SURFACE TREATING MACHINE WITH CONTROLLED DELIVERY

Abstract

A surface treatment machine, comprising a frame configured to translate with respect to a surface to treat, a surface treatment element connected to said frame and configured to treat with liquid a surface, a reservoir connected to the frame to provide liquid to the surface treatment element through a delivery mouth; an adjustment element arranged to feed adjustably the liquid supplied from the reservoir to the delivery mouth. A sensor is configured to measure an operating parameter P of the machine, such as the level of residual liquid in the reservoir, or the flow-rate of the liquid from said reservoir towards the delivery mouth, or the speed of the machine. A control unit receives by the sensor a signal proportional to operating parameter P and for adjusting the adjustment element responsive to operating parameter P, in order to deliver the liquid according to a predetermined function f(P) of optimization of the flow-rate. It is possible then to maximize the range of the machine, and to optimize the working time of the operator.

Claims

1. A surface treatment machine, comprising: a frame configured to translate with respect to a surface to treat, a surface treatment element connected to said frame and configured to treat with liquid a surface with respect to which said frame advances, a reservoir connected to said frame and arranged to provide liquid to said surface treatment element through a delivery mouth; an adjustment element arranged to adjustably pulse-feed the liquid provided from said reservoir to said delivery mouth; characterized in that it comprises furthermore: a sensor configured to measure an operating parameter P of said machine, selected from the group consisting of: level of liquid P.sub.1 residual in the reservoir, actual flow-rate P.sub.2 of the liquid from said reservoir towards said delivery mouth simultaneously to the pulses, speed P.sub.3 of said machine relatively to said surface, or a combination thereof; a control unit arranged to receive from said sensor a signal proportional to said operating parameter P and configured to adjust said adjustment element responsive to said operating parameter P, in order to pulse-feed said liquid with a duty cycle t%, expressed as a ratio between the duration of a pulse of the pulse-feed step and the time between two consecutive pulses, determined according to a predetermined function t%=f(P) of optimization of the flow-rate, wherein said function f(P) is selected from the group consisting of:
t%=f(P.sub.1)=K.sub.1*P.sub.1.sup.1/2(1)
t%=f(P.sub.2)=K.sub.2*P.sub.2.sup.1(2)
t%=f(P.sub.3)=K.sub.3*P.sub.3(3).

2. Surface treatment machine according to claim 1, wherein said operating parameter P is a measurement of the level of liquid present in said reservoir, and said sensor is a sensor of a value P.sub.1 proportional to said level of liquid present in said reservoir and said function f(P) is a function f(P.sub.1) of optimization of the flow-rate calculated on said value P.sub.1, said sensor selected from the group consisting of: a pressure sensor communicating with said reservoir and arranged to provide a signal of pressure owing to a liquid head starting from the liquid surface of said reservoir; a force sensor which can be arranged to hold the weight of support elements of said reservoir; a level sensor which is located in said reservoir, and configured to measure the distance of the liquid surface of the liquid from a bottom wall or from a top wall of said reservoir.

3. Surface treatment machine according to claim 2, wherein said adjustment element is selected from the group consisting of: a piloted valve, wherein said control unit is configured to adjust an opening section in a pulse-feed way of said valve , with a predetermined duty cycle t%, by adjusting the time for opening said valve in an increasing way responsive to decrease of the level of liquid P.sub.1 according to said function f(P.sub.1); an adjustable pump, wherein said control unit is configured to cause the pump to pulse-feed the liquid, with a predetermined duty cycle t%, by adjusting a pulse-feed rate of said pump in an increasing way responsive to decrease of the level of liquid P.sub.1 according to said function f(P.sub.1).

4. Surface treatment machine according to claim 1, wherein said operating parameter P is a measurement of the flow-rate P.sub.2 of liquid that comes to said delivery mouth, and said sensor is a flow-rate sensor, which are located between said reservoir to said delivery mouth configured to provide a signal P.sub.2 proportional to said flow-rate, said function f(P) being a function f(P.sub.2) of optimization of the flow-rate calculated on said value P.sub.2, and said adjustment element is selected from the group consisting of: a piloted valve, configured to pulse-feed the liquid, with a predetermined duty cycle t%, wherein said control unit is configured to adjust said duty cycle t% according to said function f(P.sub.2); an adjustable pump, configured to pulse-feed the liquid, with a predetermined duty cycle t%, wherein said control unit is configured to adjust a pulse-feed rate of said pump according to said function f(P.sub.2).

