GB2532608A

GB2532608A - Device for determining the drying behaviour of paints or the like

Info

Publication number: GB2532608A
Application number: GB1520285.6A
Authority: GB
Inventors: Emmerich Roland; Brinz Thomas
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-11-20
Filing date: 2015-11-18
Publication date: 2016-05-25
Also published as: DE102014223673A1; GB201520285D0

Abstract

A device for automatically determining the drying behaviour of paint or the like comprises at least two needles 10 which are moveable over a test sample or substrate 20 and at least one drive means 16 for moving the needles. The device is characterised by each needle having a respective coupling means 14 for individually coupling it to the drive means. If the paint is still liquid, the needle displaces the paint, but if dry, the needle is raised and moves over the coating. The drive means may be a threaded rod to which the coupling means meshes when engaged. In a preferred embodiment, each needle has an individual receiving means (24, Fig 4) for a substrate, and the needle is only lowered and its coupling means meshed after a sample has been inserted. This allows for a plurality of samples to be tested irrespective of the time of their production.

Description

Description Title

Device for determining the drying behaviour of paints or the like

Prior art

The invention starts with a device for determining the drying behaviour of paints or the like according to the generic part of the independent claim. A generic device is disclosed for example in DE 197 02 267 C2. This comprises a linearly movable sample carriage for receiving and transporting the coating samples, a sand distributing device which is arranged above the sample carriage and comprises a funnel, under the outlet of which a perforated strip, which is movable with the sample carriage, is arranged, the perforations of which perforated strip can receive sand from the funnel and, after the further transportation of the perforated strip, can dispense this sand towards the coating sample, whereupon the perforations in the region beneath the funnel are closed towards the coating sample by a plate.

The object of the present invention is to provide a device by means of which a plurality of samples can be tested irrespective of the time of their production. This object 30 is achieved by the features of the independent claim.

Advantages of the invention On the other hand, by means of the inventive device according to the features of the independent claim, it is possible to test a large number of samples irrespective of the time of production. According to the invention, a respective coupling means, which can be coupled to the drive means depending on the processing status of the sample, is provided for each needle. This enables each substrate or each sample to be measured shortly after the time of production. If different drying times are to be measured, the drive speed can be altered after a batch has been processed, and a new drying period can be recorded. Alternatively to this, different threaded rods can also be operated in parallel at different speeds by way of gears or other mechanical transmissions, such as toothed belts.

In an expedient further development, provision is made for the needle to be connected to the coupling means by way of a needle holder and/or a carriage. This enables the needle to be adjusted independently of the coupling in terms of the bearing force, angle of inclination or the like. It is possible to achieve optimum test results thanks to the adjustments being adapted to the respective properties of the test sample or substrate. To this end, it is particularly preferable for the needle or the needle holder to be mounted by means of a bearing which is rotatably connected to the carriage.

In an expedient further development, provision is made for a threaded rod to be provided as drive means, which threaded rod has a plurality of threaded regions for each needle to be moved. This enables a plurality of needles to be driven by way of merely a single drive means, for example the corresponding threaded rod, which needles can be individually coupled as required to the drive means by way of the respective coupling means to be provided, with the result that the coupled needles can be moved in the desired manner over the substrate to be tested.

In an expedient further development, a plurality of threaded rods with a plurality of threaded regions are provided, which are together connected to a drive by way of a coupling means. This enables a large number of automated test stations to be operated individually in particularly simple manner with merely a single drive. This reduces the complexity and cost involved for a large number of test stations. To this end, provision is particularly expediently made for the coupling means to be connected to the needle, which coupling means meshes with the threaded region of the threaded rod if the needle is coupled.

In an expedient further development, provision is made for the carriage to be displaceably and/or rotatably mounted by way of a guide means. It is thereby possible to achieve both the coupling through a pivotal movement and also a linear movement in the coupled state using only one guide means. This solution is therefore notable for a simple construction.

In an expedient further development, provision is made for 30 a fixing means, in particular a magnet, to be provided, by way of which the needle, the carriage and the coupling means can be transferred from a starting position into a test position. This type of fixing means can be released particularly simply for example by a robot which is provided in any case for supplying and removing the substrate. To this end, the robot preferably presses on the carriage from above so that this latter can be released from the fixed holding means. To this end, provision is preferably made for the carriage to pivot about the guide means after the fixing means is released, so that the coupling means comes into engagement with the drive means.

Further expedient further developments are revealed in further dependent claims and in the description.

Drawing An exemplary embodiment of the device according to the invention for determining the drying behaviour of paints or the like is illustrated in the drawing and described in more detail below.

The drawing shows: Figure 1 a schematic illustration of the device in a starting position, Figure 2 a schematic illustration of the device according to Figure 1 in a test position, Figure 3 a schematic illustration of the device in a front view for a plurality of drying tests, Figure 4 a detailed embodiment of the device in a front view, Figure 5 a more precise perspective view of two carriages arranged one above the other.

