Foldable lithium electric saw

Abstract

A foldable lithium electric saw, characterized in that it includes: a drive device comprising a drive shaft; a cutting tool assembly comprising a chain, a sprocket and a chain guide plate, wherein the sprocket is frictionally connected to the drive shaft, the sprocket is fixed relative to the drive shaft, the sprocket and the chain guide plate together support the chain and the sprocket is engaged with the chain; a first support device comprising a handle part and a first mounting unit arranged at one end of the handle part, wherein the drive device is mounted on the first mounting unit and the drive shaft is arranged perpendicular to the extension direction of the first support device; a second support device suitable for slidably supporting the chain guide plate, wherein the second support device is rotatable about the drive shaft relative to the first assembly unit, and the chain guide plate and the chain rotate synchronously with the second support device, so that the cutting tool assembly can be switched between an initial state and a folded state; an adjustment mechanism suitable for adjusting the chain tension by driving the chain guide plate along its longitudinal direction towards or away from the sprocket; wherein in the initial state the extension direction of the chain guide plate is parallel to the extension direction of the first support device and extends outwards from the first assembly unit, and in the folded state the extension direction of the chain guide plate is parallel to the extension direction of the first support device, but extends outwards away from the first assembly unit, wherein the cutting tool assembly transitions from the initial state to the folded state by rotation by 180°.

Description

Field of invention

[0001] The present utility model belongs to the technical field of electric saws and relates in particular to a foldable lithium electric saw. State of the art

[0002] In modern forestry operations, garden maintenance, and outdoor applications, electric chainsaws are frequently used as highly efficient cutting tools. Lithium-ion electric chainsaws are increasingly gaining popularity due to their cordless flexibility and ease of use. However, existing lithium-ion electric chainsaws still offer room for improvement regarding portability and the adjustability of the cutting tool assembly angle. For those who work outdoors for extended periods or frequently move between different work locations, the challenge lies in ensuring the performance of the electric chainsaw while simultaneously improving portability and flexibility. While some existing foldable electric chainsaws can be folded, they often exhibit low structural stability, and the swivel joints tend to loosen.Furthermore, the chain tension adjustment on existing lithium-ion electric chainsaws is usually done via a screw-type tensioning device, which is complicated and can cause kickback. In addition, the cutting tool assembly lubrication system often requires manual oiling, which complicates maintenance. Object of the invention

[0003] In order to overcome the aforementioned disadvantages of the prior art, the objective of the present utility model is to provide a foldable lithium electric saw that meets the requirements of the users.

[0004] To achieve this objective, the present utility model provides a foldable lithium electric saw comprising: a drive device comprising a drive shaft; a cutting tool assembly comprising a chain, a sprocket, and a chain guide plate, wherein the sprocket is frictionally connected to the drive shaft, the sprocket is fixed relative to the drive shaft, the sprocket and the chain guide plate together support the chain, and the sprocket is engaged with the chain; a first support device comprising a handle and a first mounting unit arranged at one end of the handle, wherein the drive device is mounted on the first mounting unit and the drive shaft is arranged perpendicular to the direction of extension of the first support device;a second support device suitable for slidably supporting the chain guide plate, wherein the second support device is rotatable about the drive shaft relative to the first assembly unit, and the chain guide plate and the chain rotate synchronously with the second support device so that the cutting tool assembly can be switched between a starting state and a folded state; an adjustment mechanism suitable for moving the chain guide plate along its longitudinal direction towards / away from the sprocket in order to adjust the chain tension; a lithium battery suitable for powering the drive device, wherein the lithium battery is located at the other end of the handle part.

[0005] In its initial state, the chain guide plate runs parallel to the longitudinal direction of the first support device and extends outwards towards the first assembly unit. In its folded state, the chain guide plate also runs parallel to the longitudinal direction of the first support device, but extends outwards away from the first assembly unit, with the cutting tool assembly being rotated 180° from its initial state to the folded state. Preferably, in the folded state, the overall size of the electric saw is significantly reduced, with the overall length h2 after folding being shortened to 50% to 60% of the overall length h1 in its initial state.

[0006] Preferably, the second support device comprises a rotatable guide plate and a cover plate, wherein the rotatable guide plate and the cover plate are suitable for being mounted along the direction of the drive shaft and defining a second chamber, wherein the second chamber includes an outlet, the sprocket is arranged in the second chamber, the drive shaft is suitable for projecting into the second chamber and being connected to the sprocket, and the chain guide plate projects out of the second chamber through the outlet.