5. Surface treatment machine according to claim 1, wherein said operating parameter P is a measurement of the translation speed of said frame with respect to said surface to treat, wherein said sensor is a speed sensor configured to provide a value P.sub.3 proportional to said speed and said function f(P) is a function f(P.sub.3) of optimization of the flow-rate calculated on said value P.sub.3, said adjustment element selected from the group consisting of: a piloted valve, wherein said control unit is configured to pulse-feed the liquid, with a predetermined duty cycle t%, by adjusting the opening said valve with duty cycle t% increasing responsive to an increase of said speed according to said function f(P.sub.3); an adjustable pump, wherein said control unit is configured to pulse-feed the liquid, with a predetermined duty cycle t%, wherein said control unit is configured to adjust a pulse-feed rate in an increasing way responsive to an increase of said speed according to said function f(P.sub.3).

6. Surface treatment machine according to claim 5, wherein said frame is configured to translate with respect to said surface to treat by means of wheels, and said sensor configured to provide a value P.sub.3 proportional to a speed of said machine is an encoder arranged to measure the speed of one of said wheels.

7. Surface treatment machine according to claim 5, wherein said frame is configured to translate with respect to said surface to treat operated by a motor, and said sensor configured to provide a value P.sub.3 proportional to a speed of said machine is a sensor configured to measure the pulse-width modulation (PWM) of said motor.

8. Surface treatment machine according to claim 2, wherein said operating parameter P is a combination of a measurement P.sub.3 of the translation speed of said frame and of a measurement Pi of the level of liquid present in said reservoir or of a measurement P.sub.2 of the flow-rate of liquid that comes to said delivery mouth, said function f(P) configured to maximize the range of the machine of said machine starting from settings of said machine given by the nature of said surface and/or by environmental conditions, said range of the machine being calculated as residual time or residual surface that can be treated by said machine before replenishment of liquid in said reservoir.

9. Surface treatment machine according to claim 1, wherein said control unit is associated with a display unit of said operating parameter and of a value of range of the machine calculated on the basis of instant values of said function f(P), said range of the machine being calculated as residual time or residual surface that can be treated by said machine before replenishment of liquid in said reservoir.

10. A method of treatment of surfaces, comprising the steps of: translating a surface treatment machine with respect to a surface to treat, said machine having a surface treatment element connected to a frame; feeding, at said surface treatment element, a treatment liquid, so that said surface treatment element treats with said liquid said surface during said translating; said treatment liquid being drawn from a reservoir connected to said frame, in order to provide said liquid to said surface treatment element through a delivery mouth; adjusting said delivery of liquid provided from said reservoir to said delivery mouth; characterized in that it comprises furthermore: measuring by a sensor an operating parameter P of said machine, selected from the group consisting of: level P.sub.1 of residual liquid in the reservoir, actual flow-rate P.sub.2 of the liquid from said reservoir towards said delivery mouth, speed P.sub.3 of said machine relatively to said surface, or a combination thereof; wherein said adjusting is carried out on the basis of a signal proportional to said operating parameter P and of said adjustment element responsive to said operating parameter P, in order to pulse-feed said liquid with a duty cycle t%, expressed as a ratio between the duration of a pulse of the pulse-feed step and the time between two consecutive pulses, determined according to a predetermined function t%=f(P) of optimization of the flow-rate, wherein said function f(P) is selected from the group consisting of:
t%=f(P.sub.1)=K1*P.sub.1.sup.1/2(1)
t%=f(P.sub.2)=K.sub.2*P.sub.2.sup.1(2)
t%=f(P.sub.3)=K.sub.3*P.sub.3(3).

11. Surface treatment machine according to claim 2, wherein the force sensor is a load cell.

12. Surface treatment machine according to claim 2, wherein the level sensor is selected from the group consisting of: an optical sensor or ultrasonic pulse sensor or floating sensor.

