JPH1038775A - Aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aligner in which the central offset (shift of center) and the angular offset (angular shift) of a test machine can be compensated easily. SOLUTION: The aligner comprises a central offset compensation module 2 and an angular offset compensation module 3 disposed consecutively in the direction of the vertical axis 4 of a test machine between a load frame and a test piece fastener 7. The central offset compensation module 2 comprises two components 18, 19 supported movably in the horizontal direction and the angular offset compensation module 3 comprises a ball 11 supported rotatably by bearing metals 9, 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment (centering) device in a material testing machine.

[0002]

2. Description of the Related Art In the case of a material testing machine mainly consisting of a test frame with a power meter, a tightening device and a load device, it is ensured that the test force is introduced to the center when the test piece is installed in the center. Must. In an ideal tensile test, the specimen is subjected to the same axial load at both ends, which results in the same stress throughout the specimen.

However, in practice this cannot usually be achieved on account of the manufacturing tolerances of the test frame, the integrated load cylinder, the clamping device and the force measuring device, and when the test piece is clamped and under load, The test specimen is subjected to an undesirable bending load. The requirements for the centering accuracy of the tester are becoming increasingly stringent, especially with the testing of modern materials. In particular, for example, very brittle ceramics are sensitive to bending loads. Many compensators are known in the art in order to clamp the specimen as centrally as possible and to introduce the force as centrally as possible.

[0004] DE-A 37 31 460 discloses a clamping device which can be adjusted in such a way that the test specimen is clamped precisely in the center. The clamping device has a clamping plate for receiving a test piece and a clamping body connected to a load device. To align the specimen, the clamping plate and the clamping body are aligned with each other with respect to a center offset (off-center) and an angular offset (off-axis) by means of the adjusting bolts before starting the test. The slight deformation of the test piece or the clamping head that occurs when the test piece is loaded changes the position of the test piece with respect to the load axis. Since the clamping plate and the clamping head are aligned with each other before the start of the test and this position is fixed by the adjusting bolt, its position change occurring during the loading of the test piece cannot be compensated.

[0005] Furthermore, a clamping device without bending moment of a test piece is known, in which the test piece is supported or held in contact with a spherical surface. However, this device is only applicable, for example, to tensile and / or compression tests on ceramic specimens. These known devices are only applicable for tensile tests (DE-A-67 954, DE-A-2 306 393), or the test force is applied via a receiving element via a receiving element by means of a frictional connection or a positive connection. As a result, a special clamping device is required for clamping the test piece end or the test piece head (DE-A-2028030).

[0006] The document "American Society for Testing and
Materials (American Testing and Materials Association) "Proceedings
(Newsletter), Vol. 59, p. 663, considers a clamping device without bending moment for a test piece with a crosshead, in which case the test piece is formed in a two-piece structure and has a spherical outer surface. It is supported by.
In this known clamping device, only a test piece having a specially formed test piece head end can be tightened and fixed, so that a receiving body formed in a two-piece structure is arranged around the test piece head end. I have.

In the document "Experimental Mechanics", Vol. 15, No. 9, pp. 358-364, a universal test which can compensate for center offset and angular offset in order to avoid undesired bending loads in specimen clamping. Machines are known. For this, x
A frame movably supported on the cross beam in the direction is disposed. An upper clamping device is rotatably supported with the frame via the head to compensate for the angular offset.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an alignment apparatus which can easily compensate for a center offset and an angular offset of a testing machine.

[0009]

According to the invention, this object is achieved by the measures according to claim 1. Easy addition of these modules to the test machine by utilizing a center offset and compensation module and an angular offset and compensation module which are arranged next to each other between the load frame and the test piece clamping device Can be.

A further development of the invention provides that the relatively movably supported components of the center offset and compensation module and the sphere rotatably supported by the spherical bearing can be connected to one another with a bias pressure and reduce the bias pressure. It is suggested that a component be provided. With the ball and the spherical bearing and the sliding element and the pressure ring tightened as described above, the device is loaded without play at the full rated force of the tester and with a slight force via the adjusting bolt. Can be adjusted horizontally and / or cardanically (rotatably).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an alignment apparatus according to the present invention shown in the drawings will be described below in detail. The material testing machine mainly includes a load frame and a load device including an upper cross beam, a lower cross beam, and a vertical column connecting the both cross beams. At least one force gauge and a clamping device for receiving the upper end of the test specimen are arranged on the upper cross beam. The lower cross beam or table has in the center an opening through which the piston rod of the load device passes, and at the end of the piston rod a lower clamping device is provided. This basic configuration of the material testing machine is well known and is not shown in the drawings.

