FR3079429A1 - LIQUID APPLICATION DEVICE AND APPLICATION INSTALLATION - Google Patents

Abstract

A device (14) for applying a liquid, in particular paint or, preferably, glue, to a surface (40), comprises a liquid viscosity sensor (36a-36e) in the device. application (14) and an electronic control unit (46) operably connected to the viscosity sensor. The electronic control unit (46) allows the application of liquid by means of the application device (14) as long as the viscosity (V) determined by the viscosity sensor (36a-36e) is lower than a first value of reference (C). The electronic control unit (46) interrupts the application of liquid by means of the application device (14) when the viscosity (V) determined by the viscosity sensor (36a-36e) is greater than the first reference value (VS).

Description

LIQUID APPLICATION DEVICE AND APPLICATION INSTALLATION

Field of the invention

The present invention relates to a device for applying a liquid, in particular to a spraying device, and to an application installation comprising such an application device. The invention also relates to a method for implementing a device for applying a liquid, in particular in an application installation.

The application device can in particular be used to apply a liquid product such as paint or glue to a surface, in particular a surface of a piece of interior trim for a vehicle, in particular for a motor vehicle. .

Description of the prior art

In the automotive field, in particular, it is known to apply a liquid product, such as glue or paint, to a surface, in particular a surface of a piece of interior trim of a motor vehicle. The application of the liquid product can in particular be carried out by spraying.

Changing the viscosity of the liquid over time and climatic conditions is a known problem. In this case, in fact, the properties of the liquid can change so significantly that the liquid is no longer compatible with a spray application.

The spraying of glue, for example, depends on the degree of crosslinking and / or drying and curing of the glue. Depending on these parameters, in particular, the spraying of the adhesive may not be satisfactory and may have consequences on safety functions, such as the deployment of an airbag, for example.

However, conventionally, the measurement of the viscosity of a liquid is carried out "offline", that is to say outside the operation of the device allowing the application of the liquid product. In this case, the measurement of the viscosity of the liquid is carried out by implementing a rapid but relatively imprecise method.

Alternatively, the measurement of the viscosity of the liquid is carried out on one or more samples. The latter solution is however tedious and its result does not appear reliable. In particular, due to manipulation by an operator, significant variations may appear between the measurements of these samples.

Furthermore, it is known from application EP-A-0 878 230, a device making it possible to thicken or, on the contrary, to make a lacquer more fluid, depending on the viscosity measured. This device is however complex. In addition, by modifying the composition of the lacquer, this device also modifies its properties. In the case of a lacquer, it can notably be the covering power of this lacquer. Thus, the modification of the viscosity of the lacquer causes other problems for a user wishing to apply this lacquer.

Summary of the invention

The object of the present invention is to propose a device for applying liquid, in particular a device for spraying paint or, preferably, glue, which does not have the drawbacks of the prior art.

To this end, the invention provides a device for applying a liquid, in particular paint or, preferably, glue, to a surface, the application device comprising a sensor for viscosity of the liquid in the device. application and an electronic control unit operatively connected to the viscosity sensor, the electronic control unit authorizing the application of liquid by means of the application device as long as the viscosity determined by the viscosity sensor is lower than a first reference value, the electronic control unit interrupting the application of liquid by means of the application device when the viscosity determined by the viscosity sensor is greater than the first reference value.

Thus, advantageously, the user of the application device is prevented from using the application device when the liquid is too viscous and risks not allowing a satisfactory application.

The device according to the invention allows online control, during the operation of the liquid application device. Such control is more robust than known control methods, which involve a more important human factor. The device according to the invention makes it possible in particular to test the completeness of the liquid applied by means of the device.

In addition, the device according to the invention allows continuous monitoring of the viscosity of the liquid. This allows better control of the application of the liquid and limits the possible variations between different applications.

The device according to the invention also makes it possible to limit the costs of preventive cleaning while reducing the risks of application of an unsatisfactory liquid. This reduces the risk of obtaining unsatisfactory parts produced by the application of the liquid.

