Spraying booth having a fast discharge and product change station and related method of use

Abstract

An apparatus for spray painting, such as a spray booth, includes a system for conveying pieces to be painted; a supply circuit to a spraying tool; a spray nozzle carried by a support arm movable along a predetermined direction; and a product change station having a discharge system and arranged in a predetermined position with reference to the working path of the support arm. The spraying tool is combined with a first coupling terminal which moves with the support arm and is sealingly coupled with a discharge duct, which has a second coupling terminal with the first coupling terminal, the two terminals being automatically movable by motorized movement members when aligned along a portion of their paths for mutual approaching and separation.

Claims

1. An apparatus for spray painting, comprising a spray booth provided in combination with a product change station to spraying tools, the spray booth comprising: a system for conveying one or more pieces to be painted inside the spray booth and for evacuating the one or more pieces from the booth after painting; a supply circuit of a painting product and/or a solvent to one or more spraying tools, at least one spraying tool comprising a spray nozzle and being carried by a support arm which is translatable forward and backward on a working path along a predetermined direction and has a predetermined orientation relative to a transit path of the one or more pieces to be painted through the booth; and a product change station provided with a discharge system, which includes a discharge or evacuation system and is connectable to the at least one spraying tool and/or to the supply circuit of the at least one spraying tool of the painting product and/or the solvent, the product change station being provided in a predetermined position in the spray booth with reference to the working path of the support arm of the at least one spraying tool, wherein: the at least one spraying tool is provided in combination with a first terminal for sealing coupling to at least one discharging duct of the discharging system, the first terminal is on the support arm and moves along a predetermined trajectory together with a movement of the support arm along the working path, the discharge duct is provided with a second terminal for sealing coupling with a corresponding first terminal, the product change station, the discharge duct, and/or the first terminal (121) are provided in coincidence with a dedicated section and/or point of the path of the first terminal, in correspondence with which the first and the second terminal are in an aligned position with reference to a reciprocal coupling stroke, and the first terminal and/or the second terminal or the discharge duct are movable in relation to each other along the coupling stroke in a direction of reciprocal coupling, automatically when the first and the second terminal are aligned with each other with reference to the coupling stroke; further comprising motorized movement members, which can be activated alternately for an approach in a sealed coupling condition of the first and the second terminal and for a mutual separation in a decoupling condition.

2. The apparatus according to claim 1, wherein the coupling stroke and a decoupling stroke of the first terminal and the second terminal is rectilinear and in a transverse direction to a direction defined by the working path of the support arm, and optionally with respect to a transit direction of the one or more pieces to be painted in the spray booth.

3. The apparatus according to claim 1, wherein the discharge duct is configured as a straight tubular duct and is slidably mounted in a direction of its longitudinal axis in a guide, and can be moved alternately forward and backward along a rectilinear run parallel to the longitudinal axis between a position of coupling to the first terminal and a position of decoupling of the discharge duct due to a linear translation actuator.

4. The apparatus according to claim 1, wherein the second terminal comprises a sealing flange provided at an end of the discharge duct and facing the first terminal, and wherein the first terminal is constituted by a protuberance or spout shaped to hermetically engage in the sealing flange of the second terminal, a seal being generated by axial and/or possibly also radial compression between the first terminal and the second terminal.

5. The apparatus according to claim 1, wherein the path of the support arm and therefore of the first terminal is along a direction perpendicular to the coupling stroke and a decoupling stroke of the second terminal with the first terminal.

6. The apparatus according to claim 1, wherein the working path of the support arm is straight and in a horizontal plane, and wherein the direction of the coupling stroke of the second terminal is straight and vertical.

7. The apparatus according to claim 1, wherein the product change station is positioned in correspondence with an extension of the working path of the support arm and/or with an extra stroke section of the working path.

8. The apparatus according to claim 1, wherein the support arm and the at least one spraying tool are movable along further additional directions.

9. The apparatus according to claim 1, wherein there are two or more support arms that are independent from one another, wherein of the two or more support arms carries a spraying tool for dispensing the paint in one predetermined area, and wherein at least one or more product change stations are provided, which are each devoted to respectively to one or more spraying tools of only one or of a plurality of support arms.

10. The apparatus according to claim 1, wherein: the support arm carries a plurality of groups of spraying tools each comprising at least one spraying tool, each of which groups being connected to a dedicated feed duct of a product, each group of spraying tools being associated with a corresponding dedicated first terminal, the product change station has a single discharge duct couplable in sequence to each of the first and the second terminals, or the product change station has at least two discharge ducts, each devoted to at least one of the plurality of groups of spraying tools or to some of the plurality of spray groups on the support arm, spray pipes and corresponding first terminals being arranged in positions such as to allow a simultaneous automatic coupling of the corresponding first terminals with a corresponding dedicated discharge duct.

