WO2014006593A1

WO2014006593A1 - Paint-spray gun

Info

Publication number: WO2014006593A1
Application number: PCT/IB2013/055504
Authority: WO
Inventors: Marco G. Vicentini
Original assignee: Anest Iwata Europe S.R.L.
Priority date: 2012-07-06
Filing date: 2013-07-05
Publication date: 2014-01-09
Also published as: DE212013000147U1; ITTO20120595A1

Abstract

A paint-spray gun (1) comprising a body (2) having an atomizer nozzle (4) for atomizing a paint to be sprayed, and a support (3) having a connector (8) for introducing compressed air. The body (2) and the support (3) are connected together in a readily separable way and set in the support (3) is at least one electrical and/or electronic device supplied by an electric generator (15, 16) incorporated in the support (3) and operated by the compressed air.

Description

"Paint-spray gun"

Field of the invention

The present invention relates to paint-spray guns, both of the manual type and of the so-called automatic type, comprising a body having a nozzle for atomizing a substance to be sprayed, and a support of the body having a connector for introducing compressed air to be supplied to the atomizer nozzle.

Prior art

Known from the document No. EP-B-1247586 filed in the name of the present applicant is a paint-spray gun of the manual type in which the support of the body of the gun, constituted by a grip, incorporates a digital or analog display operatively connected to a pressure sensor that may, for example, be constituted by an electronic transducer. This patent tackles the technical problem regarding the need to carry out periodic cleaning of the gun via washing with aggressive solvents, which might damage the display and the possible electronic transducer, and solves this problem thanks to the characteristic whereby the grip is constituted by an element distinct from the body of the gun and connected thereto in a rapidly dismantleable way. In this way, the body^' of the gun, i.e., the part with the functional components that come into contact with the paint and hence require periodic washing with solvents, can be readily removed from the grip and washed separately.

From European patent EP-B-1243341, which is also in the name of the present applicant, there is known an automatic paint-spray gun, for example used in the automotive industry for painting motor-vehicle bodies . Also in this case, the body with the atomizer nozzle is separably connected to the support with the connector for introducing the compressed air and may incorporate an electronic pressure transducer with corresponding display, as well as further electronic equipment for control of the pressure of the air and/or of the pressure of the substance to be sprayed as a function of parameters for optimizing the efficiency of transfer.

In both cases, the electrical and electronic devices provided in the support of the body of the manual or automatic gun evidently require an electrical supply and thus require the provision of connections and conductors for connection to a source. This entails the need for relatively complex wiring or else, for example in the case of manual guns, the use of batteries that must be protected against risks of explosion and be periodically replaced or recharged. In any case, the consumption of electrical energy is anything but negligible: it would thus be desirable to reduce this consumption, at the same time preventing the need for external wiring.

In the field of electrostatic paint-spray guns, it is known, for example from patent documents US- 4219865, US-4377838, US-4462061 and US-4978075, to use the kinetic energy of the flow of compressed air for driving an electric generator, which is incorporated in the gun and in turn supplies the electrodes thereof for generation of the electrostatic field. In all the documents referred to above, the electric generator, constituted by a turbine-alternator assembly, is housed inside the body of the gun, which cannot be separated from the corresponding support constituted by the grip, except with complex and in any case inconvenient operations of disassembly: consequently, this solution cannot be used in the case of the paint-spray guns to which the present invention expressly refers, considering the problems connected to the frequent periodic washing with solvents, as mentioned above.

Still in the case of electrostatic guns, document US-A-2002/038824 envisages positioning the turbine- alternator assembly in the handle of the gun in order to lower the centre of gravity thereof and render it more compact. Not even this document contemplates the technical problem regarding periodic washing of the gun, and in fact also in this case the handle and the body of the gun cannot be separated from one another, but are rather made of a single piece. This solution is not directly applicable to the paint-spray guns forming the subject of the present invention.

In the case of document US-B-7226004 , which also regards the specific field of electrostatic guns, the turbine-generator assembly is provided in an auxiliary element set between the grip and the body, with the atomizer nozzle that, in addition to entailing a constructional complication, does not envisage the possibility of being rapidly separated and removed for possible washing operations: instead, the bearings of the turbine are coated with substances expressly resistant to solvents.

From document US-2006/ 021982 there is also known an electrostatic spray gun equipped with a turbine- generator assembly contained in a body separably applied to the base of the grip of the gun so as to be interchangeable with similar bodies having a different source of electrical supply (battery or cables for connection to the electric-power mains, etc.) .