13. Surface treatment machine according to claim 4, wherein the flow-rate sensor is a flow meter or liter-counter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The invention will be now shown with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:

[0055] FIG. 1 shows a block diagram of a generic surface treatment machine according to the prior art;

[0056] FIG. 2 shows a block diagram of a generic surface treatment machine according to the invention;

[0057] FIG. 3 shows a block diagram of a first exemplary embodiment of the invention;

[0058] FIG. 4 shows a block diagram of a second exemplary embodiment of the invention;

[0059] FIG. 5 shows a block diagram of a third exemplary embodiment of the invention;

[0060] FIG. 6 shows a block diagram of a fourth exemplary embodiment of the invention.

DETAILED DESCRIPTION OF SOME EXEMPLARY EMBODIMENTS

[0061] As shown in FIG. 1, a surface treating machine, whose diagrammatical general view is known and indicated as 1, comprises a frame 11 configured to translate with respect to a surface 12 to treat.

[0062] The translation, in a in the direction of arrow 2, can be carried out by pushing, through a handlebar or through separate handles (not shown), or in a motorized way, through wheels or tracks (not shown), and the machine can be of ride-on type and of walk-behind type. Surface 12 to treat can be a floor but can also be vertical, as windows or vertical walls, moved on vertical guides or through lifting platforms (not shown).

[0063] Machine 1 comprises a surface treatment element 13 connected to the frame 11 and configured to treat with liquid surface 12 with respect to which the frame 11 advances.

[0064] The surface treatment element, indicated generally as block 13, can be a rotating brush or other brush element, as well as can be a vibrating pad or other treatment element, for example a spray liquid distributor. A motor can be provided or other actuating element 13a for actuating a connecting element 13b linked to the surface treatment element 13, for example a rotating shaft.

[0065] Furthermore, machine 1 comprises a reservoir 14 connected to the frame 11 and arranged to provide liquid to surface treatment element 13 through a delivery mouth 15. It is then provided an adjustment element 16 arranged to feed adjustably the liquid supplied from reservoir 14 to delivery mouth 15, and located between two branches 15a and 15b arranged for feeding the liquid from reservoir 14 to delivery mouth 15.

[0066] The treatment liquid in reservoir 14 can be water, water with detergent, pure detergent, or other treatment liquid, for example protecting film, coating film, etc. A further reservoir of chemical detergent can also be provided to mix with the water before the delivery (not shown).

[0067] The adjustment element indicated generally with block 16 can be a valve or a pump. It can be simply an On/Off device or an adjustable device, for example an adjustable tap valve. The adjustment element is of pulse-feed type, with a predetermined duty cycle t%.

[0068] In FIG. 1 a collection element 17 is also shown, for example a wiper or so-called squegee associated with a suction device, which drains, as machine 1 progressively moves in the direction of arrow 2, the surplus treatment liquid 18 that soaks surface 12. Collection element 17 is connected hydraulically to a container 19 arranged for collecting residual liquid and possible dirt.

[0069] Collection element 17 can also be missing in certain models of machine.

[0070] As shown in FIG. 2, according to the present invention, a surface treatment machine 10, starting from surface treatment machine 1 of FIG. 1, is modified in order to comprise an adjustment element 26 arranged to feed adjustably the liquid supplied by reservoir 14 to the delivery mouth. The adjustment element 26 can be, for example, an adjustment valve electrically, or an electric pump with adjustable speed, of liquid pulse-feed type according to a predetermined duty cycle t%, which is the average ratio between the duration of a pulse of the pulse-feed step and the time between two consecutive pulses.

[0071] Furthermore, it comprises a sensor 20 configured to measure an operating parameter P of the machine, selected from the group consisting of: level of residual liquid in reservoir 14, liquid flow-rate from reservoir 14 towards delivery mouth 15, translation speed of the machine relatively to surface 12, or a combination thereof. Furthermore, it comprises a control unit 30 arranged to receive from sensor 20 a signal proportional to operating parameter P and configured to set the adjustment element 26 responsive to operating parameter P, in order to pulse-feed the liquid with a duty cycle t% according to a predetermined function f(P) of optimization of the flow-rate for maximizing the range of the machine.

