chainsaw

Abstract

Summary: The present invention relates to a chainsaw provided with a longitudinally extending guide plate and a chain mounted on the outer circumference of the guide plate, the chainsaw comprising a housing body, a drive assembly and a sprocket connected to the drive assembly, the drive assembly comprising a drive shaft extending axially from the housing body, the sprocket being mounted on the axial end of the drive shaft, the chain being at least partially wound around the sprocket, and the drive shaft driving the chain through the sprocket to rotate along the outer circumference of the guide plate; the chainsaw comprising a support assembly mounted on the axial outside of the sprocket, the support assembly pressing against at least one of the two components, the chain and the sprocket, in the axial direction.The present invention eliminates the need for the user to additionally support the other end of the guide plate when installing the sprocket cover by pressing against the chain through the support assembly in advance, saving time and effort. It also avoids the situation where the chain and washer get stuck due to excessive contact with the uneven guide plate, resulting in the machine being unable to start after the chain is tightened. Furthermore, the axial play on the sprocket is compensated for by the wave-shaped pressure plate of the support assembly, preventing axial movement between the parts and effectively reducing noise.

Description

Chainsaw

Technical field

[0001] The invention relates to the field of garden tools, in particular to a chain saw with low noise, low vibration and easy tensioning. [Background Technology]

[0002] A chainsaw, as a gardening tool, consists of a housing, a drive assembly fixed within the housing, a guide plate and sprocket cover removably mounted to the housing, and a chain that fits around the outer periphery of the guide plate. The drive assembly drives the chain to rotate around the outer periphery of the guide plate, thereby cutting workpieces such as wood. To prevent the chain from loosening after a period of operation, chainsaws are typically equipped with a chain tensioning mechanism on the removable sprocket cover.

[0003] During installation, the user needs to first secure the guide plate to the housing, then place the chain around the outer periphery of the guide plate, and then lock the sprocket cover to the housing to completely secure the guide plate and chain between the sprocket cover and the housing. Due to the long guide plate, it is only fixed to the housing at one longitudinal end, leaving the remaining long section, including the center of gravity, suspended in the air. This makes the guide plate prone to tilting. When installing the sprocket cover, the user needs to use one hand to keep the guide plate upright while using the other hand to operate the chain tensioning mechanism and lock the sprocket cover, which is time-consuming and laborious. Furthermore, because the guide plate is placed unevenly, it will tilt near the sprocket. When the chain is locked, the chain will excessively contact the gasket on the sprocket, causing the chain to jam. This can cause the machine to be unable to start after locking, or the chain to fall off the teeth, posing a risk of injury.

[0004] As garden tools become increasingly popular, users are increasingly concerned about noise and vibration during operation. These noise and vibration can increase wear and tear on tool parts, and reducing them can extend tool life. For chainsaws, a popular garden tool, reducing noise and vibration is a growing challenge.

[0005] In view of this, it is indeed necessary to provide an improved chain saw to overcome the defects of the prior art.

[0006] [Summary of the invention]

[0007] In view of the deficiencies in the prior art, the present invention aims to provide a chain saw with low noise, low vibration and easy tensioning.

[0008] The present invention solves the existing technical problems by adopting the following technical solutions: a chain saw is equipped with a guide plate extending in the longitudinal direction and a chain sleeved on the outer periphery of the guide plate, the chain saw includes a housing, a drive assembly arranged in the housing and a sprocket connected to the drive assembly, the drive assembly includes a drive shaft extending out of the housing in an axial direction perpendicular to the longitudinal direction, the sprocket is sleeved on the axial end of the drive shaft, the chain is at least partially wound around the sprocket, and the drive shaft drives the chain to rotate along the outer periphery of the guide plate through the sprocket; the chain saw includes a support assembly installed axially outside the sprocket, the support assembly is axially fixed to the drive shaft and presses at least one of the chain and the sprocket in the axial direction.

[0009] A further improvement is that the support assembly includes several extensions extending toward the chain and axially pressing the chain, and the several extensions press the chain at intervals so that the front and rear ends of the guide plate on which the chain is mounted remain horizontal in the longitudinal direction.

[0010] A further improvement is that the support assembly includes a pressure plate arranged on the axial outside of the sprocket, the pressure plate is provided with an inner ring portion sleeved on the drive shaft and an outer ring portion extending in a wave shape on the outer periphery of the inner ring portion, the outer ring portion axially presses the outer end face of the sprocket to compensate for the axial gap between the sprocket and the housing.