11. A method of product change to spraying tools in a spray booth comprising: defining a position of a product change station to a position such as to fall in correspondence with a stretch of extra run or of extension of a work path of a movable arm that carries at least one spraying tool, an orientation of the stretch coinciding with an orientation of the work path, without deviations from the work path; positioning, at a predetermined position of the extra run, a discharge duct with a second terminal with automatic coupling terminal to a corresponding first terminal associated with the at least one spraying tool and carried by the movable arm; positioning the first terminal on the movable arm and in such a position that when the predetermined position of the second terminal is reached in the extra run, the first and the second terminals are aligned with each other in a condition of ready coupling due to a relative coupling stroke along a direction transversal to the direction of the extra run and/or of the work path of the movable arm that carries the at least one spraying tool; detecting an alignment position of a coupling readiness condition of the first and the second terminals; commanding an actuation of a sealing coupling stroke of the first and the second terminals; carrying out discharge operations and/or optionally loading a new product; and commanding a decoupling of the first and the second terminals and an abandonment by the movable arm of an extra parking run of the movable arm in the product change station for an execution of a work stroke.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The present invention will be described below in one of its embodiments with the aid of the following figures, which show:

[0065] FIG. 1 is a side elevational view of a painting booth according to an embodiment of the present invention seen in a direction perpendicular to the direction of advancement of the piece to be painted;

[0066] FIG. 2 is an isometric view of the painting booth according to FIG. 1;

[0067] FIG. 3 is an enlarged view of the discharge station area for product change;

[0068] FIG. 4 is an enlarged view of the detail of a movable arm carrying a plurality of spraying tools, i.e., spray guns, and the product change station with the coupling terminal of the spraying tools to the terminal of the discharge duct not yet aligned with each other with reference to the automatic coupling stroke in scaled condition of the same;

[0069] FIG. 5 is a view of the enlarged detail of the coupling terminal associated with the movable arm carrying said or said spraying tools in a condition close to that of alignment along the coupling stroke with the terminal of the discharge duct;

[0070] FIG. 6 is a view analogous to that of FIG. 5, with the coupling terminal associated with the movable arm carrying said spraying tool or said spraying tools in the condition of sealed coupling with the terminal of the discharge duct.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0071] FIGS. 1 and 2 show a typical spray painting booth 100, where pieces to be painted, either predominantly flat-extended or three-dimensional, are conveyed by a conveyor 107 inside the booth into a painting position and then discharged from it. The pieces enter the booth through an entrance and exit through an exit, which are indicated by 101 and 102 in FIGS. 1 and 2.

[0072] The painting booth according to the present invention is equipped with a mobile arm 110 that carries a plurality of spraying tools denoted by 111, which are oriented with their spray nozzles to cover a predetermined area with the spray of paint.

[0073] The spraying tools, also known as guns, are connected through conduits 112 to one of two first terminals 113, 114. Terminal 114 forms a sealing coupling terminal with a corresponding second terminal 121 provided at the end of a discharge duct 120 facing towards terminal 114 carried by the mobile arm 110.

[0074] As shown in FIGS. 1 and 2, the mobile arm can move along a straight work path that is substantially perpendicular to the direction of advancement of the piece from the entrance 101 to the exit 102 of the booth, thereby passing over a transverse band of the piece relative to said advancement direction.

[0075] In the illustrated embodiment, the translation of the mobile arm 110, and thus of the guns 103, occurs in the horizontal plane, but this is not to be considered limiting of the present invention, although it is a preferred solution.

[0076] The aforementioned discharge duct 120 is mounted in a product change station globally indicated by 20. As shown in the figures, the product change station 20 is laterally adjacent to the conveyor 107 of the piece to be painted, and this position is reachable by the mobile arm 110 thanks to an end run terminal positioning of the same with the corresponding spraying tools 111 and with terminal 113 and/or 114.

[0077] When the mobile arm reaches the product change station 20, it is stopped in a position where the coupling terminal, to which the spraying tools 113 and/or 114 are connectedin this case terminal 114is positioned vertically aligned with the coupling terminal 121 provided at the facing upper end of the discharge duct 120.

