Spindle metering pump and associated method of operation

Abstract

The invention relates to a spindle metering pump (1) comprising a material inlet (3) for receiving an application agent to be applied, a material outlet (4) for dispensing the application agent to be applied, and a rotary drive (2) for rotating the spindle metering pump (1). According to the invention, the material outlet (4) on the spindle metering pump (1) is arranged further away from the rotary drive (2) than the material inlet (3), so that the applicator can be directly mounted on the spindle metering pump (1) by means of a flange.

Description

Technical Field

[0001] The invention relates to a spindle metering pump, such as a screw pump, for metering a coating agent, such as an adhesive, an insulating material, a sealant, a PVC plastisol, which is applied to a component, such as a motor vehicle body component. Background Art

[0002] Various types of metering devices are used in the prior art for dispensing high-viscosity application agents (e.g. adhesives, insulating materials, sealants, PVC plastisols), such as piston metering devices (single or double metering devices), gear metering pumps or spindle metering pumps, wherein the spindle metering pump can be designed as a screw pump, as described in EP 2 961 988 Bl. Compared with piston metering pumps, screw pumps have the advantage that they can be metered without stopping, that is, compared with piston metering pumps, the metering process does not need to be interrupted in order to charge the piston metering pump. Therefore, in practice, it has been found that spindle metering pumps are the best choice for metering high-viscosity application agents.

[0003] Figures 1A and 1B described below show a conventional coating device with a spindle metering pump 1 for metering a high-viscosity coating agent, such as an adhesive, an insulating material or a sealant. The spindle metering pump 1 is driven by a servo drive 2, so the rotational position of the spindle metering pump 1 can be known from the controller of the servo drive 2 and can therefore be used to control or regulate the spindle metering pump 1. The spindle metering pump 1 sucks in the coating agent to be delivered through the material inlet 3 and then discharges the coating agent to be delivered through the material outlet 4. The material inlet 3 of the spindle metering pump 1 is connected to a material pressure regulator 6 via a pipe 4, which adjusts the pumping pressure at the material inlet 3 of the spindle metering pump 1 to a predetermined target value. In addition, the spindle metering pump 1 has a heating module 7 mounted via a flange for heating the coating agent. The material outlet 4 of the spindle metering pump 1 is connected to an applicator 9 via a hose line 8, which is mounted on a mounting flange 10 of a coating robot 11. The painting robot 11 has two pivotable mechanical arms 12, 13 and a robot hand axis 14, which are well known in the prior art. The spindle metering pump 1 is connected to the remote mechanical arm 13 ("mechanical arm 2"), that is, at a certain distance from the applicator 9 on the mounting flange 10 of the painting robot 11. This separation of the applicator 9 and the spindle metering pump 1 has various disadvantages, which are briefly described below.

[0004] A disadvantage of this known arrangement is the relatively long reaction time when the spindle metering pump 1 is switched on or generally when changing the volume flow of the coating agent delivered by the spindle metering pump 1. This can lead to coating errors such as so-called hammer heads or so-called pinching, in particular when applying a sealing drop at the start of an adhesive drop.

[0005] Furthermore, due to the relatively long reaction times, it is virtually impossible to dynamically vary the delivered volume flow during so-called brushing (eg during the application of a sealing drop).

[0006] In this context, it should also be mentioned that the hose line 8 between the material outlet 4 of the spindle metering pump 1 and the applicator 9 inevitably has a hose breather, so that changes in the volume flow delivered by the spindle metering pump 1 only reach the applicator 9 with a time delay.

[0007] Regarding the technical background of the present invention, reference should also be made to DE102019112792A1, DE102007053073A1, EP3450024A1 and DE102005044796A1. Summary of the invention

[0008] The invention is therefore based on the object of creating a correspondingly improved spindle metering pump.

[0009] According to the main claim of the invention, this object is achieved by a spindle metering pump.

[0010] The invention is based on the following technical recognition: The disturbing structural separation between applicator and spindle metering pump is inherent in the known spindle metering pump design and can hardly be avoided. This is because the material inlet of the spindle metering pump is located at the free end of the spindle metering pump and prevents the applicator from being directly mounted there. In contrast, in the known spindle metering pumps, the material outlet of the spindle metering pump is located at the drive end of the spindle metering pump, where the applicator cannot be mounted either. Therefore, in the known design of the spindle metering pump, a pipeline (for example a hose line) is absolutely required between the material outlet of the spindle metering pump and the applicator, which leads to the above-mentioned disadvantages.

[0011] The present invention thus provides an improved design of a spindle metering pump, wherein the spatial arrangement of the material inlet and the material outlet is actually reversed. This means that the material outlet on the spindle metering pump is arranged further away from the rotary drive (e.g. servo drive) than the material inlet. This allows the applicator to be directly flanged to the spindle metering pump, which has various advantages, which we will describe in more detail.

[0012] In a preferred embodiment of the present invention, the material outlet of the spindle metering pump is located at one third or one quarter of the pump housing of the spindle metering pump away from the direction of the rotary drive. On the other hand, the material inlet of the spindle metering pump is preferably located at one third or one quarter of the drive side of the pump housing of the spindle metering pump.

