WO2009102219A1

WO2009102219A1 - Manufacture of load -bearing and insulated structural elements

Info

Publication number: WO2009102219A1
Application number: PCT/NO2009/000053
Authority: WO
Inventors: Johannes Haumann Sund; Per Knut MØLSTAD
Original assignee: Mjøscon As
Priority date: 2008-02-12
Filing date: 2009-02-12
Publication date: 2009-08-20
Also published as: EP2257679A4; NO328025B1; EP2257679A1; NO20080762L

Abstract

The present invention relates to a machine which is used in manufacturing elongate structural elements, for example wall bearers, beams, rafters or the like. The structural elements are manufactured in a continuous process where the machine comprises a number of casting moulds which are arranged in the form of a circle, forming an angle with the horizontal plane, where this "carousel" guides the respective casting moulds to different work stations. In a preferred embodiment the machine comprises a cycle with three stations, where at station A an input of wood blanks in and closing of the casting mould is conducted, a liquid filler material is supplied to the casting mould at station B, whereupon a drying/setting of the elements occurs on the way to station C, where the casting mould is opened and the finished product removed.

Description

MANUFACTURE OF LOAD-BEARING AND INSULATED STRUCTURAL ELEMENTS

The present invention relates to a method and an arrangement for manufacturing elongate elements, for example load-bearing structural elements such as wall bearers, beams, rafters or the like, where these structural elements are manufactured in a continuous process.

The ever-increasing focus on environmental and climate policy has led to progressively greater and more stringent requirements being placed on the use of fossil fuels, the extent of emissions from, for example, industrial processes or in the car and shipping industry, waste management, etc. Another area in which changes have recently been implemented in the regulations is in the building sector. This is due to the fact that in Norway today this sector is considered to represent as much as 40 percent of the current energy consumption in society. The new regulations involve amongst other things requirements for better insulation in floors, walls, ceilings and better windows in houses and buildings. One example of the new requirements entails the necessity to increase the wall thickness in a building or house relative to today's insulating materials from 200 mm to 250 mm, thereby requiring the insulation thickness to be increased correspondingly. This means that the wood used for manufacturing wall bearers, beams, rafters and the like has to be increased correspondingly. However, since there is little timber available with such large dimensions, the requirement will be difficult to satisfy. Instead solutions such as glued wood, I-beams etc. will have to be employed, which solutions make the manufacturing process both more expensive and more complicated.

Wood has traditionally been considered to have good insulating properties, but compared with today's modern insulating materials used in houses and buildings, it will be less able to prevent heat transmission. The result is that a substantial heat loss occurs in a house or a building through wall bearers, beams, rafters or the like.

This has resulted in the attempt to manufacture structural elements which combine the properties of the wood and the insulating materials in one and the same product, for example by using polyurethane foam between two layers or strata of wood. From Swedish patent SE 437.391 the use is known of wood and polyurethane foam for manufacturing an insulating structural element. In the manufacture of the insulating structural element, casting moulds are employed, where two or more wooden flanges with a space between them are placed in the casting mould. The casting mould is closed and polyurethane foam is then added to the casting mould in a suitable manner.

Another manufacturing process is disclosed in Canadian patent CA 1.224.322, where a composite structural element forms the framework of a building. The element comprises two wooden beams with a layer of polyurethane foam disposed between them. In the manufacture of the structural element, the wooden beams are placed at intervals on a production belt. When the production belt is set in motion, the polyurethane foam will fill in the space between the wooden beams.

The known solutions, however, will be manufactured in complicated and unsatisfactory ways; the structural elements can only be manufactured one at a time, the process has to be stopped each time polyurethane is filled in the mould, etc.

An object of the present invention will be to provide an arrangement for manufacturing elongate elements, where the elongate elements can be manufactured by means of a continuous manufacturing process. A further object of the present invention will be to provide an arrangement for manufacturing elongate elements.

Another object of the present invention will be to provide a structural element which has at least the same strength as the structural element would have had if it had been manufactured from solid timber of the same dimensions. Yet another object of the present invention will be to provide an arrangement for manufacturing elongate elements where maintenance and/or replacement of casting moulds are simplified.

