DE3814589A1 - Method and apparatus for producing glued wood constructions - Google Patents

Abstract

In the method according to the invention, longitudinal hollows (2), the depth of which is no less than the thickness of the annual ring of springwood, are made in the surfaces of workpieces (1) to be glued. During the pressing operation, these hollows fill with glue, substantially increasing the strength of the bonded construction. The apparatus according to the invention includes a frame (3), to which a device (5) for feeding the workpiece (1) to a cutting assembly (6) is fixed. The knives (9) of the cutting assembly (6) are combined to form groups which are arranged symmetrically relative to one another and are mounted in housings (12) which are articulated on crossmembers (15) which are pre-mounted on the frame (3) of the machine. The housings (12) are arranged above and below the workpiece (1) to be worked. <IMAGE>

Description

The invention relates to a method and a device for the production of wood glue constructions and increased the gluing strength and the service life of this construction tion and accelerates the drying of lumber.

It is a process for gluing wooden workpieces known on micro-pegs in which to cut the micro tenon fine milling cutters can be used. This procedure takes place no application in industry because it doesn't succeed to achieve the required bond strength, as tooth shaped cones over the length of the workpiece impossible to cover can be brought.

Another method of making wood glue constructions are sawn timber in chambers up to one  Moisture content of 8 to 12% dried and by type and moisture content sorted. The workpieces are connected to strips of the required length along the length, the surfaces of the tapes to be glued are milled, spread with glue and put on top of each other in packages. These packages are in a press up to the glue polymer sation pressed and then mechanically to the products processed. However, this procedure does not guarantee uniform strength of the glue connection and generated Stress concentrations at the border glue-wood what have a significant impact on the life of the glue connections and consequently the glue constructions, esp especially with changing temperature and humidity has conditions.

They are from the company "Hübel und Platzer" (FRG) announced equipment for cutting micro-tenoners can be used. When cutting of hollows on the surfaces of sawn timber however, the cutters have a short life because of their Burning edges burn and wear during operation.

It is a device for making hollows known on the surfaces of sawn timber, on which II-shaped housing bottom arranged a damping plate is. There are right-angled screws on a tensioning screw in the housing Knife mounted, supported on the damping plate are. The disadvantages of this device include high energy expenditure for the execution of the hollows, because the arrangement of the knives on one axis ver pinching causes.

The aim of the invention is to overcome the disadvantages of the known ones  eliminate technical solutions and a process for Manufacture of wood glue structures to demonstrate that using a better glue strength of wood of common glues without much glue consumption guaranteed, as well as to create a device that is simple and has a high level of operational reliability with little wear on their cutting tools.

This object is achieved in that the method for the production of wood glue constructions, the chamber drying of sawn timber, subsequent glue application on workpieces, forms a package from machined work pieces and its pressing comprises, according to the invention longitudinally on the surfaces of the workpieces to be glued hollows are carried out, the depth of this off hollows not less than the thickness of the annual ring of early wood.

The hollows can be on the workpieces before or after the chamber drying of the lumber or appropriate be carried out during mechanical processing.

The hollows can be continuous or interrupted over the workpiece length with constant or variable Depth.

The hollows can also be variable or have a constant center distance over the workpiece width.

The device according to the invention has a frame with a table on which a device for feeding the workpiece is attached to a sectional unit, contains the boxes with knives, which with damping device directions are provided, with inventions in this machine  according to the knives of the cutting unit into groups are united, which are arranged symmetrically relative to each other and are mounted in housings, which are articulated on trusses are mounted on the frame of the machine, whereby the housing above and below the one to be machined Workpiece are arranged.

The housing mentioned are expediently with a Offset across the width and length of the work to be done To attach the workpiece.

The essence of the invention is as follows.

As is known, plywood gluing ( Fig. 1 to 3) can be stressed well on shear stresses that act in the plane of a glue joint. In the operation of wood glue constructions, shear stresses also arise, which act perpendicular to the glue line. These stresses are absorbed very poorly by the glue joint, and layers of the glued package occur. When making recesses or hollows on the surfaces to be glued, additional glue bonds are made that are perpendicular to the plane of the gluing. The stresses perpendicular to the gluing plane can be easily absorbed by these glue joints, which arise in wooden glue constructions under variable temperature and humidity conditions. According to the invention, the depth of the hollows should not be less than the thickness of the annual ring of early wood, so that a high-strength glue bond with a firmer late wood is ensured and a strong increase in the strength of the glue joint is to be noted.

