EP1712309A1

EP1712309A1 - Method for manufacturing a hollow panel and a panel obtained with that method

Info

Publication number: EP1712309A1
Application number: EP06112686A
Authority: EP
Inventors: Herman Johan Oonk; Pascal Sprakel
Original assignee: Omega Engineering Holding BV
Current assignee: Omega Engineering Holding BV
Priority date: 2005-04-15
Filing date: 2006-04-18
Publication date: 2006-10-18
Also published as: NL1028777C2

Abstract

For the manufacture of a hollow panel two metal plates are laid onto each other, connected medium-tightly to each other on their periphery and locally connected to each other over their surface by means of weld zones while leaving clear a central zone. The panel is then plastically deformed by a pressure medium via an access opening, a hole is made on at least one end of the free zone and a tube provided with perforations is inserted through the two holes. The tube is welded fixedly to the two plates and also welded to the edges of the opening. The tube acts as inlet or outlet.

A second outlet or inlet respectively is then arranged which can be constructed in the same manner as the above stated inlet or outlet.

Alternatively, the plates can for instance be pre-modelled to the correct form by plastic deformation in a mould, subsequently placed onto each other and welded to each other with their contact zones.

Description

The invention provides a method for manufacturing a hollow panel through which heat transfer medium can flow, with at least one inlet and at least one outlet for the heat transfer medium, which method comprises the following steps, to be performed in suitable sequence, of:

(a) laying two metal plates of substantially equal dimensions onto each other;
(b) mutually connecting the two plates in medium-tight manner by welding over the whole peripheral zone;
(c) locally connecting the two plates to each other by means of a pattern of weld zones distributed regularly over the surface, wherein at least one strip-like zone extending over the surface from the one side to the other is kept free of weld zones;
(d) at a suitable stage of the method, for instance prior to step (a) or following step (c), arranging a hole in a plate or arranging two corresponding holes in both plates such that an access opening is created;
(e) supplying medium under pressure via the access opening such that in the areas between the peripheral weld seams and the weld zones the two plates move apart with plastic deformation, thereby creating a panel with a cavity;
(f) optionally closing the access opening;
(g) making one or two openings respectively on the two ends of the at least one strip-like zone, in particular at least roughly on the longitudinal centre line thereof, on at least one edge or respectively at least two edges on either side of the panel by drilling, grinding, milling or similar process;
(h) inserting through an opening a medium transport tube which is provided with perforations and adapted to serve as respectively inlet or outlet;
(i) fixedly welding this medium transport tube at least partially to the two plates;
(j) fixedly welding the medium transport tube to the edges of the or each opening; and
(k) arranging respectively an outlet or an inlet.

The invention also provides a method for manufacturing a hollow panel through which heat transfer medium can flow, with at least one inlet and at least one outlet for the heat transfer medium, which method comprises the following steps, to be performed in suitable sequence, of:

(p) plastically deforming two metal plates of substantially equal dimensions in mirror-symmetrical manner such that the plates can be laid onto each other with contact zones lying at least roughly in one plane, which contact zones are the whole peripheral zones of the plates and a pattern of zones distributed regularly over the surface, wherein at least one strip-like zone extending over the plates from the one side to the other is free of contact zones, wherein the plates are deformed in outward direction in the areas between the contact zones, whereby a cavity is defined between the plates;
(q) laying the plates onto each other with said contact zones;
(r) making one or two openings respectively on the two ends of the at least one strip-like zone, in particular at least roughly on the longitudinal centre line thereof, on at least one edge or at least two edges respectively on either side of the panel by drilling, grinding, milling or similar process;
(s) inserting through an opening a medium transport tube which is provided with perforations and adapted to serve as respectively inlet or outlet;
(t) fixedly welding this medium transport tube at least partially to the two plates;
(u) fixedly welding the medium transport tube to the edges of the or each opening; and
(v) arranging respectively an outlet or an inlet.

