SE431622B - PROCEDURE AND DEVICE FOR PROCESSING OF TEMPING STOCK - Google Patents

Description

15 20 25 30 35 40 8Û09156-4 wood pieces. b) Crookedness, strong twigs, ovality, etc. in the logs lead to an increased proportion of pieces of wood that must be discarded.

Through the introduction of the reducer sawing method, which will be explained in more detail below, a considerable improvement in the sawmill technique has been achieved by the fact that during the flat milling of the logs in the reducer their outer parts, which would otherwise form so-called bakes, immediately reduced to chips. Despite this, some problems remain unresolved, as about 50-70% of the outer boards, which are produced in the saw after the face milling in the reducer, due to their deformity must be discarded before they reach the edging, or at the latest in the edging. However, sorting out after the face milling in the reducer requires extra manpower.

It has already been proposed in German patent application P 29 47 993.4 resp. in the corresponding Swedish patent application 8008297 to take into account the conical shape of the logs, tapering from the root to the top end when processing logs in a reduction saw machine, by continuously sensing the width of the log during feeding by two sensor pins which cooperate with a hydraulic or pneumatic device in such a way that when the side felling of the chip cutting tools becomes so large during the machining process that an extra side board can be obtained on each side of the log, the distance between the chip cutting tools during the machining process or the passage through the chip device is increased by double board size. double the cut joint thickness. This achieves that wood material that would otherwise have been transformed into inferior wood chips becomes an extra side board on each side of the reduced log. However, not all extra sideboards obtained in this way are useful, as some of them must be discarded, and then this procedure is more complicated and costly than when the respective volume of wood would have been cut from the chip cutting tools (reducer discs) from the beginning. In order for a board to be acceptable, it is not sufficient that it has a prescribed minimum thickness, but it must also have the prescribed minimum length and minimum width. By the said method 10 15 20 25 30 35 8lf§tl9156-4f 3, three types of products are thus obtained from the side portions of the log: chips, acceptable extra side boards, and substandard extra side boards (eg only 10 cm long and / or 2 cm wide in the bleach) which must be sorted out, removed from the production line and chopped separately into chips in any device other than the reducer. In addition, it may happen that a log e.g. due to its irregular shape can give a longer extra side board on one side than on the other, which, however, is not considered according to this method.

The object of the present invention is to provide a method and a device which allow that only two kinds of products are obtained from the side portions of the logs, namely chips and only acceptable extra side boards, and that in addition an extra side board of maximum possible length is obtained on each side of the log. , regardless of what is possible on the opposite side of the log.

This avoids the need to sort the obtained extra side boards and in a special work operation chop the substandard extra side boards into chips. In addition, the maximum possible yield is achieved as the extra board obtained on each side of the log has the maximum possible length.

This task is solved in accordance with closely related patent claims. According to the invention, the outer contour of a stock, seen in plan view, is first determined, as well as its position in relation to a reference line. A number of devices for profiling a piece of timber are known and described in the patent literature. A simple measuring device for this purpose is stated later in the present description. The reducer discs are then set so close together that from the first cut at the narrower top end of the log they begin to face a side surface on each side of the log which along its entire length is fully acceptable as a board's flat limiting surface, ie is free from waist and nowhere below the established minimum bleach width.

However, since the diameter of the log gradually increases from the narrower top end to the wider root end, as well as at the root end of the log, so much material might be milled away that it would suffice for an extra outer board, albeit shorter than the entire log.

There is a standardized minimum length for usable boards, for example 1.8 m, while the logs themselves have a considerably greater length, for example 4 m. Should the outer outer board be shorter than the minimum length, it is indicated that it is actually milled away, ie chopped into chips by the reducer discs. However, if it were to be longer than the minimum length, according to the present invention the reducer plate is moved outwards on each side by a predetermined distance (selected thickness of the extra outer board plus the saw joint width) and the log obtains a side surface with a step or ledge.

The outermost saw blade then separates in the usual way the shorter extra board after the ledge from the rest of the b10Cket_ The process can possibly be repeated.

