EP2906925A1

EP2906925A1 - Determining the soiling of a workpiece

Info

Publication number: EP2906925A1
Application number: EP13777254.7A
Authority: EP
Inventors: Hermann-Josef David; Egon KÄSKE
Original assignee: Duerr Ecoclean GmbH
Current assignee: Ecoclean GmbH
Priority date: 2012-10-10
Filing date: 2013-10-09
Publication date: 2015-08-19
Also published as: WO2014057009A1; US20150211976A1; DE102012218489A1; CN104718443A; IN2015DN01977A

Abstract

The invention relates to a means (150) for determining the soiling of a workpiece (108). The means contains a device (155) for capturing dirt particles contained in a characteristic liquid volume on a filter diaphragm (158), said dirt particles being introduced into a liquid when the workpiece (108) is subjected to the action of the liquid. In the means (150) there is a system (169) for analysing the dirt particle load, captured by the filter diaphragm (158), from the liquid. The system (169) for analysing has an analysing means (170) connected to a computer unit (202), wherein the flat filter diaphragm (158) is in the form of a band and can be moved at least sectionally relative to the analysing means (170) by means of a transport device (160). The computer unit (202) connected to the analysing means (170) is used to determine dirt particle measured value (M) in the form of the type and/or number and/or size and/or size distribution of dirt particles (166) accumulated on the section (174) of the filter diaphragm (158).

Description

Description: The invention relates to a device for detecting contamination of a workpiece, having a device for collecting dirt particles received in a characteristic liquid volume on a filter membrane, which are introduced into the liquid by applying a liquid to the workpiece, and a system for analyzing the particulate matter collected from the filter membrane from the liquid.

Moreover, the invention also relates to a cleaning device for cleaning workpieces, which contains a device for determining the contamination of a workpiece, and a method for cleaning workpieces in a cleaning system.

Dirt particles, in particular Spangut, dust, cast sand, salt residues or even liquid droplets can perform the function of industrially produced products, such as e.g. Injectors for internal combustion engines or oil passages in crankshaft housings for internal combustion engines affect. The cleanliness of workpieces in industrial production processes is therefore of great importance. In industrial manufacturing plants, therefore, the cleanliness, purity and contamination of workpieces must be systematically checked regularly. Checking for cleanliness or contamination is especially important before intermediate and final assembly of dirt-sensitive workpieces.

From WO 2012/045582 A1 a device for determining the contamination of workpieces is known, in which a workpiece can be rinsed with a fluid to close from a dirt particle load in this fluid to a degree of contamination for the workpiece. The object of the invention is to provide a device for determining the contamination of workpieces, which can be integrated into a cleaning system for workpieces and provides the measured variables that enable the monitoring and control and / or rules of the cleaning system.

This object is achieved by a device for determining the contamination of a workpiece of the type mentioned, in which the system for analyzing a connected to a computer unit analysis device, wherein the flat filter membrane is designed as a displaceable band, which by means of a transport device at least can be moved in sections relative to the analysis device, and wherein the computer unit connected to the analysis device for determining a dirt particle measured variable (M) in the form of type and / or number and / or size and / or size distribution for attached to the portion of the filter membrane Dirt particles are used.

The analyzing device can contain a scanner for analyzing the dirt particles collected on the filter membrane, which scanner detects a course of the surface of the filter membrane with dirt particles deposited thereon, preferably by scanning with a laser beam. A computer unit connected to the scanner can then be used to deduce from the scanning signal of the scanner a number and / or size and / or size distribution of dirt particles deposited on the filter membrane.

Preferably, the analysis device has a camera for the optical detection of a portion of the filter membrane with dirt particles arranged thereon, wherein the computer unit determines the dirt particle measured variable (M) by means of image processing. In this case, the computer unit is designed for comparing the determined contaminant particle measured variable (M) with a predefinable threshold value (S) and connected to a visualization device. Thus, for example, an image of the section of the filter membrane of the visualization device of an operator of a cleaning system recorded with reflected-light illumination and / or dark-field illumination can be displayed if the determined dirt particle measured variable (M) for dirt particles deposited on the section of the filter membrane reaches the predefinable threshold value (S). exceeds.

The device contains a first illumination device for providing transmitted light illumination for the section of the filter membrane that can be detected by the camera and has a second illumination device for providing incident illumination and / or dark field illumination for the section of the filter membrane that can be detected by the camera. The computer unit may then be e.g. calculate an integral brightness value (I) from at least one image of a section of the band-shaped filter membrane taken with the camera under incident illumination, in order to then display this as a degree of gloss of a dirt particle load deposited on the section.

