JPH10286802A - Saw chain stretching device for chain saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a saw chain stretching device for a chain saw which is low-priced and can be easily operated without a hindrance by a chain guide plate and can be simply adjusted to the change in an operating position for an operator through his adjustment procedures. SOLUTION: This saw chain stretching device 1 is held between a side case 2 and a body case 22 and adjusts the position of a chain guide plate 4 projecting from a gap between both cases 2, 22. In addition, the device 1 is equipped with a threaded bar member 9 with a head part 10 formed on one of the ends and a pin member 16 which moves the position of the chain guide plate 4 with the body case 22 through moving in the axial direction of the pin member 16 by rotation of the threaded member 9. On the threaded bar member 9, a driven bevel gear 23 is fixed to the end part opposite to the head part 10, in the axial direction O-0, and a drive bevel gear 23 with a shaft part 24 supported pivotally, in a freely rotating manner, on the side case 2, is engaged with the driven bevel gear 23. In addition, the rotary operating part 24b of the shaft part 24a is exposed to the outside of the side case 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a saw chain tensioning device for a chain saw, and more particularly, to a chain guide plate mounting and fixing position which is changed with respect to a case portion of an airframe.
The present invention relates to a saw chain tensioning device for adjusting the tension of a saw chain.

[0002]

2. Description of the Related Art Conventionally, various types of saw chain tensioning devices have been proposed for a chain saw. Generally, the saw chain tensioning device includes a chain guide plate held between a body case portion of a chain saw. And a threaded rod member for moving the saw chain in the longitudinal direction to apply an appropriate tension to the saw chain. By rotating the screw bar member, the chain guide plate is moved along the axial direction thereof, and a rotation operation is performed from a direction perpendicular to the longitudinal direction of the chain guide plate to facilitate the rotation. A worm and a worm wheel or two bevel gears have been proposed between the externally operated rotation unit and the threaded rod member so as to be able to achieve the above.

[0003] According to the proposal, a rotating operation is possible from a direction perpendicular to a longitudinal direction of the chain guide plate.
The structure of the saw chain tensioning device itself becomes complicated, the space occupied by the device becomes large, and worms and worm wheels require cutting work and cannot be forged, so the production cost increases. There was a problem.

[0004] For this reason, the applicant of the present invention has proposed a saw chain tensioning apparatus 1 'as shown in Fig. 8 in order to eliminate the above-mentioned problems (see Japanese Utility Model Publication No. 7-27122). The proposed saw chain tensioning device 1 ′ includes a main body case 22 and a side case 2 having a pair of front and rear side walls 2 a and 2 b integrally.
A chain guide plate 4 is interposed between the main body case 22 and side plates 5 and 6. The side case 2
Are formed on the body case 22 side, and a threaded rod member 9 inserted into the recesses 8 and 12 from the side is rotatably arranged around its axis OO. ing. The screw rod member 9 is provided with the rotary tool insertion groove 1.
The head 10 with Oa is disposed outside the front side wall member 2a, and the screw portion 11 is attached to the pair of side wall portions 2a.
It is arranged in the space 7 between a and 2b. The screw part 1
1 is provided with the concave portion 12 of the rear wall portion 2b.
It is supported rotatably.

[0005] The threaded portion 11 of the threaded bar member 9 includes
A pin member 16 is attached, and the pin member 16 is screwed with the screw portion 11 through a screw hole 18 formed in a base 17 thereof. A projecting engagement portion 19 protruding from the side of the pin member 16 penetrates a long hole 20 extending in the longitudinal direction of the side plate 5 and a through hole 21 provided in the chain guide plate 4.
Is engaged.

[0006] The saw chain tensioning apparatus 1 'having the above-described structure is constructed as follows.
When a screwdriver or the like is inserted into the turning tool insertion groove 10a of the head 10 of the screw rod member 9 and turned, the pin member 16 moves in the axis OO direction of the screw member 9. When the pin member 16 moves, the chain guide plate 4 also moves in the longitudinal direction to change the longitudinal position of the body case portions 2 and 22 to apply a desired tension to the saw chain. Then, the tension of the saw chain is adjusted.