[0072] With reference to FIG. 3, operating parameter P can be a measurement of the level of liquid present in reservoir 14. In this case, the sensor is, for example, a sensor 21 of a value P.sub.1 which is relative to the amount of liquid present in reservoir 14. In this case, the duty cycle t% would be

t%=f(P.sub.1)=K.sub.1*P.sub.1.sup.1/2(1)

i.e. proportional to the reciprocal of the square root of the level.

[0073] For example, value P.sub.1 which is relative to the amount of liquid present in reservoir 14 is a pressure value, and sensor 21 is a pressure sensor arranged to provide a signal of pressure P.sub.1 that is communicating with a lower portion of reservoir 14. Such pressure sensor 21 is a sensor of the hydrostatic pressure directly related to the level of liquid surface 14a.

[0074] In this case, the adjustment element 26 is selected from the group consisting of: [0075] a piloted valve, where control unit 30 is configured to adjust an opening section in a pulse-feed way of said valve with a duty cycle t% in an increasing way responsive to decrease of pressure P.sub.1 according to function f(P.sub.1); [0076] a pump, where control unit 30 is configured to adjust the flow-rate of the pulse-feed pump in an increasing way responsive to decrease of pressure P.sub.1 according to function f(P.sub.1).

[0077] Such function can be, as shown above, an analytical function, which allows to calculate an adjustment parameter for each value of operating parameter P.sub.1. Or it can be a table of values that associates to each pressure P.sub.1, progressively decreasing, an adjustment parameter, for example an opening parameter, progressively increasing, of the piloted valve, or a number of turns, progressively increasing, of the pump.

[0078] Measuring the level P.sub.1 is directly related to the volume of residual liquid, responsive to the geometry of the reservoir. This allows also to calculate the volume of residual liquid and then the range of the machine, versus volume. Such volume value can be advantageously, displayed on the machine, as useful information for operator. Owing to function f(P) the operator can then manage the residual range of the machine.

[0079] Alternatively, sensor 21 is a force sensor, for example a load cell, for example located under reservoir 14, or arranged to hold the weight of support elements of reservoir 14, capable of measuring instantly the weight of the reservoir, which changes from a value of weight equal to reservoir 14 full to a value of weight equal to reservoir 14 empty. The weight of the residual liquid is easily related both to the amount of residual liquid, useful as value of range of the machine, and to the level, for determining the adjustment parameter. Then, once determined the initial level from the measured weight, it is possible to calculate the formula (1) above indicated.

[0080] As further alternative embodiment, sensor 20 can be, in a way not shown, a level sensor, for example optical sensor, ultrasonic pulse sensor, electromagnetic, mechanical floating sensor located above or in the reservoir, and that is configured to measure the distance of the liquid surface 14a of the liquid from the upper wall of reservoir 14.

[0081] Also in the latter two cases, responsive to a decrease of the weight of the reservoir or the level in the liquid surface 14a, function f(P.sub.1), in analytical form (1) or implemented as table, it provides increasing values of the adjustment parameter, i.e. of the duty cycle of the pulse-feed step, for each flow-rate value of liquid. Such flow-rate value can also be referred to a specific flow-rate, i.e. volume of liquid supplied for each surface unit covered by the machine.

[0082] In the exemplary embodiment of FIG. 4, operating parameter P is a direct measurement of the flow-rate of liquid that is supplied to delivery mouth 15, and the sensor is a flow-rate sensor 22, for example a flow meter, which is arranged in a portion of duct between reservoir 14 to delivery mouth 15, and provides a signal P.sub.2 proportional to the flow-rate, and the adjustment element 26 is selected from the group consisting of: [0083] a piloted valve, where control unit 30 is configured to adjust an opening section of the valve in closed loop feedback of liquid pulse-feed type, with a predetermined duty cycle t%, according to a function f(P.sub.2); [0084] a pump, where control unit 30 is configured to adjust the speed of the pump 26 of liquid pulse-feed type, with a predetermined duty cycle t%, in closed loop feedback according to function f(P.sub.2).

[0085] Function f(P.sub.2) can be expressed as:

t%=f(P.sub.2)=K.sub.2*P.sub.2.sup.1(2)

where the flow-rate P.sub.2 is the flow-rate during feeding pulses.

