DE8121192U1 - Device for testing the hardness of a workpiece - Google Patents

Description

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June 16, 1981 By P 67P7

Georg Reicherter GmbH + Co. KG, Hindenburgstrasse 35, 7300 Esslingen (Neckar)

"Device for testing the hardness of a workpiece"

The invention relates to a device according to the preamble of claim 1.

In a known device of the aforementioned type, it is customary to apply the load to the test body by means of a weight. The weight can be precisely manufactured and easily exchanged. The test specimen must, however, be loaded slowly because of the mass present, and damping is usually also required. When applying the weight there is a risk that the measurement result due to vibrations and
Vibrations is falsified.

Another known device uses a preloaded spring for loading. Such a spring has only a small mass and is therefore insensitive to vibrations and shocks. The manufacture of such a spring and the change of the
However, the test load is expensive. The
Constant of the spring change over time.

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The present invention has for its object to provide a device with which a test load in essential without vibrations and shocks can be easily and precisely applied, with a Constantly set test load does not change over time and can easily be changed at will is. This object is achieved according to the invention by the features in the characterizing part of claim 1. The resilient transfer lever can be manufactured easily and precisely. It is insensitive to vibrations and tremors. The spring constant of the transfer lever does not change and a change in the Test load is easy to carry out.

Further advantages result from the rest. Claims, the description and the drawing. In this is a device for testing the hardness of a workpiece as an embodiment of the subject matter of the invention shown schematically.

In a stationary warehouse 1 is a means of a not shown and at will in different Direction of rotation operable motor drivable eccentric 2 in the direction of arrow A and in the opposite direction rotatably mounted. The eccentric 2 has a uniform slope.

A roller 3 cooperates with the eccentric 2, which is at the end of an arm 4 of a double-armed transfer lever 5 is rotatably mounted, the other arm 6 of which carries a set of strain gauges 7. At least that The part of the transfer lever 5, which is surrounded by the strain gauges 7, is elastic, and so are the strain gauges 7 are arranged so that in cooperation with a conventional, not shown

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June 16, 1981 By P 6707

Measuring device the bending of the elastic part of the transfer lever 5 can be displayed. The transfer lever 5 is mounted pivotably on a stationary bearing 8.

At the free end of the arm 6, one end of a sliding bushing 9 rests axially on a test body holder 10 is displaceably mounted, which carries a test body 11 at its end facing away from the sliding bush 9, which is suitable for measuring the hardness of a workpiece 20. The sliding sleeve 9 has on her from Test body 11 at the end of a shoulder 12. Between this shoulder 12 and one in the area of the Test body 11 arranged shoulder 13, a preload spring 14 is clamped, which the two shoulders 12 and 13 seeks to remove from one another and thus the sliding bush 9 from the test body holder 10.

The end of the sliding bushing 9 resting on the arm 6 is wedge-shaped and protrudes into a wedge-shaped one Recess of the arm 6 into it. The wedge angle of this arrangement is larger than the wedge angle of the wedge-shaped End of the sliding bush 9.

The shoulder 13 is surrounded with play by a stationary housing part 15 which has a conical recess for receiving a conical part of the shoulder 13 adjacent to the test body 11, the * has in the rest position of the test body holder 11 rests on the wall part delimiting the conical recess. Of the Test body 11 is surrounded by the housing part 15 with play.

On another, above arm 6 of the transfer lever 5 arranged stationary housing part 16, a housing 17 of a measuring device 18 is attached, the measuring

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element 19 with play through the housing part 16 and through the arm 6 protrudes, is arranged coaxially to the test body 10 and is present on the end face.

A workpiece 20 is attached to a clamping table 21 that can be raised and lowered as desired.

