JP2010269490A - Chain saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chain saw allowing considerable adjustment of a tension state of the chain saw by a few operations. <P>SOLUTION: A chain adjustment device of the chain saw includes an operation member, a rotary shaft, and a linear motion element. A first gear is coaxially fixed to the operation member. A second gear engaged with the first gear is coaxially fixed to the rotary shaft, and a feed screw is formed in at least a partial range in the axial direction. The linear motion element, locked to a guide bar and having a screw hole screwed by the feed screw of the rotary shaft, moves along the rotary shaft together with the guide bar according to the rotation of the rotary shaft. A gear ratio of the second gear to the first gear is less than one. When the operation member is rotation-operated, the rotary shaft rotates more than the operation member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chain saw, and more particularly to a chain adjustment mechanism that adjusts the tension of the saw chain.

Patent Document 1 discloses a chain saw. This chain saw includes a chain adjustment mechanism that adjusts the tension of the saw chain. The chain adjustment mechanism includes an operation member, a rotary shaft, and a linear motion element. The operating member is fixed coaxially to the rotating shaft. The rotating shaft is provided so as to be rotatable with respect to the main body of the chain saw, and a feed screw is formed in a part of the axial direction. The linear motion element is locked to the guide bar and has a screw hole that engages with the feed screw of the rotary shaft. As the rotary shaft rotates, the linear moving element moves along the rotary shaft together with the guide bar.
With the above configuration, when the operator rotates the operation member, the guide bar moves forward and backward with respect to the chain saw body. Thereby, the tension of the saw chain spanned between both the main body and the guide bar is adjusted.

German Patent Invention No. 10353737

  When adjusting the tension of the saw chain, it is necessary to move the guide bar with respect to the main body. However, in the conventional chainsaw, the amount of movement of the guide bar is small with respect to the amount of operation by rotating the operation member. For this reason, when adjusting the tension degree of a saw chain largely, an operator must rotate many operation members.

  The present invention solves the above problems. The present invention provides a technique capable of greatly adjusting the tension of a saw chain without rotating many operation members.

  A chain saw embodied by the present invention includes a chain saw main body, a guide bar attached to the chain saw main body so as to be movable back and forth, a saw chain provided between the chain saw main body and the guide bar, and a chain saw main body. A chain adjustment mechanism is provided that moves the guide bar back and forth with respect to the chain saw body.

The chain adjustment mechanism includes an operation member, a rotary shaft, and a linear motion element. The operation member is rotatably provided with respect to the chain saw body. A first gear is coaxially fixed to the operation member. The rotation shaft is provided so as to be rotatable with respect to the chain saw body, and a second gear engaged with the first gear is fixed coaxially. The rotary shaft is formed with a feed screw in at least a partial range in the axial direction. The linear motion element is locked to the guide bar and has a screw hole that engages with the feed screw of the rotary shaft. Thereby, the linear motion element moves along the rotation shaft together with the guide bar as the rotation shaft rotates.
In this chain adjustment mechanism, the gear ratio of the second gear to the first gear is less than 1. Therefore, when the operator rotates the operation member, the rotation shaft rotates more than the operation member. Therefore, the operator can greatly adjust the tension of the saw chain without rotating many operation members.

  In the chain adjusting mechanism described above, the rotating shafts of the operating member and the first gear and the rotating shafts of the second gear and the rotating shaft can be arranged in parallel to each other. In this case, for example, a spur gear, a helical gear, a helical gear, or the like can be employed for each of the first gear and the second gear. At this time, the number of teeth of the first gear may be larger than the number of teeth of the second gear.

  Alternatively, the rotating shafts of the operating member and the first gear can be arranged in a plane perpendicular to the rotating shafts of the second gear and the rotating shaft. In this case, the first gear may be a helical gear, the second gear may be a screw gear, and a worm gear may be configured. Also with this configuration, the gear ratio of the second gear to the first gear is less than 1, and when the operator rotates the operation member, the rotation shaft can rotate more than the operation member.

The present invention is also embodied in a second chain saw described below. This chain saw is provided on a chain saw body, a guide bar that is attached to the chain saw body so as to be movable back and forth, a saw chain that is provided across the chain saw body and the guide bar, and a chain saw body. A chain adjustment mechanism for moving the guide bar forward and backward is provided.
The chain adjustment mechanism includes an operation member and a linear motion element. The operation member is provided so as to be rotatable with respect to the chain saw body, and a screw hole is formed coaxially with the rotation shaft. The linear motion element is locked to the guide bar and has a feed screw that is screwed into the screw hole of the operation member, and linearly moves together with the guide bar as the operation member rotates.

