') and the mass of the test piece (21, 21 ').

A test device (10; 10 '; 10 "; 10"'; 10 ""; 10 "" ') according to at least one of claims 1, 2, 3, 4 or 6, wherein the test device (10; 10'; 10 ") has two tensile masses (30), and wherein each of the tensile masses (30) is adapted to be attached to one end or near one end of the test specimen (22) and / or to form part of the specimen (21).

Test device (10; 10 '; 10 ") according to at least one of claims 1 to 7, wherein the fastening device (16, 16') has two displaceable adjusting elements (16, 16 ') which are arranged and formed the test object (21). between them, each of the two adjusting elements (16, 16 ') being displaceable at least along an axis (20) passing through the two adjusting elements (16, 16').

The testing apparatus (10; 10 '; 10 ") according to claim 8, wherein each of said adjusting members (16, 16') is rotatably supported and has an adjusting rotational axis (27) and wherein said adjusting members (16, 16 ') are arranged and formed in that they form at least part of the compensation unit (15) and that rotation of the adjustment elements (16, 16 ') about their respective adjustment rotational axis (27) shifts the specimen (21) along a longitudinal axis of the specimen causing the center of gravity (52, 52') ) of the test piece (21, 21 ') is displaced relative to the axis of rotation (18).

A testing device (10; 10 '; 10 ";10"'; 10 ""; 10 ""') according to at least one of claims 1 to 9, wherein the testing device (10; 10'; 10 ";10"'; 10 ""') is formed in the form of a cable (22, 22', 22 ", 22"') having a cross section of more than 20 a test body (22, 22', 22 ", 22"') mm ² and a cable length of less than 200 mm, for example 150 mm. A test device (10; 10 '; 10 ";10"'; 10 ""; 10 ""') according to at least one of claims 1 to 10, wherein the test device (10; 10'; 10 ";10"). 10, 10 '"') is designed for a cable (22, 22 ', 22", 22 "') with a cross section of more than 20 mm ² and a cable length of less than 200 mm, for example 150 mm to generate a tensile force in the form of a centrifugal force of at least 15 kN, for example at least 25 kN, for example at least 40 kN, for example at least 50 kN, for example at least 100 kN.

A method of inspecting a device under test (21, 21 ', 21 ", 21"') comprising the steps of: Determining a length along a longitudinal axis of a test piece (21, 21 ', 21 ", 21"'),

Attaching the test piece (21, 21 '; 21 "; 21"') to and / or in a test device (10; 10 '; 10 "),

Rotating the sample (21, 21 ', 21 ", 21"') about a rotation axis (18) to a predetermined speed, wherein continuously adjusting the center of gravity (24) of the rotating system during rotation ensures that the center of gravity (24 ) of the rotating system coincides with the axis of rotation (18),

Determining a measured tensile strength value if the test piece (21 ") breaks off before reaching the predetermined speed or

Determining a strain measurement value via a change in the length of the specimen (21, 21 ', 21 "') along the longitudinal axis of the specimen (21, 21 ', 21"') when the specimen (21, 21 '; has reached predetermined speed.

Method for testing a test object (21) with at least one test body (22) by a centrifugal force acting on the test object (21) in a test device (10 "') with two holding elements (72) for holding the test body (22), at least one with a guide (62) connected adjusting element (68) for displacing the holding elements (72), a distance measuring unit (78) for detecting a covered distance of the holding elements (72), comprising the steps:

Holding a test piece (21) at or near a respective longitudinal end of the test piece (22) by the holding elements, Rotating the test piece (21) about an axis of rotation, wherein the adjusting member (68) connected to the guide (62) is driven during the rotation of the test piece (21) about the axis of rotation and the holding elements (72) moves to the guide (62) introduced tensile force is minimal and the introduced into the specimen (21) tensile force is maximum, and

Determining a strain and / or tensile strength measured value by the distance measuring unit (78) which determines the distance of the holding element (72) traveled by the adjustment element (68).

Use of the testing device (10; 10 '; 10 "; 10"'; 10 ""; 10 "" ') according to at least one of claims 1 to 1 1 in the method according to claim 12 or 13, for obtaining a test object (21, 21 '; 21 "; 21"').

15. The use of the testing device (10, 10 ', 10 ", 10"', 10 "", 10 "" ') according to at least one of claims 1 to 1 1 for testing a test piece (21, 21', 21 ", 21") by a centrifugal force acting on the test piece (21, 21 ', 21 ", 21"').