[0013] It should also be mentioned that the material inlet and / or material outlet on the spindle metering pump is preferably arranged laterally relative to the rotation axis of the spindle metering pump, for example, on the same side surface of the pump housing of the spindle metering pump. However, alternatively, the material inlet and the material outlet can also be arranged on the opposite side surface of the spindle metering pump or on the adjacent side surface of the spindle metering pump.

[0014] It should also be mentioned that the rotary drive (e.g. servo drive) of the spindle metering pump is preferably arranged coaxially with the spindle of the spindle metering pump. Thus, in the spindle metering pump according to the invention, the coating agent flows out of the rotary drive parallel to the axis of rotation of the spindle metering pump during operation. In contrast, in known spindle metering pumps, the coating agent flows to the rotary drive parallel to the axis of rotation of the spindle metering pump.

[0015] It should also be mentioned that the term spindle metering pump used in the context of the present invention should be generally understood to include all rotary pumps with a rotatable rotor to pump the coating agent from the material inlet to the material outlet. However, preferably, the spindle metering pump is a known screw pump, for example, from EP2961988B1.

[0016] Furthermore, it should be pointed out that the invention is not limited to the above-mentioned high-viscosity coating agents. On the contrary, the invention is generally applicable to the application of liquid or pasty coating agents. However, in a preferred embodiment of the invention, the spindle metering pump is designed for the application of adhesives (e.g. epoxy resins, polyurethanes (PUR), isocyanates, hot butyl rubber), insulating materials or sealants, in particular PVC plastisols (PVC: polyvinyl chloride) are also mentioned as possible coating agents.

[0017] Furthermore, it should also be noted that the present invention enables the application of the coating agent to any type of component. However, in a preferred embodiment of the present invention, it is envisaged that the coating agent is applied to a motor vehicle body component.

[0018] The present invention not only includes the above-mentioned spindle metering pump as an independent component or as a separate component. Furthermore, the present invention also claims protection for an application device having such a spindle metering pump and an applicator for applying a coating agent, wherein the applicator is directly mounted on the end of the spindle metering pump facing away from the rotary drive via a flange. The applicator is directly mounted on the spindle metering pump via a flange, and a very short flow path can be achieved between the material outlet of the spindle metering pump and the applicator. For example, the flow path between the material outlet of the spindle metering pump and the applicator can be shorter than 1m, 50cm, 20cm, 10cm or 5cm. This short flow path is advantageous because it achieves a fast reaction time, i.e. the application device can change the volume flow of the coating agent with high dynamics.

[0019] It should also be mentioned that the applicator is directly mounted on the spindle metering pump via the flange, so that the flow path between the spindle metering pump and the material outlet of the applicator is hose-free and pipe-free. The advantage of no hose between the material outlet of the spindle metering pump and the applicator is that there are no more annoying hose breathing.

[0020] It should also be mentioned that a material pressure regulator is preferably connected upstream of the material inlet of the spindle metering pump, which regulates the pumping pressure of the coating agent at the material inlet of the spindle metering pump, in particular as a function of the volume flow that is correlated with the conveying volume flow of the coating agent.

[0021] In a preferred embodiment of the present invention, the material pressure regulator receives a predetermined target value of the pumping pressure of the coating agent at the material inlet of the spindle metering pump, so that the material pressure regulator regulates the pumping pressure to the predetermined target value.

[0022] The pressure of the coating agent at the inlet of the spindle metering pump is preferably adjusted in such a way that the pump slip of the spindle metering pump is minimized or at least reduced. The pump slip is defined here as the deviation between the volume flow actually delivered by the spindle metering pump and the theoretical volume flow (related to the rotational speed) specified by the pump characteristic curve of the spindle metering pump. Ideally, the delivery volume flow of the coating agent should be independent of the pressure ratio at the inlet and outlet of the spindle metering pump. This corresponds to the ideal state of the metering device, but cannot be fully achieved in practice due to the unavoidable pump slip. However, the pump slip can be minimized by controlling the pumping pressure of the spindle metering pump using a material pressure regulator. In addition, the wear of the spindle metering pump can be minimized by adjusting the pumping pressure of the coating agent.

[0023] As mentioned above, the material pressure regulator can receive a target value and then adjust the pump pressure to the target value. The material pressure regulator can have a target input to receive this target value. For example, the target input of the material pressure regulator can be supplied with the target value by a proportional valve, which is preferably operated pneumatically.

[0024] For example, a target value for the pumping pressure can be determined in a calibration run in relation to the metering volume flow. This involves operating the spindle metering pump at various volume flows with the material pressure regulator open and determining the resulting metering pressure. This forms the basis for setting the input pressure (i.e. the target value) of the spindle metering pump in subsequent production operation.

[0025] In a preferred embodiment of the present invention, the spindle metering pump has a first pressure sensor for measuring the pumping pressure of the coating agent at the material inlet of the spindle metering pump, wherein the first pressure sensor can be connected to the material pressure regulator so as to supply the pumping pressure as an actual value to the material pressure regulator.

[0026] Furthermore, the spindle metering pump can have a second pressure sensor in order to measure the pumping pressure of the coating agent at the material outlet of the spindle metering pump, which second pressure sensor is connected to the material pressure regulator in order to supply the pumping pressure as an actual value to the material pressure regulator.

