EP3319784A1

EP3319784A1 - Method for forming an engagement portion in a workpiece

Info

Publication number: EP3319784A1
Application number: EP16735870.4A
Authority: EP
Inventors: Thomas Bettermann
Original assignee: Homag Bohrsysteme GmbH
Current assignee: Homag Bohrsysteme GmbH
Priority date: 2015-07-09
Filing date: 2016-07-06
Publication date: 2018-05-16
Also published as: RU2018104688A3; RU2726515C2; CN107848219A; RU2018104688A; DE102015212852A1; WO2017005782A1; US20180187707A1; US10443638B2

Abstract

A method for forming an engagement portion in a workpiece is provided, said workpiece preferably consisting at least partially of wood, materials containing wood fibres, wood composite materials, veneer, plastics materials and combinations thereof. The method has the following steps of: providing the workpiece having a cutout, introducing a predetermined volume of a curable filling compound into the cutout and introducing an engagement element into the curable filling compound, wherein the engagement element has an engagement structure which at least partially represents a geometric counterpart to the engagement portion, the engagement portion takes up a predetermined position in the workpiece, and the engagement structure is arranged at least partially in the filling compound.

Description

METHOD OF FORMING AN INTERCEPT IN A SINGLE

WORKPIECE

FIELD OF THE INVENTION

The present invention relates to a method for forming an engagement portion s, in particular a

Thread, in a workpiece, in particular of wood,

Wood fiber containing materials, wood composites, veneer, plastic and combinations thereof.

STATE OF THE ART

In furniture construction, it is often common practice, the

To prepare individual parts of a piece of furniture, which are then combined into corresponding kits, the

finally assembled on site. The workpieces used here are often at least

sections of wood, or wood fiber

containing materials and wood composites. Examples of this are chipboard or MDF boards

cited.

To assemble the workpieces are then the kit usually Verbindungsseiemente as screws for

Assembling enclosed in separate packs. At the

Assembly on site, these fasteners are then used at a suitable location. This procedure is disadvantageous for several reasons. On the one hand, the manufacturer of the furniture kit requires an additional amount of logistics to handle the

Unpack fasteners in appropriate packages and attach to the kit.

Furthermore, an increased workload is necessary when assembling the pieces of furniture, since the fasteners in the

Workpiece must be driven. Even if this is due to a pre-drilling on prefabricated. Workpiece is supported, it is necessary in the interest of the connection strength, however, a certain amount of force to set the fasteners suitable.

In particular, when the furniture is assembled by a private individual, there is often a lack of suitable tools as well as the necessary expertise to ensure a stable connection. Furthermore, according to this practice, it is inevitable that the precision in the

Assembly suffers.

If, for example, a screw is introduced as a connecting element directly into an at least partially made of wood workpiece, such as a chipboard, also the strength of the connection is not always guaranteed.

Especially with chipboard can often be observed the phenomenon that a screw rips out of its screw hole, or breaks out. While this may be limited by the use of suitable dowels, this, in turn, further complicates the

Assembly process as well as an increased need for logistics in the picking of the furniture kit by itself.

Furthermore, when assembling the piece of furniture there is a risk that the user confuses the attached fasteners and uses them in the wrong places. If the error is noticed, dismantling is often not easy possible, at least not without one at least partially

Damage to the workpiece or fastener to accept.

PRESENTATION OF THE INVENTION

The present invention has been conceived in view of the drawbacks described above, and it is an object of the present invention to provide a method comprising, in a workpiece, preferably at least partially made of wood, wood fiber containing materials,

Holzverbundwe fuels, veneer, plastic and combinations thereof, an engagement portion can be formed in the simplest possible way, moreover, ensures a secure engagement with a corresponding engagement element and facilitates the assembly of different workpieces by means of the engagement member.

For this purpose, the present invention provides a method according to claim 1. Further preferred embodiments are given in the dependent claims. Furthermore, the invention is to a manufactured by this method

Directed workpiece,

In particular, a method of forming a

Engagement portion in a workpiece, which workpiece preferably at least partially made of wood, wood fiber containing materials, wood composites, veneer, plastic and combinations thereof, the following steps: Provision of the workpiece with a

recess; Introducing a predetermined volume of a curable filling material in the Ausnehmu g; Pressing an engagement element having an engagement structure into the curable filler such that the engagement structure

at least partially disposed in the filling compound. Using this method can be easy on quietly

Engagement portion are formed in the workpiece, which is a "negative" of the engagement structure of the engagement element

represents. The formation of the engagement portion s works by simply pressing the engagement element into a curable filling compound and thus in a particularly simple and productive manner.