According to preferred embodiments, the application device according to the invention has one or more of the following characteristics, taken alone or in combination:

the electronic control unit commands an emission of an alert when the viscosity determined by the viscosity sensor is greater than a second reference value and less than the first reference value, the alert preferably being a light alert and / or a message on a display screen of the application device and / or a sound emission;

the liquid application device comprises at least one of an ambient air temperature sensor around the application device, an atmospheric pressure sensor around the application device, a pressure sensor measuring the liquid pressure in the application device and an ambient air humidity sensor around the application device;

the liquid application device comprises an application head, a pipe intended to put the application head in liquid communication with a container of liquid to be applied and, preferably, a container of liquid to be applied;

the device for applying a liquid comprises at least one of:

- a viscosity sensor in the application head, in particular in a nozzle of the application head;

- A viscosity sensor in the pipe, in particular in the vicinity of the end of the pipe intended to be fixed on the container of liquid and / or in the vicinity of the end of the pipe connected to the application head; and

- a viscosity sensor in the liquid container, if applicable;

the application head is a spray head provided with a spray nozzle, the application device being a spray device;

the viscosity sensor is a vibrating viscometer, in particular a viscometer with a resonance frequency; and the device for applying a liquid comprises a cleaning unit suitable for injecting a cleaning agent into the application device, in particular into the application head and / or into the pipe, if necessary, on command of the electronic control unit, when the viscosity determined by the viscosity sensor is greater than the first reference value or greater than the second reference value.

According to another aspect, the invention also relates to an installation for applying a liquid to a surface comprising:

- an application booth; and

- an application device as described above in all its combinations, inside the application booth.

According to yet another aspect, the invention relates to a method of implementing an application device as described above in all of its combinations or in an application installation as described above in all of its combinations , comprising the steps of:

- measure the viscosity of the liquid in the application device;

- interrupt the application of the liquid by means of the application device, in the case where the viscosity of the liquid is greater than the first reference value.

Preferably, the method further comprises a step consisting in: permitting the application of the liquid by means of the application device while emitting an alert for a user, in the case where the viscosity is lower than the first reference value and greater than the second reference value.

Brief description of the drawings

Other characteristics and advantages of the invention will emerge during the following description of a non-limiting example of embodiment, with reference to the accompanying drawings.

In the drawings:

FIG. 1 diagrammatically represents an example of an adhesive spraying installation provided with an adhesive spraying device, and

- Figure 2 is a flow chart of the operation of the glue spraying device of Figure 1.

Detailed description of the invention

In the various figures, the same references designate identical or similar elements. For the sake of brevity, only the elements which are useful for understanding the embodiments described are shown in the figures and are described in detail below.

FIG. 1 schematically illustrates an installation 10 for applying a liquid to a surface. In this case, it is for example an installation for spraying glue on a surface of a piece of interior trim of a vehicle. However, the following is valid for any installation for applying a liquid, in particular a paint, such as a lacquer, on a surface of a part. In addition, in the example, the adhesive is applied by spraying. However, the following applies to any installation for applying a liquid, even if it is not applied by spraying.

The installation 10 as illustrated in FIG. 1 essentially comprises a spray booth 12 and a spray device 14.

The spray booth 12 can be opened. However, the spray booth 12 is preferably closed. In particular, the spray booth 12 can be hermetically sealed to avoid any gaseous transfer between the interior of the spray booth 12 and the environment surrounding the spray booth.

12. In this case, a ducted ventilation circuit is provided which makes it possible to renew the air inside the spray booth 12. Such a spray booth thus makes it possible to isolate the interior of the spray booth 12 , where the spraying is carried out, from the outside of the spray booth 12. Such a spray booth 12 thus makes it possible to avoid the evaporation of products constituting the liquid to be applied, outside of the spray booth 12 Such products are, for example, solvents.