[0086] In other words a pulse-feed rate is carried out as a succession of instants in which there is a measurable flow-rate and instants where the flow-rate is still, i.e. it is substantially the same as zero, and value P.sub.2 is the flow-rate determined from the flow-rate sensor 22 when there is delivery, and the longer the duration of the pulse of delivery, with respect to the time between two pulses, the lower is the instantaneous flow-rate during feeding pulses.

[0087] This way, if for example the level in the reservoir decreases, owing to the hydrostatic pressure also the instantaneous flow-rate decreases, and then the duty cycle of the valve or the pump of pulse-feed type increases.

[0088] Then, control unit 30 has in memory a flow-rate threshold value, receives the actual flow-rate signal from the flow-rate sensor 22, then compares it with the flow-rate threshold value, and if the actual flow-rate signal is lower, it provides an adjustment parameter, such as an increased duty cycle of the piloted valve, or of the pulse-feed pump.

[0089] As shown in FIG. 5, operating parameter P can be, alternatively, a value P.sub.3 proportional to a translation speed of the frame 11 with respect to surface 12 to treat. In this case, the sensor is a speed sensor 23 configured to provide a value P.sub.3 proportional to the speed, the adjustment element 26 can be selected from the group consisting of: [0090] a piloted valve, where control unit 30 is configured to adjust an opening section of the liquid pulse-feed type valve, with a predetermined duty cycle t%, in an increasing way responsive to an increase of the speed according to a function f(P.sub.3); [0091] a pulse-feed pump with a predetermined duty cycle t%, where control unit 30 is configured to adjust the duty cycle of the pulse-feed pump in an increasing way responsive to an increase of the speed according to function f(P.sub.3),

[0092] wherein function f(P.sub.3) can be expressed as:

t%=f(P.sub.3)=K.sub.3*P.sub.3(3)

[0093] In this embodiment, the frame 11 is configured to translate with respect to surface 12 to treat by means of wheels 40, and sensor 23 configured to provide a value P.sub.3 proportional to a translation speed of the machine can be an encoder arranged to measure the speed of one of wheels 40.

[0094] For example, the higher the speed, function f(P.sub.3), in the form of table or analytical function, provides increasing values of the adjustment parameter, in order to keep constant the amount of supplied liquid versus treated surface.

[0095] The translation can be carried out by pushing or in a motorized way. Such solution with encoder 23 on one of wheels 40 adjusts precisely the delivery of the treatment liquid even with translation by pushing, which can be particularly irregular, since that, with respect to a driven translation, the operator in a difficult way can keep a constant value of the speed.

[0096] In case of driven translation, as diagrammatically shown in FIG. 6, the frame 11 is configured to translate with respect to surface 12 to treat operated by a motor 50. Alternatively to the encoder described of FIG. 5, the sensor, in the case of FIG. 6, can be an amperometric sensor 24 arranged to measure, as parameter P.sub.3 proportional to the speed, the pulse-width modulation (PWM) of the motor 50. Even in this case, the higher the driving current, function f(P.sub.3), in the form of table or analytical function, provides increasing values of the adjustment parameter, in order to keep constant the amount of supplied liquid versus treated surface.

[0097] Operating parameter P can also be a combination of a measurement P.sub.3 of the translation speed of the frame 11 and of a measurement P.sub.1 of the level of liquid present in reservoir 14 or of a measurement P.sub.2 of the flow-rate of liquid that is supplied to delivery mouth 15. In this case, function f(P) can be responsive to maximization of the range of the machine starting from settings of the machine given by the nature of the surface and/or by environmental conditions.

[0098] According to a further exemplary embodiment not shown in the figures, control unit 30 can be associated with a display unit of the operating parameters and of a value of range of the machine calculated on the basis of instant values of function f(P).

[0099] The adjustment element 26 of FIG. 2 can be a valve, for example a piloted valve, and reservoir 14 arranged with respect to delivery mouth 15 for delivering liquid to surface treatment element 13 by gravity through the adjustment valve 26. In this case, the control of level or flow-rate is essential to ensure an amount of liquid supplied that is constant, since the feeding by gravity is extremely affected by variation of level in the water reservoir.

[0100] In particular, the operator can set a value of range of the machine so that up to the next replenishment the flow-rate of liquid is constant and all the liquid present in the reservoir is used.

[0101] The foregoing description of specific exemplary embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.