[0027] Furthermore, the spindle metering pump may have a third pressure sensor for measuring the pressure of the coating agent at the inlet of the material pressure regulator, and the third pressure sensor may be connected to the material pressure regulator so as to supply the pressure of the coating agent at the inlet of the material pressure regulator as an actual value to the material pressure regulator.

[0028] In addition, a rotary encoder can also be provided to measure the rotational position of the spindle metering pump. Alternatively, the rotational position of the spindle metering pump can also be provided by a servo drive.

[0029] In a preferred embodiment of the present invention, the coating device has an additional piston pump, which is arranged upstream of the material pressure regulating valve and delivers the coating agent with a specified pump-out pressure to the spindle metering pump via the material pressure regulator. The pump-out pressure of the piston pump is preferably greater than the required pump-in pressure of the spindle metering pump, so the material pressure regulator between the piston pump and the spindle metering pump subsequently adjusts the pump-out pressure of the piston pump to the required pump-in pressure of the spindle metering pump.

[0030] The connection between the piston pump and the material pressure regulator can be made in a conventional manner via a rigid pipe, which can therefore also have a relatively long line length, exceeding 2 m, 4 m, 6 m, 8 m, 10 m or even 12 m. However, the piston pump can also be connected to the material pressure regulator via a flexible hose line or via a combination of rigid and flexible hose lines. Here, the total pipe length between the piston pump and the material pressure regulator can also be greater than 2 m, 4 m, 6 m, 8 m, 10 m or even greater than 12 m.

[0031] Preferably, the piston pump is a compressed air driven spoon piston pump, but in principle other pump types can also be selected. However, it should be mentioned that the piston pump preferably has a relatively high maximum delivery pressure, preferably at least 10 bar, 50 bar, 100 bar, 200 bar or 350 bar. For example, the applicant has a "EcoPump VPS TM A compressed air driven spoon type piston pump sold under the product name "" can be used as a piston pump.

[0032] With regard to the applicator, it should generally be mentioned that the applicator preferably does not contain a regulator, but only at least one main valve, which can selectively release or block the applicator from dispensing material. In a preferred embodiment of the design, the main valve is designed as a main needle valve. This means that the main needle valve has a displaceable valve needle, which, depending on its valve position, can release or block the valve seat.

[0033] In addition, the coating device according to the present invention can have a heater to heat the coating agent. For example, this heater can be designed as a heating device, so that the hose or pipeline with the coating agent is heated.

[0034] The coating device according to the present invention preferably has a mounting flange so that the coating device can be detachably mounted on the robot flange of the coating robot. The coating device preferably comprises a spindle metering pump with a rotary drive, an applicator, a material pressure regulator, a proportional valve, any pressure sensor and / or a heater. These components are integrated into the coating device, and the entire coating device comprising all components can be quickly replaced, which is impossible in the assembly of the separate structure of the prior art. The above-mentioned other components (such as rotary drive, applicator, material pressure regulator, proportional valve, pressure sensor, heater) can be mounted on the spindle metering pump by the flange so that the spindle metering pump forms a unified assembly with these components, which can be installed on the coating robot or removed from the coating robot.

[0035] Generally speaking, it should be mentioned that the spindle metering pump is preferably designed to deliver at least 5 cm 3 / s, 10cm 3 / s, 20cm 3 / s or 24cm 3 / s volume flow rate.

[0036] Furthermore, it should generally be mentioned that the spindle metering pump preferably has a sufficiently large volume flow operating range, preferably covering 2 cm 3 / s to 24cm 3 / s volume flow range.

[0037] As briefly mentioned above, the rotary drive of the spindle metering pump can be an electric servo drive. This has the advantage that the rotational position of the servo drive is known by controlling the servo drive, and thus the rotational position of the spindle metering pump is known, so that a separate rotary encoder for determining the rotational position of the spindle metering pump can be omitted.

[0038] The application device according to the invention is described above as a one-component system, which is designed for an applicator consisting of only a single component (1K). However, within the scope of the invention, two such application devices can also each deliver one component of a two-component material (2K), in which case the mixer mixes the two components of the two-component material to form the coating agent. Therefore, the invention also claims protection for the two-component system.

[0039] Furthermore, the invention also claims protection for a complete painting robot having a plurality of robot arms, optional robot hand axes and a robot flange, wherein a painting device corresponding to the above invention is mounted on the robot flange.

[0040] Furthermore, the invention also claims protection for the method for operating the above-mentioned coating device according to the invention. Here, it is provided to determine the pump slip of the spindle metering pump. In order to determine the pump slip of the spindle metering pump, the invention provides two variants of the invention, which are described separately.

[0041] In a first variant of the invention, the following steps are performed to determine the pump slip of a spindle metering pump:

[0042] Close the main valve of the applicator.

[0043] The coating agent is delivered to the closed main valve through the spindle metering pump, and a predetermined pre-pressure is established at the material outlet of the spindle metering pump.

[0044] Use a second pressure sensor to measure the pumping pressure at the material outlet of the spindle metering pump,

[0045] When the outlet pressure of the material of the spindle metering pump reaches the specified inlet pressure, turn off the spindle metering pump.

