SU641328A1 - Friction force measuring device - Google Patents

Description

(54) DEVICE FOR DETERMINATION OF FORCE OF FRICTION

I

The invention relates to the testing of materials, in particular to devices for measuring the force of dispersed materials.

A device is known for determining the strength of ground rubbing and of soil against metal, comprising a housing, a housing, a translational movement of the yoke, a loading system, and a measuring force of friction.

The disadvantage of this device is that the length of the path to the path of the unidirectional relative movement of the samples is limited, which prevents long-term testing of materials and a wide variation in the velocity range.

A device for determining friction forces is known, comprising a base, a clip, a clip rotation drive, two loading pistons (above and above), mounted in a cage forming a chamber with it to accommodate a material sample, a friction torque measuring device 12).

The disadvantage of this device is the impossibility of conducting comparative tests on the friction of a single soil sample on the ground and on metal, due to the fact that only

one sample (soil or metal), and for the second test it is necessary to replace the sample, thus violating the soil sample installed in the chamber.

The purpose of the invention is to expand the technological capabilities of the device.

The goal is achieved by the fact that the inner surface of the yoke is stepped, and the lower piston is mounted for movement along the yoke axis.

FIG. I shows the device in the study of soil friction on the ground, a longitudinal section; in fig. 2 - the same, in the study of the soil trend on the metal.

Claims (2)

On base 1, bearing 2 is installed with a stepped inner surface of the sleeve 3, using a V-belt transfer 4 connected to a rotation drive (not shown inside the sleeve 3, the lower 5 n upper 6 pistons are located, between which the soil 7 is placed. Lower piston 5 connected to the axially movable, for example, telescopic, support 8, on which the torque meter 9 is mounted. The seal 10 is located on the lower piston, the end surfaces of the pistons 5 and 6 are corrugated. A loading unit that includes weights 11, lever 12, intermediate support 13, support 14, for example, telescopic, and loads 15. The device is also equipped with pipelines 16 and 17. For supplying a lubricating medium, for example, gas. A soil sample with a diameter equal to the upper diameter of the inner cavity of the yoke 3 is placed on the grooved base of the lower piston 5 (as shown in FIG. I). Then, the load (discs) II, the piston loaded with weights 15, are installed from above. After that, the drive is turned on, which rotates the clip 4 through the worm gear 4. At the same time, part of sample 7 gets together with holder 3, and the part is at rest. The meter 9 of the moment of friction (strain element) registers the resistance to soil shear, along the line AAi. By changing the speed of rotation of the holder 3, the registration of the lateral resistance of the soil to the shear rate is made. Pipelines 16, 17 supply compressed gas or liquid, and determine the change in friction forces and the resistance of the soil to shear under the conditions of the presence of a lubricating layer at the boundary with respect to the moving surfaces. The loading unit in the form of discs 11 and grease 15 provides a wide variation of the soil specific pressures. To determine the soil friction coefficient for metal, a cut out soil sample is placed in the lower cavity of the sleeve 3 (see Fig. 2). From above and below, soil sample 7 is held by pistons 5 and 6, while in a quiescent state. Then include the drive station and the yoke 3 gets the rotation. The friction torque meter 9 records the forces of the ground resistance to shear relative to the rotating metal surface of the casing 3. When gas or liquid is supplied through pipelines 16 and 17, it is possible to measure the ground friction forces on the metal if there is a lubricating layer on the friction boundary. The proposed stand design permits a wide range of variations in shear rate to be studied to vary the ground friction force on the ground and the metal on the ground, as well as under the condition that there is a lubricating layer at the boundary relative to the displacement of the sliding surfaces. Apparatus of the Invention A device for determining friction forces, comprising a base, a holder, a rotational drive of a holder, two loading pistons (lower and upper) installed in the holder and forming with it a chamber for accommodating a sample of material, a load assembly and a meter of friction torque, characterized in that In order to expand the technological capabilities of the device, the inner surface of the cage is stepped, and the lower piston is mounted for movement along the cage axis. Sources of information taken into account in the examination: 1. USSR author's certificate number 473910, cl. G 01 L 1/04, 1975. 2. USSR author's certificate number 373593, cl. G 01 N 19/02, 1973.