CN116801988A

CN116801988A - Spray gun with improved adjustment system

Info

Publication number: CN116801988A
Application number: CN202180091361.XA
Authority: CN
Inventors: 亚力桑德罗·甘博吉; 罗伯托·格罗西
Original assignee: Barnini LLC; Aierkang Co ltd
Current assignee: Barnini LLC; Aierkang Co ltd
Priority date: 2020-11-25
Filing date: 2021-11-25
Publication date: 2023-09-22
Also published as: IT202000028433A1; WO2022113001A1; KR20230129059A; EP4251330A1

Abstract

A spray gun (3) for spraying an article, comprising an adjustment system (9) comprising a wheel (10) configured to rotate about an axis (a) to change a free section of an opening (7) of the spray gun (3) through which a spray fluid can flow in accordance with rotation in one direction or the other about the axis (a), the adjustment system (9) comprising an actuator device configured to rotate the wheel (10).

Description

Spray gun with improved adjustment system

Cross Reference to Related Applications

This patent application claims priority from italian patent application No. 102020000028433 filed on 25.11/2020, the entire disclosure of which is incorporated herein by reference.

Technical Field

The present invention relates to a spray gun, in particular an air pen gun, equipped with a regulating system for the flow of a spray fluid.

Background

Known spray coating systems typically include at least one spray gun configured to spray a spray fluid onto an object to be sprayed.

Such spray guns (gas pens) therefore comprise an opening which enables the usually pressurized spray fluid to flow out in the direction of the object to be sprayed.

In the prior art, the adjustment of the fluid flow in a spray circuit using an air pen gun can be performed by:

regulating the pressure of a central paint feed pump placed upstream of the circuit;

manually adjusting the adjustment wheel present on each lance; or (b)

Using a servo pneumatic throttle placed between the paint supply tube and the spray gun;

clearly, centralized control of the adjustment of the spray fluid flow upstream of the spray gun supply pipe is imprecise, as the same fluid flow is provided to all spray guns as each will be supplied with a flow designed to meet the maximum demand for fluid. In contrast, making a specific adjustment to each gun at the hydraulic level would be extremely complex, heavy and expensive.

On the other hand, manual adjustment substantially affects the maintenance time of the spray coating system, and each spray gun must be manually adjusted in order to modify the amount of coating material to be delivered.

Finally, when small amounts of product need to be delivered, precise adjustment cannot be achieved using intermediate adjustment devices inserted in series on the spray line. It increases the time required to manage the system because more time is required for maintenance and it may be blocked by the narrow internal passage of paint flow.

Accordingly, there is a need to provide a spray gun that can be adjusted in an automatic, compact, accurate, and economical manner.

It is also necessary to limit maintenance time and to add no other means of acting on the paint supply circuit.

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

Disclosure of Invention

The above object is achieved by a spray gun and a spray system as claimed in the appended independent claims.

Further preferred embodiments of the invention are constructed according to the dependent claims or those connected to the above independent claims.

Drawings

For a better understanding of the invention, preferred embodiments are described below by way of non-limiting example and with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of a spray coating system including a spray coating gun according to the present invention;

FIG. 2 is a cross-sectional view along line II-II of the adjustment system of FIG. 1;

FIGS. 3 and 4 are enlarged and only partial longitudinal sectional views of different stages of operation of the adjustment system for the spray gun of FIG. 1;

FIGS. 5A-5F are longitudinal cross-sectional views of different operational steps of an adjustment system for a spray gun of the system of FIG. 1; and

fig. 6 is a partially exploded perspective view of the spray gun of the system of fig. 1.

Detailed Description

In fig. 1, a part of a painting system 1 is shown, the painting system 1 comprising at least one spray assembly 2, each of which is equipped with a painting gun 3. For simplicity, there is a single spray assembly 2 in the illustrated figures. In particular, the coating gun 3 extends along a longitudinal axis a and is supported by a support 4, the support 4 being fixable to a body (not shown) which is fixed to the coating system 1.

Advantageously, the support 4 comprises a fixing portion 4a, the fixing portion 4a being configured to fix the support 4 to the body of the spray coating system 1.

Furthermore, the support 4 defines a first and a second lateral projection 5 extending longitudinally parallel to the axis a and overhanging the fixed portion 4 a. The support 4 is preferably made of a material that remains unchanged and stable over time, such as stainless steel.

The first and second lateral projections 5 define laterally therebetween a seat designed to partially house the spray gun 3.