The camera preferably has optics that receive a portion of the filter membrane at a suitable magnification. The lighting devices in the device can here be equipped with different light sources depending on the analysis target.

It is also an idea of the invention that the computer unit compares the determined dirt particle measured variable (M), such as the number of dirt particles and / or the determined size of the dirt particles and / or the determined size distribution, with a reference, eg a threshold value (S). or a reference distribution. The computer unit can then also, for example, a captured with incident illumination and / or dark field illumination image of the corresponding section of the filter membrane to a visualization device for display when the determined number of dirt particles, the determined size of the dirt particles, the determined size of the dirt particles on the portion of the band-shaped filter membrane, the reference, eg the threshold value or the determined size distribution of the Reference distribution deviates.

The band of the filter membrane may be an endless filter band. Here, it is advantageous if the device comprises a device for removing a dirt particle load deposited on the endless filter belt after being analyzed in the system.

In order to continuously move the band-shaped filter membrane, a transport device is provided in the device.

The filter membrane may e.g. be made of a fabric of polyethylene terephthalate (PET). The filter membrane has as far as possible a filter fineness matched to a desired analysis and is preferably combined with further auxiliary substances, e.g. Litmus coated and / or treated with one or more auxiliary substances.

The system for analyzing particulate matter collected by the filter membrane may also include means for aligning magnetizable particulate matter disposed on the filter membrane by generating a magnetic field.

In that the filter membrane is coated at least in sections with a substance which changes a physical and / or chemical property when it comes into contact with liquid used to pressurize the workpiece, depending on the chemical composition of the liquid, in particular the pH of the liquid; is it possible that Consistency of the liquid used in the device for applying a workpiece to monitor.

The device for capturing a volume of dirt particles taken up in a fluid volume in a device according to the invention may include a filter station through which the band-shaped filter membrane is guided for receiving dirt particles. The filter station in this case has a main body with a supply channel for the supply of fluid laden with dirt particles and has an attachable to the body counter body, with a formed in the base body and / or in the counter body recess when applying the counter body to the main body a filter chamber defined, which is divided by the flat filter membrane in a body-side portion and a gegenkörpersei- term section. The filter chamber can be selectively opened and closed by relative movement of the counter body and the base body. The mating body then has a discharge channel connected to a suction line for the suction of fluid through the filter membrane from the filter chamber. In this case, the device preferably includes a pressure sensor for detecting a suction pressure (P) in the suction line which depends on the amount of dirt particle load deposited on the filter membrane.

In order to ensure that the fluid volume guided through the filter station can be subjected to a static pressure, it is favorable if the recess formed in the base body and / or in the counterpart body is sealed and, e.g. is surrounded by a sealing means which seals the filter chamber in case of the counter body on the base body. The sealing effect can e.g. be achieved by a positive fit seat or with a sealant, e.g. an O-ring.

According to the invention, the flat, preferably band-shaped filter membrane is in the open filter chamber on the counter body and is then through an air gap separated from the body. This measure ensures that no dirt particles deposited on the side facing the main body are scraped off in the filter station when the band-shaped filter membrane is displaced

According to the invention, the device for determining the contamination of a workpiece can be designed both as a stationary system and as a mobile system which can be displaced in a production device, e.g. to sample contamination of workpieces in an industrial production process.

The device for collecting a particulate matter load received in a fluid volume may be integrated into a cleaning system having at least one cleaning station containing a device for determining an input contamination of a certain number of workpieces, a single workpiece or a section of a workpiece Purification station are supplied and / or for determining a residual contamination of a certain number of workpieces, a single workpiece or a portion of a workpiece that have been cleaned in the cleaning station.

A cleaning system according to the invention has at least one cleaning station and contains a device for determining a contamination of a workpiece, which is supplied to the cleaning station. One idea of the invention is, in particular, to provide a computer unit in the cleaning system, which contains a computer program for the automatic determination of a blank value (B) for the dirt particles accommodated in the fluid volume of the fluid in a characteristic fluid volume.

The invention also extends to a method for setting the operating parameters (At) of a cleaning station in a cleaning plant. Here it is proposed to set the cleaning parameters on the one hand as a function of a determined blank value (B) of a device for determining the contamination of a workpiece and on the other hand as a function of a residual contamination (R) detected by the device from a cleaned workpiece.

