FI114892B - Tree harvesting machine control apparatus and method - Google Patents

Abstract

The part supporting the tree is moved at the very moment of cutting to compensate for the force tending to bend the tree. This involves a momentary movement produced by control automatics and timed precisely at the moment of action of the cross-cutting saw, to make the bending moment at the time of cutting as close to zero as possible. The tree harvesting machine comprises a tree-supporting part (1) with a feeding means (2) for feeding the tree in its longitudinal direction and a cross-cutting saw (5) for cutting the tree at selected locations. The part (1) is supported by a boom assembly (6). The control apparatus comprises means for controlling the cross-cutting saw (5) and control means for controlling the movement of the tree- supporting part.

Description

114892

Method and equipment for adjusting the harvester

The invention relates to a method of adjusting a harvester as set forth in the preamble of claim 1. The invention also relates to a control apparatus of the type shown in the preamble of claim 4.

The invention is intended for use in off-road forestry machinery such as grapple harvesters. Such forestry machines include a wood-handling part at the end of a shaft arranged to be movable in a frame, a grapple having a cutting saw for performing felling of wood and cutting to specific lengths, and a wood feeder for feeding the cut wood forward. Forestry machines of this type are presented e.g. European Patent 4,285,030; Finnish Patent No. 15,997; and U.S. Patent 4,742,854.

When starting to process felled trees with such machines, the base of the tree is between feeders such as rollers or wheels, and is further supported by pruning blades. The feeder pushes the body past the cutting saw 20 a distance corresponding to the cutting length. Particularly with thick trunks, the weight of the trunk rises so that at the point of trimming it tends to bend the wood so that there is no flat trace and, in the worst case, cracks can occur.

It is not possible to support the wood at the base end when cutting, since the cutting saw is at its lowest, i.e. at the base of the femoral head at the tipping point, and it must fit at the bottom »· * [I! felling the tree, ie as close to the ground as possible.

* ': 30 Swedish Announcement Publication 409431 discloses a felling machine for felled wood, where a bottom-to-top saw during a cutting motion is followed by a wedge member to prevent cracks in the remaining part of the wood and to prevent the saw from jamming. The top-to-bottom rotation recommended for smaller · "*: trunks does not use any ', 35 aids to prevent cracks. This is not a cutter for off-road logging.

2 114892

The object of the invention is to provide a method for eliminating the above disadvantage and avoiding the quality problems of logs intended for high quality timber as much as possible. To accomplish this purpose, the method according to the invention is essentially characterized in what is set forth in the characterizing part of the appended claim 1. It is essential in the invention to move the wood-bearing member relative to the boom just at the time of cutting so that this tendency to bend the wood is compensated. This is a short-term movement of the cutting saw 10, which is precisely timed to the point of operation of the cutting saw, which allows the bending moment to be as close to zero as possible at the moment of cutting, or at least significantly less than without movement. Other aspects of the invention are set forth in the appended dependent claims 2 and 3.

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The harvesting machine control apparatus for implementing the invention, in turn, is characterized by what is set forth in the characterizing part of the appended claim 4. The functions of the invention may be carried out by means of an apparatus in which the adjusting members of the cutting saw are suitably connected to the actuators corresponding to the movements of the part carrying the wood. Other advantageous features of the apparatus are set forth in the appended independent claim 5.

The invention will now be described in more detail with reference to the accompanying silicon *** *** cartridges, in which * · · ”Figure 1 shows an overview of the wood supporting part of a forestry machine. , na, '; Fig. 2 shows a part in operation before the critical cut-off stage, Fig. 3 shows a boom of a forestry machine supporting the part shown in Figs: / - 11 and 2, and * '' ': Fig. 4 shows a control diagram for implementing the invention.

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Fig. 1 shows a '' 'wood support and handling part 1 mounted on the head of a forestry machine, in this case a hydraulically driven boom of the grapple harvester, with a grapple • · · 3 114892 mounted in the frame, consisting of two rolls hinged to the frame so that they can move towards the wood frame between them, moved by the hydraulic cylinders 4 so that the wood frame is trapped between the rolls. Further, hydraulically fixed movable pruning blades 3 are attached to the frame of the support portion 1 of the tree 5, which prun the branches of the tree as the tree frame moves under the direction of the feeder 2. Blades located on both sides of the feeder in the direction of the tree trunk can also be used to press and support the tree trunk. The part 1 is provided with a hydraulic chain saw 5 attached to the base end, which cuts the tree trunk at the base and then cuts it into logs of suitable length.