All calculations necessary for the above-mentioned control modes are performed in a conventional manner in an electronic evaluation and control unit on the basis of data entered therein, with the result that either no control signal for conversion of one or the other reduction disk is generated, or that such a control signal is generated when a longer distance than the minimum length remains to be planar reduced on the respective stock side. As a result, all the peripheral log parts, which in the end still have to be cut, have been converted into chips directly during the plan reduction, while all the peripheral log parts of which an acceptable outer board of at least minimal length can be produced have been recovered. Name fl å fi ävåtå fl d mßd Which reducer plate is moved outwards can also be determined during the calculation phase in the evaluation and control unit where an optimization of length, width and thickness dimensions of a possible extra outer board is achieved by means of one for this purpose on pre-entered program.

The invention will now be explained in more detail with the aid of close-closed schematic drawings in which part of a conventional reducer sawing machine in which a log is machined is shown in plan view. Fig. 2a and 2b show two typical outer boards with defects which can be obtained in this case, in Fig. 3 the geometric quantities which are important for the present invention are shown by means of a log cross-section and a schematically produced reducer sawing machine. Fig. 4 is a flow chart of the method according to the invention, Fig. 5 shows in plan view and on a smaller scale than in Fig. 1 a machine according to Fig. 1 device of the present invention, and Fig. 6 is a functional diagram of the electronics unit in the device according to Figs. 5.

Fig. 1 shows a reducer sawing machine according to Swedish patent specification 338 497 comprising a reducer part 50 and a saw part 40 with a common center line. A log l0 with a center line Qâ shall be plan-reduced at both its sides and then broken into several parts. The log 10 is fed on a conveyor 13 in the direction of the arrow between two chipping cutters 12 which mill away and 10 "which otherwise, ie when machining only on the saw, cutting or reducing discs 11, would chop the outermost log portions 10 '. form bakes that must be separated and chopped.

The reducer discs 11, 12 are located on each 12a which is driven by an electric motor (not shown). Conventionally, the reducer discs 11, 12 are set 12a in the longitudinal direction (double for removal from each other when one has its drive shaft 11a, only in its drive shafts 11a, the arrows B) e.g. new logs must be received, shortly after which they are returned to a predetermined and during the entire reduction process unchanged distance 1. Between the reducing discs 11, 12 and the sawing plant 40, flat guide means 23, 24 are arranged which can also be moved from and towards each other.

After leaving the reducer discs 11, 12 and passing the guide means 23, 24, it enters a block 10a with the width I reduced log with its feed end 10 in a connected band saw laying 40 SOm in the example shown comprises four conventional band saws of which in fig. The saw bands 14, 15, 18, 19 can be seen running over rollers 14a, 15a, 18a, 19a arranged on each shaft 14b, 15b, 18b, 19b, while in Fig. 1 only the inner branches 14 ', 15', 18 of the saw bands are visible ', 19'. In the sawing plant 40, the block 10a is sawn into a so-called center replacement 22, two inner boards 20, 21 and two outer boards 16, 17 separated from each other by saw grooves (saw joints) 20a, 2la, 22a, 22b.

The outer boards can in this case have an appearance according to Fig. 2a or 2b, where dashed contour lines show the parts which according to the present invention will be milled away, while in a conventional reduction sawmill they would remain at the width of the board. 10r, an outer board is generally adequate, however, next to the top end 10i it often has areas Q where the prescribed minimum bleaching width is below. slides, or areas E with a so-called waist. According to the present invention, the substandard parts are milled away, in a manner which will be explained in detail later, and after a taper or ledge E where the width E increases in steps, areas 5 are obtained from which an extra outer board can be made if of the entire length of the log l a full piece at least with a predetermined minimum length mmi remains. The present invention thus solves the task of producing only perfect outer boards, while log parts such as Q, E, which would result in incorrect outer boards, are chopped to pieces before leaving the reducer sawing plant, i.e. in the same way as hitherto in conventional reducers only with the bakers, ie the log parts 10 'and 10 ". Fig. 3 shows a cross section through the log 10 along the plane III-III in Fig. 1. The cross section is for the sake of clarity inverted by 900 so that it lies in the plane of the drawing, and all future section lines are drawn in the cross section.

