EP0519347A1 - Process and device for clearing or slitting a rigid sawn article - Google Patents

Abstract

A method and an apparatus are disclosed for separating or slitting a rigid material, in particular a piece of wood, having a modulus of elasticity of between 50,000 and 400,000 kg/cm2. A narrow tool having chip-removing elements, in particular a circular saw blade, produces a slot or kerf of finite width in the material at a cutting speed of more than 40 m/s. After the chip-removing elements having passed, a separator element bends a side piece out of the slot plane so that after the chip-removing elements have passed, the side piece is always at a distance from the tool. When viewed along the feed direction of the material, the separator element is provided with a hump at a distance from its periphery adjoining the tool and being first to come into contact with the material when the material is fed in. An imaginary connection line extending between the hump and the chip-removing elements is at a distance above a first portion of the separator element lying between the hump and the periphery.

Description

The invention relates to a method for separating or slitting a rigid material to be cut, in particular wood, with a modulus of elasticity of preferably approximately 50,000 to 400,000 kg / cm², in which a narrow cutting element has Tool, in particular a circular saw blade, creates a gap of finite width in the clippings at a cutting speed of more than about 40 m / s, and a side product after passing through the cutting elements by means of a wedge-like, fixed separating element out of the cleavage level in such a way from the main goods of the clippings is bent that the side goods are always at a distance from the tool after passing through the cutting elements.

The invention further relates to a device for cutting or slitting a rigid material to be cut, in particular wood, with a modulus of elasticity of preferably about 50,000 to 400,000 kg / cm², with a narrow tool having cutting elements, in particular a circular saw blade, which at a cutting speed of more than about 40 m / s attaches a gap of finite width in the clippings, and with a wedge-like, spatially fixed separating element, which bends a side product after passing through the cutting elements out of the splitting plane in such a way that the side product after passing through the cutting material Elements always have a distance from the tool.

A method and a device of the type mentioned above are known from WO 88/02683.

The following description is based on the example that wood is separated or slotted using a circular saw. However, it goes without saying that the invention is not restricted to this application, but also that other materials, for example plastics, whose elastic modulus is in the range described above, can be processed, and it is further understood that other tools than circular saw blades can be used, for example narrow span heads, band saws and. Like. more.

The known method and the known device have the sense to reduce the thermal load on the circular saw blade, which is caused by friction of the wood on the circular saw blade. In conventional circular saws there was always the problem that the cut wood was still on the rotating circular saw blade over a relatively long distance, with the result that considerable heat development occurred due to the friction between the circular saw blade and the wood. This deficiency has been eliminated by the known device and the known method.

Attempts have now been made in the known method and in the known device to further optimize the sawing behavior by developing a specific shape for the separating element. In the known device it has been proposed, for example, to design the separating element in such a way that its contact surface for the detached side board corresponds exactly to the natural bending line of the detached side board. In this way, one wanted achieve that the separated side board with constant pressure, viewed over its length, rests on the separating element.

However, in practical tests, especially in long-term tests in the range of several kilometers of sawing line, it has been shown that the shapes previously considered for the separating element are not yet optimal Show reachable. In the known shapes, the work of friction between the tool and the wood is already drastically reduced compared to conventional saws without a separating element, but if you use a saw with a separating element in long-term operation, for example, when sawing ten kilometers or twenty kilometers of running wood, you can the relatively low remaining friction work between the separated wood and the separating element lead to local overstressing on the separating element.

The invention is therefore based on the object of developing a method and a device of the type mentioned at the outset such that the remaining residual friction work between the separated side goods and the separating element is further reduced.

According to the method mentioned in the introduction, this object is achieved according to the invention in that when the cut material enters the tool, the side product is first bent with its tip at a smaller angle and then first with the tip and then over its entire further length at a larger angle that the side fabric after the transition to the larger angle maintains a space to the surface of a first, outer portion of the separating element adjacent to the tool.

According to the device mentioned at the outset, this object is achieved in that the separating element, viewed in the feed direction of the clippings, is at a distance from it adjacent to the tool and when the clippings run in System coming to the clippings circumference is provided with a hump, and that an imaginary connecting line between the hump and the cutting elements runs at a distance above a first section of the separating element lying between the hump and the circumference.

