SE545257C2 - Chain saw for harvester head with swivel arm, harvester head comprising such a chain saw and a method for determining the position of the guide bar of the chain saw - Google Patents
Chain saw for harvester head with swivel arm, harvester head comprising such a chain saw and a method for determining the position of the guide bar of the chain sawInfo
- Publication number
- SE545257C2 SE545257C2 SE2230071A SE2230071A SE545257C2 SE 545257 C2 SE545257 C2 SE 545257C2 SE 2230071 A SE2230071 A SE 2230071A SE 2230071 A SE2230071 A SE 2230071A SE 545257 C2 SE545257 C2 SE 545257C2
- Authority
- SE
- Sweden
- Prior art keywords
- guide bar
- chain saw
- counter
- distance
- swivel arm
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 10
- 238000005259 measurement Methods 0.000 claims description 5
- 230000001174 ascending effect Effects 0.000 claims description 4
- 230000006870 function Effects 0.000 description 4
- 241001124569 Lycaenidae Species 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 230000003455 independent Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G23/00—Forestry
- A01G23/02—Transplanting, uprooting, felling or delimbing trees
- A01G23/08—Felling trees
- A01G23/091—Sawing apparatus specially adapted for felling trees
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
- G01B5/02—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness
- G01B5/04—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness specially adapted for measuring length or width of objects while moving
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
- G01B5/02—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness
- G01B5/06—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness for measuring thickness
- G01B5/068—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness for measuring thickness of objects while moving
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Forests & Forestry (AREA)
- Environmental Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Dry Shavers And Clippers (AREA)
- Photoreceptors In Electrophotography (AREA)
- Liquid Crystal (AREA)
- Harvester Elements (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
- Sawing (AREA)
Abstract
SummaryThe invention relates to a chain saw (100) for a harvester head having a swivel arm (110) equipped with a shaft (115) and a motor (170), an elongate guide bar (120) arranged to pivot via the shaft (115), and a saw chain arranged movably on the guide bar (120). The chain saw comprises a counter-surface (113) arranged pivotably on the shaft (115) at a distance from the swivel arm (110) in the axial direction, having a cross-section that varies as a function of the pivot angle (position) of the guide bar (120), the chain saw further comprising measuring means adapted for determining the pivot angle of the guide bar based on the variable cross-section of the counter-surface (113). The invention further relates to a method for determining the position of a guide bar and to a harvester head.
Description
Chain saw for harvester head with swivel arm, harvester head comprising such a chain saw and a method for determining the position of the guide bar of the chain saw Field of the invention The present invention relates to a method for determining the position of a chain saw as defined in the preambles of the independent claims. The invention further relates to a chain saw and a harvester head as defined in the preambles of the inde- pendent claims.
Background of the invention The position of the guide bar of a chain saw used in harvester heads in harvesters, i.e., felling machines, is generally measured by measuring the rotational movement (pivoting) of the guide bar. For example, sensors measuring the position of the piv- oting cylinder, pulse sensors used by means of levers and inductive sensors for cal- culating shoulders or magnets are previously known, wherein based on the meas- urement, the pivot angle of the chain saw guide bar with respect to its initial posi- tion is detected. Measuring the oil flow to the pivoting cylinder has also been uti- lized. The problem with previously known solutions is the complexity of the levers used and the limited resolution of the sensors.
Summary of the invention The object of the invention is to solve the above-mentioned problems and to pro- vide a method for determining the position of a chain saw. It is a further object of the invention to provide a chain saw and a harvester head. The above objects are achieved by the invention, which is characterized by what is set forth in the inde- pendent claims.
A typical chain saw according to the invention comprises a swivel arm equipped with a shaft and a motor, an elongate guide bar adapted to pivot via the shaft and a saw chain arranged movably on the guide bar. The invention is characterized in that the chain saw comprises a counter-surface arranged pivotably on the shaft at a distance from the swivel arm in the axial direction, having the shape of a descending or as- cending ramp with a cross-section that varies in the direction of its shaft as a func- tion of the pivot angle (position) of the guide bar, and in that the chain saw com- prises measuring means adapted for determining the pivot angle based on the vari- able cross-section of the counter-surface, and in that the measuring means com- prise a distance measuring sensor situated at a measuring point adapted to meas- ure the change in distance from the counter-surface relative to the measuring point on the swivel arm, whereby a change in the distance between the swivel arm and the guide bar detected by the sensor can be interpreted as a change in the pivot angle of the guide bar by means of a signal produced by the sensor, which signal is proportional to the measured change in distance.