[0007] Preferably, a first chamber is formed in the first assembly unit, wherein at least part of the drive device is arranged in the first chamber.

[0008] Preferably, the outlet is equipped with comb teeth suitable for automatically removing wood chips and branches wound around the chain.

[0009] Preferably, the first assembly unit comprises a first rotating surface, the rotatable guide plate comprises a second rotating surface and a third rotating surface arranged opposite each other, wherein the second rotating surface is opposite the first rotating surface, the third rotating surface is provided with a guide rail, the chain guide plate comprises a guide groove arranged along its longitudinal direction, and the guide rail interacts with the guide groove in a reciprocating manner to avoid deviation errors during the adjustment process.

[0010] Preferably, the adjustment mechanism comprises an adjusting knob and a cam assembly, wherein the cam assembly comprises a force-transmitting disc cam and a driver, the driver being connected to the chain guide plate, the disc cam being connected to the adjusting knob, the adjusting knob setting the disc cam in rotation and thereby driving the chain guide plate via the driver to move along its longitudinal direction towards or away from the sprocket.

[0011] Preferably, the driver comprises a one-piece formed driver plate and a driver cam, wherein the disc cam, the driver plate and the chain guide plate are arranged parallel to each other, the driver plate is connected to the chain guide plate, the driver cam comprises a drive surface that is arranged perpendicular to the longitudinal direction of the chain guide plate, the outer contour of the disc cam is in contact with the drive surface and, when the disc cam is rotated, the force acting between the disc cam and the driver acts along the longitudinal direction of the chain guide plate.

[0012] Preferably, the rotatable guide plate and the cover plate are detachably connected to each other via a screw assembly to facilitate disassembly and maintenance. The screw assembly comprises a T-shaped screw, a nut, and a clamping knob. The T-shaped screw is arranged on the rotatable guide plate, the clamping knob is fixedly connected to the nut, and the clamping knob is located on the outside of the cover plate. The nut projects into the second chamber and is threaded into the screw. The T-shaped screw is arranged along the direction of the drive shaft. Furthermore, the adjusting knob is arranged on the outside of the cover plate. The adjusting knob is coaxial with the clamping knob. The clamping knob, in conjunction with the cover plate, forms an axial limit for the adjusting knob, and the nut is designed to project through the adjusting knob and form a radial limit for it.

[0013] Preferably, the foldable lithium electric saw comprises a locking mechanism suitable for limiting the rotational movement of the second support device relative to the first support device, wherein the locking mechanism comprises: at least one locking groove extending inwards perpendicular to the first rotating surface; a locking pin arranged telescopically in the second support device and extending parallel to the drive shaft; a locking knob suitable for engaging or disengaging the locking pin from the locking groove in order to set the locked or unlocked state, wherein the cutting tool assembly is in its initial state when the locking pin engages in one of the locking grooves; a return spring suitable for pushing the locking pin out of the locking groove to maintain the unlocked state.Preferably, the locking pin comprises a first stop structure projecting along its radius, the second support mechanism forms a release groove in which a second stop ring is arranged, the first stop structure bearing against the second stop ring to limit the locking pin from slipping out of the release groove, and the return spring bearing against the second stop ring and the locking knob at both ends, the return spring driving the locking pin to remain fully received in the release groove.

[0014] Preferably, the first rotary surface is designed with a pivot pin section, the rotatable guide plate forms a bushing section that is pushed over the pivot pin section, a clamping element is arranged on the third rotary surface, the clamping element being connected to the pivot pin section and forming an axial limit on the rotatable guide plate, the clamping element comprising an annular clamping plate, the inner ring area of ​​which is connected to the pivot pin section by means of several screws, and the outer ring area of ​​which contacts the rotary sleeve section.

[0015] Preferably, the third rotating surface comprises a sector-shaped stop area arranged around the bushing section, which has several stop grooves evenly distributed around the circumference; the clamping element comprises detent claws extending outwards from the clamping plate, which engage successively in the stop grooves when the second support device is rotated.

