KR20230129059A - Paint gun with improved adjustment system - Google Patents

Abstract

A painting gun (3) for painting an article, comprising a free section of an opening (7) of the gun (3) through which a painting fluid can flow upon rotation in one direction or the other about an axis (A). and a steering system (9) comprising a wheel (10) configured to rotate about an axis (A) to change, the steering system (9) comprising actuator means configured to rotate the wheel (10).

Description

Paint gun with improved adjustment system

CROSS REFERENCES TO RELATED APPLICATIONS

This patent application claims priority from Italian Patent Application No. 102020000028433 filed on November 25, 2020, the entire disclosure of which is hereby incorporated by reference.

technical field

The present invention relates to a painting gun, in particular an airbrush gun, equipped with a regulating system for painting fluid flow.

Known painting systems generally include at least one paint gun configured to spray a painting fluid onto an object to be painted.

Accordingly, such guns, ie airbrushes, generally have an opening through which this painting fluid under pressure can flow in the direction of the object to be painted.

In the prior art, adjustment of fluid flow in paint circuits in which airbrush guns are used can occur in the following ways:

- by regulating the pressure of a centralized paint supply pump located upstream of the circuit;

- by manually adjusting the steering wheel present in every case; or

- by using servopneumatic throttle devices to be placed between the paint supply tube and the gun;

Clearly, centralized control where adjustment of paint fluid flow is performed upstream of the gun supply tubes is not precise, as all guns are supplied with a flow designed to meet the needs of the gun with the greatest fluid need. This is because fluid flow is provided. Dedicated adjustments for each gun at the hydraulic level are instead very complex, bulky and expensive.

On the other hand, manual adjustment significantly affects the maintenance time of paint systems as each gun must be manually adjusted to correct the amount of paint to be delivered.

Finally, with intermediate adjustment devices to be inserted in series on the paint circuit, precise adjustment is not possible when small quantities of product have to be conveyed. These increase the time needed to maintain the system, as it requires more time for maintenance and can become clogged with narrow internal passages through which the paint flows.

Accordingly, there is a need to provide paint guns that can be operated in an automated, compact, accurate and economical manner.

There is also a need to limit maintenance time without the need to add other devices that operate in the paint supply circuit.

The object of the present invention is to fulfill the above mentioned requirements.

The above object is achieved by the paint gun and paint system claimed in the attached independent claims.

Further preferred embodiments of the invention are structured according to the dependent claims or the claims linked to the independent claims.

For a better understanding of the present invention, preferred embodiments are described in the following by way of non-limiting example with reference to the accompanying drawings:
1 is a longitudinal sectional view of a painting system comprising a painting gun according to the invention;
Figure 2 is a cross-sectional view along line II-II of the steering system of Figure 1;
3 and 4 are partially enlarged longitudinal sectional views of the different operational stages of the adjustment system for the paint gun of FIG. 1 ;
5a to 5f are longitudinal cross-sections of the different operational stages of the adjustment system for the paint gun of the system of FIG. 1;
6 is a partially exploded perspective view of the system painting gun of FIG. 1;

In FIG. 1 , a part of a paint shop 1 comprising at least one paint assembly 2 each equipped with a paint gun 3 is illustrated. In the illustrated figure there is a single paint assembly 2 for simplicity. In particular, the paint gun 3 extends along the longitudinal axis A and is supported by a support 4, which may be fixed to a main body (not shown) fixed to the paint system 1.

Advantageously, the support 4 comprises a fixing part 4a configured to fix the support 4 to the body of the paint shop 1 .

Additionally, the support 4 defines first and second lateral reliefs 5 extending longitudinally parallel to the axis A and overhanging the fixing portion 4a. The support 4 is preferably made of a material that remains stable and does not change over time, such as stainless steel.

The first and second lateral reliefs 5 transversely define between them a seat designed to partially receive the paint gun 3 .

The paint gun 3 defines a casing 3a, which is preferably cylindrical in shape and defines an interior space 3b designed to accommodate the flow adjustment system 6 for the paint gun, as described below. configured to limit

As is known, the flow regulation system 6 preferably comprises a rod 6a configured to open and close a free section of the opening 7 defined as the nozzle outlet section. The opening 7 is fluidly connected to a known source 8 of painting fluid.

In particular, the rod 6a is connected to adjusting means 9 configured to adjust the position of the maximum vertical stroke along the axis A of the rod 6a as described below.