[0046] The material pressure regulator is used to adjust the pumping pressure at the material inlet of the spindle metering pump to a constant target value.

[0047] After the spindle metering pump is shut down, during a monitoring period, measuring the time-varying pressure drop at the material outlet of the spindle metering pump or upstream of the applicator main valve by a second pressure sensor, and

[0048] Evaluate the pressure drop over time during the monitoring period to determine the pump slip of the spindle metering pump.

[0049] On the other hand, in a second variant of the present invention, the following steps are performed to determine the pump slip of the spindle metering pump:

[0050] Close the main valve of the applicator.

[0051] The coating agent is delivered to the closed main valve through the spindle metering pump, and a predetermined pre-pressure is established at the material outlet of the spindle metering pump.

[0052] Use a second pressure sensor to measure the pumping pressure at the material outlet of the spindle metering pump,

[0053] When the outlet pressure of the material of the spindle metering pump reaches the specified inlet pressure, detect the rotation position of the spindle metering pump, especially

[0054] oDetection using a rotary encoder, or

[0055] oBy querying the rotational position of the servo drive of the spindle metering pump,

[0056] ·The pumping pressure of the spindle metering pump is adjusted to a constant target value through the material pressure regulator.

[0057] By controlling the rotary drive of the spindle metering pump, the pumping pressure of the material outlet of the spindle metering pump is controlled to the specified inlet pressure,

[0058] measuring the change in the rotational position of the spindle metering pump over time during a monitoring period after reaching a predetermined upstream pressure, the monitoring period preferably comprising several minutes, in particular five minutes, and

[0059] Evaluate the change in rotational position of the spindle metering pump over time during the monitoring period to determine the pump slip of the spindle metering pump.

[0060] Based on the determined pump slip, corrections can be made to avoid metering errors. For example, a new pump characteristic curve can be measured for this purpose, which reflects the relationship between the pump speed of a spindle metering pump and the delivered volume flow. This pump characteristic curve can then be stored in the control system.

[0061] As already mentioned above, the invention enables a highly dynamic variation of the volume flow of the coating agent applied within a so-called "brush". For example, the "brush" can form a strip-shaped drop of coating agent, which is applied to a component, for example a motor vehicle body component. For example, adhesives and sealants are applied to the corresponding component in the form of such drops. The invention allows the volume flow of the coating agent to be varied along the strip-shaped drop, i.e. within the "brush". This makes it possible to optimize the application result and thus also to vary the feed rate of the applicator along the drop. In the context of the present invention, this aspect of the invention is of importance in its own right and deserves to be protected independently of the aspect of the invention which provides for determining the pump slip.

[0062] Further advantageous embodiments of the invention are described in the dependent claims or are explained in more detail below in conjunction with the description of preferred embodiments of the invention and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG. 1A shows a perspective view of a conventional spindle metering pump according to the prior art.

[0064] FIG. 1B shows a perspective view of a painting robot with the conventional spindle metering pump shown in FIG. 1A .

[0065] Figure 2A A perspective view of a spindle metering pump according to the invention is shown.

[0066] Figure 2B A perspective view of a painting robot is shown, on which a spindle metering pump corresponding to the present invention is mounted.

[0067] Figure 3 A perspective view of a spindle metering pump according to the invention is shown without further components mounted thereon.

[0068] Figure 4 A schematic diagram of an application device according to the invention is shown, which has a spindle metering pump according to the invention, an upstream material pressure regulator and a piston pump.

[0069] Figure 5 A flow chart for determining pump slip according to a first variant of the invention is shown.

[0070] Figure 6 A flow chart for determining pump slip according to a second variant of the invention is shown.

[0071] Figure 7 A perspective view of the application of adhesive drops with different adhesive volume flow rates is shown. DETAILED DESCRIPTION

[0072] Figure 2A and 2B A description now follows which partially corresponds to the prior art according to FIGS. 1A and 1B , so that in order to avoid repetitions reference is made to the above description, the same reference numerals being used for corresponding details.

[0073] A special feature of this embodiment is that, compared with the prior art, the spatial arrangement of the material inlet 3 and the material outlet 4 of the spindle metering pump 1 is opposite. The material inlet 3 is located at the drive end of the pump housing of the spindle metering pump 1, while the material outlet 4 is located at the far end of the pump housing of the spindle metering pump 1, that is, the side away from the servo drive 2 (see Figure 3). The material outlet 4 is therefore further away from the servo drive 2 than the material inlet 3. This reversal of the material inlet 3 of the material outlet 4 makes it possible for the applicator 9 to be connected directly to the pump housing of the spindle metering pump 1 via a flange. Compared to the prior art, the exchange of the spatial arrangement of the material inlet 3 and the material outlet 4 means that the applied coating agent flows out of the servo drive 2 in the pump housing of the spindle metering pump 1 along the axis of rotation of the spindle metering pump 1, whereas in the prior art the coating agent flows to the servo drive 2 in the spindle metering pump 1.

[0074] On the one hand, mounting the applicator 9 directly on the spindle metering pump 1 via the flange greatly shortens the flow path between the material outlet 4 of the spindle metering pump 1 and the applicator 9, thereby achieving more dynamic metering.