The idea of the invention is that the rotational movement of the chain saw guide bar is converted into movement of the guide bar in the axial direction of the guide bar, as it is easier to measure the rotational movement when converted into the ax- ial direction. The chain saw has an oblique surface formed therein, which may be, for example, an ascending or descending ramp, wherein the distance from its cross- section to the swivel arm varies as a function of the pivot angle of the guide bar. The change in distance from the cross-section is monitored by a distance measuring device on the swivel arm, such as a sensor, providing a signal proportional to the detected change in distance, for example as a current signal. The advantages of the invention are its structural simplicity and the good measurement accuracy achieved by it.
Other preferred embodiments of the invention are described in the dependent claims.
Brief description of the drawings Next, the invention is described in more detail with reference to the accompanying drawings, in which Fig. 1 is a diagonal side view of the chain saw according to an embodiment of the invention; Fig. 2 shows a part of the chain saw shown in Fig. 1; Fig. 3 shows the cross-section of the chain saw part shown in Fig. 2 along the line A-A.
Detailed description of the invention Fig. 1 to 3 show a chain saw 100 according to an embodiment of the invention for use in felling machines known as harvesters, i.e. forestry tractors. The chain saw 100 comprises a swive| arm 110 having an e|ongate guide bar 120 arranged to pivot via a pivot shaft 115 and secured to the swive| arm 110 by a retainer 140. A saw chain 111 adapted to move by means of a motor 170 and a sprocket 160 in the chain saw 100 is accommodated in a groove along the periphery of the guide bar 120, in use moving in the direction of the groove around the guide bar 120. The ar- rangement on the swive| arm 110 thus allows the chain saw guide bar 120 to be pivoted about the shaft 115 in the range of the pivot angle, the range of variation of which may depend on the characteristics of the harvester head and/or chain saw used.
In the example shown in Fig. 1, the swive| arm 110 is a circular steel flange at- tached to the motor 170. A control flange 112 matching the shape of the swive| arm 110 is arranged on the same shaft as the swive| arm, shown in Fig. 1 between the guide bar and the swive| arm 110. The control flange 112 is arranged such that its first side faces the guide bar 120, and the second side, opposite the first side, faces the swive| arm 110. The swive| arm 110 and the control flange 112 are spaced apart from one another and operatively arranged such that they are pivotable relative to one another about a shaft 115 passing through their centers. The guide bar 120 is attached to the control flange 112, whereby when the guide bar 120 is pivoted, the control flange 112 pivots simultaneously with the guide bar 120 relative to the swive| arm The outer edge of the control flange 112 further includes a counter-surface 113 fac- ing the swive| arm 110. The counter-surface 113 may be an integral part of the con- trol flange 112 and industrially formed or machined into the control flange, or it may be a separate part detachable from the control flange, e.g., a part, a rim or a disc formed from the flange. The counter-surface 113 extends perpendicular to the shaft 115 of the control flange 112, i.e., radially outward from the shaft of the control flange such that the edges of the cou nter-surface 113 are confined to the area be- tween the outer edges of the control flange and the swivel arm. The counter-sur- face 113 further extends in the direction of the outer edge of the control flange 112 such that the extension covers a portion of the outer edge of the control flange and forms a planar surface facing the swivel arm The side of the counter-surface 113 facing the swivel arm 110 is arranged such that the distance therefrom relative to the swivel arm in the direction of its shaft 115 (axial distance) varies as a function of the pivot angle of the guide bar. This is im- plemented such that the first end 113' of the counter-surface (see Fig. 3) is closer to the swivel arm 110 in the axial direction than the second end 113" of the coun- ter-surface, which is closer to the guide bar. The counter-surface thus forms an as- cending (or descending) ramp, i.e., a variable cross-section extending between the ends 113' and 113" along the edge of the control flange 112. The swivel arm 110 comprises a device 150 opposite the control flange 113, at a measuring point therein, detecting the current position of the guide bar 120, i.e., the initial pivot an- gle, and the change in the position of the guide bar relative to the initial position of the guide bar 120 when the guide bar is pivoted. This device 150 may be, for exam- ple, a distance measuring sensor. In the example shown in Fig. 1 to 3, the sensor 150 is arranged through the swivel arm 110, for example such that the distance measuring end of the sensor faces the counter-surface 113 in the control flange 112. In this case, the sensor is electrically connected so as to be able to produce a signal proportional to the measured change in distance. This can be, for example, a current signal between 4 and 20 mA. There may be a variety of distance measuring devices and sensors that may be suitable for the purpose described herein, includ- ing, for example, inductive and optical sensors, IR sensors, LiDAR sensors, and ul- trasonic sensors.