FIGS. 1 and 2 show an alignment apparatus 1 comprising a center offset / compensation module 2 and an angle offset / compensation module 3 which are modularly constructed.
It is shown. The alignment device 1 has a vertical axis 4 which coincides with the test piece center axis and the load axis of the test machine. A force gauge 5, which is schematically shown at the upper end, which is preferably located in the perpendicular of the alignment device 1, is connected by bolts 6. An upper tightening device 7 is connected to a lower end portion of the alignment device 1 by a bolt 8.

The angle offset / compensation module 3 includes a ball 11 received by an upper bearing 9 and a lower bearing 10.
Consists of The upper bearing metal 9 and the lower bearing metal 10 have a spherical sliding surface corresponding to the radius of the ball for receiving the ball 11. The separating surface 12 between the two bearings 9, 10 extends at right angles to the vertical axis or the load axis of the test machine. The two bearings 9, 10 are vertically separated from one another by a distance h.

The two bearings 9 and 10 are tightened toward the ball 11 by tightening bolts 13 at a rated force of the tester or more. The tightening force of the tightening bolt 13 is the adjusting bolt 14.
The ball 11 is then removed again until a play-free angular adjustment of the ball 11 or a rotational movement with a slight friction of the ball is made possible.
For this purpose, a plurality of adjusting bolts 14 are distributed in the circumferential direction and screwed vertically into the outer peripheral area of the lower bearing 10, the ends of which are supported in contact with the upper bearing 9. The adjustment of the clearance between the ball head and the bearing ring is already known from DE-A-3 301 543.

The angle of the ball 11 is adjusted via an adjusting bolt 15 which is fitted into the lower bearing 10 and moves an adjusting plate 16 in a horizontal plane. Lower bearing 10
In particular, four radial through holes are provided uniformly distributed in the circumferential direction in the lower peripheral area.
5 is fitted. The lower bearing 10 is connected to the tightening device 7.
Adjustment plate 16 having a cylindrical opening in the end portion on the side of
Is inlaid. The adjustment plate 16 is provided with a cylindrical extension 17 which is fitted in the corresponding recess of the sphere 11 so that the sphere 11 is movably supported together with the adjustment plate 16. Have been.

The center offset / compensation module 2, which is arranged vertically on the angular offset / compensation module 3, is formed in a two-part structure and comprises a sliding member 18 and a pressing ring 19 connected to the force gauge 5. ing. The pressing ring 19 is formed as a hollow cylindrical housing part, and has a ring-shaped projection projecting inward at an upper portion thereof. The sliding member 18 is a pressing ring 19
And has an outer peripheral surface fitted to the inner surface of the cylindrical housing portion, and an annular gap exists between the sliding member 18 and the pressing ring 19 to enable adjustment in a horizontal plane; The sliding surfaces are formed via annular surfaces facing one another in the vertical direction.

As already described for the angle offset / compensation module 3, in the case of the center offset / compensation module 2 as well, the sliding member 18 is fastened to the upper ring 9 via the tightening bolt 20 on the pressing ring 19. . Relaxation to a slight frictional force is performed via an adjusting bolt 21 which is fitted in the pressing ring 19 and one end of which is supported in contact with the upper bearing 9. The pressing ring 19 is preferably provided with four radial through holes, distributed in the circumferential direction, into which adjusting bolts 22 are fitted, each of which is supported in contact with the outer periphery of the sliding member 18, whereby the axial direction is increased. The adjustment of the position of the sliding member with respect to the pressing ring at is performed via the sliding surface.

[Brief description of the drawings]

FIG. 1 is a sectional view of an alignment apparatus according to the present invention in an assembled state.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alignment apparatus 2 Center offset / compensation module 3 Angle offset / compensation module 4 Vertical axis line of a test machine 7 Tightening device 9 Upper bearing 10 Lower bearing 11 Ball 18 Sliding member 19 Press ring

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ielk, Spory Darmstadt, Germany, El Bacher, Straße, 121 (72) Inventor Gerhard, Hinz Roschdorf, Germany, Holzgasse, 44

Claims (2)

[Claims] The present invention comprises a center offset / compensation module (2) and an angle offset / compensation module (3), wherein the center offset / compensation module (2) and the angle offset / compensation module (3) are connected to the vertical axis ( 4)
Two components (18) which are arranged between the load frame and the test piece clamping device (7) successively in the direction of / 19), and the angle offset / compensation module (3) is a bearing (9/10)
An alignment device for a testing machine, characterized in that the alignment device is formed from a sphere (11) rotatably supported on the test machine. 2. The center offset / compensation module (2) and the angle offset / compensation module (3),
The components (18, 19 /
2. The alignment device according to claim 1, wherein components (14/21) are provided, wherein the components (9, 10, 11) can be connected to each other with a bias pressure and the bias pressure can be reduced.