With the device according to the invention, a trend analysis of the cleanliness values or residual contamination values of workpieces over long periods of time can thus be created in a cleaning system. This allows e.g. Statements about the operating state of the cleaning system and the state of cleaning fluid filters used in the cleaning system.

The invention proposes, in particular, for the cleaning of workpieces in a cleaning system, to continuously record the residual contamination (R) of the workpieces after cleaning and to increase the cleaning time for the workpieces supplied to the cleaning system in one or more cleaning stations of the cleaning system and / or a warning signal output when the residual contamination (R) detected for a cleaned workpiece exceeds a threshold value (S).

In the following the invention will be explained in more detail with reference to the embodiment shown schematically in the drawing. Show it:

1 shows a cleaning system with several cleaning stations with a device for analyzing the contamination of workpieces and with a control computer. FIG. 2 shows a section of the device for analyzing the contamination of workpieces with a filter station; FIG.

Fig. 3 is a perspective view of the filter station; and

Fig. 4 is a partial section of the filter station.

The cleaning system 100 shown in Fig. 1 is mounted in a production line (not shown) for articles, e.g. integrated a production line for internal combustion engines for use in a motor vehicle. For the cleaning of workpieces 102, 104, 106, 108, 1 10 the plant has 100 cleaning stations or cleaning sections 1 12, 1 14, 1 16. In the cleaning stations or cleaning sections 1 12, 1 14, 1 16, the workpieces with a liquid cleaning fluid, such as provided with cleaning additives water. In the plant 100, there is a conveyor 107, with which the workpieces 102, 104, 106, 108, 1 10 can be automatically moved by the cleaning stations 1 12, 1 14, 1 16 in the direction of the arrows 1 15. In the cleaning station 1 12 spray nozzles 1 18 are formed.

The spray nozzles 18 are a cleaning device for applying cleaning fluid 120 to the workpiece 104 arranged in the cleaning station 112. A collecting container 122 is provided for the cleaning fluid 120. The dirt particles washed off the workpiece 104 by the cleaning fluid come together when the workpiece 104 is cleaned with the cleaning fluid 120 in the collecting container 122. The cleaning station 1 14 has an immersion bath 124, in which a workpiece 106 can be moved with a manipulator device 125. In the cleaning station 1 16, a workpiece 108 can be cleaned with cleaning fluid in the form of cleaning fluid 132, which is guided by a circulation pump 134 from a collecting container 136 through a line system 138 to spray nozzles 140. The plant 100 includes a stationary or mobile device 150 for determining fouling of a workpiece 108 before it is cleaned in the cleaning station 16. In the device 150, both the fouling of the surface 153 of the workpiece 108 and the fouling in a portion 152 in the interior of the workpiece 108 can be determined. The portion 152 of the workpiece 108 may be, for example, an oil passage in a crankcase for an internal combustion engine. For this purpose, the device 150 can be connected to the section 152 of the workpiece 108 via a line branch 141, 142 by means of adapter pieces 144, 146.

In this case, the workpiece 108 is clamped between the adapter pieces 144, 146 in such a way that a tight connection between the line and the workpiece 108 results in the line branch 141, 142, through which the cleaning fluid 132 is supplied and removed.

The device 150 has a buffer tank 154, which communicates with the line branch 138, 141, 142. The buffer container 154 is connected to a filter station 156 in a device 155 for collecting a dirt particle load received in a fluid volume through which a band-shaped filter membrane 158 is movably guided. For this purpose, the band-shaped filter membrane 158 is unwound from a belt roll 162 while being rolled onto a driven belt roll 160 acting as a transport device.

In a modified alternative embodiment of the cleaning system, the filter membrane band 158 can also be designed endlessly. After analysis of the collected particulate debris, the filter membrane tape 158 in the apparatus 155 is then subjected to a cleaning step in the contaminated areas and then reused to collect particulate matter in the scrubber.

Thus, the device 150 has the ability to detect a base contamination (the blank value) due to a cleaning and cleaning of the lines. automatically determine the transport fluid inherent particulate matter load. If the measured blank value does not meet the specifications, the rinsing process (without workpiece) is repeated - preferably automatically - until the blank value has been reached.

In order to analyze the contamination of the section 152 of the workpiece 108, it is rinsed for a defined time interval Δt in a rinsing process with cleaning liquid, which is freed of dirt particles in a filter device 164 arranged in the line branch 141.