  In the chain adjustment mechanism described above, a feed screw mechanism is formed between the operation member and the linear motion element. The operation member is a relatively large member, and in the structure in which the feed screw mechanism is provided between the operation member and the linear motion element, the lead of the feed screw can be made relatively large. Accordingly, it is possible to greatly adjust the tension of the saw chain without rotating many operation members.

  In the chain saw of the present invention, the tension of the saw chain can be adjusted greatly with a small number of operations. Therefore, for example, the operator can complete the replacement work of the saw chain in a short time.

The external view of the chainsaw of Example 1 is shown. The figure which shows the state which removed the cover from the chainsaw of Example 1. FIG. FIG. 3 is a diagram illustrating a chain adjustment mechanism according to the first embodiment. IV-IV sectional view taken on the line in FIG. VV sectional view taken on the line in FIG. VI-VI sectional view taken on the line in FIG. The figure which shows the state which removed the cover from the chainsaw of Example 2. FIG. FIG. 6 is a diagram illustrating a chain adjustment mechanism according to a second embodiment. IX-IX sectional view taken on the line in FIG. XX sectional drawing in FIG. The state which removed the cover from the chainsaw of Example 3 is shown. FIG. 10 is a diagram illustrating a chain adjustment mechanism according to a third embodiment. XIII-XIII sectional view taken on the line in FIG. The XIV-XIV sectional view taken on the line in FIG. XV-XV sectional view taken on the line in FIG. XVI-XVI sectional view taken on the line in FIG.

First, the main features of the embodiments described below are listed.
(Feature 1) The main body of the chainsaw is provided with a motor as a prime mover and a sprocket that is rotationally driven by the motor.
(Feature 2) The saw chain is stretched over both the guide bar and the sprocket.
(Characteristic 3) The guide bar is supported so as to be movable back and forth with respect to a sprocket provided in the main body.
(Characteristic 4) At least a part of the operation member is exposed to the outside, and is configured so that the operator can rotate it.

  Example 1 will be described with reference to the drawings. FIG. 1 shows an external view of the chainsaw 10. FIG. 2 shows an external view of the chainsaw 10 with a cover 24 and a saw chain 32 removed from the main body 12 to be described later. The chain saw 10 includes a main body 12, a guide bar 30 attached to the main body 12, and a saw chain 32. In addition, in FIG. 1, the part at the front end side of the guide bar 30 is not shown. In FIG. 2, the saw chain 32 is not shown.

  As shown in FIGS. 1 and 2, the main body 12 includes a motor 16, a first grip 14, a second grip 18, and a sprocket 38. The second grip 18 is provided with a trigger switch 20 that activates the chainsaw 10. The sprocket 38 is provided on the side surface of the main body 12 and is rotatably supported by the main body 12. The sprocket 38 is connected to the motor 16 and is rotationally driven by the motor 16. The motor 16 is configured to be supplied with power from the battery 22 in conjunction with an operation on the trigger switch 20. The battery 22 is detachably attached to the main body 12.

A guide bar 30 is attached to the main body 12. The guide bar 30 is disposed adjacent to the sprocket 38. The guide bar 30 and the sprocket 38 are located on substantially the same plane. The saw chain 32 (not shown in FIG. 2) is bridged so as to surround both the sprocket 38 and the guide bar 30 of the main body 12.
In the chainsaw 10, when the operator turns on the trigger switch 20, the motor 16 as a prime mover starts rotating. As the motor 16 rotates, the sprocket 38 rotates relative to the main body 12. As a result, the saw chain 32 as a tool rotates along the periphery of the sprocket 38 and the guide bar 30. An operator can cut wood or the like by pressing the rotating saw chain 32.

  As shown in FIG. 2, the guide bar 30 is supported on the side surface of the main body 12 by support bolts 34 and support pins 36. The support bolt 34 and the support pin 36 are fixed to the main body 12. The support bolt 34 and the support pin 36 are inserted into a long hole 30 b formed in the guide bar 30, and support the guide bar 30 so as to advance and retreat relative to the main body 12. When the guide bar 30 moves back and forth with respect to the main body 12, the distance between the guide bar 30 and the sprocket 38 changes, and the tension of the saw chain 32 changes.

