Dosing device and application system

Abstract

Metering device (100) for a liquid medium, comprising: a first metering unit (10) having a first material chamber (12), a first material outlet (14) and a first metering piston (16) slidably arranged in the first material chamber (12) for ejecting the medium from the first material chamber (12); a second metering unit (20) having a second material chamber (22), a second material outlet (24) and a second metering piston (26) slidably arranged in the second material chamber (22) for ejecting the medium from the second material chamber (22); and a common material outlet (30) of the first and second metering units (10, 20). A gearbox (42) couples the first metering piston (16) and the second metering piston (26) to the drive motor (40).The two material chambers (12, 22) each with a piston (16, 26) can be operated alternately to eject material by a single drive motor (40) which drives the pistons in opposite directions, wherein the two material chambers (12, 22) can be connected to the common material outlet (30).

Description

[0001] The present invention relates to a metering device for a liquid medium and an application system for applying a liquid medium to an object, comprising a metering device. In particular, the liquid medium can be a viscous medium. 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 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 combined into a single unit. The dosing device is used for dosing, for example, by controlling the flow of the medium. 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. Application systems include valves that control the flow of the medium. The valves have a state in which they allow the flow of material (open valve) and a state in which they prevent the flow of material (closed valve). The valves can be used in both the dosing device and the application device.

[0004] Valves can be designed, for example, as needle valves. Ordinary (needle) valves are actuated, i.e., switched, by compressed air. Such valves are therefore also referred to as pneumatic or pneumatically operated valves.

[0005] Pneumatic valves consist of a piston, a valve needle connected to the piston, and a valve seat with an opening for the flow of the medium. In the closed position, the valve needle is seated in the valve seat, thus sealing the opening and preventing the flow of the medium (closed state of the valve). To open the valve, compressed air is applied to the piston, causing it to move and lift the valve needle out of the valve seat. This releases the opening, allowing the medium to flow through it (open state of the valve). Pneumatically actuated valves have the disadvantage that compressed air must be supplied to operate them. This is both complex and energy-intensive. Summary of the invention

[0006] Conventional dispensers are equipped with a simple piston. After the material is dispensed, the dispenser is refilled and can then start the next application. The refilling process takes a certain amount of time, during which the dispenser is unavailable.

[0007] It is an object of the present invention to provide an improved dosing device. In particular, it is an object to provide a dosing device that combines an easy-to-operate drive with rapid readiness for reuse after the contents of a material chamber have been applied. It is desirable to reduce the filling time and thus shorten the cycle time, for example, for application to a vehicle. A shorter filling time means that more units can be produced in a shorter time.

[0008] These and other problems arising 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.

[0009] The core of the present disclosure is to operate two material chambers, each with a piston, alternately for ejecting material, and to provide a single drive motor that drives the pistons in opposite directions. The two material chambers are connectable via a common material outlet. Thus, only a single drive motor is required, which advances one piston towards the material outlet of its corresponding material chamber and simultaneously retracts the other piston in the other material chamber from the material outlet. Material can therefore be alternately ejected from both material chambers via the common material outlet while the other material chamber is being filled. "Connectable" here refers specifically to the ability to communicate with each other.

[0010] This allows for the simultaneous filling and emptying of individual material chambers, eliminating the need for two separate drives. Simultaneous filling and emptying of individual material chambers is also more efficient than filling them sequentially. The combination of two chambers being emptied and filled simultaneously reduces the cycle time of the dosing device.

[0011] According to a first aspect of the present disclosure, a metering device for a liquid medium is specified. The metering device comprises a first metering unit and a second metering unit, each having a piston. The metering device further comprises a common material outlet of the first and second metering units. The common material outlet can be selectively connected to the metering units to dispense a liquid medium from each of the respective metering units. The metering device further comprises a drive motor and a gearbox. The gearbox couples the first metering unit and the second metering unit to the drive motor. The gearbox is configured to convert a drive movement of the drive motor in a first drive direction into a material ejection movement of the piston of the first metering unit and a simultaneous material filling movement of the piston of the second metering unit.