The spray gun 3 defines a housing 3a, the housing 3a preferably being cylindrical in shape and configured to define an interior space 3b, the interior space 3b being designed to house a flow regulation system 6 for the spray gun, as described below.

As is known, the flow regulating system 6 comprises a stem 6a, the stem 6a being configured as a free section opening or closing the opening 7, the free section preferably being defined as a nozzle outlet section. The opening 7 is fluidly connected to a known spray fluid source 8.

In particular, the lever 6a is connected to an adjustment device 9, the adjustment device 9 being configured to adjust the maximum vertical travel position of the lever 6a along the axis a, as described below.

As is known, the movement of the rod 6a along the axis a is actuated using a pneumatic system 6 b. In particular, the pneumatic system 6b comprises a piston 6c, the piston 6c being actuated by the air coming in from the duct 6d 'and returning to the neutral position, i.e. closing against the elastic means 6f when the air is made to flow from the duct 6 d'.

The piston 6c is connected to a second piston 6g, the second piston 6g being integral with the piston 6c and configured to enable the passage of compressed air from the duct 6d ", which can then flow towards the opening 7. In particular, the air flows in a duct that is fluidly separated from the opening 7 and communicates with the outside via an orifice 3b formed around the opening 7.

Since the components of the flow regulating system 6 are known, they will not be described in more detail for the sake of brevity.

The rod 6a is carried by the cylinder 6c and follows the movement of the cylinder 6c between a lower first end position, in which the opening 7 is closed by the rod 6a, and a higher second end position, in which its maximum travel is defined by the adjusting means 9, wherein between the rod 6a and the opening 7 the section of the passage for the spraying fluid from the source 8 is free.

These adjusting means 9 mainly comprise a wheel 10 configured to rotate about an axis a and an actuator means 11 configured to adjust this rotation of the wheel 10.

Advantageously, these actuator devices 11 are pneumatic actuator devices.

According to the described advantageous embodiment, the adjustment device 9 comprises a first actuator device 11', the first actuator device 11' being configured to enable a clockwise rotation of the wheel 10 about the axis a, and according to the actuator device 11″ being configured to enable a counter-clockwise rotation of the wheel 10 about the axis a. Obviously, the actuator devices 11', 11″ work alternately with respect to each other.

The clockwise or counter-clockwise rotation of the wheel 10 enables the second end (i.e. the upper stop of the rod 6 a) to be reduced or increased, respectively, so as to vary the maximum passage section between the rod 6a and the opening 7.

According to the embodiment shown in fig. 2 and described below, each actuator device 11 comprises a tip 12, the tips 12 being freely translatably housed in a supporting element 13 and configured to cooperate in contact with a respective seat 14 formed on the wheel 10 to control its rotation.

The standoffs 14 are preferably equally angularly spaced apart in the circumferential direction so that there is the same angular spacing between one standoff 14 and the other standoff. In the case described, there are twenty seats 14 equally spaced 18 ° about the axis a.

In particular, the support element 13 is configured to be fixed to the support 4 in a position that enables at least partial lateral winding of the wheel 10 of the spray gun 3. In particular, when fixed to the support 4, the fixing element extends such that it is suspended on the fixing portion 4a of the support, preferably perpendicular thereto.

The support element 13 thus preferably comprises a fixing portion configured to fix the support element to the support 4 and an end portion configured to at least partially wrap around the wheel 10 of the spray gun 3.

The end portion preferably defines an arcuate portion facing the wheel 10 and more preferably concentric therewith.

Advantageously, the support element 13 is hollow, i.e. it defines a through opening 15, the through opening 15 being configured to house the tip 12 therein and to enable translation thereof along the axis C (preferably parallel to the axes a and B).

In particular, the through opening 15 comprises a first portion 15', an intermediate portion 15 "and a second portion 15 '" opposite to the first portion 5' along the axis C. Advantageously, all the portions 15', 15 "and 15'" are advantageously axisymmetric, preferably cylindrical, and the first portion 15 'has a transversal dimension with respect to the axis C greater than the intermediate portion 15", the intermediate portion 15" in turn having a transversal dimension with respect to the axis C greater than the second portion 15' ". According to the embodiment shown, the diameter of the first portion 15 'is greater than the diameter of the intermediate portion 15", which in turn is greater than the diameter of the second portion 15'".

The second portion 15 '"is dimensioned such that the tip 12 is in contact engagement with an inner wall radially defining the second portion 15'".

