CN106171827B

CN106171827B - Tool-free tensioning mechanism of chain saw

Info

Publication number: CN106171827B
Application number: CN201610736099.0A
Authority: CN
Inventors: 倪祖根
Original assignee: Suzhou Kingclean Precision Machinery Co Ltd
Current assignee: Suzhou Kingclean Precision Machinery Co Ltd
Priority date: 2016-08-26
Filing date: 2016-08-26
Publication date: 2022-12-09
Anticipated expiration: 2036-08-26
Also published as: CN106171827A

Abstract

The invention discloses a tool-free tensioning mechanism of a chain saw, which comprises a chain guide plate and a tensioning knob, and is characterized in that the tensioning knob is connected with a cam, the cam drives the chain guide plate to move on the chain saw, and the chain saw is also provided with a locking knob for fixing the chain guide plate and the cam on the chain saw. The tool-free tensioning mechanism can greatly improve the convenience and comfort of using the chain saw, and can adjust the tensioning degree of the chain at any time so as to improve the cutting efficiency of the chain saw.

Description

Tool-free tensioning mechanism of chain saw

Technical Field

The invention relates to a chain saw, in particular to a tool-free tensioning mechanism of the chain saw.

Background

A chainsaw is a gardening tool for cutting wood or branches by driving a chain with blades to rotate at a high speed through power. If the chain is not properly tensioned, too loose may jump off the guide plate causing injury to the operator, and too tight a chain may cause high temperature failure due to direct excessive friction between the chain and the guide plate. Also during use, the tension of the chain changes due to wear of the chain, and after a period of use, the length of the chain gradually increases and the degree of tensioning decreases.

At present, the prior known chain tensioning method needs a special tool, a direct or indirect adjusting screw rod and a fastening and clamping nut, and the structure needs to be carried by a user, so that the use is inconvenient, and the tool is easy to lose.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.

The invention also aims to provide a tool-free chain saw tensioning mechanism, which can greatly improve the use convenience and comfort level and can adjust the tensioning degree of a chain at any time so as to improve the cutting efficiency of the chain saw.

To achieve these objects and other advantages in accordance with the purpose of the invention, a tool-less chain saw tensioning mechanism is provided, including a chain guide and a tensioning knob, the tensioning knob is connected to a cam, the cam drives the chain guide to move on the chain saw, the chain saw is further provided with a locking knob for fixing the chain guide and the cam on the chain saw, the chain saw is provided with a driving disc fixedly matched with the cam, and the driving disc drives the cam to rotate; a pair of convex blocks is symmetrically arranged on two sides of the circle center of the transmission disc, the transmission disc is provided with a torsion spring and a pawl, and two torsion arms of the torsion spring are abutted between the convex blocks and the inner side of the pawl; the upper end face of the transmission disc is convexly provided with a pair of first pin shafts, a pair of second pin shafts and a pair of convex blocks, the transmission disc is further provided with a slot in a penetrating mode, the upper surface of the cam is convexly provided with a top block, and the top block enables the transmission disc to be driven by the cam to rotate in the slot;

the chain saw is provided with a guide plate lining plate fixed with the chain guide plate, the chain saw is provided with a guide plate shield arranged at the upper end of the guide plate lining plate in a covering mode, a round hole is formed in the guide plate shield, teeth are arranged on the inner ring of the round hole, when the tensioning knob rotates clockwise, a rocker arm is arranged on the tensioning knob, the rocker arm pushes the second pin shaft to drive the transmission disc and the cam to synchronously rotate clockwise, the pawl is in sliding contact with the teeth, and the cam pushes the guide plate lining plate to move so as to tension the chain; when the tensioning knob rotates anticlockwise, the tensioning knob drives the transmission disc and the cam to rotate, and the pawl is separated from the teeth to release the tensioned chain; the pawl is meshed with the teeth so that the cam cannot actively rotate anticlockwise, a cavity is formed in the tensioning knob, and the locking knob is movably arranged in the cavity;

when the chain needs to be tensioned, the tensioning knob is rotated; when the chain guide and the cam need to be fixed on the chain saw, the locking knob is rotated.

Preferably, the guide plate lining plate is provided with a convex edge protruding outwards, and the outer contour of the cam abuts against the convex edge.

Preferably, a main support is arranged at the front end of the chain saw, a protrusion is arranged on the main support, a sliding groove matched with the protrusion penetrates through the chain guide plate and the guide plate lining plate from top to bottom, the sliding groove is movably arranged on the protrusion, and the direction of the convex edge is perpendicular to the direction of the sliding groove.