As illustrated, the spray booth 12 is here provided with three sensors, outside the spray booth 12:

a temperature sensor 16 for measuring the atmospheric temperature outside the spray booth 12;

a pressure sensor 18 for measuring the atmospheric pressure outside the spray booth 12; and a humidity sensor 20 for measuring the atmospheric humidity level outside the spray booth 12.

Alternatively or additionally, the spray booth 12 is provided with three sensors, inside the spray booth 12:

a temperature sensor 22 for measuring the atmospheric temperature inside the spray booth 12;

a pressure sensor 24 for measuring the atmospheric pressure inside the spray booth 12; and a humidity sensor 26 for measuring the atmospheric humidity level inside the spray booth 12.

Furthermore, the spraying device 14 essentially comprises a spraying head 28 provided with a spraying nozzle 30. In the example illustrated, the spraying device 14 also comprises a container 32 of liquid to be sprayed, in the form of a closed reservoir, and a pipe 34 connecting an outlet of the reservoir 32 to an inlet of the spray head 28.

The spraying device 14 comprises one or more viscosity sensors 36a-36e. FIG. 1 illustrates different possible positions for this or these viscosity sensors 36a-36e:

a first sensor 36a can be installed in the container 32 of liquid to be sprayed, preferably in the vicinity of the outlet of the container 32 connected to the pipe 34;

a second sensor 36b can be installed in the pipe 34, preferably in the vicinity of the outlet of the container 32 to which the pipe 34 is connected;

a third sensor 36c can be installed in the pipe 34, preferably substantially in the middle of the pipe 34;

a fourth sensor 36d can be installed in the pipe 34, preferably near the outlet of the pipe 34, connected to the spray head 28;

a fifth sensor 36e can be installed in or in the vicinity of the spray nozzle 30.

The viscosity sensors 36a-36e are for example vibrating viscometers, in particular viscometers with resonance frequency (from the English "vibration at resonance frequency viscosimeter").

These sensors 36a-36e make it possible to measure the viscosity of the liquid during operation of the spraying device 14, in particular during the spraying of a layer of adhesive 38 on the surface of a part 40 of a motor vehicle, such as, for example , a piece of interior trim for a motor vehicle.

Furthermore, the spraying device 14 is provided, in the example illustrated, with a sensor 42 for the temperature of the atmosphere surrounding it and with a humidity sensor 44 around the spraying device. Advantageously, the spraying device 14 can be provided with a liquid pressure sensor inside the spraying device 14. This sensor can in particular be mounted at one of the positions mentioned below for the position of the viscosity 36a-36e.

The spraying device 14 also comprises an electronic control unit 46. The electronic control unit 46 is functionally connected to the viscosity sensor (s) 36a-36e to receive one or more information on the viscosity of the liquid in the device spraying device 14. The electronic control unit 46 is also connected to a display screen 48 and to a means 50 for preventing spraying of the liquid by the spraying device 14. This means 50 may be a valve which interrupts the fluid communication between the container 32 and the spray nozzle 30. Alternatively, the interruption of the spraying of liquid can be controlled by cutting off a pump putting the liquid in motion in the spraying device 14. The pump can in particular be cut in interrupting its power supply.

The electronic unit 46 is advantageously connected functionally to the various sensors 16, 18, 20, 22, 24, 26 of the spray booth 12. The electronic unit 46 allows the display of the various parameters measured by these sensors so that a user ensures that the conditions under which the glue is sprayed allow satisfactory application of the glue to the part of a motor vehicle 40.

The electronic unit 46 can be programmed to implement a method for implementing the spraying device 14, of which FIG. 2 represents a flow chart 100.

The method of implementing the spraying device 14 begins with a step 102 of switching on the spraying device 14. Advantageously, this lighting is conditioned on the start-up of a ventilation system of the spray booth 12. By switching on the spraying device 14, here we understand the start of the spraying of liquid by the spraying device 14.

