EP2173495A1

EP2173495A1 - Spraying tool with a switch-off valve

Info

Publication number: EP2173495A1
Application number: EP08784634A
Authority: EP
Inventors: Karl-Heinrich Keim
Original assignee: Henkel AG and Co KGaA
Current assignee: AED Automation GmbH
Priority date: 2007-07-05
Filing date: 2008-07-04
Publication date: 2010-04-14
Also published as: WO2009003718A1; US20100155509A1; JP5358567B2; US8425214B2; DE102007031263A1; JP2010532250A; CN101730594A; BRPI0812837A2

Abstract

The invention relates to a spraying tool (20), in particular as part of a mould-spraying device for spraying at least one section of a wall of a mould with working medium, the spraying tool comprising a plurality of spraying elements (22) for dispensing working medium, and at least one working-medium supply line (36) which supplies working medium to the plurality of spraying elements (22). According to the invention, at least some of the spraying elements (22), the spraying nozzles (62) of which point downwards during operation, are equipped with a separate valve unit (42) which is adjacent to the spraying nozzle (62) and the valve element (56) of which is prestressed elastically into a closed position in which it prevents the dispensing of working medium, but can be transferred under the action of a hydraulic and/or pneumatic pressure into an open position in which it permits the dispensing of working medium.

Description

SPRAYING TOOL WITH SHUT-OFF VALVE

description

The invention relates to a spraying tool, in particular as part of a die spraying device for spraying at least a portion of a mold wall of a mold with working medium, comprising: a plurality of spraying elements for dispensing working medium and at least one working medium supply line supplying working medium to the plurality of spraying elements.

One possible application in which such a spraying tool can be used is a mold spraying device, such as is used, for example, to prepare the walls of the mold halves of a drop forging machine for the next working cycle after one working cycle. For this purpose, the walls of the two mold halves are sprayed with a working medium. In modern die forging machines, there are two problems, namely, on the one hand, the short cycle times of only about 1 to 2 seconds per forged molding and on the other hand, the small space available for retraction of the spray tool between the mold halves of the drop forging.

In order to enable the mentioned short cycle times, both mold halves of the drop forging device must be sprayed simultaneously with working medium. For this purpose, however, it is necessary for the spraying tool to be equipped in each case with a plurality of spraying elements on two mutually oppositely directed surfaces. This doubling has corresponding consequences for the dimensions of the individual spray element. And these consequences are all the more serious because the short cycle times mentioned above do not allow the two mold halves of the drop forging machine to be separated by a great distance, as this is too much Would take time. Depending on the size of the molded parts produced in the drop forging device is only a space of between about 40 and about 80 mm available for the height of the spray tool.

The prior art discloses a spraying tool with spraying elements operating according to the internal mixing principle, the main body of the spraying element comprising the mixing chamber being screwed into a base part of the spraying tool. The working medium is supplied to the plurality of spray elements from a common check valve via a duct system. Thus, it is inevitable that after spraying the mold halves of the drop forging device remains a residue of working fluid in the channel system. If the spraying tool is then pulled out of the space between the two mold halves of the drop-forging machine at high speed, it may happen due to the mass inertia that a part of the working medium undesirably exits the spraying elements without being atomized and drips into one of the mold halves of the drop-forging device. Since too much working fluid is introduced into the drop forging device in this way, there is a risk of damage to the drop forging device.

It is therefore an object of the invention to provide a spraying tool of the type mentioned, in which the undesired leakage of working medium in operation in comparison with the prior art at least reduced, if not completely prevented.

This object is achieved by a spray tool of the type mentioned, in which at least a portion of the spray elements, the spray nozzle in operation down, with a separate, the spray nozzle adjacent valve unit is equipped, the valve element is resiliently biased in a closed position, in which prevents the release of working fluid, but under the effect of a hydraulic or / and pneumatic pressure in an opening tion position is feasible, in which it allows the delivery of working medium. As a result of this measure, the amount of working medium which can escape from the spray nozzle during a movement of the spraying tool under the influence of the mass inertia can at least be significantly reduced.