It is known to manufacture a hollow panel through which heat transfer medium can flow, with an inlet and an outlet, by making use of steps (a), (b), (c), (d), (e) and optionally (f). According to the prior art the panel is divided into two parts along the centre line of the strip-like zone, and the tube provided with perforations is placed and welded therebetween. From a production engineering viewpoint this is a difficult process because it difficult after the welding operation to still hold in one plane the panel parts extending on either side of the tube.
It is an object of the invention to obviate the described prior art drawback.
Use is made for this purpose of steps (g), (h), (i), (j) and (k).
Inexpensive and practical is an embodiment in which step (b) is performed by seam-welding or laser welding.
For step (c) use can be made of laser welding or resistance welding.
In order to limit to some extent the stress in the metal plates in the area of the weld zones and to limit the chance of tearing loose during the hydraulic deformation, the method according to the invention can preferably be embodied such that substantially linear or annular, for instance circular, oval or polygonal weld zones are formed.
The method according to the invention can advantageously have the special feature that step (d) is performed by arranging the or each hole at an end of a strip-like zone, and step (g) is performed such that the access opening is embodied by performing step (g) such that an opening replaces the access opening.
A variant is generally recommended in which a connection for medium under pressure is arranged on the access opening after step (d). In this respect it must be taken into account that the deformation pressure is in the order of magnitude of 400 bar. In respect of this high pressure, provisions are necessary for transferring this pressure safely and without problem to the interior of the panel for forming. For the hydraulic deformation use is preferably made of liquid such as water. In the case of calamity, for instance a rapid-action coupling coming loose, the pressure then immediately drops to safe values, other than in the case of a gas under pressure.
According to yet another aspect of the invention, the method according to the invention comprises a step (l) of performing step (k) by performing step (c) such that a second strip-like zone is kept free of weld zones, and
also performing steps (g), (h), (i) and (j) for this second strip-like zone.
In order to control the hydraulic deformation as well as possible, the method can advantageously comprise (m) of placing the assembly of the two plates in the mould cavity of a mould prior to step (f), wherein the shape of the mould cavity corresponds with the external shape of the panel for manufacture. The deforming process can hereby be performed with good accuracy in controlled manner such that the pipe fits more or less tightly in the elongate cavity in the panel.
The invention further relates to a hollow panel through which heat transfer medium can flow, manufactured with the method according to the invention, with at least one outlet and at least one inlet for the heat transfer medium, which panel comprises:

two metal plates of substantially equal dimensions positioned on each other;
which plates are mutually connected medium-tightly over the whole peripheral zone by means of a weld seam;
which plates are further locally connected to each other by means of a pattern of weld zones distributed regularly over the surface, wherein at least one strip-like zone extending over the surface from the one side to the other is kept free of weld zones;
which plates have moved apart plastically, except at the positions where they are connected to each other by welding;
a medium transport tube which is provided with perforations and extends in the cavity between the two plates in the area of said strip-like zone free of weld zones, and which can serve respectively as inlet or outlet, which medium transport tube is welded along the whole length to both plates and is also welded to these plates on the edges of the plates where the medium transport tube protrudes; and
respectively an outlet or inlet.

Finally, the invention relates to such a panel, wherein respectively the outlet or inlet is embodied in the same manner as said respective inlet or outlet.
The invention will now be elucidated with reference to the accompanying drawings. In the drawings:

Fig. 1 shows a perspective view of a part of a panel according to the prior art;
Fig. 2 shows a perspective view of an initial phase of the manufacture of a panel, according to the prior art and according to the invention;
Fig. 3 shows a perspective view of a subsequent phase;
Fig. 4 shows a perspective view of a final phase, in which the prior art and the invention correspond with each other;
Fig. 5 shows a perspective view of a subsequent phase in the method according to the invention;
Fig. 6 shows a perspective view of a subsequent phase;
Fig. 7 shows a perspective view of a subsequent phase;
Fig. 8 shows a perspective view of the final phase in which the panel is completed; and
Fig. 9 shows a perspective view of a panel manufactured using the method according to the invention as according to Fig. 2-8, in which the panel has three feed/discharge tubes.

It is noted that only a part of the relevant panels and plates are drawn in Fig. 1, 2, 3, 4, 5, 6, 7 and 8. This is shown symbolically by cutting short the ends by means of a wavy line. Only Fig. 9 shows a compete panel.