In the rest position of the device, the test body 11 protrudes over the housing part 15, since the conical part of the shoulder 13 rests on the housing 19. To measure the hardness of the workpiece 20, it is placed against the housing part 15, whereby the test body 11 is displaced against the action of the preload spring 14 and rests on the workpiece 20 with a preload possibly causing an impression. Subsequently, the eccentric 2 is slowly driven from its rest position in the direction of arrow A, whereby an increasing load is transferred via the transfer lever 8 and the test body holder 10 to the test body 11, which corresponds to the applied load and the hardness of the workpiece 20 in this penetrates. A static load can be applied by stopping the eccentric 2. The Sindring depth of the test body is measured continuously with the aid of the measuring device 18 as a function of the load applied by means of the eccentric 2. The magnitude of this load is continuously ^{measured by the strain gauges 1} J , which are assigned to a suitable measuring device, not shown, which continuously measures the deflection of the elastic part of the arm 6 as a function of the load applied by the eccentric 2. The measuring device 18 and the measuring device assigned to the strain gauge (s) 7 can be connected to a process computer which determines the measured values required during the hardness test. A load can be applied to the test body 11 until a preselected one

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Penetration depth of this test body 11 in the workpiece 20 or a certain maximum load is reached. In the The drawing shows the device during the measuring process. The transfer lever 5 is turned back of the eccentric 2 against the direction of the arrow A relieved.

With the aid of the device it is possible to apply a uniformly increasing load to the test body 11. The depth of penetration of this test body into the workpiece 20 is determined by the relative movement between the test body holder 10 and the stationary housing part 16 connected to the housing part 15 is measured.

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June 16, 1981 By

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Georg Reicherter GmbH + Co. KG, Hindenburgstrasse 35, 7300 Esslingen (Neckar)

summary

A device for testing the hardness of a workpiece with a movable test body holder (10) attached test body (11) has a loading device (1, 2, 3) for different loading of the Test body, a measuring element (18) for measuring the depth of penetration of the test body into the workpiece (20), a measuring device (7) for measuring the load acting on the test specimen depending on the depth of penetration and a clamping table (21) that can be raised and lowered to hold the workpiece. To create a device with which a test load can be applied easily and precisely essentially without vibrations and shocks, whereby a constantly set test load does not change in the course of time and it simply changes at will is to be changed, there is a resilient transmission lever between the loading device and the test specimen holder (5) arranged over which to be generated by the loading device and by the test body The load to be applied to the workpiece can be transferred and on which at least the part of the measuring device (7) is attached, which measures its elastic deformation occurring under load.

Claims (4)

• I «9 · ■ 1 · · DIPL.-ING. H. FINK PATENTANWALT · D 7300 ESSLINGEN NEAR STUTTGART · HINDENBURGSTRASSE FINK-O 7300 EmUhbot INwfcnr). Hlndinburmlrofi «44 June 16, 1981 By P 6707 Georg Reicherter GmbH + CO. KG, Hindenburgstrasse 35, Esslingen (Neckar) claims 1. Device for testing the hardness of a workpiece with a movable test specimen holder (10) attached test body (11), with a | _ Load device (1, 2, 3) to the difference Union loading of the test body with a measuring element (18) for measuring the depth of penetration of the test body into the workpiece (20) with a measuring device '(7) for measuring each dependent on the A penetration depth acting on the test specimen and with a liftable and lowerable clamping table (21) for Receiving the workpiece, characterized in that between the loading device and a resilient transmission lever (5) is arranged on the test body holder via which the from the load to be generated by the loading device and to be applied by the test specimen to the workpiece is transferable and to which at least that part of the measuring device (7) is attached, which is its under Measures elastic deformation occurring under load. 2. Apparatus according to claim 1, characterized in that on the resilient transfer lever (5) at least one strain gauge (7) -2- e · rf π rs t · · r « -2- June 16, 1981 By P 6707 is attached, which is part of the measuring device. i 3. Device according to claim 1 or 2, characterized in that £ indicates that the resilient transfer lever (5) is designed as a double lever which is on '; his arm facing the test body (11) Carries strain gauges (7) and the loading device (1, 2, 3) on the other arm works. j 4. Device according to one of the preceding claims f ehe, characterized in that the f Carrying lever (5) with a drivable eccentric f (2) as part of the loading device (1, I 2, 3) interacts. -3-