MXPA00003966A - Spray coating gun - Google Patents

Abstract

Spray coating gun has manually adjustable path restricting means for alternately restricting the trigger-adjustable maximum operating path of a first valve to at least two different values The spray coating gun includes a manually adjustable path restricting means (2) through which the trigger-adjustable maximum operating path of the first valve body (8) and thus the adjustable largest possible flow opening cross-section of the material valve (6, 8) can be restricted alternately to at least two different values. The path restricting means has an adjusting part (70) which is alternately adjustable corresponding to at least two values in the piston longitudinal direction to at least two different longitudinal positions and is coupled to the second valve body (18) of the throttle valve (16, 18) for common adjustment in the pistol longitudinal direction.

Description

Gun for spray coatings The present invention relates to a gun for spray coatings suitable for coating material, in particular coating liquid, according to the general concept of claim 1. Here, the concept "gun for spray coatings" it does not refer exclusively to a device for sustainable spray coating on the hand, but also to automatic spray coating devices without a handle, supported by a support device, for example, a lifting support, a robot arm or an immobile support. Although the invention can also be used for spray guns suitable for spray coating powder, it mainly relates to guns for spray coatings for coating liquid. A gun for spray coatings of the type described under the general concept of claim 1 is marketed by the patent applicant, the ITW Oberfláchentechnik GmbH in Dietzenbach, Germany, under the name "JGV Hochleistung-Pistole" ("high-powered gun"). JGV "). In this case, it is a gun for spray coating suitable for coating liquid. Contains a spray body with a nozzle at the front end of the gun; a first valve body of a material valve for the coating liquid which can be moved by activating a trigger from a first valve seat in the longitudinal direction of the gun backwards and towards the opening; a second valve body of a throttle valve for the compressed air which can be moved from a second valve seat in the longitudinal direction of the gun to the rear and the opening and which is manually adjustable. The compressed air can be introduced into the flow of the coating material, passing through said throttle valve. The compressed air passes through an air duct near the opening of the spray nozzle in the direction of the current and is introduced into the coating liquid to support its spraying and another part of the compressed air is followed in the direction of the current passing through nozzles arranged in radially opposite form and introduced into the stream of the pulverized liquid in order to transform the essentially round stream into an essentially flat jet. At the rear of the gun, the valve body of the throttle valve can be adjusted relatively by means of a tool so as to give a valve seat, in order to adjust the amount of compressed air current passing through the valve. throttling to the maximum amount of adjustable coating liquid stream using the trigger. Independently of these trigger settings, the throttle valve always remains open. The amount of current of the coating liquid that can pass through the material valve depends on how much the valve body of the material valve can be moved from the closed position against the force of a compression spring in the longitudinal direction of the valve. the gun backwards by the trigger, until this movement is limited by the impact of two stops. The valve body of the material valve is screwed into the stop body by means of a thread and can be rotated inside this stop body by means of a tool inserted on the rear side of the gun, so that it can additionally be adjusted axially. . This additional axial adjustment is an adjustment by which the length of the travel is defined which, by means of the trigger, can absolve the valve body of the material valve from the closed position in the longitudinal direction of the gun backwards to a position opening. The longer the tour, larger is the larger opening diameter for the current that passes through the material valve, adjustable by activating the trigger. In the event that this adjustment is modified, the opening diameter of the throttle valve should also be adjusted, adjusting the valve body with the tool, in order to obtain an optimum coating quality and an optimum degree of effectiveness of the coating. . Other guns for spray coatings for coating liquids are known from EP 0 157 199 A2 and DE 22 09 896 C2. The present invention has the purpose of facilitating the adjustment to different "amounts of coating material stream" and the "quantities of compressed air stream" suitable for the above. Said objective is achieved according to the present invention by means of the characteristic features indicated under claim 1. The invention has the advantage that at least two different operative versions can be easily adjusted by means of a simple device. The present invention also includes constructions which thus exhibit more than two operating versions with different current quantities. Next, the invention is described with reference to the drawings and relying on a preferred embodiment as an example. In the drawings, FIG. 1 shows schematically an axial section of a spray coating gun according to the present invention which is adjusted to a "large amount of current" of coating material and of compressed air for each unit of time, FIG. 2 schematically shows an axial section of a spray coating gun according to FIG. 1, which is adjusted to a "small amount of current" of coating material and of compressed air for each unit of time, FIG. 3 schematically a partial axial cutting of the spray coating gun in the operative position according to Fig. 1, wherein some parts are shown rotated 90 ° by their respective axis of the valve in order to illustrate additional details, and Fig. 4 a Partial axial cutting of the gun for spray coatings with parts illustrated with a 90 ° rotation by the longitudinal axes of the valve to be able to illustrate further details in the operative position according