Dense phase powder pump for conveying coated powder

Abstract

The invention relates to a dense-phase powder pump (20) for conveying a coating powder, wherein the dense-phase powder pump (20) is designed to selectively draw in the coating powder from a powder chamber of a first powder container or from a powder chamber of a second powder container via a powder inlet of the dense-phase powder pump and to supply the drawn-in coating powder to a powder discharge device or to a powder reservoir via a powder outlet (25) of the dense-phase powder pump (20), wherein a powder switch (1) is provided at the powder inlet of the dense-phase powder pump (20) or the powder inlet of the dense-phase powder pump (20) is designed as a powder switch (1), the powder switch (1) being designed to selectively fluidically connect the powder inlet of the dense-phase powder pump (20) to a first powder line / channel system leading into the powder chamber of the first powder container or to a second powder line / channel system leading into the powder chamber of the second powder container.

Description

Technical Field

[0001] This invention generally relates to a dense-phase powder pump for conveying coated powders. Background Technology

[0002] The dense-phase powder pump of the type considered in this paper has at least one delivery chamber equipped with a powder inlet valve and a powder outlet valve. Alternatively, the delivery chamber may be connected to a vacuum source during the suction phase or to a transport compressed air source during the discharge phase. Vacuum from the vacuum source draws powder into the delivery chamber through the open powder inlet valve and closed powder outlet valve. Compressed air from the compressed air source discharges the powder from the delivery chamber through the open powder outlet valve and closed powder inlet valve.

[0003] Dense phase powder pumps can have several delivery chambers arranged in parallel to each other, which operate in a time-staggered manner, such that coating powder is alternately drawn into one delivery chamber while being discharged from another.

[0004] For example, document EP1551558A1 relates to a dense phase powder pump having a first powder delivery chamber and a second powder delivery chamber arranged parallel to the first powder delivery chamber. The two powder delivery chambers of this prior art dense phase powder pump are each limited by mechanically actuated pinch valve devices on both the suction and delivery sides.

[0005] Specifically, in the suction and discharge sections of a dense phase powder pump, the powder hose connected to the corresponding powder delivery chamber of the pump can be deformed by a mechanically actuated piston to squeeze or open the hose section as needed.

[0006] Each powder delivery chamber of the dense phase powder pump known in the prior art is assigned a filter tube that restricts the circumference of the corresponding powder delivery chamber. The filter tube is permeable to air but impermeable to coating powder and is surrounded by an annular chamber, which can be alternately connected to a vacuum or compressed air system. This allows coating powder to be alternately drawn into each powder delivery chamber or ejected from the corresponding powder delivery chamber using compressed air. Two powder delivery chambers arranged parallel to each other operate in an alternating mode, meaning that one of the two powder delivery chambers draws in coating powder through the powder inlet of the dense phase powder pump, while the other of the two powder delivery chambers discharges a portion of the coating powder previously drawn into the powder delivery chamber through the powder outlet of the dense phase powder pump.

[0007] It is known from documents DE19611533B4, WO2004 / 087331A1 and EP1566352A2 that a dense-phase powder pump is used to deliver coating powder to a corresponding device for spraying the coating powder, such as a powder spray gun.

[0008] Before the use of dense-phase powder pumps of the type considered in this article for conveying coating powders was known, powder pumps designed as ejectors were used, and these ejector-designed powder pumps are still used today. However, unlike dense-phase powder pumps, ejector-designed powder pumps (dilute-phase powder pumps) have the following disadvantages: ejector-designed powder pumps wear out relatively quickly, and over time, they can typically convey a reduced amount of coating powder per unit time.

[0009] In this regard, dense-phase powder pumps have been established in practice, especially for applications where a constant amount of coating powder must be delivered per unit time.

[0010] The present invention is based on the problem that when the powder is changed (from a first type of powder to a second type of powder), the powder coating system and the associated powder supply device must be carefully cleaned, especially when the color is changed (from a first color of powder to a different color of powder), because even a small amount of powder particles from the previous type of powder can cause coating defects when coating with a new type of powder.

[0011] In particular, dense-phase powder pumps known from the prior art for powder coating systems have the following disadvantages: switching between different types of powder or between fresh and recycled powder is not easy during the coating process, which negatively impacts coating efficiency. For example, easy switching between fresh and recycled powder during an ongoing coating process is desirable. Typically, fresh powder is applied to the surface areas of the object / workpiece to be coated, forming the visible side in subsequent use, while recycled powder can be used for the remaining areas of the object / workpiece. A typical example is the coating of vehicle rims, where fresh powder is applied to the visible side of the rim, i.e., the so-called A side of the workpiece. In the case of vehicle rims, the visible side is therefore the externally visible surface.