Furthermore, the use of a curable filling material and the impressing of the engaging element into the curable filling compound ensure that both between the workpiece and

Filling compound as well as between filling compound and engagement element a particularly durable and stable connection is formed.

The hardening of the filling compound produces a kind of toothing effect between the then at least partially hardened filling compound and the structure of the workpiece, into which the hardenable {that is the not yet hardened) filling compound penetrates. The penetration of the filling material into the structure of the workpiece is thereby by the impressions of the

Supporting elements supported in the filling material, which displaces the filling compound and partially in the

Structure of the workpiece forces.

A corresponding effect applies on the part of

Engaging elements in which. the filling material penetrates into or engages around and / or surrounds the engagement structure located on the engagement element. As a result, you get a very stable connection between the workpiece, filling material and engagement element. The connection Werstück-Fül imasse input element is thereby preferably one

Positive connection. Will be a suitable filler

used, in particular in the connection between the filling compound and the workpiece and a cohesive connection is conceivable. In this case, after the engagement element has been pressed into the filling compound, curing of the filling compound usually takes place without additional processing steps, solely by cooling the soft material through, the cool ambient air. However, it is conceivable that to speed up the curing process

For example, cooling air is applied or in

Depending on the material another hardening technique is used.

In addition to the perspective, a particularly durable

To create connection, the process opens the

Possibility to simply leave the engagement element (and the curing of the same) in the workpiece after insertion into the filling compound. Thereby, a workpiece is provided, in which the engagement element is already inserted. This can then be further processed and compiled, for example, to a furniture kit.

On site, the user then only needs to remove the engagement element from the. formed in the workpiece

Remove the engaging section. The user can then connect the workpiece, for example, with another workpiece, and fix the assembly by reinserting the engagement element in the engagement portion.

In this way, on the one hand, the logistics effort when assembling kits can be reduced. On the other hand, the likelihood of operator error is reduced, since this on the finished trained

Engagement portion with the correct, i. can fit exactly matching engagement element.

Preferably, the engagement structure is on the

Engagement element an (external) thread so that in the filling material or in the workpiece an {internal) thread is formed as an engagement portion. This has the advantage that the Engagement member simply and repeatably engaged with the formed in the filling compound engagement portion

brought and can be solved again.

Preferably, the engagement is learning after holding pressed into the curable filling material for a predetermined period of time in a predetermined position, preferably until at least partially curing the filling material.

This ensures that the intervention is in progress

Workpiece is formed at the desired position and in the correct orientation.

Preferably, the predetermined volume is such

set it to the. Volume of the recess minus the volumetric displacement of the engagement element in the

Filling mass corresponds.

This allows the volume of the filling material optimal

be set so that neither too much nor too little

Fill mass is used. Too much filling material would possibly cause the problem with it that the filling material swells out of the recess during the pressing of the engagement element and hardens in this state, which could affect both the material appearance and the further processing.

In addition, with regard to the predetermined volume, the proportion which penetrates into the workpiece when the engagement element is pressed in can be taken into account. This proportion can be added to the predetermined volume accordingly.

By considering the in the workpiece

penetrating proportion of the filling compound in the predetermined volume, the optimum filling quantity of the filling compound can be adjusted more accurately. The proportion of the filling material, which penetrates into the workpiece, depends essentially on the Structure, ie the porosity ,, of the workpiece. In a coarse particle board, a larger amount of filling material will penetrate than in a plastic composite plate.

The curable filling compound is preferably a pasty mass.

This means that the mass has a pasty consistency with a corresponding viscosity. This poses

on the one hand the simple processing of the filling material

especially when introducing the filling material into the recess safe and guaranteed on the other hand, that the curable

Molding material both the engagement structure of the engagement element and the structures of the workpiece optimally "flow around" or can penetrate into this.

The method preferably has regard to

Introducing the filler further comprises the steps of: feeding granules to an extruder and melting the granules in the extruder to form the curable filler.

