Mixing device for a multi-component material and associated operating method

Abstract

The invention relates to a mixing device (1) for mixing a first component and a second component to form a multi-component material (e.g. two-component adhesive), having a first supply line (2) for supplying the first component of the multi-component material, a second supply line (3) for supplying the second component of the multi-component material, and a mixer (7), wherein the mixer (7) is connected on the inlet side to the first supply line and the second supply line in order to mix the first component with the second component to form the multi-component material. The invention additionally provides a shut-off valve (9) at the outlet of the mixer (7) in order to block the outlet of the mixer (7) during an application pause and thus to prevent the multi-component material from escaping from the mixer (7).

Description

[0001] DESCRIPTION

[0002] Mixing device for a multi-component material and associated operating procedure

[0003] Technical field of the invention

[0004] The invention relates to a mixing device for mixing a first component and a second component to form a multi-component material (e.g., a two-component adhesive). Furthermore, the invention includes an operating method for such a mixing device.

[0005] Background of the invention

[0006] It is known from the prior art that two-component adhesives which are mixed together from two components are used in motor vehicle body construction. For this purpose, static mixers (e.g. grid mixers, rotary mixers) can be used, to which the two components of the two-component adhesive are fed so that the components are then mixed together in the mixer to form the two-component adhesive. At the outlet of the mixer there is a nozzle for applying the two-component adhesive. The supply of the two components of the two-component adhesive to the mixer can be controlled by two inlet-side control valves. These known mixing devices enable the application of adhesive strips to surfaces of motor vehicle body components, with the inlet-side control valves being closed at the end of each adhesive strip to terminate the adhesive application.

[0007] A disadvantage of these known mixing devices is that the mixer can run dry during application breaks if the nozzle end is facing downward. This is especially true for large mixers and when using adhesives with low viscosity and high mass density.

[0008] A further disadvantage of these known mixing devices is that when applying the adhesive strips mentioned above, an annoying threading can occur when the inlet-side control valves are closed, since the two-component adhesive in the mixer continues to escape from the mixer even after the inlet-side control valves have been closed and forms an annoying adhesive thread.

[0009] For the technical background of the invention, reference should also be made to DE 89 11 398 Ul, US 6 691

[0010] 932 Bl, DE 10 2008014281 Al, EP 0 289 882 Al and JP 2007 / 275844 A.

[0011] The invention is therefore based on the object of creating an improved mixing device that avoids the disadvantages of the known mixing device described above. Furthermore, the invention is based on the object of specifying an operating method for such a mixing device.

[0012] This object is achieved by a mixing device according to the invention according to the main claim or by a corresponding operating method.

[0013] The mixing device according to the invention generally serves to mix a first component and a second component to form a multi-component material. However, the invention is not limited to exactly two components with regard to the number of components to be mixed together. Rather, it is also conceivable for the mixing device according to the invention to mix three or more components together. However, the mixing device according to the invention is described below only for two components.

[0014] The multi-component material is preferably a two-component adhesive, as described above in relation to the prior art. However, the invention is not limited to adhesives with regard to the multi-component material, but can also be implemented with other types of materials.

[0015] In accordance with the known mixing device described above, the mixing device according to the invention initially comprises a first supply line for supplying the first component of the multi-component material. The first supply line preferably contains a first control valve that can control the material flow of the first component through the first supply line.

[0016] Furthermore, the mixing device according to the invention, in accordance with the known mixing device described above, also has a second supply line for supplying a second component of the multi-component material. A second control valve can be arranged in the second supply line to control the material flow of the second component through the second supply line.

[0017] Furthermore, the mixing device according to the invention, in accordance with the known mixing device described at the outset, also has a mixer (e.g. grid mixer, spiral mixer), wherein the mixer is connected on the inlet side to the first feed line and the second feed line in order to mix the first component with the second component to form the multi-component material.

[0018] The invention is characterized in that a shut-off valve is arranged at the outlet of the mixer in order to shut off the outlet of the mixer during an application break and thereby prevent the multi-component material from escaping from the mixer.

[0019] Firstly, the shut-off valve prevents unwanted leakage of multi-component material from the mixer during application breaks when the mixer outlet is facing downward. This prevents the mixer from running dry when the shut-off valve is closed.

[0020] On the other hand, the shut-off valve at the outlet of the mixer also prevents the annoying thread pull at the end of an adhesive line described above when the control valves on the inlet side are closed, since the shut-off valve on the outlet side is then also closed.

[0021] In one variant of the invention, the shut-off valve can be actively controlled by a control signal. For example, the shut-off valve can be controlled by an electrical or pneumatic control signal. Such actively controllable shut-off valves are known per se from the prior art and therefore need not be described in detail.

[0022] In another variant of the invention, however, the shut-off valve is self-actuated and controlled by the multi-component material present at the inlet of the shut-off valve. For example, the shut-off valve can be a check valve that shuts off the mixer outlet when the pressure of the multi-component material at the inlet of the shut-off valve falls below a predetermined opening pressure. If the inlet-side control valves at the mixer inlet are closed, this leads to a corresponding drop in the pressure of the multi-component material at the mixer outlet, which then closes the check valve, preventing the mixer from leaking and the annoying stringing.In a third variant of the invention, the shut-off valve is actuated by an external medium, in particular as a pinch valve controlled by pneumatic pressure acting on an elastic hose. Depending on the pressure, the hose is either squeezed together, thus closing it, or not compressed, thus releasing it. The external medium for controlling the shut-off valve can therefore be compressed air, for example.