Since the valve bodies arranged adjacent to the spray nozzles are additional components in comparison to the prior art, additional space must also be provided for them. However, since due to the circumstances explained above, no additional space is available, this space must be saved elsewhere. This can be done by a number of measures that can be implemented individually or in combination with each other in development of the invention.

For example, it can be provided that the spray element atomises the working medium either using an auxiliary medium, for example air, according to the external mixing principle or atomized without the use of an auxiliary medium. As a result, the space required for the internal mixing chamber space can be saved.

Additionally or alternatively, it can be provided that the valve unit is received in a cup-shaped recess of a main body of the spray tool and secured in this by a cover plate of the spray tool. This allows a thread-free design of the valve unit and thus saves the space required for a thread space.

In a further development of the invention, the cover plate of the spray tool can also be used independently of the thread-free design of the valve unit to keep the spray nozzle or at least a portion of the spray nozzle in operative connection with the valve unit. As a result, separate connecting elements can be omitted. In this case, the spray nozzle or at least a part of the spray nozzle can be screwed in accordance with a variant with the cover plate. This variant has the advantage It is not necessary to remove the entire cover plate from the spray tool to gain access to a single valve unit, thus facilitating the maintenance of the spray tool. According to an alternative embodiment, the spray nozzle or at least a portion of the spray nozzle but also in a recess of the cover plate, preferably from the inside of the cover plate forth, be loosely inserted or frictionally held in this recess, for example, pressed into this. This alternative embodiment has due to the omission of the

Thread on the spray nozzle the advantage of easier manufacturability.

But even the valve unit itself can be easily and thus, in particular in the axial direction, space to be designed to save space. For example, the valve unit may have a working medium inlet channel, which can be brought into contact with the working medium supply line at one inlet end, and at least one branching into a valve chamber emanates from the other end, at least one discharge channel to an outlet opening of the valve chamber Valve unit starts, and wherein the valve element is received in the valve chamber. In this case, that wall section, in which the at least one branch channel opens, forms the valve seat surface for the valve element.

In order to provide the elastic bias of the valve member in a simple manner, i. In particular, without having to provide additional elements, such as springs or the like, is proposed in a further development of the invention that the valve element is formed of rubber material. In this case, the inherent elasticity of the rubber material is especially effective when the valve seat surface is formed on the outer circumference of the valve unit and surrounded by an annular valve element.

If the cross-section of the valve element is quadrangular, wherein preferably at least one of the two adjacent corners connecting lines is concave, so this can in a simple manner for a sealingly guiding the valve element to the valve unit, since the corners bounding the concave line act as sealing lips. Such elements are known, for example, under the name "quad-ring". Basically, however, the use of a simple O-ring with a circular cross-section is conceivable.

However, an undesired discharge of working medium may additionally or alternatively also be counteracted in that, seen in the direction of extension of the working medium supply channel, at least one sealing element is provided on each side of the valve element.

If desired, the effect of the elastic bias of the valve element can be supported by a control medium acting on the valve element in the closing direction, for example compressed air.

To simplify the production of the spray tool, the so-called sandwich construction can be used in a manner known per se. In this case, for example, the working medium supply line may be formed in a main body of the spraying tool as provided in a surface of this main body recess, wherein a further plate covers the recess for forming the working medium supply line. Further, a blown air supply pipe may be formed in the main body of the spraying tool as a recess provided in one of the surface opposite to a surface of this main body. This depression may be covered, for example, by the cover plate to form the blown air supply line. Finally, it has proved to be advantageous if two, preferably separated by a partition plate, main body are provided, the spray elements emit working fluid in each other in substantially opposite directions.

In addition, the spray elements need not necessarily be arranged in straight rows, but rather may also be arranged in adaptation to the geometry of the mold halves. To this In this way, the contours of the mold halves of the forming device, in particular of the drop forging device, can be prepared more effectively for the next working cycle, for example more effectively cooled and coated with lubricant.