The process then continues with a step 104 during which the viscosity V of the liquid inside the spraying device 14 is essentially measured, while the spraying of liquid is carried out. In the example illustrated, this step 104 also measures the pressure D of the liquid inside the spraying device, the temperature T, the pressure P and the humidity H inside the cabin, or even the temperature T1, the hydrometry H1 and the atmospheric pressure PI, outside the spray booth 12. As indicated above, these parameters are useful to the user of the spray device 14, to ensure that he works under satisfactory conditions of use allowing suitable spraying of the adhesive on the part 40.

Then, during a step 106, the viscosity V measured of the liquid in the spraying device 14 is compared with reference values A, B, C. Advantageously, these reference values A, B, C can be variables depending in particular on one of the parameters measured, in particular the temperature and / or the humidity in the spray booth. However, for the sake of simplicity of the description, it is considered below that the reference values are constant. It is also considered that the viscosity is only measured at one point of the spraying device 14. However, measurements at several points of the device can be carried out for example to follow any micro-variations between the values obtained near the container 32 and those obtained near the spray nozzle 30.

If the viscosity V measured is greater than or equal to a first reference value A and less than or equal to a second reference value B, then the electronic control unit 46 allows, in step 108, normal operation of the device. spraying 14. At this step 108, the electronic control unit 46 can control the display by the display device 48 of information measured by the various sensors 16, 18, 20, 22, 24, 26, 42, 44 This information is useful to the user of the spraying device 14 to ensure that he is working under satisfactory conditions for spraying the liquid.

The method 100 then continues by looping back upstream of the step 104 for measuring the viscosity V and, optionally, other parameters. Thus, the method 100 is implemented continuously. According to an alternative, the method 100 includes a time-out step before looping back. In this case, the method 100 implements a measurement of the viscosity V and, optionally, of the other parameters, which is discontinuous.

If, in step 106, the measured viscosity V of the liquid is between the second reference value B and a third reference value C, then the method 100 continues in step 110. In this step 110, the operation of the continuous spray device 14. In other words, the electronic control unit 46 does not control an interruption of the spraying of liquid. However, the electronic control unit 46 controls the display, on the display device 48 of an alert message, warning the user of the spraying device 14 that the liquid has a viscosity greater than the second reference value B. In this case, the user can decide to continue spraying, as illustrated in FIG. 2. In this case, the method 100 continues by looping upstream of the step 104 for measuring the viscosity. Alternatively, the electronic control unit 46 controls the emission of an alert in the form of the emission of a sound and / or of a light alert and / or of a message. For example, an initially green traffic light may change to orange in this case.

Instead of looping back the process, in step 110, the user can voluntarily interrupt the operation of the spraying device 14. He can then order a cleaning of the spraying device 14. This cleaning can be carried out by a cleaning unit, not shown, with which the spraying device 14 is equipped. The cleaning unit can for example inject a cleaning agent into the spray device 14, in particular into the spray head 28 and its spray nozzle 30, and / or into the pipe 34. In this case, after cleaning the spraying device, the method 100 resumes at step 102.

Finally, if in step 106, the viscosity V of the liquid measured is greater than the third reference value C, then the method 100 continues in step 112 by stopping the spraying device 14, controlled by the unit control electronics 46. The stopping of the spraying device 14 means here the interruption of the spraying of liquid by the spraying device 14.

In this case, in fact, it is considered that it is not desirable to continue spraying the liquid. This may in particular be due to a risk of damage to the spraying device and / or to a risk that the spraying thus produced is not satisfactory.

In this case also, the electronic control unit 46 can control the display of an alert message warning the user of the spraying device 14 that the liquid has a viscosity greater than the third reference value C. Alternatively or additionally, the electronic control unit 46 controls the emission of an alert in the form of the emission of a sound and / or a light alert. For example, an initially green or orange traffic light may turn red in this case.

