RU138370U1 - DEVICE FOR TESTING PRODUCTS DURING QUICK PRESSURE CHANGE - Google Patents

Abstract

1. A device for testing products with rapid pressure changes, containing a pressure source with a pipeline, characterized in that the pressure source is in the form of a pressure chamber equipped with a vacuum pump, and further comprises a sealed chamber for rapid pressure changes, made with the possibility of moving and connecting devices for monitoring pressure and pressure change time, connected to a thermal chamber by means of a vacuum wire equipped with a pneumatic valve, a control valve and a valve ravnivayuschim.2. The device according to claim 1, characterized in that the pressure change chamber is made in the form of a sealed stainless steel case with a sealed door and a transparent sealed window. The device according to claim 1 or 2, characterized in that the rapid pressure change chamber is mounted on a frame with wheels equipped with adjusting screws for adjusting the height of the frame. The device according to claim 1, characterized in that the visual control of the pressure is carried out by means of a vacuum gauge connected to a chamber for rapid pressure change. The device according to claim 1 or 2, characterized in that the time control is carried out by means of an oscilloscope connected to a pressure transducer installed inside the chamber of rapid pressure change. The device according to claim 1 or 2, characterized in that the pneumatic valve mounted on the vacuum wire provides a change in pressure from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury over a time of 0.3-0.4 seconds.

Description

The proposed utility model relates to the field of radio engineering and can be used in testing products, mainly electronic equipment, under conditions of rapid pressure changes.

A pressure chamber is known from the prior art (SU copyright certificate for invention No. 329682, published 01.01.1972, IPC: G01M 3/16), which is selected as a prototype. The pressure chamber is designed primarily for testing electronic equipment and includes a chamber vacuum system and a compressed air supply line equipped with a heater, humidifier, cooling device, as well as control and regulation devices. In this case, the cooling device is made in the form of an expansion turbine installed in the air supply line after the heater and humidifier, equipped with a bypass pipe on which an adjustable choke is mounted, electrically connected to the temperature and density sensors of the fog in the chamber.

The disadvantages of this device include the inability to provide pressure changes in a short period of time.

A known pressure chamber (Copyright certificate for the invention No. 699417, published November 25, 1979, IPC: G01N 29/00, F25D 13/00), which can be used in tests and studies of the operation of various units and equipment. The pressure chamber contains a thermally insulated cylindrical body, a casing located inside it, forming an internal test compartment, an air cavity between the inner surface of the body and the casing, as well as air supply and exhaust pipes. In this case, the casing is made in the form of two groups of belts adjacent to each other and alternately located along the entire length of the pressure chamber, which consist of an equal number of segment-shaped links attached to the inner surface of the housing and, in combination with it, through passage cavities oriented in parallel in one group of belts axis of the pressure chamber, and in another group of belts - around the circumference of the cylindrical body.

The disadvantages of this device include the complexity of the design and the inability to ensure rapid pressure changes.

Closest to the claimed utility model is a device for cyclic pressure testing of products (copyright certificate SU No. 1747974, published July 15, 1992, IPC: G01M 3/02), which is selected as a prototype. The device contains a pressure source with a pipeline intended for interaction with the tested product, a control panel, a cycle counter, the output of which is electrically connected to the input of the control panel, and a time relay. The pressure source is made in the form of a pneumatic cylinder with a piston, one of the cavities of which is connected to the pipeline, and the second to the atmosphere, and a piston movement mechanism, the inputs and outputs of which are electrically connected to the corresponding inputs and outputs of the time relay, cycle counter and control panel.

The disadvantages of this device include the lack of reliability of the device and the inability to provide pressure changes in a short period of time.

The technical result of the proposed utility model is to provide the ability to change pressure in a short period of time (0.3-0.4 seconds), as well as to provide convenience and reliability during testing of electronic equipment.

The technical result is achieved by the fact that the device for testing products with a rapid change in pressure contains a pressure source with a pipeline .. Moreover, it differs from the prototype in that the pressure source is in the form of a pressure chamber, and also contains a sealed chamber for rapid pressure changes, made with the possibility of movement and connecting devices for monitoring pressure and time of pressure change connected to a thermal chamber by means of a vacuum wire equipped with a pneumatic valve, a reg and the gate-insulating equalizer.

The pressure change chamber is made in the form of a sealed stainless steel case, with a sealed door and a transparent sealed window.

A pressure change chamber is mounted on a frame with wheels equipped with adjusting screws for adjusting the height of the frame.

Visual control of the pressure is carried out by means of a vacuum gauge connected to a chamber for rapid pressure changes.