[0012] According to a second aspect of the present disclosure, a metering device for a liquid medium is specified. The metering device comprises a first metering unit, having a first material chamber, a first material outlet, and a first metering piston for ejecting the medium from the first material chamber. The first metering piston is slidably arranged in the first material chamber. The metering device further comprises a second metering unit, having a second material chamber, a second material outlet, and a second metering piston for ejecting the medium from the second material chamber. The second metering piston is slidably arranged in the second material chamber. The metering device further comprises a common material outlet of the first and second metering units. The first material outlet of the first metering unit is connected to the common material outlet via at least one first valve.The second material outlet of the second dosing unit is connected to the common material outlet via at least one second valve.

[0013] The metering device further comprises a drive motor for powering the first and second metering pistons of the first and second metering units. The metering device also includes a gearbox. The gearbox couples the first and second metering pistons to the drive motor. The gearbox is configured to convert a rotary motion of the drive motor in a first direction of rotation into a first displacement motion of the first metering piston and a simultaneous second displacement motion of the second metering piston. The first displacement motion of the first metering piston is a displacement motion in a first direction of movement towards the first material outlet of the first metering unit. This first displacement motion of the first metering piston is a displacement motion for ejecting a medium from the first metering unit.The simultaneous second displacement movement of the second metering piston is a displacement movement in a second direction of movement to retract the second metering piston from the second material outlet of the second metering unit.

[0014] According to another aspect of the present disclosure, an application system for applying a liquid medium to an object is specified, comprising a metering device according to one of the mentioned aspects.

[0015] The terms piston and metering piston are used synonymously here. The metering device can also be referred to as a metering unit or double metering unit.

[0016] Aspects and embodiments of the present disclosure may include one or more of the following optional features: The first dosing unit can have a first material chamber. The second dosing unit can have a second material chamber. The first dosing piston can be slidably arranged within the first material chamber. The second dosing piston can be slidably arranged within the second material chamber. The first dosing unit can have a first material outlet. The second dosing unit can have a second material outlet. Each dosing piston can be used to eject the medium from its respective material chamber.

[0017] The common material outlet can be selectively connected to the metering units to dispense a liquid medium from each of the metering units. The first material outlet of the first metering unit can be connected to the common material outlet via at least one first valve. The second material outlet of the second metering unit can be connected to the common material outlet via at least one second valve.

[0018] The gearbox can couple the first and second metering units to the drive motor. In particular, the gearbox can couple the first and second metering pistons to the drive motor. The gearbox can be configured to convert a drive movement of the drive motor in a first drive direction into a first displacement movement of the piston of the first metering unit and a simultaneous second displacement movement of the piston of the second metering unit.

[0019] The first displacement movement can, in particular, be a material ejection movement of the piston in question, specifically a displacement movement to eject a medium from the first metering unit. The second displacement movement can, in particular, be a material filling movement of the piston in question. The first displacement movement of the first metering piston can be a displacement movement in a first direction of movement towards the first material outlet of the first metering unit. The simultaneous second displacement movement of the second metering piston can be a displacement movement in a second direction of movement to retract the second metering piston from the second material outlet of the second metering unit.

[0020] Each dosing unit may further include a material inlet for filling the respective material chamber. The material inlet and / or the first or second material outlet may be located at an end of the respective material chamber opposite the gearbox. Each material inlet may be connected to a corresponding inlet valve.

[0021] The first valve and / or the second valve and / or the respective inlet valve can each be a check valve, a one-way valve, or a switchable valve, in particular an electrically switchable valve. The first valve and / or the second valve and / or the respective inlet valve can each be configured to assume a closed valve position and an open valve position. The open valve position can allow at least one material flow (a flow of the liquid medium) in one direction towards the common material outlet, or, in the case of an inlet valve, in one direction towards the interior of the relevant material chamber.

[0022] The respective material chamber can be cylindrical. The respective piston can be configured to slide along the inner wall of the material chamber, sealing against it.

[0023] The drive movement of the drive motor in the first drive direction can be a rotary movement of the drive motor in a first direction of rotation.

[0024] The gearbox can comprise a first spindle drive coupled to the first metering piston and a second spindle drive coupled to the second metering piston. The gearbox can further comprise a drive belt that connects the first and second spindle drives to the drive motor. Specifically, the drive belt can connect a drive wheel of the first spindle drive and a drive wheel of the second spindle drive to the drive motor.