When the guide bar is pivoted relative to the shaft 115, the distance from the coun- ter-surface 113 relative to the measuring point on the swivel arm (device 150) changes. The change in distance in the axial direction is indicated by the bidirec- tional vertical arrow in Fig. 3. Pivoting of the guide bar about its shaft 115 in oppo- site directions, right and left, is indicated by the curved bidirectional arrow in Fig.
When the chain saw guide bar is during use pivoted to the right, for example, the distance between the counter-surface 113 and the swivel arm 110 as measured from the measuring point increases (or decreases). When the guide bar is pivoted in the direction opposite to the above, i.e., to the left, the distance between the coun- ter-surface and the swivel arm as measured from the measuring point decreases (or increases). The change in distance is dependent on how the counter-surface is ar- ranged relative to the swivel arm and the direction in which the guide bar is pivoted, to the right or to the left.
The above-described change in distance from the counter-surface can also be un- derstood as a change in the position of the guide bar, i.e., the pivot angle, relative to the initial position which the guide bar was in before pivoting of the guide bar be- gan. If the counter-surface is ramp-like, as in the example described above (see Fig. 3), the change in distance from the counter-surface is in that case detected by measuring the distance to the cou nter-surface of the ramp (its cross-section) from the measuring point on the swivel arm. Distance measurement may be carried out from more than one measuring point. When the measured distance changes, it can be concluded that the position of the guide bar, its pivot angle, changes accord- ingly.
The range of variation of the pivot angle must be taken into account when dimen- sioning the counter-surface. The minimum value of the pivot angle may be set to correspond to, for example, the first end 113' of the counter-surface and the maxi- mum value of the pivot angle may be set to correspond to the second end 113" of the counter-surface, as in the example above (Fig. 3). The range of variation of the pivot angle may be set such that it is between the minimum and maximum values of the ends 113' and 113" of the counter-surface. From an operational point of view, it should be ensured that the counter-surface covers an area in which the chain saw guide bar can be pivoted, and that the counter-surface is shaped so as to have a cross-section varying as a function of the pivot angle. As above, the counter- surface may have the shape of an ascending or descending ramp, for example, but other counter-surface shapes may also be possible.
Based on the distance measured with the sensor, the initial position of the pivot an- gle with the guide bar in place can then be detected. When the guide bar is pivoted, the sensor may be used to detect a change in the pivot angle relative to the initial position by comparing the distance measured by the sensor with previously stored data measured by the sensor. Based on the comparison, it is possible to determine the direction of the pivot angle, the direction in which the guide bar is pivoted, and the magnitude of the pivot angle. The measurement may be carried out automati- cally such that the sensor is connected to data processing means or systems, such as programmable logic or a computer. The data measured by the sensor may be further stored and processed by data processing means and systems. The sensor may be controlled so as to generate, for example, pulse trains which are stored and processed by a computer. As described herein, the sensors and data processing sys- tems thus enable the detecting and recording of very small angular movements compared to known arrangements.
It is to be understood that the above description and the accompanying drawings are intended only to illustrate the present invention. Thus, the invention is not lim- ited to the embodiment described above or defined in the claims, but it will be ap- parent to those skilled in the art that the invention may be modified in many ways within the scope of the inventive idea set forth in the appended claims. Embodi- ments may be varied, for example in such a way that the measuring means, for ex- ample a sensor, are mounted on an inclined or ramp-like surface of the control flange such that the measuring end of the sensor is directed towards the swivel arm in the axial direction, whereby a change in distance between the swivel arm and the control flange detected using the measuring means, i.e., the sensor, may be inter- preted as a change in the pivot angle of the guide bar in the manner described above.
It will be apparent to those skilled in the art that with development of technology, the inventive concept can be implemented in many ways. Further, it will be appar- ent to those skilled in the art that the described embodiments may be combined with other embodiments in various ways.