[0007]

By the way, the proposed saw chain tensioning device 1 'does not require a worm and a worm wheel for rotating the screw rod member 9, or a bevel gear, etc. Although the structure of the chain tensioning device can be simplified, the space occupied by the device can be reduced, and the manufacturing cost can be reduced.
Since the head 10 for rotating the screw bar member 9 is exposed on the front surface of the side case 2 (the surface on which the chain guide plate 4 protrudes), the screw bar member 9 is rotated. Sometimes, there is still a conventional problem that the chain guide plate 4 is obstructed to perform a rotating operation.

Further, since the rotating head 10 is located at the front of the side case 2, it can be operated only at that position, and the operator is located on the side opposite to the chain guide plate 4. In such a case, there is a problem that operation is difficult. The present invention has been made in view of such a problem, and an object of the present invention is to provide an inexpensive, easy-to-operate chain guide plate or the like without disturbing the operation of an operator. It is an object of the present invention to provide a saw chain tensioning device for a chain saw that can be easily adjusted even if the position changes.

[0009]

In order to achieve the above object,
The saw chain tensioning device of the chainsaw according to the present invention is:
While being sandwiched between the side case and the main body case,
It adjusts the position of the chain guide plate protruding from the two cases, a screw rod member having a head at one end,
A pin member for moving the position of the chain guide plate with respect to the main body case by rotating the screw rod member in the axial direction thereof, wherein the screw rod member is provided with a driven bevel gear and the head. Fixed to the axially opposite end,
A driven bevel gear having a shaft rotatably supported by the side case is meshed with the driven bevel gear, and a rotating operation portion of the shaft is exposed to the outside of the side case. Further, the drive bevel gear supported by the side case is supported in a direction substantially orthogonal to the axial direction of the threaded rod member. Further, as a specific aspect of the present invention, the head is provided with a rotary operation unit.

The chain saw saw chain tensioning device of the present invention having the above-described structure is adapted to tighten and fix the chain guide plate when adjusting the tension of the saw chain guided and supported by the chain guide plate. A nut or the like is loosened slightly, and a driver or the like is engaged with one of the rotating operation part of the drive bevel gear and the rotation operating part of the head of the screw rod member, which is easy to operate. Then, the screw bar member rotates to move the pin member in any one of the axial directions of the screw bar member. By the movement of the pin member, the chain guide plate moves in the longitudinal direction of the chain guide plate with respect to the body case, and the tension of the saw chain can be adjusted.

As described above, in the saw chain tensioning device for a chain saw according to the present invention, the means for rotating the threaded bar member is constituted by a pair of bevel gears, and the pair of bevel gears is moved from the case to the chain guide. Since it is arranged at the end of the screw bar member on the opposite side to the projecting side of the plate and in the space of the side case, the component (the bevel gear) of the rotating operation means can be easily manufactured at low cost. In addition to being able to be manufactured by forging, it can be easily operated at a position where it does not interfere with the chain guide plate, and is arranged on the side case opposite to the side where the chain guide plate protrudes. The tensioning device can have a compact structure.

In addition, since the turning operation part is also provided on the head of the screw rod member, one of the turning operation part and the turning operation part of the turning operation means comprising the pair of bevel gears is provided. The operation can be facilitated because the user can selectively select one of the easy-to-operate operations. Further, as another preferred specific embodiment of the present invention, a side plate is interposed between the side case and the chain guide plate, the screw rod member has a head with an annular flange, By arranging the head on the surface of the front wall portion on the side of the chain guide plate, and bending the front end of the side plate, the head of the head is located between the front wall portion and the bent front end of the side plate. Since the annular flange is sandwiched, the screw rod member can be easily prevented from coming off the side case.

Further, as another specific embodiment of the present invention, the saw chain tensioning device is disposed at an upper position or a lower position of a fixing stud bolt for fixing the side case to the main body case, The case is characterized in that an elongated viewing opening is formed along the axis OO direction of the screw bar member.
By providing the elongated peep opening, the moving position of the pin member of the saw chain tensioning device can be peeped from outside, and the tension of the saw chain supported and guided by the chain guide plate can be easily checked. Can be.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments of a chain saw tensioning apparatus for a chainsaw according to the present invention will be described below with reference to the drawings. Throughout the specification, the same members or those having the same functions as those of the conventional example shown in FIG.