[0012] In the intended use of a workpiece, the non-visible area is the so-called B-side, such as the rim groove of a vehicle wheel rim. Recycled powder can be used to coat the non-visible area of ​​the workpiece. The coating formed with recycled powder is of lower quality compared to a coating formed with fresh powder; however, this is irrelevant because the coating formed with recycled powder exists only on the non-visible side of the workpiece. Summary of the Invention

[0013] Therefore, the objective of this invention is to provide a dense-phase powder pump for a powder coating system, which enables the powder coating system to operate as efficiently as possible.

[0014] In addition, a possibility should be provided through which powder replacement can be performed quickly and easily.

[0015] This task is accomplished by means of the subject matter described in independent claim 1, with further advantageous improvements to the dense-phase powder pump according to the invention given in the dependent claims.

[0016] Therefore, the present invention particularly relates to a dense phase powder pump for conveying coating powder, wherein the dense phase powder pump is designed to selectively draw coating powder from the powder chamber of a first powder container or from the powder chamber of a second powder container through the powder inlet of the dense phase powder pump, and to supply the drawn coating powder to a powder discharge device or a powder storage container through the powder outlet of the dense phase powder pump.

[0017] The powder discharge device is specifically a manual or automatic powder coating device. Automatic powder coating devices are often attached to a support (especially a lifting support) or a robot positioned outside the coating chamber via a corresponding extension, whereby the extension extends through a slotted opening in the wall of the coating chamber.

[0018] According to the present invention, a powder switch is specifically provided to be disposed at the powder inlet of a powder pump, or the powder inlet of a dense phase powder pump is designed as a powder switch.

[0019] The powder switch is designed to selectively fluidly connect the powder inlet of the dense phase powder pump to a first powder piping / channel system leading to the powder chamber of a first powder container or a second powder piping / channel system leading to the powder chamber of a second powder container.

[0020] The advantages achievable using the technical solution according to the invention are obvious: by providing a powder switch, coating powder can be drawn from two different powder containers by a dense-phase powder pump. Therefore, during the coating operation, coating powder of different kinds or types can be supplied to the powder discharge device (spray gun) as desired. Thus, switching between different kinds or types of powder no longer requires cleaning the powder piping / channel system, because a powder piping / channel system is preferably available for each kind or type of powder to be sprayed, which can be fluidly connected to the powder outlet of the powder switch as needed to supply such coating powder to the powder discharge device, which is also fluidly connected to the powder outlet of the powder switch via a dense-phase powder pump.

[0021] In particular, it is conceivable in this case that fresh powder is stored in the powder chamber of the first powder container and recycled powder is stored in the powder chamber of the second powder container.

[0022] On the other hand, it is also conceivable that different powder colors exist in the powder chambers of the first and second powder containers. It is also conceivable that the same type of coating powder exists in both powder chambers.

[0023] As used in this article, “recycled powder” refers to excess coating material or so-called “oversprayed material,” which is coating material that cannot be applied to the workpiece to be coated or coating material that has been sprayed at least once during the coating process and is therefore recycled.

[0024] According to a preferred embodiment of the dense phase powder pump, the powder switch is designed to have: a first powder inlet, which is fluidly connected or can be fluidly connected to a first powder pipeline / channel system; a second powder inlet, which is fluidly connected or can be fluidly connected to a second powder pipeline / channel system; and a powder outlet, which is fluidly connected to the powder inlet of the powder pump, or fluidly connected to the powder delivery chamber of the dense phase powder pump via a powder inlet valve.

[0025] In addition, a switching mechanism is used, which is designed to selectively fluidly connect the powder outlet to either the first powder inlet or the second powder inlet of the powder switch.

[0026] This design variant is particularly characterized by the fact that the powder switch also has a purge air inlet, thereby the switching mechanism is designed such that when the powder outlet fluid is connected to the first powder inlet, the purge air inlet fluid is connected to the second powder inlet.

[0027] Preferably, the switching mechanism is also designed such that when the powder outlet fluid of the powder switch is connected to the second powder inlet of the powder switch, the purge air inlet of the powder switch is connected to the first powder inlet of the powder switch.

[0028] In this way, the first powder inlet and the second powder inlet, as well as the first powder pipeline / channel system fluidly connected to the first powder inlet and the second powder pipeline / channel system fluidly connected to the second powder inlet, can be cleaned effectively with purge air without substantially interrupting the powder supply to the powder discharge device of the powder coating system.

[0029] According to a preferred embodiment of the powder switch, the switching mechanism is provided with a carriage device. The carriage device is adjustable relative to the housing body of the powder switch and, in particular, is capable of linear movement. The first and second powder inlets of the powder switch are formed in the carriage, while the powder outlet of the powder switch is formed in the housing body of the powder switch. Specifically, this document also provides that the purge air inlet of the powder switch is also formed in the housing body of the powder switch.