A needle 10 is connected to a needle holder 18 which is in turn movably mounted by means of a bearing 12 so that the point of the needle 10 can be lifted away from a substrate 20 or brought into contact therewith. A coupling means 14 is shown schematically, for example in the form of a coupling wheel, at the other end of the needle holder 18. In the starting position according to Figure 1, the coupling means 14 is not yet in engagement with a drive means 16. A threaded rod can be provided for example as the drive means 16.

In the test position according to Figure 2, the needle holder 18 is now pivoted so that the coupling means 14 is in engagement with the drive means 16. The point of the needle 10 moreover contacts the surface of the substrate 20. The drive means 16 or the threaded rod moves and transfers the movement to the needle 10. The needle 10 is thereby moved over the substrate 20 in the drying position, in order to determine the drying behaviour of the sample.

In the illustration according to Figure 3, only a single drive 22 is provided, whereof the movement is transferred to a plurality of drive means 16 by transmission means 26 such as toothed belts, chains or the like. The drive means 16 constructed as threaded rods comprises a plurality of threaded regions 17 along which the needle 10 is moved. The threaded regions 17 on a drive means 16 are separated from one another in each case by threadless regions 15. The drive means 16 are preferably arranged one above another for the purpose of analysing a plurality of samples. Each of the needles 10 can be moved as required by a correspondingly associated coupling means 14. To this end, the respective coupling means 14 couples the associated needle 10 to the moving threaded region 17 so that its movement effects a movement of the needle 10.

Figure 4 shows a 4x5 matrix with 20 needles 10 which can be moved independently of one another. A needle 10 is moved with a respective movable carriage 30 along the threaded region 17 to the threadless region 15 if this carriage has been coupled to the drive means 16 by the coupling means 14. According to Figure 4, four drive means 16 are each equipped with five threaded regions 17. One carriage 30 is provided for each threaded region 17; therefore, a total of 20 carriages 30 can test 20 samples independently of one another.

Figure 5 shows, by way of example, two carriages 30 arranged one above the other. A guide means 32 and a strut member 38 are arranged parallel to the drive means 16 with the threaded region 17. The guide means 32 is preferably constructed as a cylindrical rod or rail. The guide means 32 is located above the drive means 16 and is somewhat offset from this. The guide means 32 is surrounded by a bearing 34 so that the carriage 30 connected to this bearing 34 can be displaced at least parallel to the axis of the drive means 16. The carriage 30 can moreover also be pivoted about the axis of the bearing 34. The carriage 30 extends from the guide means 32 over the drive means 16. The needle 10 is movably mounted on the end face of the carriage 30 and likewise connected to the carriage 30 by way of the bearing 12. The axis of rotation of the bearing 12 is orientated substantially perpendicularly to the axis of the drive means 16 or the movement direction 31 of the carriage 30.

The needle holder 18 has a substantially L-shaped form. The needle 10 is arranged at one end, an adjustable weight 40 is arranged at the other. By rotating the weight 40 in or out, the force acting on the point of the needle is altered. A bearing surface 44 is connected to the carriage 30. The bearing surface 44 is orientated parallel to the axis of the bearing 12. The bearing surface 44 cooperates with the underside of the L-shaped needle holder 18. If the needle holder 18 lies on the bearing surface 44, the point of the needle is not yet in contact with the substrate 20. If the bearing surface 44 is retracted towards the carriage 30, the needle holder 18 no longer lies on and the point of the needle is lowered onto the substrate 20.

The carriage 30 can be displaced parallel to the axis of the drive means 22 along the guide means 32. A fixing means 28 is located on the underside of a holding means 46 which is stationary with respect to the carriage 30. This fixing means is constructed for example as a magnet. The fixing means 28 fixes the carriage 30 in place. The fixing means 28 can be released in that a robot, for example, presses the upper side of the carriage 30 downwards so that the magnet (as an example of the fixing means 28), which is fixedly connected to the holding means 46, no longer holds the carriage 30. By releasing the fixing means 28, the carriage 30 is lowered downwards in the form of a pivotal movement about the axis of the guide means 32. The coupling means 14 thereby comes into contact with the rotating threaded region 17. The coupling means 14 is constructed as a narrow, preferably conically tapering peg which is connected to the carriage 30. The coupling means 14 is orientated parallel to the threaded regions 17, which extend transversely to the movement direction 31 of the carriage 30. As a result of the carriage 30 being lowered, the coupling means 14 engages in meshing manner in the rotating threaded region 17. This causes the carriage 30 to now be displaced in the movement direction 31 parallel to the axis of the drive means 16 so that the needle 10 is moved over the substrate 20 (not shown) which is received in the holder 24. The holding means 46 extending above the threaded region 17 is connected to the strut member 38 on both sides by way of fastening means 48. In the coupled state, the carriage 30 moves in the movement direction 31 until the coupling means 14 arrives in the threadless region 15 of the threaded rod 16, where it is no longer moved. The needle 10 has then moved over the entire substrate 20 to determine the drying properties of the test sample or substrate 20.