Fig. 1 shows a hollow panel 1 with a feed/discharge tube 2. The manner in which panel 1 is manufactured will become apparent from the description of Fig. 2, 3 and 4 hereinbelow.
Fig. 2 shows two optionally (high-)alloy steel flat plates 3, 4 and tube 2. Plates 3, 4 have substantially equal dimensions.
Fig. 3 shows that plates 3, 4 are laid onto each other and that their whole peripheral edges are connected to each other by laser welding or seam-welding. The relevant weld seams are designated generally with 5. Plates 3, 4 are connected to each other over their surface by means of laser welding or resistance welding via the shown regular pattern of circular weld zones, which are all designated with 6.

Not drawn is that, as according to the prior art, in the situation shown in Fig. 3 a perforation is arranged in one of the two plates 3, 4 or in both plates (on an edge thereof), whereby the contact surface between the two plates becomes accessible for medium under pressure. For this purpose a connection can optionally be temporarily connected to this access opening, for instance a pipe welded thereon. Medium under pressure, in particular a liquid such as water, is thus supplied via the access opening under high pressure (for instance in the order of 400 bar), whereby, likewise according to the prior art, the parts of plates 3, 4 not welded together move apart and a hollow panel is thus created.
Fig. 4 shows the thus obtained situation, in which the access opening is not drawn or is already closed again. The wave-shaped lines which connect the annular weld zones to each other, not being the weld zones and weld seams, show the hydraulic deformation. It will be apparent that the strip-like zone 7 free of weld zones is substantially "inflated", or hydraulically deformed. In order to keep particularly this plastic deformation under control, with a view to the subsequent processes to be described hereinbelow, this plastic deformation can advantageously take place, likewise as according to the prior art, in a mould with a mould cavity having a shape corresponding with that of the hollow panel to be finally obtained.
According to the prior art the now obtained panel 8 is divided into two parts along centre line 19 of strip-like zone 7 by means of sawing, grinding through or the like. Tube 2 is then placed between the two panel parts and welded fixedly thereto. The prior art panel, as shown in Fig. 1, is hereby completed.
A significant drawback of this prior art method is that panel parts 9, 10 cannot be held in one plane with sufficient accuracy. Clamping and positioning facilities are further necessary for positioning of the different components. As will be apparent from the description of the invention below with reference to Fig. 5 - 8, the method according to the invention does not have these drawbacks.
Fig. 5 shows that, according to the invention, openings 30, 31 are formed in the area of strip-like zone 7 at the ends of the centre line 19 thereof by grinding, drilling, milling or other suitable process. It will be apparent from the figure that an elongate cavity accessible from outside is hereby created. With a correct dimensioning, in particular making use of the above stated mould, this cavity can be dimensioned such that tube 2 fits more or less tightly therein.
In a more or less transparent perspective view, Fig. 6 shows that tube 2 is inserted in the above described manner.
Fig. 7 shows from the top that tube 2 is connected to upper plate 4 in the area of centre line 19 along a weld seam 12 by means of a welding operation. On the underside the tube is connected to lower plate 3 in the same manner by a weld seam.
Fig. 8 shows that tube 2 is connected to edges 13, 14 of openings 30, 31 by means of welding.
To the extent that Fig. 8 shows this, the thus obtained panel 15 comprises two hollow panel parts 9, 10 which are mutually separated in medium-tight and pressure-resistant manner by tube 2. Medium can flow into or flow out of panel parts 9, 10 via perforations 17 in tube 2.
Fig. 9 shows a panel 20 which is manufactured using the same method steps as panel 15. In this embodiment however, panel 20 comprises three feed/ discharge tubes 2, 21, 22.