In the manufacture of wood glue constructions after existing technology is applied to the surfaces to be glued applied a larger amount of glue than this for the manufacturer a glue joint of optimal thickness is required, to prevent possible incomplete gluing through. The excess amount of glue is released during the pressing displaced to the side surface of the package to be glued and further affects the production of wood glue constructions because they are editing the pages areas of construction difficult as well as the equipment and pollutes the air in the operations department.

According to the invention, there is no excess amount of glue expressed on the side surfaces, but it fills the hollows on the surfaces to be glued, by making additional glue bonds, which the glue strength and the lifespan of the wood glue cones structures are increased. There will also be the conditions improved for the processing of glue constructions, the equipment and air in the operations department are not contaminated, reducing the cost of the ventilation of the operating rooms is reduced.

Are the hollows on the surfaces of the workpieces were incorporated before the chamber was dried, carry them out for a better moisture removal the wood by increasing the area of moisture added; the duration of the chamber drying is ver reduces and consequently the performance of the wood drying chambers increased.

By varying the depth and arrangement of the hollows the discarding of wooden workpieces can be significantly reduced reduce and consequently the size of when milling the workpiece  reduce the layer of wood to be removed, resulting in a ver reduction of wood consumption in the production of Wood glue construction is guaranteed.

The method according to the invention can be carried out with a machine be carried out with the knives of the cutting unit are united into groups that are symmetrical relative to each other arranged and mounted in housings, which on Tra verses are articulated on the frame of the machine are mounted, with the housing above and below of the workpiece to be machined are arranged. Here are the housings with an offset across the width and length of the workpiece to be machined.

This makes it possible to work on the surfaces of the workpieces Longitudinal hollows without torn wooden sections execute and break the knife in the event of a sudden Change the wood density of the workpieces, e.g. B. in the area the branches, avoid the use of the equipment to expand and reduce energy consumption.

The glue strength of the wood is in use of the present invention increased by 30 to 50%, which a destruction of wooden glue structures on glue joints excludes and their lifespan especially when Operation under variable temperature and humidity conditions increased. Appropriately different wood types are glued. The invention allows the Chamber drying speed is 12 to 15% below simultaneous increase in drying quality through Ver reduction of the moisture gradient over the thickness of the Workpieces, through reduced discarding and bursting of Increase lumber. As a result, the invention can also  in the manufacture of carpentry products and construction elements wood.

For a better understanding of the invention, the following are the process for the production of wood glue constructions and a device for its implementation based on the Drawing described in detail. Show it:

Fig. 1 technology for gluing a package of workpieces that have longitudinal cavities with constant center spacing;

FIG. 2 shows the technology according to FIG. 1 with hollows which are designed with a variable center distance;

Fig. 3 shows the technology of Figure 1 with a variable depth of the hollows.

Fig. 4 is a processing device in a schematic front view;

Fig. 5 shows the device of Figure 4 in plan view.

Fig. 6 shows the structural design of the Schnittbaueinheit;

Fig. 7 is a damping device in cross section;

Fig. 8 is a section VIII-VIII in Fig. 6.

The method according to the invention for the production of wood glue constructions and the machine for its implementation can be used in various woodworking plants  find where from individual workpieces for the given Production required composite structures manufactured Need to become.

The device ( Fig. 4, Fig. 5) for carrying out longitudinal cavities 2 on the surface of the workpieces 1 comprises a frame 3 with a table 4 , a device 5 for feeding the workpiece 1 to a cutting unit 6 and a damping device 7 .

The device 5 for feeding the workpieces is designed as a caterpillar type. In the space between the feed device 5 and the cutting unit 6 , a guide device 8 is provided, the z. B. is in the form of sprung rollers. The sectional assembly 6 contains groups of knives 9 ( FIGS. 6 to 8) which are arranged symmetrically in individual boxes 10 and fastened with screws 11 . The boxes 10 are mounted in housings 12 which are articulated on axles 13 , are provided with springs 14 and are in contact with damping devices 7 .