The object underlying the invention is completely achieved in this way.

The wood entering the tool is namely raised in the area of the tip of the cut-off side board at a smaller angle and bent relatively slightly out of the splitting plane. As soon as the tip then runs onto the hump, the side board is practically abruptly bent again by a further angle sign from the parting plane, this larger bending angle then being maintained for the entire further sawing of the continuously incoming cut material. The detached side board then only slides on the surface of the hump, while the area between the hump and teeth of the circular saw blade is spanned by the detached side board and, as a result of the distance that occurs there, there is no contact between the detached side board and the separating element.

If you consider that the feed speed in these applications is more than 1 m / s and the distance between the teeth and the hump, viewed in the feed direction of the material to be cut, may be a few ten centimeters, it becomes clear that the detached side board stays on the outer circumference of the separating element is only a few tenths of a second until the bump is finally larger.

The mechanical and thus thermal load on the outer areas of the separating element are therefore limited to minimal periods of time which have no effect in practice. Rather, it is achieved with the invention that the mechanical loading of the separating element is limited to the area of the cusp in continuous operation, the shape of which can be optimized from various points of view. Other protective measures, such as cooling, surface coating and the like. The like. Are easier in the area of the hump because the separating element is thicker there and is therefore more suitable for corresponding additional structural measures than in the relatively narrow peripheral edge of the separating element.

Practical tests have shown that the service life of a device according to the invention with a hump that is optimized in its shape comes in the same order of magnitude as the service life of conventional circular saws without a separating element.

In a preferred embodiment of the method according to the invention, the smaller angle is between 1 ° and 10 °, preferably it is 4 °. In contrast, it is preferred if the larger angle is between 3 ° and 12 °, preferably 6 °.

In the device according to the invention, exemplary embodiments are preferred in which the separating element is arranged on a circular saw blade and is essentially in the form of a circular disk. The area of engagement of the circular saw or the circular disk-shaped separating element then has the shape of a circular section.

It is preferred according to the invention if, viewed in the direction of advance of the material to be cut, three sections of the separating element adjoin one another in the engagement area. All three sections are preferably provided with a surface whose shape corresponds to a surface that is simply curved in space, the entire surface including a certain angle to the splitting plane, the radius of curvature of the surface extending perpendicular to the direction of advance of the material to be cut, and finally the curvature of the surface in one Direction within the gap plane, but decreases from the outside inwards perpendicular to the feed direction.

It is preferred if the first section has a first angle between 1 ° and 10 °, preferably 4 °, while a second angle of the second section is between 5 ° and 30 °, preferably 15 °. Finally, the third section preferably runs parallel to the parting plane, so that its angle of inclination is 0 °.

In this way it is achieved that the incoming side board is first bent with its tip on the first, less inclined section, then runs onto the second, much more inclined section and is finally bent at its upper boundary edge, namely the hump, for the further course becomes. The bending process is two-dimensional, on the one hand the side board is bent in the feed direction out of the parting plane, but on the other hand it is also bent transversely to the feed direction, namely in the direction of engagement of the circular saw blade.

With the shape of the separating element described, an optimal stability of the separating element, in particular of the bump in the transition from the second to the third section, is achieved.

This optimal shape is present in particular when the transition from the first to the second section is a line that runs perpendicular to the feed direction and / or the transition forming the bump between the second section and the third section has a linear course, the line being constant , third angle to the feed direction is inclined. Finally, an optimal effect is achieved when the transition and the bump intersect at the periphery of the separating element.

Practical tests have shown that this design leads to optimal results.

