EP3102378A1

EP3102378A1 - Cutting and splitting device

Info

Publication number: EP3102378A1
Application number: EP15746945.3A
Authority: EP
Inventors: Tarmo Pitkäniemi
Original assignee: Agromaster Oy
Current assignee: Agromaster Oy
Priority date: 2014-02-07
Filing date: 2015-02-04
Publication date: 2016-12-14
Also published as: FI20145123A; WO2015118224A1; FI125359B; EP3102378A4

Abstract

The invention relates to a cutting and splitting device which comprises a feeder (3) provided with an endless feed belt (1) and a hydraulic motor (2) rotating it for feeding a log to be processed; a blade (4,5) reciprocated transversely relative to a log being fed for cutting the log into pieces; and a splitting blade (6) for splitting a piece cut from a log. According to the invention, a hydraulic cylinder (7) is provided in connection with the splitting blade (6) in such a way that the splitting blade is movable towards the blade (4,5) for splitting a piece of log. Further, the hydraulic cylinder (7) of the splitting blade (6) and the hydraulic motor (2) of the feeder (3) are hydraulically connected with each other for carrying out log feeding by the feeder (3) simultaneously with the back movement of the splitting blade.

Description

CUTTING AND SPLITTING DEVICE

FIELD OF THE INVENTION

The invention relates to a cutting and splitting de- vice according to the preamble of claim 1 for cutting and splitting lopped wood trunks, i.e. logs, to make firewood .

BACKGROUND OF THE INVENTION

A cutting and splitting device is a device for cutting and splitting lopped wood trunks, i.e. logs, to make fuelwood, i.e. smaller pieces of wood. Normally, the known cutting and splitting devices comprise a feeder for feeding a log, a cutter for cutting a log and a splitter for splitting a piece of log. A rotating belt or a reciprocated infeed chute is most often used as the feeder. The most common cutters include chain saws, circular saws, shearing blades, i.e. guillo^¬ tines, or rotary slitting blades. A cross blade or a similar blade with several parts is the most common splitter, through which the piece of log is pushed by means of a hydraulic cylinder. Fixed wedge shapes are also used in slitting and shearing blades, the wedge shapes also performing splitting in connection with cutting.

The known machines are functional and efficient as such. However, there is a constant need to develop simpler and thereby more affordable cutting and split- ting devices, so that the use of the cutting and splitting device would become viable for an even wider clientele. Particularly in cutting and splitting devices provided with belt feed, each operation reguires its own power engine and control for it, as the belt is rotated by its own hydraulic motor, the chain saw is rotated by another hydraulic motor or the shearing blade is pressed by a hydraulic cylinder and another hydraulic cylinder presses a piece of log through a stationary splitting blade. Each motor and the control of each motor require additional structures and func^¬ tions which bring additional costs to the manufacture and the use of the device.

OBJECTIVE OF THE INVENTION

The objective of the invention is to remedy the above- mentioned defects of the prior art. Specifically, the objective of the invention is to disclose a new cut^¬ ting and splitting device that is structurally and functionally extremely simple.

SUMMARY OF THE INVENTION

The cutting and splitting device according to the in^¬ vention comprises a feeder provided with an endless feed belt and a hydraulic motor rotating it for feed- ing a log to be processed. Further, the cutting and splitting device comprises a blade that is reciprocat^¬ ed transversely relative to a log being fed for cut^¬ ting the log into pieces of a desired length. In addi^¬ tion, the cutting and splitting device comprises a splitting blade for splitting a piece cut from a log into two or more parts in the longitudinal direction of the piece. According to the invention, in connec^¬ tion with the splitting blade there is provided a hy^¬ draulic cylinder, by which the splitting blade is mov- able towards the blade for splitting a piece of log and that the hydraulic cylinder of the splitting blade and the hydraulic motor of the feeder are hydraulical- ly connected with each other during the back movement of the splitting blade for carrying out log feeding by the feeder simultaneously with the back movement of the splitting blade. It is naturally clear that the cutting and splitting device also comprises the normal and required hydraulic pump and oil tank for providing the power units with their drive power. In the struc^¬ ture according to the invention, it is thus essential that a log to be split is held in place and the split^¬ ting blade is moved in relation to it so that the log will split. Another essential feature is that the log is not being fed during splitting; instead, log feed^¬ ing is performed during the back movement of splitting by means of the same hydraulic flow by which the splitting blade is returned to the start position. This way, as the splitting blade is reciprocated so as to split the pieces of log, the feed belt rotates in^¬ termittently and only in one direction, only during the back movement of the splitting blade. In other words, the hydraulic circuits of the feed belt and the splitting blade are connected with each other during the back movement of the splitting blade, but the hy^¬ draulic circuit of the feed belt is disconnected from the hydraulic circuit that moves the splitting blade during splitting so that the feed belt is not moving at that time.