Preferably, the guide plate shield is detachably mounted on the main support, and the tensioning knob is movably mounted at the upper end of the round hole.

Preferably, a slot is formed in the transmission disc, a top block is arranged on the upper surface of the cam in a protruding mode, and the top block is clamped in the slot.

Preferably, the cam, the transmission disc, the round hole, the tensioning knob and the locking knob are axially fixed through a locking cap, and the bottom end of the locking cap abuts against the cam, sequentially penetrates through the axial centers of the cam, the transmission disc, the round hole and the tensioning knob and is fixed in the locking knob.

The invention at least comprises the following beneficial effects:

1. the tensioning mechanism is arranged on the chain saw body, the chain tensioning function is realized by rotating the tensioning knob, the operation is convenient and reliable, and the tensioning mechanism is not easy to lose;

2. the tensioning mechanism is provided with the pawl and the torsion spring, so that the chain guide plate is effectively prevented from actively retracting to cause chain loosening.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a schematic view of a chain saw;

FIG. 2 is a schematic view of the mounting structure of the chain guide and the main bracket;

FIG. 3 is a schematic view of an installation structure of the tensioning mechanism;

fig. 4 is a schematic perspective view of the tensioning mechanism;

FIG. 5 is a schematic view of the internal structure of the tightening knob;

FIG. 6 is an exploded view of the tensioning mechanism;

fig. 7 is a schematic view of the bottom structure of the tensioning knob;

FIG. 8 is a schematic view of the internal structure of the tensioning mechanism;

FIG. 9 is a schematic structural view of the transmission plate;

fig. 10 is a structural schematic diagram of the cam.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

In one embodiment, as shown in fig. 1-10, the present invention provides a chainsaw tool-less tensioning mechanism comprising: the chain guide plate 11 and the guide plate lining plate 9 which are fixed with each other, the tensioning knob 2 which is in transmission connection with the guide plate lining plate 9 and the guide plate shield 3 which is covered outside the guide plate lining plate 9 are arranged, the guide plate shield 3 is arranged on the chain saw in a detachable mode, the chain guide plate 11 and the guide plate lining plate 9 are mutually locked and fixed together, the front end of the chain saw is provided with a main support 12 for installing a chain saw tensioning mechanism and the chain guide plate 11, the main support 12 is provided with a strip-shaped bulge 121, a locking bolt 10 extends out of the bulge 121, the chain guide plate 11 and the guide plate lining plate 9 are provided with a sliding groove 111 which is in running fit with the bulge 121, and the sliding groove 111 is movably sleeved on the bulge 121, the locking bolt 10 penetrates through the sliding groove 111 and protrudes outwards, the tensioning knob 2 is connected with the cam 7, the tensioning knob is rotated to drive the cam 7 to rotate simultaneously, the cam 7 drives the guide plate lining plate 9 and the chain guide plate 11 to move directionally on the chain saw, namely, the sliding groove 111 moves along the extending direction of the protrusion 121, the chain saw can loose a chain in the using process, at the moment, the chain guide plate 11 needs to move outwards along the protrusion 121 in time to tension the chain, the chain is prevented from loosening and affecting normal use, the tensioning knob 2 is rotated to drive the cam 7 to rotate, and then the guide plate lining plate 9 and the chain guide plate 11 are pushed outwards along the protrusion 121 to tension the chain.

The tensioning mechanism specifically comprises: the guide plate shield 3 is detachably mounted on the main support 12, a circular hole is formed in the guide plate shield 3, and teeth 31 are fully distributed on the circular hole;

the tensioning knob 2 is movably arranged at the upper end of the round hole and can freely rotate, a cavity is arranged inside the tensioning knob 2, a locking knob 1 used for locking the tensioning mechanism at the upper end of the chain guide plate is movably arranged in the cavity, and the locking knob 1 is freely rotatably arranged in the cavity;

drive plate 6, its rotation sets up in the round hole, the protrusion of drive plate up end is equipped with a pair of first round pin axle 61, a pair of second round pin axle 62 and a pair of lug 63, as shown in fig. 9, it is a pair of first round pin axle 61, a pair of second round pin axle 62 and a pair of lug 63 symmetry respectively sets up 6 centre of a circle both sides of drive plate, lug 63 is close to the setting and is in first round pin axle 61's inboard first round pin axle 61 is last to overlap respectively and is equipped with a torsional spring 4 and pawl 5, two wrenching arms of torsional spring support respectively the top in lug 63 with between the inside wall of pawl 5, make pawl 5 be in under the thrust of torsional spring with tooth 31 meshes. Still run through on the driving plate 6 and set up a fluting 64, the protrusion of cam 7 upper surface is equipped with an kicking block 71, kicking block 71 is in fluting 64 makes driving plate 6 quilt cam 7 drives rotatoryly, rotates and rises tight knob 2 and can rotate cam 7, the protrusion of baffle welt 9 surface is equipped with a chimb 91, and preferred chimb setting is at the front end of spout 111, the surface of cam 7 supports the top the inboard of chimb rotates and rises tight knob and can rotate the cam, and then promotes baffle welt 9.