[0025] In some embodiments, one of the first and second spindle drives has a right-hand rotating spindle, and the other of the first and second spindle drives has a left-hand rotating spindle. This simplifies driving the pistons in opposite directions with a common drive belt.

[0026] The first and second spindle drives can each have a rotary-driven spindle nut. This allows for a shorter, more compact design. Alternatively, the first and second spindle drives can each have a rotary-driven spindle within a stationary nut.

[0027] The dosing device may further include a common material chamber, which is arranged downstream of the first and second material chambers in the direction of media flow, and in particular, downstream of the first and second valves. The common material chamber may also be referred to as an end chamber. The common material outlet may be located upstream or downstream of the common material chamber. The common material chamber improves the continuity of media dispensing and can, for example, enable continuous operation.

[0028] The metering device can be configured to deliver the liquid medium to an applicator (application device) of the application system. The application system can include an application device for applying the liquid medium to an object, wherein the application device is located downstream of the common material outlet (i.e., arranged in the direction of flow of the medium after the common material outlet) and / or is connectable to the common material outlet.

[0029] The first and second material chambers can have the same internal cross-sectional area. In embodiments, the first and second material chambers can have different internal cross-sectional areas. The first and second material chambers can have the same volume. The first and second material chambers can have different volumes. The first and second material chambers can have the same piston stroke for their respective displacement movements. The first and second material chambers can have different piston strokes for their respective displacement movements.

[0030] The first material chamber and the second material chamber can be used with the same liquid medium, or with different liquid media.

[0031] The medium can be, in particular, a viscous or highly viscous medium.

[0032] The material chambers can be arranged side by side and / or parallel to each other. The first and second displacement movements can be opposite to each other. The first and second displacement movements can occur in opposite directions. The first and second directions of movement can be opposite to each other. This allows the paths from the respective first or second material outlet to the common material outlet to be shortened and / or the design of the gearbox to be simplified. Brief description of the character

[0033] Embodiments of the present disclosure are described in detail below with reference to a figure. It shows: Fig. 1 a metering device in a schematic cross-sectional view according to embodiments of the present disclosure. Detailed description

[0034] Fig. Figure 1 shows part of an application system for applying a liquid medium to an object, comprising a dosing device 100 and an applicator 200.

[0035] A first metering unit 10 of the metering device 100 comprises a first material chamber 12, a first material outlet 14, a first metering piston 16 slidably arranged in the first material chamber 12 for ejecting the medium from the first material chamber 12 through a first material outlet 14, and a first material inlet 58. A second metering unit 20 of the metering device 100 comprises a second material chamber 22, a second material outlet 24, a second metering piston 26 slidably arranged in the second material chamber 22 for ejecting the medium from the second material chamber 22, and a second material inlet 60.

[0036] The metering device 100 comprises a common material outlet 30 for the first and second metering units 10 and 20, wherein the first material outlet 14 of the first metering unit 10 is connected to the common material outlet 30 via at least one first valve 32, and wherein the second material outlet 24 of the second metering unit 20 is connected to the common material outlet 30 via at least one second valve 34. The first material inlet 58 is connected to a first inlet valve 59. The second material inlet 60 is connected to a second inlet valve 61.

[0037] The metering device 100 comprises a drive motor 40 for driving the first and second metering pistons 16, 26 of the first and second metering units 10, 20. A gearbox 42 couples the first metering piston 16 and the second metering piston 26 to the drive motor 40, the gearbox 42 being configured to convert a rotary movement of the drive motor 40 in a first direction of rotation into a first displacement movement of the first metering piston 16 in a first direction of movement A towards the first material outlet 14 of the first metering unit 10, for ejecting a medium from the first metering unit 10, and a simultaneous second displacement movement of the second metering piston 26 in a second direction of movement B for retracting the second metering piston 26 from the second material outlet 24 of the second metering unit 20.

[0038] The gearbox 42 comprises a first spindle gearbox 44 coupled to the first metering piston 16, a second spindle gearbox 46 coupled to the second metering piston 26, and a drive belt 48 that couples a drive wheel 50 of the first spindle gearbox 44 and a drive wheel 52 of the second spindle gearbox 46 to the drive motor 40. The drive wheels are each toothed belt pulleys.