to Fig. 2, wherein, however, a throttle valve for the compressed air appears completely closed. At the front end of a receptacle or other basic body 2, the spray coating gun according to the present invention contains a spray body 4 with an opening in the form of a spray nozzle 5. According to another embodiment, it can also be used in the Instead of a nozzle, a rotary atomizer, as is known from the current state of the art. The end against the current of the nozzle body 4 is formed as a valve seat 6 whose action is combined with a valve body 8 having an axis 9 and having, for example, the shape of a needle. By actuating the trigger 10, the valve body 8 can be moved manually from the valve seat 6 and from a closed position, in the longitudinal direction of the gun back to an open position. By means of a pivoting shaft 12, the trigger is fixed in an adjustable manner with the basic body 2 and coupled with the valve body 8 of the material valve 6, 8 so that together they perform the movement in the longitudinal direction of the gun. An adjustable throttle valve 16, 18 contains a valve seat 16 formed within the basic body 2 and a valve body 18, for example, in the form of a needle, whose action is combined with the valve seat 16. At its end in the longitudinal direction of the gun, the valve body 18 of the throttle valve has an external thread 20 by means of which it is screwed in an internal thread 22 in a through opening of a support 24 (bushing or tube). This valve body 18 can rotate relative to the support 24 disposed non-rotatably by a tool, for example, a hexagonal wrench that can be inserted through the back side of the gun into a neckline 26 on the valve body that goes backwards. In this way it is manually adjustable (adjustable) relative to the valve seat 16: back to open positions of the valve of different diameters or forward to a fully closed position of the throttle valve 16, 18. Within the basic body 2, the support 24 can move in the longitudinal direction of the gun and has on its outer circumference a guide groove 28 extending in the longitudinal direction, where a guide pin 30 of the basic body 2 enters radially and directed backwards, which prevents the support 24 from making rotary movements. However, it allows its longitudinal and relative movement with respect to the basic body 2. The valve body 18 of the throttle valve 16, 18 extends on the side with the current of the valve seat 16 by means of a channel for compressed air 32 which it extends through the basic body 2 and in which compressed air 33 can be introduced from a source of compressed air, through a valve (not shown) regulated by an electronic regulating device. If the throttle valve 16, 18 is open, the compressed air passes as forming air or as the so-called "horns" air (because the compressed air nozzles 34 are formed in bay-shaped horns of a head of gun) by the nozzle openings 34 of the nozzle body 4, arranged diagonally therebetween in the direction of the stream, and past the nozzle body 4, the compressed air flows briefly with the two-sided stream over the spray stream of the nozzle. coating material 38 and converting it from a round jet into a flatter jet or a flat jet. In addition, if the throttle valve 16, 18 is open, a portion of the compressed air can flow into the flow of the coating material, passing through nozzle openings for the atomizing air 40 formed near or in the nozzle body 4. near the opening of the nozzle 5, in order to optimize its spraying. There may be the formation air nozzles 34 and / or the atomization air nozzles 40. As is known from the prior art, one or more electrodes 44 may be arranged in the path of the coating material stream. to load the coating material with high voltage. The valve body 8 of the material valve 6, 8 has at its rear 48 that is on the side of the trigger opposite the valve seat 6 with a thread 50 by means of which it is screwed on an external thread 52 of a opening of axial passage of a support 54 (bushing or tube). The valve body 8 can be rotated by a tool, for example, a hexagonal wrench in a relative manner with respect to this support 54. This tool can be placed on the rear side of the gun in a notch 56 in a front side facing towards behind the valve body section 48. By means of the tool the maximum diameter of the current passing through the material valve 6, 8 can be adjusted (adjusted). According to this diameter, the valve body 8 can be adjusted in the longitudinal direction of the valve body. gun backwards by means of the trigger 10, starting from the closed position of the valve of the covering material 6, 8. In the event that the trigger 10 does not activate, the valve body 8 is pressed against the valve seat 6 by a compression spring 60 that presses it forward. In this way, the valve of the coating material 6, 8 is maintained in the closed position. The compression spring 60 is clamped with a pre-axial tension between a front side 62 of the support 54 of the material valve facing rearwardly and a front side 64 directed forwardly of a projecting part 66 projecting radially inwards . The end portion 66 may be a circular edge or a plug or the like introduced radially into the interior in an axial and completely hollow fitting part 70 (bushing or tube), wherein the support 54 can be moved axially and guided. The rear end of the adjustment part 70 is formed on its outer circumference as a handle 72, preferably as a push-button and rotary type. The adjusting part 70 is disposed in a displaceable and rotatable manner within the basic body 2 or within a body connected to the basic body 2 immobile in the longitudinal direction of the valve body 8 of the material valve 6, 8. In the outer circumference of the fitting part 70 is a guide groove consisting of a longitudinal section of the groove 76 and a circumferential section of the groove 78 extending from its rear axial end in a circumferential direction along a determined travel by the circumference. The basic body 2 has a guide pin 80 which fits radially inwardly with the guide groove 74 and which is guided by it. In the longitudinal section of the slot 76, the guide pin 80 prevents rotation of the adjusting piece 70 relative to the basic body 2 and guides the adjusting piece 70 in the longitudinal direction.