As is known, the movement of rod 6a along axis A is actuated using a pneumatic system 6b. In particular, the pneumatic system 6b is actuated through air intake from the duct 6d' and returns to its neutral position, i.e. to the closing of the elastic means 6f when air flows from the duct 6d'. It includes a piston 6c that resists and returns.

The piston 6c is connected to a second piston 6g, which is integral to the piston 6c and pressurized which can flow from the duct 6d″ and then towards the opening 7 It is configured to allow the passage of air. In particular, air flows in ducts that are fluidly separated from the opening 7 and communicate with the outside through orifices 3b formed around the opening 7 .

As the components of the flow adjustment system 6 are known, they will not be described in further detail for the sake of brevity.

The rod 6a is held by the cylinder 6c, with a lower first end position where the opening 7 is closed by the rod 6a and a higher end position where the maximum stroke is defined by the adjusting means 9. Between the two end positions follows their movements, between the rod 6a and the opening 7 there is an empty section for the passage of the painting fluid from the source 8.

These adjusting means 9 essentially comprise a wheel 10 configured for rotation about an axis A and actuator means 11 configured for adjusting this rotation of the wheel 10 .

Advantageously, these actuator means 11 are pneumatic actuator means.

According to the advantageous embodiment described, the adjustment means 9 comprises a first actuator means 11' configured to enable a clockwise rotation of the wheel 10 about the axis A and about the axis A. and actuator means 11'' configured to enable counterclockwise rotation of the wheel 10 to Obviously the actuator means 11', 11" act alternately relative to each other.

A clockwise or counterclockwise rotation of the wheel 10 enables a reduction or increase of the second end portion, i.e. the upper stop of the rod 6a, respectively, thus maximizing the passage between the rod 6a and the opening 7. change section

According to the embodiment illustrated in FIG. 2 and below, each actuator means 11 is housed in a support element 13 in a free state with respect to translational movement and has a respective respective one formed on the wheel 10 for controlling its rotation. and a tip 12 configured to contact and cooperate with the sheets 14 .

The sheets 14 are preferably spaced at equal angles in the circumferential direction such that there is equal angular pitch between one sheet 14 and the other. In the case described, there are 20 sheets 14 spaced at equal intervals of 18° around axis A.

In particular, the support element 13 is configured to be fixed to the support body 4 in a position where the wheel 10 of the paint gun 3 can be wound at least partially laterally. In particular, when fastened to the support body 4, the fastening element extends so as to project above and preferably perpendicularly to the fastening portion 4a of the support body 4.

Accordingly, the support element 13 preferably comprises a fixing part configured to fix the support element 13 to the support body 4 and an end part configured to at least partially wind the wheel 10 of the paint gun 3 . .

This end portion preferably defines an arcuate portion facing the wheel 10, more preferably concentric with it.

Support element 13 is advantageously hollow, ie receives tip 12 therein and translates along axis C of tip 12, preferably parallel to axes A and B. Defines a through opening 15 configured to allow the

In particular, the through opening 15 includes a first portion 15', a middle portion 15'' and a second portion 15''', the second portion being relative to the first portion 15'. They are located on opposite sides along axis (C). Advantageously, all parts 15', 15'', 15''' are advantageously axially symmetrical, preferably cylindrical, and the first part 15' is compared to the middle part 15''. With larger transverse dimensions about axis C, the middle portion 15'' then has a larger transverse dimension about axis C compared to second portion 15'''. According to the illustrated embodiment, the diameter of the first portion 15'' is greater than the diameter of the middle portion 15'', and the diameter of the middle portion 15'' is then, in turn, the second portion 15'''. ) is larger than the diameter of

The second portion 15''' is sized such that the tip 12 contacts and cooperates with the inner walls radially defining the second portion 15'''.

In particular, the tip 12 has a first end portion 12a configured to mechanically cooperate with the wheel 10 and partially slidable in the second portion 15″″ of the opening 15, and the first end portion and a second end portion (12b) opposite to (12a) and configured to slide into the first portion (15') of the fluid-tight opening (15). The first end portion and the second end portion are connected to each other by means of an intermediate portion 12c.

The second end portion 12b essentially keeps the first portion 15' in fluid contact with the pressurized fluid source F and the first portion 15' fluidly away from the first portion 15'a. It defines a piston dividing into a separate second part 15'b.