A further object of the present invention will be to provide an elongate element whereby less timber is employed in the manufacture thereof. The present invention relates to an arrangement for manufacturing elongate elements, where the arrangement comprises a number of casting moulds which form an angle with a horizontal plane and where the casting moulds are furthermore arranged in the form of a ring on a base, which base is arranged to rotate past two or more work stations. The base may be arranged to rotate stepwise or continuously.

Each casting mould comprises a box-like part and a lid, where at one end of the casting mould there is further provided a filling device for supplying a filler material. The filling device is advantageously mounted at the lower end of the casting mould when the casting mould is installed in the arrangement. At the opposite end of the casting mould, i.e. the upper end, at least one air hole is provided.

The casting mould's box-like part, moreover, is adjustable in width, length and height direction.

The base in the arrangement is driven by means of belt drive, toothed drive or the like. In the base furthermore, extendable stay bars are provided, which stay bars are connected to the upper part of the casting mould.

According to an embodiment of the present invention the arrangement comprises a work station A, which constitutes an input station, a work station B, which constitutes a filling station and a work station C, which constitutes an output station.

The present invention also relates to a method for manufacturing elongate elements, where the method comprises the following steps:

- adapting the width of the casting mould to the dimensions of the wooden flanges, loading and securing of the wooden flanges,

- closing the casting mould,

- rotating the arrangement for advancing and loading the next casting mould,

- further rotation and loading of more casting moulds,

- filling filler material in the first loaded casting mould, - rotating the arrangement for filling filler material in the next casting mould,

- further rotation and filling of filler material in more casting moulds,

- applying pressure and heat in the first loaded casting mould,

- rotating the arrangement and applying pressure and heat in the next casting mould,

- cooling the first casting mould, - cooling subsequent casting moulds,

- discharging the first loaded casting mould,

- discharging subsequent casting moulds, and

- repeating the cycle with input of the first loaded casting mould.

Other advantages and special features of the present invention will become clearly evident from the following detailed description, the attached drawings and the following claims, in which

Figure 1 shows details of a casting mould employed for manufacturing elongate elements, where the casting mould is one of a number of similarly arranged casting moulds in a circular shape forming a "carousel", Figure 2 illustrates an arrangement for manufacturing elongate elements according to the present invention, where the arrangement comprises a number of casting moulds forming an angle with the horizontal plane and different processing stations placed round the "carousel",

Figure 3 is a principle drawing of the arrangement for manufacturing elongate elements according to the present invention, viewed from above, and

Figure 4 is a principle view of a complete production plant, where the various work processes are indicated. In figure 1 a casting mould 1 is illustrated which is employed in the arrangement for manufacturing elongate elements according to the present invention, where the casting mould 1 is shown in an open condition, and where a ready-manufactured elongate element 2 is located in the casting mould 1. The elongate element 2 is fashioned from two wooden flanges 3 which are placed at a distance apart, whereupon the space between the wooden flanges 3 is filled with a filler material 4. In this case the filler material 4 is polyurethane, and the manufactured elongate element 2 is a load-bearing and insulating structural element. By means of the present manufacturing process a load-bearing structural element is provided where a complete static integration is achieved between the wooden flanges 3 and the filler material 4. The casting mould 1 comprises a box-like part 5 and a lid 6, these being interlocked by means of locking devices 7. Suitable locking devices 7 may, for example, be lock bolts, lock screws etc. When an elongate element 2 is to be manufactured, the wooden flanges 3 are firstly placed in the box-like part 5 of the casting mould 1. The wooden flanges 3 are secured in a non-illustrated manner (for example by suction cups or by mechanical means) in the box-like part 5 so as to prevent them from moving when the casting mould 1 is closed and/or moved. The casting mould 1 moreover is adjustable in width, length and height direction, thereby enabling structural elements of different dimensions to be manufactured. When the casting mould 1 is closed and locked by the locking devices 7, the casting mould will be pressurised, thereby forming an airtight cavity, and a filler material 4 is applied at the lower end of the casting mould 1, this being accomplished automatically by a robot (see also figure 2) at a processing or work station. Since the casting moulds 1 are arranged so as to form an angle with the horizontal plane, it will be advantageous to fill from the lower end of the casting mould 1 as this ensures a complete filling of the gap between the two wooden flanges 3; the casting mould 1 is also provided with one or more "air holes" (not shown) at the opposite end of the filling of filler material, thereby permitting "excess" filler material 4 to flow out through the "air holes", and also causing any air located in the casting mould 1 to be expelled from the casting mould 1. The filler material 4 will begin its foaming process the moment it is added to the casting mould, and when the space between the wooden flanges 3 is completely filled up, the casting mould 1 will be pressurised. The casting moulds 1 may also be arranged so as to be able to secure more than two wooden flanges 3, thereby permitting an elongate element 2 to be manufactured from several layers or strata of solid material and thereby also several layers of filler material 4. In an alternative form the casting moulds 1 may be arranged so as to be able to be fitted in the casting mould's 1 width direction, thus enabling the thickness of the filler material 4 to also be varied.