The chain guide plate comprises a cam 7, a transmission plate 6, a tensioning knob 2 and a locking knob, wherein the locking knob is axially fixed through a locking cap 8, a gasket 81 is arranged at the bottom end of the locking cap 8 and abuts against the lower portion of the cam 7, the transmission plate 6, a round hole and the tensioning knob 2 sequentially penetrate through the cam 7, the transmission plate 6 and the tensioning knob 2 from bottom to top and are fixed at the center of the locking knob 2, the locking cap 8 abuts against the cam 7, the locking knob 1 abuts against the tensioning knob 2 in a cavity of the tensioning knob 2, so that the locking knob 1, the tensioning knob 2, a guide plate shield 3, the transmission plate 6 and the cam 7 form an integrated tensioning mechanism, the locking nut 8 and the locking knob 1 synchronously rotate, internal threads are arranged in the locking cap 8, external threads are arranged on the locking bolt 10, the locking cap 8 is sleeved on the locking bolt 10, and the tensioning mechanism is locked on the chain guide plate 11 through rotating the locking knob, and the chain guide plate 11 is locked on a main support.

The tension adjusting process of the chain is as follows:

in one embodiment, because the outer surface of the cam is of an arc-shaped structure, the cam is also an eccentric wheel, when the tensioning knob rotates clockwise, the rocker arm pushes the second pin shaft to drive the transmission disc and the cam to synchronously rotate clockwise, the pawl is in sliding contact with the teeth to form relative motion, the transmission disc rotates relative to the guide plate shield, the track radius of the outer surface of the cam is gradually increased, and the outer surface of the cam pushes the guide plate lining plate to move outwards to tension the chain;

when the tensioning knob rotates anticlockwise, the rocker arm toggles the pawl to rotate anticlockwise around the first pin shaft and drives the transmission disc and the cam to rotate, the pawl is separated from the teeth, the transmission disc rotates anticlockwise freely, the scanning radius of the outer surface of the cam is reduced gradually, and the cam is separated from the convex edge of the guide plate lining plate to release a tensioned chain;

wherein, when needs were mediated the chain elasticity, must anticlockwise rotation locking knob, the chain guide of release locking, then just can carry out the regulation of the tight function of chain rise, rises when the chain guide tight back, clockwise rotation locking knob to relock the chain guide on the main support. And, during normal condition, the pawl under the promotion of torsional spring with the tooth meshing makes the cam can't initiatively rotate anticlockwise, only initiatively rotate anticlockwise and rise when tight knob, just can loosen the chain guide to avoid the chain guide initiatively to loosen and take off.

In another embodiment, a locking bolt is fixed on the main support, the chain guide plate and the guide plate lining plate are locked together and cannot move relatively, a sliding groove is formed in the guide plate, and the sliding groove is matched with a protrusion of the main support, so that the chain guide plate can move back and forth along the sliding groove; the convex edge is arranged on the guide plate lining plate, and when the cam rotates clockwise, the convex edge can be shifted by the cam 7, so that the guide plate lining plate 9 moves forwards, and the chain tensioning function is realized. The cam is provided with an ejector block matched with the groove of the transmission disc, the middle of the two parts is provided with a hole, a locking cap 8 is penetrated, and the cam 7 of the transmission disc 6 can rotate around the locking cap together without relative rotation. The transmission disc is provided with four pin shafts, two of the pin shafts are provided with pawls and pawl torsion springs, and the guide plate shield inner ring is provided with teeth; the tensioning knob can also rotate around the locking cap, a rocker arm is arranged on the tensioning knob, when the tensioning knob 2 is rotated clockwise, the rocker arm can stir the other two pin shafts of the transmission disc to enable the transmission disc to rotate clockwise, and the transmission disc cannot be actively reversed under the action of the pawl, the pawl torsion spring and the guide plate shield, so that the chain tensioning function is realized. When the tensioning knob rotates anticlockwise, the rocker arm on the tensioning knob can poke the pawl to release the locking of the transmission disc, and the chain can be loosened. When the tensioning knob rotates clockwise, the chain guide plate is tensioned, the locking knob rotates clockwise, the locking knob cannot rotate relatively due to being assembled with the locking cap, internal threads are formed in the locking knob, external threads are formed in the locking bolt, when the locking cap rotates clockwise, the locking function of the chain guide plate is achieved, and when the locking cap rotates anticlockwise, the locking function of the chain guide plate is released.