An unexemplified pressurized fluid source F selectively directs a pressurized air flow F into the second portion 15'b to exert a force against the second end portion 12b and thus against the tip 12. It is advantageously a pneumatic source configured to provide.

The tip 12 is in a first (resting) operating position ( FIG. 3 ), wherein the first end portion 12a is not cooperating with the wheel 10 , and in a second (working) operating position ( FIG. 4 ), where the first end portion 12a is not cooperating with the wheel 10 . One end portion 12a is configured to move along the axis C between and cooperating with the wheel 10 .

In particular, the actuator means 11 comprises an elastic means 17 configured to hold the tip 12 in a first operating condition. This resilient means is preferably operably disposed between the second end portion 12b and the support element 11', more preferably within the opening 15.

According to the described embodiment, the resilient means 17 are accommodated inside the second and third parts 15', 15'' of the opening 15.

In particular, the resilient means 17 is received around the middle part 12c of the tip 12, which is preferably coaxial with respect to it, and the second and third parts 15'', 15''' of the opening 15 ) and a second end in contact with the second end portion 12b of the tip 12 and a first end in contact with the shoulder defined by the narrowing between the helical springs 18.

The tip 12 advantageously includes a pawl 20 movably held by the first end portion 12a of the tip 12 and configured to contact and cooperate with the wheel 10 .

In particular, the pole 20 is advantageously L-shaped, ie a first arm 20' and a second arm connected via a hinged connection 21 to the first end portion 12a of the tip 12. (20''). Advantageously, the first and second arms 20', 20'' are constructed in one piece. Hinge 21 allows rotation of pole 20 about an axis parallel to axis A between a first limit and a second limit.

In particular, the first arm 20' is sized to cooperate with the seats 14 of the wheel 10 to control the movement of the wheel 10 when in one of the rotational constraints of the pawl 20. all.

The actuator means 11 advantageously comprises thrust means 23 configured to exert a direct force against the tip 12 during a stroke of the tip 12 along a corresponding axis C. In particular, the thrust means 23 is a sphere positioner 25 comprising a sphere 24 designed to enter the corresponding seat 25 under the action of a predetermined force provided by the tip 12. includes

In particular, the wheel 10 is carried by a movable part 10', which defines the aforementioned seats 14 and with which the aforementioned adjustment system 9 operates, and a casing 3a and comprises a movable part 10'. It includes a fixed part 10'' which is held to rotate freely.

In particular, the movable part 10' is integral with the threaded pin 230, for example implanted, inside the through opening 31 of the movable part 10'. The threaded pin 30 cooperates by screwing with the threaded shaft 32 which in turn is connected via a thread formed in the radial inner surface of the through opening 33 formed in the fastening portion 10''.

The integral rotation between the threaded pins 30 accompanies the rotation of the threaded pin 31 and thus causes the threaded shaft 32 to move along the axis A. The threaded shaft 31 acts as a stop for the rod 6a so that the maximum opening H of the opening changes relative to the shaft 31 and, consequently, the rod 6a and the opening 7 of the nozzle. ), the maximum opening of the space between them changes.

Additionally, the adjustment system 9 has angled timing means 35 configured to adjust the relative starting position of the adjustment system 9, i.e. between the movable part 10' and the stationary part 10'' of the wheel 10. ).

In particular, the angled timing means 35 comprises a positioner 36, for example similar to the positioner 23, which is configured to cooperate with a plurality of inner seats formed radially corresponding to the seats 14. . Additionally, the timing means 35 includes a reference dowel 37 formed on the outer surface of the body 3a.

The timing means 35 also includes an additional reference dowel 38 formed in the body 3a of the gun 3 .

The operation of the adjustment system 9 for the paint gun 3 described above with reference to Figs. 5a to 5f and the left actuator 11' is as follows.

In Fig. 5a, the rest state in which the tip 12 is in a first operating condition is illustrated. In this state, there is no pressurized air in the chamber 15'b to overcome the force exerted by the elastic means 17, thus holding the second end portion 12b at a predefined rest point. In this state, the poles 20 do not contact and cooperate with the seat 14 .

