EP0817682A1

EP0817682A1 - Method and arrangement for preserving cavities in workpieces

Info

Publication number: EP0817682A1
Application number: EP96908097A
Authority: EP
Inventors: Martin Simon; Friedrich Wilhelm; Jörg MANNHERZ; Willi Saum; Hans R. Wankelmuth
Original assignee: Eisenmann Anlagenbau GmbH and Co KG
Current assignee: Eisenmann Anlagenbau GmbH and Co KG
Priority date: 1995-03-27
Filing date: 1996-03-21
Publication date: 1998-01-14
Anticipated expiration: 2016-03-21
Also published as: WO1996030128A1; PL322868A1; EP0817682B1; ATE184512T1; EP0817682B2; DE19607586C2; DE19607586A1; ES2140072T5; PL183071B1; ES2140072T3; DE59603075D1

Abstract

The invention concerns a method and arrangement for preserving the cavities in workpieces using a molten material, for example wax, and is particularly suitable for preserving cavities in vehicle bodywork. The object of the invention is to develop the method and arrangement such that simpler servicing conditions, lower maintenance costs, reduced susceptibility to failure and adaptability to different workpiece sizes and shapes are possible. The novel features of the method and arrangement according to the invention are that a working chamber/immersion area (4) has a predeterminable operating temperature; the workpiece (W) is delivered to the working chamber in a correspondingly pre-tempered state; and at least some of the components guiding the preserving means are heated by the heating system for the working chamber (4). In a further development of the invention, an immersion frame (10), which holds the workpieces to be immersed, consists at least partially of standardized profiled structural sections and can thus be adapted over rapidly and in a variable manner.

Description

Process and plant for preserving the cavities of workpieces

The invention relates to a method and a system for preserving the cavities of workpieces with a molten material, e.g. Wax, and is particularly suitable for the cavity preservation of vehicle bodies.

Known methods and systems for cavity preservation of vehicle bodies are used for everyone Body type a separate so-called flood frame, which is also designed as a special construction for a certain cycle time, as well as external preparation and feeding devices for the preservative, which are also heated separately. Disadvantages of these processes and systems are extreme investment and running costs, susceptibility to faults and a relatively complicated system structure.

The object of the invention is therefore to create a method for preserving the cavities of workpieces, in particular for the cavity preservation of vehicle bodies, which has simpler maintenance conditions, lower maintenance costs and less susceptibility to malfunction, and is variable for different workpiece sizes and forms can be used, and to develop a system that can be produced with less technical and economic effort.

The task at hand is performed by a method according to the preamble of claim 1 or 2 by the characterizing features shown in each case.

A system according to claim 6 is used to carry out the method, which is characterized by the features mentioned. The subordinate claims 3 to 5 and 7 to 19 show further developments or advantageous embodiment variants of the method and the system.

The following advantages can be achieved by the new inventive method according to claim 1 or 2 and the proposed plants for their implementation:

Suitability also for small series (lot) quantities;

the frame heating device, which was previously additional, can be eliminated by the same temperature for the frame and workpiece that can be controlled in limited areas;

- The frame can be used for several workpiece shapes (body types); there is no cycle loss when changing the workpiece to the frame;

- The more tolerable temperatures on the workpiece reduce the consumption of the preservative, in particular due to the now possible low layer thickness; the preservative supply can be made simpler (no hot water or heating oil heating, lower proportion of solid piping);

thermal expansion is switched off as a disturbance variable;

- The integration of the storage container and the Förderlei lines for the preservative in the temperature-controlled section of the system further reduces the technical outlay on equipment

The targeted simultaneous flooding of all cavities in connection with the suction of the excess preservative brings about a further reduction in cycle time.

The invention is explained in more detail below with the aid of system parts shown schematically in the drawings and Abi on schemes of two advantageous embodiments. They show schematically: 1 to 3 the arrangement of the individual plant areas of a first plant according to the invention in different views,

Figures 4 and 5, the flood frame of the first system in a cross section and a top view with the workpiece in place;

6 shows a first device for processing the preservative,

7 is a process flow diagram;

Fig. 8 is a control scheme for the first

Investment,

9 shows a second installation for carrying out the method according to patent claims 2 and 3,

ig. 10 shows a cross section through the flood region of the second installation, 11 shows the basic structure of the flood frame of the second system and

11a details from FIG. 11.

