WO2012098196A1 - Valve device - Google Patents

Abstract

The invention relates to a valve device for metering flowable multicomponent materials, in particular for bonding and spraying techniques. The valve device has a valve mechanism (10) with a valve housing (13), a first valve piston (11), and at least one second valve piston (12). The first valve piston and the second valve piston are arranged in the valve housing and each piston is designed in a movable manner relative to the valve housing such that a first chamber (15) for a first component and a second chamber (16) for a second component can each be blocked with respect to a discharge chamber (20).

Description

 valve device

The invention relates to a valve device for metering flowable multi-component materials, in particular for the adhesive and spray technique, wherein the valve device comprises a valve means having a valve housing, a first valve piston and at least a second valve piston, wherein the first valve piston and the second valve piston arranged in the valve housing and e is in each case designed to be movable relative to the valve housing, such that a first chamber for a first component and a second chamber for a second component can in each case be blocked off from an outlet chamber. From the adhesive and spray technique, a number of valve devices are known, which serve for metering auszubringenden materials. The valve devices can be arranged or formed for example in a spray gun for spraying paints or in a metering device for dispensing adhesive mass. In particular, if the materials used consist of several components, such as a component as a hardener, it is necessary lent to mixing the components just prior to spraying in the desired ratio. For this purpose, it is known for each component to provide a valve device with which the relevant component can be metered. For example, in the case of a two-component material, two valve devices are required which in each case control a flow rate of the components or a line pressure for delivery of the components. Downstream of the valve devices is usually a mixer in which the respective components are combined and mixed. The valve devices are regularly positioned at a relatively large distance from the mixer or the point at which the components are combined, positioned away. Thus, the valve devices can be attached directly to each of the pumps associated with the components and connected to a mixer with a mixer or to a metering valve of a spray gun for mixing the components.

In the devices known from the prior art, it is disadvantageous that due to the different compressibilities of the components of a setpoint deviating mixing ratios arise. When opening the valve devices is usually one of the components always slightly more than required promoted, that is, due to the compressibility of the component in question initially flows out a slightly larger amount of material from the valve means of the component, as from the valve means of the less compressible component. The same, negative effect results from the use of long pipe sections between the j eweiligen valve devices and a mixer or a nozzle. This has the consequence that, when an injection or gluing process is started, the mixing ratio of the components deviates from the intended nominal value. Even with the use of a mixer, this error can not be satisfactorily compensated. This has the consequence that the components do not optimally crosslink to the beginning of a so-called mixing section. Especially at short intervals or mixing distances This is particularly disadvantageous and even visually recognizable for example in painted surfaces.

The present invention is therefore based on the object to propose a valve device that allows an improved dosage of multi-component materials.

This object is achieved by a valve device having the features of claim 1.

The valve device according to the invention for dosing flowable multicomponent materials, in particular for the adhesive and injection technique, has a valve device with a valve housing, a first valve piston and at least a second valve piston, the first valve piston and the second valve piston disposed in the valve housing and in each case is designed to be movable relative to the valve housing, such that a first chamber for a first component and a second chamber for a second component can be blocked off from an outlet chamber.

Compared to the dosing systems known from the prior art, a single valve device for all components is provided according to the invention. The mixture of the components takes place here directly in or subsequent to the valve device. Due to the fact that the components in the outlet chamber can be brought together, an immediate mixing of the components can take place after exiting from the respective internally associated chambers. A forwarding of the components by j eweil s associated line sections bi s to a mixer is therefore not provided. Thus it can be prevented that arise due to the compressibility of the components in the line sections deviating mixing ratios. The fact that the respective valve pistons are arranged together in a valve housing also makes it possible to take account of different compressibilities of components. It is also no longer necessary to provide a plurality of valve devices, since all components can be metered with a single valve device. Consequently, the manufacturing costs of a system for gluing or spraying can be reduced. Advantageously, the valve housing form a first valve seat for the first valve piston. The first valve piston can then form a metering valve for the first component together with the valve housing.

Furthermore, the first valve piston can form a second valve seat for the second valve piston. The first valve piston can thus together with the second valve piston a metering valve for the second

Form component. Consequently, it becomes possible to move the second valve piston relative to the valve housing independently of the first valve piston or the first valve piston relative to the valve housing and relative to the position of the second valve piston, and thus a valve opening of the second valve piston on the second valve seat to influence , Furthermore, both valve pistons can be moved or positioned with a time offset in a sequence, completely independently of one another with different movement speeds and with different opening cross-sections. This makes it possible to take account of different compressibilities of the components by the aforementioned parameters. For example, a forward advance of a component can be compensated for by opening the relevant valve piston of the component relative to the valve piston of the other component with a time delay or at reduced speed.