In particular, the tip 12 comprises a first end 12a and a second end 12b, the first end portion 12a being configured to mechanically cooperate with the wheel 10 and to be able to slide partially in a second portion 15 '"of the opening 15, the second end portion 12b being opposite to the first end 12a and being configured to slide within a first portion 15' of the fluid-tight opening 15. The first end portion and the second end portion are connected to each other by the intermediate portion 12 c.

The second end 12b substantially defines a piston, which thus divides the first portion 15 'into a first portion 15' in fluid contact with the source of pressurized fluid F and a second portion 15'b, which is fluidly separate from the first portion 15' a.

The pressurized fluid source F (not shown) is advantageously a pneumatic source configured to selectively provide a pressurized air flow F within the second portion 15' b to exert a force on the second end 12b and thus on the tip 12.

The tip 12 is configured to move along the axis C between a first (rest) operative position (fig. 3) in which the first end 12a is not engaged with the wheel 10, and a second (actuated) operative position (fig. 4) in which the first end 12a is in contact engagement with the wheel 10.

In particular, the actuator device 11 comprises an elastic means 17, the elastic means 17 being configured to maintain the tip 12 in the first operating state. These elastic means are preferably operatively placed between the second end 12b and the support element 11', more preferably within the opening 15.

According to the described embodiment, the elastic means 17 are housed inside the second and third portions 15', 15″ of the opening 15.

In particular, the elastic means 17 comprise a helical spring 18, the helical spring 18 being housed around, preferably coaxial with, the intermediate portion 12c of the tip 12 and comprising a first end in contact with a shoulder defined by the narrowing between the second and third portions 15', 15″ of the opening 15 and a second end in contact with the second end 12b of the tip 12.

The tip 12 advantageously includes a pawl 20, the pawl 20 being movably carried by the first end 12a of the tip 12 and configured for contact engagement with the wheel 10.

In particular, the pawl 20 is advantageously L-shaped, i.e. comprises a first arm 20' and a second arm 20 "connected to the first end 12a of the tip 12 via a hinge connection 21. Advantageously, the first and second arms 20', 20 "are constituted by a single piece. The hinge 21 enables the pawl 20 to rotate about an axis parallel to the axis a between a first limit value and a second limit value.

In particular, the first arm 20' is sized to cooperate with the seat 14 of the wheel 10 to control the movement of the pawl 20 when in one of its rotational limit conditions.

The actuator device 11 advantageously comprises a thrust device 23, the thrust device 23 being configured to apply a direct force to the tip 12 during a stroke of the tip 12 along the respective axis C. In particular, the thrust means 23 comprise a sphere locator 25, the sphere locator 25 comprising a sphere 24 designed to enter the respective seat 25 under the predetermined force provided by the tip 12.

In particular, wheel 10 comprises a movable portion 10' defining the aforementioned seat 14 and cooperating with the aforementioned adjustment system 9, and a fixed portion 10 "supported by housing 3a and on which movable portion 10" is freely rotatably supported.

In particular, the movable part 10 'is integral with a threaded pin 230, the threaded pin 230 being for example arranged in a through opening 31 in the movable part 10'. The threaded pin 30 is threadedly engaged with a threaded shaft 32, which in turn is threadedly coupled through a threaded opening 33 formed in the stationary portion 10″ at a radially inner surface thereof.

The overall rotation between the threaded pins 30 brings about rotation of the threaded pins 31, thereby moving the threaded shaft 32 along the axis a. The threaded shaft 31 acts as a stop for the rod 6a such that the maximum opening H of the opening is changed relative to the shaft 31, and as a result, the maximum opening of the space between the rod 6a and the opening 7 of the nozzle.

Furthermore, the adjustment system 9 comprises an angle timing device 35 configured to adjust the relative starting position of the adjustment system 9, i.e. between the movable part 10' and the fixed part 10 "of the wheel 10.

In particular, the angular timing device 35 comprises a locator 36, for example similar to the locator 23, the locator 36 being configured to cooperate with a plurality of internal seats formed radially in correspondence of the seat 14. Furthermore, the timing device 35 comprises a reference dowel 37 formed on the outer surface of the body 3 a.

The timing device 35 also comprises an additional reference dowel 38 formed on the body 3a of the lance 3.

The operation of the adjustment system 9 for the spray gun 3 described above is described below with reference to fig. 5A-5F and the left actuator 11'.

In fig. 5A, a rest state is shown, wherein the tip 12 is in a first operational state. In this case, there is no pressurized air in the chamber 15' b to overcome the force exerted by the elastic means 17, so as to keep the second end 12b at a predetermined rest point. In this case, the pawl 20 does not engage in contact with the abutment 14.