Claims

Method for manufacturing a hollow panel through which heat transfer medium can flow, with at least one inlet and at least one outlet for the heat transfer medium, which method comprises the following steps, to be performed in suitable sequence, of:
(a) laying two metal plates of substantially equal dimensions onto each other;

(b) mutually connecting the two plates in medium-tight manner by welding over the whole peripheral zone;

(c) locally connecting the two plates to each other by means of a pattern of weld zones distributed regularly over the surface, wherein at least one strip-like zone extending over the surface from the one side to the other is kept free of weld zones;

(d) at a suitable stage of the method, for instance prior to step (a) or following step (c), arranging a hole in a plate or arranging two corresponding holes in both plates such that an access opening is created;

(e) supplying medium under pressure via the access opening such that in the areas between the peripheral weld seams and the weld zones the two plates move apart with plastic deformation, thereby creating a panel with a cavity;

(f) optionally closing the access opening;

(g) making one or two openings respectively on the two ends of the at least one strip-like zone, in particular at least roughly on the longitudinal centre line thereof, on at least one edge or respectively at least two edges on either side of the panel by drilling, grinding, milling or similar process;

(h) inserting through an opening a medium transport tube which is provided with perforations and adapted to serve as respectively inlet or outlet;

(i) fixedly welding this medium transport tube at least partially to the two plates;

(j) fixedly welding the medium transport tube to the edges of the or each opening; and

(k) arranging respectively an outlet or an inlet.
Method for manufacturing a hollow panel through which heat transfer medium can flow, with at least one inlet and at least one outlet for the heat transfer medium, which method comprises the following steps, to be performed in suitable sequence, of:
(p) plastically deforming two metal plates of substantially equal dimensions in mirror-symmetrical manner such that the plates can be laid onto each other with contact zones lying at least roughly in one plane, which contact zones are the whole peripheral zones of the plates and a pattern of zones distributed regularly over the surface, wherein at least one strip-like zone extending over the plates from the one side to the other is free of contact zones, wherein the plates are deformed in outward direction in the areas between the contact zones, whereby a cavity is defined between the plates;

(q) laying the plates onto each other with said contact zones;

(r) making one or two openings respectively on the two ends of the at least one strip-like zone, in particular at least roughly on the longitudinal centre line thereof, on at least one edge or at least two edges respectively on either side of the panel by drilling, grinding, milling or similar process;

(s) inserting through an opening a medium transport tube which is provided with perforations and adapted to serve as respectively inlet or outlet;

(t) fixedly welding this medium transport tube at least partially to the two plates;

(u) fixedly welding the medium transport tube to the edges of the or each opening; and

(v) arranging respectively an outlet or an inlet.
Method as claimed in claim 1 or 2, wherein step (b) is performed by seam-welding or laser welding.
Method as claimed in claim 1 or 2, wherein step (c) is performed by laser welding or resistance welding.
Method as claimed in claim 1 or 2, wherein step (c) is performed such that substantially linear or annular, for instance circular, oval or polygonal weld zones are formed.
Method as claimed in claim 1, wherein step (d) is performed by arranging the or each hole at an end of a strip-like zone, and step (g) is performed such that the access opening is embodied by performing step (g) such that an opening replaces the access opening.
Method as claimed in claim 1, wherein a connection for medium under pressure is arranged on the access opening after step (d).
Method as claimed in claim 1 or 2, comprising step
(l) of performing step (k) by performing step (c) such that a second strip-like zone is kept free of weld zones, and
also performing steps (g), (h), (i) and (j) for this second strip-like zone.
Method as claimed in claim 1, comprising step
(m) of placing the assembly of the two plates in the mould cavity of a mould prior to step (f), wherein the shape of the mould cavity corresponds with the external shape of the panel for manufacture.
Hollow panel through which heat transfer medium can flow, manufactured with the method as claimed in any of the foregoing claims, with at least one outlet and at least one inlet for the heat transfer medium, which panel comprises:
two metal plates of substantially equal dimensions positioned on each other;

which plates are mutually connected medium-tightly over the whole peripheral zone by means of a weld seam;

which plates are further locally connected to each other by means of a pattern of weld zones distributed regularly over the surface, wherein at least one strip-like zone extending over the surface from the one side to the other is kept free of weld zones;

which plates have moved apart plastically, except at the positions where they are connected to each other by welding;

a medium transport tube which is provided with perforations and extends in the cavity between the two plates in the area of said strip-like zone free of weld zones, and which can serve respectively as inlet or outlet, which medium transport tube is welded along the whole length to both plates and is also welded to these plates on the edges of the plates where the medium transport tube protrudes; and

respectively an outlet or inlet.
Panel as claimed in claim 10, wherein respectively the outlet or inlet is embodied in the same manner as said respective inlet or outlet.