From the above, the mechanism is divided into a tension part and a locking part, the two parts are connected in series by a locking cap in the middle, the tension part can rotate relative to the locking cap, and the locking part and the locking cap rotate together; meanwhile, the tensioning part consists of two pawls, two torsion springs, a guide plate shield, a transmission disc, a cam, a guide plate bushing and a tensioning knob, the pawls cannot block the clockwise rotation of the transmission disc but can block the anticlockwise rotation of the transmission disc, and when the tensioning knob drives the transmission disc to rotate clockwise, the cam rotates together with the transmission disc to push the guide plate lining plate to move forwards, so that the tensioning function is realized; when the tensioning knob rotates anticlockwise, the pawl is shifted to unlock the drive plate, and the chain can be loosened under the action of external force; the locking part consists of a locking knob, a locking cap and a locking bolt, and is locked when rotated clockwise and released when rotated anticlockwise. The tensioning mechanism is arranged on the chain saw body, the chain tensioning function is realized by rotating the tensioning knob, the operation is convenient and reliable, and the tensioning mechanism is not easy to lose; meanwhile, the tensioning mechanism is provided with the pawl and the torsion spring, so that the chain guide plate is effectively prevented from actively retracting to cause the chain to loosen.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. A tool-free tensioning mechanism of a chain saw comprises a chain guide plate and a tensioning knob, and is characterized in that the tensioning knob is connected with a cam, the cam drives the chain guide plate to move on the chain saw, the chain saw is further provided with a locking knob used for fixing the chain guide plate and the cam on the chain saw, the chain saw is provided with a driving disc fixedly matched with the cam, and the driving disc drives the cam to rotate; a pair of convex blocks is symmetrically arranged on two sides of the circle center of the transmission disc, the transmission disc is provided with a torsion spring and a pawl, and two torsion arms of the torsion spring abut against between the convex blocks and the inner side of the pawl; a pair of first pin shafts, a pair of second pin shafts and a pair of bumps are arranged on the upper end face of the transmission disc in a protruding mode, a groove is formed in the transmission disc in a penetrating mode, a top block is arranged on the upper surface of the cam in a protruding mode, and the top block is clamped in the groove;

the chain saw is provided with a guide plate lining plate fixed with the chain guide plate, the chain saw is provided with a guide plate shield arranged at the upper end of the guide plate lining plate in a covering mode, a round hole is formed in the guide plate shield, teeth are arranged on the inner ring of the round hole, when the tensioning knob rotates clockwise, a rocker arm is arranged on the tensioning knob, the rocker arm pushes the second pin shaft to drive the transmission disc and the cam to synchronously rotate clockwise, the pawl is in sliding contact with the teeth, and the cam pushes the guide plate lining plate to move so as to tension the chain; when the tensioning knob rotates anticlockwise, the rocker arm toggles the pawl to rotate anticlockwise around the first pin shaft and drives the transmission disc and the cam to rotate, and the pawl is separated from the teeth to release a tensioned chain; the pawl is meshed with the teeth so that the cam cannot actively rotate anticlockwise, a cavity is formed in the tensioning knob, and the locking knob is movably arranged in the cavity;

2. The chainsaw tool-less tensioning mechanism of claim 1 wherein the guide plate backing plate is provided with an outwardly projecting ledge against which the outer profile of the cam abuts.

3. The tool-less chain saw tensioning mechanism as recited in claim 2, wherein the front end of the chain saw is provided with a main support, the main support is provided with a protrusion, the chain guide and the guide plate lining plate are vertically provided with a sliding slot matching with the protrusion, the sliding slot is movably arranged on the protrusion, and the direction of the protrusion is perpendicular to the direction of the sliding slot.

4. The chainsaw tool-less tensioning mechanism of claim 3 wherein the guide plate guard is removably mounted to the main support and the tensioning knob is movably mounted to the upper end of the circular aperture.

5. The chainsaw tool-less tensioning mechanism of claim 1, wherein the cam, the drive plate, the circular hole, the tensioning knob and the locking knob are axially fixed by a locking cap, and a bottom end of the locking cap abuts against the cam, sequentially penetrates through axial centers of the cam, the drive plate, the circular hole and the tensioning knob and is fixed in the locking knob.