In Fig. 5b, the stroke start state of the tip 12 under the action of pressurized air entering the chamber 15 is illustrated. In particular, the pressurized air exerts a force that overcomes the force exerted by the elastic means 17 which tends to compress. Thus, the second end portion 12b tends to enter the opening 15 . As a result, the first end portion 12a moves until the first arm 20' touches one of the walls of the seat 14 of the wheel 10 in a state held by the second end portion 12b. do. During this step, the thrust means 23 impedes the rotation of the pawl 20 so that the first arm 20' is "hooked" on the corresponding seat 14, i.e. the sphere 24 is the second Apply pressure to the arm 20''.

In Fig. 5c, the rest state in which the tip 12 is in the second operating condition is illustrated. In this state, the pressurized air in the chamber 15' completely overcomes the force exerted by the elastic means 17 so that the second end portion 12b is in contact with the shoulder between the portions 15' and 15''. come into contact In this state, since the pole 20 is caught on the seat 14, the tip 12 drags the wheel 10 during movement and causes the wheel 10 to rotate around the axis A.

In FIG. 5C , pressurized air flows from the chamber 15 when the second operating condition is reached. As a result, the elastic means 17 tends to overwhelm the force exerted by the pressurized air in the chamber 15 and push the second part 12b towards the position taken in the first operating condition of Fig. 5a. During this movement, the arm 20' is disengaged from the corresponding seat 14.

During steps 5b and 5c, the thrust means 23 provides a force configured to maintain contact between the tip 12 and the pole 10 .

Continuing its movement toward the state of Fig. 5a, the thrust means 23 has a single pole pushed by the sphere 24 tending to disengage from the seat 25 forcing the second arm 20'' ( 20) (Fig. 5e). In this way (FIG. 5F), the pole 20 will be rotated to pivot in its original position so that the cycle of operation of the wheel 10 can begin again.

The operation of the right actuator 11'' is the same as that of the left actuator 11' described above; That is, since it is simply a mirror image, it operates the wheel 10 to rotate counterclockwise.

As a function of what has been described above, counterclockwise rotation of the wheel 10 allows rotation of the threaded shaft 32, and the maximum opening H between the rod 6a and the end stop defined by the latter increases This increases the flow of the painting fluid that can flow between the rod 6a and the opening 7 of the nozzle. In contrast, clockwise rotation of the wheel 10 reduces the maximum opening H, potentially reducing this flow of painting fluid to zero.

Correct assembly of the wheel 10 is ensured by angular timing means 35 . Positioner 36 serves to hold sheets 14 in their correct angular position relative to tip 12 . In contrast, the set of criteria given by the position of the dowel 37 and the positioner 36 itself dictates assembling the wheel 10 to maintain a pre-fixed distance between the rod 6a and the opening 7 of the nozzle. make it possible

Obviously, the actuator means 11 is electrically powered by means of a control unit (not described) which processes the data necessary for painting objects by means of the paint gun 2 and consequently adjusts its operation so as to provide the correct flow of painting fluid. -Can be controlled at pneumatic level.

From the foregoing, the advantages of the paint gun and paint system according to the present invention are clear.

Thanks to the proposed gun, the liquid flow can be adjusted autonomously through opening and closing of the adjusting wheel, allowing fine, singular and quick adjustment of each individual gun in the painting system.

The use of a pneumatic actuator allows for automatic adjustment of the wheel 10 and no longer manual adjustment, providing significant economic benefits given the reduction in maintenance time used to manually adjust the guns in the prior art. do.

Additionally, the present invention allows simple and quick adjustment of the flow of liquid delivered by each airbrush device without the need to intervene additional maintenance-prone components between the paint supply circuit and the gun. The presence of two actuators per direction of rotation simplifies this pneumatic-mechanical coordination.

The presence of the seats at fixed distances makes it possible to adjust the opening of the wheel constantly and thus in a calculable way.

The presence of the thrust means facilitates the engagement between the pole and the seat, thus making it possible to repeat the operation at high speed.

Similarly, the presence of the resilient means allows rapid return of the tip to the rest position, allowing repeated actuation at high speeds.

Clearly, the proposed adjustment mechanism for the wheel 10 provides a passage between the rod 6a and the opening 7 of the nozzle, which depends on the number of seats 14 formed on the wheel and the pitch of the threads of the shaft 32. Allows for extremely fine adjustments. For example, in the illustrated example comprising 20 seats 14 and a thread of 1 millimeter, it is possible to adjust the vertical distance of the rod from the wheel 10 to 0.05 mm, thus enabling extreme precision.

