EP0505699B1 - Supporting device for holding an object during its dip-enamelling - Google Patents

Description

The invention relates to a support device for holding a workpiece to be enamelled by an immersion enamelling method with two spaced-apart through openings.

In known carrying devices of this type, which are generally suspended substantially vertically from a transport device, for example with conveyor belts or chains, workpieces to be enamelled are placed and held essentially in the vertical direction from above. The holding can be carried out by contacting workpiece areas on holding elements arranged on the carrying device. The holding elements are to be arranged in such a way that the enamel coating to be produced is not impaired or is affected as little as possible.

A substantially vertical placement of the workpiece, which can be carried out simply and quickly, is only possible if the workpiece geometry allows it and if there are no elements such as shielding sleeves, shielding plates or the like opposed to the support device.

The invention has for its object to develop a generic support device so that workpieces can still be easily and quickly held when a vertical placement of the workpiece on the support device is not possible.

This object is achieved in that two guide elements made of an insulating material are arranged on the substantially vertically oriented support device, each guide element having a guide section which adjoins an obtuse-angled section of the support device and extends below a predetermined angle to the vertical orientation of the support device extends obliquely upwards and serves to hold the workpiece in a through opening (21) during operation of the device. In a carrying device designed in accordance with the invention, the workpiece is guided for holding over the guide sections, the guide section being arranged and / or designed so that the workpiece can be pivoted in the direction of the carrying device after being pushed onto the guide elements.

The inventive arrangement of guide elements in a simple manner creates the prerequisite for the workpiece to be guided simply and with sufficient accuracy at the beginning of the placement by the interaction of the guide sections with the through openings can. The tool guided in this way is guided essentially in a direction oblique to the carrying device. In order subsequently to bring the workpiece even closer to it for a holder on the support device, it can be pivoted towards the latter according to the invention. The workpiece can then be held on the support device, for example, by resting it in regions on holding elements. A holder can also be carried out in a simple manner by contacting areas of the guide elements.

According to the invention, the prerequisite is thus created in a simple manner that a workpiece can be fixed to a carrying device in a simple, quick and safe manner, the workpiece being guided, first moved obliquely to the carrying device and then pivoted to the latter.

In an advantageous manner, in a carrying device for a workpiece with a base body and a side wall that adjoins the base body essentially perpendicularly above the through openings, at least one fastening section has a guide surface for the side wall such that the side wall is pivoted on the guide surface when the workpiece is pivoted roll and rest on the workpiece to hold it. The guide surface, which is easy to form, initially provides a pivot-type guide when arranging the workpiece and a holder on the carrying device for the pivoted-in workpiece.

The guide element is advantageously formed from an elastic plastic material. This ensures in a simple manner that with appropriate flexibility of the guide element, the workpiece can be placed simply and thus quickly and can be easily displaced relative to the guide elements while being pushed onto the guide elements without the risk of tilting. Such a guide element is still relatively insensitive and thus has a long shelf life. Finally, enamel particles can only settle on the surface of the guide element to a small extent and with little adhesion. As a result, the guide elements, if this is necessary at all, are easy to clean.

In a preferred embodiment for a carrying device for holding a workpiece with at least one projecting area to be kept essentially free of enamel, a shielding sleeve with openings distributed over a peripheral area is arranged on the carrying device for each projecting area such that each projecting area essentially with the workpiece held is arranged at a distance from the inner wall of the associated shielding sleeve and the guide elements are arranged such that the projecting regions are inserted into the shielding sleeve with a pivoting of the workpiece.

The structure and the effect of the shielding sleeves for keeping areas not to be enamelled free is the subject of a patent application of the same age rank filed by the applicant of the present invention (EP-A-0505698).

The arrangement of guide elements according to the invention ensures in a simple manner that the projecting areas engage in the respectively assigned shielding sleeves when the workpiece is pivoted around the guide elements. Although, due to the arrangement of shielding sleeves on the carrying device, a vertical placement of the workpiece from above is not possible, the workpiece can be held easily and quickly. Furthermore, no special work steps are required for the assignment of the above areas and shielding sleeves. It is also not necessary for the projecting areas to be introduced into the shielding sleeves in a substantially axial direction.

Shielding elements, such as shielding plates or the like, can also advantageously be arranged on the carrying device.