[0023] Within the scope of the invention, the shut-off valve can be actively controlled (e.g., electrically or pneumatically), actuated by its own medium, or actuated by an external medium. However, the invention is not limited to these three types of actuation of the shut-off valve, but can also be implemented with other types of actuation.

[0024] When the shut-off valve at the mixer outlet is closed, there is also a risk with the mixing device according to the invention that the multi-component material upstream of the shut-off point will harden if the shut-off valve remains closed for too long. The hardened multi-component material in the shut-off valve can then no longer be removed, which means that in the worst case scenario the shut-off valve has to be completely replaced. To reduce the costs when the multi-component material hardens when the shut-off valve is closed, the preferred embodiment of the invention therefore provides a reject part (replacement part, spare part) that is inexpensive to replace and is arranged between the mixer outlet and the shut-off valve. A continuous channel is located in the reject part to guide the multi-component material from the mixer outlet to the shut-off valve.The multi-component material in the channel of the reject part is also at risk of hardening when the shut-off valve is closed. However, if the multi-component material in the reject part hardens, only the inexpensively replaceable reject part needs to be replaced, while the shut-off valve can otherwise be reused. This significantly reduces the costs of undesired hardening of the multi-component material. In the preferred embodiment of the invention, the reject part can be replaced without tools, which further reduces the costs of replacing the reject part.

[0025] The aforementioned channel in the reject part can contain a channel bend in which a change in direction of the channel occurs. For example, the change in direction in the channel can be substantially 90°, whereby angular deviations of ±20°, ±10°, ±5°, ±2°, or ±1° from the exact value of 90° can be permitted. In a preferred embodiment of the invention, the channel in the reject part comprises a proximal channel section, a distal channel section, and the channel bend arranged therebetween, wherein the proximal channel section in the reject part preferably runs coaxially to the longitudinal axis of the mixer, while the distal channel section in the reject part preferably runs radially to the longitudinal axis of the mixer. This enables a lateral arrangement of the shut-off valve at the distal end of the mixer, wherein the valve needle of the shut-off valve runs parallel next to the longitudinal axis of the mixer.The terms "proximal" and "distal" preferably refer to the general flow direction of the components and the component mixture.

[0026] In a preferred embodiment of the invention, the shut-off valve is a needle valve with a movable valve needle and a valve seat that can be selectively closed or opened by the valve needle. The valve seat of the shut-off valve is then preferably located in the reject part, so that the shut-off point is located in the reject part. The valve drive of the shut-off valve and the valve needle can then continue to be used even if the multi-component material cures in the reject part and do not need to be replaced, which helps to keep the costs of undesired curing of the multi-component material low.

[0027] In another variant of the invention, the shut-off valve is a pinch valve with an elastic hose connected to the outlet of the mixer.

[0028] It is possible for the pinch valve to be pneumatically controlled by a controllable pneumatic pressure that presses on the elastic hose from the outside and can squeeze the elastic hose to close the pinch valve, whereby the pneumatic pressure preferably acts on the elastic hose from all sides.

[0029] Alternatively, it is possible for the pinch valve to be controlled by at least one linear actuator, which is preferably electrically controllable and presses on the elastic hose from the outside and can squeeze it together in order to close the pinch valve.

[0030] However, the invention is not limited to the two examples mentioned above (pneumatic control and linear actuator) with regard to the control of the pinch valve, but in principle also allows a different control of the pinch valve.

[0031] In another variant of the invention, the shut-off valve is specially designed to allow for a slim interfering contour at the distal end of the mixer. This is particularly advantageous when the mixer is to be inserted with its distal end into cavities in motor vehicle body components, for example to apply adhesive strips. In this variant of the invention, the shut-off valve is a needle valve with a movable valve needle, a valve seat, and a valve drive for moving the valve needle, for example with a pneumatic cylinder. The valve seat is located at the distal end of the mixer, for example in the aforementioned reject part or in a transition piece between the mixer outlet and the nozzle. There is a relatively short distance between the distal end of the mixer and the valve seat, which is preferably less than 10 cm, 5 cm, or even 2 cm.The arrangement of the valve seat at the distal end of the mixer is advantageous because the shut-off point is then very close to the nozzle, whereby the flow path of the multi-component material downstream behind the valve seat is very short, thus improving the application behavior. The valve drive, on the other hand, is set back in the proximal direction from the distal end of the mixer in order to enable the desired slim interference contour at the distal end of the mixer. For example, the valve drive is located at a distance of at least 5 cm, 10 cm, 20 cm or 50 cm from the distal end of the mixer. The valve needle preferably runs laterally next to the mixer from the proximally set back valve drive to the valve seat at the distal end of the mixer.

[0032] It was already briefly mentioned at the beginning that the shut-off valve can be a check valve that blocks the outlet of the mixer when the pressure of the multi-component material at the inlet of the shut-off valve falls below an opening pressure. In the context of the invention, the check valve has a shut-off body that can be, for example, spherical, conical, or mushroom-shaped. It should also be mentioned that the check valve preferably has a closing spring that preloads the shut-off body into a closed position, wherein the check valve blocks the outlet of the mixer in the closed position and thereby prevents the undesired escape of the multi-component material from the mixer. The closing spring preferably presses the shut-off body in the proximal direction into the closed position, so that the shut-off body is arranged proximally in the closed position and distally in the open position.

