actuator for a valve

Abstract

An actuator for a valve, in particular a metering device, comprises: a housing with an interior space; a piston movably arranged within the housing between a first position and a second position, dividing the interior space of the housing into a first sub-space and a second sub-space; and a return element arranged in the first sub-space that exerts a force on the piston, in particular in the direction of the first position. The first sub-space is connected to a vacuum environment via at least one first channel and a first valve. The first sub-space is connected to the surroundings of the housing via at least one second channel and a second valve. The second sub-space is connected to the surroundings of the housing via at least one third channel.The piston is in the first position when the first valve is closed and the second valve is open, so that the first compartment is at ambient pressure, and the piston is in the second position when the first valve is open and the second valve is closed, so that the first compartment is at negative pressure.

Description

[0001] The present invention relates to an actuator for a valve. The valve can be part of a metering device. The present invention also relates to a metering device comprising the actuator and the valve. Technical background

[0002] Application systems are used in numerous industrial applications, for example in the automotive, construction, energy, and semiconductor industries, as well as in industrial assembly. Application systems serve to apply media, especially viscous and / or liquid media, to or into components. Examples of liquid media include adhesives, foams (especially polyurethane foams), battery foams, and insulating foams, as well as paints and cleaning fluids. In the automotive sector, application systems are used, for example, to apply battery foams and / or adhesives to the batteries of electric vehicles, and / or to apply adhesives to body parts and / or vehicle windows, such as windshields.

[0003] An application system typically comprises a dosing device, also called a dispenser, and an application device, also called an applicator. The dosing device and the application device can be designed together as a single device or together form a system. The dosing device is used for dosing, for example, by controlling the flow of fluid or material. The dosing device receives the medium from a source, such as a storage container, particularly a drum. The application device is used to apply the medium to or into a component.

[0004] Metering devices typically include a valve to control fluid flow. A variety of options are available for actuating the valve to open and close it. Often, the valve is actuated or controlled by compressed air. Summary of the invention

[0005] It is an object of the present invention to provide an actuator for a valve that can be controlled precisely. It is a further object of the present invention to provide an actuator for a valve whose design is compact and / or simple. It is a further object of the present invention to provide an actuator for a valve that does not require a compressed air supply.

[0006] At least one of the problems, or further problems, that arise for a person skilled in the art from the present disclosure are solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the description.

[0007] Disclosed is an actuator for a valve. The valve may be part of a metering device. The actuator may comprise a housing with an interior space. The actuator may include a piston. The piston may be movably arranged within the housing between a first position and a second position. The piston may divide or delimit the interior space of the housing into a first sub-space and a second sub-space. The actuator may include a return element. The return element may be located in the first sub-space. The return element may exert a force on the piston. The force may act in the direction of the first position. The first sub-space may be connected to a vacuum via at least one first channel and a first valve. The first sub-space may be connected to the environment of the housing via at least one second channel and a second valve.The second compartment can be connected to the housing or its surroundings via at least one third channel. The piston can be in the first position when the first valve is closed and / or the second valve is open, in particular so that the first compartment is at ambient pressure. The piston can be in the second position when the first valve is open and / or the second valve is closed, in particular so that the first compartment is at negative pressure.

[0008] The actuator can be connected to the valve. The valve can include a valve needle and a valve seat. The actuator piston can be coupled to the valve needle. In particular, the actuator piston can be directly or indirectly connected to the valve needle.

[0009] When the piston is in the first position, the valve may be closed. In this case, the valve needle may be resting on the valve seat and preventing fluid flow through the valve.

[0010] When the piston is in the second position, the valve may be open. In this case, the valve needle cannot be seated on the valve seat, i.e., it may be spaced away from the valve seat, thus allowing fluid to flow through the valve.

[0011] The housing can essentially be cylindrical in shape.

[0012] The piston can divide, delimit, or separate the interior of the housing into a first and a second compartment. The first and second compartments can be fluid-tightly separated from each other, particularly by the piston.

