DE1628944A1 - Process and device for longitudinal milling of split logs and logs - Google Patents

Description

Dr.-lng. Wooden houses Patent attorney 4 <> August 1967

OFFENBACH AM MAIN Herrnstrasse 37 - Tel. 88 5642? 7Gr / cw

Ernest E. Eunnion, 828 Oota Street,

SheIton, Washington, USA.

"Procedure and door direction for longitudinal milling of billets or« round wood "

The invention relates to a method and a device for machining and in particular for profiling of logs or dogwood by means of a milling head, whereby the wood is given at least one surface, so that sizing wood is produced, and a new and improved chip is obtained as a by-product, which is used for Further processing into pulps is suitable. The wood to be profiled is moved along a straight feed path promoted, and the milling heads are in fixed workstations through which the wood

- 2 - 100813/0313

BAD OBiGiNAL

is passed through. The ones obtained during profiling Square timbers have four surfaces, two of which are parallel to the perpendicular and two parallel to the horizontal diameter of the wood, each flat Face is perpendicular to the neighboring faces.

When cutting chips from wood, it is known that less work is consumed by the prehead when the cuts are perpendicular to the grain than when the cuts are made parallel to the grain. In addition, cuts made parallel to the grain cause a certain degree of destruction of the chips, which does not occur if the cut is perpendicular to the grain. It is, however, to be generated at the chipping wood, wherein the square timber is not possible to make the diameter of the milling head at right angles to the longitudinal axis of the cut wood, because in this case a concave surface would be created on the wood. When a timber is to be processed for the stated purpose by means of milling heads, so that a timber is produced, which can be cut into suitable lengths, the surfaces generated by the rotating knives have to be flat. This has hitherto been achieved by arranging the cutting heads in this way

BAD ORiGINAL

, 109813/0313

that their axis of rotation is in the right Y angle to the The longitudinal axis of the wood ran

The invention is based on the knowledge that a milling head is not necessary to produce a flat surface cut parallel to the grain. A milling head that is employed in such a way that it is oblique to Grain cuts will also create a flat surface. In pursuit of this knowledge results see the task to determine the angle of attack, taking into account all circumstances gives the best results. For this purpose, extensive tests were made, with the milling head was kept adjustable in different angular positions, so that a cut under different Angles could be obtained, and this angle relative to the longitudinal axis of the wood from 0 upwards was adjustable, and this O ° limit the cutting head setting known devices called. There was a lower degree of destruction of the chips produced clearly observed, and this improvement progresses within certain limits with the increase in the angle of attack between the cutting direction and the longitudinal axis of the wood. At a cutting angle of 37 ° it will be destroyed

109813/0313

of the chips can hardly be observed any more and obviously does not occur at all at a yi angle of 45 °. According to the curves recorded during these series of tests, it was found that the power consumption drops considerably if the axis of rotation of the cutting head is set below 60 against the longitudinal axis of the wood (which corresponds to a cutting angle of 30 °), and that from this point downwards at an angle of attack of 45 ° the power requirement continues to decrease proportionally. There is only a small difference between the power requirement at this angle of attack of 45 ° and that with a further reduced angle of attack (i.e. ₀ with an increased cutting angle).

If you consider the utility value of the chips produced, which is just as important as the clean separation of the Chips from the wood, it was found that by turning the milling head, those produced during machining Chips take on a rhombohedral shape and, as a result, larger end faces with rising grain than is the case with the right-angled chips · With a chip with this rhombohedral Shape (i.e. a parallelepiped in which each of the six faces has the shape of a rhombus) runs the shape ~

.. ₅ _ 109813/0313

tion parallel to the planes in which the two side surfaces, and the level in which the upper and lower hache lie. These levels correspond to those along which the shear force initially "Kärtehen" the curved slices separated from the cutting head and then cut into chips »The respective angle of attack of the milling head determines the extent to which the rising The grain in the end faces of the rhombohedral chips exceeds that of the usual rectangular chips. This is of particular importance where the chips are used for the production of cellulose pulps and the like will.