[0016] Preferably, the clamping element further comprises a positioning block which, together with the clamping plate, forms a positioning groove, wherein the rotatable guide plate includes projections arranged on the third rotating surface on which the guide rails protrude. The projections include positioning projections which, when engaging in the positioning grooves, hold the cutting tool assembly in its initial state, wherein the second support device is rotatable only on one side.

[0017] Preferably, the arc of the sector-shaped stop area is π / 2, the locking claws engage when switching each stop groove, and the rotary mechanism rotates by 10° to 20°. Preferably, the locking claw comprises a cantilever section extending outwards along a radius of the clamping plate and a locking hook section arranged at the free end of the cantilever section, the locking hook section having a V-shaped structure. Preferably, the first rotating surface includes several markings, and the cover plate includes an indicator pointer that can be selectively aligned with one of the markings to indicate the angle of rotation. The locking grooves correspond one-to-one to the markings; each locking groove is symmetrical with its corresponding marking about the center point of the sprocket, so that the user can directly see the folding angle and state of the device, making operation more intuitive and convenient.Preferably, the inclusion angle between two adjacent markings is N times the inclusion angle between two adjacent stop grooves, where N is a natural number not greater than 18.

[0018] Preferably, the first rotating surface is provided with an oil filling opening; the rotatable guide plate comprises an oil guide groove arranged on the second rotating surface, an oil collection groove arranged on the third rotating surface, and an oil bore connecting the oil guide groove to the oil collection groove, wherein the oil guide groove is oriented towards the first rotating surface; and the radially inner and outer seals are provided with the first seal and the second seal, respectively, with the oil collection groove oriented towards the chain; the first assembly unit comprises an oil reservoir for receiving lubricating oil and an oil pump, wherein the oil pump is suitable for pumping the lubricating oil through the oil filling opening into the oil guide groove, whereupon the lubricating oil flows into the oil collection groove and lubricates the chain.In comparison to the state of the art, where the oil filling opening is located in the first assembly unit, this design prevents splashing of the lubricating oil and ensures greater overall cleanliness.

[0019] Preferably, the first support device comprises a left housing and a right housing that can be mounted along the drive shaft and that define the handle part and the first mounting unit. The removable left and right housings facilitate the installation of the drive device, the oil pump, the oil reservoir, etc.

[0020] Preferably, the first rotating surface is also provided with a viewing window so that the user can observe the remaining oil level in the oil reservoir and refill the lubricating oil in a timely manner, thus ensuring that the chain is always well lubricated, extending the service life of the chain and electric saw, and reducing maintenance costs. An oil filler neck is arranged on the oil reservoir, projecting outwards through the left housing and remaining visible.

