EP0232271A1 - Methode de guidage de lames de scies - Google Patents

Methode de guidage de lames de scies

Info

Publication number
EP0232271A1
EP0232271A1 EP19850905452 EP85905452A EP0232271A1 EP 0232271 A1 EP0232271 A1 EP 0232271A1 EP 19850905452 EP19850905452 EP 19850905452 EP 85905452 A EP85905452 A EP 85905452A EP 0232271 A1 EP0232271 A1 EP 0232271A1
Authority
EP
European Patent Office
Prior art keywords
saw
teeth
blades
blade
row
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19850905452
Other languages
German (de)
English (en)
Inventor
Waldemar Ask
Carl Sivers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
VIGILANTIA AB
Original Assignee
VIGILANTIA AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by VIGILANTIA AB filed Critical VIGILANTIA AB
Publication of EP0232271A1 publication Critical patent/EP0232271A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D61/00—Tools for sawing machines or sawing devices; Clamping devices for these tools
    • B23D61/02—Circular saw blades
    • B23D61/021—Types of set; Variable teeth, e.g. variable in height or gullet depth; Varying pitch; Details of gullet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D47/00—Sawing machines or sawing devices working with circular saw blades, characterised only by constructional features of particular parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D55/00—Sawing machines or sawing devices working with strap saw blades, characterised only by constructional features of particular parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D59/00—Accessories specially designed for sawing machines or sawing devices
    • B23D59/001—Measuring or control devices, e.g. for automatic control of work feed pressure on band saw blade
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D59/00—Accessories specially designed for sawing machines or sawing devices
    • B23D59/02—Devices for lubricating or cooling circular saw blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D61/00—Tools for sawing machines or sawing devices; Clamping devices for these tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B33/00—Sawing tools for saw mills, sawing machines, or sawing devices
    • B27B33/20—Edge trimming saw blades or tools combined with means to disintegrate waste

