RU217572U1 - CENTRIFUGAL INSTALLATION FOR RHEOLOGICAL INVESTIGATIONS OF MATERIAL - Google Patents

Abstract

The utility model relates to test equipment, to strength tests of samples of rocks and other materials. The technical result is the expansion of the functionality of centrifugal installations. Equipping the installation with a rod retainer on the guide allows testing the relaxation of mechanical stresses while maintaining the action of the centrifugal load and the compressing load, as well as switching from creep tests to tests for the relaxation of mechanical stresses and reversing these modes while maintaining the action of the centrifugal load and the compressing load. This significantly expands the functionality of centrifugal test facilities.

Description

The utility model relates to testing equipment, strength testing of rock samples and other materials.

A centrifugal installation for cyclic testing is known (RF patent No. 2532761, publ. 11/10/2014), containing a housing, a shaft mounted on it with a rotation drive, a platform fixed on the shaft, a guide rigidly fixed on the platform perpendicular to the axis of rotation, grippers for the sample.

The disadvantage of the installation is that the source of the working medium is connected to the hydraulic cylinder, the inertial load is connected to the rod, so the installation provides testing only under cyclic loading of the sample with a mechanical centrifugal load.

A centrifugal setup for testing samples is known (RF patent No. 2506557, publ. 10.02.2014), containing a housing, a shaft mounted on it with a rotation drive, a platform fixed on the shaft, a guide rigidly fixed on the platform perpendicular to the axis of rotation, grippers for the sample, and inertial weights connected to grippers.

The disadvantage is that the source of the working medium is connected to the hydraulic cylinder, the inertial load is connected to the rod, so the installation provides testing only under cyclic loading of the sample with a mechanical centrifugal load.

A centrifugal installation for testing a sample of material for strength is known (RF patent No. 2510004, publ. 07/11/2014), containing a housing, a shaft mounted on it with a rotation drive, a hydraulic cylinder connected to the shaft, the axis of which is perpendicular to the axis of the rotation shaft, grips for the sample located in the hydraulic cylinder, respectively, on two movable pistons in the hydraulic cylinder, a source of the working medium communicated with the cavity of the hydraulic cylinder by a valve, and an inertial load.

The disadvantages of the installation is that two pistons are placed in the hydraulic cylinder, between which the grippers and the inertial load are located, therefore, tests are only possible for creep.

A centrifugal apparatus for testing samples is known (RF patent No. 1493925, publ. 15.07.1989), containing a housing, a shaft mounted on it with a rotation drive, a platform fixed on the shaft, a guide rigidly fixed on the platform perpendicular to the axis of rotation, a hydraulic cylinder placed on the guide, the axis of which is parallel to the axis of the guide, the rod of the hydraulic cylinder, two grips for the sample for the sample, the first of which is fixed on the rod, the source of the working medium communicated with the cavity of the hydraulic cylinder by a valve, and an inertial weight.

The disadvantage of the installation is that the second grip is placed on the inertial load, the rod does not have a latch on the guide, and the hydraulic cylinder is movably placed on the guide. Therefore, the installation also does not provide stress relaxation tests, but only creep tests from the action of a mechanical load with simultaneous action of a centrifugal load and a compressive load are possible.

Known centrifugal installation for testing a sample of material for strength, (RF patent No. 1613918, publ. 12/15/1990), adopted as a prototype, which contains a housing mounted on a shaft with a rotation drive, a platform fixed on the shaft, a guide rigidly fixed on the platform perpendicular to the axis of rotation, placed on the guide hydraulic cylinder, the axis of which is parallel to the axis of the guide, the rod of the hydraulic cylinder, two grippers for the sample, the first of which is fixed on the rod, the source of the working medium communicated with the cavity of the hydraulic cylinder by a valve, an inertial load mounted with the possibility of moving along the guide and connected to the stem.

The disadvantages of the installation is the movable placement of the second grip in the hydraulic cylinder and the movable placement of the hydraulic cylinder on the guide. Therefore, tests for the relaxation of mechanical stresses while maintaining the action of the centrifugal load and the compressing load are also not feasible here. It is also impossible to switch from creep tests to mechanical stress relaxation tests and the reverse change of these regimes under the simultaneous action of a centrifugal load and a compressive load. This limits the functionality of centrifugal plants.

The technical result is the expansion of the functionality of centrifugal installations.

The technical result is achieved by the fact that the second grip is fixed on the end of the hydraulic cylinder, while additionally contains a latch rigidly fixed on the guide, and which is made with the possibility of fixing the rod so that the first grip remains in a fixed state and maintains the compressive deformation of the sample between the first grip and the second capture at a constant level.

The installation is illustrated by the following figure:

fig. 1 - general scheme of the installation, where:

1 - body;

2 - shaft;

3 – rotation drive;

4 - platform;

5 - guide;

6 - hydraulic cylinder;

7 - stock;

8 - first capture;

9 - the second capture;

10 - sample;

11 - source of the working environment;

12 - valve;

13 - inertial load;

14 - latch.