The first advantageous embodiment of the invention shown in FIGS. 1 to 8 is characterized by an adapter frame based on the modular principle.

The frame 10 is assembled with standard construction profiles 11-14 and corresponding assemblies. In exceptional cases, individually adapted components 18, 15, 16, 17 ... can be manufactured and screwed on.

The frame 10 can be optimally adapted to the vehicle due to the large number of available components (e.g. pneumatic elements). Furthermore, the frame 10 can be adapted to the ambient conditions (e.g. cover profiles). The required accuracy with centering guides and other centering aids is provided by the system.

The frame 10 is relatively light, so there is a short warm-up time and uniform heating In addition, the structural strength of the components is high thanks to the high strength values of the components.

Time and costs are saved both for the construction and for the assembly. Changes or adaptations of the frame 10 are possible at any time afterwards without great design and manufacturing effort. In addition, the use of series products and standard parts minimizes storage costs (few different components that can also be used in other areas). Spare parts or improved comparable parts can be reordered if necessary. No storage costs for special tools or devices.

Old frames do not have to be scrapped when changing a Model 1, but can be dismantled and adapted for new models.

The first system and the relevant flood frame 10 are explained in more detail below with reference to FIGS. 1 to 5

A preservation system 1 for treating workpieces W, in particular vehicle bodies, now has, as a new and inventive sequence, a preparation room 2 and a structurally closed, temperature-controllable section 29 with a spatial spacing separate heating zone 3 and flood zone 4, as well as a conveyor 6, preferably a ceiling conveyor, which runs through all of the aforementioned zones, and in addition a control unit 8 is assigned to everything. A cooling area 5 and / or a postprocessing and control area 7 is optionally arranged downstream of the flood area 4.

Furthermore, it is now provided here that the flood zone 4 has a robot 9 or dg1 arranged and movable outside of the latter 4. Handling technology is assigned, which reaches into the flood zone 4 with an arm 9a, some of which holds flexible and directly heatable supply lines 22a and 22b, and there 4 a movable flood frame 10 for optionally coupling the supply lines 22a and 22b with at least one connecting line 15 of the flood frame 10 engages below, and that also außer¬ half of the flood area 4, the st i ^¬ with the supply lines 22a and 22b coupled device 23 for processing and supply of the preservative arranged.

Provided in the flood frame 10 is a docking web 18 aligned in the longitudinal direction and divided into a plurality of sections 19a ... 19n, above of the latter 18, coupling pieces 16 located at the ends of the heatable and flexible connecting lines 15 and held on supports 13 and 14 are arranged.

The other ends of the connecting lines 15 held in the sections 19a ... 19n are formed at the level of the lower surface of the docking web 18 in such a way that a detachable coupling with the supply lines 22a and 22b is possible.

According to a further development, the sections 19a ... 19n are each designed to receive and hold 2 or 4 connecting lines.

The embodiment of the

Invention has the following advantages:

- Simple frame, thus minimizing the cylinders, no heated wax supply lines, no frame heating, little electrical. Components, modular principle.

- 2 different models can be preserved alternately in the same system. Conversions to other models are relatively easy during production. Robot incl. Control allows 2, but theoretically any number of vehicle models with the corresponding adapter frame to be applied.

Individual cavities can be subsequently repaired by manual control.

Application, control and dosing are less complicated and easily accessible outside the furnace area. There are no components in the application area that bake with wax due to low temperatures.

With mutual application of 2 models, roughly the same space requirement as with only one model. Significant space advantages compared to conventional floodlights.

Simple control, fewer components, much easier wax supply, especially with 2 different models. Especially with later additional Model 1 changes n increasingly cheaper

By applying in the oven and thus longer dwell time of the wax at high vehicle bodies and ambient temperatures are ^¬ even the smallest cavities reached (wax remains thin during flooding and does not cool down below the dropping point on the large body surfaces).

In the present embodiment, wax is used as a preservative. In a special embodiment, it is now provided here that the device 23 for processing and supplying the preservation means has an intermediate storage container 24 with a melting tower 25, a working container 26 and pumps for conveying the molten preservative, between the working container 26 and the supply lines 22a and 22b an eccentric screw pump 27 equipped with a frequency-controlled motor is arranged.

