WO1992011951A1

WO1992011951A1 - Automatic painting machine particularly for painting the inside of a hollow body of quadrangular section and large size such as a shipping container

Info

Publication number: WO1992011951A1
Application number: PCT/FR1992/000002
Authority: WO
Inventors: Roland Bizolier
Original assignee: Rexson Procedes
Priority date: 1991-01-03
Filing date: 1992-01-02
Publication date: 1992-07-23
Also published as: EP0565615A1; ATE121973T1; DE69202331D1; EP0565615B1; FR2671293A1; FR2671293B1

Abstract

The invention relates to an automatic painting machine (100), particularly for painting the inside of a hollow body C having a quadrangular cross-section and of large dimensions, such as a shipping container. According to the invention, the machine is comprised of a support frame (101) displaceable inside the hollow body C and at least one movable arm (102) mounted on said frame so as to oscillate in a plane parallel to the face to be painted; each arm (102) is hinged to an intermediary link point integrally of a carriage driven with a rectilinear, alternated and uniform motion, and also to a slide provided at the vicinity of its rear end, to a fixed linking point so that the free end (109) of said arm describes a substantially flat arc with a substantially constant speed. The arm (102) carries an elongate support for a spring head (110), and coupling means are provided to force each spring head support (110) to remain horizontal during the pivoting motion of the movable arm concerned, and to force said support to oscillate continuously about its axis with an angle ($g(b)) substantially proportional to the oscillation angle of said arm. Application to the painting of interior faces of a shipping container of square or rectangular cross-section.

Description

AUTOMATIC PAINTING MACHINE, PARTICULARLY FOR PAINTING THE INTERIOR OF A HOLLOW BODY WITH QUADRANGULAR SECTION AND LARGE DIMENSIONS SUCH AS A MARINE CONTAINER.

The invention relates to an automatic painting machine, making it possible in particular to paint the interior of a hollow body of αuadrangular section and of large dimensions, such as a maritime container.

The term "paint" should be understood in a broad sense within the scope of the invention, and include any type of primer or protective paint, lacquer, and other coatings applied by spraying.

When it comes to painting the exterior faces of a hollow body such as a shipping container, an automatic machine is used, in the form of a U facing downwards, which spans the hollow body and can be move at constant speed parallel to the axis of said hollow body. The branches of the U-shaped chassis carry spray heads driven in a reciprocating movement by chains and associated drive motors; a lower support equipped with spray heads is also provided for painting the exterior of the underside of the hollow body, as well as a facial support suspended from an overhead crane for painting the exterior of the front and rear end faces of said body hollow.

Such an automatic machine is perfectly mastered at the present time, and comprises a multitude of adjustments making it possible to correctly position the different spray heads as a function of the dimensioning of the faces to be painted and to adjust their speed of movement, said heads moving in parallel to the faces to be painted and with a constant speed, so that extremely satisfactory results are obtained. However, the problem is much more complex to ^'resolve when it comes to paint the inside of the hollow body, because the machine has to accommodate a space travel is limited de facto, and it fails at present to find in such a case the same operating conditions and the same performance as for painting the outer faces.

Two types of automatic machines can be mentioned which are currently used today for painting the interior of hollow bodies of quadrangular section and of large dimensions. A first automatic machine, moreover developed by the applicant, comprises a chassis mounted on a self-propelled carriage and supporting an articulated head equipped with spray guns. The head can pivot around a horizontal rear axis, and is extended by a transverse support for pistols also articulated around a horizontal axis and capable of oscillating around another horizontal axis, perpendicular to the previous one, said other axis being brought into coincidence with the axis of the hollow body. When the transverse support of guns oscillates around its axis, on either side of a horizontal plane passing through the axis of the hollow body, the guns make it possible to progressively paint two opposite faces of said hollow body as and when the advancement at constant speed of the motorized trolley. In practice, when one wants to paint the four interior faces of a container of square or rectangular section, one organizes the oscillation of the transverse support of guns so as to paint two opposite faces (for example the vertical faces) to the to go, and the two other faces (for example the horizontal faces) to the return.

Such a machine is however of complex structure, and has the drawback of having a relatively large transverse sizing support mounted in cantilever.

In addition, the setting of the axis of oscillation of the transverse support on the axis of the hollow body is difficult due to the double articulation, and this in particular in the case of a hollow body of rectangular section.

Finally and above all, the guns oscillate in a vertical plane orthogonal to the faces to be painted, so that the displacement of these guns (considered in said vertical plane) takes place in an arc of a circle, therefore along a trajectory very far from a rectilinear trajectory: it follows variations in distances (particularly sensitive at the edges of the container, during the maximum amplitude of oscillation of the transverse support), and in speeds (due to the high inertia of the transverse support) . Various attempts have been made to have a constant speed (variable control, distance compensation), but these attempts have resulted in making the structure of the machine even more complex, without any truly significant improvement in the performance obtained.

Another automatic machine was developed a decade ago, on a slightly different principle.