Claims (9)
1. A chain saw (100) for a harvester head with a swivel arm (110) equipped with a shaft (115) and a motor (170), an elongate guide bar (120) adapted to pivot about the shaft (115) and saw chain adapted to move on the guide bar (120) by means of the motor ( 170), characterized in that the chain saw comprises a counter-surface (113) arranged pivotably on the shaft (115) at a distance from the swivel arm (110) in the axial direction, having the shape of a descending or ascending ramp with a cross-section that varies in the direction of its shaft (115) as a function of the pivot angle of the guide bar (120), in that the chain saw further comprises measuring means (150) adapted for determining the pivot angle of the guide bar based on the variable cross-section of the counter-surface (113), and in that the measuring means (150) comprise a distance measuring sensor arranged to measure the change in distance from the counter-surface ( 113) relative to a measuring point on the swivel arm ( 110), whereby the change in distance between the swivel arm ( 110) and the guide bar (120) can be interpreted as a change in the pivot angle of the guide bar by means of a signal produced by the sensor, which signal is proportional to the measured change in distance.
2. The chain saw according to claim 1, characterized in that the counter-surface (113) is pivotable about a shaft (115) in the chainsaw when the guide bar (120) is pivoted.
3. The chain saw according to claim 1, characterized in that the edges of the counter-surface ( 113) are confined to the area between the outer edges of a control flange (112) and the swivel arm (110).
4. The chain saw according to claim 3, characterized in that the counter-surface (113) is an integral part of the control flange (112).
5. The chain saw according to claim 1, characterized in that the counter-surface (113) is a separate detachable part comprised of a flange, a rim, or a plate.
6. A method for determining the position of the guide bar (120) of a chain saw (100), characterized in that the method comprises measuring the axial distance from a descending or ascending ramp of a counter-surface (113) arranged pivotably on the shaft (115) of the chain saw (100) having a cross-section that varies as a function of the pivot angle of the guide bar (120), and based on the measured dis- tance, determining the pivot angle of the guide bar (120), wherein the method com- prises determining the change in distance from the counter-surface (113) relative to a measuring point using a sensor situated at the measuring point on the swivel arm, and interpreting the change in the pivot angle of the guide bar (120) by means of a signal produced by the sensor, which signal is proportional to the measured change in distance.
7. The method according to claim 6, characterized in that the step of determining the position of the guide bar (120) comprises comparing the measured distance with stored distance measurement data.
8. The method according to claim 6, characterized in that as the guide bar (120) is pivoted relative the shaft ( 115) of the chain saw ( 100), the axial distance from the counter-surface (113) changes.
9. A harvester head, characterized in that it comprises a chain saw according to any of the preceding claims 1 to 5.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20215301A FI130978B1 (en) | 2021-03-19 | 2021-03-19 | Chain saw |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| SE2230071A1 SE2230071A1 (en) | 2022-09-20 |
| SE545257C2 true SE545257C2 (en) | 2023-06-07 |
Family
ID=83603444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SE2230071A SE545257C2 (en) | 2021-03-19 | 2022-03-14 | Chain saw for harvester head with swivel arm, harvester head comprising such a chain saw and a method for determining the position of the guide bar of the chain saw |
Country Status (2)
| Country | Link |
|---|---|
| FI (1) | FI130978B1 (en) |
| SE (1) | SE545257C2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU574188A1 (en) * | 1976-05-07 | 1977-09-30 | Центральный Научно-Исследовательский И Проектно-Конструкторский Институт Механизации И Энергетики Лесной Промышленности | Device for registering output of tree-felling machine |
| US4301845A (en) * | 1980-02-04 | 1981-11-24 | Paul Lowell A | Tree shear |
| US4901612A (en) * | 1984-02-06 | 1990-02-20 | Harris Gerald R | Band saw apparatus and method with pressure controlled feed |
| WO1997025855A1 (en) * | 1996-01-16 | 1997-07-24 | Sandvik Aktiebolag | Angle measuring device |
-
2021
- 2021-03-19 FI FI20215301A patent/FI130978B1/en active
-
2022
- 2022-03-14 SE SE2230071A patent/SE545257C2/en unknown
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU574188A1 (en) * | 1976-05-07 | 1977-09-30 | Центральный Научно-Исследовательский И Проектно-Конструкторский Институт Механизации И Энергетики Лесной Промышленности | Device for registering output of tree-felling machine |
| US4301845A (en) * | 1980-02-04 | 1981-11-24 | Paul Lowell A | Tree shear |
| US4901612A (en) * | 1984-02-06 | 1990-02-20 | Harris Gerald R | Band saw apparatus and method with pressure controlled feed |
| WO1997025855A1 (en) * | 1996-01-16 | 1997-07-24 | Sandvik Aktiebolag | Angle measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| FI130978B1 (en) | 2024-07-01 |
| SE2230071A1 (en) | 2022-09-20 |
| FI20215301A1 (en) | 2022-09-20 |
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