Following this stop of the spraying device 14, the user can, as explained above, order the cleaning of the spraying device 14. This cleaning can alternatively be controlled by the electronic control unit 46, concomitantly with the interruption of the spray. Such cleaning is therefore only carried out when necessary.

The invention is not limited to only the exemplary embodiments described above, but is on the contrary susceptible of numerous variants accessible to those skilled in the art.

In particular, the viscosity of the liquid can be measured at different points on the application device. In this case, a single measured viscosity between the second reference value B and the third reference value C can lead to step 110 of issuing an alert. Likewise, in this case, a single measured viscosity greater than the third reference value C can lead to step 112 and to stop the application of the liquid.

Claims (11)

1. Device (14) for applying a liquid, in particular paint or, preferably, glue, to a surface (40), the application device (14) comprising a sensor (36a-36e) of viscosity of the liquid in the application device (14) and an electronic control unit (46) operatively connected to the viscosity sensor (36a-36e), the electronic control unit (46) authorizing the application of liquid to the means of the application device (14) as long as the viscosity (V) determined by the viscosity sensor (36a-36e) is less than a first reference value (C), the electronic control unit (46) interrupting the application of liquid by means of the application device (14) when the viscosity (V) determined by the viscosity sensor (36a-36e) is greater than the first reference value (C). 2. A device for applying a liquid according to claim 1, in which the electronic control unit (46) commands an emission of an alert when the viscosity (V) determined by the viscosity sensor (36a-36e) is greater than a second reference value (B) and less than the first reference value (C), the alert preferably being a light alert and / or a message on a display screen (48) of the application (14) and / or emission of a sound. 3. A device for applying a liquid according to claim 1 or 2, comprising at least one of a sensor of ambient air temperature around the application device (14), an atmospheric pressure sensor around the application device (14), a pressure sensor measuring the pressure of the liquid in the application device (14) and a humidity sensor of the ambient air around the application device. 4. Device for applying a liquid according to one of claims 1 to 3, comprising an application head (28), a pipe (34) intended to bring the application head (28) into communication with fluid. with a container (32) of liquid to be applied and, preferably, a container (32) of liquid to be applied. 5. A device for applying a liquid according to claim 4, comprising at least one of: - a viscosity sensor in the application head (28), in particular in a nozzle (30) of the application head (28); - A viscosity sensor in the pipe (34), in particular in the vicinity of the end of the pipe (34) intended to be fixed on the liquid container (32) and / or in the vicinity of the end of the pipe (34) connected to the application head (28); and - a viscosity sensor in the liquid container (32), if applicable. 6. A liquid application device according to claim 4 or 5, wherein the application head (28) is a spray head provided with a spray nozzle (30), the application device (14 ) being a spray device. 7. Device for applying a liquid according to any one of the preceding claims, in which the viscosity sensor (36a-36e) is a vibrating viscometer, in particular a viscometer with a resonance frequency. 8. A liquid application device according to any one of the preceding claims, comprising a cleaning unit (50) adapted to inject a cleaning agent into the application device (14), in particular in the head of application (28) and / or in the pipe (34), if necessary, on command of the electronic control unit (46), when the viscosity (V) determined by the viscosity sensor (36a-36e) is greater at the first reference value (C) or greater than the second reference value (B). 9. Installation (10) for applying a liquid to a surface (40) comprising: - an application booth (12); and - an application device (14) according to any one of the preceding claims, inside the application booth (12). 10. Method for implementing an application device (14) according to any one of claims 1 to 8 or in an application installation according to claim 9, comprising the steps consisting in: - measure the viscosity of the liquid in the application device (14); 5 - interrupt the application of the liquid by means of the application device (14), in the case where the viscosity (V) of the liquid is greater than the first reference value (C). 11. The method according to claim 10, claim 2 being applicable, 10 further comprising a step consisting in: - allow the application of the liquid by means of the application device (14) while issuing an alert for a user, in the case where the viscosity (V) is less than the first reference value (C) and greater than the second reference value (B).