RU86010U1 - PENETROMETER FOR DETERMINING THE CONSISTENT PROPERTIES OF BITUMENS - Google Patents

Abstract

A penetrometer for determining the consistent properties of bitumen, comprising a housing, an object table located in the lower part of the housing with a mechanism for its movement, a rod with a load and a needle, an electric brake, a rod and needle movement sensor, a unit for determining the moment of touching the needle of the test surface, including a bracket mounted in the housing , a mechanism for moving the bracket relative to the needle, and means fixed on the bracket for exciting and recording oscillations of the needle, as well as a control unit to which the moving mechanisms are connected Nia object stage and bracket electro-sensor displacement rod with the needle, means for excitation and oscillation of the needle, characterized in that the means for recording the oscillations of the needle used in the Hall sensor.

Description

The utility model relates to testing equipment, and more specifically to devices for determining the strength properties of materials, in particular oil bitumen, and can be used to determine the consistency of the material for measuring penetration.

Known penetrometer for determining the consistent properties of bitumen, comprising a housing on which are mounted working and measuring devices. The working device contains a penetration needle with weights, kinematically connected with the trigger mechanism, and a measuring one - a measuring metrological scale with divisions. An optocoupler is formed on the penetration needle, formed by the oppositely placed light source and receiver, electrically closed to the control unit, between which a measuring scale of translucent material is placed on the lumen. The trigger mechanism is also electrically connected to the control unit (Patent RU 25796, IPC G01N 3/42, publ. 2002.10.20).

A disadvantage of the known device: the needle is supplied to the surface of the test sample manually, and the moment the needle touches the sample is recorded visually. For a more precise installation of the end of the needle on the surface of the material, an additional light source is used. Accordingly, the accuracy of measurements with this device is low.

A penetrometer (adopted as a prototype) is also known, containing a housing, in the lower part of which there is an object table with a mechanism for its movement, a rod with a load and a needle, an electric brake, a rod movement sensor with a needle, a measuring unit, a control unit, a unit for determining the moment of touching the surface needle the test material (Autosvid. No. 1716382, IPC G01N 3/48, publ. 29.02.92). The unit for determining the moment of touching the needle of the surface of the test material includes a bracket mounted in the housing, a mechanism for moving the bracket relative to the needle, and an acoustic transducer and a piezoelectric transducer attached to the bracket, connected to the control unit and designed to excite and record the oscillations of the needle.

A disadvantage of the known device is the direct contact of the piezosensor with the needle at the time of resonance determination, which impairs the resonance properties of the needle and leads to low accuracy in determining the moment the needle touches the surface of the test product. In addition, the contact of the piezosensor with the needle increases the likelihood of damage to it during operation, which reduces the reliability of the device.

The objective of the utility model is to increase the accuracy of penetration measurement, as well as to increase the reliability of the device by eliminating direct contact of the sensor with the needle at the time of determining the resonant frequency of the needle.

The technical result is achieved by a penetrometer for determining the consistent properties of bitumen, comprising a housing, an object table located in the lower part of the housing with a mechanism for its movement, a rod with a load and a needle, an electric brake, a rod and needle movement sensor, a unit for determining the moment of touching the needle of the test surface, including a bracket, installed in the housing, a mechanism for moving the bracket relative to the needle and means fixed on the bracket for exciting and recording oscillations of the needle, as well as a control unit, to toromu mechanisms connected displacement of the object table and the bracket, electro-sensor displacement rod with the needle, means for excitation and oscillation of the needle, which, unlike the prior art, as means for registering the oscillations of the needle used in the Hall sensor.

In the proposed device for recording oscillations of the needle instead of the piezoelectric sensor, a Hall sensor is used, which allows you to determine the resonant frequency of the needle without direct contact of the needle with the sensor. This increases the reliability of the device and the accuracy of determination of penetration.

The essence of the utility model is illustrated by the drawing, where in Fig.1 shows a diagram of the penetrometer, side view; figure 2 is a front view.

The penetrometer contains a housing 1, an object table 2 located in the lower part of the housing, a rod 3 with a load of 4 and a needle 5, an electric brake 6, a rod displacement sensor with a needle 7, an arm 8, an electromagnet 9 and a Hall sensor 10 mounted on an arm, and a control unit 11 on a microprocessor (not shown).

