JPH0443281Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is a chain saw that is equipped with a support plate that projects forward of a case that houses an engine, and a saw chain that rotates around the support plate. This relates to a saw chain adjustment device.

(b) Prior art and problems to be solved Generally, in this type of saw chain adjustment device, a support plate is fixed to the case so as to be freely adjustable in the front and back direction, and the support plate is fixed to the case so as to be adjustable in the front and back direction, and the support plate is engaged with the engagement hole provided in the support plate. An adjustment screw is provided which is screwed into the mating protrusion piece to move the support plate in the front and back direction, and the tension of the saw chain is adjusted by moving this support plate in the front and back direction. Conventionally, in order to support this adjustment screw, grooves 45 and 47 were provided in the case 3 to rotatably support the front and rear ends of the adjustment screw 37, as shown in FIG. An engagement hole 49 is provided in which the protrusion piece 35 that is engaged with the engagement hole 33 provided in the adjustment screw 37 is engaged in a reciprocating manner. A two-part locking piece 53 that engages with the case 3 to lock the adjustment screw 37 from moving in the front-rear direction is attached to the case 3.
This adjustment screw 37 engages with the locking groove 55 provided in the
is prevented from coming off from the grooves 45 and 47 by a locking plate 43 held between it and the support plate 11.
This configuration has a complicated structure, and machining of the two-split locking piece 53 and the locking groove 55 is difficult. Also, as shown in Fig. 9, the adjusting screw 3
In some cases, the movement of the adjusting screw 37 in the front and back direction is restricted by the head of No. 7 and the nut 57, but with this configuration, the nut needs to be loosened or fixed during adjustment. The adjustment work was troublesome.

(c) Means and effects for solving the problem The present invention includes a support plate 11 that projects forward of the case 3 that houses the engine, and a saw chain 29 that is suspended around the support plate 11 and rotates. In the chain saw, the support plate 11 is fixedly fixed to the case 3 so as to be adjustable in the front and back direction, and the protrusion piece 3 engages with an engagement hole 33 provided in the support plate 11.
a first groove portion 45 that is provided with an adjustment screw 37 that is screwed into the case 3 to move the support plate 11 in the front-rear direction; A locking plate 43 is provided with a second groove 47 and an engagement hole 49 for movably engaging the projection piece 35 in the front and rear direction between both grooves, and is clamped and fixed between the case 3 and the support plate 11. A locking pawl 41 having a bifurcated protrusion on the locking plate 43 is provided.
is bent toward the case 3 side, and the locking claw 41
The adjustment screw 37 is rotatably held at approximately the center position by the cooperation of the upper wall portion 47a of the second groove portion 47. The present invention allows the adjusting screw to rotate smoothly around its center, making it possible to perform adjustment work stably, and locking the adjusting screw in the forward and backward direction with a simple structure. It is something.

(d) Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIGS. 1 to 7, the chain saw 1 is constructed as follows. That is, a side cover 5 is placed on the side of a case 3 containing an engine (not shown), a positioning pin 7 embedded in the case 3,
It engages with the bolt 9 to sandwich the support plate 11 and is fixed with a nut 13. An upper handle 17 equipped with a throttle lever 15 is attached to the upper part of the case 3 via a vibration isolator (not shown), and an emergency stop lever 19 equipped with a protection plate 18 is also provided. . A centrifugal clutch 23 is attached to the tip of the crankshaft 21 of the engine, and a clutch drum 2 is provided close to the outer periphery of the centrifugal clutch 23.
The sprocket 27 provided in one body with the support plate 1
A saw chain 29 is rotatably supported by a crankshaft 21 and suspended around the outer periphery of the support plate 11 on the same plane as the support plate 11 . The support plate 11 is fixed by elongated holes 31 into which the positioning pins 7 and bolts 9 are engaged, so that the position in the front and rear direction can be adjusted. A protrusion piece 3 that engages with an engagement hole 33 provided in the support plate 11
5 is screwed into the adjustment screw 37 to move the support plate 11 in the front and back direction. A locking pawl 41 with a bifurcated protrusion that engages with a groove 39 provided on the outer periphery of the adjustment screw 37
A locking plate 43 having a locking plate 43 is sandwiched and fixed between the case 3 and the support plate 11. The adjustment screw 37 rotatably engages with a first groove 45 and a second groove 47 provided in the case 3, and the locking claw 41 and the second groove 47
In cooperation with the upper wall portion 47a above, movement in the front and back direction is locked so that it can rotate around its center. The protrusion piece 35 is slidably engaged with an engagement hole 49 provided in the case 3.