The use of an extruder for feeding and for

Upon melting a granulate (i.e., to produce the granules)

hardenable filling compound) allows both a simple preparation of the filling compound with the desired properties as well as the targeted delivery of the same. By the

Processing a granulate will further be a simple one

Guaranteed storage of the starting material.

Preferably, the granules are granules which

Has wooden material.

In addition to the good availability is an advantage of such granules in the very good recyclability to look for.

Preferably, the curable filler is a

thermoplastic mass, which when heated in a thermoplastic state passes and when cooled

cures. The method then further comprises heating the filling compound before or during insertion into the recess.

A filling material made of thermoplastic material has the advantage of a simple processing. Furthermore, both in the not yet cured (curable) state and in the cured state, the desired

Material properties are ensured in terms of viscosity and strength. The step of heating prior to introduction of the filling compound can set a suitable viscosity of the filling compound so that it is both easy to process and has the desired flow properties for penetrating into the engagement structure of the engagement element and the structure of the workpiece. Thus, using the thermoplastic compound, a particularly secure engagement of the engagement element with the workpiece can be combined with the simplest possible processing.

Preferably, the thermoplastic materials are also biodegradable. Such can be, for example

thermoplastic polyesters, such as

Polyhydroxialkanoate,

Polyhydroxialbutyrate and polycaprolactone.

According to preferred embodiments, the curable filling compound can be designed such that this

Energy supply can be cured. Then the process has the additional step of curing the curable filler by supplying energy.

This energy may, for example, be thermal energy, the material then being exposed, for example, by laser,

Infrared or microwave radiation energy is supplied. By this energy supply, for example, a

Crosslinking process are induced in the material, whereby the filling material hardens. Furthermore, the curable filling compound may also be such

Be sure that they are energized by one

Raw mass can be formed. The method then further comprises the steps of introducing the raw material into the

Recess and the transfer of the raw mass in the curable filling material by energy.

The raw material can, for example, from a

Granulate be formed, which is introduced into the recess. Alternatively, a preformed "plug" in raw form can be introduced into the recess, which is then transferred by energy supply into the curable filling material.

Ultrasound or infrared action done.

The curable filling compound preferably comprises a mixture of biological polymers and natural fibers.

This has the advantage that all materials of the

Molding biodegradable, which is the recycling of the

Workpiece greatly simplified after use. If necessary uss then namely only the engagement element are removed and the workpiece with the engagement portion can be supplied to the recovery. The biological polymers or biopolymers can be prepared, for example, from sugar by fermentative and polymer chemical processes.

In particular, the biopolymer (the biological polymer) lignin, which, for example, directly from the

Woodworking can be won. To reinforce the cured filling material, for example

Reinforcing fibers such as wood fibers, flax, hemp, sisal, jute or other plant fibers may be present.

In addition, natural resin, natural wax, natural oils and cellulose may be present, with the aid of which, for example, the vi scolastic properties of the filling material and the like Hardening and softening can be adjusted. In addition, polyhydroxyalkanoates

Polyhydroxialbutyraten, polycaprolactone, polyester and / or starch.

According to a preferred embodiment, the

Recess further comprises a countersink on the workpiece, wherein the countersink is dimensioned such that in this at least the protruding from the recess part of the engagement member can be accommodated such that the engagement member does not project beyond the contour of the workpiece.

This has the advantage that despite the introduction of the

There are no protruding parts, which facilitates storage, packaging and transportation.

With further preference, the recess has an undercut with respect to the indentation direction of the engagement element into the filling compound.

This has the advantage that after curing the

Filling compound a particularly strong connection between the

Workpiece and the filling material is produced, since the hardened filling material through the rear cut like a barb acts in the workpiece.

Additionally / alternatively, in the walls of the

Recess a groove or a plurality of grooves may be formed in the workpiece, which extend transversely (in particular perpendicular) to the Eindrückrichtung of the engagement member and are cut into the walls of the recess. The grooves may be provided in parallel arrangement. Alternatively, a groove is formed thread-like or helically encircling.

This also makes it possible to promote a strong connection between the workpiece and the filling compound, since the hardened

Filling compound engages in the grooves. The grooves in the Urafangsrichtung the recess be formed in full or in sections.

Preferably, the engagement element is a screw, which further preferably has a countersunk or round head. The latter are for example advantageous if that with the.

Engagement element provided workpiece to be stacked.