Further advantages result from the description and the attached drawing.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Fig. 1

eine Seitenansicht, im Schnitt, durch ein Ausführungsbeispiel der Erfindung, in der Ansicht der Linie I-I von Fig. 5;

Fig. 2

einen Ausschnitt aus Fig. 1, in stark vergrößertem Maßstab;

Fig. 3

eine Darstellung, ähnlich Fig. 1, jedoch für eine andere Phase eines Trenn- oder Schlitzvorganges;

Fig. 4

eine perspektivische Seitenansicht, stark schematisiert, auf ein Ausführungsbeispiel eines Trennelementes, wie es im Rahmen der vorliegenden Erfindung Verwendung finden kann;

Fig. 5

eine Draufsicht auf das in Fig. 4 dargestellte Trennelement;

Fig. 6

eine Seitenansicht in Richtung der Linie VI-VI von Fig. 5, jedoch in stark vergrößertem Maßstabe;

Fig. 7

eine Seitenansicht, entlang der Linie VII-VII von Fig. 5, ebenfalls in vergrößertem Maßstabe.

Embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Fig. 1

a side view, in section, through an embodiment of the invention, in the view of line II of Fig. 5;

Fig. 2

a section of Figure 1, on a greatly enlarged scale.

Fig. 3

a representation, similar to Figure 1, but for a different phase of a separation or slot operation.

Fig. 4

a side perspective view, highly schematic, on an embodiment of a separating element, as it can be used in the context of the present invention;

Fig. 5

a plan view of the separating element shown in Fig. 4;

Fig. 6

a side view in the direction of line VI-VI of Figure 5, but on a greatly enlarged scale;

Fig. 7

a side view, along the line VII-VII of Fig. 5, also on an enlarged scale.

In Fig. 1, 10 designates a circular saw. The circular saw 10 has a circular saw blade 11 which is provided with a flat section 12 in the region near the axis. With 13 a drive shaft for the circular saw blade 11 is indicated, and 14 is an arrow with which it is symbolized that the circular saw blade 11 rotates during operation.

In the vicinity of the periphery, the circular saw blade 11 is provided with a peripheral edge 15 of a type known per se and the function of which will be discussed further below. Finally, the circular saw blade 11 is provided with teeth 16 on its circumference in the usual manner.

Coaxial with circular saw blade 11, circular saw 10 is provided with an approximately circular disk-shaped separating element 20. With 21 it is indicated that the separating element 20 is fixed in space, i.e. does not rotate with the circular saw blade 11.

A peripheral circumference 22 of the separating element 20 nestles against the inside of the raised edge 15 of the circular saw blade 11. A first inclined section 23 leads from the circumference 22 inwards in the radial direction, to which a second inclined section 24 then adjoins. The second inclined section 24 terminates in a bump 25 at its upper edge. A third, flat section 26 then adjoins the hump 25 radially inward.

30 is a wooden profile, for example a model, as it is processed in conventional sawmill systems. An arrow 31 indicates the direction of advance of the wooden profile 30 in the illustration in FIG. 1 from right to left.

Due to the engagement of the circular saw 10 in the wooden profile 30, a thicker main article 32 remains, and a side article 33, for example a side board, is separated from the main article 32 on the side. The side fabric 33 consequently runs with its tip 34 or its underside 35 onto the first inclined section 23 and is thus separated from the gap 36 or the gap plane 37 turned. A pressure element is symbolized by 38, which can act laterally on the side goods 33 in the area of the gap 36 in order to avoid undesired advancement of the gap against the feed direction 31.

Fig. 1 shows the state in which the wooden profile 30 is just entering the area of the circular saw 10. As a result, the side goods 33 are initially only slightly bent with their tip 34 from the gap plane 37, because the tip 34 rests on the relatively less inclined first section 23 at the first moment of engagement.

The enlarged representation of FIG. 2 shows that the edge 15 of the circular saw blade 11 is provided with a run-on slope, the angle β of which may be in the range between 10 and 60 °. The upper edge of the edge 15 then merges almost continuously into the circumference 22 of the separating element 20. As already mentioned several times, this is inclined gently in this area, the corresponding first section 23 having an inclination angle α of preferably 5 °.

The arrangement can be such that an imaginary connecting line 27 between the upper edge of the edge 15 and the teeth 16 extends in continuation of the inclination of the first section 23, so that the tip 34 of the side fabric 33 with its underside 35 is just parallel to the connecting line 27 lies. However, it is also possible for the tip 34 to rest on the first inclined section 23 substantially in the region of its front end.