Summary of the invention

An object of the invention is to provide a paint- spray gun of the type defined at the beginning, inwhich it is possible to supply electrically^' the electrical or electronic device or devices provided in the support of the gun without any need for wiring to provide connection to an external source but also such as to enable periodic washing of the gun with solvents, without requiring particular arrangements for protection of the above devices .

A further object of the invention is to provide a paint-spray gun of the type defined above equipped with additional functions that will enable appreciable improvement of the painting quality, without, however, adversely affecting the ease of periodic washing of the gun .

According to the invention, the above and other objects are achieved thanks to a paint-spray gun as basically set forth in Claim 1.

The electric generator of the gun according to the invention consists of a turbine-alternator assembly, conveniently set immediately downstream of a pressure regulator provided on the support of the body of the gun, and such as to supply a flowmeter for measuring the flow of the compressed air and a corresponding digital display present on the support of the gun, where the above flowmeter is advantageously constituted by the turbine of the turbine-alternator assembly itself.

The possibility of controlling and regulating the flowrate of the compressed air enables appreciable improvement of the final painting quality obtained using the spray gun according to the invention.

The turbine-alternator assembly can moreover conveniently supply also an air-pressure transducer and corresponding digital display, an air-temperature transducer and corresponding digital display, a heater for heating the compressed air, a radio-frequency transmitter, an electronic controller, and possible further sensors, all housed inside the separable body of the gun.

According to a further and particularly advantageous embodiment of the invention, the spray gun according to the invention may moreover comprise a detector for detecting the flowrate of the paint sprayed, by means of which the final painting quality can be further refined.

The above paint- flowrate detector may include a measuring device applied to the body of the gun in the vicinity of the atomizer nozzle, an electrical transducer, and an associated digital display for displaying the flowrate of the paint measured, which are supplied by the electric generator.

The possibility of controlling the flowrate of the paint enables adaptation and possible replacement each time of the atomizer nozzle so as to optimize the spray cone as a function of the various intrinsic characteristics of the paints.

Brief description of drawings

The invention will now be described in detail with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which :

- Figure 1 is a schematic view in side elevation of a paint-spray gun of a manual type, according to the inventi on ;

- Figure 2 is a view similar to that of Figure 1, which shows the grip of the paint-spray gun of Figure 1 separated from the corresponding body;

- Figure 3 is a schematic, longitudinal, cross- sectional view of the grip of Figure 2 ;

Figure 4 is an exploded perspective view of

Figure 3;

- Figure 5 is a schematic perspective view of an automatic paint-spray gun according to the invention;

Figure 6 is a partially sectioned view in elevation of Figure 5;

- Figure 7 is a view similar to that of Figure 1 representing a variant of the paint-spray gun of a manual type, according to the invention;

- Figure 8 is a front perspective view of the gun of Figure 7;

- Figure 9 is a partially exploded view of Figure 8;

- Figure 10 is a dorsal and partially exploded perspective view of the gun of Figure 7;

- Figure 11 is a view in front elevation of the gun of Figure 7;

- Figure 12 is a vertical cross-sectional view of the gun of Figure 7;

- Figure 13 is a perspective view at a larger scale of a detail of the gun of Figures 7 to 12; and

- Figure 14 is a schematic perspective view of a variant of the automatic paint-spray gun according to the invention.

Detailed description of the invention

With initial reference to Figures 1 to 4, designated as a whole by 1 is a gun for spray painting of a manual type according to the invention, basically comprising a body 2 and a support for the body 2 constituted, in this case, by a grip 3 for manipulation of the gun 1.

The body 2 and the grip 3 are connected together in a rapidly dismantleable way, for example via a bayonet or slotted coupling, conveniently with the modalities described in the already cited document No. EP-B-1247586.

In , an altogether conventional way, the body 2 may be prearranged for removable application of a cup (not illustrated) containing the paint to be sprayed that is supplied to an atomizer nozzle 4, operatively associated to which, in a way equally known, are a first manual regulator 5 and a second manual regulator 6. At the bottom, in the area of coupling with the grip 3, the body 2 is provided with an inlet connector (not shown) , which can be engaged in a fluid-tight way by a corresponding connector 7 projecting at the top from the grip 3 and in turn in communication, as is represented in Figure 3, with a tubular connector 8 projecting from its bottom part and prearranged for being connected to a flexible pipe for supply of compressed air.

Designated by 9 is a manually operated pressure regulator provided for regulating the pressure of the air, which, coming from the connector 8, is sent through the connector 7 to the body 2 and then delivered, by pulling a trigger 10, to the atomizer nozzle 4.