Furthermore, it is preferred if the screw is a deep

Thread for example in the form of a self-tapping

Has thread, since the cured filling material can then get into good engagement with the screw.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C schematically illustrate the various steps of an embodiment of the method according to the invention, cross-sections being shown in FIGS

Different process stages are drawn.

Figures 2A to 2E illustrate developments of the method according to the invention by means of cross sections.

FIG. 3 shows a preferred embodiment of a device with which the method according to the invention

can be executed in a simplified form.

Figures 4A to 4D illustrate further embodiments in the form of cross sections.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Preferred embodiments of the present invention will be described below in detail with reference to FIGS accompanying drawings. More in this

Related modifications can be made respectively

be combined with each other to form new forms of training.

Figure 1 shows in the sub-figures 1A to IC the

As an example of the engagement portion in the present case, an internal thread to be formed on or in the workpiece 10 is an essential step of a method according to the invention for forming an engagement section in a workpiece 10

considered.

First, as shown in FIG. 1A, a workpiece 10 having a recess 11 is provided. In this recess 11, a curable but not yet cured filling compound 20 is introduced in the next step.

"Hardenable" in this case means that the filling material can change its viscoelastic properties by a process of aging so that it does not become viscoelastically when cured under normal conditions

Flow behavior more, u d also their shape at least in the load-free state (i.e., without additional external

Forces) does not change by itself. In the cured state, it is further preferred that the cured filling material either withstand the occurring stresses or break, i. in particular, no plastic flow in the sense of a

Increasing strain without increasing simultaneous stress (although limited elastic deformation under load may be desirable for some applications).

"Not yet cured" refers to a state in which the filler has viscous properties and can increase (ie, increase without substantial increase in stress) in the material without unduly long stress, but at the same time, it is preferred that the material be plastically deformed

Filling compound is not completely liquid, as this is the Incorporation of the filling material in the recess would complicate. The filling compound can in this "not yet cured"

(curable) state, therefore, e.g. as "pasty" or

It is particularly preferred if the viscoelastic properties of the curable

Fill mass state are set so that the filling material, at least until the introduction of the engagement element (until the onset of Aushärtevorgancs), for example, under the influence of gravity does not flow significantly. This makes it possible to process the filling compound "overhead" or on the inclined workpiece.

At the same time, it is preferred that the viscosity is at least initially so low that the filling compound can penetrate at least partially into the rough surface of the recess 11 in the workpiece and thus "intermesh" with the workpiece during curing thought of the often rough cut edges of chipboard.

For example, a viscosity range from 20,000 mPas to 100,000 mPas is suitable for the uncured filling material. However, other viscosities may be adjusted depending on the specific application.

When introduced into the embryo 11, the filling compound 20 has egg egg predetermined volume V. After introducing the filling compound 20 is in the not yet cured

Filling compound 20 an engaging member 30 is pressed. As shown by the example of the screw shown in FIG. 1C, the engagement element 30 has an engagement structure

(In this case, the external thread of the screw on), the geometric counterpart or negative z m in / on the workpiece to be formed engaging portion (present in

Internal thread) in the hardened filling material. Preferably, the recess 11 is limited at least bodensei t ig by the workpiece 10. The recess 11 shown in the drawings is milled into the workpiece 10, for example in the form of a straight circular cylinder.

However, any other shape of recess may be used as and when required (e.g. a cuboid recess or a recess with a generally polyhedral cross-section and a tapered recess).

The recess 11 in this case has a larger cross-section than the part of the engagement member 30 which in the

.Ausnahme is to bring (see Figure IC). It is preferred that the volume of the recess 11 is slightly larger than the part of the engagement member 30 which is to be arranged in the recess. This constitutes one

needs-based displacement of the filling material 20 sure when the

Engagement element 30 is pressed into the filling material 20 located in the recess 11.

By introducing the engagement element 30 into the filling compound 20, the engagement element 30 assumes a predetermined position with respect to the workpiece. In the present case, a case is shown in which the engagement element is arranged perpendicular to the surface of the workpiece. However, any inclined orientations are conceivable.

After curing, the filling compound 20 is the

Engagement element 30 then substantially fixed in the

predetermined position with respect to the workpiece.

In the case of the screw shown in the drawings as engagement element 30, the workpiece 10 together with the screw can now be packaged in a kit. At the place of

Assembly, the user has to unscrew only the screw 30 from the cured filling compound 20, in which by pressing and curing an internal thread (engaging portion) is trained. Thereafter, the workpiece 10 may be connected to a suitable counterpart (for example, another workpiece having a corresponding through hole) by screwing the screw (engaging element) back into the internal thread {engaging portion) formed in the workpiece.