Shielding elements of this type can be provided, for example, in accordance with the cited patent application so that only small amounts of enamel particles are deposited on flat areas of a workpiece which are to be kept free of enamel when the workpiece is immersed in the enamel slip bath. The arrangement of the shielding elements can at the same time ensure that any enamel particles which have a low level of adhesion can be rinsed out in a subsequent rinsing step.

Shielding elements can also be designed and arranged so that the thickness of an enamel coating deposited on a predeterminable area of the workpiece can be influenced.

In a further preferred embodiment, at least one spacer made of an insulating material is arranged on the carrying device in such a way that the workpiece rests on the spacer after pivoting into the holding position. This results, for example in addition to the guide surfaces of the fastening sections, in a simple manner a further system for a workpiece held on a carrying device. When the workpiece is pivoted, it is also easy to see that the stop position has been reached by the workpiece resting against the spacer.

In a particularly simple to manufacture and space-saving manner, a support device for simultaneously holding two workpieces can have two support devices opposite one another on a common support frame such that guide elements, shielding sleeves or spacers of the support devices run in opposite directions in each case.

An embodiment of a carrying device according to the invention will be explained in more detail with reference to the drawings.

Fig. 1

eine Seitenansicht eines Bereiches der Tragvorrichtung mit einem Werkstück in einer Stellung beim Aufsetzen und in einer Haltestellung, und

Fig. 2

eine Vorderansicht des Werkstückes mit einem Führungselement und einem Abstandshalter nach Figur 1.

Each shows in an incomplete, schematic representation:

Fig. 1

a side view of an area of the support device with a workpiece in a position when placing and in a holding position, and

Fig. 2

2 shows a front view of the workpiece with a guide element and a spacer according to FIG. 1.

According to the incompletely illustrated embodiment, the carrying device 3 according to the invention has a supporting frame for workpieces 1 to be immersed in an enamel slip bath (not shown), of which only one incompletely shown supporting rod is shown here. The carrying device 3 is arranged essentially vertically and is connected at the upper end in a manner not shown to a transport device, such as a conveyor belt or one or more transport chains. A supporting device 3 arranged in this way not only allows the workpiece 1 to be immersed in the enamel slip bath, but also the execution of pre-treatment or post-treatment steps. Such method steps can include cleaning or degreasing of the enamel coating on the workpiece 1 prior to immersion in the enamel slip bath for electrophoretic deposition. After immersion in the enamel slip bath, for example, enamel particles deposited on workpiece areas to be kept free can be rinsed off in a rinsing step.

For immersion in an enamel slip bath, in which an enamel layer is deposited on the workpiece 1 via an electrophoretic treatment, as well as for immersion in a rinsing bath, the carrying device 3 with the transport device can be lowered. For an essentially continuous enamelling of workpieces 1, supporting devices 3 with supporting frames can be arranged on a revolving, endless transport device at a corresponding distance from one another. However, a workpiece 1 can also be assigned to a carrying device 3 for a cyclical, discontinuous treatment and immersed with it in an enamel slip bath and, if appropriate, in further pre-treatment and / or post-treatment baths.

Usually, workpieces 1 are placed in a substantially vertical direction from above onto a carrying device 3, the placing being completed when areas of the workpiece 1, such as edge or side areas, come into engagement with holding elements arranged on the carrying device 3 in such a way that the Workpiece 1 is set sufficiently securely. Due to the vertical placement and subsequent removal of workpieces 1 in the corresponding direction, the set-up times required for this are kept relatively short, so that the placement or removal of workpieces 1 can be carried out on continuously rotating support devices 3.

The workpiece 1 to be enamelled consists of an essentially flat base body 5 with a circumferential side wall 7 extending substantially at right angles therefrom. Within the base body 5 delimited by the side wall 7, the base body 5 extends essentially from it projecting areas 9 in the same direction as the side wall 7. The projecting areas 9, which in the present case are designed as fastening screws which are connected to the base body 5, for example by welding, are to be kept free from an enamel application. This is necessary for the later use of the projecting areas 9 or the screw bolts. The workpiece 1 can, for example, be a door of a domestic appliance, such as a baking oven, whereby the fastening screws can be provided for a connection to further housing elements, such as hinges.