It should also be added that the use of pressure proportional valves ensures stepless control of the amount of working fluid dispensed.

To explain the differences between the external mixing principle and the internal mixing principle, reference is made to DE 195 11 272 A1, the relevant disclosure of which is hereby made part of the disclosure of the present application.

The invention will be explained below with reference to an embodiment with reference to the accompanying drawings. It shows:

Figure 1 is a rough schematic representation of a mold spraying device, in which the spraying tool according to the invention is used;

Figure 2 is an enlarged view of a detail of the spraying tool according to the invention;

Figure 3 is a plan view of the valve unit of the spray element shown in Figure 2 from the direction of the arrow III in Figure 2;

Figure 4 is a taken along the line IV-IV in Figure 3 sectional view of the valve unit.

In FIG. 1, a drop forging device 10 is shown roughly schematically as an example of a device for hot or cold forming, in which the spraying tool 20 according to the invention can be used. The swaging device 10 comprises a lower press ram 12, which is fixedly mounted on a hall floor U, and an upper press ram 14 which can be moved by means not shown up and down. In this way, the two mold halves 12a and 14a of the two press dies 12 and 14 can be approximated to each other in order to form a pressing space for the deformation of a workpiece, or be removed from each other to form a sufficient space for the insertion of the spray tool 20 space to be able to. The latter situation is shown in FIG. In order to be able to insert the spraying tool 20 between the two mold halves 12a and 14a, it is attached to the arm 16a of a robot 16, which is likewise only shown roughly schematically in FIG. Of course, instead of a robot 16 with a merely extendable or shortenable robot arm 16a, as shown in Figure 1, a modern multi-axis robot can be used. The robot 16 and the spraying tool 20 together form a molding sprayer 18.

However, in the context of the present invention, it does not depend on the formation of the device 10 for hot or cold forming and also not on the formation of the robot 16, but on the formation of the spray tool 20, and these parts also of conventional design In this regard, a more detailed explanation is omitted here.

As shown in Figure 1, the spraying tool 20 comprises two opposing rows of spray elements 22, namely a row 24 associated with the lower mold half 12a and a row 26 associated with the upper mold half 14a.

According to Figure 2, the spray tool 20 is constructed in sandwich construction. It comprises a first main plate 28 associated with the lower row 24 of spray elements 22, a second main plate 30 associated with the upper row 26 of spray elements 22, a partition plate 32 for separating the two main plates 28 and 30, one of the first main plate 28 associated cover plate 34 and a not shown, the second main plate 30 associated cover plate. Recesses 28a and 30a are formed in the two main plates 28 and 30, which are covered by the partition plate 32 and thus form supply lines 36 and 38 for working medium. In an analogous manner, further depressions are formed on the side of the main plates 28 and 30 facing away from the depressions 28a and 30a, of which only the depression 28b is shown in FIG. This further depression 28b is covered by the cover plate 34 and thus forms a supply line 40 for blowing air, by means of which the working medium discharged from the spray elements 22 is atomized. The partition plate 32, the two main plates 28 and 30 and the two cover plates 34 are held together by means of suitable fastening means, for example by means of bolts and nuts.

In a rapid movement of the spray tool 20 in the space between the two press halves 12 and 14 in or out of this there is at least for the lower row 24 of spray elements 22 the risk that working fluid under the influence of inertia from the supply line 36 and the lower spray elements 22 exit. In order to be able to prevent this, according to the invention each spray element 22 is assigned a separate valve unit 42. The valve unit 42 is accommodated in a cup-shaped recess 28c, the bottom of the pot via a passage 28d with the working medium supply line 36 is in communication.