This process is characterized both by a very high connection precision as well as by a particularly simple handle, since the user can resort to an already trained thread (engagement section}, and not only with increased effort a thread

{Engaging section) in the workpiece cutting (training) must. In addition, other screws and not only chipboard screws can be used with it, which if necessary

higher resistance forces against "tearing" or

Ensure "pulling out" and "breaking out".

In order to support an accurate assembly, the predetermined volume V is in the recess 11th

filled filling compound 20 preferably to be dimensioned so that it is substantially the volume of the recess 11 minus the volumetric displacement of the Eingriffseiements 30th

equivalent. This is illustrated, for example, in the transition from FIG. 1B to FIG. If the engagement element is then pressed into the filling compound, then the filling compound closes in

Substantially flush with the edge of the workpiece (see Figure IC). Any post-processing is eliminated. In addition, with regard to the predetermined volume, the proportion to be taken into account when pressing in the

Engaging element penetrates into the workpiece. This proportion can be added to the predetermined volume accordingly.

For some embodiments, however, deviating volumes may also be advantageous. For example, topping up the filling compound can cause the hardened Filling compound over the edge of the workpiece 10 is also, so it can fulfill the function of a "washer" or a spacer.

In turn, a volume V that is smaller than the volume of the recess 11 minus the volumetri. See

Displacement of the engagement member 30 is, sure

ensure that the engagement element in the Ausnehrcung can be sunk, or that no portion of the hardened filling material 20 protrudes beyond the edge of the workpiece 10.

Om positionally arranging the engagement member 30 in the predetermined position in the cured

To support filling compound 20, it is further preferred, the engaging member 30 in step IC while in the

to hold predetermined position until the filling compound 20 is at least partially cured.

In this context, it is further preferred that the viscosity of the curable, not yet cured filling compound 20 is formed such that, although an impressions of the

Engagement element 30 is easily possible, but one

lateral displacement or tilting of the

Engagement element 30 is difficult.

With regard to the material of the filling compound 20, it is preferred that the material is a thermoplastic composition that when heated in a thermoplastic state

goes over, and hardens on cooling.

Preference is given to heating to a temperature of 180 ° C to 220 ° C.

Consequently, a filling compound 20 with suitable

Properties are provided by the fact that the

thermoplastic filling compound 20 before introduction into the

Recess 11 is heated. The hardening of the filling by Cooling after the engagement element 30 has been introduced is usually carried out without additional processing step, solely by cooling the softened material by the cooler ambient air. However, the cooling of the filling compound can also be supported by a dedicated cooling step. This may include, for example, the inflation of cooling air.

Particularly preferred is a filling compound 20, which has a biopolymer which is characterized by biodegradability and is substantially bio-based, for example by fermentative and polymer chemical

Processes made from sugar. In particular, the biopolymer has lignin. Further, the material may include natural resins, natural waxes, natural oils, cellulose and natural reinforcing fibers, such as

Wood fibers, flax fibers, hemp, sisal, jute or others

Vegetable fibers, The material of the filling compound may furthermore Polyhydroxialkanoate, Polyhydroxiaibutyraten,

Polycaprolactone, polyester and / or starch. As a thermoplastic component in particular biodegradable thermoplastics b z w. thermoplastic polyesters used, such as Polyhydroxialkanoate,

Polyhydroxy butyrate and polycaprolactone.

Further advantages of this material include the good biodegradability and the possibility of resource-saving production. For example, it is even conceivable for the filling compound to be wood dust or wood flour of a preceding processing step

is taken. Further, when disposing of the furniture, the filling material need not be separately taken into account with respect to a recycling operation.

Furthermore, the filling compound 20 may also be designed such that it cures with the supply of energy. So is

for example, under heat input {chemical) Crosslinking filling 20 conceivable. The filling compound then preferably has two components, a base mass and a

Crosslinker, wherein the crosslinking reaction by

Heat input is activated. The necessary heating is then for example in a range of about 195 ° C. After this

Inserting the engagement element 30, the filling compound 20 can then be cured, for example, by irradiation with artery energy or (laser) light or the action of ultrasound energy.