Definitions

  • This invention relates to a method for guiding saw blades wi h at least two rows of cutting teeth which work in the same kerf close to each other and where the saw is guided to move sideways in desired direction or to compensate for deviations from a straight line caused by knots or the like.
  • the method according to this invention can be applied to circular saws as well as to band saws and frame saws. It is known to reduce the waste in sawdust by cutting the kerf with at least two adjacent saw blades which are driven with approximately the same speed ancT each of which has one row of teeth.
  • the method according to the invention is essentially characterized in that the relative speed of the two rows of cutting teeth in the direction of movement through the piece of material to be sawn is intentionally varied so that the faster row of teeth becomes less engaged and therefore will, be subject to smaller cutting forces, whereby the resultant of the side forces perpendicular to the cutting forces will be directed towards the faster row of teeth, which causes the saw to move in the direction of the faster row of teeth, alternatively the piece of material to be sawn will move towards the slower row of teeth.
  • the method according to the invention is used to guide the cutting direction either to a straight kerf or to a kerf with a desired curve.
  • the control of the shape of the kerf can be accomplished either by means of sensors indicating the deflection of the saw blade when it has passed the . material to be sawn, or manually, or according to a computer program.
  • the computer can for a joiner's workshop be programmed for sawing a desired pattern. It then coordinates the direction of cutting with the movement of the piece of material on the table.
  • the program can also be stored immediately before sawing with data automatically measured of the curving of the log. It then guides the log and the direction of the cut to give th largest possible quantity of planks with constant thickness.
  • the total thickness of the combined saw blades can be made much smaller than the thickness of a single saw blade, the stiffness of which must guarantee the straightness of the kerf.
  • the width can be reduced to what is necessary to withstand the forces on the saw teeth. The total forces will be less since less material is wasted and a smaller width of the blade usually decreases the forces of friction. Thi also reduces the total consumption of energy for .sawing.
  • the at least two saw blades are given different frequencies of resonance in order to avoid that the discs start to vibrate. By giving them different resonance frequencies they will damp each other whereby the risk for self-oscillatio will be eliminated.
  • Figs. 1, 2 and 3 show circular saws, band saws and frame saws
  • Figs. 4 and 5 show different types of saw teeth
  • Figs. 6 and 7 show methods of removing dust and chips between saw blades
  • Figs. 8 and 9 show a circular saw and a band saw for producing long chips.
  • Fig. 1 shows a circular saw with its discs 1 and 2 which are separately and independently driven by motors 5 and 6, respectively.
  • the motors can be mechanically separated from each other or can consist of one single motor with transmissions and variable gears, all according to known technique.
  • the saw blades are equipped with teeth 3, 4 made in general according to today's practice. A main requirement is that the teeth 3 on saw half 1 and the teeth 4 on saw half 2 must never intrude into the operating spaces of one another and make mechanical contact.
  • the object 8 to be sawn, with its kerf 9, is moved on the saw table 10. Then the blade goes through the object 8 it usually gets a deflection towards one or the other side because of a structure of the material whic is oblique to the kerf.
  • the sensor 7 indicates this deflection and is in Fig. 1 shown as two rollers, the common bearing housing of which gives th rollers a slight pressure against the saw blades.
  • the movement of the bearing housing is used to vary the relative speed of the driving motors 5, 6 and thus the relative speed of the rows of teeth 3, 4.
  • the slower row of teeth gets more engagement of the teeth with higher cutting forces and thus higher side components.
  • the side-cutting forces for the two row are decreased and increased, respectively, and thus the angle 45 in Figs. and 5, not always but usually, should be larger than 90°. It can simply be said that the row of teeth which cuts faster leaves a void which allow the slower teeth row to press the blades in the direction of this void.
  • the deviation from a straight kerf can be kept small.
  • Fig. 2 shows two embodiments of a band saw with the saw blades 1 an 2, pulley wheels 21, 22 and 23, 24 and the driving motors 5 and 6.
  • the tw embodiments imply no principal differences.
  • driving equipment for the blades 1 and 2 guiding pulleys 25, 26 are usually needed in order to keep the blades close to ea other.
  • the sensor 7 for the blade deflections controls the speed of the teeth and thus the form of the kerf as shown in Fig. 1.
  • Fig. 3 shows schematically a frame saw according to the same principle.
  • the bands 31, 33 and 35 are pulled by means of a common frame by a motor 37, whereas the bands 32, 34 and 36 cooperating therewith have one frame and a driving motor each 38, 39 and 40.
  • the speeds of the separate driving motors relative to the motor in common, 37 are controll in the same way as in previous Figures by one sensor each 7, not shown, s that all kerfs 9 in the sawn object 8 will be straight, or are given the desired curve as described below.
  • Fig. 4 shows essentially the teeth of a pair of band saw blades 1, 2, where the teeth have been made from the same material as the blades themselves, which is common for frequent smaller band saw blades.
  • the design differs, however, so that the rows of teeth 41 and 42 are not set symmetrically to the rows 43 and 44 but are left straight. As the blades 1, 2 can be driven with considerably different speeds the teeth must not be permitted to hook into one another.
  • Fig. 4 further shows that the top angle to the saw direction 45 should be larger than 90° so that the teeth shall have a tendency to press the band package together, in order to obtain distinct sideforce components to produce the narrowest possible kerf and thus least possible waste and to avoid larger quantities of sawdust to penetrate between the blades. A small quantity of sawdust is desirable for lubrication.
  • Fig. 5 shows an embodiment where the cutting teeth are soldered into cut seats on the blade in a known way, and where the angle 45 is larger than 90°.