[0075] On the other hand, the applicator 9 is directly mounted on the spindle metering pump 1 via a flange, and the hose line 8 can also be omitted, as required in the prior art according to Figures 1A, 1B. This completely avoids the destructive hose breathing in the prior art.

[0076] Further, it can be seen from the accompanying drawings that the spindle metering pump 1 has a mounting flange 15, which can be detachably mounted on the mounting flange 10 of the coating robot 11. Quick release fasteners are provided between the two mounting flanges 10 and 15 to facilitate rapid assembly and disassembly. It should be mentioned here that many other components are also installed on the spindle metering pump 1, such as the heating module 7, the material pressure regulator 6 and the servo drive 2, so the complete assembly containing all these components can be quickly and easily installed and disassembled. This is also an advantage compared to the prior art, as shown in Figures 1A and 1B, in which the applicator 9 and the spindle metering pump 1 must be assembled and disassembled separately.

[0077] Furthermore, pressure sensors 16 , 17 are provided on the spindle metering pump 1 in order to measure the pressure of the coating agent upstream of the material pressure regulator 6 or downstream of the material pressure regulator 6 .

[0078] Furthermore, a pressure sensor 18 is provided on the spindle metering pump 1 for measuring the pressure of the coating agent on the coating agent 9 .

[0079] The figure also shows a pneumatic proportional valve 19 which supplies the material pressure regulator 6 with a target value for the pumping pressure at the material inlet 3 of the spindle metering pump 1. The material pressure regulator 6 then regulates the pumping pressure at the material inlet 3 of the spindle metering pump 1 to the specified target value during operation. The proportional valve 19 can be controlled by a pump controller which specifies the target value in this way.

[0080] Figure 3 A perspective view of a spindle metering pump 1 is shown. Figure 2A and 2BThe material inlet 3 and the material outlet 4 of the spindle metering pump 1 are only shown schematically.

[0081] Figure 4 A schematic diagram of an application device according to the invention is shown, which has a spindle metering pump 1 according to the invention and a material pressure regulator 6, so that in order to avoid repetition, reference is made to the above description. In addition, the figure shows a piston pump 20 that provides a delivery pressure of 350 bar. The piston pump 20 is connected to the material pressure regulator 6 via a pipeline 21, and the material pressure regulator 6 then adjusts the very high delivery pressure of the piston pump 20 to the required pumping pressure of the spindle metering pump 1. Preferably, the piston pump 20 is a compressed air-operated spoon-type piston pump, which is known by the applicant as the "EcoPump VPS TM "Product Name Sales.

[0082] Figure 5 and Figure 6 Two flow charts are shown to illustrate how the pump slip of a spindle metering pump can be determined. It should be pointed out here that a characteristic of a metering device is that the delivered volume flow is essentially independent of the pressure ratio at the inlet and outlet of the metering device. However, this ideal characteristic of a metering device cannot be fully realized in practice, for example due to mechanical wear. As a result, disruptive pump slips can lead to metering errors during operation of the spindle metering pump 1. Therefore, the invention also makes it possible to determine disruptive pump slips and subsequently correct the pump slips. For this purpose, the invention provides two variants, such as Figure 5 and Figure 6 shown.

[0083] In accordance with Figure 5 In a variant of the invention, the main needle valve of the applicator 9 is first closed in a first step S1 .

[0084] In a second step S2 , the spindle metering pump 1 then builds up a prepressure at the material outlet 4 of the spindle metering pump 1 .

[0085] In step S3 , the pressure sensor 18 continuously measures whether the required inlet pressure is reached.

[0086] When the material outlet 4 of the spindle metering pump 1 reaches the required inlet pressure, the spindle metering pump 1 is stopped in step S4 .

[0087] Then, the pumping pressure at the material inlet 3 of the spindle metering pump 1 is kept constant by the material pressure regulator 6 in step S5 .

[0088] Subsequently, due to the unavoidable interfering pump slip, a time-varying pressure drop occurs at the material outlet 4 of the spindle metering pump 1 , so that the time-varying pressure drop is continuously measured in step S6 .

[0089] In step S7 , the pump slip is then calculated from the pressure drop over time.

[0090] In a next step S6 , the pump characteristic curve can be corrected as a function of the determined pump slip, and the spindle metering pump can then be controlled using the corrected pump characteristic curve.

[0091] Figure 6 A further flow chart is shown which illustrates a second variant of the invention for determining pump slip.

[0092] Here, the main needle valve of the applicator 9 is closed in a first step S1 .

[0093] In a next step S2 , the spindle metering pump 1 then builds up a predetermined prepressure at the material outlet 4 of the spindle metering pump 1 .

[0094] Then, in the next step S3 , it is continuously checked whether the required inlet pressure is reached at the material outlet 4 of the spindle metering pump 1 .

[0095] If the inlet pressure is reached, the rotational position of the spindle metering pump 1 is measured in step S4. The measurement of the rotational position can be performed, for example, by a rotary encoder. However, when a servo drive 2 is used, the rotational position of the spindle metering pump 1 is known by the controller of the servo drive 2, so that a separate rotary encoder can be omitted.

