DE2722280A1 - Wood shaving machine cutter blade shaft - has magnetic force field acting on blade through groove bearing surface - Google Patents

Abstract

The blade is set sloping from the direction of revolution and fitting against a retainer groove surface in the blade shaft on a chipping machine for producing wood chips which has chip pockets running round lengthways in front of the plate-shaped cutting blade. It is covered from the opposite side by a clamping piece held where it cn be tightened on the shaft. A field of magnetic force is generated, at least in partial areas of the groove fitting surface (11), to act on the cutting blade (2) through this. The fitting surface may be provided on a separate bearing bar (8) let into the shaft (1), pref. made of magnetic material, to which permanent magnets may be fitted. This ensures that the blade fits firmly against the bearing surface, facilitating accurate setting.

Description

Knife shaft for metal cutting machines

for the production of wood chips The invention relates to a knife shaft For the production of wood chips, with in the direction of rotation in front of the plate-shaped cutting knife longitudinally attached chip pockets, the inclined to the direction of travel Cutting knife in a longitudinal holding groove of the knife shaft on a contact surface is in contact and is covered by a clamping piece on the opposite side, which is held securely on the knife shaft.

With knife shafts for cutting machines, as they are primarily in are used in the chipboard industry, it is known that the knife or knives to be mounted on so-called knife holders and outside of the knife shaft in one Voreinstellvorrichtunp knife setting, whereupon the knife holder with the or the knives in the knife shaft. However, this only makes sense if a knife holder can hold numerous individual knives, as is the case with upstream Scoring knives is the case. This already includes dismantling, adjusting and fastening the knife outside of the chipping machine is quite time-consuming. Especially for the bracket The use of separate knife holders is unprofitable for only individual cutting knives.

Individual cutting knives are therefore expediently directly into the Knife shaft inserted, adjusted there to the desired board and then Clamped over braces. Important is while that the knife is not is inserted too deep into the knife shaft from the start and that the rake face of the knife rests firmly on the support surface of the knife shaft so that the rewenschte Knife board is really achieved. Now it is difficult to curl knives remove any fine material such as chip dust adhering to them. If you have the clamping piece loosens, a gap is also formed between the knife and the knife shaft, into which the fine material can enter can penetrate.

If then there is no thorough cleaning, the new one comes in Cutting knife only with a distance on the contact surface that changes over its length for the system, and for the adjustment, belsplels wise with one on the knife edge Adjustments to be made, there are different protrusions of the knife edge over the circumference of the knife shaft.

From DT-Gm 76 07 045 it is known to open the knife after loosening the Clamping piece still to hold by a leaf spring on its contact surface, the holding force but it is too small there, and the leaf spring is set in such a way that the knife is light can tip out of its position, so that dirt, resin or wood dust is also easy there can get into the gap between the cutting knife and the contact surface.

The invention is based on the object of a knife shaft of a to design the above-mentioned type with a cutting knife that can be clamped directly in this, that the cutting knife is full and firm regardless of the action of the clamping piece so on its plant surface is kept that as little impurities as possible the contact surface 'can be effective and thereby the accuracy of the setting the knife edge is improved.

According to the invention, this object is achieved at least in some areas the contact surface a magnetic acting through this on the cutting knife Force field established. Since here the magnetic Krart lines are directly on the contact surface If you have to act, a full system is achieved over this entire area. Even with low magnetic forces, lifting across the contact surface is practical locked out. You can therefore confidently loosen the clamping device and only after careful cleaning of the area around the cutting knife, this surface on the system pull along, where the adhesive forces until complete release remain effective and prevent dirt from entering. Then, under certain circumstances, Another subsequent cleaning is carried out in the area of the system area and then a new cutting knife can be pushed along the contact surface. Even if In the meantime, small pieces of dirt have been deposited on the system surface or on the knife should have, these are reliably scraped off during the pushing-on process, so that a very precise setting of the knife edge in the specified position is possible is.

There are various options for applying a mapnetic force field known possibilities, for example the force field from the knife can affect the system affect the surface, for example by attaching permanent magnets to the knife itself. Then, however, the magnetic force also acts on the clamping piece, which makes the replacement process can complicate. It is also possible to have permanent magnets directly in the knife shaft to use. But close to the knife edge in the area of the contact surface Wear occurs, this area is expediently at a separate in the knife shaft recessed contact bar provided, which the magnetic lines of force can be transferred and exchanged as required.