  • a thin disc or flakes of the material are produced which penetrate into the slot between the teeth 53, 54 and further between the saw blades 1 and 2 without being disintegrated.
  • This is avoided according to Fig. 5 by means of internal teeth 56 in one of the saw halves 2, said teeth passing freely into the channel 55 which extends through all teeth 53 in the other saw half 1. All non-pulverized intruding parts of the saw object are thus broken and cut into dust.
  • the assymetry could have been made on the top of the pair of teeth but this would have caused a tendency to inclined guidance.
  • a thin layer of sawdust between the cooperating saw blades gives a certain desirable lubrication that generally eliminates contact between metal surfaces with different speeds.
  • the layer must not become so thick that on one hand the width of the kerf is unnecessarily widened, and on the other hand that fastening and guiding parts for the saw blades are unnecessarily stressed.
  • the non-cutting inner parts of the teeth can have the edges obliquely ground either to guide the sawdust inbetween the blades for lubrication or to throw the dust to the outside of the blades or to carry the dust until the tooth has passed the saw object.
  • the two circular saw blades can also be provided with holes accordin to Figs. 6 and 7.
  • the holes 61 on one blade and those 62 on the other blad are as widely as possible spread over the surfaces so that every unit of area on the two discs at least once for each turn is opposed to an opening in the other disc. To retain as much as possible of the metal discs it should be observed that two holes on one disc should not cover the same surface on the other disc.
  • Fig. 6 shows an embodiment with six holes. If for example the numbe of holes is doubled the diameter of the holes can be reduced to one half and consequently the total removed surface to one half.
  • grindings 73 which from the edge have penetrated between the blades are discharged through holes 61 and 62. At least the trailing edges 71, 72 of the holes as seen in the direction of movement, can be incl ned towards the outside to prevent them from cutting the objec to be sawn. The discharge of grindings 73 becomes faster when the speed difference between the blades increases.
  • the holes can also be made cuttin for simultaneous planing of the sawn surface.
  • each tooth cuts the fibre to a length which corresponds to the movement of the object during the time it takes for a tooth to pass.
  • the only possibility to increase the content of long chips with unbroken fibres is to decrease the angle to the line between two teeth points and the saw direction to as close to zero as possible.
  • Circular saws are usually arranged as in Fig. 1 with a saw table as close to the driving shaft as possible so that thin logs are sawn almost perpendicularly to the direction of movement of the log. Only very thick logs give a considerable quantity of long chips since they reach the upper edge of the saw blade.
  • Fig. 8 shows a saw table 10 placed below the axle and with the saw teeth scarcely projecting below the plane of the saw table 10.
  • saw table is meant at least an imaginary lower limiting sur ⁇ face for the log irrespective of the design of the means for moving the log. Since the log is positioned as close to the periphery of the saw disc as possible the obtained content of long chips is maximal. It is of course possible to use the arrangement of Fig. 8 with common single blades but th risk to obtain obl que kerfs is greater here than in the arrangement accor ding to Fig. 1. The method is suitable only with automatic guidance of a pack of saw blades. Fig.
  • FIG. 8 shows a suitable position of the sensor 7 which indicates the deflection of the saw blades after the object 8 has passed.
  • the only method to increase the length of the chips is to tilt the blades 1, 2 as much as possible relative- to the log 8. The length of passage of the blades through the log is thereby increased. A single unguided band then runs an increased risk of generating curved kerfs. Only the method described here with control of the relative speed o the blades in a pack makes the method in Fig. 9 suitable. The smaller the angle is the longer the chips will be.
  • the sensor 7 and other arrangements have the same function as in Fig. 2.
  • the driving of the motors 5 and 6 in previous Figures is to be controlled either by the sensor 7, or manually, or by means of a computer program.
  • the program is superimposed on the information from the sensor 7.
  • the sensor can be mechanical as described in connection with Fig. 1. In suitable cases it can also indicate the deflection of the saw blades magnetically, electrically or optically, without mechanical contact. Control systems for motors controlled by such sensors are well known and used in other applications.
  • An electronic control system 27 is indicated which is controlled by magnetic sensors 7. From the control system 27 the motors 5 and 6 are supplied with three-phase power electronically generated, the frequency of which is specific and variable for each motor. Since the speed of the motors is controlled by the frequency the relative speeds of the saw blade 1, 2 is controlled by the position of the blade pack in the air gap betwee the two coil systems of the sensor 7. When the band pack is positioned in the middle of the air gap the motors are fed with the same frequency. In order to get a quick rotation speed control the three-phase frequencies ar usually higher than normal mains frequency, thereby permitting the motors to be given smaller dimensions.
  • the coils of the magnetic sensor 7 can be cast in plastic to resist blows and shocks.
  • the arrangement is known for long and used in other applications.
  • the output signals of the sensor 7 can be superimposed with signals from a computer program which .was stored when the log passed a measuring station. Here the natural bends of the log have been measured and the data are stored in the program.
  • the sensor 7 all the time controls that the thickness of the sawn planks is constant.
  • the superposition from the computer program solely ensures that the lateral movements of the log on the table correspond to the cutting direction of the saw blade.
  • the invention has generally been described in connection with the sawing of wooden logs but can of course be applied also to the sawing of for example plastic a ' nd metals.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Sawing (AREA)
  • Dovetailed Work, And Nailing Machines And Stapling Machines For Wood (AREA)