[0011] A further improved solution is that the extension member is constituted by a plurality of spring tongues extending from the outer ring portion toward the chain, and the spring tongues are arranged at intervals on the outer periphery of the inner ring portion.

[0012] A further improvement is as follows: the sprocket includes a sleeve portion sleeved on the drive shaft and a plurality of spaced teeth extending axially from the outer surface of the sleeve portion, and each of the spring tongues extends between adjacent spaced teeth and presses against the outer surface of the chain.

[0013] A further improvement is as follows: the sprocket includes a sleeve portion sleeved on the drive shaft, a plurality of spaced teeth extending axially from the outer surface of the sleeve portion, and a shaft end cover connecting the axial ends of the plurality of spaced teeth, and the extension piece is configured as a protrusion extending from the inner side wall of the shaft end cover toward the chain and pressing against the chain, and the protrusion is integrally formed with the shaft end cover.

[0014] A further improved solution is: the support assembly includes a pressure plate that presses against the axial outer surface of the shaft end cover, and the pressure plate is configured as a wavy elastic plate to compensate for the axial gap between the sprocket and the housing.

[0015] A further improvement is that the drive shaft extends axially out of the outer surface of the housing, the chain saw includes a gasket installed on the axial end of the drive shaft, and the support assembly is elastically installed between the sprocket and the gasket to compensate for the axial gap between the sprocket and the gasket.

[0016] A further improved solution is: the chain saw includes a sprocket cover detachably mounted on the housing and a pressing device fixed in the sprocket cover, and when the sprocket cover is mounted on the housing, the pressing device presses against the outer surface of the guide plate.

[0017] A further improvement is as follows: the clamping device includes a fixing portion installed on the inner surface of the sprocket cover and a clamping portion extending from the fixing portion toward the guide plate. When the sprocket cover is installed on the housing, the clamping portion axially presses against the outer surface of the longitudinal rear end of the guide plate, so that the guide plate remains horizontal in the longitudinal direction.

[0018] Compared with the prior art, the present invention has the following beneficial effects: by installing a support assembly on the axial outside of the sprocket, the support assembly includes an extension piece that presses the chain in the axial direction. When installing the sprocket cover, the user no longer needs to support the other end of the guide plate to operate the tensioning structure, which saves time and effort; and the extension piece pre-presses the chain and keeps the guide plate horizontal in the longitudinal direction, ensuring that the chain is in a suitable locking position, avoiding excessive contact between the chain and the gasket due to unevenness of the guide plate and causing it to get stuck, which in turn causes the chain to be unable to start after being tightened or to fall off the teeth; in addition, the axial gap between the sprocket and the housing is compensated by the wave-shaped pressure plate of the support assembly, thereby reducing vibration between parts and effectively reducing noise.

Brief Description of the Drawings

[0019] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings:

[0020] FIG1 is a schematic structural diagram of a chain saw in a preferred embodiment of the present invention;

[0021] FIG2 is a partial exploded view of the chain saw shown in FIG1 after the sprocket cover is removed;

[0022] FIG3 is a partial cross-sectional view of the assembly portion of the sprocket cover and the housing of the chain saw shown in FIG1 ;

[0023] FIG4 is a partial cross-sectional view of the sprocket shown in FIG3 ;

[0024] FIG5 is a schematic structural diagram of the sprocket shown in FIG4 ;

[0025] FIG6 is a schematic structural diagram of the support assembly shown in FIG5 ;

[0026] FIG7 is a cross-sectional view of the sprocket cover of the chain saw shown in FIG1 ;

[0027] FIG8 is a schematic structural diagram of the pressing device of the sprocket cover shown in FIG7;

[0028] 9 is a schematic structural diagram of a sprocket according to another embodiment of the present invention;

[0029] FIG. 10 is a schematic structural diagram of a support assembly according to another embodiment of the present invention.

[0030] Meanings of the reference numerals in the figures: Chain saw 100 Guide bar 200 Limiting groove 201 Chain 300 Chain link 301 Housing 10 Positioning column 11 Sprocket cover 20 Sprocket 30, 30' Sleeve portion 31, 31' Spacer teeth 32, 32' Shaft end cover 33' Chain tensioning structure 40 Lock button 41 Locking member 411 Tensioning transmission device 42 Eccentric cam 43 Drive shaft 50 Stop groove 51 Stop member 60 Washer 70 Support assembly 80 Pressing plate 81, 81' Inner ring portion 811, 811' Outer ring portion 812, 812' Extension member 82, 82' Clamping device 90 Fixing plate 91 Mounting arm 911 Connecting portion 912 Clamping portion 92 [Specific implementation method]

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. For example, terms such as "upper," "lower," "front," "back," "left," and "right" that indicate orientation or positional relationships are based solely on the orientation or positional relationships shown in the accompanying drawings and are intended to simplify the description of the disclosure. They do not indicate or imply that the device or element referred to must have a specific orientation or be constructed or operated in a specific orientation, and therefore should not be construed as limiting the disclosure.