The housing 12 with the boxes 10 are mounted on trusses 15 above and below the table 4 with a displacement over its width and length about the axis 13 . The cross members 15 are attached to the frame 3 and provided with a pair of screws 16 . The Dämpfungsvorrich device 7 is in the form of a compressed air cylinder 17 with a membrane 18 which is verbun with a piston rod 19 is the. The total width of the group of knives 9 is 10 to 20 mm larger than the width of the workpieces to be machined.

The device according to the invention has the following mode of operation.  

A workpiece 1 is placed on the table 4 in the feeder 5 . The feed device moves the workpiece between the upper and lower groups of knives 9 , the guide device 8 ensuring the orientation of the workpiece 1 in the transverse direction.

Under the action of the damping device 7 , the knives 9 arranged in housings 12 cut into the surfaces of the workpiece 1 at the top and bottom, wherein when the workpiece 1 moves over the table 4 on the surfaces of the workpiece 1, longitudinal cavities 2 are required for the technology to be used Cut parameters.

When the damping devices 7 are switched off, the housings 12 with knives 9 withdraw from the surfaces of the workpiece 1 into the neutral position under the action of the springs 14 .

During the pressing of the package of workpieces 1 ( FIGS. 1 to 3) with hollows 2 carried out on the surfaces to be glued, the hollows are filled with excess glue, which creates additional glue bonds which increase the strength of the glue connection of the wood. Glue leakage on the side surfaces of the package is eliminated, which improves the conditions for the subsequent processing of the package, reduces the wear of the cutting tool, reduces the development of gaseous toxic substances in the operating departments for the production of wood glue structures.

Below are concrete embodiments of the invention led.  

example 1

Production of a glued wooden beam for a cowshed.

The work pieces are made of lumber with a thickness of 40 mm before the chamber drying the manufacturing section to the end result in hollows on the surfaces to be glued fed where a woodworking machine is set up is. With the help of this machine, the surfaces of the Workpieces slit throughout their entire length or notch-shaped longitudinal cavities with a constant Center distance of 3 mm and a depth of 5-6 mm leads. Then the workpieces are sent to a drying department led where their chamber drying up to a moisture content of 10-12%. Then be the workpieces sorted by types and moisture content, connected over the length to form strips of the required length and to ensure appropriate surface quality milled.

After milling, remain on the surfaces of the workpieces Receive hollows whose depth is not less than that Thickness of the early wood layer is and in the present case 3-4 mm. Then the tapes become a package shaped that to the glue application line and then in the press is led. After the required treatment in the press related to glue polymerization, the glued package of the line becomes mechanical processing processing and finishing.

By using such a manufacturing process a wood glue beam made it possible to reduce the effort for  to reduce the chamber drying of wood by 15%, the Lifetime of the woodworking tool with mechanical Processing of the constructions to increase twice, the applications for the ventilation of operating rooms to reduce the manufacture of constructions and the Extend the useful life of the glue beams by 3 times.

Example 2

Production of a curved glued wooden bow for sports hall ceiling.

The work pieces are made of sawn timber with a thickness of 32 mm before the chamber drying the manufacturing section to the end lead to hollows on the surfaces to be glued fed where a woodworking machine is set up is. With the help of this machine, the surfaces of the Workpieces along their entire length cavities carried out with a variable center distance; on the workpiece edges, the center distance on the Width of 30 mm 3 mm, in the middle area of the workpiece the center distance across the width is 6 mm, the depth the hollows are 5-6 mm. Then the workpieces fed into a drying department, where their chamber drying up to a moisture content of 8-10% becomes; then the workpieces are sorted by types and Sorted moisture content, to tapes of required Length connected and milled. After milling remain on the surfaces of the workpieces with depths received from 2-3 mm. Then the tapes become a package shaped that to the glue application line and then in the press is led. After one for glue polymerization  required treatment in the press is glued Package of the line for mechanical processing and finishing processing fed.

By using such a manufacturing process from curved glued wooden arches, it became possible Lifetime to increase twice the effort for Chamber drying of wood to reduce the usage by 12% duration of the woodworking tool during mechanical processing construction to be extended twice, the Ventilation expenses for the operating rooms at To minimize manufacturing of constructions.