The reducing saw machine is shown in a slightly modified design where the saw part 40 is close to resp. inside the reducer part SQ, whereby the construction length of the plant is shortened and special control means 23, 24 (Fig. 1) between these two parts can be omitted.

The distances from the center line of the machining machine 40, 50 to the two outermost lateral points of the log are xl and xz and are measured in the above-mentioned profile pick-up arrangement. The width of the bleach is hl resp. , while sl and sz are distances from the center line 2 go to the inner edge of the outermost saw blades l4 ', l5'. The distances sz are determined from the so-called the position program. The values toe and toe lying Sågf09är 20a, 2la. With yl and yz the thickness sl is indicated, thicknesses on outer boards 16, 17 incl. inside on the bakes l0 ', 10 "(fig. 1) which are milled away by the reducer discs ll, l2. From fig. 3 it appears that between the said quantities the following relations apply: xl = yl + tl + sl ..... ................................. (la) x2 = yz + t2 + sz ....... ............................... (lb).

From Fig. 4 it can be seen that according to the method according to the invention the values x1 and x2 are first measured, which takes place in some known device for this purpose target network results are input to an electronics unit which is also of a type known per se.

This electronic unit is programmed to carry out the operations according to Fig. 4 and for this purpose the values hminl and h have been entered in the unit for the minimum permitted bleaching width (in general2 unit hm h applies here. When one or other inl = m1n2) '. the reducer disc is to be stepped out, it means that it is moved away from the center line going to a position ll 'or 12' (fig. 3).

When one of the dimensions xl, xz exceeds a certain value, the log-reduced outer surface of the log, which at the same time constitutes the outer planar surface of the outer board, becomes narrower than what the predetermined minimum dimension hm for the bleaching width requires (for example 75mm). The reducer plate 12 remains in its inner position and all wood from which an incorrect outer board would be formed is reduced away. As soon as the distance of the reducer disc from the center line gg falls below said critical value (the dimensions x1 X2 increase I 8969156-4 l0 15 20 25 30 35 (A in step with the feed of the log, since the diameter of the log (x1 + X2) increases the closer one gets to the root end) and at the same time, the remaining, unreduced log length E according to Fig. 2a corresponds at least to the determined and entered minimum dimension mmin in the electronics unit (Fig. 2), the reducer plate 12 is stepped out, suitably after a certain pre-programmed delay, and a blank is obtained. The log length is obtained in the electronics unit by single subtraction 1: 2, s and the reduction disk 12 is concerned. The remaining m = 1 - 1 '(z) where l, ll and m represent the quantities shown in Fig. 2b , of which 1 has been input to the electronics unit 100 before, the work shift, and 11 has been calculated by means of the signals input via lines d1, d4 (Fig. 3) partly for the passage of the top end past the optical latch 38, 39, d els for the conveyor speed 13 of the conveyor.

If a waist E (Fig. 2b) is present at a shorter distance from the root end 10r than the minimum dimension mmin, the reducer disc always stays at its inner position. The following three cases may occur, for example: A) A certain length ll from the top end 10i, the reduced block 10a will have a sufficient bleach width hl and this is maintained at least along the minimum length mmin_ _ET_The bleach width is sufficient at the top in the middle area closer to the root end 10i, but not even where the minimum value hmlnl is undershot.

C) Blekbrëddëñ'är sufficient along the entire length l, but a waist E occurs closer to the root end 12; than the minimum length mmin is.

In all three cases, the reducer discs 11, 12 are in their internal position when the log 10 enters the reducer system. In cases B) and C) they remain there during the entire plan reduction operation, while in case A) they are moved outwards at a given moment. It should be noted that the profile of the log is determined on each side if the reference line is separate. If this profile is asymmetrical, and this happens in particular with curved logs, then 10 l5 20 25 30 35 40 w soo91s¿ ~ r an outward movement of the reducer disc is achieved perhaps only on one side, or in different moments on each side.