Furthermore, the valve housing can form a further valve seat for the second valve piston. That is, the second valve piston can be arranged independently of the first valve piston in the valve housing, so that the second valve piston and the valve housing together form a metering valve for the second component. Furthermore, it is also possible, however, that in addition to the second valve formed in the first valve piston Valve seat for the second valve piston is formed a further valve seat for this second piston in the valve housing. Thus, a relative movement to the first valve piston can be performed by a relative movement of the second valve piston to the valve housing simultaneously. The first component can then be metered, for example, depending on the position of the second valve piston. Overall, there is the possibility of mutual influence of the thus formed metering valves.

The valve device is particularly easy to form, when the valve piston are arranged coaxially relative to each other and slidably in the valve housing. For example, the second valve piston may be slidably disposed within the first valve piston.

In this respect, it is advantageous if the chambers are formed coaxially relative to the valve piston. Thus, the chambers can in each case be formed between the first valve piston and the valve housing or between the first valve piston and the second valve piston.

With regard to a metering of viscous media, it is particularly advantageous if the valve piston forms a conical sealing surface. A conical sealing surface allows a good flow of a viscous medium and at the same time a good seal of the relevant valve seat. All in all alone one of the valve piston or even all the valve piston can form a conical sealing surface.

A dosing accuracy can be further improved if the valve piston forms a rear sealing surface, such that by means of a movement of the valve piston against a flow direction of the associated component, a flow gap can be closed. During a closing movement of the valve piston in the direction of a flow direction of the relevant component against a valve seat, material of the component can be pressed by the associated valve piston into the outlet chamber. Consequently, an undesirable on the valve piston Material left behind, which was not intended for passage of the flow gap between one of the chambers and the outlet chamber. A design of the rear sealing surface prevents this effect, since the material in question against a flow direction out of the flow gap in the chamber in question is pressed back with a movement of the valve piston, without significant amounts of material can get into the outlet chamber.

Also, the valve device may comprise a drive device, wherein by means of the drive device, the valve piston can be moved independently of each other. An independent use of the

Valve piston can, as already described above, effectively prevent the advance of a component.

The drive device can be formed from a first linear drive and a second linear drive, wherein in each case a linear drive can be connected to a valve piston. Linear actuators are particularly suitable for actuating pistons. The linear drives used here can be pneumatically, hydraulically or electrically or electromagnetically actuated, for example. Also, an independent drive of the valve piston is made possible in particular by the use of two linear drives. However, it is also possible to couple the linear drive e to one another mechanically, electrically or sensorically in order to be able to effect a time-delayed or delayed opening of the respective flow-through valves.

The valve device may also include a control device, wherein by means of the control device, the drive device may be controllable. With a control device, an independent opening of the valve piston via the drive device direction can be influenced. Thus, an opening of the valve piston can be particularly easily adapted to the j eweiligen compressibilities of the currently used components. When changing the components or the materials to be processed, a simple adjustment of the control device is sufficient. The Control device can be designed as a data processing system in the manner of a computer. Thus, already known materials and their compressibilities can be stored in the control device.

The control device can be further improved if a flow meter is provided for each component, in which case the drive device can be controlled as a function of measured flow rates. An opening of the metering valves or valve piston can then be regulated as a function of a flow rate.

Conversely, a desired flow rate for the individual component can then be set or regulated particularly precisely via the metering valves, since the control unit receives feedback on an actual flow rate from the respective flow meters.

If the valve device is designed to be spaced apart by at least ten times its valve body width relative to the drive device, the valve device can be designed as a metering device for metering and dispensing adhesive material. Here it is necessary that the outlet chamber or the nozzle, at which the adhesive material emerges from the metering device, is arranged close to the valve body, so that a reaction of the components does not already take place within a valve line of the valve device or metering device. Since a space for the nozzle or the valve piston in favor of the handling of the valve device is relatively limited, it is advantageous if the drive means of the valve device in a large Ab was formed. The valve device can thus be designed to be particularly narrow, rod-shaped or tubular. This makes it easier to apply adhesive mass to hard-to-reach areas of a workpiece.

In order to facilitate a mixing of the relevant components, a static mixer can be arranged immediately following the outlet chamber. A static mixer can be a mixing chamber which is passed by the components concerned, resulting in an intimate mixing of the components.

