CN113263554A

CN113263554A - Chain saw

Info

Publication number: CN113263554A
Application number: CN202110392208.2A
Authority: CN
Inventors: 陈洁
Original assignee: Zhejiang YAT Electrical Appliance Co Ltd
Current assignee: Zhejiang YAT Electrical Appliance Co Ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-08-17
Anticipated expiration: 2041-04-13
Also published as: CN113263554B

Abstract

The invention discloses a chain saw, which comprises a machine shell, a chain plate, a saw chain and a tensioning and locking device, wherein the tensioning and locking device comprises a screw rod, a push plate, an elastic part and an adjusting assembly, the chain plate is connected with the push plate, the push plate is in threaded connection with the screw rod, the screw rod is connected with the adjusting assembly, the elastic part is connected between the adjusting assembly and the machine shell, the elastic part is used for driving the adjusting assembly to move, and the adjusting assembly moves to drive the screw rod to rotate so as to drive the push plate to move linearly. When the chain saw provided by the invention is applied, even if the saw chain is subjected to a larger instant impact force in the working process, the screw rod and the push plate are in threaded connection, the screw threads arranged on the screw rod and the push plate are interacted to have a locking function, and the chain plate cannot be displaced under the action of the push plate, so that the saw chain can keep the tension degree, the times of tensioning adjustment operation are effectively reduced, and the service life of the chain saw is prolonged.

Description

Chain saw

Technical Field

The invention belongs to the field of garden tools, and particularly relates to a chain saw.

Background

A chain saw is a commonly used gardening tool, and is commonly used for cutting materials such as wood, stone and the like. The material is cut continuously by a saw chain which needs to run circularly in the cutting part, and the tightness of the saw chain needs to be adjusted in the process of mounting the saw chain on the machine shell, so that a better cutting effect can be obtained. And during the cutting operation, the saw chain can be loosened due to abrasion and thermal expansion, and the tightness of the saw chain also needs to be adjusted. The operation of above-mentioned regulation rate of tension needs the operator oneself manual regulation, can have certain operation requirement to the operator like this, and ordinary consumer hardly grasps this regulation dynamics in operation process to still need hand-carry adjustment tool, very inconvenient.

Therefore, the market starts to produce a design for realizing automatic tensioning by using an elastic body, in particular, when the saw chain is loosened a little, the elastic force of the elastic body is used for driving the chain plate for fixing the saw chain to move forwards, and the saw chain is driven to be tensioned again. However, the following problems exist in the practical use of this design: even if the chain plate is fixed on the shell by the fastening piece, the chain plate for fixing the saw chain can still be displaced due to overlarge instant impact force on the saw chain during cutting operation, so that the chain plate returns relative to the chain wheel, and the saw chain is loosened again. Therefore, the chain saw with the structure always needs to be repeatedly tensioned and adjusted for multiple times in the using process, the operation is inconvenient, and the service life of the chain saw is influenced.

Disclosure of Invention

The invention aims to provide a chain saw which can effectively solve the problem that a chain plate is displaced due to instant impact force when in use so as to loosen a saw chain, and can also conveniently and quickly adjust the tension degree after the saw chain is loosened due to long-time work.

In order to solve the technical problems, the invention adopts the following technical scheme: the chain saw comprises a machine shell, a chain plate, a saw chain and a tensioning and locking device, wherein the tensioning and locking device comprises a screw rod, a push plate, an elastic part and an adjusting assembly, the chain plate is connected with the push plate, the push plate is in threaded connection with the screw rod, the screw rod is connected with the adjusting assembly, the elastic part is connected between the adjusting assembly and the machine shell, the elastic part is used for driving the adjusting assembly to move, and the adjusting assembly moves to drive the screw rod to rotate so as to drive the push plate to move along a straight line.

Preferably, the adjusting component comprises a sliding sleeve, the sliding sleeve is sleeved on the screw rod in a sliding manner, the inner wall of the sliding sleeve is provided with a containing cavity, a rolling body is arranged in the containing cavity, a spiral groove for the rolling body to roll is formed in the outer surface of the screw rod, and the sliding sleeve slides along the screw rod to drive the screw rod to rotate. The ball screw structure is formed by the sliding sleeve, the rolling body and the spiral groove, the screw rod can be driven to rotate by pushing the sliding sleeve to move, the screw rod drives the push plate to move through the thread transmission between the screw rod and the push plate, and the push plate can move back and forth. The elastic part is used for pushing the sliding sleeve to move when tensioning and adjusting are needed, and then the pushing plate is driven to act on the chain plate, so that the chain plate moves forwards to tension the saw chain.