As it flows through the section 152 of the workpiece 108, the filtered cleaning fluid 132 absorbs dirt particles 166, which are guided through the buffer tank 154 to the filter station 156. The dirt particles 166 are retained on a portion of the filter membrane strip which is penetrated by the cleaning fluid 132 in the filter station 156, when the grain size thereof is greater than the microscopic passage openings formed in the band-shaped filter membrane 158. It should be noted that, according to the invention, the filter fineness or the filter efficiency for the filter membrane strip is set in the cleaning system in such a way that, if possible, only the dirt particle load regarded as polluting is collected.

In order to return the cleaning fluid 132 passing through the belt-shaped filter membrane 158 into the collecting container 136, there is a suction pump 168 in the device 150, which sucks the cleaning fluid 132 from the filter membrane 158 through a suction line 167. In this connection, it should be noted that the device 150 in a modified embodiment may also have a fluid circuit that is separate from the fluid circuit of a cleaning station in the cleaning system 100.

The device 150 includes a system 169 for analyzing particulate matter discharged from the belt-shaped filter membrane 158 in the FIG Filter station was recorded. The system 169 has a camera 170. With the camera 170 with appropriate optics, the dirt particles deposited in the rinsing process on the workpiece can be digitally detected by the band-shaped filter membrane 158 with the dirt particles received in the filter station 156 in the direction of the arrow 171 is moved under the camera 170. The camera 170 includes an image sensor and has imaging optics. It acts as a microscope and enables a magnifying, analyzable visualization of the dirt particles on the band-shaped filter membrane 158. The camera 170 is assigned a first illumination device 172 with which transmitted light illumination can be set for a section 174 of the band-shaped filter membrane on which Dirt particles are located. In the system 169 there is further a second illumination device 176, which makes it possible to set incident illumination for the section 174 of the band-shaped filter membrane 158. It should be noted that the illumination device 176 may alternatively or additionally also be designed for setting a dark field illumination for the section 174 of the band-shaped filter membrane 158. Under a dark field illumination of the section 174 is understood to mean a lighting in which the illumination light irradiates the section 174 so that the camera 170 detected by its objective lens no directly reflected by the band-shaped filter membrane and dirt particles thereon illumination light, but only receives illumination light, the is bent at the band-shaped filter membrane and deposited thereon dirt particles.

FIG. 2 shows a section of the device 150 for determining the contamination of workpieces or workpiece sections with the filter station 156. The filter station 156 has a main body 178 with a feed channel 180 which communicates with the buffer container 154. 3 is a perspective view of the filter station 156. The filter station 156 has a displaceably arranged counter body 182, which in the direction of the double arrow 184 relative to the base body 178 with a hollow shaft drive unit 186 can be moved in a linear guide device 187. The Filtermennbranband 158 is guided with a guide means 185 between the base body 178 and the counter body 182.

As can be seen in FIG. 4, the main body 178 has a funnel-shaped recess 190. The counter body 182 has a funnel-shaped recess 192. By displacing the counter body in the direction of the double arrow 184, the counter body 182 can be applied to the base body 178 to thereby define a filter chamber passing through the filter membrane belt 158 into a base body side portion 194 and a counter body side Section 196 is shared. By moving the counter body 182 in the direction of the double arrow 184 with respect to the main body 178, this filter chamber can optionally be opened and closed. The mating body 182 has a drainage channel 188 for draining fluid 132 that has passed through a portion of the filter membrane tape 158 in the direction of the arrow 189.

By heavily contaminated with dirt load cleaning fluid 132, the filter membrane tape 158 clog during the analysis. With a pressure sensor 159 connected to the computer unit 202, the suction pressure in the suction line 167 is controlled. With a computer program stored in the computer unit 202, this makes it possible to draw conclusions about the condition and the occupancy of the filter membrane 158.

The funnel-shaped recess 192 of the counter body 182 is surrounded by an O-ring 198 acting as a sealant, which seals the filter chamber to the side when the counter body 182 rests against the base body 178.

In a modified exemplary embodiment, the base body 178 and the counterbody 182 have a form-fitting one another at their contact surfaces. a tight fit, such as a round plan seat, conical seat or circular ring seat, whereby the filter membrane strip 158 is held and clamped and with which the filter chamber 194, 196 is formed. The filter membrane tape itself acts as a sealant in this embodiment.