It has been brilliantly understood in the invention that by providing the log splitting movement in the opposite direction relative to the log feeding move^¬ ment, it is possible to alternately perform two work stages by the same power unit. This way, the splitting movement that requires most power is only for split- ting of a piece of log, and during the back movement of the splitting blade the log is also fed forward for a distance required for the next cut. The feeding length of the log and the back movement of the split^¬ ting blade are easy to synchronize as the movements are equally long. This is because the blade must be pulled back for the exact distance required by a new piece of log.

Another noteworthy feature in the invention is that splitting of a piece of log is performed against the blade structure used for cutting it. As the blade structure remains between the log and a piece cut from it, the piece of log is pressed by the splitting blade against the blade structure and is thereby pressed through the splitting blade to be divided in two or more parts, depending on the structure of the split^¬ ting blade. This splitting operation is very function^¬ al and reliable, because the piece of log is not dropped after cutting in any other splitting chute in which the piece might drop in random positions. Now, splitting is performed in the exact position and place in which the piece was cut from a log. This way, the splitting blade always moves perpendicularly relative to the cut surface of a piece of log.

The structure according to the invention can be imple^¬ mented by a series connection of the hydraulic cylin^¬ der of the splitting blade and the hydraulic motor of the feeder during the back movement of the splitting blade or by their parallel connection as well. At the simplest, the connection can be provided with two check valves whereby, during the splitting movement, hydraulic oil moves past the hydraulic motor that ro^¬ tates the feeder and, during the back movement of the splitting blade, hydraulic oil moves through the hy^¬ draulic motor that rotates the feeder. Thus, these valves do not need separate control, as they function according to the flow directions. Furthermore, due to such series connection, the back movement of the splitting blade and the feeding movement of the feed belt are precisely fixed with each other, i.e. every back movement of a certain length means a feeding movement of a certain length.

The blade for cutting a log used in the invention may be a shearing blade, i.e. a so-called guillotine blade. This blade is a thick and strong sharp-edged plate that moves along robust guides. Thus, the sharp- edged plate may itself function as a stopper in the splitting operation, i.e., after the sharp-edged plate has cut a piece of log, it remains in place until the piece of log has been pressed by the splitting blade against the sharp-edged plate and been split by it. After splitting, the guillotine blade is lifted to be able to feed the log further.

In another embodiment of the invention, the blade is a sawing blade, such as a bar provided with a sharp- edged chain. However, the bar would not withstand the forces caused by splitting, so a support plate is pro- vided in connection with the bar. The support plate is located behind the bar in the direction of its move^¬ ment when sawing a log, and after cutting the log the bar is turned to some degree further underneath the log. This way, the support plate that follows it re- mains between the log and a piece cut therefrom. The support plate is made of a material that is strong and thick enough so that the splitting blade is able to press a piece of log into parts against the support plate. After splitting, the support plate and the bar are lifted back up out of the way of log feeding to wait for the next sawing operation.