Centrifugal installation for rheological studies of the material (figure 1) contains a housing 1. Inside the housing 1, in the center of the upper part of which there is a hole in which the shaft 2 is installed with a rotation drive 3. A platform 4 is fixed on the shaft 2, with the possibility of rotation in a horizontal plane . A guide 5 is installed on the platform 4, fixed perpendicular to the axis of rotation of the platform 4. On the guide 5, a hydraulic cylinder 6 with a rod 7 is fixed, the axis of which is parallel to the axis of the guide 5. In the hydraulic cylinder 6, the first grip 8 is fixed, which is fixed on the rod 7 and the second grip 9, which is fixed at the end of the hydraulic cylinder 6, with the possibility of fixing the sample 10. On the platform 4, coaxially with the axis of rotation of the platform, a source of the working medium 11 is fixed, made, for example, in the form of a container, with the possibility of filling with liquid. The source of the working medium 11 is hydraulically connected to the cavity of the hydraulic cylinder 6 through the valve 12. The inertial load 13 is installed with the possibility of moving along the guide 5 and connected to the rod 7. The unit is equipped with a latch 14 fixed on the guide 5. The hydraulic cylinder 6 is rigidly fixed on the guide 5. The latch 14 , for example, electromagnetic, is rigidly fixed on the guide 5 and is made with the possibility of fixing the rod.

The installation works as follows. For tests in creep mode, valve 12 is opened and a given amount of working fluid is supplied from the source of working medium 11 to hydraulic cylinder 6. Then valve 12 is closed and latch 14 is turned off. As the speed of rotation of the platform 4 increases, the inertial load 13 through the rod 7 and the first grip 8 loads the sample 10 with an increasing compressive mechanical load, evenly distributed along the length of the sample 10. The rotation of the sample 10 creates on it an increasing compressive centrifugal load, unevenly distributed along the length of the sample, and namely, the maximum compressive load at the second grip 9 and zero load at the first grip 8. The rotation of the hydraulic cylinder 6 moves the working medium located in it in the direction of the second grip 9. The source of the working medium 11 creates a compressive load on the side surface of the sample 10. The compressive load is unevenly distributed over the length of the sample 10. It is maximum at the second grip 9 and decreases in the direction of the first grip 8. The length of the crimped part of the sample 10 depends on the amount of the working medium in the hydraulic cylinder 6 and is controlled by the valve 12, and the size of the compressing load depends on the rotation speed of the platform 4. When the specified compressive mechanical load on the sample 10, the platform 4 starts to rotate at a constant speed, and from this moment the sample 10 is in the creep mode: the compressive mechanical load, the centrifugal load and the compressive load remain constant in time, and the sample deformations change in time. The change in deformations with time under constant loads is the process of creep. Registration of diagrams of the development of deformations over time is the goal of this stage of research.

To switch to the test mode during relaxation of the compressive mechanical load, the latch 14 is turned on and the rod 7 is connected to the platform 4. From this moment, the movement of the rod 7 in the direction of the first grip 8 stops, the first grip 8 remains in a fixed state and maintains the compressive deformation of the sample 10 between the first grip 8 and the second capture 9 at a constant level. In this case, a decrease occurs, i.e. relaxation of the compressive mechanical load in time. The change in the compressive mechanical load over time with a constant compressive strain from the action of this load is stress relaxation diagrams, the registration of which is the goal of this stage of research.

To return to the creep mode after a predetermined duration of the relaxation mode, the latch 14 is turned off. The inertial load 13 restores the compressive mechanical creep load, and the rod 7 and the first grip 8 ensure the development of creep deformations.

Installing a rod retainer on the guide allows testing the relaxation of mechanical stresses while maintaining the effect of centrifugal load and compressing load, as well as switching from creep tests to tests for relaxation of mechanical stresses and reversing these modes while maintaining the effect of centrifugal load and compressing load. This significantly expands the functionality of centrifugal test facilities.

Claims (1)

SUBSTANCE: centrifugal installation for rheological studies of material, comprising a housing, a shaft mounted on it with a rotation drive, a platform fixed on the shaft, a guide rigidly fixed on the platform perpendicular to the axis of rotation, a hydraulic cylinder located on the guide, a hydraulic cylinder rod, the axis of which is parallel to the axis of the guide, two grippers for sample, the first of which is fixed on the rod, the source of the working medium communicated with the cavity of the hydraulic cylinder by a valve, an inertial load mounted for movement along the guide and connected to the rod, characterized in that the second grip is fixed on the end face of the hydraulic cylinder, while additionally contains a latch, rigidly fixed on the guide, and which is made with the possibility of fixing the rod so that the first grip remains in a fixed state and maintains the compressive deformation of the sample between the first grip and the second grip at a constant level.

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