Example 3

Production of curved glued wooden frames for poultry Houses.

Chamber drying of the workpieces made of sawn timber with a thickness of 25 mm up to a moisture content of 6-8% made, after which the workpieces by types and moisture content sorted into ribbons along the length required length are connected, milled. Subsequently are interrupted longitudinally on the surfaces of the workpieces hollows made with a depth that is not less than the thickness of the early wood layer and in the present Case is 2-3 mm, the hollows with a constant center distance of 3 mm. Then a package is formed from the tapes, which is used to apply glue line and then into the press. To the required treatment in the press with the Glue polymerization related, the glued package the line for mechanical processing and finishing processing fed.  

By using such a manufacturing process from curved glued wooden frames it becomes possible Increase the lifespan of the wooden frame by 1.5 times, the service life of the woodworking tool at mechani shear processing of the constructions twice extend the effort for ventilation of the operating rooms in the manufacture of constructions.

Example 4

Manufacture of joinery products (windows and doors).

The sawn timber workpieces are dried before the chamber is dried the manufacturing section for making hollows fed on their surfaces. With the help of a wooden bear processing machine on the surfaces of the workpieces Continuous hollows along their entire length a center distance of 3 mm and a depth of 2-3 mm executed. Then the workpieces are in one Wood drying department fed where their chamber drying up to a required moisture content becomes. During the subsequent processing of the workpieces the excavations made are removed because of them Depth less than the thickness to be removed during milling Shift was.

The application of such a method of manufacture of carpentry products allows the expenses for chamber drying of wood by 12% and sorting out faulty carpentry products by reducing the warpage of the workpieces and reduce the bursting of the same by 20%.

Claims (13)

1. A process for the production of wood glue constructions, in which sawn timber is dried and machined into workpieces and in which the machined workpieces ( 1 ) are shaped and pressed into a package after applying an adhesive, characterized in that the surfaces to be glued Workpieces ( 1 ) longitudinal recesses ( 2 ) are made, the depth of which is not less than the thickness of the annual ring of early wood. 2. The method according to claim 1, characterized in that the slot or notch-shaped recesses ( 2 ) on the surfaces of the workpieces ( 1 ) are carried out before the chamber drying of the sawn timber. 3. The method according to claim 1, characterized in that the recesses ( 2 ) on the surfaces of the work pieces ( 1 ) are carried out after the chamber drying of the sawn timber. 4. The method according to claim 1, characterized in that the recesses ( 2 ) on the surfaces of the work pieces ( 1 ) during their mechanical processing leads out. 5. The method according to claims 1 to 4, characterized in that the recesses ( 2 ) are carried out continuously over the length of the workpiece ( 1 ). 6. The method according to claims 1 to 4, characterized in that the recesses ( 2 ) are interrupted over the length of the workpiece ( 1 ). 7. The method according to claims 1 to 6, characterized in that the recesses ( 2 ) leads out with variable depth. 8. The method according to claims 1 to 7, characterized in that the recesses ( 2 ) with variable Mittenab stand are executed. 9. The method according to claims 1 to 7, characterized in that the recesses ( 2 ) are carried out with a constant center distance. 10. Device for the production of wood glue constructions, consisting of a frame ( 3 ) with a table ( 4 ), on which a device ( 5 ) for feeding workpieces ( 1 ) is fastened, and a cutting unit ( 6 ), the box ( 10 ) with knives ( 9 ) which are provided with damping devices ( 7 ), characterized in that the knives ( 9 ) of the cutting unit ( 6 ) are combined in housings ( 12 ) to form symmetrically arranged groups, and that the housings ( 12 ) are articulated on trusses ( 15 ) above and below the workpiece ( 1 ) to be machined. 11. The device according to claim 10, characterized in that the housing ( 12 ) over the width and length of the workpiece to be machined ( 1 ) are arranged offset. 12. The apparatus of claim 10 or 11, characterized in that a plurality of blade housing (12) are mounted adjustably and pivotably on a respective transverse axis (13), wherein at each housing (12) a return element (14) and a resilient pressing member (7) attacks off-center. 13. Device according to one of claims 10 to 12, characterized in that the knives ( 9 ) adjustable in the respective housing ( 12 ) and are inclined forward to the cutting plane at an acute angle.