In figures 2 and 3 an arrangement 8 is illustrated for manufacturing elongate elements 2, where the arrangement comprises a circular base plate 9, on which base plate 9 a stay bar 10 is mounted for the casting moulds 1. At their lower ends the casting moulds 1 are pivotably mounted round the base plate's 9 circumference and at their upper part they are pivotably attached to the stay bars 10. The stay bars 10 are designed to suit several different dimensions of the casting moulds 1. Since the stay bars 10 are extendable in a preferred embodiment, the angle which the casting moulds 1 form with the horizontal plane will be able to be changed. This may be advantageous if the filler material 4 filled in the casting mould 1 has to have a faster or slower flow through the casting mould; by increasing the angle the casting mould 1 forms with the horizontal plane, the filler material 4 will fill the casting mould 1 more slowly, while the opposite will occur if the casting moulds 1 form a smaller angle with the horizontal plane. The circular base plate 9 is further arranged, for example, to be able to rotate in the direction of the arrow R, but may also be arranged to be able to rotate in both directions. The circular base plate 9 may be rotated by means of belt drive, toothed drive, etc. On the circular base plate 9, moreover, an outlet (not shown) for power, pneumatics/hydraulics etc. may be provided, to which outlet the casting moulds 1 can be connected.

In figures 2 and 3 moreover an embodiment is illustrated of the arrangement 8 for manufacturing elongate elements 2, where the arrangement 8 comprises 16 casting moulds 1 arranged on the circular base plate 9. It should be understood, however, that any number of casting moulds 1 may be employed, this number depending on which dimensions (length/width) the elements that have to be manufactured have.

The casting moulds 1 are furthermore only attached at their lower and upper ends to the base plate 9 and the stay bars 10 respectively, resulting in ease of replacement and/or maintenance of the individual casting moulds 1. This will also provide a more flexible solution when, for example, a new product with different dimensions has to be manufactured. In this case the "old" casting moulds 1 will be removed and the "new" ones installed, thereby enabling the arrangement 9 to manufacture elongate elements 2 in other dimensions and/or shapes.

In the illustrated arrangement 8 three work stations A, B, C are provided in connection with the "carousel", where loading and attachment of wooden flanges 3 in the casting mould's 1 box-like part 5 are carried out at station A. Station A comprises a store of different wood blanks and loading can be conducted manually or automatically by robot.

In their simplest form the wooden flanges 3 used in manufacture may be rectangular or square when viewed in cross section in the wooden flange's 3 longitudinal direction, but may be of any shape whatever. For example, the wooden flanges 3 may be provided with one or more recesses in the wooden flange's 3 longitudinal direction in order for the filler material 4 to achieve better bonding with the wooden flanges 3. When the wooden flanges 3 are fixed in the casting mould 1, the casting mould 1 is closed and locked. The "carousel" is then set in stepwise motion towards station B, i.e. in the direction of arrow R, until the next casting mould 1 has to be fed. The "carousel" will gradually rotate so far that the first casting mould 1 which was fed and closed reaches station B. Here a filler material 4 from a robot will be added to the lower end of the casting mould 1 , thereby ensuring that air located in the casting mould 1 is expelled from the mould. Excess filler material 4 will trickle out through one or more "air holes" provided near the upper end of the casting mould 1, whereupon this/these "air hole(s)" are sealed with a plug. The casting mould 1 is then pressurised and heat possibly applied, thereby causing the filler material 4 to set. The "carousel" will then be rotated stepwise towards a station C, where the ready-manufactured elongate element 2 is removed. Tests conducted with polyurethane show that the setting time in the casting moulds 1 should be from 4 to 8 minutes, depending on the strength required for the plastics material and the glued joint as well as which materials and/or connections are used. A robot A will attend to input and output of the stations A and B.