To move the bracket with the Hall sensor mounted on it, the device contains a motor 12, the movement of the table 2 is carried out by the engine 13. The rod movement sensor with the needle includes a radiator 14 and a photodetector 15.

The device operates as follows.

In the initial position, the rod 3 is raised, the table 2 is lowered, and the Hall sensor 10 is retracted. On table 2, a cup with a test product filled with water (not shown) is installed.

After pressing the “START” key (not shown), the engine 12 is turned on, which starts to bring the Hall sensor 10 to the needle 5. After the Hall sensor 10 is connected to the needle 5, the engine 12 is stopped.

Initially, the microprocessor 11 must determine the moment the needle 5 touches the surface of the test material. For this, it is necessary to determine the resonant frequency of the needle. The proposed device uses a microprocessor that processes the signal from the Hall sensor with a resolution of 166.6 kHz. This frequency of signal processing allows you to more accurately calculate the weight value of the amplitude of the signal and, therefore, to more accurately determine the resonant frequency of the needle, which significantly increases the accuracy of determining the moment of contact.

To determine the resonant frequency of the needle 5, electric pulses are fed to the coil of the electromagnet 9. The magnetic field created by the coil of the electromagnet 9 causes the needle 5 to oscillate at the resonant frequency. The pulse frequency gradually changes in the range from 100 to 500 Hz in increments of 1 Hz. Oscillations of the needle are perceived by the Hall sensor 10, from the output of which a sinusoidal signal is supplied to the microprocessor device 11, which determines the resonant frequency of the needle 5.

Then there is a supply of 9 electric pulses to the electromagnet coil with a frequency corresponding to the resonant frequency of the needle 5, and a decrease in the duration of the exciting pulse, which ensures maximum sensitivity of the needle 5 when touching the surface of the test product.

Then the microprocessor device sends a signal to turn on the engine 13, which starts the rise of the table 2 with increased speed.

When the needle is immersed in water, the needle self-oscillates, i.e. the amplitude of the signal from the Hall sensor 10 decreases sharply. In this case, the microprocessor device reduces the lifting speed of table 2 and begins to adjust the duration of the exciting pulse according to the maximum amplitude of the signal from the Hall sensor 10, thereby ensuring maximum sensitivity of the needle 5.

When the needle 5 touches the surface of the test product, the self-oscillations of the needle re-break, which is recorded by the microprocessor as the moment the surface of the test material touches. Next, the microprocessor device stops the engine 13 lifting the table 2 and turns on the engine 12, which begins to divert the Hall sensor 10 from the needle 5.

After the Hall sensor 10 is withdrawn from the microprocessor 11, a signal is applied to the electric brake 6, which releases the rod 3. The needle 5 is immersed in the test product for a predetermined time. The movement of the rod is fixed by a sensor 7, which has a primary and secondary scale (not shown), emitter 14 and photodetector 15. When the load 4 penetrates together with the rod 3 of needle 5 into the test product, the main scale moves every 0.1 mm periodically blocks the luminous flux created by the emitter 14, which captures the photodetector 15. A quadrature signal is generated, processed by the microprocessor device and converted into penetration units (0.1 mm).

After the test time, the signal is removed from the brake electromagnet 6, the rod 3 is fixed, the number of pulses from the photodetector is stored in the memory of the penetrometer and displayed on the liquid crystal display. The test is considered complete.

Thus, the proposed design of the penetrometer improves the reliability of the device and the accuracy of determination of penetration.

Claims (1)

A penetrometer for determining the consistent properties of bitumen, comprising a housing, an object table located in the lower part of the housing with a mechanism for its movement, a rod with a load and a needle, an electric brake, a rod and needle movement sensor, a unit for determining the moment of touching the needle of the test surface, including a bracket mounted in the housing , a mechanism for moving the bracket relative to the needle, and means fixed on the bracket for exciting and recording oscillations of the needle, as well as a control unit to which the moving mechanisms are connected Nia object stage and bracket electro-sensor displacement rod with the needle, means for excitation and oscillation of the needle, characterized in that the means for recording the oscillations of the needle used in the Hall sensor.