[0078] In the illustrated embodiment, terminal 121 is provided on a straight terminal section of the discharge duct that has a predetermined length and is oriented with its axis in the vertical direction, while said discharge duct is connected to the rest of the discharge circuit 130 by means of at least one section of flexible tubing, and while said terminal section 120 of the discharge duct is mounted slidably axially in a guide support 122. Said terminal section 120 of the discharge duct is fixed to a linear actuator 140 that is oriented to perform a run in the vertical direction, i.e., parallel to the axis of the terminal section 102 of the discharge duct. (FIG. 3). The discharge duct may terminate in a collection system, for example in a collection container 150 shown also in FIG. 3.

[0079] Referring to FIGS. 4 and 5, these show the mobile arm in the extra positioning run stretch of the product change station and with one of the terminals 113 and 114 in a position close to alignment with the vertical run direction of the straight terminal section 120 of the discharge duct. In this case, the positioning of the mobile arm along the stretch of extra run is commanded in such a way as to bring terminal 114 into a vertically aligned position with terminal 121 at the end of the vertical section of the discharge duct 120 so that the coupling of the two terminals 121 and 114 can occur thanks to a straight and vertical coupling run performed by said terminal section 120 of the discharge duct following the actuation by the actuator cylinder 140.

[0080] The terminals 113, 114, and 121 can be configured in any manner and such that they ensure an automatic sealed coupling thanks to the sole vertical run of the terminal section of the discharge duct.

[0081] One possible solution among the many available to the expert in the field provides that terminal 113 and/or 114 on the mobile arm has a coaxial nozzle extension 115, preferably of elastically compressible material, which nozzle is intended to insert with a vertical run into the coincident hole of an annular flange which constitutes terminal 121 at the end of the vertical section of the discharge duct. Even in this case, said flange is made of elastically deformable material. The diameter of the hole has a size corresponding to a diameter of the extension 115, which is advantageously made conical or funnel-shaped. Said parts are sized so that at the time of their compression in coupling condition, axial and radial sealing surfaces are generated that produce the necessary seal for the execution of the product change operations.

[0082] The two terminals 113 and 114 can be associated with two different supply circuits 112 which each connect to a part of the spraying tools present on the mobile arm 110. Alternatively, the two circuits can be intended for performing different product change operations.

[0083] It is worth noting that the illustrated configuration provides for a single discharge duct in correspondence with which one of the two coupling terminals 113, 114, which connect to the two groups of spraying tools denoted G1 and G2, is brought according to a predetermined sequence.

[0084] Alternatively, it is possible that the product change station is equipped with two discharge ducts that are positioned side by side along the direction of said extra run of the mobile arm 110 and with a relative distance between them such that when one of the two terminals 114 or 113 is aligned relative to the coupling/decoupling run with a terminal of one of said discharge ducts, the other terminal 113 or 114 provided on the mobile arm is automatically correctly aligned with the other discharge duct. In this case, therefore, the product change operations can also be performed simultaneously for the two groups of spraying tools G1, G2.

[0085] As is evident from the above, the change operations are extremely simple and reliable, requiring only the positioning of the mobile arm and the detection of the correct alignment position of the terminal or terminals 113 and/or 114 with terminal 121 of the discharge duct 120 relative to the vertical run of coupling and decoupling of the same.

[0086] A control unit can execute a product change program that provides for commanding the mobile arm or arms, when there are more than one, in the corresponding product change station performing the expected extra run beyond the lateral limit of the piece conveying path. During the execution of this extra run, one or more sensors detect the position of the terminal or terminals 113 and/or 114 relative to terminal 121 of the discharge duct or a corresponding discharge duct when a discharge duct is provided for each terminal on the mobile arm, and stop the translation of the arm when said terminals are aligned in coincidence with the vertical run of reciprocal coupling with the corresponding discharge duct. In this condition, the linear actuator is activated, which translates the straight terminal section of the discharge duct or ducts vertically upwards, bringing the terminals into sealed engagement with each other.

[0087] At the end of the product change operations, the discharge duct or ducts are moved vertically downwards, and the mobile arm 110 can resume normal operation. [0088] 100 Paint booth [0089] 101 Entrance of the booth [0090] 102 Spray exit [0091] 107 Conveyor [0092] 110 Mobile arm [0093] 111 Spraying tool [0094] 112 Feeding conduits for spraying tools [0095] 113, 114 Coupling terminals [0096] 115 Nozzle extension [0097] 120 Discharge duct [0098] 20 Product change station [0099] 121 Coupling terminal on the discharge duct [0100] 130 Discharge circuit [0101] 140 Linear actuator [0102] 150 Collection container [0103] G1, G2 Groups of spraying tools served by a dedicated feeding circuit for each group