[0033] It should also be mentioned that the mixer is preferably arranged in a protective tube with a specific inner contour, while the shut-off valve (e.g. check valve) arranged at the distal end of the mixer has a specific outer contour. The outer contour of the shut-off valve (e.g. check valve) is preferably smaller than the inner contour of the protective tube, so that the mixer, together with the shut-off valve (e.g. check valve) mounted at the distal end of the mixer, can be pulled out of the protective tube in the proximal direction in order to replace the mixer. The shut-off valve (e.g. check valve) therefore does not have to be removed from the mixer in order to pull the mixer out of the protective tube. This makes replacing the mixer much easier, which is advantageous because the multi-component material contained in the mixer can also harden, which then makes it necessary to replace the mixer.

[0034] For example, the check valve may have a valve housing that is connected at its proximal end to an outlet of the mixer, for example by a screw connection, while the valve housing opens into a nozzle at its distal end.

[0035] The shut-off body (e.g., valve ball) of the check valve is preferably movable in the valve housing between a proximal closed position and a distal open position. In the proximal closed position, the shut-off body of the check valve closes the mixer, preventing the multi-component material from escaping from the mixer outlet. In the distal open position, however, the shut-off body releases the mixer outlet, allowing the multi-component material to exit the mixer outlet and be applied through the nozzle of the valve housing. The shut-off body is preferably biased into the proximal closed position by a closing spring (e.g., a coil spring).

[0036] It should be noted that the closing spring is preferably arranged in a separate spring chamber in the valve housing. In its distal open position, the shut-off body then closes the spring chamber with the closing spring located therein. The multi-component material emerging from the mixer outlet is thereby prevented from entering the spring chamber. The spring chamber therefore preferably does not form a dead space in which the multi-component material can harden. Rather, a flow channel surrounding the spring chamber is located in the valve housing between the inlet connection to the mixer and the outlet nozzle, allowing the multi-component material emerging from the mixer to flow through the flow channel to the nozzle without entering the spring chamber.

[0037] It has already been mentioned several times above that the shut-off valve can be a check valve. In a special design of such a check valve, a rigid tube is provided which is connected on the inlet side to the outlet of the mixer and has at least one outlet opening in its wall at its distal end. In the preferred embodiment of the invention, a number of outlet openings through which the multi-component material can escape are arranged at the distal end of the rigid tube in the wall of the tube, distributed over the circumference. The check valve has an elastic hose which surrounds the rigid tube at least at its distal end in the region of the outlet opening. When the multi-component material in the rigid tube is under slight pressure, the elastic hose then lies against the outlet opening in the wall of the rigid tube from the outside, thereby closing the outlet opening.At a high pressure of the multi-component material in the rigid tube, however, the pressure of the multi-component material in the rigid tube lifts the elastic hose from the wall of the rigid tube, so that the multi-component material can escape radially outwards through the outlet opening of the rigid tube.

[0038] It should also be noted that the shut-off valve can be screwed onto the distal end of the mixer and can have a self-tapping thread for this purpose. This is particularly possible if the mixer has a multi-stepped outer contour at its distal end with several cylindrical sections that taper in a stepped manner in the distal direction.

[0039] As already mentioned above, the multi-component material in the mixer is also prone to hardening, so the mixer must be replaced when the multi-component material in the mixer has hardened. To facilitate replacement of the mixer, the mixer can be arranged in a protective tube that can be opened to allow the mixer located inside the protective tube to be replaced.

[0040] Furthermore, it should be mentioned in general that the shut-off valve can be connected to the mixer by a screw connection. For this purpose, the mixer preferably has a first thread (e.g. external thread) at its outlet, which can be screwed to a second thread (e.g. internal thread) on the shut-off valve. Various embodiments of the shut-off valve have already been described above. The second thread of the shut-off valve can therefore be located, for example, in the rigid tube of the check valve, in the reject part or in the check valve, in particular in the valve housing of the check valve. It should be mentioned here that the screw connection is preferably tight against the multi-component material. In the case of a two-component adhesive, the screw connection between the mixer and the shut-off valve should therefore be adhesive-tight.

[0041] It was briefly mentioned above that the mixer can be a grid mixer or a rotary mixer, both of which are static mixers. However, it is also possible for the mixer to be a dynamic mixer, which has movably driven mixing elements.

[0042] Furthermore, it should be mentioned in general that the mixer preferably has an elongated lance-shaped outer contour, in particular with a cylindrical cross-section.

[0043] Furthermore, it was already mentioned at the beginning that a first control valve can be arranged in the first supply line to the mixer and a second control valve can be arranged in the second supply line to the mixer in order to control the inflow of the components to the mixer.

[0044] For example, the supply lines can end in the mixer in a V-shape.

[0045] On the outlet side, the shut-off valve can have a nozzle to apply the multi-component material through the nozzle, whereby the nozzle can be attached directly to the shut-off valve.

[0046] Furthermore, it should be mentioned in general that the shut-off valve is preferably mounted directly to the mixer, for example by means of the screw connection mentioned above.

[0047] It has already been mentioned several times that the mixing device must be partially replaced once the multi-component material in the mixing device has hardened. To enable cost-effective replacement of the respective components, it is therefore preferably provided that the components requiring replacement are made of plastic. For example, the parts requiring replacement can be the reject part, the rigid pipe, the check valve, the shut-off valve, and / or the mixer, which are then preferably made of plastic. For example, polyethylene (PE), polyurethane (PU), or polyamide (PA) are possible plastics; however, the invention is not limited to these examples with regard to the plastics for the components requiring replacement.