[0021] Preferably, a protective cover is rotatably arranged on the top of the first assembly unit, and an additional handle is attached to the left side of the first assembly unit. The advantageous effects of the present utility model are: 1. The unique design of the second support device allows the chain guide plate and chain to be rotated 180° around the drive shaft relative to the first mounting unit, enabling a change from the upright to the folded state. In the folded state, the overall size of the electric saw is significantly reduced, and the overall length after folding is only 50% to 60% of the upright state, which facilitates the transport of the electric saw to different work sites. 2. The adjustment mechanism uses a combination of an adjustment knob and cam assembly, allowing the user to rotate the disc cams simply by turning the adjustment knob. These cams, via the drive mechanism, precisely move the chain guide plate along its length towards or away from the sprocket. This enables quick and precise chain tension adjustment. 3. The locking mechanism design ensures safety during use of the electric saw. When the locking pin engages in the locking groove, the cutting tool assembly is fixed in its initial position and cannot be rotated arbitrarily, effectively preventing accidents caused by unintentional rotation of the cutting tool. Furthermore, the arrangement of multiple locking pins allows the cutting tool assembly to be fixed at different angles to adapt to various work environments. The return spring design ensures that the locking pin automatically returns to the release groove after the unlocking process and maintains the unlocked position, allowing the second support device for adjusting the tool angle to be easily rotated. 4. The sector-shaped stop area and the locking claw with a multi-angle engagement mechanism work in conjunction with the locking mechanism to provide double locking, preventing unintentional rotation of the cutting tool assembly, avoiding operator injury, and increasing the safety of the electric saw during operation. A single stop groove enables precise positioning from a minimum rotation angle of 10°. The arrangement of markings with angle indications and a synchronously rotating indicator pointer, along with the haptic feedback of the locking claw, provides dual feedback on the folding angle. 5. The lubrication system, consisting of an oil filler opening, oil guide groove, oil collection groove, and oil bore, ensures that lubricating oil is pumped from the oil reservoir through the oil filler opening into the oil guide groove and from there into the oil collection groove to lubricate the chain. The entire process is smooth and efficient. Furthermore, the oil guide groove is aligned with the first rotating surface, so that as the lubricating oil flows through the groove, it also lubricates the first and second rotating surfaces, thus increasing the smoothness of the rotation process. Brief description of the drawings Fig. Figure 1 is a schematic representation of the initial state of the foldable lithium electric saw provided by the present utility model. Fig. Figure 2 is a front view of the foldable lithium electric saw provided by the present utility model in its initial state. Fig. Figure 3 is a schematic representation of the folded state of the foldable lithium electric saw provided by the present utility model. Fig. Figure 4 is a front view of the foldable lithium electric saw provided by the present utility model in its folded state. Fig. Figure 5 is a schematic representation of the structure of the first support device and the associated components of the foldable lithium electric saw provided by the present utility model. Fig. Figure 6 is a schematic representation of the structure of the second support device and the cutting tool assembly of the foldable lithium electric saw provided by the present utility model. Fig. Figure 7 is a schematic representation of a partial cross-section of the second support device and the cutting tool assembly of the foldable lithium electric saw provided by the present utility model. Fig. Figure 8 shows a further cross-section of the second support device and the cutting tool assembly of the foldable lithium electric saw provided by the present utility model. Fig. Figure 9 is a representation of the rotatable guide plate and clamping element of the foldable lithium electric saw provided by the present utility model. Fig. Figure 10 shows the rotatable guide plate and clamping element from a different angle of the foldable lithium electric saw provided by the present utility model. Fig. Figure 11 is a representation of the rotatable guide plate of the foldable lithium electric saw provided by the present utility model. Fig. Figure 12 is a representation of the cam assembly of the foldable lithium electric saw provided by the present utility model. Fig. Figure 13 is a representation of the foldable lithium electric saw provided by the present utility model, after it has been rotated 45° clockwise from its initial state.

[0022] In the illustration: 1. Drive device; 11. Drive shaft; 21. Chain; 22. Sprocket; 23. Chain guide plate; 231. Guide groove; 3. Lithium battery; 4. First support device; 41. Left housing; 42. Right housing; 43. Handle section; 44. First assembly unit; 441. First chamber; 442. First rotating surface; 443. Pivot section; 444. Oil filler opening; 445. Viewing cutout; 45. Protective cover; 46. Auxiliary handle; 5. Second support device; 51. Rotating guide plate; 511. Second rotating surface; 512. Third rotating surface; 513. Bushing section; 514. Projection; 5141. Positioning projection; 515. Guide rail; 516. Sector-shaped stop area; 5161. Stop groove; 517. Oil guide groove; 518. Oil collection groove; 519. Oil bore; 52. Cover plate; 521. Indicator pointer; 53. Second chamber; 532. Comb teeth; 541. First seal; 542. Second seal; 551. T-shaped screw; 552. Nut; 553. Tension knob; 61. Adjustment knob; 62. Disc cam; 63. Drive pin; 631. Drive plate; 632. Drive cam; 6321.Drive surface; 71. Locking groove; 72. Locking pin; 721. First stop structure; 73. Locking knob; 74. Return spring; 75. Release groove; 751. Second stop ring; 8. Clamping element; 81. Clamping plate; 82. Detent claw; 821. Cantilever section; 822. Detent hook section; 83. Positioning block; 84. Positioning groove; 9. Oil reservoir; 91. Oil filler neck. Description of preferred embodiments

[0023] In order to illustrate the objectives, the technical solution and the advantages of the present utility model more clearly, the present utility model is described in detail below in conjunction with the drawings and specific embodiments.

[0024] It should also be noted that, in order to avoid any ambiguity of the present utility model due to unnecessary details in the drawings, only the structures and / or process steps closely related to the technical solution of the present utility model are shown, while other details less relevant to the present utility model have been omitted.

[0025] Furthermore, it should be noted that the terms “comprise”, “include” or any other variants thereof denote a non-exclusive inclusion, so that a process, procedure, object or device comprising a set of features does not only include these features, but also other features not expressly listed or features inherent in the respective process, object or device.