A preferred production plant is illustrated in figure 4, where two "carousels" can be seen using the arrangement 8. Between the two "carousels" a work station B is provided comprising a machine for filler material 4 which thereby supplies the filler 4 to each of the "carousels". Furthermore, the plant will comprise two work stations A, to which work stations A wood is supplied. A robot A placed between the "carousel" and a conveyor belt T will control both input and output of the "carousel". When the finished structural element is removed from the casting mould 1 , the robot A will place the structural element on the conveyor belt T, whereby the structural element is sent on to a temporary store M. At this temporary store M the ready-manufactured structural elements may either be packed for dispatch to the customer or they may be sent for further processing, for example to a finger jointing machine or the like and subsequently for packing and dispatch.

The invention has now been explained with several non-limiting embodiments. A person skilled in the art will appreciate that a number of variations and modifications of the arrangement and method as described may be implemented within the scope of the invention as defined in the attached claims. Even though the use of wood for manufacturing the elongate elements is mentioned in the application's description, it should be understood that other materials may also be employed. Furthermore, the manufacturing process may comprise fewer or more stations, where each station moreover may comprise more work processes than those described. It should be noted, moreover, that the arrangement and placing of the different elements illustrated in the figures are only intended to be examples. Other configurations and/or elements etc. may be employed, depending on which product is being manufactured.

Claims

1. An arrangement (8) for manufacturing elongate elements (2), characterised in that the arrangement (8) comprises a number of casting moulds (1) forming an angle with the horizontal plane and arranged in the form of a ring on a base plate (9), which base plate (9) is arranged to rotate past two or more work stations (A, B, C).

2. An arrangement (8) according to claim 1, characterised in that the base plate (9) is arranged to rotate stepwise.

3. An arrangement (8) according to claim 1, characterised in that the base plate (9) is arranged to rotate continuously.

4. An arrangement (8) according to claim 1, characterised in that in the lower end of the casting mould (1) there is provided a filling device for supply of filler material (4).

5. An arrangement (8) according to claim 1, characterised in that the casting mould (1) comprises a box-like part (5) and a lid (6).

6. An arrangement (8) according to claim 1, characterised in that the casting mould's (1) box-like part (5) is adjustable in the width, length and height direction.

7. An arrangement (8) according to claim 1, characterised in that in the upper end of the casting mould (1) there is provided at least one air hole.

8. An arrangement (8) according to claim 1, characterised in that the base plate (9) is driven by means of belt drive, toothed drive or the like.

9. An arrangement (8) according to claim 1, characterised in that on the base plate (9) are mounted extendable stay bars (10), which stay bars (10) are connected to the upper part of the casting moulds (1).

10. An arrangement (8) according to claim 1, characterised in that work station A forms an input station, work station B forms a filling station and work station C is an output station.

11. A method for manufacturing elongate elements (2), characterised in that the method comprises the following steps: - adapting the width of the casting mould (1) to the dimensions of the wooden flanges (3), loading and securing of the wooden flanges (3),

- closing the casting mould (1),

- stepwise rotation of the arrangement (8) for advancing and loading the next casting mould (1), - further rotation and loading of more casting moulds (1),

- filling filler material (4) in the first loaded casting mould (1),

- stepwise rotation of the arrangement (8) for filling filler material (4) in the next casting mould (1),

- further rotation and filling of filler material (4) in more casting moulds (1),

- applying pressure and heat in the first loaded casting mould (1),

- stepwise rotation of the arrangement (8) and applying pressure and heat in the next casting mould (1),

- cooling the first casting mould (1), - cooling subsequent casting moulds (1),

- discharging the first loaded casting mould (1),

- discharging subsequent casting moulds (1), and

- repeating the cycle with input of the first loaded casting mould (1).