This machine also comprises a chassis mounted on a self-propelled carriage, but this chassis supports two groups of pistols which are movable transversely in a reciprocating movement, being driven by a continuous chain. Each group of guns is then actuated successively, to paint a half-face following another half-face.

Such a machine is advantageous insofar as the guns are driven in a rectilinear movement parallel to the face to be painted, and therefore with a constant speed.

A machine of this type, however, remains very rigid in its applications: it is indeed practically impossible to adjust the stroke of the pistols, so that the machine must be modified each time the size of the container changes (this is particularly the case when two containers of different heights have to be painted successively).

Another drawback concerns the result obtained, due to the coating carried out successively by half-faces: in fact, there is necessarily an overlap zone at the junction of the two half-faces, which means that a greater thickness must be provided, and therefore more paint, to ensure that a central line has not escaped the coating.

There is therefore a need to have an automatic painting machine which would be more efficient than the abovementioned automatic machines.

The invention precisely aims to solve this problem, by designing a machine which is both simple and robust structure, and easy to operate. The object of the invention is also to provide an automatic painting machine which allows multiple adjustments, allowing rapid adaptation to different sizes, without being to the detriment of the results obtained. The object of the invention is also to design a machine capable of simultaneously painting several interior faces of the same hollow body, and even up to the four faces of this hollow body.

It is more particularly an automatic painting machine, in particular for painting the interior of a hollow body of quadrangular section and of large dimensions such as a maritime container, characterized in that it comprises:

. a support frame movable inside the hollow body along the axis of said hollow body; . at least one movable arm mounted on the support frame so as to be able to oscillate in a plane parallel to the face to be painted, said movable arm being articulated on the one hand on an intermediate point of connection secured to a carriage driven by motor means associated in a rectilinear, alternating and uniform movement, and on the other hand, at the level of a slide provided in the vicinity of its rear end, on a fixed point of connection integral with said support frame, so that its free end describes an arc essentially flat with a substantially constant speed; a spray head elongate support mounted at the free end of the movable arm, said support being hinged to said moving arm to oscillate in a plane parallel to the plane of oscillation of said ^'arm and carrying a spray head; a first coupling means provided between the movable arm and the elongated support of the spray head, forcing the axis of said support to keep a fixed direction parallel to the axis of the hollow body, during the oscillation movement of said movable arm; a second coupling means provided between the movable arm and the elongated spray head support, forcing said support to oscillate continuously around its axis during the oscillating movement of said mobile arm, at an angle essentially proportional to the angle of oscillation of said arm. Preferably, the fixed connection point is adjustable in a direction essentially parallel to the axis of the hollow body, so as to allow adjustment of the amplitude of the oscillating movement of the mobile arm. In particular, the fixed connection point is carried by a slider which can be moved in a fixed slide secured to the support frame, the axial position of said slider being mechanically adjustable, for example by means of a screw-nut system controlled by a crank, so that the adjustment of the fixed connection point can thus be carried out during operation. Advantageously, the first coupling means is a parallelogram tπngleπe integrated in the movable arm, said tπngleπe being connected to a rotating bearing projecting laterally from said movable arm and supporting the elongated spray head support, the associated spray head being mounted on said support elongated beyond said rotating bearing.

Preferably also the second coupling means essentially consists of a fork to which the spray head support is coupled, said fork carrying an end ball pivoting on a nut carried by the movable arm, so that the movement of said fork during the oscillation of said arm produces the oscillation of said support about its axis. In particular, the fork grips a flattened rear end of the spray head support.

Advantageously then, the nut is adjustable in position in the longitudinal direction of the movable arm, so as to allow adjustment of the amplitude of the oscillation movement of the spray head support around its axis, and in particular the nut is movable in a slide secured to the movable arm.

According to a particularly advantageous embodiment, the aforementioned machine comprises several mobile arms, each of which is associated with a respective face to be painted, each of said arms comprising respective first and second coupling means for controlling the movement of the associated spray head. Preferably then, the carriages associated with the intermediate points of connection of the mobile arms are connected together by a common drive chain, the reciprocating movement of which is ensured by associated motorized drive means, so as to synchronize the movements of oscillation of said arms. In particular, the common drive chain is arranged in a vertical plane, and the connection to said chain of the carriages associated with the mobile arms is arranged in such a way that the spray heads remain in a substantially vertical common plane during the movement of oscillation of said movable arms. According to a preferred characteristic of this embodiment, the reciprocating movement of the common drive chain is communicated by one of the carriages, via a drive chain carrying a sliding finger in a groove of said carriage, said chain drive being driven by a motor whose speed can be adjusted by an associated operating member.

Advantageously also, the movable sliders and the fixed slides making it possible to adjust the amplitude of the oscillation movement of the movable arms are mounted on a support frame situated in a vertical plane and integral with the support frame, so that the cranks controlling the screw systems associated nuts are all accessible behind said machine.

