The present invention relates to workpiece processing arrangements.
There are many industrial processes in which work pieces (components or parts) are surface treated, for example painted or powder coated.
A spray booth is a structure that provides a ventilated, air filtered and temperature controlled environment in which spraying activities such as painting and powder coating can take place. A spray booth is necessary for the safe execution of such activities, since the sprayed materials include solvents and particulate material that must not enter the atmosphere in large quantities. The particulate material that does not stick to the article being sprayed must be removed from the spraying area to ensure safe working conditions, and to manage environmental impact.
A spray booth also provides a controlled supply of filtered air that aids the spraying process and leads to higher quality finishes. In addition, it is necessary to heat sprayed materials in order to dry them (in a process known as baking), and a spray booth typically provides a controlled temperature environment in which such baking can be undertaken.
In the automotive sector, a body shop which repairs and repaints cars and other vehicles may have the need to prepare and spray small components, such as wheels. Using a spray booth designed for spraying of whole vehicles is wasteful in several respects; the energy requirements for the booth are high, relative to the objects being sprayed, the size of the booth significantly exceeds that required for the smaller objects, and the use of a full booth for smaller jobs creates organizational issues for the spray booth operator.
Accordingly, it is desirable to provide a spray booth arrangement that is tailored for smaller objects, in order to enable higher efficiency in processing of those smaller objects, whilst providing the required controlled environments for spraying and finishing at a reasonable cost.
According to a first aspect of the present invention, there is provided a workpiece processing arrangement comprising a spray booth defining a work space, and operable to provide a controlled environment for spraying of material, a first oven located adjacent a first end of the work space, the first oven defining an internal zone, and being operable to heat that internal zone to a desired temperature, a second oven located adjacent a second end of the work space, the second oven defining an internal zone, and being operable to heat that internal zone to a desired temperature, and a transport rail which extends from the internal zone of the first oven, through the work space of the spray booth into the internal zone of the second oven, the transport rail being adapted for transport of a workpiece from the work space of the spray booth to the internal zone of each of the first and second ovens and into the work space from the internal zone of each of the first and second ovens.
In one example, the spray booth comprises a roof portion, a side portion which extends from the roof portion to a floor, first and second end portions which extend from respective opposing ends of the roof portion to the floor, the roof portion, side portion and first and second end portions thereby defining the work space having a substantially closed side, a pair of substantially closed ends, and a side substantially open to the outside of the booth, the work space including a work zone in which an operative is located during use of the spray booth, and a spraying region in which a workpiece is located during spraying thereof, air input equipment operable to provide an input airflow at an input volume flow rate into the work space via the roof portion, and air extraction equipment operable to extract output airflow at an output volume flow rate from the work space.
The input volume flow rate may be greater than the output volume flow rate. For example, the input volume flow rate is at least twice the output volume flow rate.
In one example, the roof portion defines a plenum into which the airflow is supplied. In one example, the air input equipment comprises a fan unit mounted on the roof portion.
The air extraction equipment may comprise an extraction aperture located in the side portion, a fan unit located outside of the workspace, extraction ducting extending from the extraction aperture to the fan unit, and an extraction filter.
Such an example may also comprise an air outlet connected with the fan unit, and arranged for connection to an air outlet chimney. In one example, the first oven defines a baking zone and a curing zone in the internal zone of the oven, the first oven being operable to heat the baking zone to a baking temperature, and to heat the curing zone to a curing temperature, the baking temperature being higher than the curing temperature. The baking zone may be located above the curing zone. In a particular example, the first oven defines a first aperture for access into the baking zone, and a second aperture for access into the curing zone, the first and second apertures being provided with respective doors for selective closure thereof.
According to a second aspect of the present invention, there is provided a method of processing a work piece in a workpiece processing arrangement comprising a spray booth defining a work space, and operable to provide a controlled environment for spraying of material, a first oven located adjacent a first end of the work space, the first oven defining an internal zone, and being operable to heat that internal zone to a desired temperature, a second oven located adjacent a second end of the work space, the second oven defining an internal zone, and being operable to heat that internal zone to a desired temperature, and a transport rail which extends from the internal zone of the first oven, through the work space of the spray booth into the internal zone of the second oven, the transport rail being adapted for transport of a workpiece from the work space of the spray booth to the internal zone of each of the first and second ovens, and into the work space from the internal zone of each of the first and second ovens, the method comprising, locating a first workpiece in the work space of the spray booth, performing an operation on the first workpiece, moving the first workpiece to the internal zone of the first oven using the transport rail, locating a second workpiece in the work space of the spray booth, performing an operation on the second workpiece, moving the second workpiece to the internal zone of the second oven using the transport rail, moving the first workpiece from the first oven to the work space of the spray booth using the transport rail, removing the first workpiece from the work space of the spray booth, moving the second workpiece from the second oven to the work space of the spray booth using the transport rail, and removing the second workpiece from the work space of the spray booth.
The air handling plant 3 comprises an air inlet region 31, which provides air 35 into the work space 2, and an air extraction filter 32 through which air 36 is extracted from the spray booth zone 2.