In any case, with further feed it is caused that the tip 34 of the side fabric 33 runs onto the steeper inclined section 24 after the first section 23 has been measured. Its angle of inclination Φ is preferably 15 °, it should be noted that the representations of Figures 1 to 3 as well as the representations of the other figures are not to scale, but rather exaggerated representations have been chosen for the purpose of better understanding.

If a state is reached according to FIG. 3 in which the tip 34 of the side goods 33 has passed over the hump 25, the side goods 33 as a whole is lifted off the outer sections 23 and 24 of the separating element 20, as clearly shown in FIG. 3 Shape of a space 40 can be seen. The side fabric 33 runs from the moment the tip 34 has passed the bump 25 in such a way that the bottom 35 runs in a connecting line 35a between the bump 25 and the teeth 16.

As clearly shown in the comparison of FIGS. 1 and 3, this means that when the wooden profile 30 comes in, the side goods 33 are only slightly bent at first, as long as the tip 34 runs on the first section 23 of the separating element 20. By driving over the second section 24, the side goods 33 are then suddenly bent by a defined, additional angular step, so that from now on the side goods 33 is bent at a larger angle out of the splitting plane 37, as indicated by an angle δ in FIG. 3 . The angle δ is preferably between 5 ° and 10 °. With this angle specification as with the other angle specifications, however, it is understood that these are only to be understood approximately and can be optimized in individual cases.

The shape of the sections 23, 24 and 26 is shown again in detail in FIGS.

FIG. 4 shows the separating element 20 as a whole, and it can be seen that it has an outer, flat area 50 which rises slightly conically inwards in order to pass into a reinforced flange area 51 there.

The engagement area of the separating element 20 is determined by an edge 52 which defines an area in the form of a segment of a circle. This area corresponds to a center angle Θ of, for example, 90 °.

As can be clearly seen from FIGS. 4 to 7, the sections 23, 24 and 26 lie somewhat below the flat area 50 of the separating element 20, which is manifested in a step 53 below the edge 52.

A linear transition 54 is located between the first section 23 and the second section 24, while the transition from the second section 24 to the third section 26 is formed by the likewise linear bump 25. The two lines intersect at the periphery of the separating element 20. In the plan view of FIG. 5 it can clearly be seen that the transition 54 is at right angles to the feed direction 31, while the bump 25 is inclined at an angle ε to the transition 54, wherein the angle ε is preferably about 15 °.

5 and 6, contour lines of those surfaces are now shown in FIGS. 5 and 6, which are formed by sections 23, 24 and 26.

It can be seen that the surfaces of the sections 23, 24 and 26 near the edge 52 are flatter and steeper towards the periphery of the separating element 20. This can be clearly seen from FIG. 7, where the profiles of the surfaces or the transition 54 and the bump 25 (again not to scale) can be seen in a side view. In the case of the bump 25, the radii of curvature R₁, R₂ and R₃ are shown in Fig. 7 near the periphery, in the middle and near the edge 52. The values of the radii of curvature R₁, R₂ and R₃ take inwards, i.e. towards edge 52.

Overall, this means that the side goods 33 are two-dimensionally bent out of the splitting plane 37 when they hit sections 23, 24 and 26, namely once over the inclination angles α and Φ in an upward direction from the splitting plane 37, but on the other hand also due to the curvatures of the surfaces of sections 23, 24 and 26 transversely thereto, ie around the feed direction 31.