ADVANTAGES PROVIDED BY THE INVENTION

The cutting and splitting device according to the in- vention has considerable advantages over the prior art. The cutting and splitting device according to the invention is simple in structure and operation, so it is affordable to manufacture. Log feeding does not re^¬ quire the use of a separate length measurement, stop^¬ per or other arrangement, because the back movement of the splitting blade and feeding of a length of log al^¬ ways work accurately relative to each other. This way, by determining the degree of back movement of the splitting blade according to a desired length of fire^¬ wood, log feeding is also set accordingly.

Since a cut piece of log is not moved or dropped any^¬ where but is split in place, the piece is never pro^¬ vided crosswise in the splitting. This way, the fire^¬ wood is regular and straight-split, the cutting and splitting device never gets blocked due to crosswise pieces, time-consuming breaks of operation caused by blockages are avoided and the production of waste ma^¬ terial and sticks produced by crosswise splitting is minimi zed .

Furthermore, one advantage is that the entire struc^¬ ture of the cutting and splitting device is smaller and lighter, especially lower, because the cut piece of wood is not dropped into a separate splitting space. Thus, the log is moved, cut and split, and fin^¬ ished pieces of wood removed on the same line in the same plane. A further advantage is that the instanta^¬ neous power requirement is minimized, i.e. no other operations are performed during the highest power con- sumption when a log is being split, whereby log feed^¬ ing is performed during the back movement of the splitting blade, whereas traditionally the log has been fed simultaneously with pushing a piece of log by a piston through a fixed splitting blade.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described below in detail with reference to the accompanying drawings, in which

Fig. 1 schematically illustrates one connection ac^¬ cording to the invention,

Fig. 2 illustrates a splitting operation according to a first embodiment of the invention and

Fig. 3 illustrates a splitting operation according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 schematically illustrates one hydraulic connec^¬ tion according to the invention in a cutting and splitting device. The cutting and splitting device comprises a feed belt 1 rotated on support rolls 9 for feeding a log to be processed into the device. A hy^¬ draulic motor 2 drives the feed belt. Further, the cutting and splitting device comprises a splitting blade 6 which is connected to the piston rod 10 of a hydraulic cylinder 7 for moving the splitting blade in a reciprocated manner. In addition, the hydraulic con^¬ nection comprises a hydraulic pump 11 and an oil tank 12 as well as a splitting valve 13 for providing hy- draulic pressure to the hydraulic cylinder 7.

From the splitting valve 13, a feed line 14 is provid^¬ ed to the hydraulic cylinder 7 for carrying out the work stage of a splitting movement at the splitting blade 6. From the other end of the hydraulic cylinder 7, a return line 15 is provided, through which return line the oil from the opposite side of the piston of the hydraulic cylinder is able to discharge during the work stage back to the oil tank through the valve 13. The return line 15 is provided with a first check valve 16 which prevents flow in the opposite direction in this line.

In parallel to the return line 15, a back movement line 17 is provided, the back movement line comprising a second check valve 18, the flow direction of which is opposite to the first check valve 16. This way, as the hydraulic cylinder 7 is used for splitting, the return oil flows through the return line 15 and the first check valve 16, and during the back movement of the splitting blade 6 to the start position, the oil flows through the back movement line 17 and the second check valve 18 to the part of the hydraulic cylinder 7 that is on the side of the piston rod 10. Further, the hydraulic motor 2 that rotates the feed belt 1 is con^¬ nected to the back movement line 17. This way, the oil pressure of the back movement line 17 for pushing the hydraulic cylinder 7 to the start position also ro^¬ tates the feed belt 1. Since the connection is ar- ranged in series, exactly the same amount of oil al^¬ ways passes through the motor 2 as that passing to the hydraulic cylinder 7. Thus, with proper sizing of the system once, the feeding movement of the feed belt is provided precisely as desired relative to the movement of the splitting blade, for example exactly equal thereto .