[0026] As in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12 to Fig.Figure 13 shows a foldable lithium-ion electric saw comprising a drive unit 1, a cutting tool assembly, a lithium battery 3, a first support device 4, a second support device 5, and an adjustment mechanism. The cutting tool assembly includes a chain 21, a sprocket 22, and a chain guide plate 23. The sprocket 22 is connected to the drive shaft 11 and is fixed relative to the drive shaft 11 to ensure stable power transmission. Specifically, the sprocket 22 is a nine-tooth sprocket and engages with the chain 21. The sprocket 22 and the chain guide plate 23 work together to support the chain 21 and ensure its stability and safety during operation.The drive unit 1 supplies the drive power for the cutting tool assembly via the drive shaft 11 and ensures the proper operation of the chain 21 and the sprocket 22, thereby realizing the cutting function. The lithium battery 3 is suitable for supplying energy to the drive unit 1. The first support unit 4 comprises a left housing 41 and a right housing 42, wherein the left housing 41 and the right housing 42 can be mounted along the direction of the drive shaft 11 and together define a handle part 43 and a first mounting unit 44. The first mounting unit 44 and the lithium battery 3 are arranged at opposite ends of the handle part 43. The first mounting unit 44 delimits a first chamber 441, wherein a part of the drive unit 1 is arranged in the first chamber 441, and the drive shaft 11 is arranged perpendicular to the direction of extension of the first support unit 4.The second support device 5 is suitable for slidably supporting the chain guide plate 23 and is further suitable for rotating around the drive shaft 11 relative to the first mounting unit 44. The chain guide plate 23 and the chain 21 rotate synchronously with the second support device 5, so that the cutting tool assembly can be switched between an initial state and a folded state. The adjustment mechanism is suitable for adjusting the chain tension 21 by moving the chain guide plate 23 closer to or further away from the sprocket 22 along its longitudinal direction. In the initial state, the direction of extension of the chain guide plate 23 is aligned parallel to the direction of extension of the first support device 4 and extends outwards from the first mounting unit 44.In the folded state, the extension direction of the chain guide plate 23 is also aligned parallel to the extension direction of the first support device 4, but the chain guide plate 23 extends outwards away from the first mounting unit 44, so that the cutting tool assembly is transformed from the initial state to the folded state by a rotation of 180°. In the folded state, the overall size of the electric saw is significantly reduced, with the overall length h2 in the folded state being shortened to 60% of the overall length h1 in the initial state.

[0027] In this embodiment, the second support device 5 comprises a rotatable guide plate 51 and a cover plate 52. The rotatable guide plate 51 and the cover plate 52 are suitable for mounting along the direction of the drive shaft 11 and together define a second chamber 53. The second chamber 53 includes an outlet, the outlet being provided with comb teeth 532 suitable for automatically removing wood chips and twigs that have become wrapped around the chain 21. The sprocket 22 is arranged in the second chamber 53, the drive shaft 11 being suitable for projecting into the second chamber 53 and being connected to the sprocket 22, and the chain guide plate 23 extending out of the second chamber 53 through the outlet.

[0028] In this embodiment, the first assembly unit 44 comprises a first rotary surface 442. The rotatable guide plate 51 comprises a second rotary surface 511 and a third rotary surface 512 arranged opposite each other, the second rotary surface 511 facing the first rotary surface 442. The first rotary surface 442 has a projecting pivot pin section 443, and the rotatable guide plate 51 forms a bushing section 513, the bushing section 513 being mounted on the pivot pin section 443. A clamping element 8 is arranged facing the third rotary surface 512, the clamping element 8 being connected to the pivot pin section 443 and providing axial limitation to the rotatable guide plate 51.The clamping element 8 comprises an annular clamping plate 81, wherein an inner ring section of the clamping plate 81 is connected to the pivot pin section 443 via several screws, and an outer ring section of the clamping plate 81 is in contact with the rotary sleeve section. The third rotating surface 512 is provided with a projection 514, on which a guide rail 515 is arranged. The chain guide plate 23 includes a guide groove 231 extending along its longitudinal direction. The guide rail 515 and the guide groove 231 are designed for reciprocating sliding guidance in order to eliminate pivoting or offset errors during the adjustment process.

