Encoder and programmable logic controller (PLC) implementation for a rotary brush automatic car wash system

Abstract

This invention relates to an automatic vehicle wash apparatus employing one or more rotary cloth or foam rubber brushes, and more particularly to the way how the rotary brush to vehicle surface contact is managed using one or more encoders connected to the rotating shaft of each brush and one or more programmable logic controllers (PLC). The encoders, recording the revolutions per minute (RPM) of each brush shaft, provide input to the programmable logic controller. If the RPM value is at or above the high RPM limit, the pivoted boom will move the brush toward the vehicle to achieve a desired brush-to-washable surface contact. If, on the other hand, the RPM value is at or below the low RPM limit, the pivoted boom will move the brush away from the vehicle to achieve a desired brush-to-washable surface contact.

Claims

1. An automatic car wash system employing one or more vertical brushes suspended from one or more pivotable booms, at least one on each side of the longitudinal vehicle wash lane, in which the vertical rotating wheel-type brush with a rotating brush shaft, suspended from a brush support carriage, is movably attached on a guide or rail attached to the laterally swingable, horizontal, elevated boom attached on one end to a fixed support post or frame structure and unattached, or free, on the opposite end, in which at least two limit switches each of which is attached to opposite ends of the said elevated boom on which the said brush support carriage is movably attached on the said rail or guide, in which the said limit switches respectively are activated by the said support carriage movement, when said brush support carriage reaches the respective end of the said boom, and transmits a “stop-and-reverse” movement data; wherein the improvement comprises of a rotary encoder (or shaft encoder) unmovably attached to the said brush support carriage and connected to said brush shaft in which said rotary encoder reads, records and transmits the brush shaft revolutions per minute (RPM) data; wherein the improvement comprises of at least one programmable logic controller (PLC) receiving said brush revolutions per minute (RPM) data from the said rotary encoder, and said “stop-and-reverse” data from said limit switches; wherein the improvement comprises of at least two solenoid valves connected to said programmable logic controller (PLC) programmed to modulate the said valve between open-and-closed positions and thereby control air pressure, and thereby activity, of the first double-acting air cylinder and second double-acting air cylinder; whereby the said first double-acting air cylinder attached from one end to the said boom frame structure and from the opposite end to the said movable brush carriage, to effect the move of the brush carriage, and thereby the brush, horizontally back-and-fort, between said limit switches, on said guide or rail along the said horizontal elevated boom, and in which the said double-acting air cylinder movement, using said encoder data, and said programmable logic controller, is programmed to adjust the said brush to vehicle contact distance within preset revolutions per minute (RPM) limits utilizing said encoder data; whereby the said second double-acting air cylinder attached from one end to the vertical unmovable support post and from the opposite end to the said horizontal pivoting boom frame to effect the rotation of the said boom laterally about the pivot end of the said boom, and in which the said double-acting air cylinder movement, using said encoder data, and said programmable logic controller, is programmed to adjust the said brush to vehicle contact distance within preset revolutions per minute (RPM) limits utilizing said encoder data.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 presents a simplified diagram of the preferred embodiment of the control mechanism for an automatic car wash system employing one or more vertical brushes suspended from one or more pivotable booms, at least one on each side of the longitudinal vehicle wash lane.

(2) FIG. 1 shows the Brush (101), vertical rotating wheel-type brush, suspended from a brush support frame structure movably attached to a horizontal elevated boom (not shown).

(3) FIG. 1 further shows the Rotary Encoder (102) (or shaft encoder) unmovably attached to the top of the brush support frame structure or carriage. The encoder is connected to the rotatable brush shaft at the top of the brush for the purpose of reading the brush shaft revolutions per minute (RPM). In a typical application relating to the present invention the encoder output is used to control the air pressure solenoid valves (104, 105, 106, 107) using a Programmable Logic Controller (PLC) (103).

(4) FIG. 1 further shows the Programmable Logic Controller (PLC) (103) with inputs from at least one Rotary Encoder (102), and at least two Limit Switches (117), and with outputs to the Solenoid Valves (104), (105), (106) and (107).

(5) In addition, FIG. 1 shows four solenoid valves. Each Solenoid Valve (104, 105, 106, 107) serves an identical purpose and function. The Solenoid modulates the Valve between open-and-closed positions based on instructions from the PLC (103) effected by the Rotary Encoder (102) input.

(6) Still, in addition, FIG. 1 shows two double-acting air cylinders (108, 109). The Double-acting air cylinder (108) attached from one end to the boom frame structure and from the opposite end to the movable brush (101) support frame structure, or carriage, for the purpose of moving the brush (101) and brush carriage (not shown) horizontally back-and-fort on a guide or rail along the horizontal elevated boom (not shown). The Double-acting air cylinder (109) attached from one end to the vertical unmovable support post and from the opposite end to the horizontal pivoting boom frame attached to the support post for the purpose of rotating the boom laterally about the pivot end of the boom.

(7) Further, in addition, FIG. 1 shows four adjustable Air Pressure Regulators (110, 111, 112, 113). Each air pressure regulator serves an identical purpose and function.

(8) Still further, FIG. 1 shows the Lubricator (114), the Main air pressure gage (115), the Pneumatic tubes, hoses or lines (116).