The wax supply systems are located essentially to the side under the system. All wax-carrying pipes and hoses are heated. The containers and hoses are heated electrically.

Wax blocks are delivered. Long-term storage takes place in solid form. In use, the wax is fed manually to an electrically heated melting tower 25, the wax then melting flowing into an intermediate storage container 24. This is also electrically heated and has an agitator. The wax is supplied by a working container 26 with agitator and temperature control, level probes and other safety devices. The working container 26 can be pumped into the intermediate storage container 24. The dosing is carried out with mutually independent systems of identical construction. An eccentric screw pump 27, which is located in the working container 26, is driven by a frequency-controlled motor, the metering (quantity and pressure) is achieved via the motor control (see diagram wax flow system).

For each flood opening, a pressure and a quantity value are stored in the PLC via the operator panel 8. According to these entered values, over

Control circuits and frequency converters regulate the speed of the pump so that the required delivery pressure is reached. At the same time, the required quantity is measured via a pulse generator and the pump is switched off when this value is reached.

The wax flowing out after the flooding process is returned to the working container in free fall via a heated collecting trough 28 and an insulated drain with wax filter. The drip trays in the cooling area and under the inactive adapter frame, heating can be carried out independently of one another - see all of FIGS. 6 and 8 -

The application concept for the system is as follows:

Filling the cavities with liquid hot wax in preheated car bodies. The cavities of different sizes are approached by robots and flooded by an application device, the scope of which is listed below in key words:

2 or 4 eccentric screw pumps with vol u etri cal dosing of the filling quantities by frequency-controlled motor. Separate control (individual for each flood hole) of the pumps;

heated flexible hoses, suitable for robot use, fastening technology for hoses and cables on the robot;

- Control cabinet completely wired with:

- Robot control cabinet

- Operation panel for entering variables and displaying fault texts - several heating controls

- 2 or 4 frequency inverters

- Pressure monitoring of the dosage

- Speed monitoring of the dosing

- Level monitoring of the containers

- PLC control program

- adjacent areas (e.g. conveyor technology); - See Figures 1 to 3, 7 and 8 -

The second exemplary embodiment according to FIGS. 9 to 11a to be described below is used to carry out the method according to claim 2. According to the invention, a structurally closed, temperature-regulating section 30 with spatially separate heating area 31 and flood area 32, as well as a ceiling conveyor 6 and a control unit 8 are also used for this task. Compared to the first embodiment, the second now provides that a storage container 33 for the preservative K and the delivery lines 34a,... 34n leading from the storage container 33 to the second flood frame 40 are spatially integrated in the temperature-controlled second section 30. In a further development, the storage container 33 is now at least partially arranged directly below the heating area 31 and / or the flood area 32 and is connected to the latter 31 and / or 32 by air technology.

On the other hand, here the second flood frame 40 is arranged in the flood region 32 by means of brackets 41 and can optionally, e.g. with a Model 1 change.

In a special embodiment it is further provided that each coupling piece 16 'provided on the second flood frame 40 and corresponding to the flood holes WL 1 to WL 2 of the workpiece W is assigned a delivery line 34a, ... 34n, each with a displacement pump 35a, ... 35n , and that the second flood frame 40 longitudinal and transverse struts 11 'and 12', at least three receiving and clamping cylinders 17 'for the workpiece W, supports 13' and 14 'for fastening the coupling pieces 16' and of connecting pieces 42, to which 42 each one of the delivery lines 34a,... 34n is detachably connected, and each has the connecting pieces 42 with the coupling pieces 16 'connecting connecting lines 43a,... 43n. In a constructive addition, a connecting piece 42 can serve several connecting lines and can be equipped with a controllable valve.

Likewise, in the first exemplary embodiment, the flood frame 40, which has receiving and tensioning cylinders 17 'at least on its front and rear front sides for locking the workpiece W, can be designed in a variable manner, such that essentially standard construction profiles for its length - 11 'and cross struts 12' and partially used for the supports 13 'and 14'.

In both variants, it is also advantageous that the supports 14 and 14 'are designed to be movable, pivotable, tiltable or rotatable.