Thanks to the angled timing means 35, it is also possible to accurately assemble and reassemble the wheel 10 without missing the exact calibration of the opening between the rod 6a and the opening 7 of the nozzle.

Finally, it is clear that changes may be made to the paint gun and paint system according to the invention and the modifications produced therefrom, in any case without departing from the scope of protection defined by the claims.

The types of elastic means and thrust means may vary, for example in the shape of the support elements, poles or tips and their materials of construction.

Likewise the actuator means may be electromechanical or hydraulic.

Claims (12)

A painting gun (3) configured to paint an article, the painting gun (3) defining a housing (3a) extending along a longitudinal axis (A), the housing (3a) having a source of painting fluid ( configured to receive flow regulating means (6) suitable for regulating the passage of the painting fluid from 8);
the paint gun (3) comprises an adjustment system (9) for controlling the maximum amount of paint fluid which can be adjusted by means of the flow adjustment means (6);
The flow adjusting means (6) comprises an opening (7) defined by a rod (6a) and a part of the gun (3), the rod (6a) being moved relative to the opening (7). controlled and selectively contacting and cooperating to close the opening (7) or allow passage of the painting fluid between the opening (7a) and the rod (6a);
the adjustment system (9) comprises a wheel (10) configured to rotate about an axis (A) to change a maximum stroke (H) of the rod (6a) relative to the opening (7);
The steering system (9) acts alternately on the wheel (10) to turn the wheel (10) in a first direction of rotation about the axis (A) and a second direction about the axis (A). A paint gun (3) comprising actuator means configured to rotate in a second direction of rotation opposite to the first direction. 2. The steering system (9) according to claim 1, wherein the steering system (9) comprises a first actuator means (11') configured to move the wheel (10) in a direction of rotation about the axis (A) and the wheel (10). and a second actuator means (11'') configured to move in a direction opposite to the direction of the first actuator means (11''), wherein the first and second actuator means (11', 11'') Paint gun, acting alternately on the wheel (10). 3. The paint gun according to claim 1 or 2, wherein the actuator means (11) are pneumatic actuators. 5. The actuator according to any one of claims 1 to 4, wherein the actuator means (11) comprises:
a support element 13 configured to be fixed to the support body 4; and
a tip (12) held free for translation along an axis (C) by the support element (13);
wherein the tip (12) comprises a first end portion (12a) configured to contact and cooperate with the wheel (10) and a second end portion (12b) fluidly connected to a source (F) of pressurized fluid. 5. The method according to claim 4, wherein the tip (12) is movably and slidably received inside an opening (15) formed in the support element (13), and the second end portion (12b) comprises the source of pressurized fluid ( F), the paint gun defining a sliding piston sealed within said opening (15) under action. 6. The method according to claim 4 or 5, wherein the wheel (10) comprises a plurality of seats (14) arranged circumferentially on the wheel (10), the first end portion (12a) comprising and configured to selectively contact and cooperate with one of the seats (14) to exert a force against the wheel (10). 7. The method of claim 6, wherein the first end portion (12a) is hingedly retained on the first end portion (12a) and is sized to contact and cooperate with one of the seats (14). A painting gun comprising (20). 8. The paint gun according to claim 7, comprising thrust means (23) configured to apply a force against the pawl (20) such that the pawl engages the seat (14) during use. 9. Paint gun according to any one of claims 4 to 8, comprising elastic means (17) configured to apply a force to the tip (12) opposite to that supplied by the source (F) of pressurized fluid. . 10. The wheel (10) according to any one of claims 1 to 9, wherein the wheel (10) has a stationary part (10'') relative to the body (3a) and a movable part (10') centered on the axis (A). wherein the movable part 10' has a threaded shaft 32 cooperating by screwing with the fixed part 10'', the threaded shaft 32 having the movable part 10' ) moves along the axis (A) by changing the maximum stroke (H) of the rod (6a) as it rotates about the axis (A). 11. The method according to claim 10, comprising angled adjustment means (35) configured to allow assembly of the movable part (10') and the stationary part (10'') of the wheel (10) at a fixed relative angle part. To do, the painting thing. A painting system (1) for painting an article, said painting system (1) comprising at least one painting assembly (2) equipped with a painting fluid source (8) and a painting gun (3), said painting gun ( 3) The paint system (1) produced according to any one of claims 1 to 11.

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