A workpiece produced by the method illustrated in FIGS. 1A to 1C is thus characterized by a recess which is filled with a hardened filling compound 20 in which in turn an engagement section is formed which engages with an engagement structure of an engagement element. The engagement portion is the geometric counterpart (negative) to

Engagement structure and the engagement takes place in substantially complete positive connection.

If the screw 30 shown in the drawings is used as the engagement element, an arrangement results in which the engagement element 30 can only be removed from the workpiece 10 by pulling on the engagement element with great difficulty.

Test tests with an M8 screw and a chipboard showed that the arrangement according to the invention

Withstanding tensile forces that would far exceed the strength of conventional dowel joints. Usually such tensile tests ended with the destruction of the chipboard - and not with a failure of the cured filling material or a tearing of the cured filling material from the workpiece. This underpins the strength advantage achievable by the method according to the invention,

As a method for introducing the filling in the

Recess 11 has thereby supplying a granulate woody material, in particular a mixture of

biodegradable polymers and natural fiber, proven to be an extruder. The granules are then melted in the extruder to form the curable (not yet cured) filling material, which then hardens again on cooling.

In the present case, the inventive method was. Am

Example of a screw described as an engagement element.

However, other engagement elements are also conceivable here. For example, consider hooks which have external threads at one end. Also are

Engagement elements conceivable as intervention structures

(circumferential) grooves or projections (in particular circumferential annular projections). Are these suitably dimensioned and is the elasticity of the

hardened filling compound 20 adjusted accordingly, the Eingriffseiement after curing of the filling by

Pulling the Eingriffseiement be solved by the workpiece. The reconnecting is done by clicking on the

Engaging elements in the filling compound and snapping the

Engagement structure in the engagement portion of the cured filling.

In any case, after the finishing of the

Workpiece according to the inventive method the

Engagement element first in the engaging portion in the

Filling compound 20 and thus remain in the workpiece 10. For the

Furniture kit, if necessary, several such workpieces 10 assembled into packages and shipped accordingly.

Both in this case and in the storage of such a workpiece 10, however, a protruding engagement element 30 (see Figure IC) may be disadvantageous.

In such cases it is preferred that around the

Recess 11 in the workpiece one shown in Figure 2A Countersink 12 is formed. This results in a blind hole, in which the part of the engagement element 30 projecting from the actual recess 11 can be received in such a way that the engagement element 30 does not project beyond the workpiece 10. The reduction 12 and the Ausnehnmng 11 are then

dimensioned that the engagement member 30 in the

predetermined position does not protrude beyond the contour Ä of the workpiece 10. Thus, for example, a screw head of a screw 30 can be sunk for transport in the workpiece 10.

In Figure 2A, the counterbore 12 is considered to be in cross section

quade shaped depression shown. However, the recess may also be of conical cross-section with oblique sidewalls {see Figure 2C).

Thus, such is shown in Figure 2B

Workpiece characterized in that the workpiece a

Recess 11 which is potted with a cured filling compound 20, which in turn has an engagement portion with which an engagement member via a formed thereon engagement structure is engaged. Of the

Engaging portion is the counterpart (negative) to the engagement structure and the engagement takes place in substantially complete positive engagement. Further, a recess 12 is formed around the recess 11, which is dimensioned so that it can accommodate at least the protruding part of the recess 11 of the engaging member 30 such that it does not project beyond the contour A of the workpiece 10.

To further support the gearing between the filling material and the workpiece, the recess, as in

Figures 2D and 2E have shown an undercut 14 with respect to the Eindrückrichtung of the engagement member. In other words, the recess indicates. a portion which faces away in the Eindrückrichtung of the engagement member of the side, pressed from the engagement element ago is, a region having a larger inner diameter, as the portion of the recess, from which the

Engagement element is pressed. Such

Hi terschneidung 14 may take the form of an inverted

Cone vertical bore (Figure 2D) or a step section on

Transition to a section of increased diameter {FIG

2E) may be formed in the recess.