[0030] This design variant achieves a particularly compact configuration for the powder switch.

[0031] Preferably, the switching mechanism of the powder switch has a first drive device assigned to the carriage device, the first drive device being designed to move the carriage relative to the housing body of the powder switch as needed, such that the powder outlet fluid of the powder switch is connected to the first powder inlet or the second powder inlet of the powder switch.

[0032] While it is conceivable in principle that the first drive unit could be designed as, for example, an electric linear drive unit, it is advantageous to use a pneumatic drive unit for the first drive unit, which moves the carriage relative to the housing body of the powder switch by supplying compressed air. For this purpose, at least one pneumatic connection is provided to the first drive unit designed as a pneumatic drive unit.

[0033] The pneumatic drive unit (first drive unit) can be based on the operating principle of a double-acting cylinder. Such a double-acting cylinder uses aerodynamics to move during both extension and retraction. In this design variant, the pneumatic drive unit must be equipped with a first pneumatic connector and a second pneumatic connector.

[0034] However, to achieve a particularly compact design for the powder switch, it is preferable that the first drive unit, designed as a pneumatic drive, is based on the functional principle of a single-acting cylinder, so that this design requires only a single pneumatic connector. Compressed air can enter through this single pneumatic connector and move the carriage in one direction.

[0035] Preferably, the carriage assembly has a biasing element assigned to the carriage, the biasing element being in the form of a spring, the biasing element being designed to bias the carriage into a first position, in which the powder outlet of the powder switch, for example fluid, is connected to the first powder inlet of the powder switch.

[0036] The pneumatic drive is designed so that when compressed air is supplied through the (single) pneumatic connector of the powder switch, it overcomes the biasing force of the biasing element (which is specifically designed to be in the form of a spring) and moves the carriage from a first position to a second position relative to the housing body of the powder switch. In the second position, the powder outlet of the powder switch is fluidly connected to the second powder inlet of the powder switch.

[0037] According to a preferred embodiment of the powder switch, a channel system is provided in the housing body of the powder switch. The channel system is fluidly connected to the purge air inlet of the powder switch and has a first purge air outlet and a second purge air outlet. The first purge air outlet and the second purge air outlet are formed in the end face of the housing body of the powder switch adjacent to the carriage, such that when the second powder inlet of the powder switch is fluidly connected to the powder outlet of the powder switch, the first purge air outlet is fluidly connected to the first powder inlet of the powder switch, and when the first powder inlet of the powder switch is fluidly connected to the powder outlet of the powder switch, the second purge air outlet is fluidly connected to the second powder inlet of the powder switch.

[0038] This is a particularly easy-to-implement and effective solution for automatically connecting the purge air inlet fluid of the powder switch to the first powder inlet when the second powder inlet fluid of the powder switch is connected to the powder outlet of the powder switch, or for automatically connecting the purge air inlet fluid of the powder switch to the second powder inlet when the first powder inlet fluid of the powder switch is connected to the powder outlet of the powder switch.

[0039] Furthermore, integrating the channel system into the housing of the powder switch achieves a compact design for the powder switch.

[0040] In order to enable the carriage to move relative to the housing body of the powder switch with minimal wear, according to a design variant of the powder switch, a method is provided to move the carriage from a first position to a second position relative to the housing body of the powder switch. In the first position, there is a gap between the end face of the housing body of the powder switch adjacent to the carriage and the end face of the carriage adjacent to the housing body of the powder switch. In the second position, the gap between the end face of the housing body of the powder switch adjacent to the carriage and the end face of the carriage adjacent to the housing body of the powder switch is eliminated or at least reduced.

[0041] In this scenario, it is conceivable that the carriage assembly includes a (second) drive mechanism designed to move the carriage relative to the housing body of the powder switch from a first position to a second position as needed. Preferably, the second drive mechanism is also designed as a pneumatic drive mechanism and includes at least one corresponding pneumatic connector.

[0042] Similar to the first drive mechanism, an advantage in the particularly compact design of the powder switch is that the second drive mechanism, preferably designed as a pneumatic drive, is based on the operating principle of a single-acting cylinder, thus requiring only a single pneumatic connector for the second drive mechanism. In this case, it is therefore advantageous for the carriage assembly to have a biasing element associated with the carriage, which, for example, takes the form of a spring or elastic element, and is designed to bias the carriage relative to the housing body of the powder switch, particularly biasing it to the first position.

[0043] To enable particularly easy maintenance and cleaning of the powder switch when necessary, further improvements to the powder switch provide that the first and second powder inlets are designed in the carrier, and particularly in the carrier plate, wherein the carrier or carrier plate is received together with the first and second powder inlets of the powder switch and is particularly inserted into the receiving area of ​​the carriage, and is preferably held in the receiving area of ​​the carriage by quick-release fasteners.