With reference to Figures 3 and 4, the construction of the valve unit 42 will be explained in more detail below. The valve unit 42 comprises a substantially cylindrically symmetrical base body 44, from whose one end face 44a a branch passage 46 extends and extends substantially along the cylinder axis Z into the main body 44. Departing from the inner end of the branch channel 46, in deviation from the strict cylinder symmetry, are four radial channels 48, which open into an annular surface 50 a, which forms the bottom of an annular groove 50. From this annular groove 50 go with respect to the mouth openings of the channels 48 by about each 45 ° offset four other channels 52, which extend obliquely inwardly with respect to the cylinder axis Z and open into a cylinder axis Z surrounding the dispensing recess 54 through which the working medium exits the valve unit 42 again.

In the annular groove 50, a valve ring 56 is arranged, which is formed of rubber material and has a substantially square or rectangular cross-section. The diameter of the valve ring 56 is dimensioned such that it bears against the bottom 50a of the annular groove 50 in the unloaded state of external forces, wherein, if desired, a predetermined bias can be provided. Characterized in that the radially inner boundary surface 56a of the valve ring 56 is concave, the corners 56b of the valve ring 56 are slightly compressed in this case, so that they can act as a sealing lips particularly effective and can prevent the unwanted escape of working fluid. If the working fluid coming from the branch passage 46 comes into contact with the boundary surface 56a of the valve ring 56, then, when this pressure exceeds a predetermined value, it expands the valve ring 56. This condition is shown in FIG. Due to the displacement of the valve ring 56, the working medium, starting from the branch channel 46, can flow through the channels 48, the annular groove 50 and the further channels 52 to the dispensing recess 54. As soon as the pressure of the working medium subsides, the valve ring 56 contracts due to its inherent elasticity and prevents the passage of working medium from the channels 48 into the further channels 52.

The valve function provided by the valve ring 56 reliably prevents the working medium from escaping from the spray elements 22 solely as a result of its inertia during rapid movement of the spray tool 20. Should the inherent elasticity of the rubber material of the valve ring 56 not be sufficient for the provision of the valve function, then it can be considered to additionally bias the valve ring 56 from its outside, for example by means of air pressure or suitable spring elements. Yes, it could even be thought in this case, completely on the To dispense with inherent elasticity. The additional bias could also be used to control the flow rate of working fluid through the valve unit 42.

FIG. 4 also shows two sealing elements 58 and 60, designed as conventional O-rings, which serve to seal the valve unit 42 in the receiving recess 28c of the main plate 28.

In the embodiment shown in Figure 2, the dispensing nozzle 62 is formed in two parts. In particular, it includes a nozzle orifice 64 which is latched to the dispensing cavity 54 of the valve unit 42 and serves to eject working fluid, and an air guide nozzle 66 which serves to expel blast air used to atomize the working medium according to the external mixing principle. The air guide nozzle 66 passes through an opening 34 a of the cover plate 34.

Furthermore, it can be seen in FIG. 2 that neither the valve unit 42 nor the air guide nozzle 66 are formed with a thread. Rather, the valve unit 42 is simply inserted into the recess 28c of the main plate 28 and is held therein by the Luftleitdüse 66 by this applies with its inner end surface 66a against the outer end surface 44a of the main body 44 of the valve unit 42. The air guide nozzle 66 in turn has an annular shoulder 66b, with which it rests against the opening 34a surrounding portion of the inner boundary surface of the cover plate 34. In principle, however, it is also conceivable to dispense with the annular shoulder 66b and screw the Luftleitdüse 66 with the opening 34a, as indicated at 66c. In the latter case, it is possible to replace the valve unit 42, without having to remove the entire cover plate 34 from the spraying tool 20.

Of course, it is also conceivable to form the dispensing nozzle 62 in one piece. Further, the spray angle of the dispensing nozzle 62 can be arbitrarily selected by their appropriate training. Regardless of this but always the same valve unit 42 can be used.