Fig. 5 schematically shows an embodiment of the device for carrying out the method according to the invention. The device comprises a conveyor 13 on which a log 10 is fed, held thereon by retaining rollers 29, 30. In this case, the log 10 is sensed by two sensor devices located in front of the device's reduction discs 11, 12. These sensors form the profile measuring device mentioned at the beginning and are of a pair of trailers 27, 28 resp. 27 ', 28'. Their task is to determine the longitudinal outer contours of the log 10 and their position relative to a reference line, in the example shown the center line CL of the plant (dimensions xl, xz). In principle, one of the two sensing devices shown is sufficient and, of course, another known mechanical or optical sensing device can also be used. Advantageously, the log 10, resp. is also sensed at a distance in front of the reducing discs 11, 12 which correspond to a selected part is not shown in the drawing. of the log length, which, however, for space reasons Output signals from the sensors are input via lines dz and d3 resp. dz 'and d3' in an electronic evaluation and control unit 100 which is of the conventional type (computer) and whose mode of operation will be described in detail later.

Between the position sensors 28, 29 and the reduction discs 11, 12 an optical latch is arranged which comprises a light-sensitive element 38 and a light source 39 and which supplies via the line dl the electronics unit 100 a signal indicating the passage of the input end 10i of each stock.

Via the line d4, a signal sequence corresponding to the movement of the conveyor 13 is input to the electronics unit 100 further from a sensor 13a. On the basis of the data entered over the lines d1_4, the profile of the log 10 can be "recreated" in a known manner in the electronics unit 100. At a log length l of eg 4 m, the trailer shoes 27, 28 as above should be at least 2 m before the reducer discs ll 12 so that a possible waist E (Fig. 2b) can be detected with certainty.The reducer discs are mounted with their axes 11a, 12a in bearings not shown and in a manner not shown they are driven in rotation. scaffolds such as a double-acting cylinder-piston assembly 31, 32, the reducer discs can be removed from and approached each other.After the reducer part 50 of the plant, a saw part 40 is arranged.Each of the four band saws of the saw part 40, of which for the clarity only the saw blades 14, 15, 18, 19 enclosing each upper break roller 14a, 15a, 18a, 19a sitting on shafts 14b, 15b, 18b, 19b are shown in the drawing, are mounted on a base plate 140 movable towards and away from the center line , 15c, 18c, 19c This is achieved by means of position adjusting devices, for example double-acting hydraulic cylinder-piston assemblies 34-37 which are fixedly anchored at one end and connected to the respective base plate at their other ends. Thus, by means of the means 34-37, each saw blade is individually positionable relative to the center line gg; this setting is called posting. If desired, this "posting program" can be automatically entered into the electronics unit 100 via lines such as line ds.

The position adjusting devices 31, 32 for the reduction discs 11, 12 are connected via lines f, g to the electronics unit 100 for receiving control signals generated in this unit.

Fig. 5 shows the situation shortly after the moment in which the reducer discs 11, 12 have been moved out, so that additional outer boards 16 ', 17' are obtained as indicated by dashed lines 20a ', 21a' which produce the saw grooves. which will be provided by the saw blades 14, 15.

It should be noted that these saw blades 14, 15 have previously been swept past, more precisely along the outer plane-reduced surfaces of the boards 20,21 and thereby plastered these, thereby avoiding that the boards 20, 21 have outer plane surfaces which in part - before the reducer discs 11, 12 have been moved out - have a surface structure resulting from the reduction, while the other part - after the reducer discs 11, 12 have been moved out - have a surface structure resulting from the sawing.

The thickness of the extra outer board can of course be chosen from suitable standardized board thicknesses, taking into account partly the dimension> H (fig. 3) of the log half, and partly the remaining length of 10 15 20 25 30 il 8ÛÛ91S6 * fi log. You can thus take out a thinner board than with the currently prioritized thickness, if you see that with the prioritized thickness the limit for so-called stuage will be exceeded.