FIG. 1 is a perspective view showing the entire structure of a chainsaw 30 to which a saw chain tensioning device according to a first embodiment of the present invention is applied, and is located on the right side of a main body case 22 containing a small air-cooled two-cycle internal combustion engine. Are two fixed stud bolts 31 and 31 and a nut 31
The side case 2 is attached and fixed by a and 31a. On the upper part of the main body case 22, a front handle 3 is provided.
2, and a protector 33 for protecting a worker's hand is provided at the front thereof, and a rear handle 34 is provided at a rear portion thereof. The chain saw 30 is equipped with the saw chain tensioning device 1 of the present embodiment at an upper position near the two fixed stud bolts 31. A chain guide plate 4 for guiding and supporting a saw chain 4a projecting forward (to the right in FIG. 1) is interposed between the main body case 22 and the side case 2, and the two fixed stud bolts 31, 31 are provided. And the nuts 31a, 31a are clamped and fixed so that their positions can be adjusted in the longitudinal direction.

As shown in FIG. 2, the saw chain tensioning device 1 is provided in the side case 2.
The side case 2 includes a pair of front and rear side wall portions 2 that are spaced apart in the front-rear direction and extend substantially parallel to the main body case 22 side.
a, 2b are integrally formed, and the side wall portions 2a, 2a
b and the chain guide plate 4, an outer side plate 5 is interposed between the main body case 22 and the chain guide plate 4.
The inner side plate 6 is also interposed between the two. The two side plates 5,
6 defines both sides of the chain guide plate 4 so as to prevent the saw chain 4a from detaching from the chain guide plate 4, and is defined by the two fixed stud bolts 31, 31 and the nuts 31a, 31a. The chain guide plate 4
And is fixed so as to sandwich it.

The side case 2 has a longitudinally elongated space 7 between the pair of front and rear side walls 2a and 2b.
And a pair of the side wall portions 2a, 2b
Have recesses 8 and 12 opening toward the body case 22, and a threaded bar member 9 is arranged between the recesses 8 and 12 in a locked state. The screw rod member 9 includes the head 1
The head 10 is provided with a rotating tool insertion groove 10a as a rotating operation part, and an annular flange 1
0b.

The head portion 10 of the screw rod member 9 is disposed outside the front wall portion 2a (projecting side of the chain guide plate 4). The tip 9a is rotatably supported in the rear recess 12. As shown in FIG. 4, the annular flange 10b of the threaded rod member 9 is
The bent front end portion 5a of the side plate 5 is engaged with the outer surface of the front side wall portion 2a to prevent the screw rod member 9 from coming out forward in the direction of the axis OO. Also, a rear end 5b of the outer side plate 5 opposite to the front end 5a is bent and locked to the rear side wall portion 2b, and the outer side plate 5 is stopped as shown in FIG. It is attached to the side case 2 by a screw 25,
The screw rod member 9 and the like are prevented from falling off.

A pin member 16 is screwed into the threaded portion 11 of the threaded rod member 9 through a female threaded hole 18 in a base portion 17 thereof.
A projection engaging portion 19 extending to the side is provided, extends through a long hole 20 extending in the longitudinal direction formed in the outer side plate 5, and is fitted into a through hole 21 formed in the chain guide plate 4. I have. For this reason, the rotation of the screw bar member 9 prevents the pin member 16 from rotating itself, and the pin member 16 moves in the axial line OO along the screw portion 11 of the screw bar member 9. The chain guide plate 4 is moved in the longitudinal direction with respect to the main body case 22 and the side case 2 by moving and moving in the direction of the axis OO.

At the tip 9a of the screw rod member 9,
A driven bevel gear 23, which can be manufactured at low cost by forging or the like, is mounted and fixed. The driven bevel gear 23 rotates integrally with the threaded rod member 9, and the driven bevel gear 23 has a drive bevel gear that can also be manufactured at low cost. 24 are orthogonally engaged. The drive bevel gear 24 is rotatably supported by the side case 2 and the axis O- of the threaded rod member 9.
The shaft portion 24a is disposed on the outer surface of the side case 2 so that the shaft portion 24a is exposed to the O direction and, for example, a direction perpendicular to the right side of the fuselage. A rotary tool insertion groove 24b is formed as a rotary operation part into which the tool is inserted.