The system bar can itself consist of magnetic material or be magnetized. Permanent magnets can also be attached to it, the large can be interchangeable again in order to bar when replacing the system to be exchanged.

The contact bar is expediently between the chip pocket and the retaining groove attached and protrudes like a cutting edge to close to the circumferential surface of the knife shaft before. In this way, the chip flow from the knife edge can be designed as desired and can be improved again in the meantime by replacing the system bar.

Since the assignment of the cutting edge of the system to the cutting edge of the knife of particular importance for sharpness of cut and chip flow, you can use the system Let the ledge sit firmly on the bottom of an angled groove.

The rind can be done with conventional regrindable knives with a thickness between 3 and 8 mm as well as with so-called disposable knives a thickness of 1-2 mm can be used.

In the drawing, an exemplary embodiment of the invention is for example shown, namely with 1 the knife shaft shown only in the section, for each of the blade-shaped cutting knives 2 to be used in the direction of the jacket extending chip pockets 3, a retaining groove 4 and separated from one another by means of steadies has an angular groove 5 in between. The chip pockets have a rounded one Bottom 6, which forwards the cut chip. This floor goes into a wedge area 7 an abutment bar 8, which sits firmly in the angular groove 5 on the bottom and with its wedge cutting edge 9 up close to the cylindrical peripheral surface 10 of the Knife shaft reaches. With their contact surface 11 for the cutting knife 2 protrudes the contact bar slightly beyond the associated surface 12 of the retaining groove 4.

In this holding groove 4 there is a clamping piece 13 above the cutting knife attached, the screw 14 on the head of the bottom of the retaining groove rests and is supported close to the groove bottom laterally via a leading edge 15. The clamping piece 13 is clamped directly against the knife shaft by means of screws 16 and therefore presses with its free end 17 in the area of the contact surface 11, the cutting knife 2 against the system 8.

In the area of the system surface 11 is between the system bar 8 and the cutting knife 2 set up a magnetic force field that is produced by the system is applied forth. For this purpose, permanent magnets can either be attached to the contact strip be attached, the contact strip can itself consist of magnetic material or be magnetized.

In any case, after loosening the tensioning screws 16 and possibly removing them of the clamping piece 13, the cutting knife on the entire system surface 11 full and firm held on the system bar. It can only be moved along the system surface 11 can be removed from the knife shaft and a new cutting knife can be installed After the initial installation on the installation surface, only move it along it. The magnetic Holding forces therefore form an extraordinary protection against the penetration of Dirt, wood dust, etc., and when you push on a new one Cutting knife any impurities that may have penetrated are largely scraped off.

This prevents uncontrollable and possibly changing Intermediate distances between the cutting knife and the system surface the knife edge 18 at Alignment with the alignment surface 19 of an adjustment bar brought into the operative position 19 ' 20 further than specified to the right in the drawing and thereby further protrudes over the circumferential surface 10 of the knife shaft. The cutting edge 18 can definitely do so be placed in the position specified for a certain chip thickness.

The contact bar 8 is fastened in the knife shaft by screws.

In the area of its wedge cutting edge 9, it is subject to the chip flow constant wear and tear and can therefore be considered a consumable item from time to time be replaced.

Claims (6)

Claims 1. Knife shaft for cutting machines for the production of Wood chips, running lengthways in the direction of rotation in front of the plate-shaped cutter attached chip pockets, the cutting knife inclined to the direction of travel rests in a longitudinal holding groove of the knife shaft on a contact surface and is covered on the opposite side by a clamping piece that can be clamped is held on the knife shaft, characterized in that at least in partial areas the contact surface (11) acts through this on the cutting knife (2) magnetic force field is established. 2. Knife shaft according to claim 1, characterized in that the contact surface provided on a separate contact strip (8) embedded in the knife shaft (1) is. 3. knife shaft according to claim 2, characterized in that the contact strip (8) consists of magnetic magnetizable material. 4. knife shaft according to claim 3, characterized in that on the Contact bar (8) permanent magnets are attached. 5. knife shaft according to claim 2, 3 or 4, characterized in that that the contact strip (8) is attached between the chip pocket (3) and the retaining groove (4) and protrudes like a cutting edge up to the circumferential surface (10) of the knife shaft (1). 6. knife shaft according to claim 5, characterized in that the contact bar (8) is firmly seated on the bottom of an angular groove (5).