[0033] Referring to Figures 1 and 2 , an embodiment of the present invention relates to a chain saw 100 equipped with a guide bar 200 extending in a longitudinal direction and a chain 300 sleeved around the outer periphery of the guide bar 200. The chain saw 100 includes a housing 10, a sprocket cover 20 removably mounted to the housing 10, a drive assembly disposed within the housing 10, and a sprocket 30 connected to the drive assembly. The drive assembly includes a motor (not shown), a transmission device (not shown) connected to the motor, and a drive shaft 50 connected to the transmission device. The drive shaft 50 extends out of the outer surface of the housing 10 in an axial direction perpendicular to the longitudinal direction. The chain 300 is at least partially wound around the sprocket 30, which is sleeved around the axial end of the drive shaft 50. The drive shaft 50 drives the chain 300 to rotate along the outer periphery of the guide bar 200 via the sprocket 30, thereby achieving a cutting operation.

[0034] In this embodiment, the shell 10 includes a positioning column 11 extending axially out of the outer surface of the shell 10, and the guide plate 200 includes a limiting groove 201 extending longitudinally and passing through the guide plate 200. The positioning column 11 passes through the limiting groove 201 and extends into the sprocket cover 20 to fix the guide plate 200 on the outer surface of the shell 10.

[0035] As shown in FIG3 , the chain saw 100 includes a chain tensioning structure 40 fixed to the sprocket cover 20. The chain tensioning structure 40 includes a user-operated lock button 41, a tensioning transmission device 42 fixed between the lock button 41 and the sprocket cover 20, and an eccentric cam 43 fixed to the side of the sprocket cover 20 away from the lock button 41. The lock button 41 includes an axially extending locking member 411, and the eccentric cam 43 is sleeved on the locking member 411. When the sprocket cover 20 is mounted to the housing 10, the positioning post 11 extends into the locking member 411 and threadably engages with the locking member 411 to secure the guide plate 200 between the sprocket cover 20 and the housing 10. Rotating the lock button 41 drives the tensioning transmission device 42 and the eccentric cam 43 to rotate. The eccentric cam 43 then drives the guide plate 200 to move longitudinally along the limiting slot 201, thereby tensioning the chain 300.

[0036] As shown in Figures 4 and 5 , the drive shaft 50 is longitudinally located at the rear end of the guide plate 200. The sprocket 30 is sleeved on the drive shaft 50 and rotates therewith. The sprocket 30 includes a sleeve portion 31 sleeved on the drive shaft 50 and a plurality of spaced teeth 32 extending axially from the outer surface of the sleeve portion 31. The chain 300 is partially wound around the spaced teeth 32 and rotates therewith.

[0037] The chain saw 100 further includes a stopper 60 mounted on an axial end of the drive shaft 50, a washer 70 mounted axially between the stopper 60 and the sprocket 30, and a support assembly 80 mounted axially between the washer 70 and the sprocket 30. A stopper groove 51 is defined at the axial end of the drive shaft 50, and the stopper 60 is mounted in the stopper groove 51 to limit axial movement of the washer 70 and the support assembly 80.

[0038] As shown in FIG6 , the support assembly 80 is axially fixed to the drive shaft 50 and axially presses against at least one of the chain 300 and the sprocket 30. The support assembly 80 includes a pressure plate 81 disposed axially outward of the sprocket 30. The pressure plate 81 is constructed of a metal sheet and has a certain degree of elasticity. The pressure plate 81 includes an inner ring portion 811 that is sleeved around the drive shaft 50 and an outer ring portion 812 that extends in a wavy shape around the outer periphery of the inner ring portion 811. The inner ring portion 811 is provided with a through hole for the drive shaft 50 to pass through. The outer ring portion 812 presses against the axial outer end surfaces of several spaced teeth 32 of the sprocket 30 to compensate for the axial clearance between the sprocket 30, the gasket 70, the stopper 60, and the housing 10. This prevents axial movement between the various components that could cause startup noise and effectively reduces vibration.