The amount of pressure of the air determined via the regulator 9 is displayed on a digital display 11, typically a liquid-crystal display, set at one side of the grip 3 and operatively connected to- an electronic pressure transducer, designated as a whole by 12 in Figure 4.

The ■ transducer 12, or a different further transducer is, according to the invention, pre-arranged for constituting also a flowmeter for measuring the flow of the compressed air into the gun 1.

Moreover, the electronic transducer 12 (or different further transducers not illustrated nor described in detail in so far as they fall within the reach of the person skilled in the branch) may also have a section, for detection of the temperature of the flow of air through the grip 3. All the values detected (flowrate, typically expressed in litres per minute, and/or pressure and/or temperature of the air) are displayed in use on the display 11.

In Figure 4, reference number 13 designates as a whole a printed circuit board (PCB) carrying a microprocessor 14 operatively connected to the transducer or transducers 12 and to the display 11.

It should be noted that the grip 3 can house further electrical or electronic functional components, such as for example a resistor for heating the compressed air at input from the connector 8, as well as^" a transmitter operating at radio-frequency or with different wireless modalities for remote transmission of the data on the flowrate, pressure, and temperature of the air, and other parameters still. In this case, the data may be transmitted to a fixed or else portable receiver terminal, with storage capacity.

According to the invention, entrusted to the electrical supply of the electrical and electronic devices incorporated in the grip 3 is an autonomous generator assembly constituted by a turbine 15 driven in rotation by the flow- of compressed air that traverses the grip 3, and by an alternator coil 16 that surrounds the turbine 15 coaxially.

The turbine 15, positioned immediately downstream of the regulator 9, may be of any suitable type, either axial (as in the case of the example illustrated) or radial: the impeller with the corresponding shaft is conveniently made of plastic material, with one or more permanent magnets incorporated within it for generation of the field of electromagnetic induction in the coil 16. The alternating current generated thereby is then supplied to the electrical and electronic components incorporated in the grip 3 after being transformed into direct current via a rectifier 17, which is also provided on the printed circuit board 13.

Conveniently, the impeller of the turbine 15 also constitutes the flowmeter for measuring the flow of the compressed air at input to the gun 1.

It will emerge clearly from the foregoing description that the manual paint-spray gun 1 does not require any connection with an external source of electrical supply, in so far as all its electrical or electronic components can be sel f-supplied by the turbine 15-alternator 16 assembly in turn operated by the flow of compressed air supplied to the gun. Neither the turbine-alternator assembly, nor the transducers and sensors, nor again the display 11 require particular arrangements for their protection in regard to the solvents normally used for periodic washing of the gun, since for these operations the grip 3 can be rapidly removed from the body 2, which can thus be separately subjected to washing and then once again remounted on the grip 3 equally rapidly.

The same effect is achieved by the automatic paint-spray gun represented schematically in Figures 5 and 6 and designated as a whole by the reference 101. In this case, the body 102 of the gun 101, equipped with the nebulization nozzle 104, is connected in a rapidly dismantleable way to a supporting body or base 103 that can incorporate sensors and transducers, as well as possible further electrical and electronic devices similar to the ones described with reference to the manual spray gun 1. In particular, there is also provided an electrical stepper motor for regulation of the flow of paint via a mobile rod within the spray nozzle .

Also in this case, the electrical supply is provided by a generator formed by a turbine 115-winding 116 assembly operated by the flow of compressed air supplied to the base 103 through an inlet connector, designated as a whole by 108. The supporting base 103 is also equipped laterally with a digital display 111 for display of the pressure of the compressed air at input and possibly of its temperature.

The automatic gun 101 may incorporate further electronic equipment for measuring the flowrate and/or the pressure of the air, as well as the pressure of the substance to be sprayed as a function of parameters for optimizing the efficiency of transfer. This equipment may be connected in wireless mode to an electronic control unit provided for operating, for example, according to the modalities described in the aforementioned patent No. EP-B-12433 1. The remotely transmitted data will be processed on the basis of specific algorithms so as to carry out regulations suitable for optimizing the parameters of spraying and efficiency of transfer according to the objects to be painted and the movements to which the automatic guns will be subjected during painting.

Figures 7 to 12, where parts that are identical or similar to the ones already described previously are designated by the same reference numbers, show a variant of the manual gun, which is equipped not only with what has already been described with reference to Figures 2 to 4, but also with a detector for detecting the flowrate of the paint to be sprayed.

The paint-flowrate detector, designated as a whole by 17, may constitute an optional accessory or in any case may be selectively installed on the gun and be removable, and may thus also consist of an autonomous unit in the way represented in Figure 13.