In the second embodiment, a drip pan 38 is now provided in the flood area 32 below the flood frame 40, the 38 drain 39 opens into the reservoir 33. REFERENCE NUMBER

Preservation system Preparation area Heating area Flood area Cooling area Conveyor Follow-up / control area Control unit Robot or similar handling technology Arm Flood frame, 11 'longitudinal struts, 12' cross struts, 13 'supports, 14' supports connecting lines, 16 'coupling piece, 17' holding and tensioning cylinder Docking bar a ... 19n Section Driving Mechanics 2a, 22b supply line 3 device

24 intermediate storage containers

25 melting tower

26 working containers

27 progressing cavity pump

28 drip pan

29 temperable section

30 temperable second section

31 Heating up ch

32 flood area

33 Reservoirs 34a ... 34n delivery lines 35a ... 35n positive displacement pumps

36 RUckl on 1 line

37 supply wing

38 drip pan

39 process

40 second flood frame

41 brackets

42 Connector 43a ... 43n connecting cables

K preservative

W workpiece

WL1, WL2 flood holes

Claims

PATENT CLAIMS

1. A method for preserving the cavities of workpieces, in particular vehicle bodies, in which molten preservative, for example wax, is flooded into the cavities of the workpieces through flood holes located essentially in the base region of the workpieces and after a dwell time the preservative is said to have Flut¬ drains again, characterized by the following process steps:

a) workpiece preparation, e.g. with sealing plug and check,

b) heating the workpiece in a heating area to the working temperature,

c) placing, centering and clamping i egen of the temperature to the working temperature workpiece on a variable flooding frame in the likewise heatable flood area, the flood ^¬ holes of the workpiece in each of a divided into several sections Andocksteges anl to a Koppel¬ stucco by flexible connecting lines,

d) connecting preservative-carrying, partly flexible, supply lines to the connecting lines of one of the sections of the docking web and simultaneous flooding of the respectively connected cavities of the workpiece with preservatives, the amount and pressure of each cavity being chosen differently, e) detaching the supply lines from the currently operated section of the docking dock after a predeterminable dwell time and then starting up the next section of the docking dock,

f) repetition of process steps d) and e) until all sections of the docking web are served and thus all cavities of the workpiece have been flooded,

g) carrying out a dripping phase in the flood region, then detaching the workpiece from the flood frame and

h) optionally transfer into a cooling zone, and

i) final removal of the sealing plugs and, if necessary, checking the quality of the preservation,

2. A method of preserving the cavities of workpieces, particularly vehicle bodies, in which molten preservative, e.g. Wax is flooded into the cavities of the workpieces through flood holes located essentially in the bottom area of the workpieces and after a dwell time the preservative flows off again through said flood holes,

g e k e n n e e c h n e t d u r c h the following process steps:

a) Workpiece preparation, e.g. with sealing plug and check,

b) heating the workpiece in a heating area to the working temperature,

c) placing, centering and clamping of the workpiece tempered to the working temperature on a fixed flood frame in the flood region, which can also be tempered, the flood holes of the workpiece each abutting a coupling piece of the components transporting the preservative, d) simultaneous flooding of the connected cavities of the workpiece with preservative, the amount and pressure per cavity being able to be selected differently, and essentially a displacement pump being provided for each cavity.

e) optionally operating the displacement pump in the return flow for the purpose of accelerated, controlled return flow of the excess preservative from the cavities; Detaching the workpiece from the fixed flood frame after a predeterminable dwell time.

g) optionally carrying out a draining phase and h) optionally transferring to a cooling zone and

i) final removal of the sealing plugs and, if necessary, checking the quality of the preservation

3. The method according to claim 1 or 2,

characterized

that the working temperature in the range of 70 ^β C to 90 ° C and the temperature in the Uml uftte Aufheiz¬ range between 80 ° C to 100 ° C.

4. The method according to any one of claims 1 and 3,

characterized ,

that the supply lines carrying the preservatives are moved to the sections of the docking web in a controlled manner by means of a movable robot or the like.

5. The method according to any one of claims 1, 3 and 4,

d a d u r c h g e k n n z e c h n e t,

that the supply lines correspond to the respective section of the docking dock and for each of the adjacent cavities of the workpiece by means of an eccentric screw pump equipped with a frequency-controlled motor, a volumetric filling quantity is applied.