[0096] In the next step S5, the inlet pressure is kept constant at the material outlet 4 of the spindle metering pump 1. Due to the unavoidable disruptive pump slip, this requires that the spindle metering pump 1 rotate at least a little further.

[0097] In step S6 , the pumping pressure at the material inlet of the spindle metering pump 1 is then kept constant by the material pressure regulator 6 .

[0098] After the monitoring period, the rotational position of the spindle metering pump 1 is measured again in step S7 .

[0099] In a next step S8 , the pump slip is then derived from the change in the rotational position of the spindle metering pump 1 during the monitoring period.

[0100] In the last step S9 , the pump characteristic curve is then corrected again according to the determined pump slip, so that the spindle metering pump 1 can be controlled using the corrected pump characteristic curve.

[0101] at last, Figure 7A perspective view is shown to illustrate the application of a drop 22 to a motor vehicle body part 23 by an applicator 9. By way of example, a plurality of points P1, P2, P3 are shown along the drop 22, at which the movement speed v of the applicator 9 and the volume flow Q of the adhesive applied by the applicator 9 can have different values ​​v1, v2, v3 or Q1, Q2, Q3. Thus, in the context of the present invention, both the movement speed v of the applicator 9 and the volume flow Q of the adhesive applied by the applicator 9 can be varied highly dynamically along the drop 22 ("brush").

[0102] The invention is not limited to the preferred embodiments described above. On the contrary, the invention also includes a large number of variants and modifications, which also utilize the inventive concept of the invention and therefore belong to the scope of protection of the invention. In particular, the invention also claims the subject matter and features of the appended claims, which are independent of the claims mentioned in each case and, in particular, do not include the features of the main claim. Therefore, the invention includes various aspects of the invention, which enjoy protection independently of each other.

[0103] Advantages of the invention

[0104] The main advantages of the present invention are briefly summarized as follows:

[0105] In the spindle metering pump according to the present invention, since the spatial arrangement of the material inlet and the material outlet is opposite, the applicator can be directly mounted on the spindle metering pump via the flange.

[0106] The applicator is directly flanged onto the spindle metering pump, which allows for a short flow path between the spindle metering pump and the applicator, thus enabling highly dynamic metering.

[0107] · The applicator is directly mounted on the spindle metering pump through the flange, which eliminates the previously used hose between the spindle metering pump and the applicator, thus avoiding annoying hose breathing.

[0108] The material pressure regulator upstream of the spindle metering pump can smoothly handle possible pressure pulsations from the material supply (e.g. piston pump). As a result, the spindle metering pump can receive a constant pumping pressure.

[0109] ·By properly controlling the material pressure regulator, the best pumping pressure can be selected for different brushes.

[0110] By adjusting the pump inlet pressure, the pump slip can be reduced, thereby improving metering accuracy, extending the service life of the spindle metering pump, and reducing the shearing of the applied material.

[0111] By monitoring pump slip, high metering accuracy can be maintained throughout the service life and the service life of the spindle metering pump can be extended by compensating for the increase in pump slip during its service life.

[0112] The spindle metering pump is integrated with the coating machine and other components, making it easier to assemble and disassemble on the coating robot.

[0113] Reference numerals list

[0114] 1 Spindle metering pump

[0115] 2 Servo drives for spindle metering pumps

[0116] 3 Material inlet for the spindle metering pump

[0117] 4-spindle metering pump material outlet

[0118] 5 Pipe from material pressure regulator to material inlet of spindle metering pump

[0119] 6 Material pressure regulator

[0120] 7 Heating module

[0121] 8 Hose line from the material outlet of the spindle metering pump to the applicator

[0122] 9 Applicator

[0123] 10 Mounting flange for painting robot

[0124] 11. Painting Robot

[0125] 12 Proximal arm of the coating robot (“arm 1”)

[0126] 13 The remote robotic arm of the coating robot (“robotic arm 2”)

[0127] 14 Robot Hand Axis

[0128] 15 Spindle metering pump mounting flange with quick release fasteners for mounting on robot flange

[0129] 16, 17 Pressure sensor

[0130] 18 Pressure sensor on applicator

[0131] 19 Pneumatic proportional valve for specifying the target value of the material pressure regulator

[0132] 20 Piston pump

[0133] 21 Pipe from piston pump to material pressure regulator

[0134] 22 Drops

[0135] 23 Body parts

[0136] P1-P3 points along the drop

[0137] Q1-Q3 Volume flow rate of adhesive at points P1-P3 along the drop

[0138] v1-v3: The speed of the applicator moving along the P1-P3 point of the drop

Claims

1. A spindle metering pump (1), in particular as a screw pump, for metering a coating agent, in particular for metering an adhesive, an insulating material or a sealant, comprising: a) a material inlet (3) for receiving the coating agent to be applied, b) a material outlet (4) for dispensing the coating agent to be applied, and c) a rotary drive (2) for rotating the spindle metering pump (1), It is characterized in that d) The material outlet (4) on the spindle metering pump (1) is arranged farther away from the rotary drive (2) than the material inlet (3).