Fig. 2 shows the situation after the tree has been cut off at the base, has fallen and is supported by part 1 at approximately horizontal position, and the feeder 2 has fed the tree trunk R at a certain distance upstream to the first cutting position K. the free portion depends on the weight of the cleavage site D-vutusmomentti or a wood saw pushed forward in the direction of the arrow tends to bend the tree cutting site, in the worst case, the tree 20 is cleaved at the cleavage site, leaving the cut-off the body of the small tab. To sum up a bit, the phenomenon is the same as when sawing a long tree with a heavy amount of air outside the saw bar.

25 sawing At the time, preferably the saw feed movement has started, the cause-of the wood harvesting machine, the control automatics means of supporting the part 1 in the boom assembly 6 like movement so that part 1 moves suddenly "·"! Downwards in the direction of arrow F direction. The movement is fast, but the length of the movement needs only to be short so that the bending moment is compensated for by the inertia forces of the wood; / 30 at least until the saw has completed the cut, such movement being effected simply by utilizing the weight of the boom 6, the wood supporting part O1 and the wood itself time some of the boom · “[: ground-pulling actuator, which makes part 1 py /..35 the cause of its elevation, or an active high-speed actuator designed to perform that movement.

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The operation of the cutting saw 5 normally takes less than one second. As a result, it is possible to use a jerk motion to compensate for the bending moment for the period most critical to the end result of the saw. The movement can be timed, for example, in accordance with the saw movement of the saw, and is preferably initiated when, by means of an automatic adjustment mechanism, it is detected that the saw has started to feed or the saw has fallen into the wood. It is important that the movement is not timed too early, because when the compensating movement has stopped, the inertia forces will increase the bending moment much higher than the original if the part of the body 10 to be cut is still attached to the other body. The movement should last a little more than the cut-off phase, rather than being missed. The required movement lengths are not large, but the movement must be fast enough.

Fig. 3 shows a pivoting boom 6 which is pivotable about a vertical axis 15 of the forestry machine frame and has a wood part 1 hanging at its end. At the height of the boom, the supporting cylinder is denoted by reference numeral 7. When part 1 bears the cut wood and saw 5 7 is malicious and holds the boom 6 in the height position to which it is actively guided by the cylinder. When the saw 5 is operating, the cylinder is briefly released from pressure, whereby the part 1 is lowered correspondingly in a jerky manner. The position can be reset gradually with the cylinder before the next cut.

: · 25 It is also possible to use other cylinders or other actuators located at appropriate points in the boom, which provide the most direct downward movement possible. For example, the actuator on the telescopic arm 6a closest to part 1 4 »t '' of the end of the boom can be utilized. Also, instead of 6 boom arms; / 30 being moved to achieve this movement, the part 1 itself can be suspended at the end of the boom through the actuator so that it falls down with respect to the boom 6 at a convenient moment.

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Figure 4 shows a control automation that can be utilized, ν.35 in the invention. The pressure medium is guided along the line L and the feed cylinder S of the saw, which causes the saw 5 to feed, i.e. the saw pivots in the body of part 1 to perform cutting. The pressure medium is also fed to the saw motor M. The line L is branched into a line LS through the saw movement control elements 8, and through a limiting valve 9 and a control valve 10 into the line LM. The pressure medium is also passed from line L through the start valve 11 to the control valve 10 of the motor M along line LO, whereby the pressure medium 5 opens the control valve 10 when the start valve 11 is open. In this case, the pressure medium is directed through the control valve 9 through the control valve 10 to the motor M, whereby the motor starts to rotate. The start valve 11 of the motor M is electrically controlled in a manner known per se. The pressure medium return line from the engine is designated LT.

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The control elements 8 controlling the saw feeding cylinder S include a control valve 12 for controlling the pressure in the line LS, i.e. the saw force, and a directional valve 13 for controlling the saw feeding direction. In the position shown in Fig. 4, the directional valve 13 is in the starting position of the turning motion of the saw 5.

The actuator which causes the movement according to the invention, such as the hydraulic cylinder described above, can obtain its operating command from the position of the control elements affecting the operation of the saw 5. The control line, denoted by reference numeral 14 in the figure, may be informed of the position of the starter valve 11 of the motor M, e.g. directly from its coil control. Another alternative, which is illustrated by the control line 15, is to take the position of the directional valve 13, that is, when it has moved to the position providing the saw feed movement, the information is transmitted to the actuator. It is also possible to use the saw rotary position sensors or circuit breakers 25 in part 1. In order to properly schedule the action of the motion actuator with respect to the cut-off phase, it can be arranged to operate

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“With a long delay with the saw adjusting members, for example, so that the movement 'begins only after the saw has penetrated a certain distance into the tree.

