RU2244290C1 - Device for testing materials - Google Patents

Abstract

FIELD: tribometry.

SUBSTANCE: device has the platform which is provided with an article and set on rollers, drive for reciprocating, unit for loading articles, and pickups for recording forces and displacements .

EFFECT: enhanced accuracy of testing.

1 cl, 3 dwg

Description

The invention relates to the field of research of physico-mechanical properties of materials, and more specifically to the field of research of their tribological properties, and can be used to quantify the components of the forces of dry and viscous friction.

It is known a device for determining the coefficient of friction of materials, copyright certificate No. 930081, MKI G 01 N 19/02. The device contains a base, a slider for attaching a counter-sample on it, on which a sample is mounted, an adjustable reciprocating drive. In addition, the device comprises a slider acceleration sensor, a sample displacement sensor relative to the counter-sample, and instrumentation from a vibration measuring unit and a light beam oscilloscope.

The disadvantage of this device is the limited scope. This device does not allow testing of polymeric materials, including elements of flexible cables for friction, because they have a complicated process during operation, and the use of an acceleration sensor does not give a clear picture of the process, moreover, the absence of holders makes it impossible to test flexible cables.

The prototype is a device for testing materials for friction, copyright certificate No. 1821689, MKI G 01 N 19/02.

The device comprises a base placed on the base of a slider on which holders with grooves are placed. A groove is installed in the grooves and a counter sample interacting with it. The device also contains a reciprocating slide actuator, a sample displacement sensor connected to the recording equipment, and sample displacement indicators, and the slider is equipped with a displacement regulator, while the indicator and the sensor are attached to the sample holders. Thanks to the holders with grooves, it became possible to expand the range of studies, to study not only solid, but also elastic materials.

However, with this device it is impossible to obtain information on the tribological characteristics of the material, because further data processing is needed. This takes a lot of time, errors in calculating these characteristics are possible. In addition, the presence of additional elements connecting the holders to the sensors affects the accuracy of the studies.

The task is to quickly and accurately monitor the tribological characteristics of materials.

The problem is solved as follows. As well as the prototype, the claimed device contains a base mounted on the base of the mechanism, on which there are holders with grooves for the respective mutual placement of the sample and the counter sample in them, a reciprocating movement of the mechanism, a sample loading unit, a force registration sensor and an indicator connected with a counter-sample holder, a displacement sensor and an indicator connected to the sample holder, recording equipment to which a displacement sensor and a force registration sensor are connected. But unlike the prototype in the inventive device, each sensor is made optical-mechanical in the form of a slot with slots mounted on the arrow axis of the corresponding indicator between the emitter and the photosensor, and a computer is used as recording equipment, and the sensors are connected to the latter through the mouse port, in addition , the mechanism on which the holders are placed is made in the form of a platform on the rollers, and the loading unit is equipped with a trolley with rollers placed on the holder of the counter sample.

The loading unit in the inventive device is made in the form of a screw jack mounted on a trolley and connected to a reversing engine and a dynamometer.

Thus, the hallmarks of the prototype, confirming the novelty of the claimed device are the following features:

- each sensor is made in the form of a disk with slots;

- the disk is put on the axis of the arrow of the corresponding indicator;

- the disk is located between the emitter and the photosensor;

- a computer was used as recording equipment;

- sensors are connected to the computer through the mouse port;

- the mechanism for placing samples is made in the form of a platform on the rollers;

- the loading unit is equipped with a trolley with rollers;

- rollers are placed on the holder of the counter sample;

- the loading unit is made in the form of a screw jack mounted on a trolley and connected to a reversing engine and a dynamometer.

In the inventive device and the mechanism for placing the sample holders, and the loading unit is supported by rollers, which makes it possible without the influence of the loading unit, i.e. excluding the forces of resistance to movement, evaluate the forces arising between the samples in the friction pair, which affects the accuracy of the measurements. The test leads are connected directly to the sample holders, which affects the accuracy of the measurements.

Since the sensors are connected to a personal computer via the mouse port, it becomes possible to quickly and accurately examine the tribological characteristics of materials, i.e. solve the problem.

Mounted on the axis of the indicator’s arrow and placed between the emitter and the photosensor, a disk with slots, and the connection of the emitter and the photosensor to the mouse port made it possible to convert mechanical movements into an electrical signal perceived by the computer without an additional matching unit. In fact, the indicator sensors are both a force and displacement registration sensor and a matching unit (converter) with a computer. This clearly does not follow from the prior art and confirms the presence of an inventive step in the claimed device.

Figure 1 shows a general diagram of the device, figure 2 is a side view of the sensor, and figure 3 is a front view of the sensor.