According to a particular example, the machine comprises three or four movable arms whose successive oscillation planes are orthogonal to one another. Preferably then, in the particular case of four mobile arms, the mobile arms correspond in central symmetry, so that the associated spray heads are simultaneously oriented towards the four edges of the hollow body when said arms are in amplitude position. maximum oscillation. It is also advantageous for the support frame to be mounted on a self-propelled carriage which can roll on associated rails, by means of a support member which is adjustable in height and which preserves the horizontality of said support frame. Alternatively, the support frame is mounted at the end of an arm which can be animated with a linear movement.

Other characteristics and advantages of the invention will appear more clearly in the light of the description which follows and of the appended drawings, relating to a particular embodiment, with reference to the figures in which:

- Figure 1 illustrates in perspective an automatic painting machine according to the invention, here comprising three movable arms for simultaneously painting three interior faces of a hollow body of rectangular or square section;

- Figure 2 is a schematic view illustrating the particular method of mounting a movable arm, the free end of which describes an essentially flat arc with a substantially constant speed, as well as the adjustment of the stroke (adjustment of the amplitude of the swinging arm movement);

- Figure 3 is a detail view illustrating the arrangement of the fixed point of connection of a movable arm, with the associated travel adjustment members;

- The figure is a perspective view of the free end of a movable arm, making it possible to better distinguish the spray head and the associated coupling means which ensure its horizontality and its continuously variable orientation;

- Figure 5 is a schematic view illustrating the principle of the continuous variation of the orientation of a spray head;

FIG. 6 is a perspective view illustrating the means for driving the three movable arms, the arrangement of which makes it possible to synchronize their oscillating movement;

- Figure 7 is a detail view illustrating the drive mode of one of the carriages by a drive chain and a drive finger passing through a slide associated with said carriage; - Figure 8 is a schematic view illustrating the kinematics of the three movable arms;

- Figure 9 is a detail view showing a vertical support frame common to the stroke adjustment means of all the movable arms; - Figure 10 is a schematic front view illustrating a variant with four synchronized movable arms, and Figure 1 1 is the associated top view;

- Figures 12 and 13 illustrate two modes of support, respectively by a self-propelled carriage, and by a movable arm carried by an arrow.

FIG. 1 makes it possible to distinguish a hollow body C of quadrangular section, here essentially rectangular, having longitudinal faces I, II, III and IV, and the main axis of which is referenced XC. Such a hollow body C is commonly found in the field of maritime containers, that is to say that it is a large hollow body, with a bottom F (front face) of section generally ranging from 2.5 m by 2.5 m to 2.5 m by 3.5 m. The purpose of the automatic painting machine according to the invention is to paint the interior faces of the hollow body

C, and, in particular here, to paint simultaneously the three interior faces I, II, III insofar as the automatic machine comprises three movable arms. This is of course only an example, and it is understood that the automatic painting machine according to the invention may comprise from one to four movable arms so as to paint from one to four interior faces of the hollow body, simultaneously , during the relative linear movement between the automatic painting machine and the hollow body. Furthermore, as will be described later, the automatic painting machine is here designed to be able to move, either on a self-propelled cart, or by being mounted on a mobile arm carried by an arrow, in a linear movement along the interior of the hollow body C whose interior faces are to be painted, said hollow body then being fixed. It goes without saying, however, that this is only a relative movement between the hollow body and the automatic painting machine, and provision may be made to organize the linear movement for the hollow body C, the automatic machine. of paint then being essentially fixed. As regards the painting of the bottom F (rear face), and of the interior of the doors (on the front face), we can generally be satisfied with traditional means actuated manually.

The automatic painting machine 100 comprises a support frame 101 movable inside the hollow body C along the axis XC of said hollow body. The machine comprises at least one movable arm 102 mounted on the support frame 101 so as to be able to oscillate in a plane parallel to the face to be painted: the machine illustrated in FIG. 1 here comprises three mobile arms 102, the oscillation planes of which are respectively parallel to the faces I, II and III of the hollow body C. FIG. 1 also makes it possible to distinguish, at the free end of each of the movable arms 102, an elongated support 1 10 for the spray head, on which a plurality of spray guns 1 12 is provided. of the oscillation movement of each movable arm 102, the spray head support 1 10 remains contained in a plane parallel to the plane of oscillation of the associated movable arm, being additionally subject, by an associated coupling means which will be described further on, to keep a fixed direction parallel to the axis XC of the hollow body during the oscillating movement of the associated movable arm. Thus, the spray head supports 1 10 remain permanently contained in a plane which is parallel to the face to be painted, while keeping a constant direction parallel to the main axis XC of the hollow body, therefore essentially horizontal, this which allows a regular application of the paint on the respective face to be painted. In addition, thanks to another associated coupling means which will be described later, each spray head support 1 10 can rotate around its axis XS which is, remember, permanently maintained parallel to the main axis XC of the hollow body C. By rotating the spray head support 1 10 around its axis XS, it is thus possible to modify the orientation of the outlet nozzles of the spray guns 12. The associated coupling means, which will be described in more detail detail with reference to FIG. h, obliges each spray head support 1 10 to oscillate continuously around its axis XS during the oscillation movement of the associated mobile arm 102, at an angle / b essentially proportional to the angle of oscillation of said movable arm. The continuous and controlled orientation of the spray guns 12 associated with each movable arm 102 makes it possible to correctly paint the edges associated with each interior face with the same spray nozzles, which makes it possible to obtain a regular application speed. of the paint, the regularity of the application being already ensured, for the edges, by the fixed direction of each spray head support (parallel to the main axis XC of the hollow body C), and, for the faces to paint, by moving each spray head support in a plane that remains parallel to the face to be painted. The application speed is moreover made practically constant by virtue of a particular organization of the oscillation movement of each movable arm 102, thanks to connecting means ensuring that the free end of each movable arm describes an essentially flat arc , result which one could not obtain with a simple movement of oscillation around a fixed axis, because the free end of each arm would then describe an arc of circle, such a trajectory not making it possible to obtain a speed appreciably constant. We will now describe in detail the structure of a movable arm 102 and the arrangement of the associated coupling means allowing on the one hand to maintain a fixed direction for the associated spray head support 1 10, and on the other hand to force said support to oscillate continuously around its axis XS during the oscillation movement of said movable arm, at an angle essentially proportional to the angle of oscillation of this arm.