In the above embodiment, the operator uses the upper handle 17 and the side handle (not shown) provided on the left side.
The saw chain 29 rotates around the support plate 11 under the drive of the engine to cut trees and the like. To adjust the tension of the saw chain 29, when the adjustment screw 37 is rotated, the adjustment screw 37 is prevented from moving in the front and back direction by the locking pawl 41, so that the projection piece 35
moves in the front-rear direction and at the same time moves the support plate 11 to adjust the tension of the saw chain 29.

That is, when the clamping nut 13 of the support plate 11 is loosened during adjustment, even if there is play in the sliding support part of the support plate 11, the head (neck) of the adjustment screw 37 will remain on the upper side of the case 3. Since it is locked by the wall portion 47a and the bifurcated locking pawl 41 bent from the locking plate 43 on the opposite side of the case, the adjustment screw 37 can be rotated smoothly around its center with a screwdriver, making it stable. Adjustment work can be done.

(e) Effects of the invention Since the invention has the configuration as stated in the claims, it has a simple structure, can lock the adjustment screw from moving in the front and back direction, and facilitates processing and assembly work. It is.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments as well. Further, the symbols shown in the claims do not limit the technical scope of the present invention.

In addition, Fig. 8 shows a conventional example, and Case 3
Grooves 45 and 47 are provided to rotatably support the front and rear ends of the adjusting screw 37, and grooves 45 and 47 are provided on the outer circumference of the adjusting screw 37 to lock the adjusting screw 37 from moving back and forth. A split locking piece 53 engages with a locking groove 55 provided in the case 3. FIG. 9 shows another conventional example, in which the head of the adjusting screw 37 and a nut 57 restrict the movement of the adjusting screw 37 in the front-rear direction. Note that in FIGS. 8 and 9, the same reference numerals as those shown in FIGS. 1 to 7 indicate the same components.

[Brief explanation of the drawing]

Fig. 1 is a side view of a chain saw, Figs. 2 and 3 are respectively a plan sectional view and a side sectional view of one embodiment of the present invention, Fig. 4 is a plan sectional view of the main parts, and Fig. 5 is a A side view taken along the - line in the figure, FIGS. 6 and 7 are a side view and a front view of the main parts, respectively, FIG. 8 is a plan sectional view of the main parts of the conventional example, and FIG. 9 is a main part of the other conventional example. FIG. 3...Case, 11...Support plate, 29...Saw chain, 33...Engagement hole, 35...Protrusion piece, 37
... Adjustment screw, 39 ... Groove, 41 ... Locking claw,
43... Locking plate, 45... Second groove, 47...
Second groove portion, 47a...upper wall portion.

Claims (1)

[Scope of utility model registration request] In a chain saw, the support plate 11 is provided with a support plate 11 that projects forward of a case 3 that houses an engine, and a saw chain 29 that is suspended around the support plate 11 and rotates. An adjustment screw 37 is provided in the case 3 to allow the support plate 11 to move in the front and back direction by being screwed into a protrusion 35 that is freely fixed and engaged with the engagement hole 33 provided in the support plate 11. A first groove part 45 and a second groove part 47 are provided to rotatably support the screw 37 at both ends and to make it removable, and an engagement engages the protrusion piece 35 between both groove parts so as to be movable in the front and back direction. A matching hole 49 is provided to connect the case 3 and the support plate 1.
A locking plate 43 which is clamped and fixed between the locking plate 43 and the locking plate 43 is provided with a locking claw 41 having a bifurcated protrusion bent toward the case 3 side. A saw chain adjustment device for a chain saw, in which an adjustment screw 37 is rotatably held at approximately the center position by cooperation with an upper wall portion 47a of a second groove portion 47.