[0039] The support assembly 80 further includes a plurality of extension members 82 extending toward the chain 300 and axially pressing against the chain 300. The extension members 82 press against the chain 300 at intervals to maintain the guide plate 200, to which the chain 300 is mounted, longitudinally horizontal at both the front and rear ends. The extension members 82 are configured as a plurality of spring tongues extending from the outer ring portion 812 of the pressure plate 81 toward the chain 300. The spring tongues are spaced apart on the outer circumference of the inner ring portion 811, each extending between adjacent spaced teeth 32 to press against the outer surface of the chain 300. The number of spring tongues is equal to the number of spaced teeth 32.

[0040] As shown in Figures 1 and 4 , the chain 300 comprises several interconnected links 301. Each link 301 includes a cutting plate, a connecting plate, and a driving plate. When the chain 300 is tensioned, each spring tongue presses against a link 301 and rotates with the chain 300, maintaining an appropriate installation gap between the chain 300 and the gasket 70, preventing excessive tension on the chain 300 from affecting tool operation.

[0041] The pressure plate 81 of the support assembly 80 is elastically installed between the sprocket 30 and the gasket 70 to compensate for the axial clearance between the sprocket 30 and the stopper 60 and the gasket 70, thereby avoiding vibration caused by axial movement between the stopper 60, the gasket 70, the sprocket 30 and the housing 10, and effectively reducing the friction between the four, thereby extending the service life of the entire machine; the extension piece 82 of the support assembly 80 extends axially between the spaced teeth 32 of the sprocket 30 to press the chain 300 wrapped around the sprocket 30. When the chain 300 is tensioned, the user no longer needs to support the other end of the guide plate 200 to operate the tensioning structure, saving time and effort.

[0042] 7 and 8 , the chain saw 100 further includes a clamping device 90 mounted on the sprocket cover 20. The clamping device 90 includes a fixing plate 91 mounted on the inner surface of the sprocket cover 20 near the housing 10, and a clamping portion 92 extending from the fixing plate 91 toward the guide plate 200. When the sprocket cover 20 is mounted on the housing 10, the clamping portion 92 presses against the outer surface of the longitudinal rear end of the guide plate 200, thereby maintaining the front and rear ends of the guide plate 200 in a horizontal direction.

[0043] The fixing plate 91 includes a pair of interconnected, longitudinally extending, parallel mounting arms 911. Each mounting arm 911 has a screw hole at its longitudinal front end. The rear ends of the mounting arms 911 are connected to each other and have a connecting portion 912 bent toward the sprocket cover 20. The connecting portion 912 also has a screw hole. The fixing plate 91 is secured to the sprocket cover 20 using three screws threaded through these three screw holes. As shown in FIG2 , the pressing portion 92 is constructed as an elastic contact piece extending longitudinally from the connection between the connecting portion 912 and the pair of mounting arms 911 toward the guide plate 200. These elastic contact pieces are located on opposite sides of the retaining groove 201. When the sprocket cover 20 is mounted on the housing 10, the elastic contact pieces pre-press against opposite sides of the retaining groove 201 of the guide plate 200, thereby maintaining the guide plate 200 in the longitudinal direction. This effectively addresses the current issue of the guide plate 200 warping during tensioning, providing increased safety. The fixing plate 91 and the pressing portion 92 are integrally formed metal.

[0044] When the sprocket cover 20 is installed on the chainsaw 100 of the present invention, the extension member 82 of the support assembly 80 pre-presses the chain 300, and the pressing portion 92 of the pressing device 90 pre-presses the guide plate 200, thereby maintaining the guide plate 200 in a horizontal longitudinal position. This prevents excessive contact between the chain 300 and the gasket 70 when the lock knob 41 is rotated to tighten the chain 300, which could cause the chain 300 to become stuck. This could result in the chain 300 becoming unable to start after installation or falling off the teeth. The chain saw 100 of the present invention has a simple structure and is easy to tighten. Furthermore, the pressing plate 81 of the support assembly 80 compensates for the axial clearance between the sprocket 30 and other components, preventing movement or friction between the components, effectively reducing vibration and noise, and extending the life of the entire chain saw.

[0045] Figures 9 and 10 show another embodiment of the support assembly of the present invention, wherein the support assembly includes a pressure plate 81' mounted on a drive shaft (not shown) and a plurality of extensions 82' that press against a chain (not shown). The sprocket 30' includes a sleeve portion 31' mounted on the drive shaft, a plurality of spaced teeth 32' extending axially from the outer surface of the sleeve portion 31', and a shaft end cap 33' connecting the axial ends of the plurality of spaced teeth 32'. The plurality of extensions 82' are configured as protrusions that extend from the inner side wall of the shaft end cap 33' toward the chain and press against the chain. The protrusions are integrally formed with the shaft end cap 33' and the sprocket 30'.