[0013] The piston can be movable along (only or exactly) one axis. The axis can be the longitudinal axis of the housing or the longitudinal axis of the valve needle.

[0014] The return element can exert a force on the piston, holding it in the first position or pushing it towards the first position. The return element can be a spring, particularly a plastic or metal spring. The return element can contact the piston and a side wall of the housing.

[0015] The vacuum can be less than 1.0 bar, preferably less than 0.9 bar, preferably less than 0.8 bar, preferably less than 0.7 bar, preferably less than 0.6 bar, preferably less than 0.5 bar, preferably less than 0.4 bar, preferably less than 0.3 bar, preferably less than 0.1 bar. The pressure can be an absolute pressure.

[0016] The environment surrounding the housing connected to the second channel can be the same as that connected to the third channel. Likewise, the environment surrounding the housing connected to the second channel can be different from that connected to the third channel. The environment, or each of the environments, can have a pressure of approximately 1 bar.

[0017] Generally, a force acts on the piston resulting from the pressure in the first compartment and, in the opposite direction, a force resulting from the pressure in the second compartment. Additionally, the return element exerts a force on the piston in the direction of the first position.

[0018] If the pressures in the first and second sub-chambers are equal or similar, the piston is in the first position. The return element holds the piston in this position.

[0019] When the first valve is open and the second valve is closed, fluid, particularly gas, can flow out of the first compartment. The pressure in the first compartment can be reduced accordingly. Preferably, the pressure in the first compartment is approximately equal to the vacuum. Ambient pressure can prevail in the second compartment. This results in a small force acting on the piston in the direction of the first position, driven by the pressure in the first compartment, and the piston can move towards the second position.

[0020] The piston can be moved directly or indirectly, for example via a vacuum rotary actuator or a cam, between the first and second positions.

[0021] The first valve can be connected to a tank. A vacuum can exist in the tank, specifically so that a vacuum is provided in the first compartment when the first valve is open and the second valve is closed.

[0022] The tank can be a storage container. The tank can be connected to the first valve. When the first valve is open, fluid, especially gas, can flow from the first compartment into the (evacuated) tank via the first channel. This reduces the pressure in the first compartment by the amount of fluid flowing out and the volume of the first compartment.

[0023] The tank can be connected to a vacuum pump. The vacuum pump can provide the necessary negative pressure within the tank. The vacuum pump can be any type of device capable of creating a negative pressure or vacuum.

[0024] A metering device can comprise any actuator and any valve disclosed herein. Fluid flow through the metering device can occur when the piston is in the second position. Fluid flow through the metering device cannot occur when the piston is in the first position. Brief description of the characters

[0025] Embodiments of the present disclosure are described in detail below with reference to a figure. Fig. Figure 1 shows a drive 30. Detailed description

[0026] Fig. Figure 1 shows a drive 30. The drive 30 can comprise a housing 10. The housing 10 can have an interior.

[0027] A piston 11 can be arranged in the interior of the housing 10. The piston 11 can delimit or divide the interior into a first sub-chamber 12 and a second sub-chamber 13. The first sub-chamber 12 and the second sub-chamber 13 can be fluid-tightly separated from each other.

[0028] The piston 11 can be moved between a first position and a second position within the housing 10. The volume of the first sub-space 12 can be larger when the piston 11 is in the first position than when it is in the second position. The volume of the second sub-space 13 can be smaller when the piston 11 is in the first position than when it is in the second position. Thus, by moving the piston 11 from the first position to the second position, the volume of the first sub-space 12 can decrease and / or the volume of the second sub-space 13 can increase.

[0029] A return element 14 can be arranged in the first sub-space 12. The return element 14 can exert a force on the piston 11 in one direction, particularly in the direction of the first position. The return element 14 can contact the housing 10 and the piston 11. Preferably, the return element 14 is a spring.