Time control is carried out by means of an oscilloscope connected to a pressure transducer installed inside the chamber of rapid pressure change.

A pneumatic valve mounted on a vacuum wire provides a pressure change from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury for a time of 0.3-0.4 seconds.

The essence of the utility model is illustrated by figures 1 - 2. Figure 1 presents a General view of a device for testing products with a rapid change in pressure. Figure 2 presents a table of the results of measurements of pressure and time.

A device for testing products with a rapid change in pressure (Figure 1) includes:

1 - thermal pressure chamber;

2 - a chamber for rapid pressure changes;

3 - vacuum wire;

4 - pneumatic valve;

5 - the door of the chamber for rapid pressure changes;

6 - frame;

7 - wheels;

8 - adjusting screws.

9 - regulating valve;

10 - equalizing valve;

11 - a vacuum gauge;

12 - an oscilloscope.

A device for testing products, for example, electronic equipment, with a rapid change in pressure is intended for testing products with a pressure drop from a maximum of 560 ± 5% (522-588 millimeters of mercury) to a minimum of 350 ± 5% (332.5-367.5 millimeters of mercury). In this case, the rate of pressure change should be from 0.3 to 0.4 seconds. Operating temperature +25 ± 10 ° C.

The pressure chamber 1, (for example, a chamber of heat-cold-pressure TV V-2000 with vacuum pumps), is designed to create the required pressure level.

The pressure chamber 1 is connected to the pressure change chamber 2 by means of a vacuum wire 3 equipped with a pneumatic valve 4.

The pressure change chamber 2 is a welded stainless steel case, comprising a sealed door 5 with a transparent sealed window, while the pressure change chamber 2 is configured to be transported: the case is mounted on a frame 6 with wheels 7, equipped with adjusting screws 8, which allow adjust the frame 6 in height. This design of the camera rapid change of pressure 2 allows us to provide convenience and reliability of the device for testing products with rapid change in pressure. The pressure change chamber 2 is configured to connect a vacuum wire 3 (for example, by means of a pipe), and to connect measuring instruments: a vacuum gauge 11 and an oscilloscope 12 (for example, by means of fittings). An overpressure conversion sensor (for example, a pressure transducer PDTVH-1-0.2-4 / 20-0.1-0.5%) is installed inside the chamber for rapid pressure change 2, the figure is not shown. The pressure in the chamber of the rapid change in pressure 2 is created using the vacuum pump of the pressure chamber 1.

The vacuum wire 3 is equipped with a pneumatic valve 4 and two valves - a regulating valve 9 and an equalizing valve 10.

The control valve 9 is used to control the pressure level of 560 ± 5% millimeters of mercury in the chamber of rapid pressure change 2 before the pneumatic valve 4 is activated.

The equalizing valve 10 serves to equalize the pressure in the chamber of rapid pressure change 2 with the level of atmospheric pressure at the end of the test.

Pneumatic valve 4 of the vacuum wire 3 provides a change in pressure from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury in a time equal to 0.3-0.4 seconds.

Visual control of the pressure is carried out by means of a vacuum gauge 11 connected to a chamber for rapid pressure change 2.

Accurate measurement of the differential pressure time of 0.3-0.4 seconds is carried out using a sensor, for example, type A160, connected to a pressure calibrator such as Metran 517, or a strain gauge membrane sensor.

Time control is carried out by means of an oscilloscope 12, for example, Le Croy Wave Jet 352A or TDS 3012 V connected to a pressure transducer PDTVH-1-02 - 4 / 20-0.1-0.5%, installed inside the chamber for rapid pressure change 2.

The operation of the device for testing products with a rapid pressure drop is carried out in a stationary position (with locked wheels 7 of the frame 6 for installing the chamber for rapid pressure change 2) as follows. The pressure change chamber 2 is connected to the pressure chamber 1 by means of a vacuum wire 3. Before testing the product, the device is tested for testing the product at a rapid pressure drop, for which several (at least three) measurements of the maximum and minimum pressure and pressure change time from the maximum to a minimum level. The measurement results are entered in the table (Figure 2).

Then carry out the processing of measurement results. Processing of measurement results includes the calculation of indicators and determination of the accuracy characteristics of the device for testing products with rapid pressure changes. The calculation of the characteristics of the maximum (minimum) pressure values of the device is carried out separately for each given mode.

The value of the maximum (minimum) pressure is determined by the formula (1):

, где

where

k is the number of measurements (at least 3);

i is the measurement number (i = 1, k);

Pij is the value of the maximum (minimum) pressure determined during the i-th measurement.

