Principles of Operation #
- The innovateIT wheelblastIT belongs to the general category of the Car Cleaning Machines. “Wheel blasters,” as a generic term in the car wash industry, use high-pressure water spray to clean wheel hubs.
- The wheelblastIT follow-along wheel blaster features electric-powered belt-driven trolleys sliding along on five-foot rails to follow, cleaning the wheel hubs with high-pressure cone-patterned water sprayed through a rotating assembly of three nozzles.
- innovateIT Car Wash Equipment LLC’s expectation for this system is that, when correctly installed and settings adjusted for site-specific conditions, the wheel blasters will operate without trouble for several years.
System Operation #
- The wheelblastIT operation consists of a series of electronic signals that control the mechanical functions of trolley movement and high-pressure water sprayed through the 3-nozzle assembly on each trolley.
- Electronic Signals
- When the car wash tunnel operator powers on the vehicle conveyor, the Heartbeat pulse signal begins. The heartbeat pulse signal is continuously transmitted to the wheelblastIT PLC and to the web based controller.
- Trolley Movement Sequence
- As the conveyor moves a vehicle through the car wash tunnel, a tire on one side of the vehicle activates the tire pad sensor or the tire eye sensor (depending on the configuration selected by the customer at the time of order) . The tire signal is transmitted to the controller to begin a wheel blaster sequence.
- After a delay programmed into the controller when the tire is about five feet from the wheel blaster, the controller activates a relay to turn on the high-pressure water pump in the MCC.
- After a short delay, the controller transmits a tire signal to the wheeblastIT PLC to run a trolley movement cycle.
- After a moderate delay, the controller deactivates the high-pressure water pump relay to turn off the water spray.
- The above sequence repeats for each vehicle tire that activates the tire pad sensor or tire eye sensor.
- Trolley Forward Movement (Tire pad sensor)
- The controller starts a wheelblastIT trolley movement cycle when it transmits a “Tire” signal to the wheelblastIT PLC.
- If the wheelblastIT PLC has inputs that signal A) the conveyor is powered on, B) the relevant VFD is ready, and C) that the relevant trolley flag is detected by the “Home” proximity sensor, then the wheelblastIT PLC starts the “Forward” movement program on that VFD.
- If any of A, B, or C signals are not present, then the PLC will not start the Forward movement on that VFD (driver and/or passenger sides).
- The VFD controls the trolley speed by transmitting to the motor 480 Vac at frequencies that range from no movement at zero Hertz (Hz) to full speed at 60 Hz.
- The wheelblastIT PLC controls trolley ‘Forward’ speed by changing the frequency of the VFD transmitted power.
- The frequency for ‘Forward’ speed is based on the pre-calculated distance the vehicle conveyor travels for every pulse of the Heartbeat signal and the rate of the Heartbeat pulse signal at the time the ‘Forward’ movement program is started.
- If the Forward movement program is started without the Heartbeat pulse signal, the PLC will still send the trolleys forward.
- The limit of distance the trolley moves forward is calculated by the PLC from wheelblastIT pulley diameters and the ‘Forward’ speed. The ‘Forward’ distance limit to be moved is entered as inches in the wheelblastIT HMI.
- When the PLC calculates the trolley has reached the ‘Forward’ distance limit, the PLC stops the ‘Forward’ movement program and starts the ‘Reverse’ movement program.
- If there is no Heartbeat pulse signal, the PLC will not calculate how far the trolleys have moved and will continue to send the trolleys forward until powered off.
- Trolley Reverse Movement
- The ‘Reverse’ movement program includes a ‘Reverse Fast Speed’, a ‘Reverse Fast Time’, and a ‘Reverse Slow Speed.’
- The PLC runs the ‘Reverse’ movement program individually on each VFD until it receives a signal that the Home sensor detects the relevant trolley flag.
- Upon starting the ‘Reverse’ movement program, the trolley will go in high speed reverse for the amount of ‘Reverse Fast Time’, then it will decelerate to the ‘Reverse Slow Speed’ for a smooth stop.
- The ‘Reverse’ movement program can run without the Heartbeat pulse signal. This is because the ‘Reverse’ speeds are programmed in the HMI and are not related to the conveyor speed.
- This permits the trolleys to reverse to Home position should the conveyor shut down.
- High-pressure Water Spray Sequence
- The controller starts the wheelblastIT water spray when it transmits power to, and activates, a controller relay that transmits power to a control contactor in the MCC.
- When the control contactor receives power, it “pulls in” the 480 Vac contactor that then transmits power to the high-pressure water pump.
- When the controller stops transmitting power to the water pump relay, the control contactor stops pulling in the 480 Vac contactor, which springs open. Once the contactor is open, power stops transmitting to the high-pressure water pump.
- This sequence of events is separate from wheel blaster trolley movement. Therefore, high-pressure water will still spray even though the PLC may have stopped moving one or both trolleys.
- The wheelblastIT PLC can control the water pump through a pre-programmed output, spraying the water for forward travel of the trolley and only then shutting off the water. This could be a motor starter or a water solenoid.