In assembling and mounting each part of the saw chain tensioning apparatus 1, first, the side case 2
The drive bevel gear 24 is inserted and supported from the inside thereof, and the pin member 16 and the driven bevel gear 23 are screwed and attached and fixed to the screw rod member 9.
To the side wall portions 2a, 2b before and after the side case 2.
The outer side plate 5 is engaged with the side case 2 as shown in FIG. 2 and is locked from the main body case 22 side by the stop screw 25. Thereafter, the side case 2 is sandwiched between the main body case 22 and the chain guide plate 4 therebetween, and the two fixed stud bolts 31, 31 and the nuts 31a, 31
By fixing at a, the assembly and mounting are completed.

The chain saw saw chain tensioning apparatus 1 of the present embodiment configured as described above adjusts the tension of the saw chain 4a guided and supported by the chain guide plate 4 (normally, the saw chain is moderately tensioned). Nervous)
If desired, the nuts 31a, 31a of the fixed stud bolts 31, 31, which tighten and fix the chain guide plate 4, are slightly loosened, and the rotating tool insertion groove 24b of the drive bevel gear 24, When one of the rotating tool insertion groove 10a of the head 10 of the screw rod member 9 is rotated by engaging a cutting edge of a driver or the like, the screw rod member 9 rotates, The pin member 1
6 can be moved in any of the front and rear directions along the axis OO of the screw rod member 9.

By the movement of the pin member 16, the chain guide plate 4 moves in the longitudinal direction of the chain guide plate 4, and adjusts the tension of the saw chain 4a. After adjusting the tension (tension adjustment) of the saw chain 4a,
The nut 31 of the fixed stud bolt 31, 31
a, 31a are firmly tightened again, and the chain guide plate 4 is firmly fixed between the main body case 22 and the side case 2 so that the chain guide plate 4 has no rattling. The tension of the chain 4a is properly maintained.

As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and may be made without departing from the spirit of the present invention described in the appended claims. Various changes can be made in the design. For example, in the first embodiment, as shown in FIG. 1, the saw chain tensioning device 1 is attached to the vicinity of the fixed stud bolts 31 for fastening the chain guide plate 4. Although it is arranged on the front handle 32 side from the upper position, that is, the position of the fixed stud bolts 31, 31, as shown in FIGS. 5 to 7, the lower part is located near the fixed stud bolts 31, 31. They can also be placed. Even if the arrangement position of the saw chain tensioning device 1 is changed to a position below the fixed stud bolts 31 as described above, the configuration of the saw chain tensioning device 1 itself does not need to be changed at all. The arrangement positions of the through hole 21 of the chain guide plate 4 and the elongated hole 20 of the outer side plate 5 with which the projecting engagement portion 19 of the device 1 is fitted are lower than the fixed stud bolts 31, 31. Can be implemented.

The side case 2 can be provided with an elongated viewing opening 40 for viewing the inside thereof along the axis OO in the length direction of the threaded bar member 9 of the saw chain tensioning device 1. . By providing the peeping opening 40, the moving position of the pin member 16 of the saw chain tensioning device 1 can be peeped from the outside, and the saw chain 4 guided and supported by the chain guide plate 4 can be viewed.
The tension of a can be confirmed.

In order to prevent dust and the like from entering by providing the peeping opening 40, the peeping opening 40 can be closed with a transparent member such as a synthetic resin. A scale for position confirmation may be cut along the axis OO. Further, in the above two embodiments, the drive bevel gear and the driven bevel gear are meshed in an orthogonal state, but an appropriate change may be made, such as disposing the rotation operation part of the drive bevel gear in an obliquely upward state. It is possible.

[0027]

As can be understood from the above description, the saw chain tensioning device according to the present invention is manufactured by using a pair of bevel gears that can be easily and forged at low cost by using a rotating operation means for the threaded bar member. Costs can also be reduced. In addition, since the pair of bevel gears is disposed at the end of the threaded bar member on the side opposite to the projecting side of the chain guide plate and in the space of the side case, the chain guide plate is obstructed. The saw chain tensioning device can be easily operated at a position where it is not necessary, and the saw chain tensioning device can have a compact structure.