2. The spindle metering pump (1) according to claim 1, characterized in that: a) the material inlet (3) on the spindle metering pump (1) is arranged laterally with respect to the axis of rotation of the spindle metering pump (1), and / or b) the material outlet (4) on the spindle metering pump (1) is arranged laterally with respect to the axis of rotation of the spindle metering pump (1), and / or c) The material inlet (3) and the material outlet (4) are arranged on the spindle metering pump (1) as follows: c1) on the same side surface of the spindle metering pump (1), or c2) on the opposite side surface of the spindle metering pump (1), or c3) on adjacent side surfaces of the spindle metering pump (1), the adjacent side surfaces preferably extending at right angles to each other, and / or d) the rotary drive (2) is arranged so that its drive shaft is coaxial with the main shaft of the main shaft metering pump (1), and / or e) The coating agent in the spindle metering pump (1) flows along the axis of rotation of the spindle metering pump and away from the rotary drive (2).

3. A coating device comprising: a) A spindle metering pump (1) according to any one of the preceding claims, and b) An applicator (9) for applying coating agent to a component (23), in particular a motor vehicle body component (23), said applicator (9) being mounted via a flange on the end of the spindle metering pump (1) facing away from the rotary drive (2).

4. The coating device according to claim 3, characterized in that a) the material outlet (4) of the spindle metering pump (1) is connected to the applicator (9) via a flow path, b) the flow path between the material outlet (4) of the spindle metering pump (1) and the applicator (9) is preferably hose-free and pipe-free, c) The flow path between the material outlet (4) of the spindle metering pump (1) and the applicator (9) is preferably shorter than 1 m, 50 cm, 20 cm, 10 cm or 5 cm.

5. The coating device according to claim 3 or 4, characterized in that A material pressure regulator (6) is connected upstream of the material inlet (3) of the spindle metering pump (1), and the material pressure regulator (6) is capable of regulating the pumping pressure of the coating agent at the material inlet (3) of the spindle metering pump (1), in particular, regulating it according to a volume flow that is related to the conveying volume flow of the coating agent.

6. The coating device according to claim 5, characterized in that The material pressure regulator (6) is capable of regulating the pumping pressure of the coating agent at the material inlet (3) of the spindle metering pump (1) so that a) the pump slip of the spindle metering pump (1) is minimal, the pump slip representing the deviation between the volume flow actually delivered by the spindle metering pump (1) and the theoretical volume flow predetermined as a function of the speed by the pump characteristic curve of the spindle metering pump (1), and / or b) The wear of the spindle metering pump (1) is minimal.

7. The coating device according to claim 5 or 6, characterized in that The coating device comprises: a) a first pressure sensor (17) for measuring the pumping pressure of the coating agent at the material inlet (3) of the spindle metering pump (1), wherein the first pressure sensor (17) is preferably connected to the material pressure regulator (6) and supplies the measured pumping pressure as an actual value to the material pressure regulator (6), and / or b) a second pressure sensor (18) for measuring the pumping pressure of the coating agent at the material outlet (4) of the spindle metering pump (1), wherein the second pressure sensor (18) is preferably connected to the material pressure regulator (6) and supplies the measured pumping pressure as an actual value to the material pressure regulator (6), and / or c) a third pressure sensor (16) for measuring the pressure of the coating agent at the inlet of the material pressure regulator (6), wherein the third pressure sensor (16) is preferably connected to the material pressure regulator (6) and supplies the measured pressure of the coating agent at the inlet of the material pressure regulator (6) as an actual value to the material pressure regulator (6), and / or d) a rotary encoder, used for detecting the rotational position of the spindle metering pump (1).

8. The coating device according to any one of claims 5 to 7, characterized in that a) the material pressure regulator (6) has a target input, at which the material pressure regulator (6) receives a target value for the pumping pressure of the coating agent at the material inlet (3) of the spindle metering pump (1), b) the target input of the material pressure regulator (6) is supplied with the target value, preferably via a proportional valve (19), c) The proportional valve (19) is pneumatically operated.

9. The coating device according to any one of claims 5 to 8, characterized in that a) the coating device comprises a piston pump (20), which is arranged upstream of the material pressure regulator (6) and delivers the coating agent via the material pressure regulator (6) to the spindle metering pump (1) at a specified pumping pressure, b) the pumping pressure of the piston pump (20) is preferably greater than the pumping pressure of the spindle metering pump (1), wherein the material pressure regulator (6) adjusts the pumping pressure of the piston pump (20) downward to the pumping pressure of the spindle metering pump (1), c) The piston pump (20) is preferably connected to the material pressure regulator (6) in the following manner: c1) through a rigid pipe (21), c2) through a flexible hose, or c3) Through a combination of rigid pipes (21) and flexible hoses, d) the pipeline (21) between the piston pump (20) and the material pressure regulator (6) preferably has a pipeline length of at least 2 m, 4 m, 6 m, 8 m, 10 m or 12 m, e) the piston pump (20) is preferably a scoop-type piston pump operated by compressed air, f) The piston pump (20) preferably has a maximum delivery pressure of at least 10 bar, 50 bar, 100 bar, 200 bar or 350 bar.

10. The coating device according to any one of claims 3 to 9, characterized in that a) the applicator (9) does not comprise a regulator but only comprises at least one main valve which selectively releases or blocks the discharge of material through the applicator (9), b) The main valve is preferably a main needle valve.