Preferably, the elastic part is a spring, the elastic part is sleeved outside the screw rod, one end of the elastic part is connected with the casing, and the other end of the elastic part is connected with the sliding sleeve. The elastic piece is sleeved outside the screw rod, so that the occupied space can be reduced.

Preferably, be equipped with the handle that is used for promoting the sliding sleeve on the sliding sleeve, be equipped with the rectangular hole that supplies the handle to stretch out the casing on the casing, handle sliding connection is downthehole at rectangular. Therefore, when tensioning adjustment is needed, the sliding sleeve can be pushed by the handle to perform tensioning adjustment without opening the shell.

Preferably, the strip hole is provided with a limiting step, the handle is provided with a baffle, and the limiting step and the baffle are matched for limiting the sliding sleeve. The sliding sleeve is limited through the matching of the limiting step and the blocking piece, so that the push plate can be moved backwards when the chain plate is installed, the position of the push plate is fixed through the limitation of the sliding sleeve, the space for installing the chain plate can be reserved, the installation of the chain plate is not influenced, and the multi-person matching operation is not needed.

Preferably, the adjusting part comprises a screwing button, the screwing button is connected with the end of the screw rod, and the screwing button rotates to drive the screw rod to rotate. The screw rod is driven to rotate by screwing the button, and the push plate is driven to move by the screw rod through the thread transmission between the screw rod and the push plate, so that the push plate can move back and forth.

Preferably, the elastic part is a torsion spring, the elastic part is sleeved on the screw rod, one end of the elastic part is connected to the casing, and the other end of the elastic part is connected to the screw rod. The elastic part is used for driving the screw rod to rotate through torsion when the saw chain needs to be tensioned and adjusted, and then the push plate is driven to act on the chain plate, so that the chain plate moves forwards to tension the saw chain.

Preferably, it revolves the button including revolving and twisting the portion and drive the portion, drive the portion and be connected with the screw rod, be equipped with the stop collar on the casing, drive portion sliding connection in the stop collar, be equipped with spacing draw-in groove on the stop collar, be equipped with the spacing arch with spacing draw-in groove looks adaptation in the drive portion, spacing draw-in groove and spacing arch cooperate and are used for revolving to twist the button spacing. Will revolve to twist through spacing arch and turn round the button spacing, can move backward the push pedal earlier when the installation link joint like this, the rethread is twisted soon and is pressed the spacing unable rotation that makes the screw rod of button, and then with the rigidity of push pedal, can vacate the space that is used for installing the link joint like this, does not influence the installation of link joint, does not need many people to cooperate the operation.

Preferably, the cross section of one end of the screw rod connected with the driving portion is polygonal, a key groove matched with one end of the screw rod is formed in the driving portion, and the screwing button is sleeved on the screw rod in a sliding mode through the key groove.

Preferably, a chain wheel is arranged in the machine shell, a gap is formed between the chain wheel and the chain plate, a top column extending into the gap is arranged on the push plate, and the top column is connected with the chain plate and used for pushing the chain plate to move forwards. Because need set up the helicitic texture and screw rod cooperation on the push pedal, consequently the push pedal has certain length along the link joint moving direction, if set up the push pedal directly on the coplanar with the link joint, make the push pedal directly be located between sprocket and the link joint, can occupy great space to the space of push pedal still need the back-and-forth movement. Therefore, the occupied space for arranging the top column is small.