[0046] The pressure plate 81' comprises an inner ring portion 811' that fits over the drive shaft, and an outer ring portion 812' that extends from the periphery of the inner ring portion 811'. The outer ring portion 812' is constructed as a wavy elastic plate. This elastic plate axially presses against the outer surface of the shaft end cap 33' to compensate for the axial clearance between the sprocket 30' and other components. This prevents movement or friction between the various components of the sprocket 30', effectively reducing vibration and noise, and extending the life of the entire machine.

[0047] The other structures of this embodiment are the same as those of the above embodiment and will not be elaborated here.

[0048] The present invention is not limited to the above-described specific embodiments. Those skilled in the art will readily appreciate that many other alternatives exist without departing from the principles and scope of the present invention. The scope of protection of the present invention shall be determined by the claims.

Claims

1. A chain saw, comprising a guide plate extending in a longitudinal direction and a chain sleeved around the outer periphery of the guide plate, the chain saw comprising a housing, a drive assembly disposed within the housing, and a sprocket connected to the drive assembly, the drive assembly comprising a drive shaft extending out of the housing in an axial direction perpendicular to the longitudinal direction, the sprocket sleeved around an axial end of the drive shaft, the chain at least partially wound around the sprocket, and the drive shaft drives the chain to rotate along the outer periphery of the guide plate via the sprocket; characterized in that: The chain saw includes a support assembly installed on the axially outer side of the sprocket. The support assembly is axially fixed to the drive shaft and presses at least one of the chain and the sprocket in the axial direction.

2. The chain saw according to claim 1, wherein: The support assembly includes a plurality of extensions extending toward the chain and axially pressing the chain. The plurality of extensions press the chain at intervals to keep the front and rear ends of the guide plate on which the chain is mounted horizontal in the longitudinal direction.

3. The chain saw according to claim 2, wherein: The support assembly includes a pressure plate arranged on the axial outside of the sprocket, and the pressure plate is provided with an inner ring portion sleeved on the drive shaft and an outer ring portion extending in a wave shape on the outer periphery of the inner ring portion. The outer ring portion axially presses the outer end face of the sprocket to compensate for the axial gap between the sprocket and the housing.

4. The chain saw according to claim 3, wherein: The extension member is configured as a plurality of spring tongues extending from the outer ring portion toward the chain, and the spring tongues are arranged at intervals on the outer periphery of the inner ring portion.

5. The chain saw according to claim 4, wherein: The sprocket includes a sleeve portion sleeved on the drive shaft and a plurality of spaced teeth axially extending from the outer surface of the sleeve portion. Each of the spring tongues extends between adjacent spaced teeth and presses against the outer surface of the chain.

6. The chain saw according to claim 2, wherein: The sprocket includes a sleeve portion sleeved on the drive shaft, a plurality of spaced teeth extending axially from the outer surface of the sleeve portion, and a shaft end cover connecting the axial ends of the plurality of spaced teeth. The extension piece is configured as a protrusion extending from the inner side wall of the shaft end cover toward the chain and pressing against the chain. The protrusion is integrally formed with the shaft end cover.

7. The chain saw according to claim 6, wherein: The support assembly includes a pressure plate that presses against the axial outer surface of the shaft end cover. The pressure plate is configured as a wave-shaped elastic plate to compensate for the axial gap between the sprocket and the housing.

8. The chain saw according to claim 1, wherein: The drive shaft extends axially out of the outer surface of the housing, the chain saw includes a washer mounted on an axial end of the drive shaft, and the support assembly is elastically mounted between the sprocket and the washer to compensate for an axial gap between the sprocket and the washer.

9. The chain saw according to claim 1, wherein: The chain saw comprises a sprocket cover detachably mounted on the housing and a pressing device fixed in the sprocket cover. When the sprocket cover is mounted on the housing, the pressing device presses against the outer surface of the guide plate.

10. The chain saw according to claim 9, wherein: The clamping device includes a fixing portion installed on the inner surface of the sprocket cover and a clamping portion extending from the fixing portion toward the guide plate. When the sprocket cover is installed on the housing, the clamping portion axially presses against the outer surface of the longitudinal rear end of the guide plate, so that the guide plate remains horizontal in the longitudinal direction.

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