6. System for performing the method according to one of claims 1 to 5, in which the workpiece (W) to be preserved, in particular a vehicle body, is held during flooding on a flood frame (10 or 40) and the latter (10 or 40) is operatively connected to a device for supplying preservatives,

characterized ,

that within the preservation system (1) one after the other a preparation area (2) and at least one structurally closed, temperature-controllable section (29; 30) with spatially separate heating area (3; 31) and flood area (4; 32 ) and a conveyor (6) running through all of the above-mentioned areas are arranged and a control unit (8) is assigned to everything.

7. Plant according to claim 5,

characterized

that the temperable section (29; 30) is followed by a cooling area (5) and / or a postprocessing and control area (7).

8. Plant according to claim 6 or 7,

characterized ,

that the flood zone (4) or the like is arranged outside the latter (4) and movable robot (9). Handling technology is assigned, which reaches into the flood area (4) with an arm (9a) holding a partially flexible and directly heatable supply lines (22a and 22b) and there (4) a movable flood frame (10) for optional coupling of the supply lines (22a and 22b) engages with at least one connecting line (15) of the flood frame (10), and that the one connected to the supply lines (22a and 22b) is also outside the flood zone (4)

Device (23) for processing and feeding the preservative is arranged.

9. Plant according to claim 8,

characterized ,

that on the flood frame (10) there is provided a docking web (18) aligned in the longitudinal direction and divided into several sections (19a ... 19n), above the latter (18) at the ends of the heatable and flexible connecting lines (15) located and supported on supports (13 and 14) coupling pieces (16), and that the other ends of the connecting lines (15) held in the sections (19a ... 19n) at the level of the lower surface of the docking web (18) are designed so that a detachable coupling to the supply lines (22a and 22b) is possible.

10. Plant according to claim 9,

characterized ,

that the sections (19a ... 19n) are each designed to receive and hold 2 or 4 connecting lines.

11. Plant according to one of claims 8 to 10,

characterized ,

that the device (23) for the preparation and supply of the preservative has an intermediate storage container (24) with a melting tower (25), a working container (26) and pumps for conveying the molten preservative, between the working container (26) and the supply lines (22a and 22b) an eccentric screw pump (27) equipped with a frequency-controlled motor is provided.

12. Plant according to claim 6 or 7,

characterized ,

that a storage container (33) for the preservation agent (K) and the delivery lines (34a, ... 34n) leading from the storage container (33) to the second flood frame (40) spatially into the temperature-controlled second section (30) are integrated.

13. Plant according to claim 12,

characterized ,

that the storage container (33) is at least partially arranged directly under the egg zone (31) and / or the flood zone (32) and is connected to the latter (31 and / or 32) in terms of ventilation.

14. Installation according to one of claims 12 and 13,

characterized ,

that the second flood frame (40) is arranged in the flood region (32) by means of brackets (41) and optionally, e.g. with a model 1 change, is interchangeable.

15. Plant according to one of claims 12 to 14,

characterized ,

that each, provided on the second flood frame (40) and with the flood holes (WL 1 to WL 2) of the factory Piece (W) corresponding coupling piece (16 ') is assigned a delivery line (34a, ... 34n), each with a displacement pump (35a, ... 35n).

16. Plant according to one of claims 12 to 15

characterized

that the second flood frame (40) longitudinal and transverse struts (11 'and 12'), at least three receiving and clamping cylinders (17 ') for the workpiece (W), supports (13' and 14 ') for fastening the coupling ¬ pieces (16 ') and of connecting pieces (42), to which (42) one of the delivery lines (34a, ... 34n) is detachably connected, and each connecting piece (42) with the coupling pieces (16') connecting Has connecting lines (43a, ... 43n).

17. Plant according to claim 16,

characterized , that a connecting piece (42) serves several connecting lines and is equipped with a controllable valve.

18. Installation according to one of claims 6 to 17,

characterized

that the receiving and clamping cylinders (17; 17 ') for locking the workpiece (W) at least on their front and rear faces are designed in a variable design, such that essentially standard construction profiles for the longitudinal (11; 11 ') and transverse struts (12; 12') and partially for the supports (13 and 14; 13 'and 14').

19. Installation according to one of claims 9, 10, 16, 17 or 18,

characterized ,

that the supports (14 and 14 ') can be pivoted, tilted or rotated.