The object of the invention is to provide an improved device and to create an improved method for profiling logs or round wood by means of pre-heads and to obtain suitable chips for further processing, which are better suited for this further processing than those produced with previous means "

The invention is explained in more detail below with reference to the drawings, for example , showing:

Figure 1 ι schematise !! a plan view of a

_ ₆ _ 109813/0313

of several milling heads in an arrangement according to the invention and a wood processed by this milling head,

ELg. 2, 3 and 4:

schematize]! partial views of the card-like pattern in which the disks produced with a milling head according to the invention disintegrate, for such a disk; the
The pattern shown applies only to the horizontal shear forces, with FIG. 3 in
broken lines a one: a chip is shown as an example of several chips of this type, in which each card is
parted; the illustration according to FIGS. 2 to 4 shows only the cutting pattern that results from the section of a single one extending over the entire length of the milling head
Knife results, while the milling head according to Fig. 1 results in a cut with several knives, which are arranged in the form of a helix and at equal angular intervals on the circumference of the cutting head ,

OWQiNAL

109813/0313

Figure 5 ϊ schematize !! an enlarged view of a map indicating the manner in which it is breaking up into chips j this view shows the vertical shear force pattern, the terms horizontal and vertical in this sense being relative and meaningful only if it is assumed that the disc was separated from either the top or the bottom of a timber.

In the drawings, a round timber 10 is shown, which is moved in a device for profiling along a rectilinear Yorschubbahn through one or more work stations in which saw cutting or milling heads are arranged. Each of these milling heads machined one of the sides of the log by creating a segment-shaped one Area separates from the wood, the separated wood accumulating in the form of chips. The milling heads run in the same direction an increasing cut to, namely in feed direction of the wood, and with a rotational speed that is matched to the feed speed so that the wood with each revolution of the braid to the desired Chip length is advanced. A suitable chip length

109813/0313

is for example 3/4 "

Preferably four pre-heads 11 are provided, each of which creates a surface 12 on the wood 10, with two of these surfaces parallel to one diameter and the other two surfaces parallel to one run on this perpendicular diameter of the wood. Each milling head 11 consists or can consist of one Number of discs 13, each of which carries a single knife 14. The disks are suitable fixed in their relative Vfinkellage to each other on the shaft 15, the knives in the circumferential direction of the Milling head are arranged at a distance from each other.

The milling heads can be arranged in pairs and continuously act on the transported wood, the two milling heads of each pair are diametrically opposite each other. According to the invention, the arrangement is the The axes of rotation of these milling heads are essential to the longitudinal axis of the wood being conveyed. As mentioned above, they are Rotation axes in the feed direction of the timber from one plane turned out perpendicular to the longitudinal axis of the timbers. This angle of attack is preferably 45 °.

" ⁹ " .109813 / 0313

Figures 2 to 4 show one of the curved disks from the top or bottom of a round timber be separated from the assigned milling head. It is indicated here how this disk 18 even broken down into "cards" or cards 20, namely under the flow of a horizontal shear force. Figure shows how each of these cards 20 is under action broken down into chips 21 by the vertical shear force. The terms 'horizontal' and 'vertical' shear force Naming the planes in which they act assumes that the disc 18 from the top or the Underside of the wood has been severed. In one of the cards 20 in FIG. 3, for example, is shown in broken lines such a chip is drawn, the front face in accordance with FIG. 5 with a and the rear end face is denoted by b. The two end faces, the surface and the lower surface as well as the two side surfaces delimit a body which is rhombohedral to the greatest possible extent, d. do one Parallelogram with oblique angles and unequal adjoining sides. The grain of the wood runs parallel to the planes in which the upper, the lower and the two. Side faces of the chip. Here the upper and lower surfaces represent the

- 10 - 109813/0313

- ίο -

planes of the horizontal shear force along which the disks 18 disintegrate into cards 20, while the Side surfaces represent the planes of action of the vertical shear force along which the cards 20 in chips 21 disintegrate. It can be seen that a rhombohedral chip has the advantage of making a Pulp used liquid to offer a larger surface with rising grain than a rectangular one Chip is the case »At a cutting angle of 45 °, which is denoted by χ in FIG. 3, this becomes Surface almost doubled.

The speed of rotation of the milling heads should be chosen in this way be that a cutting speed of no more than 7,000 fpm. (about 2100 m / min.) achieved will. At higher cutting speeds, abrasion or grinding of the chips is observed »When using With a milling head with a 15 "diameter, this cutting speed is achieved at 1,800 rpm Wood is advanced at 3/4 "per revolution of the milling head, so that chips of this length are produced the mentioned speed a feed rate of 112 fpm »(34m / min.) for the wood. The milling heads can of course also for two cuts per

_ _u _ 109813/0313

Revolution is formed so that then the feed rate of the wood can be doubled.