It should also be added that the depressions 28a and 28b can be introduced into the main plate 28, for example by milling. Additionally or alternatively, however, it is also possible to provide these depressions in the main plate already during their shaping. For example, in the shaping a plurality of mutually unrelated depressions could be provided, which are then connected by removing, for example by means of milling, individual partitions to a channel network of the desired course.

It should also be added that as a working medium, for example, a dispersion of graphite in water can be used.

Claims

claims

A sprayer (20), particularly as part of a mold sprayer (10) for spraying at least a portion of a mold wall of a mold (12/14) with working fluid, comprising: a plurality of spray elements (22) for dispensing working fluid, at least one Working medium supply line (36) which supplies working medium to the plurality of spray elements (22), characterized in that at least a part of the spray elements (22) whose spray nozzles (62) face downwards with a separate spray nozzle (62 ) is provided adjacent valve unit (42) whose valve element (56) is resiliently biased into a closed position in which it prevents the discharge of working fluid, under the action of a hydraulic and / or pneumatic pressure, however, can be transferred to an open position in which it the delivery of working medium allows.

2. Spray tool according to claim 1, characterized in that the spray element (22) atomized the working medium either using an auxiliary medium, for example air, according to the external mixing principle or atomized without the use of an auxiliary medium.

3. Spraying tool according to claim 1 or 2, characterized in that the valve unit (42) in a pot-shaped recess (28c) of a main body (28) of the spraying tool (20) received and in this by a cover plate (34) of the spraying tool ( 20) is secured.

4. Spraying tool according to one of claims 1 to 3, characterized in that the spray nozzle (62) or at least a portion (66) of the spray nozzle (62) is held in operative communication with a valve unit (42) by a cover plate (34) of the spray tool (20).

5. Spraying tool according to claim 4, characterized in that the spray nozzle (62) or at least a part (66) of the spray nozzle (62) with the cover plate (34) is screwed.

6. Spray tool according to claim 4, characterized in that the spray nozzle (62) or at least a part (66) of the spray nozzle (62) in a recess (34 a) of the cover plate (34), preferably from the inside of the cover plate (34) ago is loosely inserted or frictionally held in this recess (34 a), for example, pressed into this, is.

7. Spray tool according to one of claims 1 to 6, characterized in that the valve unit (42) has a working medium inlet channel (46) which is engageable at an inlet end with the working medium supply line (36) in connection, and of the other At least one of these valve chamber (50) in turn at least one discharge channel (52) to an outlet opening (54) of the valve unit (46) emanates from the valve chamber (50), and wherein the valve element ( 56) is received in the valve chamber (50).

8. Spray tool according to one of claims 1 to 7, characterized in that the valve element (56) is formed of rubber material.

9. Spray tool according to one of claims 1 to 8, characterized in that the valve element (56) is annular.

10. Spraying tool according to one of claims 1 to 9, characterized in that the cross section of the valve element (56) is formed quadrangular, preferably at least one (56 a) of the two adjacent corners (56 b) connecting lines is concave.

11. Spray tool according to one of claims 1 to 10, characterized in that seen in the extension direction of the working medium inlet channel (46) on both sides of the valve element (56) in each case at least one sealing element (58, 60) is provided.

12. Spray tool according to one of claims 1 to 11, characterized in that the action of the elastic bias of the valve element (56) by a valve element (56) acting in the closing direction control medium is supported.

13. Spraying tool according to one of claims 1 to 12, characterized in that the working medium supply line (36, 38) in a main body (28, 30) of the spraying tool (20) as in a surface of this main body (28, 30) provided recess (28a, 30a) is formed.

14. Spraying tool according to one of claims 1 to 13, characterized in that a blown air supply line (40) in the main body (28) of the spray tool (20) is formed as a recess which in one of the surface opposite to a surface of this main body (28 ) is provided.

15. Spraying tool according to one of claims 1 to 14, characterized in that there are two, preferably by a

Separation plate (32) from each other, the main body (28, 30) summarizes whose spray elements (22) deliver working fluid in each other in substantially opposite directions.