FI123330B - Circular saw blade, blade element and blade unit - Google Patents

Description

Circular saw blade, blade element and blade unit

Background of the Invention

The present invention relates to a circular blade used in a chopper only, which comprises a disc-shaped blade body and has a plurality of teeth on the outer periphery. 5 Between successive blade teeth there are chewing spaces with bevelled edges. Further, the backs of the blade teeth have bevels for controlling sawdust.

A further object of the invention is a circular cutter blade element and a simple chipper blade unit.

The field of the invention is described in more detail in the preambles of the independent claims.

Sawmills cut sawn timber of different sizes from logs. In the first treatment step, the logs are fed through a chopper only, whereby the two opposite sides of the log are machined off the surface layer. By means of the chopper 15 only, the logs are shaped before the actual sawing, in the form of a rectangular saw blade, that is to say, of a simple cut. The chopper has at least two blade units on opposite sides, each comprising a saw blade and a chopper. The chopper can be equipped with vertical blade units and horizontal blade units. The saw blade cuts the surface of the log into the desired width, after which the chopping blades 20 chop the sawn piece into chips. The saw blade is typically a circular blade that gives the blade a good surface quality. The rotary blades used in chopping machines, the so-called the problem with front blades is that saw chips cause blade damage and reduce the quality of the saw.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a novel and improved blade chopper blade, a blade element included therein, and a blade chopper unit.

The circular blade according to the invention is characterized in that at the end of the sawing period there are larger chewing spaces than at the beginning of the sawing period.

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The blade element according to the invention is characterized in that the blade element of the invention has chewing spaces of different volume and that the blade surface has

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o at least one sawing cycle with a larger chopping space at the end than at the end of the sawing period.

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The blade unit according to the invention is characterized in that at the end of each sawing period the circular blade has larger chewing spaces than at the beginning of the sawing period.

The idea of the invention is that the volume of the bite in the circular blade is greater at the end of the sawing period than at the beginning of the sawing period. The size of the sawdust is thus dimensioned taking into account the amount of sawdust generated during the sawing period, which is at its highest before the chopping of the chips by the saw blade.

An advantage of the invention is that the rotary blade chewing facilities are able to receive better sawdust during the sawing period, especially at the end of the Salo sawing period. When the circular blade comprises correctly sized chewing spaces and when the formation of chewing is controlled, the blade teeth are less stressed. This allows the thickness of the circular blade to be reduced. In this way, large raw material savings can be achieved when the amount of bite is reduced due to the narrower cutting gap. When sawing with a thin blade, you get more than 15 chips, for a much better price than sawdust.

In addition, sawdust management improves the quality of the sawmill alone and thereby improves the quality of the sawn timber. Of course, high-quality sawn timber offers a better price than sawn timber, where sawdust penetrated between a circular blade and a saw blade has resulted in an uneven surface and 20 dimensional deviations.

Furthermore, by applying the solution according to the invention, the length of the chips can be increased, thus meeting the new demands made by the chippers' processors. The sawmill receives a higher price for long chips than for short chips.

The idea of one embodiment is that at the bottom of the chewing rooms the radial distance from the periphery of the circular blade is greater at the end of the sawing cycle than at the beginning of the sawing period. This increases the height of the blade teeth

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during the sawing cycle, without any change in the outer diameter of the circular blade. As the distance of the bottom of the purutha increases, the volume of the 30 puruthan increases at the same time.

| The idea of one embodiment is that the ends o) of the chewing rooms have a greater radius of curvature at the end of the sawing period than at the beginning of the sawing period.

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g By changing the radius of the curved base of Purutha can influence? puruthan the volume. The larger the radius of the base, the greater the volume of the purut 00 00.

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The idea of one embodiment is that the volume of the chewing rooms increases steadily during the sawing period. Thus, for example, the height of the blade tooth may increase linearly between the beginning and the end of the sawing cycle. Also, the radius of curvature of the bottom of the bite may increase steadily over the portion of the saw-5 cycle.

The idea of one embodiment is that the volume of the chewing rooms increases incrementally during the sawing period. Thus, for example, at the beginning of the sawing period, the height of the blade tooth may first remain constant and increase by one, two or more steps before the end of the sawing period. The radius of curvature of the bottom of the 10 puruthan can also increase in increments over the portion of the sawing cycle.

The idea of one embodiment is that the volume of the chewing space increases exponentially during the sawing period. Thus, the height of the blade tooth, after all, the radius of curvature of the bottom or both can be increased exponentially by the proportion of the sawing period.

The idea of one embodiment is that the circular blade comprises a single sawing cycle. Such a head blade is used when the chopper blade unit only has one chopper blade.

The idea of one embodiment is that the circular blade 20 comprises a plurality of cutting sections, for example two, three, four or more cutting sections. Such a head blade is used when the chopper blade unit has several chopping blades. The number of chipper blades directly indicates the number of sawing cycles.