11. The coating device according to any one of claims 3 to 10, characterized in that a) the coating device has a heater (7) for heating the coating agent, the heater (7) being in particular a heating device for heating a hose or a pipe carrying the coating agent, and / or b) the coating device has a mounting flange (15) for detachably mounting the coating device on a robot flange (15) of a coating robot (11), the coating device preferably comprising the following components, which can be mounted together on the robot flange of the coating robot via the mounting flange (15) and are preferably mounted on the spindle metering pump (1) via the flange: b1) a spindle metering pump (1) with a rotary drive (2), b2) an applicator (9), b3) Material pressure regulator (6), b4) Proportional valve (19), b5) a first pressure sensor (17) and / or a second pressure sensor (18) and / or a third pressure sensor (16), and / or b6) a heater (7), and / or c) The spindle metering pump (1) is designed to be able to deliver at least 5 cm 3 / s, 10cm 3 / s, 20cm 3 / s or 24cm 3 / s volume flow rate, and / or d) The operating range of the designed volume flow rate of the spindle metering pump (1) is 2 cm 3 / s to 24cm 3 / s, and / or e) The rotary drive (2) of the spindle metering pump (1) is an electric servo drive, so that the rotary position of the servo drive can be known through the controller of the servo drive.

12. A coating system comprising: a) two application devices according to any one of claims 3 to 11, for respectively delivering one component of a two-component material, and b) A mixer, used to mix the two components of a two-component material.

13. A coating robot (11) comprising a plurality of robot arms (12, 13), an optional robot hand axis (14) and a robot flange (10), wherein: The robot flange (10) is mounted with a coating device according to any one of claims 3 to 11 or a coating system according to claim 12.

14. A method for operating a coating device according to any one of claims 3 to 11, characterized in that The pump slip of the spindle metering pump (1) is determined.

15. The operating method according to claim 14, characterized in that: The operating method comprises one or more of the following steps for determining the pump slip of the spindle metering pump (1): a) Close the main valve of the applicator (9), b) feeding the coating agent to the closed main valve via the spindle metering pump (1) to establish a predetermined pre-pressure at the material outlet (4) of the spindle metering pump (1), c) measuring the pump outlet pressure at the material outlet (4) of the spindle metering pump (1) by means of a second pressure sensor, d) When the pumping pressure at the material outlet (4) of the spindle metering pump (1) reaches the specified inlet pressure, the spindle metering pump (1) is closed. e) adjusting the pumping pressure at the material inlet (3) of the spindle metering pump (1) to a constant target value by means of the material pressure regulator (6), f) measuring the pressure drop over time at the material outlet (4) of the spindle metering pump (1) or upstream of the main valve of the applicator (9) by means of a second pressure sensor during a monitoring period after the spindle metering pump (1) has been switched off, and g) evaluating the pressure drop over time during the monitoring period to determine the pump slip of the spindle metering pump (1).

16. The operating method according to claim 14, characterized in that: The operating method comprises one or more of the following steps for determining the pump slip of the spindle metering pump (1): a) Close the main valve of the applicator (9), b) feeding the coating agent to the closed main valve via the spindle metering pump (1) to establish a predetermined pre-pressure at the material outlet (4) of the spindle metering pump (1), c) measuring the pump outlet pressure at the material outlet (4) of the spindle metering pump (1) by means of a second pressure sensor, d) when the pumping pressure at the material outlet (4) of the spindle metering pump (1) reaches a predetermined inlet pressure, detecting the rotational position of the spindle metering pump (1), in particular by: d1) measuring the rotational position by means of a rotary encoder, or d2) Query the rotational position of the servo drive of the spindle metering pump (1), e) adjusting the pumping pressure of the spindle metering pump (1) to a constant target value by means of the material pressure regulator (6), f) adjusting the pumping pressure at the material outlet (4) of the spindle metering pump (1) to a specified inlet pressure by controlling the rotary drive (2) of the spindle metering pump (1), g) measuring the change in the rotational position of the spindle metering pump (1) over time during a monitoring period after reaching a predetermined inlet pressure, said monitoring period preferably comprising several minutes, in particular five minutes, and h) evaluating the change in the rotational position of the spindle metering pump (1) over time during the monitoring period to determine the pump slip of the spindle metering pump (1).

17. The operating method according to claim 15 or 16, characterized in that: a) Correction based on the determined pump slip to avoid metering errors, b) The correction preferably provides a new pump characteristic curve to be measured, which reflects the relationship between the pump speed of the spindle metering pump (1) and the delivered volume flow.

18. The operating method according to any one of claims 14 to 17, characterized in that: a) applying a stripe-shaped droplet (22) of coating agent to a component (23) by means of an applicator (9), wherein the applicator (9) is guided along the droplet (22) over the component (23) at a specified movement speed (v1, v2, v3), and the applicator (9) applies the coating agent at a specified volume flow rate (Q1, Q2, Q3), b) the volume flow (Q1, Q2, Q3) of the coating agent is dynamically varied during the movement of the applicator (9) along the droplet (22), and / or c) During the movement of the applicator (9) along the drop (22), the movement speed (v1, v2, v3) of the applicator (9) is dynamically changed.

Images