[0039] One of the first spindle drive 44 and the second spindle drive 46 has a right-hand rotating spindle 54, and the other of the first spindle drive 44 and the second spindle drive 46 has a left-hand rotating spindle 56. In an alternative embodiment, the drive belt 48 can be guided in the shape of an 8 around the drive wheels 50, 52, so that for one of the directions of rotation of the motor 40 the Fig.1. The specified directions of rotation of the first drive wheel 50 are clockwise (UZS) and of the second drive wheel 52 counterclockwise (GUZS).

[0040] Both pistons are driven by the same motor 40. The first piston 16 is at bottom dead center (BDC) and the second piston 26 is at top dead center (TDC) of the material chamber 12 or 22, or vice versa. The opposing movement is achieved, for example, by a left-handed or a second right-handed spindle 54 or 56, respectively, which have a left-handed or right-handed spindle thread. If the first piston 16 moves forward, the second piston 26 necessarily moves backward, and vice versa. For the drive, the operating principle of the spindle and spindle nut is reversed: The first spindle nut 64 and the second spindle nut 66 are driven, and the spindle 54 or 56 is stationary. More precisely, the spindle 54 or 56 is moved in the direction of movement A or B of the respective piston 16, 26. The spindles 54 and 56 are each guided in a guide 72, 74 by a guide rod 68, 70 connected to the spindle. The first guide rod 68 is connected to the first piston 16.The second guide rod 70 is connected to the second piston 26.

[0041] Motor 40 and all valves 59, 61, 32, 34 are electrically driven. A suitable valve control system manages the filling (F1 / F2) and emptying (E1 / E2) of material chambers 12 and 22. A shorter cycle time can be achieved by combining two material chambers 12 and 22, each with a piston 16 and 26, respectively, which feed the material to the applicator 200. While the first piston 16 discharges the material to the applicator 200, the second piston 26 fills material chamber 22. Once material chamber 12 is emptied by the first piston 16, the system switches to filling material chamber 22 with the second piston 26. The forces generated during the filling of material chambers 12 and 22 may assist the drive motor 40.

Claims

[1] Metering device (100) for a liquid medium, comprising: - a first metering unit (10) comprising a first material chamber (12), a first material outlet (14) and a first metering piston (16) slidably arranged in the first material chamber (12) for ejecting the medium from the first material chamber (12); - a second metering unit (20) comprising a second material chamber (22), a second material outlet (24) and a second metering piston (26) slidably arranged in the second material chamber (22) for ejecting the medium from the second material chamber (22); - a common material outlet (30) of the first and second metering units (10, 20), wherein the first material outlet (14) of the first metering unit (10) is connected to the common material outlet (30) via at least one first valve (32) and wherein the second material outlet (24) of the second metering unit (20) is connected to the common material outlet (30) via at least one second valve (34); - a drive motor (40) for driving the first and second metering pistons (16, 26) of the first and second metering units (10, 20); - a gearbox (42) that couples the first metering piston (16) and the second metering piston (26) to the drive motor (40), wherein the gearbox (42) is configured to convert a rotary movement of the drive motor (40) in a first direction of rotation into a first displacement movement of the first metering piston (16) in a first direction of movement (A) towards the first material outlet (14) of the first metering unit (10) for ejecting a medium from the first metering unit (10), and a simultaneous second displacement movement of the second metering piston (26) in a second direction of movement (B) for retracting the second metering piston (26) from the second material outlet (24) of the second metering unit (20). [2] Metering device according to claim 1, wherein the transmission (42) comprises: - a first spindle drive (44) coupled to the first metering piston (16); - a second spindle drive (46) coupled to the second metering piston (26); - a drive belt (48) that couples a drive wheel (50) of the first spindle drive (44) and a drive wheel (52) of the second spindle drive (46) to the drive motor (40). [3] Metering device according to claim 2, wherein one of the first spindle drive (44) and the second spindle drive (46) has a right-hand rotating spindle (54) and the other of the first spindle drive (44) and the second spindle drive (46) has a left-hand rotating spindle (56). [4] Application system for applying a liquid medium to an object, comprising a metering device (100) according to one of the preceding claims.

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