Stand for measuring the throughput of carburetor jets. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Automobile. Electronic devices

Comments on the article

Despite the fact that the production of carburetted cars has been reduced to a minimum, millions of such cars are still in operation. To maintain their performance at the proper level, it is often necessary to repair carburetors. One of the important indicators of the correct operation of the carburetor is the throughput of the jets. It is possible to measure this parameter only with the help of a special stand.

When the carburetor is operating in general, but on domestic fuel, all the more so, the calibrated part of the jet is resinified rather quickly. An almost invisible film of resin can significantly reduce the performance of the jet.

In many cases, motorists, trying to independently adjust the operation of the engine, replace the factory jets with repair ones from kits of dubious origin. As measurements on a special stand show, the deviation from the norm in such cases reached tens of percent. It is not difficult to understand the consequences of this.

Measurement of the throughput of jets is usually carried out on specialized stands.

Hydrodynamic stand NIIAT-528-A industrial production is very complicated, expensive and inconvenient to use. Therefore, I decided to make an amateur version of such a stand with a simpler hydraulic circuit and automatic control of the water supply to the jet under test.

The measurement algorithm is simple. Under the pressure of a water column 1000 ± 2 mm high, the liquid flows through the jet into a graduated beaker. Automation provides a stable flow time - 60 s. Thus, the throughput of the jet is determined in milliliters per minute.

Fig. 1

The hydraulic part of the stand is schematically shown in fig. 1 It consists of a tank into which a pressure pipe is hermetically welded (or soldered). From below, it ends with a solenoid valve, the test nozzle is screwed into its outlet. I used a Belarusian-made gas valve from gas-balloon automotive equipment, bought at an auto parts store. To reduce hydraulic resistance, I drilled out the valve inlet pipe to a diameter of 2,8 mm and removed the felt filter.

In the lower part of the tank, a fitting is welded into its side wall, which is connected to the inlet pipe of the water pump (the pump was used from the interior heater of the Gazelle minibus). Through the upper pipe, the pump drives water into the pressure pipe. Excess water flows from the upper end of the pipe into the tank. Thus, the system maintains a constant pressure of water above the jet.

Since the performance of the pump is excessive, in order to avoid splashing of the flowing water, a valve is introduced into the outlet pipe of the pump, which limits the flow of water into the pressure pipe.

The tank and pressure pipe are made of stainless steel, but aluminum alloy, brass, and even plastic are also suitable. The dimensions and shape of the stand elements are not critical. Only the height of the pressure pipe should be accurate (its diameter in my version of the stand is about 50 mm).

Fig. 2

The scheme of the electronic control unit for the water supply to the jet is shown in fig. 2 The counter DD1 has a timer designed for a shutter speed of 60 s. Since the K176IE12 counter is designed to work in an electronic clock, the minute signal appears at the output M of the counter after 59 s.

To obtain a sixty-second exposure, a separate zeroing of the timer counters was used using the synchronization trigger DD2.2.

On the counters DD4, DD5 and the digital indicator HG1, a unit for counting the measurement time is assembled, operating in the addition mode. Single vibrator on the elements DD2.1, R5, C3 controls the operation of the executive relay K1.

It is a remote switch with two windings and two stable states, switched by current pulses. For reliable operation of the relay, the pulse duration of a single vibrator is approximately 50 ms.

Elements DD3.4-DD3.6 invert and amplify the current signal of the single vibrator to the level necessary for reliable opening of the transistor VT1 and relay K1 operation. Diodes VD1, VD2 form a logical OR element.

The relay, having worked, switches its contacts K1.2. As a result, a powerful transistor VT2 opens and valve Y1 is activated, which opens the water supply to the jet.

The process of measuring its throughput consists of several stages. The tested jet is screwed into the lower branch pipe of the valve and the pump is turned on; the pressure pipe of the stand is filled with water. A measuring cup is placed under the jet.

The relay node is in the "Stop" position. Transistor VT2 is closed, since its gate is connected to a common wire by contacts K1.2. Therefore valve Y1 is closed. Through the resistor R13, a voltage is supplied to the input R of the second counter of the DD1 microcircuit, blocking its operation, and the minute counter is blocked by the voltage from the output of the trigger DD2.2. This voltage also blocked the operation of the counters DD4, DD5 of the exposure time indication unit. The LED HL1 "Stop" red glow is on.

Next, click on the "Start" button. Contacts K1 1 and K1.2 of the relay switch to the second stable state. Transistor VT2 opens, valve Y1 operates, and water begins to flow through the jet. At the same time, the second counter of the DD1 chip starts to work, and after one second, the DD2.2 trigger will switch to the zero state, which will lead to the unlocking of the minute counter of the DD1 chip and counters DD4, DD5. HG1 indicator starts timing. Contacts K1.1 of the relay turn on the "green" LED HL2 "Start" and turn off HL1.

After 60 s, a signal will appear at the output M of the DD1 chip, which will start the one-shot on the trigger DD2.1. As a result, transistor VT50 will open for 1 ms and switch relay K1 to its original state. This will close the transistor VT2 and shut off the water supply to the jet. The capacity of the jet is determined by the volume of water in the measuring cup. By pressing the SB2 "Stop" button, you can switch the relay and stop the measurement process before the exposure time expires.

The electronic unit is assembled on the technological board; the installation is made with pieces of insulated flexible wire. The unit is installed in a metal box, on the front panel of which are mounted controls, a digital indicator and LEDs. Remote switch - RPS20, version RS4.521.753

The power supply unit - transformer has no circuit features. It contains two voltage sources - stabilized at 9 V and unstabilized at 14 V.

Author: I. Osipov, Kursk; Publication: radioradar.net

See other articles Section Automobile. Electronic devices.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive Heat reduces school performance 09.10.2020 An international group of scientists has stated that rising air temperatures can negatively affect the performance of schoolchildren. According to them, future climate change will affect the education system, especially in hot countries. The study analyzed data on school performance in 58 countries, which were obtained from 2000 to 2015. The work took place in two stages. At the first, scientists reviewed the results of tests in mathematics, science and reading of the International Program for Student Assessment (PISA), which during the study were taken by more than 144 million students around the world. On the second - the results of exams that are annually taken by students in the United States as part of the annual national testing in mathematics and English (ELA). The collected data were correlated with the indicators of the average annual temperature. It turned out that temperatures above 26,7 degrees Celsius negatively affect the cognitive abilities, endurance and working memory of students. Each additional hot day reduced exam scores by 0,18%. Cold days did not affect her in any way. This trend has been particularly strong in poor countries with high average annual temperatures, where schools are often not equipped with a ventilation system. Scientists believe that the increase in global temperature caused by climate change will negatively affect the economic growth of countries and the quality of life of the population. More research is needed, they say, that could reveal other trends.

Other interesting news:

▪ Ultra-precise X-ray system for airports

▪ Trees will help find the bodies of people missing in the forest

▪ AnkerMake M3 5D printer

▪ Artificial muscle

▪ Asphalt in the greenhouse

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Chargers, accumulators, batteries. Article selection

▪ article Symbols for SMD transistors. Directory

▪ Article Who, according to Albert Einstein, makes great discoveries? Detailed answer

▪ the article of Ziziphorus is thin. Legends, cultivation, methods of application

▪ article Balancing shpi and chokes on ferrite tubes. Encyclopedia of radio electronics and electrical engineering

▪ article Watch shop in a hat. Focus Secret

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024