EP0618013B1 - Machine for the projection of a coating product - Google Patents

Description

The invention relates to a machine for spraying coating product onto objects, such as for example motor vehicle bodies.

The industrial production rates and the annual operating plans for using the production lines are such that the periods provided for the start-up or maintenance of a coating product application installation are short. Thus, the assembly and adjustments of a bodywork installation must generally be carried out in the space of three weeks. It is therefore essential to best prepare for installation before the equipment arrives at the operating site.

The usual technique consists in providing, for each projection machine, a control cabinet containing all the control elements specific to the machine in question, in addition to a common cabinet, sometimes called "wiring head cabinet" containing the elements power and control elements common to all machines in a coating installation. Thus, in such an installation for coating automobile bodies comprising three lateral machines per side and a machine known as a "roof machine" for coating the roof, the hood and the boot, it is necessary to provide nine cabinets in addition to the cabinet " wiring head ". These control cabinets occupy a large volume near the paint spray booth. One of the reasons why systems have been designed this way for so long is that the designers and maintenance operators of the sub-assemblies grouped in the cabinets on the one hand and in the machines on the other hand, are specialists of different techniques. In addition, the numerous cables and hoses which connect them to their respective machines create a very dense network which is difficult and long to set up and particularly delicate to control in the event of a problem during start-up or in the event of a fault during of operations.

Until now, these cables and pipes were installed in the ceiling or under the floor of the installation. The cabinets were a few meters apart, but the by-passes given to cables and pipes lengthened them up to several tens of meters. When the installation was in operation, it was particularly delicate to inspect these electric cables and pneumatic hoses for maintenance operations, for example when it was a question of locating a leak, the crushing of a hose or an installation. to intermittent ground.

In addition, due to their large volume, it was sometimes necessary to install the cabinets in height to free up a floor for operators. It was then necessary to provide raised platforms capable of supporting up to ten cabinets weighing approximately 250 kg each, which required a robust and, therefore, expensive infrastructure.

The invention aims to solve these problems. It relates to a machine for spraying a coating product of the type comprising at least one sprayer, characterized in that the electrical and pneumatic control elements specific to this machine are mounted in a housing mechanically integral with the body of the machine.

This arrangement makes it possible to assemble the machine and the housing and makes it possible to connect all the control elements to all the controlled elements of the spraying machine before transporting the machine from the place of assembly to the place of use.

The place of assembly, that is to say generally the production unit of the machine manufacturer, is suitable for this type of operation and the staff is sufficient. Assembly can be carried out several weeks before transport to the user and it is possible to systematically check all the electrical and fluidic connections. The assembly and connection time at the place of operation is therefore significantly reduced. Consequently, in a period of the order of three weeks as mentioned above, more time can be devoted to fine-tuning the installation under the specific conditions of use. The quality of the coating becomes optimal from the first days of use of the installation.

It is no longer necessary to install the numerous electrical connection cables and supply pipes between the control cabinet and the machine. The time saved is around a week, which is considerable. In addition, the connections between the control members and the controlled members are as short as possible and the configuration of these connections is identical from one machine to another. In fact, the cable paths are the same and the pneumatic conduits follow identical paths. This results in identical response times and pressure losses from one machine to another. Thus, the new arrangement allows the reproducibility of the conditions from one machine to another whereas, in the previous installations where the relative positions of a machine and its control cabinet could vary appreciably, such reproducibility could not be obtained. Controlling the length of the pneumatic hoses makes it possible in particular to limit the pressure losses and consequently the response time and to standardize these pressure losses from one machine to another.

The new arrangement also allows for easy maintenance since all the control elements, the piloted elements and the connection elements are accessible by simply opening the doors of the projection machine. Finally, this new arrangement is significantly more compact and saves significant space for the entire installation.

• la figure 1 est une vue schématique de dessus d'une installation de revêtement selon la technique antérieure; et
• la figure 2 est une vue schématique de dessus d'une installation de revêtement selon l'invention.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the description which follows, of an embodiment of a machine for spraying coating product in accordance with its principle, given solely by way of example and made with reference to the appended drawings in which:

• Figure 1 is a schematic top view of a coating installation according to the prior art; and
• Figure 2 is a schematic top view of a coating installation according to the invention.

FIG. 1 represents a known installation intended for coating objects 1 of relatively large size, such as for example motor vehicle bodies, carried by a conveyor 2 moving in the direction of arrow F. The installation consists of six machines, 3, 4, 5, 6, 7 and 8 called "lateral machines", distributed in equal number on the sides of the path of the objects 1 and each carrying an automatic sprayer of coating product of the pneumatic or rotary type. The installation also includes a machine called "roof machine" 9 intended for coating the horizontal surfaces of objects 1. This machine 9 carries three sprayers of the same type as those of the side machines.

The supply of coating product and air to the machines 3 to 9 is carried out in a manner known per se by branch connections on paint circulation circuits and on an air supply circuit. She is not represented. The entire system is supplied with electric current from the distribution sector through a cabinet called "wiring head" 11. The central unit of the control automaton and the flow regulator 13 which controls all the flow rates of coating product in the installation are also housed in this cabinet 11. The information from the central unit 12 and the regulator 13 as well as the necessary electrical power are transmitted to control cabinets 23 , 24, 25, 26, 27, 28, 29, 30 and 31 which correspond respectively to the lateral machines 3, 4, 5, 6, 7, 8 and 9 for the last three.