[0048] Furthermore, it should be noted that the components of the mixing device that require replacement can be manufactured using a generative manufacturing process to enable cost-effective component replacement once the multi-component material in the mixing device has hardened. For example, these components can be the reject part, the rigid pipe, the check valve, the shut-off valve, and the mixer. With regard to the generative manufacturing process, stereolithography or selective laser sintering are possible, for example, but the invention is not limited to these generative manufacturing processes.

[0049] Alternatively, it is also possible that the components that need to be replaced are made of steel, aluminum, ceramic, plastic, brass or other metals.

[0050] Furthermore, it should be noted that the invention not only claims protection for the mixing device described above. Rather, the invention also claims protection for a complete application device comprising such a mixing device and a nozzle for applying the multi-component material through the nozzle. Furthermore, the application device preferably also comprises a robot for movably guiding the mixing device with the nozzle.

[0051] Furthermore, the invention also claims protection for an operating method for the application device according to the invention, wherein the individual method steps of the operating method according to the invention already result from the above description and therefore do not need to be described separately.

[0052] In addition to the operating procedure, it should be mentioned that the mixer and / or the shut-off valve should preferably be rinsed with a rinsing agent before the so-called pot life has elapsed after the mixer has been shut off by the shut-off valve. This prevents the multi-component material from hardening in the mixing device. The pot life indicates the processability period of the multi-component material after mixing.

[0053] Furthermore, the operating method according to the invention preferably provides for the replacement of a component when the multi-component material in the respective component has cured. For example, the component at risk of curing can be the reject part, the rigid pipe, the check valve, the shut-off valve, and / or the mixer.

[0054] Finally, the operating method according to the invention provides in a variant of the invention that the mixer is pulled out of the surrounding protective tube in the proximal direction, in particular with the shut-off valve (e.g. check valve) mounted at the distal end of the mixer.

[0055] Furthermore, the mixer located in a protective tube can be easily replaced by opening the surrounding protective tube.

[0056] Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to the figures.

[0057] Brief description of the drawings

[0058] Figure 1A shows a side view of a mixing device according to the invention for mixing a two-component adhesive.

[0059] Figure 1B shows a longitudinal sectional view through the mixing device according to Figure 1A.

[0060] Figure 1C shows an enlarged detail view from Figure 1B at the distal end of the mixing device.

[0061] Figure 2A shows a side view of a mixing device with a pinch valve in the open state of the pinch valve.

[0062] Figure 2B shows the mixing device according to Figure 2A in the closed state of the pinch valve.

[0063] Figure 3 shows a side view of a modified mixing device with a recessed valve drive to achieve a slim interference contour at the distal end of the mixing device.

[0064] Figure 4A shows a longitudinal sectional view through a mixing device according to the invention with a check valve screwed onto the mixer.

[0065] Figure 4B shows a detailed view from Figure 4A in the area of ​​the check valve.

[0066] Figure 5 shows a modification of Figure 4B with a mushroom-shaped shut-off body.

[0067] Figure 6A shows a check valve with a rigid tube and an elastic hose in a closed position.

[0068] Figure 6B shows the check valve according to Figure 6A in an open position.

[0069] Figure 7 shows a variation with a mixer with a stepped end and a shut-off valve with a self-tapping thread for screwing onto the mixer.

[0070] Figure 8 showed a modification of Figure 4B.

[0071] Detailed information

[0072] In the following, a first embodiment of a mixing device 1 according to the invention will now be described, as shown in Figures 1A-1C.

[0073] The mixing device 1 is used to mix two components together to form a two-component adhesive.

[0074] The two components of the two-component adhesive are fed to the mixing device 1 via two supply lines 1, 3, with two control valves 4, 5 being arranged in the two supply lines 2, 3.

[0075] The two supply lines 2, 3 open into a mixer 7 in the mixing device 1 via a connecting piece 6. In this embodiment, this mixer is a static mixer (e.g., grid mixer, rotary mixer) made of plastic. The plastic construction of the mixer 7 allows for cost-effective replacement of the mixer 7 should the two-component adhesive in the mixer 7 cure.

[0076] It should be noted that the mixer 7 is arranged in a protective tube 8, wherein the protective tube 8 can be opened to facilitate replacement of the mixer 7 when the two-component adhesive in the mixer 7 has cured.

[0077] At the distal end of the mixer 7 is a shut-off valve 9, which allows the outlet of the mixer 7 to be shut off. Firstly, shutting off the mixer 7 using the shut-off valve 9 is useful during application breaks to prevent the two-component adhesive contained in the mixer 7 from running out of the mixer 7. This danger exists particularly with a two-component adhesive with a high mass density and low viscosity, if the mixer 7 is oriented with its outlet facing downwards.

[0078] On the other hand, shutting off the mixer 7 by means of the shut-off valve 9 is also useful when applying adhesive strips, when the control valves 4, 5 are closed at the end of an adhesive strip, since without shutting off the outlet of the mixer 7, an undesired thread pull could occur, which could result in undesired adhesive threads.

[0079] The shut-off valve 9 comprises a valve needle 10 and a valve drive 11 for moving the valve needle 10. In addition, the shut-off valve 9 comprises a valve seat 12, which can be selectively opened or closed by the valve needle 10 depending on its position.

[0080] The valve actuator 11 comprises a valve piston 13, which can be pneumatically displaced within a cylinder and is biased into a closed position by a closing spring 14. Without active pneumatic actuation, the valve actuator 11 thus moves the valve needle 10 into its closed position, in which the valve needle 10 closes the valve seat 12, thus shutting off the material flow from the mixer 7.