[0044] According to a preferred embodiment of the dense phase powder pump of the present invention, the dense phase powder pump has a modular design.

[0045] The modular design of the dense phase powder pump according to the present invention allows for the adjustment, optimization, and cost reduction of each module of the pump without causing the "ripple effect" typically found within the entire dense phase powder pump. The modularity of the dense phase powder pump according to the present invention reduces product complexity and makes the customer ordering process more efficient by configuring the pump specifically for each order rather than designing it specifically for each order.

[0046] In other words, the dense phase powder pump according to the present invention is constructed according to a component or modular principle, wherein the functional components of the dense phase powder pump are divided into modules or components. The various modules or components of the dense phase powder pump constructed according to the modular principle can be connected together in a suitable shape and function, or integrated together via corresponding interfaces.

[0047] The dense-phase powder pump (according to the invention), constructed based on modular principles and characterized by its modular design, allows for the creation of individually configurable dense-phase powder pumps without sacrificing economies of scale across series. In particular, the individual modules of the dense-phase powder pump are standardized components that can be flexibly used with the aid of various adapter elements within the modular system.

[0048] The advantages of this modular dense-phase powder pump based on the modular principle are: firstly, it improves the flexibility of product and organizational development. If various compatible modules of the dense-phase powder pump are available, these modules can be attached, removed, exchanged, or recombined to ultimately adapt the pump to new conditions, resulting in faster product cycles and greater adaptability.

[0049] On the other hand, the modular design of the dense-phase powder pump according to the invention offers another advantage: a wide variety of products can be realized in a way that is easy to implement. Furthermore, due to the identical series and simpler assembly process, more cost-effective manufacturing is possible.

[0050] Finally, the modular design of the dense phase powder pump according to the invention also provides advantages in the maintenance of the dense phase powder pump, since cost-effective repairs can be performed by replacing defective parts of the dense phase powder pump.

[0051] In particular, the dense-phase powder pump according to the invention has a pump head module designed as a module, the pump head module having at least one powder delivery chamber, the powder delivery chamber being fluidly connected to or selectively fluidly connected to the powder chamber of a first powder container or a second powder container via a powder inlet, and fluidly connected to or selectively fluidly connected to a powder reservoir or a powder spraying device via a powder outlet.

[0052] Furthermore, the dense phase powder pump of this embodiment includes a compressed air control module, which is also designed as a module. The compressed air control module includes multiple switching valves that are assigned to and designed for various preferred modular components of the pump head module to supply compressed air, suction air, or vacuum to the pneumatic control components of the pump head module as needed and, in particular, in a controlled manner.

[0053] Alternatively, a quick-change module can be used, which is arranged and designed at least partially or in certain areas between the pump head module and the compressed air control module to detachably connect the pump head module to the compressed air control module. In particular, when the pump head module is connected to the compressed air control module, the pneumatic control components of the pump head module are fluidly connected to the switching valve of the compressed air control module through the quick-change module.

[0054] By providing such a quick-change module, the pump head module can be easily separated from the compressed air control module of the dense phase powder pump in a few simple steps, for example, to replace or maintain components of the pump head module.

[0055] Specifically, the quick-change module therefore represents the interface between the pump head module and the compressed air control module.

[0056] The quick-change module has a quick-change mechanism through which the pump head module can be or releasably connected to the quick-change module.

[0057] Preferably, the powder switch is also operably connected to the compressed air control module via a quick-change module that serves as an interface.

[0058] Specifically, it is envisioned that the powder switch itself is designed as a module and can be assigned to the pump head module as needed. In other words, depending on the application, the pump head module can be connected to the powder switch, which is designed as a module.

[0059] The quick-change module also represents a flow connection between the corresponding switching valve of the compressed air control module and the pneumatic control components of the powder switch module. Specifically, the compressed air control module is also used to supply compressed air to the purge air inlet of the powder switch as needed, to supply compressed air (or vacuum) to the pneumatic connection of the first drive unit of the powder switch as needed, and / or to supply compressed air (or vacuum) to the pneumatic connection of the second drive unit as needed. Attached Figure Description

[0060] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings.

[0061] The attached diagram shows:

[0062] Figure 1 An exemplary embodiment of the dense-phase powder pump according to the present invention is shown schematically in a side view;

[0063] Figure 2 A first isometric view of a powder switch for a dense-phase powder pump is schematically shown;

[0064] Figure 3 A second isometric view schematically illustrates an exemplary embodiment of a powder switch;

[0065] Figure 4 A cross-sectional view of an exemplary embodiment of a powder switch is schematically shown;

[0066] Figure 5 A side view of an exemplary embodiment of the powder switch is schematically shown;

[0067] Figure 6 A top view schematically illustrating an exemplary embodiment of the powder switch is shown.