In fig. 5B, the beginning of the stroke of the tip 12 under the action of the pressurized air entering the chamber 15 is shown. In particular, the pressurized air exerts a force that overcomes the force exerted by the elastic means 17 that tend to compress. Thus, the second end 12b tends to enter the interior of the opening 15. Thus, the first end 12a is moved by the second end 12b until the first arm 20' contacts one wall of the support 14 of the wheel 10. In this step, thrust means 23 prevent the rotation of pawl 20, so that first arm 20' is "hooked" in respective seat 14, i.e. ball 24 exerts pressure on second arm 20".

In fig. 5C, a rest state is shown, wherein the tip 12 is in a second operational state. In this case, the compressed air in the chamber 15 'is such that it completely overcomes the force exerted by the elastic means 17, and therefore the second end 12b is in contact with the shoulders between the portions 15' and 15 ". In this case, since the pawl 20 is hooked in the seat 14, the tip 12 has dragged the wheel 10 when the wheel 10 moves, so that the wheel 10 rotates about the axis a.

Once the second operating condition in fig. 5C is reached, pressurized air is caused to flow from the chamber 15. Thus, the elastic means 17 tend to overcome the force exerted by the pressurized air in the chamber 15 and push the second portion 12b towards the position assumed in the first operating condition in fig. 5A. During this movement, the arms 20' are disengaged from the respective seats 14.

During steps 5B, 5C, the thrust device 23 provides a force configured to maintain contact between the tip 12 and the pawl 10.

Continuing its movement towards the condition in fig. 5A, the pusher 23 is in contact with a single pawl 20 (fig. 5E) pushed by a sphere 24 tending to leave the seat 25, exerting a force on the second arm 20". In this way (fig. 5F), the pawl 20 will rotate to its initial position, so that the pawl 20 can resume the actuation cycle of the wheel 10 again.

The right side actuator 11 "operates in the same manner as the left side actuator device 11' described above; it is simply a mirror image and thus the wheel 10 is actuated to rotate counterclockwise.

According to the above, the counterclockwise rotation of the wheel 10 enables the rotation of the threaded shaft 32 and increases the maximum opening H between the end stop defined by the threaded shaft and the rod 6 a. This can increase the flow rate of the spray fluid that can flow between the rod 6a and the nozzle opening 7. Conversely, clockwise rotation of the wheel 10 reduces the maximum opening H, potentially reducing the flow of the spray fluid to zero.

Proper assembly of the wheel 10 is ensured by the angle timing device 35. The locator 36 performs the function of holding the support 14 in its correct angular position relative to the tip 12. Instead, the reference group given by the position of the locating pin 37 and of the locator 36 itself enables the wheel 10 to be assembled so as to maintain a predetermined distance between the lever 6a and the opening 7 of the nozzle.

Obviously, the actuator device 11 may be controlled at an electro-pneumatic level by means of a control unit (not depicted) which processes the necessary data for spraying the object by means of the spray gun 2 and thus adjusts its actuation to provide the correct spray fluid flow.

The advantages of the spray gun and the spray system according to the invention are apparent from the foregoing.

Thanks to the proposed spray gun, the flow of liquid can be regulated autonomously by adjusting the opening or closing of the wheel, enabling fine, individual and rapid adjustment of each individual spray gun of the spray coating system.

The use of a pneumatic actuator enables automatic adjustment rather than manual adjustment of the wheel 10, with significant economic advantages in view of the reduced maintenance time for manual adjustment of the gun in the prior art.

Furthermore, the invention makes it possible to regulate the flow of liquid delivered by each gas pen device simply and quickly, without the need to insert additional components subject to maintenance between the paint supply circuit and the spray gun. The presence of two actuators per direction of rotation simplifies this pneumatic-mechanical adjustment.

The presence of the abutment at a fixed distance makes it possible to adjust the opening of the wheel in a constant, and therefore computable, manner.

The presence of the thrust means promotes the coupling between the pawl and the seat and thus enables the operation to be repeated at high speed.

Similarly, the presence of the elastic means enables the tip to return quickly to the rest position, enabling the operation to be repeated at high speed.

It is evident that the proposed adjustment mechanism for the wheel 10 enables very fine adjustment of the passage between the rod 6a and the opening 7 of the nozzle, depending on the number of seats 14 formed on the wheel and on the pitch of the threads of the shaft 32. In the example shown, comprising for example 20 abutments 14 and a thread of one millimeter, the vertical distance of the bar from the wheel 10 of 0.05mm can be adjusted, so that a very high precision is achieved.