Based on Fig. 3, the following equations can be set up which give values of hl resp. h2. The reducer discs 11, 12 are stepped out when the viiïïoren (eâï, (eb) and (7) are also fulfilled. (Wed hl) 2 = (X1 + x2 -ylnyl (sa) yl = xl - sl - tl ... ................................ (4a) which gives: hl = 2 (x2 + sl + * tl> (sa ) (0,5 h2) 2 = (xl + X2 - y2) .y2 ...................... (3b) yz = X2 - sz - t2 .................................. (4b) which gives: II hz 2 \ Åxl + sz + t2) (x2 - sz - tz) ................ (5b) (Ga) min 1 w NN 1 h h2 hminz ............. ............................ (6b) m 2? Mmin ............... ........................... (7) whereby the dimension m is shown in Fig. 2b and the value mmin is the predetermined (programmed) minimum value of this dimension. The arrangement of the electronics unit 100 in which these counting and comparison operations are performed is shown in the diagram according to Fig. 6. For the sake of clarity, only the processing of the signals from the left-hand sensor 28 in Fig. 5 and the setting of the left-hand reducer in Fig. 5 are shown. - van ll. The same scheme of course also applies to the sensor 2 7 and the reducing disc 12.

The signal .s0m corresponding to the value x1 (Fig. 3) is input to a processor l01 from which a signal representing the value E1 is output, which is the removable board thickness at a given minimum width h. Via a switch l0la the signal u1 is input in a first comparator l02 in which a value_g2 is further entered for the proposed board thickness according to the posting program (the posting program is not a computer program, but 8ÜÛ9156-å 33 indicates the relative position of the saw blades in the saw part 40). From the comparator l02 a signal 2 is output to a derivative 103 which corresponds to the difference between ul and u2 (g = ul - uz).

The signal 3 is input in parallel into a second comparator 104 and its derivatives É are input into a third comparator 105. Depending on the comparison result obtained, this is input from both comparators 104, 105 either into an AND gate 106 or into an OR gate 107. A signal 2 is further input to the AND gate 106. The outputs of the gates 106, 107 are connected to the adapter 31 of the reducer disc 11 (Fig. 5).

Thus, in the second comparator 104, if e;> 0 is determined, and when so, signal goes to AND gate 106. The derivative E of e shows whether E increases or decreases, as indicated by the signs + and - next to the first comparator 102. If é 3'0, increases É and signal goes to AND gate l06, otherwise to OR gate 107. The comparison is made in the third comparator 105. Reaches both g;> 0 and šzwo, and AND gate 106 has a signal at both corresponding inputs 20 as well as at a third input, the reducer disk 11 goes out.

Said third input is connected to a fourth comparator 108 in which it is determined whether the length of a possible extra outer board is equal to or exceeds the determined minimum length (mçæ mm). When this is the case, the signal 2 is output in to the third input of the AND gate 106.

The value E is determined in a subtraction unit 110 in which the previously mentioned counting operation (2) is performed. If desired, the electronics unit 100 may further be provided with a delay unit 109 after the three-input AND gate 106. Since no special signal is generally required to keep the reducer disk 11 in the unchanged position, the OR gate 107 in addition to its connection to the switch device 31 also completely deleted.

Processing of the signal from the position sensor 27 for setting the reducer disc 12 takes place, of course, in an analogous manner. The unit 100 can also be more simply constructed, e.g. can an algorithm that takes into account the distance from the root end of the log; be used to well- 80091564; yes suitable thickness and width of the board blank 16, 17 which is taken out between the reducer disc 11, 12 And the Outermost Saw 'blade 14', 15 '.

It is obvious that the invention can also be used in a reducer sawing system with only two saw blades where the choice is between obtaining only one I center replacement 22 or one center replacement 22 plus one or two outer boards 20, 21 with possibly smaller lengths.

Depending on the length and conicity of a stock, the step of one or both reducer discs can be repeated one or more times.

Unlike all known methods, according to the present invention no substandard extra side boards can arise, as a result of which their sorting and chopping in a separate chopping plant is eliminated. Furthermore, the even better material yield is achieved, since an extra side board is produced as soon as possible on at least one side of the log.

