Device for measuring friction force

FIELD: investigating or analyzing materials by mechanical methods.

SUBSTANCE: device comprises base, holder for specimen mounted on the base, carriage with holder for counter-body, loading unit, meter of friction force, drive for moving one of the holders, guide secured to the carriage perpendicular to the surface of the specimen, rod that can be set in translational motion in the guide, loading unit mounted at one of the ends of the rod, pivot mounted at the other end of the rod, holder made of a rod whose one end is secured to the axle of the pivot and the other end is provided with counter-body, spring, meter of friction force mounted on the carriage oppositely from both sides of the holder of counter-body and parallel to the plane of the specimen at the same distance from the axis of the pivot to the working surface of the specimen. The spring locks the holder of counter-body perpendicular to the working plane of the specimen. The axis of rocking of the pivot is parallel to the surface of the specimen and perpendicular to the direction of movement of the specimen and counter-body.

EFFECT: expanded functional capabilities.

1 cl, 1 dwg

 

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

It is known device for measuring the friction force (Kragelskii IV Friction and wear. M: mechanical engineering, 1968, s)containing a base on which is placed the sample, measuring the friction force, the carriage on which is installed the counterbody and the site of loading and carriage drive.

The main drawback of the device is similar to the evaluation of the friction forces moving in one direction, and the integral nature of the evaluation, since the registration of the frictional forces produced while testing three or more samples of the type of finger, moving with drive on a flat sample.

The closest to the technical nature of the claimed device is selected as a prototype device for measuring the friction force (A.S. No. 1388768, G 01 N 19/02, 1988, BI No. 14, "Device for measuring friction force"), containing a base, installed in the sample holder, the slide holder with the counterbody node loading, measuring the friction force and the actuator moving one of the holders.

A disadvantage of the known device is the location of the measuring element on the fixed base, leading to the necessity of applying a flexible elastic element, transmitting the measured stress is through two rollers, and a lever, which leads to a decrease in the accuracy of measurements of the friction force.

Additionally, with this known device has an asymmetric location of the site of loading and holder of the counterbody axis mounting on a movable carriage, which limits the functionality of the device case unidirectional translational motion. This is due to the fact that test-mode reciprocating motion device prototype, when the movement of the mobile carriage in the direction of the holder of the counterbody, he pushed and transverse vibrations occur counterface on the surface of the test sample having the maximum value, and in the case of movement of the movable carriage from the holder of the counterbody the latter extending along the surface of the test material, transverse vibrations of the counterbody will be minimal, therefore, violated the uniformity of the conditions of establishment and maintenance of reciprocating motion.

The objective of the invention is to expand the functional capabilities of the device and increase the accuracy of determination of friction forces.

The task functionality is achieved by the fact that the design of the device for measuring friction forces, containing a base, installed in the sample holder, the slide holder with the counterbody node naked is ugenia, measuring the friction force and the actuator moving one of the holders; node loading, the rod that transmits the normal load on the holder, the holder with the counterbody, have a symmetrical structure about the axis of the mounting of the latter in the guide mounted on the carriage. Spring and measuring the friction forces that are installed on the carriage are arranged on different sides of the holder contrapasso and parallel to the sample surface, hold the holder contrapasso perpendicular to the sample plane by a force selected from the necessary conditions of the measurement range of the friction forces in both directions. In our case, when the organization reciprocating motion, this condition is equal to half of the range of the probe that provides equal ranges of the friction force in both directions. When the movement of the counterbody relative to the specimen occurs the friction force, which tries to turn the holder around the axis of the hinge 12 in the direction opposite to the motion of the counterface, which is registered by the meter.

The goal of improving accuracy is achieved by the fact that the spring and measuring the friction force is installed on the carriage at an equal distance from the axis of the hinge to the working surface of the sample and during movement of the counterbody relative to the sample, the meter will show the strength, two times greater than the force of friction between contrareloj sample in accordance with the shoulders against the forces about the axis of the hinge.

The drawing shows a device for measuring the friction force.

The device comprises a base 1, a holder 2 sample 3, the carriage 4 with the holder 5 counterface 6, node 7 loading of the sample 3 and the counterface 6, measuring the friction force 8, the actuator 9 of the movement of the holder 5 and the carriage 4; guide 10 mounted on the carriage 4 is perpendicular to the surface of the sample 3, the spindle 11 moving in the guide 10 onward, the site loading 7 mounted on one end of the rod 11, the hinge 12, located at the other end of the rod 11 with the axis of oscillation parallel to the surface of the sample 3 and perpendicular to the direction of movement of the carriage 4 and the counterface 6, the holder 5 in the form of a rod, one end of which is fixed on the axis of the hinge 12, and the other is attached to the counterbody 6, the spring 13 and measuring the friction force 8 mounted on the carriage are arranged on different sides of the holder 5 counterface 6 and parallel to the working surface of the sample 3, at equal distance from the axis of the hinge 12 to the working surface of the sample 3 and the retaining holder 5 counterface 6 perpendicular to the plane of the sample 3 by a force selected from the necessary conditions of the measurement range of the friction forces in both directions, in our case, for the organization of the reciprocating motion, this value is half of the range of the measure concentration the El 8.

The device operates as follows.

On the holder 2 and 5 set according to the sample 3 and the counterbody 6. The carriage 4 is placed in the initial state, for example, in the extreme position. Lead in contact with the sample 3 and the counterbody 6, load them using the site loading 7 and include the actuator 9. When the movement of the counterface 6 relative to the specimen 3 occurs in the frictional force, which tries to rotate the holder 5 around the axis of the hinge 12 in the direction opposite to the motion of the counterface 6. Since the holder 5 is held by the spring 13 and measuring the friction force 8 in equilibrium, perpendicular to the plane of the sample 3 by a force equal to half of the range of the probe 8, the appearance of additional forces will shift the balance of power and the meter 8 will show strength, two times greater than the force of friction between the counterbody 6 and example 3, in accordance with the shoulders against the forces about the axis of the hinge 12.

Thus, the main technical result is to expand the functionality of the device through the implementation of this unit testing is not only unidirectional, but in the mode of reciprocating. Improving the accuracy of measurement is achieved by simplifying the structure of the device, use of a single meter under registration alternating force t is to be placed, and also due to direct exposure to the holder contrapasso for measuring the friction force.

Device for measuring the friction force, containing a base, installed in the sample holder, the slide holder with the counterbody node loading, measuring the friction force and the actuator moving one of the holders, characterized in that it is provided with a rail attached to the carriage perpendicular to the sample surface, the rod moving in a translational guide, a site of loading, fixed on one end of the rod, hinge located at the other end of the rod, and the hinge is made with the axis of oscillation parallel to the sample surface and perpendicular to the direction of movement of the sample and the counterbody holder in the form of a rod, one end of which is fixed on the axis of the hinge, and the other is attached to the counterbody, spring and measuring the friction force, mounted on the carriage are arranged on different sides of the holder of the counterbody and parallel to the sample plane at equal distance from the axis of the hinge to the working surface of the sample and holding the holder of the counterbody perpendicular to the working plane of the specimen by a force selected from the necessary conditions of the measurement range of the friction forces in both directions.



 

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