Compared with the prior art, the invention has the following beneficial effects:

1. when the chain saw is loosened due to abrasion and heating expansion after working for a long time, the screw rod can be driven to rotate by matching the elastic piece and the adjusting assembly, the screw rod rotates to drive the push plate to move through thread transmission, and the push plate pushes the chain plate to move forwards, so that the chain plate drives the saw chain to be tensioned relative to the chain wheel, an adjusting tool does not need to be additionally carried, and the operation of a user is facilitated;

2. after the tension degree of the saw chain is adjusted in place, in the working process of the chain saw, even if the saw chain is subjected to large instant impact force, due to the fact that the screw rod is in threaded connection with the push plate, the screw threads arranged on the screw rod and the push plate interact to achieve a locking effect, the chain plate cannot displace under the action of the push plate, the tension degree of the saw chain can be kept, the number of times of tensioning adjustment operation is effectively reduced, and the service life of the chain saw is prolonged.

Drawings

FIG. 1 illustrates an exploded view of a chain saw according to one embodiment;

FIG. 2 is a schematic view showing the connection of the screw, the sliding sleeve and the rolling body in the first embodiment;

FIG. 3 is a schematic view of a screw and a push plate in a screw driving connection in an embodiment I;

FIG. 4 illustrates a first embodiment of a side cover and a tension lock;

FIG. 5 is a second schematic view of the connection of the side cover and the tension lock device in the first embodiment;

FIG. 6 is an enlarged view of portion A of FIG. 5;

FIG. 7 illustrates a cross-sectional view of the chain saw with the chain plate installed;

FIG. 8 illustrates a cross-sectional view of the chain saw with tension adjustment provided;

fig. 9 is a schematic view of a tension locking device in the second embodiment when a chain plate is installed;

FIG. 10 is a schematic structural view of a screw button according to a second embodiment;

fig. 11 is a sectional view of the adjusting assembly and the screw rod in the second embodiment when the chain plate is installed;

FIG. 12 is a cross-sectional view taken along line B-B of FIG. 11;

FIG. 13 is a cross-sectional view of the second embodiment of the adjustment assembly and screw as tension is being adjusted.

Wherein: 1. the novel gear box comprises a shell, 10 parts of a main shell, 11 parts of side covers, 110 parts of strip-shaped grooves, 111 parts of strip-shaped holes, 112 parts of limiting steps, 113 parts of limiting sleeves, 1130 parts of limiting clamping grooves, 114 parts of side cover plates, 115 parts of pressing knobs, 1150 parts of connecting sections, 12 parts of a cover body, 2 parts of chain wheels, 3 parts of chain plates, 30 parts of long round holes, 4 parts of saw chains, 5 parts of screw rods, 50 parts of spiral grooves, 51 parts of threads, 52 parts of limiting clamping tables, 6 parts of push plates, 60 parts of top columns, 7 parts of elastic pieces, 8 parts of adjusting assemblies, 80 parts of sliding sleeves, 800 parts of handles, 81 parts of rolling bodies, 82 parts of screwing buttons, 820 parts, 821 parts of drivers, 8210 parts of limiting protrusions and 822 parts of key grooves.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are intended to be inclusive and mean that, for example, they may be fixedly connected or detachably connected or integrally formed; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The first embodiment is as follows: as shown in fig. 1, 2 and 3, the chain saw provided by this embodiment includes a housing 1, a sprocket 2, a chain plate 3 and a saw chain 4, where the housing 1 includes a main housing 10, a cover body 12 disposed on one side of the main housing 10 and a side cover 11 disposed on the other side of the main housing 10, the sprocket 2 is disposed in an accommodating cavity formed by the main housing 10 and the side cover 11, a rear end of the chain plate 3 is also disposed in the accommodating cavity, the saw chain 4 surrounds the sprocket 2 and the chain plate 3, the sprocket 2 is driven by a power source to rotate, and the sprocket 2 drives the saw chain 4 to perform a cutting action. The power source is disposed between the main housing 10 and the housing 12, and the power source in this embodiment is a motor, that is, the chain saw is an electric chain saw, it is understood that the chain saw may be other power chain saws, such as a chain saw or a hydraulic chain saw. The chain saw in this embodiment still includes tensioning locking device, and tensioning locking device includes screw rod 5, push pedal 6, elastic component 7 and adjusting part 8, and push pedal 6 is connected with link joint 3, screw rod 5 and push pedal 6 threaded connection, and elastic component 7 is connected between adjusting part 8 and casing 1, and elastic component 7 is used for driving adjusting part 8 motion, and adjusting part 8 motion drives screw rod 5 and rotates in order to drive push pedal 6 along rectilinear movement.