The idea of one embodiment is that the circular blade comprises a blade body 25 on whose periphery the blade teeth are formed. The blade body is thus a single continuous circular plate.

The idea of one embodiment is that the circular blade comprises

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a blade ring having a substantially circular ring shape. The blade teeth are located on the outer circumference of the blade ring and their outermost tips form one outer diameter. The blade ring may have one, two, three, four or more sawing periods.

o) The idea of one embodiment is that the circular blade comprises

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g two, three, four or more steel segments having a substantially circular? the shape of the tire sector. The tooth teeth are located on the outer circumference of the steel segment and their outermost points are on the same arc of the circle.

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The idea of one embodiment is that one steel segment corresponds to one sawing cycle. Thus, the proportion of one steel segment has different volume chipping spaces.

The idea of an embodiment is that the thickness of the circular blade 5 is 4 mm or less. If the circular blade is formed of blade components, i.e. one or more blade elements, they also have said thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention will be explained in more detail in the accompanying drawings, in which: Fig. Fig. 4 is a schematic and side elevational view of a blade unit having a circular blade and two chopping blades, Figs. schematically and viewed from the side, a blade made of four blade elements and various possibilities for not a bottom-line photographer.

Some embodiments of the invention are illustrated in the figures

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^ for simplicity. Like parts are denoted by like reference numerals in the figures.

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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION g Fig. 1 is a structure of a chopper only in the longitudinal direction of log 1;

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30 as seen from above. The chopper comprises rotary blade units 2 with which the logs 10 can be shaped to form a substantially rectangular cross-section, i.e. plain. Each chopper unit 2 of the chopper only comprises a circular blade 3, and a chopping member 4 which may be conical.

The saw blade 3 first cuts a surface 5 of a desired width from the surface of the log 1, after which the cutting blades 6 fitted to the chopping part 4 cut the severed surface 5 into chips. The rotary blade 3 and the chopping blades 6 are connected to each other and rotate simultaneously when the blade unit 2 is used. Depending on the application, there may be one or more chopper blades 6. The portion of the circular blade 3 remaining between the chopping blades 6 is called the sawing cycle 7. Each time the chopping blade 6 cuts the face piece 5, a new sawing cycle thereafter begins.

Figure 2 shows a detail of the periphery of a circular blade having a plurality of blade teeth 8 comprising a face 9 and a spine 10. The tip portion 11 of the tooth can be sharpened to a cutting surface or alternatively the blade tip is provided with an interchangeable blade 12 both the backside surface 10 of the blade tooth and the bottom 14 of the chewing space 13 may have bevels 15a and 15b respectively, which extend from the outer edge of the blade to the side 3a of the chopping portion. The purpose of these bevels 15a, 15b is to deflect the sawdust out of the bottom of the debarking space. For the remainder of the sawing period, the sawdust may not always move well enough away from the chewing space, since the blade teeth are then between the sole and the surface and a lateral chewing flow is not possible. In the circular blade 3 according to the invention, the chewing space 13 is larger during the remainder of the sawing cycle so that it is able to receive sawdust which cannot move away from the chewing room 13. The distance L of the bottom 14 of the chewing room 13 may increase The graph P passing through the bottoms 14 of the burrows is indicated by a dotted line.

In the embodiment shown in Fig. 3, the radius of curvature R of the bottom of the chipping space is smaller at the beginning than at the end of the sawing period. The radius of curvature R can influence the volume of the chewing room 13, o There are other ways to arrange the volumes of the chewing rooms larger

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^ at the end of the sawing period. The rotary blade may have a variable tooth pitch. In this case, the spacing between the blade teeth can be arranged larger at the end of the sawing period than at the beginning of the sawing period.

| Fig. 4 shows a blade unit 2 comprising an annular blade rotary blade 3 and two chopper blades 6. The rotary blade 3 then has two saw coils 7a and 7b, each of which, for the remainder of the sawing period, has chewing spaces? 13 are deeper than at the beginning of the sawing cycle. Then the blade teeth ™ 35 have a greater height Ln at the end of the sawing cycles. The rotary drill 3 shown in the figure thus has two helical sawing cycles 7a, 7b.

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Figures 5a-5c illustrate, in a highly simplified manner, some construction alternatives to the rotary blades 3 according to the invention. Figure 5a shows a circular plate-shaped blade 16 in which the blade teeth are directly formed. Fig. 5b shows a circular ring-shaped cutting element 5 17 which can be mounted directly on a chopper, or it can be attached first to a disc-shaped chisel body and then to a chopper only. Further, the solution of the invention can be applied to the rotary blades of Fig. 4c comprising two or more circular ring sector-shaped blade elements 18a-18d. For the sake of clarity, Figs. 5a-5c do not show the blade teeth and chewing spaces on the outside of the saw blade. Figures 5a-5c further indicate the arrows 6 where the chopping blades enter when the circular blade is attached to the chopping part in the cutting unit. Figures 4, 5b and 5c further indicate the attachment surfaces KP, the cutting surfaces SP and the element body T of the cutting elements 17, 18.