When the filter chamber is open, the filter membrane strip with the side facing away from the main body 178 abuts against the counterbody 182. In this case, the filter membrane band 158 in the filter station 156 is separated from the main body 178 by an air gap 200, so that dirt particles deposited from the cleaning fluid 132 on the filter membrane band 158 in a rinsing process of the portion 152 of the workpiece 108 upon displacement of the Filter membrane bands 158 are not stripped by rotating the tape rolls 160, 162 on the way to the camera 170 on the base body 178.

The camera 170 is connected to a computer unit 202. The computer unit 202 is associated with a display device in the form of a monitor 204. The computer unit 202 controls the camera 170, the optics of the camera and the illumination devices 172, 176. For each rinsing process of a workpiece 108, the computer unit 202 effects digital recording of the dirt particles separated in the filter station 156 on the filter membrane band 158 with transmitted light illumination and with incident light and / or darkfield illumination. The computer unit 202 contains a computer program for image processing. With this computer program, the computer unit 202 determines from one or more images recorded with transmitted light illumination a dirt particle measured variable M in the form of type and / or number and / or size and / or size distribution for dirt particles 166 deposited on the section 174 of the filter membrane 158, which are separated on the filter membrane band 158 in a rinsing process in the filter station 156. Alternatively or additionally, the computer unit 202 can be used with this computer Program from one or more images that are done in incident light and / or dark field illumination, as dirt particle measure M also an integral value I for the image brightness determine. The computer unit 202 then compares the determined dirt particle measured variable M with a threshold value S. entered via an input interface 206.

If the determined dirt particle measured variable M exceeds the threshold value S, the computing unit 202 initiates the display of the image of the filter membrane band 158 detected by incident light and / or transmitted light illumination on the monitor 204 and additionally the integral value I for the image brightness displayed as a dirt particle gloss value. It should be noted that in a modified alternative embodiment of the cleaning system 100, the illumination device 176 is also provided with different light sources or a combination of different light sources from the group - light sources for generating daylight-like light -, light sources for generating ultraviolet light - - Light sources for generating infrared light, in particular for generating light pulses with wavelengths that are in the infrared spectral range -, may be equipped. Daylight systems are particularly well suited, for example, for transmitted light and reflected-light analyzes. The sensitivity of the camera in the cleaning system is matched to the spectral range of the light generated by the light sources in a lighting device. For example, ultraviolet light can be used to detect organic substances deposited on the filter membrane, in particular oil residues. Infrared light in conjunction with infrared cameras makes it particularly easy to detect metal particles deposited on the filter membrane. With infrared flash light heat pulses can be generated, which cause the rapid heating of metal particles. In the decay phase, these particles are long and easy to recognize with an infrared camera. The band-shaped filter membrane 158 in the cleaning system 100 may be formed as a polyethylene terephthalate (PET) fiber fabric or may contain a fiber fabric based on the material PET or containing the material PET.

The thread density and fiber thickness in the fibrous web are selected according to a filter efficiency required for the filter membrane band, i. according to the size of the dirt particles, which is to hold back the filter membrane.

The filter membrane band 158 is preferably coated and / or treated with chemical substances, for example with litmus. By detecting a discoloration of the filter membrane band, it is then possible to determine, for example, the pH value of the cleaning fluid 132 in the cleaning station 16. For this purpose, the type of discoloration is detected with the camera system and evaluated in the computer unit 202 in order to conclude the state of the cleaning fluid 132. In addition, it should be noted that in an alternative, modified embodiment of the cleaning system 100 for analyzing deposited on the filter membrane tape 158 dirt particles 166 may be provided under the filter membrane tape 158 arranged magnet. Magnetizable ferritic metal particles are then aligned by the magnetic field lines generated by the magnet. In order to determine the number and / or size and / or size distribution of the ferritic metal particles deposited on the filter membrane 158, the metal particles are detected with a camera and the camera image is then subjected to image evaluation in the computer unit 202 in order to obtain a characteristic orientation to recognize the metal particles and to analyze in the computer unit 202. In a further modified embodiment of the cleaning system 100, a computer unit 202 may also be provided, which contains a computer program for image processing. Here, the computer unit 202 determines the particle size spectrum of the dirt particles separated on the filter membrane band 158 in a rinsing process in the filter station 156 from one or more images recorded with transmitted light illumination with the computer program. From the particle size spectrum and the average particle size, other parameters then result, which are used to determine an improved threshold value S.