Specifically, the adjusting assembly 8 in this embodiment includes a sliding sleeve 80, the sliding sleeve 80 is sleeved on the screw rod 5, a containing cavity is provided on an inner wall of the sliding sleeve 80, a rolling element 81 is provided in the containing cavity, the rolling element 81 in this embodiment is a steel ball, the screw rod 5 is provided with a spiral groove 50 for the rolling element 81 to roll, the sliding sleeve 80, the rolling element 81 and the spiral groove 50 form a ball screw structure, the sliding sleeve 80 is used for pushing the rolling element 81 to roll along the spiral groove 50, the rolling element 81 interacts with the inner wall of the spiral groove 50 in the rolling process to drive the screw rod 5 to rotate, the screw rod 5 drives the push plate 6 to move through a screw transmission with the push. It should be noted here that the receiving space is formed in a hemispherical shape, so that part of the rolling element 81 protrudes out of the receiving space and interacts with the helical groove 50. As shown in fig. 4 and 5, the side cover 11 is provided with a strip-shaped groove 110, the screw 5 is located in the strip-shaped groove 110, a limiting groove is formed in the strip-shaped groove 110, and the screw 5 is provided with a limiting clamping table 52, so that the limiting groove and the limiting clamping table 52 are matched to limit the screw 5 to move axially. In addition, two ends of the strip-shaped groove 110 also function as limiting grooves, which are matched with two ends of the screw 5 and can limit the screw 5 to move along the axial direction.

For the convenience of operation, the sliding sleeve 80 is further provided with a handle 800 for pushing the sliding sleeve 80, the side cover 11 is further provided with a side cover plate 114, a long hole 111 is formed between the side cover plate 114 and the side cover 11, and two ends of the handle 800 extend out of the casing 1 from the long hole 111, so that when tensioning adjustment is needed, tensioning adjustment can be performed without opening the casing 1. Before the chain saw is used for the first time, the chain plate 3 and the saw chain 4 need to be installed on the machine shell 1, so that the push plate 6 needs to be moved to leave the installation position of the chain plate 3, and for the convenience of single-person operation, as shown in fig. 6, a limiting step 112 for limiting the sliding sleeve 80 is further arranged on the elongated hole 111 in the embodiment. The sliding sleeve 80 is limited through the limiting step 112, so that the push plate 6 can be moved backwards firstly when the chain plate 3 is installed, and the position of the push plate 6 is fixed through the limitation of the sliding sleeve 80, so that a space for installing the chain plate 3 can be reserved, the installation of the chain plate 3 is not influenced, and the multi-person cooperation operation is not needed.

The elastic member 7 in this embodiment is a spring, one end of the elastic member 7 is connected to the casing 1, and the other end of the elastic member 7 is connected to the sliding sleeve 80. The elastic part 7 is used for pushing the sliding sleeve 80 to move so as to drive the push plate 6 to act on the chain plate 3 when tensioning and adjusting are needed, so that the chain plate 3 moves forwards to tension the saw chain 4. The elastic member 7 in this embodiment is in a compressed state when the tension is adjusted, and it is understood that it may be set in a stretched state.

The push plate 6 of the embodiment is provided with a top pillar 60, the top pillar 60 extends into the gap between the chain wheel 2 and the chain plate 3, and the top pillar 60 is used for pushing the chain plate 3 to move forwards. Because the push plate 6 needs to be provided with a thread structure to be matched with the screw rod 5, the push plate 6 has a certain length along the moving direction of the chain plate 3, if the push plate 6 and the chain plate 3 are directly arranged on the same plane, the push plate 6 is directly positioned between the chain wheel 2 and the chain plate 3, a larger space is occupied, and the push plate 6 also needs to move back and forth. The space occupied by the top post 60 is small.

In this embodiment, a pressing knob 115 is further disposed on the side cover 11, a connection section 1150 is disposed on the pressing knob, a thread 51 is disposed on the connection section 1150, a threaded hole matched with the thread 51 is disposed on the casing 1, a long circular hole 30 through which the connection section 1150 passes is disposed on the link plate 3, the length direction of the long circular hole 30 is consistent with the length direction of the push rod, and the connection section 1150 passes through the long circular hole 30 and is in threaded connection with the threaded hole. The chain plate 3 is fixed through the pressing knob 115, when the tension degree needs to be adjusted, the pressing knob 115 is loosened, the push plate 6 drives the chain plate 3 to move by utilizing the elasticity of the elastic part 7, and the connecting section 1150 cannot influence the movement of the chain plate 3 due to the arrangement of the long circular hole 30.