The general principle of the articulation of a mobile arm 102 is illustrated in FIG. 2: the mobile arm 102 is articulated on the one hand on an intermediate connection point 103 secured to a carriage driven by associated motor means according to a movement rectilinear, alternating and uniform (the associated carriage 105 is shown in FIG. 6), and on the other hand, at the level of a slide provided near its rear end 108, on a fixed connection point 104 secured to the support frame 101 (FIG. 3 makes it possible to better distinguish the fixed connection point 104 which passes through a slide 107 secured to the movable arm 102, at the rear end

108 thereof). The rectilinear, alternating and uniform movement of the intermediate connection point 103 subjects the mobile arm 102 to oscillate at an angle oc on either side of a mean axis XB which is parallel to the direction of movement of the automatic machine of paint 100, that is to say parallel to the main axis XC of the hollow body concerned. In this way, the free end 109 of the movable arm 102 describes a trajectory

T which is essentially flat, which makes it possible to guarantee a substantially constant speed. The arc T of trajectory is in fact a portion of Nicomedes conchoïde, and this trajectory is considerably flattened compared to an arc of circle which would be centered on the fixed point of connection 104 if the latter was rigidly secured to the support frame 101 of the machine.

Such an arrangement is very advantageous insofar as it makes it possible to ensure a substantially constant speed for the displacement of the free end of each movable arm 102, but it is also very advantageous insofar as it makes it possible to organize, in a simple way, an adjustment of the amplitude of the oscillation movement of the mobile arm 102. Indeed, if the fixed connection point 104 is moved forward, that is to say by approaching the segment described by the intermediate connection point 103, along the axis XB which is essentially parallel to the axis XC of the hollow body, it is easy to see that it is thus possible to increase the amplitude of the oscillation movement of the mobile arm 102. FIG. 2 thus shows that the fixed connection point 104 can be moved from a rear point A to a front point B (point 104 '), thus making it possible to pass the stroke described by the free end 109 of a value c to a larger value c '(the positio ns of oscillation of the movable arm are illustrated in dotted lines in Figure 2). Such stroke adjustment (distance R) is extremely advantageous insofar as it makes it possible to adapt to variable dimensions of the faces to be painted. It will be noted that, in all the oscillation positions of the mobile arm 102, regardless of the stroke chosen, that is to say whatever the position of the fixed connection point 104, the elongated head support of spray 1 10 which carries the spray guns 1 12 maintains a fixed direction parallel to the axis XB, that is to say to the main axis XC of the hollow body. The detail in FIG. 3 illustrates a simple embodiment of the means for adjusting the amplitude of the oscillation movement of a movable arm 102. The fixed connection point 104, which is presented here in the form of a pin passing through a slide 107 of the movable arm 102, is carried by a cursor 1 16 which is movable in a fixed slide 1 17 secured to the support frame 101, this fixed slide 1 17 being arranged along the aforementioned axis XB associated with the mobile arm 102 By providing that the axial position of the cursor 1 16 in the fixed slide 1 17 is adjustable, it is easily possible to vary the amplitude of movement of the movable arm 102 in proportion, and therefore the stroke of the spray guns. associated with this movable arm. In this case, the movable slider 1 16 constitutes the nut of a screw-nut system, the screw of which is constituted by a threaded rod 1 18 with an axis parallel to the direction of the fixed slide 1 17, the axial position of the slider 1 16 then being adjustable by means of this screw-nut system 117, 1 18 by means of a crank 1 19 formed behind a support plate 151 which is fixed to the rear end of the fixed slide 1 17. The fixed connection point 104 can thus be adjusted with great flexibility between two extreme positions which correspond to those of points A and B of FIG. 5: in each of these positions which corresponds to a given stroke for the associated spray guns, the movable arm 102 constantly slides back and forth (as shown by arrow 202 in Figure 3) throughout the oscillation movement of this movable arm. Such an embodiment is particularly advantageous, because the adjustment of the axial position of the cursor 1 16 can be carried out during operation, independently and separately by an appropriate displacement of the fixed point of connection 104. In the case where the machine automatic painting comprises several mobile arms 102, for example three mobile arms, it is advantageous to provide that the mobile sliders 1 16 and the fixed slides 1 17 making it possible to adjust the amplitude of the oscillation movement of each of the mobile arms 102 are mounted on a support frame 146, as illustrated in FIG. 9. The support frame 146 is preferably arranged in a vertical plane, and it is integral with the support frame 101. Thus, not only does this support frame 146 contribute to the rigidity overall, thus preserving the constant direction of the fixed slides 117, but it also makes it possible to obtain easy accessibility, behind the ma china, to all 119 cranks controlling the associated screw-nut systems. As a result, the operator can very quickly correct the stroke of any of the spray gun groups by acting appropriately on the associated adjustment crank 1 19, which makes it possible to adapt with great flexibility and high precision in the dimensioning of the respective face to be painted. Such an arrangement makes possible an easy and rapid adjustment when going from one hollow body to another whose quadrangular section is different. The operator has indeed all the stroke R (illustrated in FIG. 2) for adjusting the stroke of each group of spray guns, by acting appropriately on the associated adjustment crank 1 19.

