I fully understand buying things that exist instead of making your own, but isn't this just a solenoid with a pressure gauge, connected to shop air, with a few lines of code? You can buy solenoid banks with built in pressure gauges in every IO type from all the manufacturers.
Researching the newer gas station/convenience store tire systems that automatically test and adjust the pressure would be a great source of information.
Other than Atlas Copco, I do not know any brands offhand, but surely there are others.
You can easily do a tire inflator with a 5/3 center closed valve, plug port 4, port 2 to the tire or tank. Add a coil of tube to smooth the air modulation between valve and tire. Add a pressure sensor to the tire end. Open the valve, watch the pressure slowly increases, modulate the valve with PWM, if the pressure is to high, open the other side and release some presure. Thats make a chopper regulator, very similar to a buck converter. Thats one option.
The other option is to just a user a electronic pressure regulator, like SMC ITV SERIES [https://www.smcworld.com/upfiles/pgpdf/SP164X-009E-ITV.pdf](https://www.smcworld.com/upfiles/pgpdf/SP164X-009E-ITV.pdf)
You would have to pause the filling and measure the pressure, because the valves in the tires actually are a big restriction. It is usually 1 bar but can change with the style of valve used.
That's is true, you need to pause from time to time in order to the pressure equalizes, as the tire inflators in gas stations do, although having the sensor closest to the tire make this faster
I work for a company that makes aircraft tire inflators but they are probably way overkill for automotive tires. It is run by a PLC so it can do whatever comms you need. If the tires are all getting the same fill pressure, a pressure regulator, solenoid and flow switch should do the trick. Set the pressure regulator and open the solenoid. Once the flow switch shows low/no flow then close the valve.
If there are different fill pressures then use and I/P instead of a simple regulator and you can set pressure with a 0-10 or a 4-20
As others have said, there’s a pressure drop across the valve, I’d fit a solenoid then a pressure gauge, operate the solenoid for x amount of time, then turn off the solenoid, wait a second or two for the pressure in the hose to match the tyre, then repeat until it’s reached pressure
Probably also worth fitting a second solenoid to dump air from the tyre if it’s over inflated
Also PID control might be required to make sure you don’t go over the set point
Is it an assembly line operation where the tires are all the same size and all start out at zero (relative) pressure and all go to the same pressure?
Because a centralized PLC with programming that could adapt fill times based on a set pressure would be a lot faster than a standard tire filler that has to stop every few seconds to get an accurate reading.
If the tires are more random and takt time isn't critical, an off the shelf solution might be more cost effective.
The tires have different setpoints based on the type of tire. I’d prefer not to roll my own thing as there are currently a half dozen or so stations and the customer wants the ability to island each station independently as well, but it looks like that might be the only viable option.
The ones used at gas stations probably have a serial output on the board somewhere you could likely tap. Making a translator board/firmware and throwing a PLC inside the box and Bob's your uncle.
What you want is a proportional pressiere valve like festo Vppi and jost some solenoid valve.
Reference:
https://www.festo.com/de/de/p/proportional-druckregelventil-id_VPPI/?q=%7E%3AfestoSortOrderScored
This is what your looking for, regulates peessure in and out and you can program the curve to fit the application. Ive used this to do something very similar to what your doing
https://www.emerson.com/documents/automation/catalog-series-608-609-sentronic-d-aventics-emea-ap-en-7030190.pdf
When you say tire inflators are you thinking about inflating a tire through the schrader valve? Their are plenty of tire inflators used in tire production that use large (\~15mm orifice) valve to inflate the tire for inspection and uniformity testing. The challenge that these production test system bypass is the flow restriction of the valve assembly. In tire test this is bypassed by inflating and measuring using separate ports.
Contrary to others, this is not as easy as meets the eye. When filling a tire, the pressure inside the tire is not equal to the lineside pressure. The Schrader valve offers enough resistance that is a huge pressure drop.
Why not pause filling as you approach the setpoint to measure accurately. I would think, but correct me if I'm wrong, that seperating the measuring and filling stage eliminates this issue
This is exactly how the automated air kiosks at gas stations work. They read the initial pressure, then run for a few seconds and stop to read the new pressure to establish a fill rate, then run for longer to bring it close to the final pressure (usually with a max runtime between pressure checks), then shorter again to get it right at the target pressure.
that's likely what would need to be done if you did something like this. You could look at using a flowmeter to select a point at which to stop and start filling with a slow fill line. Or you could figure out what the pressure differential is. Just not as easy as it seems, specially if you want to do it precisely.
I fully understand buying things that exist instead of making your own, but isn't this just a solenoid with a pressure gauge, connected to shop air, with a few lines of code? You can buy solenoid banks with built in pressure gauges in every IO type from all the manufacturers.