The mounting and tension adjustment operation of the chain saw provided using the present embodiment is described as follows: referring to fig. 7, before use, the link plate 3 and the saw chain 4 need to be installed, the sliding sleeve 80 is slid by overcoming the elastic force of the elastic member 7, the sliding sleeve 80 drives the screw rod 5 to rotate in the sliding process, the screw rod 5 rotates to drive the push plate 6 to move backwards, the position of the front end for installing the link plate 3 and the saw chain 4 is left, then the handle 800 is axially rotated along the screw rod 5, the handle 800 is clamped with the limiting step 112, and thus the position of the push plate 6 is limited. The link plate 3 is mounted on the main housing 10, and the saw chain 4 is enclosed on the sprocket 2 and the link plate 3, as shown in fig. 8, the handle 800 is rotated to separate the handle 800 from the limit step 112, so that the sliding sleeve 80 moves forward under the elastic force of the elastic member 7 to drive the screw 5 to rotate, and further drive the push plate 6 to move forward to push the link plate 3 to take the saw chain 4 to be tensioned. Finally, the side cover 11 is covered on the main housing 10, and the link plate 3 is fixed with the machine shell 1 by using the pressing knob 115. After the tension of the saw chain 4 is adjusted in place, in the working process of the chain saw, even if the saw chain 4 is subjected to large instant impact force, due to the interaction of the threads 51 between the screw rod 5 and the push plate 6 and the internal threads, the chain plate 3 cannot displace under the action of the push plate 6, so that the tension of the saw chain 4 can be kept, the number of times of tensioning adjustment operation is effectively reduced, and the service life of the chain saw is prolonged. When the saw chain 4 is loosened due to abrasion and thermal expansion after the chain saw works for a long time, the pressing knob 115 can be unscrewed, so that the sliding sleeve 80 moves forwards under the elastic action of the elastic piece 7 to drive the screw rod 5 to rotate, further drive the push plate 6 to move forwards, push the chain plate 3 to take the saw chain 4 to be tensioned, and then the pressing knob 115 is screwed. The adjusting tool does not need to be additionally carried, and the operation of a user is convenient.

Example two: the present embodiment also provides a chain saw, which is different from the above embodiments in that the adjusting assembly 8 and the elastic member 7 in the present embodiment have different structures, specifically, as shown in fig. 9, the adjusting assembly 8 in the present embodiment includes a screwing button 82, the screwing button 82 is connected with an end of the screw 5, the screwing button 82 is used for driving the screw 5 to rotate, the elastic member 7 is a torsion spring, one end of the elastic member 7 is connected to the housing 1, and the other end of the torsion spring is connected to the screw 5.

Based on the above technical features, the adjusting assembly 8 in this embodiment rotates the screw 5 by rotating the screwing button 82, and the screw 5 drives the push plate 6 to move by the screw transmission with the push plate 6, so that the push plate 6 can move back and forth. The elastic part 7 is used for driving the screw rod 5 to rotate through torsion when tensioning and adjusting are needed, and further driving the push plate 6 to act on the chain plate 3, so that the chain plate 3 moves forwards to tension the saw chain 4.