In the following the invention will be explained with reference to the attached drawings. Show it:

Fig. L a to l c: A schematic representation of an embodiment of a valve device in a sequence of movements;

2 shows a partial sectional view of a second embodiment of a valve device;

3 shows an embodiment of a valve device in a longitudinal sectional view.

FIGS. 1 a to 1 c show a valve device 10 of a valve device not shown in a schematic representation. The valve device 10 is essentially formed from a first valve piston 1 1, a second valve piston 12 and a valve housing 13. The first valve piston 1 1 is arranged coaxially with the second valve piston 12, wherein both valve pistons 1 1 and 12 are in turn arranged longitudinally movable along a common longitudinal axis 14 in the valve housing 13. Within the valve housing 13, a concentric first chamber 1 5 between the valve housing 13 and the first valve piston 1 1 is formed. Within the first valve piston 1 1, a second concentric chamber 16 between the first valve piston 1 1 and the second valve piston 12 is also formed. The first chamber 1 5 is connected via a first feed channel 1 7 and the second chamber 16 via a second feed channel 1 8 in each case with a pump not shown here for conveying a first or second, also not shown here component. Accordingly, the first chamber 1 5 and the second chamber 16 with the j eweils associated component materials filled and subjected to a pump delivery pressure. The pump delivery pressure is formed at a lower end 19 of an outlet chamber 20 which is connectable or communicable with the first chamber 1 5 and / or second chamber 16. Subsequent to the outlet chamber 20, a static mixer (not shown here) is connected directly to it.

1a shows a closed position of the first valve piston 11 and of the second valve piston 12. In particular, the first valve piston 11 forms a conical sealing surface 21, which rests sealingly against a sealing surface 22 of the valve housing 13 which is of matching design. The valve housing 13 thus forms a first valve seat 23 for the first valve piston 1 1. Next, the first valve piston 1 1 forms a second valve seat 24 for the second valve piston 12, which is formed in the manner of a round rod s st, from. The second valve piston 12 can close with a lower end 25 a relative to the second valve piston 12 matching opening 26 in the first valve piston 1 1. It is formed in the valve housing 13 a similar opening 27 which can also be closed by the second valve piston 12 is closed. The valve housing 13 thus forms a further valve seat 28 for the second valve piston 12.

A dispensing and mixing of the components takes place, as shown in Fig. Lb, initially by a movement of the second valve piston 12 along the longitudinal axis 14 in the direction of the arrow 29, such that the second chamber 16 is connected to the outlet chamber 20 and the second component can flow in the direction of the outlet chamber 20.

According to FIG. 1c, the first valve piston 1 1 is moved along the longitudinal axis 14 in the direction of an arrow 30 with a very short time delay, so that the first and second components simultaneously enter the outlet chamber 20 through the formation of a flow gap 3 1 and 32, respectively inflow and leave them in the direction of an arrow 33. B of the movement of the first valve piston 1 1 takes place Accordingly, also a further B ewegung the second valve piston 12, so that the second valve piston 12 remains stationary relative to the first valve piston 1 1. In the present example, the first component is relatively more compressible than the second component, so that, as described above, the first chamber 1 5 with respect to the outlet chamber 20 slightly delayed to the second chamber 16 is opened. For a closure of the valve device 10, it is sufficient to close both valve pistons 1 1 and 12 or chambers 1 5 and 16 substantially simultaneously. Fig. 2 shows a part section of a valve device 34 with a first valve piston 35, a second valve piston 36 and a valve housing 37. Between the valve housing 37 and the first valve piston 35 is a first chamber 38 and between the first valve piston 35 and the second valve piston 36th a second chamber 39 is formed. Further, an outlet chamber 40 is formed in the valve housing 37. The first valve piston 35 and the second valve piston 36 each have a round shape and form conical sealing surfaces 41 and 42, which in the closed position shown here with a first valve seat 43 of the valve housing 37 and with a second valve seat 44 of the first Ven - Tilkolbens 35 get sealing to the plant. To open the respective valve pistons 35 and 36, a movement of the valve pistons 35 or 36 takes place in each case in the direction of an arrow 45 or 46 along a longitudinal axis 47 or in the direction of a flow direction. A closing of the valve pistons 35 and 36 takes place opposite to the direction of the arrows 45 and 46 or the flow direction of the material. This prevents that here not further shown material of a first and second component when closing the chambers 38 and 39 is pushed out of these into the outlet chamber 40. When opening the valve device 34, it is basically irrelevant which of the valve pistons 35 and 36 is moved first. In principle, however, the valve piston 35 or 36 is intended to be moved first with the component having the greater compressibility. It is also planned to use the components te to promote with the largest volume fraction of the mixing ratio via the first chamber 38, since the formation of the first valve piston 35 here allows a relatively larger flow area.