[0029] In this embodiment, the adjustment mechanism comprises an adjusting knob 61 and a cam assembly. The cam assembly includes a drive-connected disc cam 62 and a driver 63. The driver 63 comprises a drive plate 631 formed in one piece and a drive cam 632. The disc cam 62, the drive plate 631, and the chain guide plate 23 are arranged parallel to each other. The drive plate 631 is connected to the chain guide plate 23. The drive cam 632 comprises a drive surface 6321, the drive surface 6321 being arranged perpendicular to the longitudinal direction of the chain guide plate 23. The outer contour of the disc cam 62 rests against the drive surface 6321, and the force acting between the disc cam 62 and the driver 63 is directed along the longitudinal direction of the chain guide plate 23.The disc cam 62 is connected to the adjusting knob 61, whereby the adjusting knob 61 sets the disc cam 62 in rotation and thereby drives the chain guide plate 23 via the driver 63 to approach or move away from the sprocket 22.

[0030] In this embodiment, the rotatable guide plate 51 and the cover plate 52 are detachably connected to each other by a screw assembly, which facilitates disassembly and maintenance. The screw assembly comprises a T-shaped screw 551, a nut 552, and a clamping knob 553. The T-shaped screw 551 is mounted on the rotatable guide plate 51, the clamping knob 553 is fixedly connected to the nut 552, and the clamping knob 553 is located on the outside of the cover plate 52. The nut 552 projects into the second chamber 53 and is threaded there. The T-shaped screw 551 is arranged along the direction of the drive shaft 11. Furthermore, the adjusting knob 61 is located on the outside of the cover plate 52 and is coaxial with the clamping knob 553.The clamping knob 553, in conjunction with the cover plate 52, acts as an axial limit for the adjusting knob 61, and the nut 552 is suitable to protrude through the adjusting knob 61 and form a radial limit to it.

[0031] In this embodiment, the foldable lithium-ion electric saw comprises a locking mechanism suitable for limiting the rotational movement of the second support device relative to the first support device. The locking mechanism includes several locking grooves 71, locking pins 72, locking buttons 73, return springs 74, and release grooves 75. The locking grooves 71 extend perpendicular to the first rotating surface 442 in the direction of the first chamber 441. The release grooves 75 extend perpendicular to the second rotating surface 511 in the direction of the second chamber 53. The locking pins 72 are arranged telescopically or slidably in the release grooves 75, with the locking pins 72 being aligned parallel to the direction of the drive shaft 11.The locking knobs 73 are designed to drive the locking pins 72 to screw into or release from the locking grooves 71, thus establishing a locked or unlocked state. When a locking pin 72 engages one of the locking grooves 71, the cutting tool assembly is in its initial state. The locking pin 72 comprises a first stop structure 721 projecting along its radial direction. A second stop ring 751 is arranged in the unlocking groove 75. The first stop structure 721 rests against the second stop ring 751 to prevent the locking pin 72 from sliding out of the unlocking groove 75.The return spring 74 rests with its two ends against the second stop ring 751 and the locking button 73, whereby the return spring 74 drives the locking pin 72 to remain fully engaged in the release groove 75 in order to maintain the unlocked state.

[0032] In this embodiment, the third rotating surface 512 comprises a sector-shaped stop area 516 that circumferentially surrounds the bushing section 513. The sector-shaped stop area 516 includes several stop grooves 5161 evenly distributed in the circumferential direction. The clamping element 8 comprises locking claws 82 that extend outwards from the clamping plate 81. Each locking claw 82 comprises a cantilever section 821 that extends outwards in a radial direction of the clamping plate 81, and a locking hook section 822 arranged at the free end of the cantilever section 821, the locking hook section 822 having a V-shaped structure. During the rotational movement of the second support device 5, the locking hook sections 822 can successively engage in the respective stop grooves 5161. The sector-shaped stop area 516 has an arc length of π / 2, and with each switching of the locking claw 82 into another stop groove 5161, the rotary mechanism rotates by 15°.

[0033] In this embodiment, the first rotating surface 442 includes several markings, and the cover plate 52 includes an indicator pointer 521. The indicator pointer 521 can be selectively aligned with one of the markings to indicate the respective angle of rotation. The markings include three markings at 90°, 135°, and 180°, with the angle between any two adjacent markings being 45°, which corresponds to three times the angle between two adjacent stop grooves 5161. The locking grooves 71 are assigned to the markings one-to-one, or alternatively, only one locking groove 71 is assigned to the 180° marking. The respective assigned locking groove 71 and the corresponding marking are arranged point-symmetrically with respect to the center of the sprocket 22, so that the user can intuitively grasp the folding angle and the operating status of the device, making operation more intuitive and convenient.