[0081] In addition, the shut-off valve 9 comprises a reject part 15 with a continuous channel 16 that connects the outlet of the mixer 7 to the valve seat 12 of the shut-off valve 9. The reject part 15 is made of plastic to enable cost-effective replacement of the reject part 15 once the two-component adhesive in the channel 16 of the reject part 15 has hardened. It should be noted that the reject part 15 is shown with a dashed border in Fig. 1C. In practice, the part outlined in this way would be manufactured as a separate, screw-on plastic part. However, it is also possible for the reject part 15 to consist of several individual, interchangeable parts.

[0082] The reject part 15 has an internal thread on the inlet side, which forms a screw connection 17 with a corresponding external thread at the distal end of the mixer 7. It should be noted here that the screw connection 17 is sealed against the two-component adhesive, i.e. no two-component adhesive can escape to the outside. It should also be mentioned that the channel 16 in the reject part 15 has a channel bend which forms a directional deflection of 90°. Thus, the channel 16 in the reject part 15 has a proximal channel section which runs coaxially to the longitudinal axis of the mixer 7. Furthermore, the channel 16 in the reject part 15 has a distal line section which leads to the valve seat 12. The channel bend which effects the directional deflection is located between the proximal channel section and the distal channel section of the channel 16.This makes it possible for the valve needle 10 of the shut-off valve 9 to be offset laterally and run parallel to the longitudinal axis of the mixer 7.

[0083] Furthermore, it should be noted that the reject part 15 can be easily replaced without tools if the two-component adhesive in the channel 16 of the reject part 15 has cured. However, the remaining parts of the shut-off valve 9 can then be reused, so that curing of the two-component adhesive in the shut-off valve 9 only results in relatively low repair costs.

[0084] In addition, the drawings show a nozzle plate 18 with a nozzle 19 formed therein for dispensing the two-component adhesive.

[0085] The embodiment according to Figures 2A and 2B, which is only shown schematically in the drawings, will now be described below.

[0086] The outlet of the mixer 7 is connected to an elastic hose 20, which forms a pinch valve 21.

[0087] Figure 2A shows an open state of the pinch valve 21 when the elastic hose 20 is not exposed to any external forces.

[0088] Figure 2B, on the other hand, shows a closed state of the pinch valve 21 when the elastic tube 20 is compressed by an external pneumatic pressure and is thereby closed.

[0089] Instead of external pneumatic pressure, however, the elastic hose 20 can also be compressed by a linear actuator, to name just one example. The following describes the embodiment shown in Figure 3, which largely corresponds to the embodiment according to Figures 1A-1C. To avoid repetition, reference is made to the above description, with the same reference numerals being used for corresponding details.

[0090] A special feature of this embodiment is that the valve drive 11 is set back in the proximal direction relative to the distal end of the mixer 7. This allows for a slim interference contour of the mixing device 1 at the distal end of the mixer 7. This is particularly advantageous when the mixing device 1 with the nozzle 19 is to be introduced through narrow openings into cavities of motor vehicle bodies. The valve needle 10 runs laterally next to the mixer 7 from the valve drive 11, which is set back in the proximal direction, to the valve seat 12 at the distal end of the mixer 7 in the reject part 15.

[0091] The embodiment shown in Figures 4A and 4B will now be described, which also partially corresponds to the embodiment according to Figures 1A-1C, so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

[0092] A special feature of this embodiment is that the shut-off valve 9 in this embodiment is a check valve and has a valve ball 22 as a shut-off body. The valve ball 22 is preloaded by a closing spring 23 in the proximal direction into a closed position, in which the valve ball 22 blocks the outlet of the mixer 7. The closing spring 23 is arranged within a valve housing 24 of the check valve in a separate spring chamber 25. The spring chamber 25 is closed by the valve ball 22 in the distal open position. This prevents the two-component adhesive emerging from the mixer 7 from also entering the spring chamber 25 during application of the two-component adhesive, since the spring chamber 25 could then form a dead space in which the two-component adhesive could harden.

[0093] At its proximal end, the valve housing 24 of the check valve has an internal thread which, with a corresponding external thread at the distal end of the mixer 7, forms the already mentioned screw connection 17.

[0094] At the distal end of the valve housing 24, however, the valve housing 24 forms the nozzle 19. Within the valve housing 24, a flow channel 26 runs from the inlet to the nozzle 19, which forms a flow connection from the inlet of the valve housing 24 to the nozzle 19 past the spring chamber 25.

[0095] Figure 5 shows a modification of the embodiment according to Figures 4A and 4B, so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

[0096] A special feature of this embodiment is that instead of the valve ball 22, a mushroom-shaped shut-off body I is provided as the shut-off body.

[0097] The embodiment according to Figures 6A and 6B will now be described, which also shows a check valve 28 for closing the outlet of the mixer 7.

[0098] For this purpose, the check valve initially has a rigid pipe 29 which is connected on the inlet side to the outlet of the mixer 7, for example by a screw connection.

[0099] At its distal end of the rigid tube 29, the rigid tube is closed and has several outlet openings 30 in its outer surface.

[0100] The rigid tube 29 is surrounded by an elastic hose 31, wherein the elastic hose 31 closes and seals the outlet openings 30 in the wall of the rigid tube 29 in the closed position according to Figure 6A.

[0101] However, above a certain pressure of the two-component adhesive within the rigid tube 29, the pressure of the two-component adhesive in the rigid tube 29 lifts the elastic hose 31 from the wall of the rigid tube 29, thereby releasing the outlet openings 30 in the wall of the rigid tube, as shown in Figure 6B.