In the above method, the filling material

alternatively in a "raw state", for example in the form of granules or a preformed body in the

Recess 11 are introduced. In this case, the filling compound is designed such that, in particular by energy supply, it can be transferred from this raw state into the not yet cured state to form the curable filling compound. Thus, the filling material after the. Introducing the filling material in the raw state then be transferred in the recess 11 in the not yet cured state. This can be done for example by heating the filling compound or by ültraschalleinwirkung on the workpiece, which then not shown ultrasonic electrodes on the workpiece

can be created. As alternatives, heating may be provided in particular by hot air, laser radiation and microwaves, which may also be used in combination (possibly with the effect of the ültras). In case of

Laser radiation or microwaves, this can also by

Admixing be supported by polymers which the

Specifically absorb energy form.

Hereinafter, with reference to FIG. 3, an exemplary apparatus for carrying out the

inventive method described.

The device has a clamping device 120 for the workpiece 10. Furthermore, the device has a tool carrier 130, in which different tool heads 101, 110 and 140 can be accommodated. These tool heads include, for example, a boring / milling device 110 for mounting a workpiece in the workpiece 10

corresponding recess 11 {possibly including a reduction 12) form. Furthermore, the device has as a tool head via a holding device 140 for

Recording, holding and then discontinuing the

Engaging element 30.

Another tool head is through the

Application unit 101 given, with the filling compound 20 can be introduced into the recess 11. Im shown

By way of example, the application unit 101 has an extruder 103, which preferably conveys granular raw material while heating to an outlet opening 102. The raw material for the filling material can in a reservoir 105th

be stored, which is connected via a hose 104 with the extruder 103 in connection.

For ease of illustration, these tool heads 101, 110 and 140 are shown above one another in the apparatus shown in FIG. However, it should be noted that they can be accommodated in the tool head 130 with the aid of an exchangeable magazine, which is a change of the

Tool heads allowed. Furthermore, the tool carrier 130 can also be designed such that it also receives the tool heads for the respective method step individually from a separate magazine and after completion of the

step back into this step.

Preferably, the tool head 130 has a spindle unit for driving the drill / milling device or the extruder 103.

It is further preferred that the tool carrier 130 is designed as a so-called "five-fold tool carrier", which holds with respect to the held by the clamping devices 120 Workpiece can be moved and aligned in five directions. These directions can affect each other

Refer to longitudinal displacements along the three spatial directions and to rotational movements about two independent axes.

For this example, known structures such as systems with a five-spindle head and the like can be used. Overall, such a configuration has the advantage that the recesses 11 can be formed in a variety of geometries and positions on the workpiece 10, and also the filling compound 20 and the engagement elements 30 flexible

can be introduced or used.

Alternatively / additionally, it may also be provided that

Lerkstück 10 by a suitable device with respect to the tool carrier to move.

Furthermore, the device may have power sources 150 which are then designed to accommodate the

Apply filling compound with energy. This can, for example, for curing the filling compound after the introduction of the

Engaging elements or for transferring the filling material from a raw state in a not yet cured but curable state (which can then be cured} are used.

Such energy sources can for example

Infrared radiation, microwave or

Ultrasonic application devices exist.

The device may further include a not shown

Control unit, which is designed such that it first controls the formation of a recess 11 with a certain volume in the workpiece 10 and then calculated based on this volume of the recess, the predetermined volume of the filling material 20, which is to be introduced into the recess 11, wherein the predetermined volume V preferably so

is set, that this corresponds to the volume of the recess 11 minus the known volumetrisehen displacement of the introduced into the filling material 20 engaging member 30. Here, in addition, the porosity of the workpiece can be taken into account. Since the filling material penetrates into the pores of the workpiece, if necessary, an impact dependent on the porosity of the workpiece must be added to the volume calculated above.

As an alternative to the one described above

Five-fold tool holder 130, the device may also be designed such that the tool carrier 130 only in the X-Y and Z direction relative to the by the clamping devices

120 held workpieces 10 can be moved.

In addition, the workpiece 10 can also be transported by a conveyor, not shown, with respect to the tool carrier 130, in order to carry out the method according to the invention in one pass.

By the device described above and the

mentioned modifications, it is possible, the inventive method for forming an engaging portion in a

Workpiece easy to execute.

FIG. 4 once again schematically shows a number of possible embodiments in cross-section. FIG. 1 shows a recess 11 with countersink 12 after the hardenable filling compound 20 has been introduced. The amount or the volume of the filling compound 20 may be such that the

Countersink 12 after the introduction of the engagement element 30 is substantially completely filled with the engagement member 30 and the displaced filling compound 20 is filled (Figure 4B).