An operation wheel 54 and an adjustment pin 40 are provided on the side surface of the main body 12. The operation wheel 54 and the adjustment pin 40 constitute a part of a chain adjustment mechanism 50 described later.
The operation wheel 54 is supported so as to be rotatable with respect to the main body 12. A part of the operation wheel 54 is exposed to the outside, and the operator can rotate it. The operator is rotated by the operator when the operator adjusts the tension of the saw chain 32.
The adjustment pin 40 protrudes from the side surface of the main body 12 and is inserted into the locking hole 30 a of the guide bar 30. The adjustment pin 40 is configured to move linearly in response to an operation applied to the operation wheel 54. That is, when the operator rotates the operation wheel 54 in one direction, the adjustment pin 40 linearly moves in a direction approaching the sprocket 38, and when the operator rotates the operation wheel 54 in the other direction, the adjustment pin 40 is moved to the sprocket. It moves linearly away from 38. As a result, the guide bar 30 locked to the adjustment pin 40 moves forward and backward with respect to the main body 12, and the tension of the saw chain 32 changes. The structure of the chain adjustment mechanism 50 will be described in detail later.

  A cover 24 that covers the sprocket 38 and a fixing knob 28 for fixing the guide bar 30 are provided on the side surface of the main body 12. The fixing knob 28 is screwed into a support bolt 34 protruding from the side surface of the main body 12. When the fixing knob 28 is tightened with respect to the support bolt 34, the cover 24 and the guide bar 30 are firmly fixed to the main body 12. On the other hand, when the fixing knob 28 is loosened with respect to the support bolt 34, the guide bar 30 can advance and retract with respect to the main body 12. The cover 24 is held by a fixing knob 28. When the fixing knob 28 is removed from the fixing bolt 34, the cover 24 can also be removed from the main body 12.

The chain adjustment mechanism 50 will be described with reference to FIGS. 3, 4, 5, and 6. The chain adjusting mechanism 50 is built in the main body 12 and is a linear motion mechanism that converts the rotational motion of the operation wheel 54 into the linear motion of the adjustment pin 40.
The chain adjustment mechanism 50 includes a first rotation shaft 52, an operation wheel 54, a first gear 56, a second gear 58, a second rotation shaft 60, and an adjustment pin 40.
The first rotating shaft 52 is rotatably supported by the main body 12. The first rotating shaft 52 is supported by the main body 12 so as not to move in the axial direction. An operation wheel 54 and a first gear 56 are fixed to the first rotating shaft 52. The operation wheel 54 and the first gear 56 are located on the same axis, and when the operator rotates the operation wheel 54, the first gear 56 rotates together.

The second rotating shaft 60 is rotatably supported by the main body 12. The second rotating shaft 60 is supported by the main body 12 so as not to move in the axial direction. The second rotation shaft 60 is disposed in parallel with the first rotation shaft 52. A second gear 58 is fixed to one end side of the second rotating shaft 60. The second gear 58 is engaged with the first gear 56, and when the first gear 56 rotates, the second gear 58 also rotates. Both the first gear 56 and the second gear 58 are spur gears.
A feed screw 62 is formed at the other end of the second rotating shaft 60. An adjustment pin 40 is attached to the feed screw 62. A screw hole 44 that is screwed into the feed screw 62 of the second rotary shaft 60 is formed in the base portion 42 of the adjustment pin 40. Therefore, when the second rotation shaft 60 rotates, the adjustment pin 40 moves along the second rotation shaft 60.

  With the above configuration, in the chain adjustment mechanism 50, when the operator rotates the operation wheel 54, the first rotation shaft 52, the first gear 56, the second gear 58, and the second rotation shaft 60 rotate, and the adjustment pin 40 moves along the second rotating shaft 60. When the adjustment pin 40 moves, the guide bar 30 locked to the adjustment pin 40 also moves. As a result, the tension of the saw chain 32 changes. The operator can adjust the tension of the saw chain 32 by operating the operation wheel 54. In addition, since the guide bar 30 can be moved quickly and greatly, replacement work of the saw chain 32 and the like can be completed in a short time.