[0102] The check valve 28 opens when the two-component adhesive pressure inside the rigid tube 29 reaches a certain level, whereas the check valve 28 otherwise closes.

[0103] The embodiment according to Figure 7 will now be described, which partially corresponds to the embodiment according to Figures 4A and 4B, so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

[0104] A special feature of this embodiment is that the mixer 7 forms a stepped nozzle end 32 at its distal end, which has a plurality of cylindrical sections that taper stepwise in the distal direction.

[0105] A further special feature is that the valve housing 24 of the check valve has a self-tapping thread on the inside to enable a screw connection with the stepped nozzle end 32 of the mixer 7, which is made of plastic.

[0106] Finally, Figure 8 shows a modification of the embodiment according to Figures 4A and 4B, so that in order to avoid repetition, reference is again made to the above description, the same reference numerals being used for corresponding details.

[0107] A special feature of this embodiment is that the valve ball 22 is preloaded by the closing spring 23 in the opposite direction, ie in the distal direction.

[0108] The invention is not limited to the preferred embodiments described above. Rather, a multitude of variants and modifications are possible, which also utilize the inventive concept and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject matter and features of the subclaims, independently of the respective claims referred to, and in particular even without the features of the main claim. The invention thus encompasses various aspects of the invention that enjoy independent protection.

[0109] Advantages of the invention

[0110] The shut-off valve according to the invention at the outlet of the mixer advantageously prevents the mixer from leaking during application breaks, ie the two-component adhesive in the mixer cannot leak out of the mixer even if the mixer is aligned with the nozzle downwards.

[0111] A further advantage when applying adhesive strips is that if the supply of the two components of the two-component adhesive is shut off at the inlet side, there is no annoying threading, since at the end of an adhesive strip the adhesive flow is also shut off at the outlet of the mixer.

[0112] List of reference symbols

[0113] 1 mixing device

[0114] 2 supply lines

[0115] 3 supply line

[0116] 4 control valve

[0117] 5 Control valve

[0118] 6 Connection part in front of the mixer

[0119] 7 mixers

[0120] 8 Mixer protection tube

[0121] 9 Shut-off valve

[0122] 10 Valve needle of the shut-off valve

[0123] 11 Valve actuator of the shut-off valve

[0124] 12 Valve seat of the shut-off valve

[0125] 13 Valve piston of the valve drive

[0126] 14 Closing spring of the shut-off valve

[0127] 15 Discarded part

[0128] 16 channel in the reject part

[0129] 17 Screw connection between the distal end of the mixer and the reject part

[0130] 18 Nozzle plate

[0131] 19 Nozzle

[0132] 20 Elastic hose

[0133] 21 Pinch valve

[0134] 22 Valve ball of the check valve as a shut-off body

[0135] 23 Check valve closing spring

[0136] 24 Valve housing of the check valve

[0137] 25 Spring chamber in the valve housing for accommodating the closing spring

[0138] 26 Flow channel in the valve housing

[0139] 27 Mushroom-shaped shut-off body

[0140] 28 Check valve

[0141] 29 Rigid pipe

[0142] 30 Outlet openings in the wall of the rigid pipe 31 Elastic hose

[0143] 32 Stepped nozzle end of the mixer

[0144] 5

Claims

CLAIMS 1. Mixing device (1) for mixing a first component and a second component to form a multi-component material, in particular a two-component adhesive, with a) a first feed line (2) for supplying the first component of the multi-component material, b) a second feed line (3) for supplying the second component of the multi-component material, and c) a mixer (7), the mixer (7) being connected on the inlet side to the first feed line (2) and the second feed line (3) in order to mix the first component with the second component to form the multi-component material, characterized by d) a shut-off valve (9; 21; 28) at the outlet of the mixer (7) in order to shut off the outlet of the mixer (7) during an application pause and thereby prevent the multi-component material from escaping from the mixer (7).

2. Mixing device (1) according to claim 1, characterized in that a) the shut-off valve (9) can be actively controlled by a control signal, in particular by an electrical or pneumatic control signal, or b) the shut-off valve (28) is actuated by its own medium by the multi-component material applied to the inlet of the shut-off valve, in particular as an elastomer-loaded check valve which shuts off the outlet of the mixer (7) when the pressure of the multi-component material at the inlet of the shut-off valve falls below an opening pressure, or c) the shut-off valve (21) is actuated by an external medium, in particular as a pinch valve with a control by a pneumatic pressure which acts on an elastic hose and squeezes the hose together depending on the pressure and thereby closes it or does not compress it and thereby releases it.

3. Mixing device (1) according to one of the preceding claims, characterized in that a) at least one replaceable reject part (15) is arranged between the outlet of the mixer (7) and the shut-off valve, b) that the reject part (15) has a continuous channel (16) to guide the multi-component material from the outlet of the mixer (7) to the shut-off valve, c) that the multi-component material is at risk of hardening in the channel (16) of the reject part (15) when the shut-off valve is closed, d) that the reject part (15) is replaceable, in particular without tools, in the event of hardening of the multi-component material in the channel (16) of the reject part (15).

4. Mixing device (1) according to claim 3, characterized in that a) the channel (16) in the reject part (15) has a channel bend with a change in direction of the channel (16), b) the change in direction in the channel bend is preferably substantially 90°, c) the channel (16) in the reject part (15) preferably comprises a proximal channel section, a distal channel section and the channel bend arranged therebetween, d) the proximal channel section in the reject part (15) preferably runs coaxially to the longitudinal axis of the mixer (7), and e) the distal channel section in the reject part (15) preferably runs radially to the longitudinal axis of the mixer (7).