We will now describe the coupling means associated with each of the mobile arms 102 of the automatic painting machine 100, with reference to FIG. 4.

Figure 4 illustrates the free end 109 of a movable arm 102, with a first coupling means 1 14 provided between the movable arm 102 and the elongated spray head support 1 10, forcing the axis XS of said support to be kept a fixed direction parallel to the axis XC of the hollow body during the oscillation movement of said movable arm, and a second coupling means 1 15 provided between the movable arm 102 and the elongated spray head support 1 10, forcing said support to oscillate continuously around its axis XS during the oscillation movement of said movable arm, at an angle & essentially proportional to the angle of oscillation o of said arm.

The first coupling means 1 14 is preferably made in the form of a parallelogram linkage integrated in the free end 109 of the movable arm 102. A set of two links 120 and 121 can be distinguished here, the ends of which are articulated on associated wheels 122 and 123, said links remaining parallel to one another whatever their respective axial displacements. The rotary bearing 124 is then provided at the level of the wheel 123, to rotate around an axis XP coaxial with the latter, integrally with the parallelogram linkage formed by the members 120, 121, 122, 123 thus arranged in the form a pantograph arm. The linkage is naturally integrated into the free end 109 of the mobile arm 102, and the rotary bearing 124 projects laterally from said mobile arm to support the elongated spray head support 1 10, the associated spray head 1 1 1 being mounted on said support elongated beyond said rotating bearing. The spray head 1 1 1 here carries two spray guns 1 12, of which there are the associated spray nozzles 1 13. Thus, during the oscillating movement of the movable arm 102, the axis XS of the elongated head support of spray 1 10 maintains a constant direction thanks to the linkage to the parallelogram which has just been described. The conservation of this direction being an important parameter for obtaining a favorable result, there is no provision here for making it possible to adjust, during operation, the direction of the elongated support of the spray head 1 10.

The elongated spray head support 110 is rotatably mounted on the bearing 124 while preserving the direction of its axis XS. Behind this bearing 124, the elongated spray head support 110 is coupled in rotation to a fork 125 carrying an end ball joint 128 which pivots on a nut 129 carried by the movable arm 102. This coupling in rotation is here organized by providing a flattened rear end 130 of the spray head support 110, in such a way that the flat facets 125 remain in contact with the flat internal faces of the two branches 126 and 127 of the fork 125. During the oscillation movement of the arm mobile 102, the angular offset between the elongated spray head support 1 10, which keeps a fixed direction, and the mobile arm 102, induces a continuous oscillating movement of the fork 125 around its ball joint 128, this movement of oscillation being shown here schematically by a small deflection cone 131. Such an arrangement retains the proportionality between the angle of oscillation ot of the movable arm 102 and the angle of oscillation (b du elongated spray head support 110 around its axis XS. There is thus guaranteed a continuous oscillation movement for the spray guns 112, throughout the oscillation of the associated mobile arm 102. If we refer to the detail in FIG. 5, we can distinguish three successive positions of the mobile arm 102: when the mobile arm is in a middle position, that is to say when its axis is parallel to the axis of the hollow body to be painted, the axis XS of the elongated support of the spray heads 1 10 is horizontal, and the spray guns 112 project the paint perpendicular to the face to be painted I. On the other hand, in the extreme positions of oscillation of the arm mobile 102, high position or low position here, the elongated spray head support 1 10 has pivoted about its axis XS by an angle / maximum, so as to direct the spray towards the edge associated with .. -, or a, ^. The coupling means 1 15 which has just been described thus ensures a continuous variation of the oscillation angle 5 between the value 0 and a value / ^ _MAv defining the amplitude of oscillation of this elongated support.