In a further modified embodiment of the cleaning system 100, it is provided to cover the surface 158 of the filter membrane tape with a scanner, in particular with a laser scanner. By line or raster-shaped scanning of the surface with a laser beam, an image of the filter surface geometry is then detected and used in a connected to the laser scanner computer unit 202 by means of a computer program on a dirt particle measured variable M as the size and / or number and / or closed the size distribution of accumulated on the filter membrane dirt particles. Here, e.g. any increase on the filter membrane greater than the filter surface roughness qualifies as localized contamination of the filter membrane.

It should be noted that in a modified embodiment of the cleaning system 100, a plurality of stationary and / or mobile devices for determining the contamination of a portion of a workpiece may be provided, for example, are assigned to different cleaning stations in the cleaning system and / or for the detection of Serve contamination of different sections of a workpiece. For example, a mobile device is particularly well suited for sampling. In addition, it should be appreciated that the means 150 for determining fouling of a portion of a workpiece 108 may also be configured to determine the number of debris deposited on the surface of the workpiece 108 by analyzing the debris load in a volume of fluid becomes, with which the surface of the workpiece was rinsed off. It is also possible to analyze the number of accumulated dirt particles in a fluid stream of a plurality of work pieces to obtain a value of an average dirt load of a work piece. In particular, in an alternative embodiment, workpiece contamination determination device 150 may also include a fluid circuit that is separate from a cleaning fluid circuit in a cleaning system.

The above-described device 155 for collecting a dirt particle load received in a fluid volume and the system 169 for analyzing a dirt particle load and determining the contamination of a workpiece 108 can in principle also be used outside a cleaning system 100. They are also suitable, for example, for integration into a production or assembly line in order to realize an automatic cleanliness analysis, eg an automatic cleanliness analysis for a so-called quality audit. The cleanliness analysis is particularly useful in a production or assembly line where pre-assembly or final assembly of workpieces takes place. This means that workpieces can be randomly checked at regular intervals in a production process. This then allows a master computer in a manufacturing plant to transmit an automatic batch record. With a cleanliness analysis, which takes place before the pre-assembly and final assembly of workpieces, it can be ensured that no soiled workpieces are installed. Thus, the invention is also suitable for use in a mounting line for the pre- or final assembly of complex systems, which are composed of several components. For controlling the cleaning processes for the workpieces 102, 104, 106, 108 in the cleaning sections or cleaning stations 1 12, 1 14, 1 16, the cleaning system 100 includes a control computer 208. The control computer also controls the conveyor for the workpieces in the cleaning Anläge 100 and allows the cleaning station 1 16 to be coupled to the device 150 for determining the contamination of a workpiece and thus to determine the contamination of a workpiece. The cleaning processes for workpieces in the cleaning stations or cleaning sections 1 12, 1 14, 1 16 are controlled by there different cleaning parameters in the form of pump pressure P and / or cleaning time At and / or valve positions are set for controlling the flow of cleaning fluid ,

The control computer 208 contains a computer program which enables an automatic setting of the operating parameters for the cleaning station or cleaning sections 1 12, 1 14, 1 16 and which ensures that the workpieces 1 12, 1 14, 1 16 cleaned in the cleaning system 100 satisfy a given cleanliness criterion. This computer program has a routine for determining the blank value B of the device 150 for detecting contamination from a workpiece 152. In order to determine the blank value B of the device, in the cleaning station 16, the cleaning liquid without a workpiece arranged therein is circulated in successive flushing processes ,

The cleaning fluid is guided through a pipe piece arranged between the adapter pieces 144, 146. Preferably, this piece of pipe has as little or no contamination. It thus forms a reference for an unpolluted workpiece. The dirt particles in the cleaning liquid circulated through the cleaning station or cleaning section 16 of the device 150 are then deposited on the filter membrane 158 for each rinsing process. By analyzing and quantifying the amount of dirt particles entrained in a volume of cleaning liquid used in a rinsing process in the device 150, the computer program then determines in the control computer 208 a value for the dirty particle load related to a single rinsing process. If this value is constant in successive rinsing processes without a workpiece arranged in the cleaning station, this value corresponds to the contamination inherent in each cleaning liquid volume in the cleaning station or in the cleaning section 16 of the installation, which can not be undershot (blank value).