The adjustment part 70 can be moved manually by the handle 72 to the left by a distance "s", starting from the operative position "large amount of coating material stream for each unit of time" presented in FIG. 1, up to to reach the operative position "small amount of coating material stream for each unit of time", shown in Fig. 2. Here, the guide pin 80 moves from the leading end to the rear end of the longitudinal section of the groove 76 where the circumferential section of the groove 78 is located, so that now the adjustment part 70 can be manually rotated, the guide pin 80 engaging with the circumferential section of the groove 78. In the case of the operative position conforming Fig. 1, the guide pin 80 is at the front end of the longitudinal section of the groove 76, making contact with a stop surface 82 of the fitting part 80 which will be ige backwards and, therefore, absorbs the backward pressure of the compression spring 60. Instead of the axial limitation of the movement by this stop surface 82 or additionally, another embodiment of the present invention can be used, in where a stop surface 84 of the base body 2 facing forward makes contact with a stop surface 86 of the adjustment part 70. The valve body 8 of the material valve 6, 8 can travel a "long" distance "SM1" against the force of the spring 60 by the trigger 10, starting from the closed position of the valve shown in Fig. 1 in the direction of the opening, whereby the largest possible diameter of the opening of the valve results of material 6, 8 for the adjustments of both valve bodies 8 and 18 shown in Fig. 1. The long distance "SM1" is limited by contact with a stop surface 88 directed rearwardly of the support 54, which loads the valve body 8 of the material valve 6, 8 in a stop 90 directed forwardly of the adjustment part 70. In the operative position according to Fig. 2, the largest possible opening diameter for the flow through the material valve 6, adjustable by the trigger 10, is considerably smaller than the diameter in the operative position according to Fig. 1, since the closing piece 70 moved forward relatively relative to Fig. 1. In this way, the adjustment distance by which the trigger 10 can move the valve body of the mating valve 6, 8, starting from the closed position backwards to an open position, it was reduced to the "short" distance "SM2". From Fig. 1 to Fig. 2, the adjustment part 70 was manually rotated relatively relative to the basic body 2, the guide pin 80 engaging the circumferential section of the slot 78 and, therefore, limiting the freedom of movement of the adjustment part 70 relative to the basic body 2 in both axial directions. The surface of the rearwardly directed groove forms a stop surface 92 with which the guide pin 80 contacts and absorbs the force of the compression spring 60. By means of a drive part, for example a bracket 94, the The adjustment part 70 is coupled to the support 24 of the valve body 18 of the throttle valve 16, 18 so that both parts can carry out the longitudinal direction movement only as a whole while, however, the adjustment part 70 can be rotated manually relative to the abutment 94 and therefore also relatively relative to the support 24 of the valve body 18 of the throttle valve 16, 18. The abutment 94 has an annular part 97 which fits with a circumferential groove 96 of the adjustment part 70 and a fork part 99 that fits with a circumferential groove 98 of the support 24 assigned to the throttle valve 16, 18. Fig. 3 shows a part of the spray coating gun in the operative position according to Fig. 1, wherein both guide slots 28 and 74, as well as the corresponding guide pins 30 and 80 were drawn in rotated form in order to illustrate additional details more clearly. Adjustments: If by the fitting of the corresponding guide pin 80 the material valve 6, 8 is set to the minimum value of the maximum opening diameter, adjustable by the trigger 10, then the throttle valve 16, 18 is adjusted (regulated) by the threads 20 and 22 axially by rotating its valve body 18 in such a manner that a quantity of compressed air stream results corresponding to the current value of the coating material, while the material valve 6, 8 has the greatest possible opening, adjustable by the trigger 10. Here, the throttle valve 16, 18 can have an opening diameter as indicated by the distance "SL1" in Fig. 2 as example, or according to Fig. 4 may also be completely closed, or present another size, in case this is suitable for the respective coating process. Now by adjusting according to Fig. 2 or 4, the covering material 38 can be applied to an object to be coated directly by activating the trigger 10, as well as the compressed air by means of a valve not illustrated and activated by the trigger 10, in accordance with FIG. 2. If it is then desired to make a coating with a greater amount of coating material flow for each unit of time, simply adjust the adjustment piece 70 manually from the position according to FIG. 2 to the position according to Fig. 1 and then axially adjusted backwards. Thus, the material valve 6, 8 can be opened by the trigger 10 for the longer distance SM1 instead of the shortest distance SM2 in the longitudinal direction to give a larger opening diameter for the current. In addition, the valve body 18 of the throttle valve 16, 18 is automatically adjusted by the bracket 94 of the smaller opening diameter corresponding to SL1 in Fig. 2 (or the closed state according to Fig. 4) to the diameter more large opening for the current, indicated in Fig. 1 by the opening distance SL2. In this way, a greater amount of compressed air is automatically assigned to a correspondingly greater amount of coating material. Therefore, it can be seen that in the starting position of Fig. 2 or Fig. 4 it can be adjusted by the threads 50, 52 of the material valve 6, 8 and the threads 20, 22 of the throttle valve adjustable 16, 18, any relationship between the compressed air and the material, both in the operative position according to Fig. 2 (and Fig. 4) as in the operative position according to Fig. 1 and 3. The adjustment piece 70 makes it possible to easily and quickly change from one operating position to another, automatically changing also the amount of compressed air in form corresponding to the amounts of coating material.