The spray guns 1 12 are thus oriented progressively and continuously throughout the oscillation of the movable arm 102 which carries them, which makes it possible to guarantee the regularity of the application while preserving the constancy of the speed.

It is also very advantageous to be able to modify the oscillation angle of the elongated spray head support 110, in order to be able to adapt the machine to different dimensions of the faces to be painted. The arrangement which has just been described precisely makes it possible to easily organize such an adjustment: in fact, the nut 129 supporting the ball joint 128 at the end of the fork 126 is adjustable in position, by being movable in a slide 132, 133 secured to the movable arm 102. The distance d can then be adjusted between the axis XP of the rotary bearing 124 and the central axis XF of the fork 125 (the axis XF passing through the center of the ball joint the axis 128 of this fork), by moving the position of the nut 129 in its slide 132, 133: with a small distance d we will naturally have a low angle of deflection (cone 131) for the fork 125, and therefore an angle of oscillation / & weak for the elongated spray head support 1 10, and vice versa. The length of the slide 132, 133 will be chosen so that there is a distance d allowing oscillation angles fi adapted to the dimensions commonly encountered for the faces to be painted. When the automatic painting machine 100 comprises several movable arms 102, each of which is associated with a respective face to be painted I, II, III, or IV, each of said arms will then comprise first 1 14 and second 1 15 respective coupling means for control the movement of the associated spray head 1 1 1. As a result, it will be possible to easily adapt to the dimensioning of each of the interior faces to be painted.

We will now describe the drive means which ensure the movement of each of the movable arms, it being understood that these means may be suitable in the case of a single movable arm, with particular reference to Figures 6 and 7.

We distinguish in Figure 6 a set of three carriages 105, externally carrying a pin 103 which constitutes the aforementioned intermediate connection point of each of the three movable arms 102 of the automatic painting machine 100 illustrated in Figure 1. The carriages are fixed on a common drive chain 134, which ensures synchronization of the oscillation movement of the three movable arms 102. The common drive chain 134 is preferably arranged in a vertical plane, passing around four 135 pulleys arranged in a square. The reciprocating movement of the common drive chain 134, shown diagrammatically by the arrow 201, is provided by motorized drive means 106 which will be described below. One of the carriages 105, here the carriage associated with the movable arm which oscillates in a horizontal plane, carries a slide 136 having a groove 139, here of vertical orientation, through which a finger 137 secured to a drive chain 138 passes. This drive chain 138 passes over two pulleys 140 whose axes are in a common horizontal plane, and the finger 137 drives the associated carriage 105 as illustrated in FIG. 7: when the carriage 105 moves from right to left, the finger 137 is in the upper part of the groove 139 of the slide 136, then this finger slides at the end of the race to come into its low position which corresponds to the return of the carriage 105 for a movement going from the left to the right. Such a drive mode is commonly used, because it makes it possible to ensure simple alternating movement at constant speed of a carriage associated with spraying means. In this case, however, due to the connection of all the carriages to the common drive chain 134, the drive chain 138 synchronously drives all of these carriages, which makes it possible to organize the movements of oscillation of the mobile arms 102 of the machine. A drive chain 142 passes over a pulley 141 coaxial with the pulley 140 of the drive chain 138, and over a pulley 143 mounted on the output shaft of a motor-variator group 144 which ensures the continuous unidirectional movement of said drive chain, and the reciprocating movement of the common drive chain 134. From preferably, the speed of the motor 144 can be modified by an associated operating member 145, which makes it possible to adjust, simultaneously for all the spray guns, the running speed, and this in a perfectly synchronized manner. It is naturally appropriate to position each of the carriages 105 properly on the common drive chain 134 so as to avoid that the spray guns of two adjacent movable arms are at a given time in the same application area. We then manage to fix each carriage 105 in such a way that each of them is simultaneously in an extreme position of oscillation on the same side of the concerned middle axis: in this case, the two corresponding carriages 105 the vertical branches of the common drive chain 134 correspond in central symmetry. Thanks to such an arrangement, the spray heads 1 1 1 remain in a substantially vertical common plane during the oscillation movement of the mobile arms 102. FIG. 8, which illustrates the kinematic chain of this assembly, makes it possible to clearly see the strokes c of the two arms 102 associated with two opposite vertical faces, and the stroke c ', equal or different from the stroke c, for the movable arm 102 associated with the horizontal face to be painted. It can thus be seen that the successive planes of oscillation of the movable arms remain orthogonal to one another. This naturally remains true when the machine comprises four movable arms 102, as illustrated in FIGS. 10 and 11.