5. Mixing device (1) according to claim 3 or 4, characterized in that a) the shut-off valve (9) is a needle valve with a displaceable valve needle (10) and a valve seat (12) which can be selectively closed or opened by the valve needle (10), and b) the valve seat (12) of the shut-off valve (9) is located in the reject part (15), c) the valve needle (10) preferably runs laterally next to the longitudinal axis of the mixer (7) and parallel to the longitudinal axis of the mixer (7) and is displaceable parallel to the longitudinal axis of the mixer (7).

6. Mixing device (1) according to one of claims 1 or 2, characterized in that the shut-off valve (21) is a pinch valve (21) with an elastic hose (20) which is connected to the outlet of the mixer (7).

7. Mixing device (1) according to claim 6, characterized in that a) the pinch valve (21) is pneumatically controllable by a controllable pneumatic pressure which presses externally on the elastic hose and the elastic hose (20) can squeeze together to close the pinch valve (21), wherein the pneumatic pressure preferably acts on the elastic hose (20) from all sides, or b) that the pinch valve (21) is controllable by at least one linear actuator, which is preferably electrically controllable and presses on the elastic hose (20) from the outside and can squeeze it together to close the pinch valve (21).

8. Mixing device (1) according to one of claims 1 to 4, characterized in that a) the shut-off valve (9) is a needle valve with a1) a displaceable valve needle (10), a2) a valve seat (12) which is selectively closed or opened by the valve needle (10), and a3) a valve drive (11) for displacing the valve needle (10), in particular with a pneumatic cylinder, b) the valve seat (12) is arranged at the distal end of the mixer (7), b1) in particular in the reject part (15) or in a transition piece between the outlet of the mixer (7) and a nozzle (19), b2) in particular at a distance of less than 10 cm, 5 cm or 2 cm from the distal end of the mixer (7), and c) the valve drive (11) is arranged set back in the proximal direction from the distal end of the mixer (7), in particular at a distance of at least 5 cm, 10 cm 20 cm or 50 cm from the distal end of the mixer (7),to enable a slim interference contour at the distal end of the mixer (7), and d) that the valve needle (10) preferably runs laterally next to the mixer (7) from the valve drive to the valve seat (12).

9. Mixing device (1) according to one of claims 1 or 2, characterized in that a) the shut-off valve (9) is a check valve which shuts off the outlet of the mixer (7) when the pressure of the multi-component material at the inlet of the shut-off valve falls below an opening pressure, b) the check valve (9) preferably has a shut-off body (22) which is spherical, conical or mushroom-shaped, c) the check valve is preferably pretensioned into a closed position by a closing spring (23), wherein the check valve shuts off the outlet of the mixer (7) in the closed position and thereby prevents the undesired escape of the multi-component material from the mixer (7), d) that the closing spring (23) preferably presses the shut-off body (22) in the proximal direction, so that the shut-off body (22) is arranged proximally in the closed position and distally in the open position.

10. Mixing device (1) according to one of the preceding claims, characterized in that a) the mixer (7) is arranged in a protective tube (8) with a specific inner contour, b) the shut-off valve (9) mounted at the distal end of the mixer (7) has a specific outer contour, and c) the outer contour of the shut-off valve (9) is smaller than the inner contour of the protective tube (8), so that the mixer (7) together with the shut-off valve (9) mounted at the distal end of the mixer (7) can be pulled out of the protective tube (8) in the proximal direction in order to replace the mixer (7), d) the shut-off valve (9) is preferably a check valve.

11. Mixing device (1) according to one of claims 9 or 10, characterized in that a) the check valve has a valve housing (24), b) the valve housing (24) of the check valve is connected at its proximal end to the outlet of the mixer (7), in particular by a screw connection (17), c) the valve housing (24) of the check valve opens into a nozzle (19) at its distal end.

12. Mixing device (1) according to claim 11, characterized in that a) the shut-off body (22) of the check valve is displaceable in the valve housing (24) between a proximal closed position and a distal open position, b) the shut-off body (22) of the check valve in the proximal closed position blocks the outlet of the mixer (7) so that the multi-component material cannot escape from the outlet of the mixer (7), c) the shut-off body (22) of the check valve in the distal open position releases the outlet of the mixer (7) so that the multi-component material can escape from the outlet of the mixer (7), d) the shut-off body (22) is pretensioned into the proximal closed position by a closing spring (23), e) that the closing spring (23) is arranged within the valve housing (24) in a spring chamber (25), f) that the shut-off body (22) closes the spring chamber (25) in its distal open position in order to prevent the multi-component material emerging from the mixer (7) from penetrating into the spring chamber (25) and thereby to avoid a dead space in the spring chamber (25) which is at risk of hardening, and g) that the spring chamber (25) is surrounded in the valve housing (24) by at least one flow channel (26) which enables flow around the spring chamber (25) and connects the outlet of the mixer (7) to the nozzle (19) in the valve housing (24).