One of the most important properties of paint is the drying behaviour (DIN EN ISO 9117-4). The drying behaviour describes how quickly a paint dries or sets. One of the most established methods for determining the drying process here is a process in which a needle 10 moves evenly over the paint coating. If the paint is still liquid, the needle displaces the paint. If the paint coating is dry, the needle 10 is raised and moves over the paint coating.

The needle 10 with the corresponding needle holder 18 here can be designed so that a variable bearing weight is possible. The needle 10 can be constructed so that it is adjustable along a movement direction 31, preferably set at a slight angle. The angle of the needle 10 can be altered relative to the substrate 20. The bearing weight of the needle 10 is in the gram range. It is therefore expedient to uncouple the bearing surface of the needle 10 from its coupling by the coupling means 14. To this end, an additional pivot joint, the bearing 12, should preferably be provided. The needle 10 is not raised at the end of the movement path over the substrate 20.

If different drying times are measured, the drive speed of the drive 22 can be altered after a batch has been processed and a new drying period with different parameters 20 can be recorded.

Alternatively to this, it is also possible to operate different threaded rods 16 in parallel at different speeds by way of gears or other mechanical transmissions, such as 25 toothed belts as further examples of transmission means 26.

The substrate 20 to be tested can be inserted with the aid of a robot. The robot could also effect the release of the coupling means 14, for example in that the fixing means 28 is released mechanically or in another manner. The movement paths can be flexible, in each case depending on the length of the substrate used. An appropriate adaptation of the drive means 16 or the threaded regions 17 would be conceivable in this case.

In the device according to Figure 4, the four drive means 16 with the five threaded regions 17 in each case are moved constantly by way of a single drive 22 and the laterally arranged transmission means 26. If a new substrate 20 is now to be tested, a robot inserts the substrate 20 into an empty receiving means 24. The robot then releases the fixing means 28 in that the robot arm presses on the upper side of the carriage 30. This causes the carriage 30 with the needle 10 still held by the bearing surface 44 to be lowered downwards in the direction of the substrate 20. The bearing surface 44 is moreover retracted, whereby the needle holder 18 is no longer held so that the point of the needle is lowered onto the upper side of the substrate 20. In the meantime, the coupling means 14 meshes with the rotating threaded region 17. As a result, the carriage 30 and the needle 10 are moved evenly over the substrate 20 in the movement direction 31 until the coupling means 14 reaches the threadless region 15. The carriage 30 with the needle 10 then stops. The sample or substrate 20 can be removed again by the robot for further (optical) analysis of the needle track in the paint. This can take place individually for any random sample.

Although the device described is particularly suitable for testing the drying behaviour of paints or the like, its use is not restricted to this.

Claims

Claims 1. A device for automatically determining a drying behaviour of paints or the like, comprising at least two needles (10), which are movable over a test sample or substrate (20) to determine the drying behaviour, at least one drive means (16) for moving the at least two needles (10), characterised in that, for each of the needles (10), a respective coupling means (14) is provided for individually coupling the respective needle (10) to the drive means (16) for the purpose of moving the respectively coupled needle (10).
2. A device according to Claim 1, characterised in that the needle (10) is connected to the coupling means (14) by way of a needle holder (18) and/or a carriage (30).
3. A device according to one of the preceding claims, characterised in that the needle (10) or the needle holder (18) is mounted by means of a bearing (12) and/or is rotatably connected to the carriage (30).
4. A device according to one of the preceding claims, characterised in that the coupling means (14) is connected to the needle (10), which coupling means meshes with the threaded region (17) of the threaded rod (16) if the needle (10) is coupled.
S. A device according to one of the preceding claims, characterised in that the carriage (30) is displaceably and/or rotatably mounted by way of a guide means (32).
6. A device according to one of the preceding claims, characterised in that a fixing means (28), in particular a magnet, is provided, by way of which the needle (10), the carriage (30) and the coupling means (14) can be transferred from a starting position into a test position.
7. A device according to one of the preceding claims, characterised in that, after the fixing means (28) is released, the carriage (30) pivots about the guide means (32) so that the coupling means (14) comes into engagement with the drive means (16).
8. A device according to one of the preceding claims, characterised in that a movable bearing surface (44) for the needle holder (18) is provided with the carriage (30).
9. A device according to one of the preceding claims, characterised in that at least one threaded rod or toothed belt is provided as drive means (16).
10. A device according to one of the preceding Claims, characterised in that the threaded rod (16) provides a threaded region (17) at least for each needle (10).
11. A device according to one of the preceding claims, characterised in that a plurality of threaded rods (16) are provided, which are each movable by a drive (22).
12. A device according to one of the preceding claims, characterised in that at least two drive means (16) are connected to one another by at least one transmission means (26), such as a gear or other mechanical transmission such as toothed belts, so that the drive means (16) are moved at the same speed or different speeds.
13. A device according to one of the preceding claims, characterised in that a substrate holder (24) is provided, which is arranged beneath the threaded rod (16) to receive the sample or the substrate (20).
14. A device substantially as hereinbefore described with reference to the accompanying drawings.