It is to be noted that the figure does not illustrate any cutter, a shearing or sawing blade by which a log is cut into pieces before splitting. The controls for it can be implemented completely separately or by suitably connecting them together, suitably synchro^¬ nized with the splitting and feeding movements as de^¬ scribed below in Fig. 2 and 3. Fig. 2 illustrates part of the cutting and splitting device according to the invention as seen from the end of the splitting blade 6. Behind the splitting blade 6, a newly cut piece of log 19 rests on a support sur- face 20, i.e. on the plane where a log was fed for cutting and where the log was cut. Behind the piece of log 19, a cutting blade 4, i.e. a plate-type guillo^¬ tine, that cut it off the log is provided, which cut^¬ ting blade is reciprocated in the vertical direction on guides 21.

When a log has been fed for a desired length under the blade 4, the blade is pressed down whereby it cuts a piece off the log. The blade is left in the down posi- tion and the splitting blade 6 is pushed towards the piece of log 19 whereby it is pressed against the blade 4. Further, by pushing the splitting blade near^¬ ly against the blade 4, the piece of log is split for example in four parts. Immediately after splitting, the blade 4 can be lifted and the splitting blade started to be pulled back and a new log fed forward.

Fig. 3 illustrates a situation that corresponds to Fig. 2 when a sawing blade 5, i.e. a bar and a sharp- edged chain that circulates it, is used as a blade for cutting a log. In this case, by turning the bar in the vertical plane, a crosswise log is cut as normally. However, a piece of log cannot be split against the bar as in the guillotine, because the bar and the sharp-edged chain would not withstand it. Therefore, the path of the bar is arranged to extend, after cut^¬ ting of a log, slightly underneath the log. A support plate 8 is mounted to the frame 22 of the turning bar, the thickness of the support plate substantially cor- responding to the sharp-edged chain, but it is struc^¬ turally stronger. The support plate 8 is a rigid plate that is parallel to the bar and moves next to, i.e. follows, it, the support plate, after the bar has cut a log, being provided at the cut piece of log. This way, splitting of a piece of log as illustrated with reference to Fig. 3 is effected against the strong support plate 8. In the embodiment of Fig. 2, the guillotine blade 4 was firmly provided on strong guides 21. Since in the embodiment of Fig. 3 the bar turns and does not move on guides, it is possible to use splitting supports 23 behind the support plate 8 at both ends of the support plate 8. The splitting supports 23 receive the pressing forces exerted on the support plate 8 by the splitting blade 6, whereby these forces are not able to affect the frame 22 of the turning bar and thus the blade 5 itself.

The invention has been described above by way of exam^¬ ple with reference to the accompanying drawings, dif^¬ ferent embodiments of the invention being possible within the scope defined by the claims.

Claims

1. A cutting and splitting device which comprises a feeder (3) provided with an endless feed belt (1) and a hydraulic motor (2) rotating it for feeding a log to be processed; a blade (4,5) reciprocated transversely relative to a log being fed for cutting the log into pieces; and a splitting blade (6) for splitting a piece cut from a log, characteri z ed in that a hydraulic cylinder (7) is provided in connection with the splitting blade (6) in such a way that the split^¬ ting blade is movable towards the blade (4,5) for splitting a piece of log and that the hydraulic cylin^¬ der (7) of the splitting blade (6) and the hydraulic motor (2) of the feeder (3) are hydraulically connect^¬ ed with each other for carrying out log feeding by the feeder (3) simultaneously with the back movement of the splitting blade.

2. The cutting and splitting device according to claim 1, characteri zed in that the hydraulic cylin^¬ der (7) of the splitting blade (6) and the hydraulic motor (2) of the feeder (3) are arranged in a series connection during the back movement of the splitting blade.

3. The device according to claim 1, character^¬ i z ed in that the hydraulic cylinder of the split^¬ ting blade and the hydraulic motor of the feeder are arranged in a parallel connection during the back movement of the splitting blade.

4. The device according to any one of claims 1-3, characteri zed in that the blade is a shearing blade (4), such as a guillotine.

5. The device according to any one of claims 1-3, characteri zed in that the blade is a sawing blade (5), such as a bar provided with a sharp-edged chain .

6. The device according to claim 5, character^¬ i z ed in that, in the direction of movement of the bar (5) when sawing a log, it is followed by a support plate (8), against which a cut piece of log is split.