13. Mixing device (1) according to one of the preceding claims, characterized in that a) the shut-off valve (28) is a check valve (28), b) the check valve (28) has a rigid tube (29) which is connected on the inlet side to the outlet of the mixer (7) and has at least one outlet opening (30) in its wall at its distal end, c) the check valve (28) has an elastic hose (31) which surrounds the rigid tube (29) at least at its distal end in the region of the outlet opening (30), and d) the elastic hose (31) opens the outlet opening (30) in the wall of the rigid tube (29) when the pressure of the multi-component material in the rigid tube (29) exceeds an opening pressure and thereby separates the elastic hose (31) at the outlet opening (30) from the wall of the rigid tube (29). takes off,and e) that the elastic hose (31) closes the outlet opening (30) in the wall of the rigid tube (29) due to the elasticity of the elastic hose (31) when the pressure of the multi-component material in the rigid tube (29) is below the opening pressure.

14. Mixing device (1) according to one of the preceding claims, characterized in that a) the shut-off valve has a self-tapping thread for screwing onto the distal end of the mixer (7), and b) the mixer (7) preferably has a multi-stepped outer contour with a plurality of cylindrical sections at its distal end and tapers in the distal direction.

15. Mixing device (1) according to one of the preceding claims, characterized in that a) the mixer (7) is arranged in a protective tube (8), and b) the protective tube (8) can be opened in order to be able to replace the mixer (7) in the protective tube (8) when the multi-component material in the mixer (7) has hardened.

16. Mixing device (1) according to one of the preceding claims, characterized in that a) the mixer (7) has a first thread at its outlet, in particular an external thread, b) the shut-off valve (9) has a second thread, in particular an internal thread, in particular b1) in the rigid tube (29) of the check valve, or b2) in the reject part (15), or b3) in the check valve, in particular in the valve housing (24) of the check valve, c) the first thread of the mixer (7) is screwed to the second thread of the shut-off valve (9) and forms a screw connection (17), and d) the screw connection (17) is preferably tight with respect to the multi-component material.

17. Mixing device (1) according to one of the preceding claims, characterized in that a) the mixer (7) is a dynamic mixer (7) with movably driven mixing elements or a static mixer (7), in particular a grid mixer or a spiral mixer, and / or b) the mixer (7) has an elongated lance-shaped outer contour, in particular with a cylindrical cross-section, and / or c) the multi-component material is a two-component adhesive, and / or d) a first control valve (4) is arranged in the first supply line (2) and a second control valve (5) is arranged in the second supply line (3), and / or e) the two supply lines (2, 3) open into the mixer (7) in a V-shape, and / or f) the shut-off valve (9) opens into a nozzle (19) on the outlet side in order to apply the multi-component material through the nozzle (19), and / or g) that the nozzle (19) is mounted directly on the shut-off valve (9), and / or h) that the shut-off valve (9) is mounted directly on the mixer (7) and / or i) that the following component of the mixing device (1) is made of plastic in order to enable a cost-effective replacement of the respective component when the multi-component material in the respective component has hardened: 11) the reject part (15), 12) the rigid tube (29), 13) the check valve (28), 14) the shut-off valve (9), and / or 15) the mixer (7), and / or j) that the plastic is one of the following plastics: jl) polyethylene, j2) polyurethane j3) polyamide, and / or k) that the following component of the mixing device (1) is manufactured by a generative manufacturing process in order to enable a cost-effective replacement of the respective component when the multi-component material in the respective component has cured: k1) the reject part (15), k2) the rigid pipe (29), k3) the check valve (28), k4) the shut-off valve (9), and / or k5) the mixer (7), and / or l) that the generative manufacturing process is one of the following manufacturing processes: 11) Stereolithography, or 12) Selective laser sintering, and / or m) that the following component of the mixing device (1) is made of steel or aluminum: m1) the reject part (15), m2) the rigid pipe (29), m3) the check valve (28), m4) the shut-off valve (9), and / or m5) the mixer (7).

18. Application device with a) a mixing device (1) according to one of the preceding claims and b) a nozzle (19) for applying the multi-component material through the nozzle (19), and c) preferably a robot for movably guiding the mixing device (1) with the Nozzle (19).

19. Operating method for an application device according to claim 18, with the following steps: a) conveying the first component of the multi-component material through the first feed line (2) of the mixing device (1) to the mixer (7) during the application of the multi-component material, b) conveying the second component of the multi-component material through the second feed line (3) of the mixing device (1) to the mixer (7) during the application of the multi-component material, c) mixing the first component and the second component in the mixer (7) during the application of the multi-component material, d) dispensing the mixed multi-component material through the nozzle (19), and e) interrupting the conveyance of the first component and the second component to the mixer (7) during an application pause, characterized by the following step in the application pause: f) shutting off the outlet of the mixer (7) by the shut-off valve (9; 21;28) in order to block the outlet of the mixer (7) during the application pause and thereby prevent the multi-component material from escaping from the mixer (7); 20. Operating method according to claim 19, characterized by the following step in the application pause: Flushing the mixer (7) and / or the shut-off valve (9; 21; 28) with a flushing agent before the pot life has elapsed after the mixer (7) has been shut off by the shut-off valve (9; 21; 28) in order to prevent the multi-component material from hardening, wherein the pot life reflects the processability time of the multi-component material after mixing.

21. Operating method according to claim 19 or 20, characterized by the following step: replacing the following component when the multi-component material in the respective component has hardened: a) the reject part (15), b) the rigid pipe (29), c) the check valve (28), d) the shut-off valve (9), and / or e) the mixer (7).

22. Operating method according to claim 21, characterized by the following step for replacing the mixer (7): a) pulling the mixer (7) out in the proximal direction from the surrounding protective tube (8), in particular together with the shut-off valve (9) mounted at the distal end of the mixer (7), wherein the shut-off valve (9) is preferably a check valve, or b) folding open the protective tube (8) to replace the mixer (7) located in the protective tube (8).

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