Due to the angle timing means 35, it is also possible to assemble and reassemble the wheel 10 correctly without losing the correct alignment of the opening between the rod 6a and the opening 7 of the nozzle.

Finally, it is clear that, according to the invention, it is possible to make modifications to the spray gun and to the spray system, as well as to make modifications thereto, which do not in any way depart from the scope of protection as defined by the claims.

For example, the type of resilient means and thrust means may vary, just as the shape of the support element, pawl or tip and its construction material.

Likewise, the actuator device may be electromechanical or hydraulic.

Claims

1. A spray coating gun (3) configured to spray an article, the spray coating gun (3) defining a housing (3 a) extending along a longitudinal axis (A), the housing (3 a) configured to house a flow regulating device (6) adapted to regulate a passage of a spray coating fluid from a spray coating fluid source (8),

the spray gun (3) comprises an adjustment system (9) for controlling the maximum amount of spray fluid adjustable by the flow adjustment device (6),

the flow regulating device (6) comprising a stem (6 a) and an opening (7) defined by a portion of the spray gun (3), the stem (6 a) being controlled to move relative to the opening (7) and to selectively contact cooperate to close the opening (7) or to allow passage of the spray fluid between the opening (7 a) and the stem (6 a),

the adjustment system (9) comprises a wheel (10) configured to rotate about an axis (A) to vary the maximum travel (H) of the rod (6 a) with respect to the opening (7),

the adjustment system (9) comprises actuator means configured to act alternately on the wheel (10) to rotate the wheel in a first direction of rotation about the axis (a) or in a second direction of rotation about the axis (a) opposite to the first direction of rotation.

2. Spray gun according to claim 1, wherein the adjustment system (9) comprises a first actuator device (11 ') configured to move the wheel (10) in a rotational direction about the axis (a) and a second actuator device (11 ") configured to move the wheel (10) in a direction opposite to the first actuator device (11 '), the first actuator device (11 ') and the second actuator device (11") alternately acting on the wheel (10).

3. Spray gun according to claim 1 or 2, wherein the actuator device (11) is a pneumatic actuator.

4. A spray gun according to any one of the preceding claims, wherein the actuator means (11) comprises:

-a support element (13) configured to be fixed to the support (4);

-a tip (12) carried by the support element (13) freely translatable along an axis (C);

the tip (12) includes a first end (12 a) configured to be in contact engagement with the wheel (10) and a second end (12 b) fluidly connected to a source of pressurized fluid (F).

5. Spray gun according to claim 4, wherein the tip (12) is movably and slidably housed within an opening (15) formed in the support element (13), the second end (12 b) defining a sliding piston sealed within the opening (5) under the action of the pressurized fluid source (F).

6. The spray gun of any one of claims 4 or 5, wherein the wheel (10) comprises a plurality of abutments (14) circumferentially arranged on the wheel (10), the first end (12 a) being configured for selective contact engagement with one of the abutments (4) to exert a force on the wheel (10).

7. The lance defined in claim 6 wherein the first end (12 a) includes a pawl (20) hingedly carried on the first end (12 a) and sized for contact engagement with one of the abutments (14).

8. The lance defined in claim 7 includes a thrust device (23) configured to apply a force to the pawl (20) such that the pawl engages in the seat (14) in use.

9. A spray gun according to any one of claims 4 to 8, comprising elastic means (17) configured to exert on the tip (12) a force opposite to the force provided by the source of pressurized fluid (F).

10. The spray gun according to any one of the preceding claims, wherein the wheel (10) comprises a fixed portion (10 ") movable with respect to the body (a) and a movable portion (10 ') around the axis (a), the movable portion (10 ') carrying a threaded shaft (32) which is threadedly engaged with the fixed portion (10"), the threaded shaft (32) being moved along the axis (a) by varying the maximum stroke (H) of the rod (6 a) when the movable portion (10 ') is rotated around the axis (a).

11. The spray gun of claim 10, comprising an angle adjustment device (35) configured to allow assembling the movable portion (10') and the fixed portion (10 ") of the wheel (10) in fixed relative angle portions.

12. A spray system (1) for spraying an article, the spray system (1) comprising at least one spray assembly (2) equipped with a spray fluid source (8) and a spray gun (3), the spray gun (3) being manufactured according to any of the preceding claims.