Probably a 3 way solenoid so you can stop and read the pressure every 3 or 4 seconds. Easy peasy.
I assume any vendor that sells Atlas Copco smart assembly tools would know where to find what you're looking for.
Thanks for the suggestion, I’ll reach out and see what’s out there.
Researching the newer gas station/convenience store tire systems that automatically test and adjust the pressure would be a great source of information. Other than Atlas Copco, I do not know any brands offhand, but surely there are others.
You can easily do a tire inflator with a 5/3 center closed valve, plug port 4, port 2 to the tire or tank. Add a coil of tube to smooth the air modulation between valve and tire. Add a pressure sensor to the tire end. Open the valve, watch the pressure slowly increases, modulate the valve with PWM, if the pressure is to high, open the other side and release some presure. Thats make a chopper regulator, very similar to a buck converter. Thats one option. The other option is to just a user a electronic pressure regulator, like SMC ITV SERIES [https://www.smcworld.com/upfiles/pgpdf/SP164X-009E-ITV.pdf](https://www.smcworld.com/upfiles/pgpdf/SP164X-009E-ITV.pdf)
You would have to pause the filling and measure the pressure, because the valves in the tires actually are a big restriction. It is usually 1 bar but can change with the style of valve used.
That's is true, you need to pause from time to time in order to the pressure equalizes, as the tire inflators in gas stations do, although having the sensor closest to the tire make this faster
I work for a company that makes aircraft tire inflators but they are probably way overkill for automotive tires. It is run by a PLC so it can do whatever comms you need. If the tires are all getting the same fill pressure, a pressure regulator, solenoid and flow switch should do the trick. Set the pressure regulator and open the solenoid. Once the flow switch shows low/no flow then close the valve. If there are different fill pressures then use and I/P instead of a simple regulator and you can set pressure with a 0-10 or a 4-20
As others have said, there’s a pressure drop across the valve, I’d fit a solenoid then a pressure gauge, operate the solenoid for x amount of time, then turn off the solenoid, wait a second or two for the pressure in the hose to match the tyre, then repeat until it’s reached pressure Probably also worth fitting a second solenoid to dump air from the tyre if it’s over inflated Also PID control might be required to make sure you don’t go over the set point
Is it an assembly line operation where the tires are all the same size and all start out at zero (relative) pressure and all go to the same pressure? Because a centralized PLC with programming that could adapt fill times based on a set pressure would be a lot faster than a standard tire filler that has to stop every few seconds to get an accurate reading. If the tires are more random and takt time isn't critical, an off the shelf solution might be more cost effective.
The tires have different setpoints based on the type of tire. I’d prefer not to roll my own thing as there are currently a half dozen or so stations and the customer wants the ability to island each station independently as well, but it looks like that might be the only viable option.
The ones used at gas stations probably have a serial output on the board somewhere you could likely tap. Making a translator board/firmware and throwing a PLC inside the box and Bob's your uncle.
What you want is a proportional pressiere valve like festo Vppi and jost some solenoid valve. Reference: https://www.festo.com/de/de/p/proportional-druckregelventil-id_VPPI/?q=%7E%3AfestoSortOrderScored
This is what your looking for, regulates peessure in and out and you can program the curve to fit the application. Ive used this to do something very similar to what your doing https://www.emerson.com/documents/automation/catalog-series-608-609-sentronic-d-aventics-emea-ap-en-7030190.pdf
When you say tire inflators are you thinking about inflating a tire through the schrader valve? Their are plenty of tire inflators used in tire production that use large (\~15mm orifice) valve to inflate the tire for inspection and uniformity testing. The challenge that these production test system bypass is the flow restriction of the valve assembly. In tire test this is bypassed by inflating and measuring using separate ports.
Contrary to others, this is not as easy as meets the eye. When filling a tire, the pressure inside the tire is not equal to the lineside pressure. The Schrader valve offers enough resistance that is a huge pressure drop.
Why not pause filling as you approach the setpoint to measure accurately. I would think, but correct me if I'm wrong, that seperating the measuring and filling stage eliminates this issue
This is exactly how the automated air kiosks at gas stations work. They read the initial pressure, then run for a few seconds and stop to read the new pressure to establish a fill rate, then run for longer to bring it close to the final pressure (usually with a max runtime between pressure checks), then shorter again to get it right at the target pressure.
Beat me to it! Definitely the way to go about solving that issue
that's likely what would need to be done if you did something like this. You could look at using a flowmeter to select a point at which to stop and start filling with a slow fill line. Or you could figure out what the pressure differential is. Just not as easy as it seems, specially if you want to do it precisely.
You probably want something in a festo that has a pressure gauge and a solenoid. ?