Alternatively, the volume of the filling compound 20 may also be so

be adjusted that little of the repressed

Filling compound 20 in the region of the reduction 12 swells (Figure 4C).

Finally, FIG. 4D shows an embodiment which again demonstrates the versatility of the method

clarified. Here holds a screw as Eingriffseiement 30 a cladding layer 15 on the workpiece 10. This is the Engagement element designed as a hood, which is guided through a corresponding through hole of the cladding layer 15. In the production is conceivable, the

Dressing layer 15 to prepare together with the attached thereto engagement elements 30, and then press as a whole so to the workpiece 10 that the engagement elements 30 penetrate into the filled with the not yet cured filling compound 20 recesses 11 in the workpiece 10. After hardening of the filling compound, the coating layer 15 is firmly attached to the workpiece 10. A conventionally necessary one

Screwing process of the workpiece 10 with the cover layer 15 is eliminated.

In that an engagement element whose

Engagement structure, so to speak, a negative or geometric counterpart of in the filling (or in the workpiece)

Trainee engaging sections is, in one in one

Recess 11 of the workpiece 10 cast, curable

Fill mass is pressed, after curing

Filling a machined workpiece are provided, which is particularly suitable for further use in furniture kits and is characterized by a secure and simple connection with an engaging element.

Claims

1, method for forming an engagement portion, in particular a thread, in a workpiece (10), which workpiece (10) preferably at least partially made of wood, wood fiber containing materials, wood composites, veneer, plastic and combinations thereof, the method being the following Steps:

Providing the workpiece (10) with a recess

(Ii);

Introducing a predetermined volume (V) of a hardenable filling compound (20) into the recess (11);

Pressing in an engagement element (30) having an engagement structure into the curable filling compound (20), so that the engagement structure (30) at least in the groove

Filling compound is arranged.

2, The method of claim 1, further comprising the step of holding the engagement member (30) after being pressed into the filling material in a predetermined position for a predetermined period of time, preferably until at least

partial curing of the filling compound (20).

3. The method according to claim 1 or 2, wherein the

predetermined volume (V) the volume of the recess (11) minus the volumetric displacement of the

Engaging elements (30) in the filling compound (20),

4. The method according to any one of the preceding claims, wherein the predetermined volume (V) of the curable filling compound (20) has a volume fraction which is determined by the porosity of the workpiece.

5. The method according to any one of the preceding claims, wherein the curable filling compound (20} is a pasty mass.

6. The method according to any one of the preceding claims, wherein the introduction of the filling compound {20} further comprises:

Feeding a granulate, preferably granules comprising wood material, to an extruder (103);

Melting the granules in the extruder (103) to form the curable filler (20).

7. The method according to any one of the preceding claims, wherein the curable filling material (20) is a thermoplastic composition which when heated to a thermoplastic state and cures on cooling, further comprising the step of

Heating the hardenable filling compound {20} before or at

Insertion in the recess (11).

8. The method according to any one of the preceding claims, wherein the curable filling compound (20) by supplying energy

can be cured, further with the step of

Curing the curable filling compound (20) by supplying

Energy .

9. The method according to any one of the preceding claims, wherein the curable filling compound (20) can be formed by supplying energy from a raw mass, further comprising the steps:

Introducing the raw mass into the recess (11);

Transferring the raw mass in the recess into the hardenable filling compound (20) by supplying energy.

10. The method according to any one of the preceding claims, wherein the curable filling compound (20) is a mixture of biological

Polymers, in particular lignin, and natural fibers, the natural fibers preferably being wood, flax, hemp,

Sisal, jute and / or other plant fibers are formed.

11. The method according to any one of the preceding claims, wherein the recess (11) is formed a countersink (12) in the workpiece (10), wherein the countersink {12) in such a way

is dimensioned that in this at least the from the

Recess (11) protruding part of the engaging member {30} can be received such that the Eingriffseiement (30) does not project beyond the contour (A) of the workpiece (10).

12. The method according to any one of the preceding claims, wherein the recess (Ii) with respect to the Eindrückrichtung of the engaging member (30) has an undercut (1).

13. The method according to any one of the preceding claims, wherein the engagement structure of the engagement member (30} is a thread.

14. The method according to any one of the preceding claims, wherein the engagement element (30) is a screw, wherein the screw preferably has a countersunk or round head,

15. The method of claim 14 or 15, wherein the screw has a self-tapping thread.