As shown in fig. 10, 11, 12 and 13, in the present embodiment, the screwing button 82 includes a screwing portion 820 and a driving portion 821, the driving portion 821 is connected to the screw 5, a cross section of one end of the screw 5 connected to the driving portion 821 is polygonal, specifically, square in the present embodiment, a key slot 822 adapted to one end of the screw 5 is disposed on the driving portion 821, and the screwing button 82 is slidably sleeved on the screw 5 through the key slot 822. Be equipped with stop collar 113 on the side cap 11, drive portion 821 sliding connection is equipped with spacing draw-in groove 1130 in stop collar 113 on the stop collar 113, be equipped with the spacing arch 8210 with spacing draw-in groove 1130 looks adaptation on the drive portion 821. When the novel chain plate is used specifically, the screw rotating button 82 is pushed forwards to enable the limiting protrusion 8210 to be clamped into the limiting clamping groove 1130, the screw 5 cannot rotate at the moment, and then the position of the push plate 6 is fixed, so that the novel chain plate can be operated by a single person when the chain plate 3 is installed. When the tightness needs to be adjusted, as in the above embodiment, the pressing knob 115 is loosened, and then the screwing button 82 is pulled out to disengage the limiting protrusion 8210 from the limiting groove 1130, so that the screw 5 is driven to rotate by the torque of the elastic member 7, and the pushing plate 6 is moved forward to push the link plate 3 forward to tension the saw chain 4. In order to prevent the screw button 82 from being pulled out when the screw button 82 is pulled outward, a stopper may be provided on the side cover 11 so that the screw button 82 cannot be pulled out any more after the stopper is pulled back. In addition, the screw button 82 is pushed in to prevent the screw 5 from rotating, and the screw button 82 is pulled out to screw and drive the screw 5 to rotate, so that the arrangement is in line with the use habit of the public.

The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto, and any changes or modifications within the scope of the present invention by those skilled in the art are covered by the present invention.

Claims

1. A chain saw comprises a machine shell, a chain plate and a saw chain, and is characterized in that: still include tensioning locking device, tensioning locking device includes screw rod, push pedal, elastic component and adjusting part, the link joint is connected with the push pedal, push pedal and screw rod threaded connection, the screw rod is connected with adjusting part, the elastic component is connected between adjusting part and casing, the elastic component is used for driving the adjusting part motion, the adjusting part motion is used for driving the screw rod and rotates along rectilinear movement with the drive push pedal.

2. A chain saw as recited in claim 1, wherein: the adjusting component comprises a sliding sleeve, the sliding sleeve is sleeved on the screw rod in a sliding mode, an accommodating cavity is formed in the inner wall of the sliding sleeve, a rolling body is arranged in the accommodating cavity, a spiral groove for the rolling body to roll is formed in the outer surface of the screw rod, and the sliding sleeve slides along the screw rod to drive the screw rod to rotate.

3. A chain saw as recited in claim 2, wherein: the elastic piece is a spring, the elastic piece is sleeved outside the screw rod, one end of the elastic piece is connected with the shell, and the other end of the elastic piece is connected with the sliding sleeve.

4. A chain saw as recited in claim 2, wherein: the sliding sleeve is provided with a handle used for pushing the sliding sleeve, the casing is provided with a strip hole for the handle to extend out of the casing, and the handle is connected in the strip hole in a sliding mode.

5. A chain saw as set forth in claim 4 wherein: the sliding sleeve is characterized in that a limiting step is arranged on the elongated hole, a blocking piece is arranged on the handle, and the limiting step and the blocking piece are matched for limiting the sliding sleeve.

6. A chain saw as recited in claim 1, wherein: the adjusting component comprises a screwing button, the screwing button is connected with the end of the screw rod, and the screwing button rotates to drive the screw rod to rotate.

7. A chain saw as set forth in claim 6 wherein: the elastic piece is a torsion spring, the elastic piece is sleeved on the screw rod, one end of the elastic piece is connected to the shell, and the other end of the elastic piece is connected to the screw rod.

8. A chain saw as set forth in claim 6 wherein: the screwing button comprises an screwing part and a driving part, the driving part is connected with the screw, a limiting sleeve is arranged on the casing, the driving part is connected in the limiting sleeve in a sliding mode, a limiting clamping groove is formed in the limiting sleeve, a limiting protrusion matched with the limiting clamping groove is arranged on the driving part, and the limiting clamping groove and the limiting protrusion are matched to limit the screwing button.

9. A chain saw as recited in claim 8, wherein: the cross section of one end of the screw rod connected with the driving portion is polygonal, a key groove matched with one end of the screw rod is formed in the driving portion, and the screwing button is sleeved on the screw rod in a sliding mode through the key groove.

10. A chain saw as recited in claim 1, wherein: the chain wheel is arranged in the shell, a gap is formed between the chain wheel and the chain plate, a top column extending into the gap is arranged on the push plate, and the top column is connected with the chain plate and used for pushing the chain plate to move forwards.