In order to determine in the cleaning system 100 the cleaning parameters which are favorable for the cleaning of a workpiece, a workpiece to be cleaned is moved through the cleaning system 100 from a series of similarly soiled workpieces which are to be cleaned. The workpiece in the cleaning stations or cleaning sections 1 12, 1 14, 1 16 of the cleaning system 100 is cleaned with predetermined cleaning parameters for a certain period of time Ati. After each cleaning operation in a cleaning station 1 12, 1 14, 1 16 is completed, the cleaning result is then analyzed in the cleaning station 1 16 by means of the device 150 for determining the contamination of a workpiece 108 a residual contamination R of the corresponding workpiece. If this residual contamination R is greater than a threshold value S related to a specific cleaning station, the cleaning process in the relevant cleaning station is repeated for a defined additional period of time Δt ₂ and the cleaning result in the cleaning station or cleaning section 16 is repeated as described above checked. In this way, the computer program in the control computer 208 determines a value for a favorable cleaning time At _g = Σ, Δί _ί in the cleaning stations of the cleaning system 100 and thus cleaning parameters which ensure that when cleaning workpieces a certain residual contamination R is not exceeded.

When cleaning successive workpieces from a series of workpieces in the cleaning apparatus 100, a measurement of the residual contamination R of the workpiece is performed in the cleaning station 1 16 after completion of the cleaning operation by the apparatus 150 (trend analysis). If the computer program in the control computer 208 determines that the residual contamination detected thereby exceeds a threshold value S, then the cleaning time At in the cleaning system 100 for cleaning the workpieces in the cleaning stations 1 12, 1 14, 16 is raised accordingly. Alternatively, it is also possible that the computer program then outputs a warning signal to an operator of the cleaning system 100 via the control computer.

In particular, the following preferred features of the invention are to be noted: The invention relates to a device 150 for determining the contamination of a workpiece 108. The device comprises a device 155 for collecting dirt particles received in a characteristic volume of liquid on a filter membrane 158, which by applying the Workpiece 108 are registered with a liquid in the liquid. In the device 150, there is a system 169 for analyzing the collected from the filter membrane 158 dirt particle load from the liquid. The analyzing system 169 has an analysis device 170 connected to a computer unit 202, wherein the flat filter membrane 158 is designed as a band and can be moved by means of a transport device 160 at least in sections relative to the analysis device 170. The computer unit 202 connected to the analysis device 170 is used to determine a particle size of dirt (M) in the form of type and / or number and / or size and / or size distribution for dirt particles 166 deposited on the section 174 of the filter membrane 158. LIST OF REFERENCE NUMBERS

100 cleaning system

102, 104, 106, 108, 110 workpiece

1 12, 1 14, 1 16 cleaning station

1 15 arrow

1 18 spray nozzle

120 cleaning fluid

122 collection containers

124 dipping bath

125 manipulator device

132 Cleaning fluid, cleaning fluid

134 circulation pump

136 collection containers

138 pipe system

140 spray nozzle

141, 142 Line branch

144, 146 adapters

150 establishment

152 section

154 buffer tank

155 device

156 filter station

158 filter membrane

160, 162 tape roll, transport device

164 filter device

166 dirt particles

167 suction line

168 suction pump

169 system

170 camera

171 arrow 172 first illumination device (transmitted light)

176 second illumination device (reflected light)

174 filter denomination band section

178 basic body

180 supply duct

182 counterbody

184 double-headed arrow

185 guiding device

186 drive device

187 linear guide device

188 discharge channel

189 arrow

190 recess base body

192 recess counter body

194 Section Body

196 Section of the opposing body

198 O-ring, sealant

200 air gap

202 computer unit

204 monitor

206 input interface

208 control computer

Claims

Patent claims

1 . Device (150) for determining the contamination of a workpiece (108), with a device (155) for collecting dirt particles absorbed in a characteristic liquid volume on a filter membrane (158), which is activated by applying a liquid to the workpiece (108). the liquid is entered; and a system (169) for analyzing the dirt particle load from the liquid collected by the filter membrane (158); characterized in that the system (169) for analyzing has an analysis device (170) connected to a computer unit (202), the flat filter membrane (158) being designed as a displaceable band, which is at least partially relative by means of a transport device (160). can be moved to the analysis device (170), and wherein the computer unit (202) connected to the analysis device (170) is used to determine a dirt particle measurement variable (M) in the form of type and/or number and/or size and/or a Size distribution for dirt particles (166) deposited on a section (174) of the filter membrane (158).

2. Device according to claim 1, characterized in that the analysis device contains a scanner which detects a course of the surface of the filter membrane (158) with dirt particles (166) deposited thereon by scanning with a laser beam.