[0068] Figure 7 A schematic view of the (downstream) front side of an exemplary embodiment of the powder switch is shown;

[0069] Figure 8 A schematic view of the (upstream) rear side of an exemplary embodiment of the powder switch is shown.

[0070] List of reference numerals

[0071] 1: Powder switch;

[0072] 2: First powder inlet;

[0073] 3: Second powder inlet;

[0074] 4: Powder outlet;

[0075] 5: Purge the air inlet;

[0076] 6: Carriage assembly / carriage;

[0077] 7: Shell body;

[0078] 8: Pneumatic connectors for the first drive unit;

[0079] 9: Channel system;

[0080] 10: The end face of the shell body;

[0081] 11: First purge air outlet;

[0082] 12: Second purge air outlet;

[0083] 13: The opening at the powder outlet;

[0084] 14: Gap;

[0085] 15: Seals;

[0086] 16: Pneumatic connector for the second drive unit;

[0087] 17: Support components / support plates;

[0088] 18: Carriage receiving area;

[0089] 19: Quick-release fasteners;

[0090] 20: Dense phase powder pump;

[0091] 21: Pump head module;

[0092] 22: Quick module / connector replacement;

[0093] 23: Compressed air control module;

[0094] 24: Pump casing;

[0095] 25: Powder outlet of dense phase powder pump. Detailed Implementation

[0096] exist Figure 1 An exemplary embodiment of the dense phase powder pump 20 according to the present invention, schematically illustrated, is characterized in part by its modularity. In particular, the dense phase powder pump 20 is constructed according to the principle of components or modularity and is divided into different functional components, which are also constructed in a modular manner.

[0097] This specifically relates to a pump head module 21 having at least one powder delivery chamber that is fluidly connected to or can be connected to a powder switch 1 designed as a module via a powder inlet, and fluidly connected to or can be connected to a powder reservoir or powder spraying device via a powder outlet 25.

[0098] The pump head module 21 of the dense phase powder pump 20 is preferably fluidly connected to the compressed air control module 23 via a quick-change system or quick-change module 22. The compressed air control module 23 forms an application valve unit for the pump head module 21 and for the modular powder switch 1.

[0099] The compressed air control module 23 is at least partially or partially integrated or can be integrated into the pump housing 24, wherein the pump housing 24 further includes a control device for controlling controllable components (including the powder switch 1) of the dense phase powder pump 20.

[0100] The quick-change system or quick-change module 22 is specifically designed as a connecting block to connect the pump head module 21, which is designed as a module, and the powder switch 1 to the compressed air control module 23, which is used as an application valve unit.

[0101] The powder switch 1 is located at the powder inlet of the pump head module 21. Alternatively, the powder switch 1 may also form the powder inlet of the dense phase powder pump 20.

[0102] In principle, the powder switch 1 is designed to connect the powder inlet or pump head module 21 of the dense phase powder pump 20 to a first powder piping / channel system leading to the powder chamber of the first powder container or a second powder piping / channel system leading to the powder chamber of the second powder container, as desired.

[0103] The following reference Figures 2 to 8 The illustrations in the diagrams describe the situation in more detail according to... Figure 1 The structure and operation mode of the powder switch 1 used in the dense phase powder pump 20.

[0104] Specifically, the powder switch 1 has a first powder inlet 2, which is fluidly connected to or can be connected to a first powder pipeline / channel system. The powder switch 1 also has a second powder inlet 3, which is fluidly connected to or can be connected to a second powder pipeline / channel system.

[0105] Therefore, it is advantageous to design the first powder inlet 2 and the second powder inlet 3 of the powder switch 1 as a hose connection, and the powder hose connected to the corresponding powder reservoir can be connected to the hose connector.

[0106] In addition, the powder switch 1 includes a powder outlet 4, which is fluidly connected or fluidly connected to the powder inlet of the dense phase powder pump 20 or the pump head module 21 of the dense phase powder pump 20.

[0107] The powder switch 1 also has a switching mechanism designed to selectively fluidly connect the powder outlet 4 of the powder switch 1 to either the first powder inlet 2 or the second powder inlet 3 of the powder switch 1.

[0108] Specifically from the basis Figure 4 As can be seen from the cross-sectional view, the switching mechanism includes a corresponding actuator by means of which the first powder inlet 2 and the second powder inlet 3 of the powder switch 1 can move together relative to the powder outlet 4. For this purpose, in the embodiment shown in the figures, the actuator is provided with a carriage device having a carriage 6, which can be adjusted relative to the housing body 7 of the powder switch 1 and is particularly linearly movable, wherein the powder outlet 4 or the first powder inlet 2 and the second powder inlet 3 are formed in the carriage 6.