In Figure 10, there is shown a machine with four movable arms 102, that is to say that this machine is capable of simultaneously painting the four faces I, II, III, IV of a hollow body C, as and as the relative slow linear displacement between the machine and the hollow body. The position illustrated in FIG. 10 corresponds to a position of maximum amplitude of oscillation of the four mobile arms 102, a position in which the associated elongated spray head supports have pivoted by a maximum angle Δ so that the spray heads 1 1 1 direct the associated nozzles towards the edges a. -, a,., a,., or a ₂₃ , of the hollow body C. In this case, the four spray heads 1 1 1 are permanently in a common vertical plane, as is better visible on the view of above Figure 1 1, and these spray heads are correspond in central symmetry in this common vertical plane. It is naturally necessary to ensure that the central axis of the support frame 101, which corresponds to the axis of the support frame 146 of FIG. 9 and of the common drive chain 134 of FIG. 6, is coincident with the axis XC of the hollow body C. To this end, the support frame 101 must be able to be adjusted in height, so as to organize its initial setting on the main axis XC of the considered hollow body.

The machine 100 illustrated in FIG. 1 comprises a support frame 101 provided with three movable arms 102, which pass through associated slots 152 formed in the front face 153 of this support frame 101.

The support frame 101 is arranged on a support member 148 adjustable in height, by means of four jacks, or even by means of a linkage in

Associated X, retaining the horizontality of said support frame. This support frame 101 and its support member 148 are mounted on a self-propelled carriage 147 movable in two orthogonal directions. The self-propelled carriage 147 carries rolling means 154 allowing said carriage to move on associated rails 155 carried by a chassis 156, this movement being able to be made parallel to the axis XC of the hollow body.

C, as shown schematically by the arrow 202. The chassis 156 has meanwhile rolling means 157 allowing movement on transverse rails 158, as shown schematically by the arrow 203, with an end of travel stop 159. When the length of the hollow body C is small, the extension provided by the projecting part of the movable arms 102 with their elongated spray head support 1 10 may be sufficient to prevent the support frame 101 from itself penetrating inside the hollow body . It is however naturally possible to organize a slow linear movement of the support frame 101 inside the hollow body C, for example by providing a bearing, either on the very bottom of said hollow body, or on rails 155 'extending the rails 155 above, as shown in Figure 12.

As a variant, it is possible to provide, as illustrated in FIG. 13, that the support frame 101 is mounted at the end of an arm 149, arranged to be driven by a linear movement shown diagrammatically by the arrow 202, said arm being integral with a mobile structure 150 comprising associated motorized drive means and possibly also height adjustment means: in fact, it will be necessary to provide such height adjustment means for the movable arm 149 so as to be able to perform a precise setting of the machine on the axis XC of the hollow body C.

It is also advisable to also provide stop means preventing excessive advancement of the machine inside the hollow body, which could lead to dangerous contact between the front end of the spray head supports and the bottom of the body. hollow. We can for example provide a stop 160 formed at the end of a stop support 161 secured to the self-propelled carriage 147, as can be seen in FIG. 1; in the case of mounting on a movable arm 149 as illustrated in FIG. 13, a similar abutment system will be provided naturally with said arm. The automatic painting machine which has just been described therefore allows regular application on the faces and in the corners of a hollow body of quadrangular section, with in addition an equally regular application speed. The synchronization of the mobile arms, when the machine comprises more than two mobile arms, makes it possible to simultaneously adjust the quantities of paint deposited on all the faces concerned when the oscillation speed of the mobile arms is modified. Such a machine thus makes it possible to find the same operating conditions and the same performance as for painting the external faces. The structure of this machine is relatively simple and robust, and it avoids a relatively large cantilever mounting, insofar as only the movable arms extend forward, the main mass of the machine being concentrated at level of its support frame. The adjustment of the stroke of the spray guns, adjustment which is possible during the operation of the machine, makes it possible to adapt very quickly and very easily to different sizes for successive hollow bodies to be painted. It should also be noted that the spray guns, arranged at the end of the movable arms, are always distant from the mechanical parts associated with the drive of the movable arms, which is advantageous in terms of maintenance, but also insofar as it is possible to effectively protect the motorized drive members against any projection of paint during use.

The invention is not limited to the embodiments which have just been described, but on the contrary encompasses any variant incorporating, with equivalent means, the essential characteristics which have just been described. The field of application of the invention also includes the possibility of using each movable arm independently for other applications, such as painting parts from the outside, since it then suffices to reverse the orientation. spray guns carried by this arm.