[0034] In this embodiment, the clamping element 8 further comprises a positioning block 83, wherein the positioning block 83, together with the clamping plate 81, encloses a positioning groove 84. The projection 514 comprises a positioning projection 5141. When the positioning projection 5141 engages in the positioning groove 84, the cutting tool assembly is in its initial state, and the second support device 5 can only rotate in one direction.

[0035] In this embodiment, an oil filling opening 444 is provided in the first rotating surface 442. The rotatable guide plate 51 comprises an oil guide groove 517 arranged in the second rotating surface 511, an oil collection groove 518 arranged in the third rotating surface 512, and an oil bore 519 connecting the oil guide groove 517 and the oil collection groove 518. The oil guide groove 517 is oriented towards the first rotating surface 442, with a first seal 541 and a second seal 542 each provided on the radial inner and outer sides of the oil guide groove 517. The oil collection groove 518 is oriented towards the chain 21. The first assembly unit 44 is equipped with an oil reservoir 9 for receiving lubricating oil and with an oil pump, the oil pump being suitable for pumping the lubricating oil through the oil filling opening 444 into the oil guide groove 517, so that the lubricating oil flows further into the oil collection groove 518 and lubricates the chain 21.In contrast to the prior art, where the oil filling opening 444 is located in the first assembly unit 44, this design can prevent splashing of lubricating oil and ensure a higher overall cleanliness.

[0036] In this embodiment, a viewing window 445 is further provided in the first rotating surface 442, through which the user can observe the remaining oil level in the oil reservoir 9 and refill the lubricating oil in a timely manner to ensure that the chain 21 always remains in a good lubricated condition, thereby extending the service life of the chain 21 and the electric saw and reducing maintenance costs. An oil filler neck 91 is provided on the oil reservoir 9, with the oil filler neck 91 extending out of the left housing and being exposed to the outside.

[0037] In this embodiment, a protective cover 45 is rotatably arranged on the top of the first assembly unit 44, and an additional handle 46 is provided on the left side surface of the first assembly unit 44.

[0038] The foregoing embodiments serve only to illustrate the technical solution of the present utility model and do not constitute a limitation thereof. Although the present utility model has been described in detail with reference to preferred embodiments, a person skilled in the art in the relevant field should recognize that modifications or equivalent replacements of the technical solution of the present utility model can be made without departing from the spirit and scope of protection of the technical solution of the present utility model.