Abstract

Des scies circulaires (Fig. 1), des scies à ruban (Fig. 2) ou des scies à châssis (Fig. 3) sont destinées au sciage de troncs d'arbres droits et courbes ayant des noeuds et autres irrégularités qui tendent à diriger la lame de la scie ce qui a pour conséquence de faire dévier le trait de scie par rapport au trait de scie désiré. On connaît les lames de scie conçues sous la forme d'un ensemble d'au moins deux lames proches l'une de l'autre (1, 2). Selon l'invention, les deux lames de scie sont entraînées avec des vitesses relatives que l'on veut variables, la rangée de dents (3, 4) d'une lame ne pouvant interférer avec la rangée de dents de l'autre lame. Des écarts par rapport aux traits de scie désirés sont indiqués par des déflections de l'ensemble des lames de scie traversant l'objet à scier. La déviation commande les vitesses relatives des moitiés de lame de scie. La lame de scie qui, à un certain moment, est plus rapide, découpe un vide vers lequel l'ensemble de lame est forcé de se rapprocher par la pression exercée par les dents de l'autre lame de scie. La méthode peut être utilisée d'une part pour guider la scie et obtenir un trait de scie droit, d'autre part pour guider la scie manuellement, mais aussi pour guider la scie selon un programme dans le but d'obtenir des planches ayant une épaisseur constante à partir de billes courbes, ainsi que pour la menuiserie. Il est également possible de produire moins cher des copeaux à longues fibres pour la production de planches en aggloméré.
EP19850905452 1984-10-29 1985-10-29 Methode de guidage de lames de scies Withdrawn EP0232271A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8405405 1984-10-29
SE8405405A SE8405405D0 (sv) 1984-10-29 1984-10-29 Sjelvstyrande sag

Publications (1)

Publication Number Publication Date
EP0232271A1 true EP0232271A1 (fr) 1987-08-19

Family

ID=20357525

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850905452 Withdrawn EP0232271A1 (fr) 1984-10-29 1985-10-29 Methode de guidage de lames de scies

Country Status (3)

Country Link
EP (1) EP0232271A1 (fr)
SE (1) SE8405405D0 (fr)
WO (1) WO1986002590A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10059978A1 (de) * 2000-12-02 2002-06-06 Bosch Gmbh Robert Sägewerkzeug für eine Handkreissägemaschine
DE10059969A1 (de) * 2000-12-02 2002-06-06 Bosch Gmbh Robert Sägewerkzeug für eine Handkreissägemaschine
SE524099C2 (sv) 2001-05-16 2004-06-29 Nord Ct I Kalmar Ab Sågklingepar
SE528019C2 (sv) * 2004-12-02 2006-08-08 Indocean Diamond Tools Bermuda Sågblad och förfarande för tillverkning av ett sågblad
RU2600743C1 (ru) * 2015-08-05 2016-10-27 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Северный (Арктический) федеральный университет имени М.В. Ломоносова" (САФУ) Круглопильный станок

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2283958A (en) * 1937-04-21 1942-05-26 Tompkins Edward De Voe Portable sawing apparatus
US2591747A (en) * 1946-07-17 1952-04-08 Tompkins Edward De Voe Dual reciprocating blade sawing apparatus
FI42467B (fr) * 1961-04-05 1970-04-30 Vyzk A Vyvojovy Ustav Drevarsk
US3204674A (en) * 1962-03-12 1965-09-07 Griffwood Inc Step sawmilling with by-product chip production
US3327696A (en) * 1964-10-09 1967-06-27 Howard Aiken Ind Saw stabilizing means and method
FR2192483A5 (fr) * 1972-07-07 1974-02-08 Giraud Leone

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8602590A1 *

Also Published As

Publication number Publication date
SE8405405D0 (sv) 1984-10-29
WO1986002590A1 (fr) 1986-05-09

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