Further, since the turning operation part is also provided on the head of the screw rod member, one of the turning operation part and the turning operation part of the turning operation means comprising the pair of bevel gears is provided. Since one of the easy-to-operate operations can be selectively selected and operated, the turning operation of the screw bar member is simplified. Furthermore, by bending the end portion of the side plate, the annular flange portion of the head of the screw bar member is sandwiched between the front wall portion of the side case and the bent end portion of the side plate. Can be easily prevented from falling out of the side case.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a chain saw in which an embodiment of a saw chain tensioning device according to the present invention is employed.

FIG. 2 is an embodiment of the saw chain tensioning device according to the present invention, and is an enlarged sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged sectional view of the saw chain tensioning device of FIG.

FIG. 4 is a partial perspective view showing a head of a threaded rod member of the saw chain tensioning device of FIG. 2;

FIG. 5 is a perspective view showing an example of a chainsaw in which another embodiment of the saw chain tensioning device according to the present invention is employed.

FIG. 6 is an enlarged cross-sectional view of the saw chain tensioning device according to another embodiment shown in FIG. 5, taken along the line VI-VI in FIG.

FIG. 7 is an enlarged sectional view of the saw chain tensioning device of FIG.

FIG. 8 is a sectional view of a conventional saw chain tensioning device corresponding to FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Saw chain tensioning device 2 ... Side case 2a ... Front side wall part 4 ... Chain guide plate 5 ... Side plate 5a ... Bending front end 9 ... Screw member 10 ... Head 10a ... Rotating operation part (rotating tool insertion groove) 10b: annular flange 16: pin member 22: body case 23: driven bevel gear 24: drive bevel gear 24a: shaft 24b: rotating operation part (rotating tool insertion groove) 30: chain saw 31: fixed stud bolt 40 ... peep opening OO ... axis

Claims (6)

[Claims] 1. A side case (2) and a main body case (2).
2) and both cases (2),
In a saw chain tensioning device (1) of a chain saw (30) for adjusting a position of a chain guide plate (4) protruding from (22), the saw chain tensioning device (1) has a head (10) at one end. A screw rod member (9) and a pin member 16 for moving the position of the chain guide plate (4) with respect to the main body case (22) by moving the screw rod member (9) in the direction of the axis OO by rotation of the screw rod member (9). A driven bevel gear (23) is fixed to the screw rod member (9) at an end of the head (10) on the side opposite to the axis OO, and the driven bevel gear (23) A drive bevel gear (24) having a shaft portion (24a) rotatably supported by the side case (2) meshes with the side case (2), and a rotating operation portion (24b) of the shaft portion (24a). Is exposed to the outside of the side case (2). Chainsaw saw chain tensioning device to. 2. The drive bevel gear (24) pivotally supported by the side case (2) is pivotally supported in a direction substantially orthogonal to the axis OO of the threaded rod member (9). The saw chain tensioning device for a chainsaw according to claim 1, wherein: 3. A side case (2) and a main body case (2).
2) and both cases (2),
A saw chain tensioning device (1) for a chain saw (30) for adjusting a position of a chain guide plate (4) protruding from (22), wherein the saw chain tensioning device (1) includes the side case (2) and the chain. A side plate (5) interposed between the guide plate (4), a threaded rod member (9) having a head (10) with an annular flange (10b), and a rotation of the threaded rod member (9). The chain guide plate (4) moves in the direction of the axis OO
A pin member (16) for shifting the position of the side case (22) with respect to the main body case (22). The screw is provided on the surface of the front wall portion (2a) of the side case (2) on the side of the chain guide plate (4). Bar member (9)
And the front end portion (5a) of the side plate (5) is bent to form the front wall portion (2).
A chain saw characterized in that the annular flange (10b) of the head (10) of the threaded rod member (9) is sandwiched between a) and the front end (5a) of the side plate (5). Saw chain tensioning equipment. 4. A rotating operation part (10) is provided on said head (10).
The saw chain tensioning device for a chainsaw according to claim 1 or 3, wherein a) is provided. 5. The saw chain tensioning device (1) is disposed at an upper position or a lower position of fixing stud bolts (31) for attaching and fixing the side case (2) to the main body case (22). The saw chain tensioning device for a chainsaw according to any one of claims 1 to 4, wherein: 6. An elongated viewing opening (40) is formed in the side case (2) along the axis OO of the screw bar member (9). The saw chain tensioning device for a chainsaw according to any one of claims 1 to 5.