Claims

[1] A foldable lithium electric saw, characterized by that it includes: a drive device comprising a drive shaft; a cutting tool assembly comprising a chain, a sprocket and a chain guide plate, wherein the sprocket is frictionally connected to the drive shaft, the sprocket is fixed relative to the drive shaft, the sprocket and the chain guide plate together support the chain and the sprocket is engaged with the chain; a first support device comprising a handle part and a first mounting unit arranged at one end of the handle part, wherein the drive device is mounted on the first mounting unit and the drive shaft is arranged perpendicular to the extension direction of the first support device; a second support device suitable for slidably supporting the chain guide plate, wherein the second support device is rotatable about the drive shaft relative to the first assembly unit, and the chain guide plate and the chain rotate synchronously with the second support device, so that the cutting tool assembly can be switched between an initial state and a folded state; an adjustment mechanism suitable for adjusting the chain tension by driving the chain guide plate along its longitudinal direction towards or away from the sprocket; wherein in the initial state the extension direction of the chain guide plate is parallel to the extension direction of the first support device and extends outwards from the first assembly unit, and in the folded state the extension direction of the chain guide plate is parallel to the extension direction of the first support device, but extends outwards away from the first assembly unit, wherein the cutting tool assembly transitions from the initial state to the folded state by rotation by 180°. [2] The foldable lithium electric saw according to claim 1, characterized by , that the second support device comprises a rotatable guide plate and a cover plate which can be mounted along the drive shaft and which define a second chamber, wherein the second chamber has an outlet, the sprocket is arranged in the second chamber, the drive shaft projects into the second chamber and connects the sprocket, and the chain guide plate projects out of the second chamber via the outlet; the first assembly unit comprises a first rotary surface, the rotatable guide plate comprises a second rotary surface and a third rotary surface opposite the first rotary surface, the third rotary surface has a guide rail, the chain guide plate comprises a guide groove arranged along its longitudinal direction, and the guide rail and the guide groove slid together reciprocally. [3] The foldable lithium electric saw according to claim 2, characterized by, that the adjusting mechanism comprises an adjusting knob and a cam assembly, wherein the cam assembly includes a frictionally connected disc cam and a driver connected to the chain guide plate, and the disc cams are connected to the adjusting knob, wherein the adjusting knob rotates the disc cams and thereby moves the chain guide plate towards or away from the sprocket via the driver. [4] The foldable lithium electric saw according to claim 3, characterized by, that the driver comprises a one-piece driver plate and a driver cam, wherein the disc cams, the driver plate and the chain guide plate are arranged parallel to each other, the driver plate is connected to the chain guide plate, the driver cam has a drive surface that is arranged perpendicular to the longitudinal direction of the chain guide plate, the outer contour of the disc cams touches the drive surface, and when the disc cams are rotated, the force acting between the disc cams and the driver acts along the longitudinal direction of the chain guide plate. [5] The foldable lithium electric saw according to claim 2, characterized by , that it includes a locking mechanism suitable for limiting the rotation of the second support device relative to the first support device, the locking mechanism comprising the following: at least one locking groove that runs perpendicular to the first rotating surface inwards; a locking pin that is arranged telescopically in the second support device and runs parallel to the drive shaft; a locking button suitable for engaging or disengaging the locking pin with the locking groove in order to set the locking state or unlocking state, wherein the cutting tool assembly is in the initial state when the locking pin engages in one of the locking grooves; a return spring suitable for pushing the locking pin out of the locking groove in order to maintain the unlocked state. [6] The foldable lithium electric saw according to claim 5, characterized by, that the locking pin has a radially projecting first stop structure, the second support mechanism forms a release groove in which a second stop ring is arranged, the first stop structure engages with the second stop ring to limit the locking pin falling out of the release groove, the return spring rests at both ends against the second stop ring and the locking button and holds the locking pin completely in the release groove. [7] The foldable lithium electric saw according to claim 5, characterized by, that the first rotary surface has a pivot pin section, the rotatable guide plate forms a bushing section which is fitted over the pivot pin section, a clamping element is arranged on the third rotary surface which is connected to the pivot pin section and axially limits the rotatable guide plate, wherein: the clamping element comprises an annular clamping plate, the inner area of ​​which is connected to the pivot pin section via several screw connections, and the outer area of ​​which touches the rotary sleeve section. [8] The foldable lithium electric saw according to claim 7, characterized by , that the third rotating surface has a sector-shaped stop area arranged around the bushing section, which includes several stop grooves evenly distributed around the circumference, the clamping element has locking claws that project outwards from the clamping plate, and when the second support device is rotated, the locking claws successively engage in the stop grooves. [9] The foldable lithium electric saw according to claim 8, characterized by that at least one of the following conditions is met: The sector-shaped stop area has an arc length of π / 2, whereby the second rotary mechanism rotates by 10° to 20° each time the locking claw engages in one of the limiting grooves; The locking claws comprise a cantilever section extending radially outwards from the clamping plate and a locking hook section arranged at the free end of the cantilever section, the locking hook section having a V-shaped structure; The first rotating surface includes several markings; the cover plate includes an indicator pointer, which can be selectively aligned with any of the markings to indicate the angle of rotation. The locking grooves correspond one-to-one with the markings, each locking groove being symmetrically arranged with its associated marking about the center of the sprocket. [10] The foldable lithium electric saw according to claim 2, characterized by , that the first rotating surface has an oil filling opening, the rotatable guide plate comprises an oil guide groove arranged on the second rotating surface, an oil collection groove arranged on the third rotating surface and an oil bore connecting the oil guide groove and the oil collection groove, wherein the oil guide groove is aligned to the first rotating surface, and a first seal and a second seal are arranged on its radially inner and outer regions, respectively, and the oil collection groove is aligned to the chain; The first assembly unit comprises an oil reservoir and an oil pump, the oil pump being capable of pumping the lubricating oil through the oil filling opening into the oil guide groove, so that the lubricating oil flows into the oil collection groove and lubricates the chain.

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