The ovens 4 and 5 each incorporate a high temperature baking zone 41, 51, and a lower temperature curing zone 42, 52. Each oven 4, 5 is provided with a door 43, 53 to enable access to the curing zone 42, 52.
The work space 2 is provided with air handling plant 3 which is operable to provide clean air input into the work space 2, and to extract contaminated air from the work space 2, and in particular from the spraying region 22.
The air handling plant 3 comprises an inlet fan 34 which draws clean air in from outside of the spray booth and passes this clean air into an inlet plenum 31 which extends across the ceiling area of the spray booth work zone 21. The inlet fan 34 preferably includes an air filter or filters in order that the air input into the work space 2 is cleaned to a required standard.
An air extraction port 32 is provided in a side wall 25 of the spraying region 22. An air extraction fan 37 draws air 36 through the extraction port 32, through ducting 38, and causes the air to be expelled from the spray booth arrangement 1 via a chimney 33. The extraction port 32, the extraction fan 37 and/or the ducting 38 preferably includes one or more filter elements for removal of contaminants from the extracted air before release from the arrangement 1. In many installations it is required that the air being expelled from the arrangement has a significantly reduced level of contamination, and so suitable filtration may be provided in the extraction part of the air handling plant 3.
The transfer rail 6 extends through the spraying region 22, such that a workpiece 10 can be sprayed and worked on in a filtered controlled air environment. A worker (not shown for clarity) is able to spray the workpiece 10 as it is suspended from the transfer rail 6 in the spraying region 22 from the work zone 21. Any appropriate spraying process may be carried out in the spraying area, for example spraying of water or other liquid based paints, or powder coating in which dry particulate material is sprayed onto the workpiece 10.
The spray booth arrangement shown in
Accordingly, in an embodiment of one aspect of the present invention, the flow rate of clean air input to the work space 2 is higher than the rate of extraction of air from the spraying zone 22 of the work space 2. In one preferred example, the flow of air into the work space 2 is approximately twice the flow rate of air extracted through the extraction port 32. For example, the input flow rate may be approximately 30000 m3/hr with the extraction rate of approximately 15000 m3/hr. This difference in flow rates results in a flow of clean air out of the open side of the spray booth arrangement 1, which provides an air curtain 28. This air curtain 28 provides a barrier that serves to prevent ingress of contaminants from outside of the spray booth arrangement 1 through the open side thereof. The extraction flow rate is chosen such that all, or substantially all, of the contaminated air from the spraying region 22 is removed from the work space zone 2, without reaching the work region 21. In this way, any release of contaminated air can be closely controlled.
In accordance with another aspect of the present invention, the oven 4 defines a high temperature baking zone 41, and a lower temperature curing zone 42. The baking zone 41 is arranged above the curing zone, and operates at a temperature higher than that of the curing zone. The transport rail 6 extends into the baking zone 41. An opening in a side wall 30 of the baking zone 41 is provided, and is positioned such that a workpiece 10 can be moved into and out of the baking zone 41 using the transport rail 6. A sliding door 50 is used to selectively close the opening into the baking zone 41 of the oven 4.
In addition, the oven 4 is provided with a lower door 43 to enable access thereto from the work space 21. The lower door 43 is combined with a workpiece support 44, which is attached to the lower door 43, and which extends into the curing zone 42 when the lower door 43 is closed. The workpiece support 44 may be provided with an upstand 45 on which a workpiece 11 is supported. Operation of the lower door 43 and workpiece support 44 will described below with reference to
Processing of workpieces will now be described with reference to the schematic views of
A first pair of wheels 10 is loaded onto a frame on the transport rail 6 in the spraying zone 22 (
Once the first pair of wheels 10 have been sprayed, they are moved into the baking zone of one of the ovens, in this case the first oven 4 (
Now that the spraying zone 22 is free, a second pair of wheels 10A is loaded onto the transport rail 6 (
Some finishing operations require a second spraying stage, and that can now be completed in the spraying zone 22 for the first pair of wheels 10. The first pair of wheels may then be returned to the oven 4 for a further baking stage. Alternatively, the first pair of wheels 10 may require curing in the curing zone of the first oven 4 (the curing zone of the second oven may be used), and so this first pair of wheels 10 is moved by the operator to that curing zone.
Once the first pair of wheels 10 has been moved out of the spraying zone 22 into the curing zone of the first oven 4, then the spraying zone 22 is again free for use. A third pair of wheels 10B may then be placed in the spraying zone 22 for processing while the second pair of wheels 10A are baked in the second oven 5. Such a situation is illustrated in
The second pair of wheels 10A can be removed from the second oven 5, and then handled appropriately, for example being placed in the curing zone, thereby enabling a further pair of wheels to be processed and baked.
As will be readily appreciated, the arrangement described above enables increases in efficiency in the processing of workpieces, such as wheels, by enabling the workpieces to be transported between processing locations easily, using the transport rail, and by enabling processing to be carried out in parallel. That is the baking and curing ovens are separate to the spraying zone, thereby enabling baking and curing to carry on in parallel with one another and with a spraying process on another workpiece.
Number | Date | Country | Kind |
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1419805.5 | Nov 2014 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2015/053264 | 10/30/2015 | WO | 00 |