Fig. 6 shows four sector-shaped blade elements 18a-18d from which the outermost portion of the circular blade 3 may be formed. The portion of the blade elements 18a-18d illustrates, by dotted lines P1-P4, different ways of arranging the depths of the chewing chamber bottoms. In the blade element 18a, the graph P1 illustrates that the bottoms of the chewing areas may change stepwise during the sawing period 7a. In the blade element 18b, the graph P2 illustrates that the distance of the bottom 20 of the chewing compartments from the periphery D may increase steadily during the sawing period 7b towards the remainder of the sawing period. In blade element 18c, graph P3 illustrates an exponential change in the depth of the chewing space. The blade element 18d illustrates known solutions in which the bottoms of the chewing compartments extend an equal distance from the outer edge.

25 It should be noted that one application of a chopper alone is a so-called "chipper" for sawing machines. a profiler which also comprises a circular blade and a knife for cutting. Thus, the matters disclosed in this application also apply to the profiling device.

° In some cases, the features described in this application may

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30 is used as such, despite other features. On the other hand here is the search | If necessary, the features shown in the present invention may be combined to form various combinations.

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The drawings and the description related thereto are intended only to illustrate the idea of the invention. The details of the invention may vary within the requirements of Patent ™ 35.

Claims (10)

A flat hacker's circular blade, comprising: a blade body with a side facing a chisel and a side facing the flat hacker; A plurality of cutting teeth (8) on the outer periphery of the circular blade (3), each cutting tooth (8) comprising a clamping surface (9), a back surface (10) and a tip portion (11) having a scoop separating surface; a sawdust space (13) between consecutive cutting teeth (8), the outer edge of said sawdust space (14) being curved; 10 bevels (15a, 15b) in the cutting surface's back surface and the bottom of the sawdust space, which bevels adjoin the side of the chopper blade (6); and wherein the tip portions (11) of the cutting teeth are substantially on the same outer periphery (D), the circular blade (3) having an outer diameter; and which circular blade (3) has at least one cutting period (7), beginning in the cutting direction (S) viewed after the cutting blade (6) and ending with the following cutting blade (6); characterized in that the end of the cutting period (7) exhibits greater sawdust space (13) than the beginning of the cutting period (7). Circular blade according to Claim 1, characterized in that the volume of the sawdust spaces (13) grows from the beginning of the cutting period (7) towards the end of the cutting period. Circular blade according to Claim 1 or 2, characterized in that the distance (L) of the sawdust spaces (14) from the tip portion (11) of the cutting tooth 25 is greater at the end of the cutting period (7) than at its beginning. 4. Circular blade according to claim 3, characterized in that the height of the cutting teeth (8) becomes helically larger in the section of the cutting period (7). O 5. Circular blades according to any of the preceding claims, characterized by a sign that X at the end of the cutting period (7) at the bottom radius (R) of the sawdust spaces (14) is larger than the bottom (14) of the sawdust spaces in the said cutting period (7) the beginning. O A blade element for a flat hacker's circular blade, which element comprises: a body (T) having an inner curved mounting surface (KP) for attaching a blade element (17, 18) and an outer curved blade surface (TP); provided with several consecutive cutting teeth (8); and sawtooth spaces (13) between the successive cutting teeth (8); characterized in that the blade element (17, 18) exhibits in the volume various Large saw-clamp spaces (13), and that the blade surface (TP) exhibits at least one cutting period (7), at the end of which there are larger saw clamp spaces (13) than in the saw-blade space. The beginning of the period (7). Blade element according to claim 6, characterized in that the blade surface (TP) exhibits at least one cutting period (7), on which the volume of the sawdust spaces (13) becomes larger when the blade element (17, 18) is viewed in the direction of cutting (S). Blade element according to claim 6, characterized in that the body (T) of the blade element (17) has the shape of a circular ring. Blade element according to claim 6, characterized in that the body (T) of the blade element (18) has the shape of a circular ring segment. A flat chopper blade unit, comprising: a circular blade (3), with which a surface piece is said to be detached from a log; at least one chopper blade (6), with which said chisel surface is chipped; and wherein the circular blade (3) and the chopper blade (6) are coupled to each other and arranged to rotate simultaneously in the direction of sawing (S), the circular blade (3) having at least one cutting period (7) beginning in the direction of sawing (S). viewed after the hacking blade (6) and ending with the following CNJ ^ hacking blade (6); ° and wherein the circular blade (3) comprises on its outer periphery several cutting teeth (8), the tip parts (11) of which form the outer diameter (D) of the circular blade, and wherein | between the consecutive cutting teeth (8) are said tensioning spaces σ> (13); CD g characterized by? the end of each cutting period (7) in the circular blade (3) has larger saw gap spaces (13) than the beginning of the cutting period (7).