Claims

1 / Automatic painting machine (100), in particular for painting the interior of a hollow body of quadrangular section and of large dimensions such as a maritime container, characterized in that it comprises:

. a support frame (101) movable inside the hollow body (C) along the axis (XC) of said hollow body; . at least one mobile arm (102) mounted on the support frame (101) so as to be able to oscillate in a plane parallel to the face to be painted (I, II, III, IV), said mobile arm being articulated on the one hand on a intermediate connection point (103) integral with a carriage (105) driven by associated motor means (106) in a rectilinear, alternating and uniform movement, and on the other hand, at the level of a slide (107) provided at near its rear end (109), on a fixed connection point (104) integral with said support frame, so that its free end (109) describes an essentially flat arc (T) with a substantially constant speed; . an elongated spray head support (110) mounted at the free end (109) of the mobile arm (102), said support being articulated on said mobile arm (102) to oscillate in a plane parallel to the plane of oscillation of said arm and carrying a spray head (1 1 1); . a first coupling means (1 14) provided between the movable arm (102) and the elongated spray head support (1 10), forcing the axis (XS) of said support to keep a fixed direction parallel to the axis ( XC) of the hollow body, during the oscillation movement of said movable arm;

. a second coupling means (1 15) provided between the movable arm (102) and the elongated spray head support (1 10), forcing said support to oscillate continuously around its axis (XS) during the oscillating movement of said movable arm, at an angle (β) essentially proportional to the oscillation angle (oi) of said arm.

2 / Machine according to claim 1, characterized in that the fixed connection point (104) is adjustable in a direction essentially parallel to the axis (XC) of the hollow body, so as to allow adjustment of the amplitude of the oscillating movement of the movable arm (102). 11

3 / Machine according to claim 2, characterized in that the fixed connection point (104) is carried by a slider (1 16) which is movable in a fixed slide (1 17) integral with the support frame (101), the axial position of said slider being mechanically adjustable. 4 / Machine according to claim 3, characterized in that the axial position of the cursor (1 16) is adjustable by means of a screw-nut system (116, 1 18) controlled by a crank (119), so that the fixed connection point (104) can thus be adjusted during operation. 5 / Machine according to claim 1, characterized in that the first coupling means (1 14) is a linkage (120, 121, 122, 123) with parallelogram integrated in the movable arm (102), said linkage being connected to a rotary bearing (124) projecting laterally from said movable arm and supporting the elongated spray head support (110), the associated spray head (111) being mounted on said elongated support beyond said rotary bearing.

6 / machine according to claim 1, characterized in that the second coupling means (1 15) consists essentially of a fork (125) to which the spray head support is coupled, said fork carrying an end ball (128) pivoting on a nut (129) carried by the movable arm (102), so that the movement of said fork during the oscillation of said arm produces the oscillation of said support about its axis (XS).

7 / Machine according to claim 6, characterized in that the fork (125) surrounds a flattened rear end (130) of the spray head support (110).

8 / Machine according to claim 6 or 7, characterized in that the nut (129) is adjustable in position in the longitudinal direction of the movable arm (102), so as to allow adjustment of the amplitude of the oscillation movement spray head holder

(110) around its axis (XS).

9 / Machine according to claim 8, characterized in that the nut (129) is movable in a slide (132, 133) secured to the movable arm (102). 10 / Machine according to one of claims 1 to 9, characterized in that it comprises several movable arms (102) each of which is associated with a respective face to be painted (I, II, III, IV), each of said arms comprising first (1 14) and second (1 15) respective coupling means for controlling the movement of the associated spray head (1 1 1).

1 1 / machine according to claim 10, characterized in that the carriages (105) associated with the intermediate connection points (103) of the movable arms (102) are interconnected by a common drive chain (134), of which the reciprocating movement is provided by associated motorized drive means (106, 136, 137), so as to synchronize the oscillating movements of said arms.

12 / Machine according to claim 1 1, characterized in that the common drive chain (134) is arranged in a vertical plane, and the connection to said chain of the carriages (105) associated with the movable arms (102) is arranged in such a way that the spray heads (1 1 1) remain in a substantially vertical common plane during the oscillation movement of said mobile arms.

13 / Machine according to claim 1 1 or 12, characterized in that the reciprocating movement of the common drive chain (134) is communicated by one of the carriages (105), via a drive chain (138) carrying a finger (137) sliding in a groove (139) of said carriage, said drive chain being driven by a motor (144) whose speed can be adjusted by an associated operating member (145).

14 / Machine according to claim 4 and one of claims 10 to 13, characterized in that the movable sliders (1 16) and the fixed slides (1 17) for adjusting the amplitude of the arm swing movement mobile (102) are mounted on a support frame (146) located in a vertical plane and integral with the support frame (101), so that the cranks (1 19) controlling the associated screw-nut systems (1 16, 1 18) are all accessible behind said machine. 15 / Machine according to one of claims 10 to 14, characterized in that it comprises three or four movable arms (102) whose successive oscillation planes are orthogonal to each other.

16 / machine according to claim 15, comprising four movable arms, characterized in that the movable arms (102) correspond in central symmetry, so that the associated spray heads (1 1 1) are simultaneously oriented towards the four edges of the hollow body (a,., a ,,, a, ^, a.) when said arms are in position of amplitude of maximum oscillation. 17 / Machine according to one of claims l to 16, characterized in that the support frame (101) is mounted on a self-propelled carriage (147) which can roll on associated rails, via a support member (148) which is adjustable in height and which preserves the horizontality of said support frame. 18 / Machine according to one of claims 1 to 16, characterized in that the support frame (101) is mounted at the end of an arm (149) which can be animated with a linear movement.