The above detector 17 comprises a body 18, which may be applied, for example with a threaded coupling, to the body 2 of the gun 1 in the proximity of the atomizer nozzle 4, preferably immediately downstream thereof, and includes a geared measuring device 19 traversed in use by the flow of paint for operation of an electrical transducer 20 supplied by the electric generator 15, 16, for example via an external cable 21. In use, the datum detected is also displayed on the digital display 11, for example expressed in ml/min, as represented in Figures 7 to 10.

The detector 17 is moreover equipped with a silencer 22 connected to an outlet for the compressed air (see Figure 12), which, in the course of measurement of the flowrate of the paint, is supplied to the gun for driving the electric generator 15, 16 and is then emptied on the outside of the atomizer nozzle 4.

The possibility of controlling and regulating the flowrate of the compressed air, as well as the flowrate of the paint supplied to the gun, enables appreciable improvement of the final painting quality obtained via the spray gun according to the invention.

As is illustrated in Figure 14, also the automatic gun 101 can be equipped with a similar detector 17, substantially having the same characteristics as the one described above, as well as having the same function of measurement and representation on the display 111 of the value of flowrate of the paint supplied to the nebulization nozzle 104.

Of course, the details of construction and the embodiments may vary widely, with respect to what has been described and illustrated herein, without thereby departing from the scope of the present invention as defined in the ensuing claims .

Claims

1. A paint-spray gun (1; 101) comprising a body (2; 102) having an atomizer nozzle (4; 104) for atomizing a paint to be sprayed, and a support (3; 103) of the body (2; 102) having a connector (8; 108) for introducing compressed air to be supplied to said atomizer nozzle (4; 104) , wherein the body (2; 102) and the support (3; 103) are connected together in a readily separable way and set in the support (3; 103) is at least one electrically supplied device (11, 12; 111) , said gun being characterized in that the support (3; 103) connected in a readily separable way to the body (2; 102) incorporates an electric generator (15, 16) operated by the compressed air introduced into said inlet connector (8; 108) for supplying said at least one electrically supplied device (11, 12; 111) .

2. The gun according to Claim 1, characterized in that the electric generator consists of a turbine- alternator assembly (15, 16) .

3. The gun according to Claim 2, characterized in that said at least one electrically supplied device (11, 12; 111) includes a flowmeter (15) for measuring the flow of the compressed air and a corresponding digital display (11; 111) for displaying the flowrate measured, said display being applied to the support (3) of the gun, wherein said meter is constituted by the turbine (15) itself of the turbine-alternator assembly (15, 16) .

4 . The gun according to Claim 3, characterized in that said at least one electrically supplied device further includes a pressure transducer (12) for measuring the pressure of the compressed air and a corresponding digital display (11; 111) for displaying the pressure detected.

5 . The gun according to Claim 3, characterized in that said at least one electrically supplied device further includes a temperature transducer for measuring the temperature of the compressed air and a corresponding digital display (1; 111) for displaying the temperature detected.

6 . The gun according to any one of Claims 3 to 5, characterized in that said at least one electrically supplied device further includes a heater for heating the compressed air introduced into said connector for introducing compressed air (8; 108) .

7 . The gun according to any one of Claims 3 to 6, characterized in that said at least one electrically supplied device further includes a wireless transmitter.

8 . The gun according to any one of Claims 1 to 7, characterized in that said at least one electrically supplied device includes a flowrate detector (17) for detecting the flow of the paint.

9. The gun according to Claim 8, characterized in that said paint- flowrate detector (17) includes a measuring device (19) applied to the body (2) of the gun (1) in the vicinity of the atomizer nozzle (4) , and an electrical transducer (20) and an associated digital display (11; 111) for displaying the flowrate of the paint measured, which are supplied by said electric generator (15, 16) .

10. The gun according to Claim 9, characterized in that said paint-flowrate detector (17) is removable.

11. The gun according to one or more of the preceding claims, characterized in that it consists of a manual gun, the support of which defines a grip (3) , which is provided with a pressure regulator (9) for the compressed air introduced into said inlet connector (8) , and in that said electric generator (15, 16) is set in the grip (3) immediately downstream of said pressure regulator (9) .

12. The gun according to any one of Claims 1 to 10, characterized in that it consists of an automatic gun (101) operatively connected to remote electronic equipment for control and regulation of the pressure and/or flowrate of the air and of the pressure and/or flowrate of the substance to be sprayed as a function of parameters of optimization of the efficiency of transfer.