The device consists of mechanisms for driving the platform of the reciprocating movement of samples, a loading unit, sample holders and a measuring system.

On the basis of 1, guides 2 are made on which a platform 3 with a holder 4 of sample 5 is mounted. On top of sample 5, counter sample 6 is mounted with its holder 7. Sample 5 and counter sample 6 form a friction pair. The sample holders 4, 7 are removable. Removable specimen holders expand the range of tested structural members and materials. The platform 3 is equipped with four rollers 8. The reciprocating drive is a crank mechanism 9 with an engine 10. The loading unit of the device consists of a screw jack 11 mounted on a trolley 12 with rollers 13. The jack 11 is connected to a dynamometer 14 and a reversing motor 15 worm gear (not shown). The jack 11 is placed on the rack 16. The trolley 12 is mounted on the holder 7 of the counterblock 6. The rollers 13 of the trolley are made similar to the rollers 8 of the platform 3. The measuring system of the device consists of a displacement sensor 17 combined with a displacement indicator (not shown in the drawing). The probe 18 of the measuring indicator-sensor 17 is rigidly connected to the holder 4 of the sample 5. The measuring system also consists of a force registration sensor 19, combined with the corresponding indicator (not shown), a probe 20, which is rigidly connected to the holder 7 of the counter sample 6. Sensors 17 , 19 are placed on the rack 21, which is installed on the base 1. The recording system also includes recording equipment 22, the role of which is played by the computer. Sensors 17, 19 are connected to computer 22 through a mouse port (not shown in the drawing). The sensors 17, 19 (Figs. 2, 3) are made optical-mechanical: a light disk 24 with slots 25 is put on the axis of the arrow 23 of the indicator. The disk 24 is installed between the infrared emitter 26, the role of which is played by the infrared emitting diode, and the photosensors 27 (photoresistor ) The photosensor 27 and the emitter 26 are connected to the computer 22 through the mouse port.

The device operates as follows. From the engine 10, the movement is transmitted through the crank mechanism 9 to the platform 3, which, in turn, drives the sample holder 4 with the sample 5. The vertical load on the samples is created by a screw jack 11, driven by a reversing motor 15 through a worm gear. The load is transmitted through a dynamometer 14, which shows a fixed load. Since the trolley 12, which transfers the load to the holder 7, has rollers 13, and the platform 3, which reciprocates with the holder 4 of sample 5, has similar rollers 8, the upper holder 7 has the ability to move due to friction between the samples , and the loading mechanism does not affect the measurements.

As a result of the interaction of the friction forces between samples 5, 6, the probe 18 and the probe 20 of the indicators will move. The measured displacements are converted into electrical pulses in the sensors 17, 19. This happens as follows. The reciprocating movement of the holders 4, 7 of samples 5, 6 is converted into the rotational movement of the axes of the arrows 23 of the indicators, and consequently, of the disks 24 with slots 25 (chopper), through which the infrared radiation stream (or does not) pass from the emitter 26 (Fig. .2) (infrared emitting diode). Thus, when the disk 24 is rotated, the radiation flux is interrupted, which is detected by the corresponding photosensor 27 (photo transistor).

Information from the sensors 17, 19 is entered into the computer 22 (figure 1) through the mouse port. Each pulse of transmitted radiation is considered as one-step displacement along one of the coordinates (displacement or force coordinate). The power of the infrared emitter 26 and the photosensor 27 is carried out from the computer through the mouse port.

The direct connection of the sensors 17, 19 through the mouse port with the computer 22 makes it possible, using the appropriate programs, to obtain diagrams on the monitor: friction force - displacement; force - time and movement - time, and processing them with the help of mathematical programs - tribological characteristics: dry and viscous friction coefficients, system damping coefficient; logarithmic decrement; frequency of free and damped oscillations, etc.

Claims (2)

1. A device for testing materials for friction, containing a base mounted on the base of the mechanism, on which are holders with grooves for appropriate mutual placement of the sample and the counter-sample in them, a drive for reciprocating movement of the mechanism, a sample loading unit, a force registration sensor and an indicator, connected to the holder of the counter-sample, a motion detection sensor and an indicator connected to the sample holder, the recording equipment to which the registration sensors are connected and efforts, characterized in that each sensor is optical-mechanical in the form of a slotted disk mounted on the axis for the arrow of the corresponding indicator between the emitter and the photosensor, and a computer is used as the recording equipment, the sensors being connected to the latter through the mouse port, except of this mechanism, on which the holders are placed, is made in the form of a platform on the rollers, and the loading unit is equipped with a trolley with rollers placed on the counter-sample holder. 2. The device according to claim 1, characterized in that the loading unit is made in the form of a screw jack mounted on a trolley and connected to a reversing engine and a dynamometer.

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