In order to keep the bolts or protruding areas 9 free of an enamel application while the workpiece 1 is being immersed in the enamel slip bath, the protruding areas 9 are inserted into shielding sleeves 11 attached to the carrying device 3 or its supporting frame. In the present case, the shielding sleeves 11, one of which is assigned to a protruding area 9, are connected to the carrying device 3, for example by welding, screwing or gluing. The shielding sleeves 11 are the subject of the patent application EP-A-0505698 filed in parallel by the applicant of the present invention. The design and the effect of the shielding sleeves 11 are described in detail in this application, so that reference can be made to them. The protruding areas 9, as can be seen from FIG. 1, are arranged on a held workpiece 1 in such a way that they are at a substantially all-sided distance from the inner wall of the respectively assigned shielding sleeve 11. The shielding sleeves 11 are in the wall area surrounding the projecting area 9 with through openings 13 provided, which are arranged and designed such that any enamel particles which have reached the above areas 9 during immersion in the enamel slip bath can be rinsed out in a subsequent cleaning treatment. The shielding sleeves 11, in which the projecting areas 9 can be arranged simply and without the need for adaptation measures, can thus remain assigned to the above areas even during a subsequent cleaning treatment. Advantageously, workpieces 1 can thus be held on carrying devices 3 during immersion in the enamel slip bath and during the execution of pre-treatment and post-treatment steps.

It is therefore not necessary for workpieces 1 to be removed from the carrying device 3 in order to carry out an aftertreatment following immersion in the enamel slip bath, such as, for example, a rinsing treatment for removing enamel particles from areas to be kept free.

Because of the shielding sleeves 11 arranged on the carrying device side, it is not possible, in contrast to the usual procedure, for the workpiece 1 to be placed on the carrying device 3 in a substantially vertical direction from above.

However, in order to enable simple holding of the workpiece 1 on the carrying device 3 and to ensure that the protruding areas 9 engage properly with the shielding sleeves 11 provided for this purpose, According to the invention, a total of 15 guide elements are arranged in an upper region of the carrying device 3.

Of the total of two guide elements 15, only one guide element 15 is shown in FIGS. 1 and 2. Each of the guide elements 15, which can be of identical design, has a fastening section 17 and an adjoining guide section 19. The guide element 15 can, for example, be formed in one piece and consist of an electrically non-conductive material, so that enamel particles only penetrate into the enamel slip bath are deposited to a small extent on the guide element 15, the adhesion of which is low. In a particularly advantageous manner, the guide element 15 can be produced in one piece from an elastic plastic. The fastening section 17 can, for example, have an internal thread, not shown, which can be screwed onto a connecting bolt, also not shown, provided on the support device side.

The fastening section 17 extends essentially in the vertical direction from the support device 3 or its support frame. The guide section 19 adjoining the fastening section 17 is essentially rod-shaped, the guide element 19 extending essentially obliquely from the fastening section 17. The longitudinal direction of the guide element 19 thus also runs obliquely with respect to the carrying device 3. In the present exemplary embodiment, the guide element 19 runs essentially at an angle a of 45 ° to a vertical line and thus also a vertical axis of the support device 3. Each of the guide elements 15 is arranged and designed such that the guide section 19 engages in a through opening 21 provided on the workpiece 1. A placement of the workpiece 1 for holding it on the carrying device 3 can thus be initiated in that the workpiece 1 is initially arranged such that the free end of the guide section 19 engages in the through opening 21.

The workpiece 1 can thus be positioned simply and quickly relative to the carrying device 3 and it can then be pushed in a corresponding manner in the direction of the guide section 19 towards the carrying device 3. For example, wall areas of the through opening 21 can cooperate with the guide section 19 for a guide. After a corresponding, essentially rectilinear pushing on of the workpiece, which is indicated by the arrow A in FIG. 1, the workpiece 1 can be pivoted in the direction of the carrying device 3 in accordance with the arrow B shown in FIG. Due to a corresponding assignment of the guide elements 15 and the shielding sleeves 11, the projecting areas 9 engage in their respectively assigned shielding sleeves 11 without further action.

In order to facilitate the pivoting of the workpiece 1 in the direction of arrow B after the initial pushing in the direction of arrow A, a guide surface 23 is formed in a region of the fastening section 17, which has a support and a pivot point for a region of the side wall 7 forms. The side wall 7 can thus roll on the guide surface 23 during the pivoting in the direction of the arrow B.