  In the chain adjustment mechanism 50 of the present embodiment, the number of teeth of the first gear 56 is larger than the number of teeth of the second gear 58, and the gear ratio of the second gear 58 to the first gear 56 is less than 1. Yes. That is, when the operator rotates the operation wheel 54, the second rotation shaft 60 is configured to rotate more than the operation wheel 54. Therefore, the operator can greatly adjust the tension of the saw chain 32 without rotating the operation wheel 54 much. In this embodiment, the number of teeth of the first gear 56 is 21 and the number of teeth of the second gear 58 is 12. However, the present invention is not limited to this combination of teeth.

  A chain saw 110 according to the second embodiment will be described with reference to FIGS. The chain saw 110 according to the second embodiment is different from the chain saw 10 according to the first embodiment in the configuration of the chain adjustment mechanisms 50 and 150. In the following description, the configuration of the chain adjustment mechanism 150 in the present embodiment will be mainly described, and the description of the other configurations common to the first embodiment will be omitted by attaching the same reference numerals.

The chain adjusting mechanism 150 of this embodiment includes a first rotating member 152, an operation knob 154, a helical gear 156, a screw gear 158, a second rotating shaft 60, and an adjusting pin 40.
The first rotating member 152 is rotatably supported by the main body 12. The rotation axis of the first rotation member 152 is substantially perpendicular to the side surface of the main body 12. An operation knob 154 and a helical gear 156 are fixed to the first rotating member 152. The operation knob 154 and the helical gear 156 are located on the same axis, and when the operator rotates the operation knob 154, the helical gear 156 rotates together. Here, the operation knob 154 is provided with a handle 154a that can be accommodated.

  The second rotating shaft 60 is rotatably supported by the main body 12. Here, the rotation axis of the operation knob 154 and the rotation axis of the second rotation shaft 60 are not parallel to each other. In the present embodiment, the rotation axis of the operation knob 154 is located in a plane perpendicular to the second rotation shaft 60. A screw gear 158 is fixed to one end side of the second rotating shaft 60. The screw gear 158 is engaged with the helical gear 156, and the helical gear 156 and the screw gear 158 constitute a worm gear mechanism.

  With the above configuration, in the chain adjustment mechanism 150, when the operator rotates the operation knob 154, the first rotating member 152, the helical gear 156, the screw gear 158, and the second rotating shaft 60 rotate, respectively, and the adjustment pin 40 moves along the second rotating shaft 60. When the adjustment pin 40 moves, the guide bar 30 locked to the adjustment pin 40 also moves. As a result, the tension of the saw chain 32 changes. The operator can adjust the tension of the saw chain 32 by operating the operation knob 154.

  In the chain adjustment mechanism 150 of the present embodiment, a worm gear mechanism having a helical gear 156 as an input side and a screw gear 158 as an output side is configured, and the operation is performed when the operator rotates the operation knob 154. The second rotating shaft 60 is configured to rotate more than the knob 154. That is, the gear ratio of the screw gear 158 to the helical gear 156 is less than 1. Therefore, the operator can largely adjust the tension of the saw chain 32 without rotating the operation knob 154 many times.

  With reference to FIGS. 11-16, the chain saw 210 of Example 3 is demonstrated. The chain saw 210 according to the third embodiment is different from the chain saw 10 according to the first embodiment in the configuration of the chain adjustment mechanisms 50 and 250. In the following description, the configuration of the chain adjustment mechanism 250 in the present embodiment will be mainly described, and the description of other configurations common to the first embodiment will be omitted by attaching the same reference numerals.

The chain adjustment mechanism 250 of this embodiment includes an operation wheel 254 and a slide shaft 242. An adjustment pin 40 that is locked in the locking hole 30 a of the guide bar 30 is provided at the tip of the slide shaft 242.
The slide shaft 242 is supported by the main body 12. The slide shaft 242 has a shape that bends at a plurality of locations. With this shape, the slide shaft 242 is slidably movable with respect to the main body 12 and is supported so as not to rotate with respect to the main body 12. A feed screw 243 is provided at the base end of the slide shaft 242. The range where the feed screw 243 is formed extends parallel to the direction in which the guide bar 30 is supported so as to be able to advance and retract.