Each cabinet 23 to 31 contains the control elements necessary for the proper functioning of the corresponding machine 3 to 9, namely: the solenoid valves for driving drive air, for shaping the jet, for the skirt and possibly for the turbine, the solenoid valves supply of coating product or rinsing product, the purge solenoid valves, the electrical regulation system of the turbine (possibly), the positioner regulation systems according to the three axes of movement of the sprayer and the associated variators, pressure switches, etc ...

By way of example, the devices contained in the cabinet 23 must control the piloted, associated elements, located in the machine 3, such as the motors, the turbine (possibly), the variators, the positioners, the change blocks of coating product, drive air supplies, skirt air supplies, shaping air supplies, etc., which requires numerous electrical conductors and fluid conduits. On average, there are about thirty pneumatic hoses, represented by harness 43 and thirty electric cables, represented by harness 53 distributed between each cabinet, like cabinet 23 and each machine, like machine 3. An installation of this type includes therefore around 270 electric cables and 270 air pipes between the cabinets and the associated machines. The length of these beams is very variable, as is clear from Figure 1.

According to the invention shown in Figure 2, the elements which are identical to those of Figure 1, have the same reference numerals. Thus, on the back of each lateral machine and on a lateral face of the support posts 100 and 101 of the "roof machine" 9 are mounted boxes 103 to 111 containing all the elements which were previously contained in the cabinets 23 to 31, respectively. These boxes are integral with the bodies of the machines with which they are associated. The wardrobe "head of wiring "11 serves as a distributor for the electrical power circuit and contains the control elements common to the entire installation such as the central unit 12 and the regulator 13. This has eliminated all bundles of pipes and cables referenced 43 and 53 in FIG. 1.

According to an advantageous variant of the invention, each box 103 to 111 can contain its own control unit 12 and / or its own flow regulator 13. Each machine is then completely autonomous. This variant can be designed according to the respective costs of the equipment concerned and their modularity. The electrical power can then be distributed to the various machines from the distribution network and the "wiring head" cabinet can be omitted.

Considering more particularly the machine 3 and the associated control unit 103, it can be noted that the unit 103 is pivotally mounted around a vertical axis 150, for example by means of hinges. The housing 103 thus allows access to the interior of the machine 3. It is itself divided into two parts 103A and 103B which are connected by an articulation pivoting around an axis 151. It is thus possible to access the inside the housing 103 without separating the part 103A from the body of the machine 3. The control elements are distributed between the parts 103A and 103B according to their size. Although not shown in the drawings, the boxes 104 to 111 are similar to the box 103 and mounted on their respective machines in the same way.

Each housing 103 to 108 is placed on the opposite side of the corresponding lateral machine 3 to 8 with respect to the objects to be coated, which implies that it can be located outside the coating booth whose walls 120, 121 are generally erected in the vicinity of the front face of the lateral machine, that is to say the face of said machine situated on the side of the objects to be coated. These boxes 103 to 108 are thus of easy access, including during the installation operating phases. In addition, they are not immersed in a polluted atmosphere, which is important for the longevity of components, in particular electronic cards. The fact remains that this box can be placed on any side of the machine, including the upper and lower sides, depending on the specific constraints of installation on the operating site.

Depending on the configuration chosen for the location of the housing 103, the axes 150 and 151 could thus be horizontal.

According to another advantageous characteristic of the invention, the assembly of each housing 103 to 111 can be maintained at slight overpressure with respect to its ambient medium in order to further limit the pollution inside the housing. To do this, a conventional ventilation system is provided in the housing.

The above description has been made with reference to lateral machines or "roof machines", but the invention also applies to machines of the multi-axis robot type.

Claims (8)

1. Machine for automatically spraying a coating product, which forms a side machine or a roof machine or a multi-axis robot and which comprises a fixed body and a movable element carrying at least one spray device, characterized in that the electrical and pneumatic control elements specific to the said spray device of the said machine (3-9) are mounted in a box (103-111) mechanically fastened to the said fixed body, the said box being rendered integral with the said fixed body and the said control elements being connected to the said machine before its use on site.
2. Machine for spraying a coating product according to Claim 1, characterized in that the elements contained in the box (103-111) include the solenoid valves for controlling the pneumatic circuits specific to the said machine (3-9).
3. Machine for spraying a coating product according to Claim 1, characterized in that the elements contained in the box (103-111) include the electrical regulation system specific to the said machine (3-9) and the systems for regulating the positioners of the said machine (3-9).
4. Machine for spraying a coating product according to Claim 1, characterized in that the box (103-111) is located on the outside of the booth.
5. Machine for spraying a coating product according to Claim 4, characterized in that the box (103) can be moved about a horizontal or vertical axis (150) between two positions in which it allows and prevents access by an operator to the inside of the machine (3).
6. Machine for spraying a coating product according to Claim 5, characterized in that the box (103) consists of two parts (103A, 103B) which are connected by an articulation of the hinge type pivoting about a vertical or horizontal axis (151).
7. Machine for spraying a coating product according to Claim 1, characterized in that the box (103) is maintained at an overpressure with respect to its ambient environment.
8. Machine for spraying a coating product according to Claim 1, characterized in that all the control elements (12, 13) of the machine are mounted in the associated box (103, 111), the machine being electrically and pneumatically supplied from two respective, electrical and pneumatic, mains.

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