30! i »« <·: The actuators shown in Fig. 4 are located in the boom end part 1 and are controlled by the automation in the cab; \ with commands from the cockpit.

Similarly, at the end of an actuator, such as the hydraulic cylinder 7 described above, a fast, saw-action valve '* can be used to release the pressure medium from the pressure side of the cylinder.

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Claims: 1. A method for adjusting a harvester, wherein the harvester comprises a tree-carrying portion (1) having a feeder (2) for feeding the tree in its longitudinal direction and a cutting saw (5) for cutting the tree at selected locations, said portion (1) being supported by a boom (6) or the like, wherein at the moment of operation of the cutting saw (5) the wood supporting part (1) is moved so that the force of the wood, which tends to bend the wood at the cutting point and consequently split it, is at least partially compensated, characterized in part (1) with respect to the boom (6) by means of automatic regulation of the harvesting machine by giving a command to move the part (1) carrying the wood based on the status information of the control elements (11, 13) affecting or dependent on the operation of the saw.

Method according to Claim 1, characterized in that the movement is caused by dropping the part (1) in relation to the boom (6) downwards.

Method according to Claim 1 or 2, characterized in that the movement command of the wood-bearing part (1) is based on the status information of a sensor or circuit breaker, which is dependent on the operation of the saw (5) and detects its turning position;

"::: 25 * 1 1; 4. An adjusting apparatus for a harvesting machine, the harvesting machine comprising a tree-carrying portion (1) having a feeding device (2) for feeding the tree. or the like for supporting said part, wherein the adjusting device comprises adjusting means for the cutting saw (5) and adjusting means for controlling the movement of the part carrying the wood (1), characterized in that the part (1) is mounted at the end of the boom (6) via an actuator and the actuators of the cut-off saw (5) are connected. ·! ·. via the actuator automatically to the actuators controlling the actuator. 1) with respect to the movement (F) of the boom (6), which at least partially compensates for the weight of the wood at the point of intersection:.

Claims (5)

A control method in a harvester, wherein the harvester comprises a tree supporting part (1) provided with a feeding device (2) for feeding a tree in its longitudinal direction, and a cutting saw (5) for cutting the tree at selected places, wherein the said part (1) is supported by a turret (6) or the like, whereby at the time of the action of the cutting saw (5) the wood-bearing part (1) is moved so that the force caused by the weight of the tree which strives to bend the tree at the cutting site and thereby cleaving it, is at least partially compensated, characterized in that, at the time of the operation of the cutting saw (5), the wood supporting part (1) is moved relative to the boom set (6) by means of the harvester's control automatic provide the motion instruction for the tree supporting member (1) on the basis of status information about the action of the saw (5) affecting or depending on its effect control means (11, 13). A method according to claim 1, characterized in that the movement is caused by dropping the part (1) downwards relative to the boom set (6). 3. A method according to claim 1 or 2, characterized in that :: the movement instruction for the tree supporting part (1) is given on the basis of status information about a sensor or switch which is dependent on the action of the saw (5). part (1) and detects the swing position of the saw. • · A harvester control device, which harvester comprises a tree supporting member (1) provided with a feeding device (2) for feeding the tree in its longitudinal direction and a cutting saw (5) for cutting ···. a tree set (6) or the like for supporting said part, the control device comprising control means for the cutting saw (5) and control means for controlling the movement of the tree supporting part (1), characterized in that the part (1) is suspended at the end of the boom set (6) by means of an actuator and the control means for the cutter saw (5) are interconnected by the control automatic with control means which control the actuator which automatically causes the tree-bearing function at the time of the action of the saw (5). the movement (F) of the part (1) in relation to the boom set (6), which movement (F) at least partially compensates for the force caused by the weight of the tree which strives to cleave the tree at the cutting post. 5 Control device according to claim 4, characterized in that a detector or switch detecting in the swivel position (5) of the cutting saw (5) is connected by the control automatic with control means which affects the movement of the wood bearing part (1). > · * Φ ♦ «j · ♦ i IMI» t • * · «» · * * i »• · fi · * <t» i »» • · III * * ♦ »·» il I * · »» 114892 3 _g ψ £ ε £. ^ Βρ 1.101¾. ι Fig. 1