With the carrying device 3 according to the invention, the prerequisite is thus created in a simple manner that the workpiece 1 to be enamelled can be arranged and held simply and quickly, in which it is initially essentially linear in the direction of arrow A after the engagement of the guide section 15 in the assigned through opening 21 is pushed open, and in which the workpiece 3 is then pivoted in the direction of arrow B with the cooperation of an area of the side wall 7 with the guide surface 23 of the fastening section 17. Without further action, the projecting regions 9 of the workpiece 1, which are designed as fastening screws, enter the shielding sleeves 11 provided for their shielding.

The workpiece 1 is shown in two positions in FIG. The outer position corresponds to a workpiece position after shifting in the direction of arrow A and the inner position, in which the workpiece 1 runs essentially parallel to the carrying device 3, corresponds to the holding position of the workpiece 1. In this holding position, the workpiece 1 is made by contacting one Area of the side wall 7 is held on a corresponding part of the guide element 15 or by its fastening section 17.

One or more spacers 25 can be provided in order to facilitate the mounting or positioning. The arrangement of such a spacer is shown in FIG 25 can be seen, which is arranged at a distance from the guide element 15 so that it extends essentially in the longitudinal direction of the support device 3 as a strip-shaped element from the side wall 7 in the inward direction of the workpiece 1. In a corresponding manner, further spacers 25 assigned to the workpiece 1 can be arranged on the carrying device 3.

In a manner not shown, further shielding elements, such as shielding plates, can be arranged on the carrying device 3, by means of which flat areas of the workpiece 1 are kept free from the application of an enamel layer. In a corresponding manner, as has been described for the shielding sleeves 11, predeterminable regions of the workpiece 1 come into their intended position relative to the shielding elements solely by placing the workpiece 1 on the guide elements 15, without further adaptation measures being necessary for this.

In order to ensure the desired distance from the surface of the workpiece 1 to be enamelled to the front of the shielding sleeves 11, spacer bolts 27 are arranged on the support frame, on which the workpiece suspended on the frame is supported during the application of the enamel slip and during the flushing phases. The spacer bolt or spacers 27 are surrounded by an insulating jacket, so that no enamel slip is deposited electrophoretically in this area.

Claims (7)

1. Carrying device for the retention of a workpiece (1), which is to be enamelled by an enamel-dipping process, with two passage openings (21), which are arranged at a spacing one from the other, characterised thereby, that two guide elements (15) of an insulating material are arranged at the substantially vertically oriented carrying device (3), wherein each guide element (15) displays a guide portion (19), which adjoins at an obtuse angle at a fastening portion (17) extending substantially perpendicularly from the carrying device (3), extends obliquely upwards at a preset angle (a) to the vertical orientation of the carrying device (3) and serves in operation of the device for the retention of the workpiece (1) in a passage opening (21).
2. Carrying device according to claim 1, for a workpiece (1) with a base body (5) and a side wall (7) adjoining the base body (5) substantially perpendicularly and above the passage openings (21), characterised thereby, that at least one fastening portion (17) displays a guide surface (23) for the side wall (7) in such a manner that the side wall (7) can during a pivotation of the workpiece (1) roll along on the guide surface (23) and rest on this for the retention of the workpiece (1).
3. Carrying device according to claim 1 or 2, characterised by a construction of the guide element (15) of an elastic synthetic material.
4. Carrying device according to one of the claims 1 to 3 for the retention of a workpiece (1) with at least one projecting region (9) to be kept substantially clear of enamel, characterised thereby, that a shielding sleeve (11) with openings (13) distributed over a circumferential region is so arranged at the carrying device (3) for each projecting region (9) that each projecting region (9), when the workpiece (1) is retained, is arranged at a spacing from the inward wall of the associated shielding sleeve (11) and that the guide elements (15) are so arranged that the projecting regions (9) are introduced into the shielding sleeves (11) by a pivotation of the workpiece (1).
5. Carrying device according to one of the claims 1 to 4, characterised by the arrangement of shielding elements such as for example shielding plates.
6. Carrying device according to one of the claims 1 to 5, characterised by the arrangement of at least one spacer member (25) of an insulating material in such a manner that the workpiece (1) after a pivotation lies against the spacer member (25).
7. Carrying device according to one of the claims 1 to 6, characterised by a construction of two mutually opposite carrying devices with a common carrying frame in such a manner that the guide elements (15), the shielding sleeves (11) or the spacer members (25) of the carrying devices extend in respectively opposite directions.

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