[0030] The first sub-chamber 12 can have a first channel 15. The first channel 15 can be connected to a first valve 16. The first valve 16 can be connected to a vacuum. In particular, the first valve 16 is connected to a tank or reservoir 20 in which a vacuum prevails.

[0031] Tank 20 can be equipped with a pressure gauge 21. The pressure in tank 20 can be determined using the pressure gauge 21.

[0032] Tank 20 can be connected to a further valve 22. This further valve 22 can be connected to a vacuum pump 23. When the further valve 22 is open (and preferably the first valve 16 is closed), the vacuum in tank 20 can be provided by the vacuum pump 23.

[0033] The first sub-chamber 12 can have a second channel 17. The second channel 17 can be connected to a second valve 18. The second valve 18 can be connected to an area surrounding the housing 10.

[0034] The second sub-chamber 13 can have a third channel 19. The third channel 19 can connect the second sub-chamber 13 to the environment of the housing 10. Preferably, the third channel is not connected to a valve. The second sub-chamber 13 can be continuously connected to the environment via the third channel 19. The pressure in the second sub-chamber 13 can be at ambient pressure throughout.

[0035] When the second valve 18 is open (and the first valve 16 is closed), ambient pressure prevails in the first sub-chamber 12. Ambient pressure also prevails in the second sub-chamber 13. The return element 14 exerts a force on the piston 11 in the direction of the first position. Accordingly, the piston is in the first position.

[0036] The piston 11 can be connected to a valve needle 25. In the first position, the valve needle 25 rests on a valve seat 26. This prevents the flow of fluid. The valve needle 25 and the valve seat 26 can be part of a valve that can be actuated or controlled by the actuator 30. The valve, in turn, can be part of a metering device.

[0037] When the second valve 18 is closed and the first valve 16 is opened, the pressure in the first sub-chamber 12 is reduced by the negative pressure. Accordingly, the force balance acting on the piston 11 changes, and the piston 11 can be moved. Specifically, the piston 11 moves such that the volume of the first sub-chamber 12 decreases. The piston 11 can move up to the second position.

[0038] In the second position, the valve needle 25 can be lifted out of the valve seat 26. This allows fluid to flow through the valve.

Claims

[1] Actuator (30) for a valve (25, 26), in particular a metering device, the actuator (30) comprising: - a housing (10) with an interior; - a piston (11) which is movably arranged in the housing (10) between a first position and a second position and which divides the interior of the housing (10) into a first sub-space (12) and a second sub-space (13); and - a return element (14) which is arranged in the first subspace (12) and exerts a force on the piston (11), in particular in the direction of the first position; - wherein the first sub-space (12) is connected to a negative pressure by at least a first channel (15) and via a first valve (16); - wherein the first subspace (12) is connected to an environment of the housing (10) by at least a second channel (17) and via a second valve (18); - wherein the second subspace (13) is connected to the environment of the housing (10) by at least a third channel (19); and - wherein the piston (11) is in the first position when the first valve (16) is closed and the second valve (18) is open, so that the pressure in the first sub-chamber (12) is at ambient pressure, and the piston (11) is in the second position when the first valve (16) is open and the second valve (18) is closed, so that the pressure in the first sub-chamber (12) is at negative pressure. [2] Drive according to claim 1, wherein the first valve (16) is connected to a tank (20) and the tank (20) is under negative pressure, such that the negative pressure is provided in the first sub-space (12) when the first valve (16) is open and, in particular, when the second valve (18) is closed. [3] Drive according to claim 2, wherein the tank (20) is connected to a vacuum pump (23) by which the negative pressure in the tank (20) can be provided. [4] Metering device with the drive (30) and the valve (25, 26) according to one of the preceding claims, in particular wherein a fluid flow through the metering device takes place when the piston (11) is in the second position and a fluid flow through the metering device does not take place when the piston (11) is in the first position.

Images