[0109] In the exemplary embodiment shown in the accompanying drawings, the first powder inlet 2 and the second powder inlet 3 are formed in the carriage 6, while the powder outlet 4 is formed in the housing body 7 of the powder switch 1.

[0110] Although it cannot be directly seen from the accompanying drawings, in an exemplary embodiment of the powder switch 1 according to the present invention, the switching mechanism is provided with a pneumatic drive device associated with the carriage device, the pneumatic drive device being designed to move the carriage 6 relative to the housing body 7 as needed, so that the powder outlet 4 is fluidly connected to the first powder inlet 2 or the second powder inlet 3.

[0111] The drive unit is designed as a pneumatic drive based on the working principle of a single-acting cylinder. Therefore, the drive unit only requires a single pneumatic connector 8.

[0112] In order to achieve the most compact design of the powder switch 1, it is advantageous that the carriage device has a biasing element associated with the carriage 6, the biasing element being in the form of a spring, the biasing element being designed to bias the carriage 6 into a first position, in which the powder outlet 4 is fluidly connected to the first powder inlet 2.

[0113] The pneumatic drive is specifically designed to overcome the biasing force of the biasing element (specifically designed in the form of a spring) when compressed air is supplied through the (single) pneumatic connector 8, and to move the carriage 6 from a first position to a second position relative to the housing body 7, in which the powder outlet 4 is fluidly connected to the second powder inlet 3.

[0114] Of course, it is also conceivable in principle that a pneumatic drive device is used for the drive unit, which is based on the working principle of a double-acting cylinder and therefore has two pneumatic connectors.

[0115] A particularly distinctive feature of an exemplary embodiment of the powder switch 1 according to the present invention is that the powder switch 1 further comprises a purge air inlet 5. The switching mechanism of the powder switch 1 is designed such that when the powder outlet 4 is fluidly connected to the first powder inlet 2, the purge air inlet 5 is fluidly connected to the second powder inlet 3, and when the powder outlet 4 is fluidly connected to the second powder inlet 3, the purge air inlet 5 is fluidly connected to the first powder inlet 2.

[0116] As shown in the figure, the purge air inlet 5 is preferably formed in the housing body 7 of the powder switch 1.

[0117] according to Figure 4 The cross-sectional view shows that a channel system 9 is formed in the housing body 7 of the powder switch 1, which is in fluid communication with the purge air inlet 5. The channel system 9 has a first purge air outlet 11 and a second purge air outlet 12, wherein the first purge air outlet 11 and the second purge air outlet 12 are formed in the end face 10 of the housing body 7 adjacent to the carriage 6, such that when the second powder inlet 3 is in fluid communication with the powder outlet 4, the first purge air outlet 11 is in fluid communication with the first powder inlet 2, and when the first powder inlet 2 is in fluid communication with the powder outlet 4, the second purge air outlet 12 is in fluid communication with the second powder inlet 3.

[0118] according to Figure 4 The cross-sectional view also shows that the opening 13 of the powder outlet 4 is formed in the end face 10 of the housing body 7 adjacent to the carriage 6.

[0119] Specifically, the opening 13 of the powder outlet 4, the first purge air outlet 11, and the second purge air outlet 12 are arranged in a line (here, in a vertical line), wherein the first purge air outlet 11 and the second purge air outlet 12 are arranged equidistantly from the opening of the powder outlet 4.

[0120] The carriage 6 can be moved from a first position to a second position relative to the housing body 7. In the first position, there is a gap 14 between the end face 10 of the housing body 7 adjacent to the carriage 6 and the end face of the carriage 6 adjacent to the housing body 7. In the second position, the gap 14 between the end face 10 of the housing body 7 adjacent to the carriage 6 and the end face of the carriage 6 adjacent to the housing body 7 is eliminated or at least reduced so that the opening 13 of the powder outlet 4 is fluidly connected to the first powder inlet 2 or the second powder inlet 3 in a sealed manner, and the corresponding purge air outlets 11, 12 are fluidly connected to the second powder inlet 3 or the first powder inlet 2.

[0121] Preferably, the corresponding seal 15 (sealing ring) is also used here.

[0122] In order to move the carriage 6 relative to the housing body 7 of the powder switch 1 from a first position to a second position, a pneumatic drive device is provided for the carriage 6. The pneumatic drive device is designed to move the carriage 6 relative to the housing body 7 from the first position to the second position as needed. The drive device is specifically designed as a pneumatic drive device based on the working principle of a single-acting cylinder.

[0123] The carriage assembly may have a biasing element associated with the carriage 6, which is in particular in the form of a spring or elastic element, and is designed to bias the carriage 6 into a first position relative to the housing body 7.