  The operation wheel 254 is supported by a feed screw 243 of the slide shaft 242. As shown in FIG. 14, a hexagon nut 255 is coaxially fixed to the operation wheel 254. The screw hole 255 a of the hexagon nut 255 is screwed into the feed screw 243 of the slide shaft 242. Thereby, when the operation wheel 254 is rotated, the slide shaft 242 moves in parallel with the rotation axis of the operation wheel 254. Here, the rotation axis of the operation wheel 254 is parallel to the feed screw 243 of the slide shaft 242 and parallel to the direction in which the guide bar 30 is supported so as to be able to advance and retract. The operation wheel 254 is sandwiched from both sides by a wheel cover 257 provided on the main body 12 (see FIG. 11), and is prohibited from moving in a direction parallel to the rotation axis.

  With the above configuration, in the chain adjustment mechanism 250, when the operator rotates the operation wheel 254, the slide shaft 242 and the adjustment pin 40 at the tip thereof slide and move parallel to the rotation axis of the operation wheel 254. When the adjustment pin 40 moves, the guide bar 30 locked to the adjustment pin 40 also moves. As a result, the tension of the saw chain 32 changes. The operator can adjust the tension of the saw chain 32 by operating the operation wheel 254.

  In the chain adjustment mechanism 250 of this embodiment, a feed screw mechanism including a hexagon nut 255 and a feed screw 243 is provided between the operation wheel 254 and the slide shaft 242. According to this configuration, the diameter of the feed screw 243 can be increased, and the lead of the feed screw 243 can be increased accordingly. Thereby, the movement amount of the adjustment pin 40 can be increased with respect to the number of rotations of the operation knob 154. Therefore, the operator can largely adjust the tension of the saw chain 32 without rotating the operation wheel 254 many times.

As mentioned above, although embodiment of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in this specification or the drawings achieves a plurality of objects at the same time, and achieving one of the objects itself has technical utility.

10, 110, 210: Chain saw 12: Chain saw body 16: Motor 20: Trigger switch 22: Battery 28: Fixing knob 30: Guide bar 30a: Guide bar locking hole 30b: Guide bar long hole 32: Saw chain 38 : Sprocket 40: adjusting pin 42: adjusting pin base 44: adjusting pin screw holes 50, 150, 250: chain adjusting mechanism 52: first rotating shaft 54, 254: operation wheel 56: first gear 58: second gear 60: second rotating shaft 62: second rotating shaft feed screw 152: first rotating member 154: operation knob 154a: operation knob knob 156: helical gear 158: screw gear

Claims (4)

The chainsaw body,
A guide bar attached to the chain saw body so as to be capable of moving forward and backward;
A saw chain spanning both the chain saw body and the guide bar;
The chain saw body is provided with a chain adjustment mechanism for moving a guide bar forward and backward with respect to the chainsaw body,
The chain adjusting mechanism is
An operating member provided rotatably with respect to the chain saw body, wherein the first gear is fixed coaxially;
A second gear engaged with the first gear is coaxially fixed, and a feed screw is formed in at least a part of the axial direction. A rotating shaft,
A linear motion that has a screw hole that engages with a feed screw of the rotating shaft and a locking portion that is locked to the guide bar, and moves along the rotating shaft together with the guide bar as the rotating shaft rotates. With a child
A chain saw, wherein a gear ratio of the second gear to the first gear is less than 1, and the rotating shaft rotates more than the operating member when the operating member is rotated.   2. The chain saw according to claim 1, wherein a rotation shaft of the operation member and the first gear and a rotation shaft of the second gear and the rotation shaft are parallel to each other. The operation member and the rotation shaft of the first gear are located in a plane perpendicular to the rotation shaft of the second gear and the rotation shaft,
The chain saw according to claim 1, wherein the first gear is a helical gear, and the second gear is a screw gear. The chainsaw body,
A guide bar attached to the chain saw body so as to be capable of moving forward and backward;
A saw chain provided across the chain saw body and the guide bar;
The chain saw body is provided with a chain adjustment mechanism for moving a guide bar forward and backward with respect to the chainsaw body,
The chain adjusting mechanism is
An operation member that is provided so as to be rotatable with respect to the chain saw body, and in which a screw hole is formed coaxially with the rotation shaft;
A linear mover that is locked to the guide bar and has a feed screw that is screwed into a screw hole of the operating member, and that moves linearly with the guide bar as the rotary shaft rotates;
A chain saw characterized by comprising.

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