Claims (14)

Method for separating or slitting a rigid material to be cut (30), in particular wood, with a modulus of elasticity of preferably approximately 50,000 to 400,000 kg / cm², in which a tool having a narrow cutting element (16), in particular a circular saw blade (15), in one Cutting speed of more than about 40 m / s creates a gap (36) of finite width in the clippings, and a side product (33) after passing through the cutting elements (16) by means of a wedge-like, spatially fixed separating element (20) from the splitting plane (37) is bent out of the main product (32) of the clippings (30) in such a way that the side product (33) is always at a distance from the tool after passing through the cutting elements (16), characterized in that the side product (33) when the Cut material (30) into the tool with its tip (34) first at a smaller angle (α) and then first with the tip (34) and then over its entire further length e is bent with a larger angle (δ), in each case relative to the feed direction (31) of the clippings (30), such that the side goods (33) have a gap (40) to the surface of a after the transition to the larger angle (δ) adheres to the tool adjacent first, outer portion (23) of the separating element (20). A method according to claim 1, characterized in that the smaller angle (α) is between 1 ° and 10 °, preferably 4 °. Method according to claim 1 or 2, characterized in that the larger angle (δ) is between 3 ° and 12 °, preferably 6 °. Device for separating or slitting a rigid material to be cut (30), in particular wood, with a modulus of elasticity of preferably approximately 50,000 to 400,000 kg / cm 2, with a narrow tool having cutting elements (16), in particular a circular saw blade (15) which is used in a Cutting speed of more than about 40 m / s creates a gap (36) of finite width in the clippings, and with a wedge-like, spatially fixed element (20), which a side product (33) after passing through the cutting elements (16) from the splitting plane ( 37) bends out of the main goods (32) of the cut material (30) such that the side goods (33) are always at a distance from the tool after passing through the cutting elements (16), characterized in that the separating element (20), in The feed direction (31) of the clippings (30) seen, at a distance from its circumference (22) adjacent to the tool and coming into contact with the clippings (30) when the clippings (30) run in. is provided with a hump (25), and that an imaginary connecting line (35a) between the hump (25) and the cutting elements (16) at a distance (40) above a first, between the hump (25) and the circumference (22) Section (23) of the separating element (20) runs. Device according to Claim 4, characterized in that the first section (23) is provided with a surface whose shape corresponds to a surface which is simply curved in space, the entire surface being inclined by a first angle (α) to the splitting plane (37), Furthermore, the radius of curvature of the surface is perpendicular to the feed direction (31) of the material to be cut (30) and finally the curvature of the surface decreases in a direction within the splitting plane (37), but perpendicular to the feed direction (31) from the outside inwards. Device according to claim 5, characterized in that the first angle (α) is between 1 ° and 10 °, preferably 4 °. Device according to one or more of claims 4 to 6, characterized in that the first section (23) merges via a linear transition (54) into a second section (24) of the separating element (30), that the second section (24) with a surface is provided, the shape of which corresponds to a surface which is simply curved in space, the entire surface being inclined by a second angle (Φ) to the splitting plane (37), and furthermore the radius of curvature of the surface perpendicular to the feed direction (31) of the material to be cut (30) runs and finally the curvature of the surface decreases in a direction within the splitting plane (37), but perpendicular to the feed direction (31) from the outside inwards, and that the second section (24) ends in the feed direction (31) into the bump (25) . Apparatus according to claim 7, characterized in that the transition (54) is a line which runs perpendicular to the feed direction (31). Apparatus according to claim 7 or 8, characterized in that the second angle (Φ) is between 5 ° and 20 °, preferably 15 °. Device according to one or more of claims 4 to 9, characterized in that a third section (26) of the separating element (30) adjoins the hump (25) in the feed direction (31), that the third section (26) has a surface is provided, the shape of which corresponds to a surface which is simply curved in space, the entire surface including a third angle with the splitting plane (37), and furthermore the radius of curvature (R₁, R₂, R₃) of the surface perpendicular to the feed direction (31) of the clippings (30 ) runs and finally the curvature of the surface decreases in one direction within the splitting plane (37), but perpendicular to the feed direction (31) from the outside inwards. Device according to claim 10, characterized in that the third angle is 0 °. Device according to Claims 7 and 10, characterized in that the transition between the second section (24) and the third section (26) forming the bump (25) has a linear course, the line being at a constant third angle (ε) to the direction of advance (31) is inclined. Device according to claim 12, characterized in that the third angle (ε) is between 83 ° and 73 °, preferably 78 °. Apparatus according to claims 8 and 12, characterized in that the transition (54) and the bump (25) intersect at the periphery of the separating element (30).

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