[0124] For example, especially from Figure 2 , Figure 3 and Figure 5 As can be seen from the combined view, an exemplary embodiment of the powder switch 1 according to the present invention provides that: a pneumatic connector 8 of the first drive device, a pneumatic connector 16 of the second drive device, and a pneumatic connector associated with the purge air inlet 5 are formed in the common side wall region of the housing body 7 (here, formed in the lower side wall region of the housing body 7).

[0125] according to Figure 2 The isometric view also shows that, in an exemplary embodiment of the powder switch 1 according to the invention, a first powder inlet 2 and a second powder inlet 3 are formed in a carrier 17, and particularly in a carrier plate, wherein the carrier 17 or the carrier plate is accommodated together with the first powder inlet 2 and the second powder inlet 3 and is particularly inserted into the receiving area 18 of the carriage 6, and is held in the receiving area 18 of the carriage 6 by a quick-release fastener 19.

[0126] The present invention is not limited to the exemplary embodiments of the powder switch shown in the accompanying drawings, but arises from a combination of all the features disclosed herein.

Claims

1. A powder pump for conveying coated powder, specifically a dense-phase powder pump (20), wherein, The dense phase powder pump (20) is designed to selectively draw coating powder from the powder chamber of the first powder container or from the powder chamber of the second powder container through the powder inlet of the dense phase powder pump (20), and to supply the drawn coating powder from the dense phase powder pump (20) to the powder discharge device or powder storage container through the powder outlet (25) of the dense phase powder pump (20). A powder switch (1) is provided at the powder inlet of the dense phase powder pump (20), or the powder inlet of the dense phase powder pump (20) is designed as a powder switch (1). The powder switch (1) is designed to selectively connect the powder inlet of the dense phase powder pump (20) to a first powder pipeline / channel system leading to the powder chamber of the first powder container or to a second powder pipeline / channel system leading to the powder chamber of the second powder container.

2. The dense phase powder pump (20) according to claim 1, wherein, The powder switch (1) includes: The first powder inlet (2) is fluidly connected to the first powder pipeline / channel system or is capable of being fluidly connected to the first powder pipeline / channel system; The second powder inlet (3) is fluidly connected to the second powder pipeline / channel system or is capable of being fluidly connected to the second powder pipeline / channel system; Powder outlet (4), which is fluidly connected to the powder inlet of the powder pump, or fluidly connected to the powder conveying chamber of the dense phase powder pump (20) via a powder inlet valve; and A switching mechanism is designed to selectively connect the powder outlet (4) of the powder switch (1) to the first powder inlet (2) or the second powder inlet (3) of the powder switch (1).

3. The dense phase powder pump (20) according to claim 2, wherein, The powder switch (1) further includes a purge air inlet (5), and the switching mechanism of the powder switch (1) is designed such that when the powder outlet (4) of the powder switch (1) is fluidly connected to the first powder inlet (2) of the powder switch (1), the purge air inlet (5) of the powder switch (1) is fluidly connected to the second powder inlet (3) of the powder switch (1), wherein the switching mechanism of the powder switch (1) is preferably further designed such that when the powder outlet (4) of the powder switch (1) is fluidly connected to the second powder inlet (3) of the powder switch (1), the purge air inlet (5) of the powder switch (1) is fluidly connected to the first powder inlet (2) of the powder switch (1).

4. The dense phase powder pump (20) according to claim 3, wherein, The switching mechanism includes a carriage assembly having a carriage (6) which is adjustable relative to the housing body (7) of the powder switch (1) and is particularly capable of linear movement, wherein a first powder inlet (2) and a second powder inlet (3) of the powder switch (1) are formed in the carriage (6), and a powder outlet (4) is formed in the housing body (7) of the powder switch (1).

5. The dense phase powder pump (20) according to claim 4, wherein, The purge air inlet (5) of the powder switch (1) is formed in the housing body (7) of the powder switch (1).

6. The dense phase powder pump (20) according to any one of claims 2 to 5, wherein, The switching mechanism includes a first drive unit associated with the carriage assembly, the first drive unit being designed to move the carriage (6) relative to the housing body (7) of the powder switch (1) such that the powder outlet (4) of the powder switch (1) is fluidly connected to the first powder inlet (2) of the powder switch (1) or fluidly connected to the second powder inlet (3) of the powder switch (1).

7. The dense phase powder pump (20) according to claim 6, wherein, The first drive unit is designed as a pneumatic drive unit and includes at least one pneumatic connector (8).