Device according to claim 1 or 2, characterized in that the analysis device has a camera (170) for optically detecting a section (174) of the filter membrane (158) with dirt particles (166) arranged thereon and the computer unit (202) has the dirt particle measurement variable (M) determined using image processing.

Device according to claim 3, characterized in that the computer unit (202) is designed for comparing the determined dirt particle measurement variable (M) with a predeterminable threshold value (S) and is connected to a visualization device (204) in order to provide, in particular, with incident light illumination and /or dark field lighting to display the image of the section (174) of the filter membrane (158) of the visualization device if the determined dirt particle measurement variable (M) for dirt particles deposited on the section (174) of the filter membrane (158) exceeds the predeterminable threshold value (p ) exceeds.

Device according to one of claims 3 or 4, characterized by a first lighting device (172) for providing transmitted light illumination for the section (174) of the filter membrane (158) that can be detected with the camera (170) and a second lighting device (176) for providing incident light illumination and/or dark field illumination for the section (174) of the filter membrane (158) that can be detected by the camera (170).

Device according to one of claims 3 to 5, characterized in that the computer unit (202) for calculating an integral brightness value (I) from at least one image of a section (174) of the band-shaped filter membrane (158) recorded with the camera (170) under incident light illumination ) calculated to use this as a gloss level of a dirt particle deposited on the section (174). to display freight.

Device according to one of claims 2 to 6, characterized in that the band of the filter membrane (158) is an endless filter band and a device for removing a dirt particle load deposited on the endless filter band after analysis is provided in the system (169). .

Device according to one of claims 1 to 7, characterized in that the filter membrane (158) is a PET fabric.

Device according to one of claims 1 to 8, characterized in that the system (169) for analyzing the dirt particle load collected by the filter membrane (158) contains a device for aligning magnetizable dirt particles arranged on the filter membrane (158) by generating magnetic field lines .

Device according to one of claims 1 to 9, characterized in that the filter membrane (158) is at least partially coated with a substance which, when in contact with the liquid used to act on the workpiece (108), depending on the chemical composition of the liquid, in particular depending on the PH value of the liquid, a physical and/or chemical property changes.

Device according to one of claims 1 to 10, characterized in that the device (156) for collecting a dirt particle load taken up in a fluid volume contains a filter station (158) through which the band-shaped filter membrane (158) for collecting dirt particles (166) is guided, the filter station (156) having a base body (178) with a supply channel (180) for supplying fluid loaded with dirt particles and has a counter body (182) which can be placed on the base body (178) and which has a recess (190) formed in the base body (178) and/or in the counter body (182). 192) when the counter body (182) is placed on the base body (178), a filter chamber is defined, which is divided by the flat filter membrane (158) into a section on the base body side and a section on the counter body side, the filter chamber being formed by relative movement of the counter body (182 ) and base body (178) can be selectively opened and closed, the counter body (182) having a discharge channel (188) connected to a suction line (167) for the suction of fluid through the filter membrane (158) from the filter chamber, and where a pressure sensor (159) is provided for detecting a suction pressure (P) in the suction line (167) which is dependent on the amount of dirt particle load deposited on the filter membrane (158).

Cleaning system (100) with at least one cleaning station (1 16) and with a device (150) designed in particular according to one of claims 1 to 1 1 for determining contamination of a workpiece (108) which is fed to the cleaning station (1 16).

13. Cleaning system (100) according to claim 12, characterized by a computer unit (208) which has a computer program for automatically determining a blank value (B) of the device (150) for determining contamination of a workpiece (108) via the characteristic Fluid volume of the liquid contains inherently absorbed dirt particles.

14. Method for setting at least one operating parameter (At) for at least one cleaning station (1 16) in a cleaning system (100) according to claim 12 or 13, in which depending on a determined blank value (B) of the device (150) for determining contamination of a workpiece (108) and depending on a residual contamination (R) detected by the device (150). a cleaned workpiece (108) in a computer unit (208) which determines at least one operating parameter (At) and to which at least one cleaning station (1 16) is output for setting the operating parameter (At).

15. A method for cleaning workpieces in a cleaning system (100) designed according to claim 12 or claim 13, in which the residual contamination (R) of the workpieces (108) in the device (150) is continuously recorded after cleaning and the cleaning time ( At) for the workpieces (108) fed to the cleaning system (100) is raised and/or a warning signal (W) is issued when the residual contamination (R) detected for a cleaned workpiece exceeds a threshold value (S).