(9) Yet further, FIG. 1 also shows the Limit switches (117). A Limit Switch is attached to each opposite end of the boom structure on which the brush (101) carriage is movably mounted and connected to the programmable logic controller (PLC). The purpose of the Limit Switch is to stop the brush carriage movement on the boom rail or guide as the brush (101) carriage reaches the end of the boom, and then reverse the movement of the brush carriage toward the opposite end of the boom. As the brush (101) carriage is moved by the double-acting air cylinder (108) toward one end of the boom, and as the brush carriage reaches the Limit Switch, the Limit Switch is tripped sending a signal to the PLC (102) causing the Solenoid Valves (104) and (105) to change the air pressure in the Air Cylinder (108) and, thereby, stop the brush (101) carriage, and to reverse its direction of movement along the boom rail or guide, and to start to move the brush (101) carriage toward the opposite end of the boom.

DETAILED DESCRIPTION OF THE INVENTION

(10) This invention relates to an automatic vehicle wash apparatus employing one or more rotary cloth or foam rubber brushes, and more particularly to the way how the rotary brush to vehicle surface contact is managed and controlled using one or more encoders connected to the rotating shaft of each brush and one or more programmable logic controllers (PLC). The encoders, recording the revolutions per minute (RPM) of the brush shaft, provide input to the programmable logic controller. The programmable logic controller, using the encoder input, then signals a pair double-acting solenoid valves to increase or decrease air pressure to a double-acting air pressure cylinder to effect a move of the carriage of the brush along a horizontal boom either toward the free end of the boom or toward the pivoted end of the boom. In addition, the programmable logic controller, utilizing the encoder input, signals a second pair of double-acting solenoid valves to increase or decrease air pressure to a second double-acting air pressure cylinder acting on an angle about perpendicularly to the first air pressure cylinder to effect a move of the pivoted boom laterally either toward the vehicle, if the encoder recorded RPM value is at or above the high RPM limit, or away from the vehicle, if the encoder recorded RPM value is at or below the low RPM limit, to achieve a desired brush-to-washable surface contact.

(11) It shall be noted, considering possible brush arrangements, when a multitude of brushes, whether vertical for the front, rear and sides of the vehicle, or the roof, that the proposed invention is applicable for those car wash configurations, and are easily understood by those familiar with the art. Therefore, adaptations to various brush arrangements utilizing the presented invention do not form a new invention.

(12) Staggering of the vertical brushes, and horizontal overhead brushes, to avoid interference between the brushes, is known from the prior art, and therefore, is not further discussed here. It shall also be understood that, for example, both a movable conveyor driven wash lane and stationary wash apparatus structure with laterally across the wash lane or longitudinally along the wash lane pivoted booms, or a fixed gantry type structure, or a stationary vehicle and movable wash apparatus are variations commonly used in vehicle wash apparatus structural systems, and in which this invention can be implemented, and are, therefore, not further discussed here.

(13) FIG. 1 presents a simplified diagram of the preferred embodiment of the control mechanism for an automatic car wash system employing one or more vertical brushes suspended from one or more pivotable booms, at least one on each side of the longitudinal vehicle wash lane.

(14) Initially, as the wash operation starts, the brush (101) is not in contact with the surface to be washed, and it rotates freely above or at the high RPM limit set for wash operations. Then, when the rotating brush (101) touches the surface to be washed, the friction between the brush and the surface causes the brush RPM to decrease. The RPM is continuously read by the encoder (102) mounted on the brush carriage, and attached to the brush (101) shaft end.

(15) The RPM reading by the encoder (102) is continuously sent to the input side of the programmable logic controller (PLC) (103). The PLC (103), then in turn, sends a programmed instruction (signal) to the solenoid valves (104, 105), which, by modulating each respective solenoid air-pressure valve connected via air pressure lines (116) to the double-acting air cylinder (108), adjust the position of the brush (101) carriage longitudinally movable on the rail or guide the boom, from which the brush (101) is suspended.

(16) Similarly, the PLC (103) sends a programmed instruction (signal) to the solenoid valves (106, 107), which causes each respective solenoid air-pressure valve to modulate air-pressure connected via pressure lines (116) to the double-acting air cylinder (109), and thereby to adjust laterally the position of the pivoting boom. Thereby, the lateral pivoting movement of the boom causes the suspended brush (101) to move laterally toward or away from the surface to be washed.

(17) The PLC is programmed to maintain the brush RPM within preset limits during the wash operation. If the current RPM is above or at the high RPM limit, then solenoid valves (106, 107) receive a programmed instruction from the PLC (103) to move the pivoted boom, and thereby the brush (101) toward the surface to be washed until the RPM is within the high and low limits. On the other hand, if the current RPM is below or at the low RPM limit, then solenoid valves (106, 107) receive a programmed instruction from the PLC (103) to move the pivoted boom, and thereby the brush (101), away from the surface to be washed. The RPM increase and decrease are caused by the brush (101) to surface contact friction. When the brush (101) moves closer to the surface to be washed, the brush-to-surface contact friction increases and the brush RPM decreases. Similarly, when the brush (101) moves away from the surface to be washed, the brush-to-surface contact friction decreases and the brush RPM increases.