8. The dense phase powder pump (20) according to claim 7, wherein, The carriage assembly includes a biasing element associated with the carriage (6), specifically a spring, the biasing element being designed to bias the carriage (6) into a first position in which the powder outlet (4) of the powder switch (1) is fluidly connected to a first powder inlet (2) of the powder switch (1), wherein the pneumatic drive is designed to move the carriage (6) relative to the housing body (7) of the powder switch (1) from the first position to a second position against the biasing force of the biasing element, specifically designed as a spring, when compressed air is supplied through the pneumatic connector (8), in which the powder outlet (4) of the powder switch (1) is fluidly connected to a second powder inlet (3) of the powder switch (1).

9. The dense phase powder pump (20) according to any one of claims 2 to 8, wherein, A channel system (9) is formed in the housing body (7) of the powder switch (1), the channel system (9) being in fluid communication with the purge air inlet (5) of the powder switch (1), the channel system (9) including a first purge air outlet (11) and a second purge air outlet (12), wherein the first purge air outlet (11) and the second purge air outlet (12) are formed in the end face (10) of the housing body (7) of the powder switch (1) adjacent to the carriage (6), such that when the second powder inlet (3) of the powder switch (1) is in fluid communication with the powder outlet (4) of the powder switch (1), the first purge air outlet (11) is in fluid communication with the first powder inlet (2) of the powder switch (1), and when the first powder inlet (2) is in fluid communication with the powder outlet (4) of the powder switch (1), the second purge air outlet (12) is in fluid communication with the second powder inlet (3) of the powder switch (1).

10. The dense phase powder pump (20) according to claim 9, wherein, An opening (13) for the powder outlet (4) of the powder switch (1) is formed in the end face (10) of the housing body (7) of the powder switch (1) adjacent to the slide (6). The opening (13) for the powder outlet (4) of the powder switch (1), the first purge air outlet (11) and the second purge air outlet (12) are arranged in a straight line. The first purge air outlet (11) and the second purge air outlet (12) are arranged equidistantly from the opening (13) for the powder outlet (4).

11. The dense phase powder pump (20) according to claim 9 or 10, wherein, The carriage (6) is movable from a first position to a second position relative to the housing body (7) of the powder switch (1). In the first position, there is a gap (14) between the end face (10) of the housing body (7) of the powder switch (1) and the end face of the carriage (6) adjacent to the housing body (7). In the second position, the gap (14) between the end face (10) of the housing body (7) of the powder switch (1) adjacent to the carriage (6) and the end face of the carriage (6) adjacent to the housing body (7) is eliminated or at least reduced.

12. The dense phase powder pump (20) according to claim 11, wherein, The carriage assembly includes a second drive device designed to move the carriage (6) relative to the housing body (7) of the powder switch (1) from the first position to the second position as needed, wherein the second drive device is preferably designed as a pneumatic drive device and includes a pneumatic connector (16).

13. The dense phase powder pump (20) according to claim 11 or 12, wherein, The carriage assembly includes a biasing element associated with the carriage (6), specifically a spring or elastic element, which is designed to bias the carriage (6) relative to the housing body (7) of the powder switch (1) into the first position.

14. The dense phase powder pump (20) according to any one of claims 2 to 13, wherein, The first powder inlet (2) and the second powder inlet (3) are formed in the support member (17) and specifically in the support plate, wherein the support member (17) or the support plate together with the first powder inlet (2) and the second powder inlet (3) are received and specifically inserted into the receiving area (18) of the carriage (6), and preferably held in the receiving area (18) of the carriage (6) by means of a quick-release fastener (19).

15. The dense phase powder pump (20) according to any one of claims 1 to 14, wherein, The dense phase powder pump (20) is characterized by a modular design and includes at least the following components, each of which is designed as a module: Pump head module (21), the pump head module (21) includes at least one powder conveying chamber, the at least one powder conveying chamber is fluidly connected to or can be connected to the powder chamber of the first powder container or the powder chamber of the second powder container through a powder inlet, and is fluidly connected to or can be connected to a powder storage container or a powder spraying device through a powder outlet (25). as well as The compressed air control module (23) includes multiple switching valves, which are specifically assigned to the pneumatic control components of the pump head module (21) and are designed to supply compressed air, suction air or vacuum to the pneumatic control components of the pump head module (21) as needed and in a controlled manner, wherein the powder switch (1) is specifically part of the pump head module (21).

16. The dense phase powder pump (20) according to claim 15, wherein, The compressed air control module (23) of the dense phase powder pump (20) further includes a control valve associated with the powder switch (1) for supplying compressed air to the purge air inlet (5) of the powder switch (1) as needed, and for supplying compressed air to a pneumatic connector (8) of a first drive unit of the powder switch (1) as needed, the first drive unit being designed as a pneumatic drive unit, and / or a pneumatic connector (16) of a second drive unit of the powder switch (1) as needed, the second drive unit being designed as a pneumatic drive unit.

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