Claims (4)

1. Claims 1. A gun for spray coatings for coating material, in particular coating liquids, having an atomization body (4) at the front end of the gun for spraying the coating material; with a first valve body (8) of a valve material (6, 8) for the coating material, manually moveable by a trigger (10) from a first valve seat (6) in the longitudinal direction of the gun from a closed position to an open position; with a second valve body (18) of a throttle valve for compressed air that can be adjusted manually relative to a second valve seat (16) in the longitudinal direction of the gun, where the compressed air passes through this throttle valve and incorporated in the coating material stream near the atomization body; characterized in that it has a means that limits the distance of the travel (2, 70, 74, 80, 54), by means of which the distance of the maximum and adjustable travel can be limited by the trigger (10) of the first valve body (8) and, therefore, the largest possible diameter of the opening of the material valve (6, 8) to at least two different values alternatively; and in that the means limiting the distance of the path has an adjustment part (70) that can be alternatively adjusted to at least two different longitudinal positions of the gun, in accordance with the at least two values previously described, and which is found coupled with the second valve body (18) of the throttle valve (16, 18) for an adjustment in the longitudinal direction of the gun.
2. 2. A gun for spray coatings, according to claim 1, characterized in that the first valve body (6) of the material valve (6, 8) can be adjusted manually relative to a support (54) in the longitudinal direction of the gun, and in that this support (54) is loaded by a spring (60) in the closing direction of the material valve (6, 8) clamped between the support (54) and the adjustment part (70). ) in the longitudinal direction of the gun.
3. 3. A gun for spray coatings, according to claim 1 or 2, characterized in that the second valve body (18) of the throttle valve (16, 18) allows a manual adjustment relative to the piece of adjustment (70) of the medium that limits the distance of the travel in the longitudinal direction of the gun.
4. 4. A gun for spray coatings, according to any of the preceding claims, characterized in that the means that limits the distance of the path presents between the adjustment part (70) and a basic body (2) a pulsating and rotating device (74, 80) which has in one of the two pieces "adjustment part (70) or basic body (2)" with at least one guide slot ( 74) with a longitudinal section of the slot (76) extending in the longitudinal direction of the gun and with a circumferential section (78) extending from one end of the longitudinal section of the slot (76) by a distance defined, and that in the other respective part has a guide pin that fits into a guide slot (74).