Fig. 3 shows a valve device 48 with a valve device 49 at one end 50 of the valve device 48 and a drive device 5 1 at an opposite end 52 of the valve device 48. The drive device is formed from pneumatic cylinders 53 and 54, which in each case via an actuating rod 55 and 56 are connected to a first valve piston 57 and a second valve piston 58. The valve housing 59 is formed here from section as a tube 60. A movement of the pneumatic cylinder 53 thus causes a movement of the second valve piston 57 and a movement of the pneumatic cylinder 54 a B ewegung the first valve piston 57. Between the tube 60 and the actuating rod 55 is a first chamber 61 and intermediate the actuating rod 55 and the actuating rod 56th a second chamber 62 is formed. The first chamber 61 is sealed off from the actuating rod 56 by means of a seal 63 and has a first component connection 64. The second chamber 62 is sealed by means of a seal 65 against the actuating rod 55 and wei st a second component port 66 on. The valve device 48, together with a clamping device 67, which is shown schematically here, and a likewise schematically illustrated XY transport system 68 form a dosing unit 69 for two-component adhesive materials.

Claims

claims 1. Valve device (48) for dosing flowable multi-component materials, in particular for the adhesive and spray technique, wherein the valve device comprises a valve device (10, 34, 49) with a valve housing (13, 37, 59), a first valve piston (11, 35 , 57) and at least one second valve piston (12, 36, 58), wherein the first valve piston and the second valve piston arranged in the valve housing and is each movable relative to the valve housing, such that a first chamber (15, 38, 61 ) for a first component and a second chamber (16, 39, 62) for a second component in each case against an outlet chamber (20, 40) can be shut off. 2. Valve device according to claim 1,  characterized ,  in that the valve housing (13, 37, 59) forms a first valve seat (23, 43) for the first valve piston (11, 35, 57). Valve device according to claim 1 or 2, characterized , in that the first valve piston (11, 35, 57) forms a second valve seat (24, 44) for the second valve piston (12, 36, 58). Valve device according to one of the preceding claims, characterized in that: the valve housing (13) forms a further valve seat (28) for the second valve piston (12). Valve device according to one of the preceding claims, characterized in that: in that the valve pistons (11, 12, 35, 36, 57, 58) are arranged coaxially relative to one another and displaceable in the valve housing (13, 37, 59). Valve device according to one of the preceding claims, characterized in that: in that the chambers (15, 16, 38, 39, 61, 62) are formed coaxially relative to the valve pistons (11, 12, 35, 36, 57, 58). Valve device according to one of the preceding claims, characterized in that: the valve piston (11, 35, 36, 57, 58) forms a conical sealing surface (21, 41, 42). 8. Valve device according to one of the preceding claims, characterized g e k e n e z e c h e n e,  the valve piston (35, 36, 57, 58) forms a rear sealing surface (41, 42), such that a flow gap can be closed by means of a movement of the valve piston against a flow direction of the associated component. 9. Valve device according to one of the preceding claims,  characterized ,  in that the valve device (48) comprises a drive device (51), wherein by means of the drive device the valve pistons (12, 13, 35, 36, 57, 58) are movable independently of each other. 10. Valve device according to claim 9,  characterized ,  in that the drive device (51) is formed from a first linear drive (53) and a second linear drive (54), one each Linear drive with a valve piston (12, 13, 35, 36, 57, 58) is connected. 11. Valve device according to claim 10,  characterized ,  in that the first linear drive (53) is connected to the second linear drive (54), such that a movement of the first linear drive causes a movement of the second linear drive. 12. Valve device according to one of claims 9 to 11,  characterized , in that the valve device (48) comprises a control device, wherein the drive device (51) can be controlled by means of the control device. 13. Valve device according to claim 12,  characterized ,  a flow meter is provided for each component, wherein the drive device (51) can be controlled as a function of measured flow rates. 14. Valve device according to one of claims 9 to 13,  characterized ,  in that the valve device (10, 34, 49) is designed to be spaced at least ten times its valve body width relative to the drive device (51). 15. Valve device according to one of the preceding claims,  characterized ,  that immediately downstream of the outlet chamber (20, 40) a static mixer is arranged.