The depth of cut is obviously limited by the geometry of the prehead. The curved path covered by a knife must be laid relative to the wood in such a way that the knife falls below at least an amount which is equal to the amount of the advance of the wood, and the maximum depth of cut must therefore be smaller than the radius of the milling head. During operation, the depth of cut is limited to the order of 3 "to 4" by the power that can be effectively transferred to the milling head. The power requirement is directly proportional to the wood consumption. With conventional cutting devices, the maximum power requirement (depending on the type of wood) is 600 hp »sec. per cu. ft. (about 4.4 k \ 7h / nr). With conventional milling devices, a maximum power requirement of 400 hpi ¹ (2.95 kWh / m) was assumed. A milling head set at 45 according to the invention then has a maximum power consumption of 500 hp'sec. per eu "ft. (approx. 2.2 kWh / m-). For processing Douglas spruce, one of the lighter types of wood for chip production, the

- 12 -

109813/0313

BATH

Invention a power requirement in the order of magnitude

■ 2

from 150 hp'sec. per cu. ft. (about 1.1 klh / m) observed.

Let us point out further advantages of an inventive concept employed milling head pointed out. Milling heads that work with an increasing cut, where the The axis of rotation is perpendicular to the longitudinal axis of the wood, try the wood at a greater speed to drive than the feed rate. This property is particularly difficult to control for short woods with a small diameter, especially if the woods are wet. An employee according to the invention Milling head reduces this influence considerably. The laterally arranged milling heads, d. H. those, which produce flat surfaces on the sides of the wood, have the advantage that those of them in accordance with the invention Downward force exerted on the job reduces the pressure that must be applied, to keep the wood in its guideway.

The guideways can be designed in a known manner such that a twisting of the wood during the Editing is avoided. This can also be done through this

BATH ORIGINAL 10 9 8 1.1 / 0313

achieve that opposing 3 milling heads are driven in the opposite direction of rotation and when viewed from above on their arrangement with each other are aligned.

It can be seen that within the scope of the concept of invention other forms of execution are possible.

-H-

109813/0313

BATH

Claims (1)

Ί ϋ ^ b y 4 - - 14 claims 1. J device for the lengthwise milling of logs or round wood, whereby a flat surface is created on the log, characterized by a! guideway for the woods; at least one milling head arranged on the guideway, which is curved by these pieces of wood Slices of chips lifts off and its axis of rotation is set at an angle to the longitudinal axis of the wood is so that they are diagonal to the milling head; Means that a relative movement between the Generate wood and the milling head, with under -progressive Generating this flat surface a series of such slices are separated from the wood. 2. Apparatus according to claim 1, characterized in that the axis of rotation of the milling head (11) under a Angle between 45 ° and 60 ° relative to the longitudinal axis of the wood (10) is employed. 3 · Device according to claim 1, characterized in that the axis of rotation of the milling head at an angle is employed by 45 ° relative to the longitudinal axis of the wood. - 15 - ORIGINAL IfSISPECTED 109813/0313 4- · Device according to one of claims 1 to 3, characterized characterized in that the milling head (11) is arranged stationary, and that the wood (10) this are fed in a feed movement. 5 »Device according to one of claims 1 to 4» characterized in that a further prehead is provided, which is arranged opposite the first, and which has a flat surface on the Wood that is opposite the former and runs parallel to it » 6. Device according to one of claims 1 to 5, characterized in that over the circumference of the wood several milling heads are arranged. 7. Apparatus according to claim 5 or 6, characterized in that that opposing milling heads have opposite directions of rotation. 8. Process for the longitudinal milling of logs or round wood, by means of a device according to one of claims 1 to 7 »characterized in that a piece of wood in its Longitudinal direction on a straight feed path 9813/031 3 BATH is moved through a cutting station, the milling head being so arranged in the cutting station becomes that it eats its way into the wood in a rising cut and revolves around an axis that is arranged offset with respect to the longitudinal axis of the wood that the milling head with each revolution cut off at least one curved slice of a segment from the advanced wood and that this disc as a result of horizontal and vertical shear forces occurring along the grain disintegrates into a multitude of chips, which have the shape of rhombohedra, and that as a result continuous separation of such panes forms a flat surface on the wood. 9. The method according to claim 8, characterized in that the axis of rotation of the milling head is on a Y / inkel is employed between 45 ° and 60 ° relative to the longitudinal axis of the wood. Oo method according to claim 8 or 9 »characterized by draws that the wood rests against a guide surface during its feed movement, and that the milling head is arranged in such a way that it - 17 - 109813/0313 ten surface of the advanced wood separates and thereby exerts a force acting downwards and in the direction of advance on the wood <> 11. Wood chip, which is produced by means of a device or a method according to any one of claims 1 to 10, characterized in that it has the shape of a rhombohedron, the upper, the lower and the two side surfaces run parallel to the grain of the wood, and that the end surfaces Form oblique angles with the other surfaces. 109813/0313