Claims (10)

8ÛÛ9156 ”¿% I '/ 10 15 Patentkrav A method of machining logs (10) with a diameter increasing towards the root end (10r) and which with their narrower top end (10i) at the front are fed through a woodworking plant comprising along a common center line (CL) a plane reducing part (50) with two by means of respective position adjusting means (31, 32) axially adjustable reduction discs (11, 12) and a saw part (40) with at least two saw blades (14, 15, 18, 19) adjustable in their lateral positions for separating at least one board ( 16, 17, 20, 21) on each side of the reduced log (10a), whereby before entering the log in the reducer part St0CkbIêdå6H (X1 + X2) is measured and depending on the measurement result the mutual distance of the reducer discs is increased during the processing of the log for that a larger board yield and less chip waste are obtained, it is noted that before the log is fed into the reducer part (50) the two longitudinal contours of the log and their distance from a reference line are measured and fed into an electronic calculation unit (100), that during the feed of the log through the plant, the longitudinal position of the log is continuously measured and entered in said calculation unit in which before that the minimum thickness of an acceptable board including the saw joint width and the minimum length (mmin) and minimum width (hmin) in the bleach for an acceptable board and log length l) has been entered and which generates control signals for the lateral position setting of the reduction discs, to be determined in the calculation unit when the longitudinal contour of the log on one side has moved away from the center line of the plant with the entered minimum thickness value relative to the distance at the top end. the remaining unreduced part has a length (m) corresponding to at least the programmed minimum length (mmin) and if an additional side board would also have the programmed minimum width (hmin) in the bleach, whereby a control signal is generated to the position setting device on the stock side in question that, independently of the reducer disc at the other stock side step out the connected reduction disc with a distance corresponding to a predetermined board thickness value plus a saw joint width. , § aoo91ss-A Method according to claim 1, characterized in that the longitudinal contours of the log are sensed at at least two different distances in front of the reducer part. 3. A method according to claim 1 or 2, characterized in that the reduction of the reducer disc is achieved with a fixed delay. The method according to one or more of the preceding claims, characterized in that the outermost saw blade (14 ', 15') in the saw part is pressed so that it strokes tightly past the passing, previously 1 reducer part provided flat surface on the block, so that this surface obtains basically the same structure as a sawn surface even in the part where no extra side board has been separated. The method according to one or more of the preceding claims, characterized in that the sawing part of the saw part is entered automatically by electronic means in the electronics unit (100) - Device for processing logs by the method according to one or more of the preceding claims, comprising a timber processing plant which, along a common center line (CL), has a plane reducing part (50) with two axial positioning devices (31, 32) axially. movable reducers (11, 12) and a saw part (40) with at least two saw blades (14, 15, 18, 19) adjustable in their lateral positions, a transport device (13) for feeding the logs through the processing plant, a measuring device (27, 28 , 27 ', 28') for sensing the longitudinal contours of a stock (10) and their position relative to a reference line, devices (13a, 38, 39) for sensing the feed position of the stock, and an electronic calculation unit (100) for generating control signals to 8009156 -4 ß processing means for adjusting their lateral position for optimal yield based on the narrower top end of the log, characterized in that the electronics unit is programmed to determine whether if an reducer disc can be obtained, an acceptable additional side board can be obtained on one or the other side of a log present during processing in the reducer part, and that said position adjusting devices and reducer discs are arranged to step out a working signal upon receipt of a control signal from the electronics unit. reducer plate independent of the second reducer plate with a distance corresponding to the thickness of a board. Device according to claim 6, characterized by position adjusting devices (34-37) for the saw part's saw blade, which means are connected by wires (ds) to the electronic unit for automatic input of the saw part poshings program therein. Device according to Claim 6 or 7, characterized in that the sensing device for the longitudinal contours of the log is located just in front of the reducer part. 9. Device according to any one or more of claims 6-8, characterized in that the position adjusting means are double-acting hydraulic cylinder-piston assemblies. Device according to one or more of Claims 6 to 9, characterized in that the electronics unit comprises a processor (101), to which a first comparator (102) is connected, to the output of which a derivation unit (10 3) or a second comparator are connected in parallel. (l04), and that a third comparator (105) is connected to the output of the derivative unit, an output of the second and an output of the third comparator being connected to an AND gate (106) whose output is in turn connected to said position adjuster.