The deviation of the pressure from the set value is determined by the formula (2): ΔP = (Pav-Ppass) / Ppass · 100%, where

Pav - the average value of the pressure obtained by the formula (1);

Pspas - pressure value indicated in the passport on the device.

If the time of pressure change during certification or during the calibration period does not fall within the range of 0.3-0.4 seconds, to provide the required time parameters for the rate of pressure change from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters mercury column for 0.3-0.4 seconds, the useful volume of the chamber for rapid pressure change 2 is recommended to reduce (or increase) by partially filling (or releasing) elastic materials. It is also possible to regulate the time of pressure change by installing a diaphragm in the vacuum wire 3.

After making sure that the permissible deviations of the parameters of the device correspond, install the test product in the chamber for a rapid change in pressure 2. Check the parameters of the product according to the technical specifications for the product. Close the door 5 of the camera rapid change of pressure 2. Turn on the thermobar chamber 1 at low atmospheric pressure. Close the pneumatic valve 4 of the vacuum wire 3, and open the control valve 9, thereby creating a maximum pressure in the chamber of the rapid change in pressure 2, equal to 560 ± 5% millimeters of mercury. Override control valve 9. Create an initial pressure in the pressure chamber 1, equal to 290 ± 10% millimeters of mercury (this pressure was determined experimentally). Then open the pneumatic valve 4, applying compressed air to its pneumatic actuator with a pressure of 6 ⁺¹ kg / cm ² . The change in pressure from 560 ± 5% to 350 ± 5% millimeters of mercury should fit into the time frame from 0.3 to 0.4 seconds. Measurement of the differential pressure time of 0.3-0.4 seconds is carried out using a sensor, for example, type A160 (connected to a Metran 517 pressure calibrator type device), or a strain gauge membrane sensor. Time control is carried out by means of an oscilloscope 12, for example, Le Croy Wave Jet 352A or TDS 3012 V connected to a pressure transducer PDTVH-1-02 - 4 / 20-0.1-0.5%. Check the pressure with a vacuum gauge 11, it should be 350 ± 17.5 millimeters of mercury (332.5-367.5 mm Hg). To provide a pressure drop from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury allows the pneumatic valve 4 installed in the vacuum wire 3. Maintain the product in the on state at this pressure for 30 minutes. Then turn off the vacuum pump of the pressure chamber 1. Carry out a product check according to the procedure for technical specifications on the product.

The atmospheric pressure is set in the pressure chamber 1, for which purpose the equalizing valve 10 is opened to fill the working volume of the chamber for a rapid change in pressure 2 with air until it is equalized with atmospheric pressure. Open the door 5 of the chamber for rapid pressure change 2. Make a check of the product according to the TU method for the product, remove the test product from the chamber for rapid pressure change 2. Disconnect the vacuum wire 3 from the pressure chamber 1 and the chamber for rapid pressure change 2. Transport the chamber for rapid pressure change 2 for storage.

The proposed device for testing products with a rapid change in pressure allows testing products, mainly electronic equipment, used, for example, in helicopter technology, when the pressure changes from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury in a short period of time ( 0.3-0.4 seconds). The presence of a sealed chamber for rapid pressure change 2 of a certain volume, made with the ability to move and connect instruments for monitoring pressure and time of pressure change, connected to a thermal chamber by means of a vacuum wire equipped with a pneumatic valve, a control valve and an equalizing valve, allows to ensure the reliability and convenience of the device.

Claims (6)

1. A device for testing products with rapid pressure changes, containing a pressure source with a pipeline, characterized in that the pressure source is in the form of a pressure chamber equipped with a vacuum pump, and further comprises a sealed chamber for rapid pressure changes, made with the possibility of moving and connecting devices for monitoring pressure and pressure change time, connected to a thermal chamber by means of a vacuum wire equipped with a pneumatic valve, a control valve and a valve estimating translates. 2. The device according to claim 1, characterized in that the pressure change chamber is made in the form of a sealed stainless steel case with a sealed door and a transparent sealed window. 3. The device according to claim 1 or 2, characterized in that the rapid pressure change chamber is mounted on a frame with wheels, equipped with adjusting screws for adjusting the height of the frame. 4. The device according to claim 1, characterized in that the visual control of the pressure is carried out by means of a vacuum gauge connected to a chamber for rapid pressure change. 5. The device according to claim 1 or 2, characterized in that the time control is carried out by means of an oscilloscope connected to a pressure transducer installed inside the chamber for rapid pressure changes. 6. The device according to claim 1 or 2, characterized in that the pneumatic valve mounted on the vacuum wire provides a pressure change from 560 ± 5% millimeters of mercury to 350 ± 5% millimeters of mercury over a time of 0.3-0 , 4 seconds.

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